• 한국측량학회지
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• 제31권2호
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• pp.143-150
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• 2013

최근 기후 온난화, 오존층 파괴, 열대림의 감소, 사막화 등의 환경문제가 이미 한 국가 문제를 넘어 범세계적인 지구환경문제로 대두되면서 이를 해결하기 위한 국제적인 관심과 노력이 다양하게 진행되어 왔다. 본 연구에서는 원격탐사 기법을 이용하여 도시의 녹지증가를 정량적으로 산출하고, 온도 추출을 통해 도시의 온도변화를 파악하고자 하였다. 2002년 5월과 2009년 5월 Landsat TM영상을 이용하여 연구대상지의 녹지 면적변화와 열변화를 분석하였으며, 도심의 지표면 온도를 추출하기 위해 Landsat TM 열적외선 영역센서인 Band 6의 분광밝기정도를 이용하여 표면온도분포를 산출하였다. 연구결과, 도심지 녹지의 면적이 $2.97km^2$ 증가하였으며, 도시의 지표온도가 약$0.6^{\circ}C{\sim}0.8^{\circ}C$ 낮아졌음을 제시하였다. 향후 원격탐사 및 실측자료를 바탕으로 도심 온도변화에 대한 추가적인 연구가 이루어진다면 도시환경문제 해결에 크게 기여할 것이다.

• Corrosion Science and Technology
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• 제19권1호
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• pp.16-22
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• 2020

It is important to realize that benzoate was intercalated into hydrotalcite (HTC-Bz) by the co-precipitation method. In this case, acrylic coating with 0.5 wt% HTC-Bz was deposited on carbon steel using the spin coating method. Next, the HTC-Bz structure was characterized by Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). In fact, an ultraviolet vision spectroscopy (UV-Vis) was used to determine the benzoate content in HTC-Bz, and the UV absorption ability of HTC-Bz. Using electrochemical techniques, water contact angle measurement, and thermal-gravimetric analysis, we compared the protective properties before and after QUV test, hydrophobicity and the thermal stability of acrylic coating containing HTC-Bz. The obtained results showed that HTC-Bz with a plate-like structure was successfully synthesized; benzoate was intercalated into the interlayer of hydrotalcite with a concentration of 28 wt%. Additionally, it was noted that HTC-Bz has an UV absorption peak at 225 nm. In conclusion, the addition of HTC-Bz enhanced the UV stability, hydrophobicity and the thermal stability of acrylic coating.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.310-316
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• 2019

자동차 편의 장치에 대하여 고객들은 높은 효율과 많은 기능을 요구하고 있으며, 이러한 자동차 어플리케이션에 대한 수요가 지속적으로 증가하고 있다. 본 연구에서는 최근 자동차 편의 사양으로 개발된 무선충전기의 PCB(printed circuit board) 발열 성능 향상을 위한 열 유동해석에 관한 연구를 진행하였다. 무선충전기는 PCB의 전력 손실 및 열 저항의 특성 발열에 따라 충전의 성능이 급격히 저하된다. 따라서 열 유동해석 시뮬레이션을 통해 최적의 PCB 설계 및 부품의 실장 위치를 제안하고, 각 설계 단계에서 해석을 통해 디자인을 결정한다. 이후, 실제 환경 조건에서 해석결과 정합성 검증을 위해 시험을 수행하고 결과를 비교 분석한다. 본 논문에서는 HyperLynx Thermal와 FloTHERM 프로그램을 사용하여 PCB 모델링 및 과도 응답 열 유동해석을 수행하였다. 또한, 해석 및 측정 결과의 정합성 검증을 위해 적외선 열화상 카메라를 사용하여 시험을 진행하였다. 최종 결과 비교에서 해석과 시험의 오차는 10 % 이내로 확인되었고, PCB의 발열 성능도 향상되었다.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.169-173
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• 2007

During laser irradiation, mechanically deformed cartilage undergoes a temperature dependent phase transformation resulting in accelerated stress relaxation. Clinically, laser-assisted cartilage reshaping may be used to recreate the underlying cartilaginous framework in structures such as ear, larynx, trachea, and nose. Therefore, research and identification of the biophysical transformations in cartilage accompanying laser heating are valuable to identify critical laser dosimetry and phase transformation of cartilage for many clinical applications. quasi-elastic light scattering was investigated using Ho : YAG laser $(\lambda=2.12{\mu}m\;;\;t_p\sim450{\mu}s)$ and Nd:YAG Laser $(\lambda=1.32{\mu}m\;;\;t_p\sim700{\mu}s)$ for heating sources and He : Ne $(\lambda=632.8nm)$ laser, high-power diode pumped laser $(\lambda=532nm)$, and Ti : $Al_2O_3$ femtosecond laser $(\lambda=850nm)$ for light scattering sources. A spectrometer and infrared radiometric sensor were used to monitor the backscattered light spectrum and transient temperature changes from cartilage following laser irradiation. Analysis of the optical, thermal, and quasi-elastic light scattering properties may indicate internal dynamics of proteoglycan movement within the cartilage framework during laser irradiation.

• Journal of Korean Vacuum Science & Technology
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• 제6권1호
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• pp.46-50
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• 2002

C-SiC films with different content of SiC on stainless steel substrate were prepared with ion beam mixing. It was found that hydrogen concentrations in C-SiC coatings was higher than that in stainless steel after H$\^$+/ ion implantation followed by thermal annealing. Infrared (IR) transmission measurement was used to study the mechanism of hydrogen retention by C-SiC films. The vibrational features in the range between 400 and 3200 cm$\^$-1/ in IR transmission spectra show the Si-CH$_3$, Si-CH$_2$, Si-H, CH$_2$and CH$_3$bonds, which are responsible for retaining hydrogen.

• Carbon letters
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• 제8권4호
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• pp.313-320
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• 2007

In the present study, electrospun PAN precursor webs and the stabilized and carbonized nanofiber webs processed under different heat-treatment conditions were characterized by means of weight loss measurement, elemental analysis, scanning electron microscopy (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimentric analysis (TGA), and X-ray diffraction (XRD) analysis. The result indicated that stabilization and carbonization processes with different temperatures and heating rates significantly influenced the chemical and morphological characteristics as well as the thermal properties of the stabilized and then subsequently carbonized nanofiber webs from PAN precursor webs. It was noted that the filament diameter and the carbon content of a carbonized nanofiber web as well as its weight change may be effectively monitored by controlling both stabilization and carbonization processes.

• Membrane and Water Treatment
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• 제13권6호
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• pp.321-335
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• 2022

Copper-based Metal-organic framework (MOF) namely ([Cu (INA)₂]-MOF) is synthesized by ball milling and characterized using scanning electron microscopy (SEM) for the topography, microstructure, and elemental evidence determination, powdered X-ray diffraction (XRD) for the crystallinity measurement, thermogravimetric (TG) analysis was performed to determine the thermal stability of the material, and Fourier transformed infrared (FTIR) spectroscopy for functional groups identification. The use of [Cu (INA)₂]-MOF as hazardous removal material of β-agonists as persistent hazardous micro-pollutants in our environmental water is first reported in this study. The removal efficiency of the Cu-MOF is successfully determined to be 97.7% within 40 minutes, and the MOF has established an exceptional removal capacity of 835 mg L^-1 with 95 % percent removal on Clenbuterol (CLB) even after the 5th consecutive cycle. The Langmuir model of the adsorption isotherms was shown to be more favourable, while the pseudo-second-order model was found to be favoured in the kinetics. The reaction was exothermic and spontaneous from a thermodynamic standpoint, and the higher temperatures were unfavourable for the adsorption study of the CLB. As a result, the studied MOF have shown promising properties as possible adsorbents for the removal of CLB in wastewater.

• 대한전자공학회논문지
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• 제27권10호
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• pp.106-112
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• 1990

다공질 실리콘을 열산화할 때 산화의 온도 의존성과 IR흡수 스펙트럼을 조사하여 다공질 실리콘외 산화특성을 조사하였다. PSL(porous silicon layer)을 $700^{\circ}C$에서 1시간, $1100^{\circ}C$에서 1시간으로 2단계 습식산화시켜 bulk 실리콘의 열산화막과 같은 성질의 수십 ${\mu}m$두께의 OPSL(oxidized porous silicon layer)을 짧은 시간에 형성시킬 수 있으며, 식각율과 항복전계는 산화온도와 산화 분위기에 크게 의존하는 것으로 나타났다. 이때 PSL의 산화율은 약 390nm/s이고, 항복전계는 1.0MV/cm~2.0MV/cm의 분포를 갖는다. 웨이퍼 휨을 측정하여 고온 열산화시 발생하는 산화막의 stress를 조사하였다. $1000^{\circ}C$ 이상의 고온에서 건식산화할 경우 발생하는 stress는 ${10^2}dyne/{cm^2}~{10^10}dyne/{cm^2}$로 측정되었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.156-156
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• 2017

Most crop damages have been occurred by vermin(e.g., wild birds and herbivores) during the period between seeding and the cotyledon level. In this study, to minimize the damage by vermin and acquire the benefits such as protection against weeds and maintenance of water content in soil, immediately vinyl mulching after seeding was devised. Vinyl mulching has been generally covered with black color vinyl, that crop seeding locations cannot be detected by visible light range. Before punching vinyl, non-contact and non-destructive methods that can continuously determine the locations are necessary. In this study, a crop position detection method was studied that uses infrared thermal image sensor to determine the cotyledon position under vinyl mulch. The moving system for acquiring image arrays has been developed for continuously detecting crop locations under plastic mulching on the field. A sliding mechanical device was developed to move the sensor, which were arranged in the form of a linear array, perpendicular to the array using a micro-controller integrated with a stepping motor. The experiments were conducted while moving 4.00 cm/s speed of the IR sensor by the rotational speed of the stepping motor based on a digital pulse width modulation signal from the micro-controller. The acquired images were calibrated with the spatial image correlation. The collected data were processed using moving averaging on interpolation to determine the frame where the variance was the smallest in resolution units of 1.02 cm. For this study, the spline method was relatively faster than the other polynomial interpolation methods, because it has a lower maximum order of formulation when using a system such as the tridiagonal linear equation system which provided the capability of real-time processing. The temperature distribution corresponding to the distance between the crops was 10 cm, and the more clearly the leaf pattern of the crop was visually confirmed. The frequency difference was decreased, as the number of overlapped pixels was increased. Also the wave pattern of points where the crops were recognized were reduced.

• 대한한방내과학회지
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• 제39권4호
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• pp.495-510
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• 2018

Objective: This study was designed to investigate the possibility of quantification of the diagnosis of abdominal coldness (AC) in patients with functional dyspepsia (FD). Methods: Forty-four patients with FD were enrolled in this study. Three Korean medicine doctors each randomly examined all abdomens. Diagnosis of AC was made by consensus of at least two of the doctors. Body temperature (oral by digital oral thermometer) and skin temperature (by digital infrared thermal imaging [DITI]) were measured, followed by administration of the Cold and Heat questionnaire (CHQ) and the Instrument of Pattern Identification for Functional Dyspepsia (IPIFD). Results: Of the 44 patients with FD, 22 were assigned to the AC group and 22 to the non-AC group. The concordance rate of diagnosis among the three doctors was 63.6% (28/44), with a ${\kappa}$ of 0.504, indicating means moderate agreement). Neither the oral nor the skin temperatures showed statistically significant differences between the AC and non-AC groups. However, the CHQ scores and 'Simultaneous Occurrence of Cold and Heat Syndromes pattern' scores of the IPIFD were higher in AC group and showed statistically significant differences (p=0.010 and 0.009). Conclusions: This is the first study conducting quantitative measurements of abdominal coldness in patients with FD. Although oral and skin temperature showed no statistical significance between AC and non-AC groups, the concordance rate of diagnosis of AC among the three Korean Medicine doctors was moderate. The CHQ scores and 'Simultaneous Occurrence of Cold and Heat Syndromes pattern' scores of the IPIFD also suggest that diagnosis of AC is relevant to cold and heat patterns, and these questionnaires could be utilized as supportive data for the diagnosis of AC. Further studies should be conducted for the purpose of quantifying and standardizing abdominal examinations in Korean Medicine.