Power Generation from Radio Wave Technology

Introduction Radio wave technology is the use of airwaves in transmitting and receiving information. It is the foundation of most of our communication in the present day. Radio waves fall under the group of waves termed electromagnetic radiation, which travel at the speed of light (3Ãâ€"108 m/s).Advertising We will write a custom research paper sample on Power Generation from Radio Wave Technology specifically for you for only $16.05 $11/page Learn More These types of waves (including light, infrared, microwaves and x-rays) are classified based on their wavelengths and frequencies. The frequencies of radio waves lie between 300GHz to 3 kHz with wavelengths of 1mm to 100km. Some of the communication equipments that use radio waves include satellite dishes, radar, radios, television, mobile phones and wireless internet. The use of radio waves for powering electronic devices had not been exploited due to the nature of waves to weaken and dissipate as they spread due to their interaction with other waves and matter. Recently, a growing interest in alternative sources of energy that could provide efficient power in remote and sensitive locations has led to research into radio wave power generation. This paper looks at the history of radio waves and how power can be generated from them and how it can be applied in electronic devices. History and growth of radio wave technology The history of radio waves as medium for transmitting information started way back in the 1860s when James Clerk Maxwell, a physicist from Scotland, envisaged the existence of the waves. His prediction was enhanced in 1886 by Heinrich Rudolph Hertz, a German physicist, who went a notch further to show how variation of electric current could be sent into space as radio waves (Bellis 3). He was able to generate and compute the first waves by using an oscillator for transmitting the waves and a metal loop for detecting them (Parker 3). In 1895 Guglielmo Marconi, from Italy, sent a radio signal over a distance of 100m and received it. He used crafted antenna, transmitter, and condenser and had connections on the ground that could receive the signals. He also sent a wireless signal across the English Channel in 1899(Bellis 5), a distance of 3.5 miles. In addition, Nikola Tesla helped in developing and enhancing wireless radio transmitters.Advertising Looking for research paper on natural sciences? Let's see if we can help you! Get your first paper with 15% OFF Learn More Ships started using wireless telegraphy for sending distress calls while at sea. In 1899, the U.S Army adopted the wireless system and in 1901, the Navy also adopted the system. Lee Deforest invented the space telegraph in the early 1900s where amplifiers were used to strengthen weak signals (Bellis 12). Marconi was able to transmit voice in 1914 over a distance of 50 miles (Bellis 12). Over time, many people aided in developing and enhancing radio wave communicatio n and today we have 4G technologies that send information at very high speeds, besides audio and video streaming. Power generation using radio waves Electromagnetic radiation and photons Electromagnetic waves can be said to have an atomic structure and can either generate or expend energy (â€Å"Electromagnetic waves† par. 7). The electromagnetic radiation, in quantum terms, is said to have photons transporting energy (Joules). A single photon has energy equal to hf. h is Planck’s constant =6.626Ãâ€"10-34 J s and f =frequency of photon v is the velocity of light= 3Ãâ€"108 m/s and ÃŽ » =wavelength of photonAdvertising We will write a custom research paper sample on Power Generation from Radio Wave Technology specifically for you for only $16.05 $11/page Learn More Collection of radio waves energy Radio wave energy can be collected and harnessed using various equipments and components. The generation circuit has components such as antenn a, capacitors, diodes, transistors, inductors and resistors. The antenna is used for receiving the electromagnetic signal. This signal received is then rectified. The rectifying circuit is made of diodes. Once the signal has been rectified, it is boosted before being stored in capacitors. The power stored is used to drive a load or resistor via a switching circuit. Figure 1: Block diagram for ground circuit for capturing radio waves Figure 2: Circuit diagram for capturing and generating power from radio waves MOS transistors are used for switching or controlling the stored power to the load. The source of the MOSFET (for switching) is connected to the storage capacitor with the drain connected to the load. The link between the capacitor and load is created when the voltage of the stored charge is equivalent to the sum of the threshold voltages of both MOSFETs (Ishida et al. 4). Potential of radio wave harvesting Radio wave energy can be efficiently and sufficiently harvested if various factors are considered. These are:Advertising Looking for research paper on natural sciences? Let's see if we can help you! Get your first paper with 15% OFF Learn More Using powerful receivers which detect a wide range of frequencies as well as arresting a high concentration of the wasted waves Ensuring energy is obtained at low power density from sensors located far-off from the source for energy obtained varies inversely with distance (1/d2) Ensuring the voltage generated from the source is greater than 0.3V (1 milliwatt) for satisfactory conversion of all incoming wave Using high quality circuits and transistors Applications of the power generated using radio waves Power generated by radio waves is quite small ranging from a few microwatts to hundreds of milliwatts. The power generated can be used in devices such as: LED monitor lights Sensors LCD display thermometer Implants in the biomedical field Charging the battery for cell phones Safety hard hat Possibility of radio waves technology replacing batteries Nowadays, there is a high requirement for efficient energy sources. Furthermore, the sources should be mobile and flexible. Batteries are usually bulky, require regular maintenance and have a limited life and as such require constant replacement. With the rapid advancement in technology where electronic gadgets and devices are continually made smaller and efficient, their energy requirements have decreased over time. Proper harnessing of radio wave energy could provide an alternative source of energy for powering small electrical devices such as sensors. This is through capturing the electricity produced by the radio waves and is depended on how far the transmitter is and the magnitude of the power generated by the transmitter. The power that can be harnessed from these waves is in the range of microwatts to milliwatts which can be sufficient for powering the devices especially in remote locations. Thus, there is a possibility of radio waves technology replacing batteries. Conclusion and personal thought about radio wave technology application in future Energy harnessed from wasted radio waves is small. This energ y may not be adequate to power large electronic devices but technology has been changing very rapidly in the recent years. Many companies are developing gadgets that are very small, thus requiring less power. For example, the mobile phone industry has seen a reduction in the size of the phones but with more installed phone features and applications. Nokia has come up with a harvesting device embedded in a cell phone. This device is able to charge the phone’s battery (Dixon 3). This means that in the future, many miniature gadgets will have been developed which will totally rely on radio frequency energy. Furthermore, radio wave energy will provide a reliable source of energy since the use of cell phones, television, radios and other communication devices is on the rise. Works Cited Bellis, Mary. The Invention of Radio. 2012. Web. Dixon, Bryn. Radio Frequency Energy Harvesting. 2010. Web. Electromagnetic Waves. 2010. Web. Ishida, Makoto, Kazuaki Sawada, Hidekuni Takao, and Min oru Sudo. Power Generation Circuit using Electromagnetic Wave. 2011. Web. Parker, Bev. The History of Radio. Web. This research paper on Power Generation from Radio Wave Technology was written and submitted by user Ernesto C. to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Laetoli - 3.5 Million Year Old Hominin Footprints

Laetoli - 3.5 Million Year Old Hominin Footprints Laetoli is the name of an archaeological site in northern Tanzania, where the footprints of three homininsancient human ancestors and most likely Australopithecus afarensiswere preserved in the ash fall of a volcanic eruption some 3.63-3.85 million years ago. They represent the oldest hominin footprints yet discovered on the planet.   The Laetoli footprints were discovered in 1976, eroding out of a gully of the Nagarusi river, by team members from Mary Leakeys expedition to the main Laetoli site. Local Environment Laetoli lies in the eastern branch of the Great Rift Valley of eastern Africa, near the Serengeti Plain and not far from Olduvai Gorge. Three and a half million years ago, the region was a mosaic of different ecotones: montane forests, dry and moist woodlands, wooded and unwooded grasslands, all within about 50 km (31 miles) of the footprints. Most Australopithecine sites are located within such regionsplaces with a wide variety of plants and animals nearby. The ash was wet when the hominins walked through it, and their soft print impressions have given scholars in-depth information about the soft tissue and gait of Australopithecines not available from skeletal material. The hominin prints are not the only footprints preserved in the wet ashfall: animals walking through the wet ash included elephants, giraffes, rhinoceroses and a wide variety of extinct mammals. In all there are 16 sites with footprints in Laetoli, the largest of which has 18,000 footprints, representing 17 different families of animals within an area of about 800 square meters (8100 square feet). Laetoli Footprint Descriptions The Laetoli hominin footprints are arranged in two 27.5 meter (89 foot) long trails, created in moist volcanic ash which later hardened because of desiccation and chemical change. Three hominin individuals are represented, called G1, G2, and G3. Apparently, G1 and G2 walked side by side, and G3 followed along behind, stepping on some but not all of the 31 footprints of G2. Based on known ratios of the length of a bipedal foot versus hip height, G1, represented by 38 footprints, was the shortest individual of the three, estimated at 1.26 meters (4.1 feet) or less in height. Individuals G2 and G3 were largerG3 was estimated at 1.4 m (4.6 ft) tall. G2s steps were too obscured by G3s to estimate his/her height. Of the two tracks, G1s footprints are the best preserved; the track with footprints of both G2/G3 proved difficult to read, since they overlapped. A recent study (Bennett 2016) has allowed scholars to identify G3s steps apart from G2 more clearly, and reassess the hominin heightsG1 at 1.3 m (4.2 ft), G3 at 1.53 m (5 ft). Who Made Them? At least two sets of the footprints have been definitely linked to A. afarensis, because, like the fossils of afarensis, the Laetoli footprints do not indicate an opposable great toe. Further, the only hominin associated with Laetoli area at the time is A. afarensis. Some scholars have ventured to argue that the footprints are from an adult male and female (G2 and G3) and a child (G1); others say they were two males and a female. Three dimensional imaging of the tracks reported in 2016 (Bennett et al.) suggests that G1s foot had a different shape and depth of heel, a different hallux abduction and a different definition of the toes. They suggest three possible reasons; G1 is a different hominin from the other two; G1 walked at a different time from G2 and G3 when the ash was sufficiently different in texture, producing differently shaped impressions; or, the differences are a result of foot size / sexual dimorphism. In other words, G1 may have been, as others have argued, a child or a small woman of the same species. While there is some ongoing debate, most researchers believe that the Laetoli footprints show that our Australopithecine ancestors were fully bipedal, and walked in a modern manner, heel first, then toe. Although a recent study (Raichlen et al. 2008) suggests that the speed at which the footprints were made might affect the kind of gait required to make the marks; a later experimental study also led by Raichlen (2010) provides additional support for bipedalism at Laetoli. The Sadiman Volcano and Laetoli The volcanic tuff in which the footprints were made (called the Footprint Tuff or Tuff 7 at Laetoli) is a 12-15 centimeter (4.7-6 inches) thick layer of ash which fell on this region from the eruption of a nearby volcano. The hominins and a wide variety of other animals survived the eruptiontheir footprints in the muddy ash prove thatbut which volcano erupted has not been determined. Until relatively recently, the source of the volcanic tuff was thought to be the Sadiman volcano. Sadiman, located about 20 km (14.4 mi) southeast of Laetoli, is now dormant, but was active between 4.8 and 3.3 million years ago. A recent examination of outflows from Sadiman (Zaitsev et al 2011) showed that the geology of Sadiman does not fit perfectly with the tuff at Laetoli. In 2015, Zaitsev and colleagues confirmed that it was not Sadiman and suggested that the presence of nephelinite in Tuff 7 points to the nearby Mosonic volcano, but admit that there is not conclusive proof as of yet. Preservation Issues At the time of excavation, the footprints were buried between a few cm to 27 cm (11 in) deep. After excavation, they were reburied to preserve them, but the seeds of an acacia tree was buried within the soil and several acacias grew in the region to heights of over two meters before researchers noticed. Investigation showed that although those acacia roots did disturb some of the footprints, burying the footprints was overall a good strategy and did protect much of the trackway. A new conservation technique was begun in 1994 consisting of application of a herbicide to kill all the trees and brush, the placement of biobarrier mesh to inhibit root growth and then a layer of lava boulders. A monitoring trench was installed to keep an eye on the subsurface integrity. See Agnew and colleagues for additional information on the preservation activities. Sources This glossary entry is a part of the About.com guide to Lower Paleolithic, and the Dictionary of Archaeology. Agnew N, and Demas M. 1998. Preserving the Laetoli foodprints. Scientific American 279(44-55). Barboni D. 2014. Vegetation of Northern Tanzania during the Plio-Pleistocene: A synthesis of the paleobotanical evidences from Laetoli, Olduvai, and Peninj hominin sites. Quaternary International 322–323:264-276. Bennett MR, Harris JWK, Richmond BG, Braun DR, Mbua E, Kiura P, Olago D, Kibunjia M, Omuombo C, Behrensmeyer AK et al. 2009. Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya. Science 323:1197-1201. Bennett MR, Reynolds SC, Morse SA, and Budka M. 2016. Laetoli’s lost tracks: 3D generated mean shape and missing footprints. Scientific Reports 6:21916. Crompton RH, Pataky TC, Savage R, DAoà »t K, Bennett MR, Day MH, Bates K, Morse S, and Sellers WI. 2012. Human-like external function of the foot, and fully upright gait, confirmed in the 3.66 million year old Laetoli hominin footprints by topographic statistics, experimental footprint-formation and computer simulation. Journal of The Royal Society Interface 9(69):707-719. Feibel CS, Agnew N, Latimer B, Demas M, Marshall F, Waane SAC, and Schmid P. 1995. The Laetoli Hominid footprintsA preliminary report on the conservation and scientific restudy. Evolutionary Anthropology 4(5):149-154. Johanson DC, and White TD. 1979. A systematic assessment of early African hominids. Science 203(4378):321-330. Kimbel WH, Lockwood CA, Ward CV, Leakey MG, Rak Y, and Johanson DC. 2006. Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record. Journal of Human Evolution 51:134-152. Leakey MD, and Hay RL. 1979. Pliocene footprints in the Laetolil Beds at Laetoli, northern Tanzania. Nature 278(5702):317-323. Raichlen DA, Gordon AD, Harcourt-Smith WEH, Foster AD, and Haas WR, Jr. 2010. Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics. PLoS ONE 5(3):e9769. Raichlen DA, Pontzer H, and Sockol MD. 2008. The Laetoli footprints and early hominin locomotor kinematics. Journal of Human Evolution 54(1):112-117. Su DF, and Harrison T. 2015. The paleoecology of the Upper Laetolil Beds, Laetoli Tanzania: A review and synthesis. Journal of African Earth Sciences 101:405-419. Tuttle RH, Webb DM, and Baksh M. 1991. Laetoli toes and Australopithecus afarensis. Human Evolution 6(3):193-200. Zaitsev AN, Spratt J, Sharygin VV, Wenzel T, Zaitseva OA, and Markl G. 2015. Mineralogy of the Laetolil Footprint Tuff: A comparison with possible volcanic sources from the Crater Highlands and Gregory Rift. Journal of African Earth Sciences 111:214-221. Zaitsev AN, Wenzel T, Spratt J, Williams TC, Strekopytov S, Sharygin VV, Petrov SV, Golovina TA, Zaitseva EO, and Markl G. 2011. Was Sadiman volcano a source for the Laetoli Footprint Tuff? Journal of Human Evolution 61(1):121-124.

Renaissance Essay Example | Topics and Well Written Essays - 1000 words

Renaissance - Essay Example His history reveals those factors which played a major role in the lives of Florentines as they stood on the threshold of the Renaissance. The Chronicle of Giovanni Villani demonstrates that Florence exemplified Renaissance Italy with its emphasis on commerce and the advancement of artistic creativity and was greatly affected by the devastation caused by the plague. Villani’s account of Florence as a thriving commercial center demonstrates that it was this economic prosperity which was one of the driving factors of the Renaissance in Italy. As typical of Renaissance Italian city-states, Florence is a flourishing center of commerce and an integral part of the trade network with the Eastern Empire. As fitting in any description of a commercial center, Villani holds â€Å"the income and expenditure of the commune of Florence in this period† to be one of the â€Å"great features of our city† (41). He goes on to give a detailed account of the income generated by the c ity’s manufacturing guilds, which are obviously the power houses of Florence’s economy and the foundation of its wealth and power. Villani demonstrates the dominance of the city’s largest industry, the woolen cloth makers by asserting that their workshops â€Å"were 200 or more, and they made from 70,000 to 80,000 pieces of cloth which were worth more than 1,200,000 gold florins --- and more than 30,000 persons lived by it† (42). In addition to the manufacture of cloth, the importers and sellers of Transapline cloth â€Å"imported yearly more than 10,000 pieces of cloth, worth 300,000 gold florins† (42). Villani glosses over the noble magnates and knights and gives the greater importance to the merchants, mercers, bankers, bakers, stone and carpentry masters and â€Å"many other masters in many crafts† (42) who make up the guilds. This supports our knowledge of Renaissance Florence, in which the members of a craft or merchant organization fo rmed the commune which wielded authority over the political and economic affairs of the city. Villani confirms the erosion of the power of the traditional landed aristocracy in the Italian Renaissance, saying, â€Å"but from the time that the people began to rule, the magnates no longer had the status and authority enjoyed earlier† (41). Villani makes it clear that it is the members of the manufacturing guilds and professionals who are at the top of the social hierarchy. Renaissance Florence’s dominant position in the trade network is supported by Villani’s account of the city’s ability to meet the famine. Unlike other towns which ejected their beggars at this time of want, â€Å"the commune of Florence --- received and provided for a large fraction of the poor mendicants of all Tuscany† (39). The commune arranges for grain to be bought from Sicily and the regions surrounding the city (Romagna and Arezzo), to be transported at great expense and use d to feed all the citizens. Villani pays tribute to Florence’s economic power by asserting that â€Å"in mitigation of this famine the commune of Florence spent in those two years more than sixty thousand golden florins† (39). Villani’s chronicle bears testimony to economic power and trade being the main cause for Florence’