Search results

Columnar, coarse-grained structures can also be observed in metals and alloys that were affected by heat sources of high energy density in welding [5].
According to numerous authors, the columnar morphologies have considerable effect on mechanical properties of materials [6, 7].
However, as far as heat affected zones of welds are concerned, the major growth governing factors (peak temperature, temperature gradient, heating and cooling rates…) appear in a rather dramatic scale [8].
Standard metallographic preparation consisted in mechanical, careful polishing and chemical etching with 5% solution of nitric acid.
favourable factors of the columnar-like growth.

Introduction Titanium alloy is of great importance in many industrial applications due to its highly attractive properties ,such as good deformability ,low density ,high specific strength, excellent corrosion resistance and high temperature strength retention[1、2].
Since the mechanical characterization of titanium is of great complexity and is strongly sensitive to the processing way and processing parameters, i.e. deformation grade, strain rate and temperature, it is important to clarify its deformation modes and the relationship between the processing variables, microstructure and properties under different deformation way and loading conditions .
Based on the Eq.(1), it is well known that tow counterbalancing factors strongly influence the growth of localized shear regions : imposed strain rate due to dynamic load and heat generation due to plastic work.
Hence, both the softening modus and the imposed strain rate affect developing of the adiabatic shear process.
Ho, Physical properties of titanium alloy, in the science, technology and application of titanium, in:R.I.Jaffee, N.E.

Results show that main factor which affecting COP of heat pump unit is inlet water temperature of condenser.
(16) n polytrophic index, κ adiabatic index, α variable associated with the structure size of compressor, ηυ compressor volumetric efficiency, Vth compressor theoretical gas volume flow rate,υ3 compressor inlet refrigerant specific volume, Wel compressor electric power, ηel electricity efficiency, ηm mechanical efficiency, ηmo motor efficiency.
The main program calls refrigerant property by REFPROP subroutines and experimental values are provided by manufacturer.
References [1] Jinghui Liu, Qinggang Li, Fazhong Wang, Lei Zhou: International Journal of Refrigeration.vol. 35(2012), p861 [2] M.W.Browne, P.K.Bansal: International Journal of Refrigeration.vol.24 (2001), p.612 [3] Long Fu, Guoliang Ding, Zujian Su: Applied Thermal Engineering.vol.22 (2002), p.1731 [4] Babak Solati, Radu Zmeureanu: Energy Conversion and Management .vol.44 (2003), p.1903 [5] C V Le, P K Bansal, J D Tedford: Institution of Mechanical Engineers.vol.219 (2005), p.95

For example, it is preferable that the products in the air-conditioning sector have anti-microbial properties.
However, the round design will keep the accumulation of such factors to a minimum due to its rounded lines.
Therefore, it is aimed to give antibacterial properties to plastic products by using additives.
Silver is the most widely used technology as an antibacterial agent in the world due to its historical success, broad performance spectrum, many materials and applications suitability for use are the main factors.
[5] Polymer Additives Used to Enhance Material Properties for Medical Device Applications, Vinny R.

During the process of construction, the tunnel will pass through coal-bearing stratum and fault fracture zone with poor engineering geological properties.
The special mechanical properties of the soft layer are low-intensity, easy to soften when encounter water and have poor combining between layers (especially the coal seam roof and floor).
The fragmentized rocks will accumulate inside the goaf after the roof collapses, thus the rock mass of break zone has large gap, with better connectivity and poorer properties than the general surrounding rock.
In all, the affecting degree of underlying goaf is higher than overlying goaf.
In all, the affecting degree of underlying goaf is higher than overlying goaf.

Introduction In recent years, geotextile bags filling with sand are widely applied in the cofferdam and subgrade engineering, studies of sandbag Cofferdams’ stability are increasingly mature, but these studies usually use circular slide method for analysis, and inadequate considered the influence factors of the sandbag cofferdam’s stability.
Fig 1 Slide of the subgrade Security analysis of the subgrade C, are the main strength quotas to affect the slope’s instability, their variability will cause very big effect on safety evaluation [4].
Using the data got from soil experiment and displacement of embankment monitored on -site, we make back analysis of the soil’s mechanical parameters, main soil layer distribution and physical properties of this section are shown in Table 1.
(2) When checking cofferdam’s stability, properties of geosynthetics and soil layer’s interface are key technical indicators, cofferdam’s stability during construction is affected by construction factors, such as loading rate and construction process.

Characterization of Magnetic Properties of Nanocrystalline Ni and Ni-15%Fe alloy S.Arabi1,a, G.
Both materials exhibit soft magnetic properties.
The mechanical properties, due to their fine grain size, are characterized by the high strength and relatively high ductility [4-6].
Detailed evaluation of these factors is currently in progress.
Conclusions Nanocrystalline Ni and Ni-15wt%Fe alloy exhibit soft magnetic properties.

The analysis conclusion, contrapose the tribological properties between plastic and steel helical gear, enriched and improved the research in this field and provided some ready-made experiences.
The quantity of the contact points is relevant to the roughness, load, hardness and cleanliness and some other factors of two surfaces.
Heat generation of plastic gear contact tooth Friction heat flux density of steel and plastic helical gear pairs is decided by the contact pressure, relative sliding speed and slip factor.
Transient and stationary temperature field of plastic helical gear Summary (1)Contact stress generated by plastic helical gear meshing with steel helical gear depends on the factors such as materials, geometry, structure shapes, heat transfer coefficient and the input friction heat.
Mechanical Drive,2009，33：9-11

Theory of the Removal Function The process of bonnet tool polishing, which is not just the mechanical cutting and chemistry, molecules have been moving on the being polished surface as well.
There are a lot of factors influencing the polishing effect, such as nature and granularity of abrasives, concentration and PH value of polishing slurry, internal pressure, velocity of bonnet, polishing materials and so on.
According to the relative velocity and the stress between the element and the tool, the amount of surface material removal △Z in the processing time t is obtained (1) Where P(x, y, t) is the pressure at point (x, y) and instantaneous t, V(x, y, t) is the relative velocity between the polishing tool and point (x, y) at instantaneous t, and K is a constant related to the material properties and other process parameters.
Bonnet and component contact problem is complex and affected by multiple factors, such as the bonnet radius, structure, material properties, and the precession angle.
And influences of the material properties and other process parameters boil down to a constant of proportionality K.

A great thermal insulation properties of envelope f. e. protects inhabitants against heat losses in winter, same as overheating during summer, but it can be easy to cause overheating from internal heat gains such as electric devices or just when someone forgot to close the window during hot summer day.
Same as we choose a shape of building, an orientation in room`s disposition, composition and the rate of building`s envelope intended for fenestration and passive shading to provide indoor comfort focused on achieving desired heat gains, the same approach we should consider in other factors.
These factors are emphasized in geographical locations characterized with very different temperature levels during days and night.
Description of wind tower, solar chimney and cooling medium hybrid passive ventilation system, in the left and illustration of primary factors and their dimensions which affects the efficiency of the final solution, [6] Every system has a disadvantage.
In the case of passive system, there is a risk of inadequate continual effect, because proper function of the system depends on many factors, as was described above.