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Membrane Permeability Of A Neuron During An Action Potential
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Biological membranes include cell membranes (outer coverings of cells or organelles that allow passage of certain constituents); nuclear membranes, which cover a cell nucleus; and tissue membranes, such as mucous membrane, mucosae and serous membrane, serosae. Synthetic membranes are made by humans for use in laboratory, laboratories and industry (such as chemical plants). This concept of a membrane has been known since the eighteenth century but was used little outside of the laboratory until the end of World War II. Drinking water supplies in Europe had been compromised by The War and membrane filters were used to test for water safety. However, due to the lack of reliability, slow operation, reduced selectivity and elevated costs, membran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schematic Of Size-based Membrane
A schematic, or schematic diagram, is a designed representation of the elements of a system using abstract, graphic symbols rather than realistic pictures. A schematic usually omits all details that are not relevant to the key information the schematic is intended to convey, and may include oversimplified elements in order to make this essential meaning easier to grasp, as well as additional organization of the information. For example, a subway map intended for passengers may represent a subway station with a dot. The dot is not intended to resemble the actual station at all but aims to give the viewer information without unnecessary visual clutter. A schematic diagram of a chemical process uses symbols in place of detailed representations of the vessels, piping, valves, pumps, and other equipment that compose the system, thus emphasizing the functions of the individual elements and the interconnections among them and suppresses their physical details. In an electronic circuit d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passive Transport
Passive transport is a type of membrane transport that does not require energy to move substances across cell membranes. Instead of using cellular energy, like active transport, passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes. Fundamentally, substances follow Fick's first law, and move from an area of high concentration to an area of low concentration because this movement increases the entropy of the overall system. The rate of passive transport depends on the permeability of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane lipids and proteins. The four main kinds of passive transport are simple diffusion, facilitated diffusion, filtration, and/or osmosis. Passive transport follows Fick's first law. Diffusion Diffusion is the net movement of material from an area of high concentration to an area with lower concentration. The difference of concentrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow Fiber Membrane
Hollow fiber membranes (HFMs) are a class of synthetic membrane, artificial membranes containing a Membrane, semi-permeable barrier in the form of a hollow fiber. Originally developed in the 1960s for reverse osmosis applications, hollow fiber membranes have since become prevalent in water treatment, desalination, cell culture, medicine, and tissue engineering. Most commercial hollow fiber membranes are packed into cartridges which can be used for a variety of liquid and gaseous separations. Manufacturing HFMs are commonly produced using list of synthetic polymers, artificial polymers. The specific production methods involved are heavily dependent on the type of polymer used as well as its molecular weight. HFM production, commonly referred to as "spinning", can be divided into four general types: * Melt Spinning, in which a thermoplastic polymer is melted and extruded through a Spinneret (polymers), spinneret into air and subsequently cooled. * Dry Spinning, in which a poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distillation
Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixture and the condensation of the vapors in a still. Distillation can operate over a wide range of pressures from 0.14 bar (e.g., ethylbenzene/ styrene) to nearly 21 bar (e.g., propylene/propane) and is capable of separating feeds with high volumetric flowrates and various components that cover a range of relative volatilities from only 1.17 ( o-xylene/ m-xylene) to 81.2 (water/ ethylene glycol). Distillation provides a convenient and time-tested solution to separate a diversity of chemicals in a continuous manner with high purity. However, distillation has an enormous environmental footprint, resulting in the consumption of approximately 25% of all industrial energy use. The key issue is that distillation operates based on phase changes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkane
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula . The alkanes range in complexity from the simplest case of methane (), where ''n'' = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like hexacontane () or 4-methyl-5-(1-methylethyl) octane, an isomer of dodecane (). The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote ''any'' saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes) or polycycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) Preferred IUPAC name, recommends using the name "alkene" only for Open-chain compound, acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for Cyclic compound, cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with ''n'' being a >1 natural number (which is two hydrogens less than the corresponding alkane). When ''n'' is four or more, isomers are possible, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal–organic Framework
Metal–organic frameworks (MOFs) are a class of porous polymers consisting of metal cluster compound, clusters (also known as Secondary Building Units - SBUs) coordinated to organic compound, organic ligands to form one-, two- or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being terephthalic acid, 1,4-benzenedicarboxylic acid (BDC). MOFs are classified as reticular materials. More formally, a metal–organic framework is a potentially porous extended structure made from metal ions and organic linkers. An extended structure is a structure whose sub-units occur in a constant ratio and are arranged in a repeating pattern. MOFs are a subclass of coordination networks, which is a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination compound extending through repeating c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymers Of Intrinsic Microporosity
Polymers of intrinsic microporosity (PIMs) are a unique class of microporous material developed by research efforts led by Neil McKeown, Peter Budd, et al. PIMs contain a continuous network of interconnected intermolecular voids less than 2 nm in width. Classified as a porous organic polymer, PIMs generate porosity from their rigid and contorted macromolecular chains that do not efficiently pack in the solid state. PIMs are composed of a fused ring sequences interrupted by Spiro-centers or other sites of contortion along the backbone. Due to their fused ring structure PIMs cannot rotate freely along the polymer backbone, ensuring the macromolecular components conformation cannot rearrange and ensuring the highly contorted shape is fixed during synthesis. Synthesis PIMs require that the non-network macromolecular structure is rigid and non-linear. In order to maintain permanent microporosity the rotation along the polymer chain must be prohibited through the use of fused ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphene
Graphene () is a carbon allotrope consisting of a Single-layer materials, single layer of atoms arranged in a hexagonal lattice, honeycomb planar nanostructure. The name "graphene" is derived from "graphite" and the suffix -ene, indicating the presence of double bonds within the carbon structure. Graphene is known for its exceptionally high Ultimate tensile strength, tensile strength, Electrical resistivity and conductivity, electrical conductivity, Transparency and translucency, transparency, and being the thinnest two-dimensional material in the world. Despite the nearly transparent nature of a single graphene sheet, graphite (formed from stacked layers of graphene) appears black because it absorbs all visible light wavelengths. On a microscopic scale, graphene is the strongest material ever measured. The existence of graphene was first theorized in 1947 by P. R. Wallace, Philip R. Wallace during his research on graphite's electronic properties, while the term ''graphen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanotube Membrane
Nanotube membranes are either a single, open-ended nanotube (CNT) or a film composed of an array of nanotubes that are oriented perpendicularly to the surface of an impermeable film matrix like the cells of a honeycomb. 'Impermeable' is essential here to distinguish nanotube membrane with traditional, well known porous membranes. Fluids and gas molecules may pass through the membrane en masse but only through the nanotubes. For instance, water molecules form ordered hydrogen bonds that act like chains as they pass through the CNTs. This results in an almost frictionless or atomically smooth interface between the nanotubes and water which relate to a "slip length" of the hydrophobic interface. Properties like the slip length that describe the non-continuum behavior of the water within the pore walls are disregarded in simple hydrodynamic systems and absent from the Hagen–Poiseuille equation. Molecular dynamic simulations better characterize the flow of water molecules through the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (molecule), water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow Fiber Membrane Wall
Hollow may refer to: Natural phenomena *Hollow, a low, wooded area, such as a copse * Hollow (landform), a small vee-shaped, riverine type of valley *Tree hollow, a void in a branch or trunk, which may provide habitat for animals Arts, entertainment, and media Fictional entities * Hollow (Marvel Comics), a mutant formerly known as Penance *Hollows, fictional beings in the manga and anime series ''Bleach''; see List of Hollows in ''Bleach'' Films * ''Hollow'' (2011 film), a British horror film * ''Hollow'' (2014 film), a Vietnamese horror film Literature * ''Hollows'' (series), a series of novels and stories by Kim Harrison *"The Legend of Sleepy Hollow", by Washington Irving Music * Hollow (band), a progressive power metal band from in Umeå, Sweden Albums * ''Hollow'' (album), by the Handsome Family, 2023 * ''Hollow'' (EP), by Digital Summer, 2008 * ''Hollow'', an album by Cesium_137, 2006 * ''Hollow'', an album by Cut Off Your Hands, 2011 * ''Hollow'', an EP by Stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
