• Title/Summary/Keyword: flow control

Search Result 7,417, Processing Time 0.041 seconds

Research Trends on Achievement Emotion (성취정서의 국내외 연구동향)

  • Park, Seo-Yeon;Yun, Mi-Seon
    • (The) Korean Journal of Educational Psychology
    • /
    • v.31 no.1
    • /
    • pp.35-58
    • /
    • 2017
  • The achievement emotion experienced by students in their academic settings is directly related with achievement activities or results. As the focuses of researches in the educational psychology have been extended to students' motives and emotion, the achievement emotion is also actively studied in Korea. The purpose of this study is to analyze researches on the achievement emotion according to social/cultural backgrounds by dividing them into domestic and foreign ones and understand flow and trend of the researches by structuring them. On the basis of the findings, it also aims to provide fundamental data necessary to examine the achievement emotion matched for academic settings in Korea. The objects of this study include a total of 105 domestic (n=47) and foreign (n=58) journal articles. The criteria of analysis are divided into period, contents and method of the study: the study was conducted without control of period; the contents include variables and achievement situations; and the method includes design and type of study, analysis methods, measurement tools and objects. The descriptive statistics of the materials were estimated by using the SPSS, and were analyzed by dividing them into domestic and foreign ones. The findings show that the researches on achievement emotion can be divided into examinations of the development of achievement emotion scale and those of the relationship between related variables. Thus, the conclusion suggests comprehensive discussions by arranging the trends of researches on the development of achievement emotion scale and the relationship between related variables.

Simultaneous analysis method of 89Sr and 90Sr in liquid sample using automated separation system (자동핵종분리장치를 이용한 액체시료 중 89Sr, 90Sr 동시분석법 연구)

  • Kim, Heewon;Lee, Yong-Jin;Kim, Sun-Ha;Lee, Jin-Hong;Lim, Jong-Myoung;Kim, Hyuncheol
    • Analytical Science and Technology
    • /
    • v.33 no.6
    • /
    • pp.274-284
    • /
    • 2020
  • This study described the analytical method for simultaneous determination of 89Sr and 90Sr in liquid sample using automated separation system. Radiostrontium in 0.5 kg of liquid sample was concentrated as SrCO3 to reduce the volume of sample, and purified from the sample using Sr-resin 2 mL (BV, Bed volume). The behavior of Sr and interferences such as Ba, Ca and Y were estimated with various flow rate ranging from 1 to 4 mL min-1. The detailed procedure for the purification of Sr on Sr-resin was presented. The purified radiostronitum was measured in Cerenkov mode and then measured in Scintillation mode by mixing scintillation cocktail. The measured value in both modes were used to calculate the activity of 89Sr and 90Sr. The performance tests were carried out the lab-control-sample having various activity ratio of between 89Sr and 90Sr. The recovery of Sr was ranged from 68 to 94 %. The relative bias of 89Sr activity was ranged from -5 to 20 %, and it was ranged from -10 to 10 % for 90Sr.

Analytical Method Development of Isoscoparin in Silene seoulensis Extract Using HPLC (HPLC 를 이용한 가는장구채 추출물의 Isoscoparin 분석법 개발)

  • Kwon, Jin Gwan;Seo, Changon;Jung, Yeon Woo;Choi, Yongmun;Shin, Hyun Tak;Jung, Su Young;Choi, Jeong June;Kim, Jin Kyu
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.47 no.1
    • /
    • pp.57-63
    • /
    • 2021
  • In this study, isoscoparin was selected as an indicator component to develop Silene seoulensis extract as a functional cosmetic material, and we developed an analysis method using high performance liquid chromatography (HPLC) for quality control. HPLC was performed on a Unison US-C18 with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methanol at a flow rate of 1.0 mL/min at 35 ℃, and the detection wavelength was 330 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.02 and 0.07 mg/mL respectively. Calibration curves showed good linearity (R2 > 0.99988), and the precision of analysis was satisfied (less than 0.46%). In addition, the recovery rate was in the range of 99.10 to 101.61%, it was shown to be accurate. This result indicated that the established HPLC method is very useful for the determination of marker compounds in Silene seoulensis extracts.

A Study on the Performance Evaluation of Water(wash out) Resistance of 5-Type Repair Materials in Water Leakage of Underground Concrete Structures (지하 콘크리트 구조물 누수부위에 시공되는 5계열 보수재료의 유실 저항 성능 평가 연구)

  • Kim, Soo-Yeon;Yoo, Jae-Yong;Oh, Sang-Keun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.24 no.5
    • /
    • pp.61-68
    • /
    • 2020
  • In this study, the international standard ISO TS 16774 Part 3 Test Method for Water (wash out) Resistance and KS F 4935 「Sealant Injection type for water leakage maintenance of adhesive flexible rubber asphalt series」, which are standardized as a quality control method of injection type repair materials used for water leakage cracks in underground concrete structures, are currently used in Korea. As a result, considering the performance criteria of "mass change rate -0.1%" stipulated in KS F 4935, the remaining 13 types repair materials, excluding RG-2 of synthetic rubber and UG-1 of urethane, need to be reviewed for stabilization of the loss resistance due to the flow of ground water. The results of this study are determined to be available as a basic indicator for the selection of repair materials used for cracks in concrete structures. In addition, it is expected that the results of this study can be utilized as reference data that can be reflected in the improvement of the quality of repair materials that will be researched and developed later.

Engineering Properties of CB Cut-off Walls Mixed with GGBS (고로슬래그 미분말을 혼합한 CB 차수벽의 공학적 특성)

  • Kim, Taeyeon;Lee, Bongjik
    • Journal of the Korean GEO-environmental Society
    • /
    • v.23 no.5
    • /
    • pp.33-39
    • /
    • 2022
  • For a slag-cement-bentonite (slag-CB) cut-off wall, GGBS replaces a part of the cement mixed to build a CB cut-off wall, which is used to block the flow and leakage of pollutants or groundwater; prevent seawater infiltration; and repair or reinforcement an aged embankments. Slag-CB cut-off walls are used in various applications in different fields where groundwater control is required due to its excellent characteristics. Such properties include high strength, low permeability, high durability and chemical resistance. However, despite these advantages, slag-CB cut-off walls are not extensively studied in Korea and thus are not applied in many cases. Particularly, GGBS, which replaces cement in a mixture, has different properties depending on its country of production. Consequently, it is necessary to perform various studies on slag-CB cut-off walls that use GGBS produced in Korea in order to increase its usability. This study has evaluated the bleeding rate, setting time, strength, and permeability in relation to the cement replacement rate of GGBS produced in Korea for slag-CB cut-off walls, with the aim to increase its usability. The evaluation found that slag-CB cut-off walls, made of a mixture containing GGBS produced in Korea, have a lower bleeding rate and permeability, and higher strengththan CB cut-off walls. It was also analyzed that such improved performance is more effective with a higher cement replacement rate of GGBS.

Characterization and Phenolic Compound Analysis of Cheorwon Onion by Lime-sulphur Mixture Treatment (석회유황합제 처리에 따른 철원 양파의 생육특성 및 페놀화합물 분석)

  • Kim, Y.B.;Lee, H.J.;Kim, D.H.;Koo, H.J.;Chang, K.J.
    • Journal of Practical Agriculture & Fisheries Research
    • /
    • v.22 no.1
    • /
    • pp.15-25
    • /
    • 2020
  • The aim of this study was to evaluate the change of phenolic compounds after lime-sulphur mixture treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is cultivated much in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. After the treatment with lime-sulphur mixture, the weight, width and plant height of the onion were not affected. In the phenolic compounds, caffeic acid, ferulic acid, rutin, p-coumaric acid and kaempferol except benzoic acid and quercetin were similar to or less than the control. Therefore, it was concluded that the treatment with lime-sulphur mixture had some effect on phenolic compound contents, benzoic acid and qurercetin.

Restorative effects of Rg3-enriched Korean Red Ginseng and Persicaria tinctoria extract on oxazolone-induced ulcerative colitis in mice

  • Ullah, H.M. Arif;Saba, Evelyn;Lee, Yuan Yee;Hong, Seung-Bok;Hyun, Sun-Hee;Kwak, Yi-Seong;Park, Chae-Kyu;Kim, Sung Dae;Rhee, Man Hee
    • Journal of Ginseng Research
    • /
    • v.46 no.5
    • /
    • pp.628-635
    • /
    • 2022
  • Background: Ulcerative colitis (UC) is the large intestine disease that results in chronic inflammation and ulcers in the colon. Rg3-enriched Korean Red Ginseng extract (Rg3-RGE) is known for its pharmacological activities. Persicaria tinctoria (PT) is also used in the treatment of various inflammatory diseases. The aim of this study is to investigate the attenuating effects of Rg3-RGE with PT on oxazolone (OXA)-induced UC in mice. Methods: A total of six groups of mice including control group, OXA (as model group, 1.5%) group, sulfasalazine (75 mg/kg) group, Rg3-RGE (20 mg/kg) group, PT (300 mg/kg) group, and Rg3-RGE (10 mg/kg) with PT (150 mg/kg) group. Data on the colon length, body weight, disease activity index (DAI), histological changes, nitric oxide (NO) assay, Real-time PCR of inflammatory factors, ELISA of inflammatory factors, Western blot, and flow cytometry analysis were obtained. Results: Overall, the combination treatment of Rg3-RGE and PT significantly improved the colon length and body weight and decreased the DAI in mice compared with the treatment with OXA. Additionally, the histological injury was also reduced by the combination treatment. Moreover, the NO production level and inflammatory mediators and cytokines were significantly downregulated in the Rg3-RGE with the PT group compared with the model group. Also, NLR family pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa B (NF-𝛋B) were suppressed in the combination treatment group compared with the OXA group. Furthermore, the number of immune cell subtypes of CD4+ T-helper cells, CD19+ B-cells, and CD4+ and CD25+ regulatory T-cells (Tregs) was improved in the Rg3-RGE with the PT group compared with the OXA group. Conclusion: Overall, the mixture of Rg3-RGE and PT is an effective therapeutic treatment for UC.

Numerical study on the foam spraying for AFDSS applicable to initial fire suppression in large underground spaces (지하대공간 초동 화재진압에 적용가능한 자율형 소화체계의 폼 분사 해석 기법 연구)

  • Park, Jinouk;Yoo, Yongho;Kim, Whiseong
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.23 no.6
    • /
    • pp.503-516
    • /
    • 2021
  • Autonomous fire detection and suppression system requires advanced technology for complex detection technology and injection/control technology for accurate hitting by fire location. Also, foam spraying should be included to respond to oil fires. However, when a single spray monitor is used in common, water and foam spray properties appear different, so for accurate fire suppression, research on the spray trajectory and distance will be required. In this study, experimental studies and numerical analysis studies were combined to analyze the foam spray characteristics through the spray monitor developed for the establishment of an autonomous fire extinguishing system. For flow analysis of foam injection, modeling was performed using OpenFOAM analysis software, and the commonly used foaming agent (Aqueous Film-Forming Foam) was applied for foam properties. The injection distance analysis was performed according to the injection pressure and the injection angle according to the form of the foam, and at the same time, the results were verified and presented through the injection experiment.

433 MHz Radio Frequency and 2G based Smart Irrigation Monitoring System (433 MHz 무선주파수와 2G 통신 기반의 스마트 관개 모니터링 시스템)

  • Manongi, Frank Andrew;Ahn, Sung-Hoon
    • Journal of Appropriate Technology
    • /
    • v.6 no.2
    • /
    • pp.136-145
    • /
    • 2020
  • Agriculture is the backbone of the economy of most developing countries. In these countries, agriculture or farming is mostly done manually with little integration of machinery, intelligent systems and data monitoring. Irrigation is an essential process that directly influences crop production. The fluctuating amount of rainfall per year has led to the adoption of irrigation systems in most farms. The absence of smart sensors, monitoring methods and control, has led to low harvests and draining water sources. In this research paper, we introduce a 433 MHz Radio Frequency and 2G based Smart Irrigation Meter System and a water prepayment system for rural areas of Tanzania with no reliable internet coverage. Specifically, Ngurudoto area in Arusha region where it will be used as a case study for data collection. The proposed system is hybrid, comprising of both weather data (evapotranspiration) and soil moisture data. The architecture of the system has on-site weather measurement controllers, soil moisture sensors buried on the ground, water flow sensors, a solenoid valve, and a prepayment system. To achieve high precision in linear and nonlinear regression and to improve classification and prediction, this work cascades a Dynamic Regression Algorithm and Naïve Bayes algorithm.

Discordance between Morphological and Molecular Variations of the Genus Macroramphosus (Macroramphosidae) from Korea (한국산 대주둥치속(대주둥치과) 어류의 형태와 분자 변이의 불일치)

  • Sohn, Min-Soo;Kim, Jin-Koo
    • Korean Journal of Ichthyology
    • /
    • v.32 no.4
    • /
    • pp.199-209
    • /
    • 2020
  • In order to clarify the taxonomic status of the Korean Macroramphosus species, which were previously confused, we investigated morphological and molecular variations of Macroramphosus (18 individuals) from Korea, and Macroramphosus (35 individuals) from Japan and Taiwan, and compared with those of M. scolopax from type locality (Mediterranean Sea). Although the Korean and Japanese specimens of Macroramphosus were clearly divided into two types in the first dorsal spine length (22.8~32.1% in A-type vs. 15.6~21.4% in B-type), distance between the first dorsal fin and second dorsal fin (6.4~9.7% vs. 8.6~13.3%), and body depth (20.0~28.0% vs. 17.3~22.6%), no genetic differences among all individuals of longspine snipefish between them were found at the specific level [d=0.0~3.3% in control region (CR); 0.0~1.3% in cytochrome b (cytb); 0.0~0.5% in cytochrome c oxidase subunit I (COI)]. Whereas, they were well distinguished in genetics (9.9~11.5% in CR; 3.8~4.6% in cytb; 1.2~3.6% in COI) from those of M. scolopax in Mediterranean Sea. It needs the scientific name of the longspine snipefish (M. scolopax) in Korea be changed as M. japonicus (and/or M. sagifue). However, our results could not find evidence of consistency between morphological and mitochondrial DNA variations which suggests that their differentiation event may occur fairly recently. Further studies using more sensitive markers such as microsatellite are needed to clarify the degree of gene flow between the two types.