First World War Essays - Bulgaria In World War I, World War I

First World War The First World War began as a spark and exploded into a merciless blood bath of money, power, and land. The little spark began in the mountainous Balkans of southeastern Europe where small state-sized nations argued back and forth. For hundreds of years many of these small nations were held under the gripping powers of Turkey, Russia, and Austria-Hungary. It started in the capital of Bosnia, Sarajevo. Bosnia was also a mini-nation of the Austria-Hungary Empire. On the day of June twenty-eight, 1914, the leader of Austria-Hungary and his wife were visiting the city. Shots rang out from a young Slavic nationalist heading for the two. They were both killed. This person lived in the neighboring nation of Serbia. Someone had to be blamed for the incident and all their fingers were pointing at Serbia. The spark soon turned into a flame as of July twenty-eight, exactly one month later, Austria-Hungary declared war on the neighboring nation of Serbia. Suddenly everyone felt they must help and the card game of Alliances was dealt. The leader of the Slavic people was essentially Russia. This enormous nation felt that they must aid Serbia and begins mobilizing troops to that area. Germany allied Austria-Hungary, and Russia was allied with France. Germany was now in a great deal of trouble; they had two very large and prosperous nations coming from the East and the West sides of Germany. Germany began to get a little claustrophobic. Fearful of an attack from both sides, Germany decided to attack first before they have time to gather. Germany declared war on Russia then two days later on France. Since France was only a small step away and is a lot smaller than Russia Germany chose to attack France first. Ignoring Belgium being a neutral country, Germany forced itself through anyway to get to France. This force England to enact its defense agreement with France and join the Allied powers. Among the allied powers when the war ended were Great Britain, Ireland, France, Portugal, Italy, Russia, Romania, Serbia, and Greece. In the opposing side the Central powers were Germany, Austria-Hungary, Bulgaria, and Turkey. Other European nations stayed neutral. In America, people felt that the bloodshed of the civil war was enough to deal with and fifty years later with handling this war was too much. The optimistic Americans wanted to stay neutral. By staying neutral nations were to obey a new set of neutral rights. Any nations that were waged in war were allowed to stop and inspect neutral vessels at sea under international laws (which were not policed in any sort of way). This was in order to make sure that any ship was not the enemy under neutral flags. The warring nations were allowed to confiscate any materials such as weaponry, if found. German submarines were threatening these special rights called the freedom of the seas. President Wilson strictly warned if any American ship was hurt, they would pay. Germany killed numbers of people with their submarines and sank three American ships. This heeded for Wilson to call upon the American people to make preparations in case there is war. On April second, 1917, President Wilson asked for a declaration of war against Germany. The world must be safe for democracy, he said, as he insisted the Americans to fight for peace and safety to make the world truly free. One fear that struck the American people was the fact the Great Britain controlled the Monroe Doctrine by policing it and they also controlled the sea to allow safe trade with their advanced Navy. If Great Britain were to lose to the Germans, trade would significantly decrease and the government would be forced to spend mass amounts of money on a superb Navy. President Wilson wanted to ensure the American people of their ideals back in the 1900s of freedom, and justice all over the world. President Wilson developed his famous fourteen points. Secret diplomacy was to be abolished. All treaties would be open covenants openly arrived at. The bright light of publicity would make rulers ashamed to trade away other peoples lives and liberties. Freedom of the seas would be restored. National borders would be adjusted to

Determining Databases and Data Communications Essays (1013 words)

Determining Databases and Data Communications Essays (1013 words) Determining Databases and Data Communications BIS/320 Determining Databases and Data Communications Scenario 1 You need to track data about booth components, equipment, shippers, and shipment. List typical fields for each type of data. Provide an example of two relationships that you need to track. In order to describe fields for each type of data it is first important to understand just what a field is in this context. According to Techopedia (2015), when describing databases a field is a set of data values within a table which define data. An example of fields relating to the booth components data may include a list of the components included in the booth as well as information relating to whether the components were shipped out in use or in stock at the office. Additionally fields relating to the date of shipment may also be included. Like the booth components, fields describing each piece of equipment may be used. Fields relating to the location of the equipment as well as the date shipped are also important. Fields relating to the shippers data may include the name of the person as well as the date shipped. There could also be a field containing information as to whether the items shipped were damaged when in the shippers care. Similarly the shipment data could include fie lds describing what is included in the shipment as well as the name of the person performing the shipping. Additionally, the date and quality of shipment could also be included. One example of a relationship that may need to be tracked is that between shipper and shipment. Each shipper could possess a designated number that could then be used in the shipment table to identify who is performing the shipment. This allows for easy identification of who is shipping the equipment. Additionally, each piece of equipment could be labeled with a unique identification number that could be used relationally in the shipment table. When looking at the shipment table both the equipment and shipper are easily identifiable. This allows easy tracking of all necessary information pertaining to the shipment. Do you need a database system? If not, can Excel handle the data and the output? What are the advantages and disadvantages? While Excel could be used for storing data pertaining to scenario 1, a database system would provide a more in-depth description of what is happening. A database system is also advantageous because it provides the ability to sync information from multiple tables and sources. Ultimately, Excel could handle the input of data but would not produce the output of data and information. Kroenke (2014) states, lists of data involving a single theme can be stored in a spreadsheet; lists that involve data with multiple themes require a database (pg. 108). Excel possesses many advantages including the ability to more easily and quickly enter and manipulate data. However, the output of information received from Excel is very limited. This information is more black and white than the information retrieved from databases. Utilization of databases is advantageous due to the wealth of knowledge received from the manipulation of data. However, databases are often more complicated and require more time and ability for utilization. Would you use a personal database or an enterprise database? Explain your answer. While an enterprise database would allow multiple users and provide numerous additional features, a personal database is sufficient for scenario 1. This is because the marketing assistant is in charge of all aspects of managing the trade shows. For this reason, a personal database should provide the capabilities needed to organize and manage the task of tracking and managing equipment. However, limited details are provided, if the marketing assistant were constantly collaborating with and sharing this information with multiple coworkers an enterprise database system would become more appropriate. Would a decision support system (DSS) be helpful? Explain your answer. A well-designed DSS aids decision makers in compiling a variety of data from many sources: raw data, documents, personal knowledge from employees, management, executives and business models ("Decision Support System," 2015). Regardless of whether utilizing a personal database or enterprise database a decision support system could provide help. One example of how this system could provide help in scenario 1 is through identifying shippers who repeatedly

Common LISP Research Paper Example | Topics and Well Written Essays - 2000 words

Common LISP - Research Paper Example Table 1 shows some of the mostly used implementations of Common Lisp (Daniel, 2010). Common Lisp has been the chosen Lisp dialect in various development industries worldwide. One such industry is the Web. Some online shopping sites such as â€Å"Yahoo! Store† provide its users with a WYSIWYG editor for editing their online store through any standard web browser (Graham 2003). This editor is developed in Common Lisp. CL-HTTP is public domain web server developed by MIT Artificial Intelligence Lab. Some big companies such as AT&T have been using Common Lisp in their telecom systems. A UK based company, Harlequin, is known to have provided Common Lisp based products and consultancy services to AT&T (Kantrowitz 1994). Xanalys Ltd is another giant company that has been using Common Lisp within their application products. Xanalys LinkEXPLORER, is one of their products that is developed in LispWorks (an implementation of Common Lisp) (Levine & Pitman 2010). Besides being used in internet web services, telecom industry, document translation, fraud detection in credit cards as well as crime investigation, CL has successfully been used in applications related to analysis of investments, finances, tracking of trends in stock markets, airline scheduling systems, space exploration, robotics, process planning, process scheduling, chemistry, physics and medicine. All these discussed application areas have a common trait; the problem structure is usually too complex. The following discussion depicts the situations where it is generally advised to use CL to simplify complex problems. Common Lisp has been used in the field of Artificial Intelligence since its inception. Although it may not be an optimal solution for common problems involving bulk processing based on clear cut, well defined data, yet it can still be used in these system. In a business accounting system that usually involves straight

Create a Design for a Wireless Campus Area Network Essay

Create a Design for a Wireless Campus Area Network - Essay Example Lot of learning institutes has implemented a Campus area network. The campus area network connects to two or more local area networks of any two remote offices within limited geographical locations. The connectivity involves synchronization of data and applications such as intranet (Campus area network.2007).The network devices and computing equipments have to be reliable and extendable, if the faculty staff increases. The network design for the CAM requires an expandable and efficient network that will fulfill the requirements of speed, distance and cost. Radio Frequency Solution The radio frequency solution is quite achievable in the current scenario. As the city government offices require wireless connectivity ‘access points’ are of major concern. ‘Access points’ are the deployed to connect devices equipped with wireless technology. ‘Access points’ transmits and receive radio signals adjacent to a network hub over a limited distance. However, distance varies from different model types and the technology adopted. An IEEE 802.11n wireless network standard is recommended for connecting all the city government offices. 802.11n supports transmission speeds up to 150 Mbps and beyond. 802.11n works on 2.4 GHz and 5 GHz frequency bands (802.11n definition from PC magazine encyclopedia). Cisco is recommended for the Wi-Fi solution.

Mate Selection Essay Example | Topics and Well Written Essays - 500 words

Mate Selection - Essay Example (Greenberg, et. al., 2011, p. 73) Communication also involves sexual communication. Intimacy also plays a big role in the success of a relationship. An individual who would like to let another person be a part of his or her life for a long period of time will search for someone who can share his or her views on sex. I think an example of this can be found in the movie The Mirror Has Two Faces starring Barbra Streisand as Rose and Jeff Bridges as Gregory. In this movie, Rose is a plain-looking but witty and charming woman who had been single all her life and would like to find a handsome man to marry. Gregory, on the other hand, is a smart and sexually active professor who is trying to find a life-partner who is plain and not sexually attractive. Because sex is always appealing to him, Gregory is usually in a dilemma with sexually attractive partners because he gets easily distracted and loses focus. The two eventually marry but later separate because Rose is dissatisfied with the lack of intimacy in the marriage. Even if they were able to consequently resolve their sexual problem during the movie, their obvious miscommunication was the main reason for their separation. Another example, this time in real-life, is what happened to someone I know. He is American and married a Japanese woman. After having their child, the wife started sleeping in the child’s room more often than sharing her husband’s bed. The couple also did not have sex as often as they did before. After a year, the American husband filed for divorce. Now, he is married to an American woman who enjoys drinking, rock music and sex like he does. He says it is like being married to himself. An example of a successful relationship based on communication is that of the longest married couple in America. John and Ann Betar of Connecticut celebrated their 80th wedding anniversary in November 2012. (Sher, 2013) When

Control Of A Switched Reluctance Motor Engineering Essay

Control Of A Switched Reluctance Motor Engineering Essay The main objective of this chapter is to spot the light on the practical performance of some form of control on an actual switched reluctance motor in preference to merely theoretical method including simulation and modelling. Moreover, the design of the controller involves reducing the noise. The crucial motivation for this is to enhance new expertise, sensibly regarding circuit design and construction the use of a Programmable interface controller (PIC). A switched reluctance motor (SRM) has been appeared since the nineteenth century, but the renewal of this motor has been to discover a high-power switched device [13]. The earlier motor was facing a controversial issue in their control where the power electronic switching was very expensive and has many drawbacks. The Switched Reluctance Motor (SRM) is an electromagnetic, rotary machine in which torque is produced by the tendency of its movable part to move to a position where the inductance of the excited winding is maximized [12]. Furthermore, (SRM) has been proposed for variable speed applications [13]. In general a salient-pole synchronous machine without field excitation or permanent magnet is called a reluctance machine. From the general definition (SRM) is classified as a synchronous machine, but has different construction. These differences are both stator and rotor have salient poles. However, the stator has wound field coils but the rotor has no coils or permanent magnet. Moreover, the stator has higher number of poles or (tooth) than the rotor. While each pole in the rotor is excited by the opposite pole in the stator due to a sequence of current pulses which produce magnetic field on each stator poles. The Switched Reluctance Motor (SRM) can be more capable for variable speed than AC and DC motor. Since it is simple, robust, has a high efficiency and high power density [3, 10, 12]. Figure 1.1: two- two poles SRM [12] Over the past 30 years the power electronics growth has made the exploit of the characteristics of reluctance machines sufficiently well. Consequently, several successful products are now manufactured. The rotation of the motor depends on the angle between the rotor poles and the stator poles where the current is switched on or off to each poles in the stator where the position of the rotor is very significant. For the motoring principle example, two- two poles (SRM) where stator has two poles with two wound field coils connected in series and two poles in the rotor without magnets or windings and free to rotate as it shown in figure 1.1. If the rotor poles edge is started to be aligned, the current is switched on. Consequently, the inductance is increased and the torque in the rotor is occurred to pull the rotor in clockwise direction. The direction of the rotation is addressed by the current. The current is switched off; when the rotor poles are fully aligned with the stator poles that make the rotor free to move. However, if the current is not switched off the torque at the fully aligned is become negative that produces an attraction between the poles where the negative torque and positive torque cancel each other [12]. The ideal current waveform is therefore a series of pulses synchronized with the rising inductance intervals. The cycle of torque production associated with one current pulse is called a stroke.[12] As a result, to increase the resolution more teeth can be add to the stator and the rotor. From the instantaneous electromagnet torque equation which was derived by T.J.E.Miller(2001) [12] Te = i2/2 dL/dÃŽÂ ¸ that shows the torque is proportional to the square of the current. Therefore, the current is always unipolar. However, at the end of each stoke the voltage must be reversed to return the flux linkage to zero. The power switching IGBT, GTO and MOSFET or any other switching devices can be used in the power electronic topologies [3]. These switches are used to open and close the exiting power in the stator winding. 1.5. Applications of SRM Since the SRM has a significant characteristic operation and design which shows many advantages and makes them suitable for various applications. R.Krishnan (2001) [10] shows the wide range of applications. For example, plotter drive, air-handler motor drive, hand fork lift/ pallet truck motor drive, door actuator and washers and dryers machine, those applications are low power applications where the drives are less than 3hp. Moreover, the medium power applications range is less than 300kw such as industrial general purpose drive, train air conditioning drive and mining drive. However, the SRM did not find much attention by the manufacturers in this range of power. The high power drives are still under study for drives up to 1000hp for fan and pump applications where the converter is very competitive. The high speed applications such as screw rotary compressor drives, centrifuge for medical applications, and aerospace applications the SRM is a perfect option for them due to the small size of the rotor and high power density. Some efforts of study are in Mild Hybrid Vehicles that is reported by (Watterson, P.A. ; et al) [17] in 2008. 1.6 Research area Since the SRM has appeared and has disadvantages such as reduction of acoustic noise and torque ripple. According to the noise and vibration sources can be classified into four main categories: magnetic, mechanical, aerodynamic, and electronic. The classification was done by R.Krishnan (2001) [10] as it shows in figure 1.2. Most researches are based on the design of the motor or in the controller to improve the motor performers and reduce the noise. Iqbal Husain (1994) [8] discusses the effect of the high ripple toque which causes vibration and acoustic noise. The case was in driving SRM for low speed and high performance applications by a new PWM strategy current control. The method was based on optimum profiling of the phase current during an extended overlapping conduction period of two phases. The result shows a smooth operation with minimum torque pulsations by controlling the current profiling. Moreover, other studies were in magnetic radial force as M. N. Anwar (2000) [1] show s the lower noise is occurred when the dominant mode frequencies is high. As a result the research has experimented a proposed design considerations to a 4-phase, 8/6 (1-repetition) and a 3-phase, 12/8 (2-repetition) 1.0 kW SRM with low acoustic noise requirement. The results of the proposal design shows that the noise level has been reduced; however, a 3-phase SRM is noisier than a 4-phase SRM. There are other research was on reducing the noise by Adding extra winding to the phase winding to reduce magnetic stress during commutations with Two stage power converter. Adding extra winding to the phase winding in 6/4 SRM with Two stage power converter shows a significant improvement in the efficiency and reduce in the vibration and noise [16]. The electronic sources of noise occur by reason of the harmonics of voltage and current. The significant research is reported by (Lecointe J.P; et al) in (2004) [11]. The research was in adding an auxiliary winding to the model of a BDFRM (brus hless doubly-fed reluctance machine) to shows that the additional winding has a benefit in reducing the noise in SRMs where a specially derived current is injected to create a suppression force. The BDFRM is used to analyse the equivalent circuit where the equivalent circuit of the model is similar to SRM. However, the process still needs to be complete using two current sources. Figure 1.2: sources of noise in electrical machines [10] Advantages and disadvantages of 3 basic power electronic circuits There are many power electronic topologies that is used for SRM depends on the machine phase configurations. R. Krishnan (2001) [10], figure 1.3, has classified the power converters for switched reluctance machines. The simple three topologies are: Figure 1.3: Classification of power converters for SRM [10] 1.7.1. Single-Switch-per-Phase Circuits (Split dc supply converter) The basic operation of this topology, figure 1.4, is to split the reverse dc power supply into two capacitors. The phase voltage is half the dc voltage when the switch is on and negative half voltage when the switch is off. Consequently, this configuration is a disadvantage. Moreover, the maximum speed and the output power are half the rated while the current and the voltage are half. This topology is only used for low-cost application due to the high power losses. However, the advantages of this topology are: simple and less cost. [3, 10] Figure 1.4: Single-Switch-per-Phase Circuits (Split dc supply converter) [10] 1.7.2. Single-Switch-per-Phase Circuits (Bifilar type) The basic operation of this topology uses a bifilar winding, figure 1.5, with the motor winding to regenerate the stored energy to the supply that the phase winding is connected in series with the switch, and the diode is connected in series with the bifilar winding. The reflected energy is an advantage for this topology in some applications, where the transistor voltage is much higher than the supply voltage. However, the cost increases as the extra winding is added to the motor and the complex design of the power electronic. Moreover, the power density of the motor reduces because of the bifilar winding. [3,10] Figure 1.5: Single-Switch-per-Phase Circuits (Bifilar type) [10] 1.7.3. Two-switch/phase Asymmetric Bridge Converter From the half bridge topology that is illustrated in figure 1.6. if both Q1 and Q2 are turned on the apply voltage at the winding is equal to the supply voltage. However, if both Q1 and Q2 are turned off the apply voltage at the winding is equal to a negative supply voltage where D1 and D2 to avoid the freewheel currents. The advantages of this topology that it can give a negative voltage to reduce the torque ripple refer to noise for a high performance SRM drive system and it can be used for generator or motor operations. The disadvantages more control is needed, more fault in the switching [3, 10, 12]. Figure 1.6: Two Switched / Phase Asymmetric Bridge Converter [12] 1.8 Speed and Position Controller The switched-reluctance motor is basic control system form of a torque-controlled drive as compared in performance to a D.C motor (separately-excited). Commonly, controlled speed or even position is the most requirements. The SR motors speed increases if torque is still produced. As the D.C. drive the torque of SR motor controller is included within a speed regulating loop. The rotor position sensor, which is the encoder, is used as a feedback to derive the speed of the motor readily as it shown in figure 1.7. From the figure it can be seen that an additional feedback is introduced to achieve the position control of the SRM [3]. Figure 1. 7: basic speed and position controller for SRM [3] Aims and Objectives The aims of the project are to design, build and test a power electronic circuit for Switched Reluctance motor (SRM) using Bifilar type. The objectives are as following: Understand the operation of two- two poles SRM to realise the behavior of the motor and their characteristic. We can know from their characteristic how to make the motor spin and the control techniques that is used for them. Select and Design Power Electronic Circuit can help to active a high efficiency, low noise and low cost. Test Power Electronic Circuit with Resistive Load: to find the advantages and disadvantages of the circuit when the resistive load is applied to the motor. Design, Build and Test current limiting circuit where the current limitation can achieve low torque rebel. From the low torque rebel the noise can be decrease. Rotate motor using direct feedback where the position of the rotor is important to detect the moment of switching on and off. Study and understand PIC 18F 46K20. Program PIC to control SR Motor by designing a simulation using the MATLAB or other programmes. Chapter 2 Choosing power electronic component 2. Overview Over the time motor control has a significant growth in the industrial control where digital signal processors together with external hardware and appropriate software are used widely. In order to control the motor the switching device should switch on and off according to the position of the motor rotor and the apply current to the stator winding. The aim of this chapter is to highlight the details of the components that were used in the controller design. 2.1 Technical operation of Simple SRM The simple SRM has 2 poles in the stator and 2 poles in the rotor, figure 1 which the stator iron core has square shape with two winding in the upper side opposite the poles. Both stator and rotor are salient poles where the free spinning rotor is placed between the stator poles. In order to spin the rotor, stator poles are energised by the winding when the rotor poles are unaligned with stator poles. The inductance increased and the torque is produced as the rotor approaches the aligned. At this point the stator winding is demagnetised allows the rotor free to spin. The time of the energised and de-energised of the motor windings depend on the rotor speed. Figure 2.1: (a) Simple SRM 2/2 poles with bifilar winding[12] 2.3 Winding connections The motor has a bifilar winding to build up the current in the stator quickly, figure 1, which facilitates the higher torque and magnetic flux densities occurring. As a result the stored energy regenerated to the supply that the phase winding is connected in series with the switch device. This leaded to three achievable connections, figure 2, for bifilar winding. Figure 2.2: Possible winding connections The first connection shows the parallel connection that has a resistance connected in parallel to the motor windings to reduce the power losses when the switch is off. This connection has the main disadvantage due to the high loss. The second connection shows series connection that two switching devises are used which increase the cost of the design. However, this topology is the most common one for SRM according to reduce the switching heat losses, protections and their control flexibility that is handling the phase current and the machines acoustic noise. The third connection is the most cost effective and easier to control for the simple SRM figure 2. Moreover, it is offering the zero voltage supply as a reference for all power switching that make it suitable for low- voltage systems. Simply this configuration operates as it shows in figure 2.3, When the current of phase-A is turned off by removing the base drive signal to T1, the induced EMF in the winding is of such polarity that D1 is forward biased. This leads to the circulation of current through D1, the bifilar secondary winding, and the source, thus transferring energy from the machine winding to the source. The various timing waveforms of the circuit are shown in Figure 2.3. During current turn-off, the applied voltage across the bifilar secondary winding is equal to the dc link voltage. The voltage reflected into the main winding is dependent upon the turns ratio of the windings. Considering the turns ratio between the main winding in series with the power switch and the aux iliary winding in series with the diode as a, the voltage across the power switch is VT 1 = Vdc + aVdc =(1 + a)Vdc This shows that the voltage across T1 can be very much greater than the source voltage. One switch per phase comes with a voltage penalty on the switch. The volt ampere (VA) capability of the switch will not be very different for one switch compared to two switches per phase circuit. [10] Figure 2.3: (a) Converter for an SRM with bifilar windings; (b) operational waveforms of bifilar converter. [10] Thus, Figure 4 shows the primary plan for designing the current limiting circuit for the third connection of SRM and each block are explained next. Figure 2.4 basic configurations for current limiting 2.4. Power switching component Nowadays semiconductor and electronic switching devices offer a significant performance to control the electrical motors. Moreover, their size and cost make them more convenient to use in the motor control. The electronic devices has a significant role to control SRM where the switching on and off for the voltage is the major role to control the SRM with high performance. As a result, the main electronic devices that can be used are field effect transistors. There are two types of the field-effect transistor J-FET and MOSFET (see the appendix figure 3) [4]. The MOSFET has taken a widely role as a best choice to the simple SRM for many reasons that is discussed later in this chapter. 2.4.1 N-channel power MOSFET (STP36NF06) Simply the MOSFET is a metal-oxide-semiconductor field effect transistor where the MSFET has a significant characteristic [2]. The characteristic of N-channel MOSFET shows a significant use in switching. The structures of the MOSFET are shown in figure 5 where the MOSFET consist of Si P material substrate, two N material substrate that one is the source and the other is drain, and between them there is an insulator Sio2 and at the top metal conductor which is known as a gate. The length (L) below the gate and between the source and the drain is known as a channel. Fundamentally, the MOSFET output current is proportional to the charge in the semiconductor material by the control electrode[15]. Figure 5 MSFET structures [6] The MOSFET is used as a switching device to provide a high speed switching. The significant advantages of the field-effect transistor are: Higher operation temperature. Lower switching leakage. High input impedance. Low noise. Lower power dissipation during switching. In addition, The N-channel MOSFET has advantages such as ease to use for high frequency switching and simpler to control where the MOSFET gate drive do not require a continuous current to switch ON. When the MOSFET is needed to switch ON positive threshold voltage is needed to apply to the gate drive and Zero current to completely switch off. Moreover, the N-channel MOSFET has higher density integration and possible in rapid reduction in capacitances. [2]. MOSFET (STP36NF06) gate requires drive properly the later components are used to limit the current and the gate signal for the MOSFET. The gate drive is a power amplifier that accepts a low power input from a controller devices and generate the appropriate high current gate drive for a power MOSFET[4]. 2.5. Bipolar junction Transistor Transistors are considered one of the main elements of semiconductors that have been discovered in modern times. Transistors are used in the amplifiers of electrical signals and electronic switching, which have helped a number of factors such as small size, ease in manufacturing, cost effective and consume less power to extend significantly. Figure 2.6 (a) transistor structures (b) npn and pnp structures 2.5.1. ZTX 653 NPN transistor The NPN transistor is a type of bipolar transistors known as a medium power transistor. The NPN ZTX 653 transistor has interesting features that make it suitable for the push pull topology and amplifier topology (pre totem pole connections). The features of NPN ZTX 653 transistor are [6] * 100 Volt VCEO * 2 Amp continuous current * Low saturation voltage * Ptot=1 Watt 5.5.2. ZTX 753 PNP transistor The PNP transistor is another type of bipolar transistors that is used in the push pull topology. The PNP ZTX 753 transistor is suitable to employ in the push pull topology (Totem Pole) according to their features. Their features are [6] * 100 Volt VCEO * 2 Amp continuous current * Low saturation voltage * Ptot=1 Watt Figure 2.7: npn and pnp characters 2.5.3 Gate drivers (Totem Pole) This type of connection is known as a discrete drivers or push pull drives which is in common use today. Figure 2.8 shows the complimentary arrangement pair bipolar NPN and PNP emitter configuration. Moreover, the N-channel and P-channel MOSFT can be employing for totem pole connection. However, the N-channel and P-channel MOSFT driver suffers from shoot through current, caused by the threshold voltage overlap during ON and OFF transitions, resulting in increased drive power requirements [9]. Figure 2.8: push pull configuration The bipolar Totem Pole, figure 2.8, is non-inverting and offers no voltage gain to improve the pre-driver rise or fall times. It does provide current gain to reduce the driver impedance to speed the charge and discharge of the device capacitances. Once the input capacitances are charged and the power device has been switched, the driver does not require holding current. It has medium speed and does not perform well at higher conversion frequencies [9]. This circuit uses a complementary pair of transistors similar betas and power rating one is an npn power Darlington, and the other is a pnp power Darlington. When a high voltage (e.g., +15 V) is applied to the input, the upper transistor (npn) conducts, allowing current to pass from the positive supply through the motor and into ground. If a low voltage (0 V) is applied to the input, the lower transistor (pnp) conducts, allowing current to pass through the MOSFET gate from ground into the negative supply terminal.[14] 2.5.4. Common emitter amplifier (inverter) This configuration is a simple electronic circuit that is used to boost and invert the low signal. Figure 2.9 shows the circuit that contain a high resistance value with NPN transistor. The low signal is switch on and off the transistor where the resistance is limiting the current that apply to the transistor. This topology is used to boost and invert the output of signal processing unit to appropriate the signal that can switch the MOSFET as it will be discussed in the following point. Figure 2.9 common emitter configuration 2.6. Current control and limiting The winding current is controlled inorder to be not more than 8A. When the MOSFET is switched ON without any current limiting circuit, the current shoots up without any control. As a result, the technique for current limiting is arranged as follows When the winding current is less than 8A the MOSFET switches ON. When the winding current is exceeds 8A the MOSFET switches OFF. Therefore for appropriate current control, square wave signal is applied to the gate of the MOSFET. The frequency of input signal at the gate of the MOSFET is take into account to make the MOSFET switch properly with regard to the above current control arrangement. In order to do that feedback from the source of the MOSFET is carried to non-inverting terminal of the comparator. Figure 10 shows the operational waveform of the MOSFET. It can be seen that, the MOSFET needs to switch off when the voltage at inverting input of the comparator reaches 0.8V and switch on when the voltage is zero. Moreover, the reference voltage is 0.8 volt from the voltage divider law when a 0.1ÃŽÂ © resistance is connected to the source of the MOSFET. The 555 timer can offer the control of MOSFETs switching frequency. Figure 2.10: the expected waveforms from the design. 2.6.1 Timer NE555P The 555 timer IC is an incredibly useful precision timer that can act as either a timer or an oscillator. In timer mode is known as monostable mode the 555 simply acts as a one-shot timer; when a trigger voltage is applied to its trigger lead, the chips output goes from low to high for a duration set by an external RC circuit. In oscillator mode is known as astable mode the 555 acts as a rectangular-wave generator whose output waveform (low duration, high duration, frequency, etc.) can be adjusted by means of two external RC charge/discharge circuits.[14] In this project the monstable circuit is highlighted due to it has one stable state. Figure 2.11 (a) monostable configuration of timer 555 (b) monostable operations[14] In the monostable configuration, figure 2.11(before a trigger pulse is applied) the 555s output is low, while the discharge transistor in on, shorting pin 7 to ground and keeping C discharged. Also, pin 2 is normally held high by the 10-k pull-up resistor. Now, when a negative-going trigger pulse (less than 1à ¢Ã‚ Ã¢â‚¬Å¾3VCC) is applied to pin 2, comparator 2 is forced high, which sets the flip-flops Q_ to low, making the output high (due to the inverting buffer), while turning off the discharge transistor. This allows C to charge up via R1 from 0 V toward VCC. However, when the voltage across the capacitor reaches 2à ¢Ã‚ Ã¢â‚¬Å¾3VCC, comparator 1s output goes high, resetting the flip-flop and making the output low, while turning on the discharge transistor, allowing the capacitor to quickly discharge toward 0 V. The output will be held in this stable state (low) until another trigger is applied [14]. According to the operation of the monstable the pulse width can be modified by changing the value of R1 and C. T= 1.11 R1C Thus, to obtain capable functioning of the circuit the variable resistance R1 with a maximum value 100KÃŽÂ © and the threshold capacitance C value is 100nf are chosen. The timer input is the output of the comparator where the two values of the voltage are compared to make the output of the timer based on these two values. The two voltages are one is 5V and the other is the feedback from the MOSFETs source. 2.6.2. (LM393) Comparator The comparator is used to compare the voltage between the source voltage and the feedback from the MOSFET. This is important to control the current by triggering the timer to limit the current as it is mentioned before. LM393 has several advantages for timer input which are Higher accuracy in comparators. High voltage range (2.0V to 36V) Biasing with lower input current. Lower input offset current  ±5 nA Figure 2.12 LM393 connections to the circuit In order to establish the reference voltage variable resistance is required in the voltage dividers law. The operation of the comparator is simply as follows If IN+ > IN- the comparator output = V8. If IN+ From the previous operation it can be seen that the comparator send the signal to trigger the input of the timer and the timer acts upon the applied signal therefore the MOSFET switches on and off with regard to the timer output. However, the output of the timer switches on the MOSFET when the current is high which will be disastrous to the motor. To avoid this not to happen, a design of logic gates are incorporated in the current limiting topology of the SRM. 2.6. 3. Logic gate design (SN74LS00N) Logic gate is designed according to the output of the timer which gives the positive pulses when the current exceeds to 8A and no pulse when the current is less than 8A. With the purpose of switch (totem pole) the gate of the MOSFET turns on and off at required instants of time using an external Drive Signal. Figure 2.13 shows the technique of the combination between the Drive Signal and the timer output to control the MOSFET. SN74LS00N has four NAND gates that can be used to reduce the number of ICs in PCB connection. The logic gate is connected to the timer output which will be inverted with a common emitter configuration to switch on the MOSFET when the timer output is low (Itimer Figure 2.13: (a) SN74LS00N chip (b) logic circuit connection (c) NAND gate logic signal. The MOSFET behaviour that is need according to the timer output is shown in table 1. To do that the NOT gate, OR gate and AND gate are needed before the pre totem pole connections (common ammeter topology). Current condition Timer(A) Drive Signal(B) Output of the logic gate (C) MOSFET gate signal (Output after totem pole) I > 8A MOSFET must be off 1 0 1 0 1 1 1 0 I MOSFET can be on 0 0 1 0 0 1 0 1 Table 2.1 digital signal behaviour Boolean algebra From the logic gate output we can get the function: (1) This function can be simplified (2) Figure 2.14 (a) logic gate from equation 2 (b) table shows the equavelant NAND gates [7](c) the final simblified gates using the table (b) 2.7 Curant limiting circuit simulation Curent limiting circuit ,figure 2.15 , is the simulation circuit and the combination of each part that discussed previously. Figure 2.15: current limiting circuit

Appearance vs. Reality in Julius Caesar :: Julius Caesar Essays

Appearance vs. Reality in Julius Caesar In life, people and things are not always as they appear. William Shakespeare displays this idea throughout his play, Julius Caesar. The play portrays the historical murder of one of ancient Rome's most precious leaders, Julius Caesar. The play takes its readers through the minds of the conspirators as they plot this massive murder and deal with the responsibilities of its consequences. During the aftermath of Caesar's death, Octavius talks to Antony about how they should bring peace back to Rome. He states, "And some that smile...have in their hearts...millions of mischiefs" (4.1.50-51). Here, Octavius is referring to the false appearance of the conspirators. He says that they might appear harmless, but behind their false smiles is a heart full of dirty tricks. He is also saying that someone's outward appearance doesn't always symbolize how he or she feels inside. This theme of appearance versus reality can be seen various times throughout Julius Caesar. It is developed through the personalities and actions of Antony, Brutus, and Cassius. These characters deceive their friends and add to the intriguing plot of the play. First of all, there is Antony, a raging triumvir after the death of Caesar. Anotony is a dear friend of Caesar and is truly devastated after his beloved friend's death. Antony feels that justice must take its course, for over Caesar's dead body he states, "O, pardon me, thou bleeding piece of earth/ That I am meek and gentle with these butchers" (3.1. ). Antony then decides that he must get back at the conspirators and convince the public that the motives behind killing Caesar were unjust. In funeral speech Antony even makes it a point to refute what Brutus said in speech moments ago. However, the nether neither the public nor the conspirators comprehend his motive at first. Antony appears like he is just presenting another side to the story, but in reality he is refuting Brutus' speech and swaying the public towards his side. During his speech he even states, "I speak not to disprove what Brutus spoke" (3.2. ). To the conspirators Antony appears like "one of Caesar's man y limbs"( ). In reality he is plotting revenge.

Bhagavad Gita: The Choice of Arjuna Essay

The Bhagavad Gita is one of the most renowned pieces of literature from India. It is the most popular segment of the Mahabarata, and is recognized as an essential teaching of the Hindu religion. The title, when translated to the English language, means Song of the Blessed One. It is a profound religious poem composed of 700 stanzas, arranged in 18 chapters, within the great Sanskrit epic of Mahabarata. Various philosophic and religious points of view are expressed in the Bhagavad Gita, but its greatest message is that God can best be known and reached by man through loving devotion to Him (Bhaktivedanta Swami Prabhupada, no page). In this Indian classic, a dialogue transpired between Arjuna, the general of the Pandava forces in the epic battle, and his charioteer Krishna, who is an incarnation of the god Vishnu. Just before the battle, Arjuna has Krishna drive him into the unoccupied ground between the two marshaled armies. As he surveys them he becomes despondent that on the morrow he must fight with kinsmen, friends, and revered teachers. But Krishna, instructing him, tells him that as a warrior he must not avoid a battle of righteousness. In addition, he need fear no harm in the highest sense, for the highest part of man, the soul, cannot be destroyed, and is in fact unitary in all men. Krishna then develops his teaching of God and the soul, and in Chapter 11 reveals himself in transcendent form. Arjuna accepts the teaching, is heartened, and prepares to enter the battle, which his side is destined to win (Johnson 3-82). Ethical Issues in the Gita The opening chapter of the Gita depicts the hero Arjuna in a dilemma between his social duties and his familial obligations. His predicament is that he is a member of the warrior class, or the ksatriya varna, that instructs him to engage in a battle against his own family members. However, these blood attachments leaves Arjuna hesitant from fighting, thereby resulting to a heightened tension. This brought Arjuna absolute grief, for the mere prospect of committing wrong against his kinsmen is inconceivable. Therefore, he sought the wisdom of his charioteer and counselor. This is the human form Lord Krishna, with Arjuna oblivious of his charioteer’s real identity. Arjuna confided that he has arrived to a decision that he would not fight his family (Gupta 380). Krishna gladly came to Arjuna’s aid in resolving the latter’s dilemma using both â€Å"absolute and relative standpoints† (Gupta 380). According to Krishna, when one takes the absolute standpoint in consideration, the immortality of the self is essential. If one only regard the human body, he would eventually find it destroyed, thereby grieving for the flesh killed in the battlegrounds will be left in futility. Since humans have immortal souls, both birth and death are transcended. On the other hand, from the relative point of view, Krishna tells Arjuna that his membership into the warrior class gives him the duty to fight. Therefore, it is not negotiable whether he would perform this duty. For he must do what he ought to do, for both moral and spiritual values are in line. He is a soldier, and this is his niche. It is his mandate to act as a soldier to engage in a righteous war, fighting for both truth and righteousness and regain the balance of morality in his society. Hence, the only option, the only proper action, is for Arjuna to fight in the war. One must do what he is assigned to do for the sake of doing it, and not because of the possible results of his actions. He therefore needs to learn to detach himself from the consequential results of his actions and only commit his entire soul in doing his duty (Gupta 381). The primary teachings of the Hindu religion, especially in this context, are not comparable to that of Kant’s categorical imperative. Instead, it is â€Å"not an unconditional command† (Gupta 381). When an individual belongs to a specific caste, then the role of the caste is endowed upon him. When a person is warrior by caste, then he is obliged to participate in battles defending righteousness. And when one is priest by caste, then one must always prevent himself from engaging in fighting. One must never be associated with the duty of another, for he is expected to do his duties given to his own caste (Gupta 381). Personal Duty The choice that Krishna is imposing on Arjuna is a very difficult course to take. Perhaps it takes a strong conviction upon well-founded religious beliefs in order to stand by this decision. I personally do not agree with the reasoning that Krishna gave, for my moral compass tells me that blood is thicker than water. I can never commit evil or any act of transgression against my kin, for I do value familial relationships without extent nor condition. The decision that Krishna wishes for Arjuna to take is somehow in contrary to my personal principles. I do not condone sacrificing the lives of the people I love for the purpose of self-benefit. For in this case, I see the performance of one’s personal duty is more of a selfish act. It only served you, and not the people you love. I have been taught by my religion to give unconditional love towards others, and to always think of the welfare or my neighbor. I believe that Krishna’s argument does not apply to me as it is not applicable in my life. This does not however mean that it is impossible or far-fetched. The example I could think that this dilemma is possible to arise is on the lives of policemen and soldiers. Police officers are expected to enforce the law regardless of the person who committed the crime, for no one is above the law. However, especially in critical and life threatening cases, some are faced with the dilemma whether to arrest people they love who they know perpetrated a certain crime. Although it is one’s moral obligation to convince his loved one to confess or to arrest him, it is still difficult to do what is righteous. Here, one is give a duty that must be performed no matter what. As a student, I do believe that I have a duty. And this duty is to prepare myself to a life ahead of me in order to make a positive contribution for the betterment of this world. I am the hope of this generation to direct the world into the righteous path and correct the societal wrongs I could possibly change. With this at heart, I do believe that I have a determine nature. It is a spirit that would never be daunted in the face of obstacles, for I know what I must achieve. Conclusion The Gita presents a very important perspective of the Hindu religion, which enables us to understand the moral grounds of the people belonging to this religious belief. It is difficult to grasp the essence of the story’s moral, for it is somehow foreign to the values that I have been accustomed to. But being exposed to other kinds of belief systems, to other principles, and to other practices allows me to rethink my character. The Gita is about Arjuna and how he followed the advice of Krishna. Whether or not it is the universal choice, the important thing is to obey the dictates of the heart of what is right and what is wrong. Sticking to one’s principles somehow outweighs the actual consequences of one’s actions. For one cannot always anticipate what cannot be predicted, one can only act upon what one firmly believes in, and fight for it.

Essay on Painting and Philosophy

Essay on Painting and Philosophy Essay on Painting and Philosophy Essay on Painting and PhilosophyUnder the great impact of various brand-new ideologies that appear in the late 19th and earlier 20th century, the styles and the manners of art are changing and the cohesive group with previous art interests splits apart. The new mode of the artistic expression has begun to develop, an emphasis on decorative forms of artworks in place of the realistic representation gradually. Art as one of the most particular platforms empowers people to demonstrate the reality as well as to express the individual cognitive. In either way people treat arts as an efficient resource to define the term of â€Å"Reality†. Artists from late 19th and earlier 20th century manipulated naturalistic forms to reflect what they conceptualized to be â€Å"their realities†. The examination of decorative forms (colors, brushworks and Proportion/depth) that applied in specific paintings would provide the evidence of how artists interrupt the realities with their concept s and impression.Colors and Van Gogh  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Color is one of the most crucial components in the process of establishing the art style. According to Andrew and Markus’s theory of the Color-in-Context[1], color have 3 properties, which are hue, lightness and saturation. These three properties not only provide the aesthetic value of the color but also with the functional value. Basically, it means color shouldnt be seen as the simple representation of the reality but the ideology or the cognitive that people attempting to present. Vincent Van Gogh’s artworks always applied the dramatic colors, which demonstrate the representation of his emotional experience. â€Å"The night cafe† is one of his oil paintings from 1888 and the color tone of this painting is standing out because it got plenty of saturated and non-naturalistic colors assembled together. The title of the painting suggests the content suppose to associate with the part icular ‘Night’ time period. However, all the complimentary colors with heavy saturation mess around the reality. Van Gogh increased the intensity of the light in the night cafà © and created a new version of it with his imaginary and manipulation. Because of the bright yellow, saturated red and pure green, everything in the painting provides the spectator a feeling of horror and isolation. Refer to Van Gogh’s letter[2]:  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   â€Å"The general effect of beauty of color in nature may be lost in painfully literal imitation; it may be maintained by recreating a parallel spectrum of colorsmuch, everything, depends on my feeling for the infinite variety of tones of the same family†According to Bekker’s idea[3], Van Gogh focused more on the intensity level of his psychological emotion but obscured part of his sensory experience purposely. The inner motion of Van Gogh dominates his production process. He put his atten tion close to the beauty of color and exaggerated the great effect the color has. Also, Van Gogh did interrupt the reality with his individual feelings, and meanwhile, this individual concept empowers him to depict the idea of how he sees the world and in his words, to maintain â€Å"the beauty of color in nature†.Depth and Proportion  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the journal â€Å"On the origin of the world: ‘Expressionism’†, Donald developed the idea about the expressionism that Matisse carried in his work is reflecting an individual creative process, which covered both the result of naturalistic and pictorial.[4] Through this creative process, color and brushwork definitely play the crucial roles but the proportion of the artworks is important as well. The oil painting â€Å"Joy of life† which was done by Henry Matisse from 1906 shows how he represents the nature instead of copying it in the aspect of Proportion.[5] â€Å"Joy of life† is the painting focused on the flatness of the space by compressing multiple levels into a single platform. Regarding to Werth Margaret’s analyze of this painting, she conceptualized the proportion of the painting is divided into three different bands and has â€Å"both triangular and circular† composition.[6] All the components and figures in the painting are organized to guide the spectator’s eye toward the opening centre in the painting. Matisse recreated the reality and interrupted his individual concepts into the nature to express â€Å"his reality† to the spectators.Brushwork is the index of artists’ manipulation  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Based on Michael Newall’s study[7], visible brush marks on the painting would always be the evidence to trace the artistic movement from the artist. In another word, brushwork has the same function as the beats in a piece of music, which acts as indexes to guide spectato r going through artists’ inner world. As one of the establishers of Fauvism, Henry Matisse abandoned the naturalistic style of art expression and applied the controversial movement in his works. â€Å"Woman with the hat† from 1905 is one of the earliest Fauvism painting which done by Matisse. There are two main components in the painting draws people’s attention a lot the harsh brushstrokes and the non-naturalistic color, which was studied in the previous section. In Lauren Tracy’s journal, â€Å"Matisse emphasized the depiction of idea and feeling rather than the representation of reality, and his works served as an important shift toward the highly abstract artistic movements looming on the horizon.†[8] The free-roaming brush works that applied on the painting presents the direction of the artist’s movement with hands and arms. Bold outline of the figure demonstrates less accuracy of the reality but more depict of Matisse’s idea and emotion. This painting’s background is basically created with several color layers, for example a patch of green simply attached with the pink color on the right side of the woman. Matisse didn’t keep his eye on the delicate transaction between different colors but leave them as the separated color palettes with wild brush marks. He is presenting the reality that he sees in the world.  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   From Michael’s points of view: â€Å"That the action painter’s brushstroke was expressive of the painter’s mental state at the time of its application quickly became subject to the kind of objections that put paid to the expression theory of art.†[9] There are various ways for artists to express themselves but brush mark is the form could be identified with the dynamic movement that the artists made while they are creating artworks. Though those dynamic brushstrokes, the artists’ personalities and their mental stages could be presented and connected.Conclusion  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the later 19th century and earlier 20th centuries, artists are facing the great changes from the previous art interests to the new art expression, which focus on using the decorative forms to demonstrate the particular points of view that artists have towards the reality. Specifically, colors, proportion and the brushwork in the painting are not only presenting the aesthetic value but the function value as well. Those components of decorative form connect the nature to the artists’ manipulation of the reality and show the spectator the emotional level of artworks.[1] Andrew J.Elliot, Markus A. Maier, Advances in Experimental Social Psychology, Chapter two- Color-in-Context Theory (Elsevier Inc. 2012) 61-125http://ac.els-cdn.com.myaccess.library.utoronto.ca/B9780123942869000020/1-s2.0-B9780123942869000020-main.pdf?_tid=0e7ab44e-6ee3-11e4-ab60-00000aacb362acdnat=1416288400_4aba50b 425480bde8c969ab4e9df7a4c[2] Bejjer, K G; Bekker, A Y, Color and Emotion- a Psychophysical Analysis of Van Gogh’s work. (University of Florida, 2009)http://search.proquest.com/docview/894124164?accountid=14771.[3] Ibid.[4] Donald E. Gordon, On the Origin of the Word Expressionism- Journal of the Warburg and Courtauld Institutes (The Warburg Institute, 1966) 371[5] Ibid. 370[6] Werth Margaret, The joy of life : the idyllic in French art, circa 1900, (2002),163[7] Michael Newall, Painting and Philosophy (Philosophy Compass, 2014) P.231http://journals1.scholarsportal.info.myaccess.library.utoronto.ca/pdf/17479991/v09i0004/225_pap.xml[8] Lauren Tracy, Woman With a Hat by Henri MatisseBeauty and the Wild Beasts (JAMA Facial Plast Surg, 2014) 81-82[9] Ibid. 232

Gun Control In America Essays - Gun Politics In The United States

Gun Control In America Essays - Gun Politics In The United States Gun Control In America Gun Control in America On March 24, 1998, firing from the woods overlooking their school, 13-year-old Andrew Golden and 11-year-old Mitchell Johnson shot and killed four middle school students and a teacher and injured ten other students in Jonesboro, Arkansas. The two boys had a semiautomatic M-1 carbine with a large ammunition magazine, two other rifles, seven handguns and more than 500 rounds of ammunition which they took from the home of one of the boys grandfather, who had a large arsenal of weapons left unsecured. Officers arrested the two boys as they ran through the wooded area near the school, and they were convicted on five counts of capital murder and ten counts of first-degree battery in September 1998. I want to inform people what I have learned about gun control in America. Firearms and their consequences are so pervasive in our society that they seem to be standard fare. Each day newspapers in major cities report injuries and deaths from guns and show photographs of their bereaved families. Movie advertisements scream titles that promise plenty of bloodshed, illustrated by guns and though characters who flaunt them. A casual flip through several television channels often reveals a succession of handguns, automatic riffles, and murders. Facts are much more sobering and dont reflect the justice weve grown accustomed to seeing on televisions and in movies. The fact is that 22,000 people die each year because of firearms. Annually 12,000 people commit suicide with handguns and another 1,000 die from unintentional fatal injuries. Every year, there are about 9,000 handgun homicides in this country. In addition, there are more than 200,000 injuries due to firearms annually (Anderson 26) . Handgun Control works to enact sensible gun control legislation in the United State but does not seek to ban guns. The Brady Bill, which was signed into law by President Clinton and took effect February 28, 1994, establishes a national five business day waiting period and requires local law enforcement to conduct background checks on handgun purchasers, but our nation's primary gun law is the 1968 Gun Control Act: MAJOR PROVISIONS: Established categories of prohibited firearms purchasers and possessors: Convicted felons, fugitives from justice, illegal drug users or addicts, minors, anyone adjudicated mentally defective or having been committed to a mental institution, anyone dishonorably discharged from the military, illegal aliens, anyone having renounced U.S. citizenship. Licenses and set standards for gun dealers: Establishes licensing fee schedule for manufacturers, importers, and dealers in firearms; sets record-keeping standards; requires licenses to be obtained from the Secretary of the Treasury; requires serial numbers on all guns. Prohibits the mail-order sales of all firearms and ammunition Prohibits the interstate sale of firearms: A handgun purchaser may only buy a gun in the state in which he/she resides; Sets age guidelines for firearms purchased through dealers: Handgun purchasers must be at least 21. Long gun purchasers must be at least 18. Prohibits the importation of non-sporting weapons: Sets penalties for carrying & using firearms in crimes of violence or drug trafficking. Prohibits importation of weapons covered in the National Firearms Act and extends NFA restrictions to machine gun frames and receivers and conversion kits (i.e., parts to make machine guns). Prohibits importation of foreign-made military surplus firearms. Prohibited the sale and manufacture of new fully automatic civilian machine guns: Prohibited the sale of parts or conversion kits - used to make semiautomatic firearms fully automatic. Classifies silencer parts and kits as weapons falling under the National Firearm Act. Over the past several years, a series of important studies have provided evidence of the efficacy of gun control; the paper by Colin Loftin etal. in the December 5, 1991 New England Journal of Medicine describes one such study. He found that there was a significant, sustained decline in gun related homicides and suicides in the District of Columbia after a law was adopted that banned the circulation, purchase, sale, transfer, and possession of handguns. There was no parallel increase in mortality from causes other than guns, suggesting that other lethal weapons were not being used as substitutes. Other data also suggest that suicide rates depend on the availability of handguns. In particular, states with relatively stringent handgun laws have lower

Developing skills of critical analysis Essay Example | Topics and Well Written Essays - 1500 words

Developing skills of critical analysis - Essay Example The experimental study conducted by to evaluate the meaningfulness of the critical analysis skills in the education sector revealed very interesting facts.The texts chosen for the essay have been selected keeping in view the subject i.e.developing skills of critical analysis and focusing on the role of education in the development of these skills.In order to fully understand the relationship between the two, the sources of information I chose include journal articles, studies conducted by institutions and individuals and also research work on the importance of these skills and educations role in its development in the modern world today. (Doughty, 2007) in his study of the critical analysis skills, gives a very thorough knowledge on the subject, keeping in view the modern worlds requirements and also by focusing more on the educational aspect, that plays an important role in the development of these skills in the individuals. I believe the point of view presented in the study is good blend of both the basics of the critical analysis skills and explanation of educations impact in a good yet criticizing way, thus emphasizing on its relative importance. The techniques and alternatives described serve as a useful means to consider the developing of these skills at a large level and inculcating these skills in the students through education thus making a complete system. (Wallace, 2009) is an influential writer and has written many books for NASA. Her insight on the subject is very interesting as she provides a modern view on critical analysis skills. The discussion and views expressed in the article tend to focus on how individuals perceive information and how two different points of views are made and understood. This is where the importance of critical analysis and thinking is felt and realized that it is something which needs to be practiced and an individual needs to be skilled in it thus expressing his views in a more meaningful way. Moreover the point raised in the article is very prominent that like other skills that are measured and are thought to be meaningful, critical analysis skills should be given such importance as well. I agree with this point, that once the education system tries to adopt this approach, the individuals would be in a better position to practice these skills and this would help in their social up-bringing and overall betterment of the society as a whole. The study by (Facione, 1990) is a comprehensive report that concentrates on the importance of critical thinking and analysis skills using an appropriate research methodology and thus defining the skills requirement for critical analysis. The study also proposes recommendations as to how the education system can adopt certain methods and techniques so as to develop these skills and nurture the dispositions that can help in yielding positivity among the individual to inquire about their surroundings and interpret meaningful results. (Staff, 2005) gives a reasonabl e argument in the article that it is the educational philosophy and the student evaluation criteria in the education system that is not letting the skills of critical analysis being developed in students. It also discusses the importance of these skills for the students today and how the education system is affecting it, thus making the students suffer a great deal. The experimental study conducted by (Paul, Elder, & Bartell, 1995) to evaluate the meaningfulness of the critical analysis skills in the education sector revealed very interesting facts. The claims that the education sector should adopt measures for the development of the critical analysis skills in the students, the teachers themselves are not aware of the critical thinking and analysis skill. This definitely raises concerns that how the education system should be changed so that it becomes the practice, or norm in teaching. Developing skills of critical analysis Critical analysis is an important cognitive tool that is required in this modern world to be abreast with the world in contemplating ideas, assumptions, and actions in a reasonable and logical context. In this essay I would be discussing the importance of

Economics, Consumerism and the Environment Essay

Economics, Consumerism and the Environment - Essay Example It is typically measured in tons of CO2 equivalent. (Kyoto Protocol) Many companies can create the carbon offset by introducing the renewable energy such as installation of solar energy system, small hydroelectric projects, geothermal and biomass energies etc. Moreover there are carbon sequestration projects that destroy the carbon dioxide. (David Suzuki Foundation) Especially for large corporations promoting consumerism like Wal-Mart, Kyoto protocol can be an effective scanner to check their accomplishment of their responsibilities towards safe guarding the environment. In this age of consumerism the conservation of energy through efficient usage and the minimization of energy wastage can be most influential measures to ensure sustainable development. The Wal-Mart Supermarkets, Stores, SAM CLUBS and Neighborhood Markets have set example of utilization of daylight through skylights to restrict energy consumption that saves 250 million kilowatt of energy every day. Besides that Wal-Mart system has adopted other measures such as the efficient process of heating and cooling, the white roof system of interior lighting and retrofit program to prove how the energy can be efficiently utilized to restrict energy-demand. (Wal-Mart) However the management of Wal-Mart should keep it in mind that a long way has to be still made to provide a perfect eco friendly operational environment. Efficient energy use, on one hand saves energy and on the other protects the environment. CFL consumes less energy than conventional tube, while providing per unit more luminance; Wal-Mart might reorient the internal lighting system through CFL. Furthermore Air conditioner and refrigerators emits harmful Chlorofluorocarbon, so it might try to ration their use. (New York State: Department of Environmental Conservation) Keeping, the air condition’s temperature at a moderate level results in less consumption of energy and less emission of CFC. Wal-Mart might