• Molecules and Cells
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• 제25권1호
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• pp.78-85
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• 2008

In a search for new molecular pathways associated with asthma, we performed an mRNA differential display analysis using total RNA extracted from the tracheal tissues of ovalbumin (OVA)-challenged mice and sham controls. cDNAs corresponding to mRNAs for which expression levels were altered by OVA-challenge were isolate and sequenced. Twenty-eight genes differentially expressed in sham and OVA challenged mice were identified. A GenBank BLAST homology search revealed that they were related to cytoskeleton remodeling, transcription, protein synthesis and modification, energy production, and cell growth and differentiation. Two were selected for further characterization. Up-regulation of both the perinatal skeletal myosin heavy chain (skMHC) and fast skeletal muscle myosin light chain (skMLC) genes was confirmed by RT-PCR of trachea tissue from OVA challenged mice. Overexpression of skMLC protein was observed in the smooth muscle layers of OVA-challenged mice by immunohistochemistry, and the surface areas stained with skMLC antibody increased in the OVA-challenged mice. The overexpression of skMLC in murine asthma may be associated with the changes of bronchial smooth muscle.

• 펄프종이기술
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• 제48권3호
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• pp.91-98
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• 2016

Linerboards have been produced by recycling recovered paper such as old corrugated containers(OCC). Usually linerboards produced during summer season show weak strength compared with those of produced during winter. In order to cope with the weak strength of linerboards produced during summer, and to confirm uniform quality, it is important to understand the seasonal effect on strength properties. Effect of pulping temperature of the OCC for linearboard production was investigated by controlling pulping temperatures at $18^{\circ}C$ and $51^{\circ}C$. Low pulping temperature ($18^{\circ}C$) caused more generation of fines in stock. Consequently retention and drainage of linerboard defibrated at high pulping temperature ($51^{\circ}C$) were better than those of $18^{\circ}C$. Strength properties of handsheet at low pulping temperature were higher than those of high pulping temperature and it could be confirmed that low pulping temperature during winter is one reason of seasonal variation of recycled linerboard strength. It is considered that surface modification of OCC fibers by harsh pulping action during winter caused increase of paper strength.

• 멤브레인
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• 제26권6호
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• pp.458-462
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• 2016

염수전기분해(saline water electrolysis) 또는 클로로-알칼리 막공정(chlor-alkali membrane process)은 양이온교환막과 전극으로 구성되는 전해셀에 전기를 가하여, 고순도(> 99%)의 고부가가치 화합물(예 : 염소, 수소, 수산화나트륨)을 직접 제조하는 화학공정이다. 염수전기분해의 경제성은 동일한 양의 화합물을 생산하기 위해 투여되는 에너지 소비량을 저감시킴으로 달성될 수 있다. 이러한 이슈는 전해질이나 전극의 고유 저항을 줄이거나, 전해질과 전극 사이의 계면 저항을 감소시킴으로 달성시킬 수 있다. 본 연구에서는 전자빔 동시조사법을 사용하여, 높은 화학적 안정성을 지닌 탄화수소계 술폰산 이오노머 막의 표면에 높은 이온선택성을 갖는 고분자를 접목 시키는 시도가 이루어졌다. 이를 통해, 고분자 전해질 막의 이온전도성을 보완함과 동시에, 전극과의 계면 저항을 감소시켜, 전기화학적 효율 향상이 이루어짐을 관찰하였다.

• 한국광물학회지
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• 제15권3호
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• pp.183-194
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• 2002

안동화강암에 발달한 풍화단면에서 발견되는 흑운모 및 그 풍화산물을 대상으로 X-선회절분석, 화학분석, 전자현미경 관찰 등의 광물학적 분석을 실시하였다. 그 결과, 이 지역의 흑운모는 풍화과정에서 별개의 질석이나 흑운모-질석 규칙혼합층 구조로 변질되지 않고 10$\AA$의 회절선을 보이는 산화흑운모로 풍화되었다. Fe의 산화로 발생하는 과잉 양전하는 사면체 자리의 양이온 점유율의 변화는 없이 팔면체자리로부터 16%의 Fe와 12%의 Mg, 그리고 층간에서 13%의 K가 제거되는 방식으로 해소되었다. 동시에 흑운모의 5%는 산화흑운모와 불규칙혼합층을 이루는 질석으로 변환되었다. 흑운모 풍화초기에 Fe의 산화로 야기된 약간의 화학조성 및 구조적 변화의 결과로 생성된 산화흑운모는 대부분의 풍화 구간에서 더 이상 질석으로 풍화되지 않고 안정한 상태를 유지하다가 상부에서 부분적으로 캐올리나이트로 분해된다. 흑운모가 풍부한 기반암의 지표환경에서 원소거동을 이해하기 위해서는 신선한 흑운모가 아닌 풍화저항도가 매우 큰 산화흑운모에 대한 생성원인과 용해실험이 요청된다.

• 한국환경과학회지
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• 제1권2호
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• pp.105.2-117
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• 1992

The formation mechanism of the vortex streets in the lee of the mountain Is Investigated by a three-dimensional numerical model. The model is based upon the hydrostatic Boussinesq equations in which the vertical turbulent momentum flux is estimated by a turbulence parameterization scheme, but the horizontal viscosity is assumed to be constant. The results show that Karman vortex streets can form even without surface friction in a constant ambient flow with uniform stratification. The vortex formation is related to breaking of the mountain wave, which depends on the Froude number (Fr). In the case of a three-dimensional bell-shaped mountain, the wave breaking occurs when Fr is less than about 0.8, while a barman vortex forms when Fr is less than about 0.22. Vortex formation also depends on Reynolds number, which is estimated from the horizontal diffusivity. The vortex formation can be explained by the wave saturation theory given by Lindzen (1981) with some modification. Simulations in this study show that in the case of Karman vortex formation the momentum flux in the lower level is much larger than the saturated momentum flux, whereas it is almost equal to the saturated momentum at the upper levels as expected from the saturation theory. As a result, large flux divergence is produced in the lower layer, the mean flow is decelerated behind the mountain, and the horizontal wind shear forms between unmodified ambient wind. The momentum exchange between the mean flow and the mountain wave is produced by the turbulence within a breaking wave. From the result, well developed vortices like Karman vortex can be formed. . The results of the momentum budget calculated by the hydrostatic model are almost the same as nonhydrostatic results as long as horizontal scale of the mountain is 10 km. A well developed barman vortex similar to the hydrostatic one was simulated in the nonhydrostatic case. Therefore, we conclude that the hydrostatic assumption is adequate to investigate the origin of the Km8n vortex from the viewpoint of wave breaking.

• 복식
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• 제62권2호
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• pp.1-12
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• 2012

Cloths wrapped around the body have been the basis of the dress of people all over the world for centuries. This study is to research detailed modifiable fashion styling methods in history and to give ideas to people such as fashion professionals who are interested in fashion styling so that they can create modifiable fashion styling easily in fashion fields. The characteristics of modifiable fashion styling methods from ancient to middle ages are as follows. The first modifiable styling method is to expose the knots on the surface of the garments, and the knots were mainly located on the upper part of the body. The second method is a wrapping type of the modifiable styling method, which shows a lot of variant simple shapes of cloths. This method helped develop many wrapping methods over time. The third way is the fixed type of the modifiable styling method, and it uses accessories such as fibulae, belts to fix cloths, to create many different styles. The accessories are located on around either the neck or waist. The fourth method is the composite type of the modifiable styling methods mentioned above. This styling method is adapted in robe type clothes which makes the clothes look full of beautiful drapery. This study suggests that simple shapes of cloths can create enormous amount of styling which can be easily adapted and created nowadays.

• 대한기계학회논문집A
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• 제38권6호
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• pp.629-636
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• 2014

비정질합금이 가지고 있는 우수한 기계적 성질과 화학적 특성을 부품소재에 표면개질을 목적으로 고속화염 용사법으로 대면적 코팅층을 형성하였고 내열성이 높은 자융성합금과 초경합금 성분들을 적절히 혼합하여 비정질기지 복합재료를 제조하여 코팅들의 미세조직 관찰과 나노인덴테이션을 이용한 미세표면의 기계적 거동을 분석하였다. 각 코팅층의 미세조직을 관찰한 결과, 단일상 비정질 코팅에는 미용융 입자와 lamellae 영역이 존재하고 자융성합금이 고용된 복합재에는 in-situ $Cr_2Ni_3$ 석출물, 자융성합금과 초경합금성분이 함께 혼합된 코팅층은 석출물과 ex-situ WC 강화입자가 공존하였다. 이들 미세표면의 기계적 거동은 제 2 상이 고용된 비정질 기지 복합재의 코팅층의 기계적 특성이 전체적으로 향상되었다.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.655-658
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• 2006

Purpose: The main goals of correcting syndactyly of the hand are to form normal web appearance and to prevent motor dysfunction. We modified the original three-square-flap to improve interdigital web space and to reduce the wound healing problem due to tension. Methods: From July 2005 to February 2006, three cases of moderate to minor syndactyly were treated using modified three-square-flap. These flaps were made in such as way that the A flap from dorsal side, the B flap from the interdigital surface, and the C flap from the volar side. We modified the design of dorsal A flap as a hourglass shape instead of square shape to make normal hourglass shaped interdigital web and to reduce the tension of closure with other two flaps(B and C flap). The B and C flap were made as square shape. Results: During 4 to 10 months follow-up period, acceptable esthetic results were obtained without any specific complication, using our modification of the three-square-flap. Conclusion: Our method showed more satisfactory web appearance and was safe to use even in the cases of syndactyly secondary to burns and post-traumatic scars because of excellent blood circulation.

• 펄프종이기술
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• 제44권5호
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• pp.21-31
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• 2012

In this study, we modified the surface of ground calcium carbonate (GCC) with polyelectrolytes with different molecular weight using Layer-by-Layer (LbL) multilayering technique and investigated its effect on the paper properties. Polydiallydimethylammonium chloride (poly-DADMAC) and poly sodium 4-styrene sulfonate (PSS) which have different molecular weights were used for LbL multilayering. Zeta potential and particle size of the LbL modified GCC were measured. After preparation of handsheets, their structural and mechanical properties were evaluated. The zeta potential and average particle size of the modified GCC were affected by the molecular weight of anionic polyelectrolyte (PSS). The zeta potential was higher and the particle size was smaller when GCC was treated by PSS with high molecular weight compared to the case with low molecular weight of PSS. The tensile and internal bond strength of the handsheets was increased with an increase in the number of layers on GCC particles, but the molecular weight of polyelectrolyte did not significantly affect the paper strength.

• Environmental Engineering Research
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• 제14권1호
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• pp.41-47
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• 2009

Column experiments were performed in this study to investigate humic acid adhesion to iron oxide-coated sand (ICS) under different experimental conditions including influent humic acid concentration, flow rate, solution pH, and ionic strength/composition. Breakthrough curves of humic acid were obtained by monitoring effluents, and then column capacity for humic acid adsorption ($C_cap$), total adsorption percent (R), and mass of humic acid adsorbed per unit mass of filter media ($q_a$) were quantified from these curves. Results showed that humic acid adhesion was about seven times higher in ICS than in quartz sand at given experimental conditions. This indicates that humic acid removal can be enhanced through the surface charge modification of quartz sand with iron oxide coating. The adhesion of humic acid in ICS was influenced by influent humic acid concentration. $C_cap$ and $q_a$ increased while R decreased with increasing influent humic acid concentration in ICS column. However, the influence of flow rate was not eminent in our experimental conditions. The humic acid adhesion was enhanced with increasing salt concentration of solution. $C_cap$, $q_a$ and R increased in ICS column with increasing salt concentration. On the adhesion of humic acid, the impact of CaCl2 was greater than that of NaCl. Also, the humic acid adhesion to ICS decreased with increasing solution pH. $C_cap$, $q_a$ and R decreased with increasing solution pH. This study demonstrates that humic acid concentration, salt concentration/composition, and solution pH should be controlled carefully in order to improve the ICS column performance for humic acid removal from water.