• Journal of Korea Society of Industrial Information Systems
• /
• v.8 no.3
• /
• pp.105-110
• /
• 2003

The purpose of this paper is to development of micro particle powder feeding systems for the reduction of air leakage of the feeding system. Most of the powder-granule supply systems using compressed air supply have a large amount of air leakage interference. The results of this study lead to reduce air leakage rate by over 50% and to save production cos by. 60%.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.1
• /
• pp.60-68
• /
• 2012

In this study, the manufacturing process of micro capsulized PCM (phase changing material) for thermal storage performance of latent heat was investigated to save energy during the use of buildings: i.e. use of melamine-type resin as the micro-capsule material and paraffin wax as the inner material that are together used in concrete walls. For the manufacturing process of the micro-capsulized PCM, the amount of SDS addition as surfactant was the key variable and the resulting thermal storage performance depended on the SDS amount. With increasing amount of SDS, the micro capsulation became much easier while the capsule surface became harder. The micro capsules became uniform at an optimum SDS addition. The addition of SDS also affected the thermal capacity: with increasing SDS amount, the heat storage and release tendency at melting point was more clearly manifested. The current investigation is part of a study under progress to explore the use of PCM in concrete walls to save building maintenance cost and energy.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2003.11a
• /
• pp.225-228
• /
• 2003

• Applied Chemistry for Engineering
• /
• v.35 no.2
• /
• pp.115-121
• /
• 2024

This study analyzed the influence of process variables affecting the thermodynamic equilibrium and fluid dynamics of interfaces such as reverse micelle, salt concentration, interfacial tension, and viscosity of fluids to optimize the microencapsulation process using the W1/O/W2 double emulsion method. The process variable with the greatest impact on encapsulation efficiency was found to be the difference in osmotic pressure between the W1 and W2 phases. It was observed that increasing the salt concentration in the W2 phase or decreasing the ascorbic acid concentration in the W1 phase resulted in higher encapsulation efficiency. Additionally, a larger difference in osmotic pressure led to increased damage to the surface of the microparticles, as confirmed by SEM images. The introduction of reverse micelles, which was anticipated to increase encapsulation efficiency, either had a low contribution or even decreased encapsulation efficiency. The yield of microcapsules was expressed as a universal function, applicable to all process conditions or solution compositions. According to this universal function, no further increase in yield was observed beyond the Ca (capillary number) of approximately 20.

• Clean Technology
• /
• v.19 no.3
• /
• pp.243-248
• /
• 2013

Thermally conductive materials are widely used in various applications where effective heat dissipation is required. Graphene shows high potential for various uses owing to high electrical conductivity, good mechanical strength, and high thermal conductivity. Generally previous works used organic solvents are generally used for the dispersion of graphene in fabrication procedure. In order to achieve clean fabrication it is required to use water media. In this study, we fabricated graphene attached poly(methyl methacrylate) (PMMA) microsphere via microfluidic method. With the aid of surfactant, graphene was well dispersed in water which was used as continuous flow. Thermal conductivity was improved with the small amount of graphene addition and this indicate potential use of this system for thermally conductive composite material.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.3 s.47
• /
• pp.361-367
• /
• 2004

In this study, a different UV (ultra-violet) ray absorption system is presented in which butyl methoxydiben-zoylmethane (BMDM, a model UV-A absorbent, 320$\~$400 nm) is stabilized in phase-controlled poly(methyl methacrylate) (PMMA) microspheres. The photochemistry of BMDM in the microspheres was investigated considering its phase characteristics therein. The analysis of a differential scanning calorimeter and X-ray diffractometer showed that the BMDM in the microspheres was present with a non-crystalline state. The phase control of BMDM in the polymer microsphere has an excellent ability to protect UV-A with maintaining its photo- and thermal stability. The results obtained in this study illustrate well that the phase control of the UV absorbents in the polymer microspheres is another key factor that de-termines its photochemistry and photostability in the final formulations.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.6
• /
• pp.483-489
• /
• 2014

In this study, experiments were conducted for micro pattern printing to combine solution atomization process and stencil printing based on electrospray deposition. The stencil mask fabricated by etching the photosensitive glass placed below 0.3 mm distance to substrate has 100 um line width. The process parameters of electrospray deposition system for the atomization of the solution are applied voltage and supply flow rate of the solution. Meniscus angle of cone-jet was optimized by varying the supply flow rate from 0.3 ml/hr to 0.7 ml/hr. Voltage condition was verified having symmetric cone-jet angle and no pulsation at 8.5 kV applied voltage. In addition, a number of micro patterns are printed using a single 1 step process by solution atomization process. Variable line width of approximate 100 um was confirmed by changing conditions of solution atomization regardless of the pattern size of stencil mask.

• Journal of IKEEE
• /
• v.14 no.3
• /
• pp.244-249
• /
• 2010

We fabricated optical sensor system that take a measurement particles using a line-CCD in ocean. To measure particles, we used 680nm laser diode which is appropriate. we tested to operate optical system in water tank and ocean. It has performance that detected signal of sensors transfer microprocessor, FPGA as long as move up and down it's motion. The system algorithm also analysis output -pressure, temperature, particle numbers in depth.-For experiment, our particle sensor system has high accuracy counter. therefore, we proposed that a line-CCD is available on optical sensor system in ocean.

• Resources Recycling
• /
• v.27 no.6
• /
• pp.11-22
• /
• 2018

Magnetic separators has been used in the mining and the recycling fields in general, and is still applied in wide variety of fields. It is classified into the equipments for separating coarse ferrous scrap from non-ferrous materials and the equipments for concentrating fine ferromagnetic particles below 3mm. Magnetic separation equipments for concentrating fine materials also falls into two categories of low intensity and high intensity magnetic separators. The former is used for ferromagnetic materials but also paramagnetic materials of high magnetic susceptibility, and the latter for paramagnetic materials of lower magnetic susceptibility. Both low and high intensity magnetic separators could be utilized either dry and wet. Recently, the High gradient magnetic separators(HGMS) used in the range of less than 0.7 tesla has been gradually replaced by the magnetic separator made of rare earth permanent magnets commercialized in the 1980s. In addition, the expansion of nanotechnology in terms of synthetic magnetic materials in the environmental and biological fields is expected to contribute positively to the development of magnetic separation technology.

• Journal of Power System Engineering
• /
• v.14 no.5
• /
• pp.41-47
• /
• 2010

티타늄과 티타늄 합금은 재료적 특이성 때문에 심장 혈관 임플란트에서 일반적으로 사용되어 왔다. 일찍이 적용된 예로는 인공심장판막, 심박조율기의 보호케이스, 혈액 순환 장치 등이 있다. 하지만 물질유도혈전증(Material-induced thrombosis)은 혈전폐색에 의해 기인한 기능 손실로 심장혈관 임플란트 장치의 주된 합병증으로 존재하고 있으며, 심장혈관 임플란트의 혈전유전자는 심장혈관장치의 발달에 주된 난관 중 하나로 남아있다. 그리고 텍스처 혈액 접합 물질(Textured blood-contacting material)은 1960년대 초반 이후부터 혈액순환 보조 장치의 임상실험에 사용되고 있다. 접합 물질에 내장된 텍스처 섬유조직 표면은 형성, 성장, 안정적 부착, 생물학적 내벽(neointimal layer) 등 유도 혈액(entrapping blood) 성분에 의해 형성된다. 공동(cavity) 형상의 용해 가능한 미립자를 사용하는 SCPL법(Solvent casting/particulate leaching method)은 티타늄 기질 이전에 형성된 폴리우레탄 위에 텍스처(texture)를 생성하기 위해 사용되었다. 또한 콜라겐의 부동화(不動化)에 의한 공동(cavity)은 혈액 접합면에 잔존하기 위한 내피세포를 고정할 수 있는 효과가 있다. cpTi로 층화된 PU 기소공성(microporous)은 구조적 특성과 혈전증 감소를 위한 생물학적 내벽 사용의 잠재성을 평가하기 위한 세포 공동체 실험을 통해서 평가되었다.