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History Of Glass In Sub-Saharan Africa
Due to various differences in cultural histories and environmental resources, West African nations developed glass traditions distinct from Egypt, North Africa and the rest of the world. The presence of glass in Sub-Saharan Africa mostly consists of the importation of glass beads shipped primarily from the Middle East and Indian as early as 200-300AD; later, from Portugal, the Netherlands, and Venice. As most African cultures have long histories of crafting and adornment with beads made from wood, bone and shell, the introduction of glass as a bead material was widely and rapidly received. The exchange of glass beads for local goods such as ivory, gold and slaves aided in the accumulation of wealth and creation of unequal power dynamics still apparent today.Dubin 1987 Archaeological evidence, primarily from various burial sites from the West and coastal port cities in the East, confirm the import of hundreds of thousands of glass beads.4 Davidson 1972 3 These assemblages boast rich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resources
Resource refers to all the materials available in our environment which are technologically accessible, economically feasible and culturally sustainable and help us to satisfy our needs and wants. Resources can broadly be classified upon their availability — they are classified into renewable and non-renewable resources. They can also be classified as actual and potential on the basis of the level of development and use, on the basis of origin they can be classified as biotic and abiotic, and on the basis of their distribution, as ubiquitous and localised (private, community-owned, national and international resources). An item becomes a resource with time and developing technology. The benefits of resource utilization may include increased wealth, proper functioning of a system, or enhanced well-being. From a human perspective, a natural resource is anything obtained from the environment to satisfy human needs and wants.WanaGopa - Nyawakan From a broader biological or ecologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Glass
The history of glass-making dates back to at least 3,600 years ago in Mesopotamia. However, some writers claim that they may have been producing copies of glass objects from ancient Egypt, Egypt. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt. The earliest known glass objects, of the mid 2,000 BCE, were beads, perhaps initially created as the accidental by-products of Metalworking, metal-working (slags) or during the production of Egyptian faience, faience, a pre-glass Lustre (mineralogy)#Vitreous lustre, vitreous material made by a process similar to Ceramic glaze, glazing. Glass products remained a luxury until the Late Bronze Age collapse, disasters that overtook the late Bronze Age civilizations seemingly brought glass-making to a halt. Development of glass technology in India may have begun in 1,730 BCE. In Ancient Chinese glass, Ancient China, glass-making had a later start compared to ceramics and meta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olakunbi Olasope
Olakunbi Ojuolape Olasope is a Professor in the Department of Classics at the University of Ibadan in Nigeria. She is an expert on Roman social history, Greek and Roman theatre, and Yoruba classical performance culture. Olasope is known in particular for her work on the reception of classical drama in West Africa, especially the work of the Nigerian dramatist Femi Osofisan. Education Olasope studied Classics at the University of Ibadan, completing her BA in 1991 and MA in 1994. Her doctoral thesis, ''The Ideal of Univira in Traditional Marriage Systems in Ancient Rome and Yorubaland'', was awarded in 2005. ("Univira" is the Latin word for a woman married only ever to one man, see Pudicitia.) In 2002, she was a visiting scholar at the Department of Classics of the University of Texas at Austin. Career Olasope began teaching at the University of Ibadan as an Assistant Lecturer in 1997. She was promoted to Lecturer II in 1999, Lecturer I in 2004, Senior Lecturer in 2007 and bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of African Archaeology
The ''Journal of African Archaeology'' is a biannual peer-reviewed academic journal covering archaeological studies on Africa. It was established by Sonja Magnavita in 2003. From 2003 to 2016, the Centre for Interdisciplinary African Studies and the Department of African Archaeology and Archaeobotany of Goethe University Frankfurt published it in association with Africa Magna Verlag. Since 2017, the departments publish it in association with Brill Publishers. Abstracting and indexing The journal is abstracted and indexed in: *Anthropological Literature *Arts and Humanities Citation Index *Current Contents/Arts & Humanities * EBSCO databases *International Bibliography of Periodical Literature *International Bibliography of the Social Sciences *Scopus Scopus is Elsevier's abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles (22,794 active titles and 13,583 inactive titles) from approximately 11,678 publishers, of which 34,346 are peer-reviewed jou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technology
Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in medicine, science, industry, communication, transportation, and daily life. Technologies include physical objects like utensils or machines and intangible tools such as software. Many technological advancements have led to societal changes. The earliest known technology is the stone tool, used in the prehistoric era, followed by fire use, which contributed to the growth of the human brain and the development of language in the Ice Age. The invention of the wheel in the Bronze Age enabled wider travel and the creation of more complex machines. Recent technological developments, including the printing press, the telephone, and the Internet have lowered communication barriers and ushered in the knowledge economy. While technology contributes to econom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ingots
An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of shaping, such as cold/hot working, cutting, or milling to produce a useful final product. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods. Precious metal ingots can be used as currency (with or without being processed into other shapes), or as a currency reserve, as with gold bars. Types Ingots are generally made of metal, either pure or alloy, heated past its melting point and cast into a bar or block using a mold chill method. A special case are polycrystalline or single crystal ingots made by pulling from a molten melt. Single crystal Single crystal ingots (called boules) of materials are grown (crystal growth) using methods such as the Czoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pattern
A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper design. Any of the senses may directly observe patterns. Conversely, abstract patterns in science, mathematics, or language may be observable only by analysis. Direct observation in practice means seeing visual patterns, which are widespread in nature and in art. Visual patterns in nature are often chaotic, rarely exactly repeating, and often involve fractals. Natural patterns include spirals, meanders, waves, foams, tilings, cracks, and those created by symmetries of rotation and reflection. Patterns have an underlying mathematical structure; indeed, mathematics can be seen as the search for regularities, and the output of any function is a mathematical pattern. Similarly in the sciences, theories explain and predict reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Texture
Surface finish, also known as surface texture or surface topography, is the nature of a surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane). Surface texture is one of the important factors that control friction and transfer layer formation during sliding. Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions. Surface textures can be isotropic or anisotropic. Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture. Each manufacturing process (such as the many kinds of machining) produces a surface texture. The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial texture. The latter process may be grinding (abrasive cutting), polishing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colour
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shape
A shape or figure is a graphics, graphical representation of an object or its external boundary, outline, or external Surface (mathematics), surface, as opposed to other properties such as color, Surface texture, texture, or material type. A plane shape or plane figure is constrained to lie on a ''plane (geometry), plane'', in contrast to ''solid figure, solid'' 3D shapes. A two-dimensional shape or two-dimensional figure (also: 2D shape or 2D figure) may lie on a more general curved ''surface (mathematics), surface'' (a non-Euclidean two-dimensional space). Classification of simple shapes Some simple shapes can be put into broad categories. For instance, polygons are classified according to their number of edges as triangles, quadrilaterals, pentagons, etc. Each of these is divided into smaller categories; triangles can be equilateral, isosceles, obtuse triangle, obtuse, Triangle#By internal angles, acute, Triangle, scalene, etc. while quadrilaterals can be rectangles, rho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Import
An import is the receiving country in an export from the sending country. Importation and exportation are the defining financial transactions of international trade. In international trade, the importation and exportation of goods are limited by import quotas and mandates from the customs authority. The importing and exporting jurisdictions may impose a tariff (tax) on the goods. In addition, the importation and exportation of goods are subject to trade agreements between the importing and exporting jurisdictions. History Definition Imports consist of transactions in goods and services to a resident of a jurisdiction (such as a nation) from non-residents. The exact definition of imports in national accounts includes and excludes specific "borderline" cases. Importation is the action of buying or acquiring products or services from another country or another market other than own. Imports are important for the economy because they allow a country to supply nonexistent, scarc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
