Internet consulting firm Zefer closed $48 million in additional funding led by NEC. The Boston-based firm also formed a partnership with the Japanese computing giant to focus on research and development of new technologies as well as joint sales and marketing initiatives. Zefer, which helps clients with Web development, design and consulting, secured $20 million in funding last November at a time when the overall Internet consulting sector was getting slammed on Wall Street, as many players struggled with a sudden services slowdown. Venture capital firm GTCR, Zefer?s primary investor, also participated in the latest funding round. The proceeds will be used to pay off outstanding debts and for as general-purpose working capital, Zefer said.