APA style is most commonly used in the social and behavioral sciences as well as in first-year composition classes at UTEP. In APA style, citations to sources are placed in the text of the paper in order to briefly identify sources for readers and enable them to locate the source of the cited information in the Reference List. Appearing on its own page between the endnotes and the appendixes, the Reference List must include full citations for all sources of borrowed information. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
The Harvard System is used in many universities but it does not work very well if you are citing URLs. Whatever system you choose to use, you must be consistent with the format of your referencing. If you are referencing the same source as in a previous footnote you can shorten the reference using Op. 1906: Availability of panchromatic black and white film and therefore high quality color separation color photography.
G+ #Read of the Day: The Daguerreotype - The daguerreotype, an early form of photograph, was invented by Louis Daguerre in the early 19th c. The first photograph (1826) - Joseph Niepce, a French inventor and pioneer in photography, is generally credited with producing the first photograph. Easy Peasy Fact:Following Niepcea€™s experiments, in 1829 Louis Daguerre stepped up to make some improvements on a novel idea. Hard X-rays can penetrate solid objects, and their largest use is to take images of the inside of objects in diagnostic radiography and crystallography. The roentgen (R) is an obsolete traditional unit of exposure, which represented the amount of radiation required to create one electrostatic unit of charge of each polarity in one cubic centimeter of dry air. The rad is the (obsolete) corresponding traditional unit, equal to 10 millijoules of energy deposited per kilogram. The sievert (Sv) is the SI unit of equivalent dose, which for X-rays is numerically equal to the gray (Gy). X-rays are generated by an X-ray tube, a vacuum tube that uses a high voltage to accelerate the electrons released by a hot cathode to a high velocity. In crystallography, a copper target is most common, with cobalt often being used when fluorescence from iron content in the sample might otherwise present a problem. X-ray fluorescence: If the electron has enough energy it can knock an orbital electron out of the inner electron shell of a metal atom, and as a result electrons from higher energy levels then fill up the vacancy and X-ray photons are emitted. So the resulting output of a tube consists of a continuous bremsstrahlung spectrum falling off to zero at the tube voltage, plus several spikes at the characteristic lines. In medical diagnostic applications, the low energy (soft) X-rays are unwanted, since they are totally absorbed by the body, increasing the dose. To generate an image of the cardiovascular system, including the arteries and veins (angiography) an initial image is taken of the anatomical region of interest. A specialized source of X-rays which is becoming widely used in research is synchrotron radiation, which is generated by particle accelerators. The most commonly known methods are photographic plates, photographic film in cassettes, and rare earth screens.
Before the advent of the digital computer and before invention of digital imaging, photographic plates were used to produce most radiographic images.
Since photographic plates are sensitive to X-rays, they provide a means of recording the image, but they also required much X-ray exposure (to the patient), hence intensifying screens were devised. Areas where the X-rays strike darken when developed, causing bones to appear lighter than the surrounding soft tissue. Contrast compounds containing barium or iodine, which are radiopaque, can be ingested in the gastrointestinal tract (barium) or injected in the artery or veins to highlight these vessels. An increasingly common method is the use of photostimulated luminescence (PSL), pioneered by Fuji in the 1980s. The PSP plate can be reused, and existing X-ray equipment requires no modification to use them. For many applications, counters are not sealed but are constantly fed with purified gas, thus reducing problems of contamination or gas aging. Some materials such as sodium iodide (NaI) can "convert" an X-ray photon to a visible photon; an electronic detector can be built by adding a photomultiplier. Fresco of Approving of bylaw of Society of Jesus depicting Ignatius of Loyola receiving papal bull Regimini militantis Ecclesiae from Pope Paul 3.
This group bound themselves by a vow of poverty and chastity, to "enter upon hospital and missionary work in Jerusalem, or to go without questioning wherever the pope might direct". They called themselves the Company of Jesus, and also Amigos En El Senor or "Friends in the Lord," because they felt "they were placed together by Christ." The name had echoes of the military (as in an infantry "company"), as well as of discipleship (the "companions" of Jesus). Citations are placed within sentences and a paragraph so that it is clear what information is being quoted or paraphrased and whose information is being cited.Option 1      Bartholemew (1992) believed that all institutions are "genuinely responsive to the essential problems but may be irrelevant to those problems if necessary legal services are not readily obtainable by those who might benefit from them” (p.
Talbot was active from the mid-1830s, and sits alongside Louis Daguerre as one of the fathers of the medium.
Niepcea€™s photograph shows a view from the Window at Le Gras, and it only took eight hours of exposure time!The history of photography has roots in remote antiquity with the discovery of the principle of the camera obscura and the observation that some substances are visibly altered by exposure to light.
Again employing the use of solvents and metal plates as a canvas, Daguerre utilized a combination of silver and iodine to make a surface more sensitive to light, thereby taking less time to develop. This process produces an emission spectrum of X-ray frequencies, sometimes referred to as the spectral lines.
The intensity of the X-rays increases linearly with decreasing frequency, from zero at the energy of the incident electrons, the voltage on the X-ray tube.


A second image is then taken of the same region after iodinated contrast material has been injected into the blood vessels within this area. The contrast compounds have high atomic numbered elements in them that (like bone) essentially block the X-rays and hence the once hollow organ or vessel can be more readily seen.
In modern hospitals a photostimulable phosphor plate (PSP plate) is used in place of the photographic plate. Ignatius of Loyola, who after being wounded in a battle, experienced a religious conversion and composed the Spiritual Exercises to closely follow Christ.
The fresco was created by Johann Christoph Handke in the Church of Our Lady Of the Snow in Olomouc after 1743. Porta (1541-1615), a wise Neapolitan, was able to get the image of well-lighted objects through a small hole in one of the faces of a dark chamber; with a convergent lens over the enlarged hole, he noticed that the images got even clearer and sharper.
Though he is most famous for his contributions to photography, he was also an accomplished painter and a developer of the diorama theatre. As far as is known, nobody thought of bringing these two phenomena together to capture camera images in permanent form until around 1800, when Thomas Wedgwood made the first reliably documented although unsuccessful attempt. The spectral lines generated depend on the target (anode) element used and thus are called characteristic lines. These two images are then digitally subtracted, leaving an image of only the iodinated contrast outlining the blood vessels. Photographic film largely replaced these plates, and it was used in X-ray laboratories to produce medical images.
In the pursuit of a non-toxic contrast material, many types of high atomic number elements were evaluated.
After the plate is X-rayed, excited electrons in the phosphor material remain "trapped" in "colour centres" in the crystal lattice until stimulated by a laser beam passed over the plate surface. Electrons accelerate toward the anode, in the process causing further ionization along their trajectory. Schulze mixes chalk, nitric acid, and silver in a flask; notices darkening on side of flask exposed to sunlight. A daguerreotype, produced on a silver-plated copper sheet, produces a mirror image photograph of the exposed scene.
The radiologist or surgeon then compares the image obtained to normal anatomical images to determine if there is any damage or blockage of the vessel. In more recent years, computerized and digital radiography has been replacing photographic film in medical and dental applications, though film technology remains in widespread use in industrial radiography processes (e.g. For example, the first time the forefathers used contrast it was chalk, and was used on a cadaver's vessels. This process, known as a Townsend avalanche, is detected as a sudden current, called a "count" or "event". The alchemist Fabricio, more or less at the same period of time, observed that silver chloride was darkened by the action of light.
Chemistry student Robert Cornelius was so fascinated by the chemical process involved in Daguerrea€™s work that he sought to make some improvements himself.
When the film is developed, the parts of the image corresponding to higher X-ray exposure are dark, leaving a white shadow of bones on the film.
It was only two hundred years later that the physicist Charles made the first photographic impression, by projecting the outlines of one of his pupils on a white paper sheet impregnated with silver chloride. It was commercially introduced in 1839, a date generally accepted as the birth year of practical photography.The metal-based daguerreotype process soon had some competition from the paper-based calotype negative and salt print processes invented by Henry Fox Talbot. And in 1839 Cornelius shot a self-portrait daguerrotype that some historians believe was the first modern photograph of a man ever produced.
Photographic plates are mostly things of history, and their replacement, the "intensifying screen", is also fading into history.
The metal silver (formerly necessary to the radiographic & photographic industries) is a non-renewable resource. 27), a methods section which "describes in detail how the study was conducted, including conceptual and operational definitions of the variables used in the study," (p.
The photos were turned into lantern slides and projected in registration with the same color filters. Thus it is beneficial that this is now being replaced by digital (DR) and computed (CR) technology. 29), a results section which summarizes the "collected data and the analysis performed on those data relevant to the discourse that is to follow" (p. In 1802, Wedgwood reproduced transparent drawings on a surface sensitized by silver nitrate and exposed to light. Where photographic films required wet processing facilities, these new technologies do not. 32), and the discussion, which is where the author should "examine, interpret, and qualify the results and draw inferences and conclusions from them" (p. Nicephore Niepce (1765-1833) had the idea of using as sensitive material the bitumen, which is altered and made insoluble by light, thus keeping the images obtained unaltered.
Long before the first photographs were made, Chinese philosopher Mo Ti and Greek mathematicians Aristotle and Euclid described a pinhole camera in the 5th and 4th centuries BCE.
He communicated his experiences to Daguerre (1787-1851) who noticed that a iodide-covered silver plate - thedaguerreotype -, by exposition to iodine fumes, was impressed by the action of light action, and that the almost invisible alteration could be developed with the exposition to mercury fumes.
In the 6th century CE, Byzantine mathematician Anthemius of Tralles used a type of camera obscura in his experimentsIbn al-Haytham (Alhazen) (965 in Basra a€“ c. It was then fixed with a solution of potassium cyanide, which dissolves the unaltered iodine.The daguerreotype (1839) was the first practical solution for the problem of photography.


In 1841, Claudet discovered quickening substances, thanks to which exposing times were shortened. More or less at the same time period, EnglishWilliam Henry Talbot substituted the steel daguerreotype with paper photographs (named calotype).
Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694.
Niepce of Saint-Victor (1805-1870), Nicephorea€™s cousin, invented the photographic glass plate covered with a layer of albumin, sensitized by silver iodide. The novel Giphantie (by the French Tiphaigne de la Roche, 1729a€“74) described what could be interpreted as photography.Around the year 1800, Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance. Maddox and Benett, between 1871 and 1878, discovered the gelatine-bromide plate, as well as how to sensitize it.
As with the bitumen process, the result appeared as a positive when it was suitably lit and viewed. A strong hot solution of common salt served to stabilize or fix the image by removing the remaining silver iodide. On 7 January 1839, this first complete practical photographic process was announced at a meeting of the French Academy of Sciences, and the news quickly spread.
At first, all details of the process were withheld and specimens were shown only at Daguerre's studio, under his close supervision, to Academy members and other distinguished guests. Paper with a coating of silver iodide was exposed in the camera and developed into a translucent negative image. Unlike a daguerreotype, which could only be copied by rephotographing it with a camera, a calotype negative could be used to make a large number of positive prints by simple contact printing. The calotype had yet another distinction compared to other early photographic processes, in that the finished product lacked fine clarity due to its translucent paper negative.
This was seen as a positive attribute for portraits because it softened the appearance of the human face. Talbot patented this process,[20] which greatly limited its adoption, and spent many years pressing lawsuits against alleged infringers.
He attempted to enforce a very broad interpretation of his patent, earning himself the ill will of photographers who were using the related glass-based processes later introduced by other inventors, but he was eventually defeated. Nonetheless, Talbot's developed-out silver halide negative process is the basic technology used by chemical film cameras today. Hippolyte Bayard had also developed a method of photography but delayed announcing it, and so was not recognized as its inventor.In 1839, John Herschel made the first glass negative, but his process was difficult to reproduce. The new formula was sold by the Platinotype Company in London as Sulpho-Pyrogallol Developer.Nineteenth-century experimentation with photographic processes frequently became proprietary.
This adaptation influenced the design of cameras for decades and is still found in use today in some professional cameras.
Petersburg, Russia studio Levitsky would first propose the idea to artificially light subjects in a studio setting using electric lighting along with daylight. In 1884 George Eastman, of Rochester, New York, developed dry gel on paper, or film, to replace the photographic plate so that a photographer no longer needed to carry boxes of plates and toxic chemicals around. Now anyone could take a photograph and leave the complex parts of the process to others, and photography became available for the mass-market in 1901 with the introduction of the Kodak Brownie.A practical means of color photography was sought from the very beginning. Results were demonstrated by Edmond Becquerel as early as 1848, but exposures lasting for hours or days were required and the captured colors were so light-sensitive they would only bear very brief inspection in dim light.The first durable color photograph was a set of three black-and-white photographs taken through red, green and blue color filters and shown superimposed by using three projectors with similar filters.
It was taken by Thomas Sutton in 1861 for use in a lecture by the Scottish physicist James Clerk Maxwell, who had proposed the method in 1855.[27] The photographic emulsions then in use were insensitive to most of the spectrum, so the result was very imperfect and the demonstration was soon forgotten. Maxwell's method is now most widely known through the early 20th century work of Sergei Prokudin-Gorskii.
Included were methods for viewing a set of three color-filtered black-and-white photographs in color without having to project them, and for using them to make full-color prints on paper.[28]The first widely used method of color photography was the Autochrome plate, commercially introduced in 1907. If the individual filter elements were small enough, the three primary colors would blend together in the eye and produce the same additive color synthesis as the filtered projection of three separate photographs.
Autochrome plates had an integral mosaic filter layer composed of millions of dyed potato starch grains. Reversal processing was used to develop each plate into a transparent positive that could be viewed directly or projected with an ordinary projector. The mosaic filter layer absorbed about 90 percent of the light passing through, so a long exposure was required and a bright projection or viewing light was desirable. Competing screen plate products soon appeared and film-based versions were eventually made.
A complex processing operation produced complementary cyan, magenta and yellow dye images in those layers, resulting in a subtractive color image.
Kirsch at the National Institute of Standards and Technology developed a binary digital version of an existing technology, the wirephoto drum scanner, so that alphanumeric characters, diagrams, photographs and other graphics could be transferred into digital computer memory.
The lab was working on the Picturephone and on the development of semiconductor bubble memory. The essence of the design was the ability to transfer charge along the surface of a semiconductor.
Michael Tompsett from Bell Labs however, who discovered that the CCD could be used as an imaging sensor.



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