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
Parasitic element (electrical networks) is not always adequate. For instance, the inter-winding capacitance mentioned above is really a distributed element along the whole length of the winding and not a capacitor in one particular place. Designers sometimes take advantage of parasitic effects to achieve a function in a component, see for instance helical resonator. Non-linear parasitic elements can also arise. The term is commonly used to describe parasitic structures formed on an integrated circuit whereby an unwanted semiconductor device is formed from p-n junctions which belong to two or more intended devices or functions. Parasitic element (electrical networks) In electrical networks, a parasitic element