Introduction to Magnetism & Inductance Magnetism When elemental atomic particles move in certain materials such as iron, nickel or cobalt a magnetic field is generated. Materials that possess this property are known as ferrous or ferromagnetic materials. All ferrous materials will also react to an external magnetic field, such as a magnet or electromagnet. As a ferrous material is exposed to a magnetic field its atoms will align effectively creating many tiny magnets with north and south poles. The above diagram shows to samples of a ferrous material.
1. Why is NDT applied to Electrical Arc Furnace graphite electrodes? A graphite electrode is normally moving into the arc furnace when the part of electrode tip was consumed or cracked during the operation. The electrodes must be periodically fed into the fur- nace, and additional material need to be added to the existing electrodes. 2.
The strength of the intermolecular forces of attraction determines whether a substance will be a solid, a liquid, or a gas. It also determines the physical properties of a solid and liquids such as boiling point, surface tension, viscosity, and rate of evaporation. The two main intermolecular forces we dealt with are Hydrogen bonds and London dispersion forces. Procedure The digital thermometer was wrapped at the end with a piece of filter paper and secured with a rubber band. The thermometer was hanged from a test tube clamp on the ring stand.
This hallow molecular wire is extremely conductive as all of the atoms are on the surface and when something else interacts with the surface it could have a dramatic effect on the flow of molecules through the nanotubes. * One type of carbon nanotube has a cylindrical shape with open ends. Another type of nanotube has closed ends, formed by some of the carbon atoms combining into pentagons on the end of the nanotube. The wires, or sheets of carbon, do not need to be rolled up lengthwise. You can do it at an angle, make the tube diameter larger, or smaller, put
Degradation is a process that deteriorates polymer properties or their external appearance, changing its properties such as tensile strength, colour, shape, etc. Degradation can be cause by a number of factors, such as heat, oxygen, moisture, mechanical stresses and other factors. “Depending on the agent, the following forms of polymer degradation are distinguished: thermal, thermal oxidative, photochemical, hydrolytic, and radiation, among others.”(2) Usually numerous types of degradation processes take place simultaneously in a polymer; for example, making a polymer into a product, it undergoes thermal, thermal oxidation, and mechanical forms of degradation. Thermal degradation of polymers: thermal degradation of polymers is a molecular weakening as a result of overheating. “At high temperatures the components of the long chain backbone of the polymer can begin to separate (molecular scission) and react with one another to change the properties of the polymer” (3) thermal degradation normally results in changes to the molecular weight of the polymer usual property changes include reduced ductility, colour changes, cracking, general reduction in most other desirable physical properties UV degradation of polymers: “Common synthetic polymers which may be attacked include polypropylene and LDPE
The base of the actuator arm is connected to the voice coil actuator. The arm sits between two powerful magnets, that move’s due to a Lorentz Force. The Lorentz Force states that when you pass a current through a wire that is in a magnetic field, the wire experiences a force and reversing the current will also reverse the force. As current flows in one direction in the coil, the force created by the permanent magnet makes the arm move one way, and reversing the current makes it move back. The force in the arm is directly proportional to the current through the coil, which allows the arm’s position to be finely tuned.
2 Quasi-static testing (Lateral compression test) The quasi-static testing was performed at Structure and Material lab II of University Technical Malaysia Malacca. These tests were done using an INSTRON model 5585 with a 150kN capacity of load cell. The cross-head speed was set at 2mm/minute, 5mm/minute, 10mm/minute, 15mm/minute, 20mm/minute. The specimen was placed on the stationary lower platen and it must be centered so that the load was effectively crushing the ring. The cross-head was then lowered until the upper platen was just touching the specimen.
The plasma arc cutting and gouging processes use this plasma to transfer an electric arc to the workpiece. The metal to be cut or removed is melted by the heat of the arc and then blown away. While the goal of plasma arc cutting is severance of the material, plasma arc gouging is used to remove metals to a controlled depth and width. In a plasma cutting torch, a cool gas such as air or nitrogen (N2) enters Zone B (Figure 1-D), where a pilot arc between the electrode and
The force is also depends on whether the plate is at moving or stationary condition. Theoretically, the force of water jet striking on a static plate can be calculated using the following equation: F Qv (1 cos ) (2H5-1) where v is a velocity of jet as it strikes the plate and is the deflection angle as shown in Figure 2H5-1. The jet velocity v can be calculated using the equation given below: v u ² 2gs (2H5-2) where, u = velocity of water at the pipe nozzle = Q A Q = Discharge A = cross section area of the nozzle ©copyright 2008 Faculty of Civil Engineering UTM In this experiment, two type of plates will be tested: flat plate and hemispherical plate. i) For a flat plate, = 90o, and according to Equation (2H5-1), the force exerted on the plate can be calculated as, F Qv ii) (2H5-3) For a hemispherical plate, = 180o, and according to Equation (2H5-1), the force exerted on the plate can be calculated as, F 2 Qv (2H5-4) FIGURE 2H5-1 ©copyright 2008 Faculty of Civil Engineering UTM OBJECTIVES The objectives of the experiment are: a) To measure the magnitude of force exerted on: i. ii. b) Flat plate.