• Title/Summary/Keyword: Z-shape

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Anatomy and morphology of the nasopalatine canal using cone-beam computed tomography

  • Thakur, Arpita Rai;Burde, Krishna;Guttal, Kruthika;Naikmasur, Venkatesh G.
    • Imaging Science in Dentistry
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    • v.43 no.4
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    • pp.273-281
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    • 2013
  • Purpose: This study was performed to evaluate the general anatomy and morphology of the nasopalatine canal using cone-beam computed tomography (CBCT) and to determine the human anatomic variability of the nasopalatine canal in relation to age and gender. Materials and Methods: The study included 100 subjects aged between 20 and 86 years who were divided into the following 3 groups: 1) 20-34 years old; 2) 35-49 years old; 3) ${\geq}50$ years old. The subjects were equally distributed between the genders. CBCT was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the nasopalatine canal by two independent observers. The correlation of age and gender with all the variables was evaluated. Results: The present study did not reveal statistically significant differences in the number of openings at the nasal fossa; diameter of the nasal fossa openings; diameter of the incisive fossa; shape, curvature, and angulation of the canal as viewed in the sagittal sections; antero-posterior dimensions and length of the canal in the sagittal sections; or the level of division of the canal in the coronal plane by age. However, males and females showed significant differences in the length of the canal in the sagittal sections and level of the division of the canal in the coronal plane. Conclusion: The present study highlighted important variability observed in the anatomy and morphology of the nasopalatine canal.

Effec of different zirconia primers on shear bond strengths of composite resin to bonded zirconia (지르코니아 프라이머 종류에 따른 복합레진-지르코니아의 전단결합강도)

  • Shi, Hong-Bing;Kim, Tae-Seok;Ahn, Jae-Seok;Lee, Jung-Hwan
    • Journal of Technologic Dentistry
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    • v.38 no.3
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    • pp.135-142
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    • 2016
  • Purpose: The aim of this research was to evaluate the influence of different surface treatments on the shear bond strength of zirconia ceramic to composite resin. Methods: Seventy two cylinder-shape (diameter: 5 mm; height: 12 mm) blocks of experimental industrially manufactured Y-TZP ceramic were abraded with $125{\mu}m\;Al_2O_3$ particles and randomly divided into 4 groups. All the materials were categorized as group Gc(control group - composite resin veneering on zirconia surface), Gr - composite resin veneering after surface treatment of Rocatec system (3M ESPE, Seefeld, Germany) group; Gz - composite resin veneering after surface treatment of Zirconia primer (Z-primer, Bisco, U.S.A) group; Gm - composite resin veneering after surface treatment of zirconia primer (Monobond plus, ivoclar vivadent AG, Liechtenstein) group. Two different zirconia primers and Rocatec system were used to zirconia cylinders (n=16) onto the zirconia surface. Zirconia specimens, polished and roughened, were pretreated and composite bilayer cylinders bonded using conventional adhesive techniques. Results: Shear bond strengths were analyzed using single-factor ANOVA(p<0.05). Bond strength values achieved after airbone particle abrasion and zirconia surface pre-treatments(p<0.05). Conclusion: Shear bond strength tests denmonstrated that zirconia primer is a viable method to improved bond strength between zirconia ceramic core and veneering composites.

Fatigue crack effect on magnetic flux leakage for A283 grade C steel

  • Ahmad, M.I.M.;Arifin, A.;Abdullah, S.;Jusoh, W.Z.W.;Singh, S.S.K.
    • Steel and Composite Structures
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    • v.19 no.6
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    • pp.1549-1560
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    • 2015
  • This paper presents the characterization of fatigue crack in the A283 Grade C steel using the MMM method by identifying the effects of magnetic flux leakage towards the crack growth rate, da/dN, and crack length. The previous and current research on the relation between MMM parameters and fatigue crack effect is still unclear and requires specific analysis to validate that. This method is considered to be a passive magnetic method among other Non-Destructive Testing (NDT) methods. The tension-tension fatigue test was conducted with a testing frequency of 10 Hz with 4 kN loaded, meanwhile the MMM response signals were captured using a MMM instrument. A correlation between the crack growth rate and magnetic flux leakage produces a sigmoid shape curve with a constant values which present the gradient, m value is in the ranges of 1.4357 to 4.0506, and the y-intercept, log C in the ranges of $4{\times}10^{-7}$ to 0.0303. Moreover, a linear relation was obtained between the crack length and magnetic flux leakage which present the R-Squared values is at 0.830 to 0.978. Therefore, MMM method has their own capability to investigate and characterize the fatigue crack effects as a main source of fracture mechanism for ferrous-based materials.

A STUDY ON THE SOLUBILITY OF DENTAL RESTORATIVE MATERIALS (치과용 수복재의 용해성에 관한 분석연구)

  • Na, Keung-Kyun;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.16 no.1
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    • pp.87-105
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    • 1991
  • The purpose of this experiment was to measure the leaking and solubility of commonly used dental restorative materials - Silux plus (CS), Hi-pol (CH), Clearfil F-II, Fissureseal (FS), Glass-Ionomer cement Fuji Type II (GI), Amalgam Cavex 68 (AM), Zinc Phosphate Cement (ZP) and gutta-percha (GP) and investigate the relation between the solubility and marginal leakage. Disc-shape specimens were fabricated with each material and dipped into deionized water, 0.01M lactic acid and 0.005M KOH solution, thus the total ionic concentrations in each solution was measured with ion chromatograph after 1, 3, and 7 days, respectively. For the solubility test, each specimen was immersed in 0.001M and 0.01M lactic acid for 24 hours, respectively and total weight loss was calculated. Also, Zn leaking through the margin of restorations was measured. The obtained results were as follows: 1. The amounts of eluted ion from the eight materials were most in 0.01M lactic acid and least in deionized water. 2. Of the eight materials, the fluoride release was greatest for glass ionomer cement (GI) in 0.01 M lactic acid after 7 days. 3. In analysis of the divalent cation, Mg was eluted most for zinc phosphate cement (ZP) and Ca for Clearfil F-II (CF) in 0.01M lactic acid after 7 days. 4. In analysis of transition metals, Cu and Zn were detected only. 5. The solubility rate of eight materials was greater in 0.01M lactic acid than in 0.001M for 24 hours, for zinc phosphate cement (ZP) the rate was greatest (5.4%) in 0.001M lactic acid, and amalgam least (0.01%). 6. The Zn concentration of restorative material with Z.P.C base was greater in 0.01M lactic acid than in 0.001M lactic acid.

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Comparison of soil nutrients, pH and electrical conductivity among fish ponds of different ages in Noakhali, Bangladesh

  • Tapader, Md. Morshed Alam;Hasan, Mehedi Mahmudul;Sarker, Bhakta Supratim;Rana, Md. Enayet Ullah;Bhowmik, Shuva
    • Korean Journal of Agricultural Science
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    • v.44 no.1
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    • pp.16-22
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    • 2017
  • An experiment was conducted to detect aquaculture pond bottom soil nutrients, pH and electrical conductivity with a view to optimize production and to incorporate the scientific method of fish nursing, rearing and culturing at Noakhali district in Bangladesh. The soil samples were collected from the recently dug ponds (1 - 5 years) and older ponds (> 5 years). Samples were taken from five different spots in a Z shape from each pond and were mixed to get a composite sample. The composite samples from the ponds were collected in polyethylene bags and shipped to the laboratory for analysis. The soil samples were analyzed with respect to pH, electrical conductivity (EC), organic carbon (OC), organic matter (OM), nitrogen (N), phosphorous (P), potassium (K) and sulfur (S). The average value of pH, OC, OM, N, P, K and S were $7.43{\pm}0.40$, $2.21{\pm}1.43%$, $1.47{\pm}0.53%$, $2.52{\pm}0.94{\mu}g\;g^{-1}$, $0.126{\pm}0.047{\mu}g\;g^{-1}$, $3.84{\pm}1.77{\mu}g\;g^{-1}$, $0.191{\pm}0.106{\mu}g\;g^{-1}$ and $306.72{\pm}222.05{\mu}g\;g^{-1}$ respectively, in Noakhali. The average EC, OC, OM, N and P contents were found to be higher in Subornachar than those in Sonapur. On the other hand pH, K and S were found to be higher in Sonapur than the values of Subornachar. The pH, EC, OC, OM, N and S contents were found to be higher in new ponds than old ponds whereas P and K contents were found to be higher in old pond than in new pond.

Hydrothermal Synthesis of PZT Powders. (수열법에 의한 PZT분말 합성 연구)

  • 최승도;박병규
    • Korean Journal of Crystallography
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    • v.8 no.2
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    • pp.97-104
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    • 1997
  • Hydrothermal synthesis of PbZ1-xTixO3 has been investigated. Syntheses were performed using lead acetate triphdrate as Pb source, Ti/Zr gel by hydrolizing Ti-isopropoxide as Tiand Zr source and Zr-propoxide and KOH (0.5m, 1m, 2m) as mineralizer. The hydrothermal synthesis has been examined at 140℃, 150℃ and 160℃. Synthesized PZT powders showed a rectangular shape and were agglomerate. At 1m and 2m KOH concentrations PZT powders were synthesized the respective time of 8 hrs and 1hr but at 0.5m KOH concentration phase pure PZT powders were not synthesized for 5days reaction. At the conditions of low temperature and low KOH concentration unreacted Ti/Zr gel remained although synthesized powders were almost PZT. The size of PZT powders increased with KOH concentrations. PbO solid solutions were formed as intermediate phases and these were classified to PbO-10%TiO2 solid solution and PbO-3% TiO-3% TiO2 solid solution.

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Removal of Unburned Carbon from Fly Ash using Countercurrent Column Flotation Cell (역류형 컬럼 부선기를 이용한 석탄회정제에 관한 연구)

  • 이전언;이제군
    • Resources Recycling
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    • v.8 no.5
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    • pp.51-58
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    • 1999
  • The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

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A Study on Distribution Behavior of Ni and Sb in Reduction products of Cu Matte Converting (동 매트제련의 반응생성물중 Ni와 Sb의 분배거동에 관한 연구)

  • 김영진;이광막;김영홍
    • Resources Recycling
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    • v.8 no.5
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    • pp.44-50
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    • 1999
  • The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

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Psychological, Physical and Genetic Traits of Sasang Typology (사상인(四象人)의 생리적 특성 연구)

  • Chae, Han;Hong, Moo-Chang;Bae, Hyun-Su;Shin, Min-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.2
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    • pp.304-314
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    • 2005
  • The major concept of Sasang typology is that the disease susceptibility and drug response as well as physiological characteristics are presumed to be different depending on their Sasang types. Although characterizing fundamental basis of their traits are crucial in this research field, only pathological susceptibility and physical appearances were thoroughly studied. We evaluated their physiological characteristics by tapping psychological, physical and genetic traits of each Sasang types. After determining the Sasang type of one hundred three college students based on the Questionnaire for the Sasang Constitution Classification, the psychological, physical and genetic traits of each type were analyzed with the Myers-Briggs Type Indicator (MBTI), Bioelectrical Impedance Analysis and genetic polymorphism test, respectively. Each of the Sasang types showed significantly different profiles (Generalized estimation equation, coef=11.88, z=2.13, p=0.033), and could be distinctively classified based on their MBTI scores (discriminant analysis Wilks Lambda=0.611, df=8, chi-square=36.7, p<0.001). Subjects with the So-Eum type (Introversion and Judging) and the So-Yang type (Extroversion and Perceiving) showed contrasting psychological features, however they had similar anthropometric characteristics. Subjects with the Tae-Eum type showed bigger Body Mass Index ($R^2$=0.22, df=4, 74, F=5.07, p=0.001) and body shape compared to others. Although there were no significant differences in G-protein beta-3 subunit polymorphism, angiotensin-converting enzyme polymorphism and Methylenetetrahydrofolate reductase polymprhisms among groups with Sasang types, it was shown that the dopamine system could be one for genetic marker for Sasang typology. These results demonstrated distinctive and essential traits of Sasang typology using reproducible psychometric, anthropometric and genetic evaluations. We also found that the Sasang typology was a bio-psychological typology which could show trait-specific guideline for individualized medicine.

Three-dimensional analysis of facial asymmetry after zygomaticomaxillary complex fracture reduction: a retrospective analysis of 101 East Asian patients

  • Cho, Jakwang;Kim, Youngjun;Choi, Youngwoong
    • Archives of Craniofacial Surgery
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    • v.22 no.3
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    • pp.148-153
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    • 2021
  • Background: The zygomaticomaxillary complex (ZMC) has a protruded, convex shape and plays a vital role in determining the contour by affecting the width of the middle face. This study aimed to evaluate the efficiency of ZMC fracture reduction and explore detailed directions for outcome improvement. Methods: We conducted a retrospective study of patients diagnosed with unilateral ZMC fracture who underwent ZMC reduction surgery at a single hospital between January 2015 and May 2020. The primary outcome variable was facial asymmetry using the difference in the bilateral malar eminence (ME) position measured by computed tomography scan. The 3-dimensional distance (IA, asymmetry index) and the distance in each dimension, Dx (anteroposterior distance), Dy (mediolateral distance), and Dz (superoinferior distance) were compared. Results: A total of 101 patients with ZMC fractures and 54 non-fracture patients were enrolled in the study. The mean age of the study sample was 43.49 years (control sample, 43.35 years), and the male-to-female ratio was 66.3:33.7 (control sample, 64.8:35.2). There were 53 and 48 patients with right and left ZMC fractures, respectively. The IA was not statistically different between the two groups. In terms of position in each dimension, only Dx was significantly different between the two groups. Conclusion: The results show that overall facial asymmetry was recovered after ZMC reduction, but in certain dimension significant difference in ME position has still remained. For further improvement, treatment should be performed to relieve malar depression in the anteroposterior dimension.