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Erygmascope - Project Gutenberg EText 14009
An erygmascope is a late 19th-century electric lighting apparatus designed for the examination of the strata of earth traversed by boring apparatus. It consisted of a very powerful incandescent lamp enclosed in a metallic cylinder. One of the two semi-cylindrical sides constitutes the reflector, and the other, which is of thick glass, allows the passage of light, which illuminates the strata of earth traversed by the instrument. The base, which is inclined at an angle of 45°, is an elliptical mirror, and the top, of straight section, is open in order to permit the observer standing at the mouth of the well, and provided with a powerful spyglass, to see in the mirror the image of the geological layers or of the structure of crystalline rocks. It somewhat resembles to a kind of inverted semi-periscope aimed to look at earth downwards. The lamp is so mounted that its upwardly emitted rays are intercepted. The whole apparatus was suspended from a long cable, formed of two conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erygmascope - Project Gutenberg EText 14009
An erygmascope is a late 19th-century electric lighting apparatus designed for the examination of the strata of earth traversed by boring apparatus. It consisted of a very powerful incandescent lamp enclosed in a metallic cylinder. One of the two semi-cylindrical sides constitutes the reflector, and the other, which is of thick glass, allows the passage of light, which illuminates the strata of earth traversed by the instrument. The base, which is inclined at an angle of 45°, is an elliptical mirror, and the top, of straight section, is open in order to permit the observer standing at the mouth of the well, and provided with a powerful spyglass, to see in the mirror the image of the geological layers or of the structure of crystalline rocks. It somewhat resembles to a kind of inverted semi-periscope aimed to look at earth downwards. The lamp is so mounted that its upwardly emitted rays are intercepted. The whole apparatus was suspended from a long cable, formed of two conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Instruments
An optical instrument (or "optic" for short) is a device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include periscopes, microscopes, telescopes, and cameras. Image enhancement The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. The binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices. Analysis Another class of optical instrument is used to analyze the properties of light or optical materials. They include: *Interferometer for measuring the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Devices
An optical instrument (or "optic" for short) is a device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include periscopes, microscopes, telescopes, and cameras. Image enhancement The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. The binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices. Analysis Another class of optical instrument is used to analyze the properties of light or optical materials. They include: * Interferometer for measuring the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Geology
Historical geology or palaeogeology is a discipline that uses the principles and methods of geology to reconstruct the geological history of Earth. Historical geology examines the vastness of geologic time, measured in billions of years, and investigates changes in the Earth, gradual and sudden, over this deep time. It focuses on geological processes, such as plate tectonics, that have changed the Earth's surface and subsurface over time and the use of methods including stratigraphy, structural geology, paleontology, and sedimentology to tell the sequence of these events. It also focuses on the evolution of life during different time periods in the geologic time scale. Historical development During the 17th century, Nicolas Steno was the first to observe and propose a number of basic principles of historical geology, including three key stratigraphic principles: the law of superposition, the principle of original horizontality, and the principle of lateral continuity. 18th-century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boreholes
A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petroleum), or gases (such as natural gas). It may also be part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage. Importance Engineers and environmental consultants use the term ''borehole'' to collectively describe all of the various types of holes drilled as part of a geotechnical investigation or environmental site assessment (a so-called Phase II ESA). This includes holes advanced to collect soil samples, water samples or rock cores, to advance ''in situ'' sampling equipment, or to install monitoring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Well Logging
Well logging, also known as borehole logging is the practice of making a detailed record (a ''well log'') of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface (''geological'' logs) or on physical measurements made by instruments lowered into the hole (''geophysical'' logs). Some types of geophysical well logs can be done during any phase of a well's history: drilling, completing, producing, or abandoning. Well logging is performed in boreholes drilled for the oil and gas, groundwater, mineral and geothermal exploration, as well as part of environmental and geotechnical studies. Wireline logging The oil and gas industry uses wireline logging to obtain a continuous record of a formation's rock properties. Wireline logging can be defined as being "The acquisition and analysis of geophysical data performed as a function of well bore depth, together with the provision of related services." Note ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Borehole Imager
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties. Most optical phenomena can be accounted for by using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borehole Image Logs
Borehole imaging logs are logging and data-processing methods used to produce two-dimensional, centimeter-scale images of a borehole wall and the rocks that make it up. These tools are limited to the open-hole environment. The applications where images are useful cover the full range of the exploration and production cycle from exploration through appraisal, development, and production to abandonment and sealing. Specific applications are sedimentology, structural geology/tectonics, reservoir geomechanics and drilling, reservoir engineering. The tools can be categorized in a number of ways: simple optical borehole imaging (OBI) systems, energy source (electrical, acoustic, or nuclear with gamma rays or neutron); conveyance ( wireline or logging while drilling); and type of drilling mud In geotechnical engineering, drilling fluid, also called drilling mud, is used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Instrument
An optical instrument (or "optic" for short) is a device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include periscopes, microscopes, telescopes, and cameras. Image enhancement The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. The binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices. Analysis Another class of optical instrument is used to analyze the properties of light or optical materials. They include: *Interferometer for measuring the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Well
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets or large water bags that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age. Wells have traditionally been sunk by hand digging, as is still the case in rural areas of the developing world. These wells are inexpensive and low-tech as they use mostly manual labour, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaft (civil Engineering)
In civil engineering a shaft is an underground vertical or inclined passageway. Shafts are often entered through a manhole and closed by a manhole cover. They are constructed for a number of reasons including: * For the construction of a tunnel * For ventilation of a tunnel or underground structure, aka ventilation shaft * As a drop shaft for a sewerage or water tunnel * For access to a tunnel or underground structure, also as an escape route Construction There are a number of methods for the construction of shafts, the most significant being: * The use of sheet piles, diaphragm walls or bored piles to construct a square or rectangular braced shaft * The use of segmental lining installed by underpinning In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons: * The original foundation isn't strong or stable enough. ... or caisson sunk to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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