• Title/Summary/Keyword: Heat from Light

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Thermal Properties of Two-Layered Materials Composed of Dielectric Layer on Metallic Substrate along the Thickness Direction (금속기판에 유전체 후막을 형성시켜 제조한 2층 층상재료에서 두께 방향의 열전도 특성)

  • Kim, Jong-Gu;Jeong, Ju-Young;Ju, Jae-Hoon;Park, Sang-Hee;Cho, Young-Rae
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.87-92
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    • 2016
  • The importance of heat dissipation for the electric device modules along the thickness direction is increasing. Two types of two-layered materials, metal-metal bonding and dielectric-metal bonding, have been fabricated by roll bonding process and a thermal diffusivity of the specimens was measured along the thickness direction. The thermal diffusivity of specimens with metal-metal bonding measured by light flash analysis (LFA) showed a same value independent on the direction of heat flow. However, the thermal diffusivity of specimens with dielectric-metal bonding showed a big difference of 17.5% when the direction of heat flow changed oppositely in the LFA process. The measured thermal diffusivity of specimens when the heat flows from metal to dielectric direction showed smaller value of 17.5% compared to the value when the heat flow from dielectric to metal direction. The difference in thermal diffusivity of specimens with dielectric-metal bonding dependence on direction of heat flow is due to the electron-phonon resistance that occurred transfer process of electron energy to phonon energy near the interface.

Effect of Heat Treatment and Particle Size on the Crystalline Properties of Wood Cellulose (입자크기 및 열처리가 목재 셀룰로오스의 결정 특성에 미치는 영향)

  • Kim, Ah-ran;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.3
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    • pp.299-310
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    • 2019
  • This study was carried out to investigate the effect of heat-treatment and particle size on the crystalline properties of the wood cellulose. The color of wood flours was changed from light yellow in control sample to dark yellow or deep brown by heat treatment at $100^{\circ}C$ to $200^{\circ}C$. Relative crystallinity of the heat treated wood cellulose decreased with decreasing particle size from wood chips to 200 mesh, and there was little change in the crystal width. As the temperature was increased, relative crystallinity of the wood increased and crystal width was not changed. As a result of the FT-IR analysis, it was confirmed that the peaks were gradually decreased at -OH elongation as the heat-treated temperature was increased. The lignin C-H bending of $1425cm^{-1}$ and the hemicellulose C-H bending of $1370cm^{-1}$ did not change with the increase of the heat treatment temperature. In addition, it was revealed that C-C stretching of carbohydrate near $1031cm^{-1}$ decreased with increasing heat treatment temperature. Consequently, it is suggested that particle size and heat treatment affected the crystalline properties of wood cellulose.

Study on the Plant Growth Variation According to Change of Luminous Flux LED Light in Plant Factory (식물공장의 LED 광강도 변화에 따른 식물성장 변화에 관한 연구)

  • Hong, Ji Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.3
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    • pp.304-311
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    • 2020
  • The purpose of this study is to change plant growth according to the light quantity of LED light source and to standardize plant factories technology according to the optimal LED light range. Growth was relatively stable at the 1,400 lx and 1,600 lx intensities, and growth continued with increasing light intensity, but growth slowed down with growth without leaves (Ed- I don't understand). The growth characteristics at 400 lx to 800 lx were sustained to some extent during the experimental period, but the growth of the larvae was maintained until the 7th day and the growth of leaves was not developed. From 1,000 lx to 1,400 lx, brightness, leaf growth and daily growth increased, and the growth cycle exhibited a repeating cycle of growth and slowdown. In addition, 1,600 lx and 1,800 lx showed similar growth to that at 1,400 lx, but leaf growth was high. However, at 1,800 lx, the growth was slightly higher than at 1,400lx and it slowed down over time. In addition, the stronger the light, the higher the temperature around the plant and the greater the dryness of the leaves due to the heat emitted from the light source.

Documentational Study and Observation from the View of Hyungsang Medicine on Bangpungtongseong-san (방풍통성산(防風通聖散)의 문헌(文獻) 및 형상의학적(形象醫學的) 고찰(考察))

  • Suck, Min-Hee;Kim, Jun-Hong;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.1
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    • pp.51-59
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    • 2008
  • The following conclusions were obtained from the studies on Bangpuntongseongsan both from the documents and Hyungsang medicine. Bangpungtongseong-san was created by Yu Wan-so to relieve both interior and exterior of disease from the pathogenic fire, and it cures wind syndrome and dry syndrome. Bangpungtongseong-san is of light herbal combination and it works in the upper part of the body and is mainly applied to skin disease. Perspiration without harming the exterior and purgation without hurting the interior shows that it is not a severe prescription belonging to meditation therapy. It is mostly used for curing the disease of internal heat caused by over drinking and consuming heavy food, and it has special relationship with Yangmyung meridian. It is mentioned in the chapters of spirit, head, face, eye, ear, nose, throat, skin, hair, prescription, wind, dryness, fire, internal damage, epidemic infectious disease, carbuncle and cellulitis, ulceration, and pediatrics of ${\ulcorner}$Donguibogam${\lrcorner}$. It is usually applied to those who belong to Yangmyung type of the six meridian types or wind type, who has excessive heat, people with red complexion, reddened nose, pimples over the face and nose, coarse heel, loss of hair due to wind-heat, and to those who tend to have dandruff. Through examination over the cases treated with Hyungsan medicine, Bangpungtongseong-san was found efficacious in bloodshot eyes, brandy nose, loss of hair, various skin problems, tetanus, acute alcoholism, paralysis of hand and foot, deafness, and tinnitus.

Thermal Transient Characteristics of Die Attach in High Power LED Package

  • Kim Hyun-Ho;Choi Sang-Hyun;Shin Sang-Hyun;Lee Young-Gi;Choi Seok-Moon;Oh Yong-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.4 s.37
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    • pp.331-338
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    • 2005
  • The rapid advances in high power light sources and arrays as encountered in incandescent lamps have induced dramatic increases in die heat flux and power consumption at all levels of high power LED packaging. The lifetime of such devices and device arrays is determined by their temperature and thermal transients controlled by the powering and cooling, because they are usually operated under rough environmental conditions. The reliability of packaged electronics strongly depends on the die attach quality, because any void or a small delamination may cause instant temperature increase in the die, leading sooner or later to failure in the operation. Die attach materials have a key role in the thermal management of high power LED packages by providing the low thermal resistance between the heat generating LED chips and the heat dissipating heat slug. In this paper, thermal transient characteristics of die attach in high power LED package have been studied based on the thermal transient analysis using the evaluation of the structure function of the heat flow path. With high power LED packages fabricated by die attach materials such as Ag paste, solder paste and Au/Sn eutectic bonding, we have demonstrated characteristics such as cross-section analysis, shear test and visual inspection after shear test of die attach and how to detect die attach failures and to measure thermal resistance values of die attach in high power LED package. From the structure function oi the thermal transient characteristics, we could know the result that die attach quality of Au/Sn eutectic bonding presented the thermal resistance of about 3.5K/W. It was much better than those of Ag paste and solder paste presented the thermal resistance of about 11.5${\~}$14.2K/W and 4.4${\~}$4.6K/W, respectively.

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Fire Characteristics for Spill Rate of Light oil and Methanol (경유와 메탄올의 유출속도에 따른 화재특성)

  • Lee, Jung Yun;Kim, Hong
    • Journal of the Korean Society of Safety
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    • v.31 no.5
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    • pp.54-60
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    • 2016
  • In this study, tank truck incidents of road transport of hazardous materials to experimental investigated the potential fire hazard. Real scale fire was to perform experiments for on this qualitative and quantitative data collection and analysis. Particularly affected by radiant heat from the flames caused and damage estimates range investigated accordingly. Flame temperature, internal temperature of tank and emitted radiation from the flames was investigated. The flame of light oil spill caused a fire at a temperature of about $300^{\circ}C$ high in comparison with the methanol by combustion of diesel and methanol, according to the difference, the flame duration changes varies depending on the Burning rate. Depending on spill rate(30, 60, 90 and $120{\ell}/min$) and the longer the duration of the flame important factors for the internal temperature of tank lorry rise was found. Road accident in a fire caused by leakage of hazardous was could the higher the damaged. Therefor, Fire suppression activities should be required in particular to be around.

Effects of Additives and Sintering Method on the Properties of Light Aggregate Prepared from EAF Dust/Clay (첨가제와 소결방법이 EFA Dust/점토 소결체의 경량화에 미치는 영향)

  • 권영진;이기강;김유택;김영진;강승구;김정환;박명식
    • Journal of the Korean Ceramic Society
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    • v.40 no.3
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    • pp.309-316
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    • 2003
  • EAF(Electric Arc Furnace) Dust classified as special wastes containing heavy metal contaminants may cause to damage an environment such as underground water contamination if they were not treated properly. The possibility of producing the porous sintered body made from EAF Dust/clay composition system was studied. Mixing of EAF Dust and clay was carried out using wet-mixing process and two different sintering methods such as rapid and normal heat treatment were tried. By observing density, porosity and microstructure of sintered bodies, it was found that the bloating phenomenon depend on the contents of C, where the liquid phase occur or not during the sintering process. To obtain a light-aggregate of porous body due to bloating, the rapid heating was better than the normal heating at sintering process.

Synthesis and Dyeing Properties of Red Disperse Dyes Derived from Diaminopyridines (디아미노피리딘아조계 Red 분산염료들의 합성과 염색성)

  • Park Jong Ho;Koh Joonseok;Bae Jin Seok;Kim Sung Dong
    • Textile Coloration and Finishing
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    • v.17 no.6 s.85
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    • pp.1-10
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    • 2005
  • Disperse dyes derived from heterocyclic compounds such as phenylindole, pyridone, diaminopyridine, and carbazole have been known to exhibit high light fastness and bathochromic shift compared to the coursponding aminoazobenzene. The synthetic method to obtain diaminopyridine derivatives, which can be used as coupling components, was chlorination of pyridone with phosphorous oxychloride, followed by substitution with various primary amines. Four azo disperse dyes were synthesized by coupling four diaminopyridines with 2-cyano-4-nitroaniline as a diazo component. Structures of these dyes were confirmed by $^1H$ NMR spectroscopy. The wavelengths of maximum absorption of the synthesized disperse dyes were in the range of $517\~528nm$, and molar extinction coefficients were $45,700\~50,100$. The dyeability of four disperse dyes toward PET fiber was generally good. Wash and rubbing fastnesses were excellent, while light and dry heat fastness were good.

Comparative study of thermal gelation properties and molecular forces of actomyosin extracted from normal and pale, soft and exudative-like chicken breast meat

  • Li, Ke;Liu, Jun-Ya;Fu, Lei;Zhao, Ying-Ying;Bai, Yan-Hong
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.5
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    • pp.721-733
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    • 2019
  • Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

The in vivo photothermal treatment of gold nanorod in the mouse ear model

  • Liu, Bruce Yao Wen;Chen, Cheng-Lung;Lee, Shin-Yu;Chang, Fu-Hsiung;Lin, Win-Li;Chia, Chih-Ta;Chen, Yang-Yuan
    • Biomaterials and Biomechanics in Bioengineering
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    • v.1 no.1
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    • pp.41-50
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    • 2014
  • Gold nanorod's exceptional light to heat transduction is a robust phonomenon that has been extensively verified. The phenomenon is a trait from which many novel applications across disciplines have been proposed. In this investigation, the feasibility of utilizing heat harvested from such photothermal method to combat cancer is presented. Using non-invasive laser methods, an in vivo study is conducted on mouse ear tumors administered with gold nanorods (Au NRs). An emphasis is placed on monitoring the tumor developments after photothermal treatments, over time. The findings reveal significant tumor growth surpression at a threshold laser power of $0.6W/cm^2$ lasting 2 minutes; this energy also brought about dramatic size reduction in treated tumors. Furthermore, the apparent formation of an eschar over the laser treated region indicates extensive hemorrhagic necrosis of the tumor tissue; a phenomenon implicative to the inhibition of angiogenesis.