Evolution of crushing
The main objective of crushing theory is to express the relationship between the energy consumed and the amount of the size reduction which resulted through this energy consumption. According to Lee (2009) there are three classical crushing theories in all which assumes rocks, (ore is also classified under rocks) to be brittle. Rittinger was the first to suggest the theory in which he proposed in 1867, he suggested that the surface area produced by crushing is directly proportional to the energy consumed. Rittinger formulated an equation in which energy consumed is in the form of Rittinger. Below is the Energy Rittinger equation
ERittinger=CRittinger(1/P_80 -1/f_80 )………………………………………………………………..Equation 2.1
Where Rittinger E is the energy input, Rittinger C is a material constant, 80 p is the size which 80 % of the product passes, and 80 f is the size which 80 % of the feed passes. Nevertheless, since an unlimited number of different size distributions pass the single points of 80 p and 80 f , neither of the parameters can adequately characterize a size distribution
The second classical crushing theory was introduced by Kick in 1883. Kick declared that the energy required for breakage is proportional to the reduction in volume of the broken particles. Below is the equation which was formulated by kick and it is known as the kick equation.
EKick=CKick ln(f_80/P_80 )…………………………………………………………………………Equation 2.2
Where Kick E is the energy input and Kick C is a material constant. Regrettably, similar to Rittinger’s law, Kick’s law lacks accuracy in describing the shape of a size distribution curve as only a distinct or single point is used
Bond in 1952 proposed the third and final classical relationship of crushing. ...
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... of the longitudinal stress wave
VPP= peak particle velocity which is also equal to impact velocity Vi
The kinematics of hammer rotation
Gupta (1996) argued that the performance of crushers have some other parameters they depend upon mainly the fineness of the crushing and the life of the beaters. It is estimated that the life of the beaters depends on the kind of operation it is applied, depth of penetration of the crushed material into the beaters and the kinetics motion of the beaters. He also suggested that the life of the beaters is approximately 50 to 60 hours but this was not clear in terms of the material used to manufacture the beaters. Gupta (ibid) argued that the crushing effect does not depend on the kinetic equation of the beaters, but depends on the interchange of the beaters and particle or loss of energy due to impact. He argued that there is need
“All of us have a personal relationship with stress, but few of us know how it affects us.” In the film “Stress- Portrait of a Killer” by National Geographic, Robert Sapolsky is researching baboon’s to find a link in stress and potential health risks in humans, Carol Shively is also researching macaques for that reason. Sapolsky is an american neuroendocrinologist that went to Africa “on a hunch” to study non-human subjects to test his theory, this experiment actually got Robert Sapolsky “MacArthur Foundations Genius Fellowship”. He did this by darting the baboons with anesthetic to put them to sleep, to make for easier blood samples. In the samples Sapolsky is measuring the levels of stress hormones found in the blood, he devoted thirty years of his life to this study with the help of his wife Lisa Sapolsky. This experiment relates to sociologic analysis, because Sapolsky’s study happens to draw a conclusion between economic activities and how it genuinely affects the quality of life. Some of the sociological themes we’ll be discussing are how “stress impacts our bodies and how our social standing can make us more or less susceptible”.
Life is like a bubble; It is pretty unbelieve-bubble. Everyone will stick with a thought, and that thought bubble will keeping floating and existing until it bursts. It is natural that everyone is adapting to how society sees as fit, but is the norm of the society really the best bubble? In the novel, To Kill a Mockingbird, By Harper Lee, the author give this message to the readers that racism is not something that everyone is born with, but rather is something that is taught. Although yes, the modern world no longer sees racism as the norm, it was much bigger way back in the 1930s. Racism was the bubble that stuck with everyone in the town of Maycomb, and took quite a while for them to open their eyes, a bit, about the topic.
One main idea of this book was that with the right mindset anything is possible. This is proven in the book when Louie is in the concentration camp and has to hold up a large piece of wood while having the Japanese guards stare at him. This shows that he had the mindset that he could outlast the guards and that he could overcome any obstacles in life.
Jean Luc Godard’s Breathless is often regarded one of the earliest films exhibiting the French New Wave style of cinema due to its influence on the movement and innovation by the producers. One of the most noticeable edits that Godard does in Breathless is the jump-cuts made frequently during conversations, and other times when one would expect continuity, in order to break up the flow of story to the audience and force them to actively participate on understanding the progression of events. This is quite contrary to the typical Hollywood style of film editing as transitions between shots are usually smoothed over as much as possible so that the audience focuses solely on the plot events transpiring on the screen rather than the editing
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The Repressive hypothesis states how we currently live in a sexual repressed society. The repressive hypothesis also states that sexuality needs to be liberated, or that it does not have to be repressed. Identifying with ones sexuality is the key to unlocking ones identity and one’s happiness. The repressive hypothesis initially implies three edicts; that derive from our repressed society. According to the repressive hypothesis, specifically in the repressive culture we live in, the first edict explains how all sexuality must be silenced in all occasions, for the mention of sexuality is taboo. In modern times, specifically within the 17th century, it was also important to keep sexuality “hush-hush”, only those who belong to the lower class
As we get older our, views, and perspectives on relationships may change. An explanation for this is that we encounter different situations in different relationships. Some relationships may affect us more than others, and can even change the way we think and view things. However, we would have to evaluate our levels of communication with different people. The social penetration theory helps us to categorize the levels of interpersonal communication we have with others. Based on these levels, we are able to categorize the importance and meaning of the relationship. The purpose of this paper is to discuss the effects of social penetration theory and how it applies to our lives.
Introduction The concept of aggressive expansion sometimes also, somewhat ironically, called American Imperialism is being recognized as a phenomena of the 19th century by most historians. However, some credit its start with the first colonization of the Northern American continent. For example the historian Paul Kennedy wrote; "From the time the first settlers arrived in Virginia from England and started moving westward, this was an imperial nation, a conquering nation." (P. Kennedy, 2002) Meaning that even the Western expansion should be considered an act of aggressive expansion which makes sense considering the land was already inhabited by Native Americans.
During impact most of the impact energy in the test specimen is absorbed as plastic deformation when the test specimen yields. Temperature and strain rate effect the yield behaviour and ductility of the material and hence affect the impact energy. Materials that behave this way usually have body-centred cube crystal structures and where lowering the temperature reduces the materials ductility.
Serway, Raymond A, and Robert J Beichner. Physics: For Scientists and Engineers. United States of
In Chapter 14 (Kinetics of a Particle: Work and Energy) and Chapter 18 (Planar Kinetics of a Rigid Body: Work and Energy), both apply a same concept. It is concept of work and energy to solve the problem. Chapter 14 use the concepts of work and energy to analyze motion of a particle, while Chapter 18 apply work and energy methods to solve planar motion problems. In both chapter, problems that involve force, velocity, and displacement can be solve by using the resulting equation.
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