• Title, Summary, Keyword: functional property

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pH-sensitive drug controlled release core/shell fibers fabricated by combination of electrospinning and photopolymerization

  • Zhu, Xiaolei;Zhang, Hongwei;Nie, Jun;Ma, Guiping
    • Journal of Industrial and Engineering Chemistry
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    • v.45
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    • pp.334-337
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    • 2017
  • pH-sensitive drug loaded core shell fibers were fabricated by a combination of electrospinning and UV photo-polymerization. Combretastatin A4 (CA4) was selected as the model drug loaded in PLA to test the pH-sensitivity property of the core shell fibers. The morphology of the fibers was studied by scanning electron microscopy (SEM), and the core shell structure of the fibers was confirmed by transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The drug release assay was tested via the UV-vis spectrophotometer, and the pH-sensitivity of core shell fibers was tested by drug release assay under pH 5.0 and 7.4.

Monitoring of Chemical Changes in Explosively Puffed Ginsengvand the Optimization of Puffing Conditions

  • Yoon, Sung-Ran;Lee, Gee-Dong;Kim, Hyun-Ku;Kwon, Joong-Ho
    • Journal of Ginseng Research
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    • v.34 no.1
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    • pp.59-67
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    • 2010
  • Response surface methodology was used to predict the optimum conditions of explosive puffing process for ginseng. A central composite design was used to monitor the effect of moisture content and puffing pressure on dependent variables such as functional compounds (extract yield, crude saponin, acidic polysaccharide, and total phenolic content) and sensory properties. Correlation coefficients $(R^2)$ of models for crude saponin, acidic polysaccharide, and total phenolic content were 0.9176 (p<0.05), 0.9494 (p<0.05), and 0.9878 (p<0.001), respectively. Functional compounds increased with decreasing moisture content and increasing puffing pressure. Overall palatability was high at 15-20% moisture content and 98-294 kPa of puffing pressure. On the basis of superimposed contour maps for functional compounds and overall palatability of puffed ginseng, the optimum ranges of puffing conditions were 10-17% moisture content and 294-392 kPa puffing pressure.

A Design Problem of a Service System with Bi-functional Servers (이중작업능력의 서버로 구성된 서비스시스템 설계)

  • Kim, Sung-Chul
    • Journal of the Korean Operations Research and Management Science Society
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    • v.32 no.3
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    • pp.17-31
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    • 2007
  • In this paper, we consider a service system with bi-functional servers, which can switch between the primary service room and the secondary room. A service policy is characterized by the switching paints which depend on the queue length in the primary service room and the service level requirement constraint of the secondary room. The primary service room is modeled as a Markovian queueing system and the throughput of the primary service room is function of the total number of bi-functional servers. the buffer capacity of the primary service room, and the service policy. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simuitaneously determining the optimal number of servers, buffer capacity, and service policy to maximize profit of the service system, and develop an algorithm which can be successfully applied with the small number of computations.

Synthesis and Antifungal Property of Porous Al2O3 with Dispersions of Cu Nanoparticles (Cu 입자가 분산된 Al2O3 다공체의 제조 및 항균특성)

  • Yoo, Ho-Suk;Kim, Min-Sung;Oh, Sung-Tag;Hyun, Chang-Yong
    • Journal of Korean Powder Metallurgy Institute
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    • v.21 no.1
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    • pp.16-20
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    • 2014
  • In order to fabricate the porous $Al_2O_3$ with dispersion of nano-sized Cu particles, freeze-drying of camphene/$Al_2O_3$ slurry and solution chemistry process using Cu-nitrate are introduced. Camphene slurries with 10 vol% $Al_2O_3$ was frozen at $-25^{\circ}C$. Pores were generated by sublimation of the camphene during drying in air. The sintered samples at 1400 and $1500^{\circ}C$ showed the same size of large pores which were aligned parallel to the sublimable vehicles growth direction. However, the size of fine pores in the internal walls of large pores decreased with increase in sintering temperature. It was shown that Cu particles with the size of 100 nm were homogeneously dispersed on the surfaces of the large pores. Antibacterial test using fungus revealed that the porous $Al_2O_3$/1 vol% Cu composite showed antifungal property due to the dispersion of Cu particles. The results are suggested that the porous composites with required pore characteristics and functional property can be fabricated by freeze-drying process and addition of functional nano particles by chemical method.

Study on the Change in Physical and Functional Properties of Paper by the Addition of Chitosan (키토산 섬유를 첨가한 종이의 물성 및 기능성의 변화에 관한 연구)

  • Park, Seong-Cheol;Kang, Jin-Ha;Lim, Hyun-A
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.5
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    • pp.37-46
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    • 2010
  • This study was carried out to develop new application field and obtain the basic data of mixed paper with wood pulp and chitosan fiber for producing functional paper. Two types of wood pulp, such as SwBKP and HwBKP, were mixed with chitosan fiber. Physical and optical properties, water vapor absorption, air permeability, antibacterial activity and ash were measured. And the surface morphology of manufactured paper was observed using SEM. The results are as follows. It was revealed that density, breaking length, burst index, tear index, folding endurance and brightness were reduced but water vapor absorption and air permeability were on the rise in the structural view of SwBKP according to increasing the chitosan fiber ratio. Those HwBKP added chitosan fiber were great not only in the strength but also water vapor absorption and air permeability except for brightness. The water vapor absorption was lower and the air permeability was higher in the HwBKP added various chitosan fiber ratios than those with no chitosan fiber. It is estimated that these properties were related with various mixed rate of chitosan fiber. Particularly, air permeability was strongly dependent on the mixed rate of chitosan fiber. The chitosan fiber has superior antibacterial property, comparing with wood fiber. Adding chitosan fiber to the wood pulp was found to have an excellent antibacterial activity, more than 90%. The ashes were determined within 0.5%. Special bonds between chitosan fiber and wood pulp was observed by SEM and it means that the chitosan fiber were combined equally in the interior of wood pulp. In conclusion, mixing wood pulp with chitosan fiber can not only improves the quality of paper but also extend the usage of paper as a functional paper by using inherent property of chitosan. After all, production of functional paper added chitosan fiber is expected for new valuable industry of paper.

Development of Perfluoroalkyl Derivative for $Cr^{3+}$ Adsorbent Promotion Process (3가 크롬 흡착 증진용 과불소 알킬유도체 제조 및 적용공정 개발)

  • Shin, Jong-Sub;Kum, Chang-Hun;Yun, Jong-Kuk;Park, Il-Kyu
    • Clean Technology
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    • v.14 no.3
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    • pp.193-203
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    • 2008
  • A surfactant is used to assist the effect of cleaning, dispersibility and adhesion during leather manufacturing process. Existing surfactant for that process includes many hydrophilic groups that may cause problem such as stain, bad water resistance and poor durability, etc. It is potential problem to make high-performance property for future leather market. In this study, we have synthesized the fluorinated surfactant of which property decreases surface tension, increases dispersion, cleaning effect and the better chrome absorption by the high bond energy of C-F to complement weakness that the present alkyl derivative surfactants have. Using fluorinated surfactant, we can confirm that dispersion is increased, chrome absorption ratio is augmented with high osmosis and coherence, chrome content in the tanning waste water is reduced, BOD and COD contents are diminished and physical characteristics are improved.

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Micro-patterning for Biomimetic Functionalization of Surface

  • Jeon, Deok-Jin;Lee, Jun-Yeong;Yeo, Jong-Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.272-273
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    • 2013
  • Some living thingsuse micro- or nano- structures for living in nature. Scientists and engineers made efforts to mimic them, and they succeeded in making new types of applications. They used 'Namib desert beetle' to self-filling device by moisture harvesting and 'lotus leaf' to self-cleaning device by water repelling. 'Namib desert beetle' and lotus leaf have micro-patterns on their surface, which consists of hydrophobic or hydrophilic materials [1]. Moreover, micro-patterns on the surface make self-filling or self-cleaning property enhanced because of the surface roughness. Surface roughness enhances wettability [2]. Micro-pattern is a significant factor to make the surface be functional, so we want to make new types of functional surface by micro-patterning. In this work,we make several functional micro-patterns (radial, line, and dot arrays) using maskless lithography and analyze the characteristics of each micro-pattern. In order to analyze and understand surface characteristics, micro-patterns with varying sizes are investigated. All experiments are proceeded on mr-DWL5 photo resists coated on silicon wafers in same condition. All the experiments have demonstrated good performances about hydrophobic or hydrophilic property corresponding to their material and structural combinations. In radial micro-pattern, although the surface is flat, water drops on hydrophilic radial pattern can be convergent to a middle point and water drops on hydrophobic radial pattern can be divergent from the middle point. In line array micro-pattern, water drops can roll off along only one direction in parallel with the line arrays. Such phenomena might be mainly caused by the local change of surface roughness. From these results, controlling the movement and direction of water drops is made feasible without introducing a slope, which can potentially be used for new types of applications.

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Performance-based Tracing Non-Functional Requirements of Embedded Software (내장형 소프트웨어의 비기능적 요구사항 성능 중심 추적)

  • Choi Jung-A;Chong Ki-Won
    • Journal of KIISE:Software and Applications
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    • v.33 no.7
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    • pp.615-623
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    • 2006
  • A non-functional requirement is a property or quality that the proposed systems have to support the functional requirements. A non-functional requirement is reflected by quality attribute These non-functional requirements playa crucial role during system development, serving as selection criteria for choosing among decisions. It should be continuously considered through the software development process. In spite of the importance of the non-functional requirements, it received little attention because of ambiguousness and invisibility of non-functional requirements. Therefore non-functional model which is a process to analyze the non-functional requirement is proposed for improving the management efficiency of non-functional requirements. Also, this paper presents the trace among the UML diagrams to the conceptual model. According to the non-functional requirement development process, this paper achieved performance-based case study. After then, non-functional requirement should be traced using the UML diagrams.

Ruthenium doped carbon aerogel with CO2 surface activation for enhanced electrochemical capacitance

  • Singh, Ashish;Kohli, D.K.;Bhartiya, Sushmita;Singh, Rashmi;Singh, M.K.;Gupta, P.K.
    • Current Applied Physics
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    • v.17 no.6
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    • pp.885-889
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    • 2017
  • With the aim of enhancement of electrochemical capacitance, $CO_2$ activation of carbon aerogel (CA) prepared by polycondensation of resorcinol with formaldehyde was performed to obtain activated carbon aerogel (ACA) having improved surface area properties. Ruthenium oxide nano-particles were loaded by impregnation method for utilizing pseudo-capacitive property of ruthenium oxide ($RuO_2$) and the effect of activation treatment was studied. $RuO_2$ loading of 20% by weight was accomplished in CA and ACA to synthesize $RuO_2$ doped carbon aerogel ($CA/RuO_2$) and activated carbon aerogel ($ACA/RuO_2$). While the specific capacitance of carbon aerogel improved from 95 to 153 F/g on activation, $RuO_2$ loading further led to enhancement in capacitance and specific capacitance of 308 F/g was obtained for $ACA/RuO_2$. The studies being important for Ru economy, showed the influence of surface area enhancement of base matrix in achieving high specific capacitance.

Effect of Irradiation of Red Radish Seeds on the Seed Viability and Functional Properties of Sprouts

  • Waje, Catherine K.;Park, Ju-Hwan;Kim, Gui-Ran;Kim, Yu-Ri;Han, Bum-Soo;Lee, Yeon-Kyung;Moon, Kwang-Deog;Kwon, Joong-Ho
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.390-395
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    • 2009
  • Red radish seeds were irradiated at doses up to 8 kGy using electron beam (e-beam) and gamma ray ($\gamma$-ray). The seed viability and functional properties (carotenoid, chlorophyll, ascorbic acid, and total phenol) of sprouts grown from these irradiated seeds were evaluated. High germination percentage ($\geq$97%) was observed in seeds irradiated at $\leq$5 kGy, but the yield ratio and sprout length significantly decreased with increased irradiation dose. Irradiation at $\geq$6 kGy resulted in curling of the sprout roots. Sprouting enhanced the functional properties of red radish seeds as indicated by the increased carotenoid, chlorophyll, ascorbic acid, and total phenol contents during germination. However, radiation treatment hampered the growth of seeds resulting in underdeveloped sprouts with decreased carotenoid, chlorophyll, ascorbic acid, and total phenol contents. In general, e-beam and $\gamma$-ray irradiation of red radish seeds showed similar effects on the seed viability and functional properties of sprouts. Postharvest storage reduced the functional quality of sprouts.