Monthly Archives: November 2015

Experiment Outline

After we have received all necessary materials for the experiment we can truly begin collecting useful data. The physical set up of the experiment is the same as the solar cell experiment, which we did in class. We will have an NXT microcontroller with the same code as the solar cell Labview code. We will have a voltage probe connected to one of the ports in the NXT microcontroller and the other end is connected to the wires of the solar panels. We will collect the voltage output during a 10 second period (this duration time might be changed). We will perform 3 different trials throughout the experiment, each trial representing a different obstruction. The 1st trial is considered a reference point because we will measure the voltage output when the solar panel is clean. The 2nd trial we will pour water on the solar panels (they are encapsulated) to simulate rain and then take a voltage reading. In the 3rd trial we will take some dirt and smudge it over the solar panel gently to mimic dust build up and once again take a voltage reading. It is important to remember that the light source is held constant during all trials and will be the same distance throughout the experiment. In between each trial, we will clean the solar panel since each student group will only be given 1 solar panel for the whole experiment.

 

Once we complete the trials, we will open up the data on a excel spreadsheet and create a bar graph of the averages of the voltages of each trial. What we should observe is the voltage decreasing in between the 2nd and 3rd trial. There shouldn’t be a very big voltage difference in between the 1st and 2nd trial. Now that we have a visual of the data we want to calculate about how many voltage is being lost in between the 1st and 3rd trial. In our solar panels the difference is going to be quite small, but in commercial/residential solar panels this difference is evident. After were done dealing with the data, we will ask students 2 questions to make them think more critically:

 

  1. The most typical size for solar panels used for residential installations is 65 inches by 39 inches, while the common size for commercial applications is 77 inches by 39 inches. The solar panels we have provided are approximately 2.4 inches by 3.6 inches.

 

Estimate the voltage lost in a residential and commercial solar panel.

 

  1. The majority of solar panels in commercial installations are maintained by individuals who physically clean each solar panel (similar to window cleaners). This method is expensive and tedious for the workers.

 

What are alternative approaches to cleaning solar panels that are less expensive and more effective? (Hint: Think Autonomous Systems)

            We are looking for your ideas so let your imagination run wild!

Brainstorm Session

During our brainstorming session, my group had a lot of different ideas bouncing around of what exactly we wanted our experiment to be on. We thought it would be more helpful to think of an experiment that was simple to do but very effective at making a connection with the energy crisis we are currently experiencing. Initially we wanted to do an experiment that was completely dependent on the Lego Mindstorm Kit. We searched around online and found a few experiments, but they didn’t really have that much emphasis on sustainability and energy. A fun experiment is obviously more enjoyable to the students but if no useful data can be extracted than what was the purpose? We needed an experiment that we could get data out and make students analyze and interpret this data. After asking ourselves these essential questions, we ended up rejecting the Lego Mindstorm Kit ideas because they weren’t fitting our model of what a good experiment should be.

 

We decided to change gears and think of an experiment we have performed in class but alter it to make a different experiment but still keep the fundamental ideas the same. We decided on taking the solar energy experiment and making the obstruction in between the solar panel and the light source materials that are more accurate to those in our environment. We quickly brainstormed what type of things get on solar panels and we ended up with water (from rain) and dirt/dust (which accumulates over time). One of the most brought up obstructions during our group discussions was bird poop, which is very true but implementing it in the experiment was not going to happen for obvious reasons. We all agreed upon this experiment, in which we would measure the voltage output of solar panels with different obstructions. I will further discuss the experiment in my next blog.

Solar Energy Experiment

Since the discovery and implementation of photovoltaic cells our world has been revolutionized by this renewable energy source. Solar Panels convert sunlight into DC electricity. The more sunlight the solar panel is exposed to, it results in the electrons in the solar panel to be “excited” more aggressively, thus resulting in a higher voltage. Many companies and home owners have turned to solar panels to power several appliances being used throughout the building/house. Although solar panels are a huge investment, in the long run they become economically beneficial. During our Freshman Seminar class on October 28, we performed a photovoltaic experiment. During this experiment we measured the voltage output of a small solar panel while changing the height of the light source and the color filter above the solar panel. We used a NXT microcontroller and a voltage probe in order to collect data through a Labview prewritten code. A copy of the code can be seen below.

 

The first task of the experiment that we tested was determining the relationship between distance and voltage output. It is important to remember that as the distance between the light source and the solar panel increase, the light intensity decreases because the photons spread out more with greater distance. We tested this by using a flashlight (in my group we used a iPhone) to serve as our sunlight. We changed the distance between the light source and the solar panel during each trial. We did three trials, each having a distance of 1 cm, 5 cm, and 10 cm respectively. If you look at the graph below, you can conclude that the relationship between light intensity and voltage output is linear. Both variables are inversely proportional to each other. As the distance increases the voltage output will decrease. Our coefficient of determination was 0.9062 thus proving there is a obvious correlation between distance and voltage output.

 

Screen Shot 2015-11-13 at 11.36.27 PM

 

Screen Shot 2015-11-13 at 11.37.00 PM

 

The second task of the experiment that we tested was discovering how a colored filter affects the voltage output, while keeping the distance constant. We used a green, red, and purple/blue clear transparent filters. We compared the voltage output of each filter to the voltage output with no filter. As can be seen in the bar graph below, as the color depth got darker, the voltage output was getting lower. This is a result of the darker colors absorbing more light and allowing a smaller amount of light through it.

 

Screen Shot 2015-11-13 at 11.37.43 PM

 

Screen Shot 2015-11-13 at 11.38.17 PM

 

Overall this activity was extremely enjoyable and very educational. This activity connects directly to renewable energy sources such as solar panels. As we observed as the light intensity increases the voltage output increases simultaneously. Solar panels with tracking systems that tilt/rotate the solar panel towards the sun are applying the very basic observation we saw in the experiment. If the solar panel is exposed to the maximum light intensity available it will output the most voltage it can at that moment.

MIT’s Nuclear Reactor

On November 4, 2015 we got the opportunity to visit MIT’s nuclear reactor. MIT’s nuclear reactor is one of few reactors in the world that allows visitors to tour inside the nuclear reactor, so this was truly a chance of a lifetime. When we first entered we signed in at the front desk and then we were given a personal dosimeter. The personal dosimeter measured the amount of radiation that we were exposed to. By pointing the personal dosimeter towards a light source and then peaking through it, you would see a simple bar line that would tell you how much radiation your being expose to. Once we all signed in, we went to a room to receive a lecture on the history and the technology in the nuclear reactor.

 

MIT_Nuclear_Reactor_Laboratory_-_Tower_Tech_Cooling_Tower

 

MIT’s nuclear reactor has been operating since 1958 and has received two major upgrades in 1975 and 2010. These upgrades enhanced the power output of the nuclear reactor. As of now, the reactor produces approximately 6 MW of thermo electric power. When the 6 MW of thermo electric power is converted into usable electric power the nuclear reactor is only able to power on a 100-Watt light bulb. MIT plans on upgrading the nuclear reactor to a maximum of 10 MW over the years. By increasing the power output of the reactor, it would allow experiments to be done faster. It is important to remember that MIT’s nuclear reactor was not created to generate electricity but to be used for research. The water used for cooling the reactor comes from the city’s water source but then it is highly filtered to the point it is clearly clear. You can see the bottom of the reactor through 10ft of water. Over time the water becomes heavy water (D2O) and must be replaced. The D2O is sent to the government and more is received. The health of the nuclear reactor is highly important which results in approximately 500 maintenance items being changed per year. The actual size of the nuclear reactor is small, measuring at about 15 inches by 22 inches. If you were able to look through the top of the reactor you would notice that there is a blue glow coming from the reactor and this due to electrons traveling at the speed of light in water, which gives off the glow effect. After the long lecture, we moved on to the best part of the trip, touring inside the actual reactor.

 

ReactorGlow

 

From the outside, the reactor looks like a mid size white dome, but once your actually inside you are immediately overwhelmed by the size of it. Before entering the actual dome, we had to go through a pressurization hallway. There were two thick doors that were most likely over a ton. Our tour guide opened the first door and we squished ourselves in a small hallway. Once we were all in, the tour guide closed the first door and then proceeded to opening the second door that was the actual entrance to the reactor. When you walk in, the difference in pressure becomes extremely obvious. Inside the reactor there are many mechanical and electrical systems working in sync to operate the nuclear plant. There are many sensors throughout the systems, which make sure the reactor is working under appropriate numbers. We then walked up a set of stairs, which took us to the same level as the top of the reactor itself. On top of us there was a crane that can rotate 360 degrees around the dome. The crane is used to move heavy items from inside the dome and to also place used uranium into a basement holding tank until it can be shipped to another facility to be taken care of. The tour guide also explained how the dome is made up of 3 feet concrete walls to guarantee that it is a safe containment building.

 

After observing the nuclear reactor and its many systems, we went to the basement to check out the operation room. The operation room looks like something pulled out of a movie. There are hundred of buttons on the walls and multiple screens each displaying vital data information. The brains of this room are the operators themselves. They go through an extensive training process in which they must learn about 3 feet of information. The operators know how to deal with most problems that might arise during their shift. I highly respect those individuals who work as operators in the nuclear reactor because it must definitely be a stressful job due to the amount of responsibility on their shoulders. Before we left, we went through a station that measured our radiation level to make sure no one had abnormal values. Overall, this trip was an amazing experience. It was very informational and enjoyable.

Iran’s Nuclear Energy Program

 

Iran’s Nuclear Energy Program has always been a controversial issue to the international community. The international community is worried that Iran might be using their nuclear energy program to develop nuclear bombs, which is seen as a threat to the Western Hemisphere. “Israel and critics in the U.S. Congress say Iran can’t be trusted to make any fissile material, whether for energy, medicine or bombs” (Bloomberg). I will explore the origins of  Iran’s nuclear energy program and why their are negative conceptions of Iran’s nuclear plants.

 

Bushehr_Iran_nuclear

 

Iran’s Nuclear Program was first established in 1957 through the US Atoms for Peace program. 18 years later in 1975 the construction of two nuclear power plants near Bushehr began. In 1979, Iran experienced an Islamic revolution which resulted in “further payment [to be] withheld and work was abandoned early in 1979” (World Nuclear Association). The two nuclear plants that were being constructed ended up being destroyed in Iraqi airstrikes that occurred from 1984 to 1988. Although these two nuclear plants were damaged, the “revival of the shah’s nuclear program was initially presented as necessary to diversify energy sources” (United States Institute of Peace). Iran could economically benefit by exporting their resources such as oil and use nuclear plants to generate the electricity needed to power the nation. The concerns of Iran’s purpose for a nuclear plant began to become evident when Iran’s program may have “been a byproduct of the troubled revolution’s omnipresent need for legitimacy and Iranian nationalism’s quest for respect and international status” (United States Institute of Peace). As a result the international community was puzzled by Iran’s main goal with their nuclear plants. It is important to note that Iran works concurrently with Russia in the development of their nuclear plants. The amount of Uranium in Iran is very limited which results in Uranium from Russia to be imported in, in order to run the plants. All used and exhausted Uranium rods are then returned back to Russia.  If we fast-forwarding to the present, “The reason why such attention has been focused on Iran is because it hid a clandestine uranium enrichment programme for 18 years, in breach of the Nuclear Non-Proliferation Treaty (NPT)” (BBC News). Iran’s enrichment process of Uranium was under secrecy from the international community, which has caused the rest of the world to be skeptical towards Iran. Consequently, the United Nations Security Council has passed various resolutions, which would limit its uranium enrichment. These resolutions are in place to guarantee that Iran does not enrich uranium to be used for nuclear weapons.

 

In my opinion, these rules set in place by the UN Security council are definitely necessary. In a country like Iran where their objective is unknown and they have kept certain aspects of their nuclear program in secrecy, it is vital to set some form of regulations to how they can get things done. In addition, I don’t think these resolutions should only be applied to Iran, but they should apply to every nation with nuclear plants. This will insure that no nation is developing nuclear weapons. Nuclear plants should only be used for generating electricity and to not create weapons of mass destruction.

 

References:

Tyrone, Jonathan. “Iran’s Nuclear Program.” Bloomberg. N.p., 11 Sept. 2015. Web. 06 Nov. 2015.

“Iran Nuclear Crisis: Six Key Points.” BBC News. N.p., 14 July 2015. Web. 06 Nov. 2015.

“The Politics of Iran’s Nuclear Program.” The Iran Primer. United States Institute of Peace, Aug. 2015. Web. 06 Nov. 2015.

“World Nuclear Association.” Nuclear Power in Iran. N.p., 20 Oct. 2015. Web. 06 Nov. 2015.

Generator Experiment

During our Freshman Seminar class on October 26, we performed a Generator Experiment. Ultimately, we were testing the creditability of Faraday’s Law. Faraday’s Law states that if you change the magnetic flux through a coil it will result in a voltage to be “induced” in the coil. This would result it in a voltage and current to be created. We simulated this statement by having a shaking flashlight. The outer casing of the flashlight is transparent and inside this outer shell there is a copper coil with many turns. Also inside the flashlight is a magnet. The magnet is loose and can move freely vertically. By shaking the flashlight the magnet would move through the coil thus producing a voltage and current. We collected the data (voltage being produced) by using a NXT microcontroller, which was running Labview code. A copy of the code can be seen below:

 

Screen Shot 2015-11-06 at 11.21.37 AM

Screen Shot 2015-11-06 at 11.22.14 AM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I have provided a copy of our data points that we collected during each 30-second trial. In each trial we would increase the number of shakes. In addition, a scatterplot is provided displaying the best-fit line and the coefficient of determination (R2).

 

Screen Shot 2015-11-06 at 11.26.43 AM

 

Screen Shot 2015-11-06 at 11.32.07 AM

 

As can be observed in the graph as the number of shakes increased, the sum of voltage squared increased as well. The faster the magnet crossed through the coil the more electricity that was being produced. At times the voltage reading was negative and this is because the polarity was changing from positive to negative. In conclusion, our R2 value was 0.96 thus concluding that there is a very strong relationship between the number of shakes and sum of voltage squared.