• Title/Summary/Keyword: improving reaction

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A study for improving the surgical mess using palatal and buccal mucosal incisions in oral and maxillofacial area (구개점막과 협점막의 절개에 사용되는 칼의 개선을 위한 기초 연구)

  • Seo Byoung-Moo;Choi Jin-Young;Lee Jong-Ho;Kim Myung-Jin;Choung Pill-Hoon
    • Korean Journal of Cleft Lip And Palate
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    • v.4 no.1
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    • pp.1-11
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    • 2001
  • Disposable blade is widely used for palatal and oral mucosal incision in oral and maxillofadal surgery nowadays, But its design and durability need for improvement, Especially, there are so many hard tissues intraoral area, such as bone and tooth, therefor the sharpness of the surgical blade was easily destroyed, The purpose of this study was to make basic data for developing new design of surgical blade using in oral and maxillofacial area including for the patients who have cleft lip and palate deformities, Some questionnaires about the usefulness of currently used surgical blades were sent to 150 dentists, the 54 of them made a reply, Secondly, The used-once blade and fresh new blade were examined under the scanning electron microscope with the 4000-times magnification, Lastly, the tissue reaction following the surgical incision with a fresh-new and a used blade on rat buccal cheek mucosa and hard palate was evaluated with light microscope with hematoxilin-eosin staining, The time interval from the surgical trauma to taking a sample were 1 day, 3 days, 7 days, and 14 days, At each time schedule, 2 Sprague-Dawley rats were sacrificed, Many dentists were agreed to need for changing the design of the surgical blades and also demand to improve the durability of the blades, They were also eager to adopt the new design of blade if it was available, The blade used in surgical extraction procedure was heavily damaged in its sharpe edge of number 15 blade, The histological differences were not prominent, but the delayed healing was detected in buccal mucosal defects especially in the surgical group with used blade, There are slight different changes in hard palatal defects between a used and a new blade group, In this study, we could find that there are imperative demanding on improvement of surgical blade design and durability for oral and maxillofadal area, The blade currently using in surgical extraction was easily damaged, The animal model of this study was not perfect for the purpose of this study.

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Development of DHLT Joint for Vertical Cutoff Walls in Offshore Waste Landfill Site (해상처분장 연직차수공을 위한 DHLT 이음부의 개발)

  • Hong, Young-Ho;Lee, Jong-Sub;Lee, Dongsoo;Chae, Kwang-Seok;Yu, Jung-Doung
    • Journal of the Korean Geotechnical Society
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    • v.34 no.3
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    • pp.43-56
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    • 2018
  • Vertical cutoff walls such as steel pipe sheet piles (SPSPs) have been commonly applied for the construction of the offshore waste landfill site. Because the SPSPs are sequentially installed by connecting their joints to those of adjacent piles, their mechanical stability should be ensured against the inherent external forces on the sea. The objective of this study is to evaluate the structural performances of the newly developed types of SPSP joint compared with those of other joint types. The problems of the traditional SPSP joints are investigated, and an advanced joint shape of SPSP, which is named double H with L-T (DHLT) joint, are designed for improving the constructability and maintenance. Full-scale models of the DHLT joint are manufactured, and then its joint areas are filled with grout material. After 28 days of curing time, compressive and tensile strength tests were performed on the joint models and the test results were compared with those of the traditional joints. Experimental results show that the structural capacities of the DHLT joint models are lower than those of traditional joints due to the influence of grout and steel members. In the cases of the compressive strength test, especially, bending occurs on steel H-beam with no distinct cracks in grout due to the asymmetrical structure of joint which has no reaction force. This study shows that the performance of the SPSP joint can be improved by considering the influence factors on the structural capacities estimated by the experimental tests.

Preparation of Hexaaluminate Phosphor Particles with Spherical Shape by Gas Phase Reaction Process (기상 공정에 의한 구형 형상의 헥사알루미네이트계 형광체 제조)

  • Jung, Dae Soo;Hong, Seung Kwon;Koo, Hye Young;Ju, Seo Hee;Kang, Yun Chan
    • Korean Chemical Engineering Research
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    • v.43 no.5
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    • pp.616-620
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    • 2005
  • The morphology and photoluminescence characteristics of green light emitting hexaaluminate phosphor particles prepared by high temperature spray pyrolysis from spray solution with and without ammonium dihydrogen phosphate flux were investigated. The particles prepared from spray solution without flux material had hollow morphology at preparation temperatures between $900^{\circ}C$ and $1,650^{\circ}C$. Ammonium dihydrogen phosphate flux added into spray solution enabled the formation of particles with spherical shape and filled morphology at preparation temperatures between $900^{\circ}C$ and $1,650^{\circ}C$. The hexaaluminate phosphor particles with magnetoplumbite structure were directly prepared by spray pyrolysis from spray solution with ammonium dihydrogen phosphate flux above $1,600^{\circ}C$. Ammonium dihydrogen phosphate flux was effective in improving the photoluminescence intensity of the phosphor particles at low preparation temperatures. The phosphor particles prepared from spray solution with and without flux material by spray pyrolysis under reducing atmosphere at $1,650^{\circ}C$ had comparable photoluminescence intensities with that of the phosphor particles optimized by post-treatment.

Role of Sulfone Additive in Improving 4.6V High-Voltage Cycling Performance of Layered Oxide Battery Cathode (층상계 산화물 양극의 4.6V 고전압 특성 향상에서의 Sulfone 첨가제의 역할)

  • Kang, Joonsup;Nam, Kyung-Mo;Hwang, Eui-Hyeong;Kwon, Young-Gil;Song, Seung-Wan
    • Journal of the Korean Electrochemical Society
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    • v.19 no.1
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    • pp.1-8
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    • 2016
  • Capacity of layered lithium nickel-cobalt-manganese oxide ($LiNi_{1-x-y}Co_xMn_yO_2$) cathode material can increase by raising the charge cut-off voltage above 4.3 V vs. $Li/Li^+$, but it is limited due to anodic instability of conventional electrolyte. We have been screening and evaluating various sulfone-based compounds of dimethyl sulfone (DMS), diethyl sulfone (DES), ethyl methyl sulfone (EMS) as electrolyte additives for high-voltage applications. Here we report improved cycling performance of $LiNi_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode by the use of dimethyl sulfone (DMS) additive under an aggressive charge condition of 4.6 V, compared to that in conventional electrolyte, and cathode-electrolyte interfacial reaction behavior. The cathode with DMS delivered discharge capacities of $198-173mAhg^{-1}$ over 50 cycles and capacity retention of 84%. Surface analysis results indicate that DMS induces to form a surface protective film at the cathode and inhibit metal-dissolution, which is correlated to improved high-voltage cycling performance.

A Case Report of Insomnia and Fatigue in Alcoholic Hepatitis Patients Treated with Korean Medicine and Western Medicine (알코올성 간염 환자의 불면과 피로 개선에 대한 한양방 병용치료 치험 1례)

  • Nam, Hyun seo;Han, Seung-hee;Jeong, In-chae;Sun, Seung-ho;Kim, Mikyung;Han, In-sik;Baek, Tae hyun;Jerng, Ui min
    • The Journal of Internal Korean Medicine
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    • v.41 no.2
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    • pp.186-193
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    • 2020
  • Objectives: This study aimed to report a case that showed improvements in the symptoms of patients with alcoholic hepatitis without any indication of deterioration of the disease. Methods: Western medicine with Urusa tablets and Godex capsules and Korean medicine therapeutic approaches, including Shihogayonggolmoryo-tang, acupuncture, and moxibustion, were administered to a patient during the period of treatment. Blood tests were used to determine levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT ratio, alkaline phosphatase (ALP), gamma glutamyltransferase (GGT), total bilirubin, direct bilirubin, and total cholesterol. Fatigue was measured using the numeric rating scale (NRS), and the patient's total sleeping time was checked, daily. Results: After the combined treatment, the AST/ALT ratio and the AST, ALT, ALP, GGT, total cholesterol, and direct bilirubin levels were decreased. Through Oriental medicine for the purpose of improving symptoms, NRS of fatigue decreased from 10 to 5, and the amount of sleeping time increased from 2 to 5 hours. Conclusions: The herbal medicine had no effect on the hepatoprotective drugs such as Urusa tablets and Godex capsules used to treat alcoholic hepatitis, and no adverse reaction from the combined administration was observed. To reduce fatigue and insomnia in patients with alcoholic hepatitis, it might be helpful to combine Western medications with Korean medicine treatments, including acupuncture, moxibustion, and Shihogayonggolmoryo-tang.

Numerical Simulation of Lithium-Ion Batteries for Electric Vehicles (전기 자동차용 리튬이온전지 개발을 위한 수치해석)

  • You, Suk-Beom;Jung, Joo-Sik;Cheong, Kyeong-Beom;Go, Joo-Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.6
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    • pp.649-656
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    • 2011
  • A model for the numerical simulation of lithium-ion batteries (LIBs) is developed for use in battery cell design, with a view to improving the performances of such batteries. The model uses Newman-type electrochemical and transfer $theories^{(1,2)}$ to describe the behavior of the lithium-ion cell, together with the Levenberg-Marquardt optimization scheme to estimate the performance or design parameters in nonlinear problems. The mathematical model can provide an insight into the mechanism of LIB behavior during the charging/discharging process, and can therefore help to predict cell performance. Furthermore, by means of least-squares fitting to experimental discharge curves measured at room temperature, we were able to obtain the values of transport and kinetic parameters that are usually difficult to measure. By comparing the calculated data with the life-test discharge curves (SB LiMotive cell), we found that the capacity fade is strongly dependent on the decrease in the reaction area of active materials in the anode and cathode, as well as on the electrolyte diffusivity.

User's Satisfaction Analysis on the User-Oriented Public Transit Service in Busan (이용자 맞춤형 대중교통서비스의 이용자 만족도 분석 : 부산시 사례를 중심으로)

  • Park, Han-Young;Kim, Gyeong-Seok
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.1
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    • pp.28-41
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    • 2012
  • The User-Oriented Public Transit Service provide public transit service through media devices, such as mobile, BIT and In-vehicle display devices, which considered user's individual characteristics and specific preference anytime and anywhere. The objective of this study is to develop and improve the services in the three media devices. This study applied user-satisfaction analysis in evaluating the service in Busan, analyze factor affecting the level of service user's satisfaction, and draw remedies based on the analysis results. The user's satisfaction average values in each media are 3.29 mobile, 3.62 BIT, and 4.05 In-vehicle display devices. Overall satisfaction average value 3.54 on the service showed a positive reaction from the survey participants. The important factor affected on general satisfaction of the User-Oriented Public Transit Service is "In-vehicle display devices" scored .632 (standardized coefficient) by categorical regression analysis. But users prefer to further improve the service environment rather than to add service information because they are already contented with the information they are getting. Furthermore, this study suggested ways of improving the User-Oriented Public Transit Service based on the satisfaction analysis results from the user's perspective.

Oxidation and Removal of NO Emission from Ship Using Hydrogen Peroxide Photolysis (과산화수소 광분해를 이용한 선박 배가스 내 NO 산화흡수에 관한 연구)

  • Lee, Jae-Hwa;Kim, Bong-Jun;Jeon, Soo-Bin;Cho, Joon-Hyung;Kang, Min-Kyoung;Oh, Kwang-Joong
    • Clean Technology
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    • v.23 no.3
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    • pp.294-301
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    • 2017
  • Air pollution associated with the $NO_x$ emission from the ship engines is becoming one of the major environmental concerns these days. As the regulations on ship pollutants are strengthened, the wet absorption method, for controlling complex pollutants in a confined space, has the advantage of simultaneously removing various pollutants, but the low solubility of nitrogen monoxide is drawback. In this study, for improving existing denitrification scrubber system, NO oxidation process by hydroxyl radical produced from irradiating UV light on $H_2O_2$ is suggested and the $H_2O_2$ decomposition rates and hydroxyl radical quantum yields were measured to find the optimum condition of $H_2O_2$ photolysis reaction. As a result, the optimum quantum yield and photolysis rate of $H_2O_2$ were 0.8798, $0.6mol\;h^{-1}$ at 8 W, 2 M condition, and oxidation efficiency of 1000 ppm NO gas was 40%. In batch system, NO removal efficiency has a range of 65.0 ~ 67.3% according to input gas concentration of 100 ~ 1500 ppm. This results indicate that the scrubber system using hydrogen peroxide photolysis can be applied as air pollution prevention facility of ship engines.

Effect of Treatment Amounts of Slurry Composting and Biofiltration Liquid Fertilizer on Growth Characteristics and Bioethanol Production of Yellow Poplar (SCB액비 처리량에 따른 백합나무의 생장 및 바이오에탄올 생산)

  • Kim, Ho-Yong;Gwak, Ki-Seob;Kim, Hye-Yun;Ryu, Keun-Ok;Kim, Pan-Gi;Cho, Do-Hyun;Choi, Jin-Yong;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.6
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    • pp.459-468
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    • 2011
  • The main purpose of this study was to examine the influence of treatment amounts of Slurry Composting and Biofiltration liquid fertilizer (SCBLF) on biomass growth of Yellow poplar (Liriodendron tulipifera) and to compare bioethanol production from the harvested wood. Relative growth rate, biomass production and leaf characteristics were significantly enhanced by SCBLF treatment and medium treatment plot showed highest value. Nitrogen compounds and water content in SCBLF affected to increase chlorophyll contents which led improving biomass production (64.67%) and glucose contents (6.07%) than control. Organosolv and dilute acid pretreatments were preliminarily carried for bioethanol production, and the pretreatment processes were conducted at all the same solid to liquid ratio (1 : 10), reaction temperature ($150^{\circ}C$), preheating time (40 min) and residence time (10 min). The water insoluble solid recovery of Organosolv pretreatment with 1% sulfuric acid as a catalyst was the lowest and that of medium treatment plot was 44.81%. Exchangeable cations in SCBLF might be affected to increase pretreatment effect. The simultaneous saccharification and fermentation process was followed to determine the ethanol production of the pretreated biomass. The highest ethanol production yield based on initial weight was obtained from high treatment plotby Organosolv pretreatment with 1% sulfuric acid (16.11%). But regarding biomass production, medium treatment plot produced most, and bioethanol production was increased by 72.93% than control.

Detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus using duplex real-time PCR assay with melting curve analysis on fresh lettuce

  • Lee, Na-Ri;Kwon, Kyung-Yoon;Choi, Sung-Wook;Koo, Min-Seon;Chun, Hyang-Sook
    • Journal of Food Hygiene and Safety
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    • v.26 no.2
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    • pp.114-119
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    • 2011
  • In this study, two duplex real-time PCR approach with melting curve analysis is presented for the detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus, which are important food-borne bacterial pathogens usually present in fresh and/or minimally processed vegetables. Reaction conditions were adjusted for the simultaneous amplification and detection of specific fragments in the ${\beta}$-glucuronidase (uidA, E. coli), thermonuclease (nuc, S. aureus), hemolycin (hly, L. monocytogenes) and tetrathionate reductase (ttr, Salmonella spp.) genes. Melting curve analysis using a SYBR Green I real-time PCR approach showed characteristic $T_m$ values demonstrating the specific and efficient amplification of the four pathogens; $80.6{\pm}0.9^{\circ}C$, $86.9{\pm}0.5^{\circ}C$, $80.4{\pm}0.6^{\circ}C$ and $88.1{\pm}0.11^{\circ}C$ for S. aureus, E. coli O157:H7, L. monocytogenes and Salmonella spp., respectively. For all the pathogens, the two duplex, real-time PCR was equally sensitive to uniplex real-time PCR, using same amounts of purified DNA, and allowed detection of 10 genome equivalents. When our established duplex real-time PCR assay was applied to artificially inoculated fresh lettuce, the detection limit was $10^3$ CFU/g for each of these pathogens without enrichment. The results from this study showed that the developed duplex real-time PCR with melting curve analysis is promising as a rapid and cost-effective test method for improving food safety.