Embedded computer system

Embedded computer system is a device which consists of a programmable computer. Examples are fax machines built using a microprocessor. A microprocessor is a single chip CPU (central processing unit). Automobile industry is using microprocessors to control the engine. Microcontrollers were designed later which includes memory and input/output peripherals. For computation-intensive applications, RISC microprocessors are used which 32-bit microprocessors are offering superlative performance. Embedded microprocessors are extensively used in digital television. An antilock brake system (ABS) which reduces skidding of vehicles was developed by embedded computer technology by BMW which is known as BMW 850i. Here an automatic stability control system arbitrates the engine. In an embedded computer system, complex algorithms required. This requires sophisticated user interfaces like global positioning system. Embedded computer system performs in real time and assumes multirate behavior. While designing an embedded computer system, manufacturer should take special care in lowering power consumption and manufacturing cost. 

Air conditioning fundamentals

Air conditioning is a process of producing air controlling simultaneously its temperature, humidity, cleanliness and distribution for the fulfillment of required condition of the confined space. An absorbent is a material which removes one or more substances from vapour or liquid due to difference in pressure. Calcium chloride is a solid absorbent and ethylene glycol is a liquid absorbent. The part of air which is not processed through the air conditioning system is called recirculated air. Circulation of chilled air with high velocity is called air blast. To remove impurities from air, air cleaners are used. Commonly used air cleaners are mechanical cleaners and electrostatic cleaners. Air diffuser is a device which converts a fraction of kinetic energy into pressure energy by circulating air against flow resistances. For measuring the velocity of air, anemometers are used. Antifreeze is a chemical which can cross freezing point of water. Typical examples are alcohol, glycol, ethylene glycol and ethyl ether. Antifreeze materials are generally less corrosive and have superlative thermal properties.