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Aiming at the optimization design of spindle, this paper introduces deflection constraint, strength constraint, corner constraint, cutting force constraint, the limit of torsional deflection, boundary constraint of design variable, dynamic property constraint , realizes the expression of the mathematical model of the spindle optimization design.
The performance of spindle directly affects the Machining accuracy, surface quality and productivity, which is a key factor that decides the Whole-performance and economic and technical norms of machine tools [1-2].
A good performance spindle system must have higher static stiffness and dynamical property.
So the objective function can be represented as shown below: （2） , is weight factor, which reflects the degree of importance of each objective function. ,, and means the bending deflection of spindle itself, means the displacement caused by spindle nose.
Genetic algorithms and finite element coupling for mechanical optimization[J].

High speed mixer,GRH-10, Light mechanical and electrical equipment factory in Fuxin City,Liaoning Province.Parallel twin-screw extruder,ZSK-25WLE,WP Company in Germany.Injection molding machine,HTF120X2,Ningbo Haitian Plastics Machinery Group Co.
Fig 11 The relation between thermal conductivity and the test temperature and humidity Figure 11 shows that the thermal conductivity of composites is mainly affected by the test temperature and the air humidity.In the lower temperature (lower than the Debye temperature),the thermal conductivity increased with the temperature and humidity increasing.
The thermal conductivity of composites decreases with the injection speed increasing.The orientation of polymers affect thermal conductivity.The trend of density and electrical conductivity of some points of samples is similar,which is related to the crystallization and carbon content.
Test temperature and humidity affect the thermal conductivity.In a lower temperature,the higher temperature,the greater humidity and the higher thermal conductivity.
Properties of Iron Powder Filled High Density Polyethylene [J].

The main probable factors of its formation at each technological stage of production are established.
Khilko [1], is interpreted as a threat to the deterioration of the quality of the environment, damage to humans, populations and groups of living organisms, due to the presence or potential of harmful natural and anthropogenic factors.
It is the accumulation of waste that has become one of the most significant factors in environmental pollution, with a negative impact on all its components [7, 8].
The issue of emergency stop of the production process at an oil extraction plant, as one of the factors of ensuring environmental safety, was discussed in O.
According to the results of the monitoring of the state of ecological danger, private joint stock company “Kropyvnytskyi oil extraction plant” identified the main probable factors of its formation. 3.

The listed factors are the cause of intensive paraffin crystallization on the walls of equipment during mining, transportation and storage of oil.
Thus, here are presented results of an experimental study of impacts of the chemical nature of the solvent on crystallization/melting processes of paraffin systems in order to create an insulating layer made from paraffin deposits with specified properties.
The subjects of our study were 10% wt. solutions of this ARPD in gas condensate (GC) [3], produced in the Irelyakhskoye oil and gas field and currently used for removal of ARPD, and in n-undecane (n-С11) - as a model of its gasoline fraction, as well as in the their composite solutions with the addition of cyclohexane and p-xylene - for assessment of effects of naphthenic and aromatic components in the composition of GC and n-С11 on properties of crystallized paraffins.
This factor allows us to favor a triple solvent with GC, as its usage does not require fractionation, and, therefore, it will be more profitable.
Crystallization and dissolution temperatures, and Newtonian and non-Newtonian flow properties, Energy&Fuels. 5 (1991) 895-908

As the welding of stainless steel and copper belongs to dissimilar metal welding and their physical properties are very different, thus the welding process is difficult and it is likely to cause a variety of defects in the welding process.
In addition, after welding, the welding parts all appear deformation and thin-walled tubes are tend to have greater deformation which affects the quality of welding parts.
In the while, the cooling process between surface and inside and superimposed phase transition will also affect the axial residual stress distributions.
Analytical stress intensity factor solutions for resistance and friction stir spot welds in lap-shear specimens of different materials and thickness.
Effects of temperature-dependent material properties on welding simulation.

Under suitable climatic conditions cross-ventilation represents energy-efficient alternative to mechanical cooling.
The speed of the outdoor air flow is another key factor in determining the cooling capacity.
Prevailing wind often changes with the night period, but it may also vary throughout the day, affecting the cross-ventilation and its capacity for cooling.
The length of the tube is a function of the required cooling capacity, tube diameter, and other factors affecting the cooling, such as: local soil conditions, soil moisture, and the depth of the tube as well as other specific factors, such as vegetation or cooling by evaporation.
Technically, louvres can be optimized by increasing its dispersion reflective properties of its outer side to the degree of reflection ≈ 70% (highest light transmission) and by gray coloring of the inner side (reduction of brightness and glare) to the degree of reflection ≈ 25% at emission rate ε = 0,9.

Building Physics Institute, Housing and National Research Center (HBRC), Egypt 2Al-Azhar University, Mechanical Engineering Department, Cairo, Egypt 3King Saud University, Department of Industrial Engineering, Riyadh, Kingdom of Saudi Arabia aayazaki1979@hotmail.com, bRamy.el.kady.18@azhar.edu.eg, ctamerkhalaf@azhar.edu.eg, dMelkady@aucegypt.edu, esayed_shebl@yahoo.com *corresponding author Keywords: Intumescent coatings, fire resistance rating, steel structure, NFPA 251, EN 13381.
A comparative study was conducted between NFPA 251 and EN 13381-8 to investigate the contribution of the difference in standard specification conditions in affecting the measured fire rating time.
The parameters which affect the test results are classified as follows: Controllable parameters · Temperature -Time Curve
As the two standards possess approximately the same time-temperature curves, the details/ instructions of thermocouples (numbers and locations) used for measuring steel temperatures have been selected as the main influencing factor.
[11] Jing Han Beh, Ming Chian Yew, Lip Huat Saw, Ming Kun Yew, Fire Resistance and Mechanical Properties of Intumescent Coating Using Novel BioAsh for Steel, Coatings 2020, 10, 1117; doi:10.3390/coatings10111117

Its properties as a transducer include: wide frequency range of 0.001 Hz to 9-10 Hz, low acoustic impedance of close match to water, human tissue and adhesive systems, high elastic compliance and voltage output that is 10 times higher than piezo ceramics for the same force input, high dielectric strength, mechanical strength and impact resistance, and high stability on resisting moisture, most chemicals, oxidants, and intense ultraviolet and nuclear radiation [4,5].
Interfacial shear strength (IFSS) between fiber and matrix is one of the important factors in controlling mechanical performance of polymer composite materials.
Piezoelectric properties are induced by high dielectric properties based on chemical structure.
Thickness of PVDF sensor does not seem to affect on the sensing and thus thinner sensor might be desirable for the embedding
From the results of FFT analysis, the frequency for PZT was dissimilar to PVDF sensor case due to different sensor material's properties.

Surface quality is affected by various processing parameters and inherent uncertainties of the metal cutting process.
Surface roughness and dimensional accuracy are significant factors in predicting the performance of any machining operation.
Many of the properties of 7136 aluminum alloy are superior to other materials, including high strength to weight ratio, high wear resistance, low thermal expansion, corrosion resistance, durability, ductility, and conductivity, which make it a versatile material.
As to the productivity related to surface roughness, according to obtained data from the experiment, we found that the best ratio of these two factors is to the cutting regime: cutting speed at 530 m/min, feed per tooth at 0.14 mm/tooth and cutting depth at 4 mm, resulting a surface roughness of 0.212 μm.
D., Ambekar, A Review on Optimization of cutting parameter for surface roughness, material removal rate and machining time of aluminium LM-26 alloy, International Journal of Research in Aeronautical and Mechanical Engineering. 2 (2014) 23-28

The life time of rolling bearings of gear is affected by the vibration.
Bearing life is expressed by following equation L = a F C n p e e ⋅        ⋅60 106 (1) where: L - bearing rating life, operating hours, Ce - bearing load rating , (Ce = C ⋅ft ) , N ft - temperature adjustment factor (ft = 1 for the temperature up to 125 0C) Fe - equivalent bearing load ( Fe = F ⋅ fd ), N fd - load adjustment factor (fd = 1 at smooth operation, free from shocks) fd = 1,5 - 3,0 load factor for operation accompanied by shock and vibration p - exponent of the life equation ( p =10/3 for roller bearings) n - bearing speed , rpm ft = 1 for the temperatures up to 1250C a - resultant adjustment factor which reflects the improvements in the calculation of fatigue life (a = a1a2 a3) a1 -life adjustment factor for reliability, a2 - life adjustment factor for special bearing properties, a3 - life adjustment factor for operating conditions.
FA(B) = ⋅X Fri + Y Fai (3) where: X - radial load factor for the bearing, Y - axial load factor for the bearing.
These errors generate additional dynamic forces that result in the excessive mechanical and thermal loads of the rolling bearings of worms.
[2] Handbook of Mechanical Engineer.