• 한국축산식품학회지
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• 제42권1호
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• pp.153-174
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• 2022

This trial was conducted to evaluate the effect of overwrap, vacuum, and modified atmosphere packaging (MAP) on poultry breast fillets' microbiological, biochemical shelf life and sensory attributes. The fillets were divided into 4 groups, and each of the treatments was replicated 3 times with 60 breast fillets. The first group was a control group with overwrap packaging; the second group was vacuum packed (VP); the third and fourth groups were MAP-1: 0% O₂, 40% CO₂, 60% N₂, and MAP-2: 20% O₂, 40% CO₂, 40% N₂. The microbiological and biochemical analyses were performed for the total viable count, coliform count, Pseudomonas count, Salmonella count, total volatile basic nitrogen (TVB-N), pH, cooking loss, color, lipid oxidation, tenderness, and sensory analysis. The data were analysed through two-way ANOVA by Minitab (Minitab 17.3.1). Meat treated with understudy MAP compositions and vacuum packaging reduced total viable count, Pseudomonas count, and total coliform count than control (p<0.05). TVB-N remained below the recommended limit throughout storage except aerobic packaging (p<0.05). Cooking loss (%) was lowered and showed non-significant results (p>0.05) between vacuum packaging and both MAP concentrations. The meat stored in MAP-2 was characterised by higher (p<0.05) visual scores. Whilst MAP-1 showed higher (p<0.05) L^* values and overall acceptability. Sample packaged under aerobic packaging showed significant (p<0.05) results for b^* and thiobarbituric acid reactive substances (TBARS). Meat stored in aerobic packaging showed higher (p<0.05) shear force values. The outcome of this trial may help to promote the application of understudy MAP compositions and rapid detection of microbes by biochemical analysis under local conditions.

• Applied Biological Chemistry
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• 제11권
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• pp.67-76
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• 1969

1968년 7월 30 일에 채취한 축을 시료로하여 12월 3일 까지 저장시험을 한 결과는 1. 현재까지 가장 저장효과가 양호하다고 알려져 있는 CA저장법보다 강압저장법이 우수하였다. 2. 감압도에 있어서는 저감압이 고감압보다 저장효과가 좋으며 본 실험에서 실시한 70cmHg, 60cmHg, 40cmHg 및 20cmHg중에서 20cmHg가 가장 저장효과가 양호하였다. 3. 사과의 표면처리에 따른 효과는 1)저장중의 중량감소를 방지하는데는 Poly-ethylene film포장이 가장 효과적이나 장기저장에 있어서는 과실의 생리장해로 인하여 폐과량이 증가 하였다. 2) Poly-vinyl acetate coating은 과실 원래의 색택유지는 매우 효과적이었으나 특이한 냄새가 생겨서 미각적으로 품위를 저하시켰다. 3) Gibberellin 처리시의 저장효과는 축에서는 전연 없었다. 4. 주요성분의 변화는 1) 전당 및 환원당은 각 저장구에 따라 다소의 차는 있으나 저장 초기에는 증가하고 저장이 계속 됨에 따라 감소하였는데 냉장 20cmHg 감압구(No. 11)에서 증가 및 감소율이 가장 낮았다. 2) 산 및 Vitamin C는 각 저장구 및 처리별에 따라 감소율에 차이는 있으나 저장기간 중 계속 감소하였으며 냉장 20cmHg 감압구(No. 11)에서 그 감소율이 가장 낮았다.

• Applied Biological Chemistry
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• 제11권
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• pp.77-82
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• 1969

1968년 10월 3일에 채취한 홍옥(紅玉)을 시료로 하여 12월 3일 까지 감압도에 따라 저장시험한 결과를 보면 1) 본(本) 시험에서 실험한 감압도에 따른 시험결과는 10cmHg의 저감압이 가장 효과적이었다. 2) 상온의 10cmHg 감압구 (No.2)가 냉장상압(No.5) 보다 우수하였다. 3) 감압저장에 Poly-ethylene film 포장의 겸용은 단기 저장에서는 보다 효과적이었으나 장기 저장에서는 생리장해로 인하여 폐과량 증가하였다. 4) 청과물의 선도(鮮度), 보지제, 증산억제제 및 위조방지제인 O.E.D. coating이 저장효과에 미치는 영향은 극히 미약하였다. 5) Sodium dehydro acetate의 처리는 홍옥의 저장에서는 아무런 효과가 없었다. 6) 전당 및 환원당은 전보(前報) 축(祝)의 저장시험 때와 같이 저장 초기에는 증가하고 일정기간 후는 다 같이 감소하였으며 10cmHg 감압구(No.6)에서 증가 및 감소율이 가장 낮았다. 7) 산 및 Vitamin 도 전보(前報)와 같은 경향이었으며 역시 저감압인 10cmHg 감압구(No.6)에서 감소율이 현저히 낮았다. 지금 까지의 실험 결과로 미루어 볼 때 사과의 저장에는 10cmHg로 감압저장하는 것이 가장 효과적이며 냉장감압 함이 더욱 좋다고 할수 있겠다.

• 대기
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• 제21권4호
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• pp.415-427
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• 2011

In this study, the impacts of land surface conditions, land cover (LC) map and leaf area index (LAI), on the short-range weather forecast over the East-Asian region were examined using Unified Model (UM) coupled with the MOSES 2.2 (Met-Office Surface Exchange Scheme). Four types of experiments were performed at 12-km horizontal resolution with 38 vertical layers for two months, July and August 2009 through consecutive reruns of 72-hour every 12 hours, 00 and 12 UTC. The control experiment (CTRL) uses the original IGBP (International Geosphere-Biosphere Programme) LC map and old MODIS (MODerate resolution Imaging Spectroradiometer) LAI, the new LAI experiment (NLAI) uses improved monthly MODIS LAI. The new LC experiment (NLCE) uses KLC_v2 (Kongju National Univ. land cover), and the new land surface experiment (NLSE) uses KLC_v2 and new LAI. The reduced albedo and increased roughness length over southern part of China caused by the increased broadleaf fraction resulted in increase of land surface temperature (LST), air temperature, and sensible heat flux (SHF). Whereas, the LST and SHF over south-eastern part of Russia is decreased by the decreased needleleaf fraction and increased albedo. The changed wind speed induced by the LC and LAI changes also contribute the LST distribution through the change of vertical mixing and advection. The improvement of LC and LAI data clearly reduced the systematic underestimation of air temperature over South Korea. Whereas, the impacts of LC and LAI conditions on the simulation skills of precipitation are not systematic. In general, the impacts of LC changes on the short range forecast are more significant than that of LAI changes.

• 복식
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• 제59권3호
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• pp.42-54
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• 2009

The purpose of the study was to grasp problems through a basic survey of actual conditions of the Korean traditional costume industry and to grope a plan to settle the problems. The results were as follows. Operating Status: Rates of the companies' establishment were reduced in 2000s and their sales were also reduced. Status of Goods Development: Korean traditional costume manufacturers and Korean traditional costume textile fabric companies had the highest rate in non-trademark production. Korean traditional costume textile fabric companies and Korean traditional costume rental companies had high rate in self-design. However, Korean traditional costume manufacturers used textile companies' catalogue with the highest rate. Status of Demand and Supply in Human Resources: In human resources needing most, Korean traditional costume manufacturers were tailors, Korean traditional costume textile fBbric companies were salespersons and Korean traditional costume rental companies were designers. Status of Management and Marketing: Causes of difficulties in management were the market slump and the spreading of products made in China. They had a direct publicity through people around mainly. Therefore, it was urgently necessary to introduce special marketing methods. In an investment plan within three years in the future, about 70% did not have an investment plan. Opinions for Promotion of Korean traditional costume: In the government's support policy they wanted, construction of social atmosphere for Korean traditional costume-wearing and Korean traditional costume related educational support had the highest rate. Most of the companies answered that specialized Korean traditional costume agencies were necessary.

• 대기
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• 제25권3호
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• pp.501-510
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• 2015

In this study, the characteristics of flows around building groups are investigated using a computational fluid dynamics (CFD) model. For this, building groups with different volumetric ratios in a fixed area are considered. As the volumetric ratio of the building group increases, the region affected by the building group is widened. However, the wind-speed reduced area rather decreases with the volumetric ratio near the ground bottom (z ${\lesssim}$ 0.7H, here, H is the height of the building group) and, above 0.7H, it increases. As the volumetric ratio decreases (that is, space between buildings was widened), the size of recirculation region decreases but flow recovery is delayed, resulting in the wider wind-speed reduced area. The increase in the volumetric ratio results in larger drag force on the flow above the roof level, consequently reducing wind speed above the roof level. However, above z ${\gtrsim}$ 1.7H, wind speed increases with the volumetric ratio for satisfying mass conservation, resultantly increasing turbulent kinetic energy there. Inside the building groups, wind speed decreased with the volumetric ratio and averaged wind speed is parameterized in terms of the volumetric ratio and background flow speed. The parameterization method is applied to producing averaged wind speed for 80 urban areas in 7 cities in Korea, showing relatively good performance.

• 한국가스학회지
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• 제15권1호
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• pp.9-14
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• 2011

대형 디젤엔진은 주행거리가 길고 배기량이 크기 때문에 차량의 대수는 상대적으로 적지만 대기환경에 미치는 영향은 크다. 시내를 주행하는 시내버스의 경우 한일 월드컵을 계기로 CNG 버스로 전환되었다. 그러나 대형트럭과 장거리 시외버스의 경우 주행거리가 길고 CNG 충전소가 대도시의 시내버스 차고지 위주로 설치되어 있어 이용이 불가능하였다. 단열용기의 적용으로 천연가스를 압축상태가 아닌 액체 상태로 보관이 가능해져 주행거리가 긴 대형트럭이나 장거리 시외버스로의 적용이 가능해졌으며, 혼소엔진의 경우 LNG 충전이 어려운 지역에서는 디젤로 운행이 가능하다. 이와 같은 장점으로 인하여 석유 의존도를 크게 낮출 수 있어 에너지원의 다변화가 가능하며, 디젤차의 고질적인 단점으로 여겨왔던 매연 및 질소산화물뿐만 아니라 저탄소 연료를 사용함으로서 대표적인 온실가스중의 하나인 이산화탄소도 10%이상 저감할 수 있었다.

• 한국분말재료학회지
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• 제24권5호
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• pp.406-413
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• 2017

A Nanosized $WO_3$ and CuO powder mixture is prepared using novel high-energy ball milling in a bead mill to obtain a W-Cu nanocomposite powder, and the effect of milling time on the structural characteristics of $WO_3-CuO$ powder mixtures is investigated. The results show that the ball-milled $WO_3-CuO$ powder mixture reaches at steady state after 10 h milling, characterized by the uniform and narrow particle size distribution with primary crystalline sizes below 50 nm, a specific surface area of $37m^2/g$, and powder mean particle size ($D_{50}$) of $0.57{\mu}m$. The $WO_3-CuO$ powder mixtures milled for 10 h are heat-treated at different temperatures in $H_2$ atmosphere to produce W-Cu powder. The XRD results shows that both the $WO_3$ and CuO phases can be reduced to W and Cu phases at temperatures over $700^{\circ}C$. The reduced W-Cu nanocomposite powder exhibits excellent sinterability, and the ultrafine W-Cu composite can be obtained by the Cu liquid phase sintering process.

• 한국표면공학회지
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• 제48권4호
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• pp.158-162
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• 2015

To substitute indium tin oxide (ITO), many substituents have been studied such as metal nanowires, carbon based materials, 2D materials, and conducting polymers. These materials are not good enough to apply to an electrode because theses exhibit relatively high resistance. So metal grids are required as an additionalelectrode to improve the conductivities of substituents. The metal grids were printed by electrohydrodynamic printing system using Ag nanoparticle based ink. The Ag grids showed high uniformity and the line width was about $10{\mu}m$. The Ag nanoparticles are surrounded by dispersants such as unimolecular and polymer to prevent aggregation between Ag nanoparticles. The dispersants lead to low conductivity of Ag grids. Thus, the sintering process of Ag nanoparticles is strongly recommended to remove dispersants and connect each nanoparticles. For sintering process, the interface and microstructure of the Ag grid were controlled in 1.0 torr Ar atmosphere at aound $400^{\circ}C$ of temperature. From the sintering process, the uniformity of the Ag grid was improved and the defects on the Ag grids were reduced. As a result, the resistivity of Ag grid was greatly reduced up to $5.03({\pm}0.10){\times}10^{-6}{\Omega}{\cdot}cm$. The metal grids embedded substrates containing low pressure Ar sintered Ag grids showed 90.4% of transmittance in visible range with $0.43{\Omega}/{\square}$ of sheet resistance.

• 대한화학회지
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• 제62권2호
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• pp.118-123
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• 2018

The hexagonal tungsten bronze $Cs_xWO_3$ nanoparticle was synthesized by a chemical coprecipitation method of ammonium tungstate and $Cs_2CO_3$ in acidic condition. This synthetic method for cesium tungsten bronze is reported for the first time as far as we know. The synthesized $Cs_xWO_3$ as precipitated showed a weak crystallinity of hexagonal unit cell with a crystallite size of about 4 nm without annealing. When the synthesized $Cs_xWO_3$ was annealed in $N_2$ atmosphere, the crystallinity and crystallite size systematically increased maintaining the typical hexagonal tungsten bronze structure as the annealing temperature increased. The analyzed Cs content in the bronze was about 0.3 vs W, which is very close to the theoretical maximum value, 1/3 in cesium tungsten bronze. According to XPS analysis, the reduced tungsten ions existed as both the forms of $W^{5+}$ and $W^{4+}$ and the contents systematically increased as the annealing temperature increased up to $800^{\circ}C$. The $Cs_xWO_3$ thin films on PET substrate were also prepared by a wet-coating method using the ball-milled solution of the annealed $Cs_xWO_3$ nanoparticles at various temperatures. The near-infrared shielding property of these thin films increased systematically as the annealing temperature increased up to $800^{\circ}C$ as expected with the increased contents of reduced tungsten ions.