The invention relates to a process chamber for the selective laser fusion of material powder for the production of moulded parts. The present invention also provides polynucleotides encoding splice variants of HGPRBMY29 polypeptides, HGPRBMY29v1 and HGPRBMY29v2. Another embodiment provides a way to adjust the activities of the electrical loads such that neither adapter power rating nor the electrical load power limit is exceeded while avoiding system shutdown. A tube sleeve having an edge beveled at an angle complementary to the beveled edge of the tube is clamped to the spindle of the friction welding apparatus. The analytics engine is communicatively connected to the data acquisition system and the virtual system modeling engine and is configured to monitor and analyze a difference between the real-time data output and the predicted data output. The layer change control method includes measuring a needed time from where a focus point of the optical medium breaks away from a current layer to where the focus point arrives at a desired layer, and controlling a focus driving voltage needed to pull the focus point of the optical medium into the desired layer, and a time to output the focus driving voltage by using the needed time.