GC-ECD를 이용한 유기염소계 및 Pyrethroid계 농약 동시 분석법

김우성,이선화,김재이,정지윤,이명자,박영채,이영자,정성욱,이봉헌,박흥재 한국환경과학회 2003 한국환경과학회지 Vol.12 No.4

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with florisil, and finally analyzed simultaneously the organochlorine and pyrethroid pesticides using GC(ECD). An ultra-2 fused silica capillary column was used to separate and identify the products. The resolution between the last isomeric peak of cypermethrin(59.987min) and the first isomeric peak of flucythrinate(60.043min) was not satisfactory. The last isomeric peak of fenvalerate(62.344min) and the first isomeric peak of fluvalinate(62.397min) were overlapped. Recoveries of soybean sample for the most pesticides were 73.3% to 102.4%. Detection limits were between 0.004 and 0.063 ㎍/㎎ when this method was used.

放射電磁波에 의한 絶緣診斷에 관한 硏究

김영훈,박원주,이동인,김충년,이광식 嶺南大學校 工業技術硏究所 1995 工業技術硏究所論文集 Vol.23 No.1

In this paper, the detect of insulation disorder and process degree of insulation degradation of power apparatus, the waveform of discharge current, magnitude of discharge and frequency spectrum of the electromagnetic wave radiated from partial discharge by simulating with needle-to-plane electrode geometry and dielectric with artificial void, were investigated. The results obtained can be summarized as follows. 1) Streamer pulses occur near the positive cycle and trichel pulses near the peak of negative cycle of applied voltage. At that time, discharge magnitude of trichel pulses and streamer pulses was observed about 200[pC] and 500[pC] in air, respectively. 2) The level and frequency spectrum of radiated electromagnetic waves were increased about 20∼40[dB] at under 200[MHz] and about 2∼3[dB] above 200[MHz], compared with background noises. 3) A sudden change of discharge magnitute above 20∼30[pC] was observed with various applied voltages, but the magnitude showered to tend to saturate at 300∼300[pC] in dielectric. 4) The level and frequency spectrum of radiated electromagnetic waves were increased about 3∼6[dB] under 200[MHz]and about 2∼3[dB] above 200 [MHz], compared with background noises.

燃料節約을 위한 舶用中速機關의 最適運轉條件에 關하여 : 實習船 釜山 403號를 中心으로 With training ship "Busan 403"

尹錫勳,金鍾華,金永植 釜山水産大學校 1985 釜山水産大學 硏究報告 Vol.25 No.2

釜山水産大學 實習船 釜山 403號의 主機關인 中速디젤機關을 利用하여 機關 冷却水溫度와 給氣溫度를 변화시키며 機關性能 및 燃燒性을 考察한 結果 다음과 같은 結論을 얻었다. 1. ??를 높임에 따라 ??가 上昇하며 ?? 10℃ 上昇時 ??는 約 7.6℃ 上昇하였으며, ??를 60℃로 하여 運轉하는 경우에도 공기과잉율의 低下에 의하여 燃燒性이 不良해지는 현상은 일어나지 않았다. 2. ?? 增加時 O₂濃度 감소, CO₂濃度 增加의 현상이 나타났으며 ?? 40℃일 때 ?? 25℃ 上昇時 공기과잉율은 約 0.41程度 低下하였으나 이러한 현상은 ??가 增加할수록 둔화되었다. 3. ??가 上昇함에 따라 同一한 공기과잉율에서 이산화탄소 생성량이 增加하였으며 이는 同一한 條件에서 冷却水溫度의 上昇에 따라 燃燒性이 向上됨을 알 수 있다. 4. 馬力當 燃料消費率이 가장 적은 것은 負荷 100% BHP의 경우이며 이때 正味燃料消費率은 173.76gr/BHPㆍh이다. This investigation tries to find the better operating condition that the fuel oil is saved for the medium speed diesel engine installed on training ship "Busan" 403˝. This study observes the performance and combustibility of the engine under the condition for various temperature of cooling water and scavenging air. The combustibility increases with the increase of the cooling water temperature. Though the temperature of scavenging air rises to 60℃, the combustion of the engine is good in condition.

주파수 선택적 페이딩 채널에서의 다중반송파 CDMA의 다중채널 결합 검출 성능 분석

황용선,이종훈,김동구 延世大學校 電波通信共同硏究所 1999 電波通信論文誌 Vol.4 No.1

본 논문에서는 다중사용자/다중경로 환경에서 다중반송파 CDMA 시스템의 오류확률을 해석적으로 구하고, 다중사용자, 다중반송파, 다중경로에 의한 간섭의 영향을 분석하였다. 또한, 다중반송파 시스템에 역상관 검출기(decorrelating detector)를 결합한 다중반송파/다중사용자/다중경로 결합 검출 방식을 제시하고 성능 및 역상관 과정에 의한 백색가우시안 잡음(AWGN)의 증가를 분석하였다. 제안한 결합 검출 방식의 오류 확률은 사용자 한 명만이 존재하는 경우의 이상적인 성능에 근접하였다. In this paper, the bit error ratio(BER) performance of multi-carrier CDMA system in multi-user/multi-path environment is analytically derived, and effect of interferences due to multi-user, multi-carrier, multi-path is analyzed. A multi-carrier/multi-user/multi-path joint detection scheme incorporating a decorrelating detector is proposed, and its performance as well as the enhancement of noise due to decorrelating process are analyzed BER of the proposed joint detection scheme is only slightly degraded compared to the ideal case of single user environment.

인버터 구동용 유도전동기 고정자 권선의 절연특성 연구

황돈하,김동희,이광식,정원영,김영훈,오승훈 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Inverters with high speed switching and advanced PWM techniques are widely used for variable speed applications. But some adverse effects on the stator winding insulation are reported due to excessive voltage stress, which results in the premature insulation breakdown. This is aggravated by the high switching speed of modem switching devices such as IGBT (Insulated Gate Bi-polar Transistor) with which the rate of rise in voltage (dv/dt) increases considerably. In this paper, the test results for evaluation on the stator winding insulation of 310V induction motors are presented. Also, the insulation characteristics are presented in order to analyze the insulation strength under high voltage due to high switching speed of IGBT PWM inverter. 26 induction motors of 6 types with different wires and insulation techniques are built and thoroughly tested. The maximum partial discharge (PD) magnitude (Qm) and the discharge inception voltage (DIV) are obtained by PD test. Under AC current test, the rate of change in AC current (ΔI) and the change in dissipation factor (Δtanδ) are measured. From the above test data, the effects due to different wires and insulation techniques on the insulation characteristics of low-voltage induction motors are compared and analyzed. The insulation technique to enhance the insulation strength is suggested from the test results.

히스토아크릴을 이용한 십이지장 궤양 출혈의 지혈 후 발생한 급성췌장염

유재훈,문원,노지훈,구동영,조영화,김기수,윤준모 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.1

Upper gastrointestinal bleeding is common and potentially life threatening medical emergency. Emergency endoscopy is the first choice of diagnostic and treatment measure for patients with active upper gastrointestinal bleeding. Histoacryl should be considered a second-line treatment modality when conventional treatments were failed. However, it might cause several complications. Herein, we report a case of acute pancreatitis developed after histoacryl injection therapy for active duodenal ulcer bleeding. A 71-year-old man was admitted with melena and hematemesis. On emergency endoscopy, a 2 cm sized active ulcer with bleeding from an exposedvessel was seen at the duodenal bulb. Attempts to arrest the bleeding with hemoclipping and submucosal epinephrine injection were tried, but failed. We changed the method to endoscopic histoacryl injection, and obtained hemostasis immediately. A few hourslater, after successful hemostasis, patient complained diffuse abdominal pain. Ultrasonography revealed hyperechoic heterogenous diffuse pancreatic enlargement and right pararenal space fluid collection, this ultrasonographic findings and elevated serum pancreatic enzymes are compatible with acute pancreatitis.

국내 검정콩 육성품종의 종자특성

주용하,박재훈,윤승길,김영호,김성민,정길웅 한국국제농업개발학회 2002 韓國國際農業開發學會誌 Vol.14 No.4

1. 수분흡수율이 가장 높은 시간은 다원콩(침지 후 4시간)을 제외한 모든 품종이 침지후 2시간이었으며, 둔화되기 시작한 시간은 침지후 약 10시간이었고, 평형에 도달한 시간은 침지후 약 16시간이었다. 2. 수분흡수율은 품종간에 차이가 있었는데 가장 높은 수분흡수율을 보인 품종은 검정콩2호이었으며, 가장 낮은 품종은 다원콩이었다. 3. 발아율의 범위는 28이었으며, 평균발아율은 93.9%이었고, 가장 높은 품종은 청자콩과 흑청콩이었다. 4. 발아세의 범위는 52이었으며, 평균발아세는 81.9%이었고, 가장 높은 품종은 흑청콩이었다. 5. 평균발아일수와 T_50의 범위는 모두 2이었으며, 평균은 각각 2.6과 2.3이었고, 품종간에는 선흑콩이 가장 길었다. 6. 발아균일도의 범위는 3.1이었으며, 평균은 1.3이었고, 높은 그룹(흑청콩·청자콩·검정콩2호·다원콩·검정올콩)과 낮은 그룹(검정콩1호·일품검정콩·선흑콩)으로 분류되었다. 7. 알칼리붕괴도는 공시품종의 평균이 4.65이었으며 등급은 4∼5등급을 나타내었다. 붕괴도가 가장 높고 우수한 품종은 검정콩1호였으며 가장 낮은 품종은 선흑콩이었다. The water absorption rate after soaking of seeds was the highest at 2 hours in all varieties except Dawonkong(4 hours after soaking), and became slowed down at 10 hours, and reached moisture equilibrium in stopping almost at 16 hours. The water absorption rate was different among varieties, the highest variety was Geomjeongkong #2 whereas the lowest variety was Dawonkong. The range of germination percentage was 28, and average value 93.9%, and the highest varieties were Cheongjakong and Heukcheongkong. The range of germination speed was 52. average value 81.9%, and the highest variety was Heukcheongkong. The range of average days to germination and T_50 were all two days and these average was 2.6 and 2.3, respectively. Seonheukkong among varieties was very long in average days to germination and T_50. The range of germination uniformity was 3.1 and average was 1.3 and divide into two groups such as high group(Heukcheongkong, Cheongjakong, Gemjeongkong #2, Dawonkong, Geomjeongolkong) and low group(Geomjeongkong #1, llpumgeomjeongkong, Seonheukkong). Varietal mean of alkali digestibility value was 4.65 belong to 4∼5 class, the highest variety was Geomjeongkong #1 whereas Seonheukkong was very low among varieties.

VDT작업별 정신사회적 스트레스와 근골격계 장애에 관한 연구

백남종,강종두,주영수,배인근,권호장,박종만,조수헌,김돈규,김재용,최홍렬 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.4

It has been hypothesized that jobs that have both high psychological demands and low decision latitude("job strain") can lead to musculoskeletal disorder. The objective of this study was to test whether job strain was correlated with the presence of work-related musculoskeletal disorder, especially myofascial pain syndrome(MPS). Information on demographic factors, confounders such as household load and taking care of children or not, and scores for decision latitude, job demand, and social support was obtained by self-administered questionnaire, which had been developed in Korean language, by adopting NIOSH instrument and Extended Karasek Model(16 items). All subjects were also examined by rehabilitation medicine specialists for musculoskeletal disorders. Subjects(n=370) could be categorized into 4 groups, these were, housewives(n=89), shipyard CAD workers(n=89), general female workers(n=79; nurses, insurance counselors, public officials, clerks, etc), and telephone directory assistance operators(n=113). Results from univariate analyses indicated that all demographic factors, all confounders, scores for decision latitude and social support were not associated with the risk of musculoskeletal disorder. However, score for job demand was higher in musculoskeletal disorder cases than others. In subgroup analysis, this association was convinced again, in telephone directory assistance operators. Job strain model showed that the group of telephone directory assistance operators was high-stain group, and OR of musculo skeletal disorder was 2.446(95% C. I. : 1.174, 5.096), when comparing this with the low strain group. In conclusion, job strain is a risk factor for work-related musculoskeletal disorder.

혼합액정(80CB+50CB)의 네마틱-스멕틱 A 상전이 근처의 네마틱상에서 휨 탄성상수(K₃)에 관한 광산란 실험연구

임동건,이민규,변영태,유영훈,김두철 濟州大學校 基礎科學硏究所 1990 基礎科學硏究 Vol.3 No.1

액정 8OCB(octyloxycyanobiphenyl)에 액정 5OCB(pentyloxycyanobiphenyl)를 무게비로 혼합하여 혼합액정 (8OCB+5OCB)을 만들었다. 이 혼합액정은 5OCB의 무게비에 따라 McMillan지수 (??)가 감소하였다. 그리고 Rayleigh 광산란 실험방법을 이용하여, 순수 8OCB와 혼합액정의 네마틱-스멕틱 A 상전이 근처의 네마틱상에서 산란된 빛의 세기를 온도와 함수로 측정하였다. 실험데이타 분석결과는 휨(bend) 탄성 상수에 비례하는 세로방향 상관거리(??)는 McMillan 지수에 관계없이 임계지수 ??=0.66±0.03을 갖고 발산하였다. 이 값은 de Gennes의 모델에서 제시된 ??=0.67과 일치함을 알수있다. By utilizing Rayleigh scattering technique, we have measured the temperature dependence of scattered light intensity near nematic to smectic-A phase transition point in the pure 8OCB(octyloxycyanobiphenyl) and its mixtures contaning 5, 10, 15 weight percentage of 5OCB(pentyloxycyanobiphenyl). From analysis of these data. it is found that the longitudinal correlation length (??) diverges with critical exponent ??=0.66±0.03 independent on McMillan parameter (??). This result is consistent with de Gennes model (??).

Microwave-welded single-walled carbon nanotubes as suitable electrodes for triboelectric energy harvesting from biomaterials and bioproducts

Kim, Hyun Soo,Kim, Dong Yeong,Kwak, Ji Hye,Kim, Jong Hun,Choi, Moonkang,Hyung Kim, Do,Lee, Dong Woo,Kong, Dae Sol,Park, Jinhong,Jung, Sunshin,Lee, Gwan-Hyoung,Lee, Minbaek,Jung, Jong Hoon Elsevier 2019 Nano energy Vol.56 No.-

<P><B>Abstract</B></P> <P>Biomaterials and bioproducts have unique characteristics of being renewable, abundant, biodegradable, and having rough surfaces. In order to implement them into highly efficient triboelectric nanogenerator (TENG) applications, the contact electrode should be cheap, flexible, able to withstand outdoor environments, and have a rough surface. Here, microwave-welded single-walled carbon nanotubes (SWCNTs) are shown to effectively harvest the mechanical vibrational energy from biomaterials and bioproducts. Selective and flash microwave heating provides firm welding of SWCNTs to a polycarbonate substrate without significant losses in flexibility, transparency, and electrical conductivity. Microwave-welded SWCNT electrodes were successfully deployed as single-electrode TENGs to harvest energy from cellulose film, hanji paper, and cherry leaf. The cellulose- and paper-based TENGs showed the quite stable triboelectric outputs even after excessive contacts and a long period of time. The leaf-based TENG showed the significantly modified triboelectric outputs due to the moisture evaporation induced shrinkage and roughness of the surface. The SWCNT electrode generated ca. ten- and two-fold larger voltage and current, respectively, than those obtained using an indium-tin oxide (ITO) electrode. Using a fan-shaped leaf-based TENG, multiple light emitting diodes and a cellular phone were successfully powered without a battery. This work implies that the microwave-welded SWCNT electrode with rough pored surface and strong resistance against environmental shocks could be a good candidate for the outdoor biomaterials and indoor bioproducts implemented TENGs to harness random- and low-frequency vibrational energy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 1 Microwave welding of single-walled carbon nanotubes on a flexible substrate. </LI> <LI> 2 Rough and pored surface of SWCNT for increased contact area with cellulose, paper, and leaf. </LI> <LI> 3 Moisture evaporation dependent triboelectric outputs in leaf-based triboelectric nanogenerator. </LI> <LI> Powering multiple light emitting diodes and charging a cellular phone. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>