Topic 12 Flashcards
– the art of extracting and working on metals by the application of chemical and physical knowledge.
Metallurgy
– branch of metallurgy that involves the study of the microstructures of metals and alloys. All metals are composed of minute grains or crystals, under the naked eye and when viewed from a distance a metal appears to be homogeneous but when viewed under a metallographymicroscope the crystal structure is visible. These crystals of the metal are tightly packed.
Metallography
are coins made to imitate the real thing and used for gain.
Counterfeit coins
– coins made in molds.
Cast coins
– coins made by striking or stamping method.
Struck coins
– An impression of genuine coin is taken by use of Plaster of Paris, clay or bronze. The plaster molds bearing the image of a good coin are filled within a low temperature alloy made with lead or tin. Sand molds are used for high temperature metals such as copper or silver alloys. Cast coins have poor imitation. It can be easily detected. The surface is usually pitted and uneven. The edge of letterings and designs are rounded instead of sharp.
Cast Coins
– Made by striking or stamping method. Consists of making an impression of a coin on a metal blank by pressure. Stamping is done by way of steel dies. Often well executed. Its detection is not easy since weight, specific gravity, composition may all be good. Careful comparison of smaller details of the design with those of the genuine should be made.
Stuck Coins
are restored by the application of etching liquid. Etching fluid is a fluid used to restore tampered serial numbers. Choice of etching depends on the structure of the metal bearing the original numbers.
Tampered serial numbers
is associated with the medico-legal aspects of toxicology; it plays an essential role in criminal and coroner investigations of poisoning, drug use and death, as well as in suspected cases of doping, inhalant or drug abuse, and driving under the influence of alcohol or drugs. This forensic discipline applies analytical chemistry to isolate and chemically identify toxic substances, drugs (prescription and illicit), alcohol, volatile substances and industrial, household or environmental chemicals that adversely affect the human body.
Forensic Toxicology
– This refers to the branch of science that treats of poison, their origin, physical and chemical properties, physiological action, treatment of their noxious effect and methods of detection.
Toxicology
The etymology of toxicology came from ____ that means poison and ____ that means study or science.
“toxico”
“ology”
– are nitrogenous organic basic compound with bitter containing usually oxygen that occurs especially in seed plants.
Alkaloids
– highly irritant poisons that cause local destruction of tissues and characterized by nausea, vomiting, and great local distress. E.g. strong acids and alkalis.
Corrosives
– one that produces irritation or inflammation of the mucus membrane and characterized by vomiting, pain in the abdomen and purging. E.g. arsenic.
Irritants
– one that produce stupor, complete insensibility, or loss of feeling. E.g. opium, Demerol and cocaine.
Narcotics
– one that act chiefly on the nervous system producing delirium, convulsion and respiration as the outstanding symptoms. E.g. alcohol, opium, and strychnine.
Neurotics
– substance that act chiefly upon the spinal column producing such spasmodic and continuous contraction of muscles as a result of stiffness or immobility of the parts to which they are attached.
Tetanics
