• Title/Summary/Keyword: Infrared emissivity

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Optimization of sintering process of the far-infrared radiation ceramic (원적외선 방사 세라믹의 소결공정 최적화)

  • Park, Jae Hwa;Kim, Hyun Mi;Kang, Hyo Sang;Choi, Jae Sang;Choi, Bong Geun;Nam, Ki Woong;Nam, Han Woo;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.1
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    • pp.28-34
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    • 2016
  • Far-infrared radiation ceramic is an attractive material that provides thermal therapy by permeating the infrared rays into the deep inside of the human skin. Therefore, it is currently used for thermal therapy devices, thermal mat, heating equipment and so on. This work aims to optimize the sintering process of the far-infrared radiation ceramic with the process parameters of temperature and time. A variety of characterization tools have been used to investigate the optimal sintering condition of far-infrared radiation. The phase of far-infrared radiation ceramic was characterized by using X-ray diffraction (XRD) and microstructure of fracture surface was studied by scanning electron microscopy (SEM). The FT-IR was also performed to measure the far-infrared emissivity.

Possibility and Accuracy of Extracting Room Temperature Information from Mid-Infrared Sensor Satellite Images (중적외선 센서 위성 영상의 상온 온도 정보 추출 가능성 및 정확도)

  • Choi, SeokWeon;Seo, DooChun;Lee, DongHan
    • Journal of Space Technology and Applications
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    • v.1 no.3
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    • pp.356-363
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    • 2021
  • It was common knowledge in textbooks that images acquired using mid-infrared ray were not suitable for measuring temperature near room temperature. But a recent satellite image using a mid-infrared sensor show the possibility that the result measured using the mid-infrared sensor can also measure the temperature near room temperature. In this paper, the possibility and accuracy of extraction room temperature information from satellite images with mid-infrared sensors are reviewed. The mid-infrared satellite image reviewed in this paper showed the temperature of room temperature well, and regarding the reliability as an absolute value of the measured temperature, the effect of the heat transfer amount due to the direct reflection of sunlight on the surface and the effect of the infrared absorption amount absorbed in the atmosphere can be seen as a relatively small or constant value. However, the problem of uncertainty in the radiation coefficient due to physical properties, which is the limit of the non-contact thermometer, remained a problem to be solved.

Far-infrared Emission Characteristics of ZrC Imbedded Heat Storage Knitted Fabrics for Emotional Garment (탄화지르코늄 함유 감성의류용 축열/발열 편물의 원적외선 방출특성)

  • Kim, Hyun-Ah
    • Science of Emotion and Sensibility
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    • v.18 no.1
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    • pp.49-58
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    • 2015
  • This paper investigated far-infrared emission characteristics of ZrC imbedded heat storage knitted fabrics for emotional garment. For this purpose, ZrC imbedded heat storage PET was spun with high viscosity PET imbedded ZrC powder on the core part and low viscosity PET on the sheath part by conjugated spinning method. Ingredient analysis and far-infrared emission characteristics assessment of spun filament were carried out by EDS and FT-IR spectrometer. Two kinds of knitted fabrics were made using texturized ZrC imbedded PET for measuring thermal characteristics of ZrC imbedded heat storage PET. Zr peak was certified by EDS measurement and it was confirmed that content of Zr was 19.29%. Far-infrared analysis revealed that emission power at the range of wavelength, $5{\sim}20{\mu}m$ was $3.65{\times}10^2W/m^2$, and emissivity was 0.906. Heat storage analysis by KES-F7 system revealed that $Q_{max}$ of ZrC imbedded PET knitted fabric was lower than that of regular PET one and warmth keepability rate was higher than that of regular one, which means that ZrC imbedded PET knitted fabric has heat storage property. Thermal conductivity of ZrC imbedded PET knitted fabric was higher than that of regular PET one which was caused by high thermal conductivity of Zr itself. Hand property of ZrC imbedded knitted fabric was not inferior compared to regular PET knitted fabric, which preferably was found to be dependent on knit structure and surface property.

A study on the dyed cotton fabrics with loess for bedspreds (침구류에 사용되는 황토염색 면직물에 관한 연구)

  • Kim, Seo-In;Jeong, Sung-Hoon
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.229-230
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    • 2003
  • In these days, it is actively investigated to use loess in textile industry. The loess have been reported for emissivity of far-infrared and negative ion, and antibacterial efficacy. The loess consist of quartz, feldspar, clay mineral, iron oxide mineral, gibbsite [Al(OH)$_3$], etc. The main component of loess is clay minerals which have great adsorption about ion exchange and far-infrared emission properties. Recently, various inner-wears, sheets, and interior goods are manufactured using the loess due to its improved blood circulation, metabolism, antibacterial and deodorizing properties. (omitted)

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Infrared Signature Analysis on a Flat Plate by Using the Spectral BRDF Data (파장별 BRDF 데이터를 이용한 평판의 적외선 복사휘도 특성 분석)

  • Choi, Jun-Hyuk;Kim, Dong-Geon;Kim, Jung-Ho;Kim, Tae-Kuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.6
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    • pp.577-585
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    • 2010
  • This paper is a part of developing a software that predicts the infrared signal emitted from a ground object by considering solar irradiation. The radiance emitted from a surface can be calculated by using the temperature and optical characteristics of the surface object. The bidirectional reflectance distribution function (BRDF) is defined as the ratio of reflected radiance to incident irradiance. It is a very important surface reflection property that decides the reflected radiance from the object. In this paper, the spectral radiance received by a remote sensor over the mid-wave infrared(MWIR), and the long-wave infrared(LWIR) regions are computed and compared each other for several different materials. The results show that the optical surface properties such as the BRDF and the emissivity of the object surface can play a major role in generating the infrared signatures of various objects, and the largest infrared signal may reach up to 10 times the smallest one when the infrared signals obtained from a flat plate with different surface conditions under the sun light.

Black Body Design and Verification for Non-Uniformity Correction of Imaging Sensor and Uncertainty Analysis (영상센서의 비균일 응답특성 보정을 위한 흑체 설계 및 성능검증과 보정오차 분석)

  • Shin, Somin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.240-245
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    • 2013
  • Each pixel of InfraRed(IR) sensor differently responds to IR light as time elapses or the sensor on/off operation is repeated. As a result, the quality of IR sensor image is deteriorated, and therefore NUC(Non-uniformity Correction) is periodically needed for IR sensor. In this paper, in order to perform NUC in the Satellite, on-board V-grooved blackbody is designed with a baffle so that the emissivity of black body is to be higher than 0.995 as well as the temperature deviation is less than $1^{\circ}C$ in the range of the infrared wave length from 3.3 to $5.2{\mu}m$. To check its performance, the emissivity and the surface temperature of the blackbody by TRT(Transfer Reference Thermometer) and IR Micrometer scanner are measured, respectively. From the results, black body design is verified and the uncertainty of NUC is estimated through the measurement results.

Heat Resistant Low Emissivity Oxide Coating on Stainless Steel Metal Surface and Characterization of Emissivity (스테인리스강 금속 표면에 내열 저방사 산화물 코팅제 적용과 방사 특성 평가)

  • Lim, Hyung-Mi;Kwon, Tae-Il;Kim, Dae-Sung;Lee, Sang-Yup;Kang, Dong-Pil;Lee, Seung-Ho
    • Korean Journal of Materials Research
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    • v.19 no.12
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    • pp.649-656
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    • 2009
  • Inorganic oxide colloids dispersed in alcohol were applied to a stainless steel substrate to produce oxide coatings for the purpose of minimizing emissive thermal transfer. The microstructure, roughness, infrared emissive energy, and surface heat loss of the coated substrate were observed with a variation of the nano oxide sol and coating method. It was found that the indium tin oxide, antimony tin oxide, magnesium oxide, silica, titania sol coatings may reduce surface heat loss of the stainless steel at 300${\circ}C$. It was possible to suppress thermal oxidation of the substrate with the oxide sol coatings during an accelerated thermal durability test at 600${\circ}C$. The silica sol coating was most effective to suppress thermal oxidation at 600${\circ}C$, so that it is useful to prevent the increase of radiative surface heat loss as a heating element. Therefore, the inorganic oxide sol coatings may be applied to improve energy efficiency of the substrate as the heating element.

Effect of Annealing Temperature on the Low Emissivity of TiO2/Ag/TiO2 Films (열처리 온도에 따른 TiO2/Ag/TiO2 박막의 근적외선 반사 특성 변화)

  • Kim, So-young;Moon, Hyun-joo;Kim, Daeil
    • Journal of the Korean Society for Heat Treatment
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    • v.28 no.3
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    • pp.134-138
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    • 2015
  • Ag intermediated $TiO_2$ films were deposited by RF and DC magnetron sputtering and then vacuum annealed at 100, 200 and $300^{\circ}C$ for 30 minutes to investigate the effect of annealing temperature on the structural and optical properties of the films. For all depositions, the thickness of the $TiO_2$ and Ag films were kept constant at 24 and 15 nm by controlling the deposition time. As-deposited $TiO_2/Ag/TiO_2$ trilayer films have a weak crystalline and an optical reflectance in a near infrared wavelength region of 77.8%, while the films annealed at $300^{\circ}C$ show the polycrystalline structure and an increased mean optical reflectance of 80.4%. From the experimental results, it can be concluded that increasing the annealing temperature enhanced the structural and optical properties of the $TiO_2/Ag/TiO_2$ films.

Thermodynamics Consideration of Growth Mode of Silver Islands by Transition Metal Seeding (Nb seeding이 Ag 박막 성장모드에 미치는 영향에 대한 열역학적인 고찰)

  • Byon, Eung-Sun;Kim, Dong-Ho;Jeon, Sang-Jo
    • Journal of the Korean institute of surface engineering
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    • v.40 no.1
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    • pp.6-10
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    • 2007
  • For low-emissivity application on window glass, coalescence of thin film silver islands is crucial for high transmittance in the visible and high reflectance in the infrared. It is well known that the underlayer affects the growth mode. In this work, the effect of the underlayer on the growth of silver films deposited by filtered cathodic vacuum arc is discussed. While a nominal 0.1 nm niobium underlayer has promoted the coalescence of silver islands, a 0.2 nm layer did not show these features. From a thermodynamic approach, Nb seeding less one monolayer is considered to reduce the surface energy between the silver atoms and $Nb/TiO_2$ surface, resulting the change of its growth from 3D islands to 2D-layer modes. If the seed layer exceeds one monolayer, however, a rougher surface is formed because the surface energy of Nb itself is superior to that of $Nb-TiO_2$. The onset of silver layer on the roughened Nb surface is required more silver.

Emission of Far-infrared Ray in Packaging Paper

  • Lee, Ji-Young;Kim, Chul-Hwan;Jung, Ho-Gyeong;Shin, Tae-Gi;Seo, Jeong-Min;Lee, Young-Rok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.5
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    • pp.47-52
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    • 2008
  • The far-infrared ray (FIR) has been applied to various fields such as medical therapy, kitchen utensils, bath supplies, and so on. The FIR-emitting agent was used to make functional paperboards to have freshness-maintaining ability. The FIR-emitting agent was diluted with different concentrations at 0.5% starch solution, and the FIR-emitting solutions were coated on paperboards, i.e., liner. The more the concentration of the FIR radiating agent increased at 0.5% cationic starch solution, the higher FIR emissivity and emission power of paperboards increased. The corrugated boxes made of paperboards coated by the FIR-radiating agents at over 5% dilution concentration endowed mandarin oranges in the boxes with greater antimicrobial activity than those in boxes made of paperboards coated by the agent at below 5% concentration. In addition, it was ascertained that treatment of the FIR agents rarely affected strength properties of paperboards.