• Environmental Engineering Research
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• 제19권3호
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• pp.293-298
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• 2014

An anaerobic photosynthetic treatment process utilizing purple non-sulfur photosynthetic bacteria (PNSB) was applied to the recovery of organic carbon from food processing wastewater. PNSB cells, by-product from the treatment, have high nutrition such as proteins and vitamins which are a good alternative for fish feed. Effects of light source on performance of anaerobic photosynthetic process were investigated in this study. Two bench-scale photo-bioreactors were lighted with infrared light emitting diodes (LEDs) and tungsten lamps covered with infrared transmitting filter, respectively, aiming to supply infrared light for photosynthetic bacteria growth. The photo-bioreactors were operated to treat noodle-processing wastewater for 323 days. Hydraulic retention time (HRT) was set as 6 days. Organic removals in the photo-bioreactor lighted with infrared LEDs (91%-95%) was found higher than those in photo-bioreactor with tungsten lamps with filter (79%-83%). Biomass production in a 150 L bench-scale photo-bioreactor was comparable to a 8 L small-scale photo-bioreactor in previous study, due to improvement of light supply efficiency. Application of infrared LEDs could achieve higher treatment performance with advantages in energy efficiency and wavelength specifity.

• 천문학회보
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• 제44권1호
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• pp.67.4-67.4
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• 2019

We present preliminary results of our long-term (2009-2017) observing campaign using the NASA IRTF at Mauna Kea, to obtain $2-5{\mu}m$ spectroscopy of ~200 red point sources in the line of sight to the Galactic center. Point sources in our sample were selected from the mid-infrared images of the Spitzer Space telescope, and include candidate massive young stellar objects, which have previously been identified from our Spitzer/IRS spectroscopy. We show high foreground extinction of these sources from deep $3.1{\mu}m$ H2O ice and aliphatic hydrocarbon absorption features, suggesting that they are likely located in the central 300 pc region of the Galactic center. While many sources reveal photospheric $2.3{\mu}m$ gas CO absorption, few of them clearly indicate $3.54{\mu}m$ CH3OH ice absorption, possibly indicating a large dust column density intrinsic to a massive young stellar object.

• 천문학논총
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• 제27권4호
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• pp.129-134
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• 2012

The North Ecliptic Pole (NEP) Wide survey covered about 5.4 $deg^2$, a nearly circular area centered on the NEP, using nine passbands of InfraRed Camera (IRC). We present the photometric properties of the data sets, and the nature of the sources detected in this field. The number of detected sources varied according to the filter band: with about 109,000 sources in the NIR, about 20,000 sources in the MIR-S, and about 16,000 sources seen in the MIR-L channel. The $5{\sigma}$ detection limits are about 21 mag in the NIR and 19.5 - 18.5 mag in the MIR bands in terms of the AB magnitude. 50% completeness levels are about 19.8 mag at $3{\mu}m$, 18.6 mag at $9{\mu}m$, and 18 mag at $18{\mu}m$ band (in AB magnitude), respectively. In order to validate the detected sources, all of them are confirmed by matching tests with those in other bands. The 'star-like' sources, defined by the high stellarity and magnitude cut from the optical ancillary data, appear statistically to have a high probability of being stars. The nature of the various types of extragalactic sources in this field are discussed using the color-color diagrams of the NIR and MIR bands with the redshift tracks of galaxies providing useful guidelines.

• 천문학회지
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• 제24권1호
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• pp.55-70
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• 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.

• 천문학논총
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• 제27권4호
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• pp.325-329
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• 2012

We will report our recent study on the properties of more than 1,600 galaxies detected by the AKARI All-Sky Survey with physical quantities based on optical and 21-cm observations, to understand the physics determining the infrared spectral energy distribution (Totani et al., 2011). We discover a tight linear correlation for normal star-forming galaxies between the radiation field strength of dust heating (corresponding to dust temperature) and the galactic-scale infrared radiation field, $L_{TIR}/R^2$. This is the tightest correlation of dust temperature ever known, and the dispersion along the mean relation is 13% in dust temperature. This relation can be explained physically by a thin layer of heating sources embedded in a thicker, optically-thick dust screen. We also find that the number of galaxies sharply drops when galaxies become optically thin against dust-heating radiation, indicating that a feedback process to galaxy formation (e.g., by the photoelectric heating) is working when dust-heating radiation is not self-shielded on a galactic scale. We discuss implications from these findings for the $M_{H_I}$ -size relation, the Kennicutt-Schmidt relation, and galaxy formation in the cosmological context.

• 센서학회지
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• 제27권5호
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• pp.294-299
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• 2018

This article describes the output properties of non-dispersive infrared carbon dioxide($CO_2$) sensors resulting from the changes in ambient temperatures. After the developed sensor module was installed inside the gas chamber, the temperature was set to 267 K, 277 K, 300 K, and 314 K, and the concentrations of $CO_2$ gas were increased from 0 to 5,000 ppm. Then, the output voltage at each concentration was obtained. Through these experimental results, two observations were made. First, both the $CO_2$ sensor and the reference sensor showed an increase in the output voltages as the temperature rose from 0 ppm, Second, the full scale outputs of the $CO_2$ sensor grew as the temperature increased. The output characteristics were analyzed based on two factors: change in the radiant energy of the infrared light source and change in the absorptivity of $CO_2$ gas according to the ambient temperature. Additionally, temperature compensation methods were discussed.

• 천문학논총
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• 제27권4호
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• pp.185-186
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• 2012

We have carried out a survey of T Tauri stars (TTSs) in a 1,800-square-degrees region toward the Taurus-Auriga star forming region with the AKARI Mid-Infrared All-Sky Survey. By combination of AKARI, 2MASS, and UCAC surveys, we created new criteria to chose TTS candidates. We also considered Asymptotic Giant Branch stars and galaxies, which have similar infrared colors, to separate TTSs from these sources. On the basis of our criteria, we find 27 new TTS candidates. To verify our criteria, we performed follow-up observations for them and confirmed that 23 are TTSs.

• 조명전기설비학회논문지
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• 제27권10호
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• pp.69-74
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• 2013

There is needed the triple pyroelectric Infrared flame detector to really recognize problem, for the prevention and early suppression of fire. This system recognizes the characteristics of fire sources in various type and is communicated the message to the operators. Therefore, the prevention and early suppression of fire is available. Especially this paper focuss on development of the self diagnosis type flame detector for preventing malfunction comparing of basic and detected values.

• 천문학회지
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• 제36권3호
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• pp.149-158
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• 2003

Deep surveys at mid-infared through submillimeter wavelengths indicate that a substantial fraction of the total luminosity output from galaxies at high redshift (z > 1) emerges at wavelengths 30 - 300${\mu}m$. In addition, much of the star formation and AGN activity associated with galaxy building at these epochs appears to reside in a class of luminous infrared galaxies (LIGs), often so heavily enshrouded in dust that they appear as 'blank-fields' in deep optical/UV surveys. Here we present an update on the state of our current knowledge of the cosmic evolution of LIGs from z = 0 to z $\~$ 4 based on the most recent data obtained from ongoing ground-based redshift surveys of sources detected in ISO and SCUBA deep fields. A scenario for the origin and evolution of LIGs in the local Universe (z < 0.3), based on results from multiwavelength observations of several large complete samples of luminous IRAS galaxies, is then discussed.

• 조명전기설비학회논문지
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• 제28권1호
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• pp.88-95
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• 2014

The infrared, flame detector uses to detect fire situation from the characteristics of fire sources radiant energy. But it is able to malfunction on account of susceptible to interference of various surrounding waves. This paper is designed 6 independent PCB-boards to minimize the closed loops of siginal circuit. Also considering the interaction of electric and magnetic fields, this paper is designed protecting circuit of current and voltage output to reduced electromagnetic interference. And this paper is improving electromagnetic susceptibility by ferrite bid, capacitor filter and grounding circuits.