All posts by steven01pd2012

Silk: A new perspective after 5000 years

While on APAC rugby, watching the discovery channel, I watched an hour-long channel on China and the Silk Road. It talked about the wonders of the silk of the silk worm, and its many different properties. Unfortunately, the silk part of the channel was brief, and left me wondering about the applications of silk. Prior to this, my only knowledge of silk was that it is is used to create clothes. A few Google searches away led me to a compelling TED talk on Silk by Fiorenzo Omenetto, who talked about the many applications of Silk, an “ancient material of the future.”
Silk is a natural protein fiber, made specifically by the refolding of water-soluble fibroins into insoluble fibers. Silk’s most unique property is being one of the strongest natural fibers, due to its chemical structure. The high proportion of glycine allows tight packing and numerous hydrogen bonds, allowing greater strength. However, silk has many more properties, such as being biodegradable, and being implantable into the human body with no immune response. These properties allow for innumerable uses for silk in our society.
The most revolutionary application of silk, however, is the reverse engineering of silk, transforming silk back into its original “ingredients” that is protein and water. One example of the application of the reverse engineering is the use of these ingredients in the creation of film, in which researchers take advantage of the fact that proteins and water reassemble and create film. This film can be further applied into nanotechnology, in which the silk solution can be poured onto the surface of a DVD player, and the silk would replicate features on even a nanoscopic level, hence retaining the information stored on the DVD. The use of this technology can also be applied to other areas of nanotechnology, such as creating optical micro prisms or even holograms.

Omenetto demonstrating silk film retaining nano-information
Omenetto demonstrating silk film retaining nano-information

Silk engineering itself holds big implications. Being biodegradable and the strongest natural fiber, it could potentially eliminate the need for plastic bags, which are detrimental to the environment. Furthermore, material such as polystyrene would be obsolete, as silk can easily be created and thrown away without guilt. Additionally, silk can be programmably degradable. Scientists can create a silk film that is programmed to not degrade in water, and create another that is, allowing scientists full control of silk’s creation and descruction. Being biocompatible, silk can be inserted into the body with no negative repercussions, giving rise to possible ideas such as silk micro needle.
The greater implication that I see, however, is the completely new perspective into a material that is 5 millennia old. This new perspective not only allows revolutionizes the way we use silk, but also begs us to start looking at other materials with new lens. While looking for new discoveries may be important, it is just as important to look at what we have right now with different perspectives, and possibly discover new applications of old materials.

Works Cited
Clark, Douglas. “Researchers Find New Uses for Silk | ChEnected | Engineers talk chemicals, bio, safety, energy, sustainability..” ChEnected | Chemical engineers discuss careers, energy, and sustainability. | AIChE. N.p., n.d. Web. 20 Oct. 2011. .
“Film Festival.” Film Festival. N.p., n.d. Web. 21 Oct. 2011. .
Lewin, Menachem. Handbook of fiber chemistry. 3rd ed. Boca Raton, FL: CRC/Taylor & Francis, 2007. Print.
Omenetto, Fiorenzo. “Fiorenzo Omenetto: Silk, the ancient material of the future | Video on TED.com.” TED: Ideas worth spreading. N.p., n.d. Web. 20 Oct. 2011. .

Ethanol, a possible solution?

In the past decade, our society has increased our awareness of the limits of fossil fuels. By estimations of the world’s proved reserves of oil and coal, oil can only last 43 years, and coal can only last 148 years. I have also noticed that fossil fuels have increased dramatically in value, a prime example being the rising oil prices in China, suggesting that supply is low. As a result, scientists have been frantically trying to find alternative and renewable energy sources.

The most viable option right now is biofuels – specifically, ethanol. Biofuels are created from biomass, which is biological material from recently living organisms. The sugars from the biomass can be used to ferment and distill ethanol, using yeast through anaerobic respiration. Ethanol can then be used as an energy source; when it undergoes a combustion reaction, it releases water, carbon dioxide, and heat energy.

Ethanol fermentation’s chemical equation:
C6H12O6 + yeast → 2 C2H5OH+ 2 CO2 + heat energy

Combustion reaction of ethanol:
C2H5OH + 3 O2 → 2 CO2 + 3 H2O + heat energy

http://www.solarcity.org/biofuel.jpg

The concept is simple; however, the implications are huge. Ethanol can be created from organic wastes that would otherwise be thrown away. This way, the organic wastes can be utilized to create an energy source that is renewable. It may also be possible to grow crops such as corn specifically for the purpose of fermenting and distilling ethanol. There is a counterclaim, however, that biofuels from organic food stocks are not enough. C. Ford Runge and Benjamin Senauer, for example, observe that even if every acre in the United States currently devoted to growing corn is used for the production of ethanol, this would meet only 12-15 percent of the United States’ transportation fuel needs. While this may be true, collecting organic waste to convert to an energy source is more productive than letting it go to “waste”. Indeed, the argument currently holds that ethanol may not be able to completely replace fossil fuels, but taking action, however small, can only help in finding renewable energy and conserving fossil fuels.

Another implication of using ethanol as an alternative fuel is to prepare society for the use of alternative energy as a whole. As of now, most cars in the US can use blends of up to 10% ethanol, and by December 2010 Brazil had a fleet of 12 million flex-fuel automobiles and light trucks and over 500 thousand flex-fuel motorcycles regularly using neat ethanol fuel (known as E100) (ANFAVEA). Again, this may be a small step, but an important one in preparing society for a future of alternative fuels.

My interest in trying to find possible renewable energy sources has not only driven me to write about this topic, but also choose biofuels as a topic of research for my IB Extended Essay topic. Specifically, I will be looking at the different types of organic wastes and how it affects the amount of ethanol achieved. Though my EE will be looking at the topic intensively, hopefully this blog post will provide enough knowledge to demonstrate the implications of the biofuel ethanol.

Works Cited
ANFAVEA – Associação Nacional dos Fabricantes de Veículos Automotores (Brasil). January 2011. http://www.anfavea.com.br/tabelas/autoveiculos/tabela10_producao.pdf. Retrieved 2011-02-05. Production up to December 2010

“Understanding Resource Nationalism in the 21st Century.” Journal of Energy Security. N.p., n.d. Web. 28 Mar. 2011. <http://www.ensec.org/index.php?option=com_content&view=article&id=253:resource-nationalism-in-the-21st-century&catid=108:energysecuritycontent&Itemid=365>.

“What is Biomass?.” Biomass Energy Center. N.p., n.d. Web. 27 Mar. 2011. <www.biomassenergycentre.org.uk/portal/page?_pageid=76,15049&_dad=portal&_schema=PORTAL>.

Snap, crackle, pop? Not really

“Note: buy a new alarm” thinks Bill, late for his potential million-dollar meeting. It’s 9:30 in the morning, and Bill is frantically searching for the slightest loops in traffic to weave through. The green light is flashing; he’s not about to miss it. Pressing harder on the accelerator, Bill speeds up to gun it. 10mph, 20mph, 30…it seems he’s able to make it. Out of the corner of his eyes, a motorcyclist speeds onto his path of direction with possibly double Bill’s speed. Bill hit the brakes, but it was too late. The motorcycle hit directly into Bill’s car, the motorcyclist was thrown forward into busy traffic. Bill hurriedly got out of the car, running to the man expect a motion-less body on the ground. Instead, the man was standing and walking towards his motorcycle. How is he walking? Why isn’t he in the intensive care unit with a few cuts and broken bones?

Bill’s thinking clearly underestimated the strength of the bone. The bone is one of the strongest materials found in nature, capable of withstanding at least 19,000 pounds per one cubic inch. To give you an image, imagine taking an ice cube out of your freezer, and stacking five pickup trucks onto the ice cube. The ice cube is how big the cubic inch of bone would be, and the five pickup trucks would be how heavy 19,000 pounds are, approximately. It’s also about four times the strength of reinforced concrete. In fact, bone has a strength to weight ratio superior to any other natural material on earth.

Bet youre feeling pretty strong now.
Bet you're feeling pretty strong now.

The bone’s strength comes from its bone tissues, which has two parts. The first is a hard outer layer of bone, composed of compact bone tissue with minimal gaps and spaces in the tissue. This is the heavier part of the bone, as it factors around 80% of the bone’s weight. It is created by making a matrix, and contains a strong ionic bond between calcium and phosphorus as well. The interior of the bone is called the trabecular bone tissue. It is a matrix of hollow cells, walls as thin as paper. This part of the bone, whilst only giving 20% of the bone’s weight, has nearly ten times the surface area of the compact part of the bone. It is this part of the bone that bends, and allow for bone to be light and flexible, yet sturdy and strong.

Running increases the body mass by three times, jumping by ten. How, then, is the bone able to take this much pressure everyday without wearing out so quickly? The answer lies in the cells and the cycle that provide the maintain the body’s bones. There are three types of cells to maintain the bones:

  • Osteoblast – the cell that lays down new bones when needed, and taking minerals from extracellular fluids and creating new bone matrices.
  • Osteoclast – resorb bones by releasing acids and enzymes
  • Osteocyte – communicate to the cells about pressure and stress from inside the bone cell, and also destroy the bone through a rapid mechanism. These were originally osteoblasts that were trapped in the matrices they created.

These three cells are vital to bone regulation. As the bone is resorbed, osteoclast releases a signal (cytokines) which encourages osteoblasts to lay new bones. As the osteoblasts lay new bones, it adds small proteins into the bone structure they create. Osteoclasts come again, and both osteoclasts and osteocytes break down the bone matrices. When the bone is resorbed, these proteins are released and act as signals for osteoblasts to come and lay new bones once again. This vicious cycle of breaking down and making new bones are essential for both maintaining the bone and preventing the bone structure from going haywire. Another reason for this cycle is so the body can adapt under different stresses and under different circumstances. It is estimated that every seven years, all the old cells in your bone is replaced with new cells, and the entire of the skeletal mass may be replaced every 10 to 25 years. Indeed, it’s fascinating that the bone does this to keep our skeletal structure. So drink your milk, kids.

The cycle of bone turnover
The cycle of bone turnover

Works Cited:

Bones and Joints.” Health Lessons Online. N.p., n.d. Web. 20 Oct. 2010.

Clarkson, Paul. “The Science Creative Quarterly » DEM BONES, DEM IMPORTANT BONES.The Science Creative Quarterly. N.p., n.d. Web. 20 Oct. 2010.

Hall, Susan J. Basic Biomechanics with Online Learning Center Passcode Bind-in Card. 5 ed. New York City: McGraw-Hill Humanities/Social Sciences/Languages, 2006. Print.

Lamb, Robert. “Discovery Health “How do broken bones heal?“.” Discovery Health “Health Guides”. N.p., n.d. Web. 20 Oct. 2010.