Soldering other precipitation may wash the lead into the groundwater. Unfortunately, most lead-free solders are not eutectic formulations, melting at around , making it more difficult to create reliable joints with them. Other common solders include low-temperature formulations (often containing bismuth), which are often used to join previously-soldered assemblies without unsoldering earlier connections, and high-temperature formulations (usually containing silver) which are used for high-temperature operation or for first assembly of items which must not become unsoldered during subsequent operations. Alloying silver with other metals changes the melting point, adhesion and wetting characteristics, and tensile strength. Of all the brazing alloys, silver
C-element particular, the so-called Maevsky's implementation is a non-distributive circuit loosely based on. Non-distributivity is introduced sometimes to increase concurrency. The 3NAND gate in this circuit can be replaced by two 2NAND gates. The C-element using only two-input gates has been proposed by Tsirlin and then synthesized by Starodoubtsev et al. using Taxogram language. This circuit coincides with that attributed (without reference) to Bartky and can operate without the input latch. Yet another version of the C-element built on two RS latches has been synthesized by Murphy using Petrify tool. However, this circuit includes inverter connected to one if the inputs.