Engineers solve problems every day. I have been practicing the Mechanical Engineering profession for over 10 years and every day I solve problems. Every big problem can be broken down in small bits, which become a problem to solve on their own. Like in any profession, one very important step to solve a problem is to find the right tool to get the job done in the most effective and efficient way. In the digital age, most of these tool that I am talking about end up being some type of computer software. I often find myself mentally evaluating different software packages against the details of the problem at hand. For this reason, I have tried here to provide a decision tree style flow chart to illustrate the typical thinking process used by many mechanical engineers to choose the right software for the job.
Ideas Put to Work!
Full Moon Thu Sep-19, 2013
Here are a few shots of the moon on Thursday September 19, 2013 at around 9:35 pm. According to this website, the moon was 99% full at the time. The view was looking east from Wilsonville, OR.
LADEE Launch
The Lunar Atmosphere and Dust Environment Explorer (LADEE) successfully launched last night from NASA Wallops onboard of a Minotaur V rocket.
I am very happy to have had the opportunity to participate in the testing of the nutation characteristics of the spin-stabilized stage of the mission (minute 2:07 from video below) with the world-known rocket scientist Dr. Harrison at Applied Dynamics Laboratories. Last night launch adds one more success to over 35 years of Dr. Harrison’s work in spin-spacecraft attitude dynamics.
Quantum Computing
A quantum computer uses the quantum mechanical principles of superposition and entanglement to perform calculations. Computers today use bits to encode information in values of either 0 or 1. Quantum computers use quantum bits, or qubits. Qubits can take the value of 0, or 1, or the superposition of both of these values. This property alone opens the door to several new applications and has the potential to significantly increase computational speed. To learn more watch this video which was recorded during the 2013 Microsoft Research Faculty Summit.
Thank you to the speakers:
Krysta M. Svore: Microsoft Research
Is Digital Technology Slowing us Down
Doug Burger, a researcher at Microsoft Research gives a Closing Keynote during the 2013 Microsoft Faculty Summit where he discusses the limits of digital technology and the opportunities for embracing approximation in an analog world.
Water lilies, Lotus, and surface wetting
Last weekend I visited Hughes Water Gardens located near Wilsonville, OR
This nursery specializes in water plants and it was very interesting to see the large number of plants they had. However, I had the most fun looking at the leaves from the water lilies and the lotus plant. Their surface exhibit superhydrophobic characteristics. This means that when water comes into contact with the leaf surface, it beads up and rolls off the leaf.
When water rolls off, it cleans the surface of the leaf. This is why these leaves always seem to remain clean in murky ponds. This behavior is known as the Lotus Effect.
The Lotus Effect is attributed to both micro-scale surface bumps and nano-scale hair like structures present on the leaf surface. These surface structures trap air underneath the water droplets and create the superhydrophobic characteristics.
Source: [1]
Reference:
The Complexity of Fluids
Favorite Quantum Mechanics Interpretation
In July 2011 the “Quantum Physics and the Nature of Reality” conference was held at the International Academy Traunkirchen in Austria. A poll was carried out among 33 conference participants which included physicists, philosophers, and mathematicians. The results of the poll are quite interesting and I urge you to take a look at them here. However, to me, here is one of the most surprising results.
MITx Electricity and Magnetism
Here is an additional course recently added to the list of free courses offered by edX: Electricity and Magnetism MITx 8.02x which is the 2nd semester of the MIT introduction to physics sequence.
The course starts Feb. 18th 2013 and it covers topics like electric fields, magnetic fields, electromagnetic forces, conductors and dielectrics, electromagnetic waves, and the nature of light, as well as topics like why is the sky blue, lightning, magnetic levitation, Aurora Borealis, and particle accelerators. I am not sure if I will have the time to take this course. However, if you are interested I would strongly recommend that you take the class. The class will be taught by the legendary Professor Walter Lewin who has taught at MIT for 47 years. I have watched many of his lectures online and I highly recommend him. His enthusiasm and demonstrations make physics very enjoyable and interesting.
According to Professor Lewin, “If you take this course, your life will never be the same”. Watch this clip for more information.
Accelerometer App for Android
Here is a great free app for android users. Accelerometer Monitor is an android app that uses the accelerometer sensor in your smart phone to generate a plot of acceleration vs. time. Since smart phones have a 3-axis accelerometer, the app provides you with 3 components of acceleration (x, y, and z direction). I have been using this app for measuring vibrations for a few days and it works great. In my phone, the app collects data at a rate of approximately 15 Hz (although the sampling rate is not constant and it varies slightly from point to point).
A very useful feature is that this app allows you to save the data directly to the SD card memory in the phone inside a folder named “accData”. In addition to the 3 components of acceleration and a differential time stamp at each data point, the saved data contains information about the starting and ending date and time, the resolution of your accelerometer sensor, the type of accelerometer sensor, and the range of the sensor. For example, in my phone, the resolution of my sensor is 0.01197 m/s^2 and acceleration range is +/-19.6 m/s^2.
You can use your favorite data processing software to extract and visualize your data after extracting the file from your phone. For example, here is a Microsoft Office Excel plot of a set of data that I took after shaking my phone by hand in x (left to right), then y (forward and backward), and finally z (up and down) directions.
This app seems to be in Google Play under two different names since there is another identical app named Vibration Monitoring. Both of these apps are made by Mobile Tools.
As mentioned in the overview section of these apps, uses for the app includes:
“-shows vibrations in real time
- saves vibration data into SD card (*zip file also supported)
- provides configurable sound alarm that may be used to:
- detect the earthquakes when you sleep
- detect if somebody opens the door when you sleep“
Very useful app. If you have need for such a measurement, I recommend you check this app out.
ForceEffect for Android
A while back I wrote a post about an app called ForceEffect by Autodesk. This very useful app is now available for android on Google Play. Give it a try and see what you think. If you find it useful, also check out ForceEffect Motion.
Keep up the good work Autodesk!
Curiosity’s Power Source
Curiosity’s power is in fact nuclear and it comes from an onboard Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). The MMRTG provides electrical power by directly converting the heat generated by the decay of plutonium-238 dioxide into electrical energy using thermocouples at an operational efficiency of 6 to 7 percent. The MMRTG carries 10.6 pounds (4.8 Kg) of plutonium-238 dioxide and produces 110 Watts of electrical power (twice as much as the maximum power provided by the charger on a 13-in MacBook Pro). The MMRTG also provides heat to maintain a proper operating temperature of all the instruments and systems in the rover. Here is a schematic of a MMRTG
So, where is the MMRTG in the Rover? Take a look and see if you can find it
The MMRTG in Curiosity is capable of producing power for over 14 years, it weights 99 pounds(45 Kg), and it measures about 63.5 cm in diameter and 66 cm long. A great advantage of thermoelectric generators is that there are no moving parts associated with them. However, typical energy conversion efficiencies are quite low.
(Photo credits: NASA)
Curiosity’s Landing on Mars
After a journey of over eight months, Curiosity is scheduled to land on Mars this Sunday, August 5th at 10:31 pm PDT. Check out this video that explains how exciting, challenging, and complex this landing will be. All I can tell you is that the 7 minutes that it takes to get from the top of the atmosphere to the surface of Mars are being described as the 7 minutes of Terror. When will we know if we made it to the surface safely or not? It will take 14 minutes for a communication signal to travel from Mars back to Earth!
It might look like science fiction but it truly is just real science and engineering
LADEE
It may come as a surprise to most people but it has been nearly 40 years after the Apollo missions and we do not yet fully understand the composition, structure, and variability of the Lunar Atmosphere. This and many other questions regarding the moon’s atmosphere remain unanswered. A further understanding of the lunar atmosphere is required prior to future lunar science missions. Even the suggested existence of water on the lunar atmosphere needs to be studied further.
The Lunar Atmosphere and Dust Environment Explorer, LADEE, is a NASA mission that seeks to orbit the Moon with the main objective of characterizing the lunar atmosphere and dust environment. The instrument payload of the mission includes a Neutral Mass Spectrometer (NMS), an Ultraviolet/Visible Spectrometer (UVS), and the Lunar Dust Experiment (LDEX). In addition, the payload will also include the space terminal of Lunar Laser Communication Demonstration (LLCD) to demonstrate the technology.
LADEE is scheduled to launch on May 2013 out of the Wallops Flight Facility in Virginia and will be the first mission based on the Ames Modular Common Bus Design which for this mission consists of a Minotaur V vehicle with a spin-stabilized upper stage.
References:
MITx 6.002x
I recently completed a course in Circuits and Electronics (MITx 6.002x). This was an online learning initiative of Massachusetts Institute of Technology (MIT), through edX, an online learning initiative of Harvard University and MIT. The course itself was 15 weeks long (including an extra week that was not graded) and consisted of interactive video sequences, textbook readings, homeworks, online laboratories, and optional tutorials.
The course covered a broad range of topics including but not limited to Lumped Abstraction, KVL, KCL, Resistive Networks, Nodal Analysis, Linearity, Superposition, Thevenin and Northon Methods, Digital Abstraction, Boolean Logic, MOS switch and gate, Non-linear Networks, Large and Small Signal Analysis, Dependent Sources, Analog Amplifiers, MOSFET, MOS amplifiers, First and Second Order Systems, RCL Circuits, Digital Memory, Frequency Response, Impedance Methods, Filters, Op-amp and Op-amp Filters, Feedback Stability, and CMOS logic, among others.
The grade consisted of 15% homework, 15% labs, 30% midterm, and 40% comprehensive final exam. Overall the course was very demanding on time but also an excellent learning experience. Here is my grading chart for this course:
Course statistics from the course website: 6.002x had 154,763 registrants. Of these, 69,221 people looked at the first problem set, and 26,349 earned at least one point on it. 13,569 people looked at the midterm while it was still open, 10,547 people got at least one point on the midterm, and 9,318 people got a passing score on the midterm. 10,262 people looked at the final exam while it was still open, 8,240 people got at least one point on the final exam, and 5,800 people got a passing score on the final exam. Finally, after completing 14 weeks of study, 7,157 people have earned the first certificate awarded by MITx, proving that they successfully completed 6.002x.
At the end of the course, students that successfully completed the course received a certificate similar to this one:
Personally, I really enjoyed the course and I was able to strengthen my fundamental EE skills. I believe the course will be offered again soon and I strongly recommend it to anyone interested. However, be prepare to put in the necessary amount of time if you want to be successful.
EveryCircuit on Google Play
edX: An MIT and Harvard Partnership
Free online classes from MIT and Harvard. Doesn’t get much better than that! I encourage all of you to take advantage of this new resource. As a current MITx student enrolled in 6.002x, I can tell you first hand that these online education opportunities will eliminate geographical and socio-economical boundaries for education and will revolutionize they way we all learn.
“The Proof of Innocence”
Ok, lets be honest. What are our chances of successfully arguing against a police officer and a judge in court to get out of a traffic ticket. If the police officer claims you’re guilty, who is the judge going to believe? So, are you really left with just the hope that the judge believes you more than he believes the officer? Maybe. Unless you can mathematically prove using fundamental laws of nature that you are in fact innocent. Take for example Dimitri Krioukov, Sr. Research Scientist at University of California, San Diego who wrote a paper to show in court his innocence from being accused to fail to halt at a stop sign.
I recommend you read this paper and keep it in your records. Who knows, you might need to cite it next time you are called to court for a traffic incident. And yes, he was found innocent.
Monochrometer
A monochrometer is frequently used to measure the spectral response of a light source. The purpose of a monochrometer is to convert a broad light spectral input into a narrow spectral output. Light enters the monochrometer through a slit that directs the input light to the first mirror inside the monochrometer. The firs lens (mirror) collimates the entering light and reflects it into a grating. The groves or line on the grating have a specific spacing that produces constructing and destructing interference of the reflected light from the grating. This process called dispersion separates the different colors of light (wavelengths) in space, reflecting each color at slightly different angles. The second lens (mirror) reflects the disperse light and focus a given light color into the outlet slit, allowing only a narrow band of light to escape the monochrometer. The following diagram illustrates this principle.
It is important to note that the resolution of the monochrometer is dependent on the grating and the outlet slit. The grating geometry and configuration limits the accuracy at which the individual wavelength can be separated in space. The outlet slit limits the how narrow of a band is allowed to escape the monochrometer.
Conjugate Heat Transfer With COMSOL Multiphysics
Take advantage of this FREE webinar which explores heat transfer analysis in combined fluid and solid systems (conjugate heat transfer) using COMSOL multiphysics.
The webinar is offered on March 28, 2012. Sign up today!