• Journal of Ginseng Research
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• v.34 no.2
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• pp.93-97
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• 2010

To enhance the functionalities of ginseng, an acid impregnation pre-treatment was applied during red ginseng processing. Acetic, ascorbic, citric, malic, lactic, and oxalic acid were used for the acid impregnation treatment, and total and crude saponin concentrations and ginsenoside patterns were evaluated. Total and crude saponin contents of red ginseng pre-treated by acetic, ascorbic, and citric acid were similar to those of red ginseng without pre-treatment, whereas lactic, malic, and oxalic acid pre-treatment caused a reduction of total and crude saponin in red ginseng. From the high performance liquid chromatography analysis of ginsenosides, increased $Rg_3$ density was shown in red ginseng pre-treated by acetic, ascorbic, and citric acid impregnation. In the case of lactic, malic, and oxalic acid pre-treatment, increased $Rg_1$ density was observed in red ginseng. Increased $Rg_1$ and $Rg_3$ contents due to acid impregnation during red ginseng processing may contribute to improving bioactive functionalities of red ginseng.

• Journal of the Korean Wood Science and Technology
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• v.40 no.5
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• pp.343-351
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• 2012

A large diameter roundwood is an important element of Korean traditional buildings, Hanok, and is hard to be dried without surface cracks. Four different pretreatments, such as pre-cracking, oil heating, kerfing-oil heating and PEG impregnation, were investigated for reducing the surface cracks of large-diameter roundwood specimens during heat treatment. The roundwood specimens of pre-cracking, oil heating and kerfing-oil heating showed surface cracks during pretreatment, but that of PEG impregnation did not. It was confirmed that kerfing reduced the total crack width. Among the four pretreatments and control only the PEG impregnation roundwood specimen had no crack on both outer and inner surfaces after heat treatment. The PEG impregnation specimen shrank only 1.6% in the tangential direction while the pre-cracking did 8.0%.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.497-503
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• 2011

In order to enhance bioactive functionalities of ginseng, an acid impregnation processing was applied as a pre-treatment in producing red ginseng. Acid impregnation studies were conducted, and acids (ascorbic, malic, and citric acid) were selected. The optimal concentration of each acid was investigated in this study in terms of ginsenoside contents. The most concerned ginsenoside, $Rg_3$ was increased by ascorbic, malic, and citric acid pre-treated red ginseng up to 1 M acid concentration. In the case of ascorbic acid pre-treated red ginseng, $Rg_2$ concentration was increased depending on acid concentrations. Citric acid pre-treatment enhanced $Rg_2$, $Rg_3$, and $Rh_1+Rh_2$ formation in red ginseng. Therefore, ginsenoside patterns in red ginseng could be changed by acid impregnation pre-treatment depending on acid concentration and acid types. This research is expected to contribute to the development of the ginseng industry via new red ginseng products with selective and intensified functionality.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.301-302
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• 2006

Machinability and machining mechanism were examined in the case where resin impregnation treatment was conducted to the Mo-Co hardening particle dispersed iron-based sintered alloy. As a result, the force required for machining decreased significantly compared with the case where resin impregnation treatment was not conducted. This effect is considered to be attributable to the embrittlement of cutting chips produced by the minimization of the cut material deformation.

• Fire Science and Engineering
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• v.26 no.4
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• pp.18-23
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• 2012

After produce the extracted wood to silicic acid gel, sodium carbonate and silicon dioxide with application of the making method for carbon dioxide, ignition time, ignition temperature, mass loss rate and critical heat flux are measured according to external radiation source (20, 25, 35 and 50 $kW/m^2$). From the results, pressure impregnation wood to use with water glass and carbon dioxide has fire retardant performance at heat flux (less than 20 $kW/m^2$) of Pre-Flashover fires. If we find out the excellent maxing ratio through continuously study, it might be decided to be able to be utilized as fire-retardant wood.

• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2434-2440
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• 2008

The effect of sodium (Na) promotion was studied in the biphenol (BP) hydrogenation using various Pd/C catalysts. Different amounts of sodium metal were used for promotion with Pd/C and their effects on BP hydrogenation were observed. The promotion order was changed to compare the effect of the position of the promoter in relation to the palladium (Pd) metal on the catalytic activity and yield of the final product, bicyclohexyl-4,4'-diol (BHD). Pd/C catalysts prepared from different methods were also sodium-promoted and the changes of the reaction pathway according to the type of promoted Pd/C catalyst were compared.

• The Korean Journal of Rheology
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• v.10 no.2
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• pp.57-64
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• 1998

A pultrusion resin impregnation (PRI) die, which has been developed recently in our laboratory, was used to pre-pare various composite system. The continuous fiber reinforced composites of glass fiber/polypropylene(GFPP) and glass fiber/polyamide 6 (GFPA) were first manufactured by means of the PRI die and then cut into chopped pellets of predet-ermined length. These pellets and either virgin or modified thermoplastic resin were melt-mixed by a twin screw extruder to prepare GF/PA/PP and GF/PA/PPMA system. The mechanical properties of these blends were investigated and discussed in terms of their morphological observations. These preliminary results revealed that this new impregnation die could be suc-cessfully applied to produce prepregs suitavle for the final shaping process.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.201-216
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• 1990

A variety of surface pre-treatments have been advocated to prepare the dentin prior to placement of a bonding agent. The purpose of this study was to evaluate the effect of various dentin conditioners upon the degree of resin impregnation to the dentinal tubules and the shear bond strength of a new dentinal bonding agent (Scotchbond 2) used in conjunction with a visible light cured composite (Silux). The healthy eighty human molars extracted due to periodontal or orthodontic reasons were used and randomly divided into five groups. All the grinded dentin surfaces were conditioned with 3% $H_2O_2$, Cavity Cleanser (Columbus/Bayer), Dentin Conditioner (GC Inter. Corp.), Scotchprep (3M Co.) according to the manufacturer's directions. The specimens were then demineralized in 10% HCl for 20 sec. and 24 hrs. in order to observe the resin tags in Hitachi X-450 scanning electron microscope at 25KV. Also, shear strengths were obtained using an Instron Testing Machine with a cross head speed of 1 mm/min. The following results were obtained ; 1. In group treating with Dentin Conditioner and Scotchprep, the resin strings were formed on most of the surfaces and penetrated more than $50{\mu}m$ into the tubules. 2. The inner surface of resin treated with Cavity Cleanser, indicating the resin strings formed partly and penetrated about in depth of $30{\mu}m$. 3. In control and experimental group treated with 3% $H_2O_2$, the resin tags were not formed, if any, penetrated shortly. 4. Shear bond strengths in groups treating with Dentin Conditioner and Scotchprep were statistically significant increase than with 3% $H_2O_2$. (P<0.01). 5. The Scotchprep treatment group was significantly higher in shear strength than groups treated with no conditioning and Cavity Cleanser.(P<0.01) 6. Shear bond strengths evaluated were gradually increase in proportion to the tag length of resin impregnation.

• Carbon letters
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• v.21
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• pp.33-50
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• 2017

In this study, Fe-Ni bimetallic catalyst supported on kaolin is prepared by a wet impregnation method. The effects of mass of kaolin support, pre-calcination time, pre-calcination temperature and stirring speed on catalyst yields are examined. Then, the optimal supported Fe-Ni catalyst is utilised to produce multi-walled carbon nanotubes (MWCNTs) using catalytic chemical vapour deposition (CCVD) method. The catalysts and MWCNTs prepared using the optimal conditions are characterized using high resolution transmission electron microscope (HRTEM), high-resolution scanning electron microscope (HRSEM), electron diffraction spectrometer (EDS), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD). The XRD/EDS patterns of the prepared catalyst confirm the formation of a purely crystalline ternary oxide ($NiFe_2O_4$). The statistical analysis of the variance demonstrates that the combined effects of the reaction temperature and acetylene flow rate predominantly influenced the MWCNT yield. The $N_2$ adsorption (BET) and TGA analyses reveal high surface areas and thermally stable MWCNTs. The HRTEM/HRSEM micrographs confirm the formation of tangled MWCNTs with a particle size of less than 62 nm. The XRD patterns of the MWCNTs reveal the formation of a typical graphitized carbon. This study establishes the production of MWCNTs from a bi-metallic catalyst supported on kaolin.

• Clinical and Experimental Reproductive Medicine
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• v.2 no.1
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• pp.19-38
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• 1975

A total of 185 vasovasostomies were carried out for 11 years. Various factors which are of importance in fluencing the successful vasovasostomies are analysed and presented as follows: In recent years, demand of reanastomosis of the vas deferens increased considerably. An average age of the subjects is 39, and that of their wives, 33 in this series. An average interval between vasectomy and vasovasostomy is 4 years. An average number of living chidren is 2.6 at the time of vasectomy. and 2.1 at the time of time of vasovasostomy. Merchant and public official are the most commonly encounterd occupation in the present series. Coital frequencies are 2.2/week after vasovasostomy. The most common reasons for requesting the vasovasostomy are remarriage and deaths of children, especially son. Success rate is considerably higher among younger group than that of the older. Success rate is somewhat higher among groups of shorter interval between the operations (vasectomy and vasovasostomy) than that of longer interval group. Success rate is higher among bilateral vasovasostomy group than that of any others. Success rate is higher in solid splint group and no splint group than hollow splint group. The closed dressing technique of the end of splint on the scrotum is found to be reasonably effective in preventing infection. Ordinary end-to-end anastomosis and folded side-to-side anastomosis techniques are proved to be the most ideal form of modified operation for the successful vasovasostomies. The most common causes of failure are infection, injuries of blood supply, avascular necrosis due to extensive mobilization, inadequate approximation of both vasal end, hematoma, changes of epididymal environment, and early ambulation in this series. Overall success rate of the author's series is found the 81 per cent, and impregnation rate is 35 per cent. Overall results reported by other workers are that success rate regarding appearance of sperm in the semen after operation is 64 per cent, and that of impregnation after vasovasostomy is 33 per cent. The results of semen assessment performed on same cases prior to vasectomy and following vasovasostomy showed that post-vasovasostomy sperm count scarcely reached three-quaters of pre-vasectomy count.