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Example research essay topic: One Of The First Gas Chromatography - 2,184 words

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... e to make the whole print glow when the laser beam hits it. The technique of laser-sweeping enables large areas to be searched quickly, and prints in odd places can be found. Dusting the same surfaces with powder would take much longer and prints in unlikely places could be miss altogether.

Prints found by a laser can also be dusted with fluorescent powder to make them show up even more clearly so they can be photographed. Fibers play an important role in crime detection. A fiber found on a suspect may match fibers from clothings, carpets or upholstery at the scene of the crime. Or a fiber from the suspect's clothing maybe found at the scene of the crime. Sample of fibers from the suspect and from the scene of the crime can be compared in many ways to see if they match. The samples may appear similar through the microscope when viewed under ordinary light conditions, but one sample may look quite different under ultraviolet light.

Any dyes present in the fibers can be dissolved out and then separated by thin-layer chromatography. In a simple form of chromatography, a solution of the dye is soaked up by a strip of absorbent paper. Different substances in the dye move along the paper at different rates, so they become separated into distinct bands of diff- rent colors. If two samples of dye are identical, they will produce identical set of bands. If all of the above tests show the fibers to be similar, they are finally analyzed to make sure they are made of the same substance. Analysis can also be used to find the source of fibers.

For example, in one recent case, analysis of fibers revealed that they came from a single batch of a particular manufacturer's space carpets. Automobiles fitted with the carpets were traced, and the criminal was found among the owners. Like thin film cosmography, gas chromatography is used to separate substances in mixtures, however, in this case, substances are in gaseous form. One of the most common applications of gas chromatography in forensic science is for the measurement of the alcohol content in the blood. This is carried out when a driver has failed a breath test, and is suspected of having drunk too much alcohol. A stream of nitrogen gas is blown through a sample of the driver's blood.

The nitrogen removes alcohol from the blood, and carries it as a vapour through a long tube. This is packed with a material that holds back any other substances that have been removed from the body by the nitrogen. At the far end of the tube, any alcohol that emerges is detected and measured by an electronic device. As the original amount of blood in the sample is known, the concentration of alcohol that was in it can then be calculated.

In recent years, gas chromatography has become one of the most important techniques in forensic science and has led to thousands of successful prosecutions. FORENSIC SCIENCE TIMELINEBCE Evidence of fingerprints in early paintings and rock carvings of prehistoric humans 700 s Chinese used fingerprints to establish identity of documents and clay sculpture, but without any formal classification system. 1000 Quintilian, an attorney in the Roman courts, showed that bloody palm prints were meant to frame a blind man of his mother's murder. 1248 A Chinese book, Hsi Duan Yu (the washing away of wrongs), contains a description of how to distinguish drowning from strangulation. This was the first recorded application of medical knowledge to the solution of crime. 1609 The first treatise on systematic document examination was published by Franois Demelle of France 1686 Marcello Malpighi, a professor of anatomy at the University of Bologna, noted fingerprint characteristics. However, he made no mention of their value as a tool for individual identification. 1784 In Lancaster, England, John Toms was convicted of murder on the basis of the torn edge of wad of newspaper in a pistol matching a remaining piece in his pocket. This was one of the first documented uses of physical matching. 1800 s Thomas Bewick, an English naturalist, used engravings of his own fingerprints to identify books he published. 1810 Engine Franois Vidocq, in return for a suspension of arrest and a jail sentence, made a deal with the police to establish the first detective force, the Set of Paris. The first recorded use of question document analysis occurred in Germany.

A chemical test for a particular ink dye was applied to a document known as the Konig in Hanschritt. 1813 Matthew Orfila, a Spaniard who became professor of medicinal / forensic chemistry at University of Paris, published Trade des Poisons Tires des Regnes Mineral, Vegetal et Animal, ou Toxicologie General l. Orfila is considered the father of modern toxicology. He also made significant contributions to the development of tests for the presence of blood in a forensic context and is credited as the first to attempt the use of a microscope in the assessment of blood and semen stains. 1823 John Evangelist Purkinji, a professor professor of anatomy at the University of Breslau, Czechoslovakia, published the first paper on the nature of fingerprints and suggested a classification system based on nine major types. However, he failed to recognize their individualizing potential. 1828 William Nichol invented the polarizing light microscope. 1830 s Adolphe Quetelet, a Belgian statistician, provided the foundation for Bertillon's work by stating his belief that no two human bodies were exactly alike. 1831 Leuchs first noted amylase activity in human saliva. 1835 Henry Goddard, one of Scotland Yard's original Bow Street Runners, first used bullet comparison to catch a murderer. His comparison was based on a visible flaw in the bullet which was traced back to a mold.

James Marsh, an Scottish chemist, was the first to use toxicology (arsenic detection) in a jury trial. H. Bayard published the first reliable procedures for the microscopic detection of sperm. He also noted the different microscopic characteristics of various different substrate fabrics.

Jean Servers Stas, a chemistry professor professor from Brussels, Belgium, was the first successfully to identify vegetable poisons in body tissue. Ludwig T eichmann, in Krakow, Poland, developed the first microscopic crystal test for hemoglobin using An English physician, Maddox, developed dry plate photography, eclipsing M. Daguerre's wet plate on tin method. This made practical the photographing of inmates for prison records. Sir William Herschel, a British officer working for the Indian Civil service, began to use thumbprints on documents both as a substitute for written signatures for illiterates and to verify document signatures. The Dutch scientist J. (Izaak) Van Deen developed a presumptive test for blood using gaia, a West Indian The German scientist Schnbein first discovered the ability of hemoglobin to oxidize hydrogen peroxide making it foam.

This resulted in first presumptive test for blood. Odelbrecht first advocated the use of photography for the identification of criminals and the documentation of evidence and crime scenes. Thomas Taylor, microscopist to U. S.

Department of Agriculture suggested that markings of the palms of the hands and the tips of the fingers could be used for identification in criminal cases. Although reported in the American Journal of Microscopy and Popular Science and Scientific American, the idea was apparently never pursued from this source. Rudolph Virchow, a German pathologist, was one of the first to both study hair and recognize its limitations. Henry Faulds, a Scottish physician working in Tokyo, published a paper in the journal Nature suggesting that fingerprints at the scene of a crime could identify the offender.

In one of the first recorded uses of fingerprints to solve a crime, Faulds used fingerprints to eliminate an innocent suspect and indicate a perpetrator in a Gilbert Thompson, a railroad builder with the U. S Geological Survey in New Mexico, put his own thumbprint on wage chits to safeguard himself from forgeries. Alphonse Bertillon, a French police employee, identified the first recidivist based on his invention of Arthur Conan Doyle published the first Sherlock Holmes story in Beeton's Christmas Annual of London. Alexandre Lacassagne, professor professor of forensic medicine at the University of Lyons, France, was the first to try to individualize bullets to a gun barrel. His comparisons at the time were based simply on the number Hans Gross, examining magistrate and professor of criminal law at the University of Graz, Austria, published Criminal Investigation, the first comprehensive description of uses of physical evidence in solving crime. Gross is also sometimes credited with coining the word criminalistic's. (Sir) Francis Galton published Fingerprints, the first comprehensive book on the nature of fingerprints and their Juan Vucetich, an Argentinean police researcher, developed the fingerprint classification system that would come to be used in Latin America.

After Vucetich implicated a mother in the murder of her own children using her bloody fingerprints, Argentina was the first country to replace anthropometry with fingerprints. Alfred Dreyfus of France was convicted of treason based on a mistaken handwriting identification by Bertillon. Sir Edward Richard Henry developed the print classification system that would come to be used in Europe and North America. He published Classification and Uses of Finger Prints.

Paul Jessica, a forensic chemist working in Berlin, Germany, took photomicrographs of two bullets to compare, and subsequently individualize, the minutiae. Paul Uhlenhuth, a German immunologist, developed the precipice test for species. He was also one of the first to institute standards, controls, and QA/QC procedures. Wassermann (famous for developing a test for syphilis) and Scheme independently discovered and published the precipice test, but never received due Karl Landsteiner first discovered human blood groups and was awarded the Nobel prize for his work in 1930.

Max Richter adapted the technique to type stains. This is one of the first instances of performing validation experiments specifically to adapt a method for forensic science. Landsteiner's continued work on the detection of blood, its species, and its type formed the basis of practically all subsequent work. Sir Edward Richard Henry was appointed head of Scotland Yard and forced the adoption of fingerprint identification to replace anthropometry. Henry P. De Forrest pioneered the first systematic use of fingerprints in the United States by the New York Civil Service Commission.

professor R. A. Reiss, professor at the University of Lausanne, Switzerland, and a pupil of Bertillon, set up one of the first academic curricula in forensic science. His forensic photography department grew into Lausanne Institute of Police Science. The New York State Prison system began the first systematic use of fingerprints in United States for criminal At Leavenworth State Prison, Kansas, Will West, a new inmate, was differentiated from resident convict Will West by fingerprints, not anthropometry. They were later found to be identical twins.

Oskar and Rudolf Adler developed a presumptive test for blood based on benzidine, a new chemical American President Theodore Roosevelt established Federal Bureau of Investigation (FBI). Victor Balthazard, professor of forensic medicine at the Sorbonne, with Marcelle Lambert, published the first comprehensive hair study, Le post de l'homme et des animaux. In one of the first cases involving hairs, Rosella Rousseau was convinced to confess to murder of Germaine Bichon. Balthazard also used photographic enlargements of bullets and cartridge cases to determining weapon type and was among the first to attempt to individualize a bullet to a weapon. Edmund Locard, successor to Lacassagne as professor of forensic medicine at the University of Lyons, France, established the first police crime laboratory. Albert S.

Osborne, an American and arguably the most influential document examiner, published Questioned Master Takayama developed another microscopic crystal test for hemoglobin using hemochromogen crystals. Victor Balthazard, professor of forensic medicine at the Sorbonne, published the first article on individualizing Leone Lattes, professor at the Institute of Forensic Medicine in Turin Italy, developed the first antibody test for ABO blood groups. He first used the test in casework to resolve a marital dispute. He published L'Individualit del single nella biologia, nella clinica, nella medicina, legale, the first book dealing not only with clinical issues, but heritability, paternity, and typing of dried stains. International Association for Criminal Identification, (to become The International Association of Identification (IAI), was organized in Oakland, California.

Albert Schneider of Berkeley, California first used a vacuum apparatus to collect trace evidence. Edmond Locard first suggested 12 matching points as a positive fingerprint identification. Locard published L'enquire criminelle et les methode's scientifique, in which appears a passage that may have given rise to the forensic precept that "Every contact leaves a trace. " Charles E. Waite was the first to catalog manufacturing data about weapons.

Georg Popp pioneered the use of botanical identification in forensic work. Luke May, one of the first American criminalist's, pioneered striation analysis in tool mark comparison, including an attempt at statistical validation. In 1930 he published The identification of knives, tools and instruments, a positive science, in The American Journal of Police Science. Calvin Goddard, with Charles Waite, Phillip O. Gravelly, and John H Fisher, perfected the comparison microscope for use in bullet comparison. John Larson and Leonard Keeler designed the portable polygraph.

Vittorio Siracusa, working at the Inst Bibliography:


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Research essay sample on One Of The First Gas Chromatography

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