Friday, February 26, 2010

Superconductors!

Have you ever heard about superconductors? Recently, I listened to a lecture by my previous physics professor (Dr. Gene Bickers) about the power and potential of superconductors and became quite interested in it.
Superconductors, which are materials that demonstrate no resistance below transition temperature (Tc), are one of the latest discoveries in the scientific field that proposes wide gamut of possibilities in their applications, ranging from maglev transportation to magnetoencephalography (MEG).

The history of superconductors started in 1911, when a Dutch physicist, Kamerlingh-Onnes, observed an unusual disappearance of resistance when mercury was cooled down to 4 degrees Kelvin. Later, in 1957, American physicist, Bardeen, Cooper, and Schrieffer described theoretical understanding of superconductivity. In 1986, there was a huge step forward in superconductivity when Muller and Bednorz discovered that an alloy of barium, lanthanum, copper, and oxygen compound superconducted at the highest temperature then known which was 30 K. This alloy was a type of ceramics that normally does not conduct electricity well. Expanding from this discovery, researchers soon made combination of alloys that included yttirum which achieved a transition temperature of 90 K. The current world record of highest transition temperature is 164K with mercuric-cuprates (HgBaCaCuO). Also, just recently in 2008, a new class of iron-based superconductors was discovered (LaOFeAs).

Despite the complex and still mysterious behaviors underlying superconductors, making one is not too difficult. The most essential component is copper-oxides or cuprates which are relatively cheap. Next, along with cuprates, add barium, lanthanum or yttrium and bake the mixture at around 900 degree Celsius for about 12-13 hours. Thus, a superconnductor is made by placing rare earth atoms between CuO layers.

Superconductors can be used in wide spectrum of our society. For example, as a strong magnet, superconductors are used in MRI machines. Better the magnetic field, better the resolution of a MRI image. Also, Large Hadron Collider, or LHC, uses many superconductors in order to smash protons in hopes of producing new particles without precedence. A more well-known example comes from maglev trains that use superconductors. In such cases, trains would “float” on strong superconducting magnets and without any friction, will not lose energy through heat which will save incredible amount of energy. A maglev train was constructed in Japan, England, and China, but due to bio-hazard created by strong magnetic fields, wider use of maglev vehicles are being constrained. In addition, the development of a double-relaxation oscillation called SQUID (Superconducting QUantum Interference Device) can be used in magnetoencephalography (MEG) which can pick up magnetic fields in human brain. When SQUID devices are cooled by liquid nitrogen or liquid helium, its superconductivity is capable of sensing a change in a magnetic field and can examine the brain activity without creating too much of a strong magnetic field like the MRI’s.

The history of superconductivity has been relatively short; however, the possibilities of its applications are far-reaching. The fact that superconductors have no resistance means that it has high efficiency which can be used as an alternative energy source, non-invasive biomagnetic and life-saving device, and a high-energy collider. Nevertheless, two of the major obstructions to be overcome is to have a better and fuller understanding of its function and ways to find an economically reasonable way to cool the superconductors. If superconductor’s transition temperature can be raised to the freezing point of liquid nitrogen, the cooling process would be much more affordable.

The lecture ended with my professor’s demonstration of magnetic levitation by a small superconductor which was cooled down with liquid nitrogen. The picture above shows similar demonstration as the one done that day. Although there is much more to be learned about superconductors, perhaps one day, I may be able to transport form city to city with magnetically levitated trains through the power of superconductors.

Reference: http://www.superconductors.org/ & Lecture given by Dr. Gene Bickers of USC on Feb. 1st.

Tuesday, February 23, 2010

Hand Washing

The importance of hand washing has been emphasized since we were in kindergarten. As we grew up, we became more aware of the fact that hand washing is one of the most important primary prevention for infectious diseases. However, do we know the proper way to wash our hands? Many times I see people in restrooms just briefly running their hands through the water after they finish up their number ones or number twos. Indeed, we are all busy people who need to speed up every possible process in our lives. However, if we can prevent further damage through a simple ritual, I say that it is worth it to make it a habit. According to Center for Disease Control (CDC)’s guidelines, using warm water and rubbing hands with soap for 20 seconds is ideal. And yes, 20 seconds is the proper amount of time one should spend in soaping hands. Also, one must make sure to wash areas like beneath nails and wrists to clean places commonly dismissed. The tedious 20 seconds can be made more enjoyable by singing “Happy Birthday” twice, or singing the “ABC” song. After rinsing hands well under running water, turn off the faucet with the paper towel, not your hand. If water is not available, alcohol-based hand sanitizer is a good substitute, but make sure to rub the product over all surfaces of hands until they become dry. Washing hands not only makes you healthy, but it also prevents disease from spreading to people around you. With clean hands comes healthy body. Let’s make sure that we wash our hands along the rhythm of all-time-favorite 20 second songs, “Happy Birthday,”and the “ABC”s!

Reference: CDC’s website  http://www.cdc.gov/print.do?url=http%3A//www.cdc.gov/cleanhands/

Monday, February 22, 2010

Let’s talk about LOVE~!

In the wake of Valentine’s Day, I want to talk about love! So, what is love and why in the world is love discussed everywhere?! I would say 90% of the songs that I hear are about love-at-first-sight, love-aches, break-ups, betrayal by the loved ones, unrequited loves, etc… And talking about movies, there are always some components of love relationships in storyline and that is what really makes the story interesting. So, what is love and why does it happen? As a student pursuing science, it is sometimes difficult to read articles that state that love is simply a mixture of chemicals and hormones permeating through our bodies when we meet someone who strongly attracts us. Few years ago, the magazine, The Economist, had an article about science of love titled, Love is All About Chemistry. There are some major hormones and neurotransmitters discussed in this article. Although the exact mechanism of love within human brain is not well understood, research on voles can give us some hints about the function of hormones in love relationships. Voles are small mouse-like rodent that practice monogamy. When prairie voles have sex, there is a rise in dopamine level which is a chemical that functions as a reward system in the brain. For example, after mating in voles, there is a 50% increase in the level of dopamine which reinforces the fact that sex is enjoyable. Next comes vasopressin and oxytocin which are hormones that help the brain identify the salient features of one’s partner. Salient features can involve odor of one’s sex partner that creates an olfactory memory on the voles. Thus, these two hormones are important in prairie voles’s monogamous lives. Indeed, for human beings to fall in love based on olfactory memory is unlikely. However, human beings also have vasopressin and oxytocin release during sex. Also, when in love, brain scanner reveals activation in parts of the brain that reacts when it experiences an effect of drugs like cocaine. We simply become addicted to love. Going along the same vein, people in love behave in similar manners to people with obsessive compulsive disorder (OCD). So, the major question to be asked is this: can you manipulate love using these hormones and chemicals, a.k.a., is there such thing as love potions? Luckily this article ended with the note that human brain is way too complex to be easily manipulated by injections of drugs to promote love. Indeed, I also think that despite these trends of hormones and chemical release during the process of falling and being in love, there is yet something special about love despite time, hormones, and chemicals. And perhaps that is the reason why everyone always sings, writes, and search for love that is so mysterious yet magical.

If you want to read more about the article mentioned in this post, please visit:http://www.oxytocin.org/oxytoc/love-science.html

Thursday, February 18, 2010

Intro

Okay, I know that the title of this blog is pretty random and perhaps maybe grammatically incorrect. However, I attempted to produce a title that has some relationship and reference to my all-time-favorite childhood novel,
My Sweet Orange Tree
by Jose Mauro de Vasconcelos. So, how did sweet orange tree transform into lime orange tree? Well, Vasconcelos was a Brazilian writer and the title of his novel in its original Portuguese is Meu Pé de Laranja Lima which translates into My Lime Orange Tree. Therefore, my attempt was somehow lost in translation.
I guess the second question that may arise is what is the relationship between this novel and science, the major field that I will be exploring through this blog? Hmmm… well, other than the fact that I love this book personally, I was really touched by the main character, Zezé’s use of imagination to look at the hardships in his life more positively. Although it may sound distant from science, I think imagination and fantasy is what creates science. And childhood imagination has certain power and passion that transforms imagination into reality.
For example, going few years back, the idea that people can call each other while walking around streets with a mobile phone was unheard-of. How about airplanes? Mag-lev transportation? Going to space? Science started with “what-ifs” and all the “what-ifs” came from people’s imagination. Imagination has the motivation and power to create new reality.
Just in case my readers became curious with the title of this blog, I decided to write a brief intro… but, more fun science stuffs are to come! So let’s get started!

Monday, February 1, 2010

Welcome to Lime Orange Tree!

Hey, everyone! Welcome to Lime Orange Tree.
This blog is going to be about science and its application to life in general.
I will explore various fields of science and try to share those topics with you in a fun and informative manner to the best of my ability. Well, then, shall we start this journey together?!