Griffith attributed the discrepancy between the observed fracture strength of crystals and the theoretical cohesive strength to the presences of flaws in brittle materials. This theory is applicable only to perfectly brittle material such as glass, and cannot be used directly to metals. However, Griffith's ideas formed a base to understand the fracture in metals. Griffith proposed that a brittle [...]
The development of electron theory of solids was gradually started early in 20th century with the enunciation of Drude-Lorenze theory, the Sommerfeld modification and zone theory etc. The electron theory, in the initial stages was only a model for metals but later on with further development it became applicable to metals and non-metals. Metallic Bonding: In metallic crystals the atoms [...]
The following points highlight the main theories and methods used for determining vertical stress in soil mass. Also learn about the comparison of different methods for determination of vertical stress in soil mass. 1. Boussinesq Theory for Vertical Stress due to Concentrated Load: Boussinesq in 1885 gave a solution for stress distribution in a homogeneous and isotropic subgrade subjected to [...]
Here is a term paper on quantum tunneling. Quantum tunneling (or tunneling) is the quantum- mechanical outcome of transitioning into a previously-forbidden energy state. Consider rolling a ball up a hill. If the ball does not have the proper amount of velocity, then it will not roll over the hill. This makes sense to many of us who have read [...]
Here is a term paper on quantum entanglements. Quantum entanglement means multiple particles are linked together in a way that means the measurement of one particle's quantum state controls the possible quantum states of the other particles within the linked group. As such, these particles act on one another, much as the friends of our younger selves did. Let's look [...]
Here is a term paper on unified field theory. Albert Einstein first coined the term ‘Unified Field Theory’ to describe any attempts to unify the fundamental forces of physics, particularly between elementary particles into a single theoretical framework. Einstein himself searched for such a Unified Field Theory, but was not successful. So what brought this about? In the past, seemingly [...]
Here is a term paper on wave particle duality. Throughout history, science has been fascinated with light and how it behaves. Prisms, among other tools, have been used to observe and measure light. During the 1600s, Christiaan Huygens and Isaac Newton suggested opposite theories to explain the behavior of light. Huygens believed that light functioned as a wave, with various [...]
Following meteorological factors should be understood before studying the diffusion theories: 1. Atmospheric Temperature Lapse Rate 2. Speed and Direction of Wind 3. Wind Velocity Profile 4. Richardson's Number. Factor # 1. Atmospheric Temperature Lapse Rate: When the air has minimum velocity or more or less motionless, the accumulation of the pollution will be maximum. When the air is in [...]