frothers havea profoundeffectonbubble size and also flotation efficiency. in present study the effect of type and dosage of frothers on the flotation response of coarse particles of quartz was investigated.  therefore, flotation response of coarse particles using frothers such as mibc, pine oil, poly propylene glycol with concentration of 0, 25, 50 and 75 g/t, was obtained respectively. for all...

Zhang et al. (2005) present a parameterization for what they term the "growth factor" of a sea salt aerosol particle relative to its formation diameter, which they assert "is a function of relative humidity alone" and independent of an arbitrary reference relative humidity. Here we note that this growth factor implicitly assumes an arbitrary reference relative humidity through the salinity of t...

The paper studies optimization of shell-and-tube heat exchangers using the particle swarm optimization technique. A total cost function is formulated based on initial and annual operating costs of the heat exchangers. Six variables – shell inside diameter, tube diameter, baffle spacing, baffle cut, number of tube passes and tube layouts (triangular or square) – are considered as the design para...

soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure.so, this research has been done for achieving this purpose. this area is arounding sa...

The applications of supported metal catalysts vary widely, from selective hydrogenation in the fine chemicals industry to the control of vehicle emissions. Yet many basic questions about the structure, activity, and durability of these catalysts remain unanswered. For example, there is still much uncertainty about the mechanism of metal particle growth, or sintering, which is a major cause of c...

Preformed particle gel (PPG) has been successfully synthesized and applied to control excess water production in most of the mature, waterflooded oil fields in China. This paper reports on laboratory experiments carried out to investigate PPG transport mechanisms through porous media. Visual observations in etchedglass micromodels demonstrate that PPG propagation through porous media exhibits s...

This study presents measurements of size and time-resolved particle diameter growth rates for freshly nucleated particles down to 1 nm geometric diameter. Novel data analysis methods were developed, de-coupling for the first time the size and time-dependence of particle growth rates by fitting the aerosol general dynamic equation to size distributions obtained at an instant in time. Size distri...

Downward and upward ultrafiltration (UF) was performed using the suspensions of nanosized colloidal silica with different particle diameters and their filtration rates were compared. In downward UF, the filtration rate decreases as the particle diameter decreases because the specific filtration resistance of the filter cake becomes significantly higher. In contrast, the filtration rate in upwar...

the geometric mean particle diameter (dg) and lime are two of the most important properties from the viewpoint of soil management. nowadays remote sensing technology which has emerged walking with science development throughout the world, has made soil study faster, more facile and more cost-efficient. an investigation of soil dg and lime was performed in pol-e-dokhtar area by use of four sets ...