• Title/Summary/Keyword: LbL method

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Comparative Study of Tritium Analysis Method with High-Volume Counting Vial

  • Yoon, Yoon Yeol;Kim, Yongcheol
    • Journal of Radiation Protection and Research
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    • v.45 no.3
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    • pp.142-146
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    • 2020
  • Background: Tritium (3H) analysis in groundwater was difficult because of its low activity. Therefore, the electrolytic enrichment method was used. To improve the detection limit and for performing simple analysis, a high-volume counting vial with the available liquid scintillation counter (LSC) was investigated. Further, it was compared with a conventional 20-mL counting vial. Materials and Methods: The LSC with the electrolytic enrichment method was used 3H analysis in groundwater. A high-volume 145-mL counting vial was compared with a conventional 20-mL counting vial to determine the counting characteristics of different LSCs. Results and Discussion: When a Quantulus LSC was used, the counting window between channels 35 and 250 was used. The background count was approximately 1.86 cpm, and the counting efficiency increased from 8% to 40% depending on the mixing ratio of the volume of sample and cocktail solution. For LSC-LB7, the optimum counting window was between 1 and 4.9 keV, which was selected by the factory (Hitachi Aloka Medical Ltd., Japan) by considering quenching using a standard external gamma source. The background count of LSC-LB7 was approximately 3.60 ± 0.29 cpm when the 145-mL vial was used and 2.22 ± 0.17 cpm when the 20-mL vial was used. The minimum detectable activity (MDA) of the 20-mL vial was greater for LSC-LB7 than for Quantulus. The MDA with the 145-mL vial was improved to 0.3 Bq/L when compared with the value of 1.6 Bq/L for the 20-mL vial. Conclusion: The counting efficiency when using the 145-mL vial was 27%, whereas it was 18% when using the 20-mL vial. This difference can be attributed to the vial volume. The figure of merit (FOM) of the 145-mL vial was four times greater than that of the 20-mL vial because the volume of the former vial is approximately seven times greater than that of the latter. Further, the MDA for 3H decreased from 1.6 to 0.3 Bq/L. The counting efficiency and FOM of LSC-LB7 was slightly less than those of Quantulus when the 20-mL vial was used. The background counting rate of the Quantulus was lower than that of the LSC-LB7.

A Study on the Stimulus control of L-$\alpha$-DLPC Organic Monolayers

  • Song, Jin-Won;Lee, Kyung-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.181.3-181
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    • 2001
  • Recently, the study on development of electrical and electronic device is done to get miniature, high degrees of integration and efficiency by using inorganic materials. the study of Langmuir-Boldgett(LB) method that uses organic materials because of the limitation for the ultrasmall size. In this paper, to do research for medical artificial organs as well as principal parts living body thin film application, electrical properties of L-$\alpha$-DLPC Langmuir(L) films were investigated a displacement current measuring technique with pressure stimulation. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 20[mN/m]. LB layers of L-$\alpha$-DLPC deposited by LB method ...

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Effectiveness of Tramadol and Butorphanol as an Adjuvant to Local Anesthetic in Mandibular Nerve Block in Beagle Dogs

  • Jang, Sang Seon;Kim, Hyeonjo;Kwon, Dae Hyun;Yoon, Eunchae;Lee, Dongbin;Lee, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.39 no.5
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    • pp.226-234
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    • 2022
  • To evaluate butorphanol and tramadol as adjuvants to lidocaine in dogs undergoing mandibular nerve block. Fifteen beagles were allocated to groups based on the following treatments: lidocaine alone (L group), lidocaine + butorphanol (LB group), or lidocaine + tramadol (LT group). After mandibular nerve block with opioids as an adjunct to local anesthetics, the onset time, duration of action, and depth of anesthesia were evaluated using a quantitative method through neuromuscular blockades (NMBs) monitoring. The onset time of nerve block was 4.60 ± 2.06 min, 2.00 ± 0.00 min, and 2.60 ± 1.62 min in the L, LB, and LT groups, respectively; however, there was no statistically significant difference. The duration of nerve block was 111.88 ± 34.78 min, 302.00 ± 76.72 min, and 260.40 ± 49.88 min in the L, LB, and LT groups, respectively, with a significant difference between L and LB groups. The LB group demonstrated a more profound depth of anesthesia compared to the L and LT groups. In this study, using a quantitative method through NMBs monitoring, it was demonstrated that lidocaine and butorphanol in combination can increase the duration of nerve block and more profound the depth of anesthesia rather than lidocaine alone. Additionally, the combined use of lidocaine and opioids presented an objective indicator that could provide a more clinically stable nerve block.

A comparative study of electrical properties of arachidic acid LB films in the Al/LB/Al and Au/LB/Au electrode structure (Al/LB/Al, Au/LB/Au 전극 구조에서 arachidic acid LB막의 전기적 특성에 관한 비교 연구)

  • 오세중;김정수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.10
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    • pp.1311-1316
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    • 1995
  • The electrical properties of the Langmuir-Blodgett (LB) films layered with arachidic acid were studied at the room temperature. The sample was formed with 2 different structure ; One was Al/LB/Al and the other was Au/LB/Au. The precise structure of Al/LB/Al was considered as Al/Al$_{2}$O$_{3}$/LB/Al, because the natural oxide layer was formed on surface of lower Al electrode. The electrical conductivity of Al/Al$_{2}$O$_{3}$/LB/Al structure was determined the value of 3.5 * 10$^{-14}$ S/cm from the measurement of current-voltage (I-V) characteristics. The sample with the structure of Au/LB/Au was made to eliminate the influence of oxide layer in the electrical properties of the LB films. The short circuit current was observed in this sample from the I-V characteristics. To verify the reason of short circuit current generation, copper decoration method was employed to the 15 layers of LB films deposited on the Al and Au electrode each. The defects were shown on the films deposited with Au electrode. This results means that the defects on the LB films which layered with the Au electrode were contributed to the short circuit current. Several films (15, 31, 51, 71L) were deposited on the Au electrode and measured the size of defects with the copper decoration method. The size of defects becomes smaller as the film layer was increased. We conclude that the existence of defects affects the short circuit current generation.

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Application of Layer-by-Layer Assembly in Triboelectric Energy Harvesting (마찰대전 기반의 에너지 하베스팅에서 다층박막적층법의 응용)

  • Habtamu Gebeyehu, Menge;Yong Tae, Park
    • Composites Research
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    • v.35 no.6
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    • pp.371-377
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    • 2022
  • Triboelectric nanogenerator (TENG) devices have generated a lot of interest in recent decades. TENG technology, which is one of the technologies for harvesting mechanical energy among the energy wasted in the environment, is obtained by the dual effect of electrostatic induction and triboelectric charging. Recently, a multilayer thin film stacking method (or layer-by-layer (LbL) self-assembly technique) is being considered as a method to improve the performance of TENG and apply it to new fields. This LbL assembly technology can not only improve the performance of TENG and successfully overcome the thickness problem in applications, but also present an inexpensive, environmentally friendly process and be used for large-scale and mass production. In this review, recent studies in the accomplishment of LbL-based materials for TENG devices are reviewed, and the potential for energy harvesting devices reviewed so far is checked. The advantages of the TENG device fabricated by applying the LbL technology are discussed, and finally, the direction and perspective of this fabrication technology for the implementation of various ultra-thin TENGs are briefly presented.

Capacitance properties of DLPC LB films with MLS structure fabricated by moving wall type method (Moving wall형 LB법으로 제작된 MLS DLPC LB 박막의 제작과 캐패시턴스 특성)

  • Lee, Woo-Sun;Chung, Yong-Ho;Son, Kyeong-Choon
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1297-1299
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    • 1998
  • LB layers of L-$\alpha$-DLPC deposited by LB method were deposited onto n-type silicon wafer as Z-type film. Films made up of 8, 16 layers of lipid with long alkyl chain and the thickness of monolayer and multilayers was determined by ellipsometry. It was deposited Ag and Al onto LB layers and silicon wafer for electrode and small electrode exhibit high capacitance and low leakage current. The C-V curves of the MLS capacitor shows very high saturation value of capacitance. And cross-sectional SEM image of MLS capacitor indicated the presence of pore with Al electrode and we found that the Ag is good for electrode metal.

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Fabrication and Characteristics of LB Ultra-thin Film Capacitor (II) (LB 초박막 커패시터의 제작 및 특성 (II))

  • 유승엽;박재철;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.244-247
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    • 1996
  • We had experiment using LB method that can fabricate molecular order ultra-thin film below 100${\AA}$. LB method has known as main technology of information society in 21C, because it is not only free orientation and alignment of molecular but also ability of thickness control as molecular order. In this paper, the fabricated condition and physical properties of functional ultra-thin film of molecular order was investigated and highly efficient ultra-thin film capacitor was fabricated by using ultra-thin LB film for application as electronic device. Possibility of ultra-thin film capacitor was researched by analyzing and measuring electrical properties. Polyimide ultra-thin LB film capacitor was fabricated, ensured theoretically and experimentally its possibility in range of 10Hz∼lMHz through its frequency characteristics.

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Electrochemical Properties of Langmuir-Blodgett(LB) Films of Fatty Acid Containing Azobenzene and $L-{\alpha}-dimyristoylphosphatidylcholine$ Mixture (아조벤젠기를 가진 지방산과 $L-{\alpha}-dimyristoylphosphatidylcholine$ 혼합 LB막의 전기화학적 특성)

  • Park, Keun-Ho;Choi, Sung-Hyun;Song, Ju-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.315-322
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    • 2005
  • We investigated the electrochemical properties for Langmuir-Blodgett (LB) films mixed with 4-octyl-4'-(5-carboxylpentamethyleneoxy)azobenzene (denoted as 8A5H) and $phospholipid(L-{\alpha}-dimyristoylphosphatidylcholine$, denoted as DMPC). LB films of 8A5H monolayer and 8A5H-DMPC were deposited by using the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by using cyclic voltammetry with a three_electrode system, an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode at various concentrations(0.1, 0.5, and 1.0mol/L) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rates were 50, 100, 150 and 200mV/s, respectively. As a result, LB films of 8A5H monolayer appeared irreversible process caused by only the oxidation current from the cyclic voltammogram and LB films of 8A5H-DMPC mixture were found to be caused by a reversible oxidation-reduction process.

Mode of Transmission of a Newly Discovered Microsporidian and Its Effect on Fecundity and Hatching in Silkworm, Bombyx mori L.

  • Bhat Shabir Ahmad;Nataraju B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.11 no.2
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    • pp.81-86
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    • 2005
  • The mode of transmission, effect on fecundity, hatching and tissues specificity of a microsporidian $(Lb_{ms})$ recovered from Lamerin breed of the silkworm Bombyx mori L. was studied and compared with standard strain Nosema bombycis. Peroral inoculation of $Lb_{ms}$ or N. bombycis to zeroday of $4^{th}$ instar larvae of silkworm was the most suitable method for producing information on development of stage specific mortality, pupation and obtaining infected adults for transovarial transmission studies. It was observed that pupal mortality, the percentage of moths emerged and the percentage of moths infected were significantly high in N. bombycis infected batches as compared $(Lb_{ms})$ in all the three tested breeds of the silkworm. However no significant difference was observed in larval mortality. The fecundity and hatchability was not affected significantly in $(Lb_{ms})$ infected adults, however significant reduction in egg production, fecundity, hatchability and increased egg retention was observed in mother moths infected with N. bombycis. The $(Lb_{ms})$ is transmitted both horizontally and vertically at lower rate due to its low rate of proliferation. The trans ovarial transmission of $(Lb_{ms})$ to the $F_1$ progeny generation through eggs averaged only $61.33\pm5.10\%$ whereas N. bombycis was transmitted at $100\%$. The $(Lb_{ms})$ had low oral infectivity and low transovarial transmission in silkworm B. mori.

A Study on the Stability of Langmuir-Blodgett(LB) Films of L-${\alpha}$-Phosphatidylethanolamine Monolayer (L-${\alpha}$-Phosphatidylethanolamine 단분자층 LB막의 안정성에 관한 연구)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.1
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    • pp.44-49
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    • 2014
  • We were investigated by cyclic voltammetry to the stability through the electrochemical characteristics of phospholipid(L-${\alpha}$-phosphatidylethanolamine, LAPE) monolayer LB films. LAPE monolayer LB films was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties was measured by cyclic voltammetry with a three-electrode system in 0.5 N, 1.0 N, 1.5 N and 2.0 N $KClO_4$ solution. The measuring range is continuously oxidized to 1650 mV, with an initial potential of -1350 mV was reduced. Scanning rates of 50, 100, 150, 200, and 250 mV/s was set. As a result, LB monolayer films of LAPE was appeared on irreversible processes by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of LAPE was calculated 195, 15.9, 5.75, 1.38 and $0.754cm^2s^{-1}{\times}10^{-9}$ at 0.01 N, 0.05 N, 0.10 N, 0.15 N and 0.20 N $KClO_4$ solutions, respectively.