Inactivation of Escherichia coli O157:H7 on Orange Fruit Surfaces and in Juice Using Photocatalysis and High Hydrostatic Pressure

YOO, SUNGYUL,GHAFOOR, KASHIF,KIM, JEONG UN,KIM, SANGHUN,JUNG, BORA,LEE, DONG-UN,PARK, JIYONG ational Association for Food Protection 2015 Journal of food protection Vol.78 No.6

<P>Nonpasteurized orange juice is manufactured by squeezing juice from fruit without peel removal. Fruit surfaces may carry pathogenic microorganisms that can contaminate squeezed juice. Titanium dioxide-UVC photocatalysis (TUVP), a nonthermal technique capable of microbial inactivation via generation of hydroxyl radicals, was used to decontaminate orange surfaces. Levels of spot-inoculated Escherichia coli O157:H7 (initial level of 7.0 log CFU/cm2) on oranges (12 cm2) were reduced by 4.3 log CFU/ml when treated with TUVP (17.2 mW/cm2). Reductions of 1.5, 3.9, and 3.6 log CFU/ml were achieved using tap water, chlorine (200 ppm), and UVC alone (23.7 mW/cm2), respectively. E. coli O157:H7 in juice from TUVP (17.2 mW/cm2)-treated oranges was reduced by 1.7 log CFU/ml. After orange juice was treated with high hydrostatic pressure (HHP) at 400 MPa for 1 min without any prior fruit surface disinfection, the level of E. coli O157:H7 was reduced by 2.4 log CFU/ml. However, the E. coli O157:H7 level in juice was reduced by 4.7 log CFU/ml (to lower than the detection limit) when TUVP treatment of oranges was followed by HHP treatment of juice, indicating a synergistic inactivation effect. The inactivation kinetics of E. coli O157:H7 on orange surfaces followed a biphasic model. HHP treatment did not affect the pH, °Brix, or color of juice. However, the ascorbic acid concentration and pectinmethylesterase activity were reduced by 35.1 and 34.7%, respectively.</P>

Ada 프로그래밍 지침을 적용한 유지보수 지원 툴(Ada MAKE - UP)의 설계 및 구현

유재련(Yoo JaeRyeon),임용철(Im YongChul),류성열(Rhew SungYul) 한국정보과학회 1990 한국정보과학회 학술발표논문집 Vol.17 No.1

소프트웨어의 수명주기 동안에 유지보수의 문제로 인한 소프트웨어 생산성 저하의 문제를 해결하기 위해서는 효율적인 유지보수 지원 도구가 필요하다. 원시 텍스트가 유지보수 담당자에게 주는 가독성과 이해도는 프로그램의 코드와 직접적인 관련을 가진다. 본 연구에서는 NASA의 소프트웨어 공학 실험실(SEL)에서 사용되는 Ada 프로그래밍 지침서를 채택하여 최종 사용자에게 원시 텍스트의 가독성과 이해도를 증진시켜줌으로써 유지보수 비용을 절감하는 Ada의 유지보수 지원 도구를 개발하였다.

Large error performance of UWB ranging in multipath and multiuser environments

Lee, Joon-Yong,Yoo, Sungyul IEEE 2006 IEEE transactions on microwave theory and techniqu Vol.54 No.4

Accurate detection of direct path signal is essential for ranging to the full capabilities of ultra-wideband (UWB) signals. However, the possibility of a large error can be a challenging problem for accurate ranging and positioning. Three different kinds of potential errors encountered in correlation-based time-of-arrival (TOA) estimation are introduced, and an approximate analysis of them is posed. Upper and lower bounding technique is applied to the variance of one of them, namely an early false alarm error. Probability of occurrence of the other two kinds of error is found using the channel statistics, and the mean square of them is evaluated by simulation method. Discussion of the effect of multiple-access schemes on the accuracy of UWB TOA estimation is initiated.

Combination of TiO2-UV Photocatalysis and High Hydrostatic Pressure to Inactivate Bacterial Pathogens and Yeast in Commercial Apple Juice

Shahbaz, Hafiz Muhammad,Yoo, Sungyul,Seo, Bohyun,Ghafoor, Kashif,Kim, Jeong Un,Lee, Dong-Un,Park, Jiyong Springer-Verlag 2016 Food and bioprocess technology Vol.9 No.1

<P>The purpose of this study was to investigate the effect of combined treatments using TiO2-UV photocatalysis (TUVP) and high hydrostatic pressure (HHP) on inactivation of microorganisms in commercial apple juice as model liquid food. A synergistic effect was observed for combined treatments to inactivate microorganisms. Gram-positive bacteria, Listeria monocytogenes and Staphylococcus aureus, were completely inactivated from initial loads of 7.1 and 6.7 log CFU/mL, respectively, when treated with a combination of TUVP (8.45 J/cm(2)) and HHP (500 MPa). In contrast, reductions of only 4.8 log CFU/mL (L. monocytogenes) and 2.4 log CFU/mL (S. aureus) were achieved with 500 MPa HHP alone. Gram-negative bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium, were reduced by 7.1 and 7.2 log CFU/mL, respectively, after a combined treatment using 8.45 J/cm(2) TUVP and 600 MPa (E. coli) or 400 MPa (S. Typhimurium) HHP which were significantly higher than the effects of HHP alone. A 6.2 log CFU/mL reduction in Saccharomyces cerevisiae count was monitored after treatment with a combination of 8.45 J/cm(2) TUVP and 500 MPa HHP whereas even 600 MPa alone could not achieve complete S. cerevisiae inactivation. Combined treatments (TUVP + HHP) were more effective for microbial inactivation than alone treatments. Scanning electron microscopic images of microorganisms showed highly deformed morphologies after TUVP + HHP treatment. In conclusion, pretreatment of commercial apple juice using TUVP before HHP processing results in better disinfection and may assure complete disinfection.</P>

Long Term Follow-up Results of External Beam Radiotherapy as Primary Treatment for Retinoblastoma

Choi, Sang Yul,Kim, Mi-Sook,Yoo, SungYul,Cho, ChulKoo,Ji, YoungHoon,Kim, KumBae,Seo, YoungSeok,Park, Kyung Duk,Lee, JunAh,Lee, Tai-Won The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.4

<P>The authors reviewed their experiences of external beam radiotherapy (EBR) as an initial treatment in retinoblastoma patients to determine its long-term effect on subsequent tumor control and complications. A total of 32 eyes in 25 patients that underwent EBR for retinoblastoma were reviewed retrospectively. The patients consisted of 21 boys and 4 girls of median age at treatment of 7.1 months. Radiation doses ranged from 35 to 59.4 Gy. The 10-yr ocular and patient survivals were 75.4% and 92.3%, respectively. Nine of the 32 eyes progressed; 7 of these were enucleated and 2 were salvaged by focal treatment. According to the Reese-Ellsworth classification, 4 of 5 eyes of Group II, 13 of 16 Group III eyes, 2 of 4 Group IV eyes, and 5 of 7 Group V eyes were retained, and of the 32 eyes, 13 had visual acuity better than 20/200. Eleven patients experienced a radiation-induced complication. No patient developed a second malignancy during follow-up. Despite the limited number of patients enrolled, EBR may provide a mean of preserving eyeball and vision for some advanced lesions.</P>

Truncated Tetrahedron Seed Crystals Initiating Stereoaligned Growth of FeSi Nanowires

Kim, Si-in,Yoon, Hana,Seo, Kwanyong,Yoo, Youngdong,Lee, Sungyul,Kim, Bongsoo American Chemical Society 2012 ACS NANO Vol.6 No.10

<P>We have synthesized epitaxially grown freestanding FeSi nanowires (NWs) on an <I>m</I>-Al<SUB>2</SUB>O<SUB>3</SUB> substrate by using a catalyst-free chemical vapor transport method. FeSi NW growth is initiated from FeSi nanocrystals, formed on a substrate in a characteristic shape with a specific orientation. Cross-section TEM analysis of seed crystals reveals the crystallographic structure and hidden geometry of the seeds. Close correlation of geometrical shapes and orientations of the observed nanocrystals with those of as-grown NWs indicates that directional growth of NWs is initiated from the epitaxially formed seed crystals. The diameter of NWs can be controlled by adjusting the composition of Si in a Si/C mixture. The epitaxial growth method for FeSi NWs <I>via</I> seed crystals could be employed to heteroepitaxial growth of other compound NWs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-10/nn302141w/production/images/medium/nn-2012-02141w_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn302141w'>ACS Electronic Supporting Info</A></P>

다중경로 다중사용자 환경에서의 초광대역 거리추정의 성능 분석

이준용,유성열,Lee Joon-Yong,Yoo Sungyul 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.12C

초광대역 신호의 높은 시간해상도는 복잡한 다중경로 환경에서의 정밀한 거리추정 및 위치추적 을 가능하게 한다. 그러나 신호의 도착신호 추정시 발생하는 큰 추정오차의 발생은 거리추정의 정확도를 저하시키는 요인이 된다. 본 논문에서는 다중경로, 다중사용자 환경에서 초광대역 거리추정의 성능을 평가한다. 상호상관을 이용한 직렬검색 알고리듬을 적용할 때 발생하는 추정오차를 분석하고 모의실험 결과를 개시한다. Ultra-wideband (UWB) ranging poses a set of time delay estimation problems for designers. The possibility of a large error can be a challenging problem for accurate ranging and positioning. An approximate analysis of large error performance of UWB ranging in multipath and multiuser environments is posed. Both analytical and experimental approaches are taken to evaluate the large error variance in a correlation-based serial search scenario.

가설검증 방식을 통한 UWB Rake 수신기의 기준신호 선택 기법

이준용,유성열,윤성준,하동헌,Lee Joon-Yong,Yoo Sungyul,Yoon Sung-Jun,Ha Dong-Heon 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.2c

초광대역(UWB) 통신시스템의 응용 시나리오는 많은 경우 비가시적(non-LoS) 환경에서의 응용을 가정하고 있다. UWB 신호가 매질을 투과하여 방사될 경우 신호의 왜곡현상이 발생하며, 이는 수신부 상관기의 기준신호와 수신된 신호와의 상관계수를 감소시켜 성능을 저하시키는 요인이 된다. 본 논문에서는 가설검증 방식을 이용한 UWB Rake 수신기의 기준신호 선택 기법을 소개한다. 가설을 세우기 위한 파형의 선택을 위해 벡터 양자화 기법인 Linde-Buzo-Gray(LBG) 알고리듬을 사용하였다. 개시된 알고리듬을 성능을 non-LoS 환경에서 측정된 데이터를 이용해 평가하였다. Many application scenarios of ultra-wideband(UWB) radio assume non-line-of-sigit(non-LoS) signal propagations. Through-material propagation of UWB signal introduces a distortion of the waveform as well as attenuation, which will introduce a decrease of the correlation coefficient between the correlator template and the received signal. A hypothesis test approach to selection of the template waveform for UWB rake receivers is posed. Linde-Buzo-Gray(LBG) algorithm is used to select the candidate waveforms which are used to setup the hypothesis test. The performance of the algorithm is tested using a set of indoor non-LoS propagation measurement data.

친환경 황토 가공 신소재가 장어의 품질 특성에 미치는 영향

서유진(Yoojin Seo),길범주(Beomju Gil),경진석(Jinsuk Kyoung),유병승(Byoungseung Yoo),장윤혁(Yoonhyuk Chang),유성률(Sungyul Yu),이영승(Youngseung Lee) 한국식품영양과학회 2014 한국식품영양과학회지 Vol.43 No.2

본 연구는 가공황토 처리여부에 따른 장어시료의 품질 특성을 비교하고자 장어를 양식장에서 동일한 조건으로 사육하여 일반성분, 물성, 영양소, 기능적 특성 및 관능적 특성을 분석하였다. 그 결과 일반성분 분석에 대해서는 두 군 간의 차이가 없었으며 niacin은 실험구가 무처리 대비 더 높은 함량을 나타냈다. Tocopherol은 가공황토소재로 양식한 시료에서 무처리구 대비 약 3배 이상의 tocopherol 함량이 측정되었다(P<0.05). 냉?해동 저장기간 동안 실험구가 무처리구 대비보다 안정된 조직감을 나타냈다. DPPH 라디칼소거능과 FRAP value 분석 결과, 실험구의 항산화 활성이 유의적으로 높은 것을 확인할 수 있었다. 묘사분석 결과 ‘기름진 정도’가 무처리구에 비하여 실험구에서 낮게 평가되었으며, 이는 보다 담백하면서 기능성이 강화된 장어의 생산이 가능함을 나타낸다고 할 수 있다. 따라서 친환경 가공황토소재로 양식한 장어의 경우 기능성이 강화되고 맛이 향상된 고부가가치 제품으로 생산이 가능하여 국내 장어 시장을 한단계 업그레이드할 수 있을 것으로 사료된다. The objectives of this study were to examine the effects of red clay-processed nano-materials (RCPM) on the quality characteristics of eel (Anguilla japonica). Both eels treated with RCPM and control were farm-raised under identical environments and were commercially processed. General components, texture, nutrients, antioxidant activities, and sensory analysis were performed. RCPM-treated eels showed significantly higher DPPH radical scavenging activities and FRAP values than the of control, indicating higher antioxidant activities of eels raised by RCPM. The amounts of niacin and tocopherol in RCPM-treated eels were higher than those of the control. For analysis of freeze-thaw stability, RCPM-treated eels showed more stable texture over freeze-thaw three treatment cycles. Descriptive panelists perceived eels raised by RCPM to be less oily than the control. Overall, RCPM exhibited positive effects on the quality of farm-raised eels. Therefore, RCPM would be of benefit to produce high value-added eels of premium quality.