Abstract: The invention provides solar panel systems, which may be applied to surfaces such as residential rooftops. The invention also provides methods of installing solar panel systems. A solar panel system may comprise one or more module, which may comprise one or more solar panels and a rack. A solar panel may comprise a polymer, and may not comprise glass or a metal frame. The rack may include three footings and a plurality of adjustable fasteners that may enable the module to reside on an uneven surface. The rack may also include integrated electronic components and a microinverter. A module may yield a desired power output, and may generate performance monitoring data.

Abstract: Provided herein are exemplary embodiments of an efficient pump apparatus. In one embodiment the pump apparatus comprises a piston assembly loosely disposed within a cylinder. The piston assembly includes a driving cable connecting a top leaky piston and a bottom leaky piston having a check valve connected thereto. The cylinder includes an outlet pipe at an upper portion thereof and a check valve located at a lower end of the cylinder. The pistons move in the cylinder at a velocity relative to the conduit such that as the pistons move along the cylinder they create a substantial tortuous leak path forming a hydrodynamic seal between the pistons and the cylinder.

Abstract: The invention pertains to a delivery device for controlling the injection of discrete quantities of fluid injectable materials through a conduit such as a hypodermic needle or a catheter. The delivery device is coupled to a pressurized driving fluid source, and the control means provides controlled passage of pressurized driving fluid into a syringe body to act against a piston which forces the fluid injectable material out the needle or catheter.In addition to the delivery device, the invention includes a needle depth guide which is preferably used in combination with the delivery device for cosmetic applications when a hypodermic needle is used to deliver a fluid injectable material to the dermis.