MECHANICAL ROCKS

WORKING §   The raw material of glass are fed in to the feed stock and is electrically heated to 1400 °C the raw material include sand, lime stone and Al 2 O 3 . §   The melt is stirred and maintained at constant temperature.      The melt is passes through platinum nozzle containing around 394 holes of μ m diameter and the yarn coming out is warped in forming tube at a shape of 25m/s. §   Before the yarn drawn sizing is done, sizing solution consisting of organic agents binders, lubricants and coupling agents, Binder allow packing of stands. §   Lubricants prevent abrasion of filament and coupling agents provide better bonding with polymer. §   Fibers are then drawn into strands, each strands consisting of more then 204 filaments. The wound array of glass stands is dried in oven to remove water and other solvent. Glass strands can be converted to various forms as – a)     Continuous strands ( group of 204 fiber ) b)     Rovings ( group of

APPLICATION 1.        High strength to weight ratio. 2.        High stiffness to weight ratio. 3.        Excellent fatigue performance. 4.        High resistance to impact load. 5.        Superior styling or profiled surfaces. 6.        Better erosion resistance. 7.        Wide performance range allowing flexibility to change the type and quantities of reinforcement material. IN SPACECRAFTS,USE OF PMC'S PROVIDING THE GREATEST BENEFITS. FOLLOWING COMPONENTS HAVE BEEN USED------- .        Panel doors of space shuttle. .        Solar collector mounts. 3.        Structures for large-scale telescopes. 4.        Electromagnetic antennas. 5.        Optical benches. 6.        Space truss 7.        Filament wound tanks to contain pressurized gas. 8.        Rocket motor casings. 9.        Heat shields and nozzles for re entry vehicle.

MICROCO NTROLLERS A microcontroller is a single chip. It is the integration of CPU with memory and input/output interfaces (ports) and peripherals such as timer on a single chip. As shown in figure- Classification of microcontroller a)     Semi-conductor technology adopted in their design b)     Width of data format c)      Instruction set d)     Data type they can handle. Semiconductor technology adopted         I.             Transistor-transistor logic (TTL)       II.              complimentary metal oxide semiconductor (CMOS)    III.               Emitter coupled logic (ECL) Width of data format         As the name suggest, in this type is design as per data transfer. Such  as 4bit, 8bit, 16bit and 32bit microcontroller. Instruction set Microcontrollers are two types based on instruction set:-                    I.             CISC - complex instruction set computing.                  II.     

Ultra sonic proximity sensor ·           It is used for detect the presence or absence of an object. ·          This emits the ultrasonic waves. Working : Ø   A special type of sonic transducer is used for the ultrasonic proximity sensor, which allows alternate transmission and reception of sound waves. Ø   The ultrasonic transducer emits a number of sonic waves and which are reflected by the object, back to ultrasonic transducer. When the ultrasonic transducer emits the sound waves it’s automatically switch over the receive mode. Ø   The time elapsed between emitting and receiving is determined the distance between the ultrasonic transducer and near object. Ø   Ultrasonic proximity sensor enables the detection of different objects irrespective of colour and transparency. Types of ultrasonic sensors: a.       Analog output. b.       Digital output. c.        Retro-reflective type. d.       Thru-Beam type.