• Proceedings of the KAIS Fall Conference
• /
• 2011.12b
• /
• pp.402-405
• /
• 2011

디젤엔진에서 발생되는 PM과 $NO_X$는 강화되는 배기규제의 주요 저감대상으로서 이의 저감을 위한 다양한 후처리장치가 개발되고 있다. 이중 Urea-SCR은 $NO_X$의 전환율이 높고 연비에 미치는 영향이 작기 때문에 $NO_X$저감을 위한 최선의 장치로 인식되고 있다. 하지만, 우레아 수용액의 물성치 특성으로 인하여 동절기 $-20^{\circ}C$이하로 내려가는 지역에서 동결되는 문제점을 해결해야한다. 따라서 이러한 우레아 저장탱크에 해동 시스템을 적용하여 시동초기 우레아를 적정 시간내에 안정적으로 공급가능한 기술의 확보가 필요하다. 본 연구에서는 요소수 저장탱크 내부에 냉각수 순환 가열방식(CH)과 전기 가열방식(EH)을 이용하여 동결된 요소수의 해동현상에 대한 3차원 비정상상태 수치 해석을 수행하였다. 이를 통하여 해동 과정 중 나타난 액상분율, 온도영역 그리고 자연대류를 분석하여 각 가열 방식에 대한 해동특성을 비교하였으며 순수 갈륨 융해 실험 결과값과 수치 해석 결과값를 통하여 수치 해석 방법을 검증하였다. 결론적으로 1,000ml의 우레아 수용액이 확보되기까지의 시간은 CH의 경우, 275s, 그리고 EH의 경우, 230s임을 알 수 있었다.

• Journal of Power System Engineering
• /
• v.20 no.6
• /
• pp.93-98
• /
• 2016

Environmental problems are issued throughout all over the world and which are needed the strength management. In case of the diesel cars are also being developing and studying continuously about various after-treatments device such as EGR, LNT, SCR, DPF and DOC etc. which are used for decreasing $NO_X$ and PM. The air temperature goes up to $39^{\circ}C$ in summer and goes down to $-20^{\circ}C$ in winter because of the location. These changing of the temperature can effect to the engine and harmful exhaust gas discharged and it seems to make the increase - decrease different. The result of the evaluate while changing between the test-mode and the air temperature, which expresses that WLTC-mode is 2.2 times and FTP_75 mode is 4.1~6 times increase to the comparison NEDC-mode of the current regulation. The exhaust characteristic of $NO_X$ by the changing temperature increases in the low temperature and 4.3 times in $14^{\circ}C$ and 21.3 times in $-7^{\circ}C$ with maximum when it compares to $23^{\circ}C$. The fuel efficiency of the different weight car and engine with same data is about 5.7 % in maximum.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.24-24
• /
• 2009

현재 조선소를 비롯하여 각종 산업 전반적으로 기존의 SCR 용접기를 대체하여 용접품질이 우수한 인버터 용접기가 널리 사용되고 있는 실정이다. 그러나 기존 인버터 용접기의 전원은 Mono 타입으로 이루어져 있어 대용량 인버터 용접기의 경우 대용량 스위칭 소자가 요구되어 제조원가가 높다. 그리고 문제 발생 시 용접기의 사용이 불가능하게 된다. 개발된 단위모듈을 병렬로 연결하여 대용량 용접기를 구성하게 되면 제조원가를 절감할 수 있으며 병렬로 연결되어 단위 모듈에 문제가 발생하여도 계속적인 사용이 가능하고, 주 회로를 작은 용량으로 분산시켜 전력을 제어하므로 높은 에너지 효율을 가지게 된다. 또한 인버터 용접기의 가장 중요한 성능인 스위칭 주파수에 있어서도 기존의 인버터 용접기는 20kHz의 스위칭 주파수를 가지지만 본 기술은 낮은 전력을 병렬로 연결하여 대용량을 동시에 제어가능 하므로 약 70kHz의 고속제어가 가능하다. 본 연구에서는 개발된 용량 170A단위모듈을 병렬로 연결하여 단위모듈 집적형 인버터 아크용접기 510A, 680A급의 부하테스트 실시 및 기본출력특성에 대하여 실험하였으며, GMAW에서 ${\Phi}1.6$ 솔리드 와이어를 이용하여 두께 20t의 후판 맞대기 용접에 적용실험을 실시하였다. 그 결과 모든 전류영역에서의 부하특성 및 출력특성이 양호하게 나타났으며, 후판 맞대기 용접에서는 SAW에 버금가는 생산성과 용접특성을 얻을 수 있었다.

• Science of Emotion and Sensibility
• /
• v.1 no.2
• /
• pp.13-22
• /
• 1998

The sense of touch has both objective and subjective characteristics. During hand evaluation of the fabrics. psycho physiological processes such as emotion and stimulation. On other site, the mode of touch (passive vs. active) is also capable to modulate somatosensory responses. I.e., suppress somatocensory perception during active electrocortical responses to passive and active touch of the textiles with different subjective emotional preference. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and BIOPAC 100 systems with AcqKnowledge variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, risetime and number of SCRs) were analyzed for baseline and stimulation conditions. Analysis was manifested in a form of moderate HR acceleration. RSP increase, RSA decrease (lowered vagal tone), decreased PTT and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand)were featured by short-term alpha-blocking, slightly reduced theta, significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome.

• Quality Improvement in Health Care
• /
• v.9 no.2
• /
• pp.230-240
• /
• 2002

Background : The purpose of this study was to develop, implement and evaluate the pharmacist intervention program designed to identify and correctly adjust the dosage of $H_2$-receptor antagonists ($H_2RA$) in renally impaired patients and promote timely conversion of $H_2RA$ from IV to PO therapy. Methods : The study population consisted of renally impaired patients who received $H_2RA$ therapy from April 9 to May 8, 2001 at Hallym Medical Center. Each morning a specifically developed software program identified patients with serum creatinine (Scr) greater than 1.2 mg/dl or age greater than 65 years. The pharmacist, then screened the pharmacy profiles of the identified patients to determine if the patient was on $H_2RA$. For these patients on $H_2RA$ with renal impairement the creatinine clearance (CrCl) was calculated using Cockroft & Gault equation. The pharmacist determined the proper dosage for each identified patients based on the calculated CrCl and the oral dosage that would be appropriate for whom IV therapy was no longer indicated. Result : A total of 149 cases (101 patients) were monitored during the study period. The dosage was inappropriately prescribed for renal function in 61 of 149 cases (41%), and of those, pharmacist made recommendations for 58 cases of which 33 cases (57%) were accepted by the physicians. The administration route of H2RA was inappropriately used as IV in 22 of 53 cases (42%), and pharmacist made recommendations for those 22 cases of which 15 cases (68%) were accepted. Conclusion : Monitoring of patients with renal dysfunction by a pharmacist improved the dosing of $H_2RA$ and a dosing program of patients with renal impairment would be of benefit to other clinicians and institutions seeking to optimize patient care.

• Plant Journal
• /
• v.15 no.3
• /
• pp.23-28
• /
• 2019

In this study, ammonia consumption by gas turbine output was adjusted to find out the amount of ammonia consumption that complies with the enhanced Air Quality Preservation Act and internal regulation emission standards in SCR type DeNOx System for a 580 MW Sejong Combined Cycle Power Plant. For measurements, the gas turbine output was varied to 50, 99, 149, 198 MW and ammonia consumption was adjusted with the combustion gas and ammonia supply conditions fixed at each stage. When the emission limit were change from 10 ppm to 8 ppm, ammonia consumption was increased from 78, 93, 105, 133 kg/h to 89, 113, 132, 176 kg/h. The increase rate of ammonia consumption was 14, 22, 26, 32% per output category compared to the 10 ppm emission limit, which was shown to increase as output increased.

• Korean Journal of Clinical Pharmacy
• /
• v.9 no.1
• /
• pp.35-43
• /
• 1999

Over the last 50 years, a number of antibiotic agents have been developed and clinically used in the area of infectious diseases. Due to antimicrobial resistance problems and increasing health care costs, the rational use of antibiotics has been required. As a drug of choice to treat infections caused by MRSA, vancomycin has been extensively prescribed since the late 1970's. Recently, reports of vancomycin-resistant organisms such as VRE and VRSA have been increased to draw medical concerns. The objectives of this study were to evaluate the rational use of vancomycin and the appropriateness of the Restrictional Program of Antibiotic Utilization (RPAU) which has been operated at Samsung Medical Center. A retrospective chart review was performed in 132 hospitalized patients treated with vancomycin in the surgery departments from. January to June 1998. The guidelines of ASHP and HICPAC for vancomycin were modified and used as our criteria to determine the vancomycin DUE. In one hundred out of the patients, uses of vancomycin were approved by the Department of Infectious Diseases (DID) based on the RPAU. Vancomycin was appropriately used in $62.5\%$ of the 100 patients according to the criteria of justification of use, while $60.0\%,\;60.0\%,\;79.0\%,\;and\;51.0\%$ of the patients showed appropriate according to those of lab reports such as applicable culture obtained, pretreatment SCr, WBC and serum drug concentration monitoring, respectively. Although the rest 32 patients were not approved to receive vancomycin by the DID, twenty two percent continued receiving vancomycin treatment. This might result from the fact that the RPAU was started not before the use of antibiotics but in the middle of antimicrobial therapy. Continual education should be provide to the related health professionals and the RPAU should be simultaneously modified in order to increase the rate of appropriate uses of antibiotics.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.1
• /
• pp.108-113
• /
• 2010

The purpose of this study was to investigate the differences of driving performance and physiological responses between young male and female drivers for unexpected situation using a graphic vehicle simulator. The participants included 20 college graduates; 23 males aged $24.3\;{\pm}\;1.4$ with $2.3\;{\pm}\;1.5$ years of driving experiences and 23 females aged $23.2\;{\pm}\;2.1$ with $2.2\;{\pm}\;1.7$ years of driving experience. The participants were instructed to drive the vehicle simulator which was programed unexpected situation for two minutes. The physiological measurements used were autonomic responses of electrocardiogram (ECG) and skin conductance response (SCR), and the driving performance measurements used were the reaction time of break and the rate of collision for unexpected situation. Results showed that there were no significant differences between male and female drivers in the reaction time of break and the rate of collision for unexpected situation. Averaged R-R interval decreased and LF IHF and SCL amplitude increased for unexpected situation. There were no significant differences between male and female in the averaged R-R interval and LF/HF for unexpected situation. On the other hand, SCL amplitude of female was higher than male. Rising time to maximum SCL amplitude of female was longer than male.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.3
• /
• pp.511-521
• /
• 2000

Investigation was carried out lean burn de-NOx properties of Pt-$TiO_2$ bifunctional catalyst by propylene in order to get the high de-NOx activity and the wide temperature window under coexistence of $SO_2$ and $H_2O$. Only noncatalyst and carrier catalyst themselves had NOx conversion activity at high temperature over $400^{\circ}C$. NOx conversion activity of catalysts exchanged copper ion resulted in Cu-$TiO_2$>Cu-ZSM-5>Cu-$Al_2O_3$>CU-YZ>Cu-AZ. Catalysts impregnated with platinum based on titania gave the results of high NOx conversion activity at low temperature. $250^{\circ}C$. Bifunctional catalysts based on Pt-$TiO_2$ showed high NOx conversion activity both at a low zone of $300^{\circ}C$ and a high zone of $500^{\circ}C$. Pt-$TiO_2$/$Al_2O_3$ catalyst gave the highest NOx conversion activity at a low temperature zone. and Pt-$TiO_2$/$Mn_2O_3$(21) catalyst gave the highest NOx conversion activity at a high temperature zone. Under the coexistence of $SO_2$ and $H_2O$. NOx conversion activities of 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst was high both at a low and high temperature zone, and increased depending on oxygen concentration. 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst showed the best correlation between de-NOx activities and the propyl ere conversion rates to CO on the log function.

• Applied Biological Chemistry
• /
• v.40 no.5
• /
• pp.380-387
• /
• 1997

Phytopathogenic Erwinia carotovora subsp. carotovora (Ecc) LY34 causes plant tissue maceration by secretion of pectinolytic enzymes such as pectate Iyase (PL) existed as multiple isoenzyme form. Genomic DNA from Ecc LY34 was digested with Sau3Al and ligated into the BamHI site of pBluescript ll $SK^+$. Among them, a clone hydrolyzing polypectate was selected and its DNA was digested with BamHI. Through the subsequent subcloning the resulting 3.1 kb fragment, corresponding to a peICI, was subcloned into pLYPA 100. The structural organization of a peICI gene encoding a 374 amino acid residues consists of an open reading frame (ORF) of 1,122 bp commencing with a ATG start codon and followed by a TAA stop codon. PeICI contained a typical prokaryotic signal peptide of 22-amino acid. Since the deduced amino acid sequences of PeICl protein was very similar to those of PelIII of Erwinia carotovora subsp. carotovora, and to those of Pel3 of Erwinia carotovora subsp. atroseptica, and to those of PeIC of Erwinia carotovora subsp. carotovora, it belong to the same family PLbc group. The 374-amino acld PeICI had a calculated Mr of 40,507 and pI of 7.60.