The stability of the steady Rossby-Haurwitz wave (R-H wave) in the nondivergent barotropic model (NBM) on the sphere was investigated with the normal mode method. The linearized NBM equation with respect to the R-H wave was formulated into the eigenvalue-eigenvector problem consisting of the huge sparse matrix by expanding the variables with the spherical harmonic functions. It was shown that the definite threshold R-H wave amplitude for instability could be obtained by the normal mode method. It was revealed that some unstable modes were stationary, which tend to amplify without the time change of the spatial structure. The maximum growth rate of the most unstable mode turned out to be in almost linear proportion to the R-H wave amplitude. As a whole, the growth rate of the unstable mode was found to increase with the zonal- and total-wavenumber. The most unstable mode turned out to consist of more-than-one zonal wavenumber, and in some cases, the mode exhibited a discontinuity over the local domain of weak or vanishing flow. The normal mode method developed here could be readily extended to the basic state comprised of multiple zonalwavenumber components as far as the same total wavenumber is given.

지방산 혼합물 단분자층 LB막의 전기화학적 특성을 통하여 그 안정성을 순환전압전류법으로 조사하였다. 지방산혼합물 LB막은 ITO glass에 LB법을 사용하여 제막하였다. 전기화학적 특성은 0.01N KClO4 용액에서 3 전극 시스템으로 순환전압전류법에 의해 측정하였다. 측정범위는 연속적으로 1650 mV로 산화시키고, 초기 전위인 -1350 mV로 환원시켰다. 주사속도는 각각 50, 100, 150, 200 및 250 mV/s로 설정하였다. 그 결과 지방산혼합물 LB막은 순환전압전류곡선으로부터 산화전류로 인한 비가역 공정으로 나타났다. 지방산혼합물 LB막은 전해질농도가 0.01 N NaClO4 용액에서 확산계수(D)는 각각 7.9×10-2 cm2s-1을 얻었다.

CE RCD (Recreational Craft Directive) is a certification for the design and construction of small vessels, including pleasure yachts, which are widely used not only in the countries within the European Union, but also in Japan and Southeast Asia. Recently, South Korean leisure craft shipyards have developed interest in exporting to foreign leisure craft markets such as Europe; however, they have encountered difficulties because of the CE RCD regulations, which are relatively complex and difficult to understand. The requirements for buoyancy and stability, which are essential properties that must be understood within the early stage of ship design, are defined based on ISO 12217. However, preparing this assessment according to ship classification regulations is an exceedingly complex task, even with knowledge of naval architecture. In this research, we have developed design support tools to systematically support assessments and preemptively define design information so that buoyancy and stability assessments based on ISO 12217 can be systematically prepared. Our research results were applied to actual examples of yacht design to confirm validity. We believe that the improved yacht design process presented in this research can act as a foundational reference for enhancing the effectiveness and systematic buoyancy and stability assessments.

Retinol is a type of vitamin A that helps the skin's epidermal cells maintain their original function and plays an important role in visual acuity. However, retinol cannot simply be incorporated into foods in its pure form because of limited solubility and chemical instability. In this study, retinol was encapsulated within lipid droplets of oil-in-water (O/W) emulsion and the photo stability of retinol loaded in O/W emulsion was examined. O/W emulsions containing retinol were prepared using Tween 20, Decaglycerine myristate and WPI, respectively, at different oil concentrations (0.1, 0.5, 1.0, 2.0, and 4.0 wt%). Photo stability of retinol was determined by measuring retention rate (%) of retinol loaded in O/W emulsions after exposure to UV light for 24 h and compared to that of retinol dissolved in ethanol. The retinol retention rate was higher for O/W emulsions than retinol in ethanol and the retention rate increased as the oil concentration of emulsions increased, which might be attributed to the opaqueness of emulsions. As the oil concentration of emulsions increased, the turbidity of emulsions also increased. In terms of the type of emulsifier, decaglycerine myristate-stabilized emulsion had the highest retinol retentions rate than other emulsifier-stabilized emulsions after exposure to UV light. This study provides important information for designing effective emulsion-based delivery systems for improving the stability of retinol.

Glabridin (from licorice) and carnosic acid (from rosemary) are natural phenolic compounds which show the antioxidant and antimicrobial activities. Nevertheless, the use of licorice and rosemary extracts in food matrix is highly limited due to the low water solubility and poor chemical stability of active constituents of both extracts. Therefore, the aim of this study is to investigate the functionality and stability of O/W emulsions containing glabridin and carnosic acid for improving their efficiency for food application. To manufacture the O/W emulsions (10% oil, w/w), licorice and rosemary extracts were dispersed, respectively, in soy bean oil (3%, w/w) and then emulsified with various emulsifiers (decaglyceryl luarate, decaglyceryl monooleate, whey protein isolate and casein) using a high pressure homogenizer (10,000psi for 3 times). Particle size and ζ-potential of emulsions were then measured during the storage for 4weeks at room temperature. UV stability, antioxidant & antimicrobial activity were also tested. The size of oil droplets and the ζ-potential values remained within the margin of error during the 4weeks of storage. Core materials in extracts, glabridin and carnosic acid, incorporated into emulsion system were kept less damaged by UV rays than those dissolved in oil only. Antioxidant activity of emulsion systems remained significantly higher than that of oil system during storage period and also depended on the emulsifier type an increase in interfacial area in emulsion system might increase antioxidant activity of core materials dissolved in oil. The result obtained from the study could be beneficial for food industry interested in utilizing licorice and rosemary extracts.

The pace of development of Pickering emulsions stabilized by food-derived particles such as starches and proteins has recently soared to replace conventional emulsions using a large amount of chemical emulsifiers. The protein-stabilized emulsions cannot be transported to small intestine due to its degradation in stomach condition. The starch-stabilized emulsions have a low colloidal stability because of their large size, so they cannot be applied to beverages. In this study, to increase the colloidal stability of starch-stabilized emulsions, starch nanocrystals (SNC) obtained by sulfuric acid hydrolysis were used to stabilize emulsions, and ultrasonic treatment was added to further increase the colloidal stability. An oil-soluble dye (Nile Red) was used to visualize changes in the lipid phase during digestion. Lipid-labeled Pickering emulsions were passed through a simulated gastrointestinal tract consisting of mouth, stomach, and intestinal phases, and changes in lipid location and morphology were monitored using confocal laser scanning microscopy. The lipid droplets were slightly enlarged in the mouth condition, highly flocculated in the gastric condition, and completely digested in the small intestine condition. Our results show that the additional ultrasonication to the SNC-stabilized emulsions resulted in enhanced colloidal stability, and the SNC-stabilized emulsions produced by the above process were stable in the mouth and stomach conditions and completely digested in the small intestine condition. So, the SNC-stabilized emulsions produced through this study could be effectively applied to functional beverages as a chemical emulsifier-free delivery systems.

This study investigated the stability of ethanolic extract from fermented Cirsium setidens Nakai (FCSN) in order to develop functional materials during different storage conditions. We evaluated pectolinarin and pectolinarigenin contents, total phenol content and antioxidant activity (DPPH radical scavenging activity and FRAP assay) of ethanolic extract from FCSN obtained by bioconverison at various temperatures (4, 25 and 50℃) and pHs (4.0, 7.0 and 10.0). Our results show that the pectolinarin, pectolinarigenin, and total phenol contents in ethanolic extract from FCSN were decreased during the storage periods. Moreover, the DPPH radical scavenging activity did not significantly change at 4℃ and 25℃. Pectolinarin and pectolinarigenin contents, total phenol content and DPPH radical scavenging activity of ethanolic extract from FCSN at acidic pH (pH 4.0) and neutral pH (pH 7.0) were higher than those at the alkaline pH range. These results indicate that the optimum storage condition of the ethanolic extract from FCSN was 4℃ and pH 4.0~7.0 range.

The purpose of this study was to investigate the quality characteristics of roasted peanuts and the antioxidative effect of peanut oil added with sesame oil. Saltiness of roasted peanut increased with increasing salt content. In terms of color value, L and b values decreased as increasing concentration increased, whereas a value increased with increasing salt content. Overall, sensory evaluations proved that roasted peanuts with 15% added salt was preferred over other samples. For peanut oil added with sesame oil, acid values increased during the storage period, whereas samples made with sesame oil had lower values than the control group. Peroxide values increased rapidly for 21 days and then decreased. The acid and peroxide values were lower in peanut oil added with 50% sesame oil compared to peanut oil added with 30%, 10%, and 70% sesame oil, as well as the control. The TBA values of peanut oil made with 50% and 30% sesame oil were lower than those of the control and 70% and 10% sesame oil. According to the Rancimat method, PS-50% (524 min) and PS-30% (453 min) demonstrated longer induction periods as compared to the control (280 min), PS-70% (445 min), and PS-10% (291 min) samples.

Since 1990’s, many researches about ultra high performance concrete have been conducted. Compare to conventional concrete, it shows significantly high compressive and tensile strength so that leads to reduce the self weight of structures. However, the use of slender member may meet the buckling failure that is not common phenomenon in concrete structures so far. Most design codes have not suggested any provisions for buckling limit states and very few of researches have been conducted for buckling of concrete girders. In this study, a number of finite element analysis were carried out to investigate the buckling behavior of UHPC I-shaped girders.

During a construction of a road, a temporary bridge is often connected to a existing bridge. In this case, a fatigue stability problem, which is not considered in the design of the bridge, can be occurred in the main girder of the existing bridge due to the vehicle load direction change. In this study, the fatigue stability of the main girder and cantilever slab of the bridge was tested with the allowable fatigue stress of the design specifications of the road bridge. The big stress change was occurred at 55m away from the support, and the middle point of the span. Furthermore, the excess of the allowable fatigue stress of the design specifications of the road bridge was confirmed at the cross section. Hence, it was concluded that the reinforcements for the cantilever slab and main girder of the bridge are required. The bridge after the reinforcement was tested for the fatigue stability, and it was confirmed that the bridge is safe.

본 연구에서는 간척지에서 플라스틱 온실의 기초안전성을 평가하기 위하여 강재 나선말뚝기초를 갖는 폭 6m 연동하우스 1개동과 강재 나선말뚝기초와 파이프줄기초를 각각 적용한 폭 8.2m 단동하우스 2개동을 SPT N값 이 2인 간척지 시험포장에 설치하여 플라스틱 온실의 인발량 및 침하량을 측정하였다. 또한 플라스틱 온실에 적용된 나선말뚝기초 3종(φ50, φ75 및 φ100)을 인근의 간척지 시험포장에 설치하여 인발저항특성을 시험하였다. 평가 기간 중 플라스틱 온실의 수직변위 움직임이 관측 되었지만 온실의 규모와 비교하여 그 변위는 무시할만한 수준이었다. 평가 기간 중의 최대 수직변위는 나선말뚝 기초를 적용한 연동하우스의 경우 +9.0mm(인발)~- 11.5mm(침하), 나선말뚝기초를 적용한 단동하우스의 경 우 +1.3mm~-7.7mm, 파이프줄기초를 적용한 단동하우스 의 경우 +0.9mm~-11.2mm로 나타났다. 나선말뚝기초의 허용인발력은 모두 극한하중 판정기준에 의해 판단할 수 있었으며 φ50mm, φ75와 φ100 나선말뚝기초의 최종 허용인발력은 각각 0.40kN, 1.0kN과 2.5kN으로 산정할 수 있었다. 평가기간 중 나선말뚝기초를 적용한 플라스틱 온실의 기초안전성을 최종적으로 판단하기에는 다소 무리가 있다고 판단되나 강재 나선말뚝기초를 간척지 플라스틱 온실의 기초로 사용하더라도 큰 문제는 없을 것으로 판단되었다.

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group (n2=15). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

Vegetable seed oils (VSOs) have been extracted and used not only as ingredients in food and as sources of dietary lipids, but also as sources of nutraceuticals used to overcome the various oxidative stresses that contribute to the development of diseases, including cancer and other chronic conditions. The chemical compositions and oxidative stabilities of various VSOs were therefore investigated; samples were stored for 35 d, with each oil having been tested under O2 exposure, sealed from O2 exposure and sealed from O2 exposure while containing O2 scavengers. Oxidative stability was evaluated by peroxide value (POV), p-anisidine value (p-AnV), iodine value (IV), and thiobarbituric acid (TBA) value. Perilla seed and flaxseed oil were mostly composed of linolenic acid (45.5% and 59.7%, respectively), whereas pine seed oil was mostly composed of linoleic acid (48.3%). Meanwhile, camellia seed and olive oils contained 80% oleic acid, which correlated strongly with oxidative stability. The POV, p-AnV, and TBA values were the highest under O2 exposure, and the lowest in the presence of O2 scavengers. These results indicate that VOS oxidative stability depends not only on storage conditions, but on unsaturated fatty acid profiles as well.

We have investigated the washing method of as-synthesized CdSe/ZnS core/shell structure quantum dots (QDs) and the effective surface passivation method of the washed QDs using PMMA. The quantum yield (QY%) of assynthesized QDs decreases with time, from 79.3% to 21.1%, owing to surface reaction with residual organics. The decreased QY% is restored to the QY% of as-synthesized QDs by washing. However, the QY% of washed QDs also decreases with time, owing to the absence of surface passivation layer. On the other hand, the PMMA-treated QDs maintained a relatively higher QY% after washing than that of the washed QDs that were kept in toluene solution for 30 days. Formation of the PMMA coating layer on CdSe/ZnS QD surface is confirmed by HR-TEM and FT-IR. It is found that the PMMA surface coating, when combined with washing, is useful to be applied in the storage of QDs, owing to its long-term stability.

Nanoemulsions are actively used in several applications for pharmaceutical, cosmetic and chemical industries. In this study, we propose the use of microfluidizer known as high pressure homogenizer to prepare lipid nanoemulsion as a potent cosmetic delivery carrier. The lipid nanoemulsions were prepared by O/W emulsion with hydrogenated lecithin and different type of oils. Effects of oil type on the stability of the lipid nanoemulsion were investigated with Dynamic Light Scattering (DLS) and Zeta-potential. Arbutin was used as model drug for transdermal administration through hairless mouse skin. Transdermal arbutin delivery using the lipid nanoemulsions was studied with HPLC method.

Mesenchymal stem cells (MSCs) have been researched for use in biomedical applications, particularly for cell-based therapies and regenerative medicine due to their self-renewing capacity and ability to differentiate into multiple cell types such as adipose, bone, and tendon tissues. Cryopreservation of MSCs is a common preservation method that is advantageous for cellular therapies in human and veterinary medicine. Adipose tissue-derived cells have been shown to maintain their properties after cryopreservation. In this study, we investigated the morphology, proliferation (cumulative population doubling level and doubling time), cell surface markers (CD34, CD90, and CD105), and ability to differentiate into adipose, bone, and cartilage tissues in vitro of equine adipose tissue-derived MSCs (eAD-MSCs) and miniature pig adipose tissue-derived MSCs (mpAD-MSCs) with and without long-term cryopreservation. The eAD-MSCs and mpAD-MSCs were analyzed immediately and after being frozen in liquid nitrogen for 3 years and 2 years, respectively. Cryopreserved eAD-MSCs maintained their morphology, proliferation rate, and cell surface markers compared with fresh cells. With the exception of proliferation rate, cryopreserved mpAD-MSCs also maintained their fresh cell characteristics. The proliferation rate of cryopreserved mpAD-MSCs was higher than that for fresh cells. Cryopreservation did not change the adipogenic, chondrogenic, or osteogenic differentiation potentials of eAD-MSCs and mpAD-MSCs. In summary, long-term cryopreservation maintains the cell phenotype and differentiation ability of eAD-MSCs and mpAD-MSCs. These results might be useful when developing veterinary medicine and clinical applications.

The objectives of this study, which filled gaps in previous studies, were: (1) to find the optimal mixing condition of nanoemulsions containing oleoresin capsicum (OC), Tween 80, propylene glycol (PG), and sucrose monostearate (SES) by microfluidization; (2) to investigate their properties and stability depending on such factors as pH, temperature, and heating time; (3) to measure the effect of adding ascorbic acid. In order to test these objectives, the following three experiments were conducted: Firstly, in order to find the optimal mixing ratio, nanoemulsions containing OC - the mean diameter of which is smaller than 100 nm - were prepared through the process of microfluidization; and their mean particle size, zeta potential, and capsaicinoids were measured. The test results indicated that the mixing ratio at OC : Tween 80 : PG + water(1:2) = 1 : 0.2 : 5 was optimal. Secondly, the properties and stability of nanoemulsions were investigated with varying parameters. The test results illustrated that single-layer nanoemulsions and double-layer nanoemulsions coated with alginate were stable, irrespective of all the parameters other than/except for pH 3. Thirdly, the properties of nanoemulsions were then analyzed according to the addition of ascorbic acid. The results demonstrated that the properties of single-layer nanoemulsions were not affected by addition of ascorbic acid. In case of alginate double-layer nanoemulsions, the particle size was reduced, and zeta potential increased with the addition of ascorbic acid. In conclusion, the demonstrated stability of various nanoemulsions under the different conditions in the present study suggests that these findings may constitute a basis in manufacturing various food-grade products which use nanoemulsions-and indicate that food nanoemulsions, if adopted in the food industry, have the potential to satisfy both the functionality and acceptability requirements necessary to produce commercially marketable food-grade products.

Graphite was diffusion-bonded by hot-pressing to W-25Re alloy using a Ti interlayer. For the joining, a uniaxial pressure of 25 MPa was applied at 1600 oC for 2 hrs in an argon atmosphere with a heating rate of 10 oC min−1. The interfacial microstructure and elemental distribution of the W-25Re/Ti/Graphite joints were analyzed by scanning electron microscopy (SEM). Hot-pressed joints appeared to form a stable interlayer without any micro-cracking, pores, or defects. To investigate the high-temperature stability of the W-25Re/Ti/Graphite joint, an oxy-acetylene torch test was conducted for 30 seconds with oxygen and acetylene at a 1.3:1 ratio. Cross-sectional analysis of the joint was performed to compare the thickness of the oxide layer and its chemical composition. The thickness of W-25Re changed from 250 to 20 μm. In the elemental analysis, a high fraction of rhenium was detected at the surface oxidation layer of W-25Re, while the W-25Re matrix was found to maintain the initial weight ratio. Tungsten was first reacted with oxygen at a torch temperature over 2500 oC to form a tungsten oxide layer on the surface of W-25Re. Then, the remaining rhenium was subsequently reacted with oxygen to form rhenium oxide. The interfacial microstructure of the Ti-containing interlayer was stable after the torch test at a temperature over 2500 oC.