Muscular Disorders Case Report free essay sample

A mother presents with her 13 y/o child with a background marked by visit falls, trouble getting up from a lying or sitting position, inconvenience hopping, enormous lower leg muscles and horrible scores in school. In light of the portrayal and indications given, the reasonable analysis would be Duchenne’s solid dystrophy, or DMD; in spite of the fact that DMD and its side effects will in general appear at a prior age however not generally. This kind of strong dystrophy is the most widely recognized and extreme type of the dystrophinopathic ailments. Dystrophinopathic maladies are strong dystrophies that are of a hereditary sort brought about by a lack in the protein dystrophin. This protein is fundamental to muscle capacity and withdrawal. On account of DMD, there is a change in the quality, called the DMD quality, answerable for delivering dystrophin causing a lack. This quality change is X-connected passive and is acquired. This implies females in the family convey the quality transformation and can give is to their posterity male or female, yet it is communicated in the guys. We will compose a custom paper test on Strong Disorders Case Report or on the other hand any comparative theme explicitly for you Don't WasteYour Time Recruit WRITER Just 13.90/page DMD is typically analyzed when a little youngster gives indications of muscle shortcoming and there is a family ancestry of the ailment. Per Genome (2010), â€Å"a muscle biopsy for dystrophin studies should likewise be possible to search for irregular degrees of dystrophin in the muscle. † Genome (2010), likewise expresses that â€Å"genetic testing on a blood test for changes in the DMD quality can help build up the finding of Duchenne’s strong dystrophy without playing out a muscle biopsy. † For most people, a mix of these testing strategies is utilized to affirm a finding of DMD. There is no known remedy for DMD. Treatment includes rewarding the side effects and keeping the patient as agreeable as could reasonably be expected. Medline (2012) says that â€Å"steroid medications can slow the loss of muscle quality and might be begun when the youngster is analyzed or when muscle quality starts to decay. † Other medications, for example, Albuterol, can be utilized to control breathing issues that happen in the later phases of the illness and medications to help with heart capacities are endorsed to help control any cardio side effects that might be available. The visualization for people with DMD is disheartening; it is a quickly dynamic illness and patients with DMD normally give up to the ailment or inconveniences from it in their 20’s or 30’s, at times significantly prior. I grew up with a family nearby to me in which the two most established young men had DMD. The infection in the end took both of their lives. The most established kid did live long enough to move on from secondary school however the more youthful of the two passed on from entanglements when he was 16. It was frightful for the family to hold on and watch their children gradually decrease and in the long beyond words. This ailment kept on plagueing their lives when the little girls gave it to their young men most likely despite everything plagues them today. There have been incredible steps in the field of examination concerning DMD however starting at yet no fix has been found. Ideally one day, there will be a remedy for this staggering, crippling ailment and no more families will be compelled to watch their kids pass on directly before their eyes.

Writing Outlines For Essays

Writing Outlines For EssaysWriting outlines for essays can be a real chore. If you have a whole essay to write, this may not be such a big deal - after all, an outline can help you stay on track and get a head start on the assignment.But for smaller pieces of writing, this can become a major problem. After all, how are you supposed to find out where you are going before you start? It is often difficult to tell just how much material there is to be covered in your short essay.Writing outlines for essays can help you get a head start on the material. For example, you might notice that there are a lot of references to the period between one year and one month, or the other way around. These topics should be part of your outlines, since you will need to include them at some point.You might also need to know which of the following statements is correct, since you are only going to be dealing with the right words if you make sense of the sentence structure. For example, if you want to tell about the birds and the bees, you should use the word 'and' in your essay topic heading.It is also important to remember that any writing that you are doing should have an ending. To keep the essay brief, you may want to make sure that you only include the first few sentences. This will help you remember what the conclusion should be, and will also help you prevent the essay from getting too long.Writing outlines for essays are usually pretty straightforward. However, some essays might take more effort, and if you are unsure of a particular topic, then you might want to contact a writing coach for help.Keep in mind that the purpose of outlines is to help you write, so you can use them for future use. Use them when you have questions about a topic, and try to organize the essays that you are working on in order to make it easier to understand. If you can, write down everything you need to write and review it as you go along.Writing outlines for essays can really help you, since you will know where you are going to go next and will also be able to find out the right words to use. It is an easy way to help you focus your thoughts on the most important information.

Three Perspective Approach of Societal Changes

Three Perspective Approach of Societal Changes The Three Perspective Approach of Symbolic-Interaction Approach, Conflict-Approach, Structural-Functionalist Approach Liquor CONSUMPTION Liquor Consumption in the general public has consistently been an alluring part in merriments. By the by, in some culture this is consider to be an image that claim bliss. Emblematic cooperation clarify that an individual’s make the images that make life significant. Emblematic interactionism clarifies liquor utilization today is a gigantic issue society. As per (Harrison, 2010) it tends to be generally applied to freak conduct, and viciousness. All through society images are utilized for all parts of regular day to day existence, and in the Catholic Church it is use to imply the blood of Christ. Regardless of whether this custom culture isn't right, people acknowledge rehearses in their own recognition. In any case, this emblematic plans to everybody can be seen as more positive than restricted, it happen all the more regularly. Sadly this is something appeared in today’s society as an unconstrained thing that prompts distinctive translation and impact by other gatheri ng of culture. Be that as it may, in the Conflict hypothesis liquor utilization develop strife as it become a reliance, and inspired to have no restriction drinking. Likewise, influence the psychological procedures, and drinking conduct. Other clash are reflected in relationship, and relative; that prompts partition, aggressive behavior at home, assault, and others. In the auxiliary functionalist can be deciphered in various manner, for example, Manifest Function, and idle capacity, and brokenness. In Manifest capacity it is a piece of party, that families meet up to join together. These occasion are custom that have been practice, and exist in the general public for Christmas, thanks giving, Easter, and mirror a culture in the congregation. MONOGAMOUS RELATIONSHIPS Monogamy is alluded to two people are explicitly dynamic just with one another, as a rule in a serious relationship that could conceivably be conjugal. Be that as it may, in some culture this is consider to not adequate, for example, Islamic societies, polygamy, or the taking of more than one companion, is worthy. What's more the Jehovah, and other protestant church or religion bunch consider that marriage is between a man and a lady inside the limits of marriage, and those sexual treachery are portrayed as wrongdoing, and debases an association. In any case, the emblematic communication to Monogamous relationship is that one demonstrates fondness to the next. Through blessing, love, mindful, giving blossoms and fraternizing. This support are representative collaboration in discovering approaches to convey love. In any case, will so much well meaning goal some contention approach shows up to scatter such joy. The most well-known clash is inadequate with regards to trust, and having envy. Furthermore it might prompt a separation of the couple, and a sensitive battle between the two guardians for the youngsters care. The ladies are survivor of aggressive behavior at home, and men are for the most part in to unfaithfulness. What's more the capacity approach recommend that relationship importance of responsibility. As per (Kohol, 1983) the capacity is to forestall horrendous sexual relationship, bearing youngsters, building up relationship of closeness and commitment and sharing common objectives. In any case, in the Manifest it is consider to be involved with a drawn out sweetheart, or accomplice that sharing comparability. All things considered, dormant is somewhat the spouse being include in unclear relationship outside the house hold, and can be qualifies for be contamination by sexual illness. This mischief the spouse as well as the entire relationship and the wife. In this manner packaging a brokenness in the relationship, for example, broken trust, contemptibility, and no certainty. High school DATING High school Dating is the most mainstream society that exist in the realm of teenager. Some culture demand that this training help in finding or deciding the accomplice or love one would share common joy forever. This can be believe another method for other to be to know the individual before genuinely include or wedded to. This a representative activity has decided individuals to locate the opportune individual to set up a relationship. Moreover, the tells individual all the quality and shortcoming of the other. At times strife approach most time being the point at which the youngster become pregnant at an early age, and battle an incredible remainder with the loss of training. Some youngster additionally part take in fetus removal to abstain from being youthful parent. Parent that are not steady enough, and youthful parent that have no clue what it suggests to be a mother. In any case, in the capacity approach it appear that high school dating occur at a particular age. This shift in some culture like at age sixteen, or more seasoned. Be that as it may, the show appear to see the general public as individual cooping to make due with an accomplice, since human are normally cling to another person. Anyway in the inert view a decent relationship ought to be build up with one individual to have great child rearing aptitude, and guide the kids growing up to not commit a similar error. Mayan Rights and common land proprietorship Everybody has the option to possess land and different merchandise, and Maya been a predominant culture ought to too infer the Mayan rights and shared land proprietorship. The individual are known for their Maya Ruin, and ranch lands; culture and populace. In any case, their person with all the shared right as different societies existing today. There the person who had occupy the land and that Mayan ought to have ownership on their properties and common land possession for their locale and good to guarantee any foul play done to them. Moreover the emblematic way to deal with this is of most huge piece of them is their sanctuary that represents force and history. Their territory mean a home, and agribusiness. The most clash approach infers that the administration something don’t perceive this is a distinctive culture that should be secured. The decent variety culture make new blend whereby another culture is conceived. Anyway in the show work the convention isn't continued and some custom are not practice. Inert Function the legislature don’t give assets to exhume the rest of the ruin, and other Maya right ended. Furthermore in the brokenness somewhere show disregard in Maya right and possession. Indeed, even show bigotry toward the individuals in their convention, and attire, and joining in the general public. Ladies in governmental issues in Belize Belize has never been the most grounded, however since the coordination of ladies in to governmental issues permits balance between labor. In any case, in the representative Interaction the ladies are viewed as moms, and house holder laborers. In going into governmental issues it give a chance to ladies to voice their feelings. At long last both man and lady have consistently had equivalent rights. All things considered, the contention approach in the public eye lady are not seen as pioneers, yet as adherents. Lady are viewed as mediocre in some culture, for example, in India, Islamic, and other social gathering. Anyway the absence of standing up and be out spoken has been instructed at times by parent that are brought up as such. In basic functionalist approach show work the lady are more qualifies for work and be gainful part in the general public. The lady are the guide for the future to make a solid potential kid that look for right and equity. Anyway in the inert capacity the mother are instructed mindful and specialist. The ladies are autonomous, persevering, and effective. The ladies mirror a positive and secure home condition for the children to live at home.

The Law And Civil Law - 1707 Words

As American citizens it is our duty to follow the laws stated in the American Constitution in order to maintain our rights to be free. If we fail to follow the laws we lose our rights as free citizens in these United States. Our Department of Justice mission statement is: To enforce the law and defend the interests of the United States according to the law; to ensure public safety against threats foreign and domestic; to provide federal leadership in preventing and controlling crime; to seek just punishment for those guilty of unlawful behavior; and to ensure fair and impartial administration of justice for all Americans. This just means to keep the United States safe and justified. It is for people who threaten that need to be punished in order for our country to remain a safe place. Laws are made to protect and two types of laws are Criminal Law and Civil Law. They both punish wrong doers but different kinds. Criminal Law is the body of statutory and common law that deals with cr ime and the legal punishment of criminal offenses. While Civil Law deals with the disputes between individuals, organizations, or between the two, in which compensation is awarded to the victim. In terms of punishment they are different because in Criminal Law A guilty defendant is punished by either incarceration in a jail or fine paid to the government, or, in exceptional cases, the death penalty. Crimes are divided into two broad classes: Felonies and Misdemeanors. Defendant can beShow MoreRelatedThe Law And Civil Law1668 Words   |  7 PagesThe concepts of law and justice are interdependent and deeply intertwined. The relationship between these concepts is able to be perceived through analysis of each independently and then comparatively. One of the primary questions concerning law and justice pertains to the balance and importance of natural law compared to civil law. Problems arise when defining what natural law and civil law are. The identification of natural or civil law a s set boundaries provides its own queries. Along with theRead MoreThe Law And Civil Law872 Words   |  4 Pagesthe master answer’ which states that, in many circumstances, an employer is responsible for the actions of employees performed within the course of their employment. This rule is also called the master-servant rule, recognized in both common law and civil law jurisdictions When applied to physical torts, an employer-employee relationship must be established (meaning that no vicarious liability is established for work performed as an independent contractor) and the act must be committed within theRead MoreCommon Law And Civil Law835 Words   |  4 PagesAt the global level international law is of great importance and the legal systems such as common law, civil law, customary law, and theocratic law exist in different countries across the world. There are about 196 sovereign states in the United Nations Organization and each of the states follows a legal system created by them or by an agreement in the form of regional treaties and other accords. Common law: A common law system according to Samii (2011, p. 112) is based on tradition, judge madeRead MoreCriminal Law And Civil Law902 Words   |  4 PagesCriminal law is better known about in the U.S. than Civil Law because criminal activity is usually publicized at a result of it being news and a civil cases are of private matter. In civil law crime is not the issue, it is when an individual or business (plaintiff) files a lawsuit against another individual or business (defendant) to seek relief of a situation. Civil suits often deal with estates, property issues, malpractice, contracts, child support, divorce and other areas. In a civil suit theRead MoreCommon Law and Civil Law1669 Words   |  7 Pagesbetween the role of criminal law and civil law in relation to the legal system and analyse the purpose of the law. Criminal law is the body of  law  that relates to  crime. It might be defined as the body of rules that defines conduct that is prohibited by the state because it is held to threaten, harm or otherwise endanger the safety and welfare of the public, and that sets out the punishment to be imposed on those who breach these laws. [1] The criminal law serves several purposes and benefitsRead MoreCivil Law3967 Words   |  16 Pages------------------------------------------------- Civil law (common law) Civil law  is the branch of  law  dealing with disputes between  individuals  or  organizations, in which  compensation  may be awarded to the victim. For instance, if a car crash victim claims damages against the driver for loss or injury sustained in an accident, this will be a civil law case.[1]  Civil law differs from  criminal law, whose emphasis is more on punishment than in dispute resolution. The law relating to  civil wrongs  and  quasi-contract  is part of the civil law.[2]Read MoreCivil Law V. Criminal Law1507 Words   |  7 PagesShapley | Civil Law v. Criminal Law | Introduction to Criminal Law | Joanna Solis 3/2/2012 | Only a few people actually know â€Å"the law†. Others think that the criminal justice system is a body that only has one set of rules and laws and all act the same. Not to mention that because of television they think that every case is tried at criminal court with a judge and a panel of jurors. However that is not the case because there’s two specifically types of law, civil and criminal law. Though bothRead MoreCriminal Law VS Civil Law809 Words   |  4 Pagesï » ¿Running head: Compare and Contrast Civil with Criminal injuries Compare and Contrast Civil with Criminal injuries Nora Kelgin October 19, 2013 Tort Actions A tort actions is a form of civil law, which are intentional tort, torts of negligence, and strict liability torts, the vast majority of legal issues in the United State involve this, such as divorce, child custody, child support, domestic dispute, consumer problems, defamation, and injuries due to a personRead MoreComparison of Common Law and Civil Law1231 Words   |  5 PagesCOMMON LAW V CIVIL LAW COMMON LAW(characteristics)for comparing or contrast purpose Common law systems are mostly found in former british colony and protectorate including US, it is less prescriptive than civil law system,citizens are benefited by enactment and legislation in specific fields.more often are the implied terms usage. 1)represents the law of courts as expressed in judicial decision 2)based on precedents provided by past judicial decisions,no written statues or prescribed texts Read MoreCivil Law And Common Law System759 Words   |  4 PagesII—The source of law in civil law and common law system A- Sources of law in civil law system The Civil law is different from Common law systems in many areas. Source of law is one of the important part from each legal system in the world. Source of law is the fundamental different between both of them. In civil law the prime source or basis of the law is legislation, and big areas are codified in a systematic manner, these codes shape a very distinctive feature of a Romanist legal system

The Crucible By Arthur Miller - 1639 Words

The Importance of Intentions By the standards of virtually any society, lying is an act that is almost certain to result in some form of contempt, hatred, or even ostracism. However, not all liars are regarded in the same way- there is an obvious difference of morality between a fraudulent politician and one lying to protect his own life. In his play The Crucible, Arthur Miller demonstrates the moral and societal differences between and consequences of different types of lies: A liar’s virtue is determined primarily by intention, and while some forms of dishonesty are more acceptable than others, truth under all circumstances is vital to true morality. Miller’s stance is a rational and realistic one and can be seen not only in his play,†¦show more content†¦Then, caught by her father in the unspeakable act of dancing in the woods, Abigail resorts to claiming to being possessed by the Devil through means of Tituba, and then to â€Å"open herself† and â€Å"go back to Jesus† (4 8), significantly increasing the number of witchcraft accusations because of all the people she and Betty claim to have seen with the Devil- more than ten accused on just the last page on Act I. By the end of the play, she is responsible for countless people, even those that held their ground for so long, confessing to witchcraft. Those aware of the horrendous truth- Goody Proctor, John Proctor, Reverend Hale- hate her but are helpless as to take any action. The reader comes to despise her and her lies even more when people are not only wrongly charged with crime, but also when the admirable Rebecca Nurse and John Proctor must face their death because of the standards that Abigail has set. Lying to protect reputation is also a common theme seen in politics. One especially controversial instance was President Nixon’s Watergate Scandal: Nixon employed the FBI, CIA, and IRS to harass and spy on political rivals, going so far as to order break-ins to acquire secret information. After the scandal had been partially uncovered, Nixon publicly announced that investigations were being made although he had actually blocked any such activity from happening.

Hypertension The Most Common Chronic Disease ( Barranger )

Hypertension is one of the most common chronic disease (Barranger, 2013). Many people are unaware of the fact that they have hypertension because they do not have any symptoms associated with this chronic disease. Hypertension can be a major risk factor for many other chronic diseases such as heart disease, stroke, congestive heart failure, and kidney disease. Hypertension is strongly associated with obesity and diabetes. Hypertension caused morbidity and mortality are the highest, occur early and more severe among African American’s (Barranger, 2013). Essential hypertension is the most common type of hypertension (Barranger, 2013). Other types of hypertension include primary, idiopathic hypertension and secondary hypertension (when other causes can be identified) (Barranger, 2013). The pathophysiology of hypertension involves nervous system and/or renal system (Barranger, 2013). Centrally located beta receptors and alpha-2 receptors have effects on the production of norepinephrine. The production of norepinephrine is stimulated and inhibited by these receptors. When norepinephrine production is inhibited, vasodilation effects occur, therefore blood pressure (BP) is reduced. Beta 1 receptor blockers and beta 2 receptor stimulators of the arteries and veins will decrease blood pressure by decreasing cardiac output, peripheral resistance, and causation of vasodilation. Baroreceptors can auto regulate blood pressure in the circulatory system by sending impulse to the brain

Electrical Properties of Materials free essay sample

ELECTRICAL PROPERTIES OF MATERIALS SUBMITTED TO: PROF. MARY GRACE O. CATONG SUBMITTED BY: ALAN, ARLAN H. RAMIREZ, RONEL JAY S. RUSIANA, RODOLFO O. BSEE-3B OHM’S LAW One of the most important electrical characteristics of a solid material is the ease with which it transmits an electric current. Ohm’s law relates the current I—or time rate of charge passage—to the applied voltage V as follows: V=IR. ELECTRICAL CONDUCTIVITY Sometimes, electrical conductivity is used to specify the electrical character of a material. It is simply the reciprocal of the resistivity, or ELECTRONIC AND IONIC CONDUCTION An electric current results from the motion of electrically charged particles in response to forces that act on them from an externally applied electric field. Positively charged particles are accelerated in the field direction, negatively charged particles in the direction opposite. ENERGY BAND STRUCTURES IN SOLIDS In all conductors, semiconductors, and many insulating materials, only electronic conduction exists, and the magnitude of the electrical conductivity is strongly dependent on the number of electrons available to participate in the conduction process. For each individual atom there exist discrete energy levels that may be occupied by electrons, arranged into shells and subshells. Shells are designated by integers (1, 2, 3, etc. ), and subshells by letters (s, p, d, and f ). The electrical properties of a solid material are a consequence of its electron band structure—that is, the arrangement of the outermost electron bands and the way in which they are filled with electrons. Four different types of band structures are possible at 0 K. In the first (Figure18. 4a), one outermost band is only partially filled with electrons. The energy corresponding to the highest filled state at 0 K is called the Fermi energy Ef. CONDUCTION IN TERMS OF BAND AND ATOMIC BONDING MODELS Only electrons with energies greater than the Fermi energy may be acted on and accelerated in the presence of an electric field. These are the electrons that participate in the conduction process, which are termed free electrons. In addition, the distinction between conductors and non-conductors (insulators and semiconductors) lies in the numbers of these free electron and hole charge carriers. Metals For an electron to become free, it must be excited or promoted into one of the empty and available energy states above Ef. For metals having either of the band structures shown in Figures 18. 4a and 18. 4b, there are vacant energy states adjacent to the highest filled state at Thus, very little energy is required to promote electrons into the low-lying empty states, as shown in Figure 18. 5. Generally, the energy provided by an electric field is sufficient to excite large numbers of electrons into these conducting states. Insulators and Semiconductors For insulators and semiconductors, empty states adjacent to the top of the filled valence band are not available. To become free, therefore, electrons must be promoted across the energy band gap and into empty states at the bottom of the conduction band. The number of electrons excited thermally (by heat energy) into the conduction band depends on the energy band gap width as well as temperature. The larger the band gap, the lower is the electrical conductivity at a given temperature. Increasing the temperature of either a semiconductor or an insulator results in an increase in the thermal energy that is available for electron excitation. ELECTRON MOBILITY When an electric field is applied, a force is brought to bear on the free electrons; as a consequence, they all experience acceleration in a direction opposite to that of the field, by virtue of their negative charge. These frictional forces result from the scattering of electrons by imperfections in the crystal lattice, including impurity atoms, vacancies, interstitial atoms, dislocations, and even the thermal vibrations of the atoms themselves. ELECTRICAL RESISTIVITY OF METALS Metals have high conductivities because of the large numbers of free electrons that have been excited into empty states above the Fermi energy. Since crystalline defects serve as scattering centers for conduction electrons in metals, increasing their number raises the resistivity (or lowers the conductivity). The concentration of these imperfections depends on temperature, composition, and the degree of cold work of a metal specimen. known as Matthiessen’s Rule Influence of Temperature For the pure metal and all the copper–nickel alloys shown in Figure 18. 8, the resistivity rises linearly with temperature above about -200? C. Thus, This dependence of the thermal resistivity component on temperature is due to the increase with temperature in thermal vibrations and other lattice irregularities (e. g. , vacancies), which serve as electron-scattering centers. Influence of Impurities For additions of a single impurity that forms a solid solution, the impurity resistivity is related to the impurity concentration in terms of the atom fraction (at%/100) as follows: For a two-phase alloy consisting of and phases, a rule-of-mixtures expression may be utilized to approximate the resistivity as follows: Influence of Plastic Deformation Plastic deformation also raises the electrical resistivity as a result of increased numbers of electron-scattering dislocations. The effect of deformation on resistivity is also represented in Figure 18. 8. Furthermore, its influence is much weaker than that of increasing temperature or the presence of impurities. COMMERCIAL ALLOYS Electrical and other properties of copper render it the most widely used metallic conductor. Oxygen-free high-conductivity (OFHC) copper, having extremely low oxygen and other impurity contents, is produced for many electrical applications. Aluminum, having a conductivity only about one-half that of copper, is also frequently used as an electrical conductor. Silver has a higher conductivity than either copper or aluminum; however, its use is restricted on the basis of cost. SEMICONDUCTIVITY Two Types of Semiconductor * Intrinsic Semiconductor -are those the electrical behaviour is based on the electronic structure inherent to the pure material. Extrinsic Semiconductor -when the electrical characteristics are dictated by impurity atoms. Formula for Electrical Conduction for Intrinsic Conductivity * For intrinsic conductors, every electron promoted across the band gap leaves behind a hole in the valence band; thus, * Two Types of Change Carrier *free electrons *holes * Two Types of Extrinsic Semiconductor *n-type Extrinsic semiconductor *p-type Extrinsic semiconductor -The imp urity of the n-type is called donor. -The impurity of the p-type is called an acceptor. Doping- means adding impurities in various techniques. * The Fermi level of n-type semiconductor, is shifted upward in the band gap. * For p-type semiconductor, the Fermi level is positioned within the band gap and near to the acceptor level. * Factor that Affect Carrier mobility -the magnitude of electrons and hole mobilities are influenced by the presence of these of those some crystalline defects that are responsible for the scattering of electrons in metals. INFLUENCE OF TEMPERATURE * SEMICONDUCTOR DEVICES -Diode(rectifier diode) -Transistor Rectifier Diode- is an electronic device that allows the current to flow in one direction only. * Forward Bias -when a battery is used, the positive terminal may be connected to p-side and the negative terminal to the n-side. * Reverse Bias -opposite to forward bias that when minus to p and plus to n. TRANSISTORS Which extremely important semiconducting devices are in today’s microelectronic circuitry. Capable of two primary types of junction. * They can perform the same operation as their vacuum tube precursor, the triode;that is they can amplify an electrical signal. They serve as a switching device in computers for the processing and storage of information. TWO (2) MAJOR TYPES * JUNCTION (or BIMODAL) TRANSISTOR * MOSFET (METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR) JUNCTION TRANSISTOR The junction transistor is composed of two p-n junctions arranged back to back in either the n-p-n or the p-n-p configuration. A very thin n-type base region is sandwiched in between p-t ype emitter collector regions. (fig. 18. 22) The circuit that includes the emitter-base junction (junction 1) is forward biased. Whereas a reverse bias voltage is applied across the base-collector junction (junction 2). MOSFET One variety of MOSFET consists of two small islands of p-type semiconductor that are created within a substrate of n-type silicon. (Fig. 18. 24) The operation of a MOSFET is very similar to that described for the junction transistor but the primary difference is that the gate current is exceedingly small in comparison to the base current of a junction transistor. MOSFETs are, therefore, used where the signal sources to be amplified current. SEMICONDUCTORS IN COMPUTER In addition to their ability to amplify an imposed electrical signal, transistor and diodes may also act as switching devices, a feature utilized for arithmetic and logical operations and also for information storage in computers. Transistors and diodes within digital circuit operate as switches that also have two states -on and off, or conducting and non-conducting. MICROELECTRONIC CIRCUITRY During the past few years, the advent of microelectronic circuitry, where millions of electronic components and circuits are incorporated into a very small space, has revolutionized the field of electronic. This revolution was precipitated, in part, by aerospace technology, which necessitated computers and electronics devices that were small and had low power requirements. Also, the use of integrated circuits has become infused into many other facets of our lives- calculators, communications, watches, industrial production and control, and all phases of the electronics industry. ELECTRICAL CONDUCTION IN IONIC CERAMICS AND IN POLYMERS Most polymers and ionic ceramics are insulating materials at room temperature and, therefore, have electron energy band structures. Gives the room-temperature electrical conductivities of several of these materials. Of course many materials are utilized on the basis of their ability to insulate, and thus a high electrical resistivity is desirable. With rising temperature, insulating materials experience an increase in electrical conductivity, which may ultimately be greater than that for semiconductors. CONDUCTION IN IONIC MATERIALS Both cations and anions in ionic materials possess an electric charge and, as a consequence, are capable of migration or diffusion when an electric field is present. Thus an electric current will result from the net movement of these charged ions, which will be present in addition to current due to any electron motion. Of course, anion and cation migration will be opposite direction. The total conductivity of an ionic material ? total is thus equal to the sum of both electronic and ionic contribution, as follows: ELECTRICAL PROPERTIES OF POLYMERS Most polymeric materials are poor conductors of electricity because of the unavailability of large numbers of free electrons to participate in the conduction process. The mechanism of electrical conduction in these materials is not well understood, but it is felt that conduction in polymers of high purity is electronic. CONDUCTING POLYMERS Within the past several years, polymeric materials have been synthesized that have electrical conductivities on par with metallic conductors; they are appropriately termed conducting polymers. Conductivities as high as 1. 5107 (? -m)-1 have been achieved in these materials; on a volume basis, this value corresponds to one-fourth of the conductivity of copper or twice its conductivity on the basis of weight. These conducting polymers have the potential to be used in a host of applications in as much as they have low densities, are highly flexible and are easy to produce. OTHER ELECTRICAL CHARACTHERISTICS OF MATERIALS Two (2) other relatively important and novel electrical characteristics that are found in some materials deserve brief mention-namely: * Ferroelectricity * Piezoelectricity FERROELECTRICITY The group of dielectric materials called ferroelectrics exhibit spontaneous polarization- that is polarization in the absence of an electric field. They are the dielectric analogue of ferromagnetic materials, which may display permanent magnetic behaviour. There must exist in ferroelectric materials permanent electric dipoles, the origin of which is explained for barium titanate, one of the most common ferroelectric. PIEZOELECTRICITY An unusual property exhibit for a few ceramic materials is piezoelectricity, or, literally, pressure electricity: polarization is induced and an electric field is established across a specimen by the application of external forces reversing the sign of an external force ( i. e. from tension to compression) reverses the direction of the field. Piezoelectric materials are utilized in transducers, which are devices that convert electrical energy into mechanical strains, or vice versa. Some other familiar applications that employ piezoelectric include phonograph cartridges, microphones, speakers, audible alarms and ultrasonic imaging. In a phonograph cartridge, as the stylus traverses the grooves on a r ecord, a pressure variation is imposed on a piezoelectric material located in the cartridge, which is then transformed into an electric signal is amplied before going to the speaker.