• Journal of Wetlands Research
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• v.25 no.4
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• pp.291-296
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• 2023

DIWS system was employed to treat hydrochloric acid gas from cold rolling mill process of iron and steel industry. Chlorine gas generated from the acid regeneration system was combined with hydrogen gas and hydrogen chloride gas was increased to 50%. After the injection of Na₂S₂O₃ to remove chlorine gas, the removal of hydrogen chloride was stably kept 87.5~88.8%, where the inflow was 13.1~13.4ppm and the outflow was 1.5~1.7ppm. DIWS system can be recommended for the real iron and steel plant because it was stably maintained not only the air emission standards but also the reduction of chemical usage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.588-593
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• 2023

The advantage of OTFT technology is that large-area circuits can be manufactured on flexible substrates using a low-cost solution process such as inkjet printing. Compared to silicon-based inorganic semiconductor processes, the process temperature is lower and the process time is shorter, so it can be widely applied to fields that do not require high electron mobility. Materials that have utility as electrode materials include carbon that can be solution-processed, transparent carbon thin films, and metallic nanoparticles, etc. are being studied. Recently, a technology has been developed to facilitate charge injection by coating the surface of the Al electrode with solution-processable titanium oxide (TiOx), which can greatly improve the performance of OTFT. In order to commercialize OTFT technology, an appropriate method is to use a complementary circuit with excellent reliability and stability. For this, insulators and channel semiconductors using organic materials must have stability in the air. In this study, carbon-doped Mo (MoC) thin films were fabricated with different graphite target power densities via unbalanced magnetron sputtering (UBM). The influence of graphite target power density on the structural, surface area, physical, and electrical properties of MoC films was investigated. MoC thin films deposited by the unbalanced magnetron sputtering method exhibited a smooth and uniform surface. However, as the graphite target power density increased, the rms surface roughness of the MoC film increased, and the hardness and elastic modulus of the MoC thin film increased. Additionally, as the graphite target power density increased, the resistivity value of the MoC film increased. In the performance of an organic thin film transistor using a MoC gate electrode, the carrier mobility, threshold voltage, and drain current on/off ratio (I_on/I_off) showed 0.15 cm²/V·s, -5.6 V, and 7.5×10⁴, respectively.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.11.2-12
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• 1982

The major advancement in phonosurgery due to recent development of laryngomicrosurgery enabled more accurate diagnosis and treatment of patient with voice disorders. Among large proportion of voice disordered patients, prominent linear furrow running parallel along the free edge of vocal cord extending from the vocal process to anterior commissure can be seen as well as incomplete closure during phonation. These cases were illustrated and coined as sulcus vocalis by Salvi in 1901, since then other similar paper was reported in Europe and Japan, but has not been reported in Korea. The exact etiology and therapeutic methods of sulcus vocalis has not been elaborated. At Department of Otolaryngology of Yonsei University College of Medicine a series of voice analysis were performed among those 35 patients with sulcus vocalis visited to Vocal Dynamics Laboratory from May, 1981 to March, 1982. Following is the result of clinical statistical investgation and therapeutic modality. 1) The incidance of sulcus vocalis among 290 patients with voice disorder visited to Vocal Dynamics Laboratory was approximately 12%(35 cases). 2) Onset of this voice disorder was most frequent among patient under 10 year-old groups; 19 cases (54%) followed by second decade, third decade groups in decreasing frequency respectably. 3) The etiology of sulcus vocalis was mostly unknown. The sequelae after measle (4 cases) and severe upper respiratory infection (3 cases) and congenital deformity (2 cases) were the possible causes of sulcus vocalis. 4) These patients were involved bilaterally in 25 cases (71%), left side only in 8 cases (23%) and right side only in 2 cases (6%). 5) Almost all patients complained hoarseness and 7 patients were suffering from chronic laryngitis. 6) In aerodynamic analysis, Maximal Phonation Time was decreased in 20 cases (57%), Phonation Quotient was increased in 22 cases (63%) and Mean Air Flow Rate was increased in 23 cases (66%). 7) Among them, 33 cases were analyzed with stroboscopy. The findings were as follows; incomplete glottic closure during phonation in 31 cases (93%), regular vocal cord movement in whole cases, asymmetric cord movement in 4 cases (12%), decreased amplitude in 5 cases (21%) and small mucosal wave in 24 cases (73%). 8) Intracordal Teflon injection in 5 cases and Sulcusectomy in 1 cases were performed as therapeutic management, however, the therapeutic results were not effective except one case with Teflon injection.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.115-123
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• 2013

Stoker type incinerator is one of the most popular one used as municipal solid waste (MSW) incineration because, in general, it is quite suitable for large capacity and need no preprocessing facility. Nowadays, however, since the combustible portion of incoming MSW increases together with the decrease of the moisture content due to prohibition of directly burying food waste in landfill, the heating value of waste is remarkably increasing in comparison with the early stage of incinerator installation. Consequently, the increased heating value in incinerator operation causes a number of serious problems such as reduction of waste amount to be burned due to the boiler heat capacity together with the significant NO generation in high temperature environment. Therefore, in this study, a series of numerical simulation have been made as parameters of waste amount and the fraction of moisture in air stream in order to investigate optimal operating condition for the resolution of the problems associated with the high heating value of waste mentioned above. In specific, a detailed turbulent reaction flow field calculation with NO model was made for the full scale incinerator of D city. To this end, the injection method of moisturized air as oxidizer was intensively reviewed by the addition of moisture water amount from 10% and 20%. The calculation result, in general, showed that the reduction of maximum flame temperature appears consistently due to the combined effects of the increased specific heat of combustion air and vaporization heat by the addition of water moisture. As a consequence, the generation of NOx concentration was substantially reduced. Further, for the case of 20% moisture amount stream, the afterburner region is quite appropriate in temperature range for the operation of SNCR. This suggests the SNCR facility can be considered for reoperation. which is not in service at all due to the increased heating value of MSW.

• Reproductive and Developmental Biology
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• v.28 no.3
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• pp.181-185
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• 2004

This study was conducted to examine whether activation treatments, source of oocytes and culture conditions affect in vitro developmental ability of caprine oocytes. Mature Korean native goats were pretreated with intravaginal CIDR for 10 days. The goats were then treated with a single intramuscular injection of 1,000 IU PMSG on Day 8 or twice daily injection of a total of 70 mg FSH for 3 days from Day 8 of CIDR insertion for superovulation. All the goats were injected with 10 mg PGF/sub 2a/ on Day 8 and 400 IU hCG on Day 10 of CIDR. Oocytes were surgically collected by oviduct flushing(in vivo maturation) or direct follicle aspiration(in vitro maturation) through mid-ventral incision at 35 h after hCG injection. Fifteen to twenty oocytes were placed in TCM-199 medium containing 25 mM Hepes and hormones under mineral oil at 39℃ in a humudified atmosphere of 5% CO₂ in air for 22 to 24 h. After maturation, the oocytes were activated by electric stimulation or ionomycin + 6-DMAP. The activated oocytes were then cultured in M16, TCM-199 and mSOF media supplemented with proteins at 39℃ for 6 to 7 days. Activation treatments did not affect cleavage of the oocytes. The cleavage rates were 64.1% (41/64) in oocytes activated by electric stimulation and 76.5% (218/285) in oocytes activated by ionomycin + 6-DMAP. The proportion of development to blastocyst was 15.6% (34/218) in oocytes activated by ionomycin + 6-DMAP, but activation by electric stimulation did not support embryos developed beyond morula stage. There were no differences in the cleavage rates of activated oocytes experiencing in vivo (86.8%, 66/76) and in vitro maturation (69.0%, 127/184). However, the development rate to blastocyst stage was significantly (P<0.05) higher for oocytes matured in vivo (50.0%, 33/66) compared to in vitro (0.8%, 1/127). Culture conditions did not affect the cleavage of -activated oocytes. The cleavage rates were 51.6% (49/95) in M16, 64.3% (18/28) in TCM-199 and 81.0% (145/179) in mSOF, respectively. By contrast, the development rate of activated oocytes to stage was greater (P<0.05) for oocytes cultured in mSOF medium (23.4%, 34/145) than in M16 or TCM-199 (0.0%). Our results suggest that source of oocytes and culture conditions are major factors affecting in vitro development of caprine parthenogenetic oocytes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.13-24
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• 1988

This paper is concentrated on the development of oxygen transfer system by U-tube deep shaft in biological fluidised bed process. The depth of the shaft is 32 m, it is composed of downcomer and riser. Not only flow pattern and oxygen transfer in the deep shaft but also oxygen limitation in biofilm and oxygen utilization in biological fluidised bed are investigated. In this investigation, driving force for liquid circulation in the deep shaft is affected by air injection depth and gas hold-up in downcomer. Flow pattern of the deep shaft is revealed to plug flow. When flow velocity in the deep shaft is maintained to 0.52 m/sec, $K_La$ value is peak at 25~30 m depth in riser. The efficiency of dissolved oxygen supply which passed from the deep shaft to biological fluidised bed is estimated to 56~81 % in the organic wastewater treatment using the deep shaft and when dissolved oxygen concentration is 9.2 mg/l and over, limiting factors of flux and substrate within biofilm are organic materials. Terefore, organic loadings could be increase without decreasing of BOD removal efficiency.

• Journal of Preventive Medicine and Public Health
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• v.26 no.4 s.44
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• pp.587-598
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• 1993

Hydrofluoric acid is one of the strongest irritating, corrosive and poisonous inorganic chemicals. Hydrofluoric acid burns are occurring with ever-increasing frequency due to the wide use of this acid in industries. Hydrofluoric acid burns are characterized by severe progressive tissue destruction and excruciating pain due to the unique properties of the freely dissolvable fluoride ion. The authors reviewed medical records of 32 cases (36 spells) of hydrofluoric acid burns which occurred in a hydrofluoric acid manufacturing factory from Sep. 1, 1990 to June 30, 1993. The results are as follows; 1. Eleven measurements of air concentrations of hydrofluoric acid by detection tube method from 1990 to 1992 were all below TLV (Department of Labor, R.O. K). 2. There were 19 cases (22 spells) of hydrofluoric acid burns which occurred during the study period among regular employees. The overall incidence density of hydrofluoric acid was 17.8 cases (20.6 spells) per 100 person-year. Incidence density was 19.0 cases (22.0 spells) per 100 person-year among male workers and there were no female cases. Incidence density was 32.9 cases (38.3 spells) per 100 person-year among production workers and 1.9 cases (1.9 spells) per 100 person-years among management workers with the difference being statistically significant (P<0.01). 3. Of 32 cases (36 spells) of hydrofluoric acid burns among workers who were regularly employed or temporarily employed, 26 spells (81.2%) were between age 20 to 39. In 15 spells(41.7%) burns occurred between 12:00 and 17:59 with 16 spells(44.3%) having arrived at hospital within 2 hours after the accident. 4. Of 36 spells, the main cause of hydrofluoric acid burns were by splashes (8 spells, 22.2 %). The most frequent site of burns were fingers and pain was the most frequent symptom. Thirty spells (83.3%) of the hydrofluoric acid burns were treated with local injection of antidote (calcium gluconate). Complete recovery without scarring were observed in most of the cases (34 out of 36 cases, 94.4%). The study results suggest that to prevent hydrofluoric acid burns, environmental control and the wearing of hydrofluoric acid resistant protective clothes and gloves are important. It is also stressed that establishment of an emergency management and a transfer system for hydrofluoric acid burn victims is necessary.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.394-398
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• 2006

Background: Goal of the initial treatment of primary spontaneous pneumothorax is re-expansion of the lung by evacuation of air from pleural space. Authors thought small caliber catheter could reach to this goal instead of conventional large bore chest tube. This retrospective study was undertaken to assess the effectiveness of 7-French (Fr) catheter for the initial treatment of primary spontaneous pneumothorax. Material and Method: Between May 2003 and April 2005, 111 patients with primary spontaneous pneumothorax were managed with tube drainage; 7 Fr catheter for 86 patients and 24-French chest tube for 25 patients. We analyzed catheter indwelling time, use of analgesics, re-expansion of the lung, and catheter related problems by medical records. Result: Mean catheter indwelling time was $2.4{\pm}1.1$ days in 7 Fr group and $2.3{\pm}1.3$ days in chest tube group (p>0.05). All patients with 24 Fr catheter needed analgesics injection but never in 7Fr group. Complete re-expansion of the lung based on plane chest radiograph was obtained in 77% of 7 Fr group. The problem related with 7 Fr catheter was kinking, which showed in 5.6%. Conclusion: Application of the 7 Fr catheter for initial management of primary spontaneous pneumothorax was as effective as 24 Fr catheter.

• Applied Microscopy
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• v.23 no.1
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• pp.35-55
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• 1993

cis-Dichlorodiammineplatinum (II) (cis-Platin), a metallic compound, has widely been used as an effective anticancer chemotherapeutic agent. The precise mechanism of action of this agent is still unknown, but it is postulated that cis-Platin may act on the cancer cell like bifunctional alkylating agents. Although this agent is very beneficial to the patients with cervical cancer, germinoma of testis, neuroblastoma and others, it may also damage to the normal cell so that many side effects; severe hemorrhagic enterocolitis, bone marrow depression, renal damage and liver damage will develope. This experiment has been undertaken to pursue the cytotoxic effects of the cis-Platin on the ultrastructures of the interalveolar septum in the mouse lung. A total of 55 healthy male mice of ICR strain were used as experimental animals and divided into 5 mice of normal control group and 50 mice of cis-Platin treated group. The mice of cis-Platin treated group were sacrificed by carotid exsanguination at 6, 12, 24 hours, 3 days and 7 days after intraperitoneal injection of 6.0 mg of cis-Platin ($Abiplatin^R$ Abic Co. Ltd.) per kg of mouse body weight. The specimen obtained from the lower lobe of left lung were sliced into $1mm^3$ and prefixed with 2% glutaraldehyde -2.5% paraformaldehyde solution prepared with Millonig's phosphatae buffer solution (pH 7.4) at $4^{\circ}C$ for 3-4 hours. After postfixation with 1% osmium tetroxide solution all specimens were embedded in Epon 812. Ultrathin sections about $600-800{\AA}$ in thickness were stained with uranyl acetate and lead citrate and observed with Hitachi-600 electron microscope. The results obtained were as follows: 1. Local swellings with increase of electron density and number of pinocytic vesicles in the cytoplasms of the type I pneumocyte and endothelial cell of the blood air barrier in interalveolar septum of cis-platin treated mice were observed. 2. Cisternae of rough endoplasmic reticulum were dilated and sacculated in association with detachment of membrane bound ribosomes of the type II pneumocyte in interalveolar septum of cis-Platin treated mice. 3. Swollon mitochondria with uneven electron density of their matrix were observed in the type II pneumocyte of interalveolar septum in the cis-Platin treated mice. 4. The lamellae of lammelar bodies in type II pneumocyte of interalveolar septum in cis-Platin treated mice were devoided or transformed into homogeneous electron dense material. It is consequently suggested that cis-Platin would induce the cellular edema of type I pneumocyte and endothelial cell, and degenerative changes of cytoplasmic organelles of the type II pneumocyte in the interalveolar septum of the mouse lung.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.7-13
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• 2014

As the interest on the air pollution is gradually rising up at home and abroad, automotive and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward various main issues : whether PM emissions should be regulated for diesel and gasoline vehicles and whether gasoline and LPG powered vehicles can be further neglected from PM emission inventories. Finally, the greenhouse gas ($CO_2$, $CH_4$, $N_2O$) regulation has been discussed including automotive emission regulation. The greenhouse gas and emissions (PM) particle of automotive had many problem that cause of ambient pollution, health effects. This paper discussed the influence of LPG fuel on automotive cold startability and exhaust emissions gas. Also, this paper assessed emission characteristics due to the test temperature. These test temperature were performed by dividing the temperature of the test mode and the lowest local temperature in winter. Through this study, the correlation of cold startability, exhaust emission and greenhouse gas emission was analyzed.