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Introduction Proper thermal management is needed in Proton Exchange Membrane Fuel Cell (PEMFC) as this factor can greatly affect the efficiency of the fuel cell performance itself [1].
Kandlikar and Lu [3] have reviewed thermal management issues in PEMFC and highlighted that two critical factors need to be considered in cooling design of PEMFC which are the low temperature range of 60°C to 80°C which required a relatively larger heat exchanger compared to internal combustion engine.
Apart from the improvement in mechanical devices of fuel cell, alternative solution is seen in coolant's heat transfer coefficient enhancement through addition of nanoparticles [5].
Figure 6 : Heat transfer rate comparison between nanofluids and base fluid Table 1 : Calculated thermo-physical properties Property Base (50:50) 0.1 % Al2O3 0.5 % Al2O3 m (kg/s) 0.0482 0.0483 0.0489 Cp (kJ/kg.K) 3.3076 3.2982 3.2609 The cooling rate, Q is then plotted against the load and similar trend as DT curve is observed as illustrated in Figure 5.
[10] ASHRAE, "2009 ASHRAE® Handbook Fundamentals," in Physical Properties of Secondary Coolants (Brines), ed, 2009

In this paper, two kinds of micro-mechanical models are utilized to predict the effective Young's modulus for hybrid composites including fiber-like, spherical and needle inclusions in an isotropic matrix.
The results show that the shape and the Young’s modulus of inclusion, aspect ratio of fiber-like inclusion are the controlling factors to influence the Young's modulus, and MP model is more rational to predict the effective Young’s modulus of hybrid composites reinforced with multi-shape inclusions.
Assuming the material properties of needle-like inclusion is En=270GPa, nn=0.2, and the Young's moduli are Ef=450GPa, Es=270GPa (Subscribe f denotes fiber-like inclusion, and s denotes spherical inclusion and n denotes needle-like inclusion).
Fig.8 shows that the calculating sequence has an obvious influence on E11 even for a small aspect ratio in MP model, and the E11 for F-S sequence is much higher than that for S-F sequence, and the calculating sequence, volume fraction of inclusions and the shape of inclusions are the important factors to affect E11 for composites reinforced with multi-shape inclusions.
Fig.7 MS model for F-S and S-F sequence (a=10) Fig.8 MP model for F-S and S-F sequence Conclusions The purpose of this work is to compare the methods to predict the effective elastic properties for composites reinforced with multi-shape inclusions.

On the other hand aluminium- graphite composites are widely used in tribological applications because of their excellent antifriction properties, wear resistance and antiseizure characteristics.
To determine average flank wear, cutting speed was varied as it is one factor that affects the flank wear the most.
The significance of the factors is considered at a confidence level of 95% (α= 0.05) and the significant effects are labeled.
It is observed from Figures 1 and 2 that both the factors A (speed) and D (% reinforcement) are significant and there is no interaction between the factors when hybrid composites machined with Carbide and PCD inserts.
If the p-values of the factors is less than or equal to α= 0.05, it is concluded that the effect is significant, otherwise the effect is insignificant.

The influence charts reflect the degree which the concerned parameter affects on the system vibration.
In these parameters, the variation of damping will not affect the inherent property of the system, but only change the amplitude of the response.
Though the integrated errors and exterior force have great effect on system vibration, the influencing law of these two factors is easy to find.
The mean mesh stiffness affects the vibration of input bearing to some extent, but not greatly.
Wu: China Mechanical Engineering.

Test Study on the Resisting Shear Strengthening Effect with External Pre-Stressed Wire Rope Tianlai Yua, Qiang Mab and Leilei Tianc School of Civil Engineering, Northeast Forestry University, Harbin, 150040, China atianlaiyu@126.com, bmaqiang745@163.com, ctianleileihenan@126.com Keywords: Wire Rope; The Shear Strengthening; Influencing Factors; Reinforced Concrete Beam Abstract.
The resisting shear strengthening technology of existing reinforced concrete bridges as an important research topic in the field of old bridges, play an important significance to improve the mechanical properties of old bridges and reduce security incidents.
Introduction The shear capacity of some of the old bridges is not enough because of heavy vehicles and natural factors.
Because the effect was affected by many factors, such as the original beam reinforcement ratio, the original beam stirrup ratio, concrete strength, the spacing of external wire rope and the level of staying load when reinforcing and other factors, so these factors were analyzed in this paper.
The ultimate loads measured actually are listed in Table 5.With other factors remaining the same and only a factor being changed separately.

It is well-known that the mechanical properties of nanocomposites are better than those of conventional composites.
Along with this, considerable studies have been performed on the mechanical properties of MMT/polymer nanocomposites [4-5].
For MMT/polymer nanocomposites to have better mechanical characteristics than existing particle-reinforcing composites, it is important to appropriately insert polymer matrix between MMT layers, which is affected by its dispersibility.
This acts as microcrack or void, thereby working as a factor that decreases the tensile characteristics.
Vol. 298(2006), p. 854 [11] ASTM D638: Standard Test Method for Tensile Properties of Plastics (2003) Fig. 3 The change of the tensile strength of surface-treated MMT/epoxy nanocomposites according to the MMT content.

Especially, concrete cracking affects the durability and service life of bridges.
The mechanical behavior of the composite structure was not only determined by the properties of different materials, but also influenced by the connection structure between different materials.
And comprehensive influencing factors such as shear capacity, construction, durability, maintenance and economic performance should be considered when the connector was chosen.
These authors concluded that the structural response was influenced by several geometrical properties such as the number of holes, the plate height, length and thickness, the concrete compressive strength, and the percentage of transverse reinforcement provided in the concrete slab.
This is presumably because the rigidity of the PBL connector affects the rigidity of the entire girder when cracking has progressed to a certain degree.

Oil-immersed distribution transformers are classified into several series including S9, S10, S11, S12, S13, S15, S16 (S15 and S16 are AMT) by loss properties.
Amorphous core thin strip has characteristics of great soft magnetic properties, high hardness and good corrosion resistance.
High mechanical strength can be thought as the biggest advantage of the epoxy resin casting dry-type transformer.
The influencing factors of core annealing are more, the dispersion of core loss coefficient is bigger and the process is also more after the annealing.
So the manufacturing process is one of the important limitation factors to promote the transformer.

Thermo-mechanical fatigue properties of thin films on flexible and rigid substrates have been investigated extensively.
A detailed overview of the mechanical properties of the Cu layers can be found in table 1.
Thus due to Table 1: Grain size and mechanical properties of the Cu films.
Weiss, A study of the mechanical and fatigue properties of metallic microwires, Fatigue Fracture of Eng.
Nix, Mechanical properties of thin films, Metall.

Introduction Concrete is one of the most widely used building materials use of housing, municipal, bridges and other projects, a study on the composition and mechanical properties of concrete material deeply, has the important practical significance.
In the preparation of concrete, and the use of the solidification process, there are external environmental factors and different degrees of influence on the strength and deformation.
Compared to other materials, the mechanical properties of concrete materials more complicated.
These effects cause a variety of effects on the mechanical properties of concrete and deformation.
These factors will make concrete strength and deformation changes accordingly.