CHAPTER 2
LITERATURE REVIEW
This chapter discusses the examples of radiation particles that can be detected. This chapter also elaborates on some of the common radiation sensors that are possible to be used in this research as well as different types of kinematic models of mobile robot. The available developed path planning including the waypoints sweeping pattern and other applicable sensors for mobile robot are also discussed in this chapter.
Overview of Ionizing Radiation
Radiation is the process of emitting radiant energy in the form of waves or particles that travels through a medium or space. Radiation sources can be divided into two main categories which are non-ionizing radiation and ionizing radiation. Non-ionizing radiation includes natural background sources and man-made sources. The sun is one of the major background sources of radiation. It sends out ultraviolet rays that penetrate and damage human skin by causing sunburn. Certain minerals that make up part of the earth contain the radioactive elements. The levels may typically be in the range of 15 to 60 counts per minute that will vary depending upon one’s location on the earth, and the efficiency of the radiation sensor used.
Man-made sources that emit radiation include medical radiation sources and consumer products such as televisions and smoke detectors. Ionizing radiation includes alpha, beta and gamma particles.
Alpha
Alpha radiation consists of positively charged particles emitted from the nucleus of an atom in the process of decay. With strong positive charge, the density of alpha precludes them from penetrating more than an inch of air or a sheet of paper. Because of this, alpha particles are not a serious health hazard except when they...
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...nd commercial users around the world.
Ultrasonic Sensor
Ultrasonic sensors work on the principle of radar which interprets the characteristics of a target by evaluating echoes from radio waves. It generates high frequency sound waves and evaluates bounced echo which is received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance of an object.
Beacon
A beacon is a device designed to obtain information of a specific location. Important information such as the status of an airport based on the colour and rotational pattern of its airport beacon as well as weather information as indicated by weather beacon on top of a high building can be obtained by combining beacons with semaphoric indicators. Also, when used in such fashion, beacons can be considered a form of optical telegraphy.
Radiation exposure can affect children as well an children have the risk of being the most harmfully effected by radiation because their body absorbs substances differently also their bodies can or are more likely to get certain kinds of cancers from too much exposure, “they are also closer to the ground, where radioactive fallouts settle.”
Radiation is something that the naked eye cannot see, yet has the potential to save lives one treatment at a time or even one image at a time. Since the discovery of x-rays in 1895, it has branched out into numerous modalities each independently specializing in their own ways. X rays are used to aid in the diagnosis and treatments of patients on a case by case scenario. Sometimes doctors can make a diagnosis on the same day or conclude that a patient will require radiation therapy within weeks to follow. Whatever it may be, the importance of x rays and radiation itself is a crucial part of the medical field when it comes to saving lives. Initially it all started with the discovery of x rays but then three years later radiation therapy was introduced to aid with
Radiation has always been in everyday life even before Roentgen discovered x-ray. The mountains give off natural radiation, other forms of radiation are coal burning power plants, x-rays from a TV, and an airplane ride. The average dose from background radiation is about 360 mrem every year. There are two types of radiation, nonionizing and ionizing radiation. Examples of nonionizing radiation are microwaves and radio waves broadcasting. Ionizing radiation refers to gamma and x-rays. Ionizing radiation means that the rays are able to remove an electron from the atom then ions can be formed. The ions can cause damage when reacting with other atoms. Cells are able to be repaired if low dose are received. However, if cells get a high dose, the cells will be damaged or possibly die. If the cell is damaged permanently then it is referred to as a mutated cell.
What Nuclear power has the ability to do is get a lot of power in a little amount of space. “Roughly 1.6 billion people live without access to electricity, and 2.4 billion rely on traditional biomass because they have no access to modern fuel.” (General Dr. Mohamed ElBaradei) With nuclear power put into these countries that are without power we can have it to where electricity will be accessibility to everyone. By having power accessible to everyone we can accomplish so much more and unlock more possibilities in our world today.
Beta radiation/emission – Beta particles are electrons (0-1e) that have been released from the nucleus of a radioactive atom when a neutron decays into a proton and electron. Beta decay/emission happens when the neutron to proton ratio is too high due to excess neutrons. 10n 11p + 0-1e (mass is still conserved as well as number of protons.)
Radar: detects the presence, distance and speed of passing objects by sending out radio waves;
The sun emits electromagnetic radiation of different wavelengths. This is basically the energy given off by the sun UV Rays are anywhere from 10 nanometers to 400 nanometers. They are the cause of bad things, such as sunburn and skin cancer. They also cause a lot of good effects, like they help kill germs and bacteria. There are UV-A rays, which are longer wavelength and are helpful for the most part. There are also UV-B rays, which have a shorter wavelength, and cause sunburns and other harmful impacts. Luckily 95% of UV-B rays are absorbed by the ozone layer. There are also UV-C, which is the most harmful, but they never reach the surface.
In the process of food irradiation, food is exposed to the gamma rays or x-ray rays emitted from one of the two radioisotopes cobalt-60 or cesium-137 (The Food Irradiation Process).
The sun emits several types of radiation, most of radiation reaches the earth's surface. Warmth from the sun comes from infrared radiation. While the light and colours we distinguish is caused by visible radiation. Infrared and visible radiation are not harmful under ordinary circumstances. The higher energy part of the spectrum is ultraviolet radiation, a known carcinogen (cancer-causing agent). Both UVA and UVB radiation from the ultraviolet radiation reach the earth's surface. Exposure to either increases your risk of melanoma and other skin cancers. UVC radiation (also part of ultraviolet radi...
In order to understand why food irradiation is necessary, the definition must first be outlined and understood. “Food irradiation (the application of ionizing radiation to food) is a technology that improves the safety and extends the shelf life of foods by reducing or eliminating microorganisms and insects” (“Food irradiation is”, 2016). Eliminating microorganisms and insects is accomplished in a few ways. There are three energy sources for food irradiation. First is the use of the elements cobalt or cesium. These elements have radioactive properties that allow gamma rays to be emitted into food. The radiation from these elements ionize and prevents microorganisms from multiplying. X-rays are also
The energy in ionizing radiation can cause chemical changes in the the cells that can lead to damaging them. Most of the cells can either permanently or temporarily become abnormal or they can just die. Radiation can cause cancer by damaging the DNA in the body. The damage of the cells can also depend on how long the organs are exposed (environmental protection agency, 2017, unknown). If someone has many exposures at one time that radiation in the body keeps adding on. As well as if its only a little bit of exposure in on day and years later you get exposed again it keeps adding on the radiation will never leave the body. Having radiation in your body doesn’t affect you right away but as you get older it starts to show and you feel it. Chronic exposure is when someone is exposed many time for long periods. When this happens the type of effects it will carry is having harmful generic change, cancer, tumors, and even cataracts. Partial health effects can also depend on if it was internal or external exposure. Internal exposure is when either by drinking, breathing, eating and even an injection cause radiation to get inside your body. External exposure is when taking an x-ray out of your body and letting it go through letting all the energy go as it goes in (environmental protection agency, 2017, unknown). In the dental world radiation gets into the patients when we take x-rays on there teeth. In order to avoid to much radiation on them we put a lead apron on them and make sure to cover their thyroid which is the most common way of getting cancer when taking an x-ray. When we take the x-ray we stand behind a wall at least 6 feet away to avoid ourself from getting
Now, the three examples, Chernobyl, Fukushima, Three mile islands, show the effect of the nuclear accident. Each has different causes, but the damages were terrible.
First of all what is a Gamma Ray? A gamma ray is a high energy ionized radiation (EPA). Gamma photons have about 10,000 times more energy as photons (EPA). Along with that gamma rays wavelengths are so short they have to be measured in nanometers (EPA). They also are the strongest type of radiation which makes them the most dangerous. How are Gamma rays dangerous? A gamma-ray photon has enough energy to damage atoms in your body and make them radioactive (Christian, Eric). Gamma ray radiation also causes murderous burn, breast and a lung and thyroid cancer, genetics illnesses (Asiye, Gul). But when did we even discover gamma rays? In 1896 Henri Becquerel, a French Physicist, discovered gamma rays, he called it metallic phosphorescence (EPA). Becquerel had found gamma radiation being emitted by radium (EPA).
What is radioactivity? Radioactive isotopes are heavy nuclei of certain elements having extra neutrons. The extra neutrons in their nuclei cause them to be unstable so the nuclei break up spontaneously, emitting alpha, beta and gamma radiations. For example,
De-Cluttering Your Life to Create a Happy and Contented Existence The outward acquiring of "stuff" is not what is required for you to live an extraordinary life. Those are just "status" making "stuff". Living an extraordinary life has to start from within you.