• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.141-151
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• 1979

The selective absorption of metal ions by chelating agent-loaded resins was studied in aqueous media. The resins were prepared by loading the conventional anion exchange resin, Dowex 1-X8 (50 to 100 mesh) with chelating agents containing sulfonic group, such as 8-hydroxy-quinoline-5-sulfonic acid (HQS) and 7-nitroso-8-hydroxyquinoline-5-sulfonic acid (NHQS). The stability of the resin was markedly influenced by the following factors; (1) the affinity and concentration of anions in the external solution, (2) the pH of the media. The optimum conditions for the absorption of metal ions were determined with respect to the pH, shaking time, and the effect of anion concentration in the medium. Under the optimum condition the order of the absorption of metal ions such as Fe(Ⅲ), Cu(Ⅱ), Pb(Ⅱ), and Zn(Ⅱ) was in accord with that of the stability constants of the chelates. The total capacities of the resins were found in the range of 0.6∼1.6 mmole metal per gram.

• Analytical Science and Technology
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• v.11 no.6
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• pp.440-447
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• 1998

Polydentate Schiff base ligands 5-Br-BSDT(bis(5-bromosalicylaldehyde)diethylenetriamine) having $N_3O_2$ atoms, 5-Br-BSTT(bis(5-bromosalicylaldehyde)triethylenetetramine) having $N_3O_2$ atoms, 5-Br-BSTP(bis(5-bromosalicylaldehyde)tetraethylenepentamine) having $N_3O_2$ atoms were synthesized. Stability constants of the complexes between these ligands and the metal ions such as Cu(II), Ni(II) and Zn(II) were measured in DMSO by a polarographic method. It was observed that all metal(II) ions employed in this study formed 1 : 1 complexes with Schiff base ligands. Stability constants for the ligands were in the order of Cu(II)>Ni(II)>Zn(II), and for complex formation were in the order of 5-Br-BSTP>5-Br-BSTT>5-Br-BSDT according to the increasing in the number of donor atoms. Both enthalpy and entropy changes are obtained in negative valves. Exothermicity for the complex formation indicated tight binding between the ligands and metal ions. The negative entropy change would be related to the fact that solvent molecules are strongly interacting with the metal complexes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.159-162
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• 2009

In temperature controlled batch reactor, the effect of temperature and contact metals on the thermal stability of Exo-tricyclo[$5.2.1.0^{2,6}$]decane (tricyclodecane, exo-THDCP) were investigated by use of GC/MS. And the characteristic of metal in contact with tricyclodecane were analyzed by SEM-EDX. In fuel temperature variation test, thermal decomposition of exo-THDCP was occurred at $350^{\circ}C$. In case of fuel contact metals, Titanium was less effective to decomposition of exo-THDCP than stainless steel 304, 316.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.208-212
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• 1983

The stability constants for the complexes formed between dibenzo-18-crown-6 compound and alkaline earth metal cations in dimethylsulfoxide, dimethylformamide, and acetonitrile have been obtained by conductometry at $25{\circ}C\;and\;35{\circ}C$respectively. The stability constants were increased in order of $Ca^{2+} in any solvent, and the magnitudes were found to be reversely proportional to the solvent donicities. The result could be understood in terms of ion-cavity radius concept, solvent basicity, and solvation of the cations.

• Herbal Formula Science
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• v.24 no.2
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• pp.71-79
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• 2016

Objectives : To verify the equivalence between Atractylodis Rhizoma Alba herbal prescription(HP-ARA) and Atractylodis Rhizoma Alba herbal sub stance(HS-ARA). Methods : Safety tests by microbial regulation and heavy metal analysis (total heavy metal, Pb, As) and a stability test by long term shelf test for HP-ARA according to notification of the Ministry of Food and Drug Safety were carried out. Then, multi component profile of HP-ARA and HS -ARA were analyzed by HPLC. Results : The safety and stability of HP-ARA confirmed by several tests. Correlation coefficient of equivalence of HP-ARA and ARA-HS showed 0.992. Conclusion : Based on this result of equivalence between HP-ARA and HS-ARA, HP-ARA can substitute HS-ARA used to make herbal medicines (herbal decoction, pills and powder).

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.960-964
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• 2003

Effects of pH, sugars, organic acids, and metal ions on the stability of anthocyanin pigments extracted from mulberry (Morus alba L) fruit were studied. The pH had marked influences on the color of the anthocyanine pigment: i.e. the lower pH of the anthocyanin solution was, the more stable and intense of the pigment was. Among the sugars, sucrose was the most deleterious followed by fructose, glucose and maltose. Among the organic acids, maleic acid was found to be the most effective in stabilizing the pigment followed by acetic acid, citric acid and tartaric acid. Most metal ions except C $u^{+2}$ and F $e^{+3}$ were found to be effective in stabilizing the pigment.

• Journal of the Korean Vacuum Society
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• v.13 no.4
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• pp.182-188
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• 2004

Previous studies on the liquid Gallium ion sources used an electro-chemically etched tungsten wire with a coil-type heater. Such a structure requires excessive power consumption in the course of heating the liquid metal. In this work, a new structure is proposed that replaces the coil-type heater. It uses a Gallium reservoir made of six pre-etched 250$\mu\textrm{m}$ tungsten wires that surround the needle electrode. Gallium trading at the reservoir is observed to be much more stable, resulting in an improved beam stability.

• Advances in nano research
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• v.13 no.2
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• pp.113-120
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• 2022

In this paper, a finite element (FE) simulation has been developed in order to examine the nonlinear stability of reinforced sandwich beams with graphene oxide powders (GOPs). In this regard, the nonlinear stability curves have been obtained asuming that the beam is under compressive loads leading to its buckling. The beam is considered to be a three-layered sandwich beam with metal core and GOP reinforced face sheets and it is rested on elastic substrate. Moreover, a higher-order refined beam theory has been considered to formulate the sandwich beam by employing the geometrically perfect and imperfect beam configurations. In the solving procedure, the utalized finite element simulation contains a novel beam element in which shear deformation has been included. The calculated stability curves of GOP-reinforced sandwich beams are shown to be dependent on different parameters such as GOP amount, face sheet thickness, geometrical imperfection and also center deflection.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1356-1359
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.72-72
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• 1996