Day 18

In the morning I helped run a few tests on the commercial oil paints that we thought had paramagnetic signals (ultramarine, burnt umber, burnt sienna and, viridian). Then the rest of the group explained to me what they did on Friday (they scanned the dollar bill and took more data points to create a higher-resolution image). After that we went and started shifting the starting points for the rows of data on the dollar bill so that the image was clearer. Dr Hornak then brought in his spare tire so we could test it. We tested the tire and did not get a signal. We also recorded the background signal (when nothing is on the MOUSE). After lunch I worked on my presentation. Then we worked with excel to analyze the data we collected. We found that only the ultramarine paint out of all the commercial paints we tested had a signal (it was small, though). We then looked at the background signal we had recorded and decided to try and clean the probe in case there was some magnetic ink on it from the dollar bill that was interfering with its sensitivity. After doing that we tested the commercial paints again.
Here is the image we created after tracking the ferromagnetic signal across the dollar bill with the MOUSE:

Day 17

I didn't come to the internship today since I was out of town so there's no blog post for today (7/28).

Outline for Presentation- Draft

      I.         Introduction/Background:

A.   Electron paramagnetic resonance (EPR) spectroscopy

1.     EPR is a technique for studying paramagnetic materials

a)     Paramagnetic materials are species that contain unpaired electrons

2.     Paramagnetic materials absorb microwave radiation when subjected to a magnetic field

3.     The frequency of microwave radiation generally used in EPR is in the range of 1-10 GHz

a)     Microwaves (300MHz-300GHz) represent a subset of electromagnetic radiation that are generally referred to as radio waves (3kHz-300GHz)

B.    Low frequency electron paramagnetic resonance (LFEPR) spectroscopy and EPR MOUSE

1.     LFEPR is a variation of EPR that utilizes a lower frequency radiation (around 300 MHz-1 GHz) than in conventional EPR which utilizes higher frequencies (1-10 GHz)

2.     EPR MOUSE is a further variation of EPR
3.  LFEPR, and EPR MOUSE devices have 2 main components
                a) The magnet which creates a magnetic field
                b) The radio frequency (RF) probe 
4. The equation, hν = gβB , represents the relationship between the applied magnetic field and the frequency of the absorbed radiation               
                     a) h = Planck’s constant, ν=frequency, g=g-factor    
            (constant), β= Bohr magneton (constant), B= 
             magnetic field

    II.         Rationale & Purpose:

A.   The goal of the first half of this project was to characterize the magnetic field of various magnet designs and measure the sensitivity of the RF probe to aid in the construction of the EPR MOUSE.

B.    The goal of the second half of this project is to demonstrate the capabilities of the current EPR MOUSE design and establish the feasibility of detecting paramagnetic species on a variety of surfaces of practical relevance.

C.    Advantages of LFEPR as opposed to EPR

1.     Can study larger objects non-invasively

a)     Conventional (higher frequency) EPR can only study samples smaller than 125mm³ in volume

b)    LFEPR can be used to study important cultural artifacts that are multiple liters in volume 

2.     Can study larger objects as opposed to EPR

D.   Advantages of EPR MOUSE

1.     Can study surfaces (the sample does not need to be placed inside a spectrometer)

a)     No sample size limitation

b)    Only limitation is the depth of penetration of the magnetic field and the radiation into the sample

  III.         Methods:

A.   Characterization of the magnetic field of different iron yoke designs

1.     Goal was to optimize the homogeneity of the magnetic field because the RF absorption is dependent on it.

2.     Used the Finite Element Method Magnetics (FEMM) software to generate the theoretical magnetic field distribution around the yoke

3.     Compared the theoretical prediction (using FEMM) to experimental measurements to ensure accuracy

B.    Determination of the sensitivity of the RF probe

1.     Used an EPR machine with a known homogenous magnetic field

2.     Measured using DPPH (2,2-diphenyl-1-picrylhydrazyl), a known paramagnetic species that is commonly used for EPR measurements

3.     Measured the sensitivity of the probe at numerous locations in the 3D space (in the XZ,YZ, and YX)

4.     Analyzed this data to determine the sensitivity of the RF probe

C.    Demonstration of the capabilities of the EPR MOUSE

1.     Currency

a)     Used the MOUSE to scan the surface of a US dollar bill and recorded the spatial distribution of the ferromagnetic signal, and created a 2D image.

2.     Paint/pigments

a)     Used the MOUSE to identify paramagnetic pigments used in various paints based off the signal produced

3.     Barcode

a)     Used the MOUSE to scan a barcode and record data based off its ferromagnetic signal (from toner ink) and created a 1D image of the barcode

 IV.         Results & Conclusion (not final)

A.   Based off the projects conducted to demonstrate the capabilities of the MOUSE, the EPR MOUSE has a number of potential applications including:

1.     Analysis of paintings and historical artifacts

2.     Authentication of currency and other paper documents

a)     Paramagnetic or ferromagnetic watermarks

3.     An alternative to optical barcode readers

Day 16-updated

Today when I reached the lab Baron & Celia had finished scanning a dollar bill and a barcode with the MOUSE. I tried to use a rotation matrix to rotate the data for the dollar bill by .7369 degrees because when they scanned the bill it was tilted by around .7369 degrees so we had to rotate the data so it matched. Dr Hornak came in while we were trying to rotate the data and had a quicker method of rotating the data by just changing the starting points of each column of data by an approximated amount which we obtained by looking at a graph of the data. We then tried to find a motor we could use to rotate the micrometer setup that we used to collect data (see my previous post) so we didn't need to turn it by hand. We then went to the machine shop in building 8 where Dr Hornak found a piece of aluminum we could use to connect the motor and the micrometer. We then went back to the lab and looked for set screws for the attachment we had made. Then we left to go on the field trip to the Mees observatory in Bristol. We learned about the history of the observatory, the telescope, stars, and the planets that you could see through the telescope. We also learned about the eclipse that is occurring on August 21st that will be visible from parts of the U.S. You will not be able to see the full eclipse from Rochester but you will be able to see a partial eclipse. Unfortunately it was cloudy so we could not see anything through the telescope but I still had a fun time and enjoyed the field trip. I will not be here tomorrow (Friday, July 28th) so as a result there will be no blog post tomorrow. 

Day 15

Today we finished painting the MOUSE logo with the epoxy and paramagnetic pigment mixture. Once we did that we had to wait for around an hour for the logo to dry completely. For the rest of the day we ran a picture of the barcode (printed with magnetic ink) over the MOUSE and collected data to see if we could then replicate the barcode into a 1D image. Analyzing the barcode using the MOUSE took most of the day for various reasons. One reason was that we had to slowly pull the barcode (using the micrometer setup in the picture) over the MOUSE by hand at a constant pace (we kept a constant pace by using an online metronome). The other reason it took all day was because the data we collected had discrepancies at the ends of the barcode. After running some tests we determined that the cause of this issue was the printer, not the MOUSE. We guessed that the printer was either running out of ink or it distributed the toner unevenly on the paper. Then we analyzed the EPR MOUSE logo that we had painted earlier. However, we were not able to see a signal on any of the letters the logo (probably because the pigment was not concentrated enough in the epoxy). During lunch I went to astronomy/astrophysics talk. After that we retested some previous paint samples that we knew had a clear signal to confirm that the MOUSE was working properly. These samples did indeed give a signal so we now know that we need to paint with linseed oil rather than epoxy so we can layer the paint and thereby increase the concentration of the pigment in the painting.
Here's a photo of the micrometer setup. The MOUSE is situated under the glass pane which is then moved using the knob at the rightmost side of the photo (right under the larger, red EPR machine).
You can faintly see the MOUSE under the blue packet (the packet is filled with a paramagnetic pigment powder that we were testing).

Day 14

When I got to the lab we tested some materials with the EPR MOUSE to see if we could see a signal clearly. We tested a ceramic coin, a flowerpot, coal, and a sample of DPPH. We did get a signal from these but they weren't as clear as the ones we got from the larger EPR machine. Joe gave us a charcoal briquette to test as well. After lunch, we started to plan how we would paint the letters for our project. We had decided that we would first paint the letters EPR and the logo of the MOUSE with paramagnetic paint and while the paint was drying begin the projects with paper currency and the barcode ( which we would analyze using the MOUSE and then create a 1D or 2D image based off the change in signal as we moved the MOUSE over the money or barcode). We then began to paint the design with a mixture of epoxy and the paramagnetic pigment (which was in powder form). This was difficult because the epoxy would dry in 5 minutes so we had to make sure we painted the letters quickly. We also ran out of epoxy when we were in the middle of painting the MOUSE logo. We walked down to the Global Village to buy some more epoxy but the store was closed.

Here are some images of the work I did today:

This is a photo of the EPR MOUSE device when we were collecting data on the ceramic coin (a piece of the coin is on top of the device):

This is a photo of the EPR MOUSE logo we painted. As you can see the middle part of the MOUSE logo is blank because we ran out of epoxy:

Day 13

This morning Dr Hornak showed us the EPR MOUSE. The RF probe that we had measured last week was now inside the MOUSE device. There was one problem though, the RF probe was not level with the edge of the iron yoke and was jutting out 0.7 inches above the yoke. We decided that the best way to solve this issue would be to shave off 0.7 inches off the edge of the coils that were also in the yoke so the RF probe would fit. After coming up with this solution we started brainstorming applications and demonstrations for the EPR MOUSE that we could perform. After lunch Dr. Hornak showed us how to run the MOUSE. This procedure is very similar to the larger EPR machine except that we have to demagnetize the iron yoke each time after we run a spectra because the iron yoke gets partially magnetized. We ran some paint samples that contained paramagnetic species to ensure that we could see the signal with the MOUSE device. We also tested a piece of paper with toner ink, a barcode, and a 1 dollar bill (US currency contains magnetic ink which can be detected by the EPR MOUSE). After these tests Baron (an REU student), Celia (an RIT student), and I created plans for demonstrations that we could conduct using the EPR MOUSE and a painting, a barcode, and a dollar bill.
Here are images of the EPR MOUSE and the larger EPR machine:
This image is of larger EPR device (the copper-colored cylinder).

This image is of the EPR MOUSE (the small white box).

Day 12-updated

After the morning meeting I went down to the lab and took some more data. This time we took data points for two lines which intersected at the center of the RF probe which I have drawn out below:

Here is a more detailed diagram of where we collected data:
The red lines indicate where we took data in the Z and X direction (using the same orientation as the diagram above where Z is parallel to the longer edge of the probe and X is parallel to the shorter edge). Although we did take data at these points we did not necessarily detect a signal (especially at the edges of the circle). Thus, the area where the RF probe is sensitive enough to detect a signal is less than the area of the circle. The circle is where the coil is in the RF probe and where it should be sensitive enough to detect a signal.



After plotting the data and creating an intensity map we noticed that the RF probe was more sensitive in the z-direction than the x. We decided to turn the coil in the RF probe 90 degrees in the hope that it would increase the probe's sensitivity along the x direction where the magnetic field is more homogenous. After lunch we took data along the same points again with the RF probe after the coil had been rotated. When we compared the intensity plots of the center line data before and after the coil was rotated, however, the data was almost identical. At this point it was time to go so I hope we can figure this out on Monday.

Here's an image of the inside of the RF probe:

Day 11

At the morning meeting we continued reviewing our abstracts. Once I got to the lab I started collecting more data, like I did yesterday. Today we were able to finish collecting data for the YZ and XZ plane and create the intensity plots for both.
Here are some pictures of the micrometer we use to measure the position of the probe for each data point and some of the data we collected:
 

Day 10

During the morning meeting today we went over some more abstracts. In the lab I continued collecting data using the same method that I described in my previous post. This ended up taking all day because we had to collect around 300 data points for the XZ plane.
Here's a short time-lapse video I took of the computer collecting data and a photo of the probe with the DPPH in the EPR device:

Day 9

In the morning I started researching for online tools that would enable us to create an intensity plot based off the data matrices we had made yesterday. After lunch, Dr. Hornak used photoshop to make the plots larger and clearer. Then we compared the plots to ones that Dr. Hornak had created a few years ago. We noticed that our graphs looked different so we started brainstorming errors that could have occurred that would have affected the data. Upon examining the EPR machine we noted that the sample pipet was twisted slightly, affecting the distance the DPPH sample was from the RF probe which in turn affected our results. After learning this we went and recollected the data we had taken yesterday.

Day 8

Today I mainly took measurements with the RF probe. To do this Celia (an RIT student who also works in the lab) and I set the RF probe to a specific position and then started the LFESR program on the computer to collect data Then the RF probe would be moved slightly and the program would collect data at that point. It takes around 50-60 seconds for the program to finish collecting data for each point so we spent most of the day collecting data for around 100 different positions. We also made a matrix of the data we collected representing the change in position in the YZ plane and XZ plane.

In the picture below the YZ plane is outlined in orange and the XZ plane is in green

Abstract draft-updated

Electron Paramagnetic Resonance (EPR) Spectroscopy is a technique for studying paramagnetic species.   Low Frequency Electron Paramagnetic Resonance (LFEPR) spectroscopy is a variation of EPR that was developed to study larger objects (around 15 cm in diameter) containing paramagnetic species non-invasively. The LFEPR Mobile Universal Surface Explorer (MOUSE) spectroscopy is a further variation of the technique that is expected to enable the study of paramagnetic species on surfaces. Similar to LFEPR, EPR MOUSE has two main components: (i) the magnet and (ii) the radio frequency (RF) probe.  

The ability of the EPR MOUSE to non-invasively analyze objects allows it to assist in studying the surface of culturally significant artifacts. The purpose of this project is to characterize the magnetic field of various magnet designs that can be used in the construction of the EPR MOUSE, and assess the sensitivity of the radio frequency (RF) probe, which will then determine the concentration of the paramagnetic species that can be detected. The magnetic field of various magnet designs will be simulated using the Finite Element Method Magnetics software, and the accuracy of the models will be assessed using experimental measurements. The sensitivity of the RF probe will be measured under specific conditions with species that have stable free radicals. The characterization of the magnetic field and the measurement of the sensitivity of the RF probe will help us in the final design and construction of the EPR MOUSE spectrometer.




Old version:

Electron Paramagnetic Resonance (EPR) Spectroscopy is a technique for studying paramagnetic species.   Low Frequency Electron Paramagnetic Resonance (LFEPR) spectroscopy is a variation of EPR that was developed to study larger objects non-invasively (around 15 cm in diameter) containing paramagnetic species. The LFEPR Mobile Universal Surface Explorer (MOUSE) spectroscopy is a further variation of the technique that is expected to enable the study of paramagnetic species on surfaces. Similar to LFEPR, EPR MOUSE has two main components: (i) the magnet and (ii) the radio frequency (RF) probe.  

The ability of the EPR MOUSE to non-invasively analyze objects allows it to assist in studying the surface of culturally significant artifacts. The purpose of this project is to characterize the magnetic field of various magnet designs that can be used in the construction of the EPR MOUSE, and assess the sensitivity of the radio frequency (RF) probe, which will then determine the concentration of the paramagnetic species that can be detected. The magnetic field of various magnet designs will be simulated using the Finite Element Method Magnetics software, and the accuracy of the models will be assessed using experimental measurements. The sensitivity of the RF probe will be measured under specific conditions, using DPPH (2,2-diphenyl-1-picrylhydrazyl), which contains stable free radicals, and is used as a reference material for EPR measurements. The characterization of the magnetic field and the measurement of the sensitivity of the RF probe will help us in the final design and construction of the EPR MOUSE spectrometer.

Day 7

After the morning meeting today, I went down to the lab. Dr Hornak tried to set up the RF probe and find the signal to start characterizing it's sensitivity. However, the signal kept disappearing and there were a lot of other signals & noise as well. We eventually figured out why the signal kept disappearing—we had used superglue to stick the DPPH sample to the RF probe (DPPH has a paramagnetic signal so it can be used to determine the sensitivity of the probe). The superglue apparently reacted with the free radical in the DPPH which impacted the signal. To solve this we used a glue stick to stick the DPPH to the probe—the glue from the glue stick did not react with the DPPH.  Even after solving this issue, it was still difficult to see the signal, and we had difficulty in characterizing the RF probe's sensitivity with this signal. Dr Hornak started to look at this issue more closely,  trying to figure out how to fix the RF probe. After lunch, I generated some data using another RF probe and began graphing the data. On Monday we will look more closely at this data to determine the center of the probe.

Day 6

In the morning meeting today Matt showed us a video about imaging science at RIT and the freshman project. Once I got to my lab, I continued to refine the graphs I had made. I also learned more about my project.  For my project, I will be, in addition to modeling the magnetic field and creating plots, measuring the sensitivity of the RF (radio frequency) probe. After eating lunch with the other interns I returned to my lab and added some more data points to the graph to make it more accurate. I found out that one reason the FEMM model was not as accurate with respect to the measured Z data was because the model did not generate enough data points for it to be accurate on a small scale. To fix this, I made the model generate 1500 data points (10x more than before) for the Z data. When I compared this set of data to the measured Z data they were closer. Once I finished this I read about writing abstracts online and worked a little bit on my blog. I also learned how to take measurements with the RF probe. I am looking forward to continuing my project.

Day 5

This morning Matt showed us a short video about imaging science before we all left to go to our labs. In my lab I created some more excel plots with the data we had obtained from the FEMM models. After finishing up the graphs on the Y values (that I was working on yesterday), I started on similar graphs, except I used the measured Z values.
After a short lunch, I went back to my lab and continued working on the graphs. I found out that the measured data for the Z plots do not match the FEMM models as well as the Y data did.
Here's a sketch I made that details the Y and Z directions with respect to the iron yoke. (We are measuring the magnetic field above the iron yoke).

Day 4

Today I modeled one of the iron yokes for the LFEPR device using the FEMM software. Once I had the 2D  model completed I exported the data into Excel and started creating graphs. I created plots of the magnetic field above the yoke at 4 different points (at the center, 0.5mm from the center, 1mm from the center, and 1.5mm from the center). Shortly before lunch some of the other interns came and I showed them what I was doing. After lunch, I worked on converting the graphs of the measured magnetic field for the yokes from graphs of signal vs y to magnetic field vs y. Then I compared those to the graphs of the predicted magnetic field (the ones based off the FEMM models). I also converted the data I had from the FEMM model from inches to millimeters because the measured data was in millimeters. I am looking forward to learning more about my project tomorrow.

Here are some of my results:
This graph includes the data  from the measured and predicted magnetic field (the measured data is in blue, the predicted in red). I had to scale the measured data to make it fit with the predicted data. Once the data was scaled, however, it is clear that the FEMM model is fairly accurate.
The magnetic field is stronger at the left of the graph (where the Y values are lower).

 

Day 3

In the morning meeting today we learned about how to write an abstract and the type of abstract we would be writing for our presentation (a descriptive abstract). In the morning I mainly reviewed the notes I had taken on LFEPR and EPR. I then had the opportunity to go around and see what the other interns were doing and I learned about projects in the visual perception and machine vision and document restoration labs. Right before lunch I read through some tutorials on how to use a software called Finite Element Method Magnetics which I will be using in my project. I then experimented with the software and gained a better understanding of how to use it.

Day 2

After the morning meeting I met with Dr Hornak and learned a little more about EPR (electron paramagnetic resonance) spectroscopy and LFEPR (low frequency electron paramagnetic resonance) spectroscopy. I learned about some of the disadvantages of LFEPR (the signal to noise ratio is not as good). I also learned more about the project and what I would be doing in the coming weeks. Then we went down to the lab where I watched how they used the MOUSE instrument. I took notes and then spent some time writing up instructions for the use of the EPR-MOUSE as well. I met some of the other interns for lunch in the reading room. Then I returned to the lab and read a little more about EPR and finished up creating the instructions. After reviewing the instructions and making some changes I read some more articles on EPR. I also read a chapter from a book on EPR.

Day 1

Today was the first day of my internship in the magnetic resonance imaging group at the Center for Imaging Science at RIT. In the beginning of the day all of the interns went to the Red Barn for team building exercises. These exercises were fun and taught us about problem solving and the idea of reaching a consensus in a group. After the team building exercises we went back to the reading room and had pizza for lunch. After lunch a few of us went to complete the in-processing.
After I got my ID and computer account I went to meet my lab group. I first met with Professor Hornak and he taught me about EPR and the goals for the LFEPR device that he and his group were working on. Then he showed me the lab and the LFEPR device there. He gave me some posters and notes to read regarding EPR and LFEPR. I took these to the lab and took notes on them.  I found the concepts interesting and I am looking forward to a very fun internship.