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Subido el 30 de abril de 2019 por Isabel L.

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In this video we are going to study deeply good. Good was a very important 00:00:03
material, technical material in the past because there were a lot of trees, a lot of 00:00:12
forests, so nowadays good is not so important because there are a lot of 00:00:19
of materials which properties are better than wood but nowadays the beauty of wood is very very 00:00:26
important to do for example furniture so the the most important application of good nowadays is as 00:00:40
as a material for the furniture. In the past it was important in houses and so on but today is more 00:00:50
important in furniture. Well, we are going to study all these different things. This is the index of 00:01:00
this unit. First of all, the raw material to prepare good is obviously 00:01:15
trees. Trees are autotrophic items. This means that they can transform inorganic 00:01:39
material matter into organic matter and to do this they need a the chlorophyll 00:01:52
that they usually have in a green leaves so it's necessary to move the inorganic 00:02:01
matter which is in soil, from soil to the leaves in the crown of the trees and to do this they 00:02:12
usually use the trunk and we use the trunk to get good. The trunk has different parts. It has 00:02:26
the pit which is the most inner part of the trunk and the bark which is the outer part of trunk. 00:02:41
And between the bark and pin we have hilt wood and shaft wood which is the part of the trunk 00:02:52
that usually used to do and to to get a wood from this part of the trees well to 00:03:03
do the forest exploitation is important that we we do a selective and a 00:03:15
geological of logging in our forest because if we do this part this first 00:03:22
step perfectly we help to the forest to renew it, but if we do in a bad way it 00:03:31
could be a disaster. So this is the the most important and most critical step of 00:03:42
the forest exploitation. And after that we need to remove all the branches and 00:03:50
and the upper crush, and then chop the logs, transfer to the sun windmill, and there we 00:03:58
need to cut in, ground in, and do a surface filling. 00:04:09
Well the cutting of the goods and of the trunks can be in different ways as you can see in 00:04:17
this slide. 00:04:24
the resistance, the mechanical resistance, is not the same in the different directions of the 00:04:26
track. That's the main reason why, depending how we do the cutting, the result of this material 00:04:35
has different mechanical properties. But in any case, obviously, the mechanical properties are 00:04:46
different in different directions also you can have different shapes to good 00:04:55
different thickness plain plain shape different thickness or a square or so 00:05:08
one depending what what are going to to make with this this material 00:05:16
so we have a difference not only not only have well good can be classified into two different 00:05:29
types, which are natural and artificial or sometimes is also called engineering good. 00:05:39
In engineering good there are three types of engineering good, of artificial good. 00:05:49
One is plain, is made using different very thin plain that can be in different types. 00:05:56
The more important are play goods. 00:06:08
The other are agglomerates, which are made by different drops or similar of goods. 00:06:11
Another is tablets, which is made from different pulp and is object to different hybrids. 00:06:21
We can see the natural good can be soft or hard. 00:06:32
You have some examples of one of these. 00:06:38
Soft good usually is to materials that has leaves that are always in all the seasons. 00:06:43
They don't change, they don't lose their leaves in winter or in autumn. 00:06:57
And hardwood usually is from these trees which loses its leaves in autumn. 00:07:07
As you can see here, for example, very important can be pine as a soft wood and cherry for 00:07:18
a hard wood. 00:07:28
They usually used to do different types of furniture. 00:07:30
Here you are the different properties of hardwoods and sun example. 00:07:40
It's very important type of wood. 00:07:51
Shot wood are also important and if the soil is also have for example pine. 00:08:00
they they would have different properties and different applications and its applications 00:08:11
is connected to its properties obviously and they are very important to do from to do part 00:08:21
of a houses and structures because it has a very good resistance to compress so they 00:08:30
sometimes are used in in this way as part of a structure of construction and 00:08:38
they also are low density and because of this they usually they can be used to do 00:08:47
for example, floats and ships and different parts of the ships, for example. 00:08:58
Because it has low electricity and thermal conductivity, they can also use as insulators 00:09:18
of this physical phenomena, for example in houses, you can use the wood to cover the 00:09:30
walls and to insulate a thermal cow from heat, from losses of heat. 00:09:45
They are composed, gout is a mixture of cellulose and lignin. 00:10:00
The lignin gives rigidity to the goods, meanwhile the cellulose gives the structural part. 00:10:07
So if you can, in any way it is organic matter. 00:10:23
So in any way it can be used to burn and to get energy from its burns. 00:10:30
But it also can be used to get paper. 00:10:40
If you eliminate the lignin, it is just only cellulose, so this is part of paper. 00:10:45
This is the process to get paper. 00:10:58
It's important because you chop it and then you use some chemical products to eliminate 00:11:03
the lignin from the gul and to change its color to get this white color this is the 00:11:16
reason why this kind of industry is so unfriendly in an environmental way they use a lot of 00:11:32
water and they usually contaminate this water, so because of this we try to reduce this contamination. 00:11:43
In any case, the last part is a calendar in which you can get different papers. 00:11:57
And this is all for today. 00:12:06
Autor/es:
Isabel Lafuente
Subido por:
Isabel L.
Licencia:
Reconocimiento - No comercial
Visualizaciones:
126
Fecha:
30 de abril de 2019 - 18:03
Visibilidad:
Público
Centro:
IES JAIME FERRAN
Duración:
12′ 10″
Relación de aspecto:
4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.
Resolución:
1440x1080 píxeles
Tamaño:
226.42 MBytes

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