An apparatus for cooling containers includes a cooling chamber having a side wall with a circular interior surface defining a cylindrical interior chamber cavity. The dimming control method is characterized by outputting a continuous current with a varying amplitude to the light-emission unit under a higher brightness, and clamping the amplitude of the current output to the light-emission unit to a fixed value and outputting a discontinuous current with a fixed amplitude and a varying duty cycle to the light-emission unit under a lower brightness. The first memory stores priorities assigned to the server devices. The QPM semiconductor waveguides may be implemented as silicon-on-insulator, or germanium-on-silicon structures compatible with standard CMOS processes, or as silicon-on-sapphire structures. The invention also provides kits for isolating andor identifying nucleic acids.