• Title/Summary/Keyword: Homogenization Analysis

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Physical properties of cyclosporin A-loaded nanostructured lipid carriers (Cyclosporin A가 봉입된 nanostructured lipid carriers의 물리적 특성연구)

  • Song, Chung-Kil;Chung, Suk-Jae;Shim, Chang-Koo;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • v.38 no.1
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    • pp.39-43
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    • 2008
  • Cyclosporin A (CyA), a potent immunosuppressive drug used in allogeneic transplants and autoimmune disease, is a typical water-insoluble drug. Recently, nanoparticle carriers were investigated to improve the intestinal absorption of drugs. In this study, CyA-loaded nanostructured lipid carriers (NLCs) were prepared from a hot o/w emulsion using the high pressure homogenization method. The NLCs were consisted of cationic lipids, solid lipids, liquid lipids (oils), surfactant and stabilizer. Encapsulation efficiency of CyA in NLCs was approximately 71%. The average particle size and zeta potential of NLCs were below 250 nm and above +40 mV, respectively. The morphology of NLCs was confirmed by transmission electron microscopy (TEM) analysis. Compared to the CyA powder, higher in vitro release of CyA from NLCs was observed after burst release within 30 min. Thus, CyA-loaded NLCs could be applied not only for parenteral route but also for gastrointestinal administration, which needs further investigation.

A Study on the Statistical Representativeness of Samples taken from Radioactive Soil (방사성 토양폐기물 시료의 통계적 대표성에 관한 연구)

  • Cho Han-Seok;Kim T.K.;Lee K.M.;Ahn S.J.;Shon J.S.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.151-157
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    • 2005
  • For the treatment of regulatory clearance of the soils, a procedure for the radionuclides and radioactivity concentration analysis is under development. A strategy for soil sampling including random sampling after homogenization and standardization was set up. Statistical representativeness is considered for not only sampling strategy but also sample size. In this study, designed sample size was designed with confidence interval and error bound of soil using the pilot samples which were taken following the sampling strategy.

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Metallogenesis and Petrology of the Gwangyang Gold Deposits and Goheung Copper Deposits (광양금광상(光陽金鑛床), 고흥동광상(高興銅鑛床)의 광상생성(鑛床生成)과 암석학적(岩石學的) 연구(硏究))

  • Park, Young Surk;Shin, Byung Woo
    • Economic and Environmental Geology
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    • v.17 no.2
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    • pp.91-100
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    • 1984
  • The Gwangyang gold deposits geologically consist of granitic gneiss, metatectic gneiss and porphyroblastic gneiss which correspond to Jirisan gneiss complex. The formations of Gyeongsang system lies unconformably on these gneisses and are intruded by diorite, porphyritic andesite and Bulgugsa granites. Goheung districts are composed of quartz schist, andesitic rock, tuff and granite. The Gwangyang gold deposits are gold bearing fissure filling veins. The vein thickness varies from 15cm to 40cm and they consist of 7-10 layers in parallel. The Goheung copper deposits are sulphide bearing quartz veln which filled the fracture in andesitic rock and biotite granite. The contact zone of these rocks is partially altered. The mineral paragenesis of the Gwangyang and Goheung districts is pyrite, arsenopyrite, pyrrhotite, chalcopyrite, sphalerite, galena, sericite, quartz and calcite. The variation trends of FMA and A'KF triangular diagrams and the differentiation index (norm, Q + Or + Ab) versus oxides diagrams is similar to the Gyeonsang basin igneous rocks. From the trace element analysis of 10 samples of country rocks, wall rocks and veins, the distribution of copper and lead contents display a correlative distribution pattern in relation to gold and silver. Homogenization temperature of fluid inclusions range from $200^{\circ}C$ to $270^{\circ}C$ in quartz from the Gwangyang gold vein and the size of fluid inclusion range from 0.01mm to 0.04mm. The fluid inclusions are mainly one or two phase and the filling degree of the inclusions varies from 85 to 95.

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Petrogenesis of the so-called Masanite in the Kyeongsang Sedimentary Basin (경상퇴적분지내에 분포하는 소위 마산암에 대한 암석성인연구)

  • Kim, Kyu Han;Lee, Hwa Jung
    • Economic and Environmental Geology
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    • v.29 no.4
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    • pp.529-541
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    • 1996
  • The granitic rocks, so called Masanite, characterized by the micrographic, mylmekitic and perthitic textures, and zonal structure of the plagioclase in the Masan, Changwon and Jinhae areas belong to normal granite and granodiorite based on the modal analysis. These petrographic features strongly suggest the shallow emplacement of the plutons which are defined a typical calc-alkaline suite and I-type granitoids. The pressures of emplacement of the granitic plutons using the amphibole geobarometer were calculated to be 1.2kbar in the Masan area and 1.4kbar in the Changwon area. Their amphibole-plagioclase equilibrium temperatures were obtained to be $638^{\circ}C$ for the former ones and $724^{\circ}C$ for the latter. Homogenization temperatures and salinities for the type HI and IV fluid inclusions in quartz range from 298 to $541^{\circ}C$ (av. $425^{\circ}C$), and 10.5 to 34.6 wt.% NaCl (av. 28.2 wt.% NaCl), respectively. Gas compositions of the granitic rocks with fairly high $CO_2$ concentration relative to CH, correspond to the magnetite series granite of the mantle source. The terminology of the Masanite is not recommended usage. Because it is hard to discriminate in terms of petrological and petrogenetical characteristics between the Masanite and the Bulguksa granites in the Kyeongsang basin.

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Is the Korean Clothing and Textile Industry Processing to Globalization\ulcorner (한국 섬유 및 의류 산업의 세계화 연구)

  • 손미영;이은영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.6
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    • pp.1131-1142
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    • 2001
  • This research attempts to evaluate the globalization concept and the development of advance progress of the Korean clothing and textile industry toward globalization. Globalization is driven by technology, which create the homogenization of tastes. In the business sector, globalization drives not only the physical presence in the foreign countries, but the way of looking at world markets and organizing as a basis for construction. The process of globalization of a company simply consists of exportation, establishment of foreign branch offices and overseas operations. Entrance to the overseas market can be divided into two categories, where one is based upon exportation method, and the other is based upon direct foreign investment. To observe the development of globalization of the Korean clothing and textile industry, a analysis of exportation and direct foreign investment by the industry was conducted. The result revealed the following: (i) The exportation and direct foreign investment of Korean clothing and textile industry has been focused in Asia, and the industry is influenced by cultural and geographic consciousness: and (ii) although the clothing and textile industry of Korea is still incomplete when compared to all industry, the study shows that globalization of the textile and garment industry is well underway.

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Nonlinear dynamic analysis of porous functionally graded materials based on new third-order shear deformation theory

  • Allah, Mohamed Janane;Timesli, Abdelaziz;Belaasilia, Youssef
    • Steel and Composite Structures
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    • v.43 no.1
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    • pp.1-17
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    • 2022
  • The free and forced nonlinear dynamic behaviors of Porous Functionally Graded Material (PFGM) plates are examined by means of a High-Order Implicit Algorithm (HOIA). The formulation is developed using the Third-order Shear Deformation Theory (TSDT). Unlike previous works, the formulation is written without resorting to any homogenization technique neither rule of mixture nor considering FGM as a laminated composite, and the distribution of the porosity is assumed to be gradually variable through the thickness of the PFGM plates. Using the Hamilton principle, we establish the governing equations of motion. The Finite Element Method (FEM) is used to compute approximations of the resulting equations; FEM is adopted using a four-node quadrilateral finite element with seven Degrees Of Freedom (DOF) per node. Nonlinear equations are solved by a HOIA. The accuracy and the performance of the proposed approach are verified by presenting comparisons with literature results for vibration natural frequencies and dynamic response of PFGM plates under external loading. The influences of porosity volume fraction, porosity distribution, slenderness ratio and other parameters on the vibrations of PFGM plate are explored. The results demonstrate the significant impact of different physical and geometrical parameters on the vibration behavior of the PFGM plate.

Protective Effect of Placental Extract against Oxidative Stress through Autophagy Activity in Schwann Cells (태반 추출물의 자가포식 활성을 통해 산화스트레스에 대한 슈반세포 보호 효과)

  • Lim, GyeongMin;Cho, Gwang-Won;Jang, Chul Ho
    • Journal of Integrative Natural Science
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    • v.15 no.3
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    • pp.123-129
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    • 2022
  • Schwann cells play a critical role for myelination in peripheral nerve system. It also plays an important role in nerve protection and regeneration. In peripheral nerve damage, regeneration is induced by the migration and proliferation of Schwann cells which were promoted by suppressing the oxidative stress. In this study, Human placental extract was prepared by homogenization and estimated its efficacy in RSC96 cells. Placental extract exhibited a protective effect against hydrogen peroxide-induced oxidative stress in RSC96 cells, confirmed by MTT assay. Furthermore, placental extract decreased intracellular ROS against oxidative stress, confirmed by DCFH-DA assay. Autophagy was visualized with Cyto-ID staining to confirm the autophagy activity of placental extracts. The activity of autophagy was confirmed by immunoblot analysis of autophagy flux-associated proteins such as LC3 conversion and SQSTM1 degradation. Thus, we confirmed the antioxidant effect of placental extract to protect RSC96 cells from oxidative stress, and observed that it activated autophagy and restored autophagy flux.

A computationally efficient numerical integration scheme for non-linear plane-stress/strain FEM applications using one-point constitutive model evaluation

  • Hector R. Amezcua;Amado G. Ayala
    • Structural Engineering and Mechanics
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    • v.85 no.1
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    • pp.89-104
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    • 2023
  • This work presents a proposal for employing reduced numerical integration in the formulation of the 4-node quadrilateral solid finite element. The use of these low-order integration rules leads to numerical instabilities such as those producing the hourglass effect. The proposed procedure allows evaluating a given constitutive model only in one integration point, achieving an attractive computational cost reduction and, also, successfully controls the hourglass effect. A validation of the proposal is included and discussed throughout the paper. To show the efficiency of the proposal, several application examples of masonry structures are studied and discussed. To represent the non-linear mechanical behaviour of masonry a plastic-damage model is implemented within the application of this sub-integration scheme. Also, in order to have a full and computationally efficient strategy to determine the behaviour of masonry structures, involving its evolution to collapse, a homogenization technique with a macro-modeling approach is used. The methodology discussed throughout this paper demonstrates a substantial computational cost reduction and an improved approximation of the non-linear problem evidenced by a reduction of up to 85% of the computational time for some cases.

Beam pattern analysis for beam homogenization of conformal array sonar (곡면 배열 소나의 빔 균일화를 위한 빔 패턴 분석)

  • Jeong-Ung, Choi;Wooyoung, Hong;Jun-Seok, Lim;Keunhwa, Lee
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.6
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    • pp.637-646
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    • 2022
  • Sub-arrays of arbitrary conformal array have different geometric shape through steering direction, thus the beam patterns of sub-arrays are always non-uniform. In this paper, we apply the beam pattern synthesis method using convex optimization into the conformal array, and shows the improvement of uniformity of beam performance. The simulation is performed with the conformal array of cut-sphere shape. As a result, the standard deviation of 3 dB beamwidth in elevation is greatly reduced but the directivity index is also reduced. To alleviate this trade-off, we propose a convex optimization using a shading function.

Axial frequency analysis of axially functionally graded Love-Bishop nanorods using surface elasticity theory

  • Nazemnezhad, Reza;Shokrollahi, Hassan
    • Steel and Composite Structures
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    • v.42 no.5
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    • pp.699-710
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    • 2022
  • This work presents a comprehensive study on the surface energy effect on the axial frequency analyses of AFGM nanorods in cylindrical coordinates. The AFGM nanorods are considered to be thin, relatively thick, and thick. In thin nanorods, effects of the inertia of lateral motions and the shear stiffness are ignored; in relatively thick nanorods, only the first one is considered; and in thick nanorods, both of them are considered in the kinetic energy and the strain energy of the nanorod, respectively. The surface elasticity theory which includes three surface parameters called surface density, surface stress, and surface Lame constants, is implemented to consider the size effect. The power-law form is considered for variation of the material properties through the axial direction. Hamilton's principle is used to derive the governing equations and boundary conditions. Due to considering the surface stress, the governing equation and boundary condition become inhomogeneous. After homogenization of them using an appropriate change of variable, axial natural frequencies are calculated implementing harmonic differential quadrature (HDQ) method. Comprehensive results including effects of geometric parameters and various material properties are presented for a wide range of boundary condition types. It is believed that this study is a comprehensive one that can help posterities for design and manufacturing of nano-electro-mechanical systems.