• 셀메드
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• 제4권1호
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• pp.3.1-3.8
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• 2014

Spa represents a treatment widely used in many rheumatic diseases (RD). The mechanisms by which immersion in mineral or thermal water ameliorates RD are not fully understood. The net benefit is probably the result of a combination of factors, among which the mechanical, thermal and chemical effects are most prominent. Buoyancy, immersion, resistance and temperature play important roles. According to the gate theory, pain relief may be due to the pressure and temperature of the water on skin; heat may reduce muscle spasm and increase the pain threshold. Mud-bath therapy increases plasma ${\beta}$-endorphin levels and secretion of corticotrophin, cortisol, growth hormone and prolactin. It has recently been demonstrated that thermal mud-bath therapy induces a reduction in circulating levels of prostaglandin E2, leukotriene B4, interleukin-$1{\beta}$ and tumour necrosis factor-${\alpha}$, important mediators of inflammation and pain. Furthermore, balneotherapy has been found to cause an increase in insulin-like growth factor-1, which stimulates cartilage metabolism, and transforming growth factor-${\beta}$. Beneficial anti-inflammatory and anti-degenerative effects of mineral water were confirmed in chondrocytes cultures, too. Various studies in vitro and in humans have highlighted the positive action of mud-packs and thermal baths, especially sulphurous ones, on the oxidant/antioxidant system. Overall, thermal stress has an immunosuppressive effect. Many other non-specific factors may also contribute to the beneficial effects observed after spa therapy in some RD, including effects on cardiovascular risk factors (e.g. adipokines) and changes in the environment, pleasant surroundings and the absence of work duties.

• 한국결정성장학회지
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• 제6권2호
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• pp.263-274
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• 1996

타이타늄 옥사이드층을 태양전지의 표면 보호막으로 사용시, 그 적합성에 대해 조사하였다. 스프레이법으로 형성된 타이타늄 옥사이드의 박막층은 태양전지 제조 과정중 사용되는 화학약품에 잘 견디며, 이 층을 사용함으로서 고온산화공정을 줄일 수 있다.

• 한국진공학회지
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• 제7권4호
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• pp.328-333
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• 1998

저압 유기금속 화학증착법을 이용하여 (001) InP 기판 위에 격자 일치된 InAlAs 에 피층 성장 결과 620~$700^{\circ}C$범위에서 성장 온도가 증가할수록 산소 유입량의 감소 때문으로 생각되는 광학적 성질의 향상이 관찰되었으나 $750^{\circ}C$이상의 고온에서는 InP완충층의 열화에 의한 결정성의 감소가 발견되었다. 또한, AsH3의 유량이 증가됨에 따라 성장된 InAlAs층의 Al함유량이 증가하는 현상이 관찰되었고, 이는 Al-As와 In-As의 bond strength 차이로 설 명하였다. InGaAs/InAlAs 단일 양자우물구조에서 측정된 우물두께에 따른 photoluminescence peak energy는 계산 값과 잘 일치하였고, high resolution x-ray diffraction 측정을 통하여 뚜렷한 satellite peak와 fine thickness fringe들이 관찰되는 우수 한 계면특성을 가지는 다중 양자우물구조가 성장됨을 확인하였다.

• 한국작물학회지
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• 제68권4호
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.

• 한국조경학회지
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• 제47권5호
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• pp.66-77
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• 2019

본 연구는 인천해안지역의 난온대성 상록활엽수 겨울철 생장에 영향을 미치는 미기후 요인을 시뮬레이션 기법을 통해 도출하였다. 인천 해안지역 서구 오류동~남동구 고잔동의 온량지수는 $98.9^{\circ}C{\cdot}month{\sim}109.0^{\circ}C{\cdot}month$이었고, 1월 평균기온 $-2.9^{\circ}C{\sim}-1.6^{\circ}C$, 최한월 최저기온 $-13.9^{\circ}C{\sim}-3.6^{\circ}C$ 수준으로, 상록활엽수 분포기준인 온량지수 $101.0^{\circ}C{\cdot}month{\sim}117.0^{\circ}C{\cdot}month$, 최한월 최저기온 $-9.2^{\circ}C$이하로 상록활엽수가 생장하기 부적합한 지역으로 나타났다. 상록활엽수가 생장하는 공간에 도달하는 풍속의 저감정도와 가온효과에 대한 시뮬레이션을 실시한 결과, 상록활엽수 생장공간에서는 겨울 북서풍이 건축물 등에 의해 해안풍속이 8.6m/sec에서 도달풍속은 5~7m/sec로 완화되었고, 건축물 1m 이내에서는 건축물 복사에너지의 영향으로 $1.1^{\circ}C{\sim}3.4^{\circ}C$ 가량의 가온효과가 나타났다. 시뮬레이션 결과, 상록활엽수의 겨울철 생장피해에 영향을 미치는 기후요소는 풍속으로, 차폐에 의한 풍속저감과 함께 건축물에 의한 국부적 가온효과가 상록활엽수의 겨울생장이 가능한 것으로 추정되었다. 또한 인천 해안지역에 생장하고 있는 상록활엽수는 중부지방의 겨울철 저온에 점진적으로 식물이 적응하는 순화의 과정으로 판단할 수 있었고, 기온이 $-18.0^{\circ}C$ 이하의 겨울한파에 견디는 내동능력과 바람에 의한 증발산을 견딜 수 있는 동건해(凍乾害)에 내성이 상록활엽수 겨울 생장을 좌우하는 것으로 나타났다.

• 한국분말재료학회지
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• 제21권3호
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• pp.207-214
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• 2014

In this study, nano-scale copper powders were reduction treated in a hydrogen atmosphere at the relatively high temperature of $350^{\circ}C$ in order to eliminate surface oxide layers, which are the main obstacles for fabricating a nano/ultrafine grained bulk parts from the nano-scale powders. The changes in composition and microstructure before and after the hydrogen reduction treatment were evaluated by analyzing X-ray diffraction (XRD) line profile patterns using the convolutional multiple whole profile (CMWP) procedure. In order to confirm the result from the XRD line profile analysis, transmitted electron microscope observations were performed on the specimen of the hydrogen reduction treated powders fabricated using a focused ion beam process. A quasi-statically compacted specimen from the nano-scale powders was produced and Vickers micro-hardness was measured to verify the potential of the powders as the basis for a bulk nano/ultrafine grained material. Although the bonding between particles and the growth in size of the particles occurred, crystallites retained their nano-scale size evaluated using the XRD results. The hardness results demonstrate the usefulness of the powders for a nano/ultrafine grained material, once a good consolidation of powders is achieved.

• 대한기계학회논문집B
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• 제20권7호
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• pp.2397-2408
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• 1996

A numerical study was made of the control of transient oscillatory flow modes in Czochralski convection. The reduction of temperature oscillation was achieved by changing the rotation rate of crystal rod, .OMEGA.$_{S}$=.OMEG $A_{S0}$(1+ $A_{S}$sin(2.pi. $f_{S}$/ $t_{p}$t)). The temporal behavior of oscillation flow was scrutinized over broad ranges of two parameters, i.e., the rotation amplitude( $A_{S}$.leq.0.5) and the nondimensional frequency (0.9.leq. $f_{S}$.leq.1.5). The mixed convection parameter was ranged 0.225.leq.Ra/PrR $e^{2}$.leq.0.929, which encompassed the buoyancy-and forced-dominant convection regimes. Computational results revealed that the temperature oscillations could be reduced effectively by a proper adjustment of the control parameters. The uniformity of temperature distribution near the crystal rod was examined. The control of oscillatory flow modes was also made for a realistic, low value of Pr.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.953-956
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• 2003

Transparent conductive ZnO:Ga thin films were deposited on glass substrates using rf magnetron sputtering method for flat panel display. The ZnO:Ga films were preferentially oriented to c-axis (002) of on substrates. The surface morphology was smooth and had not porous whatever substrate temperature was. The electrical conductivity of the thin films were in the range of $1.6{\times}10^2{\sim}6.7{\times}10^3\;{\Omega}^{-1}cm^{-1}$ at the growth temperature from 50 to $400^{\circ}C$, whereas has a maximum at around $250^{\circ}C$. By combining of XRD and EXAFS, the crystallinity and grain size decreased with increasing substrate temperature corresponding to the reduction of the grain-boundary scattering. The optical transmittance of sputtered ZnO:Ga thin films had an improved about 86% in the UV-visible region.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.163-171
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• 1999

The abnormal grain coarsening in wire rolling induces detrimental defects, such as jagged size tolorance, severe bending after heat treatments and drawing troubles, in the following secondary processes. Neishi et al observed that there is a band type region where grain coarsenting occurs in the plastic strain vs. deformation temperature plot. Based on the finding, we have investigate whether grain sizes and ferrite volume fractions are correlation to deformation strain with three kinds of wire rod diameters as for the different average deformation conditions. The samples were chosen from the No.2 Wire Rod Mill of POSCO where 3-roll type of finishing mill stand are used. It was found in the present work that the grain size and ferrite volume fraction of the rolled and cooled microstructure were changed with rolling reduction and rolling temperature. Abnormally grown grains at various observed points were also found. To have homogeneously fine grains of microstructure from the No. 2 Wire Rod Mill, it will be easier to control finish rolling temperature at around 750$^{\circ}C$ rather than to find another rolling schedule.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1316-1323
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• 2017

Geosmin and 2-methylisoborneol (2-MIB), responsible for earthy or musty smell, are a major concern for safe drinking water supplies. This study investigated the effects of environmental factors on odorous compound production and cell growth in cyanobacterial strains. Anabaena sp. FACHB-1384, a 2-MIB producer, was sensitive to low temperature (<$20^{\circ}C$). However, geosmin producers, Anabaena sp. Chusori and Anabaena sp. NIER, were sensitive to high light intensity (>$100{\mu}mol/m^2/sec$), but not to low temperature. Geosmin concentrations increased under higher nitrate concentrations, being linearly proportional to cell density. A P-limited chemostat showed that P-stress decreased the geosmin productivity and extracellular geosmin amount per cell in Anabaena sp. NIER. However, only 2-MIB productivity was reduced in Planktothrix sp. FACHB-1374 under P-limitation. The extracellular 2-MIB amount per cell remained constant at all dilution rates. In conclusion, high light intensity and P-stress can contribute to the lower incidence of geosmin, whereas 2-MIB reduction could be attainable at a lower temperature.