Structural Conformation of Polytetrafluoroethylene Composite Matrix

2016 ◽  
Vol 10 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Oleg Budnik ◽  
◽  
Anatoliy Budnik ◽  
Valentin Sviderskiy ◽  
Kristina Berladir ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Activation ◽  
Supramolecular Structure ◽  
Physical And Mechanical Properties ◽  
Composite Matrix ◽  
Service Properties ◽  
Operating Modes ◽  
Structural Conformation ◽  
First Time

Enhancement of physical and mechanical properties and structuring activity of polytetrafluoroethylene as matrix of composites by means of mechanical activation is shown. Operating modes of mechanical activation equipment are defined, in which the service properties of PTFE are maximized. The effect of mechanical activation technology on restructuring and change of morphology and supramolecular structure of PTFE is detected for the first time.

Mechanical activation of volcanic ash for geopolymer synthesis: effect on reaction kinetics, gel characteristics, physical and mechanical properties

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39106-39117 ◽  
Author(s):  
Jean Noël Yankwa Djobo ◽  
Antoine Elimbi ◽  
Hervé Kouamo Tchakouté ◽  
Sanjay Kumar
Keyword(s):  
Mechanical Properties ◽  
Mechanical Activation ◽  
Reaction Kinetics ◽  
Volcanic Ash ◽  
Physical And Mechanical Properties

Mechanical activation is a suitable route to enhance the reactivity of volcanic ash and the final properties of the resulting geopolymers.

scholarly journals Extracellular Matrix Hydrogels Originated from Different Organs Mediate Tissue-Specific Properties and Function

2021 ◽  
Vol 22 (21) ◽  
pp. 11624
Author(s):  
Tzila Davidov ◽  
Yael Efraim ◽  
Rotem Hayam ◽  
Jacopo Oieni ◽  
Limor Baruch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Pluripotent Stem Cells ◽  
Physical And Mechanical Properties ◽  
Tissue Specific ◽  
Gene Expression Analyses ◽  
Composition Structure ◽  
Induced Pluripotent ◽  
And Function ◽  
First Time

Porcine extracellular matrix (pECM)-derived hydrogels were introduced, in recent years, aiming to benefit the pECM’s microstructure and bioactivity, while controlling the biomaterial’s physical and mechanical properties. The use of pECM from different tissues, however, offers tissue-specific features that can better serve different applications. In this study, pECM hydrogels derived from cardiac, artery, pancreas, and adipose tissues were compared in terms of composition, structure, and mechanical properties. While major similarities were demonstrated between all the pECM hydrogels, their distinctive attributes were also identified, and their substantial effects on cell-ECM interactions were revealed. Furthermore, through comprehensive protein and gene expression analyses, we show, for the first time, that each pECM hydrogel supports the spontaneous differentiation of induced pluripotent stem cells towards the resident cells of its origin tissue. These findings imply that the origin of ECM should be carefully considered when designing a biomedical platform, to achieve a maximal bioactive impact.

scholarly journals Research of properties of cement-soil piles of foundations of buildings and structures

2020 ◽  
Vol 24 (5) ◽  
pp. 104-108
Author(s):  
N.G. Seregin ◽  
◽  
V.I. Zaprudnov ◽  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Activation ◽  
Russian Federation ◽  
Western Siberia ◽  
Physical And Mechanical Properties ◽  
Soil Types ◽  
Ground Mixture ◽  
Mixing Method ◽  
The Russian Federation ◽  
Cement Soil

The review of soil types prevailing in Western Siberia of the Russian Federation is presented. The compositions and physical and mechanical properties of soils are analyzed. Special attention is paid to loess subsidence soils. The problem of obtaining a homogeneous cement-ground mixture is formulated and set. The technological scheme of production of cement-ground piles of foundations of buildings and structures by drilling-mixing method with mechanical activation is considered. Considers methods of strengthening the loess subsidence of soils. Methods for studying the properties of cement-based piles of foundations of buildings and structures are formulated. A multi-factor experiment was conducted to evaluate the parameters that affect the properties of cement-based piles. Based on the research results, conclusions and recommendations are formulated.

The Effect of Andreasen ́s Packing Distribution Modulus on the Physical and Mechanical Properties of a Low Cement Refractory Castable

2019 ◽  
Vol 1156 ◽  
pp. 97-104
Author(s):  
Vitoria Gabrieli Malimpensa ◽  
José Antonio Alves Júnior ◽  
João Baptista Baldo
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Refractory Concrete ◽  
Physical And Mechanical Properties ◽  
Dynamic Elastic Modulus ◽  
Conventional Concrete ◽  
Key Indicator ◽  
Temperature Ranges ◽  
S Model ◽  
First Time

Among modern refractory concretes (MRC), those with low cement content (LCC) where CAC = 4-6wt%, are widely commercialized, considering that their properties approximate those of burned bricks of the same class. In this work, the effect of the modulus q of Andreasen ́s particle size distribution, on the physical (porosity, bulk density) and mechanical (flexural strength and dynamic elastic modulus) properties, of either pre-fired or simply dried specimens of a ≥85% Al2O3 LCC ́s, was investigated. The different LCC ́s samples were formulated according to the Andreasen ́s model, using several distribution modulus (q = 0.22, 0.26, 0.30, 0.33 and 0.42). Measurements of the Dynamic Elastic Modulus (DEM) as a function of temperature (25 to 1500°C), using the Impulse Excitation Technique (IET), were taken as a key indicator of the microstructure dynamic behavior. For the sake of just a punctual comparative term, the physical and mechanical properties of a conventional type refractory concrete (CRC) with a higher CAC percentage (15%) formulated with q = 0.26 was also evaluated. The results indicated that distribution modulus values of; q =0.22, 0,26, 0.30 and 0.33 lead to higher DEM values. While q=0.42 lead to the smallest value in the LCC series. Also, higher DEM values ​​were obtained for LCC ́s (CAC = 5%) than for conventional concrete with CAC = 15% under the same value of q for pre-fired samples. In addition, by observing the occurrence of damping effects in specific temperature ranges, the loss of crystallization water from the calcium aluminate hydrates, as well as the development of pyroplastic behavior could be inferred. The gathered information is relevant to predict the behavior of LCC ́s and CRC ́s when put into service for the first time.

The improvement of physical and mechanical properties of sealers based on nitrile-butadiene rubber and combination of nano-metal oxides

2020 ◽  
pp. 174-182
Author(s):  
R.F. Khankishiyeva ◽  
◽  
H.N. Akhundzada ◽  
Keyword(s):  
Mechanical Properties ◽  
Metal Oxides ◽  
Chemical Interaction ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
Butadiene Rubber ◽  
Nanosized Powders ◽  
Nitrile Butadiene Rubber ◽  
Crosslinking Process ◽  
First Time

The chemical interaction of disulphochloride aromatic compounds with nitrile butadiene rubber (NBR) in the presence of combined nanosized powders of metal oxides (ZnO and Al2O3) was studied for the first time. Vulcanization of the prepared blends has been induced with two methods: by irradiation of gamma rays (D=300 kGy) and by pre-heating in the hydraulicpress and then subsequent irradiation (150 oC x 5', 300 kGy). In order to activate the crosslinking process, a combination of nano-oxides ZnO and Al2O3 were used. The surface of the nanocomposite was studied by using scanning electron microscopy. The mechanical properties of modified blends were studied and then compared with controlling sample (vulcanized with sulphur) and analyzed by the mechanical tests in aggressive environments after thermal aging. The study found that the use of 1,3-disulphochloride benzene with nano oxides produces cured materials with good resistance to aging and provides high service properties in air, seawater, and oil-bearing solution.

scholarly journals Printability and properties of 3D-printed poplar fiber/polylactic acid biocomposite

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2774-2788
Author(s):  
Zhaozhe Yang ◽  
Xinhao Feng ◽  
Min Xu ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Rheological Properties ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Longitudinal Stripe ◽  
3D Printed ◽  
First Time ◽  
Printing Parameters

To efficiently and economically utilize a wood-plastic biocomposite, an eco-friendly biocomposite was prepared using modified poplar fiber and polylactic acid (PLA) via 3D printing technology for the first time. First, the effects of poplar fiber (0, 1, 3, 5, 7, and 9%) on the mechanical and rheological properties of the printed biocomposites were investigated. Subsequently, the printing parameters, including printing temperature, speed, and layer thickness, were optimized to obtain the biocomposite with superior properties. Finally, four printing orientations were applied to the biocomposite based on the optimized printing parameters to study the effect of filament orientation on the properties of the biocomposite. Favorable printability and mechanical properties of the biocomposite were obtained at 5% poplar fiber. The optimal printing temperature of 220 °C, speed of 40 mm/s, and layer thickness of 0.2 mm were obtained to produce the desired mechanical properties of the biocomposite with the printing orientation in a longitudinal stripe. However, the printing parameters should be chosen according to the applications, where different physical and mechanical properties are needed to achieve efficient and economical utilization of the biocomposites.

scholarly journals Mutual spectral densities calculation of the moments of resistance on the peat milling unit working bodies

2021 ◽  
Vol 251 ◽  
pp. 745-756
Author(s):  
Konstantin Fomin
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Structural Heterogeneity ◽  
Movement Speed ◽  
Spectral Densities ◽  
Engine Operation ◽  
Operating Modes ◽  
Random Forces ◽  
Variable Nature ◽  
Working Bodies

When performing technological operations in the peat industry, various units with milling-type working bodies are used. They differ in design, layout, number and type of cutting elements, operating modes, and may have one or more working bodies. During operation, random forces and moments act on the cutters, which have a dramatically variable nature, which is associated with the periodic interaction of the knives with the peat deposit, its structural heterogeneity, variations in the milling depth, physical and mechanical properties of peat, the rotational speed of the cutter and the movement speed of the machine. In this case, significant dynamic loads arise in the structural elements, which leads to a decrease in their reliability, deterioration of the energy characteristics of the engine operation and technical and economic indicators of use. In the dynamic analysis of drive elements, when using machines with several working bodies, it is necessary to know both spectral and mutual spectral load densities.  For their calculation, expressions were obtained that take into account the physical and mechanical properties of peat, the operating modes of the unit and their probabilistic characteristics, as well as the design features of the working body. The expressions are obtained for the case when there are several working bodies with the same diameters and the number of knives in the cutting plane. In this case, the number of planes, width, type of cutting element and type of cutting (locked, semi-locked, etc.) may differ. As an example of using the developed approaches, the calculation of spectral and mutual spectral densities of moments on cutters and loads in the drive elements of the machine for surface-layer milling MTF-14 is presented.

scholarly journals The relationship between the anomalies of the properties of alloys with a semiconductor component and special features of glass formation and state diagrams

2020 ◽  
pp. 67-77
Author(s):  
K. Yu. Shakhnazarov ◽  
◽  
A. V. Mikhailov ◽  
D. V. Tzykanov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Diagram ◽  
Glass Formation ◽  
Physical And Mechanical Properties ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
State Diagrams ◽  
First Time ◽  
The Relationship ◽  
Qualitative Changes

The analysis of literature data on the properties of alloys with a semiconductor component shows a significant number of anomalies of physical and mechanical properties left without a comment of the researchers of these alloys. Based on the anomalies in the properties of twelve alloys (Ge–Si, InAs–GaP, GaSb–GaAs, HgTe–CdTe, GaSe–GaS, InSb–AlSb, PbSe–GeTe, Zn–Ge, Ti–Ge, Ge–Tl, ZnTe–HgTe, P–As), the paper attempts to identify a regularity that allows associating these anomalies with state diagrams. For the first time, the authors introduce the concept of phase diagram as a concentration dependence of qualitative changes in crystallization intervals, which allows associating phase diagram with the extremes of physical and mechanical properties of industrially used alloys with a semiconductor component that cannot be explained by the peculiarities of phase composition or structure. The second part of the paper deals with the special aspects of glass formation (amorphization) of multicomponent alloys. Modern literature expresses mutually exclusive judgments about the possibility of using phase equilibrium diagrams to predict the ability to glass-formation, which is well-founded and is probably associated with the absence of a general theory of glass formation. Nevertheless, the analysis of literature data on SiO2–Na2O, Ge–S, GeSe–Se, S–Se alloys shows that the glass formation (amorphization) boundaries are associated with phase diagrams. Based on the identified criterion, the paper shows the possibility of using equilibrium state diagrams built for slow-cooled alloys to predict the glass-forming ability of (fast-cooled) alloys.

scholarly journals ПОЛІМЕР-ПОЛІМЕРНИЙ КОМПОЗИТ ОТРИМАНИЙ ШЛЯХОМ ПЕРЕРОБКИ ВІДХОДІВ ПВХ ЛІНОЛЕУМУ

2018 ◽  
Vol 122 (3) ◽  
pp. 45-51
Author(s):  
І. М. Костюк ◽  
Н. В. Сова ◽  
Б. М. Савченко ◽  
Р. Ш. Іскандаров ◽  
Б. П. Савчук
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Capillary Viscometer ◽  
Pet Waste ◽  
Waste Production ◽  
Hydrostatic Weighing ◽  
Mixed Waste ◽  
First Time ◽  
Positive Effect

Development of technology for the processing of mixed waste of vinyl flooring by their joint milling and plasticization. The determination of the MFI was carried out according to ISO 1133: 1997 on a capillary viscometer with a constant pressure and temperature (190 ± 0.5) ° C and a weight of 2.16 kg. The thermostability and melting temperature were determined on the Hipro RM 200C plastograph. Mechanical properties were determined on a breaking machine according to ASTM D638. Hardness - using a Shore D durometer, hydrostatic weighing density on an analytical balance RADWAG AS-X2. Equipment for milling and plasticization of a mixture of PVC / PET waste was selected. Qualitative milling of mixed waste is achieved by using a low speed rotary knife grinder with rotor speed of 300 rpm. The properties of the reinforced PVC were obtained. The strength of this film compared with the classic recipe is lower but when by using such materials in the composition it is possible to obtain a material with high physical and mechanical properties and achieve maximum non-waste production which will also have a positive effect on the economy of the enterprise. The technology for joint processing of mixed vinyl flooring waste was developed for the first time. The features of reinforcing PVC matrix with fibers of a PET was obtained at the receipt of films from mixed vinyl flooring waste. The developed technology allows to provide non-waste production of vinyl flooring at enterprises.

scholarly journals Study On Parameters and Operating Modes of the Device for Deseeding Flax in the Field

2021 ◽  
Vol 15 (2) ◽  
pp. 13-18
Author(s):  
V. G. Chernikov ◽  
R. A. Rostovtsev ◽  
S. V. Solov’ev
Keyword(s):  
Mechanical Properties ◽  
Technological Process ◽  
Physical And Mechanical Properties ◽  
Experimental Plant ◽  
Fiber Flax ◽  
Theoretical Substantiation ◽  
Operating Modes ◽  
Harvesting Process ◽  
Flax Seeds ◽  
The Cost

The authors showed that the main technological process in the combined and separate methods of fiber flax harvesting is deseeding or separating the seed part of the crop from the stems. It was confirmed that there is a direct impact of this process success on seed and straw losses, the fiber yield and quality, the heap composition, the labor intensity and energy consumption of flax drying and processing. (Research purpose) To develop a technology for stripping fiber flax with a comb deseeder during harvesting, to study the deseeder’s specifications and operating modes. (Materials and methods) The authors studied the technological process of stripping flax with a comb deseeder. An experimental plant of a comb deseeder was designed. A model of theoretical calculation was proposed based on the physical and mechanical properties of fiber flax and agrotechnical requirements for its harvesting. (Results and discussion) The authors theoretically determined the comb deseeder’s optimal height, operation kinematic mode, stripping cleanliness, the radius of the stripper drum. Laboratory studies were conducted. It was shown that threshing seeds in the field will reduce the loss of flax seeds by 10 per cent and the stem waste due to tangling during the harvesting process – by 18 per cent. It will also reduce the number of harvesting vehicles, personnel, and the cost of product. The authors identified an opportunity to increase productivity by increasing the width of the header grip: for example, the width of a grain harvester header is about 4 meters, and the width of a flax harvester header is 1.52 meters, that is, the productivity of flax harvesting will increase 2.6 times at the same speed, and 3 times at a higher speed. It was possible to eliminate one piece of equipment – a heap separating machine, since the technological operation of heap processing is carried out by a grain harvester. (Conclusions) The authors presented a theoretical substantiation of the comb deseeder’s operating parameters and modes for stripping fiber flax in the field. The authors proposed a model to determine them based on the physical and mechanical properties of flax and agrotechnical requirements for its harvesting.

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