Sasha's Blog

    We already know that solar energy and the use photovoltaic  panel is the future of renewable energy; therefore we shouldn’t be surprised that countries around the world are starting to integrate this methods among their  energy sources. After doing some research on the implementation of solar panels around the world, I have to admit that I was not surprised  that countries such as Japan, China, and  Germany are among the top list of countries using this energy method. [4]

Table 1 :   Top 10 countries  generating photovoltaic power [4]

    According to  the energy informative; “ Germany has by far the highest capacity of solar photovoltaic power (PV) in the world at 32,4 GW (31%) at the end of 2012. Newly connected PV systems worth 7.6 GW were added this year. Germany’s solar panels generated about 23 TWh (terawatt hours) of electricity in 2012, which is impressive, but still only covers 3% of the country’s total electricity consumption.” [4]

    On the other hand, in the geographical center of Japan we have a 315m-wide, 37m-tall facility named The Solar Ark. This structure is an ark-shaped solar photovoltaic power generator that offers activities to cultivate a better appreciation of solar power generation, and thereby of both ecology and science. [1]  This ark is formed by over 5000 panels and produces over 500 000 kWh of energy per year[5]

Image 1 : The Solar Ark in Japan

    Similarly in Dezhou, a city located in the northwest of Shandong province, in China is branding itself as a Solar City, and a national center using green energy. [2] This solar city has among its structures , the  largest solar powered building in the world [4].  It it thank to this structure that China’s nation has been able to save 30% more  energy than the standard.  [4]

Image 2:  Solar City in China

    Even though one of the main factors that prompted several countries to convert to using solar power is the fact that the energy completely renewable, [3] I believe that not all the countries should use photovoltaic cells and solar energy their main source of energy.  Countries should  individually consider the benefits and disadvantages of implementing this renewable energy  source in their territory, specially those   countries that are  farther  away from the Equator should consider other sources of energy besides  solar panels.  Then as well, those countries that are  near the Equator  that experience  direct sunlight  all year long should  consider  the use of solar panels as one of their primary sources for energy.

[1] http://panasonic.net/sanyo/solarark/en/

[2] http://english.sina.com/business/p/2010/0926/341237.html

[3] http://planetsave.com/2012/03/06/top-6-countries-using-solar-energy/

[4] http://energyinformative.org/where-is-solar-power-used-the-most/

[5] http://inhabitat.com/the-worlds-6-coolest-solar-powered-projects/

   When it comes to buying a car, we are all presented with a very large amount of options. I believe it is fair to say that among all the available options one of the most significant features that we are looking for is the car’s fuel efficiency. It is for this same reason that some people have chosen to purchase  what is known as a hybrid car, and only another few lucky ones become the owner or a fully electric  car. I will like to spend some time discussing these modern vehicles  that requires only a fraction of gasoline or even down to no gasoline at all. On one hand we have one of the world’s first  plug-in hybrid vehicle,the Fisker Karma. On the other hand  we  have the Tesla  car which is completely electrical, hence no gasoline is required to run the  motor of the car.

    “The Karma’s charging strategy includes an on-board generator hooked to a 260-horsepower, 2.0-liter, four-cylinder, turbocharged, direct injection Ecotec engine”[1].  Depending on the terrain, speed and driving style the Karma’s software, that manages the battery and engine, will alternate the electric power and the use to gasoline. The Karma’s battery pack will operate the vehicle for a range of about 50 miles; as the battery run  down, the system will kick-in the engine to drive the generator and provide additional power to the electric motors.[1] Similarly, “the heart of the Tesla Roadster is its 3-phase, 4-pole electric inductor motor, which weighs just 70 pounds. Tesla’s claims and independent testing show that the Roadster can reach 60 mph in about four seconds and its speed will.”[2]

    In order for you to have a better idea of what are  the main characteristics of  these vehicles  I decided to  include  the main specs of them:

Tesla Roadster:[2]

• Acceleration: zero to 60 in about 4 seconds

• Dimensions: 155.4 inches long, 73.7 inches wide, 44.4 inches tall with a 92.6-inch wheelbase

• Weight: 2,500 pounds (subject to change due to safety regulations)

• Top Speed: Over 130 mph

• Range: 250 miles EPA highway

• Battery Life: Useful battery life in excess of 100,000 miles

Fisker Karma: in order to improve its performance; the Karma offers the driver two driving modes the Stealth Drive and the Sport Drive below are the specs of each mode[1]

Stealth Drive

• Quiet, economy mode

• Allows drivers to travel up to 50 miles (80.5 kilometers) on a full battery charge

• Zero emissions

• 0 to 60 miles per hour (96.6 kilometers per hour) in 7.5 seconds

Sport Drive

• Driving range is estimated at 300 miles (482.8 kilometers)

• An average of about 100 miles per gallon (42.5 kilometers per liter)

• The gas engine powers the generator that charges the  batteries which then power the electric motors.

• Some emissions, but less than a typical gasoline engine

• 0 to 60 miles per hour (96.6 kilometers per hour) in 5.8 seconds

You may wonder what makes these vehicles so interesting; and personally I believe that their biggest benefit is their electric powered motor. One of the advantages of using an electric motor to power a car is that, maximum torque can be produced almost instantly, unlike gasoline engines that need to ramp-up to several thousands of revolutions per minute before producing their maximum torque [1]. In the case of the Karma, like other hybrids,  it  takes advantage of regenerative braking to help stop the car and take advantage of the kinetic energy potential of the car during a coast or break situation. Regenerative braking uses generators that receive power from the wheels when the car either coasts or brakes and use the wheels inertia to generate a small charge which is then fed to the batteries. [2].

    The Karma also can get recharged through a traditional AC home electrical system of a 240-volt AC system . On the other hand the Tesla  Roadster gets  the only  power source through the Supercharger . “The Supercharger is a proprietary direct current  (DC) fast-charging station that provides almost 120 kW of power, giving the 85 kWh Model S an additional 150 miles (240 km) of range in about 20 minutes, or 200 miles (320 km) of range in about 30 minutes.”

    Because these cars are using little to zero gasoline; their emission an impact to the environment is very little. I believe that if  this kind of vehicles become more affordable; they can become the car of the future and reduce significantly all the pollution from  gas emission of gasoline motors

Sources

[1] http://auto.howstuffworks.com/fuel-efficiency/hybrid-technology/fisker-karma.htm

 [2] http://auto.howstuffworks.com/tesla-roadster1.htm

 [3] http://en.wikipedia.org/wiki/Tesla_Motors

   Have  you ever wondered how  a hand crank  generator works?  I know I have wondered about it few times. Luckily  for you, I had to opportunity to learn how they work and actually test the theory of a lab experiment .

   Lets start with the basics; the principle behind a hand crank generator is  Faraday’s Law.  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. The change could be produced by changing  in the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out  of the magnetic field, rotating the coil relative to the magnet,etc.  For this lab we shaked a tube which has a magnet that will travel back and forth through a coil of wires (see image below); and like we just learned the moving magnet through the coil will produce a change in the magnetic field which will result in  a voltage.

   Our voltage was measured and recorded with the LEGO mindstorm. The use of this program allowed us to  transfer the data that was obtained into an Excel spreadsheet.  We performed this experiment 4 times;  each time  decreasing the tube’s shaking speed. We expected that   the faster we shaked the tube(results in a greater number of shakes), the greater will be the generated voltage and vice versa.

   One  more thing that I believe is worth mentioning; is that the data acquired by the software consisted of 30 data points per run. These numbers  were squared and added all together; this process is also know as the sum of squares method. The reason we did this is because this method  provide a quantity that can used in describing how well a model, often a regression model, represents the data being modeled. The table of results that I am showing below only provides the final quantities after this modeling method was applied to each run

Table 1 : Final results after 4 trials  with power generator

These results can also be  represented graphically

Graph 1 : Graphical representation of  Sum squares of the voltage vs number of shakes

   From the results from above we can happily conclude that our results matched the expected outcome. The faster  the tube was shaken the higher was the voltage obtained.

I hope you enjoyed this post .

When it comes to obtaining fossil fuels such as oil and gas from deep underground levels; there are a few methods that are being used. One of the most controversial extraction process is the Hydraulic Fracturing, also known as Fracking.This process consists of drilling and injecting fluids (water and other minor additives) into the ground at high pressure in order to fracture  shale rocks to release the natural gas inside [1].  Personally, I believe that this method is not as harmful as some people portraits its, as long as companies follow  the correct process and keep all of the equipment necessary under a rigorous inspection and maintenance. But, I will be presenting the Pros and Cons that I gathered from different sources so you can  decide whether or not this method is good or bad for the environment:

Lets begin with the Pros

1. Jacob Wheeler from The Center for Michigan [2]  wrote that “ there are enough fossil fuels ‘locked’ in bedrock shale formations under  North American soil  to make the United States energy independent” and “less dependent economically and politically on unstable countries such as Venezuela and the Middle East”

2. On the same article Wheeler also mentions that  “using natural gas to heat our homes and power our cars releases far fewer  carbon emissions than coal”  [2]

3. Even though  one of the main  arguments against fracking is water pollution; “a significant portion of the water used is recovered and reused for subsequent fracking operations” [3]

Thank to hydraulic fracturing , it is no longer necessary to drill multiple wells in order to obtain natural gasses. Fracking allows  to get access to multiply  reservoirs of gasses through horizontal drilling. By doing this , only one portion of the natural environment will get  affected instead of  a larger portion that will get  affected if multiple wells  get placed. A clear example of this difference can be seen  in the picture below:

 Reducing-Surface-Footprint-With-Horizontal-Drilling.jpg

Now, we can go ahead and discuss the Cons

1) As you already know  the main element that is involved  during each fracking process is water; therefore we are going to cover some concerning points that involve water .

• The first  point  related to where is the water coming from? Wheeler, mentions on his  article that  “as many  as 35 million gallons of freshwater are removed from nearby aquifers per frack in the process”[2] If this continues to happen and the “energy company  Encana’s push for the Michigan Department of Environmental Quality to allow multiple drilling wells from the same site, could exponentially deplete the local water supply”  [2]
• “In the case fracking, the basic mixture of water and sand has a number of minor additives: a biocide (to prevent microbial growth) at about 0.01% and about 0.1% each of a surfactant, a polymeric lubricant and a stabiliser”[3]It is believes that; in some situations that “methane gas and toxic chemicals leach out from the system and contaminate ground water”[1] .“There have been over 1,000 documented cases of water contamination next to areas of gas drilling as well as cases of sensory, respiratory, and neurological damage due to ingested contaminated water.”[1]

2. Another aspect has been brought up against fracking is that this process  causes  earthquakes. However,it has been proven that even though fracking does result in very small earth tremors; they are not strong enough to be considered an earthquake.[3]

As  you can see   the main concern towards this process is water contamination; but if  this process is regularly  monitored and all the equipment is properly used then  water contamination will no longer be an  issue and  we will have more pro’s than con’s regarding this drilling and extraction method.

Sources

[1] http://www.dangersoffracking.com

[2]  http://www.mlive.com/environment/index.ssf/2014/05/fracking_a_divisive_practices.html

[3] http://scientific-alliance.org/scientific-alliance-newsletter/pros-and-cons-fracking

Whenever I mention that I am taking a contemporary science class, I can see people spacing out and picturing horrible things, maybe they are remembering a horrible experience from high school or an experiment that went wrong; either way this is not how this class is. This class is rapidly becoming a really fun experience; I mean what else would you call a class that allows you to play with LEGO robots; yes, LEGOs. Being an electrical engineering student has given me the opportunity to do really cool things, but to be honest, nothing beats playing with Legos. I know what you may be thinking, what was the purpose of having student play with a LEGO robot besides having fun? Well, after building our 2 motor robot; we wanted to (for different time intervals) measure the distance the wheels travel and the speed at which the car travels.

We took these measurements through to different methods; manually, which involved calculating the diameter of the wheel, the distance traveled and doing some hand calculations; and digitally, through a software that gathers the data directly from the robot and displays the final and exact numbers on the computer. Below you will be able to see a table that has all of our results for 3 different scenarios:

As you can see we had 3 different measurements for each of the 3 time and power configurations. If you pay close attention you will notice that for the first configuration ( Time=3 seconds and Power= 75 Watts) the %error values are higher than those that we obtained for the other 2 settings. A %error is a calculation that we use to determine how off were our manual measurements from the real (digital) results. For the first scenario our measured values were off by 11.7%, 12.5% and 12.7%.These are high values for a %error. We revisited our measurements and noticed that the diameter value of the wheel that we used to calculate the circumference of the wheel was 5.5 cm instead of 5.0 cm. These 0.5 where the reason for our high%error values.Once we recalculated the circumference value all of our measurements were really close to the real values ; hence obtaining a %error <2%

From all this fun experience we learned a really good experience; sometimes we need to pay more attention to our measurements or actions; a small difference such as 0.5 cm could cause really big differences in our final results.

Welcome to Blogs.cas.suffolk.edu. This is your first post. Edit or delete it under Manage>Posts or make a new one under Write>Posts then start blogging! Be sure to visit the Design tab to choose a new look for your blog as well.

Also, for immediate “how-to’s” visit the Tutorials section, or the Getting Started section.