14 research outputs found

    Acridine Based Small Molecular Hole Transport Type Materials for Phosphorescent OLED Application

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    Two small molecular hole-transporting type materials, namely 4-(9,9-dimethylacridin-10(9H)-yl)-N-(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)-N-phenylaniline (TPA-2ACR) and 10,10′-(9-phenyl-9H-carbazole-3,6-diyl)bis(9,9-dimethyl-9,10-dihydroacridine) (PhCAR-2ACR), were designed and synthesized using a single-step Buchwald–Hartwig amination between the dimethyl acridine and triphenylamine or carbazole moieties. Both materials showed high thermal decomposition temperatures of 402 and 422 °C at 5% weight reduction for PhCAR-2ACR and TPA-2ACR, respectively. TPA-2ACR as hole-transporting material exhibited excellent current, power, and external quantum efficiencies of 55.74 cd/A, 29.28 lm/W and 21.59%, respectively. The achieved device efficiencies are much better than that of the referenced similar, 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC)-based device (32.53 cd/A, 18.58 lm/W and 10.6%). Moreover, phenyl carbazole-based PhCAR-2ACR showed good device characteristics when applied for host material in phosphorescent OLEDs

    Detection and hazard assessment of pathogenic microorganisms in medical wastes

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    This study was undertaken to investigate the types and concentrations of microbial agents in various medical wastes as well as to characterize their survivals in these wastes at different temperatures for microbial risk assessment. Medical wastes collected from 5 major hospitals in South Korea were classified and stored at three different temperatures (-20, 6, and 30 degrees C). Presence of various microorganisms such as pathogenic viruses and bacteria were investigated by both cultivation and by (RT)-PCR assays. A number of (opportunistic) pathogenic bacteria, including Pseudomonas spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp., Kocuria spp., Brevibacillus spp., Microbacterium oxydans, and Propionibacterium acnes, were identified from the various medical wastes. In addition, pathogenic viruses such as noroviruses and hepatitis B virus were also detected in one of the human tissue wastes. Commonly identified bacterial and viral pathogens such as Pseudomonas spp., Corynebacterium diphtheriae, Escherichia coli, Staphylococcus spp., and respiratory synctial virus (RSV) were inoculated into either gauzes or diapers, and their survivals were characterized. Viral agents such as RSV showed poor survival in most environmental conditions, and demonstrated that various pathogens could be present in medical wastes but that the associated health risk appeared to be low. However, medical waste should be carefully controlled and monitored to prevent nosocomial infection associated with the exposure to these wastes.Lee J, 2008, APPL ENVIRON MICROB, V74, P2111, DOI 10.1128/AEM.02442-07Marinkovic N, 2008, WASTE MANAGE, V28, P1049, DOI 10.1016/j.wasman.2007.01.021Shariati B, 2007, J OCCUP HEALTH, V49, P317de Bruin E, 2006, J VIROL METHODS, V137, P259, DOI 10.1016/j.jviromet.2006.06.024Garcia C, 2006, J CLIN MICROBIOL, V44, P2997, DOI 10.1128/JCM.00065-06Jang YC, 2006, J ENVIRON MANAGE, V80, P107, DOI 10.1016/j.jenvman.2005.08.018ZIEBUHR W, 2006, INT J ANTIMICROB AG, V28, P14Phipps LP, 2004, J VIROL METHODS, V122, P119, DOI 10.1016/j/jviromet.2004.08.008Loberto JCS, 2004, BRAZ J MICROBIOL, V35, P64Seo SH, 2002, NAT MED, V8, P950, DOI 10.1038/nm757Nema SK, 2002, CURR SCI INDIA, V83, P271Katayama K, 2002, VIROLOGY, V299, P225, DOI 10.1006/viro.2002.1568Katayama H, 2002, APPL ENVIRON MICROB, V68, P1033, DOI 10.1128/AEM.68.3.1033-1039.2002Monpoeho S, 2001, APPL ENVIRON MICROB, V67, P2484SALKIN IF, 2001, REV HLTH IMPACTS MICManfredi R, 2000, EUR J EPIDEMIOL, V16, P111Kuo HW, 1999, WATER AIR SOIL POLL, V114, P413Kim BJ, 1999, J CLIN MICROBIOL, V37, P1714HAAS C, 1999, QUANTITATIVE MICROBIKane A, 1999, B WORLD HEALTH ORGAN, V77, P801PRUSS A, 1999, SAFE MANAGEMENT WAST, P20Schlegel L, 1998, EUR J CLIN MICROBIOL, V17, P887Frank U, 1997, CLIN INFECT DIS, V25, P318BELL DM, 1997, AM J MED S5B, V102, P9Lee CC, 1996, J HAZARD MATER, V48, P1GOLDENBERGER D, 1995, PCR METH APPL, V4, P368OHMAN SC, 1995, ACTA ODONTOL SCAND, V53, P49PATEL R, 1994, CLIN INFECT DIS, V18, P207PATTI JM, 1994, INFECT IMMUN, V62, P152TANAKA MM, 1994RUTALA WA, 1992, INFECT CONT HOSP EP, V13, P3848EDWARDS U, 1989, NUCLEIC ACIDS RES, V17, P7843

    Noise Localization Method for Model Tests in a Large Cavitation Tunnel Using a Hydrophone Array

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    Model tests are performed in order to predict the noise level of a full ship and to control its noise signature. Localizing noise sources in the model test is therefore an important research subject along with measuring noise levels. In this paper, a noise localization method using a hydrophone array in a large cavitation tunnel is presented. The 45-channel hydrophone array was designed using a global optimization technique for noise measurement. A set of noise experiments was performed in the KRISO (Korea Research Institute of Ships & Ocean Engineering) large cavitation tunnel using scaled models, including a ship with a single propeller, a ship with twin propellers and an underwater vehicle. The incoherent broadband processors defined based on the Bartlett and the minimum variance (MV) processors were applied to the measured data. The results of data analysis and localization are presented in the paper. Finally, it is shown that the mechanical noise, as well as the propeller noise can be successfully localized using the proposed localization method
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