In one aspect, methods of purifying WC compositions are described herein. The plasticizers used are one or more of the formula in which the radicals are each as defined in the rest of the disclosure and are branched-chain alkyl radicals having 9 or 10 carbon atoms, and advantageously one or more further plasticizers. The variety of cases comprise combinations of unsorted, sorted, and indexed inputs, and the variety of sizes comprise input sizes from smaller than the available memory to input sizes substantially larger than available memory. An electrical connection that connects to the drain of the FET. The thermostat includes a ring-shaped controller that rotates about a central axis, and an optical sensor directed away from the central axis and toward a radially inward-facing surface of the ring-shaped controller so as to accurately detect optical signals indicating controller’s rotational movement.