In our first team meeting, our teams decided what experiment we would do. We went through a list of several examples and concluded that for our safety, it would be best to omit any that involved chemicals. We looked at several and decided that we would try one called “Good Sock”.  It is an insulation experiment that measures which material is best for insulation.  We found it was c;ear and concise and directly correlates to sustainability in the sense that it can give ideas on how to sustain heat loss in the cold season. We looked at what we needed for this experiment and allocated responsibilities to each team member.

Materials:

1. 4 glass bottles

2. cotton socks

3. nylon socks

4. foil

5. temperature probes

6. LabView software and NXT robots

After that, we decided that the best way to communicate with each other was on a social network: facebook. We created a page called “a Good Sock” and all joined it that way we wouldn’t have to send multiple messages at a time.

A group of classmates and myself took a trip to the MIT Nuclear reactor. On our way, we got a little lost but finally arrived after the use of cellphone GPS. Never having visited a nuclear plant  I did not know what was in store ahead. Many of us were not sure if this was the right place; we expected large signs pointing us in the right direction or even people walking in and out in hazmat suits. Instead, we found plain clothes employees with the only piece of uniform being a name tag and a dosimeter.

Our safety being of key importance, we went through the long procedure of siigning in by showing photo ID and being handed  a dosimeter with different readings.  The dosimeters measured our levels of radiation. After the readings were recorded,  walked along a hall so that we could measure the levels of radiation on our hands and feet on a Greiger device. After we were all cleared, we went into this chamber that sealed both doors completely and measured the radiation in the air for 10 seconds before allowing us to open the oter door. I must admit I became very claustrophobic at that point.

Our tour guide proceeded to explain to us what was inside the chamber. he told us that the reactor infact, was not a nuclear reactor like that of Fukushima; it did  not generate power. Instead, it was used for research purposes. A bit disappointed, we continued on with the tour. The terminology used was a bit difficult to remember especially since most of us are far from researchers on the material. The main part of this tour was listening because what we got to see was concrete walls and led domes that within them contained these highly dangerous chemicals.

On our way out, we got inline to get scanned for radiation again. There was a new machine made to measure this however, a student in the previous trip had broken the machine with her high heels. Therefore, we used the same Greiger machine as before and proceeded out.

 

Faraday’s Law states that changing magnetic fluxes through coiled wires generate electricity (currents and voltage).   The greater is the change in magnetic flux, the greater are the currents and voltages.

In our lab today, we tested this claim by conducting an experiment that involved using a transparent flashlight with metal could at the center and a bullet-like magnet that when shaken, travelled back and forth between the coil. This flashlight acted as our generator. By shaking the generator, we made the magnet travel through the wire coils thus conducting voltage; the more frequent the magnet travelled, the more voltage it conducted.

Ideally, there should be an almost perfect positive correlation between the number of shakes and the energy generated. However, there were a few discrepancies. 1st, some of the shakes were sone very quickly therefore human error in counting while shaking simultaneously should be taken into account. Also, the shakes were not done with equal power; for example, if you were on your 4th trial shake and the shaking was fast, you’re more likely to be a little tired and not shake as enthusiastically as you would have on your first trial.  However, the chart does show a positive correlation and that is what is important in understanding how the generator works in terms of generating voltage

Tom Vales Sterling Engine, Peltier Junction

We’ve been discussing alternative energy in class. There are several different methods of alternative energy that are quite known. Especially now that Global Warming continues to be a rising issue, it  is important that we as students avail ourselves to more knowledge about alternative energy.

in a time when Global Warming is still an issue.

Last week, Mr. Tom Wales came into our class and gave a presentation on alternative energy. He

This week, we worked on and learned about solar energy and photovoltaics.

“Photovoltaics is the direct conversion of light into electricity at the atomic level.

The diagram below illustrates the operation of a basic photovoltaic cell, also called a solar cell. Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current — that is, electricity. This electricity can then be used to power a load, such as a light or a tool.”

In our lab experiments, we looked at the voltage output of the solar cells and the light intensity output of the light sensor (in some cases flashlights) of the NXT. We then performed two  experiments whereby in our first experiment our independent variable was source of light (voltage output) and our dependent variable was distance from the source (light intensity)and in our second experiment our independent variable was distance form the source of light (light intensity) and our dependent variables were select colored film filters (voltage output).

Equipment:

• One solar cell
• One voltage probe
• One NXT adaptor
• NXT with light sensor
• One light source
• Labview VI  solarlab1.vi
• Ruler
• Colored film filters
• Excel sheet

For the first experiment, we first placed the flash light immediately over the solar cell (distance 0) and then ran the NXT programme. The programme produced 10 numbers that measured the light intensity. Then, we did the same thing, only this time using a ruler, set the flash light 3cm above the solar cell (furthering away the intensity of the light to the solar cell) and ran the NXT programme again. We performed this same task, each time changing the distance to a greater number.

This first Excel chart shows the relationship between the light intensity and the distance from the source of light (in our case a flashlight).

Because the numbers are so miniscule, I calculated the averages for each column and plotted out the averages. Below is a visual scatter plot to show the correlation between the two.