• Title/Summary/Keyword: Self-reaction

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Behavioral reaction of hairtail (Trichinus lepturus) to different colors of LED light (LED 색광에 대한 갈치의 행동반응)

  • KIM, Mun-Kwan;AN, Young-Il;PARK, Su-Hyeon;OH, Tae-Cheol;KANG, Hyeong-Cheol;PARK, Yong-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.3
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    • pp.183-190
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    • 2016
  • This study carried out an experiment to find out the reaction of hairtail, Trichinus lepturus to the colors of LED light as a basic study on the development of the trolling gear and a method to enable the day-night operation. We used hairtails caught around Seongsan-po, Jeju Island by set nets and hairtail angling. The seven hairtails of the average length 68.9 cm (SD 9.2 cm) and the average weight 135.9 g (SD 47.9 g) were adapted themselves in the experimental water tank, 15 m Self-Governing 1.7 m in height and 1.5 m in depth, and then they were studied. We conducted experiment at the Ocean and Fisheries Research Institute in Jeju Special Self-Governing Province, from November to December 2015, and the sea surface temperature was between 16.5 and $19.5^{\circ}C$. The four colors of LED light, blue, white, green and red, were set up to transmit downward from the marginal area of tank. The 1 meter depth light intensity of LED colors is as follows: $0.09w/m^2/s$ (blue), $0.18w/m^2/s$ (white), $0.04w/m^2/s$ (green) and $0.007w/m^2/s$(red) To know the optimum LED color light, we selected one with better reaction rate after comparison of two colors simultaneously and the selected color was again compared to the other color in a tournament style two times a day (day and night) and ten times totally. The reaction rates were shown as the frequencies of hairtail appearance for 5 minutes in the lighting zone after turning on the LED lights. The reaction rate of the blue was at 97% unlike the red 3% (p < 0.001). The blue was at 75% unlike the green at 25% (p < 0.001). The blue was at 67% unlike the white at 33% (p < 0.001). Therefore, the color of light source showing the highest reaction rate was the blue.

NUMERICAL APPROACH FOR QUANTIFICATION OF SELFWASTAGE PHENOMENA IN SODIUM-COOLED FAST REACTOR

  • JANG, SUNGHYON;TAKATA, TAKASHI;YAMAGUCHI, AKIRA;UCHIBORI, AKIHIRO;KURIHARA, AKIKAZU;OHSHIMA, HIROYUKI
    • Nuclear Engineering and Technology
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    • v.47 no.6
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    • pp.700-711
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    • 2015
  • Sodium-cooled fast breeder reactors use liquid sodium as a moderator and coolant to transfer heat from the reactor core. The main hazard associated with sodium is its rapid reaction with water. Sodium-water reaction (SWR) takes place when water or vapor leak into the sodium side through a crack on a heat-transfer tube in a steam generator. If the SWR continues for some time, the SWR will damage the surface of the defective area, causing it to enlarge. This self-enlargement of the crack is called "self-wastage phenomena." A stepwise numerical evaluation model of the self-wastage phenomena was devised using a computational code of multicomponent multiphase flow involving a sodium-water chemical reaction: sodiumwater reaction analysis physics of interdisciplinary multiphase flow (SERAPHIM). The temperature of gas mixture and the concentration of NaOH at the surface of the tube wall are obtained by a numerical calculation using SERAPHIM. Averaged thermophysical properties are used to assess the local wastage depth at the tube surface. By reflecting the wastage depth to the computational grid, the self-wastage phenomena are evaluated. A two-dimensional benchmark analysis of an SWAT (Sodium-Water reAction Test rig) experiment is carried out to evaluate the feasibility of the numerical model. Numerical results show that the geometry and scale of enlarged cracks show good agreement with the experimental result. Enlarged cracks appear to taper inward to a significantly smaller opening on the inside of the tube wall. The enlarged outer diameter of the crack is 4.72 mm, which shows good agreement with the experimental data (4.96 mm).

Synthesis Characteristics of ZnO Powder from Precursors Composed of Nitrate-Citrate Compounds (Nitrate-Citrate 혼합 전구체로부터 ZnO 입자의 합성반응 특성)

  • Yang, Si Woo;Lee, Seung Ho;Lim, Dae Ho;Yoo, Dong Jun;Kang, Yong
    • Korean Chemical Engineering Research
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    • v.54 no.3
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    • pp.299-304
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    • 2016
  • Characteristics of self-propagating reaction for the preparation of ZnO powder from precursors composed of nitrate and citrate compounds were examined. The ratio of C/N was maintained in range of 0.7~0.8 to initiate the self-propagating reaction between the reducing citrate and oxidizing nitrate groups. The samples were decomposed thermally by using TGA. The sudden decomposition occurred in the range of X > 0.5 in a very short time with a very sharp decrease of mass, indicating that the self-propagating reaction would occur. Friedman, Ozawa-Flynn-Wall and Vyazovkin methods were employed to predict the activation energy, reaction order and frequency factor of the reaction rate in the rate determining step of X < 0.5 range. The activation energy increased with increasing fractional conversion in the range of 46~130 (kJ/min). The reaction order decreased in the range of 2.9~0.9, while the frequency factor increased in the range of 85~278 ($min^{-1}$), respectively, with increasing the rate of temperature increase.

Effect of Gelling Agent Molecular Weight on Self-Discharge Behavior for Zinc-Air Batteries (아연-공기 전지용 전해질의 Gelling Agent 분자량에 따른 자가 방전 억제 효과)

  • Park, Jeong Eun;Jo, Yong Nam
    • Korean Journal of Materials Research
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    • v.29 no.12
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    • pp.812-817
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    • 2019
  • A zinc-air battery is one of most promising advanced batteries due to its high specific energy density, low cost, and environmental friendliness. However, zinc anodes in zinc-air batteries lead to several issues including self-discharge, corrosion reaction, and hydrogen evolution reaction (HER). In this paper, viscosity of electrolyte has been controlled to suppress the corrosion reaction, HER, and self-discharge behavior. Various viscosity average molecular weights of poly(acrylic acid) (PAA) are adopted to prepare the electrolyte. The evaporation of electrolytes is proportional to the increase in molecular weight. In addition, enhanced self-discharge behavior is obtained when the gelling agent with high molecular weight is used. In addition, the zinc-air cell assembled with lower viscosity average molecular weight of PAA (Mv ~ 450,000) delivers 510.85 mAh/g and 489.30 mAh/g of discharge capacity without storage and with 6 hr storage, respectively. Also, highest capacity retention (95.78 %) is obtained among studied materials.

A Grounded Theory Approach to the Comfort Experience of Hospitalized Patients (입원대상자의 안위경험에 대한 근거이론적 접근)

  • 김경희;김금순;강규숙;강현숙;김원옥;백훈정;원종순;임난영;정인숙
    • Journal of Korean Academy of Nursing
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    • v.30 no.3
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    • pp.750-763
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    • 2000
  • This study is based on grounded theory methodology by Strauss & Corbin(1998). Ten hospitalized subjects were interviewed for data collection. In the process of data analysis, 'acceptance' is found to be the causal condition, while 'health professionals' skillfulness', 'ward environment', 'history of hospitalization', and 'general conditions' were identified as context, 'felling of relief' as the core phenomenon, 'self-efficacy', 'support of others', and 'life style' as the intermediate situation, 'passive reaction', 'alternative reaction' and 'active reaction' as the strategy and 'stabilization', 'satisfaction', 'hope' and 'carrying out' as consequences. 'Feeling of relief' is found to go through the three stages of recognition-generation-maintenance after the five different patterns. 1) In case the health professionals are skillful, the ward environment is favorable, the general conditions of the patients improved and as a result the feeling of relief is strong, during the first hospitalization, the self-efficacy of the subjects tends to be strong. They proceed toward the goal set for themselves with a renewed hope and active or alternative reaction toward the feeling of relief. 2) The subjects tend to proceed toward the goal set for themselves with a renewed hope and active and alternative reaction toward the feeling of relief in case health professionals are skillful, the ward environment is favorable the general conditions of the subjects improved, self-efficacy is strong, and lifestyle is autonomous, during the second hospitalization even though support of others is merely superficial. 3) The subjects tend to stabilize, and satisfy themselves with the given situation with passive and alternative reaction to the feeling of relief in case health professionals are skillful and the ward environment is favorable but the general conditions worsened and accordingly the feeling of relief, is weak and life style is dependent during the second hospitalization although the subjects' self-efficacy is strong and support of others is specific. 4) The subjects tend to stabilize and satisfy themselves with the given situation with passive and alternative reaction to the feeling of relief in case health professionals are unskillful the ward environment is unfavorable, the general conditions improved, support of others is specific but life style is dependent and self-efficacy is weak during the first hospitalization. 5) The subjects tend to stabilize and satisfy themselves with the given situation in case health professionals are unskillful the ward environment is unfavorable but the general conditions improved support of others is specific and as a result self-efficacy is strong but life style is dependent.

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SHS of Oxide Systems Based on MCR of Quartz Modified by Organometallic Compounds

  • Soh, Dea-Wha;Tlek, Ketegenov;Z.A., Mansurov
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.666-669
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    • 2002
  • The differences of the effects of mechanical substance pre-activation in the mills with divers force effect schemes on the self-propagating high temperature synthesis (SHS) of the $SiO_2$ + 37.5% Al system were investigated. The power saturation of activated material state are estimated referring on the variations of dilatometry curve paths. The effects of activation time on the temperature of sample self-ignited in the furnace, combustion temperature and completeness of the quartz reaction with aluminium were determined. The enhancing effects of organic modifiers of quartz particle surfaces on the further SHS synthesis development were shown.

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Reduction Behavior of Self-Reducing Pellets of Chromite and Si Sludge with and without Carbon

  • Jung, Woo-Gwang;Hossain, Sakib Tanvir;Kim, Jong-Ho;Chang, Young-Chul
    • Korean Journal of Materials Research
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    • v.29 no.10
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    • pp.592-602
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    • 2019
  • Feasibility is investigated for reduction of chromium ore by Si sludge with mixed silicothermic and carbothermic reaction. The reduction behavior of chromium ore using Si sludge is investigated precisely to determine the effects of carbon addition, reaction time, and reaction temperature. The pellets are dropped into the furnace after temperature stabilized. As the amount of C addition increases, the amounts of CO and $CO_2$ gas generation increase. After the dropping of the pellets, the pellets are heated and the reaction starts at about 1,573 K or higher. The pellets maintain their shape until 10 min after the drop, and then melted. As the holding time increased, the size of the reduced metal particles increased. The chromium ore is rapidly reduced by the Si sludge, and the slag penetrated into the chromium ore and reduction progressed inside. As the reduction temperature increased, the reaction initiation time is shortened and the reaction fraction of the reduction reaction increased. As the reaction temperature increased, agglomeration of reduced ferrochrome metal is promoted.

Perceptions of the Self-regulation in Patients with Diabetes Mellitus

  • Han, Hye-Sook;Bae, Sun-Hee;Park, Young-Sun
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.4
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    • pp.169-179
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    • 2021
  • The purpose of this study is to examine types and characteristics of self-regulation which explain how individual diabetic patients determine their behavior in terms of diabetes management. Based on the results, we proposed the management method of the diabetic patients. As a method of analyzing the subjectivity of each item, a Q method study was used. There were 38 subjects who were treated with oral drugs or insulin injections, but not currently hospitalized. And 40 statements in Q samples were classified in the form of a normal distribution using a 9-point scale. Research results regarding self-regulation in diabetic patients, type 1 is evidence-based compliance, type 2 is crisis responding denial reaction, type 3 is information-based orientation to relationship, type 4 is independent practice, and type 5 is willingness deficit impulse reaction. Therefore, for effective management of diabetic patients, it is necessary to understand the characteristics of each type of self-regulation and develop a program that reflects motivation for diabetes management, improvement of confidence, and countermeasures for negative emotions related to disease.

Effect of Acid Leaching Conditions on the Properties of Cr Powder Produced by Self-propagating High-temperature Synthesis (자전연소합성법을 이용한 Cr 분말 제조시 산세조건에 따른 물성평가)

  • YongKwan Lee;YeongWoo Cho;ShinYoung Choi;SungGue Heo;Ju Won;KyoungTae Park;MiHye Lee;JaeJin Sim
    • Journal of Powder Materials
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    • v.30 no.3
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    • pp.233-241
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    • 2023
  • In this study, we evaluated the effects of acid leaching on the properties of Cr powder synthesized using self-propagating high-temperature synthesis (SHS). Cr powder was synthesized from a mixture of Cr2O3 and magnesium (Mg) powders using the SHS Process, and the byproducts after the reaction were removed using acid leaching. The properties of the recovered Cr powder were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), particle size analysis (PSA), and oxygen content analysis. The results show that perfect selective leaching of Cr is challenging because of various factors such as incomplete reaction, reaction kinetics, the presence of impurities, and incompatibility between the acid and metal mixture. Therefore, this study provides essential information on the properties under acidic conditions during the production of high-quality Cr powder using a self-propagating high-temperature synthesis method.

A reaction-diffusion modeling of carbonation process in self-compacting concrete

  • Fu, Chuanqing;Ye, Hailong;Jin, Xianyu;Jin, Nanguo;Gong, Lingli
    • Computers and Concrete
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    • v.15 no.5
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    • pp.847-864
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    • 2015
  • In this paper, a reaction-diffusion model of carbonation process in self-compacting concrete (SCC) was realized with a consideration of multi-field couplings. Various effects from environmental conditions, e.g. ambient temperature, relative humidity, carbonation reaction, were incorporated into a numerical simulation proposed by ANSYS. In addition, the carbonation process of SCC was experimentally investigated and compared with a conventionally vibrated concrete (CVC). It is found that SCC has a higher carbonation resistance than CVC with a comparable compressive strength. The numerical solution analysis agrees well with the test results, indicating that the proposed model is appropriate to calculate and predict the carbonation process in SCC. The parameters sensitivity analysis also shows that the carbon dioxide diffusion coefficient and moisture field are essentially crucial to the carbonation process in SCC.