They do not conduct electricity when in a solid state, but only when dissolved in water or melted. Ionic compounds also tend to be solid at standard pressure and temperature. Also, because of the difference in electronegativity, they tend to have high polarity too. The melting point of magnesium chloride is 714oC, and its boiling point is 1 412oC. These melting and boiling points are quite high – since ionic compounds use up a great amount of energy to break their bonds.
The test is based on the principle that the rebound of an elastic mass depends on the hardness of the surface against which the mass impinges. Fig. 8.2 shows the rebound hammer. The spring controlled hammer mass slides on a plunger within a tubular casing. The plunger retracts against a spring when pressed against the concrete surface, and this spring is automatically released when fully tensioned, causing the hammer mass to impact against the concrete through the plunger.
These properties can be used for design and analysis of engineering structures, and for developing new materials that better suit a specified use.The basic idea of a tensile test is to place a sample of a material between two fixtures called "grips" which clamp the material. Procedure: The tensile test was on three different materials, aluminum, steel and brass. The Aluminum had the highest resilience if compere with the steel or brass it got 5.5mm of extension after the load. Diode characteristics Experimental Procedure:
By adding the cobalt additive, the phosphate crystals formed on the zinc get more uniform and contain less porosity. The densest coating of the phosphate coating samples was obtained with 3g/lit ions of cobalt. However, the excessive addition of additive (4
However, the almost linear promoting effects of DME addition were found in propane and n-butane ignition delays [23, 25]. This is mainly due to that the reactivity of methane is much lower relative to that of DME. Therefore, even with a small amount of DME addition, the ignition was strongly promoted by the decomposition of DME accompanied by the rapid build-up of free radicals, thus lead to the nonlinear promoting effect on methane ignition [21, 22]. However, for the higher order alkanes such as propane and butane, the reactivity of which are higher and the ignition delay times are much shorter relative to methane. Moreover, in the high temperature oxidation of methane, the rate of the governing reaction CH4 + O2 CH3 + HO2 is much slower than of the similar reactions of the higher order alkanes .
the average fuel economy for a gas truck is around 14mpg. Along with the poor fuel economy, the gas that goes through the truck does not burn as clean. When the gas does not burn as clean, that means that it puts out more pollution than a diesel engine. A diesel engine also has 25-30% better fuel economy that a gas engine. With the 25-30% better fuel economy, a diesel engine can deliver much more fuel economy that electric hybrids.
The second reason is that the nonmetals have smaller atomic sizes making it easy to attract electrons but difficult to pull them away. 12. A lot of energy is required to break a strong intermolecular bond. This is because atoms in certain compounds have very strong bonds that require energy to break. This explains why some compounds have higher boiling points than others.
It is suitable for hardness tests on large unfinished parts such as forged parts, cast parts, hot rolled or pressed and heat treated parts.This is large advantage that the Brinell test has over the Rockwell test because it is easier to perform on steel or iron parts. These larger parts are heavier and inherently more expensive making it a crucial factor that they can still be used. It can be concluded that the Rockwell test is easier and more accurate for smaller samples of less coarse material. On the other hand, there is a limitation of range of application for a maximum Brinell hardness of 650 HBW and limitation for testing small and thin specimen and relatively large degree of damage to the specimen by the indentation. The advantages of the Vickers hardness test are that extremely accurate readings can be taken, and just one type of indenter is used for all types of metals and surface treatments.