• Title/Summary/Keyword: Zone plate

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A COMPARATIVE STUDY OF THE DIFFUSIBILITY AND ANTIMICROBIAL EFFECTIVENESS OF INTRACANAL MEDICATIONS (근관용 약제의 근관내 확산성 및 항균효과에 관한 비교연구)

  • Park, Young-Sook;Lee, Chung-Suck
    • Restorative Dentistry and Endodontics
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    • v.12 no.1
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    • pp.25-37
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    • 1986
  • This study was undertaken to measure the diffusibility and antimicrobial effectiveness of the medication used in clinical practice. To study the diffusibility of the root canal medicament, loss of formocresol and camphorated phenol from a cotton pellet after insertion into the pulp chamber of 260 molars prepared as routine endodontic treatment was measured. Measurement was done for the one time insertions and for the reinsertions using ultraviolet spectrophotometer. Antibacterial effectiveness against three microoganisms, Staphylococcus aureus, Staphylococcus epidermidis and a-hemolytic streptococcus, on the blood agar plate was observed by measurement of the inhibition zone with. various amount of medicaments. The following results were observed. 1. Nearly all of the medication were lost in the first day after insertion and the residual amount of camphorated phenol was greater than that of formocresol. 2. Residual amounts of medication in the reinsertion group were greater than that of the one time insertion group. 3. Within the pulp chamber diffusibility of formocresol was greater than that of camphorated phenol. 4. The amount of formocresol diffusing out from the tooth was greater than that of camphorated phenol. 5. Antibacterial effectiveness was observed from the residual amount of formocresol in the reinsertion group and in other groups no antibacterial effectiveness was observed.

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Design and Fabrication of Movable Micro-Fersnel Lens on XY-stage (XY-Stage에 의해 정적인 변위를 갖는 미세 프레넬 렌즈(Micro-Fresnel Lens)의 설계 및 제작)

  • Kim, Che-Heung;Ahn, Si-Hong;Lim, Hyung-Taek;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2515-2517
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    • 1998
  • The micro fresnel lens(MFL) was modeled and fabricated on a XY-stage electrostatically driven by comb actuator. The modeled MFL was approximated as a step shape with 4-phase and 4-zone plate. The focal length and diameter of the MFL is 20mm and 912${\mu}m$, respectively. The XY-stage suspending the MFL is designed to generate a large static displacement up to about 20${\mu}m$. On SOI substrates, we first fabricated MFL using the RIE(reactive Ion etching) technology and then patterned and etched bulk silicon to make XY-stage. After the fabrication of all structures on top side of the SOI substrates. $Si_3N_4$ was deposited for passivation of all structures using PECVD(plasma enhanced chemical vapor deposition). All the MFL systems width comb drive actuator were released by KOH etching from the bottom side of the SOI wafer using double-sided alignment technique. In fabrication of MFL, a dry etching conditions is established in order to improve surface roughness and to control the etched depth.

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Assessment of Microbiological Quality of Outsourced School Meals (외부 운반 학교급식의 미생물학적 품질 평가)

  • Jeong, Hyun-Suk;Ryu, Kyung
    • Journal of the Korean Dietetic Association
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    • v.18 no.4
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    • pp.372-384
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    • 2012
  • The purpose of this study was to provide a basic resource for establishment of hygienic management standards for meal delivery from the central kitchen to schools. Flow diagrams for delivery of food were analyzed, and time-temperature conditions of the food and environment were measured. Four different foods samples including Mexican salad, radish salad, stir-fried pork and vegetables, and stir-fried chicken and vegetables were collected after production and before service. Microbiological analysis was performed for aerobic plate counts (APC), Enterobacteriaceae, coliforms, E. coli, Salmonella spp., S. aureus, B. cereus, C. perfringens, and L. monocytogenes. After completion of production of cooked foods 2~3 hours were taken for the cooked foods to reach the temperature danger zone. Food temperatures at the meal service did not meet the recommended temperatures ($10/57^{\circ}C$) for conventional school food service systems. The highest APC counts were observed in radish salad (5.70 log CFU/g), followed by Mexican salad (5.18 log CFU/g). Enterobacteriaceae and coliform counts were within acceptable levels of those recommended by the UK Public Health Laboratory Service. No E. coli or pathogens were found. These results provide useful information for determination of microbiological hazards in school food service systems, and suggest that time-temperature control during delivery is necessary for the safety of cooked foods.

Characterization of Fibrinolytic Proteases from Gloydius blomhoffii siniticus Venom

  • Choi, Suk-Ho
    • Journal of Pharmacopuncture
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    • v.14 no.3
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    • pp.71-79
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    • 2011
  • Objectives : This study was undertaken to identify fibrinolytic proteases from Gloydius blomhoffii siniticus venom and to characterize a major fibrinolytic protease purified from the venom. Methods : The venom was subjected to chromatography using columns of Q-Sepharose and Sephadex G-75. The molecular weights of fibrinolytic proteases showing fibrinolytic zone in fibrin plate assay were determined in SDS-PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis) The effects of inhibitors and metal ions on fibrinolytic protease and the proteolysis patterns of fibrinogen, gelatin, and bovine serum albumin were investigated. Results : 1) The fibrinolytic fractions of the three peaks isolated from Gloydius blomhoffii siniticus venom contained two polypeptides of 46 and 59 kDa and three polypeptides of 32, 18, and 15 kDa and a major polypeptide of 54 kDa, respectively. 2) The fibrinolytic activity of the purified protease of 54 kDA was inhibited by metal chelators, such as EDTA, EGTA, and 1,10-phenanthroline, and disulfhydryl-reducing compounds, such as dithiothreitol and cysteine. 3) Calcium chloride promoted the fibrinolytic activity of the protease, but mercuric chloride and cobalt(II) chloride inhibited it. 4) The fibrinolytic protease cleaved preferentially A${\alpha}$-chain and slowly B${\beta}$-chain of fibrinogen. It also hydrolyzed gelatin but not bovine serum albumin. Conclusions : The Gloydius blomhoffii siniticus venom contained more than three fibrinolytic proteases. The major fibrinolytic protease was a metalloprotease which hydrolyzed both fibrinogen and gelatin, but not bovine serum albumin.

Characteristics of Elliptic Fresnel Zone Plate Antenna (메쉬 네트워크를 이용한 RFID 데이터 전송 시스템 구현에 대한 연구)

  • Jo, Heung-Kuk;Kim, Tae-Yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.51-53
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    • 2011
  • Data collection and classification of products for factory automation is one of important processes. If conveyor systems corresponding to factory automation have crossroads, a lot of difficulties arise. These issues can be solved by using Zig-Bee technology capable of network configuration. Network with Zig-Bee is configured to coordinators, routers, and end-device. And Zig-Bee for up to 65,536 network formation is possible. In this paper, system to transmit the data of RFID tag to the host PC has been implemented, after connecting multiple EM4095 RFID system to Zig-Bee transmitter/receiver system.

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Inhibitory Effect of Dalbergioidin Isolated from the Trunk of Lespedeza cyrtobotrya on Melanin Biosynthesis

  • Baek, Seung-Hwa;Kim, Jin-Hee;Kim, Dong-Hyun;Lee, Chan-Yong;Kim, Ji-Young;Chung, Dae-Kyun;Lee, Choong-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.874-879
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    • 2008
  • Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. The methanol extract of Lespedeza cyrtobotrya $M_{IQ}$ showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of L. cyrtobotrya, followed by several chromatographic methods, and identified as dalbergioidin (DBG) by spectroscopic methods. The results showed that DBG exhibited tyrosinase inhibitory activity with an $IC_{50}$ of $20\;{\mu}M$. The kinetic analysis of tyrosinase inhibition revealed that DBG acted as a noncompetitive inhibitor. In addition, DBG showed a melanin biosynthesis inhibition zone in the culture plate of Streptomyces bikiniensis that has commonly been used as an indicator organism. Furthermore, $27\;{\mu}M$ DBG decreased more than 50% of melanin contents on the pigmentation using the immortalized mouse melanocyte, melan-a cell.

Geochemical Characteristics of the Sub-alkaline Basalt in the Udo Island, Jeju (제주도 우도 화산섬의 서브알칼리 현무암의 지화학적 특징에 대하여)

  • Lee, Jin-Soo
    • Economic and Environmental Geology
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    • v.47 no.6
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    • pp.601-610
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    • 2014
  • Udo is the site of a short-lived monogenetic submarine volcanic vent which builts basaltic clastic deposits below sea level, by early Surtseyan-type explosive eruption and later effusive lava eruptions. Mineral assemblage, major and trace element chemistry indicate that the Someori sub-alkaline lava flows were related to the WPTB(within plate tholeiitic basalt) rather than IAT(island-arc tholeiite) and that the geotectonic regime of Korean Peninsula went away from the subduction zone after the Later Miocene.

Nondestructive inspection of spent nuclear fuel storage canisters using shear horizontal guided waves

  • Choi, Sungho;Cho, Hwanjeong;Lissenden, Cliff J.
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.890-898
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    • 2018
  • Nondestructive inspection (NDI) is an integral part of structural integrity analyses of dry storage casks that house spent nuclear fuel. One significant concern for the structural integrity is stress corrosion cracking in the heat-affected zone of welds in the stainless steel canister that confines the spent fuel. In situ NDI methodology for detection of stress corrosion cracking is investigated, where the inspection uses a delivery robot because of the presence of the harsh environment and geometric constrains inside the cask protecting the canister. Shear horizontal (SH) guided waves that are sensitive to cracks oriented either perpendicular or parallel to the wave vector are used to locate welds and to detect cracks. SH waves are excited and received by electromagnetic acoustic transducers (EMATs) using noncontact ultrasonic transduction and pulse-echo mode. A laboratory-scale canister mock-up is fabricated and inspected using the proposed methodology to evaluate the ability of EMATs to excite and receive SH waves and to locate welds. The EMAT's capability to detect notches from various distances is evaluated on a plate containing 25%-through-thickness surface-breaking notches. Based on the results of the distances at which notch reflections are detectable, NDI coverage for spent nuclear fuel storage canisters is determined.

Chemical Composition and Antimicrobial Activity of Cone Volatile oil of Cupressus macrocarpa Hartwig from Nilgiris, India

  • Manimaran, S.;Themozhil, S.;Nanjan, M.J.;Suresh, B.
    • Natural Product Sciences
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    • v.13 no.4
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    • pp.279-282
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    • 2007
  • The aim of the present study was to investigate the various chemical components present in the cone volatile oil of Cupressus macrocarpa and also determine its antimicrobial activity. Totally 13 compounds were identified with 99.99% by GC-MS analysis. The major compounds identified were terpinene-4-ol (19.42%), dinopol (15.63%), ${\alpha}$-pinene (13.58%), and ${\beta}$-pinene (12.16%). The antimicrobial activity was carried out for the oil and a 2% cream formulation using cup plate method by measuring the zone of inhibition. The gram positive organisms used were Bacillus subtilis, Staphylococcus aureus, Bacillus megaterium, and Bacillus cogulans. The gram negative organisms used were Escherichia coli, Kleibseilla pneumonia, Pseudomonas aeruginosa and Salmonella typhi. In vitro antifungal studies were also carried out by using organisms, Candida albicans, Aspergillus flavus, Trichoderma lignorum and Cryptococcus neoformans. The standard drugs used were penicillin ($100{\mu}g/mL$), gentamycin ($100{\mu}g/mL$) and griseofulvin ($100{\mu}g/mL$) for gram positive bacteria, gram negative bacteria and fungi respectively. Both oil and cream formulation showed good activity against fungi than bacteria. This study is being reported for the first time on cone volatile oil of this plant.

Statistical Distribution of Fatigue Crack Growth Rate for Friction Stir Welded Joints of Al7075-T651 (Al7075-T651의 마찰교반용접된 접합부의 피로균열전파율의 통계적 분포)

  • Ahn, Seok-Hwan;Kim, Seon-Jin
    • Journal of Power System Engineering
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    • v.17 no.4
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    • pp.86-93
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    • 2013
  • This paper deals with the effects of driving force and material properties on statistical distribution of fatigue crack growth rate (FCGR) for the friction stir welded joints of Al 7075-T651 aluminum plate. In this work, the statistical probability distribution of fatigue crack growth rate was analyzed by using our previous constant stress intensity factor range controlled fatigue crack growth test data. As far as this study are concerned, the statistical probability distribution of fatigue crack growth rate for the friction stir welded (FSWed) joints was found to evaluate the variability of fatigue crack growth rate for base metal (BM), heat affected zone (HAZ) and weld metal (WM) specimens. The probability distribution of fatigue crack growth rate for FSWed joints was found to follow well log-normal distribution. The shape parameter of BM and HAZ was decreased with increasing the driving force, however, the shape parameter of WM was decreased and increased with increasing the driving force. The scale parameter of BM, HAZ and WM was increased with the driving force.