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All posts for the month February, 2015

Pros and Cons of Alternative Energy

Posted by Andrew (Team UV) on February 26, 2015
Posted in: Presentations. Tagged: , , , , , , , , , , .

Photo Credit: thirdyearabroad.com

The world we live in today is driven by how much energy we have.  For example when oil prices are high, we drive less and complain about all the things wrong with oil supply.  When oil prices are low, we drive more and tend to forget about the core problem.  The problem is not that there isn’t enough oil in the world or where it comes from, it’s how we go about energy production.  There is no doubt that energy produced from coal and oil is “dirty” but it does have it’s perks.  Traditional means of energy production (petroleum and coal) have been in use for a while now so the infrastructure is already there and its technology is well known.  Petroleum and coal resources are abundantly found and the power produced from these plants is highly reliable.  The same can’t be said for most forms of renewable energy.  Renewable energy resources like solar and wind power, although very clean for the environment, have a few major hurdles to overcome if they are ever to be mainstream.  A VERY long post can be made about how energy production, both on a national scale and a global scale, can be changed to better the environment and strengthen global ties but that’s not my plan.  I simply want to share the pros and cons of each renewable resource and share why they aren’t currently taking the place of traditional energy production methods.

Renewable energy is diffuse, meaning low energy content per unit area and time.  This is mainly due to the resources being in variable supply.  You may be thinking: How is renewable energy variable?  Well, take sunlight for example.  The sun rises and sets in a full day.  Energy from the sun can only be used when it’s out and most efficiently, when the suns rays are collected perpendicular to the surface of the solar panel.  When the sun light fades out for the day, that’s it!  Makes sense since solar collectors only work when there’s sun light to collect.  At night, the solar plant no longer has its resource available unlike the coal or oil plant across town which can continue to generate power long after the sun sets.  Now, a solar plant can store thermal energy from the sun’s rays but it can be unpractical or too costly to do so.  Let’s take a closer look at individual renewable resources and the pros and cons associated with each one.

Solar Energy

Simple Solar Grid. Photo Credit: solarpowernotes.com

Pros:
– Large resource (any incident light that passes through the Earths atmosphere can be used for energy production!)
– Minimal pollution (sunlight can be used directly for electricity or as a thermal resource)
-Free! (Power plants don’t have to “BUY” sunlight)

Cons:
– Diffuse
– Cyclical (Can cause fluctuating thermal stresses in components)
– Not dependable (Sun goes down = no more resource)
– Design for high temperatures (Sun collectors need to handle the high temps of the solar irradiance)
– Storage (Electricity can be stored in batteries or heat can be stored in salt thermal pools)
– Concentrated Thermal Pollution (Higher temperature levels concentrated in a single area)
– Land use (collectors and receiver efficiencies range from 40-70% so many are needed to make the plant worth it)

Hydroelectric Power

Typical Hydro Plant Layout. Photo Credit: amailahydropower.com

Pros:
– Long Lasting (As long as there’s rain and moving water the plant can generate power)
– Low temperatures (No thermal cycles needed as it uses the energy of falling water to spin a turbine/generator)
– High efficiency (Converts work (falling water) to work (rotating turbine) which is the most efficient conversion possible)
– Cheap! (All it takes is a dam, a powerhouse (with a turbine and generator), and pipes!)
– Reliable (Water can be stored behind a dam for long running times even through droughts)

Cons:
– Habitat loss (Animals can be forced out of their homes to build a site)
– Nutrient loss (Nutrients needed downstream for plants and animals can be blocked upstream by the dam)

Wind Power

Wind Power Plant Layout. Photo Credit: yokogawa.com

Pros:
– Free! (No resource cost)
– Low operating cost (No thermal cycles; similar work to work conversion found in Hydropower)
– Huge resource (Wind is generated by a number of mechanisms making it abundant everywhere)

Cons:
– High capital cost (Huge Turbines = Huge Cost; machinery is large and over designed pushing cost high)
– Visual pollution (Usually located by mountains and deserts, wind power plants can take away from nature’s beauty)
– Noise pollution (Each passing blade produces a buffeting noise that make living near one hard)
– Bird Kills (Birds often times don’t see the blades of wind turbines)
– Land usage (Like solar energy, a lot of land is needed to make the plant worth it)

Biomass

Biomass Resources. Photo Credit: energy.ca.gov

Pros:
– Large Supply (literally anything can be used: plants, animals, wood, sugar cane, kelp, menure, sewage, waste, etc)
– Efficient use of byproducts (Nutrient rich byproducts are left over from this process which can be re-fed to starting point)
– Low pollution (low levels of carbon dioxide gas)
– Cheap supply cost (example: the old grease from the fast food place down the street can be used)

Cons:
– Soil depletion and erosion (Compostables once used for fertilizing are now used for energy production)
– Competes with food/feed growing (Land and resources are split between food and products used in energy production)
– Bulky (Transportation of waste and resources must be considered)

There is certainly enough renewable resources out there with many of them being able to provide for the worlds energy needs on their own.  The problem, as I hope I showed here, is that many design issues must be tackled before moving away from traditional fuels.  There is no overnight solution and there won’t be one for little while.  Some of the cleaner processes pollute less than oil but physically harm the earth they sit on.  Others are just too theoretically perfect to be implemented in real life.  If you want my full view on how we can tackle this energy production problem let me know…I wrote a paper!

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Until next time…

Combating Icing

Posted by Brian (Team UV) on February 24, 2015
Posted in: Well Read. Tagged: , , , , , , , , , , . Leave a comment

F/A-18F Super Hornet at high angle of attack over a snowy mountain range. Photo Credit: navy-pictures.blogspot.com

 Let’s start off with a scenario: You’re flying a sortie for the Navy in a reconnaissance-configured F/A-18F Super Hornet to fly in high over some mountain range in Afghanistan, take some pictures, and come home.  You’re flying at 40,000 ft in order to both stay clear of the immensely tall mountain ranges and to remain undetectable and stay out of reach of small arms fire.  Unfortunately, at 40,000 ft in this region, icing conditions are very common.  Due to the low temperatures in this region (and especially at this elevation) combined with the all-too-often rainy or snowy conditions, you end up having to fly through falling snow or rain (which would be either already ice due to the low temperatures, or supercooled, meaning that the water drops are far below the freezing point, but have not frozen yet due to the absence of a nucleation site – which is essentially a solid surface on which the water can freeze…i.e. dust, other particulate matter, or the wing of an aircraft). 

As you begin to fly into the poor weather, the water droplets begin to freeze on impact with the wing, building up a layer of ice on the wing of your aircraft.  This ice quickly changes the surface roughness of your aircraft wings, changing the aerodynamics and lowering the speed or angle of attack that you can travel at without stalling (flow separation that leads to loss of lift).  Furthermore, say due to the angle of incidence between your flight path and the direction the water droplets are coming from, the ice is forming more heavily on one side/wing of your aircraft than the other (and probably unevenly on each side).  You start to feel the aircraft wobbling around in flight and find it much more difficult to control your roll, pitch, and yaw.  You are now having issues flying the aircraft at the required speed, are having to fly at a lower angle of attack, and are having trouble controlling the aircraft.  You have a decision to make: continue to put yourself, your Radar Intercept Officer (RIO), and your $60,000,000 aircraft in danger or abort the mission.  Unfortunately, this situation is not too uncommon when icing presents a real problem to pilots.

F-35 undergoing icing tests. Photo Credit: AF.mil (Left), globalaviationreport.com (Middle, Right)

F-35 undergoing icing tests.
Photo Credit: AF.mil (Left), globalaviationreport.com (Middle, Right)

With the development of unmanned drones for reconnaissance missions, we are able to push the envelope a little more, but still are wary of putting a very expensive aircraft into poor weather conditions (for both financial losses and the possibility of having a high-tech aircraft downed in enemy territory).  This problem also exists for civilian air travel, and in many cases, general aviation pilots are not certified for flight into known icing conditions due to the clear and present danger.  So what do we do to reduce the threat posed by icing conditions?

Aircraft wing icing and an expandable rubber boot used to break up the ice. Photo Credit: cloudman23.files.wordpress.com

There are a few traditional ways of dealing with aircraft icing.  One is shown above, in which a rubber “boot” is expanded in order to break up the ice on the leading edge of the aircraft; obviously, this is not an optimal solution, as it temporarily changes the profile of the wing, and also does not get rid of all of the ice.  Other methods include bleeding hot engine exhaust air over the wing and using “weeping” wings that release antifreeze over the surface of the wing, to name a few.  These methods are all quite complex, require a lot of power, can alter the airflow significantly, and may even present environmental dangers (as in the case of the weeping wing). 

 In order to fill this void of optimal solutions, a company called Batelle has employed its researchers to develop a solution that consists of a carbon nano-tube coating that can be included beneath the topcoat of the aircraft wing and then act as a resistance heater of sorts to warm the wing from inside the wing to prevent or get rid of ice on the wings.  This solution employs advanced materials science concepts in order to introduce a more elegant, non-invasive means of dealing with aircraft icing.  Furthermore, the coating is controlled through an “intelligent controller [that] monitors the heater performance and applies only the power levels required for the flight conditions”, making it less power-hungry and more adaptable to any given situation!  These benefits are realized even further on military Unmanned Aerial Vehicles (UAVs) (their principal application), where large sensor (or other) payload power requirements and desired lightweight dictate that a smaller than ordinary amount of power can be dedicated to de-icing.  This solution has the capability to revolutionize the way we go about preventing or dealing with aircraft icing; now only if they could further development this solution for use in the de-icing of pitot tubes (devices used to measure airspeed – to figure out how fast you are flying; pitot tubes are notorious for encountering problems in icing conditions, where a false airspeed reading can lead to disaster).

Read more at: Engineering.com

1…2…3…Think! Pop-up Design Challenge

Posted by Andrew (Team UV) on February 22, 2015
Posted in: Open Mind. Tagged: , , , , , , , , , , .

Hubble Telescope. Photo Credit: NASA.org

I approached this Open Mind a little differently from my latest round of posts.  Instead of developing ideas and solutions over the course of a month, I gave myself a “pop” design challenge.  The topic: If you were the lead designer for a new NASA Telescope, what considerations would be most important to you?  My goal: Instead of developing the best or most important considerations for this challenge, I would develop the first three considerations that popped into my head.

My first thought dealt with finances.  As the project manager, I would need to know how much funding the team has and what it will be used for.  To me, the days of dumping money into a project especially for exploration are far and few between.  It’s unfortunate but there are companies out there that are reviving the passion for space and underwater exploration; our team included.  In order to justify spending money on a new exploration project, the team will absolutely have to design intelligently.  By using sustainable materials and avoiding “reinventing the wheel”, the design team can focus on improving technology already available thus potentially saving money.

The second thought to pop up was about the project’s overall life cycle.  As a manager, I would need to establish an efficient way to not only start and end the project, but see if the telescope has life after decommission.  Can anything off the telescope be used or recycled after it’s no longer needed?  There’s more to “design” now than ever since there’s a push to go green in all industries.  Anything from control systems to frame material can be inspected and potentially approved for reuse.  These parts don’t have to be used for serious missions but can be utilized in testing scenarios or for higher education.

The final thought before I called time revolved around power generation.  Fuel supply and consumption are always design concerns for any project but none more than in space/underwater applications.  There are particles of various sizes translating across space.  If a designer can harness the power of small impacts on the telescope by the particles or generate rotational motion from the moving particles, power can be generated.  This power can be used to charge batteries in times of need.

Well there you have it, an expedited Open Mind that took place in less than one minute.  Take a look at other Team UV Open Minds from previous months and don’t forget to support our GoFundMe site!

Until next time!

Stress Concentrations

Posted by Brian (Team UV) on February 19, 2015
Posted in: Presentations. Tagged: , , , , , , , , , , . 1 Comment

Stress concentration around a hole visualized using photoelastic methods, with strain gages attached to the surface to measure strain, which can be back-converted to find the state of stress. Photo Credit: alliance.seas.upenn.edu

Stress concentrations (commonly referred to as stress risers or raisers) are areas in a material that, owing to problematic geometry, lead to…well, greater stress concentration in portions of the material/part.  These concentrations can be great headaches to engineers, as the localized concentration of the stress means the part experiences much higher stresses in said specific regions than the average stress in the material as a whole (or than the material would experience without the riser), which can lead to failure at much smaller loadings than originally thought.  Well what in the world does that mean?

To better explain this, we will examine a very simple case: pure tension in a rectangular sample.  Imagine that you take a rectangular bar and pull on it along it’s axis, as shown below.  We will make some simplifying assumptions for the purpose of ease of demonstration; assume that when you pull on the sample, you pull on the entire end face equally; that is, you distribute the loading across the entire face equally.  Also assume that the material is homogenous (the same physical & mechanical properties at all points throughout the material), isotropic (the same properties in all directions), and uniform in cross-section.  These assumptions will hold for demonstration and are sometimes used in applications in which strength is not of major concern, but generally speaking, it will be very difficult to apply a load evenly across a surface (picture gripping a piece of metal with a pair of pliers…the grip point is the point of load application and does not cover the entire face, but rather is localized), materials will never be homogenous (due to voids, inclusions, and other manufacturing defects), many materials will not be isotropic (a piece of un-altered steel is isotropic, but wood, for example, has directional strength in the directions of its “grains”; many other materials also express different properties in different directions), and many geometries will betray the assumption of uniform cross section (as we will see shortly).

Simple case of pure tension. Photo Credit: Wikipedia.org

Simple case of pure tension.
Photo Credit: Wikipedia.org

When we pull on the material, that force is transmitted through the material with an equal and opposite reaction internal to the material, as shown in the center image of the above picture.  This force may be shown as a single resultant force vector (like in the center image), but is actually distributed over the entire inside of the material (as shown in the right/3rd image).  When this load/force acts over this area (and remember, we are only looking at pure tension…the load is applied perfectly perpendicular to the material cross section, as otherwise we would induce bending), it creates a normal stress that is defined as the applied load divided by the cross-sectional area.  Under the assumptions we made before, this should mean that every point in the material experiences the same normal stress, meaning that in order for the material to fail, the average normal stress in the material needs to exceed the failure strength (in this case, the applicable tensile strength).

But what happens when we apply a stress concentration, by introducing a discontinuity in the geometry (i.e. a crack, sharp edge/corner, or change in cross-sectional area)?  The stress distribution can no longer be uniform, as the loading has to be re-routed to avoid the discontinuity as it travels through the material (for the case of geometric stress concentration), as shown for the simple case of a circular hole in the material below.

Effect of geometric discontinuity on stress distribution. Photo Credit: Wikipedia.org

Effect of geometric discontinuity on stress distribution.
Photo Credit: Wikipedia.org

As can be seen, the distribution tends to bunch up around the hole, creating a higher concentration of stress.  From a mathematical standpoint, the local normal stress in the region of the hole has also decreased as the cross-sectional area of the sample at the hole location is now less (imagine cutting the bar in half perpendicular to the loading and looking at it from the end…instead of being the full rectangular cross-section of before, there is material missing), thus the normal stress is higher because we are applying the same load, but now are dividing it by a smaller area than before.  This means that if we apply a loading to the uniform sample that created a stress under the tensile strength of the material before, that materials would not fail, but now if we apply the same exact loading to this new sample with the stress riser, the sample could very well fail due to the heightened stress at the discontinuity.  This should be seen as quite alarming as this means that parts can fail at lower loadings than expected, and while our example shows a huge hole in the part, it should be noted that small cracks, or simpler sharp corners and other minimal, yet abrupt changes in the geometry can affect the state of stress in a major way. 

Effect of geometric discontinuities on stress distribution. Photo Credit: teachengineering.org

We should also note that highly concentrated stress regions can be formed by applying loads non-uniformly, as in the example of gripping material with pliers discussed in the 2nd paragraph, where we apply a load on a very localized, concentrated region (picture taking a 10 lb weight and placing it directly on a table vs. taking the same weight, balancing it on a thumbtack, and then placing it on the table with the tack point down).  Just as before, we have decreased the effective are that the load is applied over, except this time, we reduced the area of the stress region by changing how the load was applied, whereas before we did it by changing how the load was transmitted.

Exaggerated demonstration of effect of concentrated loading on stress distribution. Photo Credit: mace.manchester.ac.uk

For this reason, engineers must be very careful when they design parts to include factors of safety to account for material imperfections, possibly use non-destructive inspection (NDI) techniques to examine critical parts for cracks in situations where a crack could prove catastrophic (for example a crack in the side wall of a submarine hull that could spread due to cyclic fatigue due to cycles of compression/de-compression when traversing great depths, surfacing, sinking again, surfacing again, etc.), and must avoid abrupt changes in geometry in the design of the part itself.  Luckily, in this day and age, we understand much more about internal stresses and stress distribution thanks to new testings and stress visualization techniques, but the subject of stress concentrations is one that I cannot stress the importance of enough! (I apologize for the bad pun)

Effect of rounding sharp corners using “fillets” on stress concentration. Photo Credit: corrosionpedia.com

Additionally, this was purely looking at one-dimensional loading in an over-simplified material and geometry, but in the real world we can have parts of really intricate geometry, made from materials with unbelievable amounts of anisotropy (different properties in different directions), subjected to combined three-dimensional loading of tension, bending, torsion, shear, perhaps compression in a different region, with hygrothermal loading (loading due to both moisture and thermal effects), subjected to different kinds of corrosion, vibrational modes, impact loading, and the list just goes on and on!  Anyways, hopefully today you learned a little bit more about one of the endless topics that engineering encompasses!  I will leave you with some really cool photoelastic stress visualization pictures in which the refraction of light is a function of stress (due to birefringence), thus the material essentially shows different wavelengths (and thus different colors) due to differences in stress throughout the material, helping to visualize stress (and stress concentrations).

Stress concentration at a sharp corner in a plastic protractor (Photoelastic visualization). Photo Credit: Wikipedia.org

Photoelastic visualization of stress distribution in plastic eating utensils. Photo Credit: flickr.com/photos/chrisar/ (Christian Rein)

Photoelastic visualization of contact stresses on a marble in a C-clamp. Photo Credit: osa-opn.org

Photoelastic visualization of rolling contact stresses due to a cylinder rolling on a flat surface; the cylinder is rolling to the left. Photo Credit: Wikipedia.org

When Old Things are Made New Again

Posted by Ben (Team UV) on February 17, 2015
Posted in: Well Read. Tagged: , , , , , , , , , , . Leave a comment
Stainless Steel I Beam

Stainless Steel I-Beams. Photo Credit: stainlessshapes.net

Steel is the foundation of the modern structure, be it buildings, airplanes, or ships.  Plain carbon steel is a simple mixture of carbon and iron in just the right proportion to provide excellent strength.  As humans have taken to the sky lighter materials have been required.  This has led to dominance of aluminum, titanium, and composite materials for weight savings.  These materials are stronger per unit weight than steel but more expensive and less plentiful.  Scientists have just recently discovered a new steel alloy that provides the strength to weight ratio of titanium using much more available materials.  This could lead to a revolution in the structural steel world, but for now they need to find a way to manufacture it outside of a lab setting.  Read more here: http://www.gizmag.com/steel-alloy-strong-light-titanium/35996/

Hydrodynamic Instabilities

Posted by Brian (Team UV) on February 15, 2015
Posted in: Open Mind. Tagged: , , , , , , , , , , . Leave a comment

Plateau-Rayleigh Instability in a water sheet from a fountain. Photo Credit: f***yeahfluiddynamics.tumblr.com

Here at TeamUV.org, we have often discussed some of the finer intricacies of fluid mechanics (or usually more specifically, fluid dynamics, as opposed to fluid statics).  Generally speaking, however, we have looked at fluid flow and behavior from a very macroscopic view, that is we have looked at fluids as they act on the macroscopic length scale, within which objects are practically visible by the naked eye.  In the various fields of engineering, most engineers would only need a macroscopic understanding of fluid mechanics in order to perform rather rudimentary calculations and analysis.  For example, if an engineer was asked to determine the hydrostatic pressure exerted on a submerged pressure vessel lying on the bottom of the ocean or if they were asked to size (determine pump impeller diameter, pump speed, power input necessary, pump type, capacity/flow rate, etc. for) a pump based off of the known pressure gradient (perhaps it has to force water through a very fine filter while maintaining a certain amount of pressure), elevation change, or required change in speed, a macroscopic view of fluid mechanics would often be sufficient.  But is this always the case?

Of course not!  The golden rule of engineering regarding what you need to know to perform your job is that there is no golden rule of engineering regarding what you need to know to perform your job.  Engineering is a highly dynamic field, with ground-breaking discoveries made continuously…right now, somewhere in the world a scientist or engineer is making a major contribution to the future of STEM.  Additionally, engineers (especially mechanical engineers, who have a very large, diverse knowledge base) can be asked to do anything at any given time, and they must be able to figure it out!  So to say that the macro scale is the only one an engineer needs to be aware of (especially in the field of fluid mechanics) would be a gross understatement.  So where does that leave us?  Well now would be a good time to explain what is meant by “length scale” and to share some of the typical ones.  After that, we will very briefly roll through some of the fluid effects that exist on smaller length scales, as these highly complex phenomena are beyond the scope of this post.

Orders of magnitude as they apply to the Eiffel Tower viewed from different length scales, demonstrating how different length scales reveal different details. Photo Credit: iupui.edu

A length scale is essentially a parameter for deciphering the characteristic length associated with a phenomena.  For example, if we are talking about the atomic scale, we are generally talking about phenomena that occurs in the size range of atoms, on the order of magnitude of pico- to femto-meters (10^-12 or ^-15 m).  If we are talking about the microscale, we are talking about things on the order of micrometers (10^-6 m) such as water droplets or the thickness of a human hair.  The macroscale would be associated with cars, mountains, you and I, etc. and would be essentially anything in your field of vision, i.e. probably from millimeters on up to kilometers (although the macroscale is not precisely defined).  From here, we would likely move on to the astronomic scale, which is generally used to refer to phenomena on the scale of the universe, or Megameters (10^6 or 1,000,000 m) on up.  For example, if you were to move from an atomic to micro to macro to larger with regards to your hand, you could envision protons and neutrons in your skin cells and then zoom out to bacteria under a microscope and then zoom out further to your hand itself and then zoom out further to the Earth itself, further to the Milky Way Galaxy, and so on and so on.  In fact, if you have a second, you should check out this zoomable tool for visualizing the scales of the universe.

So back to fluid dynamics after a very lengthy detour, why should we care about length scales smaller than the macroscale?  Because turbulence (as well as all fluid motion and  other physical phenomena in general), is a result of phenomena on smaller length scales.  So in order to actually understand the onset of turbulence or how fluids react with each other or with structures, etc. within the framework of deeper understanding, we must understand the microscopic behavior of fluids.  Much of this behavior is defined by fluid stability and instabilities, which are not only very interesting to look at, but are the building blocks for the entire field of fluid dynamics as we know it!  At this point, I will quickly show some pictures of some of the more common instabilities, but will not go into descriptive detail as scientifically, mathematically, etc. they are extremely complex phenomena that many fluid dynamicists spend their entire careers studying.


Kelvin-Helmholtz Instability simulation. [Media Credit: Wikipedia.org]

Kelvin-Helmholtz Instability made visible by clouds. Photo Credit: UP.edu

Rayleigh-Taylor Instability simulation. Photo Credit: Wikipedia.org

Rayleigh-Taylor Instability seen in dye drops in water. Photo Credit: Colorado.edu

Gortler Vortices on an oscillating cylinder within a flow marked by fluorescent dye. Photo Credit: APS.org

DIY Olive Oil

Posted by Ben (Team UV) on February 12, 2015
Posted in: Presentations. Tagged: , , , , , , , , , , .
Olive Tree

Olive trees. Photo Credit: bymovement.com

Note: Due to miscommunication, this post was submitted late and thus scheduled late; rest assured, regular scheduling will resume on Sunday.

Back at my parent’s house in North County San Diego we have a lot of olive trees and every year they drop their fruit on the ground and make quite a mess.  There is no sense in letting all of these olives go to waste so I looked into ways to turn them into a usable oil.  It was surprisingly simple, just follow a few steps.

First the harvest.  The olives are pretty small and there are a lot of them all over the tree making it way too labor intensive to pick by hand.  The simplest way to do it is to lay a tarp on the ground, get a ladder and comb the branches with a garden fork or rake.  Let the olives and leaves fall on the tarp then collect them all and pick the olives out.

Now that you’ve got a good amount of olives you’ve got to get the oil out of them.  This is where industrial manufacturers use massive hammer mills and centrifuges.  That’s a bit of an overkill for home production.  First you need to crush the olives, to do this you can just get a strong bag, fill it with olives and go at it with a hammer.  I tried a meat grinder and it worked OK but the pits jammed up the machine, a bag and hammer wont have that problem!

Once you have a pretty good pulp of olives you’ve got to mix them so that the oil can form large enough droplets to be pressed out.  Don’t mix for much longer than 15 min because you’re adding oxygen to the oil and that will give it an undesirable flavor and color, but if you mix much less than that the oil won’t form large enough droplets.

Now for the pressing.  It takes quite a lot of pressure to get the most out of this olive paste so I got a 20 ton bottle jack for a car, built a frame with a two plates and used the jack to press the olives.  First spread the paste on burlap or cheese cloth, really any porous fabric that will allow the solids to stay in place and the liquids to flow.  Then fold up the cloth, put it in the press and press.  Collect all the liquid that comes out and pour it into bottles.

The liquid in the bottles will be about 90% water and 10% olive oil.  Leave these bottles in a cool dark place for several weeks to give the oil plenty of time to settle out then pour off the oil on top and store for later, or enjoy now.  It will taste very different from store bought oil, in a great way!

Well Read: Chemists Discover How to Unboil Eggs in Minutes!

Posted by Abraham (Team UV) on February 10, 2015
Posted in: Well Read. Tagged: , , , , , , , , , , . Leave a comment

Cracked egg. Photo Credit: WashingtonPost.com

Boiled eggs are delicious, I’m pretty sure no one will object to that, but have you ever thought of unboiling eggs?  A group of chemists out of UC Irvine and Australia have made this discovery which has the potential to change the biotechnology industry and dramatically reduce the time and cost for production of cancer treatments among other applications!

Now this wasn’t done simply for the sake of unboiling eggs, it was used to demonstrate how powerful this new technique of returning tangled proteins to their original form really is.  Proteins are made of chains of amino acids that are folded and arranged in a specific way.  Changes in pH and/or temperature disrupt the bonds holding the proteins in their original shape causing it to deform and tangle.  So when you cook an egg you are actually tangling proteins which causes them to change from clear to white.  The process is known as denaturation and is problematic for scientists who are trying to recycle valuable proteins after use.  Previous methods of solving this issue exist but they are time consuming and expensive.  This new process, however, gives results in minutes.

Professor Colin Raston’s vortex fluid device. Photo Credit: WashingtonPost.com

In the findings published in ChemBioChem, egg-whites were first boiled for 20 minutes at 90 degrees Celsius (194 deg. F) (plenty of time to tangle the delicious proteins).  To revert a protein in the cooked eggs called lysozyme, urea was added to liquefy the solid whites.  The resulting substance was then placed in a vortex fluid device which is a high powered machine designed by Professor Colin Raston’s laboratory at South Australia’s Flinders University.  This machine applied shear stress to the proteins which encouraged them to untangle and re-fold to their original form.

There is huge potential for this discovery that can streamline protein manufacturing and make cancer treatments more affordable.  Think about this next time you’re making omelets.  For more information on the findings please visit http://onlinelibrary.wiley.com/doi/10.1002/cbic.201402427/abstract

Engineering Rock Climbing

Posted by Ben (Team UV) on February 8, 2015
Posted in: Open Mind. Tagged: , , , , , , , , , , . Leave a comment
Rock Climber

Rock climbing. Photo Credit: asme.berkley.edu

Rock climbing is becoming more and more popular as gyms pop up all over Southern California.  This sport, like all sports, has many components that have been analyzed and optimized by engineers.  Rock climbing brings its own unique challenges, most of all the balance between safety and weight.  The more safety gear a climber uses the heavier they are and the more likely they will get tired and make a crucial mistake.

Climbing ropes are the major staple for safety gear.  A climbing rope must be strong enough to catch a falling climber, tough enough to withstand almost constant rubbing against rough rocks, and still stretch enough so that the climber isn’t injured by a quick stop from a long fall.  This is quite a bill for any rope to withstand but climbing rope does the job incredibly well.  For a class project, standard nylon rock climbing rope was tested and compared to nylon 550 paracord and standard polypropylene utility rope.  The differences were very apparent.  While the paracord and utility rope broke fairly easily the climbing rope withstood more weight and stretched beyond the range of the testing machine.  Try as we might we could not break the climbing rope within the range of motion that we had.  This rope had a few interesting properties that led to its great success.  First there was a protective casing of a tough material that could resist abrasion very well, then within, in the load carrying section the fibers had a special weave.  This weave allowed the rope to stretch very far without breaking and slowly load the fibers that made up the rope.  Some engineer did their job very well.

The very act of rock climbing can be helped by a brief engineering analysis.  First off is conservation of energy.  A climber’s muscles have a limited amount of energy in them so that energy needs to be saved for actual motion on the rock.  When a climber is hanging on the rock, looking for the next hold or clipping in the rope their arms are fully extended allowing the weight of their bodies to be held by their bones, a rigid structure, rather than their muscles, an energy devouring structure.  Another concept is as simple as balance, when a climber can just hang on a rock rather than resist swing or spin they are in a low energy state, even if this means that they are horizontal to the ground.  A trick for this is being aware of your own center of mass as a climber and ensuring that it is perpendicular to the hold surface.

The more a climber can think about the physics of climbing the more energy they will be able to conserve and the better technique they will have.

Presentation: Turning is Risky Business

Posted by Abraham (Team UV) on February 7, 2015
Posted in: Presentations. Tagged: , , , , , , , , , , . 2 Comments

Mechanics of an airplane in flight. Photo Credit: av8n.com

Update on technical issues: issues have been fixed, regular posting will resume tomorrow (Sunday).

Turning is also tricky business.  On airplanes, aerodynamic forces can be broken down into two components: drag and lift.  Lift is a two dimensional vector in the plane (geometrically speaking, not to be confused with a physical airplane) perpendicular to the direction of relative wind, however in “normal flight” we can make the assumption that lift is in the direction of perpendicular to the relative wind and wing span as seen above.  Basically we can assume all these forces are happening in a single plane.  Weight is mass times local gravitational acceleration (which can/will change during flight).  Thrust is a force produced by the engine that is in direction along the axis of the engine.  This is especially important if your engine is right smack dab in the middle of your vehicle…

Only when you’re flying straight, level, at a constant speed, constant altitude, and through still air can you assume thrust+drag=0 and lift+weight=0.  So pretty much in any other case there are forces going on all kinds of crazy directions in three dimensional space.

Non-intuitively, lift is less then weight in two situations: high power nose climb and low power down decent.  Sounds paradoxical but in fact thrust takes up some weight in climb and drag takes up some weight in decent.  Force balance, it helps.

Any who, why do we even care about these forces?  Well during normal flying (sounds weird to say because I don’t consider flying normal) we don’t, except during a turn.  During a banked turn the lift vector is inclined out of the plane (geometric) of the image above, so in order to pull the airplane around the turn and keep it at that altitude, the lift vector must be significantly greater than the weight.  So the lift vector can be summarized into two components during a turn: a vertical component to oppose lift and a horizontal component to change direction in which the airplane is flying.

Let’s start simple.  Boat turns are relatively simple because they neither have to fly or dive.  A flying boat would be pretty cool though…but I digress.  Say you want to make a right turn, in the figure below, turning the rudder to the right will cause the boat to yaw starboard.  Relative wind will hit the port side of the boat and create tremendous drag which will incidentally turn the boat to the right.  The force on the rudder by the wind is smaller than the force of the wind of the portside of the boat which means turning.  Now apply all this to airplanes and you have a simple boat turn on an airplane.  This sounds great and all, however, turning the airplane properly by using the wings is way more effective and efficient than boat turning.  There is also a lot more going on during banked turning as well.

Boat turn. Photo Credit: av8n.com

Airplane turn. Photo Credit: av8n.com

When using your wings to turn, there is a tendency to overbank which basically means overturning.  As seen in the figure below, the distance the inside wingtip has to travel is smaller than the outside wingtip and since the outside wing is traveling farther in the same amount time, it must be moving faster.

Airplane planar simple circular motion. Photo Credit: av8n.com

The lift generated by airfoils depends on the square of airspeed, so the outside wing will be producing more lift which leads to overbanking which leads to a spiral dive into oblivion.  Luckily for us, this effect depends on the ratio of wingspan to the radius of turn.  For stubby wings, high airspeed, and shallow bank angle, you’ll never notice the effect.  For a glider however, you need to deflect the ailerons against the turn to create an opposing force.  And to make things even more convoluted, to counteract something called long-tail slip effect, you will be holding your rudder into the turn.  So your controls seem like a paradox at this point  but this will mean a much better turn then a simple boat turn.  Long-tail slip effect is a topic for another day, but if you’re an aspiring pilot or you just want to learn more, please visit http://www.av8n.com/how/#contents for more of your aerodynamic needs.

 

Purify Water Using Sunlight!

Posted by Ketton (Team UV) on February 5, 2015
Posted in: Well Read. Tagged: , , , , , , , , , , . Leave a comment

Panasonic’s photocatalytic water purification system. Photo Credit: wonderfulengineering.com

Note: Our apologizes for the missed post on Tuesday; we had some technical difficulties and so have posted the original Tuesday post (this post) for today and will be posting the original Thursday post tomorrow (Friday 1000 hours) instead.  Regular scheduling will resume on Sunday.

In some parts of the world clean drinking water is quite rare as the water sources are polluted and purification methods are not available.  Panasonic is developing a new technology to address this problem.  This technology uses the sunlight for purification of the water extracted from the ground.  Recently, a system was presented by the company that uses photocatalysts and sunlight to purify water at a high reaction speed.  This readily improves access to clean water, in areas where needed.

The recent breakthrough that led to the discovery of this technology is the system’s ability to bind titanium dioxide (TiO2), a photocatalyst capable to react under ultraviolet light.  TiO2 comes in super fine particles and is hard to collect once it has dispersed in the water.  Previously, other larger materials were used to bind the TiO2 to them, but it was a loss of active site surface area.  The way this technology by Panasonic differs from those found before, is the discovery of Zeolite particles’ (a commercial adsorbent and catalyst) ability to bind the TiO2 particles.  This solves the problem by enabling photocatalysts to maintain their active site.  As the two particles are bound together by electrostatic force, there is no need for the binder chemicals.  As the new photocatalytic particles are stirred, the Zeolite releases the TiO2, which then disperses throughout the water.  The resultant reaction speed is much faster as compared to other methods and the processing of large amounts of water is supported.  The TiO2 binds to the Zeolite again if the water is still left, which makes it easy to separate and recover the photocatalysts from the water for later use.

The main idea of this project is to develop a small-scale version of this purification system, which may then be deployed at different places where purification of water is needed.  See how the system works below!

Panasonic’s photocatalytic water purification system process diagram. Photo Credit: wonderfulengineering.com

 

Open Mind: What is an Engineer?

Posted by Abraham (Team UV) on February 1, 2015
Posted in: Open Mind. Tagged: , , , , , , , , , , .

Prompt: Mechanical engineering is inherently ambiguous to those without an intimate knowledge of its principles.  As mechanical engineering students, there is an excellent chance that most of the people you know believe that your job consists of working on cars, acting in the role of a technician, or some related role.  Even people from many other engineering disciplines rarely know exactly what we study or what we do.  None of these people are to blame; rather, this is simply a consequence of the fact that the only people who take (many) actual mechanical engineering classes are mechanical engineers (/mechanical engineering students).  When a person grows up and moves along through the educational system, they take classes in History, Mathematics, Literature, Biology, Chemistry, Art, etc., and perhaps even Physics, but they never take any sort of engineering class unless that is the career path they choose to follow.  As a result, many people who could have possibly unearthed a deep love for engineering never received the chance to do so.  In recent years, many K-12 schools have been moving to fix this and have been especially working to expose traditionally-underrepresented student groups to the world of engineering at an early age.  Come up with either 3 ideas (or one idea from 3 perspectives) to help spread awareness with regards to the existence of the world of engineering (more specifically, mechanical engineering)  to people at a younger age, thus hypothesizing as to how we can help more possible future (mechanical) engineers discover their ambitions.

“Ownbot” a robot created by engineering students from Victoria University of Wellington (New Zealand). Photo Credit: victoria.ac.nz

It’s true.  When I say that I’m studying mechanical engineering, people think I work on cars or I’m learning to work on cars.  Even after explaining what I actually learn in my classes, most people stop listening after about ten seconds and conclude that just I’m a “fancy” mechanic.  Not the case.  When I was as freshman in high school I had no idea what engineering was.  All I heard was that it involved a lot of math and it was not for everyone.  I agree with both statements but the latter I think overstated.  How can you decide something is not right for you if you don’t even know what it is?  This is why I’ve come up with three ways to spread awareness of the world of engineering.

1) Teach team oriented problem solving, systematic reasoning, and creative problem solving at a young age.
I feel too many kids do not know how to work together effectively or know how to logically solve a problem they’ve never faced before.  I was with my thirteen year old cousin recently and asked him to set up a music stand for me while I got everything else ready.  There were three pieces to the stand and after 30 seconds of trying he said it was broken.  It clearly wasn’t.  Now I’m not saying he’s “dumb” but he had no idea how to logically figure out how to solve this problem.  He just simply tried one thing, it didn’t work, and decided it was must be broken.  That is not the kind of world I want to live in which is why these kinds of things should be taught much earlier.  Even if you have no idea how to solve something, there are creative, logical, and scientific steps you can take to better understand what is going on.  MIT has developed programs like Scratch to teach these ideas to kids through basic programming. http://scratch.mit.edu/

2) Presentations
Now I’m not saying a thorough and extensive lecture on PID control to 5th graders, but a very well polished presentation on how cool engineering can be.  I think people have to be exposed to a more visual representation of what an engineer actually does instead of rumors and hear-say.  I’m sure 10 year old Abe would have been incredibly impressed and inspired if he saw an underwater vehicle designed and created by students at the local university.  How all these engineering principles came together into something that he could touch and see move around a pool so swiftly and majestically.  A really good presentation can make the word “engineer” seem not so scary for an entire generation.

3) Engineering Competitions
I think recently more schools have gotten into engineering competitions.  There’s high school solar boat, elementary school robot programming, and even model bridge building competitions.  These are incredibly fun because most of these projects are in collaboration with engineering programs at universities so young minds can really get into the engineering mindset through a mentor.  I did solar boat and it was one of the most fulfilling things I did at Warren High.  If I wasn’t a part of it then and there I probably wouldn’t have chosen mechanical engineering as my major so I definitely encourage more of these types of competitions.

Overall there has been a bigger push to teach kids how to do things they could never do before.  Building, problem solving, and working together.  They are all a big part of engineering but of life also.  In today’s 21st century I don’t think you can progress without these skills so I’m glad that I learned them in the classroom.  Hopefully in the coming years more people will realize how important and interesting the field of engineering really is.