• Membrane Journal
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• 제3권3호
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• pp.126-135
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• 1993

Perchlorate ion-selective PVC membrane electrode responsive to $10^{-6}M$ was developed by incorporating the ion-pair complex of perchlorate with the quaternary ammonium salts as a active material. The effect of chemical structure, the content of active material, the kinds of plasticizers, and the membrane thickness on the electrode characteristics such as the linear response range and Nernstian slope of the electrode were studied. With the results, the useful pH range and the selectivity coefficients to various interfering anions were compared and investigated. It was obtained that the effect of the chemical structure of an active material on the electrode characteristics was improved with increasing the alkyl chain length of the quarternary ammonium salts in the ascending order of Aliquat 336P, TOAP, TDAP, and TDDAP. The electrode characteristics was improved with the decrease of the active material content below the optimum membrane composition, and DBP was the best as a plasticizer. The optimum membrane composition was 9.09wt% of TDDAP, 30.3wt% of PVC, and 60.6wt% of ptasticizer(DBP). And the optimum membrane thickness was0.45mm at this composition. Under the above condition, thelinear response ranger was $10^{-1}~1.2 {\times} 10^{-6}M$, and the detection limit was $5.1{\times}10^{-7}M$ with the Nernstian slope of 57mV/decade of activity of perchlorate ion. The electrode potential was stable within the pH range from 4 to 11. The selectivity coefficient was as shown below : $SCN^->I^->NO_3^->Br^->ClO_3^->F^->Cl^->SO_4^{2-}$

• Journal of the Korean Chemical Society
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• 제45권1호
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• pp.31-39
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• 2001

Newly synthesized 15-Crown-5 derivatives including anthracene were used as neutral carriers for ion selective electrodes to determine potassium ion by potentiometry. Among the five neutral carriers studied in this work, N-(4'-benzo-15-crown-5-ether)-anthracene-9-imine was found to be the best in terms of selectivity and stability. The optimal composition of ion selective membrane was 1.0, 33.0 and 66.0 wt% for neutral carrier, PVC and plasticizer, resperctively. Addition of KTpCIPB used as a lipophilic additive improved the Nernst slope and the selectivity of potassium ion over alkali and alkaline earth metals. Especially, the selectivity of potassium ion over ammonium ion was remarkably good ($logK^{pot}_(K^+,NH_4^+}$=-2.59). The response time was also excellent ($t_{100}$=5sec) and continuous use of this electrode for three weeks has not changed the selectivity and analytical characteristics.

• Journal of information and communication convergence engineering
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• 제6권1호
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• pp.73-79
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• 2008

Result that study magnet nerve curer for treatment induced current generation and current of ion for development in main point incontinence, prostate, sphincter, nervous system, rigidity, headache, retrogression arthritis, ligament damage, Rheumatism arthritis, peripheral nerve etc., can classify by 4. Embodied do first, full bridge magnet occurrence chapter, and communication with PC is available, confirmed various action loops an experiment. Could confirm correct treatment probe second, woman and man disease person. Third, derived so that healing may be possible naturally by addition of apron form according to disease. Because composition of finally, treatment probe composes by act of negative plate form, manufacture is easy and cooling designed for easy direction. More superior result of cooling appeared than existing in incidental and ingredients, cooling efficiency, composition, complexity, convenience etc. that expense and composition manufacture very straightforwardly and experimental by 2 - Tank ways.

• Journal of the Korean institute of surface engineering
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• 제44권1호
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• pp.1-6
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• 2011

A NiW functional alloy plating was investigated as variables of metal ion concentration, complexing agent, temperature, pH and applied current density. Even if numerous studies on reaction mechanism of NiW induced codeposition were carried out during couples of decade, it has not been acceptable reaction mechanism. This study was focused on the effect of the plating variables on the alloy composition in the NiW alloy plating. Applied current density could control mainly the alloy composition rather than other plating variables. It has also been confirmed that the functional alloy plating such as layered or gradient plating was possible by controlling applied current density.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.401-405
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• 2010

The Schiff base 1,2-bis(E-2-hydroxy benzylidene amino)anthracene-9,10-dione has been synthesized and explored as ionophore for preparing PVC-based membrane sensors selective to the copper ($Cu^{2+}$) ion. Potentiometric investigations indicate high affinity of these receptors for copper ion. The best performance was shown by the membrane of composition (w/w) of ionophore: 1 mg, PVC: 33 mg, DOP: 66 mg and KTpClPB as additive were added 50 mol % relative to the ionophore in 1 ml THF. The proposed sensor's detection limit is $2.8{\times}10^{-7}$ M over pH 5 at room temperature (Nernstian slope 31.76 mV/dec.) with a response time of 15 seconds and showed good selectivity to copper ion over a number of interfering cations.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.408-412
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• 2004

A total of 23 springs distributed in the southern and northern sides of Mt. Hala in Jeju Island were seasonally sampled and analyzed for their major ion chemistry and oxygen and hydrogen isotope compositions to investigate their hydrogeochemical and isotopic characteristics. Dissolved ion concentrations of the south-side springs slightly increase with decreasing altitude. This indicates that dissolved ion concentrations of groundwater recharged at higher altitudes increase by water-rock interaction during the downgradient migration of groundwater through highly permeable volcanic aquifer. Dissolved ion concentrations of the north-side springs also slightly increase with decreasing altitude, but dramatically increase at ～300 m.a.s.l. This may indicate a sudden input of contaminants to the north-side groundwater system around ～300 m.a.s.l. Springs located in areas above ～300 m.a.s.l. have very low concentrations of dissolved ions, showing little seasonal variations. Whereas springs located in areas below ～300 m.a.s.l. show a big seasonal variation in the concentration of dissolved ions. Seasonal variation of oxygen isotope compositions of springs is ～3$\textperthousand$ for high-altitude springs (～1700 m.a.s.l.) and is ～2$\textperthousand$ near shore, indicating an attenuation of the variation through mixing with other groundwater bodies during migration.

• Journal of Korean Ophthalmic Optics Society
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• 제9권1호
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• pp.161-166
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• 2004

In this research, TiN films has been grown to the stainless steel substrate by ion beam assisted deposition. TiN film was grown to the nitrogen atmosphere of around $10^{-15}$ Torr with Arion bombardment. The chemical composition, color and adhesion of TiN films were examined as a variation of En(ion energy per atom). The N/Ti ratio increased linearly as the increase of En and saturated around 1.2 at high En. As a results, the bright golden color was obtained when En reached a certain value of Ecn. As a results, the N/Ti ratio is about 0.9.

• Journal of the Korean institute of surface engineering
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• 제34권3호
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• pp.231-239
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• 2001

The structure and composition of Cr-nitrides formed on an electroplated hard Cr layer during an ionnitriding process was analyzed, and the growth kinetics of the Cr-nitrides was examined as a function of the ion-nitriding temperature and time in order to establish a computer simulation model prediction the growth behavior of the Cr-nitride layer. The Cr-nitrides formed during the ion-nitriding at $550~770^{\circ}C$ were composed of outer CrN and inner $Cr_2$N layers. A nitrogen diffusion model in the multi-layer based on fixed grid FDM (Finite Difference Method) was applied to simulate the growth kinetics of Cr-nitride layers. By measuring the thickness of each Cr-nitride layer as a function of the ion-nitriding temperature and time, the activation energy for growth of each Cr-nitride was determined; 82.26 KJ/mol for CrN and 83.36 Kj/mol for $Cr_2$N. Further, the nitrogen diffusion constant was determined in each layer; $9.70$\times$10^{-12}$ /$m^2$/s in CrN and $2.46$\times$10^{-12}$ $m^2$/s in $Cr_2$N. The simulation on the growth kinetics of Cr-nitride layers was in good agreements with the experimental results at 550~72$0^{\circ}C$.

• Journal of the Korean Ceramic Society
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• 제34권1호
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• pp.13-22
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• 1997

Water-soluble phosphate glasses containing Ag and Cu ion were prepared through melting process. Dis-solution characteristics, bactericidal effect and cytotoxicity were investigated with composition and time in D. I. water using the powdered sample. Surface change were observed with increasing dissolution time us-ing the bulk specimen. Dissolution amount was maximum at the molar Ag:Cu ratio of 1 and increased with increasing time. The behavior of dissolution was total dissolution from the early stage. But no new layer was observed at the glass surface during dissolution. The bactericidal effect for pseudomonas sp, e. coli, sta-phylococcus aureus, and salmonella increased with increasing dissolution amount and therefore great bac-tericidal effect appeared. The result of cytotoxicity experiment to L929 showed that solution with more than 10 ppm of Ag ion had strong cytotoxicity.

• Journal of the Korean Society of Safety
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• 제6권4호
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• pp.13-20
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• 1991

Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows：Cl $O_4$$^{[-10]}$ ＞ $I^{[-10]}$ ＞N $O_3$$^{[-10]}$ ＞B $r^{[-10]}$ ＞ $F^{[-10]}$ ＞C $l^{[-10]}$ ＞O $A_{c}$ $^{[-10]}$ 〓S $O_4$$^{2-}$.