• 한국수소및신에너지학회논문집
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• 제34권3호
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• pp.274-282
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• 2023

This study conducted direct numerical simulations of the natural convection phenomena of gaseous hydrogen in a physical storage container containing four circular cylinders. Rayleigh numbers (Ra) in the range of 10⁴≤Ra≤10⁶ and a Prandtl number (Pr)=0.69 (gaseous hydrogen) were considered. The main parameter is a horizontal distance of four circular cylinders and the values of ε_h=0.1, 0.2, 0.3, 0.4, and 0.5 are considered. The flow and thermal structures and corresponding heat transfer characteristics are investigated with respect to the transition of the flow regime. The time- and surface-averaged Nusselt number on the cylinder surface and the wall of physical storage container increased by about 57% and 69% according to the Ra and ε_h, respectively. Thus, the horizontal distance has an influence on the heat transfer characteristics on natural convection of gaseous hydrogen.

• 한국포장학회지
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• 제27권3호
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• pp.175-180
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• 2021

Although it has recently been regulated for use as an eco-friendly policy in Korea, the use of EPS (Expanded Polystyrene) cooling boxes, which are used as cold chain delivery insulation boxes for fresh agricultural and livestock products, is also increasing rapidly as e-commerce logistics such as delivery have increased rapidly due to COVID-19. Studies were conducted to optimize the EPS cooling container through internal air heat flow of CFD (Computational Fluid Dynamics) analysis and FEM (Finite Element Method) random vibration analysis using domestic PSD (Power Spectral Density) profile of the EPS cooling box to which the refrigerant is applied in this study. In the analysis of the internal air heat flow by the refrigerant in the EPS cooling box, the application of vertical protrusions inside was excellent in volume heat flow and internal air temperature distribution. In addition, as a result of random vibration analysis, the internal vertical protrusion gives the rigid effect of the cooling box, so that displacement and stress generation due to vibration during transport are smaller than that of a general cooling container without protrusion. By utilizing the resonance point (frequency) of the EPS cooling box derived by the Model analysis of ANSYS Software, it can be applied to the insulation and cushion packaging design of the EPS product line, which is widely used as insulation and cushion materials.

• 소성∙가공
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• 제22권3호
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• pp.133-142
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• 2013

Recently, electric vehicles and hybrid cars are being promoted as alternatives to reduce automobile emissions. Generally, thin sheet materials such as aluminum alloy AA300X and cold-rolled steel sheet such as JIS-G-3141 are used for the container for the lithium-ion secondary batteries. In this study, a multi-stage deep drawing process is used to produce a rectangular cup from thin stainless steel sheet material, SUS409L, with an initial blank thickness of 0.4mm for the battery container application. Numerical simulations of the first through the fifth stages for the multi-stage deep drawing with thin SUS409L sheet were conducted using LS-Dyna3D Implicit/Explicit. Special consideration was given to the deformation characteristics due to the normal anisotropy of the sheet material. The numerical simulations were conducted with both isotropic properties and the anisotropic properties of the initial blank material. An unexpected forming failure, barreling in the bottom region of the deep drawn rectangular cup, was observed. This failure mode can be avoided by additional ironing thickness control during the process.

• 한국식품영양과학회지
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• 제5권1호
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• pp.11-17
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• 1976

Put four different kinds of Jangdongsi, Pasi, Gamsi, and Taebongsi etc. into glass bottle(Fig. 1) of 1150ml and after modulated constitution of air girding this, by means of $CO_2$ the keep in cold storage on $0{\sim}5^{\circ}C$. The results are as follows : 1. $CO_2$ non-addition group was not changed it's own color to four months regardless of kind of persimmons 2. $CO_2$ added test group by double quantity of container was not more rapidly discoloration. 3. One - half quantity of test group added double, same, one-half and one of fifth quantity of container was the most effect, $CO_2$ as the same kind in S. T. P. 4. Taebongsi of test group of four different kinds added one-half quantity of $CO_2$ was maintained effectually possible it's natural color till seven months. 5. In taste, non-addition of $CO_2$ existed astringency taste but addition of $CO_2$ showed sweet taste like a Gamsi since two months of storage.

• 디지털융복합연구
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• 제12권12호
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• pp.351-356
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• 2014

일반적으로 신선물류를 내장하고 있는 컨테이너 화물 혹은 일반 화물 등의 상태 및 위치를 파악하는 것은 콜드 체인 시스템 구축에서 매우 중요한 문제로 인식되어 왔지만, 관련업계에서 활용하고 있는 상태 및 위치 파악 방식은 아직까지 전통적인 방식에서 크게 벗어나지 못하고 있다. 때문에 본 논문에서는 이러한 문제를 해결하고 사물 인터넷 기반 스마트 콜드 체인 모니터링 자동화 시스템 구축 시 적용할 수 있는 설계 기법 및 아키텍처를 제안한다. 제안하는 스마트 콜드 체인 모니터링 자동화 시스템 구조는 oneM2M 표준을 기반으로 S/W 및 H/W로 구현되는 Network Services Layer 및 Entity, Common Services Layer 및 Entity, Application Layer 및 Entity로 구성되어 있으며, 이를 통해 신선물류 유통 시 해당 물류의 상태 및 위치를 자동으로 파악할 수 있을 뿐 아니라 해당 물류의 유통비용을 획기적으로 절감할 수 있을 것이다.

• 한국식품저장유통학회지
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• 제8권1호
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• pp.30-36
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• 2001

월동배추(품종 : 동풍)를 $0^{\circ}C$에서 저온저장중 선도 유지를 위하여 포장과 적입방법 개선에 대한 효과가 조사되었다. 저장과정중 배추의 상품성을 보았을 때 월동배추는 $0^{\circ}C$에 저온 저장한 경우 4개월 이상 저장, 출하가 가능한 것으로 여겨졌다. 포장용기간 저장성은 0.03mm 폴리에칠렌 플라스틱필름에 4포기씩 세로로 적입하여 플라스틱콘테이너에 저장한 경우가 기존의 폴리프로필렌 그물망과 철제파레트를 이용한 경우에 비하여 우수하게 나타났다. MAP 저장시 포장내의 가스 조성은 처리구간에 큰 유의적인 차이를 나타내지는 않았는데 대체로 산소 농도는 8.2~19.5% 정도, 이산화탄소는 0.35~8.58% 범위를 나타내었다. 저온저장중 비타민C, 환원당, 클로로필 색소는 계속 감소하였으며 폴리에틸렌 플라스틱필름과 콘테이너에 의한 MAP가 기존 저장방법에 비하여 10~20% 정도 선도 저하를 억제하는 효과를 가져왔다.

• 대한본초학회지
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• 제37권1호
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• pp.31-39
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• 2022

Objectives : It is very important to know the exact dosage of the Decoctions in 《Treatise on Cold Damage Diseases》. This study identified the characteristics of 15 Medicinal marked in volume and calculated their dosages in weight. Methods : The origin, processing methods, and properties of 15 Medicinal were identified. The shape of the appropriate container that measures the volume of one seung was estimated, and the dosage in volume was converted into weight. These were compared with the dosages indicated by weight or count. Results : The 15 Medicinal were categorized into liquids, powders, and grains. Ten items had only one dosage, of which three items had one seung, and seven items had 0.5 seung. Five items had two different dosages, of which four items had one or 0.5 seung, and only Suis Fel was 0.2 or 0.1 seung. Pinelliae Tuber and Urine were marked as 0.5 seung for convenience of measurement, although 0.4 seung were accurate. There were 20 different dosages in total, and when converted into weight, they matched 1, 2, 3, 4, 6, 8, or 16 Ryang, with none of 5 Ryang. Some exceptions that did not fit in the above were indicated by weight or count. Conclusions : In the Decoctions of 《Treatise on Cold Damage Diseases》, dosages of 15 Medicinal were easy to measure by volume, and when converted into weight, they were consistent with the dosages originally indicated in weight or count.

• 한국결정성장학회지
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• 제19권4호
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• pp.190-195
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• 2009

스컬용융법에 의해 Na사규소운모를 합성하였다. $Mg_3(OH)_2Si_4O_{10}:Na_2SiF_6:SiO_2=8.3:24.8:66.9$ mol% 비율로 혼합한 출발원료를 ${\phi}13{\times}H14cm$의 냉각도가니에 채우고 2.84MHz 출력주파수의 고주파발진기를 이용하여 가열하였다. 원료는 융액상태에서 1시간 유지하였으며 도가니 내에서 냉각시켰다. 운모의 비저항은 추정하였으며, 원주모양과 판상으로 합성할 수 있었다.

• 펄프종이기술
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• 제35권2호
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• pp.33-38
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• 2003

In order to design the high strength corrugated fiberboard containers for agricultural products that can be used for the cold chain system, a large number of individual boxes were placed in various humidity environments at two different temperature of 5 and $20^{\circ}C$. The results indicated that temperature changes do not effect on physical strength of corrugated fiberboard containers as much as humidity changes did. The main conclusion from this study was that compression strength of corrugated fiberboard containers dropped significantly at high humidity condition, but the rates varied depending on the number of walls, temperature, and perimeter of containers. The packaging designer must consider the corrugated fiberboard boxes are also greatly affected by dimensional variations such as the length versus width ratio. Based on this study, water-resistant board would not be necessary if the ambient relative humidity does not reach to a critical point, 85 percent in the cold chain system. However, the designer must count for the unexpected fluctuation of rotative humidity resulting in severe loss of the compression strength of corrugated fiberboard container.

• Elastomers and Composites
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• 제54권2호
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• pp.123-127
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• 2019

Shrink film is currently being used for plastic container lavels to avoid the use of glue. Polyethylene terephthalate (PET) bottle lavels also use shrink films in the same PET materials for easy recycling of PET bottles. An air layer is generated between the shrink film and PET bottle surface due to the bent shape of the bottle surface. This air layer can insulate external heat, as air has a relatively lower thermal conductivity. In this study, the insulation property of the air layer was examined by computer simulation. Two PET bottle models were used, one with and the other without an air layer between the PET bottle surface and lavel. The two bottle models were filled with cold liquid and exposed to room temperature for 6 h, and the temperatures of the contents were then compared. The results showed that the temperature of the contents in the bottle with the air layer was lower than that without the air layer by at least $2^{\circ}C$. This study suggests an effective lavel design of PET bottles while ensuring that the temperature of the bottle contents is maintained.