The Knights Hospitaller of St. John of Jerusalem

The Knights Hospitaller of St. John of Jerusalem In the mid-eleventh century, a Benedictine convent was built up in Jerusalem by dealers from Amalfi. Around 30 years after the fact, a medical clinic was established close to the convent to think about wiped out and poor explorers. After the accomplishment of the First Crusadeâ in 1099, Brother Gerard (or Gerald), the medical clinics prevalent, extended the emergency clinic and set up extra emergency clinics along the course to the Holy Land. On February 15, 1113, the request was officially named the Hospitallers of St. John of Jerusalem and perceived in an ecclesiastical bull gave by Pope Paschal II. The Knights Hospitaller were otherwise called Hospitalers, the Order of Malta, the Knights of Malta. From 1113 to 1309 they were known as the Hospitallers of St. John of Jerusalem; from 1309 to 1522 they passed by the Order of the Knights of Rhodes; from 1530 to 1798 they were the Sovereign and Military Order of the Knights of Malta; from 1834 to 1961 they were the Knights Hospitaller of St. John of Jerusalem; and from 1961 to the current they are officially known as the Sovereign Military and Hospitaller Order of St. John of Jerusalem, of Rhodes, and of Malta. Hospitaller Knights In 1120, Raymond de Puy (a.k.a. Raymond of Provence) succeeded Gerard as pioneer of the request. He supplanted the Benedictine Rule with the Augustinian Rule and effectively started to develop the requests influence base, helping the association to obtain terrains and riches. Perhaps enlivened by the Templars, the Hospitallers started to wage war so as to ensure pioneers just as tend their ailments and wounds. Hospitaller Knights were still priests and kept on following their pledges of individual neediness, submission, and chastity. The request likewise included clergymen and siblings who didn't wage war. Migrations of the Hospitallers The moving fortunes of the western Crusaders would likewise influence the Hospitallers. In 1187, when Saladin caught Jerusalem, the Hospitaller Knights moved their central station to Margat, at that point to Acre ten years after the fact. With the fall of Acre in 1291 they moved to Limassol in Cyprus. The Knights of Rhodes In 1309 the Hospitallers procured the island of Rhodes. The amazing expert of the request, who was chosen forever (whenever affirmed by the pope), managed Rhodes as an autonomous state, stamping coins and practicing different privileges of power. At the point when the Knights of the Temple were scattered, some enduring Templars joined the positions at Rhodes. The knights were presently more warrior than hospitaller, however they stayed an ascetic fraternity. Their exercises included maritime fighting; they equipped ships and set off after Muslim privateers, and delivered retribution on Turkish dealers with robbery of their own. The Knights of Malta In 1522 the Hospitaller control of Rhodes reached a conclusion with a six-month attack by Turkish pioneer Suleyman the Magnificent. The Knights gave in on January 1, 1523, and left the island with those residents who decided to go with them. The Hospitallers were without a base until 1530, when Holy Roman sovereign Charles V organized them to possess the Maltese archipelago. Their essence was restrictive; the most remarkable understanding was the introduction of a bird of prey to the sovereigns emissary of Sicily consistently. In 1565, thousand ace Jean Parisot de la Valette displayed brilliant administration when he halted Suleyman the Magnificent from dislodging the Knights from their Maltese central station. After six years, in 1571, a consolidated armada of the Knights of Malta and a few European powers essentially decimated the Turkish naval force at the Battle of Lepanto. The Knights manufactured another capital of Malta out of appreciation for la Valette, which they named Valetta, where they developed excellent safeguards and a clinic that pulled in patients from a long ways past Malta. The Last Relocation of the Knights Hospitaller The Hospitallers had come back to their unique reason. Throughout the hundreds of years they progressively surrendered fighting for clinical consideration and regional organization. At that point, in 1798, they lost Maltaâ when Napoleonâ occupied the island while in transit to Egypt. For a brief timeframe they returned under the support of the Treaty of Amiens (1802), however when the 1814 Treaty of Paris gave the archipelago to Britain, the Hospitallers left again. They finally settled forever in Rome in 1834. Enrollment of the Knights Hospitaller In spite of the fact that respectability was not required to join the ascetic request, it was required to be a Hospitaller Knight. As time went on this prerequisite developed progressively exacting, from demonstrating honorability of the two guardians to that of all grandparents for four ages. An assortment of gallant characterizations advanced to oblige lesser knights and the individuals who surrendered their pledges to wed, yet stayed associated with the request. Today, just Roman Catholics may become Hospitallers, and the administering knights must demonstrate the respectability of their four grandparents for two centuries. The Hospitallers Today After 1805 the request was driven by lieutenants until the workplace of Grand Master was reestablished by Pope Leo XIII in 1879. In 1961 another constitution was embraced in which the requests strict and the sovereign status was unequivocally characterized. Despite the fact that the request no longer oversees any domain, it issues international IDs, and it is perceived as a sovereign country by the Vatican and some Catholic European countries.

Ethnographic Comparison Account Essay Example | Topics and Well Written Essays - 750 words

Ethnographic Comparison Account - Essay Example This paper features arrangement issues in strict practices and issues the referenced social orders face while rehearsing their strict convictions. Great and contemporary ethnographical records are utilized in this examination. African Americans are residents of United States of America and they have their lineage in Sub-Saharan Africa. They are the single biggest minority bunch in United States of America and the vast majority of them are offspring’s of Africans gotten America during the slave time frame. The Chinese are residents of the People’s Republic of China.There are 56 ethnic gatherings in China, and Han is the biggest, establishing 91.5% (Berlatsky, 2010). The Han are the world’s biggest single ethnic gathering and assume a predominant job in Chinese legislative issues and financial spheres.Lack of legitimate information makes it hard to know the precise number of strict practices among the Chinese; in any case, Religion picked up unmistakable quality am ong the Chinese in the late 1980s with the most recent study led in 2007, portraying 23% of the Chinese populace being strict (Berlatsky, 2010). The most predominant strict convictions in China are the Chinese people religion, Taoism and Buddhism. half of the Chinese populace are Buddhists, while Taoist record for 30% of the populace. These figures are estimations since it is hard to get the specific number of Buddhists, Taoist and those rehearsing Chinese society religion since they cover with each other, and there is no open interest and congregational enrollment. Christianity is a minor religion among the Chinese and was presented during the Tang line, in 635 AD. Numerous Christians in China have a place with un-approved house holy places and along these lines it is hard to know the specific level of Chinese Christian (Cavali, 2002). The Government of China assesses the quantity of Chinese Christians to associate with 25 million, an expected 3% of the all out populace. The Chines e, practice Islam, however it is a minority and was presented in the period 651 AD. Different religions, for example, Bon and Hinduism are additionally rehearsed in China albeit under guideline by the Chinese Government (Cavali, 2002). Among the African Americans greater part of them are Protestant Christians who follow the chronicled places of worship shaped by individual blacks, as indicated by the 2007 Religious review directed in America. The biggest Protestant gathering is the Baptists and is separated into four sections (Gates et al, 1996). The second biggest protestant gathering is the Methodists, whose biggest church is Methodist Episcopal Church. African Americans are additionally individuals from white Pentecostal development, and an expected 16% of African Americans are accepted to go to such categories. The Roman Catholic confidence is additionally rehearsed among the African Americans, yet it is a minority religion (Bankston, 2006). Islam is a religion among this gather ing however in minority, and they establish 20% of Muslims in United States of America, lion's share being Sunni Muslims. Religion among the Chinese and the African American is extraordinary. One distinction exudes from the idea of the strict practice. The most predominant religion in China is Buddhism, while the most prevailing religion among the African Americans is Christianity. Buddhists revere Buddha as god, while Christians have faith in Jesus Christ as the child of God, and savior of humankind from transgression. A huge contrast emerges in the participation of

Is Google making us stupid Essay Sample

Is Google making us stupid Essay Sample An article that was written by a Nicholas Carr “Is Google making us stupid?” impressed me and many other people disclosing the hidden truth about the Internet and its influence on people. The results of the analysis provided in the article are quite pessimistic. According to the data provided there, people are losing an ability to read and think critically. It doesn’t mean that one day people forget how the alphabet looks like, it only means that the way how people read and think is quite different from the one it was before the Internet era. At the very beginning of the article, Nicholas Carr mentions that he has some problems with reading long pieces of works. As a result, he decided to analyze this question. He mentions that the more time he spends on the web, the worse situation with reading is. For example, it became harder for him to read even three pages pieces. To understand whether it is a unique case or other people also suffer from this problem, it was decided to ask other quite smart people, who were fond of reading long books. All of them states, that their ability to read is worse than it was a few years ago. A lot of them have complaints about their attentiveness when reading. For example, Scott Karp, who is a writer of a blog about online media confessed that he just stopped reading books. However, in college, he was a lit major. The conclusion of the analysis is quite simple â€" the web has changed the way we read. One more example that can prove that there are great changes in the reading sphere, is that people, who use online libraries don’t read the books â€" they skim them. It is enough for them to look through the title and outline to understand the information. A lot of people don’t understand why this is happening with them. People always search for the convenience and create amazing things, such as the Internet, computer, and typewriter to make the life easier. However, they don’t understand that we are connected with our machines. The answer is simple â€" the author thinks that the equipment we use to read or write down information have an impact on how the information is taken or provided. The simplest example will be a typed letter and a hand-written letter. Everyone can see the difference between these things. More free time? Better grade? Click on this button nowOrder Now One more thing that the author is worried about is what kind the information we get from Google. People get used to believe mass media and the Internet. However, it is necessary to be very attentive because none of them presents the pure information. It is always shaped the way the authority wants this. Unfortunately, critical thinking skills are also bad nowadays. It is very hard for people to decide when they see the truth, and when they get the shaped information. I totally agree with the Nicholas Carr’s arguments provided in the article. I think that we really have a great connection to the equipment we use for communicating and reading. From the one side, it is very convenient and it makes the lives of the people easier. On the other hand, people forget how to read and how to think. They only can scan the material because after a few minutes it is hard to stay attentive. Apart from this, the author states that deep reading is the basic thing of deep thinking. Unfortunately, I couldn’t find much information about the solution of this problem. Apart from this, I didn’t notice many reasons, why it is necessary to search for a solution. I think that every person can control him/herself, so everything, including deep reading and thinking, depends on the personal abilities and desires.

Ancient Egyptian Influence on Modern Religion Essay

Egypt is considered the birthplace of many world religions. It contains some of the oldest religious artifacts, texts, and art that can be traced to modern religions. Signs of early Egyptian religion date back to the Predynastic period, beginning with evidence of polytheistic worship. Many scholars have researched the development of Ancient Egyptian religion over the centuries and have studied the direct correlation between it and the modern religions of Judaism and Christianity. Questions arise as to whe Judaism developed because of social and political conditions of Ancient Egypt or rather through conscious adaptation of Egyptian stories, values, and traditions. Was it through divine inspiration that the faiths formed, or was it simply†¦show more content†¦Ptah was also a creator god who built the boats that carried the souls of the dead into the Underworld. Osiris was the ruler of the Underworld and husband to Isis, the goddess of fertility and the ideal wife. Isis†™ song, Horus, was the god of the sky and depicted with a hawk-like head often portrayed with a double crown. These deities were worshipped daily by the Egyptians in temples built by the ruling pharaoh and his priests. The pharaoh was viewed as the intermediary between the deities and his people. Through his kingship and divine power, he was expected to maintain universal peace and order. Egyptians also underwent extensive and excessive processes to preserve their souls after death through tombs, mummification, and offerings to the gods for preservation of the deceased bodies (â€Å"Ancient Egyptian Religion†). The concept of life after death is rooted in ancient Egyptian religion where funerary processes and burial rituals were fundamental and crucial to an afterlife. Egypt was one of the first countries to convert to Christianity in 43 A.D. From the persecution of Christ by the Romans to the acceptance of Christianity as the imperial religion of the empire, Christia nity underwent significant changes in the first few centuries after Christ’s ascension. Many Egyptian pagan beliefs and deity legends were unconsciously transferred to infant Christian faith and reformed in stories of the new deity, Jesus. Several elementsShow MoreRelatedEgyptian Religion s Influence Over Christianity1588 Words   |  7 PagesEgyptian Religion’s Influence Over Christianity Religion is present in almost every single culture in the world and has been for several thousands of years. Egypt is one of the first known and recorded civilizations in the world and has been studied for as long as its artifacts have been founded. In the discoveries of these artifacts, historians have found religious-like stories with Gods and supernatural elements. This is one of the first ever recorded religions in the world and the religions thatRead MoreAncient Egypt and Mondern Society981 Words   |  4 Pageslasting mark on the world, especially not one so profound that influences the world as it exists today. One such civilization that has had a profound impact on daily modern lives was that of Ancient Egypt. Their systems of religion and technological innovation helped not only to leave a permanent impression on the world, but also served to mold both the civilizations that directly followed it as well as society today. The Ancient Egyptian civilization spanned several thousand years and is one of theRead MoreAncient Egypt : Unique And Defining Burial Practices1172 Words   |  5 PagesAncient Egypt is memorialized for its opulent history and culture along with the unique and defining burial practices. Ancient Egyptian religion was a very intricate yet complex way of belief. 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Egypt is located in Northern Africa and is surrounded by and impacted by the Sahara Desert, Mediterranean Sea, Red Sea, and running throughRead MoreCivilization is Connected from the Mesopotamians to the Powerful Roman Empire836 Words   |  4 Pagesevents, people, and concepts that have left an enduring influence. Society has developed many components which became foundational to Western culture from the Mesopotamian civilizations to the emergence of the Romans. The contributions of a variety of cultures shaped the course of Western history. The Mesopotamians and Egyptians are among the first civilizations to make a valuable contribution to Western Civilization. Both Babylonians and Egyptians managed to produce written systems of communicatingRead MoreEssay about Comparing Ancient Egypt/America733 Words   |  3 Pagescomparing Ancient Egypt and modern day Americas, I found a few similarities and differences in their every day lifestyles. Things like religion, government, social class, writing, and their job specializations. It was surprising to me to find out that the ancient Egyptians way of leaving was somewhat like ours. Of course there are heavier differences, but still they were very modern for their times. Also I am in strong belief that we learned many things that are in our culture today from Ancient EgyptRead MoreEgypt And The Muslim Influence On Eating999 Words   |  4 Pages Egypt and the Muslim Influence on Eating Maquelin Santana Hudson County Community College  Abstract This paper explores the religion, history, and food culture of Egypt. It discusses the geographic setting and environment that affects the food availability and water supply for the Muslims. The distinct eating and dietary habits are explained and how they have evolved into modern society. Also, Egypt’s national food is listed along with the history behind it. Lastly, the paper explores

Vlsi design and embedded systems - Free Essay Example

Sample details Pages: 21 Words: 6255 Downloads: 4 Date added: 2017/06/26 Category Statistics Essay Did you like this example? CHAPTER 1 INTRODUCTION 1.1 Motivation Phase locked loop (PLL) [1-3] is the heart of the many modern electronics as well as communication system. Recently plenty of the researches have conducted on the design of phase locked loop (PLL) circuit and still research is going on this topic. Most of the researches have conducted to realize a higher lock range PLL with lesser lock time [4] and have tolerable phase noise. Don’t waste time! Our writers will create an original "Vlsi design and embedded systems" essay for you Create order The most versatile application of the phase locked loops (PLL) is for clock generation and clock recovery in microprocessor, networking, communication systems, and frequency synthesizers. Phase locked-loops (PLLs) are commonly used to generate well-timed on-chip clocks in high-performance digital systems. Modern wireless communication systems employ Phase Locked Loop (PLL) mainly for synchronization, clock synthesis, skew and jitter reduction [5]. Phase locked loops find wide application in several modern applications mostly in advance communication and instrumentation systems. PLL being a mixed signal circuit involves design challenge at high frequency. Since its inspection in early 1930s, where it was used in the synchronization of the horizontal and vertical scans of television, it has come to an advanced form of integrated circuit (IC). Today found uses in many other applications. The first PLL ICs were available around 1965; it was built using purely analog component. Recent advances in integrated circuit design techniques have led to the development of high performance PLL which has become more economical and reliable. Now a whole PLL circuit can be integrated as a part of a larger circuit on a single chip. There are mainly five blocks in a PLL. These are phase frequency detector (PFD), charge pump (CP), low pass loop filter (LPF), voltage controlled oscillator (VCO) and frequency divider. Presently almost all communication and electronics devices operate at a higher frequency, so for that purpose we need a faster locking PLL. So there are a lot of challenges in designing the mentioned different blocks of the PLL to operate at a higher frequency. And these challenges motivated me towards this research topic. In this work mainly the faster locking of the PLL is concentrated by properly choosing the circuit architectures and parameters. The optimization of the VCO circuit is also carried out in this work to get a better frequency precision. 1.2 Organization of Thesis Before going into the details of the PLL, the motivation behind this work is mentioned in the Chapter 1 of the thesis. Chapter 2 briefly describes the whole PLL system. An introduction to the PLL circuit is mentioned in the section 2.1. Section 2.2 contains the detail architecture of the whole PLL system. Different types of PLLs are mentioned in the section 2.3. Section 2.4 explains the basic terms used in the PLL system while the consecutive sections give the details about the noise and application of the PLL. Chapter 3 builds the concepts of optimization. Definition of optimization technique and different circuit optimization techniques are presented in section 3.1 and 3.2 respectively. Section 3.3 gives the brief outline of the concept of geometric programming and convex optimization. The optimization of the CSVCO circuit is explained in section 3.4. The design and synthesis of the PLL is described in Chapter 4. The different design environments used in this work is mentioned in the section 4.1. The adopted design procedure is explained in section 4.2. Section 4.3 gives the design specifications and parameters of the work. The simulation results of the different circuits used in the PLL are depicted in the different sections of the Chapter 5. The performance of the CSVCO designed using convex optimization is compared with that of the traditional method in section 5.3. Section 5.5 gives the different simulation results of the PLL and its performance comparison between schematic and post layout level. At last Chapter 6 provides the conclusion that inferred from the work. CHAPTER 2 PHASE LOCKED LOOP 2.1 Introduction A PLL is a closed-loop feedback system that sets fixed phase relationship between its output clock phase and the phase of a reference clock. A PLL is capable of tracking the phase changes that falls in this bandwidth of the PLL. A PLL also multiplies a low-frequency reference clock CKref to produce a high-frequency clock CKout this is known as clock synthesis. A PLL has a negative feedback control system circuit. The main objective of a PLL is to generate a signal in which the phase is the same as the phase of a reference signal. This is achieved after many iterations of comparison of the reference and feedback signals. In this lock mode the phase of the reference and feedback signal is zero. After this, the PLL continues to compare the two signals but since they are in lock mode, the PLL output is constant. The basic block diagram of the PLL is shown in the Figure 2.1. In general a PLL consists of five main blocks: Phase Detector or Phase Frequency Detector (PD or PFD) Charge Pump (CP) Low Pass Filter (LPF) Voltage Controlled Oscillator (VCO) Divide by N Counter The Phase frequency Detector (PFD) is one of the main parts in PLL circuits. It compares the phase and frequency difference between the reference clock and the feedback clock. Depending upon the phase and frequency deviation, it generates two output signals UP and DOWN. The Charge Pump (CP) circuit is used in the PLL to combine both the outputs of the PFD and give a single output. The output of the CP circuit is fed to a Low Pass Filter (LPF) to generate a DC control voltage. The phase and frequency of the Voltage Controlled Oscillator (VCO) output depends on the generated DC control voltage. If the PFD generates an UP signal, the error voltage at the output of LPF increases which in turn increase the VCO output signal frequency. On the contrary, if a DOWN signal is generated, the VCO output signal frequency decreases. The output of the VCO is then fed back to the PFD in order to recalculate the phase difference, and then we can create closed loop frequency control system. 2.2 PLL Architecture The architecture of a charge-pump PLL is shown in Figure 2.2. A PLL comprises of several components. They are (1) phase or phase frequency detector, (2) charge pump, (3) loop filter, (4) voltage-controlled oscillator, and (5) frequency divider. The functioning of each block is briefly explained below. 2.2.1 PhaseFrequency Detector The Phase frequency Detector (PFD) is one of the main part in PLL circuits. It compares the phase and frequency difference between the reference clock and the feedback clock. Depending upon the phase and frequency deviation, it generates two output signals UP and DOWN. Figure 2.3 shows a traditional PFD circuit. If there is a phase difference between the two signals, it will generate UP or DOWN synchronized signals. When the reference clock rising edge leads the feedback input clock rising edge UP signal goes high while keeping DOWN signal low. On the other hand if the feedback input clock rising edge leads the reference clock rising edge DOWN signal goes high and UP signal goes low. Fast phase and frequency acquisition PFDs [6-7] are generally preferred over traditional PFD. 2.2.2ChargePump and Loop Filter Charge pump circuit is an important block of the whole PLL system. It converts the phase or frequency difference information into a voltage, used to tune the VCO. Charge pump circuit is used to combine both the outputs of the PFD and give a single output which is fed to the input of the filter. Charge pump circuit gives a constant current of value IPDI which should be insensitive to the supply voltage variation [8]. The amplitude of the current always remains same but the polarity changes which depend on the value of the UP and DOWN signal. The schematic diagram of the charge pump circuit with loop filter is shown in the Figure 2.4. When the UP signal goes high M2 transistor turns ON while M1 is OFF and the output current is IPDI with a positive polarity. When the down signal becomes high M1 transistor turns ON while M2 is OFF and the output current is IPDI with a negative polarity. The charge pump output current [3] is given by IPDI=IPUMPIPUMP4 =2IPUMP4 =IPUMP2 =KPDI (1) Where KPDI=IPUMP2 (amps/radian) (2) The passive low pass loop filter is used to convert back the charge pump current into the voltage. The filter should be as compact as possible [9].The output voltage of the loop filter controls the oscillation frequency of the VCO. The loop filter voltage will increase if Fref rising edge leads Fin rising edge and will decrease if Fin rising edge leads Fref rising edge. If the PLL is in locked state it maintains a constant value. The VCO input voltage is given by Vinvco = KF IPDI (3) Where KF is the gain of the loop filter. 2.2.3Voltage ControlledOscillator An oscillator is an autonomous system which generates a periodic output without any input. The most popular type of the VCO circuit is the current starved voltage controlled oscillator (CSVCO). Here the number of inverter stages is fixed with 5. The simplified view of a single stage current starved oscillator is shown in the Figure 2.5. Transistors M2 and M3 operate as an inverter while M1 and M4 operate as current sources. The current sources, Ml and M4, limit the current available to the inverter, M2 and M3; in other words, the inverter is starved for current. The desired center frequency of the designed circuit is 1GHz with a supply of 1.8V. The CSVCO is designed both in usual manner as mentioned in [3], [10, 11]. The general circuit diagram of the current starved voltage controlled oscillator is shown in the Figure 2.6. To determine the design equations for the CSVCO, consider the simplified view of VCO in Figure 2.5. The total capacitance on the drains of M2 and M3 is given by Ctot=52Cox(LpWp+LnWn) (4) The time it takes to charge Ctot from zero to VSP with the constant current ID4 is given by t1=VSPID4Ctot (5) While the time it takes to discharge Ctot from VDD to VSP is given by t1=VDD-VSPID1Ctot (6) If we set ID4= ID1=ID then the sum of t1 and t2 is given by t1+t2=VDDIDCtot (7) The oscillation frequency of CSVCO for N number of stage is fosc=1Nt1+t2=IDNCtotVDD (8) This is equal to fcenter when Vinvco=VDD2 (9) The gain of the VCO is given by KVCO=fmax-fminVmax-Vmin HzV (10) 2.2.4 FrequencyDivider The output of the VCO is fed back to the input of PFD through the frequency divider circuit. The frequency divider in the PLL circuit forms a closed loop. It scales down the frequency of the VCO output signal. A simple D flip flop (DFF) acts as a frequency divider circuit. The schematic of a simple DFF based divide by 2 frequency divider circuit is shown in the Figure 2.7. 2.3 Types of PLL There are mainly 4 types of PLL are available. They are . Liner PLL Digital PLL All Digital PLL Soft PLL 2.4 Terms in PLL 2.4.1 Lock in Range Once the PLL is in lock state what is the range of frequencies for which it can keep itself locked is called as lock in range. This is also called as tracking range or holding range. 2.4.2 Capture Range When the PLL is initially not in lock, what frequency range can make PLL lock is called as capture range. This is also known as acquisition range. This is directly proportional to the LPF bandwidth. Reduction in the loop filter bandwidth thus improves the rejection of the out of band signals, but at the same time the capture range decreases, pull in time becomes larger and phase margin becomes poor. 2.4.3 Pull in Time The total time taken by the PLL to capture the signal (or to establish the lock) is called as Pull in Time of PLL. It is also called as Acquisition Time of PLL. 2.4.4 Bandwidth of PLL Bandwidth is the frequency at which the PLL begins to lose the lock with reference. 2.5 Noises in PLL The output of the practical system deviates from the desired response. This is because of the imperfections and noises in the system. The supply noise also affects the output noise of the PLL system [12]. There are mainly 4 types of noises. They are explained below. 2.5.1 Phase Noise The phase fluctuation due to the random frequency variation of a signal is called as phase noise. This is mostly affected by oscillators frequency stability. The main sources of the phase noise in PLL are oscillator noise [12-15], PFD and frequency divider circuit. The main components of the phase noise are thermal and flicker noise. 2.5.2 Jitter A jitter is the short term-term variations of a signal with respect to its ideal position in time [16-19]. This problem negatively impacts the data transmission quality. Jitter and phase noise are closely related and can be computed one from another [18]. Deviation from the ideal position can occur on either leading edge or trailing edge of signal. Jitter may be induced and coupled onto a clock signal from several different sources and is not uniform over all frequencies. Excessive jitter can increase bit error rate (BER) of communication signal [19]. In digital system Jitter leads to violation in time margins, causing circuits to behave improperly. 2.5.3 Spur Non-desired frequency content not related to the frequency of oscillation and its harmonics is called as Spur. There are mainly two types of spur. They are reference spur and fractional spur. Reference spur comes into picture in an integer PLL while fractional spur plays a major role in fractional PLL. When the PLL is in lock state the phase and frequency inputs to the PFD are essentially equal. There should not be any error output from the PFD. Since this can create problem, so the PFD is designed such that, in the locked state the current pulses from the CP will have a very narrow width as shown in the Figure 2.9. Because of this the input control voltage of the VCO is modulated by the reference signal and thus produces Reference Spur [20]. 2.5.4 Charge Pump Leakage Current When the CP output from the synthesizer is programmed to the high impedance state, in practice there should not be any current flow. But in practical some leakage current flows in the circuit and this is known as charge pump leakage current [20]. 2.6 Applications of PLL The demand of the PLL circuit increases day by day because of its wide application in the area of electronics, communication and instrumentation. The recent applications of the PLL circuits are in memories, microprocessors, hard disk drive electronics, RF and wireless transceivers, clock recovery circuits on microcontroller boards and optical fiber receivers. Some of the PLL applications are mentioned below. 1.FrequencySynthesis A frequency synthesizer is an electronic system for generating a range of frequencies from a single fixed time base or oscillator. 2.Clock Generation Many electronic systems include processors of various sorts that operate at hundreds of megahertz. Typically, the clocks supplied to these processors come from clock generator PLLs, which multiply a lower-frequency reference clock (usually 50 or 100 MHz) up to the operating frequency of the processor. The multiplication factor can be quite large in cases where the operating frequency is multiple GHz and the reference crystal is just tens or hundreds of megahertz. 3.Carrier Recovery (Clock Recovery) Some data streams, especially high-speed serial data streams (such as the raw stream of data from the magnetic head of a disk drive), are sent without an accompanying clock. The receiver generates a clock from an approximate frequency reference, and then phase-aligns to the transitions in the data stream with a PLL. This process is referred to as clock recovery. 4. SkewReduction This is one of the very popular and earliest uses of PLL. Suppose synchronous pair of data and clock lines enter a large digital chip. Since clock typically drives a large number of transistors and logic interconnects, it is first applied to large buffer. Thus, the clock distributed on chip may suffer from substantial skew with respect to data. This is an undesirable effect which reduces the timing budget for on-chip operations. 5. Jitterand Noise Reduction One desirable property of all PLLs is that the reference and feedback clock edges be brought into very close alignment. The average difference in time between the phases of the two signals when the PLL has achieved lock is called the static phase offset. The variance between these phases is called tracking jitter. Ideally, the static phase offset should be zero, and the tracking jitter should be as low as possible. CHAPTER 3 CONVEX OPTIMIZATION OF VCO IN PLL 3.1 What is an optimization technique? Optimization technique is nothing but the finding of the action that optimizes i.e. minimizes or maximizes the result of the objective function. Optimization technique is applied to the circuits aiming at finding out the optimized circuit design parameter to achieve either the best performance or the desired performance. Optimization techniques are a set of most powerful tools that are used in efficiently handling the design resources and there by achieve the best result. Mainly optimization techniques are applied to the circuit for the selection of the component values, devices sizes, and value of the voltage or current source. 3.2 Types of circuit optimization method There are mainly four types of circuit optimization methods exist. They are Classical optimization Knowledge based optimization Global optimization method Convex optimization and geometric programming 3.2.1 Classical Optimization Methods: In case of analog circuit CAD, classical optimization methods [21], such as steepest descent, sequential quadratic programming, and Lagrange multiplier methods are mainly used. These methods are used with more complicated circuit models, including even full SPICE simulations in each iteration. This method can handle a wide variety of problem. For this there is a need of a set of performance measures and computation of one or more derivatives. The main disadvantage of the classical optimization methods is that the global optimal solution is not possible. This method fails to find a feasible design even one exist. This method gives only the local minima instead of global solution. Since many different initial designs are considered to get the global optimization, the method becomes slower. Because of the human intervention (to give good initial designs), the method becomes less automated. The classical methods become slow if complex models are used. 3.2.2 Knowledge-Based Methods: Knowledge-based and expert-systems methods such as genetic algorithm or evolution systems, systems based on Fuzzy logic, and heuristics-based systems have also been widely used in analog circuit CAD [21]. In case of knowledge based methods, there are few limitations on the types of problems, specifications, and performance measures that are to be considered. These methods do not require the computation of the derivatives. This is not possible to find a global optimal design solution using these methods. The final design is decided on the basis of the initial design chosen and the algorithm parameters. The disadvantage of the knowledge based methods is that they simply fail to find a feasible solution even when one may exist. There is a need of human intervention during the design and the training process. 3.2.3 Global Optimization Methods: Global optimization methods such as branch and bound and simulated annealing are also used in analog circuit design [21]. These methods are guaranteed to find the global optimal design solution. The global optimal design is determined by the branch and bound methods unambiguously. In each iteration, a suboptimal feasible design and also a lower bound on the achievable performance is maintained by this method. This enables the algorithm to terminate non-heuristically, i.e., with complete confidence that the global design has been found within a given tolerance. The branch and bound method is extremely slow, with computation growing exponentially with problem size. The trapping in a locally optimal design can be avoided by using simulated annealing (SA). This method can compute the global optimal solution but not guaranteed. Since there is no real-time lower bound is available, so termination is heuristic. This method can also handle a wide variety of performance indices and objects. T he main advantage of SA is that it handles the continuous variables and discrete variables problems efficiently and reduces the chances of getting a non-globally optimal design. The only problem with this method is that it is very slow and can not guarantee a global optimal solution. 3.2.4 Convex Optimization and Geometric Programming Methods: Geometric programming methods are special optimization problems in which the objective and constraint functions are all convex [22-24]. Convex optimization technique can solve the problems having a large number of variables and constraints very efficiently [22]. The main advantage of this method for which people generally adopt is that the method gives the global solution. Infeasibility is unambiguously detected. Since a lower bound on the achievable performance is given, so the method uses a completely non- heuristic stopping criterion. 3.3 Geometric programming and convex optimization Geometric programming is a special type of optimization technique in which all the objective must be convex. Before applying this technique it has to confirm that whether the given problem is convex optimization problem or not. Convex optimization problem means the problem of minimizing a convex function subject to convex inequality constraints and linear equality constraints. In IC integration convex optimization and geometric programming has become a more efficient computational tool for optimization purpose. This method has an ability to handle thousands of variables and constraints and solve efficiently. The main advantage of convex optimization technique is that it gives the global optimized value and the robust design. The fact that geometric programs can be solved very efficiently has a number of practical consequences. For example, the method can be used to simultaneously optimize the design of a large number of circuits in a single large mixed-mode integrated circuit. The de signs of the individual circuits are coupled by constraints on total power and area, and by various parameters that affect the circuit coupling such as input capacitance, output resistance, etc. Convex optimization is used to find out the optimized value of these parameter and sizing of the devices in the circuit [25]. Another application is to use the efficiency to obtain robust designs i.e., designs that are guaranteed to meet a set of specifications over a variety of processes or technology parameter values. This is done by simply replicating the specifications with a (possibly large) number of representative process parameters, which is practical only because geometric programs with thousands of constraints are readily solved. A real valued function fx defined on an interval (space) is called convex if ftx1+1-tx2tfx1+1-tfx2 (11) For every t,0t1 and x1x2 In the Figure 3.1 function fx is represented as a convex function on an interval. The convex optimization problem is in the form of minimize f0x Subjected to fix1 , i=1, 2, 3, m gix=1 , i=1, 2, 3, p xi1 , i=1, 2, 3, n Where fix is a posynomial function gix is a monomial function Let x1,x2xn be n real positive variables. We can denote the vector (xi,xi.xi) of these variables asx. A function f is called a posynomial function of x if it has the form fix1,x2xn=k=1tCkx11kx22k..xnnk (12) Where Cj0 and ij R. The coefficients Cj must be nonnegative but the exponents ij can be any real numbers including negative or fractional. When there is exactly one nonzero term in the sum i.e. t=1 and C10, we call f is a monomial function. 3.3.1 Advantages: Handle thousands of variables and constraints and solve efficiently. Global optimization can be obtained. 3.3.2 Disadvantages: * Strictly limited to types of problems, performance specification and objectives that can be handled. 3.4 Optimization of the VCO circuit In my earlier design of the VCO circuit, the sizes of all the five inverter stages are same. Now the convex optimization technique is applied to find out the optimal scaling ratio of the different inverter stages to get the optimal design with a better performance. There are 5 inverter stages and the design has to give a delay of 100ps. The load capacitance of the VCO circuit is 65 fF. All these design constraints are formulated and applied to the convex optimization technique. Mainly optimization techniques are applied for selection of component values and transistor sizing. In this work I have used the geometric programming technique to find out the optimized scaling ratio of the different stages in CSVCO to meet the desired center frequency with lesser deviation. Let xi is the scaling ration of the ith stage, CL is the load capacitance, and D is the total delay of the inverter stages then optimization problem is in the form of Minimize sum (xi) Subjected to CLCLmax DDmax Where CLmax and Dmax are required design parameters and has a constant value. CHAPTER 4 DESIGN AND SYNTHESIS OF PLL 4.1 Design Environment The schematic level design entry of the circuits is carried out in the CADENCE Virtuoso Analog Design Environment. The layout of the PLL is designed in Virtuoso XL using GPDK090 library. In order to analyze the performances, these circuits are simulated in the Spectre simulator of CADENCE tool. Different performance indices such as phase noise, power consumption and lock time are measured in this environment. Transient, parametric sweep and phase noise analyses are carried out in this work to find out the performances of the circuit. The optimization of the current starved VCO circuit, the scale factor for transistor sizing is found out using the MATLAB environment. 4.2 Design Procedure 4.2.1 VCO Design Since VCO is the heart of the whole PLL system, it should be designed in a proper manner. The design steps for the current starved VCO are as follows. Step 1 Find the value of the propagation delay for each stage of the inverter in the VCO circuit using the following equation. p=1Nf (13) Where p= phl= plh= half of the propagation delay time of the inverter N= no of inverter stages f= required center frequency of oscillation Step 2 Find the WL ratio for the transistors in the different inverter stages using the equation in below. WL n=CloadphlnCoxVdd-VT,n2VT,nVdd-VT,n+ln4Vdd-VT,nVdd-1 (14) WL p=CloadplhpCoxVdd-VT,p2VT,pVdd-VT,p+ln4Vdd-VT,pVdd-1 (15) Step 3 After finding the WL ratio, find the values for W and L. Step 4 Find the value of the total capacitance form the expression Ctot=52Cox(LpWp+LnWn) (16) Where Cox is the oxide capacitance Lp,Wp,Ln,Wn is the width and length of the PMOS and NMOS transistors in the inverter stages. Step 5 Calculate the value of drain current for the center frequency which is given by IDcenter=NCtotVddf (17) Step 6 Find the WL ratio for the current starving transistors in the circuit from the drain current expression which is represented as WL n=2IDcenternCoxVgs-VT,n2 (18) Similarly WL p=2.5WL n (19) 4.2.2 Design of Phase Locked Loop The value of the charge pump current and the component parameters of the loop filter play a major role in the design of the phase locked loop circuit. The value of the lock time mainly depends upon these parameters. So while designing the circuit proper care should be taken in calculating these parameters. For the given values of reference(Fref) and output frequency(Fout) as well as the lock in range, the following steps to be carried out in designing the filter circuit. Step 1 Find the value of the divider circuit to be used which is given by n=FoutFref (20) Step 2 Find the value of the natural frequency (n) from the lock in range as given below lock in range=2n (21) Step 3 Find the value of the charge pump gain (KPDI) from the charge pump current used in the circuit which is given by KPDI=Ipump2 (Amps/radian) (22) Step 4 Find the value of the gain of the VCO (Kvco) circuit from the characteristics curve using the following expression. Kvco=fmax-fminVmax-Vmin (Hz/V) (23) Step 5 Find the values of the loop filter component parameters using the following expressions. C1=KPDIKvcoNn2 (24) C2=C110 (25) R=2nC1 (26) 4.3 Design Specifications and Parameters 4.3.1 VCO Design Specification The current starved VCO design specifications are mentioned in the following table. Parameter Value Center frequency 1GHz No. of inverter stage 5 Inverter delay 100ps Load capacitance 65fF Supply voltage 1.8V Table 1 VCO design specifications 4.3.2 VCO Design Parameters Parameter Value Width of Current starved PMOS(WPCS) 2.33m Width of Current Starved NMOS(WnCS) 140nm Width of PMOS in Inverter(WP) 2.44m Width of NMOS in Inverter(Wn) 150nm LPCS = LnCS = LP = Ln = L 100nm Table 2 List of design parameters of the CSVCO circuit 4.3.3 PLL Design Parameters The whole PLL system design specifications and parameters are shown in the Table 3. Parameter Value Reference frequency((Fref) 500 MHz output frequency(Fout) 1 GHz Lock in range 100 MHz Supply voltage 1.8 V Divider circuit By 2 Charge pump current(Ipump) 600 A Capacitor (C1) 15 pF Capacitor (C2) 1.5 pF Resistor (R) 1.384 K Table 3 PLL design specifications and parameters CHAPTER 5 SIMULATION RESULT AND DISCUSSION 5.1 Phase Frequency Detector The Pass Transistor DFF PFD circuit is shown in Figure 5.1. The PFD is same as to a dynamic two-phase master-slave pass-transistor flip-flop. The clock skew is minimized by using single edge clocks. In this design synchronous reset is used for master while asynchronous reset is used for slave. i.e., the reset is allowed only when the slave latch is transparent. The operating range of the design is increased with the help of synchronous resetting and also the power consumption is reduced compared to the traditional PFD. If the master latch is reset while it is transparent, then there will be significant short-circuit current will produce, resulting in more power. The output of the PFD when Fref signal rising edge leads Fin signal rising edge and vice versa is shown in the Figure 5.2 and Figure 5.3 respectively. 5.2 Charge Pump and Loop Filter When the reference signal clock edge leads the feedback clock edge, the UP signal of the PFD goes high. So to make both the clock have rising edge at the same time the VCO output signal frequency has to be increased. For this purpose an increase in control voltage is needed from the output of charge pump and loop filter circuit. The simulation result which is shown in the Figure 5.4 below gives an increase in the control voltage at the output of the loop filter circuit. From the Figure 5.4 its clear that the control voltage increases for a period during which the UP signal of the PFD remains high. In the other case a decrease in the control voltage is produced at the output of the filter circuit which is shown in the Figure 5.5. When the rising of feedback signal leads the reference signal rising edge the control voltage decreases for the period during which the DOWN signal of the PFD remains high. 5.3 Voltage Controlled Oscillator 5.3.1 Result using traditional method The heart of the PLL circuit is the voltage controlled oscillator. The circuit is designed to give a center frequency of oscillation of 1 GHz. The frequency of oscillation of the output signal for the different input control voltage is mentioned in the Table 4. The center frequency of oscillation at an input control voltage of VDD/2 is 1.012 GHz. The output signal of the VCO at a control voltage of VDD/2 is shown in the Figure 5.6. Control Voltage (VC)(in volt) Frequency of Oscillation (f) (in MHz) 0.103 24.415 0.154 50.929 0.206 91.05 0.257 139.32 0.309 188.179 0.36 234.277 0.411 282.125 0.463 342.256 0.514 412.889 0.566 489.48 0.617 569.178 0.669 650.037 0.720 731.72 0.771 812.946 0.823 893.63 0.874 973.461 Control Voltage Frequency of Oscillation 0.926 1051.851 0.977 1128.02 1.03 1200.67 1.08 1271.818 1.13 1338.398 1.18 1401.32 1.23 1460.798 1.29 1517.121 1.34 1570.371 1.39 1620.798 1.44 1668.416 1.49 1713.913 1.54 1757.073 1.59 1798.081 1.65 1836.986 1.7 1873.865 1.75 1909.109 1.8 1943.021 Table 4 Oscillating frequency of the VCO output signal for different control voltage The VCO characteristics curve is shown in the Figure 5.7. The X-axis of the curve represents the input control voltage while the Y-axis represents the corresponding frequency of oscillation. The gain of the CSVCO circuit is 1.531 GHz/V. The phase noise of the VCO in the schematic level is found to be -82.87 dBc/Hz. The phase noise plot for schematic level is shown in the Figure 5.8. The layout of the 5 stage current starved VCO is shown in the Figure 5.9. The schematic and post layout level simulation results are compared in the Table 5. Parameter Schematic Result Post-Layout Result Frequency(f) 1.012 GHz 1.00256 GHz Frequency Deviation(f) 12 MHz 2.56 MHz Power(P) 432.456 W 480.63 W Phase Noise @1MHz offset -82.7 dBc/Hz -84.88 dBc/Hz Table 5 Comparison of schematic and post layout level simulation results 5.3.2 Result using convex optimization method Using convex optimization method the scaling ratio is found out to satisfy the center frequency of oscillation (i.e. delay of the circuit) from the MATLAB environment. The scaling ratio for different stages of the inverter in the VCO is 1,1,1,1 and 1.4058. The scaling ratio result is shown in the Figure 5.10. Now the transistor sizes are modified according to the scaling ratio. Since the scaling factor of all the stages are 1 except 5th stage, so the transistor sizing of the 5th stage has only changed to get the better frequency precision. The sizes of the transistors of CSVCO optimized using convex optimization technique are listed out in the Table 6. Before optimization the centre frequency of the oscillation is found out 1.012GHz. And after applying the convex optimization and geometric programming to this circuit, the centre frequency of oscillation is 1000.0457MHz. So the frequency deviation from its centre frequency is reduced to .00457% from 1.2%. The performance of CSVCO for both traditional and geometric programming is compared in the Table 7. The comparison of control voltage versus oscillating frequency characteristics of the CSVCO circuit is shown in the Figure 5.11. Stage Parameter value 1 WPCS WnCS WP Wn 2.33m 140nm 2.44m 150nm 2 WPCS WnCS WP Wn 2.33m 140nm 2.44m 150nm 3 WPCS WnCS WP Wn 2.33m 140nm 2.44m 150nm 4 WPCS WnCS WP Wn 2.33m 140nm 2.44m 150nm 5 WPCS WnCS WP Wn 3.28m 195nm 3.435m 215nm Table 6 Size of the transistors of CSVCO circuit after optimization Factor CSVCO using traditional method CSVCO using convex optimization method Frequency(f) 1.012GHz 1.0000457GHz Frequency Deviation(f) 12MHz 45.7KHz Power(P) 432.456W 539.65W Phase Noise @1MHz offset -82.7 dBc/Hz -82.6 dBc/Hz KVCO 1.531GHz/V 1.5926GHz/V Table 7 Performance comparison of CSVCO designed using traditional method and convex optimization 5.4 Frequency Divider The circuit diagram of a pass transistor based DFF frequency divider circuit is shown in the Figure 5.12. The circuit divides the frequency by a factor of 2. The simulation result of the divide by 2 circuits is shown in the Figure 5.13 5.5 Phase Locked Loop The output of the charge pump and loop filter circuit i.e. the control voltage will maintain a constant value when the references signal and feedback signal are in lock. The control voltage of PLL for the schematic level is shown in the Figure 5.14. From the Figure 5.14 its clear that the control maintains the constant value of 0.9 V at time 280.6 ns. So the lock time of PLL is 280.6 ns. The layout of the PLL is shown in the Figure 5.15. The most of the area of the PLL is consumed by the resistor and capacitor used in the filter network. Different signals like UP, DOWN, Control Voltage, reference signal and feedback input signal of the PLL in the lock state are shown in the Figure 5.16 and Figure 5.17 for schematic level and post layout level respectively. From the Figure 5.16 and 5.17 its clear that when the control voltage is constant, the reference signal and the feedback input signal are almost similar as their phase and frequency are approximately same. The phase noise analysis of the PLL is carried out both in the schematic as well as in the post layout level. The phase noise is found to be -86.21 dBc/Hz and -101.7 dBc/Hz in schematic and post layout level respectively. The phase noise variation of the PLL both in schematic and post layout level simulation are shown in the Figure 5.18 and 5.19 respectively. The performance comparison of the PLL both in schematic and post layout level simulation are mentioned in the Table 8. Parameter Result of Schematic Level Simulation Result of Post Layout Level Simulation Technology 90 nm 90 nm VDD 1.8 V 1.8 V Lock Time 280.6 ns 345.5 ns Frequency 1 GHz 1 GHz Maximum Power Consumption 11.9 mW 10.408 mW Phase Noise @ 1MHz offset -86.21 dBc/Hz -101.7 dBc/Hz Table 8 Performance comparison of PLL circuit CHAPTER 6 CONCLUSION AND FUTURE WORK In this work a PLL with a better lock time is presented. The lock time of the PLL is found to be 280.6 ns. The PLL circuit consumes a power of 11.9 mW from a 1.8 V D.C. supply The lock time of the PLL mainly depends upon the type of PFD architecture used and the parameters of the charge pump and loop filter. So by properly choosing the PFD architecture and adjusting the charge pump current and the loop filter component values a better lock time can be achieved. The centre frequency of oscillation of the VCO depends upon the sizing of the transistors. The frequency deviation from the desired value can be reduced by properly choosing the transistor sizes. By applying the convex optimization technique with frequency of oscillation as the main objective function, the deviation of oscillation frequency is minimized to 0.00457% from 1.2%. Here the convex technique to find out the transistor sizing to meet only the desired frequency specification. The other constraints like area, power and phase noise can also be applied.

Jekyll and Hyde Essay Introduction and Para 1 Free Essays

I am going to write an essay on Robert Louis Stevenson’s supernatural story, the strange case of Dr Jekyll and Mr Hyde, which was the inspiration for lots of modern movies showing dual nature of mankind e. g. The Hulk, Two Face and The Nutty Professor to name a few. We will write a custom essay sample on Jekyll and Hyde Essay Introduction and Para 1 or any similar topic only for you Order Now The story is told mostly in third person by Mr Utterson the lawyer, it is about the scientist Dr Jekyll and his â€Å"friend†, the hated Mr Hyde. Utterson suspects that Hyde may be bribing Jekyll when Jekyll changes his will to one where in the event of his death all his money and his house will be given to Hyde. However when Hyde disappears after brutally murdering the highly respected Sir Danvers Carew, Utterson is pleased, but when Jekyll starts acting weird and will not leave the confines of his cabinet Utterson becomes worried and after Jekyll becomes a recluse and starts making strange demands in a voice that is not his own, Jekyll’s butler and Utterson break down the doctor’s door to find Hyde lying dead on the floor from apparent suicide. The story is later explained in the novella through the testimony of Dr Lanyon, in which he reveals that he witnessed a transformation of Hyde to Jekyll and then explained in more detail by Jekyll. It turns out that Hyde was the result of one of Dr Jekyll’s experiments, where by drinking the ‘transforming draught’ he becomes the hated character who was the complete opposite of his usual self. Over time Jekyll found himself transforming without even drinking the potion, and when the drug ran out he became trapped as Hyde. Upon drinking the very last of the drug Jekyll writes, ‘I bring the life of that unhappy Henry Jekyll to an end’. I thought this book was very interesting and would recommend it to all. This novel is all about the dual nature of mankind. Stevenson believed that every person had a good and bad side to them. The book says a lot about Victorian society as they were all meant to be very good people but really lots of them were corrupt inside. The characters inside this novel show his theory about this very well. For example Jekyll is a well respected man, who was ‘born to a large fortune’ and ‘fond of respect of the wise and good among my fellow men†¦ with every guarantee of an honourable and distinguished future’. Like most people in Victorian society Dr Jekyll was obsessed with respect and he also had an evil side to him. He hated doing â€Å"evil† things such as gambling and drinking so much that he decided to make a potion to split his personality in two. When he first became Hyde, the evil side of his personality he felt ‘younger, lighter and happier in body’ which is because his evil side would not be as developed as his good side as he has done more good than evil in his life. He enjoyed being Hyde because he could do evil things without consequence or people finding out, or so he thought. He felt he did not need to feel guilty about the things he had done as they technically weren’t him. How to cite Jekyll and Hyde Essay Introduction and Para 1, Essays

Kurt Cobain (820 words) Essay Example For Students

Kurt Cobain (820 words) Essay Kurt CobainFor our modern day hero we used the singer and songwriter Kurt Cobain from the band Nirvana. This punk Seattle band moved almost mainstream almost overnight. Nirvana caught on fast and changed rock and roll music forever and molded the music of the 90s, alternative. Cobain had an enormous amount of talent but unfortunately his life was cut short by a still controversial suicide in his Seattle home. On April 9, 1994, his body was discovered. He is a hero for many of todays troubled youth because his music influences how these troubled kids feel. They are able relate to Cobain and his music. Kurt Cobain was born in 1967. He lived with his sister and parents two hundred miles away from Seattle in the small logging town of Aberdine. His aunt, who helped him form his first band, introduced him to music at a very young age. His parents divorced when Kurt was only seven years old. Torn up by his parents divorce, he went to live with his mother in a trailer. After the divorce, Kur t was forced to look at his life in a different light. Kurt became extremely anti-social, had few friends, and was picked on in school because kids thought he was gay or weird. Kurt started writing poetry at the age of thirteen, and when he was 14, he received his first guitar. Throughout high school he was in many bands- Fecal Matter, Skid Row, Brown Cow, The Sellouts and Pencap Chew. He formed Nirvana during his senior year of high school with his friends Chris Novoselic and Dave Grohl who Kurt called ?the worlds best drummer.? Shortly after the band was formed, Kurt dropped out of high school, and his mother kicked him out of the house. Homeless, he lived under a bridge at the end of his street. It was here that he would spend time alone writing his own songs. From his parents divorce to his mother pushing him out of the house, Kurt had become even more alienated from other people and life. He was very detached. Kurt hated the music of big rock bands like the Sex Pistols, Rolling Stones and Aerosmith. He felt their lyrics were sexist and pointless with no meaning. Kurt was a very sensitive and emotional person, a characteristic that showed through all of his songs. Eventually he became so famous that he a cult following. The songs exemplified the kids world. In the song ?Dumb? Kurt sings, ?I think Im dumb? over and over again to show how his years of neglect from his peers at high school and his family made him feel as if he was to blame. Kids relate to his music because it portrays how the world was so cruel and how he and the kids were treated badly. He was responsible for the most creative rock music of the last decade. Kurt didnt have to hide behind face paint or wear tight clothes to grab attention as the other rock stars. He wore fla nnels and jeans, something that every other kid wore, and he wasnt ashamed by it. In one song ?Come As You Are? Kurt sings ?Come as you are as I want you to be.? He wanted to show the youth that they dont have to follow the crowd and do something someone else wants them to do to fit in. Every modern alternative song has a tint of ?Nirvanaism? in it. Just like bands that followed the Beatles, many groups that followed Cobain tried to sound or copy his same music pattern. In his music he didnt communicate in complete sentences or elaborate arguments. Instead his lyrics were a stream of conscious insights that inspired and appealed to the short attention span of his audience. We picked Kurt Cobain as a hero because he is different than the conventional hero who just goes out and saves lives. Kurt was an emotional leader for the troubled youth, and he gave them a place to escape from a life that was hard to live. His music gave them a hideaway from the harsh realities of the real world. All they had to do was listen, and they felt instant relief because they knew that not only they felt the way they did. They could relate to Kurt and his fragile emotions. In the song ?Rape Me? Kurt sings; ?Rape me, my friend. Rape me again. Im not the only one. Hate me. Do it and do it again. Waste me. Taste me, my friend. My favorite inside source, Ill kiss your open sores. Appreciate your concern. Youll always stink and burn.? This shows how he believed society took advantage of him because he was weak and emotional. These kids relate to Kurt. Kurt once said that he would rather be in pain than fame. His words and music make him a modern day hero. .ua8f7a3d3d91ff22d487105490d1dc276 , .ua8f7a3d3d91ff22d487105490d1dc276 .postImageUrl , .ua8f7a3d3d91ff22d487105490d1dc276 .centered-text-area { min-height: 80px; position: relative; } .ua8f7a3d3d91ff22d487105490d1dc276 , .ua8f7a3d3d91ff22d487105490d1dc276:hover , .ua8f7a3d3d91ff22d487105490d1dc276:visited , .ua8f7a3d3d91ff22d487105490d1dc276:active { border:0!important; } .ua8f7a3d3d91ff22d487105490d1dc276 .clearfix:after { content: ""; display: table; clear: both; } .ua8f7a3d3d91ff22d487105490d1dc276 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .ua8f7a3d3d91ff22d487105490d1dc276:active , .ua8f7a3d3d91ff22d487105490d1dc276:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .ua8f7a3d3d91ff22d487105490d1dc276 .centered-text-area { width: 100%; position: relative ; } .ua8f7a3d3d91ff22d487105490d1dc276 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .ua8f7a3d3d91ff22d487105490d1dc276 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .ua8f7a3d3d91ff22d487105490d1dc276 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .ua8f7a3d3d91ff22d487105490d1dc276:hover .ctaButton { background-color: #34495E!important; } .ua8f7a3d3d91ff22d487105490d1dc276 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .ua8f7a3d3d91ff22d487105490d1dc276 .ua8f7a3d3d91ff22d487105490d1dc276-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .ua8f7a3d3d91ff22d487105490d1dc276:after { content: ""; display: block; clear: both; } READ: Reflection on Mentorships EssayMusic Essays

Langston Hughes Essays (488 words) - Jazz Poetry, Harlem Renaissance

Langston Hughes Doorknobs Langston Hughes is considered by many readers to be the most significant black poet of the twentieth century. Except for a few examples, all his poems are about social injustice in America. The somber tone of his writing often reflected his mood. Race relations were present in almost his whole career, following him from his first poem to his last. The poem Doorknobs was written in 1961 after his subpoena to appear before Senator McCarthy for subversive activities. Although many other poems by Hughes deal with prejudice, race, or politics, Doorknobs deals with life itself. Hughes anger over the political attacks are seen on many of his poems. Hughes Doorknob describes a child who seems to be afraid of life and afraid of the adults in his life By the end of the poem this child is now an adult himself who appears to be insecure, and perhaps, afraid of life itself. This man portrays a sad, non-confident, scared life as we can see on the lines 1 to 3. We experience first hand the lack of control, the terrorizing feelings this door holds for this child: The simple silly terror of a doorknob on a door that turns to let in life From lines 4 to 10, we can assume that we are reading of a child who is terrorized of the grownups that live with him; perhaps he is an abused child: on two feet standing, walking, talking, wearing dress or trousers, maybe drunk or maybe sober, maybe smiling, laughing, happy, maybe tangled in the terror of a yesterday past grandpa Lines 11 to 15 reinforce the terror this child is feeling and carrying with him. It is apparent that the child is experiencing some kind of abuse, either mental or physical: when the door from out there opened into here where I, antenna, recipient of your coming, received the talking image of the simple silly terror From lines 16-25 Hughes repeats the first stanza of the poem with minor changes to the order of t the words; this perhaps is now when the child is now remembering his past. Another interpretation is that when the child became a grownup instead of being afraid of the adults in his life, he is afraid now of life itself, and death. of a door that opens at the turning of a knob to let in life walking, talking, standing wearing dress or trousers, drunk or maybe sober, smiling, laughing, happy, or tangled in the terror of a yesterday past grandpa not of our own doing. Doorknobs is a sad poem; the poem deals with the struggle and search for identity, and a struggle of the individual vs. the Universe. The mood is fear, and perhaps terror of his surroundings. At the end, we are left with the feeling that the child went on living his life in terror and afraid of everything that surrounded him even after becoming an adult.

My Professional Career Goals Essay Example

My Professional Career Goals Essay Example My Professional Career Goals Essay My Professional Career Goals Essay I am determined to work in a Career field that will offer me the opportunity to do something that I enjoy doing as a job. My objective career goal is to work as a medical officer in the United States Army, specifically a Licensed Clinical Social Worker (LCSW). I have thoroughly considered the skills that I presently have and the abilities that I need to either change or perfect. I been embarking on more educational avenues since I have being in the army to get close to this career goal. The ultimate goal I set out for myself was to get accepted in the United State Army Masters of Social Work Program.The program is one that helps determined individuals work on acquiring their Masters Degree in Social Work Services and become officers in the United Army. As I am already in the field of psychology I though a special interest in the Social Work Services and have come to enjoy working in this department. My professional career goal is to get the schooling through the Army because it is al l paid for. Finish my obligation and try to retire from the Army after 20 years of service. I know once I complete my service, I can always work for the federal employee for the Army.Also one may ask the question, but why social work services? I have always been interested in working in the medical field because I am good understanding people and can be a good listener and also because it is a respected profession. I have spent time in many different types of jobs in my short time in the Army but one of the fields I enjoyed the most The Department of Social Work Services. It has become a commonly acceptable practice that we use different methods of learning to obtain information. Information technology allows us to easily identify with the various aspects and methods of social learning.The Web has also made it so easy to collaborate with other student in the process of learning and training. In pursuit of my short term goal which is to attain a Bachelor’s degree in Clinical P sychology, I have taken a few online courses to include this class and it is amazing how much information and insight I have been able to obtain from other students from the online environment. I was also able to obtain an undergraduate certificate in Terrorism and Homeland Security by online education. I am getting closer and closer to finishing my Bachelor’s Degree in Psychology.Online Education has made my dream meeting all the requirements of the Masters Program possible. The ability to share information with others in a participatory manner has allowed me to see and learn from my peers. The online method of learning brings synergy to the table and can also be very effective within the professional arena. I can’t emphasis enough how I’m able to learn from others in the comfort of my own living room or office. In the world of web learning, I’m able to keep up with current information concerning my career options as well as keep up with advancing techno logies within my career.According to the Bureau of Labor Statistics the Employment of healthcare social workers is expected to grow by 34 percent, much faster than the average for all occupations in the United States. As baby boomers age, they and their families will require help from social workers to find care, which will increase demand for healthcare social workers. The average full-time medical social worker earned $50,500 per year as of 2011, according to the U. S. Bureau of Labor Statistics, but wages varied over a wide range with those workers that holds a masters degree in any subject averaged approximately $12,000 more in annual income.Career progression in this field is very rapid because of the constant need and demand for Licensed Clinical Social Workers. I do know that I will have to improve on any skills that could help in making me more sought after; for example a manager could be one that has knowledge, skills and interests in many areas but has no real specialty. T hen there is the professional manager who will conform to the skills, competence and/or character which is expected of a properly qualified/experienced person. I also know I have work to do and things to learn as well as ideas to offer.I see another thing I will need to do and that is to place more emphasis on my writing skills and hopefully I can better myself within the next two years. I know that I still have a way to go in order to reach my goal; but I can withstand all I will need to in order to make dreams come true. With the above plan of completing my Bachelor’s Degree and Master’s Degree, I can be that ultimate military social worker.Cited Sources Eliminating Mental Health Disparities tmhguide. org Health Careers Center is a division of Mississippi Hospital Association. (2002-2004). Health Care Administrator. ttp://www. mshealthcareers. com/careers/healthcareadmin. htm Individual Development Plan fsa. usda. gov/FSA/hrdapp? area=home;amp;subject=trai;amp;topi c=idp Landis, S. (2002). Career Goals. Mountain Area Health Education Center. http://depts. washington. edu/ccph/pdf_files/Landis%20%20Career%20Goals. pdf Occupational outlook Handbook bls. gov/ooh/Community-and-Social-Service/Social-workers. htm#tab-5 Promoting Mental Health in the Web 2. 0 Era (updated version) by Instut Douglas slideshare. net/institutdouglas/promoting-mental-health-in-the-web-20-era-updated-version

Career Zone Interest Profiler Assignment Example | Topics and Well Written Essays - 250 words

Career Zone Interest Profiler - Assignment Example Managers, education programs or rather career related programs must never use the results as a screening process for training or jobs. Generally, from the Interest Profiler results I obtained, I can comment that most of the jobs I have an interest on have the code EC. This code often implies personalities who in most instances have an interest on Enterprising. In addition, it also implies people with a higher preference on Convectional environments. Furthermore, this code implies individuals who value independence a lot with inclusion of proper working conditions for their occupations (Career Zone California). Actually, a keen evaluation of my results provides various other codes such as the ERI, CES, and ESC among others. These codes relate a lot to the most common code (the EC) particularly with regards to having a greater value on independence. Further, my results portray that I have I great interest on managerial positions, for instance, Architectural and Engineering Managers, Loan Officers, Information Technology Project Managers, Morticians, Undertakers, and Funeral Directors, Supply Chain Managers, etc. This is particularly because of the fact that most of my job preferences have established that I have a greater Convectional interest and most of my preferences relate to Enterprising, Investigative, Social or Realistic environments (Career Zone California). Moreover, the results show that most of my interests are business oriented, particularly with regards to controlling, coordinating as well as the managing of business

Advertising through social media is mor affective than traditional Essay

Advertising through social media is mor affective than traditional form of advertising - Essay Example Due to huge competitive market scenario, it is pivotal for every organization to use more effective advertising strategy to influence the mind of viewers. Social media advertising is perfect medium for every organization to make customers fell valued. This essay will discuss about social media advertising which is more effective than traditional advertising. The emergence of social media has provided perfect platform for every individual all over the world to connect with each other via internet. It has become pivotal for every organization to connect with customers efficiently and swiftly (Lovett, 2011, p.18a). The application of social media in regard to advertising or linking with customers cannot be ignored (Lovett, 2011, p.18b). Customers are regarded as the crucial part for every organization to maintain its sustainability for forcible future (Hoverstadt, 2011, p.82). Every business is trying their utmost best to reach out to people with the help of social media and gain attention of new leads, service and feedback. Social media has become inevitable part of every user where they can share their views and opinions. The immense growth of this technology is solely due to the ability of producing contents, which are user-generated. Technology has changed the life of every people. In case of advertising and marketing of products, the utilization of social media has become as beneficiary factor for every organization (Li and Poser, 2008, p.95). The tool of social media is totally different from traditional marketing and advertising. The significant impact of social media sites on human beings is immense. This huge impact of social media sites cannot be replaced by any other form of communication tool (Rantanen, 2005, p.3a). This is basically due to the fact that there is gradual increase in number of user. Every organization wants to gain new clients and

Smart Systems And Smart Materials

Smart Systems And Smart Materials Science and technology has made amazing developments in the design of electronics and machinery by using standard materials, which did not have particularly special properties (i.e. steel, aluminum, gold etc). Imagine the range of possibilities, which exist for special type of materials that have properties scientists can manipulate. Some such materials has the ability to change shape or size or simply by adding a little bit of heat, or to change from a liquid to a solid almost instantly when it is near a magnet; these materials are called smart materials. Smart materials are the materials that have one or more properties that can be dramatically altered. Most everyday materials have physical properties, which cannot be significantly altered; for example if an oil is heated it shall become little thinner, whereas a smart material with variable viscosity may turn from a fluid which flows easily to a solid. A variety of smart materials already exists, and is being researched extensively. These includes piezoelectric materials, magneto-rheostatic materials, electro-rheostatic materials, and shape memory alloys. Some everyday items are already incorporating smart materials (coffeepots, cars, the International Space Station, eyeglasses) and the number of applications for them is growing rapidly. Each individual type of smart material has a different type of property which can be significantly altered, such as viscosity, volume, and conductivity. The property which can be altered influences what types of applications the smart material can be used for. Smart systems and smart materials Smart structures are the new emerging materials systems which combines contemporary materials science with information science. The smart system is composed of these:- sensing, processing, actuating, feedback, self-diagnosing and self-recovering subsystems. These system uses the functional properties of advanced materials to achieve high performances with the capabilities of recognition, discrimination, and adjustification in response to make change of its environment. Each component of this system must have functionality, and the entire system is integrated to perform a self-controlled smart action, similar to a living creature that can think, make judgment and take actions. A smart system can be considered as a design philosophy that emphasizes predictivity, adaptivity and repetivity. A smart system/structure is defined as a non-biological physical structure having the following attributes: (1) a definite purpose; (ii) means and imperative to achieve that purpose; and (iii) a biological pattern of functioning. Smart materials are the subset of the smart systems, i.e. smart structures at the microscopic or mesoscopic scales. Smart systems are the non-biological structures which means that the system functions as a biological system rather than the pattern of functioning as a Turning machine. These materials will generally include at least one structural element, some for means of sensing the environment and its own state, and some type of processing and adaptive control algorithm. Science and technology in the 21st century will have to rely heavily on the development of new materials that are expected to respond to the environmental changes and manifest their own functions according to the optimum conditions. The development of these materials will undoubtedly be an essential task in many fields of science and technology such as informatics science, micro-electronics, computer science, medical treatment, life science, energy, transportation, safety engineering and military technologies. Materials development in the future, therefore, should be directed toward creation of hyperfunctional materials which will surpass even biological organ in some aspects. The present materials research is to develop various pathways that will lead the modern technology towards the smart sy stems. Types of Smart Materials Piezoelectric materials:- Piezoelectric materials have two unique properties that are interrelated. When a piezoelectric material is deformed, it gives off a small but a measurable electrical discharge. Alternately, when an electrical current is passed through a piezoelectric material it experiences the significant increase in size (approx. up to a 4% change in volume) Piezoelectric materials are widely used as sensors in different type of environments. They are often used to measure fluid composition, fluid density, fluid viscosity, or the force of an impact. An example of a piezoelectric material in everyday life is an airbag sensor in our car. The material senses the force of an impact on the car and thus sends and electric charge deploying the airbag. Example of Piezoelectric materials Electro-rheostatic (ER) and magneto-rheostatic (MR) materials:- Electro-rheostatic (ER) and magneto-rheostatic (MR) materials are fluids, which can experience dramatic change in their viscosity. These type of fluids can change from thick fluids (similar to motor oil) to nearly a solid substance within a span of a millisecond when exposed to a magnetic or an electric field. The effect can completely be reversed just as quickly when the field is removed. MR fluids experience viscosity changes when exposed to a magnetic field, while ER fluids experience similar type changes in an electric field. The composition of each type of smart fluid varies widely. The most common form of MR fluid consists of the tiny iron particles suspended in oil, while ER fluids can be as simple as milk chocolates or corn-starch and oil. MR fluids are mostly being developed for use in the car shocks, damping washing machine vibration, prosthetic limbs, exercise equipment, and surface polishing of machine parts. ER are mainly being developed for use in the clutches and valves, as well as engine mounts designed to reduce noise and vibration in the vehicles. Shape memory alloys:- Shape memory alloys (SMAs) are the metals, which exhibit two intresting unique properties, pseudo-elasticity, and shape memory effect. Arne Olander first observed these unusual properties in 1938 (Oksuta and Wayman 1998), but until the 1960s were no any serious research advances made in the field of shape memory alloys. The most effective and widely used alloys includes-NiTi (Nickel Titanium), CuZnAl, and CuAlNi. The unusual properties mentioned in the above are being applied to a wide variety of applications in the number of different fields. Shape memory alloys use ) pH sensitive polymers:- pH sensitive or pH responsive polymers are the materials which responds to the changes in the pH of the surrounding medium by varying or changing their dimensions. Such materials either swell or collapse depending on the pH of their own environment. These behaviour are exhibited due to the presence of certain type of functional groups in the polymer chains. There are only two kinds of ph sensitive materials:- one that have acidic group (-COOH, -SO3H) and swells in basic pH, and others that have basic groups (-NH2) and swells in acidic pH. Polyacrylic acid is an example of a former and Chitosan is an example of a latter. The mechanism of response is just same for both, just the stimuli varies. Their response is triggered due to the presence of ionisable functional groups (eg -COOH, -NH2) which get ionized and acquires a charge +/- in a certain pH. The polymer chains are now having similarly charged groups which causes repulsion and thus the material expands in dimensions. The opposite of this happens when pH changes and the functional groups loses their charge hence the repulsion is therefore gone and the material collapses back. These materials are being widely used for controlled drug delivery systems and biomimetics Halochromic material:- Halochromic materials are the materials which changes colour when pH changes occurs. The term chromic is defined as the materials that can change their colour reversibly in the presence of a factor. In this case, the factor is pH. The pH indicators have this type of property. Halochromic substances are suited for use in environments where pH changes occur very frequently, or the places where changes in pH are most. Halochromic substances can detect alterations in the acidity of substances, eg- detection of corrosion in metals. These substances can be used as indicators to determine the pH of the solutions of unknown pH. The colour obtained is compared with the colour obtained when the indicator is mixed with solutions of known pH. The pH of the unknown solution can then be estimated. Obvious disadvantages of this type method include its dependency on the colour sensitivity of the human eye, and those of unknown solutions that are already colour can be used. example of halochromoic The colour changes of halochromic substances occur when a chemical binds to existing hydrogen and hydroxide ions in solution. Such bonds result in changes in the conjugate systems of the molecules, or the range of electron to flow. This alters the amount of light absorbed, which in turns results in a visible change of colour. Halochromic substances does not display a full range of colour for a full range of pH because, after certain acidities, the conjugate system does not changes. The various shades resulted from different type of concentrations of halochromic molecules with the different conjugate systems. (6)Dielectric elastomers (DEs):- Dielectric elastomers are the smart material systems which produces large strains (even up to 300%) and belong to the group of electro active polymers (EAP). Based on their simple principle of working dielectric elastomers actuators (DEA) transform electric energy directly into the mechanical work. DE are lightweight, and have a high elastic energy density and are investigated since the late 1990s. Many of its potential applications exist as prototypes. Every year in spring a SPIE conference takes place in San Diego where the newest research results concerning DEA are exchanged between. Self-healing materials:- These materials are the class of smart materials that are having the structurally incorporated ability to repair damage caused by mechanical usage over time. The inspiration comes from the biological systems, which have the ability to heal after being wounded. Initiation of cracks and other types of damage on a microscopic level have been shown to change the thermal, electrical, and acoustical properties, and eventually lead to the whole scale failure of these materials. Usually, cracks are mended by hand, which is difficult because cracks are often hard to detect. A material (polymers, ceramics, etc.) that can intrinsically correct the damage caused by normal usage could lower production costs of the number of different industrial processes through longer part lifetime, reduction of inefficiency over time caused by degradation, as well as prevent costs incurred by material failure. For a material to be called as self-healing, it is necessary that the healing process shall occur with out human intervention. Examples shown below include healing polymers that are not self-healing polymers. Example of self healing Temperature-responsive polymer:- Temperature-responsive polymer is a polymer which undergoes a physical change when an external thermal stimulus is presented. Their ability to undergo such changes under easily controlled conditions makes this class of polymers fall into the category of smart materials. These physical changes can be exploited for many analytical techniques, especially for separation chemistry. After numerous investigations of poly(N-isopropylacrylamide) (poly-NIPAAm), there was a sparked interest in the applications of this and many other stimuli-responsive polymers. There have been extensive research in the applications of intelligent polymers for use as stationary phases, extraction compounds, surface modifiers, drug delivery, and gene delivery. Temperature responsive polymer Applications of smart materials There are many possibilities for smart materials and structures in this world. Engineering structures can be operated at the very limited of their performance envelopes and to their structural limits without fear of the exceeding either. These structures can also give maintenance engineers a full report on the performance history, as well as the location of the defects, whilst having the ability to counteract the unwanted or potentially dangerous conditions such as excess vibration, and effect self repair. Smart Materials in Aerospace:- Some materials and structures are termed sensual devices. These are structures which can sense their environment and generate data for use in health and usage monitoring systems (HUMS). Today the most well established application of HUMS are in the field of aerospace, in the areas such as aircraft checking. An aircraft constructed from a sensual structure could self-monitor its performance to a level beyond that of current data recording, and provide ground crews with the enhanced health and usage monitoring. This would minimise the overheads associated with HUMS and allow such aircraft to fly for more hours before any human intervention is required. Smart Materials in Civil Engineering They can be used in the monitoring of civil engineering structures to assess durability. Monitoring of the current and long term behaviour of a bridge would lead to enhanced safety during its life since it would provide early warning of structural problems at a stage where minor repairs would enhance durability, and when used in conjunction with structural rehabilitation can be used to safety monitor the structure beyond its original design life. This will influence the life costs of such structures by reducing upfront construction costs and by extending safe life of the structures. Sensual materials and structures also have a wide range of potential domestic applications, as in food packaging for monitoring safe storage and cooking. The above example addresses only sensual structures. However, the smart materials and structures offer the possibility of structures, which not only sense but also adapt with their environment. Such types of adaptive materials and structures benefit from the sensual aspects highlighted earlier, but in addition have the capability to move, vibrate, and exhibit a multitude of other real time responses. Potential applications of such adaptive materials and structures range from the ability to control the aeroelastic form of an aircraft wing, thus minimising drag and improving operational efficiency, to vibration control of lightweight structures such as satellites, and power pick-up pantographs on trains. Ken Materials Mechatronic smart structures have demonstrated the capability of its technology, but raise the important issue of the complexity of the resulting system. This smart type of structures contains a multitude of different materials, and in the case of sensual structures it will generate large amounts of data. This increase in complexity has been described as the spaghetti syndrome, and has led to the proposal for an alternative type of smart structure based on the concept of ken materials (the Chinese characters which means wisdom, structure, monitoring, integration and benignity is being pronounced ken in the Japanese language). Such structures will move functional integration into the constituent engineering materials by themselves. Some of the practical examples of ken materials exist at present, although a structural composite based on this concept had been developed in Japan. This is a carbon and glass fibre reinforced concrete which able to monitor concrete structures by using only the structural reinforcing fibres, thus reducing the complexity of the system. (4) Structural Uses (a) Active control of structures The concepts of the adaptive behaviour have been an underlying theme of active control of structures which are subjected to an earthquake and other environmental types of loads. The structure adapts its dynamic characteristics to meet the performance objectives at any instant. Sun and Sun (vi) used a thermo mechanical approach to develop a constitutive relation for bending of a composite beam with a continuous SMA fibers embedded eccentric to neutral axis. The authors finally concluded that SMAs can be successfully used for the active structural vibration control. Thompson(iii) also conducted an analytical investigation on the use of SMA wires to dampen the dynamic response of the cantilever beam constrained by SMA wires. (b) Passive control of structures Two families of the passive seismic control devices which are exploiting the peculiar properties of SMA kernel components has been implemented and tested within our MANSIDE project (Memory Alloys for New Seismic Isolation and Energy Dissipation Devices). They are the Special braces for the framed structures and isolation devices for the buildings and bridges. (c) Smart Material Tag These smart materials tag can be used for composite structures. These tags can be monitored externally throughout the life of those structures to relate the condition of internal material. Such measurements as stress, moisture, voids, cracks and discontinuities might be interpreted via a remote sensors. (d) Retrofitting SMAs can use as self-stressing fibres and therefore they can be applied for retrofitting. Self-stressing fibres are the ones in which the reinforcement is placed into the compositenon-stressed state. A prestressing force is therefore introduced into the system without the use of large mechanical actuators, by providing SMAs. These materials thus do not need specialized electric equipments nor do they create safety problems in the field. Treatment can be applied at any time after hardening of matrix instead of during its curing and hardening. So the Long or short term prestressing is introduced by triggering the change in SMAs shape using temperature or electricity. The Future The development of true smart materials at the small atomic scale is still progressing a little, although the enabling technologies are under the development. These require the novel aspects of nanotechnology (technologies which are associated with materials and processes at the nanometre scale, 10-9m) and the newly developing science of shape chemistry. Worldwide, a considerable effort is being made to develop these smart materials and structures. The technological benefits of such types of systems have begun to be identified and, demonstrators are therefore under construction for a wide range of applications from space to aerospace, to civil engineering and to domestic products. In many of above, these applications, the cost benefit analyses of such systems are yet to be fully demonstrated. The Office of Science and Technologys Foresight Programme has recognised these types of systems as a strategic technology for the future, having considerable potential for creation of wealth through the development of various unknown products, and performance enhancing the existing products in a broad range of the industrial sectors. The concept of engineering materials and structures which respond to their own environment, including their human owners, is somewhat an alien concept. So it is therefore not only important that the technological and financial implications of these materials and structures are addressed, but also issues associated with public understanding and acceptance.Techno-democracy could only come about only through education and exposure of the general public to these technologies. However, such a general acceptance of smart materials and structures may in fact be more difficult than some of the technological hurdles which are associated with their development. A new smart materials process Multiple Memory Material Technology developed by University of Waterloo engineering researchers promises to revolutionize the manufacture of diverse products such as medical devices, microelectromechanical systems (MEMS), printers, hard drives, automotive components, valves and actuators.