Uploaded April 2015 | Updated September 2026, 1 hour ago
Throughout history mankind has developed and advanced due to its discovery of new sources of energy such as fire and hydraulic power. Currently our advancement is hampered by the lack of new renewable energy sources that will allow us to grow while not polluting our planet. The U.S. consumes on average 18.89 million barrels of petroleum products on a daily basis. Solar energy has emerged as a potential alternative to fossil fuels, with rapid developments in the 21st century. Although there are limitations such as the need for solar exposure as well as the inability to store the electricity produced, solar cells currently provide clean energy with ever-increasing efficiency. Photovoltaics cells work due to the photoelectric effect in which certain materials absorb photons of light and release electrons. When these released electrons are captured an electric current is created. The photoelectric effect was first noted by French physicist Edmund Bequerel in 1839, but it was Albert Einstein in 1905 whose paper on the nature of light forms the basis of photovoltaic cells today. In 1908 a Carnegie Steel employee developed a solar collector that’s design is still roughly used today.
The most widely used material in modern solar cells is monocrystalline silicon. Grown using the Czochralski process, mono-Si has a continuous crystal structure free of grain boundaries, which allows it to more efficiently conduct electricity. The resulting crystal is cut into rectangular wafers which form the solar panels. Their longevity and efficiency make mono-Si cells the preferred material for capturing solar energy. Although gallium arsenide has emerged as a competitor, its high cost and novel development mean that is it currently used for research as opposed to widespread implementation. Monocrystalline silicon continues to be a forerunner in photovoltaic technology due to its uniform structure, which produces predictable behavior and decreased impurities.
eia.gov/tools/faqs/faq.cfm?id=427&t=3
solarenergy-usa.com/solar-info/solar-facts
solar-facts-and-advice.com/monocrystalline.html
www1.eere.energy.gov/solar/pdfs/solar_timeline.pdf
solar-facts-and-advice.com/polycrystalline.html
arstechnica.com/science/2014/02/is-it-time-to-move-away-from-silicon-based-solar
energyinformative.org/best-solar-panel-monocrystalline-polycrystalline-thin-film
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/sili2.html
pveducation.org/pvcdrom/manufacturing/single-crystalline-silicon
h2g2.com/edited_entry/A912151
tf.uni-kiel.de/matwis/amat/elmat_en/kap_6/illustr/i6_1_1.html
pcmag.com/encyclopedia/term/47578/n-type-silicon
http://www.tindosolar.com.au/poly-vs-mono-crystalline/
science.nasa.gov/science-news/science-at-nasa/2002/solarcells
Ghosh, Amal K, Tom Feng, and Charles Fishman. Heterostructure Single Crystal Silicon Photovoltaic Cell, Extension : Type A, Semiconductor Heterojunction Silicon Devices. [Washington]: Dept. of Energy , 1979.
Rea, Samuel N. Lsaa Large Area Silicon Sheet Task Continuous Czochralski Process Development.[Washington]: Dept. of Energy , 1978.
Throughout history mankind has developed and advanced due to its discovery of new sources of energy such as fire and hydraulic power. Currently our advancement is hampered by the lack of new renewable energy sources that will allow us to grow while not polluting our planet. The U.S. consumes on average 18.89 million barrels of petroleum products on a daily basis. Solar energy has emerged as a potential alternative to fossil fuels, with rapid developments in the 21st century. Although there are limitations such as the need for solar exposure as well as the inability to store the electricity produced, solar cells currently provide clean energy with ever-increasing efficiency. Photovoltaics cells work due to the photoelectric effect in which certain materials absorb photons of light and release electrons. When these released electrons are captured an electric current is created. The photoelectric effect was first noted by French physicist Edmund Bequerel in 1839, but it was Albert Einstein in 1905 whose paper on the nature of light forms the basis of photovoltaic cells today. In 1908 a Carnegie Steel employee developed a solar collector that’s design is still roughly used today.
The most widely used material in modern solar cells is monocrystalline silicon. Grown using the Czochralski process, mono-Si has a continuous crystal structure free of grain boundaries, which allows it to more efficiently conduct electricity. The resulting crystal is cut into rectangular wafers which form the solar panels. Their longevity and efficiency make mono-Si cells the preferred material for capturing solar energy. Although gallium arsenide has emerged as a competitor, its high cost and novel development mean that is it currently used for research as opposed to widespread implementation. Monocrystalline silicon continues to be a forerunner in photovoltaic technology due to its uniform structure, which produces predictable behavior and decreased impurities.
eia.gov/tools/faqs/faq.cfm?id=427&t=3
solarenergy-usa.com/solar-info/solar-facts
solar-facts-and-advice.com/monocrystalline.html
www1.eere.energy.gov/solar/pdfs/solar_timeline.pdf
solar-facts-and-advice.com/polycrystalline.html
arstechnica.com/science/2014/02/is-it-time-to-move-away-from-silicon-based-solar
energyinformative.org/best-solar-panel-monocrystalline-polycrystalline-thin-film
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/sili2.html
pveducation.org/pvcdrom/manufacturing/single-crystalline-silicon
h2g2.com/edited_entry/A912151
tf.uni-kiel.de/matwis/amat/elmat_en/kap_6/illustr/i6_1_1.html
pcmag.com/encyclopedia/term/47578/n-type-silicon
http://www.tindosolar.com.au/poly-vs-mono-crystalline/
science.nasa.gov/science-news/science-at-nasa/2002/solarcells
Ghosh, Amal K, Tom Feng, and Charles Fishman. Heterostructure Single Crystal Silicon Photovoltaic Cell, Extension : Type A, Semiconductor Heterojunction Silicon Devices. [Washington]: Dept. of Energy , 1979.
Rea, Samuel N. Lsaa Large Area Silicon Sheet Task Continuous Czochralski Process Development.[Washington]: Dept. of Energy , 1978.
![Ballistic Vests -Teflon MCV
For the MCV, we decided to research/discuss bulletproof materials, specifically bulletproof body armor, and ways they are being improved in many properties such as weight, cost, and mobility. Almost any material could be considered bulletproof if it were stacked enough, but some materials are better than others due to their specific traits regarding strength and thickness. Currently, there are numerous situations where current bulletproof materials are sufficient for their task and protect the human body well enough, but this often comes at the cost of high weight and flexibility losses. For example, a square foot of 3-inch thick steel plate will definitely stop a 9mm bullet, but it will be extremely heavy and completely inflexible. If this plate (or many of these plates) was attached to a vehicle, then the flexibility does not matter, but this is obviously not a viable option for body armor. The most popular solution for body armor is Kevlar, so we will focus on this when researching vests and body armor. Other materials have been designed and used in bulletproof vests but they tend to be much too expensive for mass use and still have their downfalls and drawbacks . As well as looking into the properties of conventional and nonconventional ballistic materials, we will research how materials are processed to gain the strength necessary to stop a speeding bullet. One specific material that we are interested in focusing on is carbon nanotubes. We believe that they could be used as a suitable bulletproof material because they are extremely strong, yet light. The fibres of the tubes are excellent at absorbing strong forces and distributing those forces throughout their structure. Carbon nanotubes are a good choice for this specific report because all of their remarkable properties can be explained by their structure and then applied to real world situations. Nanotechnology will undoubtedly become increasingly more relevant in the future and it would be interesting to learn more about it before then, and the possible uses it might have in terms of bulletproof material.
References
Informational:
http://en.wikipedia.org/wiki/Strength_of_materials
http://i.ytimg.com/vi/0FOkyKbG8s0/hqdefault.jpg -mythbusters (video is a different link)
Ballistic resistance of personal body armor([2000]). . Washington, D.C. : U.S. Dept. of Justice, Office of Justice Programs, National Institute of Justice
M. Grujicic et al., Mater. Sci. Eng. A (2007), doi:10.1016/j.msea.2007.06.013
http://www.nanowerk.com/spotlight/spotid=17548.php -carbon nanotubes information
https://books.google.com/books?id=O379nM3QZwsC&pg=PA85&lpg=PA85&dq=kevlar+density+kg/m3&source=bl&ots=NcNDtpwM_x&sig=QOgNngHSAjyaTSDlTPRKUJMQfUo&hl=en&sa=X&ei=ixkwVdfxMoadyATZ-oHIAg&ved=0CD8Q6AEwBA#v=onepage&q=kevlar%20density%20kg%2Fm3&f=false -Kevlar stats
http://www.space.com/29062-new-horizons-pluto-bulletproof-vest-video.html -spacecraft kevlar video
http://www.aramid.eu/advantages disadvantages.html -aramid fibers
https://www.usconcealedcarry.com/stopping-bullets/ -Stopping Bullets
https://www.youtube.com/watch?v=qd0m5INHXJ8 - Weave Clip
http://en.wikipedia.org/wiki/Kevlar -kevlar structure
http://www.nij.gov/topics/technology/body-armor/pages/welcome.aspx -NIJ Statistics
Images:
http://johndyerco.com/Dad/Block2.jpg -block
http://autocww2.colorado.edu/~toldy2/E64ContentFiles/MilitaryWeapons/Ballistics.html-first bullet image
http://science.howstuffworks.com/body-armor1.htm -body armor diagram
http://www.dvhardware.net/article23154.html - carbon nanotubes pic
http://parksandrecreation.wikia.com/wiki/Dave_Sanderson Image
http://www.careercast.com/career-news/most-stressful-jobs-2013-police-officer Image
http://ymcichem.wikispaces.com/B+-+Synthetic+Fibres Wet Spinning
Wikipedia Kevlar Silk Comparison. Licensed under CC BY-SA 3.0 via Wikipedia -
http://en.wikipedia.org/wiki/File:Wikipedia_Kevlar_Silk_Comparison.jpg#/media/File:Wikipedia_Kevlar_Silk_Comparison.jpg
http://inglesebox.com/pizzaboxes.asp - Pizza Image
http://www.policemag.com/channel/patrol/articles/2013/04/rethinking-body-armor.aspx Picture
http://www.acs.org/content/acs/en/education/whatischemistry/women-scientists/stephanie-kwolek.html
http://www.scielo.br/scielo.php?pid=S1516-14392014000500012&script=sci_arttext Ballistic Vests -Teflon MCV](https://i.ytimg.com/vi/XrYcTzXB6-c/mqdefault.jpg)


![Xenon MCV - Aerogel as a Thermal Insulator (720p Re-upload)
Aerogel as a Thermal Insulator
Brooke Adams
Hyoeun Kim
Oscar Sandoval
Scott Weiss
Our chosen technical challenge is the loss of energy due to poor insulators in building infrastructure. The problem with the insulators of todays buildings is that they are composed of materials that are not energy efficient in the long run. For starters, a typically large amount of material is needed for the insulators to even accomplish their task, compromising space in the building that is not necessary for its construction. Todays insulators also tend to be brittle, calling out for maintenance fees that make the tenure of the material to be expensive as well. Should a thermal insulator be inefficient in its duty, the more energy is needed for a building to stay warm or cold during the extreme seasonal temperatures occurring throughout the year. Energy unnecessarily spent compromises the source of where it is obtained from, depleting the already stretched energy sources demanded by humans worldwide.
Our chosen material will address many of these dilemmas in a unique and efficient way. Our chosen solution for the problem of insulation is the use of a green material named Aerogel. Aerogel is amazing for addressing thermal insulation because its composition almost nullifies almost all methods of heat transfer (convection, conduction, and radiation). This is due to the fact that the material is composed of 99.98% air, which is a terrible thermal conductor due to its properties as a gas. Aerogel also has other incredible properties such as being 500 times the strength of its counterpart silica aerogel. This could be because aerogel has certain polymers that support the silica chains within it, such as polyimide, along with interchain linking (networking). Aerogels are also extremely thin, hydrophobic, breathable, and fireproof, adding more properties that make it a desirable thermal insulator. The processing of aerogels is very costly, however, leading to expensive pricing for its acquisition. Although its cost may be exorbitant, aerogels astounding properties grants it much potential as a green building material in thermal insulation.
Works Cited:
[ RT ISOLAZIONI - Soluzioni termoisolanti in Aerogel ] - Tecnologia Aerogel. (n.d.). Retrieved April 27, 2014, from http://www.rtisolazioni.com/technology.php
Berge, A., & Johansson, P. (2012). Literature Review of High Performance Thermal Insulation (2). Retrieved from Chalmers University of Technology website: http://publications.lib.chalmers.se/records/fulltext/local_159807.pdf
Fricke, J., & Tillotson, T. (1997). Aerogels: production, characterization, and applications. Thin Solid Films, 297(1-2), 212-223. doi:10.1016/S0040-6090(96)09441-2
The Frontier - Aerogels: Their History, Structure, and Applications. (n.d.). Retrieved April 27, 2014, from http://geobeck.tripod.com/frontier/aerogels.html#link
Gromicko, N. (n.d.). Aerogel - Intl Association of Certified Home Inspectors (InterNACHI). Retrieved April 27, 2014, from http://www.nachi.org/aerogel.htm
Hartmann, J., Rubin, M., & Arasteh, D. (1987). Thermal and Solar-optical Properties of Silica Aerogel for Use in Insulated Windows. Retrieved from U.S. Department of Energy website: http://eande.lbl.gov/sites/all/files/publications/23386.pdf
What Makes Polymers Different? (n.d.). Retrieved April 27, 2014, from http://pslc.ws/macrog/kidsmac/differnt.htm
Media:
https://www.youtube.com/watch?v w0uQLHrVw0
https://www.youtube.com/watch?v=E-xhxS581Uc
https://www.youtube.com/watch?v=8E-MtJBAZvw
https://www.youtube.com/watch?v=ZDe6GNCilV4
http://sweetclipart.com/hourglass-design-873
http://www.thermablok.com/images/flame-heat-resisant-thermablok-face.jpg
http://upload.wikimedia.org/wikipedia/commons/e/ea/Aerogelbrick.jpg
http://mycrazytown.com/wp-content/uploads/2013/08/aerogel.jpg
http://mynameisnotomlette.files.wordpress.com/2012/11/shattered-glass.jpg
http://pamelanorris.files.wordpress.com/2010/04/aerogel-process2.jpg
http://supercriticalfluids.blogspot.com/2012/01/supercritical-fluids-in-2012.html
http://pamelanorris.wordpress.com/research/aerogel-lab/
http://faculty.uscupstate.edu/llever/Polymer%20Resources/Crystalline.htm
https://www.llnl.gov/str/Foxhighlight.html Xenon MCV - Aerogel as a Thermal Insulator (720p Re-upload)](https://i.ytimg.com/vi/Zd_R1iLRTVo/mqdefault.jpg)






