Abstract: A process for treating ammonia containing wastewater includes bringing an ammonia-treating material and ammonia containing wastewater into contact with each other to remove ammonia in the wastewater continuously as nitrogen gas, the ammonia-treating material including a long carrier and complex bacterial sludge attached and immobilized on the biomass carrier, the carrier including a net, a nonwoven fabric or a woven fabric of fibers or filaments, the carrier being attached to a support, the complex bacterial sludge containing bacterial sludge including autotrophic anammox bacteria and bacterial sludge including autotrophic ammonia-oxidizing bacteria, the ammonia containing wastewater containing dissolved oxygen at a concentration of not less than 0.5 mg/l.

Abstract: A linear measuring machine is provided, the linear measuring machine having a base (11), a column (12) disposed on the base, a slider (14) elevatable along the column and an elevation driving mechanism (44) including a motor for lifting and lowering the slider. The linear measuring machine further includes a touch-and-back mechanism for driving the elevation driving mechanism in a direction for a probe (13) to move away from a measurement surface of the workpiece after fetching a detection value of a displacement sensor (45) when the probe touches the measurement surface of the workpiece and for stopping the elevation driving mechanism.