• Journal of the Microelectronics and Packaging Society
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• v.6 no.4
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• pp.1-7
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• 1999

We developed Fabrication process of embedded passive components in MCM-D substrate. The proposed MCM-D substrate is based on Cu/photosensitive BCB multilayer. The substrate used is Si wafer and Ti/cu metallization is used to form the interconnect layer. Interconnect layers are formed with 1000$\AA$ Ti/3000$\AA$ Cu by sputtering method and 3$\mu\textrm{m}$ Cu by electrical plating method. In order to form the vias in photosensitive BCB layer, the process of BCB and plasma etch using $C_2F_6$ gas were evaluated. The MCM-D substrate is composed of 5 dielectric layers and 4 interconnect layers. Embedded resistors are made with NiCr and implemented on the $2^{nd}$ dielectric layer. The sheet resistance of NiCr is controlled to be about 21 $\Omega$/sq at the thickness of 600$\AA$. The multi-turn sprial inductors are designed in coplanar fashion on the $4^{th}$ interconnect layer with an underpass from the center to outside using the lower $3^{rd}$ interconnect layer. Capacitors are designed and realized between $1^{st}$ interconnect layer and $2^{nd}$ interconnect layer. An important issue in capacitor is the accurate determination of the dielectric thickness. We use the 900$\AA$ thickness of PECVD silicon nitride film as dielectric. Capacitance per unit area is about 88nF/$\textrm {cm}^2$at the thickness of 900$\AA$. The advantage of this integration process is the compatibility with the conventional semiconductor process due to low temperature PECVD silicon nitride process and thermal evaporation NiCr process.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.3-10
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• 1993

Polycrystalline CdS thin films were grown on ceramic substrate using a chemical bath deposition method. They were annealed at various temperature and X-ray diffraction patterns were measured by X-ray diffractometer in order to study CdS polycrystal structure. Using extrapolation method of X-ray diffraction patterns for the CdS samples annealed in $N_{2}$ gas at $550^{\circ}C$ it was found hexagonal structure whose lattice constants $a_{o}$ and $c_{o}$ were $4.1364{\AA}$ and $6.7129{\AA}$, respectively. Its grain size was about $0.35{\mu}m$. Hall effect on this sample was measured by Van der Pauw method and studied on carrier density and mobility defending on temperature. From Hall data, the mobility was likely to be decreased by piezo electric scattering at temperature range of 33K and 150k and by polar optical scattering at temperature range of 150K and 293K. We measured also spectral response, sensitivity (${\gamma}$), maximum allowable power dissipation and response time on these samples.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.81-86
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• 1993

Polycrystalline CdSe thin films were grown on ceramic substrate using a chemical bath deposition (CBD) method. They were annealed at various temperature and X-ray diffraction patterns were measured by X-ray diffractometer in order to study CdSe polycrystal structure. Using extrapolation method of X-ray diffraction patterns for the CdSe samples annealed in $N_{2}$ gas at $450^{\circ}C$ it was found hexagonal structure whose lattice parameters $a_{o}$ and $c_{o}$ were $4.302{\AA}$ and $7.014{\AA}$, respectively. Its grain size was about $0.3{\mu}m$. Hall effect on this sample was measured by Van der Pauw method and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by piezo electric scattering at temperature range of 33 K and 200 K, and by polar optical scattering at temperature range of 200 K and 293 K. We measured also spectral response, sensitivity (${\gamma}$), maximum allowable power dissipation and response time on these samples.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.522-527
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• 2010

Onion has been reported to contain various organosulfur compounds which have antibiotic and anticarcinogenic properties and flavonoid like quercetin which is a valuable natural source of antioxidants. Carbohydrates in onion constitute about 80% of dry matter, and the major non-structural carbohydrate of onion bulb is fructo-oligosaccharides, well known as fructan, followed by glucose, fructose, and sucrose. The sugar concentration is associated with dormancy and storage life of onion, occurring as decrease in glucose, fructose and fructan, particularly towards the end of storage. Forced air pre-drying for 15-20 days at room temperature is an essential procedure to reduce freezing injury and sprouting, then onion bulbs can be stored at $0^{\circ}C$ for 6 months to control sprouting and decay. Bacterial soft rot caused by $Erwinia$ and $Pseudomonas$ is the main postharvest disease when the bulbs are infected with the bacteria and stored at room temperature. Browning in sliced onion is due to oxidation of phenolic compounds by polyphenol oxidase and it can be inhibited by citric acid treatment, packing with nitrogen gas, and polyethylene film.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.483-490
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• 2012

Ready-to-eat chicken breasts were packaged in a multilayer, gas-tight tray with top film and various quality changes were investigated during the 24 wk of storage at $10^{\circ}C$. Over the storage period, total aerobes, mesophilic aerobic and anaerobic spore formers, and Clostridium spp. were not detected above 1.0 log CFU/g (detection limit). The residual oxygen ratio in the head space of tray and pH values tended to decrease with storage time, namely from initial values of 5.7% and 6.56 to 3.3% and 6.34 at week 24, respectively. Thiobarbituric acid reactive substances and volatile basic nitrogen values increased from 0.52 mg malonaldehyde (MA)/kg and 2.1 mg/100 g initially, to 3.70 mg MA/kg and 39.9 mg/100 g at week 24, respectively. In terms of the change in meat color during storage, the samples showed a slight increasing trend of CIE $a^*$, $b^*$, and ${\Delta}E$ values over the storage period until week 24 (p<0.05). The change in brine color showed a similar trend with meat of which Hunter $b^*$ and ${\Delta}E$ values increased slightly during storage during 24 wk (p<0.05). The values for the transmittance degree of brine in the samples tended to decrease. Moreover, values for the absorbance degree tended to increase with storage time until week 24. The sensory scores for color, texture, odour, and flavour were evaluated below 5.0 (marketability level) after 24 wk of storage. Based on this sensory evaluation, it could be concluded that retorted RTE chicken breast could remain marketable for at least 20 wk at $10^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.402-408
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• 2016

Master packaging system consists of an inner individual package and secondary outer package. During the stages of chilled transport and distribution, the combination of primary individual package and secondary package was used to maintain a modified atmosphere for shiitake mushrooms. During the retail stage at higher temperature ($25^{\circ}C$), the primary individual package was exposed to display conditions after dismantling of the secondary packaging. The master packaging system was constructed to contain eight individual $30-{\mu}m$ thick polypropylene film bags of 500 g shiitake mushrooms inside a $40-{\mu}m$ low-density polyethylene bag. Carbon dioxide absorbent material [$Ca(OH)_2$] and/or moisture absorbent (superabsorbent polymer) were designed in their required amounts based on respiration characteristics and then applied to the outer secondary packaging in sachet form. Gas concentration of the packaging, temperature, and humidity were monitored throughout transport and storage. The quality of shiitake mushrooms was measured at the retail stage to determine the packaging effect. During the distribution stage of 108 h, $O_2$ and $CO_2$ concentrations in the master packaging system were maintained at 9~11% and 1~4% in the inner packaging, respectively, which are good for quality preservation. Compared to the control, the master packaging with $CO_2$ and/or moisture absorbents improved mushroom preservation and particularly reduced decay.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.525-530
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• 2019

The performance and stability of solid oxide fuel cells (SOFCs) depend on the microstructure of the electrode and electrolyte. In anode, porosity and pore distribution affect the active site and fuel gas transfer. In an electrolyte, density and thickness determine the ohmic resistance. To optimizing these conditions, using costly method cannot be a suitable research plan for aiming at commercialization. To solve these drawbacks, we made high performance unit cells with low cost and highly efficient ceramic processes. We selected the NiO-YSZ cermet that is a commercial anode material and used facile methods like die pressing and dip coating process. The porosity of anode was controlled by the amount of carbon black (CB) pore former from 10 wt% to 20 wt% and final sintering temperature from $1350^{\circ}C$ to $1450^{\circ}C$. To achieve a dense thin film electrolyte, the thickness and microstructure of electrolyte were controlled by changing the YSZ loading (vol%) of the slurry from 1 vol% to 5 vol. From results, we achieved the 40% porosity that is well known as an optimum value in Ni-YSZ anode, by adding 15wt% of CB and sintering at $1350^{\circ}C$. YSZ electrolyte thickness was controllable from $2{\mu}m$ to $28{\mu}m$ and dense microstructure is formed at 3vol% of YSZ loading via dip coating process. Finally, a unit cell composed of Ni-YSZ anode with 40% porosity, YSZ electrolyte with a $22{\mu}m$ thickness and LSM-YSZ cathode had a maximum power density of $1.426Wcm^{-2}$ at $800^{\circ}C$.

• Fire Science and Engineering
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• v.32 no.6
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• pp.1-6
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• 2018

This study is to analyze the characteristics of the yellow insulation ring type of the CSST used for tubing when it is artificially deteriorated and damaged by burning. The CSST for tubing consists of a tube, protective coating, nut, yellow insulation ring, packing, and socket. In addition, it is thought that a yellow insulation ring and rubber packing were used to connect the tube and socket in order to improve the airtightness and insulation performance. The result of the verification of the data acquired from the tests in the 95% confidence interval shows that the Anderson-Darling (AD) and P value were analyzed to be 0.945 and 0.015, respectively. This confirms that the test data of the CSST for tubing is reliable. The analysis of the arithmetic mean of the insulation resistance of a CSST showed that the CSST damaged by burning by a torch, and the one damaged by electrical burning, was $16.7k{\Omega}$ (the greatest relatively) and $208{\Omega}$ (the lowest), respectively, while it was $1.72k{\Omega}$ in the case of a normal product. Therefore, the analysis result of the insulation resistance of the CSST collected from the scene of a fire can be utilized to examine the cause of damage by burning. In addition, it was found that when the maximum current of 97 A was applied to the CSST for about 5 s using a Primary Current Injection Test System (PCITS) the protective film and insulation ring of the CSST has no difference from that of a normal product. However, a part of the metal tube was melted.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1308-1314
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• 1999

The effects of modified atmosphere(MA) packaging and coating on the quality of mushroom (Agaricus bisporus) were investigated. Whole mushrooms(100 g) were packed with polyvinyl chloride(PVC) film wrap, PD941 and PD961 film bags and were stored in a chamber at $12^{\circ}C$ and 80% RH for 6 days. Gas composition of packages, respiration rate, weight loss, color and maturity index of MA packaged mushrooms were examined. The wrap packaged mushrooms showed different level of internal $CO_2$ concentrations among water washed, chitosan coated and $CaCl_2$ coated subgroups significantly at 5% level. The maximum $CO_2$ concentration of PD941 and PD961 packages for all coated showed $4.1{\sim}4.7%$ and $10.4{\sim}11.7%$, respectively, for the first day. PD961 package showed the lowest $O_2$ concentration compared to other groups. There were no significant respiration rate differences between wrap packed and PD941 packaged. Respiration rate of water washed. chitosan coated and $CaCl_2$ coated in PD961 packaged was 192 mg, 226 mg and 245 mg, respectively. Maturity index of PD961 packaged were not significantly different among the water washed, chitosan and $CaCl_2$ coated packages. Chitosan coating showed a negative effect on color change of mushrooms. The weight loss of 961 packaged was lower $(7.0{\sim}8.0%)$ that those of wrap packaged and PD941 packaged.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.452-458
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• 2010

This study aimed at improving the packaging technology of Yukwa to improve the quality and extend the shelflife using secondary packaging. After packaging the Yukwa using an OPP film, P2, P3, and P4 packaging materials were applied secondarily. Various films including (1) P1: OPP (oriented polypropylene), (2) P2: P1+OPP/LLDPE (linear low density polyethylene), (3) P3: P1+PET (polyethylene terephthalate)/NY (nylon)/CPP (cast polypropylene) and (4) P4: P1+PET/AL (aluminum)/NY/CPP (P4) were used for packaging Yukwa. The experiment was conducted at $25^{\circ}C$ for 12 weeks. P1 showed the highest acid value score (1.26 mg KOH/g), and P3 had the highest peroxide value score (32.91 meq/kg) among all packaging groups. Nevertheless, these values did not exceed the guideline values of 2.0 g KOH/g and 40 meq/kg specified in the Korean food code. The overall color difference showed a tendency for decreasing Hunter 'L' values and increasing 'a' and 'b' values; however, no noticeable difference in the outer appearance was observed in any of the packaging treatments except in the P1 for greater than 10 weeks of storage. Some texture defects were observed in the Yukwa when the moisture contents dropped below 5%. The P4 packaging treatment had the lowest moisture permeability and showed the least rheological deterioration change, followed by P3 and P2. In conclusion, the use of a secondary packaging with less gas and moisture permeability was more effective for maintaining the quality and extending the shelf-life of Yukwa than other types of packaging material.