Crystal Definition, Examples, and Common Types

Crystal Definition, Examples, and Common Types A crystal consists of matter that is formed from an ordered arrangement of atoms, molecules, or ions. The lattice that forms extends out in three-dimensions. Because there are repeated units, crystals have recognizable structures. Large crystals display flat regions (faces) and well-defined angles. Crystals with obvious flat faces are called euhedral crystals, while those lacking defined faces are called anhedral crystals. Crystals consisting of ordered arrays of atoms that arent always periodic are called quasicrystals. The word crystal comes from the Ancient Greek word krustallos, which means both rock crystal and ice. The scientific study of crystals is called crystallography. Examples of Crystals Examples of everyday materials you encounter as crystals are table salt (sodium chloride or halite crystals), sugar (sucrose), and snowflakes. Many gemstones are crystals, including quartz and diamond. There are also many materials that resemble crystals but are actually polycrystals. Polycrystals form when microscopic crystals fuse together to form a solid. These materials do not consist of ordered lattices. Examples of polycrystals include ice, many metal samples, and ceramics. Even less structure is displayed by amorphous solids, which have disordered internal structure. An example of an amorphous solid is glass, which may resemble a crystal when faceted, yet isnt one. Chemical Bonds in Crystals The types of chemical bonds formed between atoms or groups of atoms in crystals depend on their size and electronegativity. There are four categories of crystals as grouped by their bonding: Covalent Crystals - Atoms in covalent crystals are linked by covalent bonds. Pure nonmetals form covalent crystals (e.g., diamond) as do covalent compounds (e.g., zinc sulfide).Molecular Crystals - Entire molecules are bonded to each other in an organized manner. A good example is a sugar crystal, which contains sucrose molecules.Metallic Crystals - Metals often form metallic crystals, where some of the valence electrons are free to move throughout the lattice. Iron, for example, can form different metallic crystals.Ionic Crystals - Electrostatic forces form ionic bonds. A classic example is a halite or salt crystal. Crystal Lattices There are seven systems of crystal structures, which are also called  lattices  or space lattices: Cubic or Isometric - This shape includes octahedrons and dodecahedrons as well as cubes.Tetragonal - These crystals form prisms and double pyramids. The structure is like a cubic crystal, except one axis is longer than the other.Orthorhombic - These are rhombic prisms and dipyramids that resemble tetragons but without square cross-sections.Hexagonal - Six-sided prisms with a hexagon cross section.Trigonal - These crystals have a 3-fold axis.Triclinic - Triclinic crystals tend not to be symmetrical.Monoclinic - These crystals resemble skewed tetragonal shapes. Lattices may have one lattice point per cell or more than one, yielding a total of 14 Bravais crystal lattice types. Bravais lattices, named for physicist and crystallographer Auguste Bravais, describe the three-dimensional array made by a set of discrete points. A substance may form more than one crystal lattice. For example, water can form hexagonal ice (such as snowflakes), cubic ice, and rhombohedral ice. It can also form amorphous ice. Carbon can form diamond (cubic lattice) and graphite (hexagonal lattice). How Crystals Form The process of forming a crystal is called crystallization. Crystallization commonly occurs when a solid crystal grows from a liquid or solution. As a hot solution cools or a saturated solution evaporates, particles draw close enough for chemical bonds to form. Crystals can also form from deposition directly from the gas phase. Liquid crystals possess particles oriented in an organized manner, like solid crystals, yet able to flow.

Typing Spanish Accents and Punctuation on a Mac

Typing Spanish Accents and Punctuation on a Mac They say computing is easier with a Mac - and indeed it is when typing Spanish accented letters and punctuation symbols. Unlike Windows, the Macintosh operating system does not require you to install a special keyboard configuration to type letters with diacritical marks. The capability for the characters is ready for you from the first time you turn your computer on. The Easiest Way To Type Accented Letters on a Mac If you have a newer Mac (OS X Lion and later), youre in luck. It provides what may be the easiest way in computing today to type accented letters without using a keyboard made specifically for Spanish. The method uses the Macs built-in spelling correction software. It will seem familiar if youve ever had to type an accented letter on a cellphone, either Mac or Android. If you have a letter that needs a diacritical mark, simply hold the key down longer than usual and a pop-up menu will appear. Simply click on the correct symbol and it will insert itself in what youre typing. If the method doesnt work, it may be because the software youre using (such as a word processor) doesnt take advantage of the feature built into to the operating system. It is also possible that you may have the key repeat function turned off. The Traditional Way To Type Accented Letters on a Mac If the method above doesnt work, heres another way - it isnt intuitive, but it is easy to master. The key is that to type a modified letter (such as an à ©, à ¼ or à ±) you type a special key combination followed by the letter. For example, to type vowels with an acute accent on them (namely the , à ©, à ­, à ³ and à º) press the Option key and the e key at the same time, then release the keys. This tells your computer that the next letter will have the acute accent. So to type , press the Option key and the e at the same time, release those keys, and then type the a. If you want it capitalized, the process is the same, except press the a and the shift key at the same time. The process is similar for the other special letters. To type the à ±, press the Option and n keys at the same time and release them, then press the n. To type the à ¼, press the Option and u keys at the same time and release them, then press the u. To summarize: - Option e, a- Option e, Shift aà © - Option e, eÉ - Option e, Shift eà ­ - Option e, ià  - Option e, Shift ià ± - Option n, nÑ - Option n, Shift nà ³ - Option e, oÓ - Option e, Shift oà º - Option e, uÚ - Option e, Shift uà ¼ - Option u, uÃÅ" - Option u, Shift u To type Spanish punctuation, it is necessary to press two or three keys at the same time. Here are the combinations to learn: inverted question mark ( ¿) - Shift Option ?inverted exclamation point ( ¡) - Option 1left angle quote ( «) - Option \right angle quote ( ») - Shift Option \quotation dash (- ) - Shift Option - Using the Mac Character Palette To Type Accented Letters Some versions of the Mac OS also offer an alternate method, known as the Character Palette, that is more cumbersome than the above method but can be used if you forget the key combinations. To open the Character Palette if you have it available, open the Input menu on the top right of the menu bar to find it. Within the Character Palette, select Accented Latin for the characters to display. You can insert the characters in your document by double-clicking on them. In some versions of the Mac OS, the Character Palette may also be available by clicking on the Edit menu of your word-processing or other application and selecting Special Characters. Typing Accented Letters With iOS Chances are that if you have a Mac youre a fan of the Apple ecosystem and are also using an iPhone, or an iPad  using iOS as an operating system. Never fear: Typing accents with iOS isnt difficult at all. To type an accented vowel, simply tap and lightly press on the vowel. A row of characters including the Spanish characters will pop up (along with characters using other types of diacritical marks such as those of French). Simply slide your finger over to the character you want, such as the à ©, and release. Similarly, the à ± can be selected by pressing on the virtual n key, and the inverted punctuation marks can be selected by pressing on the question and exclamation keys. To type angular quotes, press on the double-quote key. To type a long dash, press on the hyphen key. The above procedure also works with many Android phones and tablets.

The Law on Occupiers Liability Essay Example | Topics and Well Written Essays - 4500 words

The Law on Occupiers Liability - Essay Example When the girl poured the contents in the glass, it contained the decomposed remains of a snail. The girl was ill in consequence and sued the manufacturer for damage in tort. It was held the defendant was liable as he owed her duty of care to ensure that the bottle should contain objectionable matter as it did. (Jertz, 2004) We find that the occupiers' liability act provides a limited duty of care on occupiers to ensure that measures for protection of properties or other people from the risks that exist, in this law we find that there are provisions that follow this act, these provisions are: it abolishes the old distinction between licensees and invitees this category of persons include anyone to whom the occupier has expressly or implicitly allowed to enter or use his premises in this case the trespasser is not included. The act provides that an occupier of premises owes to all visitors that duty to take care in all circumstances therefore, it is necessary for the occupier to ensure that the visitor will be safe in using the premises for the purpose for which he has been permitted to be there. We also find that under the act, the occupier however has a right to restrict his liability by giving adequate warning such as about slippery floors. Here the occupier is not liable where the accident has occurred through the defective work of an independent contractor was competent and so far as he was able he had inspected the work done. (Jertz, 2004) The law on occupiers' liability to an injured trespasser is usually classified under the law of tort according to the present law. Whereby tort is defined as a civil wrong free of contracts, meaning it is an act that causes harm to a determined person whether intentionally or not. The remedies for these acts are always unliquidated damages which indicate that the court has power to fix the damages. Tort normally vary from contracts whereby we find that in contracts the duties are usually fixed by the parties under agreement themselves while in tort the duties are imposed by the law. Also we find that the law of tort is an infringement of the civil rights belonging to an individual in this case we find that the wrong doer has to compensate the injured party, according to the recent law the action is brought by the aggrieved party so that he can obtain compensation. This law constitutes of three major elements that is there must be a wrongful act or omission by the defendant this means that there must a person who is being sued for his wrongful acts. Secondly there must be a legal damage and lastly the wrongful act must be of such nature as to give rise to a legal remedy in the form of an action for the damages. There also exist some civil wrongs that are actionable even though no damage is suffered by the plaintiff. An example of such a civil wrong is the trespass on land. In recent law we find that there are many types of torts such trespass and defamation but in the real sense it represents a civil wrong whose only remedy is a common law. In the case of the law on the occupier's liability to injured trespassers we find that it

The Laramie Essay Example | Topics and Well Written Essays - 1500 words

The Laramie - Essay Example in which religion puts people apart in the play as paradoxically as it is through judgment and the feelings when he questions if his priest and father are right about their arguments against homosexuality. The questioning raises the difference between reality and religion as well as the statement of not giving the organized religion permission of the contents of the said character (Kaufman 21). Evident from the text is the ability to differentiate between religion and spirituality. The idea of well-established religion as well as that of orthodoxy as shown in a way that practices the singular notion of the best. Such traits are depicted by Reverend Phelps when he tries to make the matter of homosexuality be the one who questions whether ones allegiance to his God as it creates a setting that looks to separate individuals from "us or them" situation (Kaufman 32).  Moreover, such also is the same as it discourages the Muslim woman in the play as it awakens the social status of some townspeople simply because of the cultural traditions.   At such point, also, one can get the difference such regards the approach that separates individuals from religion does not represent all the established religions when Matts funeral is held in a Catholic church, the time where establishment of religion does look to bring people collectively. Moreover,  there are also other religions, which cannot really be ready for them to accept fully homosexuality, and as well as its implications on the clergy, given so they cannot respond in the way of Reverend Phelps.   The play makes the greatest statement on religious views of love together with compassion by the individuals as it is seen in the play.   Those who live in the town like Jedidiah work extra hard to reconcile the meaning being loyal to the town, and they also commit themselves to the fraternity by accepting all individuals living there. Romaine Patterson also willingness to remove the perception of "angels" 23 is a good

Ernest Hemingways Code Hero in For Who The Bell Tolls and A Farewell T

Ernest Hemingway's Code Hero in For Who The Bell Tolls and A Farewell To Arms They were American innocents negotiating the river of life wherever it took them: to Italy, to Spain, to Africa, to the Caribbean, wounded men laughing through the pain, sometimes risking their skins but never sacrificing their honor. It was a river into which countless writers would thrust their paddles.(Papa) Ernest Hemingway is arguably one of the most important writers in American history. Though this is disputed, Hemingway has undoubtedly had a major influence on contemporary American literature. One aspect of Hemingway's famous writing that shines in almost all of his works is the hero. Hemingway created the famous Hemingway code by which all of his heroes, often called code heroes, lived. One critic asserted that, 'Hemingway invented more than a style he invented the Hemingway hero.' (Papa) Hemingway attempted to live by this code but did not enjoy the success of his fictional characters. In fact, critic Joseph DeFalco states, 'The type of hero that can accomplish such a feat [living up to the Hemingway code] is rare in any area of life.' (195) The code hero was not rare, however, in Hemingway writing. Robert Jordan in For Whom The Bell Tolls and Frederic Henry in A Farewell To Arms are perfect examples of the Hemingway code hero. The Hemingway code is, ?a grace under pressure. It is made of the controls of honor and courage which in a life of tension and pain make a man a man and distinguish him from the people who follow random impulses.? (Young 63) Additionally, this ?grace under pressure? can be expressed as, ?an ability to be in difficult situations without succumbing to either panic, enthusiasm, or indifference, is the hall... ...back Fiction, 1929. Hemingway, Ernest. For Whom The Bell Tolls. New York: Scribner Paperback Fiction, 1940. Molesworth, Charles. ?Hemingway?s Code: The Spanish Civil War and World Power.? Blowing the Bridge. Ed. Rena Sanderson. Westport: Greenwood Press, 1992. 83-97. Norton, Charles A. ?The Alcoholic Content of A Farewell to Arms.? Hemingway in Italy and Other Essays. Ed. Robert W. Lewis. New York: Praeger Publishing, 1990. 309-313. ?Papa and All His Children,? U.S. News & World Report: 1 Jun. 1998, Vol. 124: Issue 2. Mas Full Text Premiere. Rehberger, Dean. ?I Don?t Know Buffalo Bill?s; or Hemingway and the Rhetoric of the Western .? Blowing the Bridge. Ed. Rena Sanderson. Westport: Greenwood Press, 1992. 159-184. Young, Phillip. Ernest Hemingway: A Reconsideration. University Park: The Pennsylvania State University Press, 1966.

Efficiency Ratios

Efficiency Ratios The efficiency ratio is an indicator of how well Johnson and Johnson (J&J) is run on an organizational wide basis. Efficiency ratios are also defined as asset turnover ratios (Finkler, Kovner & Jones, 2007). The asset turnover ratio measures how productive J&J is in managing all of its assets to generate Sales. This efficiency ratio is calculated by dividing sales by total assets by total revenue. For year 2010, J&J had an asset turnover of 0. 6. Comparing J&J’s asset ratio to the industry, it is the same (Key Financial Ratios: Financial Results – Johnson & Johnson,  2011). Thus J&J is as efficient in the use of its assets as its healthcare competitors in the industry. Revenue to assets = Total revenueTotal assets Total revenue $61,587. 0= 0. 598 or 0. 6 Asset turnover Total assets $102,908. 0| The days' receivables ratio is calculated by dividing the accounts receivable by the revenue per day. The days' receivables will indicate how long, on average, it takes for J&J to collect on its sales to customers on credit. This ratio is also known as the average collection period (ACP). The shorter the collection period, the sooner the organization can pay bills or invest to earn interest (Finkler, Kovner & Jones, 2007). A short ACP is more efficient for the organization. J&J had an ACP of 58 days in 2010. This is a slight increase from previous year’s ACP of 57 days. Revenue per day = Total revenue 365$61,857. 0 = $168. 731 365 days Day’s receivable = Accounts receivable Revenue per day AR $9774. 0 = 57. 92 days DR $168. 731/day| Reference Key financial ratios: financial results – johnson & johnson . (2011). Retrieved from http://moneycentral. msn. com/investor/invsub/results/compare. asp? Page=ManagementEfficiency&symbol=JNJ

`` Nosedive `` Themes And Serves As A Strong Critique Of...

â€Å"Nosedive† addresses a different set of existential themes and serves as a strong critique of the modern age and the nature of being the Other. Within â€Å"Nosedive,† there is a world in which everyone is involved in a social media application that completely runs everyone’s life. After every interaction, people will rate one another on a scale of one to five. Everything from social status to one’s ability to rent a car is based upon the score. There are organizations devoted entirely to consultations on how to become more popular, gain more followers, and move up in these superficial ranks. The episode follows a weekend in the life of Lacie: a girl with 4.2 stars and a chronic desire for acceptance. She experiences the same events we all do†¦show more content†¦In the case of Lacie, morality is not the thing they follow blindly but the ratings. They remain entrenched in their technology and follow along that system as though there were no o ther alternative. In the same way that Nietzsche saw the people of his modern era as herd animals moving toward democracy, the people of Lacie’s time blindly move toward ratings. If they cannot attain those ratings they are excluded from the herd. This episode also shows a clear distinction between those with high-ratings and those who do not. This dichotomy is similar to the nature of being the Other as discussed by Simone de Beauvoir and Frantz Fanon. Each of these existentialists focused on applied existentialism- feminist existentialism and Africana existentialism respectively. Yet they share a common concept, one’s place is society is not determined by one’s essence so much as external factors like gender or race. The same can be applied to the rating system that is a core element of Lacie’s lived experience. In The Second Sex, Simone remarks on the female lived experience stating â€Å"In actuality the relation of the two sexes is not quite like that of two electrical poles, for man represents both the positive and the neutral, as indicated by the common use of man to designate human beings in general; whereas woman only represents the negative† (Beauvoir, Page xxi). While in Lacie’s wo rld there is certainly more