• 자원환경지질
• /
• 제50권1호
• /
• pp.15-26
• /
• 2017

열수 광상의 잠두 광체를 예측하는데 중요한 인자로 인식되는 고(산성)점토 변질대, 점토 변질대 및 필릭 변질대의 정량성을 확보하기 위해 명반석-고령석 조합과 일라이트-고령석 조합에 대한 합성 혼합시료를 대상으로 단파장적외선 스펙트럼의 흡광특성과 광물함량의 점이적인 변화추이를 비교하였다. 명반석-고령석 조합에서 명반석은 Hull quotient 반사도가 가장 높은 상관관계(0.99)를 보이며, 고령석은 가우시안 피크가 가장 높은 상관관계(0.92)를 나타내고 있다. 일라이트-고령석 조합은 흡수영역이 중첩하고 있어 가우시안 분해가 필수적이며, 일라이트와 고령석은 각각 0.93과 0.98의 높은 상관도를 보이고 있다. 단파장적외선 분광분석법에서 유도한 명반석-고령석과 일라이트-고령석 조합의 오차범위(8%, 5%)는 리트벨트 X-선 회절정량분석법에서 구한 성분비의 오차범위(29%, 26%)보다 작아 분광분석결과가 상대적으로 정량적 신뢰도가 높다는 것으로 확인되었다.

• 자원환경지질
• /
• 제49권5호
• /
• pp.335-347
• /
• 2016

정선 지역 고품위 석회석 광산인 강원, 충무 및 백운 광산을 대상으로 풍촌층 상부 층준의 대표적 탄산염암을 구분하고 각 유형의 전암 분석 및 VNIR-SWIR(visible near infrared-short wavelength infrared) 분광분석을 실시하여, 현장에서 고품위 석회석의 CaO 함량, 이질 불순물 및 백색도를 평가할 수 있는 분석법을 제시하였다. 동일 시료에서 분말 시료의 분광 반사도는 절단 시편에 비하여 매우 높은 분광 반사도를 보였고, 탄산염암의 분말 시료는 백색도와 분광 반사도가 0.99의 매우 높은 상관관계를 보이고 있다. 전암 분석에서 확인된 충무광산의 방해석과 백운석 분말 시료를 75:25, 50:50, 25:75 질량비로 혼합하여 각각 스펙트럼의 변화를 확인하고, 탄산염암의 CaO 함량과 흡수파장을 비교한 결과 0.98~0.99로 매우 높은 상관도를 보이고 있다. 탄산염암의 흡수파장과 화학조성은 2340 nm(55.86 wt.%)에서 2320 nm(29.71 wt.%)로 이는 $CO{_3}^{-2}$ 성분과 결합하고 있는 Ca 함량과 이를 치환하는 Mg 성분 함량의 차이에 따라 흡수 위치가 변화되는 것을 의미하며, 현장에서 분광분석을 통한 탄산염광물의 CaO 함량을 정량적으로 적용할 수 있다.

• 천문학회지
• /
• 제24권1호
• /
• pp.55-70
• /
• 1991

Infrared emission maps are constructed at 12.5, 25, 60, and $100{\mu}m$ for dark globules B5, B34, B133, B134, B361, L134 and L1523 by using Infrared Astronomical Satellite data base. These clouds are selected on the basis of their appearance in Palomar print as dark obscuring objects with angular sizes in the range of 3 to 30 arcminutes. The short wavelength(12.5 and $25{\mu}m$) maps show the embedded infrared sources. We found many such sources only in B5, B361 and B34 regions, Diffuse component at 12.5 and $25{\mu}m$, possibly arising from the stochastically heated very small dust grains(a < $0.01{\mu}m$) by interstellar radiation field, is found in B361 and L1523 regions. Such emission is characterized by the limb brightening, and it is confirmed in L1523 and in B361. Infrared emissions at the long wavelengths(60 and $100{\mu}m$) are due to colder dusts with temperature less than 20 K. The distribution of color index determined by the ratio 60 to $100{\mu}m$ intensities shows monotonic decrease of dust temperature toward the center. The black body temperature determined from these ratios is found to lie between 16 and 23 K. Such temperature is possible for small(i.e., $a\;{\lesssim}\;0.01{\mu}m$) graphite grains if the grains are mainly heated by interstellar radiation field. Thus IRAS 100 and $60{\mu}m$ emissions are arising mainly from small grains in the colud. The distribution of such dust grains implied from the emissivity distributions at 100 and $60{\mu}m$ resembles that of isothermal sphere. This contrasts to earlier findings of much steeper distribution of dusts contributing visible extinction. These dust grains are mainly larger ones(i.e., $a{\simeq}0.1{\mu}m$). Therefore we conclude that the average grain size increase, toward the cloud center.

• 콘크리트학회논문집
• /
• 제15권3호
• /
• pp.425-432
• /
• 2003

콘크리트 시공 이음부는 콘크리트 시공시 발생되는 기술적 문제들 중의 하나이다. 이 시공 이음부는 콘크리트의 구조적 측면뿐만 아니라 누수 등의 중대한 결함을 초래하게 되는 요인으로 작용한다. 본 연구에서는 이러한 콘크리트 구조물의 시공 이음부를 비파괴적으로 검사하기 위해 레이더법과 적외선법을 이용하였다. 대상부재로서는 콘크리트 기둥을 선정하여 본 방법들의 적용에 따른 여러 가지 형태의 시공 이음부의 검출특성에 대하여 검토하였다. 그 결과, 레이더법의 경우는 해석모델에 의한 모의해석을 실시하여 실제 측정치와 비교하여 해석할 경우, 시공 이음부에 대한 검출 정도를 보다 향상시킬 수 있음을 알 수 있었다. 또한, 적외선법의 경우는 빛의 작용을 받지 못하는 실내조건 하에서도 측정 표면부를 사전 가열하여 측정하면 결함의 형상까지도 뚜렷이 식별하여 검출 가능함을 알 수 있었다. 따라서, 이들 두 방법을 병행할 경우, 육안으로는 검사가 곤란한 콘크리트 시공 이음부에 대해 빠른 시간내에 넓은 대상의 구조물에 대해 효율적인 검사가 가능함이 입증되었다.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2007년도 동계학술발표대회 논문집
• /
• pp.203-208
• /
• 2007

Drying characteristics are confirmed by experiment to a printing machine which use Gravure ink or metal ink for an optimum design of direct radiation drying system room using NIR. As a result, Drying is easily accomplished in short distance and low moving speed in Gravure ink, but drying is dropped in metal ink because of oil. This confirmed that the development of water metal ink had to be proceeded to accomplish a perfect drying condition.

• 천문학회지
• /
• 제32권1호
• /
• pp.1-6
• /
• 1999

We have conducted near-infrared (J- and H-band) surface photometry for two early type barred galaxies, NGC 3412 and NGC 3941. The bulges of NGC 3412 and NGC 3941 show isophotal twists which indicate that they are triaxial. NGC 3412 has a very short bar and its bulge is more centrally concentrated than that of NGC 3941. The unusually short bar and the centrally concentrated triaxial bulge of NGC 3412 might be the result of bar dissolution. The colors of the nuclear region of NGC 3941 resemble those of the blue nuclei, implying the presence of young stellar populations.

• 천문학논총
• /
• 제14권1호
• /
• pp.33-37
• /
• 1999

We have constructed a synthetic spectrum of the 2.5 micron $C_2H$ bands and compared them with diminutive structures in the near-infrared spectra of Comets P/Halley and West (1976 VI). We found that the Q branches of the $C_2H$ bands coincide with two small emission peaks in the spectra of the comets. We undertook Monte Carlo simulations using observed emission intensities of $C_2$ and possibly $C_2H$ in Comet P/Halley in order to derive a lifetime range of $C_2H$ and a production rate at the time of observations of P/Halley. We obtained a $C_2H$ production rate of $1\times10^{27}\;sec^{-1}$ for P/Halley on December 20, 1985, assuming the 2.5 micron features are due to $C_2H$. We derived a very short lifetime (<100 seconds) of $C_2H$ at 1AU heliocentric distance, assuming that the only parent molecule for $C_2H$ and $C_2$ is $C_2H$. Using this short lifetime we were unable to fit our $C_2$ distribution model to $C_2$ distribution curves observed by O'Dell et al.(1988), because our curve shows a steep slope compared with the observed one. We conclude that there must be significant additional source(s) for $C_2H$ and $C_2$ other than $C_2H_2$.

• Bulletin of the Korean Chemical Society
• /
• 제28권8호
• /
• pp.1249-1255
• /
• 2007

We have investigated the photophysical properties of dansyl-N-methylaminobenzoic acid (DABAH) as a ligand and its lanthanide (Ln3+)-cored complexes (Ln3+-(DABA)3(terpy)) in order to determine the main energy transfer pathway for sensitized near infrared emission of Ln3+ ions (Ln3+ = Nd3+ and Er3+) in Ln3+- (DABA)3(terpy). The fluorescence spectrum of DABAH shows a large Stokes shift with increasing solvent polarity. This large Stokes shift might be due to the formation of a twisted intramolecular charge transfer (TICT) state, as demonstrated by the large dipole moment in the excited state. It is in good agreement with the result that the phosphorescence even in the Gd3+-cored complex based on the DABAH ligand was not observed, maybe due to the highly forbidden character of the S1 → T1 transition in the DABAH ligand. A short decay component (ca. 1 ns) was observed in Er3+-(DABA)3(terpy) whereas the fluorescence lifetimes of DABAH and its Gd3+-(DABA)3(terpy) are observed about ~10 ns. The short component could be originated from the energy transfer process between the ligand and the Ln3+ ion. Based on the fluorescence of DABAH its Ln3+- (DABA)3(terpy), the sensitization of Ln3+ luminescence in the Ln3+-(DABA)3(terpy) takes place by the energy transfer via the TICT state of DABAH in the excited singlet state rather than via the excited triplet state.

• Journal of the Optical Society of Korea
• /
• 제16권4호
• /
• pp.331-335
• /
• 2012

A miniaturized laser beam transmitter, in which a visible laser module at ${\lambda}$=650 nm is precisely stacked upon an infrared (IR) module at ${\lambda}$=905 nm, has been proposed and constructed to provide an IR collimated beam in conjunction with a collinear monitoring visible beam. In particular, the IR beam is selectively dispersed through a perforated sheet diffuser, so as to create a rapidly diverging close-range beam in addition to a highly defined long-range beam simultaneously. The complementary close-range beam plays a role in mitigating the blind region in the vicinity of the transmitter, which is inevitably missed by the main long-range beam, thereby uniformly extending the transmitter's effective trajectory that is sensed by a receiver. The proposed transmitter was designed through numerical simulations and then fabricated by incorporating a diffuser sheet, perforated with an aperture of 2 mm. For the manufactured transmitter, the IR long-range beam was observed to have divergences of ~2.3 and 1.6 mrad in the fast and slow axes, respectively, while the short-range beam yielded a divergence of ~24 mrad. The angular alignment between the long-range IR and visible beams was as accurate as ~0.5 mrad. According to an outdoor feasibility test involving a receiver, the combination of the IR long- and short-range beams was proven to achieve a nearly uniform trajectory over a distance ranging up to ~600 m, with an average detectable cross-section of ${\sim}60{\times}80cm^2$.

• 한국축산식품학회지
• /
• 제43권6호
• /
• pp.1150-1169
• /
• 2023

Edible insects are gaining popularity as a potential future food source because of their high protein content and efficient use of space. Black soldier fly larvae (BSFL) are noteworthy because they can be used as feed for various animals including reptiles, dogs, fish, chickens, and pigs. However, if the edible insect industry is to advance, we should use automation to reduce labor and increase production. Consequently, there is a growing demand for sensing technologies that can automate the evaluation of insect quality. This study used short-wave infrared (SWIR) hyperspectral imaging to predict the proximate composition of dried BSFL, including moisture, crude protein, crude fat, crude fiber, and crude ash content. The larvae were dried at various temperatures and times, and images were captured using an SWIR camera. A partial least-squares regression (PLSR) model was developed to predict the proximate content. The SWIR-based hyperspectral camera accurately predicted the proximate composition of BSFL from the best preprocessing model; moisture, crude protein, crude fat, crude fiber, and crude ash content were predicted with high accuracy, with R² values of 0.89 or more, and root mean square error of prediction values were within 2%. Among preprocessing methods, mean normalization and max normalization methods were effective in proximate prediction models. Therefore, SWIR-based hyperspectral cameras can be used to create automated quality management systems for BSFL.