scholarly journals Influence of the manipulation technique of acrylic resin on mechanical strength of orthodontic plates

2015 ◽  
Vol 31 (6) ◽  
pp. 1881-1886 ◽  
Author(s):  
Matheus Melo Pithon ◽  
Rogério Lacerda-Santos ◽  
Nathalia Soares ◽  
Davi Novaes Ladeia Fogaça ◽  
William Soares da Silva ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Acrylic Resin

scholarly journals Influence different amount of cellulose on the mechanical strength of dental acrylic resin

2020 ◽  
Vol 743 ◽  
pp. 012044 ◽  
Author(s):  
Joanna Taczała ◽  
Chang Fu ◽  
Jacek Sawicki ◽  
Joanna Pietrasik
Keyword(s):  
Mechanical Strength ◽  
Acrylic Resin ◽  
Dental Acrylic

scholarly journals ADDITION OF RICE HUSK NANOCELLULOSE TO THE IMPACT STRENGTH OF RESIN BASE HEAT CURED

2021 ◽  
Vol 4 (3) ◽  
pp. 119
Author(s):  
Muhammad Aditya Ramadhan Hasran ◽  
Dian Noviyanti Agus Imam ◽  
Bambang Sunendar
Keyword(s):  
Impact Strength ◽  
Mechanical Strength ◽  
Rice Husk ◽  
Acrylic Resin ◽  
Control Group ◽  
P Value ◽  
Test Results ◽  
Nano Cellulose ◽  
Reinforcing Material ◽  
The Impact

Background: One of the materials for denture bases is heat-cured acrylic resin (PMMA). This material still lacks impact strength as a mechanical strength property. The addition of reinforcing material is known to increase the mechanical strength of PMMA. One of the reinforcing materials added to PMMA is nano cellulose from rice husks, one of the wastes from agricultural products. Purpose: This study aims to determine rice husk nano cellulose's addition to the PMMA denture base's impact strength. Method:  The research sample consisted of six groups, each group consisting of 8 samples selected by simple random. The PI, P2, P3, P4, P5, and K groups were PMMA with 1%, 2%, 3%, 4%, 5% nano cellulose, and without nano cellulose. Result: Mean impact strength test results were 41.50 x 10-3 ± 3.891 J / mm2 for P1, 44.13 x 10-3 ± 3,980 J / mm2 for P2, 45.63 x 10-3 ± 4,438 J / mm2 for P3, 46.87 x 10-3 ± 4,824 J / mm2 for P4, 49.12 x 10-3 ± 4.016 J / mm2 for P5 and 36.25 x 10-3 ± 1.982 J / mm2 for K. One way Anova test results with p-value of 0.000 indicates differences in the six groups (p<0.05). Conclusion: This study concludes that the impact strength value of PMMA with the addition of rice husk nano cellulose has increased compared to the control group without the addition of rice husk nano cellulose.

scholarly journals Consolidation treatments applied to ceramic tiles: are they homogeneous?

2017 ◽  
Vol 67 (325) ◽  
pp. 113 ◽  
Author(s):  
D. Costa ◽  
A. S. Leal ◽  
J. M. Mimoso ◽  
S. R.M. Pereira
Keyword(s):  
Mechanical Strength ◽  
Penetration Depth ◽  
Acrylic Resin ◽  
Measuring System ◽  
Strength Testing ◽  
Testing Methods ◽  
Ceramic Tiles ◽  
Consolidation Treatment ◽  
Extensive Evaluation ◽  
Drilling Resistance

The mass consolidation treatment of azulejos is necessary when ceramic biscuits show signs of disaggregation. Such treatment is often used as a complementary conservation technique to the reestablishment of weakened glaze-ceramic bonds. In this research, two commonly used consolidants (ethyl silicate and acrylic resin) were tested on artisanal ceramic tiles via mass consolidation and the resulting impregnation profiles were evaluated. The results indicated that after consolidation, hard zones frequently formed due to localized consolidant concentration after the polymerization and curing processes. These inhomogeneous hard zones subsequently influenced the results obtained through conventional mechanical strength testing (i.e. flexural and compression), creating a false impression of success. This research demonstrated that by using the Drilling Resistance Measuring System, impregnation characteristics such as penetration depth and distribution of consolidant could be observed that otherwise could not be discerned through the more common testing methods. As such, a more extensive evaluation of consolidation effects was achieved.

scholarly journals Kekuatan Mekanis Antibacterial Resin Campuran Titanium Dioksida

2021 ◽  
Vol 12 (1) ◽  
pp. 227
Author(s):  
Azamataufiq Budiprasojo ◽  
Feby Erawantini
Keyword(s):  
Impact Strength ◽  
Mechanical Strength ◽  
Tio2 Nanoparticles ◽  
Bending Strength ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Impact Testing ◽  
Universal Testing ◽  
The Impact ◽  
Pendulum Impact

<p class="Abstract">The aim of this research is to analyze the effect of Titanium Dioxide (TiO2) nanoparticles as resin concentrate on mechanical strength. The tested mechanical strength is Bending strength, Impact Strength, and Microhardenest Strength. The types of resin used in this study were acrylic resin without conventional modification and acrylic resin with an additional 0.01 gr and 0.06 gr of TiO2. Specimen dimensions are made revered to ISO 20795-1 (2008) standard specifications. Mechanical strength was determined by using the universal testing machine, Izod pendulum impact testing machine, and also Vickers microhardness tester. From the analysis, the researcher found that the bending strength of resin acrylic was greatly decreased by increasing the TiO2 concentration. It happens in both TiO2 0.01gr and 0.06gr of acrylic resin compared to the non TiO2 resin. The impact strength of 0.01gr TiO2 acrylic resin was significantly increased compared to non TiO2 acrylic resin. But on the other hand for 0.06gr acrylic resin, impact strength was decreased and recorded the lowest impact strength. The highest Micro hardness strength was found in 0.06gr TiO2, It is significantly increased compared to 0.01gr TiO2 and 0gr TiO2. The general conclusion is, adding 0.01gr TiO2 nanoparticles as concentrated into acrylic resin can significantly increase the bending strength, bending strength, and microhardness strength. Meanwhile, adding 0.06gr Tio2 nanoparticles as concentrated into acrylic resin can only increase the bending strength and the microhardness strength, but not for its impact strength.</p>

Immunocytochemistry after fast freeze fixation-freeze substitution: Advantages and limits

1990 ◽  
Vol 48 (3) ◽  
pp. 42-43
Author(s):  
Marie-Thérèse Nicolas
Keyword(s):  
Osmium Tetroxide ◽  
Freeze Substitution ◽  
Acrylic Resin ◽  
Expected Improvement ◽  
List Type ◽  
Chemical Fixation ◽  
Freeze Fixation ◽  
Liquid Chemical ◽  
Luciferase Enzyme ◽  
Lower Background

An alternative to aqueous chemical fixation consists in immobilizing physically the specimen by freezing it as fast as possible without using any cryoprotectant. This Fast Freeze Fixation (FFF) followed by Freeze Substitution (FS) avoids osmotic artefacts due to the slow penetration of liquid chemical fixative. Associated with Immuno-Gold labeling (IGS), FFF-FS allows a more precise localization of antigens.Using the bioluminescent bacteria Vibrio harveyi, a comparison of IGS with an antibody directed against its luciferase (enzyme of the luminescent reaction) has been done after liquid chemical fixation versus FFFFS. This later technique, beside an expected improvement of the ultrastructure always shows a better preservation of antigenicity and a lower background. In the case of FFF-FS technique (Figure 3):–labeling in acrylic resin (LRWhite) is 2 to 4 fold more intense than in epoxy resin (Epon),–but the ultrastructure is always better in Epon.–but the ultrastructure is always better in Epon.–The addition of fixatives in the substitution medium, results in a decrease of labeling which is more important in the case of a mixture of fixatives than with osmium tetroxide alone; with one exception: the substitution with glutaraldehyde which produces a dramatic increase in the density of the labeling but also, at the same time, a swelling of the cells of about 30%.

FORMULATION AND DEVELOPMENT OF FAST DISSOLVING TABLET OF METOCLOPRAMIDE: AN ANTI-EMETIC DRUG

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya
Keyword(s):  
Mechanical Strength ◽  
Standard Procedure ◽  
Flow Property ◽  
Storage Conditions ◽  
Angle Of Repose ◽  
Dissolution Time ◽  
Disintegration Time ◽  
Powder Blend ◽  
Standard Curve ◽  
The Stability

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet

Plasma Enhanced Chemical Vapor Deposition of Porous Organosilicate Glass ILD Films With k ≤ 2.4.

2003 ◽  
Vol 766 ◽  
Author(s):  
Raymond N. Vrtis ◽  
Mark L. O'Neill ◽  
Jean L. Vincent ◽  
Aaron S. Lukas ◽  
Brian K. Peterson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Chemical Vapor Deposition ◽  
Mechanical Strength ◽  
Thermal Annealing ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organosilicate Glass

AbstractWe report on our work to develop a process for depositing nanoporous organosilicate (OSG) films via plasma enhanced chemical vapor deposition (PECVD). This approach entails codepositing an OSG material with a plasma polymerizable hydrocarbon, followed by thermal annealing of the material to remove the porogen, leaving an OSG matrix with nano-sized voids. The dielectric constant of the final film is controlled by varying the ratio of porogen precursor to OSG precursor in the delivery gas. Because of the need to maintain the mechanical strength of the final material, diethoxymethylsilane (DEMS) is utilized as the OSG precursor. Utilizing this route we are able to deposit films with a dielectric constant of 2.55 to 2.20 and hardness of 0.7 to 0.3 GPa, respectively.

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