Category Archives: Earth Science

Exceptional Bioethanol

One of the videos that particularly struck me from Chemistry class was “Bioethanol,” from the Periodic Table of Videos. In the video, Professor Poliakoff discusses his travels in Brazil, a country known for its high use of ethanol fuel, as well as his discovery regarding the use of bioethanol versus common gasoline. He found that while Brazilians domestically produced an abundant supply of ethanol fuel for use, most citizens continued to use regular gasoline to fuel their cars because it was more cost-effective (meaning that their cars could run on more kilometers per gallon with gasoline than with ethanol, and the difference in price between the two fuels was minimal). Poliakoff then went on to provide an economic explanation for this – because ethanol is fermented from sugar, and because sugar is also consumed in the diet, there is an increasing demand for sugar in both industries. Thus, the costs of producing bioethanol from sugar increase, and in turn, its price as a fuel increases. He then briefly mentioned that an alternative to using sugar in the production of ethanol could be cellulose, a material that is not specifically used for food (Haran, n.d.).Upon mentioning this, he piqued my interest and I decided to further investigate bioethanol and cellulose. This brought me to my question: How is bioethanol manufactured from cellulose, and to what extent is the use of cellulosic ethanol a cost-effective solution to preserve our environment?

(Bioethanol for Sustainable Transport, n.d.)
(Bioethanol for Sustainable Transport, n.d.)

To begin, I conducted background research on bioethanol, otherwise known as ethanol. Ethanol, whose chemical formula is C2H5OH, belongs to the chemical family of alcohols. It is “a colorless liquid and has a strong odor.” (European Biomass Industry Association, n.d.) A number of incentives have fostered the use of ethanol as an alternative fuel source. Among the most pressing of these include the increasing greenhouse gas emissions and harmful pollutants such as carbon monoxide and nitrogen oxide to the environment (Derry et al., 2008), the increasing scarcity of fossil fuel resources, and the growing dependence on foreign imports of oil (CropEnergies AG, 2011). All these concerns for developed countries, such the United States and those in the EU, that result from excessive consumption of fossil fuels contribute to the utilization of ethanol as a cleaner alternative energy source for automobiles. Ethanol releases energy according to the following equation when combusted:

CH3CH2OH (l) + 3O2 (g) –> 2CO2 (g) + 3H2O (g)

(Derry et al., 2008)

There are three main steps in manufacturing ethanol. The first is the formation of “a solution of fermentable sugars,” the second is the “fermentation of these sugars to ethanol,” and the third requires the “separation and purification of the ethanol, usually by distillation.” (Badger, 2002) Traditionally, the fermentable sugars used to produce ethanol come from either sugar crops, such as sugar cane or sugar beet, or cereal crops, such as maize or wheat (European Biomass Industry Association, n.d.). Fermentation of these sugars occurs when microorganisms, such as yeast, ferment the C-6 sugars (commonly glucose) obtained from the crops by using them as food and producing byproducts that include ethanol (Badger, 2002). However, because these sugar crops and cereal crops are also necessary for human consumption, they can be relatively expensive to use for production of ethanol.

(Warner & Mosier, 2008)

So, a third mechanism of developing ethanol for fuel has been developed, using cellulose, the waste residues from forests and the parts of plants that are not needed for food. Also known as Lignocellulosic or Cellulosic bioethanol, this biofuel is considered less expensive and “more energy-efficient than today’s ethanol because it can be made from low-cost feedstocks, including sawdust, forest thinnings, waste paper, grasses, and farm residues (i.e. corn stalks, wheat straw, and rice straw).” (Detchon, 2007) As a person who never likes when things go to waste, I was delighted at the fact that we could create fuel from cellulose, which in turn helps to save so many of our natural resources and eliminate much of our waste. To my dismay, however, I discovered that this advantage is accompanied with many costly limitations.

Cellulose, like starch, is composed of long polymers of glucose, which can be used for fermentation in producing ethanol. However, the structural configuration of cellulose is different from that of starch, and this, combined with its encapsulation by lignin, a material that covers the cellulose molecules, makes hydrolysis of cellulosic materials very difficult because the process requires the aid of enzymes or specific reaction conditions or equipment (Badger, 2002).

(Warner & Mosier, 2008)
(Warner & Mosier, 2008)

The three main methods of cellulosic hydrolysis are acid, thermochemical, and enzymatic hydrolysis (Badger, 2002). For the purposes of this blog post, I will focus on the latter form, involving enzymes, which are “biological catalysts.” Enzymes are introduced into a reaction to provide an alternative pathway with a lower activation energy so that the reaction can take place (Derry et al., 2008). However, enzymes must be able to make contact with the reactants of the reaction, which is quite difficult to achieve with cellulose molecules. Thus, a “pretreatment process” is needed to separate the tightly-bound sugars that comprise cellulose. These processes are often energy-intensive, and are thus associated with high costs (Badger, 2002). In addition, the costs of the enzymes are also currently quite high, although biotechnology research is gradually decreasing their costs (Novozymes, as cited in Detchon, 2007) The National Renewable Energy Laboratory (NREL) uses a process known as simultaneous saccharification and co-fermentation (SSCF) to hydrolyze cellulose. A “dilute acid pretreatment” to “dissolve the crystalline structure” of the cellulose is first employed. A portion of the “slurry” that results is then placed into a vessel that grows a cellulase enzyme, while another portion is placed into another vessel to grow a yeast culture (Badger, 2002). In this process, sugar conversion and fermentation occur simultaneously, rather than consequentially, to yield the product of ethanol as quickly as possible, usually a few days (Lynd, 1999 as cited in Warner & Mosier, 2008). However, SSCF still requires expensive enzymes in order to occur, and because the process lasts a few days, the reactor vessels must run for long periods of time (Badger, 2002).

So, simply from observing the process of SSCF, I realize that the industrial creation of ethanol from cellulose is a tiresome process. The reactions needed to convert a molecule of cellulose into its glucose constituents are both costly and time-consuming, contrary to what I had believed would have been quite simply a breaking down of a polymer of glucose. There are numerous implications to this issue, and this brings me to the second part of my question: to what extent is the use of cellulosic ethanol a cost-effective solution to safeguard the environment? Here I discovered the advantages and disadvantages of cellulosic bioethanol. Firstly, greenhouse gas emissions from ethanol-fueled cars are reduced by 85% to 94% compared to those running on regular gasoline. Cheap feedstock that is non-related to food materials is another added benefit of bioethanol created from cellulose, since the question of food vs. fuel is eliminated. And, much of the infrastructure adapted for ethanol fuel use is already in place – roughly 2,000 stations serving E85 (a fuel containing 85% ethanol and 15% petrol) and most automobiles are already built to run on both gasoline or ethanol-based fuel. What’s even more favorable to the environment from using bioethanol is that because ethanol is an organic compound, it is highly biodegradable, making fuel spills much less hazardous than regular gasoline spills (Green the Future, 2008).

Furthermore, the overall benefits gained from using bioethanol made from any other means also cannot be ignored – for example, lower carbon emissions, less reliance on foreign oil reserves, and conservation of finite fossil fuel resources (CropEnergies AG, 2011).

These pros do no exist without their cons, however. I also found that in addition to the high costs of production of cellulosic ethanol that may make it relatively expensive for consumers, there were other disadvantages as well. Commercialization of this type of ethanol is limited, as most production plants are pilot plants and find it difficult to transition to full-scale commercial plants. In addition, because ethanol absorbs water, it is easily contaminated as a fuel and thus is difficult to transport. The high costs of production also could not be outweighed by ethanol-run automobile performance, since it takes about 1.4 gallons of E85 to run the same distance as it would take 1 gallon of regular gasoline (Green the Future, 2008). This was also the main reason, as stated by Poliakoff, that Brazilians continued to use regular gasoline as opposed to bioethanol – their cars simply ran more efficiently on petrol.

From analyzing both sides of the argument, I have come to the conclusion that even though bioethanol seems to have its many disadvantages, the biofuel has come a long way in improving the welfare of our environment. The implications of a better environment per se are perhaps enough to convince me to purchase ethanol as the source of fuel for my car (when I get one, eventually). But also, because cellulosic materials are often wasted and abundant in nature, I find it simply fascinating that we have come across yet another resource with which to provide energy to sustain our lifestyles. Of course, though, I am careful not to jump to the conclusion that this is a panacea to the global peril of climate change, because I know that exploitation of our environment will lead to destruction of it. But now I have understood that even the smallest of steps taken to achieve ecological sustainability can have drastic rewards for the wellbeing of society.

Sources:

Badger, P.C. (2002). Ethanol from Cellulose: A General Review. Trends in new crops and new uses, 1, 17-21. Retrieved from http://www.hort.purdue.edu/newcrop/ncnu02/v5-017.html

CropEnergies. (2011). Bioethanol report [Brochure/report]. Retrieved from http://www.cropenergies.com/en/Bioethanol/Produktionsverfahren/Bioethanol-Magazin_CE_2011-en_1_1.pdf

Derry, L., Clark, F., Janette, E., Jeffery, F. Jordan, C., Ellett, B., & O’Shea, P. (2008). Chemistry for use with the IB diploma programme: Standard level. Port Melbourne, Victoria: Pearson Education Australia.

Detchon, R. (2007). The Biofuels FAQs: The Facts about biofuels: ethanol from cellulose. Retrieved from http://www.energyfuturecoalition.org/biofuels/fact_ethanol_cellulose.htm

European Biomass Industry Association. (n.d.). Bioethanol Production and use [Brochure]. Retrieved from http://www.erec.org/fileadmin/erec_docs/Projcet_Documents/RESTMAC/Brochure5_Bioethanol_low_res.pdf

Green the Future. (2008). Cellulosic Ethanol: Pros and cons. Retrieved from http://greenthefuture.com/CELLETHANOL_PROSCONS.html

Haran, B (Producer). (n.d.). Bioethanol [Video episode]. United Kingdom: University of Nottingham. Retrieved from http://periodicvideos.com/videos/feature_brazil_bioethanol.htm

Warner, R.E. & Mosier, N.S. (2008). Ethanol from Cellulose Resources. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

Image Sources:

Bioethanol for Sustainable Transport. (n.d.). CO2 cycle for bioethanol [Image]. Retrieved from http://www.best-europe.org/Pages/ContentPage.aspx?id=120

Warner, R.E. & Mosier, N.S. (2008). Fermentation of glucose to carbon dioxide and ethanol [Image]. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

Warner, R.E. & Mosier, N.S. (2008). Structure of cellulose polymer [Image]. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

The ‘Plaster of Paris’ Explored

Over the Chinese New Year break, I had to opportunity to relive one of my favorite art experiences from middle school, carving plaster, more specifically Plaster of Paris or Gypsum. (Chemistry Daily, 2007) After day four of carving I became acutely aware of the physical properties of Gypsum, its softness and hygroscopic qualities (ability to take moisture out of the air) to name a few and began to wonder what made the substance that way. Gypsum, formally known as calcium sulfate dihydrate (CaSO4.2H­­20) is a mineral, which is chemically defined as being a “naturally occurring inorganic element or compound having [homogenous crystalline structure, chemical composition], and physical properties.” (Kentucky Geological Survey, 2005)

The calcium sulfate dihydrate is comprised of sheets of intramolecular ionic bonded Ca2+ and So42- ions held together by the intermolecular hydrogen bonding of water. The dihydrate means that for every molecule of calcium sulfate there are two molecules of water attached to the sulfate ion with coordinate covalent bonds. (Kauffman, 2013) Due to the weak intermolecular hydrogen bonding, calcium sulfate dihydrate is quite soft, as these bonds being easily broken, a physical property I am very thankful for. Now for most commercial applications, Gypsum is typically sold and kept as a grind up power, that has been calcined, or had its moisture removed with intense heat, as calcium sulfate hemihydrate (one water molecule for every two calcium sulfate molecules).(Lafarge Prestia , 2000) The reaction is shown by:

CaSO4.2H2O + Heat → CaSO4.0.5H2O + 1.5H2O

Depending on at what pressure this reaction occurs at, a product with different physical properties is formed. Alpha plaster is formed when calcium sulfate dihydrate is calcined at about 150 degrees Celsius in an autoclave (a heated, pressurized container for chemical reactions) at higher than atmospheric pressures. Beta plaster on the other hand is calcinated at atmospheric pressure. (Lafarge Prestia , 2000) Manufactures do this to control the shape and size of crystal growth in the plaster, with alpha plaster having larger crystals, a higher mechanical strength, and low porosity while beta plaster has smaller crystals, lower mechanical strength, and higher porosity. (National Research Development Corporation) This reaction can be taken further to the point where calcium sulfate becomes an anhydride (compound with water removed) and all of the water of crystallization evaporated. In this form there are no polar water molecules to interfere with the ionic lattice formed by electrostatic attractions of Ca2+ and So42- ions, so it’s hardness increases dramatically. (Chemistry Daily, 2007) However this reaction is actually reversible, with the anhydride or hemihydrate form reverting back in an exothermic reaction to the dihydrate form if introduced to enough water. I had found the reaction that I crudely did to create the plaster for my sculpture, which was using beta plaster.

CaSO4.0.5H2O + 1.5H2O → CaSO4.2H2O + Heat

It turns out this material I used for an art project has roots stretching back 9000 years to the Anatolia region. Throughout history Gypsum has had various applications, from being used in Egyptian monuments to modern day drywall, with most stemming out of the field of construction. (Lafarge Prestia , 2000) There are some of the historical uses, where due to its ability to protect internal structures from fire it was used to cover the exteriors of houses. More specific and diversified uses for calcium sulfate have developed over time, some requiring particular physical attributes like “setting times, fluidity, viscosity, their hardening kinetics, their permeability (through pore [size]), their mechanical strengths, [and] their resistance to abrasion.” These conditions are met through a combination of alpha plasters, beta plasters, and neutral fillers. (Lafarge Prestia , 2000)

Calcium sulfate’s uncanny ubiquity in modern life, from the molds used to fashion ceramic molds or dentures, to the internal walls and ceilings in most buildings, to the decorative art on the outside of the building, to its discovery on mars (Webster & Cole, 2011) all remind me of how much a single substance can impact the direction of human society and culture. Additional uses for calcium sulfate include agricultural applications to increase the water penetration and aeration of sour (lime lacking) soil but run the risk of excess sulfate tainting the groundwater. Also just recently medical applications for calcium sulfate, acting as a bone void filler to be introduced slowly into the body at the same rate as new bone growth, have been posited. (Tangri, Prasad, Suri & Agrawal, 2004) All these from a single mineral, but while considering its uses one must also ponder the process it takes to produce. The arduous industrial process involved with mining, classifying, processing, and distributing this one mineral puts into perspective how much of the production line we as consumers are not typically aware of. (Lafarge Prestia , 2000) However based on the recent applications of this substance, calcium sulfate will be continued to be an integral but underemphasized part of people’s lives.

References:

Chemistry Daily. (2007, January 04). Plaster. Retrieved from http://www.chemistrydaily.com/chemistry/Plaster_of_paris

hydrate. (2013). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/EBchecked/topic/278148/hydrate

Kentucky Geological Survey. (2005, December 12). Many definitions of minerals. Retrieved from http://www.uky.edu/KGS/rocksmn/definition.htm

Lafarge Prestia (2000, December 11). Caso4?,h20. Retrieved from http://www.lafargeprestia.com/caso4___h2o.html

National Research Development Corporation. National Research Development Corporation, (n.d.). High strength plaster of paris – alpha plaster. Retrieved from website: http://www.nrdcindia.com/pages/highplas.htm

Tangri, R. P., Prasad, R., Suri, A. K., & Agrawal, P. R. Bhabha Atomic Research Centre, Materials Processing Division. (2004). α-calcium sulphate hemihydrate as bone substitute. Retrieved from website: http://www.barc.gov.in/publications/nl/2004/200406-2.pdf

Webster, G., & Cole, S. (2011, December 07). Nasa mars rover finds mineral vein deposited by water. Retrieved from http://marsrover.nasa.gov/newsroom/pressreleases/20111207a.html

Images Cited:

Guidechem. (Producer). (2010). Calcium sulfate dihydrate. [Web Photo]. Retrieved from http://www.guidechem.com/products/10101-41-4.html

Lafarge Prestia (Producer). (2000). Plaster manufacture. [Web Photo]. Retrieved from http://www.lafargeprestia.com/caso4___h2o.html

Smith, S. E. (Photographer). (2003). Calcium sulfate dihydrate. [Web Photo]. Retrieved from http://www.wisegeek.com/what-is-calcium-sulfate.htm

The Hole in Our Ozone

Remember back in 2006 when there was a big panic about the news of a hole in our ozone? However as time past, the talks about this hole gradually died down. Recently I came across a news article that states, “Some scientists believe the ozone layer, protecting earth from the sun’s ultraviolet radiation, could be recovering.” (Valente, 2012). At the moment since Earth is the only known home for human beings, it is important for us to understand and protect the environment we call home for our future generations. Therefore I decided to do some further research and reading into our Earth’s Ozone layer.

For those of you who don’t know what the Ozone is, here is a brief summary. The Ozone layer is a thin layer of gas that naturally occurring in the Earth’s stratosphere, an area roughly 20-50km above the Earth’s surface. (Figure 1) This layer of ozone protects us from the harmful UV radiation from the sun. (Wilson, 2013) UV radiation has high energy and a short wavelength therefore it can penetrate the skin, manipulating DNA, which in result can cause cancer and other skin disorders. (Office of Air and Radiation, 2010).

The location of the Stratosphere
The location of the Stratosphere (Figure 1)

What exactly is the Ozone layer made of? How does it prevent the penetration of UV radiation? The ozone is composed of the 3 different allotropes of oxygen, O, O2, and O3. These atoms and molecules undergo the Ozone Oxygen Cycle, where the molecules are broken down into atoms and atoms rejoin to make molecules. (Wilson, 2013). Here are some photographical representations of this process:

Under UV light, O2(g) ---> 2 O(g)
Under UV light, O2(g) ---> 2 O(g)
O(g) + O2(g) ---> O3(g)
O(g) + O2(g) ---> O3(g)

Both processes are exothermic. The light energy from UV light is transferred in to thermal energy or heat therefore being absorbed, preventing it from reaching the Earth’s surface. (NASA, 2008)

The Ozone hole is found above Antarctica and covers averagely around 17.9 million square kilometers. (Welch, 2012). (Figure 2)The hole is not a physical or literal hole but an area where there is severe depletion of Ozone. As National Geographic states, “Chlorofluorocarbons (CFC) used by industrialized nations for much of the past 50 years, are the primary culprits in ozone layer breakdown.” Because CFC’s are quite nonreactive as they are they are nontoxic, noncorrosive, nonflammable, and very stable. They were found in fire extinguishers, as propellants in aerosols, solvents in electronics manufacture, coolants for refrigerators and air conditioners and as foaming agents in plastics.

Biggest measured hole, Sept 22 2012, 21.2 million square kilometers
Biggest measured hole, Sept 22 2012, 21.2 million square kilometers

CFC’s easily rise to the stratospheric level on earth. In Antarctica, especially during the cold winter nights where there is no sunlight, a polar vortex, strong circular winds, isolates the air in the polar region that traps the CFC in the stratosphere.  (Carver, 1998) When the sun finally comes out again, and the UV light hits the clouds of CFC’s it breaks it down into atoms of chlorine and bromine. These acts as catalyst in the destruction of ozone

O3—>O2 + O

Cl + O3—>ClO + O2

ClO + O—>Cl + O2

According to the U.S. Environmental Protection Agency, One chlorine atom can break apart 100,000 ozone molecules, and bromine is 40 times more destructive. These atoms destroy much of the ozone over Antarctica, by causing an imbalance of ozone to the natural cycle. (Wilson, 2013). Luckily as of 2000, the Montreal protocol demands the removal of CFC in production of products. However even after regulations have been put into place for the ban of these harmful chemicals, the hole hasn’t had significant improvements. Paul Newman, a chemist from NASA predicts, “the ozone layer above Antarctica likely will not return to its early 1980s state until about 2060.”(LiveScience, 2012)

Bibliography:

LiveScience. (2012, Oct 25). Antarctic Ozone Hole Is The Second Smallest Since It’s Been 20 Years. Huffington Post. Retrieved from: http://www.huffingtonpost.com/2012/10/25/antarctic-ozone-hole-size-2012_n_2016713.html

Valente, M. (2012, Nov 24). Hopes grow on shrinking ozone hole. Aljazeera. Retrieved from: http://www.aljazeera.com/indepth/features/2012/11/20121124142740268174.html

Welch, C. (2012). The Ozone Hole (weblog). Retrieved from:http://www.theozonehole.com/2012ozonehole.htm

Wilson, T.V. (2013). Can We plug the hole in the ozone layer? HowStuffWorks. Retrieved from: http://science.howstuffworks.com/environmental/green-science/question778.htm

National Geographic. (n.d.). Ozone Depletion. National Geographic:Environment. Retrieved from: http://environment.nationalgeographic.com/environment/global-warming/ozone-depletion-overview/

Carver, G. (1998). Part III. Science of the Ozone Hole. University of Cambridge Centre for Atmospheric Science. Retrieved from: www.atm.ch.cam.ac.uk/tour/part3.html

Office of Air and Radiation. (2010, June). UV Radiation. U.S Environmental Protection Agency. Retrieved from: http://www.epa.gov/sunwise/doc/uvradiation.html

University of Wisconsin. (2008, Sept. Chemical of the Week: Ozone. Retrieved from: http://scifun.chem.wisc.edu/chemweek/ozone/ozone.html

National Weather Service. (2007). Layers of the Atmosphere. National Oceanic and Atmospheric Administration. Retrieved from: http://www.srh.noaa.gov/srh/jetstream/atmos/layers.htm

Bug Repellent

mosquito
mosquito

Bzzzzz. Bzzzzz. Bzzzzz. SMACK!! Mosquitos – maybe the most annoying pest to ever fly, are the always the ones that ruins my sleep. As usual, mosquito visited me during midnight and woke me up. The sound that mosquito emits right beside my ear disturbed my sleep. So I picked up bug repellent and sprayed it to myself. Bug repellent was very effective. Within few minutes, it nullified mosquitos, and I could go back to sleep peacefully. But then, I started to wonder what is bug repellent and how it works.

In order to understand how bug repellent works, I thought that it is important to understand how mosquitoes detect us as targets. Mosquitoes contains three different sensors: chemical sensors, visual sensors and heat sensors, which allow them to target their prays. Among those three sensors, mosquitoes largely rely on their chemical sensors. “Scientists have identified several proteins found in mosquitoes’ antennae and heads that latch on to chemical markers, or odorants, emitted from our skin.” (Knight) And mosquitoes use these proteins to detect carbon dioxide and lactic acid, which are the gases that mammals and birds emit as part of their normal breathing.

The U.S. Environmental Protection Agency (EPA)
The U.S. Environmental Protection Agency (EPA)

What is bug repellent? There are two different types of bug repellents: natural and synthetic bug repellent. Basic idea of each repellent can be deduced from its own names. Literally, natural repellent is from nature and synthetic repellent is a mixture of chemical substances. Although natural repellent is much more safe than synthetic repellent, people prefer to use synthetic repellent because it is much more effective and lasts longer than natural repellent. The U.S. Environmental Protection Agency (EPA) recommends people to use repellent that contain active ingredients that the EPA approved their safety. Some examples of active ingredients are DEET, and Picaridin.

Then how does mosquito repellent actually work? When chemical substances i.e. DEET or Picaridin, from the repellent are sprayed on a surface of skin, those chemical substances prevent mosquitos’ bites by disturbing their ability to detect protected surface. So basically, mosquitos are no longer able to detect us using their chemical sensor. But bug repellent is effective for limited amount of time because repellent is not on the surface it is sprayed permanently.

What are the implications of knowing this? These days the most dangerous living organism is, with no surprise, mosquito. According to Illinois Department of Public Health, every year, “mosquitoes transmitting malaria kill 2 million to 3 million people and infect another 200 million or more.” (“Illinois Department of Department of Health”) Nearly half of world’s population is at risk for malaria. By developing the technology of getting away form mosquito bites, people can lower the risk of getting malaria. Although bug sprays or repellents are widely supplied to urban area, since the major areas, where people suffer from malaria, are not developed, people there do not have access to bug repellents. So it is important to find out natural repellents, which can be found naturally and is not harmful to children. Also, in the course of developing efficient bug repellents, just as other inventions came about accidentally, scientists may be able to invent malaria vaccination.

Word Count: 520

Bibliography

“Mosquitoes and Disease.” Illinois Department of Department of Health. Illinois Department of Department of Health, March 29, 2007 . Web. 7 Oct 2011. <http://www.idph.state.il.us/envhealth/pcmosquitoes.htm>.

“Active Ingredients Found in Insect Repellents.” The U.S. Environmental Protection Agency (EPA). The U.S. Environmental Protection Agency (EPA), September 10, 2009. Web. 7 Oct 2011. <http://www.epa.gov/pesticides/health/mosquitoes/ai_insectrp.htm>.

“Repellents are an important tool to assist people in protecting themselves from mosquito-borne diseases..” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, October 13, 2009. Web. 7 Oct 2011. <http://www.cdc.gov/ncidod/dvbid/westnile/repellentupdates.htm>.

Freudenrich, Craig. “How Mosquitoes Work.” How Stuff Works. How Stuff Works, n.d. Web. 7 Oct 2011. <http://science.howstuffworks.com/environmental/life/zoology/insects-arachnids/mosquito.htm>.

Knight, Meredith. “Why do mosquitoes bite some people more than others?.” Scienceline. Scienceline, September 10, 2007. Web. 7 Oct 2011. <http://scienceline.org/2007/09/ask-knight-mosquitoes/>.

Organic Food – For Better or For Worse?

I admit, for the longest time, I believed all fruits and vegetables were organic. When I first began seeing and hearing about organic produce, I remember naively thinking, “Isn’t the label ‘organic’ redundant? Aren’t all fruits and vegetables organic anyway?”

For most of human history, the answer to these questions would be yes. Between the 1940s and the 1970s, however, agriculture began to become more and more industrialized and the Green Revolution began. To make food production easier, better, and faster, synthetic chemicals began to be used, resulting in genetically altered and human-processed foods. As a result of these new synthetic methods for farming, the organic farming movement began to grow, resulting in the rise of organic food stores and products all over the world, with consumers growing more and more environmentally conscious.

Contrary to popular belief, the label “organic” does not mean that these products are free from pesticides and chemicals. Rather, organic simply means that the pesticides and chemicals that are used when farming are not man-made, but come from natural sources. According to Lou Holm of the University of California, Berkeley, “Most organic farmers (and even some conventional farmers, too) employ mechanical and cultural tools to help control pests. These include insect traps, careful crop selection (there are a growing number of disease-resistant varieties), and biological controls (such as predator insects and beneficial microorganisms).” While organic produce is not completely chemical-free, organic farmers are more environmentally conscious than conventional farmers. Is this really worth the extra effort? Perhaps more importantly to us, is organic produce worth the extra cost?

These two questions cannot be easily answered. Insecticides, which are used in agriculture to kill insects, are generally considered harmful to the environment, but increase agricultural production. They are generally classified as organochlorines (contain one covalently bonded chlorine atom), organophosphates (esters of phosphoric acid), or carbamates (derived from carbamic acid) – all of which have shown signs of toxicity. As they are transferred through the air, water, and land, pesticides contaminate other ecosystems, affecting things that they were not intended for, including up to 20,000 human deaths reported annually.

Perhaps what’s more startling is that recent studies have begun to show that organic pesticides are no better than their synthetic counterparts. A study conducted by the University of Guelph shows that because organic pesticides often require larger doses, they are actually less environmentally friendly. Environmental studies professor Rebecca Hallett said of the experiment, “It’s too simplistic to say that because it’s organic it’s better for the environment. Organic growers are permitted to use pesticides that are of natural origin and in some cases these organic pesticides can have higher environmental impacts than synthetic pesticides often because they have to be used in large doses.” Organic produce may, in fact, not be worth the extra cost to both producers and consumers.

As the world grows more conscious about the need for green living practices, organic produce will become more popular and for good reason – while organic produce may also affect the environment, organic farming also has numerous benefits. Generally, organic farmers have been shown to promote the sustainability of their crops, allowing their plants and soil to remain healthier for longer. In the modern day and age, the implications of higher sustainability levels are certainly welcomed. But before you decide to buy organic, consider that they aren’t necessarily perfect for the environment either.

Works Cited:

“Advantages and Disadvantages Organic Farming: Good Things, Barriers and Environmental Effects.” Sustainable Living on a Small Farm. Web. 16 May 2011. <http://www.small-farm-permaculture-and-sustainable-living.com/advantages_and_disadvantages_organic_farming.html>.

Drinkwater, Laurie E. (2009). “Ecological Knowledge: Foundation for Sustainable Organic Agriculture”. In Francis, Charles. Organic farming: the ecological system. ASA-CSSA-SSSA. p. 19. ISBN 9780891181736.

“Pesticide.” Wikipedia, the Free Encyclopedia. Web. 15 May 2011. <http://en.wikipedia.org/wiki/Pesticide>.

“Pesticides.” Pollution Issues. Web. 16 May 2011. <http://www.pollutionissues.com/Na-Ph/Pesticides.html>.

University of Guelph. “Organic pesticides not always ‘greener’ choice, study finds.” ScienceDaily, 23 Jun. 2010. Web. 15 May 2011.

Mother Nature: Our greatest resource

Harnessing energy from the air
Harnessing energy from the air

My last post was on using black as a way of optimizing solar energy. After that, I got to thinking. This couldn’t possibly be the only advancement in harnessing energy so I went online and stumbled upon the revisiting of Tesla’s electricity-from-air ideas. In layman’s terms, Tesla postulated long ago that electricity could be transferred through the air. Due to lack of funding his experiments were never followed to completion, but now, many years later, scientists looking for alternative means of energy are revisiting the idea.

The idea is largely based on how lightning is created. Lightning, a form of electrical energy, is formed when water vapor collects on microscopic particles of dust and other material in the air. Scientists speculate that under humid conditions metal rods could gather the charges released from the air. “The basic idea is that when you have any solid or liquid in a humid environment, you have adsorption of water at the surface,” says Dr Galembeck, from the University of Campinas in Brazil (BBC). His experiment sprayed water vapor over many types of metals, specifically particles of silica and aluminum phosphate. The results, as expected by the team, revealed that the metals would gain a positive or negative charge. The team hopes to connect the charge to a circuit and capitalize on the naturally occurring resources (BBC).

Similar to the concept of solar cells optimizing energy intake in sunny areas, hydroelectric panels would be most efficient in areas with high humidity (Science Daily). Of course this idea is too good to be true, and like all experimental trials, problems will arise. Many, including Hywel Morgan of the University of Southampton, argue that the concept has its validity but at this stage but “harnessing enough of it to be widely useful” is still in question. He asserts that what is really causing the electrical charge is the pumping of water, causing a tribocharge. Others such as Marin Soljacic from the Massachusetts Institute of Technology say, “at this point it is far-fetched to see how it could be used for everyday applications” (Science Daily).

Even though the experiment is in its primitive stages, the possibilities are appealing to me because I know that with enough research and time put into the experiment, the possibilities can soon become realities. Galembeck believes that the same technology and plates can be placed on top of buildings in areas that experience frequent thunderstorms (Science a gogo). The panels will absorb the charge in the air and prevent the buildup of electrical charge that is released in the form of lightning. Considering that “lightning causes thousands of deaths and injuries worldwide and millions of dollars in property damage” it might be a bit early to discard the research (Science Daily).

For now, I have to agree with the skeptics. The information thus far is just not enough to rely on the innovation because the process has not been perfected, but regardless, I keep my faith in it because I know scientists haven’t given up on developing the theory into tangible metal plates.  Similarly Galembeck holds the same faith stating, “We certainly have a long way to go. But the benefits in the long range of harnessing hygroelectricity could be substantial” (Science A Gogo). When scientists find out more about the mechanisms of lightning and how to harness the power, there will be enough information to rely on any innovation derived from it. I look forward to the day when I won’t be paranoid about holding an umbrella while there is lightning.

Citations:

“Electricity Collected from the Air Could Become the Newest Alternative Energy Source.” Science Daily: News & Articles in Science, Health, Environment & Technology. Web. 17 Apr. 2011. <http://www.sciencedaily.com/releases/2010/08/100825185121.htm.>

Palmer Science, Jason. “BBC News – Scheme to ‘pull Electricity from the Air’ Sparks Debate.” BBC – Homepage. Web. 17 Apr. 2011. <http://www.bbc.co.uk/news/technology-11100528>.

“Scientists Revisit Tesla’s Electricity-from-air Ideas.” Science News, Research And Discussion. Web. 17 Apr. 2011. <http://www.scienceagogo.com/news/20100729212533data_trunc_sys.shtml>.

A Wall of Water

March 11, 2011. Breaking News: Japan’s most powerful earthquake since records began has struck the north-east coast, triggering a massive tsunami. In the family room, we watched in silence as the footage of the giant debris-filled wall of water making its way inland was replayed over and over again. As the reporter recounted the details of this earthquake with an intensity of 9.0 on the Richter scale, my mind drifted towards the science behind the formation of these giant havoc-wreaking monsters that have frequently caused heart-breaking destruction and loss of life. More importantly, how do earthquakes lead to these deadly 10meter tall tsunamis?

Before we understand how tsunamis are formed, it is important to understand that the Earth’s crust is not one giant spherical unbroken land mass. Rather, it is made up of jigsaw puzzle like pieces called tectonic plates. These plates move approximately 2 inches a year because of the movement of heat carried from the inner core to the Earth’s crust; however, sometimes the plates move abruptly (as the regular movement is restricted by friction), causing an earthquake.

“But not all earthquakes are the same. It depends on whether the relative movement between the plates is horizontal or vertical.” In addition, the location of an earthquake could be on land, or under the ocean floor. Tsunamis are only formed when the relative movement of the tectonic plates is vertical and under the ocean floor. When the plates move vertically under water, the movement (“thrust”) produces a large displacement of water from its equilibrium position that needs to somehow regain its equilibrium as the gained potential energy converts to kinetic energy in the form of a fast-moving wall of water.

“The water has to go somewhere,” explains Dr Wayne Richardson of the International Seismological Centre, “and it has to go at once. It’s not like a wave breaking at the beach. It’s a mass movement. It can travel, depending on the depth of the water, at up to 950 kilometres per hour (589mph) in the deep ocean.”

As the topography of the sea floor changes and the wave approaches shallow water, the speed slows down and the height of the wave increases (as illustrated in diagram below).

How Tsunamis are Formed

Yet, it is important to note that not every single underwater earthquake will form a tsunami – the magnitude of an earthquake, measured by the Richter’s Scale, must be taken into consideration. Scientific research has proven that usually earthquakes 7.0 and below do not result in tsunamis, and if they do, they rarely lead to massive destruction.

Tsunamis are natural disasters, and they cannot be prevented. It is, therefore, our responsibility to be adequately prepared for this natural calamity.

Due to the fact that Tsunamis have a small amplitude and a long wavelength (up to hundreds of miles) offshore, they can frequently pass unnoticed until they reach shallow water, and therefore it is very important for tsunami-prone nations to install adequate and accurate tsunami sensing and early warning technology. This can be a challenge for poor, underdeveloped nations and I believe that they should be supported by developed nations.

It is also important for the governments of tsunami-prone nations to make wise decisions when building infrastructure offshore/close to shore that could have catastrophic and life-threatening consequences if hit by a tsunami e.g: nuclear power plants, offshore drilling rigs, etc. (as seen in the recent nuclear plant meltdown in Japan)

Last but not the least, it is important that a communication system is in place that allows tsunami warnings to reach every individual in the risk region and an evacuation policy that allows all to be evacuated in due time.

Bibliography:

“Earth Plate Tectonics.” Windows to the Universe. Web. 15 Mar. 2011. <http://www.windows2universe.org/earth/interior/plate_tectonics.html>.

News, Roland Buerk BBC. “BBC News – Japan Earthquake: Tsunami Hits North-east.” BBC – Homepage. Web. 15 Mar. 2011. <http://www.bbc.co.uk/news/world-asia-pacific-12709598>.

Melina, Remy. “Why Do Some Earthquakes Cause Tsunamis But Others Don’t? | Earthquakes & Tsunamis | Life’s Little Mysteries.” Life’s Little Mysteries – A Daily Investigation of the World Around You. Web. 15 Mar. 2011. <http://www.lifeslittlemysteries.com/why-do-some-earthquakes-cause-tsunamis-but-others-dont-1125/>.

“Tsunami Science: a Wall of Water.” Tsunami Science: a Wall of Water. Channel 4 News, 11 Mar. 2011. Web. 15 Mar. 2011. <http://www.channel4.com/news/tsunami-science-a-wall-of-water>.