"Physics of Radiation" - 10 nuclear power plants are currently in operation in our country. This definition of radioactivity was given by Marie Curie, a famous physicist. Completed by: Nalivaiko G.G. Negramotnov I.A. Small doses of radiation are not dangerous, rather the opposite. Radioactivity helps a person in real life. Such a source is the energy of atoms.
"The structure of the atom, Rutherford's experience" - The mechanism of dispersion. Facts indicating the complexity of the structure of the atom. Models of the structure of the atom. Rutherford's experience. The structure of the atom. Scientists of antiquity on the structure of matter. All models were speculative and were not the result of an experiment. The charge of the nucleus is equal in magnitude to the charge of all the electrons, so the atom is neutral.
"Thermonuclear reaction" - Of particular great practical importance is the fact that during a thermonuclear reaction much more energy is released per nucleon than during a nuclear reaction, for example, during the fusion of a helium nucleus from hydrogen nuclei, an energy equal to 6 MeV is released, and during fission of a uranium nucleus one nucleon accounts for »0.9 MeV. What a huge and "inexhaustible" source of energy man has!
"The biological effect of radioactive radiation" - A person with the help of the senses is not able to detect any dose of radioactive radiation. Radioactive radiation has a strong biological effect on the tissues of a living organism, which consists in the ionization of atoms and molecules of the medium. Completed: 2009.
"The effect of radiation on a person" - - "Hormone of vivacity." The cell phone affects the whole cardio - vascular system as a whole. How to protect yourself from EMF. Ozone layer. How does the state help? Fundamental question: How do radiation and electromagnetic radiation affect human health?
"Model of the atom" - 7. , Where? 0 = const, n = 3, 4, 5, ... 7.1. Regularities in atomic spectra. 7.3. Bohr's elementary theory. When moving in a circle, there is centripetal acceleration. Hydrogen atom according to Bohr's theory. Where k = 1, 2, 3,…; n = k + 1, k + 2,…. In physics, the Rydberg constant is also called another value equal to R = R?·s.
There are 11 presentations in total in the topic
Initially, before the appearance cellular communication, radio transmission was carried out directly, from one device to another. This system had significant drawbacks:
- The devices could be separated from each other at a distance of several hundred, and even thousands of kilometers. Therefore, the transmitters had to have enormous powers in order for the signal to reach the target.
- Signals from different transmitters often crossed at the same frequency and interfered with each other.
- On one radio frequency channel, only one transmitter could work without interference. Accordingly, the channels were not enough.
The use of cellular communications relieves us of these problems. Our country is completely strewn with a huge number of base stations - transceivers raised above the ground. When making a call, the mobile phone sends a signal not to the interlocutor's phone, but to the neighboring base station. The base station turns the radio signal into light and sends it over a fiber optic cable to the switch. The switch redirects the light signal to the base station located near the interlocutor:
As a rule, several base stations are within reach of a mobile phone at once. The connection occurs with the one that is closer. Given the small distances between the phone and the station, the power of their transmitters is minimal. I would like to note that the denser the stations are installed, the weaker the radio emission around us. And if one of these stations is installed right next to you, you should not worry. Emissions from modern mobile communication stations are very weak and quickly dissipate, but the emissions from your phone may decrease many times over. On the dangers of mobile phones.
Despite the huge density of base stations, they practically do not intersect at the same frequency and do not interfere with each other. How this can be achieved is shown in the figure:
Each cell is the main coverage area of one of the mobile communication stations. F1-F7 - designation of the radio frequency channel. Distance between neighboring stations transmitting on the same frequency D, much less than their range R. It is from these cells that the name came - cellular communication.
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The presentation on the topic "Cellular communication" can be downloaded absolutely free of charge on our website. Project subject: Physics. Colorful slides and illustrations will help you keep your classmates or audience interested. To view the content, use the player, or if you want to download the report, click on the appropriate text under the player. The presentation contains 39 slide(s).
Presentation slides
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Municipal educational institution "Secondary school No. 9 named after. K.K Rokossovsky
Creative project in physics on the topic "Cellular communication"
The project was completed by: Lebedev Anton, student of class 9A
Project manager: Viktor Ivanovich Ovcharov, physics teacher
Zheleznogorsk 2012
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The purpose of the work: to collect information from various sources in order to find out the history of the development of cellular communications, the principle of operation of telephones, the reasons for the impact of cellular communications on the human body.
Tasks: 1. To study the history of the discovery of electromagnetic waves, the standards of generations of cellular communication. 2. The purpose of the base stations, the device and the principle of operation of the phone in cellular network. 3. Harmful effects on the human body and cell phone radiation standards. 4. Develop guidelines for use cell phones. 5. Questioning school students.
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Heinrich Hertz
Guglielmo Marconi
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In July 1947, Bell Laboratories W. Shockley, J. Bardeen, and W. Brattain invented the transistor.
D. Ring's idea - Base stations form cells with their coverage areas, the size of which is determined by the territorial density of network subscribers. Frequency channels used for the operation of one of the base stations of the network can be used by other base stations of this network.
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Martin Cooper
Taking the Motorola Dina-TAC in his hands, Martin Cooper went outside and made the world's first cell phone call.
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Cellular communication of the first generation (1G).
Standard CDMA, TDMA, iDEN, PDS, PHS Data in such networks could be transmitted only at low speeds up to 2.4 kbps, and the spectrum is limited from above by a frequency of 900 MHz.
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Cellular communication of the second generation (2G).
GSM standard The main difference between the second generation systems is that they are "digital", i.e. voice is transmitted digitally.
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Cellular communication of the third generation (3G).
The systems operate at the following data rates: for subscribers with high mobility (up to 120 km/h) - at least 144 kbit/s, for subscribers with low mobility (up to 3 km/h) - 384 kbit/s, for fixed objects at short distances - 2.048 Mbps.
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base stations.
Base station (in relation to cellular communication) - a complex of radio transmitting equipment (repeaters, transceivers) that communicates with the end subscriber device - a cellular phone.
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1. Mouse button 2. Call acceptance button 3. Phonebook 4. Keypad 5. Antenna 6. Sound speaker 7. LCD display 8. On/off and call reject key 9. Cancel key 10. Microphone (located at the bottom)
mobile phone appearance
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A cell phone is different in that it inflicts a "triple blow" on our body. Here we mean three radiation sources of microwave fields located in the same device and generating different EMFs in different modes of its operation. 1. The first of these is a cell phone antenna, which emits EMF, the power of which is determined in units of watts. 2. This radiation is carried out in the transmission mode, and a significant part of the EMR, partially attenuated by the cranium, penetrates into our brain. In standby mode, a cell phone is like other electronic devices and emits weak fields of non-thermal intensity, which, if accumulated in the body, can lead to negative consequences. 3. In the receiving mode, microwave radiation through the ear canal penetrates directly into the brain.
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As a result of numerous studies in the field of the biological effect of electromagnetic radiation, it was found: 1. that they have the property of accumulating in the human body over time, violating its bioenergetic balance and, first of all, the structure of the so-called. energy-information exchange (ENIO), which ensures the normal functioning of information-exchange processes between all organs and systems, at all levels of the organization of the human body, including those between the body and the environment. 2. The most sensitive systems of the human body are: nervous, immune, endocrine and reproductive (sexual). 3. The biological effect of EMF under conditions of long-term, long-term exposure can lead to the development of long-term consequences, including degenerative processes of the central nervous system, blood cancer (leukemia), brain tumors, hormonal diseases, etc. 4. EMF are especially dangerous for children and pregnant women women, since the still unformed children's body has an increased sensitivity to the effects of such fields. 5. People with diseases of the central nervous, hormonal, cardiovascular system, allergy sufferers and people with weakened immune systems are also very sensitive to the action of EMF.
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Children slow down ... Alan Preece, head of the biophysics department at the Bristol Cancer Center, gave phones to children aged 10-11 for half an hour. For half, they worked in talk mode, for others they were turned off. And then the scientist conducted neurophysiological tests. For those who got the included mobile phones, all reactions turned out to be slow. Another experiment showed that even after a two-minute conversation in adolescents aged 11-13, the bioelectrical activity of the brain changes. It returns to normal only after two hours. What does it mean? The child’s mood changes, he perceives the material worse in the lesson if he chatted on his cell phone during the break.
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And adults' blood boils Hungarian biologist Turoci asked 76 volunteers to make two calls, 7.5 minutes each. The body trembled with all the fibers: the biocurrents of the brain changed, cerebral circulation slowed down, blood pressure dropped. Doctors recorded anxiety and stress in the subjects. And Russian professor Igor Belyaev, who works at Stockholm University, turned on the phone next to test tubes with human blood. An hour later, the blood in several of them “boiled”! “No, it didn't get hot,” the researcher explains. “But the blood cells, the lymphocytes, behaved as if a person had a very high fever - 44 degrees.” The effect of "heat shock" persisted for 72 hours.
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Embryos die... At the Moscow Institute of Biophysics Professor Yury Grigoriev made two incubators. I put 63 chicken eggs in each. Above one "bird house" at a height of 10 cm, a GSM mobile phone was hung. The phone worked in this mode: 1.5 minutes on, half a minute off. Violations of embryonic development began on the third day. Only 16 birds hatched, which "listened" to the phone! But they were also not viable. For comparison: in an incubator where eggs were not pestered by calls, 51 chicks were born without any problems.
scientists from Moscow State University found that yeast fungi and acetic acid bacteria wither from a mobile phone. And this means that the apparatus on a belt or in a pocket - next to the intestines - can ruin the life of one of the 500 microorganisms living there! And they will take revenge on the careless owner.
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SAR - Specific Absorbtion Rate - a unit of measurement showing the maximum specific power absorbed by the human body (W / kg) during a normal conversation on a cell phone.
The maximum safe level is 2.0, most modern phones have an SAR between 0.5 and 1.0.
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At what age did you start using a cell phone? How much time per day do you talk on your cell phone? What phone model do you have now? Where do you usually keep your cell phone? Where is your cell phone at night? Do you know the device of a cell phone? Do you know about the harmful effects of cell phones on the human body?
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SAR RESULTS ARE THE SAFEEST mobile phones, which have the lowest SAR radiation level. All data are based on phones operating in the GSM 900 standard. The table shows the SAR values determined for 10 g of tissue. Remember: the lower the SAR value, the less impact a mobile phone has on a person! More about SAR Model SAR MagCom MagCom 0,04 Motorola StarTac 130 ? 0.07 Samsung SGH-F700v Qbowl 0.07 Motorola V100 0.09 Samsung SGH-Z560 0.10 Swisscom XPA v1615 0.10 Motorola MPx200 0.12 Philips 362 0.12 Telefoon Totaal BasicPhone 0.12 Mitac Mio A501 0, 12 Samsung SGH-X830 0.12 LG S5200 0.12 Audiovox XV6600 0.12 LG KG320S 0.13 Sagem myMobileTV2 0.13 Motorola V101 0.14 SonyEricsson T292a 0.15 Nokia 8810 0.15 E-ten M500 0.16 Vodafone VPA IV 0.17 BlackBerry 7280 0.17 Samsung GT-I8000 Omnia II 0.17 T-Mobile MDA Pro 0.17 BlackBerry 6280 0.18 Samsung SGH-s105 0.18
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7. Do you know about the harmful effects of cell phones on the human body?
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REMEMBER! Talk limit - 15 minutes per day (children from 8 to 14 years old), adults - 30 minutes. Maximize the period between two conversations (the minimum recommended is 15 minutes). Doctors do not recommend the use of mobile phones for children under 8 years old. Do not carry a switched on phone in your breast pockets (risk of developing malignant tumors). The mobile phone must be at least 2 cm away from the human body in a special case. During a conversation, it is desirable to use a headset and a hands-free system. Do not purchase used mobile phones. Use whenever possible speakerphone. Instead of talking, use SMS services. Do not talk on a cell phone in a car. The metal body of the car acts as a "screen", radio communication deteriorates. In response, the mobile device increases its power, which leads to greater exposure of the subscriber. When living in buildings made of reinforced concrete structures, a conversation on a mobile communication device should be carried out near a large window, on a loggia or balcony. During a conversation, be sure to hold the device by the lower part. If you hold the phone in the "fist", the power of the device increases by about 70%, and thus the exposure increases. Change the position of the handset during the conversation (left and right).
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Conclusion: the influence of electromagnetic fields on human health is the research problem of science. A person can ensure his own safety if he has the necessary information. Each of us can and even must take simple precautions. A cell phone is only safe if you treat it reasonably.
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List of used sources and literature http://teleffon.info/principle.htm http://www.hardline.ru/9/70/1847/ http://ru.wikipedia.org/ http://www.3dnews. ru/ http://cxem.net/sotov/sotov8.php http://www.krugosvet.ru/ A. Gridin, K. Romanov, I. Zubik “MOBILE PHONE FOR ALL. The device and operation of mobile phones "Malyarevsky A., Olevskaya N. Your mobile phone (a popular tutorial). M, "Peter", 2004 Zakirov Z.G., Nadeev A.F., Faizullin R.R. Cellular communication of the GSM standard. Current state, transition to third generation networks ("MTS Library"). M., "Eco-Trends", 2004 Popov V.I. Fundamentals of cellular communications of the GSM standard ("Engineering Encyclopedia of the Fuel and Energy Complex"). M., Eco-Trends, 2005
Research work in physics On the topic: “Cellular communication. From origins to the present. The effect of electromagnetic radiation from a cell phone on the human body. Completed by: student 11 "a" class MOU secondary school 2 Voronova Elena Voronova Elena Teacher: Borshchenko I. B.
Plan Introduction. Introduction. Objective. Objective. The first mobile phones. The first mobile phones. Modern phones. Modern phones. mobile connection in Russia. Mobile communications in Russia. Not a means of communication. Not a means of communication. The influence of a cell phone on the human body. The influence of a cell phone on the human body. Health. Mobile phone damage. Health. Mobile phone damage. Conclusion. Conclusion. Bibliography. Bibliography.
The purpose of the work To explore: To explore: 1. the development of cellular communications; 1. development of cellular communication; 2. harm caused to the human body by the electromagnetic radiation of a cell phone. 2. harm caused to the human body by the electromagnetic radiation of a cell phone.
Introduction Today, electromagnetic exposure is 100 million times greater than what our grandfathers experienced. Prolonged exposure to artificial electromagnetic radiation seriously impairs health. Epidemiologists have found that cancer is more common among people living in close proximity to sources of strong electromagnetic fields, such as high-voltage power lines. Today, electromagnetic exposure is 100 million times greater than what our grandfathers experienced. Prolonged exposure to artificial electromagnetic radiation seriously impairs health. Epidemiologists have found that cancer is more common among people living in close proximity to sources of strong electromagnetic fields, such as high-voltage power lines.
The first "mobile" phones This is the great-great-grandfather of the mobile phone: This is the great-great-grandfather of the mobile phone: The telegraph device of the 1912 model. The so-called Morse apparatus. To send a telegram, its text must be converted to dots-dashes. Telegraph device of the 1912 model. The so-called Morse apparatus. To send a telegram, its text must be converted to dots-dashes.
The first "mobile" phones Fully automatic system Mobile Telephony A (MTA), operated since 1956 in Stockholm and Gothenburg on a frequency of 160 MHz Fully automatic system Mobile Telephony A (MTA), operated since 1956 in Stockholm and Gothenburg on a frequency of 160 MHz
The first "mobile" phones American Martin Cooper created the first mobile phone - Motorola DynaTec, which weighed 1 kg. But it took another five years of research for the first commercial cellular operator to appear. They became the telephone company of Bahrain. American Martin Cooper created the first mobile phone - Motorola DynaTec, which weighed 1 kg. But it took another five years of research for the first commercial cellular operator to appear. They became the telephone company of Bahrain.
Not a means of communication Many people know that the mobile phone has ceased to be just a means of communication!!! Now, for example, you have a communication diagram between a mobile phone and a car alarm. Many people know that the mobile phone has ceased to be just a means of communication!!! Now, for example, you have a communication diagram between a mobile phone and a car alarm.
And how does a cellular radiotelephone affect the human body? In 1994, within the framework of the European project "Biomedical Effects of Electromagnetic Fields", scientists from Europe, including Russia and Ukraine, Japan and the USA, began special studies of the possible effect of cell phone radiation on the health and life of their users. In 1994, within the framework of the European project "Biomedical Effects of Electromagnetic Fields", scientists from Europe, including Russia and Ukraine, Japan and the USA, began special studies of the possible effect of cell phone radiation on the health and life of their users. In 1996, the first stage of collective work was completed. The results were more than disappointing. For radiotelephones, and it is cellular telephones with a carrier frequency of MHz, that have a negative impact on the physical state and the health of their users. The brain (the region of the hypothalamus), peripheral analyzers in the middle ear, vestibular and auditory analyzers are exposed to the greatest detrimental effect. All this leads to mental disorders, including changes in conditioned reflex activity, behavioral reactions, states of short-term and long-term memory loss, changes in the bioelectrical activity of various brain structures. In 1996, the first stage of collective work was completed. The results were more than disappointing. For radiotelephones, it is cellular telephones with a carrier frequency of MHz that have a negative impact on the physical condition and health of their users. The brain (the region of the hypothalamus), peripheral analyzers in the middle ear, vestibular and auditory analyzers are exposed to the greatest detrimental effect. All this leads to mental disorders, including changes in conditioned reflex activity, behavioral reactions, states of short-term and long-term memory loss, changes in the bioelectrical activity of various brain structures. Research is still ongoing, but today it is reliably known that electromagnetic radiation has a harmful effect on the endocrine and immune systems, genital organs, and the genetic apparatus. Research is still ongoing, but today it is reliably known that electromagnetic radiation has a harmful effect on the endocrine and immune systems, genital organs, and the genetic apparatus.
Health. Mobile phone harm Prolonged use of a mobile phone can heat a person's brain up to one degree. Prolonged use of a mobile phone can heat the human brain up to one degree. WiFi wireless data transmission technologies can have a negative impact on the cerebral cortex, and the lack of legislation in this area does not prevent the terrible consequences of mobile phone exposure to the human body. WiFi wireless data transmission technologies can have a negative impact on the cerebral cortex, and the lack of legislation in this area does not prevent the terrible consequences of mobile phone exposure to the human body. The fact that the constant exposure to radio frequency signals can adversely affect human health, scientists have repeatedly said. Many phone owners complain about various side effects from cellular communication: frequent headaches, loss of memory and concentration, tension in the eardrums and sudden bouts of fatigue Scientists have repeatedly said that constant exposure to radio frequency signals can negatively affect human health. Many phone owners complain about various side effects from cellular communication: frequent headaches, loss of memory and concentration, tension in the eardrums and sudden bouts of fatigue.
Health. Harm of a mobile phone According to studies conducted by European scientists, 3% of people suffer from the so-called "hyperelectrosensitivity", that is, the body of these people is extremely sensitive to electromagnetic fields. According to studies conducted by European scientists, 3% of people suffer from the so-called "hyperelectrosensitivity", that is, the body of these people is extremely sensitive to electromagnetic fields. Among the possible diseases in connection with the use of mobile phones, scientists call childhood leukemia, ocular cataracts, brain tumors, cardiovascular diseases, disorders of the nervous system, which can lead to DNA damage. Among the possible diseases in connection with the use of mobile phones, scientists call childhood leukemia, ocular cataracts, brain tumors, cardiovascular diseases, disorders of the nervous system, which can lead to DNA damage. Now in the world more than two billion people are users of cell phones, of which more than 500 million use GSM phones. At the same time, scientists note that analog phones are much more harmful to human health than digital ones. Now in the world more than two billion people are users of cell phones, of which more than 500 million use GSM phones. At the same time, scientists note that analog phones are much more harmful to human health than digital ones.
Conclusion For its part, the World Health Organization recommends caution in the use of wireless systems. In turn, the research director of the International GSM Association (trade organization, which includes more than 700 mobile operators) Jack Rowley believes that the fears of scientists are too exaggerated. For its part, the World Health Organization recommends caution in the use of wireless systems. In turn, research director of the International GSM Association (a trade organization that includes more than 700 mobile operators) Jack Rowley believes that scientists' concerns are too exaggerated. "Single studies say little. Claims that mobile phone technology is harmful are unfounded," Rowley said, adding that five studies found no evidence for WiFi's effect on cancer. "Single studies say little. Claims that mobile phone technology is harmful are unfounded," Rowley said, adding that five studies found no evidence for WiFi's effect on cancer.
List of used literature. 1. Big technical encyclopedia. Moscow 2007 1. Big technical encyclopedia. Moscow 2007 2. Big Encyclopedia of Cyril and Methodius Big Encyclopedia of Cyril and Methodius Internet resources: 3. Internet resources: Brilliant inventors. M .: Tera - book club, 4. Brilliant inventors. Moscow: Tera - book club
