scholarly journals Composite bond strength improvement with thermal vibration: an experimental non-randomised study

2021 ◽  
Vol 28 (4) ◽  
pp. 53-71
Author(s):  
A. A. Gushchin ◽  
A. A. Adamchik ◽  
V. Ya. Zobenko ◽  
V. N. Samhaev
Keyword(s):  
Thermal Analysis ◽  
Bond Strength ◽  
Polymer Matrix ◽  
Chemical Properties ◽  
Thermal Vibration ◽  
Inorganic Filler ◽  
Vibration Exposure ◽  
Synchronous Thermal Analysis ◽  
Physical And Chemical ◽  
And Chemical Properties

Background. Secondary caries formation is a relevant issue due to poor long-term quality of composite fillings, with inherent subsequent chipping and cracking of the material. We developed a method to improve physical, mechanical and chemical properties of available composites based on thermal vibration imposed on unpolymerised composite in the formed tooth cavity directly prior to polymerisation.Objectives. Effect assessment of thermal vibration exposure on bond strength in composite restorative polymer matrix in various composite brands.Methods. The study used synchronous thermal analysis, including differential scanning calorimetry and thermogravimetry, to estimate and register thermal effects of physical and chemical processes within a temperature programme, as well as determine gaseous release, air contact and decomposition-related sample mass variation, thermal stability, reaction kinetics, polymer and inorganic filler component chemical composition, humidity and softening degree. The study covered 90 specimens 30 mg each prepared of three different composites.Results. Synchronous thermal analysis revealed a statistically significant increase in polymer matrix bond strength in the composites Estelite Sigma Quick (Tokuyama Dental), Filtek Bulk Fill Posterior Restorative (3M Espe) and DentLight (VladMiVa) after thermal vibration exposure vs. classical polymerisation of same composites (p < 0.0001). The bond strength increased by 17.00, 22.51 and 11.31%, respectively.Conclusion. The developed exposure method for altering the composite filling physical and chemical properties has been shown advantageous in a laboratory setting. Thermal vibration-pretreated composite fillings had a higher polymer matrix bond strength vs. same composites polymerised under standard conditions.The pretreatment improves composite filling quality via directly affecting the material physical and mechanical properties of hardness and bending strength.

The Thermal Decomposition Characteristics of Sodium Pyroxenite Gangue in Baiyunebo Iron Ore

2014 ◽  
Vol 887-888 ◽  
pp. 939-946
Author(s):  
Guo Ping Luo ◽  
Sheng Li Wu ◽  
Xiao Long Nie ◽  
Yi Ci Wang ◽  
Yue Cong Wang
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Iron Ore ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Physical And Chemical ◽  
And Chemical Properties

The changes of physical and chemical properties of sodium pyroxenite gangue such as decomposition and phase transformation were researched by means of differential thermal analysis and X-ray diffraction. The results show that the natural sodium pyroxenite gangue contains the main mineral of aegirite(NaFe+3Si2O6), and it contains a number of BaSO4 and Na3Ca2(SO4)3F, etc. The water of crystallization decomposes at 554.7°C. The Na3Ca2(SO4)3F decomposes into the composite sulfate and CaF2 over a wide range of temperatures. The main mineral of aegirite(NaFe+3Si2O6) reacts with CaF2 into NaF gas at 993.4°C. The sodium pyroxenite gangue is melts and releases a small amount of SiF4 gas in the range of 1193.5-1300.7°C.

Physical and Chemical Properties of Adhesives Based on Geocement for Restoration and Rehabilitation of Building Materials

2013 ◽  
Vol 688 ◽  
pp. 123-129 ◽  
Author(s):  
Grigorii Vozniuk ◽  
Еlena Kаvalerova ◽  
Pavel Vasiljevich Krivenko ◽  
Оleg Petropavlovsky
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Building Materials ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Physico Chemical ◽  
User Friendly ◽  
Physical And Chemical ◽  
And Chemical Properties

This paper covers the results of study of physico-chemical and mechanical properties of the adhesives based on geocements which have a number of advantageous properties, among them: high compressive and bond strength in the conditions of long-term exposure of various factors, excellent durability, etc. These adhesives are environmentally and user-friendly and safety, their cost is compatible to the known-in-the-art analogs. The results of study suggested to draw a conclusion that they could be successfully used for rehabilitation and restoration of the building materials such as concrete, ceramics, natural stone.

scholarly journals The study of fly ash filler behaviour in the polymer matrix of polyethyleneterephthalate

2019 ◽  
pp. 28-36
Author(s):  
Tlek Ketegenov ◽  
Natalya Khan ◽  
Olesya Tyumentseva ◽  
Ardak Karagulanova
Keyword(s):  
Electron Microscopy ◽  
Composite Material ◽  
Fly Ash ◽  
Polyethylene Terephthalate ◽  
Polymer Matrix ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Optical And Electron Microscopy ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of the investigation was to study the behavior of mechanically activated fly ash filler containing carbon in a polymer matrix of polyethylene terephthalate (PET). By means of the methods of optical and electron microscopy the change of physical and chemical properties of fly ash after intensive grinding in planetary mills of centrifugal type was considered. The research showed that mechanically activated filler, in contrast to its non-activated analog, structures the polymer matrix and provides improving the characteristics of the composite material.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

THE IMPORTANCE OF THE RED BOOK OF SOILS FOR MONITORING AND JUSTIFICATION OF CONSERVATION MEASURES

2020 ◽  
Author(s):  
O.S. Bezuglova ◽  
Keyword(s):  
Chemical Properties ◽  
Natural State ◽  
Soil Maps ◽  
Rostov Region ◽  
Conservation Measures ◽  
Background Data ◽  
The Russian Federation ◽  
Physical And Chemical ◽  
And Chemical Properties

Rostov Region belongs to the highly protected natural territories characterized by the continuous plowing. There territories are the only reserves with the soils preserved in their natural state. However, these areas often lack detailed information about the soils quality and composition. Surveying soils on these territories is crucial for determination of their basic physical and chemical properties. The resulted compilation of soil maps could lay a foundation for creating the Red Book of Soils and the formation of a section in the soil-geographical database of the Russian Federation. Subsequently, such information can be used as a background data for the main types of soils in the region. It will be also valuable during monitoring and justification of conservation measures.

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