The Zoning Board of Appeals, in specific cases, after due notice and public hearing, and subject to appropriate conditions and safeguards, determine and vary the application of the provisions of this chapter in harmony with the general purposes and intent by granting temporary conditional use permits for such periods of time as shall be appropriate with regard to the circumstances of each particular case, for structures and uses in contravention of the requirements of this chapter, provided such uses are not prejudicial or injurious to adjoining and neighboring properties, and provided further that the public convenience and welfare will be substantially served thereby. Such permits may be personal, subject to plenary renewal, upon transfer of ownership of the property.