석유화학업종에서의 비산배출원 배출 특성 분석

구치완,안승효,마병철 한국가스학회 2022 한국가스학회지 Vol.26 No.6

Technologies for collecting and treating pollutants from point sources are steadily being developed, but Non-point sources, it is difficult to develop emission treatment technologies and effective emission coefficients. However, since non-point sources make up about 60% of domestic emissions, and first of all, the method of calculating emissions should be reasonable, and the workplace should develop emission reduction technologies based on this. This study suggest the effectiveness and improvement of the emission coefficient currently used for the petrochemical industry with high emissions. The emission characteristics of non-point sources emission were confirmed by analyzing the LDAR (Leak Detection And Repair) data of 00 company located in Yeosu, Jeollanam-do over the past five years. As a result, there was no difference in discharge characteristics according to fluid phase, but it was confirmed that there was a difference in the size of the device and the characteristics of each manufacturer. In addition, it was confirmed that the emission coefficient applied in the petrochemical industry was larger than that of the refining industry, and improvement measures were suggested. Through these studies, it is expected that emission coefficients specialized in the petrochemical industry can be applied and that the workplace itself will contribute to the development of technologies that can drastically reduce them. 고정된 점배출원(Point source)에서 배출되는 오염물질을 포집하여 처리하는 기술은 꾸준히 개발되고 있으나, 비산배출원(Non-point source)의 경우 배출원이 다양하고, 일정하지 않아 배출물질 처리기술 및 실효성 있는 배출계수 등을 개발하는 것은 어려운 실정이다. 그렇지만, 비산배출원은 국내 배출량의 약 60%를 차지하고 있기 때문에 배출량 산정방법이 타당하여야 하며 이를 토대로 사업장은 배출저감기술 등을 개발하여야 한다. 이에, 본 연구에서는 배출량이 많은 석유화학업종을 대상으로 현재 사용되고 있는 배출계수의 실효성과 개선 방안 등을 제시하고자 한다. 이를 위하여, 전남 여수 소재 00회사의 최근 5년간의 LDAR(Leak Detection And Repair)데이터를 분석하여 비산배출원의 배출특성 확인하였다. 그 결과, 유체 성상에 따른 배출 특성의 차이는 없으나 장치의 크기, 제조사별 특성의 차이가 있음을 확인할 수 있었다. 또한, 석유화학 업종에서 적용하는 자체 배출계수가 정유업종에 비해 크게 나타나는 것을 확인하였으며 이에 대한 개선방안 등을 제시하였다. 이러한 연구를 통하여 석유화학업종에 특화된 배출계수를 적용할 수 있으며 사업장 스스로 이를 획기적으로 감할 수 있는 기술을 개발하는데 기여할 것으로 기대한다.

미세유체 제어방법을 사용한 가변 커패시터

구치완 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.3

This paper demonstrates a variable capacitor using fluids as dielectric material and investigates the possibility of itsapplication to a magnetic resonance microscopy's coil. The capacitor structure was integrated with a microfluidic channeland the capacitance was measured while changing the filling percentage of fluids in the channel. The measuredcapacitance when filling DI water and mineral oil was changed from 1.7 pF to 12 pF and from 1.7 pF to 2 pF,respectively. 본 연구에서는 유체를 유전체 재료로 사용하는 가변 커패시터를 시연하고, 자기 공명 현미경(MRM)의 코일에 적용 가능성을 알아보려고 하였다. 전극으로 이루어진 커패시터 구조는 마이크로 유체 채널과 통합하여 제작되었고, 커패시턴스는 채널내의 유체 충전율을 변화시키면서 측정되었다. DI water와 미네랄 오일을 사용하여 측정된 커패시턴스는 1.7 pF에서 12 pF,그리고 1.7 pF에서 2 pF으로 변하였고, 유체의 유전율에 따라 커패시턴스의 변화를 확인하였다.

저항소자를 이용한 휴대형 Real-time PCR 기기용히터 제작

최형준,김정태,구치완 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.1

A heater in a portable real-time polymerase chain reaction(PCR) system is one of the important factors for controllingthe PCR thermocycle precisely. Since heaters are integrated on a small-sized PCR chip for rapid heating and fabricatedby semiconductor processes, the cost of producing PCR chips is high. Here, we propose to use chip resistors as aninexpensive and accurate temperature control method. The temperature distribution was simulated using one or two chipresistors on a real-time PCR chip and the PCR chip with uniform temperature distribution was fabricated. Thetemperature rise and fall rates were 18°C/s and 3°C/s, respectively. 바이오샘플의 DNA를 대량 증폭할 수 있는 휴대형 실시간 중합효소연쇄반응(Real-time PCR) 기기에서 히터는 PCR 반응온도를 제어하기 위한 중요한 요소 중의 하나이다. 보통 빠른 히팅을 위해 소형 PCR 칩에 집적화되어 있고, 반도체 공정을이용하여 박막형태로 제작되어 PCR 칩 제작 단가가 높은 편이다. 따라서 본 연구에서는 값싸고 온도제어를 정확히 할 수 있는 히터로 칩 저항을 사용하는 것을 제안한다. 칩 저항을 사용한 히터는 구조가 단순하고 제작이 쉽다는 장점이 있다. 2.54× 2.54 cm² 크기의 실시간 PCR 칩 위에 칩 저항을 1개 또는 2개를 사용했을 때 온도분포를 시뮬레이션 하였고, 고른 온도분포를 갖는 PCR 칩을 제작했다. 또한 효율적인 PCR 칩 냉각을 위해 소형 fan이 내장된 하우징을 설계하였고, 3D 프린터로제작했다. 온도제어는 마이크로프로세서를 이용한 PID제어법(Proportional-Integral-Differential control)을 적용했다. 온도상승비와 하강비는 각각 18℃/s, 3℃/s이며, 각 PCR 반응 단계의 유지 시간을 30초로 하였을 때, 한 사이클은 약 2.66분이 걸렸고, 35 사이클은 약 93 분 내로 진행할 수 있었다.

Implantable Bladder Sensors: A Methodological Review

Mathias Naangmenkpeong Dakurah,구치완,최원석,정연호 대한배뇨장애요실금학회 2015 International Neurourology Journal Vol.19 No.3

The loss of urinary bladder control/sensation, also known as urinary incontinence (UI), is a common clinical problem in autistic children, diabetics, and the elderly. UI not only causes discomfort for patients but may also lead to kidney failure, infections, and even death. The increase of bladder urine volume/pressure above normal ranges without sensation of UI patients necessitates the need for bladder sensors. Currently, a catheter-based sensor is introduced directly through the urethra into the bladder to measure pressure variations. Unfortunately, this method is inaccurate because measurement is affected by disturbances in catheter lines as well as delays in response time owing to the inertia of urine inside the bladder. Moreover, this technique can cause infection during prolonged use; hence, it is only suitable for short-term measurement. Development of discrete wireless implantable sensors to measure bladder volume/pressure would allow for long-term monitoring within the bladder, while maintaining the patient’s quality of life. With the recent advances in microfabrication, the size of implantable bladder sensors has been significantly reduced. However, microfabricated sensors face hostility from the bladder environment and require surgical intervention for implantation inside the bladder. Here, we explore the various types of implantable bladder sensors and current efforts to solve issues like hermeticity, biocompatibility, drift, telemetry, power, and compatibility issues with popular imaging tools such as computed tomography and magnetic resonance imaging. We also discuss some possible improvements/emerging trends in the design of an implantable bladder sensor.

심전도와 심음을 측정하기 위한 무선 전자 심전도 -심음 청진기 개발

조한석,강영환,박재순,최진규,정연호,구치완 대한의용생체공학회 2022 의공학회지 Vol.43 No.2

In this paper, we proposed a portable electronic cardiogram and stethoscope (ECGS) that can simulta- neously perform the electrocardiogram (ECG) and auscultation tests to increase the reliability of diagnosis of heart disease. To measure the ECG and heart sound (HS) at the same time, three ECG electrodes and a microphone sensor were combined into a triangular shape with a width of 90 mm and a height of 97 mm that can be held in one hand. In order to prevent skin problems when they contact the patient’s skin, a capacitive coupled electrode was selected as the ECG electrode and a silicone material was used in a chest piece with the microphone sensor. For the signals measured from the electrodes and the chest piece, filters were respectively configured to pass only the signals of 0.01-100 Hz and 20-250 Hz, which are frequency bands for ECG and HS. The filtered ECG and HS analog signals were converted into digital signals and transmitted to a PC using wireless communication for monitoring them. The HS could be auscultated simultaneously using an earphone. The monitored ECG had an SNR of about 34 dB and a P-QRS-T waveform is clearly visible. In addition, the HS had an SNR of about 28 dB and both S1 and S2 are clearly visible. It is expected that it can aid doctors’ inexperience in analyzing the ECG and HS.

NH4OH-H2O2-H2O 혼합액을 이용한 GaAs 의 습식식각 특성 연구 및 이를 이용한 부유된 시각형 단면을 가지는 GaAs 미세구조물의 제작 방법

조동일,박상준,이승기,김종팔,백승준,김세태,구치완 한국센서학회 2001 센서학회지 Vol.10 No.5

In this research, we investigate wet-etching properties of GaAs in NH₄OH-H₂O₂-H₂O, and develop the fabrication method of GaAs microstructures with rectangular cross section using (001) GaAs substrate. For obtaining wet-etching properties with respect to crystallographic orientation, the etch rates and cross-section etch profiles of (001) GaAs with 16 different compositions and the undercut rates with 5 different compositions are measured using NH₄OH-H₂O₂-H₂O mixed solutions. From these experimental data, a new GaAs micromachining method in bulk (001) GaAs is proposed, and used to fabricate a released microbridges with a rectangular cross section. The developed GaAs micromachining method can be very useful for low-less, highly-tunable capacitors for RF components and for integration with GaAs optical components.

펨토초 레이저 기반 유리 미세가공과 응용

김성일(S. I. Kim),김정태(J. T. Kim),구치완(C. Koo),정연호(Y. H. Joung),안상훈(S. Ahn),최지연(J. Choi) 한국정밀공학회 2018 한국정밀공학회 학술발표대회 논문집 Vol.2018 No.5월

고독사 위험에 노출된 노인을 위한 Emergency Notifier 서비스

서보민(Bo Min Seo),최선호(Seon Ho Choi),박현주(Hyun-Ju Park),구치완(Chiwan Koo) 한국정보과학회 2017 한국정보과학회 학술발표논문집 Vol.2017 No.12

심전도와 마이크 센서를 이용한 맥파전달시간 측정

최진규(Jin-Gyu Choi),강영환(Young-Hwan Kang),박재순(Jae-Soon Park),정연호(Yeun-Ho Jeong),구치완(Chi-Wan koo) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.6

소방관의 효율적인 PTSD 치료를 위한 시제품 제시

이근혁(Geun-Hyeok Lee ),김남준(Nam-June Kim),이수빈(Soo-Bin Lee),박현주(Hyun-Ju Park),김정태(Jeongtae Kim),조한석(HanSeok Cho),구치완(ChiWan Koo) 한국정보과학회 2017 한국정보과학회 학술발표논문집 Vol.2017 No.12