An agency in a contested case may take official notice of judicially cognizable facts, and may take notice of general, technical or scientific facts within the agency’s specialized knowledge. The agency shall notify parties at the earliest practicable time of any noticed fact which pertains to a material disputed issue which is being adjudicated, and on timely request the parties shall be given an opportunity before final decision to dispute the fact or its materiality. An agency may use its experience, technical competence and specialized knowledge in the evaluation of evidence presented to it.