• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.2
• /
• pp.135-143
• /
• 2017

Purpose: This research was conducted to compare the marginal and internal fit of zirconia prostheses fabricated with the model scan method and the intraoral scan method. Materials and methods: In this study, 20 extracted human mandibular first molar was used in the preparation of abutment tooth for the fabrication of zirconia prostheses. In the first group, the model scan method was applied on 10 prepared teeth. In the other group, the intraoral scan method was used on other 10 prepared teeth. Datum of both groups were transmitted to the software system. Afterwards, 20 zirconia prostheses were fabricated using the Ceramill system. Weight technique was used to evaluate the internal gap of the zirconia prostheses. In the Replica technique, marginal gap of the zirconia prostheses were analyzed by optical microscopy. Statistical analysis was based on one-way ANOVA. Results: Model scan group showed lower average weight than intraoral scan group when weight technique was applied, which has significance (P < .05). Also, model scan group showed significantly lower figures in all 5 measurements of replica technique than intraoral scan group (P < .05). Conclusion: Zirconia prostheses of both groups demonstrated clinically acceptable margin and internal fit. However, model scanned zirconia prostheses showed higher marginal and internal fit than intraoral scanned crowns.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.11
• /
• pp.1207-1212
• /
• 2006

In this study, Chemical Oxygen Demand(COD) which is the measure of organic substances, Total nitrogen(T-N), Total phosphorous(T-P), Fe and Mn were analyzed in the sediments of dam reservoir. The purpose of this study were to understand the relevances among the analytical methods adopted and the applicabilities of those methods. For the determination of COD, Standard Method for the Examination of Marine Environment(SMEME) and Standard Method for the Examination of Sanitary(SMES) was used. Both method had wide dynamic range and the deviations of the values obtained by two methods were small because $KMnO_4$ method closely reflected BOD and organic substances. For the determination of T-N and T-P, Standard Method for the Examination of Food(SMEF) and Standard Method for the Examination of Sanitary(SMES) were used. Two methods for T-N were both the acid-base titration but SMES gave less T-N values than SMEF because of the differences in digestion and distillation steps. Two methods for T-P gave the comparable values after acid digestion of $HNO_3$ and $HClO_4$. The determination of heavy metals as a Fe, Mn was mainly divided to the leaching method and acid digestion method. The values obtained by leaching method were less than those by digestion method. It is thought that the condition of acid digestion was more severe than that of leaching method.

• Resources Recycling
• /
• v.2 no.2
• /
• pp.1-8
• /
• 1993

This study was carried out in order to define the effective collectors and the opitimum conditions for the removal of iron ion in waste water by flotation method. The results obtained in this study are summarized as follows. Fe(II) and Fe(III) were removed effectively at pH7 and 6 respectively by using sodium lauryl sulfate, an anionic collector. The anionic collector, aeropromotor 845, removed both Fe(II) and Fe(III) effectively in pH ranges of from 5 to 9. The cationic collector, trimetyl dodecyl ammonium chloride, removed both Fe(II) and Fe(III) effectively in pH ranges from 10 to 11 and from 4 to 10, respectively. Therefore, Fe(II) and Fe(III) could be effectively removed by forming the iron hydroxide precipitates by simple pH adjustment of the solutions above precipitation point of ferrous and ferric ion by flotation method. Then, the effective pH regulator and collector were NaOH and $Na_2CO_3$,aeropromotor 845 and trimetyl dodecyl ammonium chloride, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.6
• /
• pp.405-415
• /
• 2000

To determine application rate of elemental sulfur to adjust pH of alkaline soil, buffer curve method was investigated. The elemental sulfur required to control pH 8.3 to pH 6.3 by buffer curve calculation was treated in two soils of silty loam and sandy loam, and the sulfur-mixed soils were moistened with 50% of water holding capacity during incubation of 6 weeks at $30^{\circ}C$. Soil pH was lowered with incubation and reached to target point after 4 weeks of incubation, and elemental sulfur was oxidised entirely to sulfate. This means that buffer curve has the accuracy to determine sulfur application rate in alkaline soil. However it is estimated that application rate of sulfur should be carefully determined in the field scale. Excess application of elemental sulfur resulted in extremely low soil pH and caused the hinderance of lettuce growth by nutritional imbalance and ion toxicity. To simplify the determination procedure of sulfur requirement, buffer curve method by addition of 0.1N-HCl solution as unit of mL was developed, it was compared with theroutine methods which diluted $H_2SO_4$ solution and $Ca(OH)_2$ are added as cmolc per kg soil to adjust each pH step. Buffer capacities, cmolc kg $soil^{-1}$ $pH^{-1}$, calculated from two buffer curves were not significantly different. The result indicates that buffer curve method by 0.1N-HCl can be used to adjust high pH of alkaline soil.

• Journal of the Korea Convergence Society
• /
• v.10 no.3
• /
• pp.373-382
• /
• 2019

This study was performed to investigate the effects of creative teaching technique(CTT) on critical thinking disposition(CTD), problem solving process(PSP), and self-leadership(SL) in 5 majors of first to third grades in a college nursing department. CTT was developed to promote memory and practical ability. The study was conducted from August 1 to December 31 in 2017, and the survey was performed before and after applying the CTT. As a result, there was no difference in CTD, PSP, and SL in the first graders whom applied various teaching techniques to one subject. But CTD was 6.8point(p<0.001), PSP was 7.5~7.9point(p<0.001) and SL was 2.9~3.3point(p<0.001) improved in the second and third grades whom applied similar teaching techniques in two subjects. In order to improve the students' core competency, it is more effective for students to apply one or two methods repeatedly in several subjects than to apply various methods to one subject. Since the CTT was more effective in the group that selected the major depending on aptitude and interest, it is necessary to develop various teaching and learning strategies to enhance the interest in nursing major.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.1 no.1
• /
• pp.107-114
• /
• 1998

Purpose: The purpose of our study is to provide useful information for me-asurement methods of childhood obesity and to provide clinical significance of bioelectrical impedance analysis. Methods: We measured height, weight, waist to hip ratio, skinfold thickness and bioelectrical impedance from 206 elementary students in Kwangju from May to July 1997. Results: In males; 1) There were statistically high correlations between tri-ceps skinfold thickness and body mass index (BMI), percentage of body fat (%BF), weight, Rohler index (RI), total fat weight (TFW), waist to hip (W/H) ratio, height, lean body mass (LBM) (all, p<0.001). 2) There were statistically high correlations between subscapular skinfold thickness and BMI, RI, weig-ht, %BF, TBW (all, p<0.001). 3) There were statistically high correlations between %BF and BMI, triceps skinfold thickness, RI, TFW, subscapular skinfold thickness, weight (all, p<0.001). In females; 4) There were statistically high correlations between triceps skinfold thickness and BMI, weight, LBM, height, %BF (all, p<0.001). 5) There were statistically significant correlations between subscapular skinfold thickness and BMI, weight, LBM, RI, height. 6) There were statistically high correlations between percentage of body fat and BMI, RI, triceps skinfold thickness. The percentage of body fat according to the bioelectrical impedance analysis highly correlated with that calculated by skinfold thickness in males (r＝0.57, p<0.01) and in females (r＝0.30, p<0.01). Conclusion: The results of our study suggests that bioelectrical impedance analysis is a useful method of estimating body fat in the childhood obesity.

• Journal of Chest Surgery
• /
• v.32 no.6
• /
• pp.518-524
• /
• 1999

Background: This study has proven the effect of modified ultrafiltration(MUF) performed after the cessation of cardiopulmonary bypass in pediatric patients who underwent open heart surgery. Material and Method: From Jan. to Dec. 1997, modified ultrafiltration was performed after cardiopulmonary bypass in 50 infants with cyanotic heart disease and the results were compared to the control group of 50 patients with cyanotic heart disease in whom modified ultrafiltration was not used. Changes of hematocrit, central venous pressure, systolic and diastolic pressure, heart rate and body weight were compared. Result: Age and body weight were not different(p=0.38, p=0.46). Disease categories were similar. Average filtering volume was 60.0$\pm$29.2cc/kg for 7.0$\pm$2.4minutes of filtration. Mean hematocrit after filtration(MUF=36.1%, control=26.4%, p=0.001) was higher in the MUF group. Systolic (p=0.0001) and diastolic blood pressure(p=0.0001) were observed to increase more and the central venous pressure(p=0.02) and the heart rate(p=0.02) were lower after filtration in the MUF group. Conclusion: This study demonstrated that modified ultrafiltration after cardiopulmonary bypass was a technically feasible option to improve the post-surgical course through the effective hemoconcentration, hemodynamic improvements, and body water control.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.6
• /
• pp.277-280
• /
• 2004

p-ZnO films have been grown on (0001) sapphire substrates by RF-DC magnetron co-sputtering. The p-ZnO single crystalline thin films of the thickness about 120 nm were grown successfully. The dopant (Aluminum) was sputtered simultaneously from Al metal target by DC sputtering during rf-magnetron sputtering of ZnO at the substrate temperatures of $400^{\circ}C$ and $600^{\circ}C$ respectively. The crystallinity and optical properties of as-grown P-ZnO films have been characterized.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.143-144
• /
• 2010

As KCI under U.S.D is impossible to calculate all sections compared P-M Interaction Curve of the circular concrete column under EC2 of limit state design and KCI. Result of the construction, P-M Interaction Curve according to design for standard is about the same. If a covering depth rased, EC2 is better safety than KCI.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.05a
• /
• pp.155-158
• /
• 2005

닭가슴살을 이용해서 수리미 제조 시 4회 수세한 대조구, pH 3.0으로 산 처리한 T1, pH 11.0으로 알카리 처리한 T2로 하여 그 품질 특성을 비교한 결과 일반성분에서 수분, 조단백질과 염용성단백질 및 수율은 대조구에 비하여 pH 조절법으로 한 두 구가 높았으며, 조지방은 T2가 다른 두 구에 비하여 높았다. pH, 보수력, 파괴강도, 변형값은 처리 간에 유의적인 차이를 보이지 않았다. 전단가는 T2가 가장 높고, T1, 대조구 순이었다. $L{\ast}$값은 T2가 다른 두 구보다 낮았으며, $a{\ast}$값은 T1이 다른 두 구에 비하여 낮았다. $b{\ast}$값은 대조구가 가장 높고, T2가 가장 낮았다. 조직감에서 파쇄성 및 경도는 처리 간에 유의적인 차이를 보이지 않았으며, 응집성은 T1이 다른 두 구보다 낮았으며, 탄력성과 부착성은 대조구에 비하여 T1과 T2가 높았다. 검성은 대조구와 T1에 비하여 T2가 높았다. 조직감의 전 항목에서 T2 가 가장 높았다. 관능검사 결과 외관과 맛은 T1이 가장 높고, 대조구가 가장 낮았다. 색, 향, 다즙성, 연도 및 전체적인 기호도는 처리 간에 유의적인 차이가 없었다.