Natural Rubber
I’m going to talk to you about rubber, I’ll talk about natural rubber
first and then go on to talk about the way in which its natural state
can be modified and manipulated so its advantageous properties can be
used.
(slide 2)
Natural rubber is an excellent engineering material and is used as the
main material in many everyday items the most prevalent being car
tires which I’ll discuss later also.
(slide 3)
Natural rubber is obtained from the milky white fluid called latex,
found in many plants however synthetic rubbers are produced from
unsaturated hydrocarbons (basically this means that there are carbon
atoms in the rubber molecule that have a potential to be bonded to
more hydrogen.
Latex is a milky fluid found in specialized cells, called lactiferous
cells. To gather the latex from plantation trees, a diagonal cut
angled downward is made through the bark; this cut extends one-third
of the circumference of the trunk. The latex spills out from the cut
and is collected in a small cup this is called rubber tapping which we
can see in this picture.
(slide 4)
I’ll briefly describe the chemical constitution and physical state
that we find natural rubber in first. Firstly it’s a polymer. It is
found in a viscous, high-elastic form, (a thick gooey mess in other
words) these conditions depend on long hydrocarbon chains (don’t worry
the chemistry part is brief!), which are normally coiled and tangled.
The high elasticity of rubber is made possible by the ability of the
chains to straighten and recoil. The bonds between the molecules in
the rubber are what cause this structure but I’ll just refer to these
bonds as its cohesion for the benefit of those of you who don’t do
chemistry. On breaking down the cohesion between the chains by
various means, normally by heating, rubber has some of the
characteristics of a thick oil (due to its hydrocarbon structure);
whilst, on the other hand, certain conditions, especially those of
however, too reservedly to scientific studies ever to be weaned from the, by any second
In this essay I am going to compare and discuss the ways in which the
In this essay I am going to show you how they are presented to the
the body works in harmony with nature, the natural rhythms of the body and spirit work
the way. Whether big or small, very few reach a level that evolves into a phenomenon
Some examples will be added that are necessary to assist us, in sustaining the main argument as well as to facilitate defining some requirements, for a HOT to occur in a conscious state.
change form life to death, and death to life, until from the midst of this darkness a sudden light broke in upon me- a light so brilliant and wondrous, yet so simple, that while I became dizzy with the immensity of the prospect which it illustrated, I was surprised that among so many men of genius who had directed their inquires towards the same science, that I alone should be
John Locke has a chapter named State Of nature. Now this chapter is a rather significant part in his reading. The reason being is the chapter speaks about foundation
Within the realm of philosophy, how creatures operate is a mystery that craves to be solved. Within Paul Churchland’s “Matter and Consciousness”, materialism, functionalism, and eliminative materialism attempt to explain such mystery.
German Chemist Hans von Pechmann first synthesized Polyethylene by accident in 1898 by heating diazomethane. His colleagues characterized the waxy substance polyethylene due to the fact that they recognized that it consisted of long ethene chains. It was then first industrially synthesized by accident in 1933 by applying extremely high pressure to ethylene and benzaldehyde. Over the years, development of polyethylene has increased due to the additions of catalyst. This makes ethylene polymerization possible at lower temperatures and pressures.1
Denture teeth can be made of acrylic poly(methyl methacrylate) (PMMA) or composite resins. PMMA is a polymer - a material made the from joining of methyl methacrylate monomers. Properties of PMMA include resistance to abrasion, chemical stability and a high boiling point. (Jun Shen et al. 2011). However, weak flexure and impact strength of PMMA are of concern as they account for denture failure. (Bolayir G, Boztug A and Soygun K. 2013). Composite denture teeth are made of a three distinct phases - filler, matrix and coupling agents. Out of the types of composite teeth available, nano-filled composite teeth are preferred. Composite teeth have a PMMA coating around the tooth and a high content of filler particles. This gives them strength, higher resistance to forces than acrylic teeth and provides compete polymerization due to the PMMA coating. (Anusavice, K. J., Phillips, R. W., Shen, C., & Rawls, H. R, 2012). If the interface between the PMMA denture base and PMMA or composite teeth was weak, the denture will not be able to sustain occlusal forces, making the base-teeth interface, an entity of significance.
...s or Aristotle in explaining the essence of a thing and its value to humanity (Martinez-Gil, 2001). The essence of nature is most especially defined by properties that define it such as its molecular structure. All through history and in present times, the conditions of society have permitted the existence of very rich “water cultures”, and what has been gravely considered as a necessary resource and in certain instances a spiritual wellbeing.
... yet present in all things […] something underlying the change and transformation of all beings, the spontaneous process regulating the natural cycle of the universe” (3).
An incredible event happened in the 1930¡¯s that has changed lives ever since. That event, the creation of nylon, has manipulated the way people dress and live their everyday lives. It even provided more employment opportunities and job improvements throughout the years.