Abstract: The present application discloses methods, and systems for laser-scribing a solar panel and the solar panels. The method for laser-scribing the solar panel may comprise: capturing consecutively images of parts of a first line on the solar panel, the first line having a pre-designed shape; acquiring location information of each of the captured images of the first line; and laser-scribing parts of a second line on the solar panel consecutively, according to the acquired location information of the first line, so that the scribed second line has the pre-designed shape of the first line and maintains a fixed distance from the first line.

Abstract: The invention relates to copolymers effective as slump retention agents for hydraulic compositions such as cement, mortar and concrete. The copolymers are formed by reacting monomers A, B and C, wherein monomer A is a compound of formula I, monomer B is a compound of formula II, and monomer C is a compound of formula III or IV as shown herein. The copolymers may be used alone or in combination with a water reducing agent or slump retaining agent, e.g. a superplasticizer such as PNS or PMS or a low range water reducer such as lignosulfonate. The copolymer includes a group that is hydrolyzable at elevated pH (e.g. around pH 12) typically present in hydraulic compositions, so that the group hydrolyzes when present in such compositions and forms a charged group that provides extended slump retention properties without introducing undesirable air-entraining characteristics.