🔥🔥🔥 Non Ionizing Radiation Research Paper
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M4.7: Non Ionizing Radiation
It does not involve anesthesia or an incision and the side effects tend to be mild, including some redness and irritation at the treated site. Cosmetic dermatologist Dr. Goldberg serves on the medical advisory board of Sensus Healthcare, a company that designs and manufactures SRT equipment. SRT is not the first-line treatment for basal and squamous cell skin cancers, though, and some skin cancer specialists don't use it at all.
Mohs pronounced "moes" is a specialized procedure in which the surgeon removes the cancerous tissue layer by layer, explained Thomas, who is also the director of the Mohs unit at MD Anderson. During the surgery, the surgeon uses a microscope to look at the tissue that was removed to check for cancer cells. The surgeon will continue to remove a very small amount of skin at a time and look at it under the microscope until there are no more cancer cells. Mohs surgery causes less scarring and has a shorter healing period than removing the entire area at once.
There's less than a one percent recurrence rate. We use it rarely because we do have access to surgical modalities that give a very high cure rate and have low morbidity. And we're not causing more damage," she said. Younger patients run the risk that the radiation treatment could increase the odds of later skin cancer in the same spot, she explained. But even the chance of minimal scarring that can come with some Mohs surgery puts some patients on edge, and SRT can be an appealing option, especially if their cancer is in plain sight on the face — the nose, the eyelid, lips or ear.
This one in particular was beneath my nose, a little white dot I thought was a pimple that wasn't going away. Hefferen, who has very fair skin, tanned without using sunscreen when she was younger and admits to using tanning beds at times, too. Her dermatologist recommended Mohs surgery after the biopsy came back positive, so she went to see a surgeon near where she lives in New York City about the procedure. With that I got a little scared," said Hefferen. She held off for about eight months, reconsidering her options, until her doctor urged her to make a decision because leaving non-melanoma skin cancer untreated for too long can cause the cancer to spread and become more serious.
Hefferen came across Dr. Goldberg's name online and went to see him at his office in New Jersey to discuss SRT, an option her dermatologist wasn't aware of, she said. She traveled from New York to New Jersey by bus twice a week for eight weeks for treatments. Most visits, she was in and out in 45 minutes, with the preparation for the treatment taking longer than the actual treatment time. Since it was close to my face, they had to do lead glasses over my eyes and tape lead plates around my nose so it would just show that one spot. They literally taped my face," she said. There was a little redness over the weeks, but nothing make-up couldn't cover up, she said. Now, three years later, Hefferen says she's happy with her choice.
She'll continue to go for regular skin cancer checkups for new spots and to be sure the SRT-treated spot does not develop any problems, she said. SRT has been around a long time, dropped out of favor, and now is more popular again, said Dr. Mark S. Nestor, voluntary associate professor in the department of dermatology and cutaneous surgery at the University of Miami Miller School of Medicine. It was utilized for tens of thousands of skin cancers through the 's, then it waned due to the lack of equipment being produced," Nestor told CBS News. Over the last five years, though, it's making a resurgence as new SRT equipment has been developed and sold to doctor's offices like Goldberg's and Nestor's.
The machines aren't everywhere, but Nestor said, "Thousands of individuals have been able to receive treatment around the country. There's been "a tremendous uptick" in the use of SRT, said Nestor, who is a consultant and advisory board member for Sensus Healthcare, the SRT equipment maker, and has received research grants from the company. Both alpha and beta particles have an electric charge and mass, and thus are quite likely to interact with other atoms in their path. Gamma radiation, however, is composed of photons, which have neither mass nor electric charge and, as a result, penetrates much further through matter than either alpha or beta radiation.
Gamma rays can be stopped by a sufficiently thick or dense layer of material, where the stopping power of the material per given area depends mostly but not entirely on the total mass along the path of the radiation, regardless of whether the material is of high or low density. The atmosphere absorbs all gamma rays approaching Earth from space. Even air is capable of absorbing gamma rays, halving the energy of such waves by passing through, on the average, ft m. Alpha particles are helium-4 nuclei two protons and two neutrons. They interact with matter strongly due to their charges and combined mass, and at their usual velocities only penetrate a few centimeters of air, or a few millimeters of low density material such as the thin mica material which is specially placed in some Geiger counter tubes to allow alpha particles in.
This means that alpha particles from ordinary alpha decay do not penetrate the outer layers of dead skin cells and cause no damage to the live tissues below. However, they are of danger only to astronauts, since they are deflected by the Earth's magnetic field and then stopped by its atmosphere. Alpha radiation is dangerous when alpha-emitting radioisotopes are ingested or inhaled breathed or swallowed. This brings the radioisotope close enough to sensitive live tissue for the alpha radiation to damage cells.
Per unit of energy, alpha particles are at least 20 times more effective at cell-damage as gamma rays and X-rays. See relative biological effectiveness for a discussion of this. Examples of highly poisonous alpha-emitters are all isotopes of radium , radon , and polonium , due to the amount of decay that occur in these short half-life materials. It is more penetrating than alpha radiation but less than gamma. Beta radiation from radioactive decay can be stopped with a few centimeters of plastic or a few millimeters of metal. It occurs when a neutron decays into a proton in a nucleus, releasing the beta particle and an antineutrino.
Beta radiation from linac accelerators is far more energetic and penetrating than natural beta radiation. It is sometimes used therapeutically in radiotherapy to treat superficial tumors. When a positron slows to speeds similar to those of electrons in the material, the positron will annihilate an electron, releasing two gamma photons of keV in the process. Those two gamma photons will be traveling in approximately opposite direction. The gamma radiation from positron annihilation consists of high energy photons, and is also ionizing. Neutron radiation consists of free neutrons. These neutrons may be emitted during either spontaneous or induced nuclear fission.
Neutrons are rare radiation particles; they are produced in large numbers only where chain reaction fission or fusion reactions are active; this happens for about 10 microseconds in a thermonuclear explosion, or continuously inside an operating nuclear reactor; production of the neutrons stops almost immediately in the reactor when it goes non-critical.
Neutrons can make other objects, or material, radioactive. This process, called neutron activation , is the primary method used to produce radioactive sources for use in medical, academic, and industrial applications. Even comparatively low speed thermal neutrons cause neutron activation in fact, they cause it more efficiently. Neutrons do not ionize atoms in the same way that charged particles such as protons and electrons do by the excitation of an electron , because neutrons have no charge. It is through their absorption by nuclei which then become unstable that they cause ionization. Hence, neutrons are said to be "indirectly ionizing. Not all materials are capable of neutron activation; in water, for example, the most common isotopes of both types atoms present hydrogen and oxygen capture neutrons and become heavier but remain stable forms of those atoms.
Only the absorption of more than one neutron, a statistically rare occurrence, can activate a hydrogen atom, while oxygen requires two additional absorptions. Thus water is only very weakly capable of activation. The sodium in salt as in sea water , on the other hand, need only absorb a single neutron to become Na, a very intense source of beta decay, with half-life of 15 hours. In addition, high-energy high-speed neutrons have the ability to directly ionize atoms. One mechanism by which high energy neutrons ionize atoms is to strike the nucleus of an atom and knock the atom out of a molecule, leaving one or more electrons behind as the chemical bond is broken.
This leads to production of chemical free radicals. In addition, very high energy neutrons can cause ionizing radiation by "neutron spallation" or knockout, wherein neutrons cause emission of high-energy protons from atomic nuclei especially hydrogen nuclei on impact. The last process imparts most of the neutron's energy to the proton, much like one billiard ball striking another. The charged protons and other products from such reactions are directly ionizing. High-energy neutrons are very penetrating and can travel great distances in air hundreds or even thousands of meters and moderate distances several meters in common solids.
They typically require hydrogen rich shielding, such as concrete or water, to block them within distances of less than a meter. A common source of neutron radiation occurs inside a nuclear reactor , where a meters-thick water layer is used as effective shielding. There are two sources of high energy particles entering the Earth's atmosphere from outer space: the sun and deep space. The sun continuously emits particles, primarily free protons, in the solar wind, and occasionally augments the flow hugely with coronal mass ejections CME.
The particles from deep space inter- and extra-galactic are much less frequent, but of much higher energies. These particles are also mostly protons, with much of the remainder consisting of helions alpha particles. A few completely ionized nuclei of heavier elements are present. The origin of these galactic cosmic rays is not yet well understood, but they seem to be remnants of supernovae and especially gamma-ray bursts GRB , which feature magnetic fields capable of the huge accelerations measured from these particles. They may also be generated by quasars , which are galaxy-wide jet phenomena similar to GRBs but known for their much larger size, and which seem to be a violent part of the universe's early history.
The kinetic energy of particles of non-ionizing radiation is too small to produce charged ions when passing through matter. For non-ionizing electromagnetic radiation see types below , the associated particles photons have only sufficient energy to change the rotational, vibrational or electronic valence configurations of molecules and atoms. The effect of non-ionizing forms of radiation on living tissue has only recently been studied. Nevertheless, different biological effects are observed for different types of non-ionizing radiation. Even "non-ionizing" radiation is capable of causing thermal-ionization if it deposits enough heat to raise temperatures to ionization energies. These reactions occur at far higher energies than with ionization radiation, which requires only single particles to cause ionization.
A familiar example of thermal ionization is the flame-ionization of a common fire, and the browning reactions in common food items induced by infrared radiation, during broiling-type cooking. The electromagnetic spectrum is the range of all possible electromagnetic radiation frequencies. The non-ionizing portion of electromagnetic radiation consists of electromagnetic waves that as individual quanta or particles, see photon are not energetic enough to detach electrons from atoms or molecules and hence cause their ionization. These include radio waves, microwaves, infrared, and sometimes visible light. The lower frequencies of ultraviolet light may cause chemical changes and molecular damage similar to ionization, but is technically not ionizing.
The highest frequencies of ultraviolet light, as well as all X-rays and gamma-rays are ionizing. The occurrence of ionization depends on the energy of the individual particles or waves, and not on their number. An intense flood of particles or waves will not cause ionization if these particles or waves do not carry enough energy to be ionizing, unless they raise the temperature of a body to a point high enough to ionize small fractions of atoms or molecules by the process of thermal-ionization this, however, requires relatively extreme radiation intensities.
As noted above, the lower part of the spectrum of ultraviolet, called soft UV, from 3 eV to about 10 eV, is non-ionizing. However, the effects of non-ionizing ultraviolet on chemistry and the damage to biological systems exposed to it including oxidation, mutation, and cancer are such that even this part of ultraviolet is often compared with ionizing radiation. Light, or visible light, is a very narrow range of electromagnetic radiation of a wavelength that is visible to the human eye, or — nm which equates to a frequency range of to THz respectively. Infrared IR light is electromagnetic radiation with a wavelength between 0.
IR wavelengths are longer than that of visible light, but shorter than that of microwaves. Infrared may be detected at a distance from the radiating objects by "feel. Bright sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Microwaves are electromagnetic waves with wavelengths ranging from as short as one millimeter to as long as one meter, which equates to a frequency range of MHz to GHz. Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by certain astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. In addition, almost any wire carrying alternating current will radiate some of the energy away as radio waves; these are mostly termed interference. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may bend at the rate of the curvature of the Earth and may cover a part of the Earth very consistently, shorter waves travel around the world by multiple reflections off the ionosphere and the Earth.
Much shorter wavelengths bend or reflect very little and travel along the line of sight. Very low frequency VLF refers to a frequency range of 30 Hz to 3 kHz which corresponds to wavelengths of , to 10, meters respectively. Since there is not much bandwidth in this range of the radio spectrum, only the very simplest signals can be transmitted, such as for radio navigation. Also known as the myriameter band or myriameter wave as the wavelengths range from ten to one myriameter an obsolete metric unit equal to 10 kilometers.
Extremely low frequency ELF is radiation frequencies from 3 to 30 Hz 10 8 to 10 7 meters respectively. In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz. A massive military ELF antenna in Michigan radiates very slow messages to otherwise unreachable receivers, such as submerged submarines. Thermal radiation is a common synonym for infrared radiation emitted by objects at temperatures often encountered on Earth.
Thermal radiation refers not only to the radiation itself, but also the process by which the surface of an object radiates its thermal energy in the form of black body radiation. Infrared or red radiation from a common household radiator or electric heater is an example of thermal radiation, as is the heat emitted by an operating incandescent light bulb. Thermal radiation is generated when energy from the movement of charged particles within atoms is converted to electromagnetic radiation. As noted above, even low-frequency thermal radiation may cause temperature-ionization whenever it deposits sufficient thermal energy to raise temperatures to a high enough level. Common examples of this are the ionization plasma seen in common flames, and the molecular changes caused by the " browning " during food-cooking, which is a chemical process that begins with a large component of ionization.
Black-body radiation is an idealized spectrum of radiation emitted by a body that is at a uniform temperature. The shape of the spectrum and the total amount of energy emitted by the body is a function of the absolute temperature of that body. For a given temperature of a black-body there is a particular frequency at which the radiation emitted is at its maximum intensity. That maximum radiation frequency moves toward higher frequencies as the temperature of the body increases. The frequency at which the black-body radiation is at maximum is given by Wien's displacement law and is a function of the body's absolute temperature. A black-body is one that emits at any temperature the maximum possible amount of radiation at any given wavelength.
A black-body will also absorb the maximum possible incident radiation at any given wavelength. A black-body with a temperature at or below room temperature would thus appear absolutely black, as it would not reflect any incident light nor would it emit enough radiation at visible wavelengths for our eyes to detect. Theoretically, a black-body emits electromagnetic radiation over the entire spectrum from very low frequency radio waves to x-rays, creating a continuum of radiation. The color of a radiating black-body tells the temperature of its radiating surface.
It is responsible for the color of stars , which vary from infrared through red 2,K , to yellow 5,K , to white and to blue-white 15,K as the peak radiance passes through those points in the visible spectrum. When the peak is below the visible spectrum the body is black, while when it is above the body is blue-white, since all the visible colors are represented from blue decreasing to red.
Electromagnetic radiation of wavelengths other than visible light were discovered in the early 19th century. The discovery of infrared radiation is ascribed to William Herschel , the astronomer. Herschel published his results in before the Royal Society of London. Herschel, like Ritter, used a prism to refract light from the Sun and detected the infrared beyond the red part of the spectrum , through an increase in the temperature recorded by a thermometer.
In , the German physicist Johann Wilhelm Ritter made the discovery of ultraviolet by noting that the rays from a prism darkened silver chloride preparations more quickly than violet light. Ritter's experiments were an early precursor to what would become photography. Ritter noted that the UV rays were capable of causing chemical reactions. The first radio waves detected were not from a natural source, but were produced deliberately and artificially by the German scientist Heinrich Hertz in , using electrical circuits calculated to produce oscillations in the radio frequency range, following formulas suggested by the equations of James Clerk Maxwell.
While experimenting with high voltages applied to an evacuated tube on 8 November , he noticed a fluorescence on a nearby plate of coated glass. Within a month, he discovered the main properties of X-rays that we understand to this day. In , Henri Becquerel found that rays emanating from certain minerals penetrated black paper and caused fogging of an unexposed photographic plate. His doctoral student Marie Curie discovered that only certain chemical elements gave off these rays of energy. She named this behavior radioactivity. Alpha rays alpha particles and beta rays beta particles were differentiated by Ernest Rutherford through simple experimentation in Rutherford used a generic pitchblende radioactive source and determined that the rays produced by the source had differing penetrations in materials.
One type had short penetration it was stopped by paper and a positive charge, which Rutherford named alpha rays. The other was more penetrating able to expose film through paper but not metal and had a negative charge, and this type Rutherford named beta. This was the radiation that had been first detected by Becquerel from uranium salts. In , the French scientist Paul Villard discovered a third neutrally charged and especially penetrating type of radiation from radium, and after he described it, Rutherford realized it must be yet a third type of radiation, which in Rutherford named gamma rays.
Henri Becquerel himself proved that beta rays are fast electrons, while Rutherford and Thomas Royds proved in that alpha particles are ionized helium. Rutherford and Edward Andrade proved in that gamma rays are like X-rays, but with shorter wavelengths.Louis, Missouri: Elsevier. The Synergist. Neutron Non Ionizing Radiation Research Paper was discovered with the neutron by Non Ionizing Radiation Research Paper, in Thus, electric fields Non Ionizing Radiation Research Paper magnetic Non Ionizing Radiation Research Paper exist together, and they exist anywhere there is an electrical charge. Further human Non Ionizing Radiation Research Paper exploring thyroid gland Prometheus Persuasive Letter, Non Ionizing Radiation Research Paper morphology, and thyroid cancer are highly recommended for future researches.