All posts by Nick Chin

Wait, A New Element?

So while I was reading the news, I happened to discover a page titled ‘Existence of New Element Confirmed’. That got me to wonder, was there really a new element discovered? It turns out, researches at Lund University has confirmed that a new element with the atomic number 115 exists, temporarily named Ununpentium (Uup abbreviation). Currently, the name is being debated by the International Union of Pure Applied Chemistry (IUPAC). The research verified findings of the same element during a prior experiment performed in 2004 led by a Russian research team (“Existence of New Element“, 2013). Both research teams performed the same experiment; calcium-48 ions were bombarded at a thin film of americium-243. The collision of the ions and atoms resulted in a formation unupentium, which decayed milliseconds later due to its radioactive nature (“Ununpentium“, n.d.). Although this begs the question “how was this element confirmed to exist”, analysis of  the energy released through radiation matched the theoretical values of the element confirming its existence (“Existence of New Element“, 2013).

Ununpentium Bohr Model
Ununpentium Bohr Model

That got me to ponder, what chemical/physical properties does this new element have? Unfortunately, it is currently impossible to give a definitive answer to that. Every isotope of Uup that has been discovered all have an average half-life of 100ms. That means a large enough sample cannot be collected to observe the element’s properties. However, it is predicted that the element has similar properties to that of the group 5 elements on the periodic table (“Ununpentium“, n.d.). Uup is classified as a synthetic element, elements which have a half-lives so short relative to the Earth’s age, that most or all naturally occurring elements would have decayed completely (“Synthetic Element“, n.d.). The majority of them lie within period 7 of the periodic table.

Synthetic Elements
Synthetic Elements

So why discover new elements if they decay so quickly? Not the most moral or conventional example but plutonium, an element discovered in 1941 and was used in the atomic bomb dropped on Nagasaki (“Plutonium“, 2012). Since most of the synthetic elements are all radioactive, the majority of the are used for nuclear weapons. On a more accepted aspect of usage, plutonium is used in nuclear reactors to provide electrical energy for cities around the world (“Nuclear Reactors“, 2013). Atomic energy is considered clean as it doesn’t produce air pollutants through usage and can be used as an alternative to fossil fuel burning. However, disasters such as the recent Fukushima earthquake in 2011 and the Chernobyl meltdown in 1986 serves as a constant reminder and strong argument against atomic energy.

I want to highlight the importance of the scientific method here. The original research experiment performed in 2004 produced quantifiable results. At the time, technology could not confirm such results found. The important thing was the experiment set up was reproducible in another lab. With more advanced technology and further research into the theoretical data was the reason why the team at Lund University could confirm results. Without a reproducible experiment, a scientific claim cannot be verified.

Works Cited

“Existence of New Element Confirmed.” ScienceDaily. Lund University, 27 Aug. 2013. Web. 28 Aug. 2013. <http://www.sciencedaily.com/releases/2013/08/130827091636.htm>.

“Nuclear Reactors.” World Nuclear Association. N.p., July. 2013. Web. 28 Aug. 2013. <http://world-nuclear.org/info/Nuclear-Fuel-Cycle/Power-Reactors/Nuclear-Power-Reactors/#.Uh3uPxsSZVV>.

“Plutonium.” US Environmental Protection Agency. N.p., 6 March. 2012. Web. 28 Aug. 2013. <http://www.epa.gov/radiation/radionuclides/plutonium.html>.

“Synthetic Element.” Princeton University. N.p., n.d. Web. 28 Aug. 2013. <http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Synthetic_element.html>.

“Ununpentium.” Wikipedia. N.p., n.d. Web. 28 Aug. 2013. <http://en.wikipedia.org/wiki/Ununpentium>.

Cleaning Water, Step by Step

After listening to and reading India’s blog post about water pollution, I decided to further investigate the methods used to clean the water we drink and bathe with. Covered in her blog post, she mentioned pollutants within the water such as bacteria, chlorine, nitrates, and heavy metals. With all these particles and microbial life swimming in our tap water, it’s a miracle we aren’t ridden with diseases. I began to wonder, what do private firms and the government do to remove and minimize all these pollutants?

Huangpu River Pollution
Huangpu River Pollution

So I began my search on the companies who clean Shanghai’s water supply. Veolia Water is one of the major companies who purify and distribute water to households around Pudong. Veolia first extracts their water from underground aquifers and surface water bodies. These areas are protected to prevent pollution. All the water then passes through a purification process, which includes coarse and fine screening, flocculation and settling, filtration, ozonation and chlorination. (Veolia Water, 2010)

Screening is a process in which water is ran through different sized screens to stop rocks and other larger objects from entering the rest of the system. It then moves into a system called flocculation and settlement. Within water, there are usually small clay or dirt particles are suspended, giving water the yellowish, brownish look. These particles are often negatively charged, preventing them from clumping together. Hydrated ammonium alum (NH4Al(SO4)2Ÿ 12H2O) is  added to the water to neutralize the negative charges, allowing particles to combine and form larger particles called flocs. The water passes through a paddle chamber that assist flocculation of particles. The following chamber allows the larger particles to settle due to gravity, removing the majority of the clay. (Drinking Water Treatment – Flocculation, n.d.)

Flocculation of Clay Particles
Flocculation of Clay Particles

After flocculation, water is passed through a gravel and sand filter that removes the remaining clay particles. However, this does not remove metal ions, nitrates, or microbial life from the water. Ozonation, the process of bubbling ozone through water to purify it, is often performed to clean water but is more costly than adding chlorine as a disinfectant. Ozone, O3, is synthesized by the use of UV light or electrical discharges. Bubbling ozone through the water kills microbial life. It also reacts with metal ions such as Iron and Manganese, creating insoluble metal oxides, which can be filtered out. (Oram, n.d.) Unlike ozonation, chlorination is relatively inexpensive and will continue disinfecting after leaving the water purifying plant. Chlorine is added into the water, which kills microbial life; however, it doesn’t remove metallic ions. (Drinking Water Treatment – Disinfection, n.d.)

Once the water leaves the purifying plant, it is transported to households across Shanghai, but chlorine and nitrates still remain within the water. In addition, faulty and leaky pipes allow contamination of minerals and other compounds into the water system.  To combat this, some houses have granulated active carbon filters and water softeners. Water passes through grains of active carbon (organic material or coal treated with heat) to react and trap chlorine and some trihalomethanes (THMs, carcinogens), preventing them from being consumed or absorbed by the skin while bathing. (Water Treatment Using Carbon Filters, 2012)

Water softeners are used to reduce calcium and magnesium ions. Although these metals are not harmful to the body in small amounts, they cause pipes to calcify and clog up, decreasing water pressure. Calcium and magnesium ions are replaced with sodium ions found on the ion exchange resin sites found within the filter. (Skipton, 2008)

Despite all these processes, nitrates still persist within the water. Currently, the only way to remove nitrates would be through reverse osmosis or demineralization, both of which require lots of energy and are expensive to maintain. (Runyan, 2011) Often, some people use faucet filters to further purify the water. These are often carbon filters, which still don’t remove nitrates from the water supply.

With all these methods used to purify the water, it still comes down to the question, is tap water in Shanghai safe to drink? Or is any tap water safe to drink for that matter? Ultimately, it becomes the individual’s decision. How much does one trust the government and others to handle their water? Do the benefits outweigh the cost of purchasing distilled water? Judgment of these crucial matters always lies within the person.

References:

Drinking Water Treatment – Disinfection. (n.d.). Tech Alive Home Page. Retrieved March 25, 2013, from http://techalive.mtu.edu/meec/module03/Sources-SurfaceWater.htm

Drinking Water Treatment – Flocculation. (n.d.). Tech Alive Home Page. Retrieved March 25, 2013, from http://techalive.mtu.edu/meec/module03/DrinkingWaterProcess.htm

Oram, B. (n.d.). Ozone Water Treatment, Ozonation, Ozonator Dirty bad tasting water, contaminated colored water, unfiltered water, bad smelling water. Private Well Owner Drinking Water Pennsylvania Ground Water Research . Retrieved March 25, 2013, from http://www.water-research.net/ozone.htm

Runyan, C. (2011). Nitrate in Drinking Water. NMSU: College of Agricultural, Consumer and Environmental Sciences. Retrieved March 25, 2013, from http://aces.nmsu.edu/pubs/_m/m-114.html

Skipton, S. (2008, October 8). Drinking Water Treatment – Water Softening (Ion Exchange). NebGuide. Retrieved March 25, 2013, from http://ianrpubs.unl.edu/epublic/live/g1491/build/g1491.pdf

Veolia Water | Production and supply of drinking water. (2010). Veolia Water | The world leader in water services and water treatment. Retrieved March 25, 2013, from http://www.veoliawater.com/solutions/drinking-water/

Water Treatment Using Carbon Filters (GAC). (2012, August 1). Health State MN. Retrieved March 25, 2013, from http://www.health.state.mn.us/divs/eh/hazardous/topics/gac3.pdf

Transistors or Semiconductors? The Cells of Electronics

When I first began building my computer, I learned that most computer parts only require about three different voltages, but wall sockets in the US produce 110 volts and other countries use 220 volts. That got me wondering, wouldn’t the 110 volts travel all throughout the computer? How do computer parts reduce the voltage? After getting my computer running, I researched my question for the answer: transistors. It didn’t really gave me a full understanding of how, so I decided to do more research.

If cells are the building blocks of life, transistors are the building blocks of the digital revolution. Without transistors, the technological wonders you use every day — cell phones, computers, cars — would be vastly different, if they existed at all.

Nathan Chandler at HowStuffWorks, (Chandler, n.d., p. 1)

So the guys at HowStuffWorks gave a brief overview of how transistors work. Transistors are somewhat like water faucets. In addition to starting and stopping the current, they can control how strong the current is, allowing the resulting voltage to be bigger or smaller than the original. All this is thanks a series of semiconductors, once made out of germanium is now mostly produced with silicon. Semiconductors are materials that can conduct electricity, but not very well. Naturally, Si and Ge are very weak semiconductors, conducting almost no electricity at all, but through a process called doping, the conductive properties can be changed.

Transistors from Wikipedia
Transistors from Wikipedia

Doping is the process of adding small amounts of impurities into, in this case, silicon or germanium crystal lattice. Both Ge and Si have 4 valence, the impurities usually come from either group 3 or group 5 elements, depending on the type of semiconductor desired. Having 3 valence electrons, elements such as boron and aluminum can be added to Si, creating a substance where the added impurity is missing an electron. This is called a P-type due to its positive charge from the missing electrons. Conversely, phosphorus or arsenic, elements with 5 valence electrons can be added to create N-type semiconductors due to its additional electrons giving a negative charge. A nice diagram is can be seen here in Hyperphysics.

Now equipped with both types of semiconductors, you can create a transistor by placing a series of either P-N-P or N-P-N. When applying an electrical current in the middle, “electrons will move from the N-type side to the P-type side.” Depending on the initial strength of the current and how impure the semiconductors are, the transistor will either amplify or decrease the current.

All this got me thinking on another question of mine. What other uses are there for semiconductors? The simplest use of semiconductors is diode. A diode consists of one P-type and N-type semiconductors. When put together, an electrical current can flow through from the P-type region to N-type region, but not the other way. This is because electrons can only flow from positive to negative, but not the other way around, as the N-type region will repel the moving electrons.

These can be made into Light Emitting Diodes, or LED’s, that emit a multitude of colors. Multiple semiconductors can be combined to create Random Access Memory (RAM) to increase your computer’s speed or Microprocessors for calculators and other electronic devices.

Light Emitting Diodes
Light Emitting Diodes

So to put it in perspective, just as cells build living things, transistors, according to Nathan Chandler, are the building blocks of all electronics. But seeing as semiconductors build transistors, I believe that these special compounds are the true cells in electronics. Although semiconductors have existed in electronics for quite some time, new uses and circuitry of electronics is being discovered every day.

Bibliography

Chandler, Nathan. “HowStuffWorks “How Transistors Work”.” HowStuffWorks. N.p., n.d. Web. 13 Jan. 2013. <http://electronics.howstuffworks.com/transistor.htm>.

Semiconductor Device.Wikipedia. N.p., n.d. Web. 13 Jan. 2013. <http://en.wikipedia.org/wiki/Semiconductor_device>.

The Doping of Semiconductors.Hyperphysics., n.d. Web. 13 Jan. 2013. <hyperphysics.phy-astr.gsu.edu/hbase/solids/dope.html>.