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This study aimed to evaluate antimicrobial property of vanillin-incorporated orthodontic retainer PMMA resin on the biofilm formation of cariogenic bacteria.
The use of this appliance may affect the quantitative and qualitative distribution of oral microbiota [13, 14].
In addition, the presence of orthodontic retainers in the oral cavity limits the mechanical self-cleansing process providing by saliva and musculature movement.
With the resultant effect of all these factors, pH value of biofilm drops in the presence of fermentable carbohydrates and promotes the deposition and maturation of cariogenic biofilm that leads to enamel decalcification and dental caries.
Further studies are required to investigate the flexural strength, which is an important mechanical property, and other physical properties of this vanillin-incorporated PMMA resin along with the clinical evaluations to verify these results as well as the biocompatibility of this material.

Main auxiliary variables which affected the dyeing uptake rate including temperature, holding time and pH.
where is the forgetting factor,; is a sufficiently large positive number; is the correct power factor; is the positive covariance matrix.
According to the equivalence property between GPC and DMC control law, the predictive vector is shown as (8):
Considering the robustness of the control system and how the present control output affects the future time of the system, we define the performance index as (9):
The predictive length n=6; the length of time domain p=6; the length of control m=2; control weighting coefficient; forgetting factor;;.

In recent years, a great deal of research have been done [2]~[5].However, the most studies have been on solid piles, and research on the vibration property of pipe pile is relatively rare.
The longitudinal vibration boundary value problem of thin-wall cast-in-situ pipe piles in embedded axisymmetric uniform viscoelastic foundation and dynamic response problem of thin-wall pipe pile on low strain and variable impedance are researched by Xuan ming Ding etc[7], [8].The coupled torsional vibration theory between the saturated heterogeneity soil and pile was studied by Zhi Qing Zhang[9].Because the soil in the lasting load usually show creep characteristics, in order to depict the mechanical behavior of soil, it is necessary to take the soil as a viscoelastic media.
Torsion vibration displacement amplitude of the soil of inside pile is as follows: (14) Where, .From Eq. 14, amplitude of tangential shear stress on unit area affected by the soil of inside pile, ‘’,can be written as: (15) Where, represents the first type of Bessel function for the second order deformation.
of the torsional complex stiffness of the pile top, (30) In order to convinient for calculation, the dimensionless factor of the torsional complex stiffness of the pile top is written as: ,is the real stiffness of the pile top, is the Dynamic damping of the pile top。
Conclusion Through parameter analysis, the factors influencing the torsional dynamic impedance of the viscoelastic soil are discussed.

Heat transfer characteristics of MEPCMS in turbulent flow: a review Mei He 1, a, Zhongzhu Qiu2,b and Pan Zhang 3,c 1, College of Energy and mechanical engineering, Shanghai University of Electric Power, 2103 Pingliang Road, Shanghai, China ahemei90328@126.com, b 1050079260@qq.com Keywords: heat transfer coefficient, degree of turbulence, heat transfer correlations Abstract.
This article mainly makes a brief introduction about Microencapsulated Phase Change Material Slurries(MEPCMS) and its preparations ，the research status and several correlations of heat transfer in turbulent flow of MEPCMS are also listed.The influencing factors of turbulent heat transfer are mainly the degree of turbulence, the mass fraction and wall heating rate,particle size effects weakly.
polymerization Melamine-formaldehyde n-Octadecane 59 2.2 40.6 144.0 In situ polymerization Polyurea Hexadecane - 2.5 15.5 66.1 Interfacial polycondensation Polyurea Butyl stearate 66 20-35 28.6 76.3 Interfacial polycondensation Melamine-formaldehyde n-Octadecane 70 9.2 30.5 169.0 In situ polymerization Urea-melamine- formaldehyde n-Octadecane 72 0.8 36.5 167.0 In situ polymerization Urea-melamine- formaldehyde n-Nonadecane 69 — 30.3 233.0 In situ polymerization Urea-melamine- formaldehyde n-Eicosane 71 — 45.3 172.0 In situ polymerization Melamine-formaldehyde n-Octadecane 40 1.6 — 166.0 Emulsion polymerization Melamine-formaldehyde Lauryl alcohol 75 9.2 — — In situ polymerization Polymethylmethacrylate n-Docosane 28 0.16 41.0 54.6 Emulsion polymerization Polymethylmethacrylate n-Eicosane 35 0.7 35.2 84.2 Emulsion polymerization Fig 1 The appearance of MEPCMS Research status and heat transfer correlations Several researchs have been conducted to explore the flow and heat transfer properties
Conclusions Turbulent slurry flows are not only affected by the mass fraction and wall heating rate, but are greatly influenced by turbulent degree.

Introduction Nanocrystalline metals and alloys, with average grain sizes typically smaller than 100 nm, exhibit superior mechanical properties such as the superior yield strength[1-3], sensitivity to strain rate[4] and low temperature superplasticity [5] etc. and so have been the subject of considerable research in recent years.
There is extensive literature published on the fabrication [6-9] and mechanical properties of NC materials [1-4, 10-12].
Numerical simulation of the fabrication process The strain of the sample and the strain rate are important factors which will affect the grain refining, but exact and full-scale data cannot be obtained by the current testing method due to the gleam process and the ununiform of the strain.
In general, the response of material under high-speed impact involves consideration of the effect of strain, strain rate and temperature, so the Johnson–Cook material model was used here to discribe the materials’ mechanical property[14] and Mie Grüneisen equation of state(EOS) was adopted to describe the compressive materials which can be written as [15] Eqs.(4) and (5): (4) wherein is the flow stress; is the equivalent plastic strain; is the strain rate; is the reference plastic strain rate; T is the temperature of the work material; Tm and Troom is the melting temperature of the work material and room temperature respectively.
Morris: Mechanical behavior of nanostructured materials(Trans Tech Publication Inc, Geneva 1998 )

In processing of structure ceramics materials with diamond grinding wheel, grinding heat is one of vital factors influencing workpiece surface quality.
It was proved that grinding depth is the most vital factor influencing grinding temperature field through orthogonal experiments.
Introduction Owing to many merits, such as high intensity, high hardness, low density, low expansion coefficient and so on, structure ceramics have become a kind of key engineering material widely used in aerospace, petrochemical engineering, instrumentation, mechanical manufacture and nuclear industry.
Grinding temperature speed descends slowly just because ceramic material with poor thermal conductivity property can preserve heat, as is far differences from metal material.
Because the increase of grinding depth will consume more mechanical work, which will result in more heat energy produced, therefore the grinding temperature is affected deeply by grinding depth. 2) Regardless of common grinding or ultrasonic grinding, the grinding temperature increases with the wheel speed.

The latter characterize the thick-wall (>10mm) part for high shock resistance and high optical properties requirement.
Although ICM is a recent developed process, a few researchers have studied its design, process, properties to make it progress on industry application.
Based on the experimental results, some analyses will be conducted to identify the most important factor to influence the part property. 2.
The material properties were summarized in Table. 1.
Table 1 Material Properties of Selected PC Material Properties Value Relative Molecular Mass, Mn 2.03×104 Special Gravity, ρ (g/cm3) 1.196 Melt Flow rate, (g/10min) 8.6 Glass Transition Temperature, Tg (oC) 148 Light Transmission, (%) 89.9 2.2 Parts geometry and mold design The length and width of part1 are 550mm*280mm, and the thick is 4mm, which is typical thin-wall part.

Saeed AhmadiSoleymani 1, b Amir Abdullah 1, c , Omid Asgari 2,3,d, Foad Rezai 2,e 1 Department of mechanical engineering, Amirkabir University of technology, Tehran, 15875-4413, Iran 2 Department of Mechanical Engineering, Sharif University of Technology, Tehran, 11365-9567, Iran 3IranKhodro Powertrain Co.
Constant volume transparent test combustion chambers are extensively used for investigating injection and fuel burning properties of various combustion engines.
The material properties of quartz windows (based on the manufacturer report [5]) are as shown in table 1.
Material properties of fused silica Density 2200 Young’s modulus 72 Poisson’s ratio 0.17 Modulus of rapture (Abraded) 52.4 Thermal conductivity 1.46 Coefficient of thermal expansion 5.4 Specific heat 700 A hex- mapped mesh was used to increase the accuracy of the results.
Results and Discussion Since fused silica has a very low coefficient of thermal conductivity and the period of temperature increase is short, ignition could not extensively affect the quartz windows and it could only increase the temperature of the surface of the windows.

Electromagnetic wave absorbing properties in GHz region were investigated for magnetite prepared by hydrogen reduction of hematite, which was synthesized via drip thermal oxidation using a fluidized bed.
Referring to Table 1, it seemed that the absorption properties improved when the specific surface area of the powder product was high.
As indicated in Fig. 3(c), primary particles of the latter had both needle-like and sheet-like shapes, which could be one of the factors leading to the improvement in the electromagnetic wave absorption properties.
These properties were compared with those obtained via hydrogen reduction of hematite prepared by wet precipitation.
Puryanti, Magnetic and microwave adsorbing properties of magnetite-thermoplastic natural rubber nanocomposites, J.

Then the total mass flow through a face is computed by adding the groove and land mass flows averaged by the appropriate weight factor, ψη and (1-ψη), respectively.
The same principle is also used in groove/dam boundary through another weight factor, ψξ, in Figure 4(b).
We can see that the using JFO model increases cavitaiton area, at the same time, cavitation model affects the calculated positive pressure distribution.
Thus, we can conclude that cavitation occurrence significantly affects the sealing performances.
The effects of cavity fluctuation on the elastic and damping properties of journal bearings[J].