Part I: Producing X-rays from adhesive tape
A Collaboration with Johnny Lu
Continuing with our previous build we made some progress. After attempting a higher vacuum without success using an oil diffusion pump we later sought the assistance of Kent Lab at NYU Physics. Andy Kent and Pradeep Subedi generously let us use their turbo pump after which we surpassed our desired pressure of 10−4 Torr and reached a vacuum of 10−6 Torr.
At this pressure we observed greater triboluminescence, but failed to detect any X-Rays using two different geiger-mueller tube detectors. No phosphorescence was observed with our Gadolinium phosphors either.
We considered the possibility that our motor speed was insufficient. Our initial build used a 24v 40RPM geared motor that we later ran at 36v briefly to see if any improvement would result. This is not the right way to make a motor run faster!
We later rebuilt our tape pulling assembly entirely with a new motor (a disassembled cordless drill) which gave the needed torque and the variable speed control that we lacked before. Using the refitted chamber we attempted once again at Kent Lab and observed an even greater increase in triboluminescence with the motor running at full speed, but still no X-Rays were detected.
At present we are considering how we will continue towards a successful build. So far this investigation has led us through a series of multilayered technical problems, from which we have had the pleasure to learn a great deal.
Possible problems and solutions:
Materials: Tribolelectric similarities between chasis material of our tape pulling assembly (cast acrylic sheet) and the Scotch tape film and polymer adhesive. On the the tribolectric series both Plexiglass (methyl methacrylate) and adhesive tapes tend to be in the same range.. about -10 nC/J (nano ampsec/wattsec of friction). It’s unclear if changing the chasis material would have an effect, but it may be the next step.
Detection: Another possibility that Daniel Bedau, a research scientist at NYU Physics, suggested is that our detection methods may be inadequate, and that we may possibly be producing X-Rays but at such rapid or sporadic pulses that the basic circuitry on our Geiger counter simply can’t detect them. Another possibility is that our relatively thick .71″ cast acrylic window on our chamber can’t be penetrated by the X-Rays being produced. We should try alternate methods of detection which could include using a scintillator device or something as simple as a Kearny Fallout Meter —a simple to build radiation detector that is particularly sensitive to low level radiation.
Part II: The Effects of Ionizing Radiation On Plant Growth and Mutation
Our Exposure Candidates: Pumpkin seeds and Sunflowers seeds
We exposed two groups of seeds, one at 0.1 mSv and the other at 0.2 mSv using a Gendex 765DC Intraoral X-ray Unit. We germinated the exposed seeds alongside control groups under identical conditions. Below are the initial observations after one week of growth.
Though no significant loss (ungerminated seeds) was apparent against the controls, there was significantly less growth with the X-Ray exposed sets. It is unclear so far if any genetic mutation has taken place. Further observation will be needed.
Part III: The Effects of Aqueous Ferro Fluid and Magnetic Fields On Plant Growth
As outlined in a previous post, we investigated the effects of ferrofluid injection on vascular plant growth. Our test plants were the homely pumpkin and the joyous sunflower.
As the end target for our ferrofluid was injection into plants, we were unable to directly purchase the usually kerosene-based pre-made ferro fluid but instead had to formulate a water-based ferrofluid that replaces chemicals such as tetramethylammonium hydroxide (used as a surfactant) in the synthesis of our ferro fluid for more plant-friendly replacements such as oleic acid, linoleic acid, and citric acid.
We purchased from Sigma-Aldrich the following chemicals:
- 12.0 M Hydrochloric Acid
- Iron(II) Chloride Tetrahydrate
- Iron(III) Chloride Hexahydrate
along with store bought ammonia, distilled water, and the aforementioned oleic acid, linoleic acid, and citric acid.
We ended up making several batches of ferrofluid, basically following the instructions found here, but for slightly smaller portions and having to recreate their concentrations for solutions by diluting our own heavily concentrated solutions.
We split the resulting batch of magnetite in three so that we could test the three different replacement surfactants.
Unfortunately, we may have left the magnetite for too long after synthesizing them and it looked as though some of the particles had aggregated into larger particles. We also found that our test surfactants with linoleic and oleic acids did not seem to pan out very well.
Shortly after, we made another run with a smaller batch. The resultant magnetite particles seemed better and we were armed with a larger magnet. Our results were still not quite behaving the same way as ferrofluid was expected and we decided to run a separate test batch using a different method found in this paper. Instead of using hydrochloric acid as in the initial batches, we decided to heat the mixture of ferric and ferrous salts in distilled water to 80ºC while vigorously stirring to accelerate the process. While far more time consuming, this method seemed to generate better ferrofluid with little noticeable clumping though there was an unexplained slightly red tint to our ferrofluid. We decided to use the ferrofluid from this batch, using a citric acid surfactant, as the base for our plant treatment.
Application to plants
The resulting ferrofluid was mixed with water in two separate concentrations (a lower concentration .5 ml of ferrofluid diluted in 10 ml of water and a higher concentration of 10 ml of ferrofluid diluted in 10 ml of water). Each of these ferrofluid concentrations were then injected directly into ten seeds each of two separate fast-growing plants: the lowly pumpkin and the kingly sunflower. These seeds were from the same source and were randomly assigned to a high concentration, low concentration, and control (no ferrofluid injection) groups.
We used an insulin needle to apply these solution and placed these within moistened cotton balls in order to let them sprout along with strong rare earth magnets that were placed above the seeds. Our initial results showed that the high concentration was somewhat antithetical to life as seeds for both plants quickly developed a terrible mold and seemed more or less sterile with the exception of two seedlings for each plant. The low concentration group for sunflowers, surprisingly, were the first to sprout and seemed to orient themselves towards the magnet despite not having a strong vascular system. The control group for both plants and the low concentration group for pumpkins sprouted later than the low concentration group for sunflowers. These initial results were heartening.
After a period of five days, the seedlings were transported into small plots of potted soil. The low concentration sunflowers continued to grow, but soon after (and currently), the control sunflower group overtook them in growth. However, the low concentration group has shown a far greater survival/sprouting rate in that there are more.
|Survival Rate (out of ten)||Sunflower||Pumpkin|
|Control, no ferrofluid||4||6|
While the surviving sunflower control group seems to have matured greater than our low concentration sunflowers, the survival rate seems to be much in the latter’s favor. We recognize that this is a very small sample group, but feel this might be promising for further research.
Unfortunately, we were unable to create a good controlled environment in terms of equal distribution of magnetic fields so are unable to make any conclusions about how that might have changed the growth patterns of our plants and is something to pursue later.