Chromium is a very important trace element in regarding both environmental and biological point of view. Most of the research about chromium focused on the biological activity of trivalent chromium and carcinogenicity of hexavalent chromium. It is a lustrous and hard metal that takes high polish and have high melting point 1 . In 1798, a French chemist Nicholas-Louis Vauquelin successfully isolated metallic chromium by heating chromic oxide with charcoal by means of chemical reduction 2 .Chromium oxidation states are ranging from -2 to +6. But in nature it exists in only three oxidation states. Those three oxidation states of Cr are 0, +3 and +6. It exists in 0 oxidation state in metallic Cr, in chromic compounds it is in +3 states and in CrO 4 2-, Cr 2 O 7 2compounds it exists in +6 oxidation state. Among all oxidation states, +3 and +6 states are more commonly observed in chromium compounds but the remaining oxidation states are rare 3 .According to the International Minerals Association, 82 minerals were recognized for chromium. Among these, the important chromium mineral is chromite. The concentration of chromium in chromite mineral is 46.46 % on average 2 . Most

With growth of nano-bio industry, it is of significant importance to develop an automated system to exploit cell behaviors, including migration, mitosis, apoptosis, shape deformation of individual cells and their interactions among cells in the process of cell growth. In this paper, we proposed preprocessing techniques, a classification method which classifies clusters (overlapping multiple cells) from cells and an automated method which counts the number of cells and clusters in order to analyze 2D or 3D deformations of the cells in the real-time images from microscope in the cell culture. We conducted the 3T3 cell images taken from each thirty-minute interval. It showed the average 99.8% accuracy automatically for separating cells and clusters.

In this paper, transient temperature and vibration characteristics of a brushless DC (BLD(c) motor are studied for external load (165W~495W) and rotational speed (2000 rpm~4000 rpm). For experiment, a simple measurement system is developed to allow a change in load and speed for measuring transient temperature and vibration simultaneously. Temperature and vibration were also measured under the conditions of natural convection and forced convection. Vibrations in the directions of x-axis (#Ch1), y-axis (#Ch2) and z-axis (#Ch3) were obtained by three accelerometers and temperature was obtained by a thermo-couple with respect to time until the motor is steady. Experimental results show that the amplitude of vibration is higher in the order of z-axis (#Ch3), x-axis (#Ch1) and y-axis (#Ch2) and the amplitude of vibration at the forced convection conditions is 10.6% to 17.8% lower than that of vibration at the natural convection. However, the ratio of the vibration value is similar on average regardless of external convection condition.