• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1990.11a
• /
• pp.1-15
• /
• 1990

엔진 성능의 향상에 맞추고 에너지 절약을 위한 방법으로써 엔진 오일의 마찰 마모 특성등 오일의 성능을 높이려는 노력이 꾸준히 시도되고 있다. 특히 마찰력 손실을 감소기키기 위해서 낮은 마찰특성을 갖도록 몰리브데늄(Mo)을 유용성인 금속 착화합물로 만든 Mo-DTP를 제조하여 현재 첨가제로 널리 사용되는 Zn-DTP와 대체시키려는 연구가 활발하고 최근엠 많은 논문이 발표되고 있다. 또 일부 윤활유 제조 회사에서는 몰리브레늄을 첨가 시키는 등 제품 기술을 향상시켜 오일 교환의 기간이나 자동차 주행 거리를 대폭적으로 늘려줄 수 있는 상품도 생산되고 있다. 윤활 첨가제로써 Mo-DTP를 Zn-DTP와 대체시켜 기유에 혼합한 경우에는 마찰 감소 기능이 매우 향상 되었고 내 마모성도 비교적 좋으나 산화 억제 능력이 부족하고 온도의 상승에 따른 점도 지수의 증가도 비교적 크다는 단점을 갖고 있음이 발표된바 있다. 따라서 Mo-DTP의 단점을 보완하려는 연구가 필요되고 그의 한 방법으로써 현재 첨가제로 가장 많이 사용되는 Zn-DTP와 혼합하여 첨가 하였을 경우에 대한 연구를 하였다. 이때 기본 윤활유에 Mo-DTP와 Zn-DTP를 적당한 혼합 비율로 첨가하고 하중, 온도를 변화 시키면서 마찰, 마모등의 성질고 산화 안정성 및 마모 입자 분석 등 전반적인 윤활유로써의 특성을 살펴 보았다.

• YAKHAK HOEJI
• /
• v.13 no.1
• /
• pp.33-37
• /
• 1969

A new organic reagent, 1-isonicotynyl-2-furfurylidene hydrazine synthesized from isonicotinic acid hydrazid and furfural, gives yellow liquid with cadmium (II). Cadmium complex of the reagent is soluble in water with yellow coloration. The complex has a maximum absorption at 363 m${\mu}$ and molar ratio of cadmium to reagent was estimated as 1:1 by continuous variation method and slope method. Molecular extinction coefficient and apparent formation constant of this complex was spectrophotometrically determined. K=4.48 $\times$ 10$^{3}$ (Babko's method) K=1.33 $\times$ 10$^{3}$ (Anderson's method)

• YAKHAK HOEJI
• /
• v.9 no.1_2
• /
• pp.18-22
• /
• 1965

A new organic reagent, 1-isonicotinoyl-2-furfurylidene hydrazine was synthesized from isonicotinic acid hydrazide and furfural, gives precipitate with copper(II), mercury(II) and argent(I), whereas, it gives a water soluble yellow complex with iron(III). Copper complex of the reagent is soluble in EtOH MtOH, pyridine, dioxane and dimethylformamide with green yellow coloration. The complex has a maximum absorption at 385 m.$\mu$ and molar ratio of copper; reagent was estimated as 1:1 by continuous variation method, slop method and chelate titration method. Molar extinction coefficient (9600) and apparant formation constant of this complex was spectrophotometrically determined. K=1.7 * $10^{7}$ (Babko's method) K=2.1 * $10^{7}$ (Anderson's method). This reagent reacted with copper so sensitive that it would be available for determination of Cu (II).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07a
• /
• pp.214-217
• /
• 2002

The internal quantum efficiency of organic light emitting devices(OLEDs) using fluorescent organic materials is limited within 25% because of the triplet excitons which can hardly emit light. So there has been considerable interest in finding ways to obtain light emission from triplet excitons. One approach has been to add phosphorescent compounds to one of the layers in OLEDs. Then triplet excitons can transfer to these phosphorescent molecules and emit light. In this study, multilayer OLEDs with phosphorescent emitter, Iridium complexes were prepared. The devices with a structure of ITO/TPD/Ir complex doped in the host material/Alq3/Li:Al/Al were fabricated, and its electrical and optical characteristics were studied. Using various Ir complexes and the host materials, we fabricated several devices and investigated the device characteristics.

• Journal of the Korean institute of surface engineering
• /
• v.21 no.4
• /
• pp.149-159
• /
• 1988

Electrodeposition of chromium from low concentration chromjum (III) sulfate complexess in aqueous using sodium formate-glycine mixtures as a complexing agent was studied. In the bath formation, it is found that the optimum again temperature and time for equilibration of the electrolytes are nrcessary for 24 hrs at 45$^{\circ}C$and the optimum elecrical charge for low current electrolysis which might be produced Cr(II) ions in the electrolytes is necessary for minum 2Ah/$\ell$. The optmun concentration off standard electrolyte for main composition is 0.05M chromium(III) sulfate, 0.2M sodium formate-0.2M glycine, and I mMNaSCN as a catalysea, respectivwly. The standard electrolyte is shows good covering, good throwing power, and 6% of current efficiency (Cr(III)basis). The oppearance of electrodeposits shows att active bright chromium. The SEM morphology of the chromjum coating is observed as smooth surfaces and dispersed micro prcro pores. X-ray diffraction analysis shows a bcc structure which the perferred orintation of the chromium electrodeposits is strongin(200)plane.

• Journal of the Korean institute of surface engineering
• /
• v.21 no.4
• /
• pp.160-167
• /
• 1988

Electrochemical behaviors od chromium electrodeposition from 0.05M chromium (III) sulface complexes in aqueous solutions using sodium formate-glycine mixtures as a complexing agent were studied. In the cathodic current-potential cures, it is found that the intial limiting current of Cr(III) is proportional to square root of scan rate and activiation energy from Arrhenius plot is s obtained 3.05Kcal/mol. From this results, the reaction is considered, Cr3++e longrightarrow Cr2+, which is controlled diffusion of Cr (III). It is also found that the chromium is deposited when the potential reaches to hydrogen evolution potential. Effects of NaSCN as a catalyser in the electrolyte were investigated NCS- anion seems to react strongly by specific absorption at the inner HelmholtZ layer, so that, it is considered to suppress the electrodeposition reaction reaction for chromjum, and also it is considered multipe-bridge such as Cr(III)-NCS---M(M;cathode).

• Journal of the Korean Society of Industry Convergence
• /
• v.13 no.4
• /
• pp.191-196
• /
• 2010

This study explores the solution of a variety of conditions of the natural dyeing with the Mulberry. To obtain this, the Cu complex compound was added into the extracts. The Mulberry extract was added the Copper acetate to obtain the Black sediment the metal complex compound of anthocyanidin. According to the result of using the complex compound of the solid material, the dyeing properties were excellent. The metal complex compound acted as a mordant, thus it reduced the process of mordanting in the natural dying.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.431-432
• /
• 2008

We have investigated low temperature sintering characteristics of organic Ag complex. Organic Ag complex was coated on the glass substrate by spin coating method. The coated Ag complex was sintered in an air atmosphere. The sintering temperature was varied from 100 to $300^{\circ}C$ and sintering time was varied from 1 to 4 min. The thickness of the coated film was significantly decreased as the film was sintered at the temperature between 110 and $120^{\circ}C$. The sintered Ag film at temperature higher than $115^{\circ}C$ shows very low sheet resistance less than 1 ${\Omega}{/\square}$.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.5
• /
• pp.524-533
• /
• 2008

Industrial wastewater generated in the electroplating and metal finishing industries typically contain toxic free and complex metal cyanide with various heavy metals. Alkaline chlorination, the normal treatment method destroys only free cyanide, not complex metal cyanide. A novel treatment method has been developed which destroys both free and complex metal cyanide as compared with Practical Plant(I). Prior to the removal of complex metal cyanide by Fe/Zn coprecipitation and removal of others(Cu, Ni), Chromium is reduced from the hexavalent to the trivalent form by Sodium bisulfite(NaHSO$_3$), followed by alkaline-chlorination for the cyanide destruction. The maximum removal efficiency of chromium by reduction was found to be 99.92% under pH 2.0, ORP 250 mV for 0.5 hours. The removal efficiency of complex metal cyanide was max. 98.24%(residual CN: 4.50 mg/L) in pH 9.5, 240 rpm with 3.0 $\times$ 10$^{-4}$ mol of FeSO$_4$/ZnCl$_2$ for 0.5 hours. The removal efficiency of Cu, Ni using both hydroxide and sulfide precipitation was found to be max. 99.9% as Cu in 3.0 mol of Na$_2$S and 93.86% as Ni in 4.0 mol of Na$_2$S under pH 9.0$\sim$10.0, 240 rpm for 0.5 hours. The concentration of residual CN by alkaline-chlorination was 0.21 mg/L(removal efficiencies: 95.33%) under the following conditions; 1st Oxidation : pH 10.0, ORP 350 mV, reaction time 0.5 hours, 2nd Oxidation : pH 8.0, ORP 650 mV, reaction time 0.5 hours. It is important to note that the removal of free and complex metal cyanide from the electroplating wastewater should be employed by chromium reduction, Fe/Zn coprecipitation and, sulfide precipitation, followed by alkaline-chlorination for the Korean permissible limit of wastewater discharge, where the better results could be found as compared to the preceding paper as indicated in practical treatment(I).

• Elastomers and Composites
• /
• v.49 no.1
• /
• pp.59-65
• /
• 2014

In this study, in order to complete curing reaction of the molding compound comprising an epoxy/anhydride at $71^{\circ}C$ for 40 hours, metal coordination complexes such as cobalt (II) acetylacetonate, potassium acetylacetonate, iron (III) acetylacetonate and chromium (III) octoate as a catalyst were applied to the epoxy/anhydride compounds respectively. The weight ratio of an epoxy part/an anhydride part was adjusted to improve the mechanical properties of the molding compound. According to the experimental results, an epoxy/anhydride compound containing chromium (III) octoate showed a high conversion at $71^{\circ}C$ for 40 hours as well as a proper processability at room temperature among the several metal coordination complexes. For the mechanical properties of the cured epoxy/anhydride compound, the compounds containing weight ratio from 0.9/1 to 0.5/1 of the epoxy part/anhydride part with chromium (III) octoate showed the high flexural strength, and higher compressive strength was shown with increasing of the hardener part.