• Proceedings of the KSME Conference
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• 2000.04b
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• pp.258-263
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• 2000

River water is higher in temperature than the surrounding environment during the winter. It is highly suitable a heat source for heat pump system. Despite its suitability, however, it is not widely used, due to its fouling and corrosive nature in heat exchanger tubes of evaporator. It is designed prior-treatment system which come into direct contact with the river water, such as auto-seamer, ozone generator for bactericidal test and auto-cleaning system. And it is analyzed treatment effects for its operation. It is designed two-stage compression heat pump system using R-134a with heating load 35.16kW, ad analyzed its performance. As a result it is obtained 3.08 COP when mid-point pressure is 1,200kPa, and bypass ratio of flowing refreigerant to high-stage compressor is 25.1%

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.2
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• pp.133-140
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• 2000

Purpose : Posterior Neck Pain and Back Pain are common diseases in human daily life. For reducting symptom and treatment of these diseases, many methods have been used and studied until now. The mechanisms of Ceragem Master Heat Bed(R)(Ceragem Co. Seoul, Korea) are infrared-heat therapy from natural nephrite and pressure therapy by up-down movement of natural nephrite ball. Through this study, authors would evaluate the clinical effectiveness of Ceragem Master Heat Bed(CMHB) on relieving posterior neck pain and back pain. Materials and methods : From 12-01-2000 to 01-13-2001, posterior neck pain and back pain patients were selected for experiment group(23patients) and control group(14patients). In both group, Visual Analog Scale(VAS) of pre-treatment stage is above 5 points. Experiment group were cared with acupuncture therapy, buhang therapy and CMHB. Control group were managed with only acupuncture therapy and buhang therapy. They were treated more than three times at least. At pre-treatment and post-treatment stage, we measured VAS for individual patients, and then compared effect of treatment in experiment group and in control group. Statistical analysis was preformed using SAS program. Results : In this study, a mean difference of VAS between pre-treatment and post-treatment stage was large in experiment(CMHB) group more than in control group(p〈0.01). Conclusion : Experiment(CMHB) group was more effective pain relief than control group in the treatment of posterior neck pain and back pain. CMHB was available for stimultaneous application of heat therapy and pressure massage together that gave another effects of mental stability and fatigue recovery. As the results of this study, CMHB could be used as a helpful treatment modality for posterior neck pain and back pain.

• Journal of the Korean Ceramic Society
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• v.28 no.4
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• pp.269-278
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• 1991

Fine AlN powder was synthesized by carbothermal reduction and nitridation of alumimun hydroxide prepared from Al-isopropoxide. AlN ceramics with Y2O3 and CaO were prepared by hot-pressing under the pressure of 30 MPa at 180$0^{\circ}C$ for 1 h in N2 atmosphere. Grain boundary behavior and purification mechanism of AlN lattice were examined by heat treatment of AlN ceramics at 185$0^{\circ}C$ for 1-6 h in N2 atmosphere. AlN ceramics without sintering additives showed poor sinterability. However, Y2O3-doped and CaO-doped AlN ceramics were fully densified nearly to theoretical density. As the heat treatment time increased, c-axis lattice parameter increased. This is attributed to the removal of Al2O3 in AlN lattice. This purification effect of AlN attice depended upon the quantity of secondary oxide phase in the inintial stage of heat treatment and the heat treatment time.

• The Journal of Korean Medicine
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• v.17 no.2 s.32
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• pp.100-116
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• 1996

Gastric cancer shows the most high friquency in cancers that occurs in Korea. The western medicine treatment for gastric cancer has radiation and surgery, chemical treatment. While, oriental medicine cures the gastric cancer by herb-drugs, acupunture , moxa and srigma. With just one way of treating gastric cancer can't be effective remedy. Because each medicine has a strength and weakness. Thus, it is effective treatment when two medicine combins and supplement each other. We got the following result about a trend of oriental and westernal combination treatment for gastric cancer through studing records. 1. The western medicine treats gastric cancer patient with surgery first and right after surgery. They need on assembly treatent such as chemical and immune treatment. In oriental medicine, they treats gastric cancer patients with differentiation of symptone and signs and treatment(辨證施治)[for example:incoordination between liver and stomach(肝胃不和), insufficiency of spleen and stomach(脾胃虛弱), stagnation of blood stasis and toxic agent(瘀毒內阻), deficiency of yin by stomach heat(胃熱傷陰), reinforcing both qi and blood(氣血雙虧), stagnation of damp-phlegm(痰濕凝結)] and cure for them by acupuncture and stigma, too. 2. In combination with oriental and western medical treatment principle of gastric cancer by each stage is as follows. First stage and second stage gastric cancer is cured with radical surgery mainly. After operation, the herb of invigoration of the spleen(健脾), coordination of the stomach(和胃), and smoothing the liver and regurating the circulation of qi(疏肝理氣), is used for good gastroenteric condition. The second stage patients can be concidered using in combination with chimical treatment. The third stage gastric cancer is treated with radical surgery or with temporizing surgery. After those surgery, herb-drugs treatment is used jointly. The fourth stage patients who have no extensively metastasis or local contraindication can undergo temporizing and curcuit surgical operation. Herb-drugs and chemical treatments are used together for patients after operating. If he has operating contraindication, he would be treated with herb-drugs and chemical treatment. 3. In case of using in combination with oriental and western medical treatment as follows. As for herb-drugs with chemical treatment, reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach(健脾和胃), reinforcing liver and kidney(滋補脾腎), clear out the heat and relieve the toxic agent(淸熱解毒), can be used and with radiation treatment, clear out the heat and relieve the toxic agent(淸熱解毒), promoting the production body fluid and moisturizing the vicera(生津潤燥), reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach (健脾和胃), reinforcing liver and kidney(滋補肝腎) etc, can be used. 4. According to the research of oriental and western medical combination treatment are the 5-year-survival degree with oriental and western medicine combination treatment was for better than that just with oriental or western medical treatment. Especially, it has good effect on the third, fourth stage gastric cancer. That is, the middle and the end of stage gastric cancer. 5. The merits of oriental and western medicine combination treatment are lengthers one's life and diminish the bad effect of chemical treatment and radiation treatment be near completion, prevent from relapsing, maintain the balance in their eveirenment of body and improve immunity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.495-500
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• 1998

To compare the extent of heat treatment in domestic infant formula, pH,titratable acidity, undenatured whey protein contents, HMF contents and protein-reducing substances of three commercial products (A, B, C) were measured. The pH of B products was lowest and the titratable acidity of B product was highest. The contents of undenatured whey protein per 100ml serum were 0∼30mg(A products), 90∼130mg(B products)and 80∼90mg(C products), respectively. Distinct differences of undenatured whey protein contents according to the manufacturer and infat's stage in age could be observed. The HMF contents of tested products showed 10.9∼21.5umol/L and B-2 product(B products for the second stage of 5∼9 month) was the highest among tested products. The protein-reducing substances showed 4.46∼9.50mg K4Fe(CN)6/100ml serum nd B-2 product was the highest among tested products.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.5
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• pp.226-231
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• 2020

The Cu-Co-Si alloy shows high strength by forming precipitates by aging precipitation heat treatment of supersaturated solid solution treated with solution treatment such as Cu-Ni-Si alloy, and the Co₂Si precipitated phase is dispersed in the copper matrix. The effect of aging treatment on the microstructure, mechanical and electrical properties of Cu-Co-Si alloys for electronic devices was investigated. As a results of SEM/EDS analysis, it was found that Co₂Si precipitates of 30~300 nm size were distributed in grains. By performing the double aging treatment, it was possible to improve the strength and electrical conductivity by dispersing the fine precipitate evenly.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.129-134
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• 2009

The dimension of forged part is different from that of die. Therefore, a more precise die dimension is necessarys to produce the precise part, considering the dimensional changes from forging die to final part. In this paper, both experimental and FEM analysis are performed to investigate the effect of several features including die dimension at each forging step and heat-treatment on final part accuracy in the closed-die upsetting. The dimension of forged part is checked at each stage as machined die, cold forged, and post-heat-treatment steps. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the DEFORM-$2D^{TM}$. The effect of residual stress after heat-treatment on forged part could be considered successfully by using DEFOAM-$HT^{TM}$.

• Journal of the Korean Society for Heat Treatment
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• v.11 no.3
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• pp.216-226
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• 1998

Heat treatment conditions and the formation of microstructures were studied for improving the transformation-induced plasticity(TRIP) effect of retained austenite and mechanical properties of Fe-0.2%C-1.5%Si-1.5%Mn sheet steel. An excellent combination of elongation about 30% and high strength over 760MPa was achieved by processing of intercritical annealing and isothermal holding Intercritical annealing the sheet steel produced fine particles($1{\sim}2{\mu}m$) of retained austenite which were stabilized due to C enrichment by subsequent holding in bainite transformation range. Heat treatment conditions were depended on the shape and distribution of second phases as well as the volume fraction and stability of retained austenrte. In this work, the heat treatment condition of optimal strength-elongation balance was obtained by holding the steel at $400^{\circ}C$ for 200sec, after intercritical annealing at $790^{\circ}C$ for 300sec.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.2
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• pp.139-146
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• 1996

The aero-industry is union industry which includes a research development type, a knowledge accumulation type and a developed country type. The aero-industry of Korea is in semi-developed type stage but departed later than that of other country such as Taiwan, Indonesia etc. Therefore, the necessity of domestic airplane material is required. This study on 7050Al extruded alloy aims to suggest an adequate heat treatment conditions of T73, T74 and T76. The results of this study show that; 1. The optimum conditions of T7x heat treatment in extruded 7050Al alloy show this; $$T73:121^{\circ}C{\times}7hr+177^{\circ}C{\times}14hr$$. $$T74:121^{\circ}C{\times}7hr+177^{\circ}C{\times}10hr$$. $$T76:121^{\circ}C{\times}7hr+163^{\circ}C{\times}21hr$$. 2. The 2nd step aging heat treatment such as T73, T74 and T76 etc. is efective in 7050Al alloy but the variation otf microstructure and mechanical property with dispersive inclusions produced for extrusion process causes some troubles. Accordingly, in order to produce a good 7050Al alloy, a careful attention is needed in manufacturing process.

• Journal of Korea Foundry Society
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• v.34 no.1
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• pp.1-5
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• 2014

The austempering transformation behavior in Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn steel is investigated. Each specimen was austenitized for 60 min at $900^{\circ}C$, and austempered at $380^{\circ}C$ for different time periods varying from 2 min to 256 min. After the austempering heat treatment, the Stage I and II evolutions are performed using optical metallography, X-ray diffraction and image analyses. Variations in the X-ray diffraction patterns and lattice parameters of the ferrite and austenite demonstrate that the residual austenite decomposes into ferrite and carbide during the Stage II evolution; moreover the amount of ferrite increases during the Stage I evolution. While the amount of austenite increases during Stage I, it dicreases during Stage II. Overall, the variations in the volume fractions of the microstructure and carbide formation in stages I and II meet high temperature austempering reaction of the ausferrite microstructure.