• Title/Summary/Keyword: VITA

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A COMPARATIVE STUDY ON THE FLEXURE STRENGTH OF THE CERAMICS FOR ALL-CERAMIC CROWNS (All-ceramic Crown 용 도재의 굽힘강도에 관한 비교연구)

  • Yu Hyoung-Woo;Song Chang-Yong;Bae Tae-Seong;Song Kwang-Yeob;Park Chan-Woon
    • The Journal of Korean Academy of Prosthodontics
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    • v.32 no.2
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    • pp.195-211
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    • 1994
  • The purpose of this study was to evaluate the fracture resistance of the four kinds of dental porcelains for the all-ceramic crown(Vita In-Ceram, Vita Hi-Ceram, IPS-Empress, Vitadur-N) and one kind for the metal-ceramic non(Vita VMK 68) was used as the control group. In order to determine the fracture resistance, the hi-axial flexure strength was measured at a crosshead speed of 0.5mm/min, and the Vickers hadrness was measured at an indentation load of 1kg for 20 seconds. The results obtained were summarized as follows ; 1. The maximum Weibull modulus of 24.61 for Vitadur-N and the minimum one of 852 for IPS-Empress were observed ; the maximum characteristic strength of 353.26MPa for Vita In-Ceram and the minimum that of 63.20MPa for Vitadur-N were also observed. 2. The maximum mean bi-axial flexure strength of 339.12MPa for Vita In-Ceram and thd minimum one of 61.99MPa for Vitadur-N were calculated. Results of the Scheffe test indicated that the statistically significant difference(P<0.05) existed between Vita In-Ceram or Vita Hi-Ceram and the others ; also between IPS-Empress and Vitadur-N. 3. The maximum mean hardness of $980.55kg/mm^2$ for Vita VMK 68 appeared. Results of the Scheffe test indicated that statistically significant difference(P<0.05) existed between Vita In-Ceram or Vita Hi-Ceram and the others ; also between IPS-Empress and Vita VMK 68.

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Effect of Dietary Supplementation of Silicate Mineral $(Vita2000^{(R)})$ on Growth Performance and Intestinal Microflora in Broiler Chicks (사료 내 규산염 광물질$(Vita2000^{(R)})$ 첨가 급여가 육계 생산성과 장내 균총에 미치는 영향)

  • Ahn S.M.;Shin S.C.;Park S.S.;You S.J.;Kim Y.R.;Kim E.J.;Ahn B.K.;Kang C.W.
    • Korean Journal of Poultry Science
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    • v.33 no.1
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    • pp.25-32
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    • 2006
  • This experiment was conducted to investigate the effects of dietary Vita2000 on growth performances and immune response in broiler chickens. One-day-old male chicks were fed diets containing 0, 0.5 and 1% Vita2000 (with or without antibiotics) for 5 wks. There were no significant differences in daily weight gain among the treatments, but feed intake in 1% Vita2000 groups (T3 and T4) were significantly lower than control (P<0.05). The relative abdominal fat weight and the level of crude fat in leg meat on groups fed diets containing 1% Vita2000 (T3 and T4) were significantly decreased as compared to those of control (P<0.05). The content of cholesterol in leg meat was not affect by dietary treatment. The intestinal total microbes, Coli form, Lactic acid bacteria and Salmonella spp. from bird fed 1% Vita2000 diets was significantly reduced compared to those of control. The production of IB antibody in chicks fed diet containing 0.5% Vita2000 was significantly higher than that of control groups. The overall results indicate that dietary Vita2000 may be a valuable alternative to antibiotics for optimizing growth performances, particularly for reducing the abdominal fat of broiler chicks.

The effects on the color change of dental porcelain due to repeated firing (도재 소성 횟수가 색조변화에 미치는 영향)

  • Kim, Wook-Tae;Park, Chang-Keun
    • Journal of Technologic Dentistry
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    • v.30 no.1
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    • pp.33-39
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    • 2008
  • Recently natural characteristics and esthetics have been interested increasing in clinical dentistry. Thus the evaluation of the shade of dental porcelain has become an important part in dental research. Noritake Super Porcelain EX-3 Vita shade A2 (Noritake, Japan) Vintage HaLo Vita shade A2 (Shofu, Japan), Vita omega 900 Vitapan 3D-master shade 2M2 (Vita, Germany) were conducted for six times for repeated firing in a way to observe the change of color with respect to the number of firing. The repeated firing was implemented with the vacuum firing and air firing, and by using Shade Eye-EX Chroma meter (Shofu, U.S.A.), the changes in values of shade, value and chroma were compared. With the above results, the change of color was not noticed only in Vita when repeated firing was applied.

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AN EVALUATION OF FRACTURE TOUGHNESS OF DENTAL CERAMICS BY INDENTATION FRACTURE METHOD (압자압입법에 의한 치과용 도재의 파괴인성 평가)

  • Ahn, Seung-Geun;Lee, Ju-Hyung;Bae, Tae-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.2
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    • pp.309-319
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    • 1996
  • This study was performed to evaluate the fracture toughness of seven commercially available dental ceramics by indentation fracture method. All specimens were fabricated to the final dimensions of approximately 12mm in diameter 2mm in thickness. The characte-ristic indentation dimensions of Vickers or Knoop indentation were measured to calculate the fracture toughness values and Young’s moduli. The results obtained were summarized as follows; 1. Young’s modulus and Vickers hardness of Vita In-Ceram showed the maximum values of $154.4{\pm}49.2$ Gpa and $12.60{\pm}0.71$Gpa, respectively. Results of Scheff test exhibited the significant difference between Vita In-Ceram group and others(p<0.01). 2. Maximum fracture toughness of $2.562{\pm}0.37 MPam^{1/2}$ for Vita In-Ceram and the maxi-mum one of $0.908{\pm}0.132MPam^{1/2}$ for Vitadur-N were calculated. Results of Scheff test showed the significant difference between Vita In-Ceram group and Vita Hi-Ceram(p<0.05) : also between Vita In-Ceram or Vita Hi-Ceram and others(p<0.01). 3. The alumina-based core ceramics showed the aspect of Palmqvist crack for the indentation load of 49.0N, but others showed the median/lateral crack for the indentation load of 9.8N.

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A Case Study on Introducing Vita Parcours as Forest Leisure Sports Facility in Saneum Healing Forest (산음 치유의 숲 Vita Parcours 도입 사례 연구 - Vita Parcours 도입을 사례로 -)

  • Lee, Jin-Kyu;Kim, Ki Weon
    • The Journal of the Korean Institute of Forest Recreation
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    • v.22 no.4
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    • pp.71-81
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    • 2018
  • It is necessary to build a quality-enhancing forest leisure sports facility according to values that value life quality, national forest policy. Vita Parcours (fitness trails) is found to be the activities highly convenient, so their introduction and promotion in Korea should be highly considered. field survey was necessary to explore the possibility of installing Vita Parcours. Several sites were selected, such as Asean recreational forest, Unaksan recreational forest, Yumyeongsan recreational forest, Saneum recreational forest, Jungmisan recreational forest and National center for forest therapy. At these locations, we explored the current status of forest facilities and forest trails. A total number of 31 exercise facilities has been identified and surveyed, some of which are located on the trails (2), alongside the trail (9), alongside trail boundaries (2) or represent facilities suitable for both outdoor and indoor exercise within the forest (18), all of whom provide location for 44 different exercise routines (flexibility exercises (23), endurance (12) and strength exercises (9)). Field work also included identification of forests paths, the total number of whom was 34 paths - 30 identified as trails, 2 as hiking trails, 1 as a forest path for relaxation and healing and 1 as an exploratory path. Regarding the structure and shape of these trails, 32 was straight in shape and only 2 designed as a circular forest trails. Average length of these trails was 652.2m with the highest and the lowest point altitude difference of 60m, on average. Saneum recreational forest provide the most suitable site/environment for Vita Parcours and as a result of this, Saneum recreational forest is proposed as a location to support the endeavors in promotion of these valuable forest fitness trails. Among the forest paths at this site, a forest path which has a length of 1.84km and 73.0m the highest and the lowest point altitude difference was selected as the most suitable, and may be equipped with necessary stations for exercise or obstacles. In addition, if these trails are to be introduced and welcomed by its users, we must assure that they are properly maintained.

Comparative Study of Color Correspondence According to Size of Vita CAD/CAM Ceramic Block Using ShadeEye-Ncc$^{(R)}$ System (ShadeEye$^{(R)}$ NCC system을 이용한 Vita CAD/CAM Ceramic Block의 크기에 따른 색조 일치성 비교연구)

  • Kim, Jae-Hong;Kim, Hae-Young;Kim, Woong-Chul;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.33 no.3
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    • pp.203-210
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    • 2011
  • Purpose: The purpose of this study was to compare color correspondence of different sizes of Vita Mark II$^{(R)}$ and TriLuxe$^{(R)}$ Feldspar blocks. Methods: The three commercially available shades(1M2, 2M2, 3M2) of Mark II & TriLuxe blocks for the CEREC$^{(R)}$ CAD/CAM system were examined. For each of three colors, three different sizes were tested, 5 blocks each. The measurements were made using a spectrophotometer equipped with an integrating sphere using the CIE $L^*$, $a^*$, $b^*$ colorimetric system. Results: The $L^*$, $a^*$, $b^*$ value of Vita Mark II$^{(R)}$ ceramic block showed significantly higher than TriLuxe$^{(R)}$ ceramic block(p<0.05). In comparing the Vita Mark II$^{(R)}$ specimen of the three different shade, color differences between materials(${\Delta}E^*$) showed the lowest value of 2.09, and the highest was 2.24. ${\Delta}E^*$ values of the materials of Vita Mark II$^{(R)}$ were higher than 2. As the size of ceramic block differed, the color correspondence of Vita Mark II$^{(R)}$ showed statistically significant difference but, this result is clinically acceptable. Conclusion: All the different sizes of the different shades of Vita TriLuxe$^{(R)}$ blocks for the CEREC$^{(R)}$ system showed the high degree of color correspondence necessary in industrially prefabricated CAD/CAM blocks. The results of the present study suggested that it would be necessary to establish the reproducible and constant color specification system for an esthetic restoration.

Clinical Experiment Results of Cerec Inlab using Vita9 (VITA VM9 Zirconia powder를 이용한 Cerec inlab의 임상증례에 관하여)

  • Jung, Hyo-Kyung;kim, Jeong-Sook;Lee, Jong-Do
    • Journal of Technologic Dentistry
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    • v.29 no.2
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    • pp.119-128
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    • 2007
  • Although there are many different ways that restorations can be made, it can be said that the biocompatibility of abutment and crown is very important in this experiment. When placed in the actual oral cavity, the differences were obvious. Compared to In-ceram Aluminium, the structure that is obtained after firing reveals a particularly homogeneous distribution of the crystal and glass phase. The In-ceram aluminium system had many problems, such as having weak tensile strength, and having low bonding strength due to the shrinking that occurs after firing. Because of the opaque finish of the metal frame, the two may look similar from the outside, but it is evident that there are differences between using a metal frame and In-ceram. VITA VM9 has been designed as a special ceramic featuring a fine structure or stabilized Zro2 substructures, and so the VITA VM9 excels in its light refraction and reflection behavior, which is similar to natural teeth. It also has outstanding chemical balance, which presents advantages such as considerably reduced accumulation of plaque on the ceramic surface.? This ultimately results in easier care and cleaning for the patient.

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Purification and enzymatic properties of a peroxidase from leaves of Phytolacca dioica L. (Ombú tree)

  • Guida, Vincenzo;Criscuolo, Giovanna;Tamburino, Rachele;Malorni, Livia;Parente, Augusto;Maro, Antimo Di
    • BMB Reports
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    • v.44 no.1
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    • pp.64-69
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    • 2011
  • A peroxidase (PD-cP; 0.47 mg/100 g leaves) was purified from autumn leaves of Phytolacca dioica L. and characterized. PD-cP was obtained by acid precipitation followed by gel-filtration and cation exchange chromatography. Amino acid composition and N-terminal sequence of PD-cP up to residue 15 were similar to that of Spinacia oleracea (N-terminal pairwise comparison showing four amino acid differences). PD-cP showed a molecular mass of approx. 36 kDa by SDS-PAGE, pH and temperature optima at 3.0 and $50.0^{\circ}C$, respectively and seasonal variation. The Michaelis-Menten constant ($K_M$) for $H_2O_2$ was 5.27 mM, and the velocity maximum ($V_{max}$) $1.31\;nmol\;min^{-1}$, while the enzyme turnover was $0.148\;s^{-1}$. Finally, the presence of $Ca^{2+}$ and $Mg^{2+}$ enhanced the PD-cP activity, with $Mg^{2+}$ 1.4-fold more effective than $Ca^{2+}$.

Correlation of the Wall Skin-Friction and Streamwise Velocity Fluctuations in a Turbulent Boundary Layer(II) (난류경계층에서 벽마찰력과 유동방향 속도성분과의 상관관계(II))

  • Yang, Jun-Mo;Yu, Jeong-Yeol;Choe, Hae-Cheon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.3
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    • pp.427-435
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    • 1997
  • Conditional sampling techniques are utilized to investigate the relation between the wall skin-friction and stream wise velocity fluctuations in a turbulent boundary layer. Conditionally averaged results using a peak detection and the VITA (variable-interval time-averaging) technique show that a high skin friction is associated with high frequency components of the wall skin-friction fluctuations. The conditionally averaged wall skin-friction fluctuations obtained by using the VITA technique have a positively-skewed characteristics compared with the conditionally averaged stream wise velocity fluctuations. It is confirmed that there exists a phase shift between the wall skin-friction and stream wise velocity fluctuations, which was also found from the long-time averaged space-time correlations. The amount of phase shift between the wall skin-friction and stream wise velocity fluctuations is the same as that from the long-time averaged space-time correlations and does not change despite the variation of the detection threshold.