Posts belonging to Category STEM



Guest Blog: UV LED for Revolutionizing Water Purification

Thomas Edison’s most iconic invention was the incandescent bulb, in use since the 1880s. Today, LEDs, are entering the world at an unprecedented pace. In fact, you are likely reading this article from an LED-lit screen either on a LCD monitor, smartphone or tablet.

Most of the current LEDs on the market emit visible light (blue, green, yellow, red) and white light. However, a more recent LED can emit ultraviolet, or UV light, that has the potential to revolutionize the water purification industry.

The use of UV light for water purification dates back to 1916 in the U.S. UV light is effective in disrupting DNA of micro-organisms, preventing them from functioning and reproducing. Today, UV light is widely utilized in municipal wastewater treatment, the beverage industry and in family-size water treatment applications. Compared to traditional chemical purification, UV purification is a fast and purely physical process, which does not leave any taint, chemical or residues in the treated water.

However, nearly all the sources of UV light derive from mercury lamps- a vapor gas discharge lamp. Such lamps are fragile, bulky and toxic, not to mention the high working voltage that could be hazardous to users. On the other hand, UV LED lights are durable, operate at low-voltage, and do not contain toxic materials. The most notable difference between the UV LED and UV mercury lamp is their size. The size of a UV LED chip is hundreds of times smaller than a typical UV mercury lamp, opening up new avenues for portable water purification applications.

US troops and outdoor enthusiasts still heavily rely on chemical tablets to purify individual drinking water. It takes the tablets several hours to purify a gallon of water and the tablets leave a terrible taste in the water. Nausea, diarrhea and headache have also been reported from those who are sensitive to the residual chemicals. With reliable and compact UV LEDs, Ipod-size water purifiers can be designed to replace the chemical tablets and avoid any bad taste and side effects. Meanwhile the UV LED will work much faster, and can purify gallons of water in just several minutes. Travelers will benefit from UV LEDs too, as they can go farther off-road with reliable water purification.

The major obstacle for UV LED entry into the market is lower efficiency compared to the UV mercury lamp. Fortunately, the situation could change rapidly, as many leading universities and research institutions begin to heavily invest in UV LED research. Low-power UV LED is already for sale today, mainly used for scientific research. In the near future, high-power or practical UV LED will be offered, thus allowing life-saving water purification technologies to become more affordable and ubiquitous.

Xiaohang ‘X’ Li
Graduate Student
Georgia Institute of Technology
xquva.com@xiaohangxli
linkedin.com/xiaohangxli

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Thomas Edison on Time Magazine“I find out what the world needs. Then I go ahead and try to invent it.”

Time ® is a registered trademark of Time Inc.

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Guest Blog – A STEM Teacher’s Story

Highlighting a Guest Blog - a STEM Teacher’s StoryAt the beginning of this year, I heard my students buzzing about the game Minecraft, which allows players to build constructions out of textured cubes in a 3D generated world. This was an opportunity to infuse 21st century skills with technology in a relevant and meaningful way. Just as Thomas Edison was able to refine his ideas, making them more desirable, it was my intention to adapt a game that students were already highly interested in to make it thought-provoking and engaging.

I changed the premise and purpose of the Minecraft game, and combined it with a method of systems thinking known as DSRP; i.e. a theory and method of thinking, an acronym, standing for Distinctions, Systems, Relationships, and Perspectives. I challenged students to form teams and build a world from one specific perspective-one that uses algae as a fuel source. After some research on algae cultivation and biofuels, the students were able to build, virtually authentic, algae farms.

I was impressed with their ability to understand the relationships between the parts of their system [systems thinking]. This became evident when students decided to put their algae farms next to the power plant so carbon dioxide off-gases from the power plant could be used to promote accelerated algae growth, thereby keeping the off-gases from adversely affecting earth’s ozone layer.

Since this project, we have tackled problems such as disaster preparedness and the waste/trash epidemic, through similar studies. It was amazing to see middle school students attacking real-world problems. This technology has proven to be engaging and also an effective tool to facilitate skills necessary in the 21st century.

Louis Rossi Think STEM Coach Green Hills School Greendell, NJ 07839

Louis Rossi
Think STEM Coach
Green Hills School
Greendell, NJ 07839

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Thomas Edison on Time MagazineThomas Edison said … “The man who doesn’t make up his mind to cultivate the habit of thinking misses the greatest pleasure in life.

Time ® is a registered trademark of Time Inc.

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The MOOCS are Coming, The MOOCS are Coming!

The MOOCS are Coming, The MOOCS are Coming!

The MOOCS are Coming, The MOOCS are Coming!

Yes they are, and with the potential to redefine education. A product of the Internet revolution, MOOCS are “Massive, Open, On-line Courses” designed to reach as many students, formal and informal, as possible. Think of them as super webinars for the world, distance learning on steroids.

Universities are experimenting with them as a way to reach larger audiences, leveraging their intellectual capital on campus; and as a potential way to reduce the spiraling costs of on-campus education. Big name schools like Stanford University, Princeton University, University of Pennsylvania, City University of New York, The University of Michigan, MIT, Harvard and others are developing delivery platforms with strategic partners. Even high schools are potential application areas for MOOCS.

What could this mean for the traditional bricks and mortar, red brick schoolhouses of yesteryear? Might this be a way to reduce high school costs at all levels? What could this mean for how our “kids” gain socialization through the interactions of fellow students? Certainly such questions remain to be answered, just like they did when the Internet began re-defining how business does business. Big change, gale force winds, could be coming to our education system.

Because of many potential learners at once, i.e. very high student teacher ratios, MOOCs can use several approaches for feedback and interaction; such as peer-review, group collaboration or online assessments, quizzes, and exams; and in the future there is likely to be even more ways for on-line students to interact.

The MOOCS are Coming, The MOOCS are Coming!

Thomas Edison, a devoted and disciplined life-long learner would certainly applaud this technology. To him it would be a massive way to digest new information and keep a-pace with changing times. Remember, this was the man who thought so much about information being the key to invention/innovation/entrepreneurship that he put his business office in his library. Imagine what this great man could have done with an Internet connection! Imagine what it would be like if we could teach many kids around the world, through MOOCS, about inventing like Edison. Go MOOCS!

Editor’s Deep Dive

Thomas Edison on Time MagazineThomas Edison – Man of the Millennium – said … “I find out what the world needs. Then I go ahead and try to invent it.”

Time® is a registered trademark of Time Inc.

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