• 청정기술
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• 제13권2호
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• pp.115-121
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• 2007

본 연구에서는 유전체 장벽 방전-광촉매 복합 공정에 의한 NO 및 $SO_2$ 제거를 실험적으로 분석하였다. 유전체 장벽 방전을 위해 유전체로서 유리구가 사용되었고 $TiO_2$ 광촉매 입자는 딥코팅(dip-coating) 방법에 의해 높은 비표면적을 가지는 스펀지 형태로 유리구에 코팅되었다. 플라즈마 반응기에 인가된 전압이나 펄스 주파수, 혹은 기체의 체류시간이 증가함에 따라, NO 및 $SO_2$의 제거효율은 증가하였다. NO 및 $SO_2$ 공급농도 증가하면 NO 및 $SO_2$ 제거에 더 많은 에너지가 요구되어 NO 및$SO_2$의 제거효율이 감소하였다. 본 연구의 실험 결과들은 NO 와 $SO_2$를 제거하기 위한 유전체 장벽 방전-광촉매 복합 공정 설계의 기초 자료로 사용될 수 있다.

• 한국대기환경학회지
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• 제27권4호
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• pp.387-394
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• 2011

A study on the removal of sulfur dioxide and nitrogen oxide was carried out using a non-thermal nano-pulse corona discharger at different gas temperatures. Pulse voltage with a high voltage of 50 kV, a pulse rising time of about 100 ns, a full width at half maximum of about 500 ns and a frequency of 1 kHz was applied to a wire-cylinder corona reactor. Ammonia and propylene gases were added into the corona reactor as additives with a static mixer. Ammonia addition had less effect on $SO_2$ reduction at the higher temperature because of the retardation of ammonium sulfate formation. However, propylene addition enhanced NO reduction at higher temperature due to increased gas mixture. $SO_2$ was further removed at the mixed $SO_2$ and NO gas due to increased $NO_2$ by the conversion of NO. The addition of ammonia and propylene gases was more highly dominant for the removal of sulfur dioxide compared to the sole pulse corona without the additives. However, the specific energy density per unit concentration of pulse corona as well as propylene additive was an important factor to remove NO gas. Therefore, the specific energy density per unit concentration of 0.04 Wh/($m^3{\cdot}ppm$) was necessary for the NO removal of more than 80% with the concentration ratio of 2.0 for propylene and NO. Hydrogen peroxide was another alternative additive to remove both $SO_2$ and NO in the nano-pulse corona discharger.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.470-475
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• 2009

We deposited $Al_2O_3$ thin films on GaN by remote plasma atomic layer deposition (RPALD) technique, trimethylaluminum(TMA) and oxygen were used as precursors, at fixed process condition, the number of cycle were changed. Growth rate per cycle was $1.2\;{\AA}$/cycle. and Growth rate was in proportion to a number of cycle, the GaN MIS capacitors that $Al_2O_3$ thin film were deposited above 12 nm, have excellent electrical properties, a low electrical leakage current density(${\sim}10^{-10}\;A/cm^2$ at 1.5 MV), but below 12 nm, we can see the degradation of the leakage current density. After post deposition annealing, Dielectric constant was estimated by 1 MHz high-frequency C-V method, it was varied with the anealing temperature from 6.9 at no post anealed to 7.6 at $800^{\circ}C$, and we can see a improvement of the leakage current density and breakdown voltage by post deposition anealing below $700^{\circ}C$, but, after anealed at $800^{\circ}C$, we can see the degradation of the leakage current density and breakdown voltage.

• Radiation Oncology Journal
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• 제3권1호
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• pp.19-28
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• 1985

Twenty-four cases of pituitary adenoma, 13 males and 11 females with the age ranging from 11 to 65 years, received radiation therapy(RT) on the pituitary area with 6MV linear accelerator during past 25 months at the Division of Radiation Therapy, Kangnam St. Mary's Hospital, Catholic Medical College. Of 24 cases of RT, 20 were postoperative and 4 primary. To evaluate the effect of RT, we analysed the alteration of the endocrinologic tests, neurologic abnormalities, major clinical symptoms, endocrinologic changes and improvement in visual problems after RT. The results were as follows ; 1. Major clinical symptoms were headache, visual defects, diabetes insipidus, hypogonadisms and general weakness in decreasing order of frequency. 2. All but the one with Nelson's syndrome showed abnormal neuroradiologic changes in the sella turcica with an invasive tumor mass around supra· and para-sellar area. 3. Endocrinological classifications of the patient were 11 prolactinoma, 4 growth hormone -secreting tumors, 3 ACTH-secreting tumors consisting of one Cushing's disease and two Nelson's syndrome, and 6 nonfunctioning tumors. 4. Eleven of 14 patients, visual problems were improved after treatment but remaining 3 were unchanged. 5. Seven of 11 prolactinomas returned to normal hormonal level after postoperative and primary RT and 3 patients are being treated with bromocriptine (BMCP) but one lost case. 6. Two of 4 growth hormone·secreting tumor returned to normal level after RT but the remaining 2 are being treated with BMCP, as well.

• 한국발생생물학회지:발생과생식
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• 제23권1호
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• pp.21-34
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• 2019

The effects of the anaesthetic agents, clove oil and mixture of clove oil with lidocaine-HCl were evaluated on river puffer, Takifugu obscurus and tiger puffer, T. rubripes. Anaesthesia times of clove oil were affected by water temperature ($20^{\circ}C$, $24^{\circ}C$, and $28^{\circ}C$) and salinity (10, 20, and 30 ppt). Anaesthesia times of mixed samples were significantly similar with regard to exposure and recovery times, and all samples satisfied anaesthesia criteria (exposure time within 3 min and recovery time within 5 min) under the various temperatures and salinities, and the lowest to highest concentration of anaesthetics (p<0.05). Both species river puffer and tiger puffer had short exposure time with a high anaesthesia dose, high temperature ($28^{\circ}C$) and intermediate salinity (20 ppt), and were highly affected by temperature and salinity (p<0.05). The mixed anaesthetics had rapid exposure times and long recovery times in contrast to the effects of clove oil. Cortisol concentrations under the conditions of various clove oil dosages, salinity, and temperature for both species increased until 12 hrs after recovery from anaesthesia (p<0.05). After 12 hrs, cortisol concentrations decreased until after 48 hrs (p<0.05). During the simulated transportation of both species, control and sedated clove oil groups (5 ppm) were measured for water parameters, dissolved oxygen (DO), $CO_2$, respiratory frequency, $NH_4{^+}$, and pH for 6 hrs in 1 hr intervals. Water parameters of sedated groups and controls were significantly different after 2 hrs (p<0.05).

• Journal of Ginseng Research
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• 제45권6호
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• pp.706-716
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• 2021

Background: Irritable bowel syndrome (IBS), the most common functional gastrointestinal disorder, is characterized by chronic abdominal pain and bowel habit changes. Although diverse complicated etiologies are involved in its pathogenesis, a dysregulated gut-brain axis may be an important factor. Red ginseng (RG), a traditional herbal medicine, is proven to have anti-inflammatory effects and improve brain function; however, these effects have not been investigated in IBS. Methods: Three-day intracolonic zymosan injections were used to induce post-infectious human IBS-like symptoms in mice. The animals were randomized to receive either phosphate-buffered saline (CG) or RG (30/100/300 mg/kg) for 10 days. Amitriptyline and sulfasalazine were used as positive controls. Macroscopic scoring was performed on day 4. Visceral pain and anxiety-like behaviors were assessed by colorectal distension and elevated plus maze and open field tests, respectively, on day 10. Next-generation sequencing of gut microbiota was performed, and biomarkers involved in gut-brain axis responses were analyzed. Results: Compared to CG, RG significantly decreased the macroscopic score, frequency of visceral pain, and anxiety-like behavior in the IBS mice. These effects were comparable to those after sulfasalazine and amitriptyline treatments. Moreover, RG significantly increased the proliferation of beneficial microbes, including Lactobacillus johnsonii, Lactobacillus reuteri, and Parabacteroides goldsteinii. RG significantly suppressed expression of IL-1β and c-fos in the gut and prefrontal cortex, respectively. Further, it restored the plasma levels of corticosterone to within the normal range, accompanied by an increase in adrenocorticotropic hormone. Conclusion: RG may be a potential therapeutic option for the management of human IBS.

• BMB Reports
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• 제54권12호
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• pp.620-625
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• 2021

Microglia are known to be activated in the hypothalamic paraventricular nucleus (PVN) of rats with cardiovascular diseases. However, the exact role of microglial activation in the plasticity of presympathetic PVN neurons associated with the modulation of sympathetic outflow remains poorly investigated. In this study, we analyzed the direct link between microglial activation and spontaneous firing rate along with the underlying synaptic mechanisms in PVN neurons projecting to the rostral ventrolateral medulla (RVLM). Systemic injection of LPS induced microglial activation in the PVN, increased the frequency of spontaneous firing activity of PVN-RVLM neurons, reduced GABAergic inputs into these neurons, and increased plasma NE levels and heart rate. Systemic minocycline injection blocked all the observed LPS-induced effects. Our results indicate that LPS increases the firing rate and decreases GABAergic transmission in PVN-RVLM neurons associated with sympathetic outflow and the alteration is largely attributed to the activation of microglia. Our findings provide some insights into the role of microglial activation in regulating the activity of PVN-RVLM neurons associated with modulation of sympathetic outflow in cardiovascular diseases.

• 한국재료학회지
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• 제33권4호
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• pp.124-129
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• 2023

This study assessed the influences of fluorine introduced into DLC films on the structural and mechanical properties of the sample. In addition, the effects of the fluorine incorporation on the compressive stress in DLC films were investigated. For this purpose, fluorinated diamond-like carbon (F-DLC) films were deposited on cobalt-chromium-molybdenum substrates using radio-frequency plasma-enhanced chemical vapor. The coatings were examined by Raman scattering (RS), Attenuated total reflectance Fourier transform infrared spectroscopic analysis (ATR-FTIR), and a combination of elastic recoil detection analysis and Rutherford backscattering (ERDA-RBS). Nano-indentation tests were performed to measure hardness. Also, the residual stress of the films was calculated by the Stony equation. The ATR-FTIR analysis revealed that F was present in the amorphous matrix mainly as C-F and C-F₂ groups. Based on Raman spectroscopy results, it was determined that F made the DLC films more graphitic. Additionally, it was shown that adding F into the DLC coating resulted in weaker mechanical properties and the F-DLC coating exhibited lower stress than DLC films. These effects were attributed to the replacement of strong C = C by feebler C-F bonds in the F-DLC films. F-doping decreased the hardness of the DLC from 11.5 to 8.8 GPa. In addition, with F addition, the compressive stress of the DLC sample decreased from 1 to 0.7 GPa.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.38.1-38.1
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• 2009

In this paper we present the first results of summer-time F region irregularities during low solar condition observed using the Gadanki MST radar. Echoes were observed on all 20 nights of radar observations and were mostly confined to the post-midnight hours. Echo morphology is very different from the equinoxial post-sunset plume-like features reported earlier from Gadanki. Echo SNRs are lower by 25 dB than their equinoxial post-sunset counterpart, and are quite comparable to the equinoxial irregularities in the post-midnight hours, which are essentially the decaying post-sunset irregularities. The Doppler velocities, which lie in the range of $\pm$ 100 m s-1, show upward/northward motion of the irregularities during the initial phase in contrast to the observed predominant downward/southward velocities associated with the decaying equinoxial post-midnight F region irregularities. Spectral widths of the summer echoes, which are well below 50 m s-1 and are very similar to those of the decaying equinoxial irregularities, represent the presence of weak plasma turbulence. Simultaneous observations made using a collocated ionosonde show no ionogram trace during 2200-0530 LT except for a few occasions. Weak frequency type spread F observed during midnight hours occurred without prior occurrence of range spread F. Concurrent ionosonde observations made from magnetic equatorial location Trivandrum also show very similar result and thus no height rise of the F layer during the midnight hours could be monitored. The preliminary analysis suggests that the post-midnight irregularities reported here are mostly freshly generated ones. The observations are discussed in the light of other observational results reported earlier and the current under standing on the post-midnight occurrence F region irregularities in summer.

• 대한방사선기술학회지:방사선기술과학
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• 제46권4호
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• pp.303-313
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• 2023

This study aimed to investigate the relevance of cardiovascular disease risk factors AI and AIP, divided into three groups, among 300 individuals who underwent health checkups at the hospital. Various variables such as Age, Sex, BMI, WC, TC, TG, HDL-C, LDL-C, FBS, HbA1C, SBP, DBP, HR, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) were analyzed using statistical methods including frequency analysis, cross-tabulation, one-way ANOVA, Pearson's correlation analysis, and multiple linear regression analysis. The cross-analysis based on cardiovascular disease risk criteria revealed that men and individuals in their 50s had higher cardiovascular disease risk based on AI and AIP. Significant differences were observed in TG, TC, HDL-C, LDL-C, SBP, DBP, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) according to AI criteria. For the AIP criteria, TG, TC, HDL-C, FBS, HbA1C, HR, AI (TC/HDL-C), and AIP (log(TG/HDL-C)) were identified as cardiovascular disease risk factors. FBS and HbA1c showed the highest positive correlation In the correlation analysis, followed by TC and LDL-C. The lowest positive correlation was observed between LDL-C and DBP. In terms of negative correlation, HDL-C and AI had the highest negative correlation, while LDL-C and TG showed the lowest negative correlation. Multiple regression analysis indicated that the AI and AIP risk criteria had explanatory powers of 73.6% and 72.5%, respectively. HDL-C had the greatest negative effect on the AI risk criterion, while TG had the most significant influence on the AIP risk criterion. In conclusion, while other serological variables are important, managing HDL-C and TG levels may help reduce the risk of cardiovascular disease.