• Title/Summary/Keyword: $CV^2$

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Elucidation of Electrode Reaction of EuCl3 in LiCl-KCl Eutectic Melts through CV Curve Analysis

  • Kim, Tack-Jin;Jung, Yong-Ju;Kim, Si-Hyung;Paek, Seung-Woo;Ahn, Do-Hee
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.863-866
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    • 2011
  • The electrode reaction of $Eu^{3+}$ in a LiCl-KCl eutectic melt has been re-examined using cyclic voltammetry (CV). In this work, for the first time, the kinetic details of a $Eu^{3+}/Eu^{2+}$ redox system have been completely elucidated, along with the thermodynamic property, through a curve fitting applied to experimental CV data, which were obtained in a wide scan rate range of 0.5 to 10 V/s. The simulated results showed an excellent fit to all experimental CV data simultaneously, even though the curve fittings were performed within a large dynamic range of initial transfer coefficient values, formal potentials, and standard rate constants. As a result, a proper formal potential, transfer coefficient, and standard rate constant for the $Eu^{3+}/Eu^{2+}$ redox system were successfully extracted using the CV curve fitting.

Adsorptive Behavior of Catechol Violet and Its Thorium Complex on Mercury Electrode in Aqueous Media

  • Rabia Mostafa K. M.
    • Journal of the Korean Electrochemical Society
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    • v.7 no.1
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    • pp.9-15
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    • 2004
  • Cyclic voltammetry and chronocoulometry have been used for characterization of catechol violet (CV) at the hanging mercury drop electrode in acetic acid-sodium acetate buffer solution. At pH 2.94 a nearly symmetric cyclic voltammetric wave due to an irreversible weak adsorption of CV on mercury was obtained at concentration of $0.53{\mu}mol\;dm ^{-3}$. Under these conditions, CV adsorbes in a monolayer. Upon increasing the concentration, the symmetry of the wave decreases; it can be attributed to a mixed diffusion adsorption process. The amount of the adsorbed catechol violet on the HMDE expressed as surface concentration as well as the surface areaf occupied by one molecule$(\sigma)$ were calculated. It was found that the values obtained for f and o utilizing cyclic voltammetric and chrono-coulometry are almost identical. A 1:1 and 1:2 Th (IV)-CV complexes are formed on addition of thorium (IV) to catechol violet. These complexes are adsorbed and reduced on the HMDE at more negative potentials than the peak potential of free CV, Using the square-wave (SW) technique, the adsorptive cathodic stripping voltammetry, ACSV, of these complexes was studied. It was found that the SW-ACSV of Th(IV)-CV can be applied to the determination of thorium at the nanomole level. Optimum conditions and the analytical method of determination were presented and discussed.

Occurrence Pattern of Insect Pests on Several Varieties of Potato (감자 품종별 해충 발생 양상)

  • Kwon, Min;Park, Chun-Soo;Hahm, Young-Il
    • Korean journal of applied entomology
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    • v.36 no.2
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    • pp.145-149
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    • 1997
  • Occurrence pattern of major insect pests on 7 recommended potato cultivars in Korea was investigated from sowing to harvesting time at Kangneung and Daegwallyung experiment fields in 1996. Green peach aphid (Mym persicae Sulzer), potato aphid (Macrosiphum euphorbiae Thomas) and beet armyworm (Spodoptera enigua Hubner) were the major insect pests on potato leaves, and wireworm (Selatosomus puncticollis Mot.) was the major pest on tubers. There was a slight difference of average number of aphids per 50 leaves among cultivars; ranged from 22.7 on cv. Dejima to 46.3 on cv. Superior. Numbers of leaves damaged by beet armyworm larvae on cv. Shepody and cv. Jopung were 11.0 and 14.3, and these cultivars are thought to be resistant against the larvae infestation. However, degree of damage on cv. Dejima and cv. Namsuh was higher 10 times than cv. Shepody and cv. Jopung. In wireworm, the percentage of damaged tubers on cv. Irish Cobbler was lowest of 8.1%, and followed by cv. Superior, cv. Dejima, cv. Jopung, and cv. Atlantic. Whereas, those on cv. Namsuh and cv. Shepody were significantly high of 50.0% and 46.8%.

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Synthesis and Properties of Amphiphilic Polymers Containing Silicone (실리콘을 함유한 양친성 중합체의 합성 및 성질)

  • Yoon, Koo Sik;Sung, Yong Kiel;Kim, Sung Wan
    • Journal of the Korean Chemical Society
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    • v.39 no.1
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    • pp.76-80
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    • 1995
  • Polydimethylsiloxane(PDMS)-co-poly(2-hydroxyethyl methacrylate)(PHEMA) was prepared and the degree of swelling of solvents into the polymers was examined. It was confirmed that the solubility parameter of PHEMA homopolymer is 26 (J/cm3)1/2. Ethanol was significantly absorbed into copolymers containing large amount of PHEMA, while tetrahydrofuran was effectively absorbed into copolymers containing large amount of PDMS. Absorption of polar solvents into the copolymers were increased with the increase of PDMS content. The model drug, crystal violet (CV), was more absorbable into PDMS-HPEMA copolymers than PHEMA homopolymer. Absorption of CV was decreased with the increase of PDMS content of the copolymers.

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Optimal Structures of a Neural Network Based on OpenCV for a Golf Ball Recognition (골프공 인식을 위한 OpenCV 기반 신경망 최적화 구조)

  • Kim, Kang-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.2
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    • pp.267-274
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    • 2015
  • In this paper the optimal structure of a neural network based on OpenCV for a golf ball recognition and the intensity of ROI(Region Of Interest) are calculated. The system is composed of preprocess, image processing and machine learning, and a learning model is obtained by multi-layer perceptron using the inputs of 7 Hu's invariant moments, box ration extracted by vertical and horizontal length or ${\pi}$ calculated by area of ROI. Simulation results show that optimal numbers of hidden layer and the node of neuron are selected to 2 and 9 respectively considering the recognition rate and running time, and optimal intensity of ROI is selected to 200.

Anti-Oxidative and Anti-Proliferative Effect of 70% Ethanol Extracts from Green Pepper (Capsicum annuum L. cv. DangZo) (당조고추 70% 에탄올추출물의 항산화 및 항암활성측정)

  • Lee, Youn Ri
    • The Korean Journal of Food And Nutrition
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    • v.30 no.5
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    • pp.1127-1131
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    • 2017
  • To evaluate the anti-oxidant and anti-tumor potential of the green pepper (Capsicum annuum L. cv. DangZo), total polyphenol content, radical scavenging activities and anti-tumor properties were measured. The total polyphenol content of the 70% ethanol extracts from green pepper (Capsicum annuum L. cv. DangZo) was 30.29 mg gallic acid equivalent/g extract. The DPPH radical and hydroxyl radical scavenging activities of 70% ethanol extracts of green pepper (Capsicum annuum L. cv. DangZo) were documented at 2.87 and 10.55, respectively. For ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory activity, 70% ethanol extracts of green pepper (Capsicum annuum L. cv. DangZo) were documented at 35.67% and 58.41% respectively. The green pepper (Capsicum annuum L. cv. DangZo) demonstrated greater capability in terms of anti-neoplastic activity vis-a-vis colon cancer cell lines when compared to other cancer cell lines.s. er (Capsicum annuum L. cv. DangZo) higher activities of anticancer activities on colon cancer cell lines compared to other cancer cell lines.

Characterization of Acetobacter sp. Strain CV1 Isolated from a Fermented Vinegar (고산도 생성 초산균의 분리 및 발효특성)

  • Baek, Chang-ho;Baek, Seong-yeol;Lee, Se Hee;Kang, Ji-Eun;Choi, Han-Seok;Kim, Jae-Hyun;Yeo, Soo-Hwan
    • Microbiology and Biotechnology Letters
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    • v.43 no.2
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    • pp.126-133
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    • 2015
  • Ten types of farm-made brewing vinegars were collected and four high acetic acid-producing strains (CV1, CV3, CV5, and CV6) were isolated. Among them strain CV1, exhibiting highly alcohol-resistant and acetic acid-producing properties, was selected and its taxonomic properties were investigated by phenotypic (particularly chemotaxonomic) characterization and phylogenetic inference based on 16S rRNA gene sequence analysis. On SM broth agar, cells of strain CV1 were gram-stainingnegative and formed pale white colonies with smooth to rough surfaces. Strain CV1 produced acetate from ethanol and was resistant to up to 8% (v/v) ethanol in LM broth. Strain CV1 had a G+C content of 61.0 mol%, contained meso-DAP as the cell wall amino acid, and possessed Q-10 as the major ubiquinone. A comparison of 16S rRNA gene sequences showed that strain CV1 was most closely related to Gluconacetobacter saccharivorans (≥99.0% identity). In liquid media, the optimum growth conditions for acetic acid production were 30℃ and pH >3.0 and strain CV1 produced 9.3% and 8.4% acetic acids from 10% and 9% alcohol concentrations, respectively.

Effect of Location, Year and Variety on Winter Cereal Forage Yield and Quality in the Southern Plateau of the Spain

  • Otal, J.;Quiles, A.;Quiles, A.;Perez-Sempere, J.I.;Ramirez, A.;Fuentes, F.;Hevia, M.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.10
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    • pp.1416-1424
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    • 2008
  • The objective of this research was to study the production and quality of forage at three different times of the year (April, June and July) of six winter cereals in the southern plateau of the Iberian Peninsula. The cereals studied were Triticale (xTriticosecale wittm) cv. "Tritano", Oat (Avena sativa L.) cv. "Prevision" and cv. "Saia; Rye (Secale cereale L.) cv. "Giganton", Barley (Hordeum vulgare L.) cv. "Cameo" and cv. "Albacete". The study was carried out in three different locations and over three successive years of harvesting. The three variables considered were location, year and cereal. The % dry matter (DM), % crude protein (CP), % acid detergent fiber (ADF), % neutral detergent fiber (NDF) and % ash content were determined for the three sampling periods and the quality was calculated in milk forage units (MFU/kg DM), the production in kg DM/ha, MFU/ha and kg CP/ha. In all three sampling periods the quality of the cereals was significantly influenced only by the year and by species. However, for production of dry matter (kg DM/ha), milk forage units (MFU/ha) and gross protein (kg CP/ha) all three variables were of significant influence as were their interactions. In the April sampling, the species which showed a significantly higher production ($p{\leq}0.05$) was rye (1,693 kg DM/ha), which, along with its forage quality (16.56% CP, 0.886 MFU/kg DM) meant that the same occurred in MFU/ha and kg CP/ha. Significant differences between species were also found for the June sampling. The most productive cereal was again rye with 2,656 kg DM/ha, although its sharp fall in forage quality meant that barley cv Albacete (2,513 kg DM/ha) returned the highest production in forage units (1,934 vs. 1,951 MFU/ha) and barley cv. Cameo (2,413 kg DM/ha) in gross protein production (242 vs. 264 kg CP/ha). The significantly highest cereal production for July was barley cv. Albacete (4,923 kg DM/ha, 9.11% CP 0.722 MFU/kg DM). As a consequence of the results, we conclude that from the viewpoint of nutritional quality and production, rye is the most suitable for use in early spring in whatever year and location. However, barley cv. "Albacete" is the most appropriate for utilisation in later spring or early summer.

Calculation of the Least Significant Change Value of Bone Densitometry Using a Dual-Energy X-ray Absorptiometry System

  • Han-Kyung Seo;Do-Cheol Choi;Cheol-Min Shim;Jin-Hyeong Jo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.27 no.2
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    • pp.95-98
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    • 2023
  • Purpose: The precision error of a bone density meter reflects the equipment and reproducibility of results by an examiner. Precision error values can be expressed as coefficient of variation (CV), CV%, and root mean square-SD (RMS-SD). The International Society for Clinical Densitometry (ISCD) currently recommends using RMS-SD as the precision error value. When a 95% confidence interval is applied, the least significant change (LSC) value is calculated by multiplying the precision error value by 2.77. Exceeding the LSC value reflects a significant difference in measured bone density. Therefore, the LSC value of a bone density equipment is an essential factor for accurately determining a patient's bone density. Accordingly, we aimed to calculate the LSC value of a bone density meter (Lunar iDXA, GE) and compare it with the value recommended by the ISCD. We also assessed whether the value measured by the iDXA equipment was below the LSC value recommended by ISCD. Material and Methods: The bone densities of the lumbar spine and thighs of 30 participants were measured twice, and the LSC values were calculated using the precision calculation tool provided by the ISCD (http://www.iscd.org). To check the reproducibility of the measurement, patients were asked to completely dismount from the equipment after the first measurement; the patient was then repositioned before proceeding with the second measurement. Results: The LSC values derived using the CV% values recommended by the ISCD were 5.3% for the lumbar spine and 5.0% for the thigh. The LSC values measured using our bone density equipment were 2.47% for the lumbar spine and 1.61% for the thigh. The LSC value using RMS-SD was 0.031 g/cm2 for the lumbar spine and 0.017 g/cm2 for the thigh. Conclusion: that the findings confirm that the CV% value measured using our bone density meter and the LSC value using RMS-SD were maintained very stably. This can be helpful for obtaining accurate measurements during bone density follow-up examinations.

Hydroacoustic survey on distribution and density of fisheries resources in the Marado coastal area of Jeju, Korea (제주도 마라도 연안해역의 어업생물자원에 대한 분포밀도의 음향학적 조사)

  • SEO, Young-Il;OH, Taeg-Yun;CHA, Hyung-Kee;LEE, Kyounghoon;YOON, Eun-A;HWANG, Bo-Kyu;LEE, Yoo-Won;KIM, Byung-Yeob
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.3
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    • pp.209-219
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    • 2016
  • The survey was conducted to investigate biomass and distribution of fisheries resources using a quantitative echo sounder and a fixed gillnet around Marado coast of Jeju to obtain the scientific basic data for dispute resolution with a large purse seine fishery and coastal fishing and policy establishment of reasonable fisheries resources. Hydroacoustic surveys were conducted six times (November 28~29, 2015 (night), February 23~24, 2016 (night) and March 3~4, 2016 (night/day), March 30~31, 2016 (night/day)) using a quantitative echo sounder. The pelagic fish densities were relatively higher around Marado in November 2015, February 2016 and March 3~4, 2016. However, demersal fish densities were relatively higher in Jeju coastal waters on March 30~31, 2016. Catch data using fixed gill net were used to calculate biomass. Based on the hydroacoustic data, fish length-weight function and target strength information of dominant fish, the biomass of fishes were estimated as follow: 5.64 ton CV = 70.2% at night on November 28-29 2015, 7.14 ton CV = 35.8% of pelagic fish and 530.77 ton CV = 34.6% of demersal fishes at night on February 23-24 2016, 2.34 ton CV = 56.7% of pelagic fish and 571.93 ton CV = 40.3% of demersal fish at daytime, 1.39 ton CV = 48.4% of pelagic fish and 194.59 ton CV = 54.3% of demersal fish at night on March 3~4 2016, 0.37 ton CV = 72.9% of pelagic fish and 338.79 ton CV = 99.7% of demersal fish at daytime, 0.24 ton CV = 21.3% of pelagic fish and 68.61 ton CV = 53.8% of demersal fish at night on March 30~31 2016.