• Korean Journal of Optics and Photonics
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• v.12 no.5
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• pp.425-428
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• 2001

In this work, we propose a new optical configuration for a 3-stack color LCD using subtract color mixing method. This configuration consists of 3 color polarizers, a neutral polarizer and 3 LC cells. With the proposed configuration, we can increase the contrast ratio practically by using a neutral polarizer and reduce the manufacturing cost. To reduce wavelength dispersion, the sequence of polarizers is optimized.

• Journal of Electrochemical Science and Technology
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• v.14 no.2
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• pp.145-151
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• 2023

Planer-type electrolyte substrates are often utilized for stack manufacturing of electrolyte-supported solid oxide fuel cells (ES-SOFCs) to fulfill necessary requirements such as a high mechanical strength and redox stability. This work did an electrochemical analysis of ES-SOFC with different NiO-YSZ anode thicknesses to find the optimal value for the high performance of the fuel cell. The cell resistivities were constant at anode thickness between 25-58 ㎛, but a thick anode (74 ㎛) caused a high electrode resistivity leading to a dramatic reduction in cell performance. A stability test was performed for 50 hours at 700℃, and the results showed a degradation rate of 0.3% per 1000 h by extrapolated fitting.

• Design & Manufacturing
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• v.17 no.2
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• pp.33-41
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• 2023

Metal raw materials and chemical additives, which are raw materials for secondary batteries, are pulverized by the high-speed rotation of the Grinding Disc of the Classifier Separator Mill (CSM). Grinding discs are required to withstand abrasion, corrosion, high-speed rotational force and impact. In order to analyze the stability of domestic and foreign grinding discs, quality tests including surface roughness, surface lubrication, surface state measurement, and surface 3D shape measurement were analyzed. When producing developed products, it shows that excellent products can be produced.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.147-157
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• 2024

The objective of standard guideline for utilization of human lung organoids is to provide the basic guidelines required for the manufacture, culture, and quality control of the lung organoids for use in non-clinical efficacy and inhalation toxicity assessments of the respiratory system. As a first step towards the utilization of human lung organoids, the current guideline provides basic, minimal standards that can promote development of alternative testing methods, and can be referenced not only for research, clinical, or commercial uses, but also by experts and researchers at regulatory institutions when assessing safety and efficacy.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.158-181
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• 2024

This study offers a comprehensive overview of brain organoids for researchers. It combines expert opinions with technical summaries on organoid definitions, characteristics, culture methods, and quality control. This approach aims to enhance the utilization of brain organoids in research. Brain organoids, as three-dimensional human cell models mimicking the nervous system, hold immense promise for studying the human brain. They offer advantages over traditional methods, replicating anatomical structures, physiological features, and complex neuronal networks. Additionally, brain organoids can model nervous system development and interactions between cell types and the microenvironment. By providing a foundation for utilizing the most human-relevant tissue models, this work empowers researchers to overcome limitations of two-dimensional cultures and conduct advanced disease modeling research.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.87-87
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• 2010

Photoelectrochemical (PEC) systems are promising methods of producing H2 gas using solar energy in an aqueous solution. The photoelectrochemical properties of numerous metal oxides have been studied. Among them, the PEC systems based on TiO2 have been extensively studied. However, the drawback of a PEC system with TiO2 is that only ultraviolet (UV) light can be absorbed because of its large band gap (3.2 - 3.4 eV). Two approaches have been introduced in order to use PEC cells in the visible light region. The first method includes doping impurities, such as nitrogen, into TiO2, and this technique has been extensively studied in an attempt to narrow the band gap. In comparison, research on the second method, which includes visible light water splitting in molecular photosystems, has been slow. Mallouk et al. recently developed electrochemical water-splitting cells using the Ru(II) complex as the visible light photosensitizer. the dye-sensitized PEC cell consisted of a dye-sensitized TiO2 layer, a Pt counter electrode, and an aqueous solution between them. Under a visible light (< 3 eV) illumination, only the dye molecule absorbed the light and became excited because TiO2 had the wide band gap. The light absorption of the dye was followed by the transfer of an electron from the excited state (S*) of the dye to the conduction band (CB) of TiO2 and its subsequent transfer to the transparent conducting oxide (TCO). The electrons moved through the wire to the Pt, where the water reduction (or H2 evolution) occurred. The oxidized dye molecules caused the water oxidation because their HOMO level was below the H2O/O2 level. Organic dyes have been developed as metal-free alternatives to the Ru(II) complexes because of their tunable optical and electronic properties and low-cost manufacturing. Recently, organic dye molecules containing multi-branched, multi-anchoring groups have received a great deal of interest. In this work, tri-branched tri-anchoring organic dyes (Dye 2) were designed and applied to visible light water-splitting cells based on dye-sensitized TiO2 electrodes. Dye 2 had a molecular structure containing one donor (D) and three acceptor (A) groups, and each ended with an anchoring functionality. In comparison, mono-anchoring dyes (Dye 1) were also synthesized. The PEC response of the Dye 2-sensitized TiO2 film was much better than the Dye 1-sensitized or unsensitized TiO2 films.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.5
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• pp.438-443
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• 2021

This paper uses a multiplex deposition sputter system and aims to improve transmittance and reduce production costs by depositing a CdS thin film on an ITO glass substrate. When manufacturing CdS thin films, we wanted to find excellent conditions when manufacturing solar cells by changing heat treatment time. It was observed that thickness and sheet resistance were not significantly different depending on heat treatment time changes. The specific resistance was measured from a minimum of 6.68 to a maximum of 6.98. When the heat treatment time was more than 20 minutes, the transmittance was measured to be more than 75%. When the heat treatment time was 10 minutes, the bandgap was 3.665 eV and more than 20 minutes was 3.713 eV, which was measured as the same result. The XRD analysis showed that the structure of CdS was hexagonal and only CdS thin films were deposited without any other impurities. The result of calculating the FWHM was a maximum of 0.142 when the heat treatment time was 20 minutes, and a minimum of 0.133 when the heat treatment time was 40 minutes, so there was no significant difference in the FWHM when the heat treatment time was changed. The particle size was measured at 11.65 Å when the heat treatment time was 40 minutes, and at 10.93 Å when the heat treatment time was 20 minutes.

• Journal of Dairy Science and Biotechnology
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• v.24 no.1
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• pp.53-63
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• 2006

Nano and micro capsulation (NM capsulation) involve the incorporation for nanofood materials, enzymes, cells or other materials in small capsules. Since Kim D. M. (2001) showed that a new type of food called firstly the name of nanofood, which means nanotechnology for food, and the encapsulated materials can be protected from moisture, heat or other extreme conditions, thus enhancing their stability and maintaining viability applications for this nanofood technique have increased in the food. NM capsules for nanofood is also utilized to mask odours or tastes. Various techniques are employed to form the capsules, including spray drying, spray chilling or spray cooling, extrusion coating, fluidized bed coating, liposome entrapment, coacervation, inclusion complexation, centrifugal extrusion and rotational suspension separation. Each of these techniques is discussed in this review. A wide variety of nanofood is NM capsulated - flavouring agents, acids, bases, artificial sweeteners, colourants, preservatives, leavening agents, antioxidants, agents with undesirable flavours, odours and nutrients, among others. The use of NM capsulation for sweeteners such as aspartame and flavors in chewing gum is well known. Fats, starches, dextrins, alginates, protein and lipid materials can be employed as encapsulating materials. Various methods exist to release the ingredients from the capsules. Release can be site-specific, stage-specific or signaled by changes in pH, temperature, irradiation or osmotic shock. NM capsulation for the nanofood, the most common method is by solvent-activated release. The addition of water to dry beverages or cake mixes is an example. Liposomes have been applied in cheese-making, and its use in the preparation of nanofood emulsions such as spreads, margarine and mayonnaise is a developing area. Most recent developments include the NM capsulation for nanofood in the areas of controlled release, carrier materials, preparation methods and sweetener immobilization. New markets are being developed and current research is underway to reduce the high production costs and lack of food-grade materials.

• Composites Research
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• v.29 no.5
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• pp.243-248
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• 2016

Although thermoset carbon fiber composite bipolar plates not only have high mechanical properties but also high corrosion resistance in acid environment, high manufacturing cost and low bulk electrical conductivity are the biggest obstacle to overcome. In this research, thermoplastic polymer is employed for the matrix of carbon composite bipolar plate to increase both the manufacturing productivity and bulk electric conductivity of the bipolar plate. In order to increase the electrical conductivity and strength, plain type carbon fabric rather than chopped or unidirectional fibers is used. Also nano particles are embedded in the thermoplastic matrix to increase the bulk resistance of the bipolar plate. The area specific resistance and the mechanical strength of the developed bipolar plate are measured with respect to the environmental temperature and stack compaction pressure.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.108-115
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• 2018

In bone tissue engineering, polycaprolactone (PCL) is one of the most widely used biomaterials to manufacture scaffolds as a synthetic polymer with biodegradability and biocompatibility. The polymer deposition system (PDS) with four axis heads, which can dispense bio-polymers, has been used in scaffold fabrication for tissue engineering applications. A dual-head deposition technology of PDS is an effective technique to fabricate 3D scaffolds. The electrospinning technology has been widely used to fabricate porous and highly interconnected polymer fibers. Thus, PDS can fabricate nanofiber-combined hybrid scaffolds using fused deposition modeling (FDM) and electrospinning methods. This study aims to fabricate nanofiber-combined scaffolds with uniform nanofibers using PDS. The PCL nanofibers were fabricated and evaluated according to the fabrication process parameters. PCL nanofibers were successfully fabricated when the applied voltage, tip-to-collector distance, flow rate, and solution concentration were 5 kV, 1 cm, 0.1 ml/h, and 8 wt%, respectively. The cell proliferation was evaluated according to the electrospinning time. Scanning electron microscopy was used to acquire images of the cross-sectioned hybrid scaffolds. The cell proliferation test of the PCL and nanofiber-combined hybrid scaffolds was performed using a CCK-8 assay according to the electrospinning time. The result of in-vitro cell proliferation using osteosarcoma MG-63 cells shows that the hybrid scaffold has good potential for bone regeneration.