An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another. Circuits can be constructed of discrete components connected by individual pieces of wire, but today it is much more common to create interconnections by photolithographic techniques on a laminated substrate (a printed circuit board or PCB) and solder the components to these interconnections to create a finished circuit. In an integrated circuit or IC, the components and interconnections are formed on the same substrate, typically a semiconductor such as silicon or (less commonly) gallium arsenide.
Breadboards, perfboards or stripboards are common for testing new designs. They allow the designer to make quick changes to the circuit during development.
Auto maintenance describes the act of inspecting or testing the condition of car subsystems (e.g., engine) and servicing or replacing parts and fluids. Regular maintenance is critical to ensure the safety, reliability, drivability, comfort and longevity of a car. During preventive maintenance, a number of parts are replaced to avoid major damage or for safety reasons, e.g. timing belt replacement.
The actual schedule of car maintenance varies depending on the year, make, and model of a car, its driving conditions and driver behavior. Car makers recommend the so-called extreme or the ideal service schedule based on impact parameters such as
Electrical polarity (positive and negative) is present in every electrical circuit. Electrons flow from the negative pole to the positive pole. In a direct current (DC) circuit, one pole is always negative, the other pole is always positive and the electrons flow in one direction only. In an alternating current (AC) circuit the two poles alternate between negative and positive and the direction of the electron flow reverses.
In DC circuits, the positive pole is usually marked red (or "+") and the negative pole is usually marked black (or "-"), but other color schemes are sometimes used in automotive and telecommunications systems. On a car battery, the positive pole usually has a larger diameter than the negative pole.
A nipple clamp is a clamp that can be applied to the nipples of either men or women. It is a sex toy which can be attached to the nipples to create pain by restricting blood flow from erect nipples by applying pressure to them. Some people derive erotic pleasure from seeing nipple clamps applied. They are used in some BDSM activities, such as tit torture. The use of nipple clamps is often portrayed in the media as deviant or kinky sexual behavior.
The main types of nipple clamp are the clover clamp, tweezer clamp, and clothes-pin style, though any device that applies direct pressure can be used. For self-use, successful application requires the user to find a personal balance between the amount of pain and pleasure by fine tuning the degree of pressure exerted by the clamp. The clamps are typically used in pairs and connected by a chain. Weights may be hung from the clamps to increase the pressure on the nipples, and to discourage the clamped person from moving suddenly (for example, jumping when spanked or caned), since this would make the weights swing and increase the pain.
Mechanical engineering is a discipline of engineering that applies the principles of engineering, physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the design, production, and operation of machines and tools. It is one of the oldest and broadest engineering disciplines.
The engineering field requires an understanding of core concepts including mechanics, kinematics, thermodynamics, materials science, structural analysis, and electricity. Mechanical engineers use these core principles along with tools like computer-aided engineering, and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices, weapons, and others.
Finance is the allocation of assets and liabilities over time under conditions of certainty and uncertainty. A key point in finance is the time value of money, which states that a unit of currency today is worth more than the same unit of currency tomorrow. Finance aims to price assets based on their risk level, and expected rate of return. Finance can be broken into three different sub categories: public finance, corporate finance and personal finance.