This past week was a bit slower than last. Neither me nor my partner have any experience with capacitive deionization techniques, so a majority of the week was spent reviewing capacitive deionization research. The lab has already done research with electrodialysis and there is a previously used electrodialysis system already in place, so we really just need to modify it to include carbon electrodes. Easy enough right? Not necessarily. Since we’re reusing a pre-existing stack, it requires a specific size of electrode in order to operate optimally. However, we’ve only been able to find about 3 distributors of carbon electrodes and none so far have been able to meet our specifications. So we’ll have to either figure out how to modify our stack or continue looking for an electrode distributor that can meet our specifications.

This weekend my lab group planned a trip to Carlsbad Caverns, which was pretty amazing. I knew it was something I wanted to do before arriving and was already disappointed when I realized how far it actually was from El Paso, since I don’t have a car here. Fortunately, everything worked out in my favor and we all had a great time.

I also went for a short hike with the other UTEP intern, Alex, at Billy Rogers Arroyo. It didn’t seem particularly well kept, but it was a fun experience all the same. About halfway down the trail, I stepped on a thorn, which went straight through my shoe and into my foot. It took about 5 minutes for me to work up the courage to pull it out (during which Alex captured that wonderful picture below).

Cheers to new friends and experiences.

 

 

 

 

 

 

 

 

This past week my mentor teach me how to isolate phages, in order to make my own phage stock solution. First we started by cultivating the a bacteria together with an specific phage, after that we plate both and left them overnight in the 26C fridge. The next day we separate the phage out from the agar and the bacteria throughout the use of different procedures to purify our phage. This method allowed us to cultivate phages with a wide host range. By the end of the week we were able to isolate two phages, and create two phage stocks solutions, that I will later use for other experiments. During this week I also had the opportunity to learn about the real-time quantitative PCR, and learn how to use an electrostatic force microscope.

 

During the weekend I was able to assist to the Houston Ballet and also visit the Galleria mall, with other students.

So to start off, I have been waiting for a Yale net ID for what is going on 2 weeks now. This has severely impacted my participation in the lab because I have not yet been able to complete the lab safety training and therefore can not work in the lab independently. A certain level of bureaucracy exists that the registration form has to make its way through. As a result, I have been shadowing the (soon to be Dr.) Humberto Jaramillo during his routine tasks and experiments in the lab. To my benefit, instead of going off and doing things on my own, I have been receiving a wealth of knowledge about each step and procedure as they are performed (plus I wouldn’t say that I am completely incapacitated, but my participation has still been minimal). Thankfully, Humberto is a top notch mentor, and goes out of his way to make me feel comfortable and well informed.

The lab PI, the famed Menachem Elimelech, who happily took me under his wing this summer, has been out of town this week, but seems to be a more hands-off type of mentor to his graduate students. Last week, I attended a meeting with Humberto, Changhe (a fellow researcher with a similar research topic), and the very own Dr. Elimelech in the flesh. It consisted of Humberto detailing his current progress and future endeavors accompanied by data to support the basis of his plans. Elimelech was very direct and blunt with his opinions and directions, quickly weeding out what he deemed unnecessary and lacking quantifiable backing. He’s a busy man and there’s a certain feeling I get throughout the lab that he is pushing for as many papers to be published as quality allows. That’s not to say that he is a respectful and intellectually considerate mentor that allows his students to figure out many lessons of grad school on their own (to their advantage of course).

Furthermore, in that quick meeting, Humberto outlined some of his goals. Another part of his research involves running a reverse osmosis system using the control and modified membranes. That means that he has the system running almost 24/7 in a unit that he constructed with the help of the lab technician, Evy. Two plates sandwiching a membrane act as the center of the system. A feed source containing calcium chloride and sodium sulfate is pressurized through a pump and pushed into the bottom plate and through the membrane’s active layer. The concentrated feed is left behind while filtered water is fed through the top plate and through a flux meter where the flow (mL/min) is gauged. Ideally, we run the system until a 40% reduction in flux occurs, which takes approximately 12 hours. The first few hours of runtime is known as the induction period, which is the initial slow, steady stage of crystallization of gypsum. The remaining time consists of rapid surface crystallization on the membrane surface that inhibits the flow.

We have been running the reverse osmosis (RO) system under varying conditions, but currently, the parameters have included a temperature of about 25°C (the chiller has been broken for weeks), a pressure of between 300 and 400 psi (we want an initial flux of about 1.7 mL/min), and a feed stock with a concentration of 0.019M for both calcium chloride and sodium sulfate to give us a conductivity (slightly above saturation) of approximately 6.1 mS (microsiemen). All of these factors affect how much salt is dissolved in the solution because we don’t want bulk crystallization in the feed that could damage the pump and be confused with surface crystallization if deposited on the membrane surface. Pressure affects the flux. Intuitively, as the pressure increases, the flux increases but scaling also occurs more quickly. Pressure is also important because, on an industrial scale, higher pressures means more input energy and therefore higher operational and capital costs, so we want our modified membranes to have higher fluxes at lower pressures.

Presently, only our control commercial membranes for brackish water have been tested in the system, so the next step is to modify membranes based on results from the self-assembled monolayers (SAMs). We used a goniometer to measure the contact angles of three known liquids on our newly modified monolayers on which the acid, amino, and alcohol were grown through wetting experiments. The surfaces of the three different monolayers were tested with drops of water, glycerol, and diiodomethane. Currently, we are working on calculating the van der Waals and acid-base interaction forces for the surface using complicated derivations of Young’s equation (the complex, grad-level equation). The contact angle and the known Lifshitz-van der Waals surface tension, electron-acceptor, and electron-donor components of each liquid (two of which must be polar) can be used to determine the different surface energy components of the solid (membrane or SAM). The results from the wetting experiments will then be used to justify how the different modifications of the membrane work to reduce fouling.

We are in the stage of experimentation, which involves a lot of trial and error, especially when running the RO system under varying conditions for optimal results. Wish us luck on our endeavors as we face uncertainty head on and stay updated to learn more about our finding!

 

It is really hard to believe that week two went that quickly so much got done and so much more has to be done before my time here is over. So far my time here has involved me building and testing the material that are apart of our Solar MD system and another chunk of my time involves learning to process data on COMSOL. The best part of last week involved me finishing the the base of each project. For the Solar MD project, we were able to build the frame work for the skid on which the system will be laid on. For my computational model I was able to create to create functioning base that computes reasonable data. This next week will involve me finishing the building of each model, for our solar MD model we will attach the actual system (panels, tanks, flow-meter, etc.) to our framework. For my computational model I need to do a bit more programming to export data from the models that I have created. So far the program has been very rewarding, the technical work that I have been doing has gone from me handling a screwdriver and wrench to learning a new software as well as putting my programming skills to the test.

The other day my mentor, Humberto, was telling me about imposter syndrome. It was first coined in 1978 by clinical psychologists and refers to “a collection of feelings of inadequacy that persist even in face of information that indicates that the opposite is true. It is experienced internally as chronic self-doubt, and feelings of intellectual fraudulence” (as defined by the Caltech Counseling Center). Researchers have divided it into three sub-categories reflective of general feelings: (1) feeling like a fake, (2) attributing success to luck, and (3) discounting success. All three of which are associated with similar symptoms including a belief that one does not deserve his or her success and a fear of being, “found out”, discovered or “unmasked”.

After doing my own research on the topic and some “soul-searching”, I realized that I, by actively deflating my ego, have subconsciously been causing myself to take on some of these symptoms. I have always preferred to be the type of person who is modest rather than overly-confident about his or her successes, but when it starts affecting my outlook on my post-graduate plans, I’d consider it an issue. Humberto was relating his own feelings of inadequacy to me when he brought up imposter syndrome. He attributed grad school and the resulting environment as the reason for a lot of the self-doubt he experiences. Being surrounded by the cream of the crop and feeling like you are expected to know things that you may not know yet is intimidating, to say the least.

“Are you considering grad school?” has been the question of the week. It’s a simple yet loaded question and being at Yale has given me some time to seriously consider the answer. It’s definitely not for everyone because it requires time, dedication, independence, and focus. Not everyone can direct that type of energy into a specific field of expertise for 5 (or more) years. Not to mention, the amount of trial and error and associated stress that begins to weigh over you may begin to compromise your initials goals and dreams. However, for me, a big aspect of my inner-contemplation with the idea, has been whether or not I want to place myself in an environment where self-doubt and fear of failure are constantly looming. You must have the ability to find value in your research and the experience as a whole. The title is one thing, but actually making a difference in your field (or even the world) is another. Currently, it’s hard to know whether or not I will feel passionately enough about a certain issue associated with the environment or the world’s resources to pursue a Ph.D researching it, but I guess a lot of what grad school is about is uncertainty.

These intellectuals are researching because they simply don’t know. They may have educated guesses or ideas about answers but they’re still uncertain. For me, uncertainty has come to define a large aspect of grad school and show me that it isn’t just about intellectual maturity, but emotional maturity. Controlling and balancing your thoughts while maintaining your focus. Finding significance in your work depends wholly on what you seek out of your research and it doesn’t have to mean saving the world. Most importantly, understanding that your path does not have to coincide with others’ and may take different twists and turns, but may still lead you to your final destination. It’s an arduous process and I hope that through the next few years I can build the knowledge, confidence, and decisiveness to figure out what next step I want to take with my life.

I dedicate this post to Humberto himself for showing me (whether he realizes it or not) that imperfections and errors will always persist in research and to stay optimistic and confident in your position and efforts that got you there. Error is not a reflection on who you are as a student, researcher, or intellectual, it’s how you approach an issue that says more about who you are as a person. Stay tuned for research updates to come and potentially more personal streams of consciousness. ;P

 

 

The first three days of this week really saw things pick up. Not in terms of quantity, but quality. So much so, it was difficult getting to this blog. As the laboratory tasks become more imperative, focus and patience becomes more important. The Graphene Oxide samples underwent the first stages of cleaning. I had to dispose of the supernatant and wash with HCl multiple times. This required a steady hand and a lot of waiting. However, your mind can never truly rest. I found these down times are perfect for recollection and planning your next actions efficiently. It was actually quite exciting for me to have time to sit and wait. The waiting periods gave me time to contemplate certain concepts and ideas to improve my proficiency.

Update: There are two types of Graphene Oxide(GO). Each used a different synthesis method. 4 days were required to allow the chlorine gas to evolve from the GO. The synthesis of GO included sulfuric acid, nitric acid, and potassium chlorate; therefore, in order to get the best GO, those substances needed to be removed. That is where the washing with HCl comes in. The HCl washing is complete. Now, I will continue cleaning with nanopure water until the supernatant has a pH matching with the nanopure water, indicating that the only substances present are nanopure water and GO.

It was 3:00am and I was surprisingly awake considering how early it was. My mom shuffled out of her room, half awake, yet still loaded with questions to fill her mental checklist (typical to a worried mother, whose youngest is about to embark on a journey across the country). “3:30,” she said, “that’s when we’ll leave for the airport.” My flight was at 5:50am…Fine, I thought, better early than rushing to my gate (more to appease my worrisome mother than anything). My father, on the other hand, was savoring his last few minutes in bed and protested overruled that we leave so early. “We don’t need to leave sooner than 4,” he commanded. Overall, it was just too much discord for 3 in the morning, so, as usual, we listened to my father.

We embarked on the 30 minute drive to the airport and my mother insisted on waiting with me to check in my baggage, which resulted in us waiting in the wrong line for 15 minutes (after I urged her that we were in the wrong line more than once). So with that 15 minutes plus the additional 20 minutes of waiting in the right line, I was feeling a little stressed for time entering the TSA security line. To my relief, everything worked out, with me arriving at my terminal 1 minute before boarding. After nearly 8 hours, I landed in the tiny Tweed Airport in New Haven around 2:30 pm with 5% of battery left on my phone, which added a little excitement to my journey. I was happy to finally be able to grab an uber (before my phone died) and head to the apartment I would call home for the next 7 weeks, when I realized that I did not have my debit card. The card that contained all of my money was missing at the worst time possible. After about 15 minutes of searching, panicking, and then finally composing myself, I managed to call my mom (without my phone dying) and arrange for an uber.

Once on the streets, I noticed it was a damp and chilly day in New Haven (not the greatest first impression), but I reached the charming atmosphere of Chapel St. and entered my apartment. It was adorable with the perfect amount of old New England yet modern East Coast charm. I settled in, and, despite unpacking my things, an empty feeling began to settle in. Being in a unfamiliar place where I didn’t know anyone was lonely, especially after a long day of traveling and unanticipated obstacles. So I ended up doing what takes my mind off things the best–cook. I made a hodgepodge of what was left in the fridge from the previous tenant (to my benefit, she was very into high-quality food products). This random mixture of ingredients came to reflect my emotions the next morning. Anticipation, anxiety, excitement, and determination.

I woke up earlier than I was used to and made the 15 minute trek to the Mason Laboratory on the Yale campus. To my delight, the weather juxtaposed the dreariness of the previous day, giving me a wave of optimism as I soaked in the brisk air and sunlight. I finally reached the office of Humberto Jaramillo, room 306, with the direction of a kind, older woman who sensed my unfamiliarity with the building. After a quick, “hello” and “nice to meet you”, Humberto quickly made me feel at ease and comfortable. He took his time going through his research topic as well as taking breaks to talk about his personal life and influences for entering grad school and asking questions about my life and interests. The anxiety I had built up over the past few days had finally subdued and I was finding myself more and more intrigued by his research. I began to draw away from my own personal issues (like a lost debit card) and contemplate how living without clean water would affect my life.

Today, water quality and accessibility have come to define many major global issues. According to a review on reverse osmosis by Menachem Elimelech, presently, over one-third of the world’s population lives in water-stressed countries and by 2025, this figure is predicted to rise to nearly two-thirds. Currently, our only option is to improve the use of existing water resources and that means utilizing more efficient desalination and water reuse technologies. So, as a part of NEWT’s Thrust III team, Humberto has tasked himself with the job of reducing the deposition of gypsum on the surface of reverse osmosis membranes by modifications through polymer growth on the membrane surface itself. With me as his trusty sidekick, we will be producing self-assembled monolayers of gold-coated, silicon wafers on which three different polymers will grow–an acid (COOH), an amino (NH3), and an alcohol (OH). The contact angle of three different liquids will then be measured on the three uniquely modified surfaces and a control membrane for brackish water. These angles will then be used in very complex and graduate-level equations to solve for the surface energy of each surface.

The premise behind finding the surface energies is that the energies correlate to how likely gypsum is to crystallize on the membrane surface and cause fouling, which ultimately decreases the flux of the treatment system by reducing the flow and therefore separation of salt from water. Currently, commercial brackish water membranes have a certain surface energy that we expect to be higher than the membranes we modify. With a higher surface energy, gypsum is more likely to attach and grow into what we call rosette structures, which are reflective of surface crystallization. By lowering the surface energy, gypsum is less likely to attach to the surface and instead remain in the feed source without causing scaling. Ultimately, by reducing fouling, reverse osmosis membranes will have longer periods between cleanings (lower maintenance costs), require less energy for higher fluxes (lower capital and operational costs), and have overall longer lifespans.

I hope I covered enough background to build a basis for understanding membrane modifications. Despite how complex it can be, there is more to my research than contact angles and equations. I am slowly realizing that my time can be better spent on work that can actually impact more than just myself. I hope to touch on our other research endeavors in future posts, so stay tuned for more to come!

My experience in El Paso has been pretty great so far and UTEP has a beautiful campus, whose sand colored buildings along with the dry, hot sun never let you forget that you’re in the desert. I met Dr. Walker’s research group as well as my mentor for the summer, Seye, Monday morning and immediately began my training on different types of water analyses. Seye had some water samples from the desalination plant that he had to test, so we used that as an opportunity train me. Throughout the week, I learned how to measure alkalinity and total dissolved solids, test for silica, and use the Ion Chromatography machine. I’m happy to report that everyone is very friendly here.

On Thursday, I got to help disassemble a solar powered water desalination system located at the Kay Bailey Hutchinson desalination plant, which is the world’s largest inland desalination facility producing 27.5 million gallons per day. We arrived at the desalination plant around 7:30am to beat the sun, but it was tough work and the disassembly took longer than expected. I appreciated the experience because it gave me an opportunity to see the world’s largest inland desalination facility in action as well as see the setup of a solar powered desalination system that will be used to produce water suitable for human consumption or irrigation in Honduras this summer. By the way, I cannot carry a cinder block by myself and the El Paso heat should not be underestimated.

This weekend I made it downtown and stumbled upon a free music show with a band called Sangre Gitana. It was an enjoyable experience and I felt fully immersed in El Paso’s culture for the first time as I watched people dance and enjoy themselves with their family and friends on a typical Friday night. I also stumbled across San Jacinto Plaza, which seemed to be located at the heart of downtown El Paso. There was a fountain at the center of this plaza with a statue depicting several alligators climbing one another. A man passing by informed me that the fountain used to be a pond that held real alligators, which I found hard to believe of course, but turns out he wasn’t kidding! Apparently, the pond was permanently removed after 1974 for the alligators’ safety and today, the sculpture honors the original alligators that were once a staple of El Paso culture.

In our first day, me and Evelyn woke up really early to start our NEWT internships. We went early to breakfast and by 9 in the morning we went looking for our respective laboratories. We found out that we work in the same building, in the same floor, really close to each other. We had a great week, just fitting a little to adjust to the weather, and the hour difference. My first day at the laboratory I assist to a safety training, to be able to enter the laboratory. The following days, I focus on learning their techniques, machinery, and procedures. I am working with Ping, whom is a graduate student at the laboratory, he teach me every technique, and then let me try to do the techniques on my own. I also got to know awesome people living in Martel College, that are from different parts of the world, and even get to know the city a little bit better. I look forward for Monday, to learn new techniques and refresh last week’s acquired knowledge.

Week one at Rice, has been amazing. My roommate and I have met some international students and have been traveling Houston on our spare time. Other than my time visiting the city I got to meet Dr. Qilin Li as well as her research team. The project that I will be working on this summer is referred to as solar MD, or more formally solar membrane distillation. I will be working with the time to make a large scale model of a membrane distillation system that will be fully functional under the sun. Also when I meet Dr. Li an told her that I am getting a concentration in Computational mechanics she recommended working on COMSOL and making computational models that will test different types of membrane characteristics and see how they work. So my days here at Rice will be 60% working on the large scale solar MD system, and 40% working on COMSOL. This past week has consisted of me reading everything and anything on MD systems, as well as trying to configure the mathematical models for COMSOL. This upcoming week I will be getting my lab safety training and officially start working on the solar MD project. Monday morning should be busy but I’m ready!

Cheers,

Evelyn