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Electrical Resistance Survey
Electrical resistance surveys (also called earth resistance or resistivity survey) are one of a number of methods used in archaeological geophysics, as well as in engineering geology investigations. In this type of survey electrical resistance meters are used to detect and map subsurface archaeological features and patterning. Overview Electrical resistance meters can be thought of as similar to the Ohmmeters used to test electrical circuits. Archaeological features can be mapped when they are of higher or lower resistivity than their surroundings. A stone foundation might impede the flow of electricity, while the organic deposits within a midden might conduct electricity more easily than surrounding soils. Although generally used in archaeology for planview mapping, resistance methods also have a limited ability to discriminate depth and create vertical profiles (see Electrical resistivity tomography). Further applications include the measurement of the electrical resistivity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geophysical Survey (archaeology)
In archaeology, geophysical survey is ground-based physical sensing techniques used for archaeological imaging or mapping. Remote sensing and marine surveys are also used in archaeology, but are generally considered separate disciplines. Other terms, such as "geophysical prospection" and "archaeological geophysics" are generally synonymous. Overview Geophysical survey is used to create maps of subsurface archaeological features. Features are the non-portable part of the archaeological record, whether standing structures or traces of human activities left in the soil. Geophysical instruments can detect buried features when their physical properties contrast measurably with their surroundings. In some cases individual artifacts, especially metal, may be detected as well. Readings taken in a systematic pattern become a data set that can be rendered as image maps. Survey results can be used to guide excavation and to give archaeologists insight into the patterning of non-excavate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering Geology
Engineering geology is the application of geology to engineering study for the purpose of assuring that the geological factors regarding the location, design, construction, operation and maintenance of engineering works are recognized and accounted for. Engineering geologists provide geological and geotechnical recommendations, analysis, and design associated with human development and various types of structures. The realm of the engineering geologist is essentially in the area of earth-structure interactions, or investigation of how the earth or earth processes impact human made structures and human activities. Engineering geology studies may be performed during the planning, environmental impact analysis, civil or structural engineering design, value engineering and construction phases of public and private works projects, and during post-construction and forensic phases of projects. Works completed by engineering geologists include; geologic hazards assessment, geotechnica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feature (archaeology)
In archaeological excavation, a feature is a collection of one or more contexts representing some human non-portable activity, such as a hearth or wall. Features serve as an indication that the area in which they are found has been interfered with in the past, usually by humans. Features are distinguished from artifacts in that they cannot be separated from their location without changing their form. Artifacts are portable, while features are non-portable. Artifacts and features can both be made from any available material, with the primary distinction being portability. Features and artifacts differ from ecofacts. Ecofacts are natural remains, such as plants and animals. Types Features are categorized by the time period, as either historic or prehistoric. Prehistoric archaeology refers to the time in history before human life was recorded or documented, while historic archaeology refers to the time period where there was a documented human past. In relation to site stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistivity Tomography
Electrical resistivity tomography (ERT) or electrical resistivity imaging (ERI) is a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface, or by electrodes in one or more boreholes. If the electrodes are suspended in the boreholes, deeper sections can be investigated. It is closely related to the medical imaging technique electrical impedance tomography (EIT), and mathematically is the same inverse problem An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, sound source reconstruction, source reconstruction in ac .... In contrast to medical EIT, however, ERT is essentially a direct current method. A related geophysical method, induced polarization (or spectral induced polarization), measures the transient response and aims to determine the subsurface chargeability propertie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistivity Measurement Of Concrete
Concrete electrical resistivity can be obtained by applying a current into the concrete and measuring the response voltage. There are different methods for measuring concrete resistivity. Laboratory methods Two electrodes Concrete electrical resistance can be measured by applying a current using two electrodes attached to the ends of a uniform cross-section specimen. Electrical resistivity is obtained from the equation: :\rho = R \frac, \,\! :''R'' is the electrical resistance of the specimen, the ratio of voltage to current (measured in ohms, Ω) :''\ell'' is the length of the piece of material (measured in metres, m) :''A'' is the cross-sectional area of the specimen (measured in square metres, m2). This method suffers from the disadvantage that contact resistance can significantly add to the measured resistance causing inaccuracy. Conductive gels are used to improve the contact of the electrodes with the sample. Four electrodes The problem of contact resistance can be ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Res Survey
Res or RES may refer to: Sciences Computing *Russian and Eurasian Security Network * Spanish Supercomputing Network (''Red Española de Supercomputación'') Energy *RES - The School for Renewable Energy Science * US Renewable Electricity Standard * Renewable Energy Systems, a UK company Mathematics * Residue (complex analysis) function Medicine * Reticuloendothelial system, in anatomy Archaeology * Répertoire d'Épigraphie Sémitique, a journal publishing Semitic language inscriptions Latin word meaning "thing" * Entity (other) *Object (philosophy) *The first word of several Latin phrases: **'' Res divina'' (''service of the gods'') **'' Res cogitans'', Descartes' mental world **''Res communis'', a thing that is owned in common **''Res extensa'', Descartes' physical world **'' Res gestae'' (''Things done'') **'' Res inter alios acta'' (''A thing done between others'') **''Res ipsa loquitur'' (''The thing speaks for itself'') **''Res judicata'' (''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrode Array
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a variety of materials (chemicals) depending on the type of cell. An electrode may be called either a cathode or anode according to the direction of the electric current, unrelated to the potential difference between electrodes. Michael Faraday coined the term "" in 1833; the word recalls the Greek ἤλεκτρον (, "amber") and ὁδός (, "path, way"). The electrophore, invented by Johan Wilcke in 1762, was an early version of an electrode used to study static electricity. Anode and cathode in electrochemical cells Electrodes are an essential part of any battery. The first electrochemical battery was devised by Alessandro Volta and was aptly named the Voltaic cell. This battery consisted of a stack of copper and zinc electrodes s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wenner Electrode Array
Wenner is a surname. Notable people with the surname include: *Axel Wenner-Gren (1881–1961), Swedish industrial magnate * Charles F. Wenner (died 1882), American politician from Maryland * Christopher Wenner (1954–2021), British journalist * François Wenner (1889–1964), Lusambo provincial governor, Belgian Congo (1940–1944) *Jann Wenner (born 1946), creator of ''Rolling Stone'' magazine * Kurt Wenner, street artist * Max Wenner (1887–1937), known for mysterious death *Rosemarie Wenner Rosemarie Wenner (born July 1, 1955) is a German Methodist bishop. She was the Presiding Bishop of the United Methodist Church in Germany from April 2005 until May 2017. Rosemarie Wenner studied in Reutlingen, Germany. After her ordination she w ... (born 1955), Methodist bishop in Germany * Violet B. Wenner (1884–1970), portrait painter See also * Corliss v. Wenner, 34 P.3d 1100 (Idaho 2001), case decided by the Court of Appeals of Idaho * Wenner-Gren Center, tower and building co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Electrical Sounding
Vertical electrical sounding (VES) is a geophysical method for investigation of a geological medium. The method is based on the estimation of the electrical conductivity or resistivity of the medium. The estimation is performed based on the measurement of voltage of electrical field induced by the distant grounded electrodes (current electrodes). Measurements Figures 1–4 show the possible configuration of the measurement setup. The electrodes ''A'' and ''B'' are current electrodes which are connected to a current source; ''N'' and ''M'' are potential electrodes which are used for the voltage measurements. As source, the direct current or low frequency alternating current is used. The interpretation of the measurements can be performed based on the apparent resistivity values. The depth of investigation depends on the distance between the current electrodes. In order to obtain the apparent resistivity as the function of depth, the measurements for each position are performed w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
