• YAKHAK HOEJI
• /
• v.18 no.3
• /
• pp.197-202
• /
• 1974

The data pf dosspcoatopm cpmstamts for aliphatic amines and quaternary ammonium-methylorange salts are based on the electrosatic theory of conductance. Dissociation constants for primary amines nad quaternary ammonium-methylorange salts (1$\times$10$^{-5}$~1$\times$10$^{-3}$ M) in nitrobenzene solution or water solution was evaluated from the relation of the concentration and the electric conduction and the electric conductance at $25^{\circ}C$ Plots of ${\delta}C$ against reciprocal conductance were linear ; hence the center-to-center distance of this salt was 1.75 $\AA$ in nitrobenzene solution.

• The Korean Journal of Quaternary Research
• /
• v.19 no.1
• /
• pp.1-17
• /
• 2005

This study aims to study the distribution and formation age of Quaternary deposits in the downstream of Yeongsan Estuarine River, encompassing Muan, Illo and Donggang counties. For this purpose the authors examine several borehole data, and step trench survey for excellent profiles was studied in connection with grain size population and magnetic susceptibility. As a result, it is interpreted that the coastal plain of the Yeongsan River was formed by sea level rise after Last Glacial Maximum(LGM). The fore edge/escarpment of coastal terraces distributed 7-10 m asl is assumed to be formed during the last glacial period, while the coastal terraces distributed above 7-10m asl formed during MIS 5a. In addition, the fore edge/escarpment of coastal terraces distributed above 15 m asl is presumed to be have been formed during the stadial of last interglacial period, while the formation age of coastal terraces distributed above 15m(asl) is assumed to be MIS 5e. This formation age can be estimated by the coastal terrace ages of the southeastern coast of Korean Peninsula. The characteristics of Quaternary deposits linked to paleolithic culture will eventually lead to the reconstruction of ecosystem environment of paleolithic peoples.

• Journal of Preventive Medicine and Public Health
• /
• v.48 no.6
• /
• pp.271-273
• /
• 2015

Quaternary prevention should be implemented to minimize harm to patients because the ultimate goal of medicine is to prevent disease and promote health. Primary care physicians have a major responsibility in quaternary prevention, and the establishment of clinical epidemiology as a distinct field of study would create a role charged with minimizing patient harm arising from over-medicalization.

• YAKHAK HOEJI
• /
• v.33 no.4
• /
• pp.226-228
• /
• 1989

In connection with the synthesis of the biologically active pimarane diterpenoids, some synthetic routes to the quaternary carbon unit were examined. Especially, Claisen rearrangement of allyl acetates prepared from acetol provided ${\gamma}-hydroxy$ acid containing vinyl substituent as the desired unit.

• ETRI Journal
• /
• v.43 no.4
• /
• pp.717-727
• /
• 2021

In this study, new multiplier and adder method designs with multiplexers are proposed. The designs are based on quaternary logic and a carbon nanotube field-effect transistor (CNTFET). The design utilizes 4 × 4 multiplier blocks. Applying specific rotational functions and unary operators to the quaternary logic reduced the power delay produced (PDP) circuit by 54% and 17.5% in the CNTFETs used in the adder block and by 98.4% and 43.62% in the transistors in the multiplier block, respectively. The proposed 4 × 4 multiplier also reduced the occupied area by 66.05% and increased the speed circuit by 55.59%. The proposed designs are simulated using HSPICE software and 32 nm technology in the Stanford Compact SPICE model for CNTFETs. The simulated results display a significant improvement in the fabrication, average power consumption, speed, and PDP compared to the current bestperforming techniques in the literature. The proposed operators and circuits are evaluated under various operating conditions, and the results demonstrate the stability of the proposed circuits.

• Proceedings of the IEEK Conference
• /
• 2003.07c
• /
• pp.2621-2624
• /
• 2003

In this paper, we designed 12Bit DAC(Digital to Analog Converter) that applied to multiple-valued logic system to Binary system. The proposed D/A Converter structure consists of the Binary to Quaternary Converter(BQC) and Quaternary to Analog Converter(QAC). The BQC converts the two input binary signals to the one Digit Quaternary output signal. The QAC converts the Quaternary input signal to the Analog output signal. The proposed DAC structure can implement voltage mode DAC that high resolution low power consumption with reduced chip area. And also, it has advantage of the easy expansion of resolution and fast settling time.

• YAKHAK HOEJI
• /
• v.35 no.1
• /
• pp.15-21
• /
• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.

• Korean Journal of Pharmacognosy
• /
• v.30 no.1
• /
• pp.54-58
• /
• 1999

A method using coloric and spectrophotometric detection have been developed for the identification of the tertiary or quaternary alkaloids contained in Corydalis tuber and its preparations. The principle is based on the formation or decomposition of complex compounds. The complex compound of the tertiary and quaternary alkaloids have been formed by adding tetrathiocyanatocobaltate [II] ion to the test soln. Diverse crude drugs were screened using this method and the results indicated that isoquinoline, aconitine-type alkaloids in crude drugs can be readily detected. The method is simple, convenient, reproducible and applicable to the verification of the crude drug Corydalis tuber and its preparations.

• Journal of the Korean Society of Safety
• /
• v.13 no.4
• /
• pp.192-198
• /
• 1998

MRSM(modified response surface methodology)-2 model is presented for the prediction of boiling points in combustible solution of quaternary systems. This model requires only normal boiling points of pure substances and group-group parameters which are based on the group-group concepts without the use of experimental data under consideration. By means of this methodology, it is possible to predict the boiling points of the combustible mixture of quaternary systems by plotting of isothermal lines using computer graphics. The proposed methodology has been tested and compared successfully with reported boiling points in journals for the combustible solution of quaternary systems. It is hoped eventually that this methodology will permit prediction of the flash point and flammability limit for the combustible mixture of multicomponent systems.

• Journal of Ginseng Research
• /
• v.13 no.2
• /
• pp.189-197
• /
• 1989

A new quaternary ammonium compound, hydrolyzed ginseng-saponin quaternary (HGSQ), from Korean ginseng saponin and 2,3-epoxypropyltrimethylammonium chloride has been developed as a conditioning agent in cosmetics. This structure has a hydrophobic group from the aglycone of ginseng saponin which is biologically active and considered to be the most important component of the Korean ginseng. Its properties : surface tension, critical micelle concentration (CMC), eye irritation, sorption onto hair, force reduction(%) and moisture retention effect were studied. Its cationic character allows the molecule to be more substantive than ginseng saponin. HGSQ had good physical properties and was safe. enough as a cosmetic raw material. Also half-head tests of HGSQ-containing shampoo were carried out to compare the conditioning effects in shampoos. HGSQ was an excellent conditioning agent in shampoo..