Dear Diary

If you recall last week, I wrote about how OCT (Optical Coherence Tomography microscope) could possibly steal my heart from FoMD (Fouling of Membrane Distillation).  Well…it was almost so.  I spent even more time with OCT and everything was going swimmingly when I had the opportunity to use a new scientific toy.  And let me tell you, Diary, it had me all in a flutter.

The new toy is SEM, or the scanning electron microscope, and the images it took for me were absolutely stunning.  SEM and I spent two hours together getting to know one another and it was wonderful.  SEM likes spectrometry, photography, Fifty Shades of Gray, and chillin’ in nice cool rooms.  I guess I should explain those interests a little bit more to you, Diary.  SEM can do spectrometry of samples which is scanning them to determine what elements are present and roughly the quantity; this is useful to help determine the type of minerals that are precipitating out of the salty water in FoMD (see the first time I wrote to you, Diary, for more details about FoMD).  SEM can take images that are magnified over 10,000x meaning one micrometer (10^-6 meters) appears to be one-centimeter in length.  To put it another way, imagine taking a picture of your foot and enlarging it so that your foot is nearly two miles long so now you can see each individual skin cell on your foot since they will be about the length of your arm…Well not your foot and arm, Diary, because you’re a diary; you don’t have feet or arms.  The photographs are amazing but they are all in gray-scale; see what I did there in listing SEM’s interests (don’t worry, I’ll pat myself on the back).  The room that SEM lives in is nice and cool, around 70^oF which feels awesome after walking a quarter mile in the 110^oF+ heat we have.

Here’s some samples of images that SEM and I took together.  The magnification is shown in the bottom left and the white bar in the bottom center shows you the scale of the image.  SEM and I didn’t take any 10,000x magnified images; only up to 5,000x magnification.  The first one, 300x magnification, shows what appears to be two different crystals forming.  There are long and thin crystals near the top of the image and short and thick crystals near the center.

The next image, about 1000x magnification shows that a short and thick crystal is actually thin in the 3^rd direction, noticeable in the bottom of the image.  This means that the short crystals could actually be the same crystals as the long ones but oriented differently and shorter.

The 5000x magnified image shows that there are even smaller crystals that were still forming when the FoMD experiment was stopped.

The spectrometry shows that there was carbon, oxygen, sulfur, and calcium present which is what I was expecting.  It also showed chlorine present and no magnesium present which I was not expecting.  This means that my previous models might be wrong but I’m not going to make such a claim based off of only one sample.

SEM likes to take things slow, a little too slow for me.  After two hours together we only analyzed two samples.  I was hoping to get to four samples but SEM said we were out of time.  As I was leaving, another person was coming in to use SEM.  I was hurt so I told SEM that it had to choose either this other “engineer” or me.  Luckily for me, SEM said it would see me again on Monday.  I hate to brag, Diary, but no scientific equipment can resist my charm.

I’ll write to you again next week, Diary. – Chay

Dear Diary,

It’s been a short week so this will probably a short post.  As you know, FoMD (Fouling of Membrane Distillation) and I are still going strong.  We’ve experimented every day this week!  Last week I created the model of the materials that we should see using Visual MINTEQ.  After having those two old programs fighting over me last week, I haven’t had to use either one this week.

This week I got another new toy scientific tool to use.  And to be honest, Diary, if anything can steal me away from FoMD, it is this new tool.  It is an Optical Coherence Tomography microscope (OCT) and it is used for microscopy.  Microscopy is a sciency word (AKA fancy) for “the use of a microscope.”  This one, however, is not like your high school biology microscopes.  An OCT uses near-infrared light beams to reflect off of the object to create an image.  But wait, it gets even cooler.  The infrared beams can penetrate a lot of objects so it also creates 3D images.   Below is a picture of the whole setup.  The OCT is on the right and sitting below the lens is a USB flash drive.  On the computer screen, you can see a picture of the flash drive in the bottom right with the letter Y clearly visible.  The big image is the microscopic view of the flash drive (whitish blue, mostly hidden by the orange) with part of the letter Y (green) and a lot of noise created by the plastic (orange and pink at the top and bottom of the image).  Each pixel created by the program is 1µm or about 1/20^th the thickness of human hair and the different colors indicate different densities.  I was told that I can put anything I want under OCT as encouragement to learn how to use OCT.  I have to level with you, Diary, my first ideas went all the way back to the five-year-old me with “I should put boogers under the microscope!”  Sometimes I’m proud that I’m not growing up…this was not one of those times.

OCT and I are going to have lots of fun together creating images of the membranes that FoMD and I are fowling up.  The next image is a membrane that only had de-ionized water pass through it so there should be no fouling.   This creates a nice standard of what a clean membrane will look like since we might find parts of other membranes that are clean.  This image is showing a piece of the membrane that is less than 2mm by 2mm.

Here is a membrane that was in FoMD for nearly 48 hours and had a lot of salt build up or “fouling.”  You can see that there is still a lot of clean membrane visible but there are also cool salt structures.  Using another feature, bottom picture, we can start to see what pores became “wet” which is membrane distillation speak for “got contaminates in the pore so now liquid water can pass through the pore.”  As you can see, “wet” is a much friendlier term.  The wet pores have large downward cones visible in this side view image.

Guess what else, Diary?  Next week I get to start putting these cells into other new toys scientific tools (I can’t believe I keep making that mistake) to determine what those solids are.  I don’t remember what these toys’ names are but that helps make them more mysterious.  The solisd should match the precipitates determined by the Visual MINTEQ program that I was using last week.  One can only hope!

I guess this post wasn’t as short as I expected, oh well.  Until next week, Diary – Chay

Dear Diary,

What a week it has been!  I’m still working with FoMD (Fouling of Membrane Distillation) and I had two computer programs fighting over me.

We were able to work out all the kinks that FoMD was displaying last week.  FoMD is now running like the dream experiment that I knew it was.  In fact, FoMD has become so reliable that I can now set it up to run throughout the night and when I return in the morning FoMD greets me with some rather thrilling data.  Usually by the time I get in, FoMD has already crashed a couple of hours earlier due to all that saltiness coating the membrane but FoMD keeps on trying to pass water through the membrane.  I’m pretty sure FoMD will do anything to make me happy…Maybe I’ll get FoMD to do a bank heist for me.

Well, Diary, I guess I should talk a little about the data that FoMD is producing for me.  We’ve been starting with a water/salt concentration that is two times the starting concentration; one times concentration is approximately 1.2 kg of salt per liter of water.  By starting at two times this it makes sure FoMD will crash in a timely manner and before too much water is lost to evaporation.  As expected, FoMD consistently crashes around 2.8x the initial concentration meaning there is too much salt on FoMD’s membrane to effectively remove water from the briny mixture.  But bless its heart, FoMD keeps on chugging along and continues to remove water throughout the night.

When not working with FoMD I am working on computer programs to determine when different ions will precipitate out of the briny liquid based on concentration amount.  There are two different programs vying for my usage and, Diary, I certainly have felt like the Belle of the ball this week; although the ball is a little decrepit.  The first program is Visual MINTEQ which was originally released in 2010 but it’s had a few version releases or “face-lifts” since then.  The other programing competing for my attention is MINTEQA2 which was originally released around 1991, hasn’t had a face-lift since 2006, and cannot run on anything newer than Windows XP (yes, I said “newer than”).  Visual MINTEQ was created using the MINTEQA2 program to have a much cleaner interface and run on newer computers.  In the computer world, both of these programs are extremely old and it feels like I have both Michael Douglas (Visual MINTEQ) and Kirk Douglas (MINTEQA2) fighting over me.  The reason I had to use both programs was because Visual MINTEQ, while nice and clean, is only programmed to produce reliable data up to a maximum temperature of 40^oC and I need to produce data for water at 65^oC.  MINTEQA2 can create data reliable up to a simulated temperature of 100^oC but is run through the MS-DOS screen which requires you to know exactly what you need to know a bunch of keywords to run the program since it doesn’t have an actual interface.  If you don’t know what to type there is fortunately several documents that combine to create a 200-page manual with some conflicting information and some completely incorrect information.  On top of that, the final data is displayed using notebook and also requires the manual to understand what you are looking at.

As the Belle of this program ball I certainly did have my choice of inferiorities to choose from.  I decided to put the same simulated data into both programs at 20^oC, 40^oC, and 65^oC to compare how their answers changed as Visual MINTEQ got out of its reliable range.  After comparing the data, I had my The Bachelor moment and I gave a rose to … [COMERCIAL BREAK] … And now back to The Bachelor: Scientific Computer Programs edition… I gave a rose to Visual MINTEQ.  It turns out Visual MINTEQ is still reliable enough at the necessary 65^oC and I’m a sucker for a clean interface.

Now Visual MINTEQ and I can create graphs of the percentage of ions dissolved in water as the salt concentration increases.  I am also working with FoMD at the same time so as long as the two don’t find out about each other everything should continue smoothly.

Until next week, Diary – Chay.

Dear Diary,

Last week I met the dreamiest lab setup.  It has two pumps, two flow-meters, a hot AND a cold bath, and tubes in all the right places.  It’s enough to make any budding young engineer swoon.  I got to spend a whole week with this lab setup and it prefers to go by Fouling of Membrane Distillation (FoMD).  It took me some time to get to know the intricacies of FoMD but I’ve enjoyed every minute of it.  Looking at the picture that FoMD posed for me we can see that the right side has a container in styrofoam; this is the hot and salty side of FoMD.  The water on the right gets pulled through a pump and into the top part of the membrane cell.  The water then goes to a flow-meter and back to the hot and salty container.  The left side of FoMD is cool and clean.  The water from the large container gets pulled through a pump, goes through the bottom of the membrane cell, through a flow-meter, and back to the cool and clean container.  The middle picture shows the inside of the cell with the top portion on the left and the bottom on the right; the right picture shows the heart of FoMD – err, the membrane, within the cell.  The membrane is a hydrophobic (but Chayphilic) plastic that is a quarter of a millimeter thick and full of pores that are 0.45 nm diameter.  The water from the hot, salty side of FoMD evaporates through these pores making FoMD gradually become full of cool, clean water.  This also means that the salty side of FoMD becomes even more saltier or more concentrated throughout the day – MEOW!

The objective of spending all my time with FoMD is to determine at what concentration of salt to water will the membrane lose effectiveness.  FoMD should be losing its effectiveness around 3x concentration, meaning it is three times saltier than when it started and three times more to my liking.  However, FoMD’s builder has been out of town all week and, Diary, you know how wild experiments are when their builders are gone.  FoMD has certainly been crazy: producing erratic data, finding new locations to leak through, not keeping a constant flux, and providing a lot of membranes with holes in them.  I know they say to like an experiment for its qualities, love an experiment for its flaws but, Diary, I am not looking for a fix-up project.

That’s about it.  Until next week, Diary. – Chay