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Introduction Plastics were quickly introduced to people’s everyday lives and its consumption has grown mainly due to very good properties such as low density, long life, light weight, satisfactory mechanical resistance and so on, besides having low cost and easy fabrication.
Aware of the importance of the mechanical properties of this type of material, structural and civil engineers have been incentivized to use it in infra-structure renovation, allowing plastics to be used as structural reinforcement, among other applications [1].
The table 1 summarizes the norm’s required properties for recycled aggregates to be eligible to paving applications.
Table 7 – Properties of aggregate mixtures Property Natural aggregate mixture Recycled aggregate mixture Specified standards Uniformity coefficient (Cu) 15 12 > 10 Maximum aggregate diameter (mm) 9.5 9.5 ≤ 63.5 Passing 0.42 mm sieve percentage 41 29 10% to 40% Passing 0.075 mm and 0.42 mm sieves percentages ratio 0.1 0.1 < 2/3 As seen in Table 7, the results fulfill the specified standards [13, 19].
Variations in the results of the compaction curves of recycled aggregates with respect to the literature might be due to several factors, such as energy applied, source and heterogeneity of aggregates and amount of water added to the samples.

Compared to Y-TZP ceramics, alumina ceramics shows a lower bulk dense, higher Young's modulus and hardness, low linear thermal expansion coefficient and higher thermal conductivity, and cheaper, on the other hand, inferior mechanical properties.
It was reported that the method of adding Y2O3 had effect on the microstructure and properties [5].
Table 1 The properties of CYADZ and MYADZ Properties Density [g.cm -3] Hardness [GPa] Strength [MPa] Toughness [MPa.m -1/2] Average ZrO2 grain Size [µm] Maximum ZrO2 grain size [µm] CYADZ MYADZ 5.616 5.498 12.5 11.6 873.89 ± 31.43 527.44 ± 28.52 12.32 ± 0.56 11.19 ± 0.86 0.30 0.50 0.7 1.8 Fig. 1 SEM micrographs of the surface sintered at 1510℃for 2 h (a) CYADZ, (b) MYADZ Results and Discussion Properties and microstructure.
The properties of the specimens are given in Table 1.
Wear properties.

The aggregates are the main composition in cement concrete and have important effects on the properties of the concrete.
The properties of aggregates are measured according to the national standard GB/T50080-2002(Ordinary Concrete Mixture Performance Test Method Standards) and GB/T50069-2002 (Mechanical Properties Methods Of Ordinary Concrete).
The effects of composition on the properties of the man-made aggregates were studied and the compositions of the aggregates were optimized.
As shown in Fig.1, that the calcination temperature is the major factor which affects the artificial aggregate properties.

Increasing torsional deformation can obviously improve the dynamic softening properties of the material and metal mobility, improve the deformation uniformity, reduce the deformation dead zone, reduce the central strain, and increase the edge strain.
Introduction Inconel 718 was initially developed in the 1950s and has since gained widespread recognition for its exceptional properties [1,2], including high strength at elevated temperatures [3-5], outstanding corrosion resistance [6].
Structural samples were fabricated using 3D printing technology, and their corresponding compression-torsion properties were studied through compression experiments.
To predict the temperature and deformation evolution of Inconel 718 alloy, the material properties were investigated and acquired from previous works of hot deformation behavior of the Inconel 718 alloy to achieve the desired properties and used to optimize the thermomechanical processing variables, details of finite element model are given in Table 3.
Process parameters adopted in the simulation Paremeters Value Thermal properties Convection coefficient (N/s/mm/C) 0.02 Thermal conductivity at 1000 °C (W/m K) 23 Thermal expansion coefficient (°C) 1.86 × 10–5 Emissivity 0.5 Mechanical properties Flow stress Ref [19] Young’s modulus (MPa) 202,706 Poisson’s ratio 0.37 3.

In order to overcome the poor fatigue properties of threaded fasteners, a simple concept is used to keep the stress range in the fasteners to a low value.
Although the concept is simple, there are a great many factors to be taken into account in order to achieve a successful design and installation.
The standard considers a comprehensive range of factors relating to the behaviour of bolted joints, including for instance: · Initial tightening, preload and losses, · Additional longer term loss of preload tension, · The effects of applied loads (including in particular cyclic loads), and · A range of factors such as pressures under bolt heads, nuts and washers, minimum thread engagement lengths, and safety against joint slip.
Modern structural engineering design approaches, such as Limit States Design (Australia) [4] and Load & Resistance Factor Design (USA)[5], establish a margin of safety between an assessed load capacity and an estimated maximum design load (the total margin of safety may be expressed as partial factors applied to the design load and to load capacity).
In addition to the design issues noted above, particular practical issues to be considered include bolt quality, the potential for corrosion and other environmental factors to affect bolt fatigue performance, tolerances to achieve proper mating of the flange faces, and the preload which can be reliably achieved in the bolts.

Concentrations of heavy elements in the studiey region Cobalt is affected by the concentration of carbon dioxide in the soil and is affected by several factors, including: the origin and composition of the soil, and weathering operations, as well as the effect of wastewater, it was affected by human activities, the highest cobalt rise was recorded in Mohammed Sakran which is (160) (Ppm) Figure 4 (h).
This is because crops are affected by copper deficiency and benefit from fertilization and copper, which generally leads to reduced incidence of agricultural diseases, increased plant growth and better quality.
The industrial waste and car exhaust should be treated and handle a control law to limit their affects Acknowledgements Thanks to the Ministry of Science and Technology, Department of Materials, for their assistance in analyzing and measuring the samples References [1] Al Saadi and Hussein A.
The Aquatic Environment, Al Yazouri Scientific Publishing House, Amman Jordan, pp: 307,(2006) [2] Kareem Ali Jassim, Haider Sahi Hussein, Effect of Partial Substitution of Lanthanum (La) on the Structural and Electric Properties of Bi2Sr2Ca2Cu3-xLaxO10+δ, Ibn Al-Haitham J. for Pure & Appl.
Thejeel, Raghad Subhi Al-Khafaji, The Effect of Doping by Sr on the Structural,Mechanical and Electrical Characterization of La1Ba1-xSrx Ca2Cu4O8.5+δ, Ibn Al-Haitham J. for Pure & Appl.

Many research works [5-8] have been conducted to obtain polymer electrolytes with high ionic conductivity and good mechanical properties as well as good electrochemical stabilities.
Both cation - anion and cation - polymer interactions presumably affect the ionic mobilities.
The ion transport property depends on various factors like the degree of salt dissociation and its concentration, dielectric constant of host polymer, degree of ion aggregation, and mobility of polymer chains [12].
The linear plots of log σ versus 1000/T suggests an Arrhenius-type thermally activated process, which can be expressed by: σ = σo exp (-Ea/RT) (3) where σo is the conductivity pre-exponential factor and Ea is the activation energy for conduction [20].
The relationship between the conductivity and the dielectric loss factor can be expressed by: (4) where w and eo is the angular frequency and permittivity of free space, respectively.

Factors that affect the polymerization of silica sol are SiO2 concentration, temperature, electrolyte and water soluble organic matter (such as alcohol, ketone, etc.) and pH, etc[5].
Therefore, when the above factors are appropriate, it's easy for -OH on the surface of SiO2 particles to polymerize and form gel.
Liu, Preparation and adsorption property of phenyltriethoxysilane modified SiO2 aerogel, Wuhan Univ.
Kumar, Reduction of processing time by mechanical shaking of the ambient pressure dried TEOS based silica aerogel granules, J.
We, Effect of acids on properties of silica aerogels prepared from silica sol at ambient pressure, J.

If concrete is subject to high temperature, the bearing capacity is obviously decreased and the failure is attained in the end of continuing fire and its mechanical behavior changes dramatically with the increase of temperature.
However, the property of polypropylene fiber concrete (PFC) under fire has not been investigated enough.
After several decades of research, it is known that there is a complex combination of chemical, physical and thermodynamic factors that influence explosive spalling.
Increased fibre content did affect the anti spalling performance of the concrete when compared to plain concrete. 3）More tests are required to establish precise data with regard to fibre content effectiveness to prevent spalling, particularly with different strength concrete and different moisture contents.
B., "Effects of Polypropylene Fibers on the Properties of High-Strength Concretes."

Abstract: The construction of subway engineering, with its internal properties, was regarded as a high risk project.
The intrinsic properties in rail transit construction determined it is a high-risk project.
These unique properties determine that the subway construction is a high risk project.
The accident causation sequence theory, which is put forward by Heinrich, clarified that the various factors led to deaths and injuries as well as the relationships among these factors.
Most proportions of risk factors, the people’s unsafe behaviors, cannot be avoided by monitoring.