The principal of and interest on any bonds issued by the corporation shall be secured by a pledge of the revenues, proceeds and receipts or any portion thereof out of which the principal and interest are made payable, and may be secured by a mortgage covering all or any part of the projects and properties from which the revenues, proceeds or receipts so pledged may be derived, including any enlargements of and additions to any such projects and properties thereafter made. The resolution under which the bonds are authorized to be issued and any such mortgage may contain any agreements and provisions respecting the maintenance of the projects and properties covered thereby, the fixing and collection of rents for any portions thereof leased by the corporation to others, the fixing and collection of proceeds from the sale of any projects and properties by the corporation to others, the creation and maintenance of special funds from such revenues and the rights and remedies available in the event of default, all as the board of directors shall deem advisable and not in conflict with the provisions of this article. Each pledge, lease, agreement and mortgage made by the corporation for the benefit or security of any of the bonds of the corporation shall continue effective until the principal of and interest on the bonds for the benefit of which the same were made have been fully paid. In the event of default in such payment or in any agreements of the corporation made as a part of the contract under which the bonds were issued, whether contained in the proceedings authorizing the bonds or in any mortgage executed as security therefor, may be enforced by mandamus, the appointment of a receiver, or by foreclosure of any such mortgage, or any one or more of such remedies.