• YAKHAK HOEJI
• /
• v.49 no.2
• /
• pp.180-184
• /
• 2005

The purpose of this study was to develop the best methods to sterilize Moutan Root Bark which is frequently used as a herbal medicine, and known to have high susceptibility to m icrobial contamination. We used dry heat, gamma irradiation and alcohol gas treatment for sterilization, and evaluated these methods in terms of the followings; I) the efficacy of sterilization, and ii) the chemical alteration of a major component of the harbal medicines. Treatment with dry heat effectively got rid of contaminated microorganisms, and did not significantly alter the content of paeonol. However it seriously changed the color and morphology which are an essential criterion to estimate a measure of quality of medicinal herbs. Treatment with gamma irradiation showed a strong sterilizing effect, and no alteration of the content of paeonol, color and morphology. Alcohol gas treatment resulted in similar effects as those in gamma irradiation. Collectively, these results suggest that appropriate sterilizing methods to guarantee the microbial quality of this herbal medicine may be those using gamma irradiation or alcohol gas.

• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.6
• /
• pp.70-77
• /
• 2000

In this paper, the effect of solution and age heat treatment to the corrosion behavior for the Ti-6Al-4V alloy were studied by cyclic polarization methods. Ti-6Al-4V was solution heat treated at $1,066^{\circ}C$ and $966^{\circ}C$ for 5 hours, and followed by age heat treated at $650^{\circ}C$, $600^{\circ}C$ and $550^{\circ}C$ with 1, 2, 4, 8 and 16 hours under vacuum environment. Test solution was 3.5% NaCl with temperature $25^{\circ}C$. The obtained results were as follows: 1. Base metal was exhibited higher electrical charge than that of solution and aged material. With decrease of solution-treatment temperature from 1066 to $966^{\circ}C$, the electrical charge was increased due to softening of micro structure. 2. The corrosion resistance of specimen that solution treated at $966^{\circ}C$ for 5 hours and age heat treated at 650, 660 and $550^{\circ}C$ were increased with increase of aging time to 4, 8 and 16 hours respectively, and then decreased. 3. In case of 316L stainless steel, measured charge and corrosion potential was 0.0627 coulomb and -614 mV respectively. Corrosion resistance of Ti-6Al-4V was higher than that of 316L.

• The Journal of Advanced Prosthodontics
• /
• v.8 no.2
• /
• pp.75-84
• /
• 2016

PURPOSE. To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS. 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with $60^{\circ}C$ heat-treatment), and G4 (silane alonethen dried with $100^{\circ}C$ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in $N/mm^2$). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin-ceramic interface. RESULTS. SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION. The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

• Journal of Korean Society of Forest Science
• /
• v.61 no.1
• /
• pp.45-52
• /
• 1983

This study was carried out to find the effect of heat treatment on the pitch content and the properties of the kraft pulp produced from Pinus koraiensis. In the results of this experiments, the heat treatment with $40^{\circ}C$ showed the best result in the yields and the pitch contents of kraft pulp of the woods from both artificial and natural stands. Other properties, however, were not improved. They were rather deteriorated with heat treatment. Therefore, it needs to select, the heat treatment conditions according to the properties of raw material, the pulping methods and the final use of pulp.

• Corrosion Science and Technology
• /
• v.9 no.6
• /
• pp.310-316
• /
• 2010

Recently a fuel oil of the diesel engine of the marine ship is being changed with heavy oil of low quality as the oil price is higher more and more. Therefore the wear and corrosion in all parts of the engine such as cylinder liner, piston crown, spindle and seat ring of exhaust valves are predominantly increased. In particular the degree of wear and corrosion of piston crown is more seriously compared to the other parts of the engine due to operating in severe environment such as the high temperature of exhaust gas and repeating impact. Thus the repair weldment of the piston crown is a unique method to prolong the its life in a economical point of view. In this case, filler metals having a high corrosion and wear resistance such as stellite 6, Inconel 625 and Inconel 718 are mainly being used for repair welding. However it has been often happened that piston crown on the ship,s job site is being actually inevitably welded with mild filler metals. Therefore in this study, filler metals such as E4301, E4313 and E4316 were welded at SS401 steel as the base metal, and corrosion property of their weld metals in the case of post weld heat treatment or not was investigated with some electrochemical methods such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram and polarization resistance etc. in 0.1% $H_2SO_4$ solution. Corrosion resistance of the weld metal of E4301 was better than the other weld metals in the case of no heat treatment, however, its resistance was considerably decreased with post weld heat treatment(annealing:$625^{\circ}C$, 2 hr) compared to other weld metals. The weld metals of E4313 and E4316 showed a relatively good corrosion resistance by post weld heat treatment.

• Restorative Dentistry and Endodontics
• /
• v.38 no.3
• /
• pp.134-140
• /
• 2013

Objectives: There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. Materials and Methods: Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment. Also, the crystalline structures were observed using field-emission scanning microscopy (FE-SEM, Hitachi) and x-ray diffraction (XRD, Rigaku) analysis. The mean values of the biaxial flexural strength were analyzed by the Mann-Whitney U test at a significance level of p = 0.05. Results: There were no statistically significant differences in flexural strength between IPS e.max CAD and Rosetta SM either before heat treatment or after heat treatment. For both ceramics, the initial flexural strength greatly increased after heat treatment, with significant differences (p < 0.05). The FE-SEM images presented similar patterns of crystalline structure in the two ceramics. In the XRD analysis, they also had similar patterns, presenting high peak positions corresponding to the standard lithium metasilicate and lithium disilicate at each stage of heat treatment. Conclusions: IPS e.max CAD and Rosetta SM showed no significant differences in flexural strength. They had a similar crystalline pattern and molecular composition.

• Journal of the Korean Society for Heat Treatment
• /
• v.21 no.1
• /
• pp.3-9
• /
• 2008

Al-Co-N thin films, Al-Co-N/Al-N and Al-Co-N/Al-Co multilayers containing various amounts of Co content were deposited by using a two-facing targets type dc sputtering (TFTS) system. The films were also annealed successively and isothermally at different annealing temperatures. Irrespective of Co content and preparation methods, all the as-deposited films were observed non-magnetized. It was found that annealing conditions can control the magnetic and electrical properties as well as the microstructure of the films.

• Weed & Turfgrass Science
• /
• v.2 no.2
• /
• pp.170-175
• /
• 2013

Korea is carrying out weed quarantine by plant quarantine regulations including heat-treatment method to prevent the influx of exotic weeds. In order to confirm suitability for current heat-treatment criteria and find field-applicable methods which can completely devitalize quarantine weed seeds, the conditions for heat-treatment with/without 40% relative humidity were studied with 9 species among quarantine weed seeds and one weed species similar to quarantine weed. Dry heat-treatments had been tested under various temperatures and time conditions. All seeds were dead at the conditions of $95^{\circ}C$ for 48 hours, $100^{\circ}C$ for 36 hours, $110^{\circ}C$ for 24 hours, $121^{\circ}C$ for 4 hours and $130^{\circ}C$ for 30 minutes. Heat-treatments at 40% relative humidity resulted in complete seed death at the conditions of $85^{\circ}C$ for 36 hours and $90^{\circ}C$ for 16 hours. The above results show that current heat-treatment criteria are not suitable for several quarantine weeds and these conditions could be applied as a quarantine method to prevent the influx of quarantine weeds along with agricultural imports. More specific conditions for heat tolerant species such as Picris echioides and heat susceptible species such as Cuscuta spp. are necessary and will improve plant quarantine process in devitalizing quarantine weed seeds with different heat tolerances.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.7
• /
• pp.639-646
• /
• 2014

The comparative analysis of near-wall treatment methods that affect the prediction of heat transfer over the gas turbine nozzle guide vane were presented. To achieve this objective, wall-function and low Reynolds number methods, and the transition model were applied and simulated using NASA's C3X turbine vane. The predicted turbine vane surface pressure distribution data using the near-wall treatment methods were found to be in close agreement with experimental data. However, the predicted vane metal temperature and heat transfer coefficient displayed significant differences. Overall, the low Reynolds method and transition model did not offer specific advantages in the prediction of temperature and heat transfer than did the wall-function method. The Reynolds stress model used along with the wall-function method resulted in a relatively high accuracy of prediction of the vane metal temperature and heat transfer coefficient.

• Herbal Formula Science
• /
• v.24 no.1
• /
• pp.31-43
• /
• 2016

Objectives Based on related literature, cold and heat, deficiency and excess, true and false, and actually used formulas, paradoxical treatments presented in the 『Plain Questions of Inner Canon of Yellow Emperor』 including ‘treating pseudo-heat symptoms and real cold syndrome with cold herbs, treating pseudo-heat symptoms and real cold syndrome with cold herbs’ were analyzed.Methods Out of literature, paradoxical treatment related classics and papers were investigated and analyzed. Among diseases and syndromes, real cold syndrome with pseudo-heat symptoms, real heat syndrome with pseudo-cold symptoms, real deficiency syndrome with pseudo-excess symptoms, and real excess syndrome with pseudo-deficiency symptoms were reviewed. Among formulas, typical examples of the above mentioned paradoxical treatments were used as examples to analyze paradoxical treatments.Results Treating pseudo-heat symptoms and real cold syndrome with cold herbs is a method that uses herbs with cool and cold nature to treat real cold syndrome with pseudo-heat symptoms and Tongmaeksayeokgajeodamjeuptang is suitable for this method. Treating pseudo-cold symptoms and real heat syndrome with hot herbs is a method that uses herbs with warm and hot nature to treat real heat syndrome with pseudo-cold symptoms and Baekhogainsamtang is suitable for this method.Conclusions Based on the related literature, cold and heat, deficiency and excess, true and false, and actually used formulas examined as mentioned above, the paradoxical treatments presented in the 『Plain Questions of Inner Canon of Yellow Emperor』 are thought to be reasonable paradoxical treatments that fit the diseases and syndromes that actually appeared in our bodies.