Food Safety; Pests and Vectors; Air Quality Essay

Food Safety; Pests and Vectors; Air Quality - Essay Example Among the two approaches stated above; training the restaurant employees seems more practicable and productive. This approach has also been applied at Philadelphia in 2009; Don Sapatkin (2009) explains that they adapted a risk-based approach in which emphasis was given to food worker’s knowledge and behavior. It is very important for them to comprehend as to how contamination is spread and how to prevent it. Frequent inspections by restaurant inspectors also play a crucial role in maintaining a good and healthy standard of food service. Personal hygiene of the workers in the restaurants is mandatory. It is noticed that restaurant owners serve much time on the cleanliness of the kitchens and tables etc. but don’t pay attention if the cooks and workers are washing their hands at regular intervals. The workers should be trained and made aware of the food-borne illnesses they are likely to transmit through their food if they are not hygiene cautious. US Food and Drug Administration (2009) states that there is another very important factor regarding food safety; which is the knowledge of temperatures for cooking specific ingredients .e.g. each portion of cooked chicken must reach a minimal internal temperature of 165F for 15 seconds. They should also be aware as to which food is more prone to develop bacteria and at what temperature they should be cooked to remove them. Workers should be urged to wear head gears whenever they are in contact with food to promote a proactive approach rather than a reactive approach. Another thing that should be monitored is that the temperatures of refrigerators are maintained at a suitable temperature. It is often noticed by inspectors that the air temperature of walk-in refrigerators are kept warm. Question 2: Describe the recommendations you would give the public to prevent further spread of West Nile Virus by mosquitoes. Describe the

Article Response Essay Example | Topics and Well Written Essays - 500 words - 2

Article Response - Essay Example Ziegelman then provides a brief history about the introduction of pickle in America in 19th century by immigrants. She terms a pickle as pungent, toxic and morally suspect. The pickle became popular due to its cheap price. Pickles were also considered by charity and health workers to be a stimulant like coffee, whiskey and tobacco. Children from poor families always had a strange fascination about pickles. Efforts were then made to transform immigrant food into American food. This began with the separation of children from their pickles. Cooking classes were established to teach immigrants about American way of cooking and homemakers were trained how to make simple American food including chowders and pies. In 1919 and 1920, New York City’s Board of Education started to feed immigrant children with American food in place of pickles. Pickles had not ceased by mid 1920s, so quotas were issued to stop immigrants from Eastern and Southern Europe. However, the pickle did not stop; Americans started to use it as diet reforms declined, and nowadays pickles are enjoyed as normal food. This story shows that one can eat any kind of food and speak any language and still be an American. Therefore, what makes an American to be an American is citizenship and not food or culture. Immigrants can be assimilated to become American without necessarily forcing them to abandon their culture and food. American society is made up of diverse communities with different cultures and behaviours, but those differences never make them less or more American than others. In my case, I eat pickles. The introduction of pickles to United States is a thrilling story that may make some people who are radical to the American culture to hate pickles. However, I think that the story just indicates how the society accepts diversities in form cultural values and ways of life. I can eat food from any community as long as they do not have any negative health effects. Pickles have been eaten

Fed Corner Truncated Microstrip Patch Antenna

Fed Corner Truncated Microstrip Patch Antenna Ultra-Wide band communications attracted great interest of researchers as it has become one of the most promising technologies for short range mobile systems, Personal Area Networks (PAN) and high speed indoor data communication applications. FCC mentioned parameters for the complete functioning of UWB antennas and they have to cover the bandwidth specified by FCC to attain adequate performance. UWB has the advantage of high data rates with extremely low interference to other narrow band systems. The ultra short pulses provide extremely good spatial resolution, as the range provided by UWB is enough to seize down the major applications of daily life like in ground penetrating radars, parking radars, biomedical imaging, precision tracking and location finding. Various types of UWB antennas have been proposed and implemented with different feeding techniques, such as transmission line, probe feed, dual feed and coplanar waveguides (CPW). A compact antenna design fed by coplanar waveguide (CPW) is proposed. Overall dimensions of antenna are 28ÃÆ'-24 mm2. The design is fabricated and further analyzed to confirm its proper working in UWB range. The design of antenna is quite flexible as fiddling with the patch of microstrip antenna has been done in order to enhance the bandwidth which is the most valued obsession in the current environment. On the other hand, CPW has many advantages such as low radiation leakage, less dispersion at higher frequency, small mutual coupling between two adjacent lines which is helpful to place circuit elements close together without adding an additional layer of substrate and coplanar capability. Using CPW as feeding structure to excite a patch antenna has become very popular recently. The proposed antenna offers an excellent performance for UWB systems by providing bandwidth ranging up to 15.65GHz. Critical design parameters return loss and radiation patterns are investigated in detail. Proposed antenna provides good impedance matching, stable gain characteristics and consistent radiation patterns over its almost whole frequency band of interest. Chapter 1 Introduction Project Overview IEEE defines antenna as a device for radiating and receiving electromagnetic waves. They are used both as transmitter and receiver. This is era of wireless communication. Antennas are an important means of wireless communications now days. The need of time is compact small size antennas with enhanced bandwidth and gain. Amongst all antenna types microstrip patch antennas are most common. They are light in weight and consume low power. But patch antennas have disadvantage that they have narrow bandwidth. Many techniques are used to enhance bandwidth. Ultrawide band antennas have many applications and for many years they have been used for broadband and spread spectrum features in radar systems. The UWB performances of antennas result from excitation by non-sinusoidal signals with quickly time-varying performances [1]. UWB are low power consumption antennas and are for unlicensed applications. As name suggests, they have broad spectrum. Problem Statement Ultra wideband technology is used in low power, short range and high bandwidth communication. In UWB; through spreading information can be transmitted over a larger bandwidth and spectrum is also shared with the other users at the same time. Federal Communication Commission (FCC) allocated the license free band of 3.1GHz-10.6GHz for use in UWB applications. Since then there is a growing demand of UWB antennas for high data rate applications i.e. wireless personal area network (WPAN). UWB has had a important effect on antenna design. The major challenge in UWB antenna design is to achieve wide impedance bandwidth and stable gain while maintaining high radiation efficiency. Project Objective The purpose of this project is to design, stimulate, analyze and fabricate ultra wide band antenna using co-planer waveguide. Design and analysis of a compact antenna fed by CPW for UWB Applications is proposed Bandwidth of the proposed antenna is 15.65 GHz. Antenna offers an excellent performance for ultra-wide band systems by providing an ultra-wide bandwidth ranging from 3.1 18.75 GHz. Gain of the proposed antenna is 4.91dBi over its almost whole frequency band of interest Small size of antenna makes it suitable for applications which demand miniaturization of antenna structure and input impedance of 50 à ¢Ã¢â‚¬Å¾Ã‚ ¦. Methodology We have simulated the designed antenna using Ansoft HFSS. Then the simulated antenna is fabricated and tested on the network analyzer. The simulated and measured results are also explained. Organization of the thesis This report is divided into 6 chapters. Chapter 2 presents the fundamental parameters of antenna. This includes an explanation of various parameters related to antenna performance including radiation intensity ,radiation pattern, power density , gain, directivity and polarization etc. Chapter 3 discusses the Microstrip Patch Antenna and Feeding techniques. Chapter 4 includes Ultra wide band microstrip patch antenna, history of UWB antennas, their features and advantages. Chapter 5 describes antenna design, simulated results, 2D and 3D radiation patterns for different frequencies and fabricated results. Chapter 6 concludes the entire work done throughout the designing of proposed antenna. Conclusion and future work helps to explore enormity of the subject. Chapter 2 Fundamental Parameters of Antenna 2.1 Radiation Pattern The radiation pattern describes the strength of the radiated field in different directions from the antenna, at a constant distance. The radiation pattern is also reception pattern, as it describes the receiving properties of the antenna. It is defined as a mathematical function or a graphical representation of the radiation properties of antenna as a function of space coordinates. In most cases the radiation pattern is determined in far field regions and is defined as a function of the directional coordinates. Radiation properties include power flux density, radiation intensity, field strength, directivity phase or polarization [2]. The radiation pattern is three-dimensional, but measured patterns are usually two dimensional in vertical or horizontal plane view. These measured patterns are presented in either rectangular or polar format. Following figure shows radiation pattern of an antenna in polar plane and Cartesian coordinate systems. http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/images/0900aecd806a1a3e_null_null_null_08_07_07-03.jpg Figure-2.1: Radiation Pattern of an antenna in Cartesian and polar coordinates Radiation patterns are further categorized as relative and absolute radiation patterns. Absolute radiation patterns have absolute units of power or field strength. Relative radiation patterns are presented in relative units of power or field strength. The radiation measurement patterns are mostly relative to isotropic antennas, absolute gain of the antenna is established by antenna gain transfer method. The radiation pattern varies with the distance i.e. the patterns in near filed and far filed are different. The field pattern that exists close to the antenna is known as near filed, and far-field refers to the field pattern that exists at large distances. The far-field is called radiation field. Radiation field and power are what is commonly of interest, so antenna patterns are generally measured in the far-field region. For antenna pattern measurement the distance should be chose large enough not to be in near-field or in far field. The minimum allowed distance depends on the dimensions of the antenna relative to the wavelength. The formula for this distance is: rmin = 2d2/ÃŽÂ » (2.1) Where, rmin is the minimum distance from the antenna d is the largest dimension of the antenna ÃŽÂ » is the wavelength. 2.1.1 Radiation Pattern Lobes Radiation lobes are defines as portion of radiation pattern bounded by regions of relatively weak radiation intensity [3]. These lobes are categorized as follow Major Lobes Minor Lobes Side Lobes Back Lobes 2.1.2 Major Lobe A major lobe is defined as the radiation lobe containing the direction of maximum radiation [2]. Normally an antenna has one major lobe. 2.1.3 Minor Lobe Any lobe except major lobe is called minor lobe. It usually represents the radiation pattern which is not desirable. 2.1.4 Side Lobe A side lobe is a radiation lobe in any direction other than the main lobe [2]. Usually a side lobe is next to the main lobe and is in direction to the main lobe. 2.1.5 Back Lobe A back lobe is a radiation lobe whose axis makes an angle of approximately 180 ° with respect to the beam of an antenna or that is directed away from the main lobe [2]. File:Typical Antenna Pattern.jpg Figure 2.2: An illustration of major and minor lobes of radiation pattern 2.2 Field Regions The antenna fields are divided into three regions Reactive near field Radiating near field (Fresnel) Far field (Fraunhofer) http://www.nearfield.com/images/theory-ffdist.jpg Figure 2.3: Figure of Near Field and Far Field Regions 2.2.1 Reactive Near Filed It is the region immediately around the antenna. In this region the reactive filed predominates. The distance of this filed with antenna is usually R 2.2.2 Radiating Near Field (Fresnel) Radiating near filed is defines as that region of the field of an antenna between the reactive near-filed and the far-filed region wherein radiation fields predominate and wherein the angular field distribution is dependent upon the distance from the antenna [2]. The distance of inner boundary is R 2.2.3 Far Field Region (Fraunhofer) Far Field region is defined as that region of the field of an antenna where the angular filed distribution is essentially independent of the distance from the antenna [2]. 2.3 Radiation Intensity Radiation Intensity is the power radiated from an antenna per unit solid angle. It is the parameter of far field radiation. 2.4 Directivity Directivity is figure of merit for antennas. It is the power density an antenna radiates in direction of maximum radiation to the average power density radiated by an isotropic antenna. Directivity for an isotropic antenna is always unity. It is expressed as D= (2.2a) (2.2b) Where, D is directivity and U is radiation intensity, Uo is Intensity if an isotropic source and Prad is total radiation power. 2.5 Gain The gain and directivity of an antenna are closely related to each other. However for gain in denominator it is total power accepted by an antenna rather than total power radiated by an antenna. G= (2.3) Gain is dimensionless. According to IEEE standards, gain doesnt include losses arising from impedance mismatching or polarization mismatches. 2.6 Bandwidth The bandwidth is basically the difference or range between highest and lowest frequencies on which an antenna is operated. It is advantageous to have an antenna with high bandwidth. The bandwidth is expressed in term of ratio of upper cut off to the lower cutoff for broadband antennas. 2.7 Beamwidth Beamwidth is the angle usually measured in degrees; between the -3dB power radiated in the main lobe of radiation pattern. img383 Figure 2.4: Illustration of Beamwidth 2.8 Return Loss It is the amount of power that is reflected back in to the transmission line due to mismatching or any other error. It is the efficiency of power delivered to the load from the transmission line. Mathematical representation of Return loss is RL = 10log (2.4) Return loss is measured in dB. http://www.mwrf.com/Files/30/11240/Figure_05.gif Figure 2.5: Return Loss 2.9 Polarization Polarization is defined as point of reference of the electric field of the wave radiated by the antenna. It is categorized in three types: Linear Circular Elliptical 2.9.1 Linear Polarization When there is zero phase difference between x and y component of a wave then polarization is called linear polarization. Linear polarization is further divided into Horizontal polarization Vertical polarization http://www.ccrs.nrcan.gc.ca/glossary/images/3104.gif Figure 2.6: Linear Polarization 2.9.1.1 Horizontal Polarization Horizontal polarization is the one in which wave propagates in x-direction and there is no propagation along y direction. A horizontally polarized wave is explained as a function of time T and E-field position Ex = E1 sin ( É ·t à ¡Ã‚ µÃ‚ z) (2.5) http://www.cfht.hawaii.edu/~manset/PolHoriz.gif Figure 2.7: Horizontal Polarization 2.9.1.2 Vertical Polarization Vertical polarization is the one in which wave propagates in y-direction and there is no propagation along x direction. It can be written in mathematical form as Ey = E2 sin ( É ·t à ¡Ã‚ µÃ‚ z) (2.6) http://www.cfht.hawaii.edu/~manset/PolVert.gif Figure 2.8: Vertical Polarization 2.9.2 Circular Polarization If there is equal phase difference between two waves then there is circular polarization, either clockwise or anticlockwise. Wave moving in clockwise rotation is said to be left circularly polarized and the one propagating in counterclockwise rotation is right circularly polarized. Mathematically it is defined as Ex = E1 sin (É ·t à ¡Ã‚ µÃ‚ z) (2.7) Ey = E2 sin (É ·t à ¡Ã‚ µÃ‚ z + ÃŽÂ ´) (2.8) E1 is the amplitude of wave linearly polarized in x direction. E2 is the amplitude of wave linearly polarized in y direction. ÃŽÂ ´ is the phase difference. http://www.cfht.hawaii.edu/~manset/PolCirc.gif Figure 2.9: Circular Polarization 2.9.3 Elliptical Polarization If two waves have unequal amplitude or phase then there is elliptical polarization. graphic 1 Figure 2.10 (a): Graphical Representation of Elliptical Polarization http://www.nsm.buffalo.edu/~jochena/images/elliptic2.gif Figure 2.10 (b): 3-D view of Elliptical Polarization 2.10 Voltage Standing Ratio VSWR is the ratio between maximum voltage and the minimum voltage. If there is a difference between load impedance and input impedance then there occurs reflection which causes instructive interference and destructive interference. Instructive and destructive interference produces maximum and minimum amplitudes respectively. Mathematical Expression for VSWR is VSWR= (2.9) http://www.microwaves101.com/encyclopedia/images/VSWR/waves5.jpg Figure 2.11: Different Voltage amplitudes at different distances 2.11 Types of antennas There are six different types of antennas [2]. Microstrip Patch Antenna Lens Antenna Wire Antenna Array Antenna Reflector Antenna Aperture Antenna 2.11.1 Microstrip Patch Antenna Microstrip patch antennas fall into the category of printed antennas [4]. A radiating patch is printed on a grounded substrate which is usually feed via a transmission line or coaxial cable. Patch can be of any shape and size i.e. circular, square, triangular or rectangular. Amongst all printed antennas i.e. Dipole, Slots, Tapered Slots antennas; Microstrip Patch Antennas are most famous. They are small in size, light in weight and low power consuming. But their bandwidths are smaller and have low gain. They are easy to integrate, good radiation control and cost of production is low. To increase bandwidth many techniques are used that is introducing slots and slits etc. They are used commercially in radars, wireless communications, satellites and mobiles etc. Figure 2.12: Microstrip patch Antenna http://images.books24x7.com/bookimages/id_22121/fig188_01.jpg Figure 2.13 (a): Rectangular Patch Antenna (b): Circular Patch Antenna Microstrip Patch antennas are used in Microwave frequency range. They are used in arrays to increase the bandwidth and gain and for other purposes. http://www.antennamagus.com/database/antennas/99/Stacked_microstrip_patch_array-antenna_design.png Figure 2.14: Array of rectangular patch antennas 2.11.2 Lens Antenna Lens antennas are used to convert spherical radiated waves into plane waves in specific direction by using a source with microwave lens. It actually stops the divergent radiated energy to spread in undesired directions. These are mostly used for the high frequencies. A lens antenna may be of concave or convex shape. They are directional antennas and can scan wider angles. In comparison to reflectors; their gain is 1 or 2 dB less. Lens antennas may be constructed of non-metallic dielectrics or of metallic (artificial) dielectrics [5]. http://www.xibao-electronictech.com/images/product/2/210Lens-Antenna.gifhttp://telecom.esa.int/telecom/media/img/largeimage/WaveguideLensAntennaPrjObj_404.jpg Figure 2.15 (a): Lens Antenna Figure 2.15 (b): Wave guide Lens Antenna 2.11.3 Wire Antenna Wire antennas consist of a simple wire that is used to radiate electromagnetic energy. These wire antennas can be of different shapes. Most commonly used are straight wire antennas i.e. dipoles, loops and helix. Beside half-wave dipoles and quarter wave monopoles, wires of arbitrary lengths are often used to form antennas. Wire antennas can be vertical, horizontal or sloppy with respect to the ground. They may be fed from centre, at end or anywhere in between. The wires can be thick or thin, the radiation of antenna depends upon the thickness of the wire. Antennas with length larger than ÃŽÂ »/2 are called Long-wire antennas. Figure 2.16 (a): Wire Antennas (a) Figure 2.16 (b): Dipole Circular loop 2.11.4 Array Antenna Array antennas are made up of more than one element basic of which is a dipole. Array antennas are the combination of radiating elements in such way that the radiation from these add up giving maximum or minimum radiation in a specific direction. They are used for higher directivity. They are made up of helices, dishes and other antennas. These elements are arranged to form broadside, end fire, collinear, driven and patristic arrays [5]. They are used in applications in which radiation cannot be achieved from single radiating element. They are low weight and low cost antennas. Examples of array antennas are Yagi-Uda, http://www.tennadyne.com/images/tennlpdanavy.JPG Figure 2.17: Log Periodic Dipole Array Antenna 2.11.5 Reflector Antenna They are widely used to modify the radiation pattern of radiating elements. They are classified as active and passive reflectors. The active reflectors have corners made up of plane surfaces and they include periscopic antennas, flat-sheet reflectors and corner-reflector antennas. An active reflector may have corner elliptical, parabolic or spherical shape. Active reflectors include parabolic dish, truncated parabola, pill box etc. Reflectors are simple in design, involve only one surface and obey simple laws of optics. The applications of reflector antennas are radars and other point to point communication systems [5]. http://www.sameercal.org/images/reflector_antenna.jpg Figure 2.18: A co-secant Reflector Antenna 2.11.6 Aperture Antenna Aperture antenna is an important antenna for space communication. As the name suggests they consist of some cavity through which electromagnetic waves are transmitted or received. Apertures may be of any shape i.e. rectangular, circular or spherical. Larger the size of antenna larger will be the gain. Aperture antennas have to be placed carefully because they have narrow beam widths. Examples of aperture antennas include waveguides, reflectors horns, slots and lenses. Aperture antennas are commonly used in aircraft and spacecraft applications. http://www.analyzemath.com/antenna_tutorials/introduction_3.gif Figure 2.18: Horn Aperture Antenna Chapter 3 Microstrip Patch Antenna and Feeding techniques 3.1 Introduction Spaceships, aircrafts and other military applications such as missiles where important constraints to consider are performance, manufacturing expenditures, smooth profile and ease of installation and now a days other systems such as wireless communication requires similar type of specifications to consider . And the basic component which is required by these listed applications for transmission of instructions or data and to receive these instructions on the receiver end is antenna. Hence to meet the requirements listed above e.g. smooth profile, cost and performance etc Microstrip antennas are used. Microstrip antennas are diminutive profile, conformable to planar and non-planar surfaces, easy and cheap to construct using the up to date printed circuit technology. Microstrip antennas have very flexible behavior to polarization, resonant-frequency, and impedance and radiation pattern. They are also used to increase the bandwidth. They consist of a ground plane over which a substrate is mounted and the radiating patch is mounted on the substrate. Generally the ground plane and the dielectric substrate have equal length and width. The Microstrip antennas are illustrated by the width, length and the height of the dielectric substrate which is sandwiched in between the ground plane and the radiating patch 3.2 Structural Configuration The structural configuration of micro strip patch antenna is shown in figure Figure 3.1: Structural Configuration of Patch Antenna It consist of a thin (t Figure 3.2: Side View of Patch Antenna The length of the patch is usually ÃŽÂ »/3 3.3 Formula for Rectangular Patch Antenna To draw the width of the patch we use the formula (3.1) And the length of the patch can be drawn as: (3.2) To reduce the fringing effects we use the following formula à ¢Ã‹â€ Ã¢â‚¬  L= 0.412h (3.3) Here à ¢Ã‹â€ Ã¢â‚¬  L is the trimmed length from antenna. (3.4) 3.4 Feeding Methods Following feeding methods are most popular and are used with microstrip antennas 1. Microstrip line feed 2. Coaxial probe feed 3. Aperture coupled feed 4. Proximity coupled feed 5. Coplanar waveguide feed These methods are either contacting or non-contacting. Contacting methods are those in which there is a direct contact between the transmission line and the radiating surface whereas in non-contacting methods, electromagnetic field coupling method is used to transfer the power. 3.4.1 Microstrip Line Feed In this feeding method, the line feed is conducting strip of small width as compared to the patch. It is the easiest feeding method; easy to fabricate and simple to model. The radiating strip is placed at radiating patchs edge and it is of the same material that is used for patch. If length of the strip is greater than the wavelength, losses will be generated. It can be reduced if the strip line has a substrate with high dielectric constant and low weight, so that the fields are confined to the strip line. A line feed of dimensions 17x3mm is used to obtain 50ÃŽÂ © input resistance. Figure 3.1: Patch with Microstrip Line Feed 3.4.2 Coaxial probe feed In coaxial probe feeds, coax inner conductor is attached to the radiating patch while the other conductor is connected to the ground plane. It is used widely. Its fabrication is easy and has low spurious radiation that is radiation outside the band frequency. It is has narrow bandwidth and it is hard to model for thick substrate. Matching also becomes difficult for thicker substrate because of increase length of probe make it more inductive, its inductance effect can be reduced by using a series of capacitors. Figure 3.2: Patch with coaxial probe feed 3.4.3 Aperture coupling feed It is the non-contacting feed. The two substrates are separated by ground plane in it. The microstrip feed line is on the bottom side of the lower substrate there is a; whose energy is coupled to the patch through a slot on the ground plane which separates the two substrates. A material with higher dielectricity is used for bottom substrate therefore, by this arrangement independent optimization of the feed mechanism and the radiating element can be carried out. For top substrate a thick, low dielectric constant material is used. The ground plane between the two substrates isolates the feed from the radiating element and minimizes the interference. The configuration is shown in the figure Figure 3.3: Patch with aperture coupling feed Matching is performed by controlling the width of the feed line and the length of the slot. Amongst all four techniques this is the hardest to fabricate and has narrow bandwidth. It is somehow easy to model and has moderate spurious radiation. 3.4.4 Proximity coupling feed In this feeding method, microstrip line is placed between two substrates and the radiating patch is placed on the upper substrate. This coupling is capacitive in nature. This coupling has the largest bandwidth as high as 13%. It is easy to model and has low spurious radiation. Its fabrication is somehow difficult. However, length of the stub help in improving the bandwidth, and width-to-line ratio of the patch can be used to control the match. The coupling feed is shown Figure 3.4: Patch with Proximity Coupling Feed 3.4.5 Coplanar Waveguide Feed This feeding technique is used when patch antenna is used in microwave monolithic integrated circuits (MMIC). The coplanar feed is fabricated on a ground plane and coupling is achieved through a slot. This feeding method reduces the radiation from feed structure because of its unusual method of coupled slot. Since CPW (coplanar waveguide) has many advantages such as low radiation leakage, less dispersion and small mutual coupling between two adjacent lines, which is helpful to place circuit elements close together without adding an additional layer of substrate, using CPW as the feeding structure to excite the patch antenna through a slot has become very popular recently. In addition, CPW structure can maintain constant characteristic impedance while varying its geometry, which provides a better impedance matching possibility Figure 3.5: Patch with Coplanar Waveguide Feed 3.3 Categorization on the basis of bandwidth:- On the basis of range of frequency bands, microstrip patch antennas can be categorized into three main classes which are: antenna for narrow band applications antenna for wide band applications antenna for ultra wideband applications Chapter 4 ULTRA WIDEBAND 4.1 Introduction A series of very short baseband pulses with time duration in nano-seconds that exist on ALL frequencies simultaneously. Pulse repetition frequency (PRF) can range from hundreds of thousands to billions of pulses/second. Very low power: 41dbm/MHz (FCC) and wide bandwidth: 3.110.6 GHz Modulation techniques include pulse-position modulation binary phase-shift keying And others Radio technology that modulates impulse based waveforms instead of continuous carrier waves 4.1.1 Narrow band vs. Wide band signals UWB could be used to Indoor, short-range communications for high data rates, OR Outdoor, long-range, but for very low data rates 4.1.2 Large Relative Bandwidth UWB is a form of extremely wide spread spectrum where RF energy is spread over gigahertz of spectrum. Wider than any narrowband system by orders of magnitude. Power seen by a narrowband system is a fraction of the total.UWB signals can be designed to look like imperceptible random noise to conventional radios 4.1.3 Large Fractional Bandwidth Large fractional bandwidth leads to High processing gain and Multipath resolution and low signal fading. Fractional Bandwidth is the ratio of signal bandwidth (10 dB) to center frequency: Bf = B / FC = 2(Fh-Fl) / (Fh+Fl) 4.1.4 Scalable Technology with Low Power UWB benefits from basic information theory results when: Signal Bandwidth >> Data Rate .Power efficient low-order modulation can be used even for relatively high data rates.Data rates can scale independent of PRF by integrating bit intervals over multiple pulse intervals 4.1.5 Multipath Performance Ultra-wide bandwidth provides robust performance in multipath environments . 4.1.6 UWB Data Rates 4.2 UWB channels Indoor Within a room (LOS NLOS) Investigates the impact of Distance Rx/Tx antenna heights Antenna polarization C:mat_dirsuwblimitsindoor5.tif UWB Emission Limit for Indoor Systems Outdoor Campus environment Low altitude Mobility C:mat_dirsuwblimitsoutdoor5.tif UWB Emission Limit for Outdoor Hand-held Systems 4.3 Emission limits for UWB UWB Emission Limits for GPRs, Wall Imaging, Medical Imaging Systems. Operation is limited to law enforcement, fire and rescue organizations, scientific research institutions, commercial mining companies, and construction companies. UWB Emission Limits for Thru-wall Imaging Surveillance Systems 4.4 Features of UWB :- Ultra-short pulses Baseband transmission Low duty

Leukemia Essay -- Health Medical Cancer

Leukemia Leukemia is a disease that affects blood-forming tissues, mainly bone marrow. Leukemia also affects the lymph glands and spleen. Leukemia causes the body to produce an extreme amount of abnormal white blood cells. This causes infections because the abnormal cells cannot stop infections like the normal cells do. Leukemia also causes anemia. Anemia is a disease in which the body makes less blood cells. This happens because the leukemic cells crowd the system. Leukemia also causes excessive bleeding. This happens because the amount of platelets will decrease and clotting will not occur, Researchers think a change in genetic structure causes leukemia. Changes in gene structure could be caused by environmental problems. Some of these problems could be: birth defects, radiation, viruses, and chemicals. Leukemia is not inherited and is not contagious. There are two major types of Leukemia, Lymphocytic and Granulocytic. In Lymphocytic Leukemia white blood cells known as Lymphocytes, which are made in the Lymph glands and bone marrow are abnormal or immature. In Granulocytic Leukemia this causes an increase in white blood cells known as granulocytes. Granulocytes are made in the bone marrow, and other tissue. Granulocytes that are affected by leukemia cannot fight of infections. There are two ways in which leukemia can occur. One is acute, and the other is chronic. Acute leukemia is found most in children. It progresses r...

Candide by Voltaire Essay

Through Candide’s perplexing adventures and enlightening encounters, Voltaire illuminates the numerous diverse cultures of which Europeans consider themselves superior. Yet rather than supporting the foreign practices of cannibalism, bestiality, and the abolishment of priests, Voltaire is ridiculing the Europeans’ own methods of torture in an abusive social hierarchy. Therefore, while freedom of expression and a consensus of the majority constitute faucets of good behavior, the European practice of elitist rule and inequitable punishments is revealed as unjust. This criticism suggests the need for reform by deriving authority from somewhere other than the traditional roles of the royalty, clergy, and nobility, a rather radical move at the time. Voltaire at first reveals the fault of Europeans through his description of the savage land of Oreillon. Upon their dissent from Paraguay, Candide and Cacambo come across two women, completely nude, who cry out and â€Å"spryly† run away from two monkeys who snap â€Å"at their buttocks† (73). Instantly sympathetic, Candide shoots his musket and kills the monkeys, thinking that he has redeemed himself from earlier sins by saving these distressed women. However, to his surprise he discovers that he has just killed the ladies’ lovers. Without questioning the practices of this foreign society, Candide reacts based on his own perceptions of right and wrong. His actions reflect the naivety of Europeans concerning what is thought to be normal based on their own â€Å"superior† culture. As punishment for Candide’s rash actions, the Oreillons attempt to roast the travelers over a spit to eat, justifying this through the proclamations that Candide and Cacambo are Jesuits and thus deserve to die. This behavior is explained by Cacambo as being â€Å"appropriate† because â€Å"if we Europeans do not exercise our right to eat others, it is because we have other ingredients for a good meal† (pg. 74). He recognizes that each society contains its own equally valid practices which cannot be altered or condemned by those who think they are predominant. In addition, Voltaire is not justifying that bestiality and cannibalism constitute a righteous society, but rather satirically commenting on the Europeans own practices, for it would be hypocritical to condemn these practices without evaluating whether the European’s own forms of punishment are just. As the innocent Candide ventures to Eldorado, he is once again introduced to a land unlike that found in contemporary Europe. Upon their arrival, the travelers bewilderingly walk upon pavement made up of rubies, emeralds, and gold and rapture in the delights of a free feast at a common inn. The generous, humble citizens then guide them to an old man and, later, even the approachable king, in order to answer their many questions. Through these communicators they come to realize that the most striking aspects of the village do not constitute its physical features, but rather its ideology. They are told that all men are free, and thus there is no need for the establishment of courts, trials, or prisons. While Candide is quite baffled by these assertions which completely contrast the structured social organization of Europe, he is even more confused by the lack of priests or an enforced religion, upon which he exclaims, â€Å"What! You have no monks who lecture, debate, govern, conspire, and burn people who don’t agree with them?† (79). These seemingly sarcastic remark is a reflection of the binary thinking in which the Europeans have taught their citizens to believe. Candide had always considered the church as an institution which interjects in every aspect of life and constantly ridicules and punishes others while denying the fact that there are other practices and religions besides the order of the church and Catholicism. Voltaire is not suggesting the elimination of priests, which would be a radical idea at the time, but is rather demonstrating a deeper criticism of Europeans who assume that they are superior and must punish all those who defy this idea. Although Oreillon and El Dorado are societies completely unlike that of the Europeans in law and culture, they are seen as portraying decent human behavior because they allow their citizens to express free will and they derive authority from the consent of the masses. For instance, in Oreillon, women are allowed to mate with whomever they please without judgement or persecution from others. This freedom of expression illustrates that the culture seeks to facilitate the happiness of its people. Additionally, when the two monkeys are murdered by Candide, the leaders instantly capture and attempt to punish the travelers, reflecting the society’s dedication to protect its citizens from harm and condemn those who impinge on basic freedoms. While this culture may seem bizarre compared to more civilized nations, the fact that it derives its authority from the people illustrates that bestiality and cannibalism are enforced as appropriate human behaviors so long as there is a general consensus. Similarly, good behavior does not necessarily need to be derived from praise towards the king or daily sacrifices to a church, as portrayed in Eldorado. Unlike in Europe, the king is humble, approachable and genuinely concerned with the welfare of his citizens. For example, the feast the travelers consume at the inn is free because the state is said to assist business, thus revealing that the government is willing to contribute to the success of its people despite their class or wealth. Therefore, despite their practices, these societies emulate good behavior. However, Voltaire forms a critic of the Europeans due to the unjust practices in which they derive and maintain authority. In Candide’s hometown of Westphalia, for example, the naive Candide is exiled from the castle of the Thunder-ten-tronckh because he kissed the Baron’s daughter, Cunegonde. He was unfairly punished because he stepped out of the social hierarchy to which he was born, while Cunegonde was not disciplined for her actions due to her rank. Similarly, in places like Paris, the elites haughtily criticize their fellow man’s creations and do not hesitate to manipulate and greedily conspire against others. When Candide is led into a ploy by the despicable Abbe and arrested even though he had not committed any crimes, he is able to buy his freedom with three diamonds. The officer then exclaims, â€Å"Ah sire, even if you committed every crime imaginable, you’re still the best man in the world† (97). One’s fate depends on the inconsiderate word of the elite, one’s wealth, and the act of bribery. Since Candide had money, he was able to secure his freedom while the majority of peasants who are near penniless would have to suffer. These scenarios represent the unjust rule of the elites over the consensus of the majority. While Voltaire formulates the components of good behavior based on the legitimacy the authority derives from its citizens, he also constitutes bad behavior as punishment without just cause. For instance, when Candide and Martin arrive in Portsmouth, they view the execution of a British Admiral. The Admiral’s crime was explained in that he had stayed too far from the French enemy and that his death would encourage others to fight more fervently during war. This nonsensical behavior represents the paradox of European punishments which reduce war heros to criminals. Another such scene is presented when Candide and Pangloss reach the city of Lisbon in which a haphazard earthquake kills thirty thousand people. Faculty of a university decide that, in order to prevent another earthquake, they must â€Å"roast several persons over a slow fire†¦ They had therefore seized a man from the Basque province who had been convicted of marrying the godmother of his godchild, and two Portuguese men, who when eating a chicken, had removed the bacon seasoning† (52-53). As a manner of electing their sacrifices, they choose those who had committed even questionable offenses, though even those forms of misconduct can be viewed as unsubstantial enough to deserve punishment, much less death. While it is firstly completely unreasonable to attribute a natural phenomenon to personal actions, Voltaire goes so far as to satirically illustrate that this is a commonsense European belief, for both offenses appear inconsequential to the victims’ punishment. Meanwhile, most Europeans would be disgusted with the culture of the Oreillons who engage in cannibalism after enacting a punishment. However, Candide’s death penalty after murdering two of its citizens is a much more equitable offense in terms of its punishment than removing bacon seasoning from chicken, such as in Europe. Furthermore, once a body has been burnt, it seems inconsequential whether it is eaten or not. Voltaire is thus able to portray the irony as well as the unjust nature of European punishments as a bad behavior of society. The figures of the time who would be most notably perturbed by Voltaire’s suggestions constitute the royalty, the nobility, and the clergy. Firstly, for centuries the royalty had uncontestedly derived authority through lineage and from claims to divine right. Candide’s embrace with the King of Eldorado would probably be perceived as strange because the royalty was considered far above the common people in class, stature, and rights, and thus did not need the consent of its citizens to govern. Thus, the monarchy would be opposed to Voltaire’s ideas because they undermine his authority. This is reflected in eighteenth century Europe when the National Assembly made a radical move by sending Louis XVI to the guillotine as a symbol of the growing dissatisfaction of the peasants and workers. Secondly, the nobility consisted of a small number of elites who mainly derived their elevated status from patronage. Voltaire’s view of this social class, at least in Paris, is illustrated in the abode of Marquise de Parolignac, in which these morose intellectuals portray that their sole interests are to spread slander, hypocritically belittle art, and greedily take advantage of Candide’s treasures. Similarly to the monarchy, Voltaire’s proposal that society’s values and laws should be supported by the consensus of the masses was a scandalous assertion because it would undermine the power of the elites and force them to surrender their privilege. Finally, the clergy’s word penetrated all aspects of life in eighteenth century Europe while Religious Orthodoxy formed local allegiances and bound communities together by preaching sacred traditions. However, it can also be said that the institutions of the church hypocritically valued their own self-preservation over educating the masses. Therefore, these religious authorities would not consent in being forced to adhere to stricter laws by having to give proper, legitimate reasons as a means to punish nonbelievers or delinquents of the church. Despite these opponents, Voltaire suggests a need for reform by deriving authority from somewhere other than the norm. Although European society appears far more advanced than that of the savages and more structured than Eldorado, that does not necessarily determine that its laws and people are superior. In fact, Voltaire constitutes good behavior in a society as something that has been consented upon by its people, while bad behavior derives from unjust punishment and the dangerous rule of elites. Voltaire thus forms a critic of Europeans through comparisons to these foreign lands and furthermore questions whether a reformation of authority is a necessary means to benefit society. Source Voltaire. Candide. Boston: Bedford/St. Martin’s, 1999.

Ch 1 H.W Consumer Behavior

Q1:describe the interrelationship between consumer behavior and the marketing concept. A1: marketing concept determine the needs and wants of specific target markets and Deliver satisfaction better than competition. consumer behavior includes all the decisions a consumer makes when spending their time and money. The what, why, when, where, and how of consumer purchases are examined in consumer behavior. It is not just individuals, but households, families, and groups that influence the decisions we make. ————————— Q2: describe the interrelationships between consumer research, market segmentation and targeting, and the development of the marketing mix for a manufacturer of HDTV sets. A2: consumer research The process and tools used to study consumer behavior. Market segmentation : Process of dividing the market into subsets of consumers with common needs or characteristics Market targeting : The selection of one or more of the segments identified to pursue.The development of the marketing mix for a manufacturer of HDTV consist the product the features ,designs and the price including discounts and the place (distribution of the product ) and promotion ( the advertising) —————————- Q3: select any one of the company web sites and product specific site pairs listed in table 1. 1 that interests you . then systematically examine each of the two sites in terms of how you as a consumer respond differently to the two sites A3:We're not going to work publicity for this company, but we want to highlight how the company deals with customers and most importantly its olicy in respect for the customer and if we see the slogan â€Å"the customer is always right† appears to us every time we press a button to complete the purchase. —————————- Q4: Discuss The Interrelationships Among Cus tomer Expectation And Satisfaction, perceive Value And Customer Retention. Why Is A Customer Relation Essential? A4 :The goal of all marketers is to build and maintain successful relationships with their consumers. This occurs by offering a product which has benefits that the consumer values.In addition, they see the value of those benefits as exceeding the cost of the product – the cost in terms of money, time, and opportunity costs. If a product delivers value, the company is likely to have a high level of customer satisfaction. They will trust the marketer and continue to purchase the product. In addition, they will tell others about the product and speak highly of it when asked or when reviewing the product online. A company with strong customer relationships will be able to achieve a high level of customer retention – their customers will not defect to the competitor or stop using their product.They will retain these customer over time and will be more profitable due to these valuable loyal customers. —————————- Q5: Discuss the role of the social and behavioral sciences in developing the consumer decision-making model. A5: The input stage includes sources of information to the consumer – how they learn and are influenced by the marketer and their environment. The process stage ties to the decision-making process the consumer undergoes when considering a purchase.It moves from the inputs to the psychological factors involved in recognizing a need, searching for information, and evaluating alternatives. The output stage involves the actual purchase and the post-purchase evaluation. —————————- Q6:Apply each of the two models depicted in Table 1. 3 (i. e. , traditional marketing and value and retention marketing) to the marketing of cellular phone services. You may want to incorporate into your answer your own and your peers experiences in selecting cellular communication providers. A6:VALUE- AND RETENTION-FOCUSED MARKETING| THE TRADITIONAL MARKETING CONCEPT| Use technology that enables customers to customize what you make. | Make only what you can sell instead of trying to sell what you make. | Focus on the product’s perceived value, as well as the need that it satisfies. | Do not focus on the product; focus on the need that it satisfies. | Utilize an understanding of customer needs to develop offerings that customers perceive as more valuable than competitors’ offerings. | Market products and services that match customers’ needs better than competitors’ offerings. Research the levels of profit associated with various consumer needs and characteristics. | Research consumer needs and characteristics. | Understand consumer behavior in relation to the company’s product. | Understand the purchase behavior process and the influences on consumer behavior. | Make each customer transaction part of an ongoing relationship with the customer. | Realize that each customer transaction is a discrete sale. | Use hybrid segmentation that combines the traditional segmentation bases with data on the customer’s purchase levels and patterns of use of the company’s products. Segment the market based on customers’ geographic, demographic, psychological, sociocultural, lifestyle, and product-usage related characteristics. | Invest in technologies that enable you to send one-to-one promotional messages via digital channels. | Target large groups of customers that share common characteristics with messages transmitted through mass media. | Use interactive communications in which messages to customers are tailored according to their responses to previous communications. | Use one-way promotions whose effectiveness is measured through sales data or marketing surveys. Create customer tiers based on both volume and consumption patterns. | Cre ate loyalty programs based on the volume purchased. | Make it very unattractive for your customers to switch to a competitor and encourage them to purchase ‘better’ – in a manner that will raise the company’s profitability levels. | Encourage customers to stay with the company and buy more. | Base your marketing budget on the ‘lifetime value’ of typical customers in each of the targeted segments compared with the resources needed to acquire them as customers. Determine marketing budgets on the basis of the numbers of customers you are trying to reach. | Conduct customer satisfaction surveys that include a component that studies the customer’s word-of-mouth about the company, and use the results immediately to enhance customer relationships. | Conduct customer satisfaction surveys and present the results to management. | Create customer intimacy and bonds with completely satisfied, ‘delighted’ customers. | Create customer tr ust and loyalty to the company and high levels of customer satisfaction. |

Writing with Rhythm

Writing with Rhythm Writing with Rhythm Writing with Rhythm By Guest Author This is a guest post by Hugh Ashton. If you want to write for Daily Writing Tips check the guidelines here. When I was substantially younger than I am now, I wrote masses of anguished adolescent poetry. My favorite verse form was the sonnet, a style and format that is maybe little surprising for a teenager to be writing. For those who slept through this part of their English course, a sonnet is a formal 14-line poem with a complex rhyme scheme in iambic pentameter. I no longer indulge in such musings, but I learned many tricks and techniques from writing my sonnets and other poems. First and foremost, writing poetry, especially formal poetry, tells you a good deal about the internal rhythms of the English language. Most of the spoken English language moves to a fundamental iambic rhythm: di-DUM di-DUM di-DUM. Put five of these together and you have a line of blank verse: Now is the winter of our discontent Or Is this the face that launched a thousand ships? Or The stars move still, time runs, the clock will strike, The devil will come, and Faustus must be damnd. In the second line of the last quotation, note how Marlowe breaks the rhythm slightly for emphasis (if you dont slur the word devil into one syllable, that is), and then reverts to the set rhythm for the second half of the line. You dont have to write in this formal style, of course, but you should make yourself aware of the internal stresses in English prose, and how they carry readers through your writing. Until relatively recently (a few hundred years ago), all reading was done out loud everyone read by vocalising the written words. When these rules of internal rhythm are broken, as in this quotation from a camera manual, the result is clotted prose prose which does not flow: Depth of field is the area of acceptable sharpness in front of and behind the subject in focus. The larger the F-number used (from F2.8 to F22), the deeper the depth of field. On the contrary, the smaller the F-number (from F22 to F2.8), the shallower this zone of acceptable sharpness. Its not bad English its free of jargon but its not good either. Another reason why these sentences do not flow is the lack of macro rhythm,the pauses for comprehension (and breath!) in the middle of a sentence. For another example, take this sentence from a recent Pentagon report: There is a crisis of confidence among Afghans in both their government and the international community that both undermines our credibility and emboldens the insurgents. If you read this out loud, its all got to be done in one breath. Theres no pattern to the sentence. By the time youve got to the end, you forget what the beginning was like. Heres a suggested rewriting: The Afghan people are experiencing a crisis of confidence in both their own government and the international community, and this is undermining our credibility, as well as emboldening the insurgents. Not perfect Id probably split this sentence into two but the sentence now has a beginning, a middle, and an end. Note how there is also an implied contrast between the Afghan people and the insurgents in my version that is somewhat lacking in the Pentagon original. Returning to my youthful bad poetry (and here is an example of super-macro rhythm in a piece of writing the thematic tie-up between the start of a piece and the end), the other major thing I learned from writing formal verse was to use a mental thesaurus, and not to be afraid to change the order of my words. I say a mental thesaurus, because a paper thesaurus can be too restrictive; wandering around the canyons of your mind can produce some interesting twists and turns that would never be explored using a printed page. Its all too easy to write bad ungrammatical verse: As on my bed I toss and turn Remembering things I tried to learn But relatively easy to recast these lines into something more grammatical and natural: Im lying wide-eyed in my bed While half-learned facts race round my head By forcing the grammar to be natural, I have also forced myself to think of different words and thereby avoid clichà ©s and hackneyed phrases. It works for prose too. Try to read your work out loud before you submit it. Does it work as a live reading? Does the language flow? Do the sentences hang together? Does the piece have thematic coherency? In other words, have you got rhythm? Hugh Ashton is a writer and journalist who has lived in Japan for the past 21 years. As a copywriter and rewriter of translated material, he has become increasingly pernickety and critical of his own writing and that of others. His latest published work is an alternate history novel, Beneath Gray Skies, which is available from Amazon, etc. Details of the book may be found at beneathgrayskies.com. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Writing Basics category, check our popular posts, or choose a related post below:50 Synonyms for â€Å"Leader†8 Types of Parenthetical PhrasesCapitalizing Titles of People and Groups