scholarly journals Role of sintered temperature and sintering time on spectral translucence of nano-crystal monolithic zirconia

2019 ◽  
pp. e146-e153 ◽  
Author(s):  
S Attachoo ◽  
N Juntavee
Keyword(s):  
Sintering Time ◽  
Monolithic Zirconia ◽  
Nano Crystal ◽  
Sintered Temperature

scholarly journals Effect of Silicon Crystal Size on Photoluminescence Appearance in Porous Silicon

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Pushpendra Kumar
Keyword(s):  
Porous Silicon ◽  
Crystal Size ◽  
Energy Gap ◽  
Electrochemical Etching ◽  
Silicon Crystal ◽  
Nanocrystalline Silicon ◽  
Different Temperatures ◽  
Nano Crystal ◽  
Optical Silicon

The photoluminescence (PL) study in porous silicon (PS) with decreasing Si crystallites size among the pores was reported. The PL appearance is attributed to electronic confinement in columnar-like (or dotlike) structures of porous silicon. Three different pore diameter PS samples were prepared by electrochemical etching in HF-based solutions. Changes in porous silicon and Si crystallite size were studied by observing an asymmetric broadening and shift of the optical silicon phonons in Raman scattering. Fourier transform infrared spectroscopy (FTIR) was used to study the role of siloxene or other molecular species, for example, in the luminescence mechanism. This mechanism was further studied by thermal annealing of PS at different temperatures. The PL of PS sample annealed at ≥300°C for 1 hr shows that trap electronic states appear in the energy gap of the smaller nano-crystal when Si–O–Si bonds are formed. From the observation of PL, Raman, and FTIR spectroscopy, the origin of PL in terms of intrinsic and extrinsic properties of nanocrystalline silicon was discussed.

scholarly journals Effect of Sintering Time on The Marginal and Internal Fit of Monolithic Zirconia Crowns Containing 3-4 Mol% Y2O3

2021 ◽  
Author(s):  
Yunus Emre Ozden ◽  
M.Baris Guncu ◽  
Guliz Aktas ◽  
Senay Canay
Keyword(s):  
Tetragonal Zirconia ◽  
Cubic Phase ◽  
Marginal Gap ◽  
Sintering Time ◽  
Zirconia Crowns ◽  
Monolithic Zirconia ◽  
The Mean ◽  
Internal Fit ◽  
Tetragonal Zirconia Polycrystal ◽  
Gap Values

Abstract Background Short-time sintering may offer advantages including saving time and energy but there is limited evidence on the effect that altering sintering time has on the accuracy of monolithic zirconia crowns. The purpose of this in vitro study was to investigate the effect of shortened sintering time on the marginal and internal fit of 3Y-TZP (three mol% yttria-stabilized tetragonal zirconia polycrystal) and 4Y-TZP (four mol% yttria-stabilized tetragonal zirconia polycrystal) monolithic crowns. Methods Sixty monolithic zirconia crowns were fabricated for the maxillary first molar tooth on the prefabricated implant abutment. Groups were created according to the material composition: 3Y-TZP Generation 1 (alumina wt; ≤0.5%, < 15% cubic phase), 3Y-TZP Generation 2 (alumina wt; ≤0.05%, < 15% cubic phase) and 4Y-TZP (alumina wt; ≤0.05%, > 25% cubic phase). Two different sintering protocols were performed: same final sintering temperature (1500°C) and various rates of heating (10°C/min and 40°C/min), cooling down speed (-10°C/min and − 40°C/min), holding time (45 and 120 minutes), and total sintering time (approximately 2 and 7 hours, respectively). The marginal and internal fit of the crowns were determined using the silicone replica technique. Comparisons between groups and sintering times were analyzed using two-way ANOVA. Pairwise multiple comparisons were performed using the t-test (p < 0.05). Results The mean marginal gap values of 4Y-TZP zirconia revealed statistically significant increase for the speed sintering protocol (p < 0.0001), while no difference was observed between the sintering protocols for the mean marginal gap values of 3Y-TZP groups. Conclusions Although all groups showed clinically acceptable gap values (<120 µm), altering the sintering time had an effect on the marginal fit of the crowns manufactured from 4Y-TZP zirconia. Shortening the sintering time may lead to differences within clinically acceptable limits. The manufacturer's recommendations according to material composition should be implemented with care.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

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