Chromatography Questions Essay Example for Free

Chromatography Questions Essay Procedure: 1. Define chromatography: 2. Gather materials for the lab. 3. Mark the filter paper with a pencil line 2.0 cm from the end of the paper. 4. Write the color of the felt marker in pencil at the top of the filter paper. 5. With a felt pen, make a dot on the middle of the pencil line. Let the spot dry. 6. Repeat the process adding more ink to the spot. Try to make it thicker, not wider. 7. Set that filter paper aside. 8. Repeat #2-5 using a new filter paper and another color. 9. Secure the two pieces of filter paper using the paper clip and hang them so they reach the 25-50 ml mark in the DRY 400 ml beaker. 10. Remove the papers from the DRY beaker and set aside. 11. Using the 10 ml graduated cylinder, measure and pour 2.0 ml of vinegar into the 400 ml beaker. 12. Fill the 400 ml beaker with enough water to make a water-vinegar solution to the 25-50 ml mark. 13. Carefully place the two pieces of filter paper in the beaker so the dots are not touching the water-vinegar solution. If they fall into the solution, you will have to start over. 14. Observe the ink spot as the water-vinegar solution moves up the paper. 15. When the solution reaches the paper clip, remove it and mark the end of the solution with a pencil. 16. Let the filter papers dry on a paper towel. 17. Record your observations. 18. Measure and sketch the colors that you observe. Analysis: Answer these on another sheet of paper in ink or type. (Rewrite questions.) 1. Define chromatography. 2. With the black marker, how many different colors can you identify? Describe this. 3. Why do you see different colors at various locations on the filter paper? 4. Compare and contrast the colors in the black and/or brown markers on the filter paper with one other marker that is not black/brown. 5. How is the technique of chromatography used to separate a mixture? 6. Is chromatography a physical or chemical change? Explain! Conclusion: 1. Describe what you have learned from this lab. 2. Research different types of chromatography to understand how it is used. Rewrite this in your own words.

Chromatography Questions Essay Example for Free

Chromatography Questions Essay Procedure: 1. Define chromatography: 2. Gather materials for the lab. 3. Mark the filter paper with a pencil line 2.0 cm from the end of the paper. 4. Write the color of the felt marker in pencil at the top of the filter paper. 5. With a felt pen, make a dot on the middle of the pencil line. Let the spot dry. 6. Repeat the process adding more ink to the spot. Try to make it thicker, not wider. 7. Set that filter paper aside. 8. Repeat #2-5 using a new filter paper and another color. 9. Secure the two pieces of filter paper using the paper clip and hang them so they reach the 25-50 ml mark in the DRY 400 ml beaker. 10. Remove the papers from the DRY beaker and set aside. 11. Using the 10 ml graduated cylinder, measure and pour 2.0 ml of vinegar into the 400 ml beaker. 12. Fill the 400 ml beaker with enough water to make a water-vinegar solution to the 25-50 ml mark. 13. Carefully place the two pieces of filter paper in the beaker so the dots are not touching the water-vinegar solution. If they fall into the solution, you will have to start over. 14. Observe the ink spot as the water-vinegar solution moves up the paper. 15. When the solution reaches the paper clip, remove it and mark the end of the solution with a pencil. 16. Let the filter papers dry on a paper towel. 17. Record your observations. 18. Measure and sketch the colors that you observe. Analysis: Answer these on another sheet of paper in ink or type. (Rewrite questions.) 1. Define chromatography. 2. With the black marker, how many different colors can you identify? Describe this. 3. Why do you see different colors at various locations on the filter paper? 4. Compare and contrast the colors in the black and/or brown markers on the filter paper with one other marker that is not black/brown. 5. How is the technique of chromatography used to separate a mixture? 6. Is chromatography a physical or chemical change? Explain! Conclusion: 1. Describe what you have learned from this lab. 2. Research different types of chromatography to understand how it is used. Rewrite this in your own words.

History Of Exhaust Fan And Ventilation Information Technology Essay

History Of Exhaust Fan And Ventilation Information Technology Essay Abstract An automatic ventilation system with an exhaust fan included with a supply fan is presented in this report. With this smart system being proposed, detailed annual energy-efficient operation strategies and methods of control for the air-handling unit are presented. Compare to the traditional type of exhaust fan, the proposed smart system shows that not only does it maintain the indoor air quality but also improve the energy efficiency. Due to the increased outdoor air, the proposed smart system can improve indoor air quality further. An external DC motor will be driven the fan. The reason why an external DC motor is used is because it is able to make the exhaust fan to have the ability of air exhausting and illumination. It also helps to reduce the noise and power consumption of the exhaust fan efficiently. So the proposed smart system is not only energy saving but also environmentally friendly. Acknowledgement This final year report is the end of my long journey in obtaining my Degree in Electrical and Electronic Engineering at University of Sunderland. I have not travelled alone in this journey. There are people who made this journey easier by offering different places to look to expand my theories and ideas. I should specially thanks to my supervisor, Mr Bob Young, for his great interest and assistance of helping me for preparation of this report. Besides, encouragements, supports and advices are continually given by him from the start. It helps me to develop an understanding of the subject thoroughly. Besides, I would also like to thanks to the staffs in the lab, Chris and George for their availability of resources, readiness and skills. Their help in finding the materials that are needed is invaluable. My project will not be in shape without their helps. Last but not least, my deepest thanks to my family, friends and others encouragement and constructive advices that have make the full support of my report completion. Chapter 1: Introduction Overview The purpose of this chapter is to give a rough idea of Intelligent Cooker Hood Exhaust Fan (ICHEF) and how it integrates into and changes the lifestyle of human beings and most importantly, being green. The usual perception of an exhaust fan by the public is simply act as a ventilation system which ventilates the air in an area. But often there are things which are important and being neglected by the public, health. Cooking does not only produce aroma, it often produces more than that, particles of smoke, grease and combusted gasses which are not healthy to breathe in and is environmental pollutants. Food like pepper and onions also produce irritants which can be unpleasant to be continuously exposed to. Exhaust fan are used to remove these pollutants from the air in a specific area. Health, has been an important concern to all of us these days. Because of that, having lots of biological pollutants and dust mite in the living place may cause a serious threat to our health. Thus, the improvement of the indoor air quality is an increasing concern to many people. Molds and dust mites will grow at a high relative humidity and there is one area in the home where moisture is generated, kitchen. Thus, adequate control of moisture in the kitchen is necessary and important. It is generally known that global warming is a severe issue that is happening in the world right now which eventually will bring unwanted natural disasters due to the overheating in the atmosphere and dilapidates the ability of earth to deal with these situations accordingly. To save the world, a few methods are being suggested by ecologists. Energy saving, one of the most effective and most commonly applied by the industries, are used throughout the world in order to avoid the earth from overheating. As a result, the concept of energy saving is being applied in the project to reduce the use of power thus saving money as well. To achieve the goals mentioned above, integrated circuits and sensors are needed to provide aids to control the exhaust fan to either on or off and the speed of the fan according to the data received from the sensors. It is also a low-cost solution and differs from the already-in-market exhaust fan which will cost a fortune. Aims The primary aim for this project is to develop an intelligent cooker hood exhaust fan to make ones life easier with the help of electronic knowledge and most importantly environmental friendly due to energy saving. Objectives The objective of this project is to design a system or programme to determine whether to on or off the exhaust from the readings of the sensors by using MicroCode Studio Plus. An effective and low-cost hardware is designed with sensors attached onto it to obtain data. It will increase or decrease the speed of the exhaust fan according to the level of the heat and smoke detected. Chapter 2: Project Background 2.1 Overview This section presents the general information and history of exhaust fan. It also provides short statement and the application and the hardware which are constructed on Intelligent Cooker Hood Exhaust Fan (ICHEF). Other than hardware, a brief of the software will be provided in this chapter as well. 2.2 History of Exhaust Fan and Ventilation As all of us understand that the purpose of ventilation is to reduce or dilute the indoor contaminants, the experienced engineers should determine how much air is necessary to dilute and reduce the contaminants to a desired level. The existence of ventilation and indoor air quality can be traced back to 17th century. However, concerns about the bad air go back much farther than that. One of the earliest reasons to implement the idea of ventilation is to ventilate the indoor air to a desired level and environment and it is probably still the same problem we have today as why we implement ventilation system in the house is to reduce and remove the products of combustion used for heat, light or cooking. People dated back to 17th undoubtedly learned very quickly that if one brought fire inside the house for cooking, one needed to take the smoke out. The design for ventilation has changed quickly over the time, but it has usually been associated with the indoor contaminants or biological pollutants that can cause health or comfort problems. Looking back into the archeological records, several examples can be found on how houses are built to accommodate ventilation and improve the indoor air quality. There are a few different approaches to deal with the use of fires in the roof. Back in 4000-5000BC, the Banpo villagers in China had implemented chimneys into their houses. The Romans put a hole in the middle of their houses roofs to suck the smoke out of the living place. The basket weavers pit houses found in Mesa Verde National Park, circa 750 AD, use the same approach. The Romans then invented and created a heating system called hypocaust heating system and it is usually for the big buildings. The hypocaust was then preceded and integrated into British parliament buildings in the late 1800s due to its superior heating design in that time. It works by getting the outdoor air into the hypocaust and gains heat from the fire and channeled all the way through the under floor channels and then go up through channels in the walls and vented to the outdoor which acts like a heating system. A system is also built in the late 1880s that uses a similar approach and directs the outside air to the building. The air from the outside is directed over the steam pipes in a heating chamber and conveys into the building. Exhaust openings in the upper reaches of the building provides a stack effect to pull the air through the building. But in year 1631, after one finds that bad indoor air quality can cause health problems, King Charles I ordered that the ceilings in the houses must be at least 10 feet high and that the windows should be higher than the width to allow rooms for ventilation. These improvements were slowly implemented into the buildings in the UK. After the great London fire of 1666, implementations of good ventilations were being speed up because a lot of houses were destroyed. Thus, it makes way for construction of bigger and better ventilated houses with chimneys and large windows which leads to have better indoor air quality when the air ventilates in the house. 2.3 Modern Background of Exhaust Fan and Ventilation With all the history in the previous section, we do of course have some modern background about the exhaust fan and ventilation. Nonetheless in the modern times which due to large demand in the world now, end-product of exhaust fans are being produced in a way of mass production. An american company specialized in kitchen exhaust fan, American Hood, has came out with some different products, ie, fire suppression system. It consists of smoke detector and fire alarm system and use a special wet chemical agent that provides quicker flame knockdown and superior fire prevention if extremely high level of smoke and temperature is detected. 2.4 Introduction to Microcontroller Figure 2.1 Microcontroller What is microcontroller? Microcontroller is sometimes called as a microcomputer or commonly called as MCU, is a kind of small or mini computer that you can find in almost all electronic devices and products. Some examples of common products that we have microcontroller built-in are microwave oven, handphone and etc. If there are buttons and a digital display in a product, chances are it also has a programmable microcontroller brain. Often, microcontrollers are called as an embedded microcontroller, it is mainly because they are often part of an embedded system and usually integrated into a larger device or system. Microcontroller is designed specifically for a particular tasks or jobs such as controlling a particular system which is different with the general purpose microprocessor, the one that is generally used in a PC. A typical microcontroller consists of an integrated CPU (Central Processing Unit), RAM for data storage and ROM for programme storage. Other than that, it also provides input and output interfaces on the same chip. It has its advantage because a general purpose microprocessor may require another addition chip to support similar function. 2.5 Introduction to PIC16F876A PIC, initials refer to Peripheral Interface Controller, is a type of microcontroller made by a company called Microchip. They are 8 bit microprocessors with small RAM, ROM and simple peripherals bundled on a same chip. The figure below shows the number of pins and functions of each pin. C:Documents and SettingsUserDesktoppic16f876a.png Figure 2.2 Integrated Circuit PIC16F876A The PIC16F876A was chosen for this project because it has the function of Pulse Width Modulation (PWM) in the integrated circuit itself, which is located at pin 12 and 13. The PWM function can be set through the configuration during the progamme codes writing in the software. PWM will be explained more in details in the next few chapters. By using this integrated circuit, it helps to save the trouble and works to construct an external circuit to perform a similar function. 2.6 Introduction to L293D C:Documents and SettingsUserDesktopl293d.gif Figure 2.3 Integrated Circuit L293D The L293D is a quadruple high-current half-H driver. It is designed to provide a bidirectional drive currents of up to 600mA at voltages ranging from 4.5V to 36V. Not only that, it drives the inductive loads such as relays, DC motors, solenoids as well as other high current or voltage loads in positive supply applications. In this project of Intelligent Cooker Hood Exhaust Fan (ICHEF), L293D was chosen to drive one DC motor to show the speed of the motor driven by the frequency (PWM) from the microcontroller. 2.7 Introduction to MAX232 Figure 2.4 Integrated Circuit MAX232 MAX232 is a communication tool used mainly for serial commands to and from a flash rom. Besides, it is also an integrated circuit that changes the signals from RS232 serial port to signals that is compatible to use in TTL (Transistor-Transistor Logic). The MAX232 is a duo driver and receiver and typically converts the RX (Receive), TX (Transmit), CTS and RTS signals. Figure 2.4 shows MAX232s structure and pin in/out of MAX232 chip. MAX232 chip was chosen for converting signals because it has long been used for microcontroller boards. It provides 2-channel RS232 port and requires external 10uF capacitors. 2.8 Introduction to Temperature Sensor (LM35) C:Documents and SettingsUserDesktopLM35.jpg Figure 2.5 LM35 The LM35 is an integrated circuit sensor that is used to measure the temperature with an electrical output which is about the same compare to the temperature in degree celsius. LM35 acts as temperature sensor in this project. It was being chosen because it does not require any extra calibration or trimming to keep its accuracy to measure the temperature. There is another main characteristic of the LM35 which act as a temperature sensor is that it takes 60mA from its supply only. Since the main objective of this project is being green and save energy, LM35 was chosen instead of other type of thermistor. 2.9 Introduction to Light Dependent Resistor (LDR) C:Documents and SettingsUserDesktopvdiv1.gif Figure 2.6 Light Dependent Resistor (LDR) A light dependent resistor (LDR) is a small semiconductor. LDR is used to recharge the light during different changes in light or made to turn a light on during certain changes in lights. One of the most commonly used areas that LDR implemented is in fire alarm system. It relies upon on the smoke which is produced in the event of a fire. When this smoke passes and covered the LDR and the amount of light falling on the LDR decreases, it will then send a signal to the microcontroller. Microcontroller will act accordingly from the pre-set programmes, in this case of the project, the microcontroller will drive the motor according to the data received. The aim of a LDR is to vary the brightness of a light in the different conditions. This can be described easily by the concept of a digital watch. Some watches get to glow in the dark so that it is possible to tell the time without pressing any buttons. It is the LDR that let the watch to know when it is dark and changes the emission level of the light accordingly. There are of course many good benefits and advantages to the LDR. A smaller amount of power will be consumed with the aid of LDR in many different kind of lights. It also helps lights to last much longer which is good for environment in a way. 2.10 Computer Interfacing Module Even though its easy especially when there is plug-and-play internal hardware solution for the computer, connecting some of the external tools or devices may still require a certain amount of technical knowledge and experience. There are generally two types of ways for data transmission, parallel and serial. Serial transmission has been chosen for this project. C:Documents and SettingsUserDesktopDB9.jpeg Figure 2.7 Layout of DB-9 Female In the past, old type of computer used 25 pins connectors while in fact that only 9 pins were actually used. Thus nowadays most of the connectors are manufactured in 9 pins instead. Each of the 9 pins usually connects to a wire. Besides the two wires which are used for transmitting (TD) and receiving (RD) data shown in Figure 2.7, the other pin is for signal ground. The voltage on any other wire is measured with respect to the ground. So, the minimum number of wires of a connector to use for 2 way transmission of data is 3. Although it has been known that it works without the signal ground wire, it will degrade the performances and often with errors. There are more wires which are for controlling purposes and not for sending bytes. Even though all of the signal can share on one wire, but there is still a separate wire dedicated to every type of signal instead. C:Documents and SettingsUserDesktopmax232.gif Figure 2.8 Connection of MAX232 and Microcontroller While communicating with different type of microcontrollers, one needs to convert the RS232 levels down to lower levels, usually 3.3V or 5V. Serial RS232 communication works with voltages -15V to 15V for high and low. On the other hand, TTL logic operates between 0V and 5V. Modern low power consumption logic operates in the range of 0V and 3.3V or even lower. The MAX232 chip from Maxim was the first integrated circuit in the market contains the necessary drivers  and receivers  to adapt the RS232 signal voltage levels to TTL logic. The reason why it became popular was because it needs only one voltage (3.3V or 5V) to generates the necessary RS232 voltage levels. . 2.11 MicroCode Studio C:Documents and SettingsUserDesktopscreen1.gif Figure 2.9 Layout of MicroCode Studio MicroCode Studio is integrated development software which has the capability to debug and was developed and used for microEngineering labs PICBASIC and PICBASIC PRO compiler. Microcode Studio is packed with a code explorer that helps to jump automatically to files, constants, variables, symbols, defines and labels, which are consisted in respected source code. Besides, there are too other features available in this software such as cut, copy and paste, undo and replace options. Not only that, it has the ability to correct and identify the assembler errors. It features views for serial output from the external of the microcontroller. The software helps the user to set up assembler and compiler options. Other than that, it has auto-search feature included in the software which helps the user to do all the work which is involved. It too has the error result window which helps to identify errors and correct them easily. The good thing about this compiler is that when the user clicks on the errors in the compiler, MicroCode Studio will automatically jump into the line location and it efficiently helps the users to know where and how to debug the serial output from the microcontrollers. Chapter 3: System Description 3.1 Overview This chapter focuses on the system design, description and illustration of block diagram of the Intelligent Cooker Hood Exhaust Fan. Several descriptions of the systems will be explained in this chapter as well. 3.2 Introduction The system consists of mainly 4 parts, namely:- Temperature sensor (LM35) / LDR (act as a smoke sensor) and its readings The temperature sensor and LDR will sense the heat or smoke level. If the level exceeds the pre-set level, the fans will be activated automatically via the control of microcontroller. Liquid Crystal Display (LCD) A LCD will be installed in the system to display the temperature reading and LDR values according to the data received. It is to give the user an insight or idea of what is the current values of temperature or light density at that particular time. Speed of exhaust fan by Pulse Width Modulation (PWM) The speed of exhaust fan will be adjusted according to the heat level detected and generate the pulses accordingly. The speed may go higher only when the heat level is higher thus saving the wasted energy which is required to run the fans to full speed at all time. This type of exhaust fan differs from the traditional type of exhaust fan. The fans will then still be activated for a short period of time after the reading drops back to the pre-set heat level in order to remove all the excessive smoke or odour away. Driver Circuit A circuit by L293D to control DC motors with external power supply. 3.3 System Design Microcontroller (PIC16F876A) Temperature Sensor (LM35) Light Dependent Resistor Fans High Speed Low Speed LCD Display Determine speed according to heat smoke level Fans still on for a pre-set time Controller Circuit Figure 3.1 Overall Block Diagram of Intelligent Cooker Hood Exhaust Fan The concept of Intelligent Cooker Hood Exhaust Fan is smart. It helps to reduce the workload of human beings and also it will save energy as well. The microcontroller which uses PIC16F876A serves as a main brain of the whole system. It uses 2 types of sensors which are the temperature sensor (LM35) and light dependent resistor (LDR). With the help of both sensors, data are easily received and displayed on the LCD Display with some aids of the programming. After the data are received and displayed on LCD Display, pulses will be generated by the function of Pulse Width Modulation (PWM) in PIC16F876A and it sends the signal to the controller circuit, DC motor in this case, and drive the motor accordingly to what the readings are being obtained. The fans should still be on for a period of time to ensure the remaining smell and odour are sucked away. 3.4 Pulse Width Modulation (PWM) Pulse Width Modulation (PWM) is a useful technique that controls the analog circuits with the aids of the processors digital outputs. It is employed in different types of areas. It is widely used from power control and communications to measurement and conversion. To control the analog circuit in digital way, it helps to reduce the cost of the system and most importantly, it reduces the level of usage of power consumption as well. 3.4.1 Duty Cycle PWM Signals Figure 3.2 PWM Signals of Varying Duty Cycles Figure 3.2 shows three different PWM signals. The upper figure shows a PWM output with a 10% duty cycle. It just means that the signal is on for 10% of the period and off the other 90% of the period, so the average is low. Likewise, the middle figure shows the analog signal value at 50% and lower figure shows 90%, so its average is half and high accordingly. If it is fully on, it requires 100% of the period while when it is 0%, it is off. 3.4.2 PWM Frequency The PWM signal frequency is important depending on the hardware that one is using. If the main purpose is to create a DC signal then the high frequency will be required (kHz) so that the low pass filter can eliminate the frequency component. To determine how high the frequency, it is to depend on how much frequency components are allowed at the output and how it is used. 3.4.3 Communication and Control One of the reasons why PWM is so popular is because that the signal remains digital at all times, from the microcontroller to the driver circuit. There is no Digital-To-Analog Conversion (DAC) is required. The noises in the signal will be reduced to minimum level because the signals are in digital form. Noises can affects digital forms signal only if it is great enough to change from Logic 1 to Logic 0 and likewise. PWM is often used for communication is mainly because PWM has the ability to increase the noise immunity over analog control. By converting the analog signal to PWM, it increases the length of a communication channel. An appropriate RC (Resistor-Capacitor) or LC (Inductor-Capacitor) network can remove the modulated high frequency wave form and return the PWM signal back to analog form at the recipient side. 3.5 DC Motor C:Documents and SettingsKLTDesktopelectric-motor.jpg Figure 3.3 DC Motor Almost all mechanical movement that surrounded us is caused by either an AC or DC electric motor. It converts the electrical energy into the mechanical movement. One needs to have a little background knowledge about electromagnet and electricity in general to understand how a motor works. 3.5.1 How It Works? In any kind of electric motor, in this case, a DC motor, the operation is mainly based on a simple electromagnetism. A magnetic field is then generated by a current carrying conductor. By doing so, it will experience a force proportional to the current in the conductor when it is placed in the external magnetic field. Everyone is well aware of playing the magnets when young. The opposite polarities attract, in this case, north and south pole. Vice versa, the same polarities repel, north-north and south-south. The operation of a DC motor has similar concept. The internal arrangement of a DC motor is outlined to compose the magnetic interaction between an external magnetic field and a current carrying conductor to generate rotational movement. Image Figure 3.4 Layout of DC Motor Almost all the basic DC motor has these six common parts in them, namely axle, commutator, rotor, stator, brushes and field magnets. In most DC motor, the external magnetic field is produced by high level strength of permanent magnets. The rotor rotates according to the stator which is stationary as well as two or more permanent magnet pole pieces. The windings of the rotor are being connected electrically towards the commutator. The above figure shows a common motor layout with the rotor inside the stator magnets. 2-pole motor in action Figure 3.5 Operation of DC Motor The relationships between the commutator contacts, the brushes and the rotor windings are that when the power is being supplied to the motor, the stator magnets will be incorrectly aligned, the rotor will rotates till it is aligned with the stators field magnet and polarities of the energized winding. The brushes will move to the next commutator contacts and next winding will be energized only when the rotor are in alignment. It can be given by the simple example of 2-pole motor. The rotation reverses the direction of current flow through the rotor winding, causing to the flip of the rotors magnetic field, making it to continue rotating. Image Figure 3.6 Inner view of DC Motor Iron core armature is commonly used in a DC motor as it has a few advantages. The iron core provides a strong and firm support to the windings, it is specifically important considering for the high torque motors. The core, in a way, also dissipate the heat away from the rotor windings very well that it allows the DC motor to rotate even harder. And most importantly, to construct an iron core is comparably cheaper than other type of construction. Unarguably, there are always pros and cons about almost everything. There are a few disadvantages about the construction of iron core. The high level of inertia in iron armature reduces the motor acceleration dramatically. This type of construction also causes the high winding inductances which reduce the life of the brush and commutator. Chapter 4: Circuitry Explanation 4.1 Overview This chapter is about the circuits that are used in this project. Circuit operation and the performance of the entire circuit are roughly explained in this chapter. All datasheets of the Integrated Circuits used in this project are attached in the appendixes section. Circuit diagrams for every part of the overall circuit in this project are provided so that the operation of the circuit can be understood easily by non-engineer readers. 4.2 Microcontroller Unit (PIC16F876A) Figure 4.2 Microcontroller Unit The PIC16F876A CMOS FLASH-based 8-Bit microcontroller consists of a 200 nanoseconds instruction execution, self programming, an ICD (In-Circuit Debugger), 2 comparators, 256 bytes of EEPROM data memory, 2 PWM functions and a UART. The main brain of this control unit replies upon on the PIC16F876A with a 4MHz resonator that produces the clock pulses which is required buy the targeted microcontroller. 4.3 Universal Asynchronous Receiver/Transmitter (UART) Figure 4.3 Circuit of Universal Asynchronous Receiver/Transmitter (UART) with MAX232 An UART (Universal Asynchronous Receiver/Transmitter) is a type of computer hardware that converts the data between the serial and parallel forms. UART is often used with other types of communication means such as, RS232. It is usually a single IC (Integrated Circuit) that used for serial communication or through peripheral device serial port. UART is usually used for embedded system such as microcontroller with RS232. Different interface equipment is usually used to change the logic level of the UART to and from the external signaling levels. It doesnt usually receiver nor generate the external signals which are used between the different types of equipment. 4.4 Light Dependent Resistor (LDR) Figure 4.4 Circuit of Light Dependent Resistor The circuit shown above is about the sensor of the circuit. LDR in this project is to activate the microcontroller. It acts as an input and will send the analogue data into microcontroller and microcontroller will determine the data received and perform a task accordingly. These values will be sent into microcontroller on PortA.0. 4.5 Temperature Sensor (LM35) C:Documents and SettingsKLTDesktopuntitled.bmp Figure 4.5 Circuit of Temperature Sensor (LM35) The power supply (Vcc) can be ranging from 4V to 20V depending on the project requirement, but 5V will be used in this project. To use the LM35 sensor, one can just connect the Vcc to 5V, Ground to Ground and the Out to the Analog-Digital Converter channel. The output varies with temperature obtained. The values will be sent to microcontroller via PortA.1. 4.6 Motor Controller (L293D) C:Documents and SettingsKLTDesktopuntitled.JPG Figure 4.6 Circuit Connection of L293D to Microcontroller The DC motor can be driven in clockwise or anti-clockwise direction depending to the requirements. To do so one first needs to connect the motor and find out the commands that are needed to give to the microcontroller to perform the specific rotation. Pin 1 and pin 8 will need to connect to 5V. Pin 3 and 6 are connected to the output which is DC Motor. Pin 4 and 5 are for grounding. Pin 2 and 7 act as an input which connect to PortC.7 and PortC.6 respectively. Pin 1 of the L293D will also connect to Pin 12 or 13 for Pulse Width Modulation (PWM) function in microcontroller. 4.7 Overall Circuit C:Documents and SettingsKLTDesktopoverall.JPG Figure 4.7 Overall Circuit Chapter 5: Materials 5.1 Overview The main purpose of this chapter is about the materials and tools that are used in this project whereby components, software and tools used will be listed for reference purposes. Budget and stores for all components are also listed at the end of this chapter as well. 5.2 Preface of Materials Used All materials used in finishing this project can be further categorized into 3 main groups of computer software, apparatus and electronic components. These 3 major groups of materials will be further discussed in following subchapters. 5.2.1 Computer Software Computer software used in this project is shown below. No. Computer Software Function 1. Live Wire Do the simulation of the circuit 2. Micro Code Programming for the Microcontroller 3. Microsoft Word Report typing Table 5.1 List and function of the software used to complete this project 5.2.2 Apparatus The table below shows the apparatus that required for c

supreme court desicion of hypothetical case :: essays research papers

The appellant, Salim abdul Aziz Rahman, the founder of the group called the Global Islamic Jihad, was convicted under the USA Patriot Act of 2003 for â€Å"furthering the aims of known terrorism organizations by advocating the violence of the United States government that is called for by those organizations.† He was tried and convicted by the Federal District Court, and has challenged the constitutionality of this Act on the grounds that it violates his First Amendment right of Freedom of Speech as protected by the United States Constitution. The United States Patriot Act of 2003 makes it a crime to â€Å"further the aims of known terrorist organizations by advocating the violence against the United States government that is called for by those organizations.† This act was formulated and put into effect after the acts of terrorism in September of 2001.   Ã‚  Ã‚  Ã‚  Ã‚  The record shows that a man identified as the appellant, distributed to the inhabitants of his predominantly Middle-Eastern New York City neighborhood, pamphlets stating â€Å"the American government is controlled by Zionist agents and is using it’s arrogant power to murder believers around the world.† These pamphlets also contained the sentence â€Å"The penalty for murder is death.† These pamphlets were printed and distributed by his organization, Global Islamic Jihad.   Ã‚  Ã‚  Ã‚  Ã‚  At a rally of his organization in April of 2002, Mr. Rahman burned a flag (though protected by Texas v Johnson, 491 US 397, ‘O’Brien 626’), and presented a speech where he called for â€Å"death to any country that supports Zionist aggression against true believers† as well as cataloging â€Å"American crimes against humanity.† In a speech on the day of his arrest in this same Middle-Eastern neighborhood, the appellant catalogued â€Å"America’s crimes against humanity and the believers,† as well as declaring â€Å"We must not sit by idle. We must stand up with all of our strength with our brothers and sisters who struggle against the Zionists and against those who help them with money and weapons. The treacherous Jews and Crusaders must go down. Jihad knows no boundaries and no limitations on its means.†   Ã‚  Ã‚  Ã‚  Ã‚  Through legal FBI wiretaps, it was found that Mr. Rahman was in direct contact with representatives of the Muslim Brotherhood, a political group both in the United States and abroad. Previously an Egyptian terrorist group whom publicly renounced violence, this group now claims to advocate a â€Å"peaceful transition to a worldwide Islamic state.† However, this group often conveys ideas by known terrorist organizations that it calls â€Å"brothers in the great cause.

Police Brutality: A Minority Group Concern Essay -- Use of Excessive Fo

"Relations between the police and minority groups are a continuing problem in many multiracial societies. Surveys consistently document racial differences in perceptions of the police, with minorities more likely than whites to harbor negative views." (Weitzer and Tuch, Race and Perceptions of Police Misconduct, 2004) A great deal of society views law enforcement officers as heroic and honorable individuals, whose main purpose is to protect and serve the community. For many officers, this description is accurate, however for others; violence and brutality against innocent citizens is part of getting the job done. For years, minorities have fallen victim to police brutality based on racial profiling, stereotypes and other unjustifiable reasons that has cost innocent lives. The involvement of officers in police brutality against minority groups causes tainted and negative views on policing. This reduces their ability to protect and serve the community. Police brutality is a violent incident involving an officer and a victim, usually including excessive force, unnecessary violence and sometimes resulting in a senseless fatality. Minority groups such as African Americans and Hispanics have often been the victims of this form of abuse by officers, however little justice has been done in order to protect these individuals from this form of cruelty by the hands of those with the most power. For many individuals, police brutality is a non-existent matter because it does not directly affect them or the community in which they live. Yet for others, this is an everyday occurrence and few limitations have been set as to what is unjust and malicious behavior of an officer towards the public, therefore, several officers are rarel... ..., 747-763. Simmons, K. C. (2008). The Politics of Policing: Ensuring Stakeholder Collaboration in the Federal Reform of Local Law Enforcement Agencies. The Journal of Criminal Law and Criminology (1973- ), 98(2), 489-246. Smith, B. W. & Holmes, M. D. (2003). Community Accountability, Minority Threat, and Police Brutality: An Examination of Civil Rights Criminal Complaints. Criminology, 41(4), 1035-1063. Tyler, T. (2005). Policing in Black and White: Ethnic Group Differences in Trust and Confidence in the Police. Police Quarterly, 8(3), 322-342. Weitzer, R. and Tuch, S. (2004) Race and Perceptions of Police Misconduct. Society for the Study of Social Problems, Inc. SOCIAL PROBLEMS, Vol. 51, No. 3, pages 305–325. ISSN: 0037-7791; online ISSN: 1533-8533 Web. 4 Sept. 2015. http://web.missouri.edu/~jlfm89/Race%20Perceptions%20of%20Police%20Misconduct.pdf

Work for Migrant Workers Essay -- Immigration Labor Essays Papers

Work for Migrant Workers Works Cited Not Included In the early 1970’s, by examining profit rates globally, it was determined that a falling rate of profit existed. The chief method to counter this problem was to seek out cheaper labor. Global factories were then created as the solution to this problem of falling profit rates. With the birth of these global factories, came not only transnational corporations but also transnational migrant workers. Therefore, why is there so much debate concerning migration when it was basically conceived and in many cases continues to be, a solution to a problem? Through global economic integration and the birth of global factories, many â€Å"underdeveloped† countries believed that these corporations would resurrect their dying economies by providing jobs to their many unemployed workers. However, these corporations did not hire the unemployed male but women usually between the ages of sixteen and twenty-one who worked approximately ten hours per day in extremely poor working conditions for very low wages. As a result, this left mostly the unemployed male (and/or the unemployed female over twenty-one) in a position to either migrate for work or become a caretaker for their families’ children. As documented by several of the films we’ve watched during class, many of these unemployed workers chose to migrate – sometimes both mother and father leaving behind children to be cared for by extended family members. One such child when asked if he missed his mother and father replied â€Å"No, because I don’t even know them† which truly epitomizes the migrant workers’ sacrifices for their families!! One might ask why do these migrant and/or global factory workers do the things they do? ... ...storical context of differential power and inequality.† (Schiller, Basch & Blanc-Szanton 8). Again, migrant workers exist because of economic circumstances and the innate sense of survival. Therefore, why are there so many beliefs and debates concerning migration? Because some people just don’t get it! What some seem to be missing in these debates is that with global economic integration obviously come transmigrant workers (and in some cases their families too), so why debate whether they should be allowed to cross borders as they are simply the product of globalization. Further, one should not forget that in many instances, these workers were â€Å"solutions† to economic or wartime problems!! Therefore, I strongly feel that migrant workers must be given the right to work regardless of what country they are from or what country they must work in!

Creating Human Service Agencies Essay

Human Services agencies play a vital role in connecting community resources to those in need of services. Some of the agencies are more beneficial to the community than others. Some of the larger agencies that are well connected with political figures tend to receive more funding, and directly affect local policy changes. Inadequate, funding prevents most human services agencies from conducting program evaluations that could be used to help strengthen their capacity, increase funding and track success. One small organization located in Tallahassee, Florida defies those odds. The agency is located inside Bond Community Health Center the largest community health center in Tallahassee. The small agency is a pioneer of social change in the field of HIV/AIDS creating the only active Peer Navigator program. The Minority Alliance for Advocating Community Awareness and Action, Inc. (MAACA’s) mission statement is to empower the minority community through the linkage of services, the creation of culturally sensitive programs and through mobilization strategies. According to the history â€Å"the Minority Alliance for Advocating Community Awareness and Action, Inc. MAACA), formerly known as the Minority AIDS Action Committee (MAAC) was established in October 1999, under Shisa, Inc. Shisa, applied for federal funding from the Center for Disease Control (CDC) to help with the increasing number of new African American HIV infections cases in the United States. The CDC cooperative agreement capacity-building grant no. PA00003 Priority 3: Strengthening Community Capacity for HIV Prevention was awarded to Shisa, Inc. Shisa’s task was to build the capacity of African American communities to address the growing need for HIV prevention. States and counties covered under the cooperative agreement included Mobile, Alabama, the pan handle of Florida down to Jacksonville, Florida and then over to Thomasville, Georgia. According to the contract the boards were to provide three areas: 1) create community boards in each of the locations, 2) the board provides prevention events in the African American community especially during National HIV Observance Days and 3) the MAAC boards were to host community capacity building workshops. â€Å"In the early days of the HIV/AIDS pandemic, there has been since the 1980s a â€Å"profound re-medicalization of sexuality. One of the best-known works on the history of HIV is 1987’s book And the Band Played On, by Randy Shilts. Shilts contends that Ronald Reagan’s administration dragged its feet in dealing with the crisis due to homophobia, while the gay community viewed early reports and public health measures with corresponding distrust, thus allowing the disease to spread and hundreds of thousands of people to needlessly die. This resulted in the formation of ACT-UP, the AIDS Coalition to Unleash Power by Larry Kramer,† Wikipedia. According to Wolf Wolfberger, conscious rather than unconscious ideology; â€Å"One thing that can be very bad about our ideologies is that more often than not, we are not aware of them. Sometimes we take them so for granted that we lose sight of their existence†¦ At other times, we simply are not equipped intellectually to formulate our ideologies into words. At yet other times, our ideologies are so bad that we cannot consciously face up to them. † â€Å"For example, we all claim to believe in equality – and then we practice gross discrimination, but deny it because we cannot admit it and therefore do not realize that we discriminate. It is with those ideologies that the stigma, fear, discrimination, homophobia, and negative perceptions about HIV/AIDS that places too many US citizens at a higher risk of infection. Many at risk for infection fear stigma more than actual infection itself especially in the African American communities. They instead choose to hide their high-risk behavior rather than get counseling and testing. The lack of awareness of one’s HIV status can affect the overall HIV rates. According to CDC data, â€Å"approximately 1 in 5 adults and adolescents in the U. S. living with HIV don’t know their HIV status. This translates to about 116,750 persons in the African-American community. † Just as it was in the early years of the pandemic the African American community was not prepared for HIV prevention and did not understand capacity building. The rural south communities did not welcome HIV prevention work especially HIV prevention work in the black churches. Many of the other agencies were not willing or not culturally sensitive to the needs of the African American community. Human service organizations are archetypically â€Å"institutionalized organizations. That is, their growth and survival depend less on the technical proficiency of their work and more on their conformity with dominant cultural symbols and belief systems, that is, institution rule (Meyer & Rowan, 1977) (page 14 – 15). † By 1990, those institutional rules fo r HIV prevention became more structural. Policy, laws and standard operating procedures were beginning to take form such as the US Congress enacting â€Å"the Ryan White Comprehensive AIDS Resources Emergency (CARE) Act. Ryan White is the largest federal program dedicated to providing care and treatment for people living with HIV. A key component of the public health safety net, it reaches hundreds of thousands of people every year with medical care, drugs, and support services. The CARE Act has been a huge success in reducing sickness and death from HIV disease and helping people live longer, more healthy and productive lives. † Yeheskel Hasenfeld writes, â€Å"recognizing that human service organizations engage in moral work impede that they must constantly seek and maintain legitimacy for what they do. They do so by making references to institutionalized moral system in their environment. That is, they adopt and uphold moral systems and cultural frames that resonate well with their significant audiences, such as legislative bodies, government bureaucracies, regulatory agencies, professional associations, other human services organizations, various civic and political associations, and clients (Scott, 2008). † By 2005, the Centers for Disease Control (CDC) guidelines stated that all agencies providing HIV prevention intervention programs must follow the â€Å"Behavior theory Interventions† as outlined in the CDC procedure guidance book. With this shift many of the small minority based CBO closed their doors to HIV prevention work. Of the fifteen Minority AIDS Action Committee (MAAC) boards formed during the five year of the CDC contract only the agency in Tallahassee, Florida remains. There is still a great need for the African American community to engage in HIV/AIDS prevention work. MAACA host some of the largest events in North Florida from HIV conferences to community workshops and forms. It is only when we chose to engage, constantly seek and maintain legitimacy that what we do in the field of HIV/AIDS that MAACA will continue to exist. MAACA is a champion for the people and was able to diversify funding sources while remaining true to its mission.