• Title/Summary/Keyword: Counter-current

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Information Dissemination During the COVID-19 Pandemic in Bangladesh

  • Sayed, Abu;Haque, Md. Ziaul;Mahmud, Md. Rifat
    • Journal of Information Science Theory and Practice
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    • v.10 no.4
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    • pp.66-86
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    • 2022
  • The main aim of this study is to identify the role of information dissemination on urban and rural citizens of Bangladesh during the COVID-19 pandemic and the role of misinformation in this process. The study also aimed at finding appropriate counter misinformation strategies regarding COVID-19. An online questionnaire was prepared to collect the viewpoints of the urban and rural citizens of Bangladesh regarding dissemination of information during COVID-19, misinformation regarding COVID-19, and counter misinformation strategies. Along with demographic and general information, a five-point Likert scale was used to measure COVID-19 related misinformation beliefs and how to counter them. Chi square tests were used to determine the association between current residency, information sources, the importance of information dissemination, reactions after getting COVID related information, and evaluative steps after getting information and before disseminating it. Additionally, nonparametric Mann-Whitney U and Kruskal-Wallis tests were conducted to know the significance of difference in respondents' assessment on COVID-19 related misinformation in terms of their demographic characteristics. Cronbach's alpha score was obtained to see the reliability of the questionnaire items. The current study reveals that both urban and rural citizens of Bangladesh are influenced by information dissemination regarding COVID-19 and they have lower level of misinformation belief. The respondents have differences in misinformation belief by different demographic groups. Respondents' educational status, information literacy, sources of getting information, and evaluative steps after getting information have significant differences in misinformation belief. The study also noticed the support of respondents for countering misinformation strategies regarding COVID-19.

Effects of the Sputtering Thickness and the Incident Angle of Pt Film Deposition as a Counter Electrode for Dye-sensitized Solar Cells (염료감응형 태양전지의 상대전극 Pt 필름 두께와 증착 각도가 효율에 미치는 영향에 관한 연구)

  • Kim, Hee-Je;Yeo, Tae-Bin;Park, Sung-Joon;Kim, Whi-Young;Seo, Hyun-Woong;Son, Min-Kyu;Chae, Won-Yong;Lee, Kyoung-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.3
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    • pp.588-593
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    • 2010
  • Sputter deposition on a Pt counter electrode was studied using radio frequency (RF) plasma as the improvement of incident photon to current conversion efficiency (IPCE) for dye-sensitized solar cells (DSCs). Effects of the sputtering thickness and the incident angle on a Pt counter electrode for DSCs were investigated. Experiments to get the optimal sputtering time for the performance of the DSCs were carried out. And it is found that the optimized sputtering time was 120 seconds, in addition, the incident angles of the substrate was adjusted from $0^{\circ}$ to $60^{\circ}$. The maximum efficiency of 5.37% was obtained at the incident angle of $40^{\circ}$ with an active cell area of $1cm^2$.

Design of Counter Circuit for Improving Precision in Distance Measuring System (거리 측정 시스템의 정밀도 향상을 위한 카운터 회로의 설계)

  • Choi, Jin-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.7
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    • pp.885-890
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    • 2020
  • In the distance measurement system the time-to-digital conversion circuit used measures the distance using the time interval between the start signal and the stop signal. The time interval is generally converted to digital information using a counter circuit considering the response speed. Therefore, a clock signal with a high frequency is required to improve precision, and a clock signal with a high frequency is also required to measure fine distances. In this paper, a counter circuit was designed to increase the accuracy of distance measurement while using the same frequency. The circuit design was performed using a 0.18㎛ CMOS process technology, and the operation of the designed circuit was confirmed through HSPICE simulation. As a result of the simulation, it is possible to obtain an improvement of four times the precision compared to the case of using a general counter circuit.

Effects of Deposition Method of Thermally Decomposed Platinum Counter Electrodes on the Performance of Dye-Sensitized Solar Cells (염료 감응형 태양전지 효율에 미치는 백금 상대 전극 제조공정의 영향)

  • SEO, HYUN WOO;BAEK, HYUN DUK;KIM, DONG MIN
    • Journal of Hydrogen and New Energy
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    • v.28 no.1
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    • pp.63-69
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    • 2017
  • In this work, two different platinum (Pt) counter electrodes have been prepared by spin coating a Pt solution and screen printing a Pt paste on fluorine doped tin oxide (FTO) glass substrate followed by sintering at $380^{\circ}C$ for 30 min. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) analyses of the Pt electrodes showed that the spin coated electrode was catalytically more active than the screen printed electrode. The above result agrees well with the surface morphology of the electrodes studied by atomic force microscopy (AFM) and the photovoltaic performance of the dye-sensitized solar cells (DSSCs) fabricated with the Pt electrodes. Moreover, calculation of current density-voltage (j-V) curves according to diode model with the parameters obtained from the experimental j-V curves and the EIS data of the DSSCs provided a quantitative insight about how the catalytic activity of the counter electrodes affected the photovoltaic performance of the cells. Even though the experimental situations involved in this work are trivial, the method of analyses outlined here gives a strong insight about how the catalytic activity of a counter electrode affects the photovoltaic performance of a DSSC. This work, also, demonstrates how the photovoltaic performance of DSSCs can be improved by tuning the performance of counter electrode materials.

An Empirical Study on Korea's Open and Integrated Counter-Terrorism System (한국의 개방・통합형 대테러시스템에 관한 실증적 연구)

  • Kwon, Jeong-Hoon
    • Korean Security Journal
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    • no.57
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    • pp.137-156
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    • 2018
  • The purpose of this study is to analyze the current status of counter terrorism system and to identify the causes of problems and to suggest alternatives by selecting legal and operational sectors based on theories of open systems and integrated systems. According to the results of the research, first, the degree of agreement on the open system and the integrated system is low with regard to the characteristics of the counter-terrorism system. Second, in relation to the importance and necessity of major factors of construction and operation of counter-terrorism system, counter-terrorism workers recognize that it is the most important and necessary. In the case of strengthening international cooperative system, the difference of recognition between importance and necessity was the biggest. The importance and necessity of reviewing the Anti-Terrorism Act for the protection of the public and public safety were relatively low, and the cooperation with the private sector showed the lowest importance and necessity. In the case of academic achievement, the average level of high school graduates is higher than that of professional high school graduates. Therefore, this research concludes that counter terrorism operation system with open and integrated system has to be applied to national counter terrorism operation structure in South Korea in increasing the quality and efficiency of nation counter terrorism response capability.

Counter-Current Flow Limit of a Vertical Two Phase (Water/Air) Flow (상반류(물/공기) 유동한계에 관한 연구)

  • 오율권;조상진;김상녕;이종원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.308-322
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    • 1991
  • A set of experiments of Counter-Current Flow Limit(CCFL or Flooding) was performed to improve the drawbacks of Wallis' Correlation which neglects the effects of channel size, channel length, injection method and the boundary conditions at the inlet of liquid and gas phase. In these experiments using water and air, the followings were found ; (i) The effects of channel size and length were quite significant. In large tubes(D>20mm), the flooding front occurred at the bottom of the channel and when the gas flow increased the front moved upward ; however, in small tubes(D<20mm), there were no upward movement of flooding front and the flooding just occurred at the liquid inlet. (ii) The effect of water inlet device was not as significant as that of channel length though the inlet boundary conditions could affect the flow development and flooding afterward. (iii) Once the flooding front reached the inlet of water injection device, an newly reduced flow condition was set up and resulted in another flooding corresponding to the new condition.

Distribution of Catches and Condition of Fishing Ground for Tuna Purse Seine in the Western Pacific Ocean (서부태평양에서 다랑어 선망어업의 어획분포와 어장환경)

  • 김형석
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.3
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    • pp.227-236
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    • 1999
  • Temperal and spacial analysis for catches have been drawing up a catch distribution chart and analysing catches and CPUE(Catch Per Unit Effort) using catch data with purpose of obtaining basic data to establish a selective method of effective fishing the tuna purse seine fishing ground.The temperature profile section and catch was surveyed to analyse the effect of catch in relation to the fishing ground environment.The results are as follows ;1. As for the catch variation between 1983 and 1984, the catch mainly took place on150^{\circ}E$, and after that it moved eastward enlarging the range of catch. In the monthly catch variation between January and February, the catches mainly happened on 135$^{\circ}$~ 150$^{\circ}$E, and then moved to the gradually westward. However, from July it moved to the South and from October Southeast.2. As to the eatch ratio for the school associated with the drifted object, the pelagic migrating school and the school associated with the biological objects, the catch ratio for the school associated with the drift objects was the highest. The catch ratio for the school associated with the drifted object was high in June, July and November whiles between January and March for the pelagic migrating school.3. SST(Sea Surface Temperature) was around 28~29^C$ on the observing line of 137^{\circ}E$ and the catches took place in the north equatorial counter-current situated on around $5^{\circ}~6^{\circ}N$. SST in the northern summer was 1^C$higher than winter and it was about 29~30^C$. The catch happened with the center of north equatorial counter-current. The reason why the catch mainly took place on the north equatorial counter-current is that main catch of tuna purse seine was the school associated with drift objects. It is thought that the fishing grounds are made in waters that have many drift objects like drift logs from the coast.

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Optimization of Extraction Process for Mass Production of Paclitaxel from plant Cell Cultures (Paclitaxel 대량생산을 위한 추출공정 최적화)

  • 김진현
    • KSBB Journal
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    • v.15 no.4
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    • pp.346-351
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    • 2000
  • Several solvents or combinations of solvents were tested for the extraction of wet or dried biomass at different extraction mode from plant cell cultures. Methanol gave the highest paclitaxel recovery with the least amount of solvent usage. before extraction drying of biomass wass helpful to decrease solvent usage in extraction step./ in this case drying method was very important to obtain high yield from dried biomass. In thid mode of operation counter-current extraction process can be able to decrease solvent usage but paclitaxel recovery was almost same with both batch and counter-current mode of operation. The number of extraction times was at least four to obtain high yield(>99%) from cell and one to obtain highyield(>96%) from cell debris in batch mode. Equilibrium (i.e. the ratio of paclitaxel in biomass to paclitaxel in the extraction solvent) was reached within 5 minutes. The minimum methodal concentration (90%) and solvent amount(biomass : solvent=1 Kg : 1L) are enough to obtain high yield(>98%) for extraction from biomass.

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Effects of pH on the Separation and Purification of Model Protein using Counter Current Distribution (역류분배를 이용한 모델단백질의 분리정제시 pH의 영향에 관한 연구)

  • Lee, Boo-Yong;Lee, Chang-Ho;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.22 no.1
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    • pp.56-60
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    • 1990
  • The changes in the partition coefficient of model proteins (lysozyme, myoglobin, conalbumin, bovine serum albumin) in an aqueous two-phase system formed by polyethylene glycol and dextran were examined in order to improve the capacity of counter current distribution for the protein fractionation and concentration. The protein distribution patterns in CCD with 30 tubes varied with the pH of the system, and both theoretical and measured values agreed well. From the mixture of model protein, pure BSA fraction was appeared at the upper-phase of 14th tube having pH 4.5, pure myoglobin at the lower-phase of the 16th be with pH 6.5 and conalbumin at the lower-phase of 4th tube with pH 12. The result indicated the possible use of CCD method for protein fractionation, if the partition coefficient of proteins was manipulated by pH and other means.

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