Category Archives: Technology

Āina-kāri

Āina-kāri (Persian: آینهکاری) is a kind of Persian interior decoration where artists assemble finely cut mirrors together in geometric, Its origin and invention is from Persians. lligraphic or foliage forms (inspired by flowers and other plants). This creates a beautiful shining surface covered with complex facets, reflecting light as intricate abstract patterns or glittering reflections. Beside their decorative use, this art an used as a strong durable cover for an interior space of a building. This type of mosaic work is commonly done in Iran, Pakistan and is also found is Mughal era buildings of India. In ancient Iranian culture, water and mirrors symbolized purity and light and truthfulness, and their use in Iranian architecture also has the same meaning and comes from the same concept. In the Zand and Qajar periods, this craft was applied over doorways, window-frames, walls, ceilings, and columns in pavilions and private houses, tea-houses and…

Barrel vault

A barrel vault, also known as a tunnel vault, wagon vault or wagonhead vault, is an architectural element formed by the extrusion of a single curve (or pair of curves, in the case of a pointed barrel vault) along a given distance. The curves are typically circular in shape, lending a semi-cylindrical appearance to the total design. The barrel vault is the simplest form of a vault: effectively a series of arches placed side by side (i.e., one after another). It is a form of barrel roof. As with all arch-based constructions, there is an outward thrust generated against the walls underneath a barrel vault. There are several mechanisms for absorbing this thrust. One is to make the walls exceedingly thick and strong – this is a primitive and sometimes unacceptable method. A more elegant method is to build two or more vaults parallel to each other; the forces of…

Triumphal arch

A triumphal arch is a free-standing monumental structure in the shape of an archway with one or more arched passageways, often designed to span a road, and usually standing alone, unconnected to other buildings. In its simplest form, a triumphal arch consists of two massive piers connected by an arch, typically crowned with a flat entablature or attic on which a statue might be mounted or which bears commemorative inscriptions. The main structure is often decorated with carvings, sculpted reliefs, and dedications. More elaborate triumphal arches may have multiple archways, or in a tetrapylon, passages leading in four directions. Triumphal arches are one of the most influential and distinctive types of ancient Roman architecture. Effectively invented by the Romans, and using their skill in making arches and vaults, the Roman triumphal arch was used to commemorate victorious generals or significant public events such as the founding of new colonies, the…

Truss arch bridge

A truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the bridge’ design. If no horizontal thrusting forces are generated, this becomes an arch-shaped truss which is essentially a bent beam – see moon bridge for an example. If horizontal thrust is generated but the apex of the arch is a pin joint, this is termed as a three-hinged arch. If no hinge exists at the apex, it will normally be a two-hinged arch. In The Iron Bridge shown below, the structure of each frame emulates the kind of structure that previously had been made of wood. Such a wood structure uses closely fitted beams pinned together, so the members within the frames are not free to move relative to one another, as they are in a pin-jointed truss structure that allows rotation at the pin joint.…

Skew arch

A skew arch (also known as an oblique arch) is a method of construction that enables an arch bridge to span an obstacle at some angle other than a right angle. This results in the faces of the arch not being perpendicular to its abutments and its plan view being a parallelogram, rather than the rectangle that is the plan view of a regular, or square arch. In the case of a masonry skew arch, the construction requires precise stonecutting, as the cuts do not form right angles, but once the principles were fully understood in the early 19th century, it became considerably easier and cheaper to build a skew arch of brick. The problem of building skew arch masonry bridges was addressed by a number of early civil engineers and mathematicians, including Giovanni Barbara (1726), William Chapman (1787), Benjamin Outram (1798), Peter Nicholson (1828), George Stephenson (1830), Edward Sang…

Network arch bridge

A network arch bridge is a tied arch bridge with inclined hangers that cross each other at least twice. Structure The inclined hangers with multiple intersections make the network arch bridge act like a truss, with only axial compressible and tensile forces. Bending moments and shear forces are very small in network arches. The hanger arrangement is what separates network tied arch structures from other types of tied arches, such as those with vertical hangers. It is defined by the number of hangers, hanger inclination and hanger distance. A radial hanger arrangement provides an efficient structure, as shown by Benjamin Brunn and Frank Schanack in 2003. In the radial hanger arrangement the distances between the upper hanger nodes and the angle between hangers and arch remain constant. In order to avoid too long hangers this angle may be increased towards the bridge ends. History The network arch idea was developed…

Hinged arch bridge

A hinged arch bridge is one with hinges incorporated into its structure to allow movement. In structural engineering, a hinge is essentially a “cut in the structure” that can withstand compressive forces. In a steel arch the hinge allows free rotation, somewhat resembling a common hinge. The most common hinged arch bridge varieties are the two-hinged bridge with hinges at the springing points and the three-hinged bridge with an additional hinge at the crown of the arch; though single-hinged versions exist with a hinge only at the crown of the arch. Hinges at the springing point prevent bending moments from being transferred to the bridge abutments. A triple-hinged bridge is statically determinate, while the other versions are not. Description A fixed arch bridge, that is one without hinges, exerts a bending moment at the abutments and stresses caused by change of temperature or shrinkage of concrete have to be taken…

Tied-arch bridge

A tied-arch bridge is an arch bridge in which the outward-directed horizontal forces of the arch(es) are borne as tension by a chord tying the arch ends rather than by the ground or the bridge foundations. This strengthened chord may be the deck structure itself or consist of separate, independent tie-rods. Description Thrusts downwards on a tied-arch bridge deck are translated, as tension, by vertical ties between the deck and the arch, tending to flatten it and thereby to push its tips outward into the abutments, like for other arch bridges. However, in a tied-arch or bowstring bridge, these movements are restrained not by the abutments but by the strengthened chord, which ties these tips together, taking the thrusts as tension, rather like the string of a bow that is being flattened. Therefore, the design is also called a bowstring-arch or bowstring-girder bridge. The elimination of horizontal forces at the…

Through arch bridge

A through arch bridge, also known as a through-type arch bridge, is a bridge that is made from materials such as steel or reinforced concrete, in which the base of an arch structure is below the deck but the top rises above it. It can either be lower bearing or mid-bearing. Thus, the deck is within the arch, and cables or beams that are in tension suspend the central part of the deck from the arch. Function For a specific construction method, especially for masonry arches, the proportions of the arch remain similar no matter what the size: wider arches are thus required to be taller arches. For a semi-circular arch, the height is half of the span. Bridges across deep, narrow gorges can have their arch placed entirely beneath a flat roadway, but bridges in flatter country rise above their road approaches. A wide bridge may require an arch…

Arch bridge

An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side, and partially into a vertical load on the arch supports. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today. History Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks, the Romans were – as with the vault and the dome – the…

Gravity dam

A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Characteristics Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil. Stability of the dam primarily arises from the range of normal force angles viably generated by the foundation. Also, the stiff nature of a gravity dam structure endures differential foundation settlement poorly, as it can crack the dam structure. The main advantage to gravity dams over embankments is the scour-resistance of concrete, which protects against damage from minor over-topping flows. Unexpected large over-topping flows are still a problem, as they can scour…

Arch-gravity dam

An arch-gravity dam or arched dam is a dam with the characteristics of both an arch dam and a gravity dam. It is a dam that curves upstream in a narrowing curve that directs most of the water pressure against the canyon rock walls, providing the force to compress the dam. It combines the strengths of two common dam forms and is considered a compromise between the two. They are made of conventional concrete, roller-compacted concrete (RCC), or masonry. A typical example of the conventional concrete dam is the Hoover Dam. Changuinola Dam is an example of the RCC arch-gravity dam. A gravity dam requires a large volume of internal fill. An arch-gravity dam can be thinner than the pure gravity dam and requires less internal fill. Overview Arch-gravity dams are dams that resist the thrust of water by their weight using the force of gravity and the arch action.…

Arch dam

An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthening the structure as it pushes into its foundation or abutments. An arch dam is most suitable for narrow canyons or gorges with steep walls of stable rock to support the structure and stresses. Since they are thinner than any other dam type, they require much less construction material, making them economical and practical in remote areas. Classification In general, arch dams are classified based on the ratio of the base thickness to the structural height (b/h) as: Thin, for b/h less than 0.2, Medium-thick, for b/h between 0.2 and 0.3, and Thick, for b/h ratio over 0.3. Arch dams classified with respect to their structural height are:…

Character sketch

The word character sketch means a rough-and-ready rendering or thumbnail portrayal of an individual, capturing, in brief, that person’s physical characteristics, psychological attributes, and the like. The brief descriptions often capitalize on the more unusual or humorous aspects of the person’s character. Character sketches are usually identified by irony, humor, exaggeration, and satire. The term originates in portraiture, where the character sketch is a common academic exercise. The artist performing a character sketch attempts to capture an expression or gesture that goes beyond coincident actions and gets to the essence of the individual. In composition, a character sketch is a brief description in prose of a particular person or type of person. The ultimate goal of a writer is to take these character sketches and use them to craft a wonderfully engrossing, character-driven work of fiction. In an early-20th-century textbook, C.M. Stebbins noted that the character sketch is “a form…

Consumption distribution

In economics, the consumption distribution or consumption inequality is an alternative to the income distribution or wealth distribution for judging economic inequality, comparing levels of consumption or spending rather than income or wealth. This is an important measure of inequality as the basic utility of the wealth or income is the expenditure. People experience the inequality directly in consumption, rather than income or wealth. There is an important distinction between income and wealth. Income refers to a flow of money over time, commonly in the form of a wage or salary; wealth is a collection of assets owned, minus liabilities. In essence, income is what people receive through work, retirement, or social welfare whereas wealth is what people own. While the two are related, income inequality alone is insufficient for understanding economic inequality for two reasons: It does not accurately reflect an individual’s economic position. Income does not portray the…

Cultural behavior

Cultural behavior is behavior exhibited by humans (and, some would argue, by other species as well, though to a much lesser degree) that is extrasomatic or extragenetic—in other words, learned. Learned behavior There is a species of ant that builds nests made of leaves. To build a nest, some of these ants pull the edges of two leaves together and hold them in place, while others carry larva in their jaws and ‘sew’ them together with the silk they secrete. This is certainly a complex feat of engineering, but it is not cultural. This behavior is instinctive, built into the ants’ behavior mechanisms. They cannot alter their plans or think of better ways to join leaves. They cannot teach or be taught to do so. But there are examples of animals that can learn behaviors, such as dogs and cats. A dog doesn’t know instinctively not to urinate or defecate…

Cultural translation

Cultural translation is the practice of translation while respecting and showing cultural differences. This kind of translation solves some issues linked to culture, such as dialects, food or architecture. The main issues that cultural translation must solve consist of translating a text as showing the cultural differences of that text while also respecting the source culture as well. Translation of cultures Cultural translation is studied through cultural anthropology, a field of anthropology focused on cultural issues among humans. This discipline questions translation through cultural differences. Indeed, translation studies are not only based on language issues, but also on cultural contexts between people. An anthropological translator of cultures needs to deal with the issues between the source and the target language, that is to say he must respect at the same time the cultural source of point of view and the target culture. Wilhelm von Humboldt shared this opinion of translation…

Fiction writing

Fiction writing is the composition of non-factual prose texts. Fictional writing often is produced as a story meant to entertain or convey an author’s point of view. The result of this may be a short story, novel, novella, screenplay, or drama, which are all types (though not the only types) of fictional writing styles. Different types of authors practice fictional writing, including novelists, playwrights, short story writers, radio dramatists and screenwriters. Categories of prose fiction Genre fiction A genre is the subject matter or category that writers use. For instance, science fiction, fantasy and mystery fiction are genres. Genre fiction also known as popular fiction, is plot-driven fictional works written with the intent of fitting into a specific literary genre, to appeal to readers and fans already familiar with that genre. Genre fiction is storytelling driven by plot, as opposed to literary fiction, which focuses more on theme and character.…

Fiction-writing mode

A fiction-writing mode is a manner of writing imaginary stories with its own set of conventions regarding how, when, and where it should be used. Fiction is a form of narrative, one of the four rhetorical modes of discourse. Fiction-writing also has distinct forms of expression, or modes, each with its own purposes and conventions. Currently, there is no consensus within the writing community regarding the number and composition of fiction-writing modes and their uses. Some writing modes suggested include action, dialogue, thoughts, summary, scene, description, background, exposition and transition. Overview The concept goes back at least as far as Aristotle who, in Poetics, referred to narration and action as different modes or manner of representing something. For many years, fiction writing was described as having two types: narration and dialogue. Evan Marshall, in The Marshall Plan for Novel Writing (1998) noted that writers should know what they are doing…

Description

Description is any type of communication that aims to make vivid a place, object, person, group, or other physical entity. It is one of four rhetorical modes (also known as modes of discourse), along with exposition, argumentation, and narration. Fiction writing Fiction writing specifically has modes such as action, exposition, description, dialogue, summary, and transition. Author Peter Selgin refers to methods, including action, dialogue, thoughts, summary, scenes, and description. Description is the mode for transmitting a mental image of the particulars of a story. Together with dialogue, narration, exposition, and summarization, it is one of the most widely recognized of the fiction-writing modes. As stated in Writing from A to Z, edited by Kirk Polking, it is more than the amassing of details; it is bringing something to life by carefully choosing and arranging words and phrases to produce the desired effect. Purple prose A purple patch is an over-written…

Essay

An essay is, generally, a piece of writing that gives the author’s own argument, but the definition is vague, overlapping with those of a letter, a paper, an article, a pamphlet, and a short story. Essays have been sub-classified as formal and informal: formal essays are characterized by “serious purpose, dignity, logical organization, length,” whereas the informal essay is characterized by “the personal element (self-revelation, individual tastes and experiences, confidential manner), humor, graceful style, rambling structure, unconventionality or novelty of theme,” etc. Essays are commonly used as literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author. Almost all modern essays are written in prose, but works in verse have been dubbed essays (e.g., Alexander Pope’s An Essay on Criticism and An Essay on Man). While brevity usually defines an essay, voluminous works like John Locke’s An Essay Concerning Human Understanding and Thomas Malthus’s…

Diegesis

Diegesis is a style of fiction storytelling in which a participating narrator offers an on-site, often interior, view of the scene to the reader, viewer, or listener by subjectively describing the actions and, in some cases, thoughts, of one or more characters. Diegetic events are those experienced by both the characters within a piece and the audience, while non-diegetic elements of a story make up the “fourth wall” separating the characters from the audience. Diegesis in music describes a character’s ability to hear the music presented for the audience, in the context of musical theatre or film scoring. Origin Diegesis (Greek διήγησις “narration”) and mimesis (Greek μίμησις “imitation”) have been contrasted since Aristotle. For Aristotle, mimesis shows rather than tells, by means of action that is enacted. Diegesis is the telling of a story by a narrator. The narrator may speak as a particular character, or may be the invisible…

Cliché

A cliché is a saying, idea, or element of an artistic work that has become overused to the point of losing its original meaning, novelty, or figurative or artistic power, even to the point of now being bland or uninteresting. In phraseology, the term has taken on a more technical meaning, referring to an expression imposed by conventionalized linguistic usage. The term, which is typically pejorative, is often used in modern culture for an action or idea that is expected or predictable, based on a prior event. Clichés may or may not be true. Some are stereotypes, but some are simply truisms and facts. Clichés often are employed for comedic effect, typically in fiction. Most phrases now considered clichéd originally were regarded as striking but have lost their force through overuse. The French poet Gérard de Nerval once said, “The first man who compared woman to a rose was a…

Characterization

Characterization or characterisation is the representation of characters (persons, creatures, or other beings) in narrative and dramatic works. The term character development is sometimes used as a synonym. This representation may include direct methods like the attribution of qualities in description or commentary, and indirect (or “dramatic”) methods inviting readers to infer qualities from characters’ actions, dialogue, or appearance. Such a personage is called a character. Character is a literary element. History The term characterization was introduced in the 19th century. Aristotle promoted the primacy of plot over characters, that is, a plot-driven narrative, arguing in his Poetics that tragedy “is a representation, not of men, but of action and life.” This view was reversed in the 19th century, when the primacy of the character, that is, a character-driven narrative, was affirmed first with the realist novel, and increasingly later with the influential development of psychology. Direct vs. indirect There…