Nomura has upgraded its rating for Egyptian gold miner Centamin from neutral to buy and increased its target price from 100p to 130p, saying that operational momentum may be turning positive after '18 months to forget'."Centamin has faced many challenges over the past 18 months including delays in receiving blast equipment during the Egyptian revolution, government inspectors allegedly failing to reasonably perform their duties, industrial disputes, a poorly managed 43-101 update and the loss of a fuel subsidy," the broker said in a research note on Thursday morning.However, Nomura says that in spite of this, the group has progressed its Stage IV expansion at its flagship Sukari project and successful built the initial underground operations; operationally, 2012 production is expected to improve sequentially."With the planned open-pit pushback now optimised for 2013-15 [following last week's update on its mine plan], we are increasingly comfortable with the company's operational momentum and earnings profile," Nomura said.BC