History, Theory, and Applications of Capacitors :: capacitor electronics

Static electricity was discovered in 600 B.C., but it was not until the mid 1700's when energy storage properties were discovered. 'With the discovery of the first Leyden jar, it was referred to as a condenser because electricity was thought of as a fluid which could condense. The Lehden jar is a glass partially filled with water that has a wire inserted through the top of an insulating stopper (cork). When the wire is charged by static electricity, it holds the charge until the wire comes into contact with a conductor which will discharge the glass. It was roughly one hundred years later when Michael Faraday discovered a variable capacitor. He did this by measuring the varying capacitance of different dielectrics on capacitor.'(4) When the first aluminum capacitor was discovered, some thirty years after Faraday's work, the SI unit used measuring capacitance was named a farad (F) in his honor. 1F = 1 C / V In words: one Farad is equal to one Coulomb per Volt Since the farad is a large unit of capacitance, most capacitors have units of picofarads (pF) or nanofarads (nF). To this day only one type of capacitor has the ability to store enough energy to warrant measurements using a farad as the standard unit, and this is the super capacitor. A capacitor consists of two conducting surfaces separated by an insulator (dielectric). The value of capacitance depends not only on the geometry of the capacitor, but the dielectric as well. (1) "Since capacitance (C) of a capacitor is the ratio of the magnitude of the charge on either conductor to the magnitude of the potential difference (V) between them: " (1) : When a DC voltage source is applied to the 10 mF capacitor shown to the left, a charge is stored on each side of the electrode. A mulitmeter is used to measure resistance, it is shown that when the capacitor is charging, current is moving and when the capacitor is fully charged, the current will stop flowing, because there is no change in electric potenial, so the resistance goes to zero. You can see that when the electodes are switched, the resistance again goes to zero when the capacitor is fully charged. AC current is allowed to pass through the conductor continuously because it works similiar to the way the probes are switching, so the current is allowed continuos flow. The main function of a capacitor is for it to store energy and to act as a filter, passing current (AC) and blocking current (DC).

Walt Whitman Poetic Devices

Poetic Devices Walt Whitman: Parallel Structure – In â€Å"I Hear America Singing† lines 2-8 are the best examples of Parallel Structure. Those of mechanics, each one singing his as it should be blithe and strong, The carpenter singing his as he measures his plank or beam,The mason singing his as he makes ready for work, or leaves off work, The boatman singing what belongs to him in his boat, the deckhand singing on the steamboat deck, The shoemaker singing as he sits on his bench, the hatter singing as he stands, The wood-cutter’s song, the plowboy’s on his way in the morning, or at noon intermission or at sundown, The delicious singing of the mother, or of the young wife at work, or of the girl sewing or washing, Free Verse – Free verse is a poem that is written without any type of rhyme in it and â€Å"A Noiseless Patient Spider† is a perfect example.It doesn’t rhyme, but to make the poem make sense he uses repetition, metaphor, all iteration and personification. Apostrophe – An example of apostrophe in â€Å"A Noiseless Patient Spider† was when the narrator addresses his soul. Mood – in the beginning mood of the poem â€Å"When I Heard the Learned Astronomer† was kind of tired and sick. But in the second part of the poem his mood changes it to kind of romantic. Catalog – Catalog is like to make a list, and Whitman makes a list of worker like carpenter, mason, wood maker, etc. in the poem â€Å"I hear America Singing†

Comparing Dracula, And I Am Legend By Richard Matheson

Since the beginning of time vampires have been categorized into different types† and are portrayed in different ways throughout several books. This paper will focus on three vampires from the following books: Dracula by Bram Stoker, and I am Legend by Richard Matheson. Dracula is considered to be the traditional vampire, where it all started, and the vampires in Matheson’s book, follow somewhat Stoker’s concept, but is more of a modern â€Å"type† of vampires. Certain vampire elements have been presented, but others have been completely removed or altered. In addition, elements along with appearances are used to infer if the vampire is a form of â€Å"the other†. There are two types of vampires; the traditional or modern vampire which can be distinguished based on the elements present in their storyline. Dracula is one of the earliest and successful vampire novels in history, which is why Dracula is considered to be the traditional vampire. Beginning with the fact that Dracula must sleep during the day, otherwise he will weaken in sunlight. The first clue was Jonathan Harker’s thought, â€Å"I have not yet seen the Count in the daylight† (Bram Stoker, 49). His thought is later proved to be true when Harker sneaks into Dracula’s room and is said, â€Å"There in one of the great boxes, of which there were fifty in all, on a pile of newly dug earth, lay the Count† (50). The next being the obvious and most important is his consumption of blood. Another element is he is petrified ofShow MoreRelatedBram Stoker s Dracula And Richard Matheson s I Am Legend2160 Words   |  9 Pagesscience and religion. In Bram Stoker’s Dracula and Richard Matheson’s I Am Legend, the mythical horror creatures, the vampires, have many differences in their mythical abilities, functionality and origin; however, they both serve to underline themes that remind the reader of what makes us human and what defines us as ultimately good or evil. Stoker’s Count Dracula is the product of a religious strike against the antagonist whereas the vampires in I Am Legend are a product of mankind’s scientific ignoranceRead MoreVampires : The Symbolism Of Horror In Dracula By Bram Stoker1180 Words   |  5 Pagesmore romantic and â€Å"sympathetic† comparing to the past. Vampires have abandoned their horror and evolved to a more attractive and appealing version because today we have many figures and stories that are threatening the position of vampires in the field of horror, and if vampires don’t change they will have nowhere to go except fall into oblivion. Vampires used to be terrifying because they represent the death, darkness, and evil. For example, in the portion of Dracula by Bram Stoker, the author showsRead MoreVampire Vs. Vampire Myth2146 Words   |  9 Pagesand the traits they harbor. Many European and Western vampire narratives share similar appearances, habits and afflictions. Most readers and viewers are extensively familiar with what they believe a vampire to be most often comparing these vampires to Bram Stoker’s Dracula. Dracula is the quintessential example of modern vampires and has a significant and lasting impact on the genre of vampires both from the novel and subsequent films. Simply put, most individuals are familiar with the traditional vampire