• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.165-169
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• 2015

N-propyl-N,N-dimethylethanolamine was directly ultrasonicated in acidic water for 6 minute to give clear stock solutions. The catalytic hydrolysis of N-propyl-N,N-dimethylethanolamine was studied at $30{\sim}55^{\circ}C$ in the presence of uni-lamellar vesicle and mixture of uni- and multi-lamellar aggregates. The difference of rate between uni- and mixture was observed, where uni-lamellar reaction was more catalytic effect. The phase transition temperature of vesicle was $37{\sim}44^{\circ}C$. The particle size of multi-lamellar than that of uni-lamellar of biological membrane was measured more largely.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1165-1171
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• 2010

The lyotropic mesomorphism of lamellar liquid crystalline phase was examined by observing the swelling behavior of Distearoylphosphatidylcholine(DSPC) in glycerin and panthenol without water. The lyotropic mesomorphism was examined by using DSC, XRDs and Cryo-SEM. Increase of two polar solvents under non-hydrous condition showed distinctive differences in the lyotropic mesomorphism from forming different anisotropic structures with DSPC. Glycerin did not affect to the crystalline region of lamellar phase, whereas typical swelling mesomorphism was shown in the noncrystalline region. In contrast, panthenol showed some effect on the crystalline region, but common swelling mesomorphism was found in the non-crystalline region. In this case, the isopropyl and propyl groups in panthenol were the main factor to affect to the lipophilic domain in the crystalline region of lamellar phase. Also, it was found that the formation of well-arranged lamellar structure only by introducing glycerin and panthenol as a solvent without water, was possible. These results were confirmed by examination of the swelling mesomorphism of liquid crystal membrane triggered by introducing the two polar solvents.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.357-368
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• 2003

II-A isotherms and phase behaviors of 'tocomide', a newly synthesized 1,3-bis(N-(2-hydroxyethyl)-tocopherol succinylamino)-2-hydroxypropane, mixed with cholesterol and linoleic acid, was studied for its monolayer miscibility and a stable delivery formulation for antioxidant applications. The monolayer of tocomide and cholesterol was formed in a homogeneously mixed state at air-water interface. The ternary mixtures with linoleic acid showed various bulk structures, including a stable and transparent solution of thermodynamically stable lamellar phase. The lamellar structure was confirmed by the X-ray diffraction (XRD) patterns and polarized microscopy such that pure tocomide formed a liquid crystal at room temperature with a lamellar periodicity of 36.7 $\AA$(2$\theta$=2.41$^{\circ}$).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.227-230
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• 2007

The multi-lamellar and liquid crystal structures have drawn great public attention in the functional cosmetic and skin-related medicinal areas recently. The structure of an emulsion containing aqueous phase as a binding water and fixed oil phase components forming an association compound of the multi-lamellar structure can reconstruct the intercellular lipid lamellar structure in the stratum corneum and restore barrier function of the skin. In this study, we investigated the beneficial effect of bio-mimic liquid crystal emulsions (BLCE) containing higher fatty alcohol, lecithin, and cholesterol on the skin barrier function, and evaluated its cytotoxicity.

• Korean Journal of Materials Research
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• v.26 no.1
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• pp.13-16
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• 2016

Morphology and formation processes of lamellar grain boundaries in titanium rich binary TiAl intermetallics were studied. TiAl alloys containing aluminum content of 44 to 48 at.% were induction-heated to 1723 K followed by helium-gas-quenching at various temperatures. For the Ti-44%Al, few lamellae were observed in samples quenched from higher than 1473 K. Although small peaks of beta phase were detected using X-ray diffraction, only the ordered hexagonal phase (${\alpha}_2$) with clear APB contrast was observed in TEM observation. For the Ti-48 at.%Al alloy, almost no lamellar structure, and straight grain boundaries were observed in samples quenched from higher than 1623 K. The formation of lamellae along grain boundaries was observed in the sample quenched from 1573 K. The fully lamellar microstructures with serrated boundaries were observed in samples quenched from lower than 1473 K. It was found that the formation of ${\gamma}$ platelets took place at higher temperatures in Ti-48 at.%Al than in Ti-44 at.%Al. Although the size of the serration is different, serrated lamellar grain boundaries could be obtained for all alloy compositions employed. The serration appeared to be due to the grain boundary migration induced by precipitation and growth of ${\gamma}$. Differences in transformation characteristics with aluminum content are discussed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.27 no.1
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• pp.3-15
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• 2001

The bilayer forming ability of pseudo-ceramide PC104 in octanoic acid/water/n-octyl $\beta$-D-glucoside mixtures was investigated through the phase diagram. Because of its low solubility in water and of its crystallization, pseudoceramide PC104 was dissolved in octanoic acid, which is nontoxic additive for foods and cosmetics. The mixtures formed four different phases (L1, L2, LC and two phases). Depending on the concentration of PC104 in octanoic acid, the region of each phase was extended or contracted. On the contrary to the region of L2, regions of lamellar phase and L1 phase were expanded. The bilayer-forming ability of PC104 was explained on the basis of concentration of PC104 at interface and interaction between PC104 and octanoic acid. From FT-IR results, it was found that the interactions of PC104’s polar head group with octanoic acid increased as the amount of PC104 in octanoic acid increased. Also emulsion size and size distribution have been studied depending upon the emulsification path. droplets of emulsion prepared from lamellar phase were smaller and more homogeneous compared to those of emulsions formed from L2 phase.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.162-169
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• 2004

High temperature uniaxial compression tests in the alpha single phase region were carried out on the Ti -43mo1%Al intermetallic compound, in order to obtain oriented lamellar microstructure. The compression deformation temperatures and strain rates are from 1573k to 1623k and 1.0x10$^{-4}$ s to 5.0x10$^{-3}$ s, respectively. Fully lamellar microstructure was observed after the uniaxial compression deformation in a single phase region followed by cooling to room temperature. Lamellar colony diameter depended on strain rates and test temperatures. The diameter varied between 8601m and 300fm. Stress-strain curve showed a work softening and the size of lamellar colony diameter varied depending on peak stresses. This shows the occurrence of dynamic recrystallization. Texture measurements after the uniaxial compression deformation, showed the development of fiber during dynamic recrystallization. It is seen that the area for the maximum pole density existed in 35 degrees away from the compression plane. The texture sharpens with a decrease in strain rate

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.1021-1030
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• 2007

The effects of the creamide III (CER3) and cholesterol (CHOL) on the structure of a non-hydrous distearoyl phosphatidylcholine (DSPC)-based lamellar liquid crystal (LC) hydrated by only propylene glycol (PG) without water were investigated by differential scanning calorimetry (DSC), X-ray diffractions (XRDs), and polarized microscope (PM). As soon as CER3 was incorporated into the lamellar phase, the characteristic LPP was appeared as well as the characteristic SPP, and the formation of separated CER3 crystalline phase was observed depending upon the increase of CER3 content by XRDs. Also, by DSC, it was shown that the increase of CER3 made the monotectic thermal transition be changed to the eutectic thermal transition which indicates the formation of separated CER3 crystalline phases and the main transition temperatures (Tc1) to be gradually decreased and the enthalpy change (ΔH) to be linearly increased. Incorporating CHOL, the formation of LPP and SPP showed almost similar behaviors to CER3, but incorporating small amounts of CHOL showed the characteristic peaks of CHOL which meant the existence of crystalline CHOL phase due to the immiscibility of CHOL with DSPC swollen by PG differently from CER3, and increasing CHOL made the intensity of the 1st order diffraction for LPP weakened as well as the intensities of the characteristic diffractions for DSPC. Also, in the results of DSC, it showed more complex thermal behaviors having several Tc than CER3 due to its bulky chemical structure. In the present study, the inducement of CER3 and CHOL as other lipids present in human stratum corneum (SC) into a non-hydrous lamellar phase is discussed in terms of the influence on their structural and thermal transition.

• Journal of Technologic Dentistry
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• v.34 no.4
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• pp.345-352
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• 2012

Purpose: The age-hardening mechanism of an Au-Ag-Cu-Pt-Zn alloy for crown and bridge fabrication was investigated by means of hardness test, X-ray diffraction study and field emission scanning electron microscopic observation. Methods: Before hardness testing, the specimens were solution treated and then were rapidly quenched into ice brine, and were subsequently aged isothermally at $400-450^{\circ}C$ for various periods of time in a molten salt bath and then quenched into ice brain. Hardness measurements were made using a Vickers microhardness tester. The specimens were examined at 15 kV using a field emission scanning electron microscope. Results: By the isothermal aging of the solution-treated specimen at $450^{\circ}C$, the hardness increased rapidly in the early stage of aging process and reached a maximum hardness value. After that, the hardness decreased slowly with prolonged aging. However, the relatively high hardness value was obtained even with 20,000 min aging. By aging the solution-treated specimen, the f.c.c. Au-Ag-rich ${\alpha}_0$ phase was transformed into the Au-Ag-rich ${\alpha}_1$ phase and the AuCu I ordered phase. Conclusion: The hardness increase in the early stage of aging process was attributed to the formation of lattice strains by the precipitation of the Cu-rich phase and then subsequent ordering into the AuCu I-type phase. The decrease in hardness in the later stage of aging process was due to the release of coherency strains by the coarsening of tweed structure in the grain interior and by the growth and coarsening of the lamellar structure in the grain boundary. The increase of inter-lamellar space contributed slightly to the softening compared to the growth of lamellar structure toward the grain interior.

• Applied Microscopy
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• v.28 no.4
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• pp.603-613
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• 1998

The present study was designed in order to observe relationship between the endoplasmic reticulum and the Golgi complex during spermiogenesis of the long-fingered bat (Miniopterus schreibersi fuliginosus). The testes were obtained from adult bats and treated with the prolonged osmification or fixed with ferrocyanide reduced osmiun. In the Golgi phase, The Golgi complex shows an oval shape, and was composed of a cortex and a medullar enclosing acrosome. The Golgi vacuoles with electron-dense granules of crescent shape were fused with each other. The smooth endoplasrnic reticulum was scattered in all the area of the cytoplasm. In the cap phase, The Golgi complex was crescent in shape, and faced to a nucleus. Large and small vesicles were fused with each other, and then fused with a acrosomal vacuole. The rough endoplasmic reticulum was close to the large Golgi vacuole. In the acrosome phase, The Golgi complex was moved to behind of the acrosome face. Small vesicles were fused with an acrosome, and cisternae of the trans-face of Golgi complex was connected with an acrosome in the early acrosome phase. The smooth endoplasmic reticulum was distributed in the cytoplasm. The annulate lamellar was originated from a radial body-annulate lammellae complex. In the maturation phase, The Golgi complex with dilated cistrern appeared in the cytoplasm, and also, annulate lamellar was observed in the cytoplasm. The connection of the annulate lamellar with the cistern of radial body suggests that an annulate lamellar seems to be closely related to radial body. The smooth endoplasmic reticulum was scattered in the cytoplasm in the early Golgi phase, but annulate lamellar-radial body complex which might be a residual and disappearing form of the smooth endoplasmic reticulum appeared in the acrosome phase. The Golgi complex steadily remained in the late maturation phase when the endoplasmic reticulum began to disappear from the cytoplasm: the Golgi complex was still occurred after acrosome formation. The observations obtained in the present study, which was characterized by the presence of the Golgi complex in the late maturation phase, suggests that the Golgi complex may play an important role also even after the acrosome formation.