Direct current (DC) motors have variable characteristics and are used extensively in variable-speed drives. DC motor can provide a high starting torque and it is also possible to obtain speed control over wide range. Why do we need a seed motor controller? For example, if we have a DC motor in a robot, if we just apply a constant power to each motor on a robot, then the poor robot will never be able to maintain a steady speed. It will go slower over carpet, faster over smooth flooring, slower up hill, faster down hill, etc. So, it is important to make a controller to control the speed of DC motor in desired speed. DC motor plays a significant role in modern industrial. These are several types of applications where the load on the DC motor varies over a speed range. These applications may demand high-speed control accuracy and good dynamic responses. In home applications, washers, dryers and compressors are good example. In automotive, fuel pump control, electronic steering control, engine control and electric vehicle control are good examples of these. In aerospace, there are a number of applications, like centrifuges, pumps, robotic arm controls, gyroscope controls and so on.

Hydropower is essentially a product of solar energy. The sun begins the hydrologic cycle by evaporating water from land and sea. Hot air, which rises over the water, carries moisture to the land as rain or snow. Much of the water falls on high lands and drains into streams and rivers as it flows back down to the sea. This flow over the different elevations can be harnessed by a hydroelectric project to produce electricity. Hydroelectric generation is the cleanest source of electrical energy available and is a renewable resource since the natural flow of water is a continuous process. It is almost pollution free and can provide power without producing waste. It is easy to control and is highly efficient.It is a technology that has been utilized throughout the world, by a diverse range of societies and cultures, for many centuries. Micro-hydro power is the small-scale harnessing of energy from falling water; for example, harnessing enough water from a local river to power a small factory or village.

A comparative study of the two nutrients solution recipes in different strengths(Full and Half) for growing various vegetables in a non-circulating hydroponics system" was conducted at NWFP Agricultural University Peshawar, Pakistan, during the spring and fall seasons of 2006.The objectives of the study were to promote the activity of clean gardening/ urban home gardening for the landless city dwellers through the adoption of non-circulating hydroponics technology for growing fresh vegetables in their cemented court yards, verandas or the cemented rooftops. The results indicated that Cooper's 1988 solution recipe remained better than the Imai's 1987 solution recipe for almost all crops(Cucumber, Tomato, lettuce and spinach) because of an ease in keeping the pH and EC of the solution with in the optimum range when prepared with the ordinary tap water.

The video compression techniques developed in the past deployed DCT (Discrete Cosine Transform) for removing spatial redundancies and MEC (Motion Estimation and Compensation) for removing temporal redundancies in the video stream. These techniques suffer from blocking artifacts and produces low quality compressed video when the bandwidth availability is low in case of simultaneous transmissions on the link. Many DWT based video compression techniques have been proposed, but, unfortunately no standard has been developed to deploy these techniques because either most of the techniques have not been implemented practically or desired results have not been obtained successfully. This study presents a new compression technique deploying DWT for removing spatial redundancies and MEC for removing temporal redundancies. 10% improvement in compression ratio is obtained using the proposed approach, when applied to already compressed format such as AVI, WMV etc. This work is a first step towards the development of scalable video codec using DWT and MEC, which can be deployed as a future video compression standard.