Here we can see charcoal being made in  mass production situation.

Charcoal

How is it formed: Woodlands (2008) and Amazingribs (2011) both agree on the production of charcoal and how it is formed. Charcoal is the solid residue left when carbon is burnt, or as some say ‘pyrolysed’ in an absence of oxygen and other possible impurities often in a closed case such as a kiln. This method can take a while to produce charcoal though. So often in industry or mass-market, they have systems to eliminate all oxygen as it provides a higher yield as no extra wood is burnt.

Once the process starts it produces its own heat but the decomposition doesn’t start until it reaches 300°C

Charcoal is available as either a ‘lump’ or a briquette. SeriousEats looks the the differences between lumps and briquettes. A ‘lump’ will lights quickly, burn hotter, have little ash production, easier temperature adjustment, and all natural. However, it will burn faster, can be more expensive, less consistent (bags can contain unusably small pieces of charcoal) where as a briquette will burn longer, easier to maintain consistent temperature, cheaper.
However, they are often take longer to light, give a chemical smell, large ash production. 

How can we make better charcoal?

A good place to start when making our own charcoal is removing as much water moisture as possible and other volatile substances such as methane, tar and hydrogen.

What are the uses of charcoal? 

Charcoal has been used by ancient peoples for hundreds of years as tool for communication and also many new uses. 

UK agriculture (2013) demonstrates these uses, both current and ancient.

 

Bibliography

Amazingribs, (2011). The Zen Of Charcoal: How Charcoal Is Made And How Charcoal Works. [Online]
Available at: http://www.amazingribs.com/tips_and_technique/zen_of_charcoal.html
[Accessed 28 3 2013].

UK Agriculture, (2005). Charcoal Uses. [Online]
Available at: http://www.ukagriculture.com/countryside/charcoal_uses.cfm
[Accessed 20 4 2013].

Woodlands, (2008). How do you make charcoal?. [Online]
Available at: http://www.woodlands.co.uk/blog/practical-guides/how-do-you-make-charcoal/
[Accessed 16 3 2013].

 SeriousEats, (2008). Grilling Smackdown: Lump Charcoal vs. Briquettes. [Online]

Available at: http://www.seriouseats.com/2008/05/grilling-smackdown-lump-charcoal-vs-briquette.html [Accessed 18 3 2013]

Redwoods - and why are they fireproof?

The Redwood trees are some of the tallest trees on the earth, they can reach over 350ft in height. The name Redwood coming from the red colour of the bark. The bark itself is very thick, can be up to 1 foot, and contains tannins which make it form a protective layer against fire, insects, fungus's and diseases which could cause any harm to the tree. They can live for 2000 years although many of them only live between 500 and 700 years. 

The roots

You would expect a tree that's so tall to have very deep roots, however this is not the case for the Redwood tree. It has very shallow roots which are only between 6 and 12 feet deep and have a small span of 50 to 80 feet with a diameter of 1 inch. 

Why is the Redwood tree fireproof?

Redwood trees have very thick bark which has a lot of water inside it. They also do not have any pitch inside the trunks which is a very flammable substance found in many other trees. Another factor that helps to make the redwood trees fireproof is the fact that they do not have any of the resins that other trees like pine and the sap that the tree contains is made up of a majority of water also adding to the fireproofing ability. However over time as the tree has to survive more fires, the fire will eventually find its way into the tree through cracks in the bark and it will then begin to hollow out parts of the tree leaving the rest of the tree to remain in tact. 

The redwoods themselves can actually benefit from the fires as it helps to remove some of the other non fireproof plants and trees from around them giving them access to more light and nutrients etc. 

How does the tree get water from the ground to the top?

With the trees being so tall one question that could be asked is how does the tree manage to actually get the water to the top. Scientists have discovered that in order for the water to reach the top, the molecules have an interaction with the walls of the capillaries inside the tree. The bond that is then created forces the water to be dragged up the capillaries, also at the same time evaporation from the leaves will create a vacuum effect which also pulls the water up. The tree will stop growing when its suction can no longer pull the water up to the top of the tree. 

New trees

The redwood trees spread their seeds by producing cones with seeds in, each of the seeds will be tiny - only about 3 mm and when they fall out of the cone they will only usually travel between 60 and 120m away from the parent tree. If it lands on moist, warm soils it will begin to germinate within a month and if the conditions are suitable it will start to root itself. Then after it has started to grow its first leaves it can then begin to produce its own food and they usually grow about 5-7cm in their first year. 

They also have the ability to reproduce by stump sprouting, this can be very advantageous especially compared to those which can only reproduce by seeds. Stump sprouting allows the tree to grow new sprouts from burls around the base of the tree when the tree has been badly damaged by cutting or fires. Burls being developed from buds that do not turn into shoots. The buds will continue to grow as wart like patches on the side of the tree until they are needed, when the tree is damaged and they will then use the parent trees roots as their own. 

Other facts

• After repeated fires the bark is eventually damaged and then the middle rots out and settlers used to use the hollowed out redwood trees as pens for animals. 
• The bark is often used as a soil conditioner especially for plants that need a lot of space around their roots such as orchids. 
• Used to be used as an insulator due to its nature of not pests not being able to live in it and the fact it doesn't absorb water. 

Biography

About Coast Redwoods available at: http://www.parks.ca.gov/?page_id=22257 (accessed 18/04/13)

First Image available at: http://www.coolcrack.com/2012/06/redwood-ancient-giants-14-pics.html (accessed 18/04/13)

Redwood Trees available at: http://www.shannontech.com/ParkVision/Redwood/Redwood2.html (accessed 18/04/13)

Second image available at: http://www.visualphotos.com/photo/1x7038921/redwood_cones_sequoia_sempervirens_3L1024.jpg (accessed 18/04/13)

The Redwood Forest available at: http://sunnyfortuna.com/explore/redwoods_facts.htm (accessed 18/04/13)

Third Image available at Thick Redwood Bark http://sunnyfortuna.com/explore/redwoods_facts_02.htm (accessed 18/04/13) 

What are Lichens and How do they live?

What are Lichens and how do they live?

Lichens are 'dual' organisms, consisting of two or more different forms of life living together symbiotically in a body and all of which benefit from the partnership. Generally the main part of the Lichen is a fungus and the other part being a green alga or cyanobacterium. The function of the alga or cyanobacterium is to produce nutrients via the process of photosynthesis that then are used to feed both parts. The fungus has the basic function of creating a body which forms a sheltered environment protecting against the elements. The fungus also produces chemical compounds that build up to create a protective 'sunscreen' layer over the photosynthetic partner.

There are four main Lichen growth forms each having many subcategories.
1. Crustose - these are encrusted forms and they cannot be removed from surfaces without them crumbling away.
2. Squamulose -
3. Foliose - these can be removed very easily using a knife and they are attached with root like threads. They  are leaf like and spread across in a hroizontal layer over surfaces.
4. Fructicose - these can be easily removed by hand and they are much more shrub like with many branches.

Reproduction

Most Lichens reproduce by production of spores, however some also reproduce by having parts of the lichen breaking off and simply growing somewhere else. If a lichen has a powdery substance on the outside then these are the bits of lichen that will break off and spread to create new ones. These bits contain both fungal and alga partners and are known as soredia. When the the spores break off they do not have any of the alga cells and although they can germinate once leaving the Lichen they can only create a new lichen if they find a suitable alga partner as the fungus cannot survive on its own so will die.

Growth

Lichens tend to grow very slowly and their growth is greatly affected by the environment around them. For example small encrusting lichens can grow as little as 1mm each year and larger forms can grow up to 1cm per year. The lichens use their large surface area to absorb minerals and water from the atmosphere and this is why they tend to struggle to grow in areas with high pollution with different species being able to stand different levels of pollution. This therefore makes them a good indicator of air pollution.

They can grow nearly anywhere and it is thought that Lichens cover about 8% of land surface. Lichens tend to grow especially well on rocky coasts, mountain summits, icy polar regions and in steamy tropical rain forests.

Uses for Lichens

Lichens have many practical uses, as well as being an indicator of air pollution, they can be used to make a variety of different coloured dyes. They also create a lot of acids which we use, for example litmus dye and some of the species contain substances with antibiotic properties which can be more effective than penicillin.

Biography 

Lichens. Available at http://countrysideinfo.co.uk/fungi/lichens.html (accessed 4th April 2013)

Stuff on Rocks 2: All about Lichens. Available at http://watchingtheworldwakeup.blogspot.co.uk/2009/03/stuff-on-rocks-2-all-about-lichen.html (accessed 4th April 2013)

What are Lichens? Available at: http://www.britishlichens.co.uk/whatarelichens.html (accessed 4th April 2013)

The Science of Toasting Marshmallows

If you've ever spend a few nights out camping with a roaring campfire you may have the extraordinary experience of toasting a marshmallow. Some would say that all you have to do is put a marshmallow on the end of a stick and put it over your fire and that's that. But to make that perfect marshmallow there is a hidden science behind it. 

Paica (2012) gives us an insight into this hidden world of perfect marshmallow toasting; the trick seems to be picking the right spot in the fire. It is important to have your marshmallow over the glowing hot coals but also a small amount to the side of the flames. Cate states that the hot coals give off radiant heat and we have convection heat from the hot gasses of the flames; this is partly why we want to be careful of getting too close to the unpredictable flames. WiseGEEK adds that you should also rotate your marshmallow to allow for an event exposure to the flames so you can create that golden brown delicious coating. 

But it's not just down to that. We also have to consider the stick to use for our marshmallow. WiseGEEK suggests to select a straight as possible stick so when you rotate your stick the marshmallow rotates with a centred orientation and give the most optimal exposure needed. They also suggest whittling the stick to reduce possible germs.

Just in case you want to start from scratch with your marshmallow as well, Kidspot has come up with a list of cooking ingredients and a method to make your very own marshmallow.

Wildomar has come on marshmallow radar and has been picked up by The Press-Enterprise as they discover Sixth-grade students have made their very own solar roasters at Sycamore academy of Science and Cultural Arts. This could be a very novel way to roast a marshmallow but would it be perfect?

Eat Sleep Science gives a little insight on what is happening to marshmallow whilst it is toasting. They state that the sugar (known as sucrose) breaks down due to the heat of the fire and water molecules in the sugar are evaporated; this gives us the carbon crunchy outside of the toasted marshmallow, which holds the juicy liquid inside for us to enjoy.

What do you think is the 'perfect' marshmallow?

Biography

Cate, C. Science Around the Campfire: Science off Center [Online]

Available at: http://www.scienceoffcenter.org/news/496-science-around-the-campfire (Accessed 5th April 2013)

Eat Sleep Science [Online]

Available at: http://eatsleepscience.com/ess/index.php?option=com_content&view=article&id=49:marshmallow-science&catid=34:ess-details&Itemid=50 (Accessed 6th April 2013) 

Fun Zone. Toasted Marshmallows [Online]

Available at: http://www.kidspot.com.au/omofunzone/cook-toasted-marshmallows+3470+569+sponsor-recipe.htm (Accessed 9th April 2013)

 Palca, J. Summer Science: The perfectly Toasted Marshmallow: NPR. [Online]

Available at: http://www.npr.org/2012/06/12/154781777/summer-science-the-perfectly-toasted-marshmallow (Accessed 8th April 2013)

The Press-Enterprise. WILDOMAR: Students use science to roast marshmallows [Online]

Available at: http://www.pe.com/local-news/riverside-county/wildomar/wildomar-headlines/20120926-wildomar-students-use-science-to-roast-marshmallows.ece (Accessed 5th April)

WiseGEEK. How Do I Roast Marshmallows? [Online]

Available at: http://www.wisegeek.com/how-do-i-roast-marshmallows.htm (accessed 5th April)