• Title/Summary/Keyword: stripping

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A Study on in-situ Electrolytic Stripping of a Metal Ion by Using a Highly Packed Glassy Carbon Fiber Column Electrode System (고밀집 Glassy Carbon 섬유 다발체 전극 전해계를 이용한 금속 이온의 in-situ 전해 역추출 특성 연구)

  • Kim, Kwang-Wook;Kim, Young-Hwan;Lee, Eil-Hee;Yoo, Jae-Hyung
    • Applied Chemistry for Engineering
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    • v.9 no.4
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    • pp.475-480
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    • 1998
  • A study on the electrochemical reduction of uranium (VI) to uranium (IV) was carried out in the mixed phases of an organic phase with uranium (VI) and aqueous phase of nitric acid by use of a highly packed glassy carbon (GC) fiber column electrode system, and a model for in-situ electrolytic stripping of uranium (VI) was suggested. The electrochemical reduction of uranium (VI) occurred faster in organic phase than in aqueous phase of the mixed phases. The uranium stripping yield increased and then became constant with the increase of organic flow rate of the electrolytic system due to the increase of diffusion resistance of uranium ions in the organic phase into the aqueous phase. Aqueous flow rate, on the other hand, didn't affect the total uranium (VI) reduction current in the system. The system combined with electrochemical reduction was confirmed to be much more effective than the simple system without it in stripping uranium.

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Process Design for Recovery of Unreacted Styrene Monomer for Utility Saving (유틸리티 절감을 위한 미반응 스티렌 모노머 회수공정의 설계)

  • Bong, Jooyoung;Na, Sujin;Lee, Kwang soon
    • Korean Chemical Engineering Research
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    • v.55 no.1
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    • pp.54-59
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    • 2017
  • A study for process design to curtail the utility consumption during residual styrene monomer recovery in an ABS polymerization process was carried out. Among different techniques for residual monomer recovery, the steam stripping is dominantly employed in industries. The existing process, however, consumes a large amount of utility (steam and cooling water), and this study focused on the design of a new process that can substantially spare the utility consumption. A new process was configured to utilize the latent heat of the stripping steam, which is condensed with the monomer using cooling water after exiting the stripper. The condenser was modified to use vacuum state water as coolant and to generate vacuum state steam using the latent heat of the stripping steam. The steam is injected to the stripper as the stripping steam after upgrading using a compressor. Through this modification, consumption of steam and also cooling water could be significantly reduced at some expense of electricity for compressor operation.

A Study on Applicability of Turbulence Models for Unsteady Turbulent Flow with Temperature Variation (온도변화를 수반한 비정상 난류유동장에 대한 난류모델의 적용성에 관한 연구)

  • 유근종;전원대
    • Journal of the Korean Society of Propulsion Engineers
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    • v.6 no.1
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    • pp.1-11
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    • 2002
  • The suitable turbulence model is found to be required in the course of establishing a proper analysis methodology for thermal stripping phenomena which are shown in strong temperature variation area such as reactors and propulsion devices. Three different turbulence models of $\kappa$-$\varepsilon$ model, modified $\kappa$-$\varepsilon$ model, and full Reynolds stress(FRS) model, are applied to analyze unsteady turbulent flows with temperature variation. Three test cases are selected for verification. These are vertical jet flows with water and sodium, and parallel jet flow with sodium. Analysis yields the conclusion that 3-D computation with FRS betters others. However, modified modeling is required to improve its heat transfer characteristic analysis. Further analysis is performed to find momentum variation effects on temperature distribution. It is found that the momentum increase results increase of fluid mixing and magnitude of temperature variation.

SOME MECHANICAL FACTORS AFFECTING MACHINE MILKING CHARACTERISTICS UNDER SEMI-ARID CONDITION

  • Ali, A.K.A.;Farah, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.3
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    • pp.475-480
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    • 1992
  • The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.

A Study of Concrete with Large Quantity of Fly-Ash (플라이애쉬 다량 함유 콘크리트에 관한 실험적 연구)

  • 이동하;공민호;백민수;김성식;이영도;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.1219-1224
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    • 2001
  • In this study, concrete what plenty of fly ash used as binder is left in three condition humid condition($35^{\circ}C$), normal condition($20^{\circ}C$) and cold condition($5^{\circ}C$). Fly ash concrete is tested in fresh properties and early strength. The result of tests could give the decisive factor of form side's stripping time. The purpose of this study is presenting the stripping time data to help the construction work. The result of this study is below. 1. The plain concrete specimen in humid condition developed high strength before 5 days, then strength development is declined. 10 day strength of plain specimen is smaller than the normal condition specimen's. 2. The strength of the concrete which plenty of fly ash used is more developed than the concrete in normal condition. It says that fly ash concrete is useful in the humid condition. 3. As fly ash substitution rate is downsizing and outdoor temperature degree is low, form stripping times is getting shorter.

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A Study on the Processing Aptitude and Storage of Common-European Squid(Loigo vulgaris) 2. The Skin Stripping, Freezing and Thawing Conditions (유럽화살오징어의정장성 및 가공적성에 관한연구 2. 탈피 동결 및 해동조건)

  • 박희열;허종화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.2
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    • pp.175-179
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    • 1990
  • Investigations of skin stripping freezing and thawing conditions of common-European squid (Loigo vulgaris) were carried out. The most effective method of skin stripping was to immerse the sample at 5$0^{\circ}C$ for 10-15 minutes in fresh water or salt solution(5-10% w/v) Contact freezing and fresh water thawing method was found to be effective. The muscle structure of the sample thawed after contact freezing was almost the sample after contact freezing was almost the same as that of raw sample.

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The evolution of dark matter halo profiles in a cosmological context

  • Park, Jinwoo;Choi, Hoseung;Yi, Sukyoung
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.73.3-73.3
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    • 2017
  • Environment has a significant impact on the evolution of dark halo profiles. We used a cosmological N-body simulation based on WMAP5 cosmology to study environmental effects on halo profiles. Host haloes located in sparse regions are highly concentrated, and more massive haloes have higher concentration index. This is because mass accretion affects only the outer part of the halo and consequently increase the virial radius having no effect on the scale radius. Conversely, host haloes located in dense regions have low concentration index. This is because frequent mergers affect even the inner part of the halo. So, scale radius increases with the growth of virial radius. Evolutions of subhalo profiles are essentially different from those of host haloes because subhaloes undergo tidal stripping. The stripping begins once a subhalo approaches closer than ~3 virial radii of the host halo. During the stripping, the inner part of the subhalo keep following NFW profile, but the mass of the outer part gradually decreases. As a result, when the subhalo reaches the pericenter of its host, only about inner 30% of the subhalo follows the NFW profile.

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DEVELOPMENT OF ANODIC STRIPPING VOLTAMMETRY FOR THE DETERMINATION OF PALLADIUM IN HIGH LEVEL NUCLEAR WASTE

  • Bhardwaj, T.K.;Sharma, H.S.;Jain, P.C.;Aggarwal, S.K.
    • Nuclear Engineering and Technology
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    • v.44 no.8
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    • pp.939-944
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    • 2012
  • Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, $10^{-8}$ and $10^{-7}M$, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

Voltammetric Assay of Silver Ions in Frog's Tissue

  • Ly, Suw-Young;Lee, Jin-Hui;Lee, Chang-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.139-145
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    • 2013
  • The electrochemical analysis of silver ion was performed using cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry, and electrode cell systems were fabricated with graphite pencil electrode (GE) of working, reference and counter electrodes. Also electrolyte was the use of sea water as electrolyte solutions instead of ionic controlled solutions. The optimum analytical conditions for the cyclic and stripping parameters were determined using GE. The results approached the microgram working ranges of SW(ug/L) and CV(ug/L) Ag, and the optimum conditions were applied to frog's tissue and the food samples.

Fine Blanking Characteristics of T-shaped Blanks (T 형 제품의 파인 블랭킹 가공 특성)

  • 장영도;최치수;김대현;김종호;류제구
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.598-602
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    • 1996
  • This study is performed for investigating the effects of stripping and counter punching force on shearing characteristics in fine blanking, such as camber, burr-height and dimensional accuracy, etc by experiments. Conventional hydraulic press equipped with specially designed hydraulic unit is used for experiments so that both the stripping force and counter punching force are arbitrarily adjusted according to experimental conditions. Two kinds of materials, hot rolled steel sheet(1mm, 3mm) and pure aluminum(1mm, 3mm) are selected in order to examine the influence of strength and thickness of working materials in blanking of T-shaped products. Based on the experimental results of this study, it can be concluded that the finely cut surface of sheared blank can be obtained even in conventional hydraulic press if additional equipments and special dies are employed.

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