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Soil Physics
Soil physics is the study of soil's physical properties and processes. It is applied to management and prediction under natural and managed ecosystems. Soil physics deals with the dynamics of physical soil components and their phases as solids, liquids, and gases. It draws on the principles of physics, physical chemistry, engineering, and meteorology. Soil physics applies these principles to address practical problems of agriculture, ecology, and engineering. Prominent soil physicists * Edgar Buckingham (1867–1940) :The theory of gas diffusion in soil and vadose zone water flow in soil. *Willard Gardner (1883-1964) :First to use porous cups and manometers for capillary potential measurements and accurately predicted the moisture distribution above a water table.Sterling A. Taylor: Willard Gardner, 1883-1964. Soil Science 100(2), 1965. * Lorenzo A. Richards (1904–1993) :General transport of water in unsaturated soil, measurement of soil water potential using tensiom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Discipline
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Thermal Properties
The thermal properties of soil are a component of soil physics that has found important uses in engineering, climatology and agriculture. These properties influence how energy is partitioned in the soil profile. While related to soil temperature, it is more accurately associated with the transfer of energy (mostly in the form of heat) throughout the soil, by radiation, conduction and convection. The main soil thermal properties are: * Volumetric heat capacity, SI Units: J∙m−3∙K−1 *Thermal conductivity, SI Units: W∙m−1∙K−1 *Thermal diffusivity, SI Units: m2∙s−1 Measurement It is hard to say something general about the soil thermal properties at a certain location because these are in a constant state of flux from diurnal and seasonal variations. Apart from the basic soil composition, which is constant at one location, soil thermal properties are strongly influenced by the soil volumetric water content, volume fraction of solids and volume fraction of air. Air i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitance Probe
Capacitance sensors (or Dielectric sensors) use capacitance to measure the dielectric permittivity of a surrounding medium. The configuration is like the neutron probe where an access tube made of PVC is installed in the soil; probes can also be modular (comb-like) and connected to a logger. The sensing head consists of an oscillator circuit, the frequency is determined by an annular electrode, fringe-effect capacitor, and the dielectric constant of the soil. Each capacitor sensor consists of two metal rings mounted on the circuit board at some distance from the top of the access tube. These rings are a pair of electrodes, which form the plates of the capacitor with the soil acting as the dielectric in between. The plates are connected to an oscillator, consisting of an inductor and a capacitor. The oscillating electrical field is generated between the two rings and extends into the soil medium through the wall of the access tube. The capacitor and the oscillator form a circuit, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulk Density
Bulk density, also called apparent density or volumetric density, is a property of powders, granules, and other "divided" solids, especially used in reference to mineral components (soil, gravel), chemical substances, (pharmaceutical) ingredients, foodstuff, or any other masses of corpuscular or particulate matter (particles). Bulk density is defined as the mass of the many particles of the material divided by the total volume they occupy. The total volume includes particle volume, inter-particle void volume, and internal pore volume. Bulk density is not an intrinsic property of a material; it can change depending on how the material is handled. For example, a powder poured into a cylinder will have a particular bulk density; if the cylinder is disturbed, the powder particles will move and usually settle closer together, resulting in a higher bulk density. For this reason, the bulk density of powders is usually reported both as "freely settled" (or "poured" density) and "tapp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agrophysics
Agrophysics is a branch of science bordering on agronomy and physics, whose objects of study are the agroecosystem - the biological objects, biotope and biocoenosis affected by human activity, studied and described using the methods of physical sciences. Using the achievements of the exact sciences to solve major problems in agriculture, agrophysics involves the study of materials and processes occurring in the production and processing of agricultural crops, with particular emphasis on the condition of the environment and the quality of farming materials and food production. Agrophysics is closely related to biophysics, but is restricted to the physics of the plants, animals, soil and an atmosphere involved in agricultural activities and biodiversity. It is different from biophysics in having the necessity of taking into account the specific features of biotope and biocoenosis, which involves the knowledge of nutritional science and agroecology, agricultural technology, biote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John R
John R. (born John Richbourg, August 20, 1910 - February 15, 1986) was an American radio disc jockey who attained fame in the 1950s and 1960s for playing rhythm and blues music on Nashville radio station WLAC. He was also a notable record producer and artist manager. Richbourg was arguably the most popular and charismatic of the four announcers at WLAC who showcased popular African-American music in nightly programs from the late 1940s to the early 1970s. (The other three were Gene Nobles, Herman Grizzard, and Bill "Hoss" Allen.) Later rock music disc jockeys, such as Alan Freed and Wolfman Jack, mimicked Richbourg's practice of using speech that simulated African-American street language of the mid-twentieth century. Richbourg's highly stylized approach to on-air presentation of both music and advertising earned him popularity, but it also created identity confusion. Because Richbourg and fellow disc jockey Allen used African-American speech patterns, many listeners thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensiometer (soil Science)
A tensiometer in soil science is a measuring instrument used to determine the matric water potential (\Psi_m) (soil moisture tension) in the vadose zone. This device typically consists of a glass or plastic tube with a porous ceramic cup and is filled with water. The top of the tube has either a built-in vacuum gauge or a rubber cap used with a portable ''puncture tensiometer'' instrument, which uses a hypodermic needle A hypodermic needle (from Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)), one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used ... to measure the pressure inside the tensiometer. The tensiometer is buried in the soil, and a hand pump is used to pull a partial vacuum. As water is pulled out of the soil by plants and evaporation, the vacuum inside the tube increases. When the soil is wetted flow can also occur in the reverse direction: as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorenzo A
Lorenzo may refer to: People * Lorenzo (name) Places Peru * San Lorenzo Island (Peru), sometimes referred to as the island of Lorenzo United States * Lorenzo, Illinois * Lorenzo, Texas * San Lorenzo, California, formerly Lorenzo * Lorenzo State Historic Site, house in New York State listed on the National Register of Historic Places Art, entertainment, and media ;Films and television * ''Lorenzo'' (film), an animated short film * '' Lorenzo's Oil'', a film based on a true story about a boy suffering from Adrenoleukodystrophy and his parents' journey to find a treatment. * '' Lorenzo's Time'', a 2012 Philippine TV series that aired on ABS-CBN ;Music * Lorenzo (rapper), French rapper * "Lorenzo", a 1996 song by Phil Collins Other uses * List of storms named Lorenzo * Lorenzo patient record systems, a type of electronic health record in the United Kingdom See also * San Lorenzo (other) * De Lorenzo * di Lorenzo * Lorenzen (other) Lorenzen may refer to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vadose Zone
The vadose zone, also termed the unsaturated zone, is the part of Earth between the land surface and the top of the phreatic zone, the position at which the groundwater (the water in the soil's pores) is at atmospheric pressure ("vadose" is from the Latin word for "shallow"). Hence, the vadose zone extends from the top of the ground surface to the water table. Water in the vadose zone has a pressure head less than atmospheric pressure, and is retained by a combination of adhesion (''funiculary groundwater''), and capillary action (''capillary groundwater''). If the vadose zone envelops soil, the water contained therein is termed soil moisture. In fine grained soils, capillary action can cause the pores of the soil to be fully saturated above the water table at a pressure less than atmospheric. The vadose zone does not include the area that is still saturated above the water table, often referred to as the capillary fringe. Freeze, R.A. and Cherry, J.A., 1979. Groundwater. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Gas
Soil gases (soil atmosphere) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. Oxygen is critical because it allows for respiration of both plant roots and soil organisms. Other natural soil gases include nitric oxide, nitrous oxide, methane, and ammonia. Some environmental contaminants below ground produce gas which diffuses through the soil such as from landfill wastes, mining activities, and contamination by petroleum hydrocarbons which produce volatile organic compounds. Gases fill soil pores in the soil structure as water drains or is removed from a soil pore by evaporation or root absorption. The network of pores within the soil aerates, or ventilates, the soil. This aeration network becomes blocked when water enters soil pores. Not only are both soil air and soil water very dynamic parts of soil, but both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar Buckingham
Edgar Buckingham (July 8, 1867 in Philadelphia, Pennsylvania – April 29, 1940 in Washington DC) was an American physicist. He graduated from Harvard University with a bachelor's degree in physics in 1887. He did graduate work at Strasbourg and then studied under the chemist Wilhelm Ostwald at Leipzig, from which he was granted a PhD in 1893. He worked at the USDA Bureau of Soils from 1902 to 1906 as a soil physicist. He worked at the (US) National Bureau of Standards (now the National Institute of Standards and Technology, or NIST) 1906–1937. His fields of expertise included soil physics, gas properties, acoustics, fluid mechanics, and blackbody radiation. He is also the originator of the Buckingham π theorem in the field of dimensional analysis. In 1923, Buckingham published a report which voiced skepticism that jet propulsion would be economically competitive with prop driven aircraft at low altitudes and at the speeds of that period. Buckingham's first work on s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porosity
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure the "accessible void", the total amount of void space accessible from the surface (cf. closed-cell foam). There are many ways to test porosity in a substance or part, such as industrial CT scanning. The term porosity is used in multiple fields including pharmaceutics, ceramics, metallurgy, materials, manufacturing, petrophysics, hydrology, earth sciences, soil mechanics, and engineering. Void fraction in two-phase flow In gas-liquid two-phase flow, the void fraction is defined as the fraction of the flow-channel volume that is occupied by the gas phase or, alternatively, as the fraction of the cross-sectional area of the channel that is occupied by the gas phase. Void fraction usually varies from location to location in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
