• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.294-298
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• 2013

A FeRh alloy is a well-known efficient magnetocaloric material and some experimental and theoretical studies of bulk FeRh have been reported already by several groups. In this study we report first-principles calculations on magnetic properties of different thickness FeRh thin films in order to investigate the possibility to enhance further the magnetocaloric efficiency. We used two methods of a Vienna Ab-initio Simulation Package (VASP) code and SIESTA package. We found that the FeRh thin films have quite different magnetic properties from the bulk when the thickness is thinner than 6-atomic-layers. While bulk FeRh has a G-type antiferromagnetic(AFM) state, thin films which are thinner than 6-atomic-layers have an A-type AFM state or a ferromagnetic (FM) state. We will discuss possibility of magnetic phase transitions of the FeRh thin films in the view point of a magnetocaloric effect. And we found 4-, 5-, 6-layers films with Fe surface and 7-layers film with Rh surface are FM and they have relatively small magnetocrystalline anisotropy (MCA) energy about less than 70 meV. The small MCA energy leads to reduction of the strength of magnetic field in operating a magnetic refrigerator.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.8-14
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• 2013

In this study, we propose the method of optimally selecting material of front pillar (A-pillar) and package tray for minimizing weight while satisfying vehicle requirements on static stiffness and dynamic stiffness. First, we formulate a material selection optimization problem. Next, we establish the CAE procedure of evaluating static stiffness and dynamic stiffness. Then, to enhance the efficiency of design work, we integrate and automate the established CAE procedure using a commercial process integration and design optimization (PIDO) tool, PIAnO. For effective optimization, we adopt the approach of metamodel based approximate optimization. As a sampling method, an orthogonal array (OA) is used for selecting sampling points. The response values are evaluated at the sampling points and then these response values are used to generate a metamodel of each response using the radial basis function regression (RBFr). Using the RBFr models, optimization is carried out an evolutionary algorithm that can handle discrete design variables. Material optimization result reveals that the weight is reduced by 49.8% while satisfying all the design constraints.

• Culinary science and hospitality research
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• v.9 no.4
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• pp.1-12
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• 2003

This study was conducted to evaluating the antioxidative activities of waffle by natural antioxidants combination (tocopherol, rosemary extract and tea polyphenol) and packaging. Waffle stored at $25^{\circ}C$ and 35$^{\circ}C$ for 70 days were evaluated for acid value, peroxide value and Q$_{10}$ value. Tocopherol, either alone or with rosemary and tea polyphenol, was highly effective in inhibiting lipid oxidation of waffle at $25^{\circ}C$ and 35$^{\circ}C$. Especially among them, rosemary extract exhibited the best synergistic effect, as determined by peroxide value measurement. Waffle was then packaged under the following packing materials (OPP/DL/VMCPP, PET/DL/VMCCP). As the temperature condition, the modified atmosphere decrease in waffle package and increase peroxide value. This result indicated that the PET package was more effective in reducing oxidation than the OPP package.

• Journal of Pharmaceutical Investigation
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• v.8 no.4
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• pp.23-36
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• 1978

Since the active center of digestive enzymetic preparations, while under storage, lose their activity and potency by the exposure to moisture, colorization, solidifying and other physical changes. It is more important than beautiful package form that protected packaging form from moisture to get a pharmaceutical safety preparations and to maintain a definite potency. Then, in order to get a desirable conditions of storage and packaging, we used shellac and $AEA^{\circledR}$ as a coating base, and blister package, foil and bottle container as a packaging material. Temperature were set on room temperature and $37^{\circ}C$, moisture was adjusted to 40% RH and 80 % RH as a accelerated conditions. Accelerated test was carried out 6 times. The results are as follows: 1) The effect of packaging conditions give great influence on the maintenace of the stable potency. 2) Best result was produced with bottle container package. 3) $AEA^{\circledR}$ is more useful than shellac as a coating base of prevention from moisture. 4) Absorption of moisture gave considerable effects on potency and it has a limited point. 5) Difference in potency between optimal and worst condition is 472 u/2T, and difference in effective period is about 44 months.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.1
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• pp.35-40
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• 2021

Calcium hydroxide (CH) reacts with CO2 to produce moisture, and sodium carbonate (SC) reacts with CO2 in the presence of moisture. Using these different characteristics of these two reactants, a CH/SC mixture of CO2 absorber tuned for kimchi ripening to produce CO2 in a flexible package was selected. A ratio of CH:SC (1:2) in highly gas permeable microporous spunbonded film (Tyvek) sachet was found to be appropriate for delayed and consistent CO2 absorption useful for kimchi package. Addition of superabsorbent polymer (SAP) as moisture buffer was helpful for boosting the consistency of CO2 absorption. In a package of 0.5 kg kimchi at 10℃, the sachet consisting of 0.794 g of CH + 2.276 g of SC + 0.4 g of SAP suppressed its volume expansion and maintained a suitable range of CO2 partial pressure (PCO2) steadily inside. These optimal conditions may vary depending on the type and salinity of kimchi, storage and distribution temperature, and the material and area of the absorber sachet. This study showed a potential of mixture CO2 absorber to be tuned for CO2 producing packaged kimchi for the purpose of keeping consistent PCO2 at tolerable volume expansion.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.32-39
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• 2015

With the simplicity of process and high reliability in chip or package bonding, epoxy solder paste (ESP) has been recently considered as a competitive bonding material. The ESP material is composed of solder powder and epoxy formulation which can remove oxide layers on the surface of solder powder and pad finish metal. The bonding formed using ESP shows outstanding bonding strength and suppresses electrical short between adjacent pads or leads owing to the reinforced structure by cured epoxy after the bonding. ESP is also expected to suppress the formation and growth of whisker on the pads or leads. With the mentioned advantages, ESP is anticipated to become a spotlighted bonding material in the assembly of flexible electronics and electronic modules in automotive vehicles.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.49-60
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• 2010

Semiconductor packages are increasingly moving toward miniaturization, lighter and high performance. Futhermore, packages become thinner. Thin packages will generate serious reliability problems such as warpage, crack and other failures. Reliability problems are mainly caused by the CTE mismatch of various package materials. Therefore, proper selection of the package materials and geometrical optimization is very important for controlling the warpage and the stress of the package. In this study, we investigated the characteristics of the warpage and the stress of several packages currently used in mobile devices such as CABGA, fcSCP, SCSP, and MCP. Warpage and stress distribution are analyzed by the finite element simulation. Key material properties which affect the warpage of package are investigated such as the elastic moduli, CTEs of EMC molding and the substrate. Geometrical effects are also investigated including the thickness or size of EMC molding, silicon die and substrate. The simulation results indicate that the most influential factors on warpage are EMC molding thickness, CTE of EMC, elastic modulus of the substrate. Simulation results show that warpage is the largest for SCSP. In order to reduce the warpage, DOE optimization is performed, and the optimization results show that warpage of SCSP becomes $10{\mu}m$.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.96-100
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• 2008

To extend the shelf-life of kidney bean (Phaseolus vulgaris L.) after harvest, we investigated the effect of packaging material and storage temperature. In case of film package, there was no weight loss during storage, but in paper-box package, remarkable weight loss occurred as storage period extended and storage temperature risen. Firmness of kidney bean was greater in low temperature than ambient temperature storage. Content of vitamin C was decreased rapidly during storage, and in paper package, low temperature storage group had lower decrease of vitamin C than that of room temperature. Total chlorophyll content was not difference among storage temperatures in film package treatments. However, in paper-box package, decrease of chlorophyll in room temperature storage was greater than that of low temperature ($8{\sim}10^{\circ}C$). In terms of freshness of kidney bean, we suggest that shelf-life by low temperature storage ($8{\sim}10^{\circ}C$) after PP film or paper package was 8 days, but that by room temperature storage after paper package was 4 days.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.2
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• pp.143-150
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• 2001

원자력발전소의 1차 계통에서 오염된 장비들을 취급이 용이하고 안전하게 운반하기 위한 운반용기는 내부의 방사성 물질에 대한 방사능 평가에 의하여 방사성물질 A형 운반용기로 분류된다. 방사성물질 A형 운반용기는 IAEA Safety Standard Series No. ST-1 및 국내 원자력법 등 관련규정의 기술기준을 만족하여야 하는데, 운반용기는 중량에 따라 0.3∼1.2m의 높이에서 소성이 일어나지 않는 단단한 바닥면으로 가장 심각한 손상을 주는 방향으로 낙하시키는 정상운반조건(normal transport conditions)에 대하여 구조적 건전성을 유지하여야 한다. 여기서는 ABAQUS/Explicit 코드를 이용하여 컨테이너형태의 A형 운반용기에 대하여 최대손상이 야기되는 0.9m 경사낙하조건에 대한 3차원 충격해석을 수행하고 구조적 건전성을 평가하였는데, 운반용기는 경사낙하시 코너피팅(corner fitting)의 분쇄(crush)에 의하여 대부분의 충격을 흡수하였으며 운반용기의 격납경계는 구조적 건전성을 유지하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.661-665
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• 2000

In this study, the control of mounting system for MLGA package was developed using machine vision for the control of rotating position compensation and mounting position of X-Y table. Two type of material (polymer, alumina )were used for the dielectric insulator of the MLGA. And the illumination system and the algorithm of position compensation that be suitable for these materials was developed. Also, the position control order that compensated by machine vision actuated to micro stepping motor and X-Y servo motor by controlled PC and mounted the MLGA on PCB in resolution to$\pm10\mum$ .