scholarly journals Experimental Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 55 ◽  
Author(s):  
Hengfeng Liu ◽  
Jixiong Zhang ◽  
Weiqing Zhang ◽  
Feng Gao ◽  
Hao Yan ◽  
...  
Keyword(s):  
Percolation Threshold ◽  
Apparent Resistivity ◽  
Coal Mines ◽  
Mechanical Tests ◽  
Test Results ◽  
Mechanical And Electrical Properties ◽  
Distribution Rules ◽  
Perceptual Characteristics ◽  
Conductive Mechanism ◽  
Perceptual Mechanism

For investigating perceptual stress characteristics of Functional Cemented Backfilling Materials (FCBM) in coal mines, we prepared functional specimens based on Cemented Backfilling Materials (CBM) with the perceptual stress ability, and clarified their conductive mechanism, perceptual mechanism, and possible engineering applications. Using mechanical tests and the network parallel dynamic method, the mechanical and electrical properties of the prepared materials and the perceptual characteristics under mechanical–electric coupling conditions were analyzed in depth. The test results demonstrate that the deformation of FCBMs obey standard stress–strain rules, while the conductive phase addition can deteriorate their mechanical properties and simultaneously enhance the electrical conductivity of materials. Through fitting, the percolation threshold was determined to be 9.85%. Before the failure, the spatial distribution of the apparent resistivity in the materials was shown to follow the X-shaped radial pattern; after the failure, the material apparent resistivity obeys different distribution rules at various stages. The apparent resistivity of FCBM is negatively correlated with the strain value at the elastic and plastic stages and positively correlated with it at the failure stage. When the graphite content exceeds the percolation threshold, the materials exhibit a favorable perceptual functionality at the elastic stage.

Medium Density Particleboard with Addition of Impregnated Paper

2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Test Results ◽  
Thickness Swelling ◽  
Adhesion Test ◽  
Layer Medium ◽  
Determine Moisture Content

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

scholarly journals Research on Lifespan Prediction of Cross-Linked Polyethylene Material for XLPE Cables

2020 ◽  
Vol 10 (15) ◽  
pp. 5381
Author(s):  
Yi Zhang ◽  
Zaijun Wu ◽  
Cheng Qian ◽  
Xiao Tan ◽  
Jinggang Yang ◽  
...  
Keyword(s):  
Operating Time ◽  
Prediction Method ◽  
Hardness Test ◽  
High Accuracy ◽  
Future Research ◽  
Test Results ◽  
Scanning Calorimetry ◽  
Characterization Methods ◽  
Gel Content ◽  
Mechanical And Electrical Properties

In this paper, cross-linked polyethylene (XLPE) cables of the same batch from Factory A, which ran from 1 to 8 years in Jiangsu Province, are sampled. Some widely accepted aging characterization methods of XLPE cables such as the gel content test, differential scanning calorimetry (DSC) test, tensile test and hardness test are employed to obtain the physicochemical, mechanical and electrical properties of the samples. Then, some lifespan prediction parameters significantly correlated with operating time are obtained through correlation calculations. Finally, a prediction method is proposed to predict the operating time of XLPE cables from Factory A. The test results indicate that parameters including the gel content Cge, the crystallinity XC, tensile strength σ, ultimate elongation δ, the dielectric permittivity ε, and the dielectric loss Jtan are significantly correlated with operating time, which can be used in evaluating the aging degree of XLPE cables. Moreover, due to the high accuracy of the experimental verification, it turns out that the lifespan prediction method proposed in this paper can be used to determine the operating time of XLPE cables from Factory A in future research.

scholarly journals Failure Mechanism of a Coal-Rock Combined Body with Inclinations of Structural Planes and a Calculation Model for Impact Energy

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Yi-Chao Zhao ◽  
Ming-Shi Gao ◽  
Yong-Liang He ◽  
Dong Xu
Keyword(s):  
Mechanical Properties ◽  
Failure Mechanism ◽  
Impact Energy ◽  
Coal Mines ◽  
Calculation Model ◽  
Engineering Practice ◽  
Test Results ◽  
Failure Characteristics ◽  
Coal Rock ◽  
Rock Strata

A coal-rock (CR) combined body can be used to simulate structures of coal and rock strata, and its impact-induced failure characteristic conforms more close to engineering practice. Exploring the mechanical properties and impact energy in a CR combined body contributes to better predictions of rock bursts in coal mines. In the study, the mechanical properties of CR combined bodies with four different inclinations (0°, 15°, 30°, and 45°) of structural planes were measured, and also their failure mechanism was analysed. Based on the theory of particle mechanics, a calculation model for impact energy in a CR combined body with inclinations was established and then verified by using monitored acoustic emission (AE) data. The test results showed that inclination affected mechanical properties and failure characteristics of the CR combined body, i.e., the larger the inclination, the lower the strength and impact energy in the CR combined body and the lower the level of damage. The proposed calculation model for impact energy revealed the mechanical essence of energy accumulation and release of a CR combined body, providing a reference for investigating rock burst in coal mines.

Rheological Flow Study of Molten Weld Metal Using the Modified Casson Prediction Model

2011 ◽  
Vol 403-408 ◽  
pp. 491-495
Author(s):  
Joseph I Achebo
Keyword(s):  
Shear Stress ◽  
Weld Metal ◽  
Prediction Model ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Test Results ◽  
Upward Flow ◽  
Viscoplastic Flow ◽  
Flow Equations ◽  
Flow Study

This paper principally examines the flow pattern that occurs when molten weld metal droplets are detached from globule formations at the tip of an electrode and are thereafter transported to the weldpool. This viscoplastic flow study was done using the modified Casson prediction model which is based on the Newtonian Homogenous Flow equations. Both chemical and mechanical tests were done. The inclusions (Slag) were found to possess an upward flow of 3 ms-1. The mechanical test results show that the shear stress of 483.2 MPa, which exceeded a yield stress of 230 MPa, was responsible for the continuous slipping movement of the molten metal towards the center of the weld pool at a velocity of 1.2ms-1. The results obtained by the application of this model were validated by both computational and experimental results obtained by other researchers.

scholarly journals Mechanical properties of highly porous PEEK bionanocomposites incorporated with carbon and hydroxyapatite nanoparticles for scaffold applications

2019 ◽  
Vol 8 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Md. Nizam Uddin ◽  
Puttagounder S. Dhanasekaran ◽  
Ramazan Asmatulu
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Pore Size ◽  
Mechanical Tests ◽  
Bone Diseases ◽  
Filler Materials ◽  
Test Results ◽  
Micro Computed Tomography ◽  
Carbon Particles ◽  
Highly Porous

Abstract Bone regeneration is of great importance worldwide, because of various bone diseases, such as infections, tumors, and resultant fracture, birth defects, and bone loss due to trauma, explosion, or accident. Bone regeneration can be achieved by several materials and templates manufactured through various fabrication techniques. Uses of different materials and scaffold fabrication techniques have been explored over the past 20 years. In this research, polyetheretherketone (PEEK) was used to fabricate highly porous bionanocomposite foams for bone scaffolding. Melt casting and salt porogen (200–500 µm size) leaching methods were adapted to create an adequate pore size and the necessary percent of porosity, because pore size plays a vital role in cell implantation and growth. Porosity (75% and 85%) of the prepared scaffolds was adjusted by changing salt concentrations in the PEEK powder. Hydroxyapatite (HA) and carbon particles were used to improve cell attachments and interactions with the porous PEEK and to increase the mechanical properties of the scaffold materials. Carbon fiber (CF) and carbon nanotubes (CNTs) were uniformly dispersed into the PEEK powder before melt casting to enhance the mechanical properties and to observe the influence of the carbon particles on the properties of PEEK bionanocomposite foam. Compression test results of the fabricated bionanocomposites showed that HA and carbon particles are the potential filler materials for the enhancement of bionanocomposite mechanical properties. About 186% enhancement of compression modulus and 43% enhancement of yield strength were observed while incorporating only 0.5 wt% of CNTs into PEEK/HA bionanocomposites having 75% porosity, compared to PEEK/HA 20 wt% bionanocomposites. Micro-computed tomography (micro-CT) test results reveal that pore size and interconnectivity of the nanocomposite foams are in order and within the designed sizes. Mechanical tests proved that PEEK bionanocomposite foam has the potential for use in bone scaffolding and other biomedical applications.

Experimental Analysis of Interlocking Load Bearing Wall Brickool System

2013 ◽  
Vol 594-595 ◽  
pp. 439-443 ◽  
Author(s):  
S.A. Osman ◽  
Zawawi Samba Mohamed ◽  
A.R. Sulaiman ◽  
M. Fikri Ismail
Keyword(s):  
Experimental Analysis ◽  
Failure Load ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Structural Behavior ◽  
Test Results ◽  
Wall Panel ◽  
Load Bearing ◽  
Minimum Requirement ◽  
The Individual

This paper presents the results of investigation on structural behavior of the load bearing walls of interlocking bricks system called Brickcool. The model of Brickcool load bearing walls with and without reinforcement were tested in the laboratory until they failed. Both models were prepared with the same dimension of 1.3 m height, 1.0 m wide and 125 mm width. The influence of reinforcement on the deflection and strain of the load bearing walls were examined. Physical and mechanical tests of the individual brick were also been carried out. Results of this study proved that the model of load bearing wall with reinforcement have higher failure load with lower displacement at the top of the wall. The presence of reinforcement in strengthening the wall panel also increase the compression and tension strain compared to the wall panel without reinforcement. The physical and mechanical test results also found that the bricks have satisfied the minimum requirement values set by the British and American Standards.

scholarly journals Mechanical Studies of Injection Molded Composites with Polypropilene Matrix

2018 ◽  
Vol 1 (2) ◽  
pp. 105-109
Author(s):  
Ráthy Istvánné ◽  
Pinke Péter ◽  
Huszák Csenge
Keyword(s):  
Mechanical Tests ◽  
High Tech ◽  
Test Results ◽  
Processing Technologies ◽  
Standard Specimens ◽  
Glass Fibre Reinforced ◽  
Injection Molded ◽  
Polypropylene Matrix ◽  
Reducing Costs ◽  
New Processing

Abstract The wide use of composite materials is mainly due to their excellent strength / mass ratio, corrosion resistance and relatively low price. Approximately 35-40% of the fibre-reinforced composites are made of thermoplastic polymers in which fibreglass, carbon or natural fibres are most often used as reinforcement, while the remaining 60 – 65% is made up of high-tech carbon or glass fibre-reinforced thermosetting composites. Most of them are used in the transport and electronics industries. New processing technologies not only improve the properties of the products but also contribute to reducing costs. In this paper, we compare the results of mechanical tests with molded standard specimens with polypropylene matrix and test results from cut-outs from injection molded products.

Physical and Mechanical Properties of Warm Compacted Carbon-Copper Composite by Different Powder Formulation

2016 ◽  
Vol 1133 ◽  
pp. 146-150
Author(s):  
Mohd Afiq Nurul Hadi ◽  
Mohd Asri Selamat ◽  
Salina Budin ◽  
Talib Ria Jaafar ◽  
Ahmad Aswad Mahaidin ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Rupture Strength ◽  
Physical And Mechanical Properties ◽  
Hydraulic Press ◽  
High Porosity ◽  
Test Results ◽  
Commercial Sample ◽  
Mechanical And Electrical Properties ◽  
Three Samples ◽  
Copper Composite

Carbon(C)/Copper(Cu) Composites based materials were developed by associating both pressure and heat to the mixture of the powder. Three samples of different formulations were prepared by the powder metallurgy route in which the C-Cu powder were mixed with E-poxy Resin in a tubular mixer, pre-compacted using an automated hydraulic press machine, warm compacted using a warm compaction machine and finally post baked in oven. Each sample was subjected to density, hardness, transverse rupture strength and resistivity tests. The microstructures of the sample were observed under the scanning electron microscope. Test results of the developed samples show that sample C produced the highest physical, mechanical and electrical properties. However, the samples developed had lower physical, mechanical and electrical properties as compared with the commercial sample. This phenomenon was taught to be due to high porosity and insolubility of carbon and copper in the sample developed. Thus, father study will be done based on sample C formulation.

Development of a Self-Opening Neural Interface

2013 ◽  
Vol 7 (2) ◽  
Author(s):  
Annarita Cutrone ◽  
Sivia Bossi ◽  
Silvestro Micera
Keyword(s):  
Electrical Properties ◽  
Nervous Tissue ◽  
Three Dimensional ◽  
Mechanical Tests ◽  
Neural Interface ◽  
Dimensional Structure ◽  
Biocompatible Polymer ◽  
Three Dimensional Structure ◽  
Preliminary Results ◽  
Mechanical And Electrical Properties

This article illustrates the development and preliminary results of SELINE, a self-opening neural interface. The advantages of this innovative neural interface are: higher selectivity due to its three-dimensional structure and efficient anchorage system to the nervous tissue. The device is made of polyimide that is a lightweight, flexible and biocompatible polymer. The electrode has been microfabricated using lithographic techniques; electrical and mechanical tests have been performed to evaluate the integrity of the device. Successful results have been obtained in the development of the electrode with excellent mechanical and electrical properties.

Microstructure and Mechanical Properties of n-Irradiated Fe-Cr Model Alloys

2006 ◽  
Vol 981 ◽  
Author(s):  
Milena Matijasevic ◽  
Abderrahim Al Mazouzi
Keyword(s):  
Mechanical Stability ◽  
Tensile Tests ◽  
High Energy ◽  
Mechanical Tests ◽  
Test Results ◽  
Martensitic Steels ◽  
Irradiation Hardening ◽  
Cr Concentration ◽  
Accelerator Driven Systems

AbstractHigh chromium ( 9-12 wt %) ferritic/martensitic steels are candidate structural materials for future fusion reactors and other advanced systems such as accelerator driven systems ADS). Their use for these applications requires a careful assessment of their mechanical stability under high energy neutron irradiation and in aggressive environments. In particular, the Cr concentration has been shown to be a key parameter to be optimized in order to guarantee the best corrosion and swelling resistance, together with the least embrittlement.In this work, the characterization of the neutron irradiated Fe-Cr model alloys with different Cr % with respect to microstructure and mechanical tests will be presented. The behavior of Fe-Cr alloys have been studied using tensile tests at different temperature range ( from -160°C to 300°C). Irradiation-induced microstructure changes have been studied by TEM for two different irradiation doses at 300°. The density and the size distribution of the defects induced have been determined. The tensile test results indicate that Cr content affects the hardening behavior of Fe-Cr binary alloys. Hardening mechanisms are discussed in terms of Orowan type of approach by correlating TEM data to the measured irradiation hardening.

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