During our visit to the Museum of Science, we were asked to visit four (4) different exhibitions and perform the hands-on activities. We visit catching the wind, conserve @ home, energized! and investigate. All these exhibitions had activities to perform along the information which was helpful to see how the theory we learned in class relates to the practice.

The first exhibition I visit was Energized; this exhibition focused on sunlight, moving water, and other self-replenishing sources that generate cleaner energy with fewer negative side effects. Along the exhibition, the viewer has the opportunity to perform hands- on activities and informative content that make us realized and think twice about the power we are using in our everyday. We use energy every day and for everything from powering our personal devices to even powering our buildings and unfortunately, our main source of energy is coming from sources that will eventually run out and are not good four our planet. Energized, makes you want to pay more attention toward this type of energy and rethink about the options and abilities that renewable energy has and the benefits this could bring us. It was nice, to see and have some hands-on activities to do since we have discussed this topic in class several times. Having this topic here again is a reinforcement of what we have learned and possibly seeing it from a different perspective other than the classroom.

The next exhibition was Catching the Wind; this was just around the corner from energized which makes a great combination with the amount of information that both share. This display was an informational exhibition about wind turbines and how they are slowly but surely appearing more frequently in both the news and along our highways. Along this exhibition, the viewer learns how wind turbines generate electricity, in addition to it there is also an activity called “Wind Power Challenge” which consist of choosing a location and a turbine type, and then see if this can power your home, business or community. A great “game” to see and understand the process of a wind turbine and its advantages.

Continuing through the Museum of science moving on to the upper floors, we can encounter a variety of exhibits all very interesting and diverse great for anyone that would like to learn a few different topics; however, the next exhibition I visit was conserve @ home. This exhibit was all about teaching us how to save energy and its importance, and how this can also help us to save money on our daily basis by only doing some modification to our energy spending routine. Through the exhibition just as in the others there are some hands on actives, but there are some examples of how turning everyday things into more usable ones can help us recycle and repurpose the use of materials we daily encounter. One of the activities “turn your energy into light” (see picture above) I found to be very interesting because it has three different types of a lamp such as LED, Incandescent, and CFL which will lead up while you turn the wheel around giving it the power to turn on. The different activities offered at this exhibit will teach anyone who comes to it different ways to make the most out of energy consumption, time, and money.

The next exhibition I visited is called Investigate, this exhibit without a doubt was one of my favorites for it the particular way of displaying its information. This exhibit is set up in a unique way as it looks as you are entering a house, starting from the living room and learning the different scientific process.  Then we encounter the bathroom which shows two sinks that allow you to investigate if water always drains in the same direction in this hemisphere and then a toilet which was one of my favorite parts because it shows it in section (cut through half) allowing you to see how its process works when your flush it (this link will show a video I recorded during my visit Video). Something that we use every day and we do not really think about how it works. Moving on the “house” continues to develop into a kitchen kind of shape, a garage and a front yard each of these with different experiments, hands-on experiences and a broad amount of information that allow us to learn and appreciated many different aspects of science.

In conclusion, without a doubt the museum of science was a great experience to put in practice the theory we have learn through class, add some information and learn more while in a different set up rather than the classroom.

 

Pandora’s Promise is a documentary about the history and future of nuclear power. The film covers the discussion about this controversial topic. Through the documentary, a neutral concept and position about the nuclear power are “try” to be maintained by presenting the different sides of this issue and at the same time trying to answer the question we all ask “how do we continue to power modern civilization without destroying it?”. However; many said this is a pro-nuclear propaganda which I found to be an interesting attitude toward the topic provides a curious perspective on how environmentalist and supporters of nuclear power support stand on this issue.

Although a stronger “neutral” position will be preferable when talking about nuclear power; the documentary shows support towards nuclear power and even takes the time to expose the myths behind this topic. Most of these are concentrated the discussion over the danger that comes together with nuclear power and in discussion to the historic events that have been inevitable and, unfortunately, relevant because of this problem.

Through the documentary I was very impressed with the amount of support nuclear power got from different “environmentalist”; in my opinion, a person is either with or against something and this is the same with nuclear power you either love the environment or support and believed nuclear power is actually helpful for the environment and for our future and for the future generations.

Underexposing this extremely dangerous power, and hiding it under “pro-nuclear” words, mean supporting a developing of a process that with more power and support could end up affecting us all around the world. It’s been proved, and we have lived through many different nuclear disasters that have been underestimated in this film just to hide the causes of nuclear power. Underestimating the amount of death and horrible causes that a nuclear disaster brings with it is just not correct. Unluckily, It is extremely hard for me to agree with the statement established along this documentary, after researching about different causes of nuclear disasters and its horrible effects on the environment and humans life I find extremely hard to support a cause that it’s been originally known as bad, dangerous, and even in my opinion “lethal top our health” to be considered as “not as bad.” There are many things that can go “wrong” when dealing with such a delicate issue. It is not just to say that we will build safe nuclear power station when back in 2011 one of the worst nuclear disaster happened followed by a natural disaster even though the nuclear station was well built and put together and was consider as “safe” this end up causing a horrendous disaster to be remembered through history.

The way they showed facts and “proves” did not do a good job convincing me that nuclear power is “good” I strongly believed it’s not, even more after watching the documentary.  Exposing and “highlighting “other causes dangerous effects to hide the once produced by the nuclear power it’s not a right way to achieve or convey a concept.

“An event that has led to significant consequences to people, the environment or the facility.” IAEA

Fukushima Accident

In 2011, one of the world worst accidents took place in Japan. An earthquake of magnitude 9.0 at 2:46pm on Friday March 2011 changed the live of a whole country leaving considerable damages which was followed by a 15-meter tsunami which resulted in outrageous amount of human death, over a million building  destroyed and a huge damage to costal ports and towns.

During the accident eleven (11) reactors at four nuclear power plants were operating in the region and immediately shut down with the earthquake. Even though the reactors proved robust seismically, they were vulnerable to the tsunami; the 15-meter tsunami flooded the entire site disabling the power supply and cooling of three Fukushima Daiichi reactors, causing a huge nuclear accident. This disabled 12 of 13 back- up generators on site and also heat exchanges for dumping reactor waste heat and decay heat to the sea. To add up to this tragedy a hardened emergency response center on site was unable to be used in grappling with the situation, due to radioactive contamination.

This accident was rated 7 on the INES scale, due to high radioactive releases over days 4 to 6, eventually a total of some 940 PBq (I-131 eq Although, there have been no deaths or cases of radiation sickness from the nuclear accident, however over 100,000 people were evacuated from their homes to ensure this. Government nervousness delays the return of many.

-The following picture color code different areas, the green areas show “Areas to which people may return but no stay overnight and there is not a required equipment to return” the orange area are restricted, pink area is named “difficult” meaning its accessible but only for public interest, red area represents fully evacuated and yellow represents planned evacuation area.

Chernobyl Accident

This accident took place the April of 1986 in Ukraine, The Chernobyl accident was the result of a flawed Soviet reactor designed that was operated with inadequately trained personnel. This was a direct consequence of Cold War isolation and the resulting lack of any safety culture.

This horrific accident ended up destroying the whole Chernobyl 4 reactor, killing more than 20 operators and firemen within three months later, acute radiation syndrome was diagnosed in more than 200 people on-site confirming 134 cases from which about 28 people died.

The Chernobyl disaster has been the only even in history of commercial nuclear power where radiation-related fatalities occurred; this led to major changes in safety culture and industry operation over time.

Safer Nuclear Technology

After the Fukushima accident the U.S has develop some safety proposal that should be consider in order to prevent a tragedy. While the probability of a nuclear power accident may be small, the human and environmental consequences of a radiation release can be catastrophic. Enforcing fire and earthquake regulations, addressing flood risk, and safer storage for nuclear waste are just a few of the ways we can help prevent nuclear accidents. Although nature is a big threat for nuclear facilities it’s not the only one. These facilities are key targets for sabotage and terrorist attack, and these could have horrible consequences if successfully performed. Nuclear Regulatory Commission (NRC) makes security rules that all plats must follow in order to maintain a safe status some of these are: security access zones, size and capability of security staffing, testing security systems and more; however these are not the only ways to prevent a nuclear technology, and there are many theories that agree that the NRC must do more to prevent and make nuclear technology safer.

Safely store waste

“Nuclear fuel remains dangerously radioactive for thousands of years after it’s no longer useful in a commercial reactor.”

• Dry cask for short term solution

Spent fuel pools at nuclear plants tend house nuclear waste only until it is cool enough to be transferred to permanent storage, have become dangerously overcrowded as the search for a permanent repository has stalled.  Experts recommend that instead of doing this it’s better to store it right away into dry casks to reduce safety hazard.

• Repositories for long term solution

• Reprocessing

 According to some research reprocessing is not a good solution, although many have been doing it over the past years this process separates nuclear waste into component materials, including plutonium, which can then be re-used as nuclear reactor fuel BUT it can also be used as the raw material for a nuclear weapon which can lead to terrorism attacks putting ourselves into a serious risk.

References

http://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-accident.aspx#.UZn0laL2axo

http://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx#.UZn2DKL2axo

http://www.ucsusa.org/nuclear-power#.VuHaHPkrK9K.

http://www.ucsusa.org/nuclear-power/nuclear-waste#.VuHoCPkrK9I

 

 

Thermoelectric devices

Thermoelectric devices are made from thermoelectric modules. A thermoelectric module is an array of thermocouples connected electrically in series but thermally in parallel

 How do they work?

A thermoelectric device converts thermal energy into electrical energy by using an array of Thermocouples. This device is a reliable source of power for satellites, space probes, and even unmanned facilities. Satellites that fly toward planets that are far away from the sun cannot rely exclusively on solar panels to generate electricity. These satellites will have to use an alternative energy source, such as thermoelectric devices, to generate their power, as in NASA’s Pluto New Horizons spacecraft. Thermoelectric devices for deep-space missions use a radioactive material, like plutonium, to generate heat, and thermocouples to convert the heat to electricity. Since a thermoelectric device has no moving parts, it is reliable and can generate electricity for many years. Studies have been done on improving the efficiency of the thermoelectric generator by incorporating other technologies, like nanotechnology. By achieving a better efficiency, thermoelectric devices would need less radioactive material to produce the same amount of power, making the power generation system lighter. The Less radioactive material will also decrease the cost of spaceflight launches. Although these devices are used mostly in spacecraft technologies, they can be also applied to technologies on earth, which might further contribute to the advancement of technology. Some applications of this technology include automobiles, computers, household appliances, etc.

The image below shows a graph explaining how this system works 

The following video is a detailed explanation showing how this process works:

What are the most common applications for it?

Thermoelectric effects can be used to make solid-state refrigeration devices, or to sense temperature differences, or to convert thermal energy directly into electricity. While the Peltier effect is used within thermoelectric cooling devices, the Seebeck effect is responsible for the conversion of temperature gradients to an electrical voltage.

• Peltier effect: Thermoelectric cooling

Thermoelectric cooling uses the Peltier effect to create a heat flux between the junctions of two different types of materials. A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other, with consumption of electrical energy, depending on the direction of the current.

The image below shows a schematic of a Peltier cooler

• Seebeckeffect: Thermoelectric temperature sensing and power generation

This effect is the conversion of a temperature gradient across the junctions of two dissimilar metals to electrical voltage in the range of millivolts per Kelvin difference. The effect is non-linear with temperature and depends on absolute temperature, type and structure of materials.

The picture below is an example Seebeck voltage generator

• The Thomson effect

The Thomson effect,” or “Kelvin heat, describes the heat release in a material with a current through it. This heat release is directly measurable. That is unlike the Peltier and Seebeck effects, for which only the net effect of two different materials can be measured. Since the Peltier and Seebeck coefficients can be computed from the Thomson one, in principle the Thomson effect allows all three thermoelectric coefficients to be found without involving the second material.

Example of thermoelectric devices:

The thermoelectric devices can enhance the energy production of hybrid automobiles by producing electricity using the waste heat of the engine.

This image shows the inside of GMZ Energy’s TEG module. When waste heat enters the top of the module and moves through the semiconductor material (shown here as P and N) to the cooler side, the resulting temperature difference creates a voltage that’s extracted as electricity. Credit: Screenshot from a video by GMZ Energy

References

http://thermoelectrics.caltech.edu/thermoelectrics/engineering.html

http://www.spacegrant.hawaii.edu/reports/22_FA09-SP10/SLee_FA09.pdf

http://www.iue.tuwien.ac.at/phd/mwagner/node18.html

https://www.eng.fsu.edu/~dommelen/quantum/style_a/semicte.html

http://phys.org/news/2014-08-thermoelectric-devices-electricity-vehicles-machines.html

“Geothermal power facilities currently generate 25% of the country’s total electricity production.”

Over the past of a few years, Iceland has definitely made a change. Iceland went from what was known as one of Europe’s poorest countries to a country with high standard of living. Studies have shown that “In 2014, roughly 85% of primary energy use in Iceland came from indigenous renewable resources. Thereof 66% was from geothermal.”

Iceland as a country…

Iceland is relatively a young country geologically. It lies astride one of the earth’s major fault lines, the Mid-Atlantic ridge. This is the boundary between the North American and Eurasian tectonic plates. As a result of its location, Iceland is one of the most tectonically active places on earth, More than 200 volcanoes are located within the active volcanic zone stretching through the country from the southwest to the northeast, and at least 30 of them have erupted since the country was settled. In this volcanic zone, there are at least 20 high-temperature areas containing steam fields with underground temperatures reaching 250°C to 1,000 m depth.

As a way to understand its “concept” in an easier way, the video below explains and shows how Iceland is based on geothermal energy and  describes how this benefits the country in many different ways by showing geothermal potential around the world:

Now that we have some background information about this country let’s talk a little bit about how they use geothermal resources…

The island itself its basically a blister of porous basalt at the crack in Earth’s crust where the North America. There are enormous underground reservoirs of water that are continually renewed by levels of annual precipitation that range as high as 177 inches over Iceland’s glaciers, and shallow patches of magma that heat the deepest reaches of these reservoirs to temperatures in excess of 750 degrees Fahrenheit.

The graphic below represents the use of geothermal energy during the year of 2013.

The following image shows how electricity generation has developed since 1970-2013.

It is clear to see, how the demand for geothermal energy has significantly increased over the years.

Iceland is known around the world as a leader in the use of geothermal district heating. Today, about 9 out of 10 households are heated with only geothermal energy.

Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth’s internal heat. This thermal energy is contained in the rock and fluids beneath Earth’s crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma

There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes the steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, high-pressure hot water into the cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants.

---

Generating Heat:

In  difference from the U.S there is not a national grid in Iceland- harnessing the energy comes via the remarkably simple method of sticking a drill in the ground near one of the country’s 600 hot spring areas, and using the steam that is released to turn the turbines and pump up water that is then piped to nearby settlements.

Geothermal water is used to heat around 90% of Iceland’s homes, and keeps pavements and car parks snow-free in the winter. Hot water from the springs is cooled and pumped from boreholes that vary between 200 and 2,000m straight into the taps of nearby homes, negating the need for hot water heating. It’s also purified and cooled to provide cold drinking water.

Generating electricity:

Once this heated water is forced to the surface, it is a relatively simple matter to capture that steam and use it to drive electric generators. Geothermal power plants drill their own holes into the rock to more effectively capture the steam.

There are three basic designs for geothermal power plants, all of which pull hot water and steam from the ground, use it, and then return it as warm water to prolong the life of the heat source. In the simplest design, known as dry steam, the steam goes directly through the turbine, then into a condenser where the steam is condensed into water. In a second approach, very hot water is depressurized or “flashed” into steam which can then be used to drive the turbine.

In the third approach, called a binary cycle system, the hot water is passed through a heat exchanger, where it heats a second liquid—such as isobutane—in a closed loop. Isobutane boils at a lower temperature than water, so it is more easily converted into steam to run the turbine.

These systems are best representing in the picture below

References:

http://www.nea.is/geothermal/

http://www.scientificamerican.com/article/iceland-geothermal-power/

http://www.theguardian.com/environment/2008/apr/22/renewableenergy.alternativeenergy

http://ourworld.unu.edu/en/geothermal-energy

http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-geothermal-energy-works.html#.Vtkn-JwrKhc