Manmade and Natural Materials
Students like myself need to know what materials are available, how
they behave in use and how they can be worked or processed during
manufacture and construction. Having a good understanding of these
will help me to select suitable materials for my products.
In choosing materials for a particular project, I will need to
consider their physical and working properties, so that I am able to
decide which material is best and which method of processing is
required in order to turn raw materials into finished products.
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I have to use a procedure called product analysis. This involves
analysing and existing product in order to identify the materials that
have been used, the properties that make them suitable for the task
for which they have been designed as well as an awareness of the
processes used in their manufacture, construction and assembly. All
man-made materials are derived from one or several naturally found
materials.
History of materials
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Early human history is divided into eras named after the materials
that were predominantly used at the time. The Stone Age, Copper age,
Bronze Age and Iron Age suggest how important these materials were in
the development of early technology.
Early humans could only utilize the materials that they found to hand.
Stone, reeds, clay, wood, animal hides, hair and bone enabled them to
survive in otherwise inhospitable conditions. During these earliest
periods organic materials were by far the most important and useful.
Human resources were greatly enhanc...
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... the way things look. I have to see if it will be fixed or if
it will be carried, as these factors could be very important. Weight
in the right place might be needed for balance and stability. I have
to look at how long a material will last before it is affected by its
environment, and how much energy the material can absorb.
After looking at all the information, and thinking about what
materials I use and how I use them, I have decided that the most
useful materials are natural. These were around at the beginning of
time when man didn't even exist. Apart from using these for products,
we eat them and use them in everyday life. If there wasn't wood to
burn for fire, there would not have been various man made materials.
Man-made materials are necessary in everyday life, but not as
necessary as natural materials.
A rate is a measure of change that occurs in a given time whilst a
Michael Pollan’s purpose of writing Omnivore’s Dilemma came about when he realizes that society is unbelievably unhealthy due to the abundance of food. The two conflicting logics that Pollan introduces are the logic of nature and the logic of industry; these two logics are reflected through various ways of raising livestock animals. The logic of nature consists of raising livestock animals in a pastoral environment where animals interact with one another and avoid the use of artificial chemicals; whereas, the logic of industry settles on raising livestock animals unnaturally. Growing cattle through the use of corn has allowed meat to be produced in large quantities and in a short time as described in the chapter “Feedlot: Making Meat”
This is the transitional state from potentiality of the materials to the actualization of the form as describes in the previous step. This step is described by Aristotle ?Again, the primary source of the change or coming to rest; e.g. the man who gave advice is a cause, the father is cause of the child, and generally what makes of what is made and what causes change of what is changed? (Physics, Book II, Chapter III, 194b 30-33). This is a very important stage as we see that though the changes are taking place by changing the physical looks of the materials the underlying nature of the materials is never changed. Thus the internal motions that nature imbues the materials with is in full effect. The reality is nature will not stops is slow movement to the end of the materials it simply allows the physical changes to
Dental materials are used for a variety of reasons. The basic reason for using dental materials is to restore the tooth back to its original anatomy. Some materials are used more than others but it depends on their characteristics. Composite resin is a type of dental material. Some dental materials do not have the esthetic characteristic that composite resin has. That is why sometimes, it is more favorable than other dental materials. It is one of the most common dental materials that are used to restore a tooth back to its natural appearance.
the reaction; if it speeds it up, slows it down or changes it in any
Roof tiles are designed to block out rain, this is because the tiles will have a ‘waterproof glaze’ ensuring that rain will not enter the home and that inside will stay dry.
Lead time, the time taken for a unit to go through all the steps of a process from start to finish, is computed.
The idea that man can create materials which have properties not found in nature is profound, however in reality this is a relatively simple process. One designs a unit cell or meta-atom and then binds these meta-atoms into a structure creating a metamaterial [1]. Such a metamaterial can have optical properties which can be adapted to a certain requirement. To make a Negative index metamaterial, NIM, the requirement is that the refractive index, n, should be negative. By building certain shapes of meta-atom the permeability, µ, and permittivity, ԑ, of the metamaterial can in theory be chosen. From a construction point of view there are two branches of metamaterials which are 2D and 3D NIMs, and the construction techniques differ between the two branches. 2D NIMs are metamaterials constructed with just one layer of meta-atoms, whereas 3D NIMs are constructed with many layers placed above one another.
b) Aging of the insulation material due to temperature, especially points of local overheating is quickened by the presence of moisture and oxygen [65].
Measurement of plastic or glassy material glass transition temperatures or softening temperatures, which change dependent upon the temperature history of the polymer or the amount and type of fill material, among other effects.
Turn the lamp on and start timing it as soon as the edge of the solution starts moving. After ten minutes measure and write down in millimeters the distance the edge moved.
The word ‘composite’ does not fully explain the wide range and varied compositions of materials that are categorized under it. This paper deals with some of the commonly used composites. Common materials such as metallic, ceramic and polymers consists of substances that can be classified as composites. The steel family, which is considered as the biggest group of material that is used in construction and complex engineering, is composed of composites that are made out of soft metallic matrix and hard ceramic components. [11] Such metallic composites could be shaped as a plate, needle, sphere or be polygonal. Polymeric composites are also found in a similar matrix model where one polymer forms the skeleton and another hard or soft polymer fills the matrix. A good example of this would be wood. Concrete is also a popular matrix composite where the Portland cement provides the matrix phase and the inner filling is made up of sands of different size. Scientists are now able to adjust the composition of these composites to suit the various needs. This adjustment is done by tweaking the microstructure of the materials by changing the state, shape, amount and distribution of the filling, which is also called as the reinforcing phase. Instead of restricting this tweaking process within a certain material class, the idea is being implementing in cross-material classes as well. Ceramics powder can be added to plastics to make hard and fireproof polymers. Ceramic powder when mixed with metals, gives cermets, which are used in tips of metal cutting tools. Another branch of the same idea is the blending of metal filaments, ceramic and polymer into one large bulk to form metal-matrix composites (MMCs), reinforced plastics (RP) and ceramic-matrix composites (CMCs). Such a radical idea of mixing all the three classes of materials has resulted in composites such as carbon fibre reinforced plastic (CFRP), glass reinforced plastic (GRP) and silicon-carbon-fibre-reinforced aluminium. Figure1 shows Comparison between conventional monolithic material and composite material. [17, 18,10and1
In order to change the physical or chemical properties of a metal, the time taken and the temperature of the heat treatment are crucial. The time and temperature vary from material to material. It is important
I believe that Archeology is very intriguing. It is a sub area of anthropology. It is very cool how they find things from millions of years ago. In my attitude if we did not have archeologist I don’t understand if we would understand anything about what dwelled million years before or how their heritage was what they used what they did. personal things help us understand all this. And if people did not gaze for the things where would we be in this day and age. The main point that I am going to converse about is how does archaeology gets finished. What kind of steps they take to get the outcomes they desire.
Natural products, in general terms, are chemical substances produced in nature1. Or simply putting it, they are molecules found in living organisms, according to Mcmurry2. Natural products are secondary metabolites, which are small molecules living in the organism without effecting in a major way, like nucleus acids, which are essential for the survival of the organisms19. While many of them don’t have a specific biological role, some of them act as sex attractants and anti-feedants19. They differ with other biological micro molecules in their complexity, since they are much smaller than average micro molecule, tend to be more diverse and have the ability to conserve themselves for a long period of time even without a specific biological activity or role19. The importance of natural products relay on its variety of uses, since natural products are used in pharmaceutical industry, food production and pesticides3. The techniques commonly used to produce natural products are: Column chromatography, extraction and distillation. In this paper, the efficiency of the extraction method in synthesizing natural products will be evaluated. Extraction of natural products in an economic and environmentally-friendly way is of high importance to all industries involved.