• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1062-1068
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• 2009

Diacylglycerol (DAG) were synthesized by enzymatic esterification of glyceryl monooleate (GMO) and conjugated linoleic acid (CLA) in a shaking water bath. The reaction was catalyzed by Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosa). Effects of reaction time, molar ratio, enzyme road and molecular sieves were studied. Results of normal-phase high performance liquid chromatography (NP-HPLC) analysis were performed. At 1:1, 2:1 and 3:1 (GMO : CLA) molar ratio and Lipozyme TLIM of 20% amount, DAG were produced in 42.6, 54.4 and 54.6 area% in 1 hr, respectively. When different Lipozyme TLIM amounts (2, 5, 10, 20%) were used with 2:1 (GMO : CLA) molar ratio, DAG were produced 21.4 (24 hr), 51.7 (12 hr), 56.2 (6 hr) and 54.4 (1 hr) area%, respectively. The reaction in the absence of molecular sieves increased DAG contents. The maximum DAG concentration conditions were obtained with molar ratio of 2:1 (GMO : CLA), lipase concentration of 10% (of substrate), 10% molecular sieves and reaction time of 6 hours at 55$^{\circ}C$. Under this reaction condition, produced DAG-rich oil was composed of 69 area% DAG, 7.9 area% TAG, 2 area% FFA, and 21.1 area% MAG.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.79-92
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• 2000

The purpose of this study was to estimate the morphology and the size of permanent maxillary molar in Korean Adult. The 100 dental college students with a normal dentition and without any dental prosthesis and severe caries were selected for this study. The subjects were taken impression to make study model. On the study model, authour three times measured those sizes and estimated morphological structures with a calipers, a Boley gauge and a protractor. The results were as follows; 1. In the maxilary first molar's clinical crown height, mesiolingual cusp height was 6.34mm, mesiobuccal cusp height was 6.05mm, distobuccal cusp height was 5.20mm. And in the maxillary second molar's clinical crown height, mesiobuccal cusp height was 5.85mm, mesiolingual cusp height was 5.71mm, distobuccal cusp height was 5.51mm, distolingual cusp height was 3.53mm. This result considered that the maxillary first molar inclined to distobuccal, and the maxillary second molar more upright than the maxillary first molar. 2. In the width of clinical crown, the maxillary first molar was 10.43mm, the maxillary second molar was 10.20mm, and the difference between the first molar's width and the second molar's width was 0.23mm. 3. The crown thickness was measured divided into mesial buccolingual half and distal buccolingual half. The mesial buccolingual half was 11.14mm, and distal buccolingual half was 10.35mm in the maxillary first molar, and in the maxilary second molar, mesial buccolingual half was 11.25mm, and distal buccolingual half was 9.72mm. This result considered that height of convergency located in mesial half of crown. 4. In the buccal groove length, total length and ratio, the maxillary first molar was 52.5%, the maxillary second molar was 50%. And the development of buccal groove in the maxillary first molar was 59% in case of the well developed buccal groove and 41% in case of the weak developed one. And frequency of buccal pit of the maxillary first molar was 12.5%. Whereas, the frequency of buccal of the well developed buccal groove in the maxillary second molar was 37% and that of the weak developed one was 63%. And frequency of buccal pit of the maxillary second molar was not seen. 5. The 3 cusp type tooth cannot be found in the maxillary first molar and the frequency of 3 cusp type tooth in the maxillary second molar was as small as 6% 6. In the case of 4 cusp type tooth, the size of distal lingual cusp molar was difference between in the maxillary first molar and in the maxillary second molar by about 1mm. 7. The intercuspal distance was similar in the maxillary first premolar and second molar. And intercuspal distanc of mesial half of the maxillary first molar and the maxillary second molar was silmillar, too. 8. The an measurement of occlusal surface in 4 cusp type tooth showed that the angle of occlusal surface between the distobuccal and mesiolingual was an obtuse angle, and the angle of occlusal surface between mesiobuccal and distolingual was an acute angle in the both cases of maxillary first and second molar. 9. The measurements of the development of Carabelli cusp showed that the frequency of the well developed one was 7% and that of the weak developed one was 56% in the maxillary first molar. And there cannot be found the well developed one and can be found 2.5% only in the case of the weak developed one in the maxillary second molar. 10. The well developed oblique ridge in the maxillary first molar showed the 100% frequency and that in the maxillary second molar showed the 85.5% frequency. The frequency of mesiomarginal ridge tubercle in the maxillary first molar was 82% and that in the maxillary second molar was 30.5%. And the frequency of distal accessory tubercle in the maxillary first molar can be seen about 19% and that in the maxillary second molar can be seen about 12%.

• Journal of Powder Materials
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• v.16 no.6
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• pp.410-415
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• 2009

Hexagonal barium ferrite ($BaFe_{12}O_{19}$) nano-particles have been successfully synthesised using selfassembly method. Diethyleneamine (DEA) surfactant was used to fabricate the micelle structure of Ba-DEA complex under various DEA concentrations. $BaFe_{12}O_{19}$ powders were synthesized with addition Fe ions to Ba-DEA complex and then heat treated at temperature range of 800-1000${\circ}C$. The molar ratio of Ba/DEA and heat-treatment temperature significantly affected the magnetic properties and morphology of $BaFe_{12}O_{19}$ powders. $BaFe_{12}O_{19}$ powders synthesized with Ba/DEA molar ratio of 1 and heat-treated at 1000${\circ}C$ for 1 hour showed the coercive forces (iHc) of 4.84 kOe with average crystal size of about 200 nm.

• Journal of Forest and Environmental Science
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• v.31 no.1
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• pp.1-6
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• 2015

Microwave assisted biodiesel production from crude Pongamia pinnata oil using homogeneous base catalyst (KOH) was unsuccessful because of considerable soap formation. Therefore, a two step process of biodiesel production from high free fatty acid (FFA) oil was investigated. In first step, crude P. pinnata oil was acid catalyzed using $H_2SO_4$ and acid value of oil was reduced to less than 4 mg KOH/g. Effect of sulfuric acid concentration, alcohol-oil molar ratio and microwave irradiation time on acid value of oil was studied. Result suggested that 1.5% $H_2SO_4$ (w/w), 6:1 methanol oil molar ratio and 3 min microwave irradiation time was sufficient to reduce the acid value of oil from 12 and 22 mg KOH/g to 2.9 and 3.9 mg/KOH/g, respectively. Oil obtained after pretreatment was subsequently used for microwave assisted alkali catalyzed transesterification. A higher biodiesel yield (99.0%) was achieved by adopting two step processes. Microwave energy efficiency during alkali catalyzed transesterification was also investigated. The results suggested a significant energy saving because of reduced reaction time under microwave heating.

• Journal of Powder Materials
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• v.17 no.4
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• pp.263-269
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• 2010

Hexagonal barium ferrite ($BaFe_{12}O_{19}$) nano-particles have been successfully fabricated by spraypylorysis process. $BaFe_{12}O_{19}$ precursor solutions were synthesized by self-assembly method. Diethyleneamine (DEA) surfactant was used to fabricate the micelle structure of Ba-DEA complex under various DEA concentrations. $BaFe_{12}O_{19}$ powders were synthesized with addition of Fe ions to Ba-DEA complex and then fabricated $BaFe_{12}O_{19}$ powders by spray-pyrolysis process at the temperature range of $800{\sim}1000^{\circ}C$. The molar ratio of Ba/DEA and heat-treatment temperatures significantly affected the magnetic properties and morphology of $BaFe_{12}O_{19}$ powders. $BaFe_{12}O_{19}$ powders synthesized with Ba/DEA molar ratio of 1 and heat-treated at $900^{\circ}C$ showed the coercive forces (iHc) of 4.2 kOe with average crystal size of about 100 nm.

• Analytical Science and Technology
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• v.12 no.1
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• pp.13-21
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• 1999

Silicate used as laundry detergent builder was good for pH buffering capacity and solubility but calcium-ion binding capacity and surfactant adsorption ability were lower. As $SiO_2/Na_2O$ molar ratio became higher, pH buffering capacity and ion exchange ability were lower and surfactant adsorption ability was little higher. Anionic surfactant LAS (linear alkylbenzene sulphonate), nonionic surfactant LA-9 (lauryl alcohol EO-9) were used to investigate the detergency performance. Zeolite was better than sodium silicate in detergency performance. In case of LAS, detergency performance was good when $SiO_2/Na_2O$ molar ratio was lower. In case of LA-9, detergency performance was similar without discrimination of molar ratio of $SiO_2/Na_2O$.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1570-1576
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• 1994

Effect of Na2O/SiO2 molar ratio, calcining temperature and addition of NaCl were investigated on the hydrothermal formation of X-type zeolite from the natural mordenite, which is a kind of rock deposited abundantly in kuryong po. Pulverized mordenite was first mixed with NaOH or NaOH-NaCl solution, and crystallized under hydrothermal condition at 90~10$0^{\circ}C$ for 10 hrs. Optimum condition for synthesis of the X-type zeolite were \circled1 the ratio Na2O/SiO2, NaCl/Al2O3 and H2O/Na2O:0.68, 11.4 and 40, respectively, \circled2 calcining temperature of starting materials: 90$0^{\circ}C$, \circled3 aging time: 48 hrs. and \circled4 crystallization temperature: 10$0^{\circ}C$. The yield of X-type zeolite under the optimum condition was about 55~60%, and the major crystallized X-type zeolite was faujasite phase. Zeolite of then type X was crystallized when NaCl was added to treating solution with in the limit 14.25 of NaCl/Al2O3 molar ratio. As the calcination temperature (from 50$0^{\circ}C$ to 95$0^{\circ}C$) of starting materials increases, yield of zeolite x increase.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.5-12
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• 2006

This study was conducted to investigate the effect of operational parameters such as dosage of magnesium and phosphate, pH, reaction time and existence crystal core for the removal of nitrogen and phosphorus in anaerobic fermentation supernatant by struvite crystallization. Optimal mole ratio of $Mg^{2+}:NH_4{^+}:PO_4{^{3-}}$ was 1.2:1.0:1.2. Under the optimal molar ratio, removal ratio and reaction rate constant of $NH_4{^+}-N$ and $PO_4{^{3-}}-P$ were 79.2, 96.8%, 0.157 and $0.344min^{-1}$, respectively. Optimal pH and reaction time were 11 and 10 minutes, respectively, in the optimal molar ratio. Residual concentration of $NH_4{^+}-N$ and $PO_4{^{3-}}-P$ showed lowest value with 1 g/L of crystal core addition. SEM analysis of struvite crystallization with crystal core showed higher crystal core growth than that of without crystal core. Struvite precipitate proved to be orthorhomic crystal structure by XRD analysis.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.370-377
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• 2018

Although the frequency of composite resin restoration in children is gradually increasing, there are insufficient researches about the rate of composite resin repair in children. The purpose of this study was to evaluate the repair rate of composite resin restorations in the permanent first molar in children under 12 years old. This study retrospectively analyzed 169 children treated with composite resin restoration in the permanent first molar from May 2014 to April 2015. According to the location of the tooth, the repair rate was higher in the mandible than maxilla and in the left than right. In the classification of restoration, the repair rate was the highest in the class II cavity, and the repair rate was the lowest in the restoration of the occlusal surface only. Repair rate in two years was 14.8%, and repair hazard ratio decreased with age. The most common reason of composite resin restoration replacement was the secondary caries (74.1%). Within the limits of study, the repair rate of children was higher than that of adult due to the characteristics of children. Therefore, dentists should understand these characteristics and try to reduce the repair rate of composite resin composite restorations.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.455-459
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• 2023

Three different optimization studies were conducted for the synthesis of MIL-100(Fe) and MIL-100(Fe)@COF using design of experiments. In the first study, the optimal concentration of precursors was determined using a mixture design method, and a modified molar ratio of 0.4155:0.2664:0.3182 was found to yield the highest crystallinity. In the second study, a central composite design was used to optimize the main factors of synthesis temperature and time with a synthesis temperature of 161℃ and a synthesis time of 12 hours. In the third study, a screening design method was used to determine the effect of five precursors on the formation of MIL-100(Fe)@COF, and the presence of characteristic peaks at 1552, 1483, and 1354 cm^-1 was found to be important for the existence of the COF structure. MIL-100(Fe)@COF synthesized with a modified molar ratio of 0.4831:0.4169:0.1 was predicted to exhibit optimal conditions.