• Title/Summary/Keyword: far-infrared emission

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A Study on the Temperature and Electrical Characteristics of Carbon Heater (카본 발열체의 온도 및 전기적 특성에 관한 연구)

  • Jin, Z.H.;Shim, K.J.;Kong, T.W.;Jeong, H.M.;Chung, H.S.
    • Journal of Power System Engineering
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    • v.10 no.1
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    • pp.71-76
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    • 2006
  • This paper aims to study several type heaters which are mica heater, film heater, quartz heater and rod heater and to get an temteraturel and electrical characteristics. These four type heaters have a merit in many fields than present electric heater with nichrome wire. Carbon and mica plate heater have higher heat efficiency and less electromagnetic waves. Also it has been reported that far infrared ray emission from this heater is good for our health. Additionally heating element is thin and lighter plate. For these reasons, they will be widely used to various application such as room-heating or manufacturing goods. Experimental result confirmed that when 220V current authorized, the temperature, electric current, electric power and the resistance rise to stationary state in early stage. Moreover, the temperatures and electric characteristics show a good stability.

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Electronic and Vibrational Spectroscopy of cis-Diisothiocyanato(1,4,8,11-tetraazacyclotetradecane)chromium(Ⅲ) Thiocyanate

  • Choi, Jong-Ha;Park, Yu-Chul
    • Bulletin of the Korean Chemical Society
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    • v.24 no.3
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    • pp.384-388
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    • 2003
  • The emission and excitation spectra of $cis-[Cr(cyclam)(NCS)_2]NCS$ (cyclam = 1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room temperature are also measured. The vibrational intervals due to the electronic ground state are extracted from the far-infrared and emission spectra. The ten pure electronic origins due to spin-allowed and spin-forbidden transitions are assigned by analyzing the absorption and excitation spectra. Using the observed transitions, a ligand field analysis has been performed to determine the bonding properties of the coordinated ligands in the title chromium(Ⅲ) complex. According to the results, it is found that nitrogen atoms of the cyclam ligand have a strong σ-donor character, while the NCS ligand has medium σ- and π-donor properties toward chromium(Ⅲ) ion.

THE PROPERTIES OF DUST EMISSION IN THE GALACTIC CENTER REGION REVEALED BY FIS-FTS OBSERVATIONS

  • Yasuda, A.;Kaneda, H.;Takahashi, A.;Nakagawa, T.;Kawada, M.;Okada, Y.;Takahashi, H.;Murakami, N.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.221-222
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    • 2012
  • We present the results of far-infrared spectral mapping of the Galactic center region with FIS-FTS, which covered the two massive star-forming clusters, Arches and Quintuplet. We find that two dust components with temperatures of about 20 K and 50 K are required to fit the overall continuum spectra. The warm dust emission is spatially correlated with the [OIII] $88{\mu}m$ emission and both are likely to be associated with the two clusters, while the cool dust emission is more widely distributed without any clear spatial correlation with the clusters. We find differences in the properties of the ISM around the two clusters, suggesting that the star-forming activity of the Arches cluster is at an earlier stage than that of the Quintuplet cluster.

SH 2-128, AN H II AND STAR FORMING REGION IN AN UNLIKELY PLACE

  • BOHIGAS JOAQUIN;TAPIA MAURICIO
    • Journal of The Korean Astronomical Society
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    • v.37 no.4
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    • pp.285-288
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    • 2004
  • Near-infrared imaging photometry supplemented by optical spectroscopy and narrow-band imaging of the H II region Sh 2-128 and its environment are presented. This region contains a developed H II region and the neighboring compact H II region S 128N associated with a pair of water maser sources. Midway between these, the core of a CO cloud is located. The principal ionizing source of Sh 2-128 is an 07 star close to its center. A new spectroscopic distance of 9.4 kpc is derived, very similar to the kinematic distance to the nebula. This implies a galactocentric distance of 13.5 kpc and z = 550 pc. The region is optically thin with abundances close to those predicted by galactocentric gradients. The $JHK_s$ images show that S 128N contains several infrared point sources and nebular emission knots with large near-infrared excesses. One of the three red Ks knots coincides with the compact H II region. A few of the infrared-excess objects are close to known mid- and far-infrared emission peaks. Star counts in J and $K_s$ show the presence of a small cluster of B-type stars, mainly associated with S 128N. The $JHK_s$ photometric properties together with the characteristics of the other objects in the vicinity suggest that Sh 2-128 and S 128N constitute a single complex formed from the same molecular cloud, with ages ${\~}10^6$ and < $3 {\times} 10^5$ years respectively. No molecular hydrogen emission was detected at 2.12 ${\mu}m$. The origin of this remote star forming region is an open problem.

Double Resonance Spectra Involving Torsional Excited Levels and CO Stretch Band Transitions of $CD_3OH$

  • Choi, Sung-Eul
    • Korean Journal of Optics and Photonics
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    • v.6 no.2
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    • pp.165-171
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    • 1995
  • Infrared-Radio frequency double resonance (IRRFDR) and Infrared-Microwave double resonance (IRMWDR) spectroscopy have been used to probe a level of A symmetry for $CD_{3}$OH. Double resonance spectra of $CD_{3}$OH have been investigated over the range of 940 to 1020 $cm ^{-1}$ . Twenty K-type doublet transitions have been observed in both the radio frequency region, which covers 50 MHz to 1 GHz, and the microwave region, which covers 8 GHz to 12 GHz. The results propose new assignments of infrared (IR) absorption transitions and far-infrared (FIR) laser emission lines. These involve torsional excited levels and CO stretch states. Measurements of the A state splitting have permitted the determination of the asymmetry splitting parameters $S^{o}$(n, K) and $^{co}$ (n, K) for (n, K)=(0.3) and (1.3)

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COSMIC STAR FORMATION HISTORY AND AGN EVOLUTION NEAR AND FAR: AKARI REVEALS BOTH

  • Goto, Tomotsugu;AKARI NEP team, AKARI NEP team;AKARI all sky survey team, AKARI all sky survey team
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.347-352
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    • 2012
  • Understanding infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and AGN evolution, since their most intense stages are often obscured by dust. Japanese infrared satellite, AKARI, provided unique data sets to probe this both at low and high redshifts. The AKARI performed an all sky survey in 6 IR bands (9, 18, 65, 90, 140, and $160{\mu}m$) with 3-10 times better sensitivity than IRAS, covering the crucial far-IR wavelengths across the peak of the dust emission. Combined with a better spatial resolution, AKARI can measure the total infrared luminosity ($L_{TIR}$) of individual galaxies much more precisely, and thus, the total infrared luminosity density of the local Universe. In the AKARI NEP deep field, we construct restframe $8{\mu}m$, $12{\mu}m$, and total infrared (TIR) luminosity functions (LFs) at 0.15 < z < 2.2 using 4,128 infrared sources. A continuous filter coverage in the mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and $24{\mu}m$) by the AKARI satellite allows us to estimate restframe $8{\mu}m$ and $12{\mu}m$ luminosities without using a large extrapolation based on a SED fit, which was the largest uncertainty in previous work. By combining these two results, we reveal dust-hidden cosmic star formation history and AGN evolution from z = 0 to z = 2.2, all probed by the AKARI satellite.

DETECTION OF Hα EMISSION FROM z>3.5 GALAXIES WITH AKARI-FUHYU NIR SPECTROSCOPY

  • Sedgwick, Chris;Serjeant, Stephen;Pearson, Chris;Takagi, Toshinobu;Matsuhara, Hideo;Wada, Takehiko;Lee, Hyung Mok;Im, Myungshin;Jeong, Woong-Seob;Oyabu, Shinki;White, Glenn J.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.357-360
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    • 2012
  • This paper presents $H{\alpha}$ emission line detections for four galaxies at z > 3.5 made with AKARI as part of the FUHYU mission program. These are the highest-redshift $H{\alpha}$ detections to date in star-forming galaxies. AKARI's unique near-infrared spectroscopic capability has made these detections possible. For two of these galaxies, this represents the first evidence of their redshifts and confirms their physical association with a companion radio galaxy. The star formation rates (SFRs) estimated from the $H{\alpha}$ lines under-predict the SFRs estimated from their far-infrared luminosities by a factor of ~ 2 - 3. We have also detected broad $H{\alpha}$ components in the two radio galaxies which indicate the presence of quasars.

POLYCYCLIC AROMATIC HYDROCARBON (PAH) MOLECULES IN THE DISKS AROUND LOW MASS STARS

  • Kim, Kyoung Hee
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.36.1-36.1
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    • 2015
  • We present $5-14{\mu}m$ Infrared Spectrograph spectra of 14 T Tauri stars which show Polycyclic Aromatic Hydrocarbon (PAH) features and reside in 0.7 pc from ${\Theta}_1$ Ori C. The spectral types of nine out of 11 stars have spectral type information, with types ranging from K7-M5. These stars do not supply strong enough UV photons to excite PAH emission in their disks. Therefore, we consider the detection of PAH emission in disks around low mass stars illuminated by an external source of UV photons, namely, from Trapezium OB association, including ${\Theta}_1$ Ori C. The morphological features of PAH emission from most disks around K-M type host stars are unique, not belonging to any known classes of PAH features. We found that the PAH emission strengths decrease as the projected distance of the objects from ${\Theta}_1$ Ori C increase. We suggest future far-IR and submm/mm observations for better understanding of the characteristics and distribution of PAHs in these disks.

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Influence of Fluorinated Illite on Thermal, Antibiotic and Far-infrared Emission Properties of Polypropylene Non-woven Fibers (폴리프로필렌 부직포 섬유의 열, 항균 및 원적외선 방사 특성에 미치는 불소화 일라이트 첨가의 영향)

  • Kim, Jinhoon;Im, Ji Sun;Seo, Kyeong-Won;Lee, Young-Seak
    • Polymer(Korea)
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    • v.37 no.1
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    • pp.86-93
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    • 2013
  • In this work, the thermal, antibiotic properties and far-infrared emissivity of fluorinated illite embedded polypropylene non-woven fibers (f-illite/PP fibers) were investigated in the presence of 0, 1, 3, 5 and 7 wt% illite powders. The thermal properties of f-illite/PP fibers were studied by thermogravimetric analysis (TGA). Their antibiotic properties were examined by Staphylococcus aureus and Klebsiella pneumoniae test. Their far-infrared emissivity was also investigated by Fourier transform infrared spectroscopy. From the experimental results, thermal, antibiotic properties and far-infrared emissivity of f-illite/PP fibers were improved by increasing fluorinated illite contents and the property values of 5 wt% f-illite/PP fibers were increased remarkably by about 10.3, 41.2 and 9.8% respectively in comparison with PP non-woven fibers having no fluorinated illite additive. This result was interpreted as the development of interfacial adhesion force between the polymer chains due to the fluorination of illite power.

Survey of Globular Clusters with the AKARI FIS for the Intracluster Dusts

  • Pyo, Jeong-Hyun;Jeong, Woong-Seob;Kim, Eun-Hyeok;Lee, Myung-Gyoon;Hong, Seung-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.52.2-52.2
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    • 2010
  • In search of the intracluster dusts, we have made a survey of globular clusters (GCs) with the Far-Infrared Surveyor (FIS) aboard AKARI, the Japanese infrared space satellite. The GCs are thought to host dust particles that are condensed from the material injected by the cluster asymptotic giant branch (AGB) stars. However, attempts to detect dust emission from GCs had not been successful until a significant amount of far-infrared (FIR) emission was detected close to the NGC 7078 center by the ISO observations (Evans et al. 2003). Recent FIR observations by the AKARI (Matsunaga et al. 2008) and the Spitzer Space Telescope (Boyer et al. 2006; Barmpy et al. 2009) reported a tentative detection of the dusts in NGC 5024 and NGC 6341, and also confirmed the previous ISO dust detection from NGC 7078. We have observed 17 selected GCs in four FIS wavebands at 65, 90, 140, and 160 micrometers. Each observation covers about $10'{\times}10'$ area centered at each GC. The resulting images show extended structures and/or blobs around the GCs. The extended structures are very suggestive of the Galactic cirrus, while the blobs around NGC 288 and NGC 4833 seem to be related to the two clusters. In this presentation, we will report four representative cases of our survey results and discuss the properties of newly detected sources.

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