Catalytic properties of metallosilicates

Metallosilicates with MFI structure containing metal atoms such as Ni, Co, Cu, Zn-Cu and Zn in framework have been synthesized with various metal/silicone (Me/Si) ratios (up to 0.1). The acidities of H-form metallosilicates were evaluated by some acid-catalyzed reactions (decomposition of 2-propanol, cracking of cumene and isomerization of 1-butene). The Zn-Si catalyst showed the highest acidities among various metallosilicates. In the metallosilicates-supported noble metal catalysts, 5%Pt/Zn-Si and 0.1%Pd/Cu-Si catalysts showed the highest activities for hydrodesulfurization of thiophene and hydrodechlorination of chlorobenzene, respectively.研究報

Improving sensitivity of residual current transformers to high frequency earth fault currents

For protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed the modification in the structure of residual current devices. This modification improves sensitivity of residual current devices when high frequency earth fault current occurs. The test of the modified residual current device proved that the authors’ proposition is appropriate