After a rather painful two hours of meeting, our team decided how the experiment will be carried out.

Materials:

1 track, 2 carts, 2 motion sensors, some masses, computer and interface software.

Procedure:

We are going to place the two carts on the track. On each cart we will place some masses to avoid having them go too fast. We will measure the mass of each cart(with the added masses). Then, we will place two motions sensors,each on the end of our track. Finally, we will push one cart towards the other cart(which is stationary) to make them collide. Our motion sensors will determine the velocities of the two carts. Then, using the formula p=m*v, we will determine the momentum of each cart during the whole process. We hope they will will be the same in value. Finally, we will repeat this process 5 different times, each time changing the mass on the carts.

Wish us luck!

Last week, we met to divide the class in four groups with each group being responsible for devising an experiment.  The most striking and noteworthy group was that of Anestis, Nurta, Cristian and Ramon(who was absent due to the fact that he was in the hospital after rescuing a kitty cat from the tires of a car). Oh and Darwin joined the group too…

What we did:

Well, after we formally introduced ourselves we started thinking about potential projects. Of course, Nurta, being the crazy girl that she is, suggested we make an experiment that has”explosions or collisions or something cool!”. Having no other choice we started searching for such experiments and after rejecting making a hydrogen bomb we decided we would have two things collide and then observe the interaction between the two.

And?

Then, we wondered “What happens when two objects collide?” And this question prompted us to do an experiment on the conservation of momentum during the collision of two objects.

Process:

As i said we are going to design an experiment where an object collides with another object. We will measure the velocity of the first object, determine its momentum and then do the same thing for the second object after they have collided. Hopefully, the two momenta will be equal to each other, though opposite in direction.

How does the experiment relate to the class?

Well,  the class is called sustainability and energy and momentum is related to velocity and  in extent kinetic energy).

 

In this week’s experiment we dealt with the way that generators and turbines function to produce electricity. The lab that we did captured the process of electrical energy production.

Hypothesis:

In our lab we wanted to show that the more a turbine spins(or moves), the more voltage it will generate. This assumption is based on the fact that the spinning turbine which has a copper foil in the middle and is surrounded by magnets, turns mechanical energy to electrical energy. Of course, the more this process is repeated, the more electricity will be produced so we expected that the more we moved the coil the more voltage it would produce.

Procedure:
In this experiment, we had a flashlight that worked on shakes, which means that as it was shook it produced energy to power the bulb. In our experiment we shaked the flashlight 2 times per second(60 shakes in 30 seconds), 1,5 times per second(45 shakes per 30 s), 1 time per second(30 times per 30 s), half a time per second(15 times per 30 s) and 0 times. Here, we connected the flashlight to our NXT device to measure its voltage and see whether it depended on the shaking of the light. Next, we put together the data in an excel file to produce clearer results.

Data:

In the table above we can see the measurements for each number of shakes. The first thing one can spot is the existence of some negative values, which in this case indicate the direction of the voltage. What we did to eliminate the difference in direction was to calculate the sum of the squares for each column and then we took that one step further by finding the square root of the sum of the squares to get only positive values for voltage.

In the tables below you will see the sum of the squares of the columns vs the number of shakes and the sum of the columns vs the number of shakes. From the latter table we also composed our graph of the situation.

 

Data Analysis:

From the above data we can see that as we increase the number of shakes we are also increasing the Voltage produced. Of course, the relationship between the two is definitely not linear(as we can see from our graph, it looks more like it is an exponential function of the form x^k, where k is a constant).

Conclusion:

Our hypothesis in the beginning was that the more we shook the flashlight, the more voltage we would produce due to the theory of electromagnetic induction. As we saw in this experiment, our hypothesis was completely verified, as the amount of Voltage produced increased as the number of shakes increased. From our graph we were also able to estimate the form of the relationship of the two which is probably something like V=x^k, where k is some constant, V is the voltage and x is the number of shakes.  A way to improve the results would be by using integration, through which we could have found the exact relationship of the function, but this was not the scope of the experiment. Another way to improve the accuracy of our results would have been to have a machine shake the flashlight the amount of times we wanted, so as to avoid the human error we introduced in this series of experiments. Finally, the use of more measurements could help define the relationship between our variables even better. All in all though, this was a largely successful experiment that managed to verify our initial hypothesis.

 

Last week the awe-inspiring class of Seminar for Freshman visited the MIT Nuclear Reactor. Needless to say, that both the reactor and the class were equally impressive. But let’s get to the reactor first.

What is it?

The MIT Nuclear Reactor is a facility where nuclear fission is achieved along with other experimental facilities. The main operation of the reactor though is the production of neutrons primarily for experimental purposes. As i mentioned earlier in the nuclear reactor, the process of fission takes place. Fission is the process in which a radioactive element(usually uranium) is bombed with neutrons that break its nucleus into more nucleii while releasing more neutrons.(and forming a chained reaction process)

In the MIT Reactor this chained reaction is limited and controlled by six shin blades made of boron. Boron is an element that has the ability to absorb neutrons without releasing any, thus stopping the chained reaction. In addition to the control rods, the Reactor is also made up of a moderator coolant(water in this case) that cools the core enough to avoid overheating. For the specific information on the reactor and the way it is arranged refer to the site: http://web.mit.edu/nrl/www/reactor/reactor.htm

What is it used for:

From the above information one can see that the MIT Reactor is not used to produce energy or create bombs. It is used for experiments and research projects, that currently consist of : In-core experiments group,  Boron Neutron Capture Therapy, Trace Element Analysis, Neutron Scattering and Spectroscopy, Neutron Radiography and Silicon Dopping. Below i will elaborate more on the most prominent of those research facilities.

In-Core Experiments:

“The In-Core Experiments (ICE) group performs a variety of corrosion, chemistry, and materials-related experiments in pressurized water reactor (PWR), boiling water reactor (BWR), and other environments.”

Boron Neutron Capture Therapy:

Is a form of cancer therapy that uses a compound containing borons that concentrates on tumors. Aftet Boron has concentrated on the tumor site, a neutron beam is applied on the site, which makes the boron atoms split into lithum nucleii and alpha particles. The release of these particles greatly damages the cells at which they are located, which in this case are the cancer cells(for a more in-depth explanation go to: http://web.mit.edu/nrl/www/bnct/info/description/description.html). This treatment is mainly used as a substitute for chemotherapy in cases of brain cancer and can provide a few additional months of life to terminal cancer cases. Despite the promise of this therapy, the MIT nuclear reactor has not been able to run the BNCT area for the past 5 years, due to a lack of qualified staff interested in the position.

Neutron Radiography:

Neutron Radiography is an imaging technique that utilizes the thermal energy of neutrons. Its applications vary from arts to aircraft engines. The one in MIT,though is primarily used to test the performance of fuel cells. This technique is preferred over X-ray scans, CAT scans, etc due to the fact that it can go in more depth and also it does less damage due to the fact that it is a non-penetrative imaging technique.

Silicon Doping:

Silicon doping is the process of introducing various impurities to silicon(or any semi-conductor) to change its electrical properties. The MIT reactor uses a process called Neutron Transmutation Doping(NTD). In NTD, the silicon sample is placed close to the reactor(that is emitting neutrons) and as a result is bombarded by neutrons. Those neutrons manage to uniformly produce more phosphorus atoms, thus making the doping more strongly n-type.  Also, NTD doping is the main source of income for the MIT reactor, due to the fact that it is not producing energy.

Conclusion:

The MIT reactor seemed huge even though in reactor criteria, it is considered small , which prompts one to think of the magnificence of this structure. Not only did it appear strong and safe, but it also seemed like a glimmer of hope for our energy production needs. Our first contact with the reactor was nothing short of spectacular and further convinced me that nuclear energy is the future.

Once again for more references and information on the MIT nuclear reactor, visit the MIT nuclear reactor page at http://web.mit.edu/nrl/www/index.html

References for images: http://www.wpclipart.com/medical/treatment/Boron_neutron_capture_therapy.png

http://www.trtr.org/Links/Image11.jpg

http://web.mit.edu/museum/150/items/reactorcloudy.jpg