• Economic and Environmental Geology
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• v.53 no.4
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• pp.347-362
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• 2020

Iron (hydro)oxides in aqueous environments are primarily formed due to mining activities, and they are known to be typical colloidal particles disturbing surrounding environments. Among them, hematites are widespread in surface environments, and their behavior is controlled by diverse factors in aqueous environments. This study was conducted to elucidate the effect of environmental factors, such as ionic composition and strength, pH, and natural organic matter (NOM) on the behavior of colloidal hematite particles. In particular, two analytical methods, such as dynamic light scattering (DLS) and single-particle ICP-MS (spICP-MS), were compared to quantify and characterize the behavior of colloidal hematites. According to the variation of ionic composition and strength, the aggregation/dispersion characteristics of the hematite particles were affected as a result of the change in the thickness of the diffuse double layer as well as the total force of electrostatic repulsion and van der Walls attraction. Besides, the more dispersed the particles were, the farther away the aqueous pH was from their point of zero charge (PZC). The results indicate that the electrostatic and steric (structural) stabilization of the particles was enhanced by the functional groups of the natural organic matter, such as carboxyl and phenolic, as the NOM coated the surface of colloidal hematite particles in aqueous environments. Furthermore, such coating effects seemed to increase with decreasing molar mass of NOM. On the contrary, these stabilization (dispersion) effects of NOM were much more diminished by divalent cations such as Ca²⁺ than monovalent ones (Na⁺), and it could be attributed to the fact that the former acted as bridges much more strongly between the NOM-coated hematite particles than the latter because of the relatively larger ionic potential of the former. Consequently, it was quantitatively confirmed that the behavior of colloidal hematites in aqueous environments was significantly affected by diverse factors, such as ionic composition and strength, pH, and NOM. Among them, the NOM seemed to be the primary and dominant one controlling the behavior of hematite colloids. Meanwhile, the results of the comparative study on DLS and spICPMS suggest that the analyses combining both methods are likely to improve the effectiveness on the quantitative characterization of colloidal behavior in aqueous environments because they showed different strengths: the main advantage of the DLS method is the speed and ease of the operation, while the outstanding merit of the spICP-MS are to consider the shape of particles and the type of aggregation.

• Archives of design research
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• v.12 no.4
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• pp.33-44
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• 1999

Fashion is subjected to newness and change by itself. Fashion trend and tendency which could predict next season akeady indicated that digital and cybel11ation environment lliould be factors in fashion. Changes in future life styles and values caused by digital environment must be variables as fashion objects by themselves. Therefore digital environment of a fashion itself and that all encountered in fashion will not only be an existing situation but also an objective and a factor which must be pursued with fashionable sense in future fashion. Advanced technology and social change in relation to digital environment requires that educational method as well as its content will be changed on the scene of education for future. Thus we should seek an educational direction in fashion design for future society in which digital environment requires new paradigm. Subject to these backgrounds this study has an intension to study the change in fashion extensively influenced by expanded digital environment on a limited situational level of fashion design education and to suggest an educational direction for professional in future fashion design who will serve as a core of fashion area in the future. It is essential that education of professional in fashion for future should be achieved by digital-minded level that eagerly understands and accepts future society in which digital environment will be a main axis. It is necessary for this to make them expetience computers, digital media including CAD program. We have to note that education of digital media is more effective and applicable when accomplished in CAI level which can be related and expetienced with fashion education rather than mere functional training in media themselves. Intellectual creativity will be a vety source of producing values and national competence in 21st centtury. Education of design professional in fashion area must positively accept these environmental charactetistics in future society, as well as deeply reflect the education for the future.

• Archives of design research
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• v.12 no.4
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• pp.231-241
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• 1999

This study propose to analyze the design method and the form elements of museums, of works by Richard Meier, and through the analysis, spacial characteristics of museums will be understood. The museum works of Richard Meier, as an exhibition space, not only display the art works efficiently, but they also offer visitors the opportunity to experience the art of architecture, as a cultural space. Richard Meier, when working on the projects, has utilized the design methods and the architectural language, learned from Mies van der Rohe and Le Corbusier, resourcefully. Having the structural grid as basis, the rational rectangular forms were intended for exhibition space, while the circular and partial circular forms of geometry were utilized in formative space. This was able to maintain the balance between functional and formative space. In the museums of his works, the ramp and the glass wall separated from the structure become very important means of expression. The ramps, not only make people to enjoy the interior and exterior of museum, but also able them to see the works of art from different distances and angles repeatedly and the large glass wall reveals the various shapes of interior to exterior. In comparing with the design method and language of two masters mentioned, the design principles and elements, developed by Meier were applied to the site plans, exhibition space planning and elevations to manifest its originality. The design concept, derived from the urban fabric and historical buildings around, gave harmony to the museum with its surroundings, and employing the deformed axis brought variation and the effect of diversion to the site plan. The exhibition space is much vitalized by the well arrangement of various exhibition fixtures in the museum. The exhibion fixtures, which the partitions, shelves, miches, and stages were put together in flexibility, play multiple roles as partitions dividing spaces, as furniture displaying art works, and as elements creating forms. The systematically arranged fixtures, also produce several visual axes and centers, which have visitors appreciate the works of art in various perspectives, hence create a unique environment.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1329-1336
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• 1996

From January, 1994 to January. 1996, mitral valve replacement was performed in 27 patients. Among these, 17 patients underwent mitral valve replacement(MVR) with preservation of the annulo-papillary continuity(PAPCMVR) (-Group I), and 10 patients underwent conventional methods of excision of all the chordae(Group II). The operative technique for PAPCM VR consists of the division of the anterior leaflet into anterior and posterior segments, shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas. This retrospective study has been designed to evalute the postoperative left ventricular function in the two groups. In the group 1, LVEF(Left Vnetricular Ejection Fraction : %) was 52 $\pm$ 3 preoperatively And 50$\pm$3 postoperatively, LVESI Vent icular End Systolic Volume Index/mL/m2) wIns 59 :6 and 51 $\pm$ 7, LVEDI Ventricular End Diastolic Volume Index/mL/m2) was 124$\pm$ 11 and 91 :8. In the group II, LVEF was 56$\pm$1 and 47:), LVESVI 62$\pm$12 and 61$\pm$15, LVEDVI 133$\pm$27 and 104$\pm$17. : the variation of the LVEF in these two group was statistically different(p(0.05). A comparison of left ventricular function data between Group I(n: 17) and Group II(n: 10) revealed better results in echocardiographic LVEF(p<0.05), LVEDVI(p<0.01) in the former group. The mean functional class(UYHA) was 2.6 preoperative and improved to 1.0 postoperatively In group 1, and 2.8 and to 1.0 in group II. We conclude that maintenance of continuity between the mitral annulus and papillary muscles is expected to have a beneficial effect on postoperative left ventricular performance.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.207-216
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• 2021

This study was conducted to determine the nutritional quality of two newly-developed native chicken strains, compared to the commercial Korean native chicken. A total of 600 chickens (CON: Hanhyup No. 3, CL1: candidate line C, CL2: candidate line D) raised under the same conditions were slaughtered at either 5 or 12 weeks. Leg meat was then obtained and analyzed for its physicochemical properties. The results showed that regardless of the growing period, there was no variation in proximate composition (P>0.05), except for crude protein, between strains. Water holding capacity did not differ between strains at either slaughter age; however, it was significantly lower in the 12-week group than in the 5-week group (P≤0.05). For both skin and muscle color, a^* and b^* values were lower at 12 weeks than at 5 weeks (P≤0.05). DPPH radical-scavenging activity tended to be lower at 12 weeks than at 5 weeks (P≤0.05). Furthermore, all chickens slaughtered at 5 weeks were found to have greater contents of linoleic acid (18:2) and polyunsaturated fatty acids (PUFA) and lower atherogenicity and thrombogenicity indices than those slaughtered at 12 weeks (P≤0.05). However, anserine, betaine, and glucose were more concentrated among the lines at 12 weeks than at 5 weeks (P≤0.05). In conclusion, the quality traits of native chickens were distinct by different production stages rather than chicken lines.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.84-98
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• 2022

Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.