A metal is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, conducts electricity and heat well. Metals are malleable or ductile. A metal may be a chemical element such as iron. In physics, a metal is regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not classified as metals become metallic under high pressures. For example, the nonmetal iodine becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure; some materials regarded as metals can become nonmetals. Sodium, for example, becomes a nonmetal at pressure of just under two million times atmospheric pressure. In chemistry, two elements that would otherwise qualify as brittle metals—arsenic and antimony—are instead recognised as metalloids, on account of their predominately non-metallic chemistry. Around 95 of the 118 elements in the periodic table are metals; the number is inexact as the boundaries between metals and metalloids fluctuate due to a lack of universally accepted definitions of the categories involved.
In astrophysics the term "metal" is cast more to refer to all chemical elements in a star that are heavier than the lightest two and helium, not just traditional metals. A star fuses lighter atoms hydrogen and helium, into heavier atoms over its lifetime. Used in that sense, the metallicity of an astronomical object is the proportion of its matter made up of the heavier chemical elements. Metals, as chemical elements, comprise 25% of the Earth's crust and are present in many aspects of modern life; the strength and resilience of some metals has led to their frequent use in, for example, high-rise building and bridge construction, as well as most vehicles, many home appliances, tools and railroad tracks. Precious metals were used as coinage, but in the modern era, coinage metals have extended to at least 23 of the chemical elements; the history of refined metals is thought to begin with the use of copper about 11,000 years ago. Gold, iron and brass were in use before the first known appearance of bronze in the 5th millennium BCE.
Subsequent developments include the production of early forms of steel. Metals are lustrous, at least when freshly prepared, polished, or fractured. Sheets of metal thicker than a few micrometres appear opaque; the solid or liquid state of metals originates in the capacity of the metal atoms involved to lose their outer shell electrons. Broadly, the forces holding an individual atom's outer shell electrons in place are weaker than the attractive forces on the same electrons arising from interactions between the atoms in the solid or liquid metal; the electrons involved become delocalised and the atomic structure of a metal can be visualised as a collection of atoms embedded in a cloud of mobile electrons. This type of interaction is called a metallic bond; the strength of metallic bonds for different elemental metals reaches a maximum around the center of the transition metal series, as these elements have large numbers of delocalized electrons. Although most elemental metals have higher densities than most nonmetals, there is a wide variation in their densities, lithium being the least dense and osmium the most dense.
Magnesium and titanium are light metals of significant commercial importance. Their respective densities of 1.7, 2.7 and 4.5 g/cm3 can be compared to those of the older structural metals, like iron at 7.9 and copper at 8.9 g/cm3. An iron ball would thus weigh about as much as three aluminium balls. Metals are malleable and ductile, deforming under stress without cleaving; the nondirectional nature of metallic bonding is thought to contribute to the ductility of most metallic solids. In contrast, in an ionic compound like table salt, when the planes of an ionic bond slide past one another, the resultant change in location shifts ions of the same charge into close proximity, resulting in the cleavage of the crystal; such a shift is not observed in a covalently bonded crystal, such as a diamond, where fracture and crystal fragmentation occurs. Reversible elastic deformation in metals can be described by Hooke's Law for restoring forces, where the stress is linearly proportional to the strain. Heat or forces larger than a metal's elastic limit may cause a permanent deformation, known as plastic deformation or plasticity.
An applied force may be a compressive force, or a shear, bending or torsion force. A temperature change may affect the movement or displacement of structural defects in the metal such as grain boundaries, point vacancies and screw dislocations, stacking faults and twins in both crystalline and non-crystalline metals. Internal slip and metal fatigue may ensue; the atoms of metallic substances are arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others. In fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layer
Neil Clifford Ramiller is an American academic, Professor of Management at the Portland State University School of Business Administration, known for his work with Swanson, E. Burton on the management of information-technology innovations on organizing vision. After received his BA in Anthropology and Chemistry from Sonoma State University, Ramiller has done graduate work in anthropology and linguistics in the 1970s. In 1996 he received his PhD from the UCLA Anderson School of Management under supervision of E. Burton Swanson, his MBA from University of California, Berkeley. In the 1970s Ramiller had started his career in cultural resources management, doing both archaeological fieldwork and administration. In the 1980s he moved into the software industry, working in software development, documentation and consultancy. In the 1990s he joined the UCLA Anderson School of Management. In the new millennium he was appointed Professor of Management at the Portland State University School of Business Administration.
Ramiller was part of the editorial board of the journals Information & Organization, Information Technology & People, was associate editor for MIS Quarterly. He has been member of the International Federation for Information Processing Working Group 8.2. Ramiller was awarded for best paper published in MIS Quarterly in 2004. Ramiller co-authored many publications. Articles, a selection: Swanson, E. Burton, Neil C. Ramiller. "Information systems research thematics: submissions to a new journal, 1987–1992." Information Systems Research 4.4: 299-330. Ramiller, Neil C. "Perceived compatibility of information technology innovations among secondary adopters: Toward a reassessment." Journal of Engineering and Technology Management 11.1: 1-23. Swanson, E. Burton, Neil C. Ramiller. "The organizing vision in information systems innovation." Organization science 8.5: 458-474. Swanson, E. Burton, Neil C. Ramiller. "Innovating mindfully with information technology." MIS Quarterly: 553-583. Wang and Neil C. Ramiller. "Community learning in information technology innovation."
MIS Quarterly 33.4: 709-734. Neil Ramiller at Portland State University
Fields of Sacrifice is a 1964 documentary by Donald Brittain about Canadian war dead. The film visits former battlefields where over 100,000 Canadian soldiers lost their lives in World War I and World War II and examines Canadian military cemeteries and memorials from Hong Kong to Sicily. Fields of Sacrifice was produced by the National Film Board of Canada for the Canadian Department of Veteran Affairs; the film was intended to be a straightforward look at Canadian military cemeteries. Brittain, a staff filmmaker who had just completed the 13-part Canada at War series, decided on different approach, he combined stock footage with glimpses of the former battlegrounds a generation and added his own commentary. Brittain shows that while these former battlefields are now peaceful and people are getting on with their lives, the sacrifices of Canadians are not forgotten; the film was shot in 35 mm. Fields of Sacrifice premiered in Ottawa in October 1963, attended by Governor General of Canada Georges Vanier.
It would enjoy a two-year theatrical run shown as part of a double bill with the NFB's 70-minute drama Drylanders. It was broadcast on CBC-TV in 1965 on Remembrance Day. Fields of Sacrifice is considered Brittain's first major film as director, it received an Order of Merit at the Canadian Film Awards. Watch Fields of Sacrifice at NFB.ca