• Title/Summary/Keyword: chemical elements

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Online control type total chemical dosing system(CCK)

  • Choi, Hyun-Seuk;Kim, Dong-Kwon;Bae, Jum-Ho
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2009.03a
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    • pp.205-206
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    • 2009
  • The trouble with small & medium dyeing company is balance and transfer of the chemical by man. And due to manual operation occur various environmental issues, and harmful elements in the human body. And the price of imported equipment (CCK) is very high. To solve these problems, this equipment was developed.

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Geometrical Construction of the S Matrix and Multichannel Quantum Defect Theory for the two Open and One Closed Channel System

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.23 no.7
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    • pp.971-984
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    • 2002
  • The multichannel quantum defect theory (MQDT) is reformulated into the form of the configuration mixing (CM) method using the geometrical construction of the S matrix developed for the system involving two open and one closed channels. The reformulation is done by the phase renormalization method of Giusti-Suzor and Fano. The rather unconventional short-range reactance matrix K whose diagonal elements are not zero is obtained though the Lu-Fano plot becomes symmetrical. The reformulation of MQDT yields the partial cross section formulas analogous to Fano's resonance formula, which has not easily been available in other's work.

Study on the Several Factors in the Fractional Leaching Method of Mixed Hydrated Oxides of Monazite Sand (Monazite로 부터 유도된 혼합수산화물에 대한 분별 용출법의 검토)

  • Rhee, Chin-Taik;Ko, Hyo-Tae;Chun, Sang-Moon
    • Journal of the Korean Chemical Society
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    • v.14 no.3
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    • pp.257-261
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    • 1970
  • Some factors such as the weight ratio, reaction time and temperature for the separation of rare earth elements from monazite are studied. The influence of the inorganic phosphate for the leaching is also studied.

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A New On-line Coprecipitation Preconcentration Technique for Trace Metal Analysis by ICP-AES

  • Park, Gyeong Hui;Park, Yong Nam
    • Bulletin of the Korean Chemical Society
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    • v.16 no.5
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    • pp.422-427
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    • 1995
  • In a stream of water sample, trace metal ions are quantitatively coprecipitated with Indium hydroxide and filtered. The filtered precipitate is continuously dissolved in 3 M nitric acid and introduced to ICP directly. The lead, cadmium, and copper are concentrated more than 10-fold and determined with ICP-AES at a sampling frequency of 10/hour. The detection limits are 2.89, 1.43,0.52 ppb for lead, cadmium, and copper respectively. Recoveries of lead, cadmium, and copper are 98.7, 94.3, and 104.5% respectively. The RSD values for three elements are about 3-5% currently.

Semiconducting Behavior in the Polymeric Zintl Phase Material $K_2Ga_2Sb_4$

  • Wu, Biao;Birdwhistell, Teresa L.T.;Jun, Moo-Jin;O'Connor, Charles J.
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.464-466
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    • 1990
  • A ternary Zintl phase material of the formula $K_2Ga_2Sb_4$ has been prepared directly from reaction of the elements following a high temperature procedure. The compound consists of potassium ions and planar ribbons of $(Ga_2Sb_4^{-2})_{\infty}$ consisting of five membered $[Ga_2Sb_3]$ rings bridged by Sb atoms. The variable temperature specific resistivity measurements show the material to be an intrinsic semiconductor.

Analysis of Sclerotia and Sporophores of Pleurotus tuber-regium Fr. an edible mushroom in Nigeria

  • Okhuoya, J.A.;Ajerio, C.
    • The Korean Journal of Mycology
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    • v.16 no.4
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    • pp.204-206
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    • 1988
  • Chemical analysis of both sclerotia and the fruits of Pleurotus tuber-regium showed higher values for such elements as calcium(Ca), iron(Fe), zine(Zn) in the fruits than in the sclerotia. On the contrary magnessium(Mg) was found to be higher in sclerotia than in the fruits. protein and carbohydrate were also found to be more in the fruits. There was no significant difference between the chemical values of old(1 year) and fresh sclerotia. Oil palm fruit fibre substrate produced sporophores with higher values for the minerals, protein and carbohydrate than those on riversand substrate.

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Evaluation of the Changes in Local Paper Structure and Paper Properties Depending on the Forming Elements Types (탈수소자에 의한 종이 미세구조 및 물성 변화 평가)

  • Sung, Yong-Joo;Keller, D. Steven
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.1
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    • pp.17-23
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    • 2009
  • The influence of different forming elements on the local paper structure and the related paper properties was investigated in this study. Specifically, a conventional papermaking foil system and a velocity induced drainage (VID) system were compared. The study involved the analysis of the product samples obtained from the commercial machine trials. The paper samples produced with VID forming systems showed better formation. The deterministic patter in the local structural profile map of the Foil samples indicated the structure of foil samples was more supple after forming process and then easier to be marked by various fabrics such as wet pressing fabric. The higher bulk was observed in the VID samples, which resulted in higher scattering coefficient, lower ZDT strength, and higher bending stiffness.

Dissolution Properties of Phosphate Glasses with Trace Elements

  • Lee, Hoi-Kwan;Kang, Won-Ho
    • Journal of the Korean Ceramic Society
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    • v.42 no.6 s.277
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    • pp.371-376
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    • 2005
  • Phosphate glasses were prepared by melting quenching process, and glass formation and dissolution properties were studied. The glass forming region in the $K_2O-CaO-P_2O_5$ system is quietly agreed with the report by Mazurin OV et al. with $M_2O-M'O-P_2O_5$ system (M : monovalent cation, M'divalent cation). Conditionally these glasses have solubility from absorbing the moisture or water and then release elements with trace elements, and the thermal and chemical properties were controllable by the $CaO,\;K_2O,\;P_2O_5$ contents. In the abnormal glass properties, this paper showed the possibility the present glasses can be a good candidate for one component of the slow released agriculture fertilizer.

Chemical Composition and Sources of Atmospheric Particulates Collected on the West Coast of Korea (서해안 대가 분진의 화학 조성 및 기원에 대한 연구 (1))

  • 최만식;조성록;이동수
    • Journal of Korean Society for Atmospheric Environment
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    • v.5 no.2
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    • pp.72-83
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    • 1989
  • Twenty-five atmospheric particulates were collected using a high volume aerosol sampler from Septermber to December, 1988 on a site located on the West coast of Korea and analysed for twelve elements (Na, Mg, Al, Mn, Fe, Cu, Co, Ni, Zn, Ag, Cd, and Pb) by AAS. The particles being mainly crustal minerals, large quantity of spherical fly ashes were also observed. In order to identify the origin of trace metals in atmospheric particulates, enrichment factor, interelemental correlation and factor analysis were performed. Based upon these analysis, the twelve elements can be classified into three groups; the elements dominantly present in soil particles (Al, Mn, Fe, Co, and Ni), those in sea salt aerosols (Na and Mg), and those in air pollution-derived particles (Cu, Cd, Pb, Ag and Zn).

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