Abstract: An analytical rotor system comprises a rotor and interface. The rotor defines a plurality of chambers configured to process a sample to perform a Method of Standard Additions (MSA) test in response to centrifugal force. The rotor also defines a plurality of capillaries configured to transfer the sample between the chambers in response to the centrifugal force. The interface is configured to couple to the rotor and to an analytical device that spins the rotor to provide the centrifugal force. A first one of the chambers comprises a sample-only chamber that includes a first portion of the sample in response to the centrifugal force but does not include a standard. A second one of the chambers comprises a first standard addition chamber that includes a first portion of the standard that is added to a second portion of the sample in response to the centrifugal force.

Abstract: An analytical rotor system is configured to perform a plurality of tests selected by a user. The analytical rotor comprises a plurality of rotor blocks and a rotor base. The rotor blocks are each configured to perform at least one of the tests on at least one sample in response to centrifugal force. The rotor blocks are physically separate units from one another. The rotor base is a physically separate unit from the rotor blocks and is configured to allow the user to manually install the rotor blocks on the base. The rotor base is configured to hold the installed rotor blocks in place during the centrifugal force and to connect to an analytical device that provides the centrifugal force.

Abstract: An analytical rotor system comprises a rotor and an interface. The rotor defines a plurality of chambers configured to process a sample to perform a test in response to centrifugal force. The rotor also defines a plurality of capillaries configured to transfer the sample between the chambers in response to the centrifugal force. The interface is configured to couple to the rotor and to an analytical device that spins the rotor to provide the centrifugal force. The rotor includes a sample chamber configured to receive and hold the sample, and in response to the centrifugal force, to transfer the sample through a sample port to at least one of the chambers. The sample chamber is shaped so a fluid level of the sample does not reach the sample port while the sample chamber is at rest, but the fluid level of the sample does reach the sample port when the sample chamber is spinning.

Abstract: An aquarium filter-aerator device having a substantially pyramidic construction with water inlets on all sides that operates on an air-induced water flow principle anywhere along the bottom of an aquarium. The filter-aerator has an inner construction that defines a pre-filter chamber which accumulates impurities and a post-filter chamber for aerating the purified aquarium water. The particular construction and disposition of the filter-aerator facilitates the forming of a plurality of directional water currents to sweep aquarium impurities into the filter-aerator.

Abstract: A unique cover is provided for connecting an aquarium to provide effective regulation of the environment therein whereby the structure may serve as a terrarium. The cover includes a cover member which is adapted to overlie a typical aquarium tank or vessel, and a continuous frame support member extending around the periphery of the cover member and adapted to abut with the tank when the cover is in place. The cover member is provided with at least one opening, into which ventilation control pieces are positioned. The ventilating pieces may be selectively adjusted to control the ventilation of the aquarium or terrarium. The support member, being continuous, provides a substantially moisture impermeable seal with the tank when the cover is in position.