1.3 Radio Frequency Glow Discharge (RFGD) Treatment
A typical Radio Frequency Glow Discharge (RFGD) device consists of a chamber filled with dilute gas (e.g. Oxygen/ Air, Carbon Tetrafluoride or Argon), and a coil wrapped around the chamber that gives the voltage needed to excite the gas (Figure 1.3). The gas in the chamber ionizes (i.e. becoming a plasma) when the voltage hits the striking voltage and starts conducting electricity, causing it to glow. The color depends on the gas used. The RFGD treatment involves the removal of impurities and weakly bound organic contamination from surfaces through the use of the energetic plasma created from gaseous species. The device is connected to a vacuum to remove all atmospheric contaminants and debris produced throughout the process. RFGD can treat a wide-range of materials as well as surfaces with high level of roughness and different geometries. It can be applied to samples that are electrically conductive or non-conductive, whether bulk solids or layered materials. It is very important that the RFGD has his ability, which expands the use of analytical methods that are based on the use of the glow-discharge.
Figure 1.3 – A simple RFGD treatment device. Before Treatment (left), during treatment (right). (308 Squire Hall, SUNY UB 2016)
Plasma Treatment
Plasma, one of the four fundamental states of matter, exists in the form of ions and electrons. Basically, plasma is any ionized gas that has extra electrons. Plasma is electrically conductive because of the presence of charge carries. Moreover, plasma acts like a gas; no definite shape or a definite volume. Plasma is abundant in the universe; natural occurrences are seen in lighting and the Aurora Borealis (northern ligh...
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...ettability, sanitized, and ready for further processing. During this process, light is emitted (discharged) by the excited gas molecules and atoms in the plasma. As the atoms and molecules “relax” to their normal, lower energy states they release photons of light. This is what causes plasma to "glow". Treatment generally takes only about two to three minutes. Using a different gas can provide a different outcome. For example, treating with carbon tetrafluoride (CF4) plasma forms hydrophobic coatings of fluorine-containing groups (CF, CF2, CF3) and decreases the number of hydrophilic polar end groups on surfaces; this decreases surface wettability.
Figure 1.4 – Schematic of cleaning of a substratum using plasma glow discharge. Note the removal of adsorbed molecules by bombardment on the surface and the presence of dangling bonds (Wikipedia – the Free Encyclopedia).
This experiment was conduct to investigate the fluorescent behaviour of Leucophor PAF and to investigate the quenching of QBS with NaCl. It was found that the Leucophor PAF indeed satisfied the characteristic to act as whitening agent. It was also found that the quenching of QBS with NaCl was a diffusion-controlled collision process.
In the article,"Energy Story", it tells you all about basic energy and how scientists found out how it works. It tells you about each part of an electron and what part is what. The center is called the Nucleus. Electrons and atoms move together to create what is known as electricity. Atoms and electrons flow through an object
Glow sticks get their “glow” when two chemicals are mixed together because of a chemical reaction. The chemical reaction is called Chemiluminescence. A Typical glow stick has a plastic tube with a smaller inner tube inside. There are three components, two chemicals and a fluorescent dye which accepts the energy and helps covert to light. There is more than one way to make a glow stick, but the most common uses a solution of hydrogen peroxide and phenyl oxalate ester along with the fluorescent dye. The hydrogen peroxide is in its own compartment away from the other two components until ready to use. The fluorescent dye is what determines the subsequent color of the glow stick when the chemical solutions are combined.
Isolaz laser treatment has three basic stages. The cost and length of treatment varies depending on the problem and the total size of the area of skin that you wish to be treated. In a typical session of isolaz treatment, the isolaz hand device is applied on the affected area. Then, a vacuum is used that helps to raise that part of skin. The vacuum at the same time (again, that depends on the reason of treatment) may loosen and suck out the oil, dirt and other impurities or softens the black heads. The vacuum treatment can alone deep clean your pores. The laser is then switched on to help zap those bacteria, dead skin cells, brown or red patches, hair or ...
Light sticks work in a similar way. When you “snap” a light stick, the chemical in the glass capsule mixes with a chemical in the plastic tube and creates light energy. Instead of the chemicals used by a firefly, other chemicals are used to create a glow. The light stick that you can buy at a store usually contains hydrogen peroxide, phenyl oxalate ester, and fluorescent dye (New York Times Company, 1 of 3). The light stick will glow the same color as the fluorescent dye placed in it. In luminescence, the chemical reaction “kicks an electron of an atom out of its ‘ground’ (lowest-energy) state into an ‘excited’ (higher-energy) state, then the electron give back the energy in the form of light so it can fall back to it’s ‘ground’ state (Fluorescent Mineral Society, 1 of 2).
Skiba, R. J., Horner, R. H., Chung, C. G., Karenga-Rausch, M., May, S. L., & Tobin, T.
Steam sterilisation is the process where “dry saturated steam comes into contact with a cooler surface, that causes water condensation and immediate release of the latent heat” (Rohanizadeh, 2016). This process was carried out in an autoclave and is the preferred method of sterilisation as the ampoules are sealed and made from glass. Being sealed causes a high amount of pressure to build up inside the ampoule, though in an autoclave they will not burst due to the high pressure in the autoclave equalizing and compensating for the high pressure in the ampoule. If a dry heat method of sterilisation was used, e.g. an oven, the ampoules would burst due to evaporation of the solution occurring, and no compensation or equalised pressure availability, like we see in the autoclave.
Wood, W. M., Karvonen, M., Test, D. W., Browder, D., & Algozzine, B. (2004). Promoting
Polman, H., Orobio De Castro, B. & Van Aken, M. A.G. (2008). Experimental Study of the
Duley, S. M., Cancelli, A. A., Kratochwill, T. R., Bergan, J. R., & Meredith, K. E. (1983).
2. Clean the surface of a 20 cm strip of magnesium ribbon using steel wool
Flame retardants refer to a class of several chemicals that are used to slow or prevent the ignition or growth of fires. A variation of different chemicals, with diverse properties and structures, are combined in different ways to suit the different types of materials to make them fire-resistant without interfering with their intended use or performance. Since the 1970’s, FRs have been and still are widely added or applied to a big variety of major consumer products.
The ingredients that will be included are: dish soap, 30% hydrogen peroxide, potassium iodide, and corn starch. Adding the cornstarch to the mixture has a chemical reaction to the hydrogen peroxide. It will have light and dark patches due to the uneven placement of the cornstarch; it will have an uneven reaction. Which will then make it appear “glowing”. The fourth experiment is very similar when it comes to the ingredients the only thing that changes is that we are no longer using potassium iodide but we are using yeast instead. Also, since yeast is being used, we are adding in fluorescent dye to it so we can shine a UV (ultraviolet) light on it to see the reaction occurring. Using the dye under a light helps us observe the reaction between the dye and cornstarch. I had to replace the potassium iodide with yeast for a slow reaction and also so it is possible to use the dye. In both of these experiments the reaction is a massive production of foam. The hydrogen peroxide will be decomposed into water and by the oxygen by the iodide and/or the yeast. A substance called catalyst speeds up the
As x-rays exit the patient, they interact with a cesium iodide input phosphor which converts the x-ray energy into visible light. Cesium iodide crystals are a tightly packed layer of linear needles which help improve spatial resolution by allowing little light dispersion. Attached to the input phosphor is the photocathode. Bushong describes the photocathode as, “a thin metal layer usually composed of cesium and antinomy compounds that respond to stimulation of input phosphor light by the emission of electrons.” (Bushong, 2013, p. 405). This phenomenon of electron emission following light stimulation is called photoemission. The emission of just one electron through photoemission is dependent upon numerous light photons. The amount of electrons produced by the photocathode is directly proportional to how much light reaches it from the input phosphor, which is directly proportional to the intensity of the initial x-ray beam. These electrons will be accelerated to the anode where they will pass through a small hole to the output phosphor. The output phosphor, made of zinc cadmium sulfide, is where the electrons produced through photoemission will interact and produce light. It is extremely
What type of gas do they disperse in the chamber? The type of gas that