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Comparison of the Fluoride Ion Release from nanofluorapatite-modified orthodontic cement under different pH Conditions - an in Vitro Study

Dobrzynski Wojciech, Nikodem Anna, Diakowska Dorota, Wiglusz Rafał Jakub, Watras Adam, Dobrzynski Maciej, Mikulewicz Marcin

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 3

EN

Construction of the orthodontic bracket promotes food accumulation, which is the cause of plaque formation. Modern trends in the design of adhesive orthodontic cements focus on the ability to release cariostatic fluoride ions. One of the methods is to incorporate the material with fluorapatite nanoparticles. The aim of the study was to determine the fluoride release capacity of orthodontic cement doped with nanosized fluorapatite in selected media and solution pH over a 12-week period.

2

Effect Of Heat-Treatment On Microstructure And Magnetic Properties Of Nanocrystallized Mn-Zn Ferrite Powders

Lee W. H., Hong C. S., Chang S. Y.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1347--1350

EN

The initial ferrite powders were subjected to high energy ball milling at 300rpm for 3h, and subsequently heat-treated at 573-1273K for 1h. Based on the observation of microstructure and measurement of magnetic properties, the heat-treatment effect was investigated. The size of initial powders was approximately 70μm. After milling, the powders with approximately 230nm in size were obtained, which were composed of the nano-sized particles of approximately 15nm in size. The milled powders became larger to approximately 550nm after heat-treatment at 973K. In addition, the size of particles increased to approximately 120nm with increasing temperature up to 973K. The coercivity of initial powders was almost unchanged after milling, whereas the saturation magnetization increased. As the heat-treatment temperature increased, the saturation magnetization gradually increased and the maximum coercivity was obtained at 773K.

3

The Advantages and Shortcomings of Using Nano-sized Energetic Materials

Zohari N., Keshavarz M. H., Seyedsadjadi S. A.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 1

135--147

EN

Energetic materials are substances that can store chemical energy in their chemical bonds. An ideal energetic material is a substance with high performance, safety and shelf life. Many recent researches have concentrated on the synthesis or the development of new energetic materials with optimized properties, such as thermal stability, sensitivity and burn rate. The reduction of the particle size of energetic materials from micron to nano-sized is one of the suitable approaches for obtaining desirable properties. Recent progress on the reduction of the particle size of energetic materials is reviewed in this work. The effects of nano-sized particles on the performance of energetic compounds are also investigated.

4

Rheology of concentrated suspensions of plasma-processed fine alumina

Jakobsons E., Faitelson L., Palcevskis E.

International Journal of Applied Mechanics and Engineering

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2003

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Vol. 8, no spec.

251-258

EN

The rheological properties (flow curves and viscoelastic behavior) of the injection-moulded suspensions prepared from two nanosized plasma-processed Al2O3 powders and water were investigated on wide ranges of shear rates and frequencies . Tiron (disodium salt of 4,5-dihydroxy-1,3-benzene-disulfonic acid) was chosen as a surfactant for preparation of the concentrated alumina suspensions. It is stated that, at an optimal Tiron content in suspensions, their viscosity, yield stress, and complex shear modulus have minimal values. A correlation was shown to exist between the optimal concentration of the dispersant obtained by rheological tests on the alumina powder water suspensions and the mentioned optimal concentration determined by measuring the zeta potential.

5

Rheology of injection moulding suspension prepared from nanosized plasma processed AlN powder

Palcevskis E., Jakobsons E., Faitelson L.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

375-380

EN

The rheological properties (flow curves and viscoelastic behavior) of injection moulding suspension prepared from nanosized plasma processed AlN powder and paraffin wax were investigated in the broad region of shear rates (0.07-1350 s-1). Two viscosity platoaux are observed on the flow curves and the values of two yield stresses are obtained. The linear viscoelastic region is not reached at the lowest deformation amplitude (0.66 %). Higher values of dynamic viscosity than those of effective viscosity at 'gamma'='omega' are observed in all the range of the used frequency and shear rate (0.1-80 s-1). The rebuilding of destroyed particle packing structure during ultrasound or shear treatment is observed. It results in the dependence of rheologic properties on the pretreatment history of suspensions.