• Title/Summary/Keyword: Thermal Spectrum

Search Result 406, Processing Time 0.039 seconds

Dynamic Quasi-Elastic Light Scattering Measurement of Biological Tissue

  • Youn, Jong-In;Lim, Do-Hyung
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.2
    • /
    • pp.169-173
    • /
    • 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.

CLINICAL APPLICATION OF ARGON LASER IN PEDIATRIC DENTISTRY (아르곤 레이저의 소아치과에서의 임상적 적용)

  • Lee, Mi-Na;Lee, Sang-Hoon;Kim, Chong-Chul
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.24 no.1
    • /
    • pp.139-147
    • /
    • 1997
  • Argon laser used in this case report, is special in having two wavelength of 488, 514nm blue-green visible light spectrum. Blue light is used for composite resin polymerization and caries detection. Green light is used for soft tissue surgery and coagulation. Maximum absorption of this laser light occurs in red pigmentation such as hemoglobin. The argon laser may be well-suited for selective destruction of blood clots and hemangioma with minimal damage to adjacent tissues. Argon laser light penetrates tissue to the 1 mm depth, so its thermal intensity is lower than $CO_2$ laser light. Also, due to its short wavelength it can be focused in a small spot and even single gene can be excised by this laser and microscopy. After applicating argon laser to 4 patient for surgical procedure and to 1 patient for curing the composite resin, following results were obtained. 1. Improved visibility were gained due to hemostasis and no specific technique were needed according to easy recontouring of the tissue. 2. Ability to use by contact mode, tactile sense was superior but tissue dragability and accumulation of tissue on the tip needed sweeping motion. 3. Additive local anesthetic procedure was needed. 4. No suture and less curing time reduced chair time, this made argon laser available in pediatric dentistry.

  • PDF

THE DIFFUSE NEAR-INFRARED BACKGROUND SPECTRUM FROM AKARI

  • Kohji, Tsumura;Toshio, Matsumoto;Shuji, Matsuura;Itsuki, Sakon;Takehiko, Wada
    • Publications of The Korean Astronomical Society
    • /
    • v.32 no.1
    • /
    • pp.321-326
    • /
    • 2017
  • We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI InfraRed Camera (IRC) in the $1.8-5.3{\mu}m$ wavelength region. Advanced reduction methods specialized for slit spectroscopy of diffuse sky spectra have been developed, and a catalog of 278 spectra of the diffuse sky covering a wide range of Galactic and ecliptic latitudes was constructed. Using this catalog, two other major foreground components, the zodiacal light (ZL) and the diffuse Galactic light (DGL), were separated and subtracted by taking correlations with ZL brightness estimated by the DIRBE ZL model and with the $100{\mu}m$ dust thermal emission, respectively. The isotropic emission was interpreted as the extragalactic background light (EBL), which shows significant excess over the integrated light of galaxies at <$4{\mu}m$.

Ultra Wideband (UWB) - Introduction and Signal Modeling

  • Manandhar, Dinesh;Shibasaki, Ryosuke
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.1421-1423
    • /
    • 2003
  • Ultra Wideband is a new technology from commercial or civilian application viewpoint. It uses already allocated radio spectrum without causing significant interference to other users. It uses very low power, which is below the thermal noise of the receiver and is inherently difficult to detect by un-intentional users. Since, FCC approved the regulation for the commercial use of UWB in February 2002, the development of UWB technology is drastically gaining momentum. However, the technology itself is not new. It has already been used in military applications. UWB has three basic areas of applications, which are communication, positioning and imaging (UWB Microwave). The main commercial application will be for communication since it has very high data transfer rate for short distance. It can also be used for both indoor and outdoor 3-D positioning. Another important application is imaging like microwave remote sensing. An UWB sensor can pass through doors and walls and hence detect the objects inside the room. In this paper, we will introduce about UWB technology along with it’s various possible applications. We will also present some models to generate UWB signal and it’s analysis using signal-processing tools.

  • PDF

Effect of Thermal Annealing and Growth of ZnO:Li Thin Film by Pulesd Laser Deposition (펄스 레이저 증착법에 의한 ZnO:Li 박막 성장과 열처리 효과)

  • Hong Kwangjoon
    • Korean Journal of Materials Research
    • /
    • v.15 no.5
    • /
    • pp.293-300
    • /
    • 2005
  • ZnO:Li epilayers were synthesized on sapphire substrates by the pulesd laser deposition (PLD) after the surface of the ZnO:Li sintered pellet was irradiated by the ArF (193 nm) excimer laser. The growth temperature was fixed at $400^{\circ}C$. The crystalline structure of epilayers was investigated by the photoluminescence (PL) and double crystal X-ray diffraction (DCXD). The carrier density and mobility of epilayers measured by van der Pauw-Hall method are $2.69\times10cm^{-3}$ and $52.137cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of epilayers obtained from the absorption spectra is well described by the Varshni's relation, $E_g(T)=3.5128eV{\cdot}(9.51\times10^{-4}eV/K)T^2/(T+280K)$. After the as-grown ZnO:Li epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO:Li has been investigated by PL at 10 K. The Peaks of native defects of $V_{zn},\;V_o,\;Zn_{int},\;and\;O_{int}$ showned on PL spectrum are classified as a donors or accepters type. We confirm that $ZnO:Li/Al_2O_3$ in vacuum do not form the native defects because ZnO:Li epilayers in vacuum existe in the form of stable bonds.

Synthesis and Characterization of a New PPV Derivative Containing a Sterically Hindered 2,5-Dimethylphenyl Group

  • Kim, Yun-Hi;Lee, Hyun-Ouk;Lee, Ki-Suk;Kwon, Soon-Ki
    • Macromolecular Research
    • /
    • v.11 no.6
    • /
    • pp.471-475
    • /
    • 2003
  • A new poly[2-(2',5'-dimethylphenyl)-1,4-phenylenevinylene] (PDMPPV) that features a bulky 2',5'-dimethylphenyl substituent, which can induce steric hindrance between the PPV backbone and the methyl groups, was designed and synthesized. The polymer structure having no TBB defects was confirmed by $^1$H-NMR and $\^$13/CNMR spectroscopy. The polymer showed good thermal stability with high T$\_$g/. The polymer film showed a maximum absorption at 415 nm with an absorption onset at 480 nm. The maximum emission peak showed at ca. 515 nm, with a shoulder at 530 nm. The turn-on voltages of ITO/PEDOT/PDMPPV/Al and ITO/PDMPPV/Al devices were 8 and 10 V, respectively. The electroluminescence spectrum from the device showed a maximum peak at 510 nm with a shoulder at ca. 535 nm.

The Changes of Facial Temperature by Miso Facial Rejuvenation Acupuncture : A case study (미소안면침 시술 후 안면부 체온변화에 대한 임상적 고찰 : A case study)

  • Hwang, Deok-Sang;Song, Jeong-Hwa;Kim, Yong-Suk;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
    • /
    • v.6 no.1
    • /
    • pp.32-38
    • /
    • 2008
  • Objective: To investigate the changes of facial temperature by Miso Facial Rejuvenation Acupuncture treatment. Methods: One middle-aged women who has no other disease was recruited. The Miso Facial Rejuvenation Acupuncture was performed on only right face. We measured the facial temperature using the Digital Infrared Thermal Imaging (DOREX Inc. Spectrum 9000 MB, USA, D.I.T.I.) before, immediate after and 10 minutes after treatment. And we used the Wilcoxon signed rank test (P<0.05) to compare the difference of facial temperature at each time. Results: Right facial temperature (the area treated by acpuncuture) increased immediately from $30.02{\pm}1.87^{\circ}C$ to $32.24{\pm}1.03^{\circ}C$, the change of temperature is statistically significant. At 10 minutes after treatment, right facial temperature decreased little, but there was no statistical significance. Left facial temperature increased little, but there was no statistical significance. The difference between right and left face increased after Miso facial rejuvenation acupuncture treatment. Conclusion: Miso facial rejuvenation acupuncture could make the facial temperature increase.

  • PDF

The Development of UV-IR Combination Flame Detector (UV-IR 복합형 화재감지장치 개발)

  • 이복영;권오승;정창기;박상태
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.1
    • /
    • pp.1-8
    • /
    • 2001
  • All objects emit thermal radiation and this radiation is the basis of the techniques used to detect flames. The usual phenomena occurring in the initial stage of the fire are generally invisible products of a combustion and visible smoke. Liquid or gaseous materials do not undergo a smoldering stage so that fires develop very rapidly. Also, the heat generated by the initial flames is usually not sufficient to activate a heat detector. In this case the most effective criterion for automatic fire detection is the flame. According to the fire regulation of korea, the compulsory standard provided that a flame detector shall be installed in a place that the attachment height of detector is higher than 20 m, chemical plants, hangar, refinery, etc.. The results of the research and development are discriminated between a flame and other radiant emitters, developed a UV detector tube contains an inert gas which absorbs UV radiation, developed PZT pyroelectric element is based on the use of photovoltanic cell, developed IR band-pass filter that only allow a 4.3 $\mu\textrm{m}$ radiation wavelength to reach the sensors and developed UV-IR combination flame detector combined into a single detection device.

  • PDF

Effect of Polyethylene Glycol Molecular Weight and NCO Index on Properties of the Hydrophilic Reactive Hotmelt Polyurethane Adhesives (Polyethylene Glycol의 분자량 및 NCO index의 변화에 따른 Hydrophilic Reactive Hotmelt Polyurethane의 물성 변화)

  • Han, Young Chul;Kim, Dack Han;Oh, Kyung Seok;Shin, Hyeon Jeong;Yang, Jeong Han;Jeong, Han Mo
    • Textile Coloration and Finishing
    • /
    • v.30 no.2
    • /
    • pp.90-97
    • /
    • 2018
  • Hydrophilic reactive hot-melt polyurethane adhesive(HRHA) using a hydrophilic polyol having different molecular weight and NCO index was synthesized. This HRHA was synthesized using Polyethylene glycol(PEG) as a hydrophilic polyol, Polypropylene glycol(PPG) and Polycaprolactone diol(PCL) as hydrophobic polyols, and Methylene diphenyl diisocyanate(MDI) as an isocyanate. The changes in IR spectrum, viscosity and thermal properties of HRHA with different PEG molecular weights and NCO index were investigated, and the tensile strength and elongation of the HRHA casting film and the peel strength, moisture permeability and water pressure of the HRHA coated fabric were confirmed. In this experiment, as the molecular weight of PEG and NCO index increased, the adhesive strength, tensile strength, elongation and moisture permeability was increased but viscosity and Tg was decreased.

Fabrication and Characterizations of ITO Film as a Transparent Conducting Electrode for PDP Application (PDP 투명전극의 응용을 위한 ITO 박막의 제작평가)

  • Park, Kang-Il;Lim, Dong-Gun;Kwak, Dong-Joo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.07b
    • /
    • pp.788-791
    • /
    • 2002
  • Tin doped indium oxide(ITO) films are highly conductive and transparent in the visible region whose property leads to the applications in solar cell, liquid crystal display, thermal heater, and other sensors. This paper investigated ITO films as a transparent conducting films for application of PDP. ITO films were grown on glass substrate by RF magnetron sputtering method. To achieve high transmittance and low resistivity, we examined the various film deposition such as substrate temperature, gas pressure, annealing temperature, and deposition time. We recommend the substrate temperature of $500^{\circ}C$ and post annealing of $200^{\circ}C$ in $O_2$ atmosphere for good conductivity and transmittance. From XRD examination, ITO films showed a preferred(222) orientation. As substrate temperature increased from RT to $500^{\circ}C$, the intensity of the (222) peak increased. The highest peak intensity was observed at a substrate temperature of $500^{\circ}C$. with the optimum growth conditions, ITO films showed resistivity of $1.04{\times}10^{-4}{\Omega}-cm$ and transmittance of 81.2% for a film 300nm thick in the wavelength range of the visible spectrum.

  • PDF