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Introduction In general, fibers have been used to improve mechanical properties of materials.
They have also been used in biomaterials applications, where their use, however, is not limited only to improvement of mechanical properties.
Mechanical properties can be improved with intensive heat-treatment, but it is obvious that biodegradation and bioactivity is reduced due to denser structures and decreased surface reactivity, respectively.
The problems with mechanical properties and moldability can be overcome by preparing composites with polymers.
The in vitro properties of the sol-gel derived silica fiber-PLA composites have not been studied earlier.

Input factors No.
In the mentioned method, the signal-to-noise ratio (S/N) is used to justify the influence of process factors.
Optimization of machining time The results of analyzing the impact of the input factors on S/N of the machining time are defined in Table 6, 7 and Fig. 3.
From the ANOVA results of the average machining time values (Table 5), it is noted that IP is the most important factor that affected the machining time.
Calculated and experimental results Objective properties Optimal process parameters Calculation Experiment Error (%) Ton2/Cp3/Toff1/IP3/SV1 Ton2/Cp3/Toff1/IP3/SV1 Machining time (s) 2849 2568 9.86 To evaluate the proposed model, an experiment was done with the optimum input factors and Table 8 shows the experimental and calculated results.

Progress on Cytotoxicity in Vitro of Carbon Nanotubes Xing Zhi-hua College of Pharmacy ,Harbin University of Commerce, Harbin，China 150076 xzhh0451@163.com Keywords: Carbon nanotubes,Cytotoxicity in vitro,Progress Abstract.According to recent references, the progress on cytotoxicity in vitro of carbon nanotubes (CNTs) including the factors such as size , residual metal catalysts,and detection methods influencing cytotoxicity of CNTs are summarized.
Practical research results of CNTs in application field of electronic, optical, biomedical, catalytic, and energy storage were reported after almost twenty years, among which study on the application of biomedical is a newly arisen research direction and a research focus in nanomedicine field.Due to their unique electronic and mechanical properties combined with chemical stability, CNTs has been produced in ton quantities, and their potential application ranges from biomedicine through nanoelectronics to mechanical engineering are more and more wider. 1 Manifestations of toxicity of carbon nanotubes There were many kinds of literatures on cytotoxicity in vitro of carbon nanotubes recently .
The main cyto- toxity manifestations have mainly dose-dependent and time-dependent manner, Content of reactive oxygen species(ROS) in cells increased with the high dose and long action time of CNTs[2-5].ROS results in cell apoptosis/ necrosis [6-9], inhibition of cell growth and proliferation[10], gene expression maladjustment[11]. 2 The factors influencing celsl toxicity of CNTs 2.1 Effect of CNTs size on cells toxicity When studying on cells toxicity of CNTs, many researchers showed the toxity mainly depends on the size of CNTs including diameter and length[12].The thinner the CNTs is,the higher the toxity is,which is corresponding to SWCNTs > MWCNTs in toxicity.Maybe the reason is the smaller the CNTs is, the easier the CNTs enters into the cell interior.
The degree and kind of agglomeration affect carbon nanotube cytotoxicity.

Introduction Aluminum matrix composites (AMCs) are being widely applied in many areas due to its good compressive strength, wear resistance, light weight and useful mechanical properties.
Ex-situ methods are usually expensive because it needs to produce reinforcement phases first, and if their size is required to be from some hundreds nanometers to some micrometers, that needed for improving mechanical properties of AMCs, the cost is even higher.
So, in this work the attention is focused on the kinetics of AlN particles formation, that was mentioned in [6], but in which the method only was suggested without concrete calculation, may be because of the lack of value of some factors.
However, these factors are difficult to determine and there is no further calculation so far.
The factor, ƟAlN, can be determined more easily based on the XRD results.

KCl drilling study Wellbore instability is due to mechanical and chemical factors that caused two aspects.
The ultimate expression of the mechanical imbalance.
Wellbore instability problem solving, first through the brittle shale mineral composition and physical and chemical properties analysis, understanding the main factors causing wellbore instability, whereby technical ideas and research design sloughing of the pages of brittle knowledge base on the rock collapse mechanism, preferably a sloughing treatment agent, so the composition of a proper anti-sloughing drilling fluid system.
Different amounts of KCl plus segment selector and economic evaluation wells From a technical point of view, KCl content is higher, more stable drilling fluid properties, wellbore is also more stable, KCl content is higher, drilling fluid properties to resolve conflicts between stability and wellbore stability more thoroughly, but also the more meet the needs of mine.
Affects the formation of oil and gas in this system is small, and therefore may not be considering.

Introduction With the growing shortage of resources and people's awareness of environmental protection,the waste concrete dispositions and recycling of waste concrete more and more get attention, Therefore the domestic and foreign scholars have conducted a series of studies for recycled aggregate grading, RAC material and structural properties [1,2,3], the conclusion is also different.
Because of ITZ especially the second ITZ are weak and complex, therefore the transition zone on the mechanical properties of RAC effects are far greater than the ordinary concrete.
This indicates that the old and new interface of RAC specimens is the most prone to crack, which are the weak parts , it’s properties great impact on the mechanical properties of RAC.
Influencing Factors Table 2 Parameter settings parameters Shape Thickness(mm) strength（MPa） RA Trilateral/quadrilateral/hexagon — 30000 50000 70000 Old mortar — 1.5/2.5/3.5/4.5 25000 30000 25000 Old interface — — 10000 10000 15000 Because of Figure 7 is a simplified model considerations , so, in order to investigate the impact of various material parameters, this part taking into account the aggregate shape , old mortar layer thickness ,RA strength and other factors , Analysis of RAC differences in force in different circumstances , each factor listed in Table 2.2.
Cement and Concrete Research,Vol.30(2000),P.579 [5] P.K.Mehta, P.J.M.Moneteiro, Concrete Microstructure, Properties and Materials (in Chinese).

Introduction Fiber-reinforced composites are employed in a variety of engineering applications due to their excellent physical and mechanical properties.
The heterogeneous constituents of composite materials may sustain multiple, distributed localized fractures with little influence on the global properties that control the life of the material or component [1].
Although composites which are designed to be damage tolerant that may affect by many factors, such as type of matrix [5], stacking sequences[6], defects [7], temperature [8,9] et al.
But no matter what consequence, their fractural characters and whole mechanical properties may always change gradually during the life [10].
The specimens were machined by wire-electrade cutting and mechanical polishing.

The selection of a surface for a sports facility can be influenced by a number of factors.
This property has the strongest biomechanical foundation of all properties contained within the EN14904 standard.
The actual magnitude of the storage potential is dependent on the surface’s mechanical properties, as energy storage is a function of the surface’s stiffness and deformation characteristics [6].
Surface to athlete interactions are highly complex scenarios to model and replicate, as many independent factors influence these interactions, including footwear and athlete characteristics and of course surface properties.
Demker, Determination of mechanical comfort properties of floor coverings, SP Report 2009:04, SP Technical Research Institute of Sweden, 2009

Their tangential spreading factors both increase obviously with the tangential velocity at the impact point, while their radial spreading factors vary a little.
The liquid properties are summarized in Table 1.
Two spread factors, the tangential spread factor (), and the radial spread factor (), are proposed in this paper.
Figure 6 Effect of surface tension on the evolution of tangential spread factors.
In addition, the tangential spread factors for them increase evidently with the tangential velocity at impact point, however, their radial spread factors varies a little.

Mechanical properties in terms of hardness and microhardness of obtained phases and structure were investigated.
Such an advanced structure leads to enhancement in the whole mechanical properties of the high carbon steel.
The microstructure and the mechanical properties were investigated.
Much increment of aluminum generates a fraction of polygonal ferrite which will cause a deteriorative effect on the whole mechanical properties.
[16] Mohamed Soliman, Heinz Palkowski, "Microstructure development and mechanical properties of medium carbon carbide-free bainite steels," vol.