Thermal properties are approached by discussing the Einstein and Debye solids and the concept of lattice waves and phonons. These courses present educational material and credit courses at the high school level to students using online resources. Calendar - Virginia Virtual Academy - K12 DPOR Perimeter Center Summer Sessions has you covered. Virtual Virginias Select enrollment options allow students in grades 612 to choose not only their VVA courses, but also the meeting times for their daily synchronous instruction. Virtual Loudoun courses are full-year courses offered in a condensed term. [CDATA[/* >