Basic-oxygen furnace (BOF) slag is the second abundant by-product from the steel-making process. It is not readily recycled for high phosphorus content and volume instability. To eliminate its phosphorus-hosting dicalcium silicate (C 2 S) and volumetrically unstable free-lime, reductive heating experiments on BOF-slag are carried out at 1300-1600 8C using quartz-sand or serpentine as a basicity modifier. In the products, C 2 S and free-lime are consumed through reacting with CaO and MgO, which are produced by Ca-ferrite and Mg-wustite reduction, respectively, to form merwinite and akermanite. The products are also characterized by silicatemetal segregation and the extent of that increases with increasing temperature and decreasing particle size of starting mixtures. Thermodynamic calculations show that phosphorus in C 2 S is mostly converted to Fe 2 P in the metal domain. Compared to the slag-serpentine experiments, the slag-quartz experiments resulted in higher extents of silicate-metal segregation with lower phosphorus contents of %0.1% in the silicate domain, which therefore is recyclable. To optimize silicate-metal segregation for recycling BOF-slag, it is suggested (i) bringing the BOF-slag composition within the low-temperature side of the C 2 S-merwinite-akermanite Alkemade triangle by adding quartz-sand; (ii) reductively heating to 1500-1600 8C; and (iii) cooling slowly then quenching to suppress C 2 S crystallization from melts.
For robot car, positioning or finding coordinate of robot are important in robot competition. Because which position a robot locates will decide which way it will go or which operation it will perform. How to position accurately becomes a key technology for robot system. Most of the robot positioning systems in competition depends on some special assisted black lines or dots on the competition site. However, in order to enhance the robot design, cancel those assisted lines becomes a new trend. Without those assisted lines, we must develop a new positioning technology to face an environment without any assisted lines. In this paper, we use both Arduino microprocessor and optical mouse sensor to design an optical positioning system for robot. We install an optical mouse sensor in the bottom of robot. When the robot moves, the mouse sensor will return the raw data of movement vector. The middle device Arduino will analyze the movement vector base on previous coordinate and finds the new coordinate of robot. The robot is built by the Lego NXT system and is connected to the Arduino system by I2C interface. In robot, we can build a digitalized map of competition site in advanced. Then it can continuously read the new coordinate from Arduino while moving, and decide which way to go or perform some operation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.