• Tribology and Lubricants
• /
• v.25 no.3
• /
• pp.141-149
• /
• 2009

The effect of micro-cavities fabricated using laser surface texturing (LST) technique on polyoxymethylene (POM) surface was studied in terms of heat affected zone (HAZ), cavity geometry, surface roughness, deformation of cavity along with sliding cycles, and tribological characteristics. Cavity process parameters were lamp current, process time, and the stream of air used to minimize the flow of molten polymer into cavity. Especially, the deformation of cavity geometry was extensively studied to provide deep insight into morphological analysis of the cavities. Also, this paper presents the behavior of friction and wear of POM specimens as a function of sliding cycles.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.1090-1100
• /
• 1996

Heating floor is the most profitable system of air heating at poultry houses. THe tubes with heating elements inside are laid into the layer of concrete. To prevent lossese of heat penetration deep into the ground the layer of isolation material is laid below the tubes . The depth of isolation laying in every point of the heating floor may be calculated according to the author's formula using the data of temperature on the floor surface and the tube, the distance between tow nearest tubes, and the distance between the tube and the floor surface. Technological investigations allow to estimate the optimal density for greese and ducks when they are bred on the heatuing floor.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.17 no.2
• /
• pp.127-130
• /
• 2004

Pompholyx is a special vesicular type of hand and foot dermatitis. It is an acute, chronic or recurrent dermatosis of the fingers, palms and soles, characterized by a sudden onset of many deep-seated pruritic clear vesicles. We diagnosed a patient with pompholyx as damp heat and treated with wet dressing by gauze soaked in distilled solution of Gamihwangryunhaedok-tang(Jiaweihuanglianjiedu-tang). After treatment with wet dressing, we observed the improvement. Based on this study, it is considered that wet dressing with Gamihwangryunhaedok-tang(Jiaweihuanglianjiedu-tang) can be applied to the treatment of pompholyx.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.370-373
• /
• 2008

It is known that the temperatures of die, punch, holder and punch pad need to be kept different to get better formability in Mg sheet forming processes. Heating and cooling channels are usually equipped in each tool to assign different temperature. This study focused on the optimal design of the heating and cooling channels for a cross-shaped deep drawing die set. While the die and blankholder were heated to and kept at $250^{\circ}C$ by using heat cartridges, the punch and punch pad were kept at much lower temperature than that of the die and blankholder by water circulating through cooling channels. All the approaches were done by numerical analyses, aiming to maximize the cup height and to minimize the punch corner radius without any failure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.3
• /
• pp.263-269
• /
• 1990

Aqueous solution pigment produced by Steptomyces californicus KS-89 showed a vivid bluish purple pigment and purified by silica gel column chromatography. The pigment indicated a deep purple color zone by the C. I. E chromatic diagram and showed UV absorption maxima at 575nm. The color intensity in aqueous solution was fairly stable in the ranges of pH5-8 and was not affected by UV light however sometimes it had faded slightly by the heat. It was possible to prevent significantly by the addition of metal salt. Especially this pigment has no mutagenicity and antitumor activity and it appears to be devoid of antibiotic activity.

• Proceedings of the ESK Conference
• /
• 1992.10a
• /
• pp.96-103
• /
• 1992

To get a comfortable sleep, the most improtant thing is how well we do thermorgulate during the rest in bed before sleeping as well as during sleep. In other works, the ambient temperature of the sleeping room is very improtant in the organization of human sleep. In recent years, the effect of ambient temperature on human sleep has been increasingly stueided. These studies were primarily concerned with the relation between thermorgulatory processes and sleep, and more precisely with the findings that various thermoregulatory processes are inactivated or severly curtailed during REM sleep in a number of animals, also that panting and shivering in heat and cold, respectively, cease during REM sleep in cats. Haskel et al. noted that although REM sleep latency was increased at thigh and low temperature. REM sleep was depressed to a greater extent by lower than by higher temperatures whereas the reverse was obseved for SWS. It has also been found that a load omposed upon thermoregulatory mechanisms should markedly affect sleep processes, and that conversely, sleep in conditions of thermic stress should interfere with adequate thermorgulatory reactions. Sleep in an animala under thermic stress is, on the whole, both shorter and less deep than under normal thermic conditions.

• Elastomers and Composites
• /
• v.59 no.1
• /
• pp.22-33
• /
• 2024

Passive radiative cooling is a promising technology for cooling objects without energy input. Passive radiative cooling works by radiating heat from the surface, which then passes through the atmosphere and into space. Achieving efficient passive radiative cooling is mainly accomplished by using materials with high emissivity in the atmospheric window (8-13 ㎛). Research has shown that polymers tend to exhibit high emissivity in this spectral range. In addition to elastomers, other materials with potential for passive radiative cooling include metal oxides, carbon-based materials, and polymers. The structure of a passive radiative cooling device can affect its cooling performance. For example, a device with a large surface area will have a greater amount of surface area exposed to the sky, which increases the amount of thermal radiation emitted. Passive radiative cooling has a wide range of potential applications, including building cooling, electronics cooling, healthcare, and transportation. Current research has focused on improving the efficiency of passive radiative cooling materials and devices. With further development, passive radiative cooling can significantly affect a wide range of sectors.

• Journal of Haehwa Medicine
• /
• v.8 no.2
• /
• pp.107-122
• /
• 2000

As a result of studing on the "shashen(沙蔘)", we could reach conclusions as follows. 1. Shashen is the root of "lunyeshashen(潤葉沙蔘)", "kuoyeshashen(闊葉沙蔘)", and its same generic plants that belong to Companulaceae. In china people has used twenty-four species as a shashen together with other generic plants, in korea sixteen species as a shashen. 2. At first, in the "Shen Nong's Herbal(神農本草經)" it was recorded and then in the "Benchingfengyuan(本經逢原)" divided into "nanshashen(南沙蔘)" and "beishashen(北沙蔘)". Recently, nanshashen called shashen belongs to Companulaceae and have strong efficacies of clearing away heat from lung, resolving phlegm, beishashen belongs to Umbelliferae and have strong efficacies of nourishing stomach, nourishing yin. 3. Shashen is the root of Adenophora stricta Miq., and yangru(羊乳) is that of Codonopsis lauceolata Bentham et Hooker, jini is that of Adenophora remotiflora (SIEBOLD et ZUCCARINI.) MIQUEL. From a efficacious point of view, it is the characteristics that shashen have efficacies of nourishing yin and clearing away heat from lung, supplementing stomach and promoting production of body fluid, resolving phlegm and relieving cough, eliminating pus and abscess, expelling wind and pruritus, jini have those of clearing away heat and toxic material, resolving phlegm and yanru have those of nourishing yin and moistening lung, resolving phlegm and eliminating pus, clearing away heat and toxic material, stimulating milk secretion. 4. After being recorded as "zhimu(知母)" in Shen Nong's Herbal, the alias of shashen was recorded as kuxin(苦心), shimei(識美), huxu(虎須), baishen(白參), zhiqu(志取), wenhu(文虎), baolishen(保利參), paoshen(泡參), jibantui(鷄半腿), yangponai(羊婆妨) and so on. Moreover shashen was named after its characteristics of that it grows well in the sandy soil and as a wushen(五參) with a renshen(人蔘) its form is different from that of wushen but their chief virtues are alike. 5. In the numerous medical books, xinyeshashen(杏葉沙蔘) regarded as nanshashen. It was called as the alias of jini, so I thouhgt that it was wrong xinyeshashen to be regarded as nanshashen. 6. It was used shashen for renshen, renshen was used to treat lung-cold syndrome by its efficacy of tonifying yang and shashen lung-heat syndrome by its efficacy of nourishing yin, the reasons of that because shashen had amount of sap, its properies and flavours of herbs are light and clean. 7. The constituents of shashen were essential oil, starch, shashen-saponin, furocoumarin, xanthotoxin(ammoidin), inulin, sugar, mucus and have efficacies of resolving phlegm, promoting production of body fluid, immunomodulational and antibiotic efficacies. above results indicated that the origin of shashen and substitutional plants was various. Their efficacies are somewhat alike, but there were characteristic efficacies each other. Nowadays they are used together with, so we should know the characteristic efficacies of them and then we using them clinically, more deep discrimination and experimental support shoud be accomplished.

• Journal of the Korean Society for Heat Treatment
• /
• v.32 no.5
• /
• pp.201-211
• /
• 2019

Low carbon steel (S20C steel) and SPCC steel sheet have been austenitic nitrided at $700^{\circ}C$ in a closed pit type furnace by changing the flow rate of ammonia gas and heat treating time. When the flow rate of ammonia gas was low, the concentration of residual ammonia appeared low and the hardness value of transformed surface layer was high. The depth of the surface layer, however, was shallow. With increasing the concentration of residual ammonia by raising up the ammonia gas flow, both the depth of the surface layer and the pore depth increased, while the maximum hardness of the surface layer decreased. By introducing a large amount of ammonia gas in a short time, a deep surface layer with minimal pores on the outermost surface was obtained. In this experiment, while maintaining 10~12% of residual ammonia, the flow rate of inlet ammonia gas, 7 liter/min, was introduced at $700^{\circ}C$ for 1 hour. In this condition, the thickness of the surface layer without pores appeared about $60{\mu}m$ in S20C steel and $30{\mu}m$ in SPCC steel plate. Injecting additional methane gas (carburizing gas) to this condition played a deteriorating effect due to promoting the formation of vertical pores in the surface layer. For $1^{st}$ transformed surface layer for S20C steel, maintaining 10~12% residual ammonia condition via austenitic nitriding process resulted in ${\varepsilon}$ phase with relatively high nitrogen concentration (just below 4.23 wt.%N) among the mixed phases of ${\varepsilon}+{\gamma}$. The ${\varepsilon}$ phase was formed a specific orientation perpendicular to the surface. For $2^{nd}$ transformed layer for S20C steel, ${\gamma}$ phase was rather dominant (just above 2.63 wt.%N). For SPCC steel sheet, there appeared three phases, ${\gamma}$, ${\alpha}(M)$ and weak ${\varepsilon}$ phase. The nitrogen concentration would be approximately 2.6 wt.% in these phases condition.

• Food Science of Animal Resources
• /
• v.25 no.4
• /
• pp.507-512
• /
• 2005

This study was designed to investigate the effect of $\beta-carotene$ on the heat oxidation stability of deep fried laid with different healing temperature. Commercially purchased $\beta-carotene$ was used to this experiment $\beta-carotene$ was added to the deep fried lard at final concentration of $0\%\;0.001\%\;and\;0.004\%$ (wt/wt fat basis). Total plate count peroxide value, acid value, and TBA(thiobarbituric acid) values of the samples were determined regulary at $50^{\circ}C$ during 15 days. The result of the study are as follows: The number of microorganism was decreased by $\beta-carotene$ added to the deep fried lard Deep fried lard with $0.004\%$ $\beta-carotene$ have higher antioxidative effect than those of control and $0.001\%$ treated group. Peroxide and TBA values were significantly (P<0.05) decreased in all samples by added $\beta-carotene$ at $0.004\%$ Antioxidative effect increased with increasing concentration of $\beta-carotene$. These results suggest that $\beta-carotene$ might inhibit the growth of microganisms and retard lipid oxidation in the deep fried lard.