• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.408-413
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• 1995

A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.90-100
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• 2019

Hypergolic thrusters have been extensively researched and applied to spacecraft propulsion based on their simplicity and high reliability of ignition. Research on the impingement characteristics of $N_2O_4$/amine has been profoundly carried out since the 1960s in advanced countries, especially the United States. Recently, enhancements to advanced hypergolic thrusters using MON/MMH have been planned by NASA to improve compactness and high performance. In this work, technical studies were investigated on the mixing of hypergolic propellant and its combustion instabilities such as reactive separation flow and popping.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.72-81
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• 2024

In this study, DEIPA was used for enhancing cementitious performance of bottom ash replaced cement. By applying the partial or no-known crystal structure method to X-ray diffraction data, the amounts of amorphous bottom ash and calcium silicate hydrate(C-S-H) could be separated and quantified. In the sample without DEIPA, the bottom ash hardly reacted, resulting in low compressive strength. However, the addition of DEIPA not only altered the hydration behavior of the cement but also enhanced the pozzolanic reaction between bottom ash and calcium hydroxide, leading to the generation of additional C-S-H. This resulted in high compressive strength not only in the early stages but also in the later stages. Therefore, with the addition of DEIPA during the pulverization of the bottom ash, the reactivity of the bottom ash was significantly improved. Hence, there is potential in the development of bottom ash replacement cement.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.14-19
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• 2013

We have successfully synthesized $Bi_{4-x}La_xTi_3O_{12}$ (x~2) having Aurivillius-type layered perovskite structure from exfoliated layered perovskite oxide of $K_2La_2Ti_3O_{10}$ with Ruddlesden-Popper structure. The reaction between the exfoliated lanthanum titanate nanosheets and BiOCl nanocrystal resulted in the formation of polycrystalline $Bi_{4-x}La_xTi_3O_{12}$ (x~2) after heating above $700^{\circ}C$. Colloidal suspension of the nanosheets could be obtained by intercalating ethylamine (EA) into the protonated lanthanum titanate, $H_2La_2Ti_3O_{10}$, derived from $K_2La_2Ti_3O_{10}$. Transmission electron microscopic (TEM) analysis show that the exfoliated lanthanium titanate nanosheets have a thickness of a few nano meters. According to X-ray diffraction (XRD) analysis, the exfoliated lanthanium titanate was found to be transformed into $Bi_{4-x}La_xTi_3O_{12}$ (x~2) after restacking with BiOCl and subsequent thermal treatment at > $700^{\circ}C$.

• Polymer(Korea)
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• v.39 no.2
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• pp.338-345
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• 2015

Poly(phenylene oxide) (PPO) and polyether imide (PEI) were sulfonated and aminated to create sulfonated poly(phenylene oxide) (SPPO) and aminated polyether imide (APEI), respectively. Characterization of the SPPO and APEI were performed via measurements of FTIR, thermogravimetry (TGA), swelling degree, ion exchange capacity (IEC), and ion conductivity. Next, the surfaces of these membranes were modified by surface fluorination at room temperature. The surface fluorinated SPPO and APEI membranes underwent characterization again for the mentioned measurements to determine any differences. The 3 types of bi-polar membranes were prepared by varying the IEC of the APEI at a fixed SPPO IEC value, which were applied to the low and high NaCl concentration of feed solution at the different current density, respectively. The hypochlorite concentration derived from the surface fluorinated membranes was dependent on the IEC of the APEI and ranged from 491 to 692 ppm at $80mA/m^2$. At low current density of $5mA/m^2$, the hypochlorite concentrations ranged from 18 to 28 ppm for the 4 hrs surface fluorinated membranes and their durability increased greatly.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.543-550
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• 2016

Amine-type PP-g-VBC-EDA adsorbent, which possesses anionic exchangeable function, was prepared through photoinduced graft polymerization of vinylbenzyl chloride (VBC) onto polypropylene non-woven fabric and subsequent amination reaction using ethylenediamine (EDA). Adsorption characteristics of anionic nutrients on the PP-g-VBC-EDA adsorbent have been studied by batch adsorption experiments. The equilibrium data well fitted the Langmuir isotherm model, and the maximum monolayer sorption capacity was found to be 59.9 mg/g for $NO_3-N$ and 111.4 mg/g for $PO_4-P$. The adsorption energies were higher than 8 kJ/mol indicating anion-exchange process as the primary adsorption mechanism. The pseudo-second order kinetic model described well the kinetic data and resulted in the activation energy of 9.8-36.7 kJ/mol suggesting that the overall rates of $NO_3-N$ and $PO_4-P$ adsorption are controlled by the chemical process. Thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ indicated that the adsorption nature of PP-g-VBC-EDA for anionic nutrients is spontaneous and exothermic. The PP-g-VBC-EDA could be regenerated by washing with 0.1 N HCl.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.41-50
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• 1995

2염기성 산의 모노메틸에스테르류와 에틸렌디아민을 반응시켜 얻은 아미도아민 유도체류를 고급지방산 염화물로 아실화하여 N-아실 아미도에틸 N-아미도카르복시산 유도체 9종을 합성하였다. 카르복시기와 디아미드기 그리고 소수성의 긴 알칼사슬을 갖는 모든 반응생성물들은 얇은 막 크로마토그래피와 컬럼크로마토그래피로 분리 ${\cdot}$ 정제하였다. 합성 수율은 $74{\sim}87%$였으며 그들의 구조를 FT-IR, $^1H-NMR$, 그리고 원소 분석으로 확인하였다.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.498-503
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• 2006

i-(2',5'-Diketotetrahydrofuranyl)octadecenyl acid (OSA), an intermediate for the lubricating oil additive, was prepared by the ene-reaction of oleic acid with maleic anhydride. The reaction progress was monitored by gas chromatography by analyzing the amount of OSA. The series of succinimidyl compounds were synthesized by the reaction of alkyl amines and OSA. As a kind of lubricant additives, demulsibility, anti-wear, and anti-corrosion properties of these succinimidyl compounds were measured. The derivative of octadecylamine which has relatively long-chained alkyl group has showed good properties.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.34-45
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• 1998

We provide the reader with a brief introduction to the neurobiology of neuropeptides. Several comprehensive reviews of the distribution and neurochemical, neurophysiological, neuropharmacological and behavioral effects of the major neuropeptides have recently appeared. In reviews of the large number of neuropeptides in brain and their occurance in brain regions thought to be involved in the pathogenesis of major psychiatric disorders, investigators have sought to determine whether alternations in neuropeptide systems are associated with schizophrenia, mood disorders, anxiety disorders, alcoholism and neurodegenerative disease. There is no longer any doubt that neuropeptide-containing neurons are altered in several neuropsychiatric disorders. One of the factors that has hindered neuropeptide research to a considerable extent is the lack of pharmacological agents that specifically alter the synaptic availability of neuropeptides. With the exception of naloxone and naltrexone, the opiate-receptor antagonists, there are few available neuropeptide- receptor antagonists. Two independent classes of neuropeptide-receptor antagonists has been expected to be clinically useful. Naltrexone, a potent ${\mu}$-receptor antagonist, has been used successfully to reduce the need for alcohol consumption. And cholecycstokinin antagonists are now in development as a new class of anxiolytics, which would be expected to be free from tolerance and physical dependence and lack of sedation. In this review, we deal with these two kinds of neuropeptide system, the opioid system and cholesystokinins in the brain. The role of opioid systems in the reinforcement after alcohol consumtion and that of cholesystokinins in the pathogenesis of anxiety will be discussed briefly. As we know, the future for neuropeptides in psychiatry remains bright indeed.

• Membrane Journal
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• v.21 no.1
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• pp.91-97
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• 2011

In this study, the anionic exchange membranes were prepared through the impregnation of polyethylenimine (PEI) into porous polyethylene (PE) separator and then crosslinking with isophrhaloyl dichloride (IPC). To characterize the resulting membranes, the contact angles, FT-IR, ion exchnage capacity and ion conductivity were measured. The amide group is produced the reaction between amines in PEI and -COCl in IPC. In case of ion exchange capacity, 1.96 meq./g dry membrane at the reaction time, 30 sec was decreased to 1.14 meq./g dry membrane at 600 sec reaction time. The ion conductivity, $9.15{\times}10^{-2}S/cm$ at 30 sec reaction time, was obtained.