GAS SENSOR APPLICATIONS WITH PHOTONIC CRYSTAL FIBER AND CARBON DIOXIDE SENSOR DESIGN
It’s very important to control and monitor gases that are produced by industrial applications in different values and kinds because they can cause environmental pollution and health problems. Photonic Crystal Fiber (PCF), which is a different kind of optical fiber, is a new alternative for gas sensors due to their small sample volumes, low transmission losses and high flexibility properties. PCF’s are silica-glass fibers, made by periodic sequence of hollows along the fiber. By filling these hollows with optical liquids or gases very sensitive sensors can be made. In this project, we aimed to design a sensitive sensor by filling the hollows with proper gases and liquids in the solid core PCF. For these applications ethanol, methanol, toluene vapors and carbon dioxide was used. And to observe carbon dioxide’s effects ionic liquid (EMIMBF4), which carbon dioxide can dissolve in, was filled then the experiments were repeated. It was observed that the transmission of light in PCF changed depending on the refractive index of the gas that was filled. With this change, it was understood that there were another gas besides the usual containments of air. Our system could measure the absorbtion peak of toluen so it can be used as a toluen dedector and when ionic liquid filled the fiber, two steps that occur in the spectra of corbon dioxide so it can also be used as a carbon dioxide dedector. The system was customized as a carbon doxide sensor in a cost-efficient and portable way. Our system can be specialized and easiliy used with right light source, which is efficient to see the absorbtion peaks, and proper liquids to dedect intended gas. Making a carbon dioxide sensor by filling PCF with ionic liquid was never attempted before. Also the lack of carbon dioxide sensor studies supports the originality of our project. That’s why we think our project will contribute very importancies to the existing literature.
Random number generators and their applications in Computer Science with the Monte Carlo Method
Monte Carlo methods are non-parametric algorithms that use random numbers and theorems of probability theory to approximate values that are not random. The purpose of my research was to approximate the surface of different geographical areas that can be easily approximated to polygons (e.g. lakes, glaciers, deserts) with Monte Carlo simulations starting from either Cartesian coordinates or pictures. Computer science would not exist without math, and this research project showed me the importance of a deep understanding of probability theory in the world of simulations and, more generally, the importance of developing new theorems and algorithms. The results of my research could be developed in different ways: it would be interesting to produce software that allows one to approximate areas from pictures taken from a smartphone; as well, the theorem I found has to be proven, and also Monte Carlo methods as a means of random number generation can always be improved. There are still many possibilities.
The Levitating Ball
This project was inspired by a tournament call the International Young Physicist’ Tournament (IYPT). The problem could be broken into two aims: ‘Investigate the forces that cause a ball to levitate in a titled airstream’ and ‘optimize the system for the maximum angle of tilt that results in a supported ball’. The first stage of the investigation was research and learning. Two fluid mechanics courses online were used to build a basic of knowledge of the subject. Next a force diagram was created to model the forces acting on the ball. The diagram identified a force called the lift force that must be acting on the ball to be supported. There were three contending theories that could explain the lift force: The Bernoulli theory, the Coanda theory and the Magnus theory. A practical investigation was then instigated to differentiate between these three theories. Since the Magnus theory is only applicable if the ball is spinning in the airstream, this theory was isolated by changing the center of mass of the ball but keep everything else constant (this allowed control of how much the ball spun in the airstream). Changing the center of mass didn’t impact on the maximum angle of tilt at all, proving that the spinning of the ball isn’t producing a significant amount of lift, and therefore the Magnus theory couldn’t be a cause for lift. Because further testing couldn’t isolate the Coanda and Bernoulli theories, a solution was developed to explain why the two remaining theories might co-exist. Further testing methods have been designed to investigate this possibility in more depth. To meet the second aim of this project, an investigation was launched to see how parameters affected the maximum angle that the ball could be supported at. The parameters investigated were: Ball radius, ball mass, ball surface, air speed and airstream diameter. A lot of time was spent creating a reliable experimental method. The method could be used to support a ball in an air stream, slowly tilt the air stream, and then measure the angle of tilt the moment that the ball fell out. After experimentation, a table was created to describe how the listed parameters affect the maximum angle of tilt that a ball can be supported at. Explanations were proposed for why each parameter affected this angle. Future experiments have been devised to build a deeper understanding of the effects of a wider range of parameters.
Totarol
Research Question: To what extent does totarol show antibiotic potency against significant strains of Staphylococcus aureus causing skin and soft tissue infections in New Zealand, compared with commonly prescribed drugs used to treat the specific strain of Staphylococcus aureus being tested? Purpose of research: This essay will investigate the antibacterial potency of totarol against significant strains of Staphylococcus aureus (S.aureus) causing skin and soft tissue infections (SSTIs) in New Zealand. Only a small amount of research on totarol has been conducted. They all suggest totarol possesses antibiotic potency against various species of bacteria. The mode of action of totarol is currently unknown. Procedure 1: The totarol I ordered from Mende Biotech Ltd arrived in two forms; a powder called Totarol™ and a viscous brown liquid called Liquid K7 (LK7) in which the Totarol™ powder was dissolved in mostly sunflower oil. The investigation took place in two stages. In the first stage, the MIC value of the LK7 against reference strain S.aureus 29213 was determined by following the CLSI methodology for MIC testing (M07-A9 Clinical and Laboratory Standards institute). The MIC test was also conducted to identify whether any major ingredients in the LK7 possessed significant antibacterial potency. MIC values where compared with that of flucloxacillin. Data from stage 1 testing: LK7 had an MIC value of 1µg/mL, which was very similar to flucloxacillin’s MIC value of 0.5µg/mL. No other major ingredients in LK7 showed antibacterial potency. Totarol™’s antibacterial activity could not be accurately measured, due to the powder resisting even mixing. Procedure 2: In the second stage, disc diffusion tests were conducted against various S.aureus clinical isolates obtained from SSTIs in the Waikato community. The discs that were placed for each clinical isolate included LK7, cefoxitin, fusidic acid, mupirocin and erythromycin discs. Data from stage 2: 75% of LK7 discs produced double zones of inhibition. I hypothesized that this was due to two active ingredients found in the LK7. I predicted the one that produced larger zones of inhibition to be Totarol™. The other more stable ingredient producing the inner zones of inhibition is unknown. Conclusion: I proposed a breakpoint of outer zone sizes that were ≥ 15 mm in diameter to signify that that particular clinical isolate was ‘susceptible’ to LK7. From this breakpoint, LK7 and fusidic acid both had the same number of clinical isolates that were classified as ‘susceptible’. LK7 was the median of the number of susceptible clinical isolates. This data answered my research question; totarol in the LK7 form specifically, would be just as effective in treating SSTIs caused by S.aureus, as even the most commonly prescribed antistaphylococcal drugs currently being used.