CALIFORNIA KITE SURFER NARROWLY MISSES HUMPBACK WHALE WHILE RIDING WAVES NEAR GOLDEN GATE BRIDGE "They are often surface active, jumping out of the water and slapping the surface with their pectoral fins or tails," the NOAA said.
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Additionally, the Gibbs surface excess of a surface active component for an aqueous solution can be found using the radioactive tracer method. The surface active component is usually labeled with carbon-14 or sulfur-35.
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A surface active molecule consists of a lyophobic and a lyophilic group.
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Sixth Int. Conf. Surface Active Substances, Bad Stuer, Akademie Verlag, Berlin (1987) 251. # M. Kaisheva, Ann. Sof. Univ., Fac. Chem.
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The Plains black-headed snake is often secretive and can be found seeking refuge in leaf-litter or in small burrows, while being surface active at night. It has been collected from February into September in Arizona, but most are found in August. It is susceptible to desiccation and unlikely to be found surface active or under surface debris in dry periods or seasons.
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An oil-in-water type emulsified composition containing a non-steroidal antiphlogistic and analgesic drug, wherein the composition comprises a monoalkylglyceryl ether and a hydrophilic surface-active agent.
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The spontaneous assembly of a single layer of molecules at interfaces is usually referred to as two-dimensional self-assembly. One of the common examples of such assemblies are Langmuir-Blodgett monolayers and multilayers of surfactants. Non-surface active molecules can assemble into ordered structures as well. Early direct proofs showing that non-surface active molecules can assemble into higher-order architectures at solid interfaces came with the development of scanning tunneling microscopy and shortly thereafter.
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Observing phase changes, phase separation, domain size, shape and packing. Monitoring of surface reactions. Photochemical reactions, polymerizations and enzyme kinetics can be followed in real time. Monitoring and detection of surface active materials.
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Interfacial rheology is a branch of rheology that studies the flow of matter at the interface between a gas and a liquid or at the interface between two immiscible liquids. The measurement is done while having surfactants, nanoparticles or other surface active compounds present at the interface. Unlike in bulk rheology, the deformation of the bulk phase is not of interest in interfacial rheology and its effect is aimed to be minimized. Instead, the flow of the surface active compounds is of interest.
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In marshmallows, proteins are the main surface-active agents responsible for the formation, and stabilization of the dispersed air. Due to their structure, surface-active molecules gather at the surface area of a portion of (water- based) liquid. A portion of each protein molecule is hydrophilic, with a polar charge, and another portion is hydrophobic and non-polar. The non-polar section has little or no affinity for water, and so this section orients as far away from the water as possible.
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A sophorolipid is a surface-active glycolipid compound that can be synthesized by a selected number of non-pathogenic yeast species. They are potential bio- surfactants due to their biodegradability and low eco-toxicity.
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An interesting phenomenon observed with probe electrospray ionization is the sequential and exhaustive ionization of analytes with different surface activities. During the development of PESI, it was discovered that analytes could be sequentially ionized throughout the electrospray, thus enabling a temporal separation of components within a sample. In normal ESI, the sample solution is typically continuously supplied through a capillary and the charged droplets contain all sample components, with more surface-active analytes being constantly preferentially ionized. In PESI, surface-active analytes are also preferentially ionized.
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Interfacial rheology enables the study of surfactant kinetics, and the viscoelastic properties of the adsorbed interfacial layer correlate well with emulsion and foam stability. Surfactants and surface active polymers used for stabilising emulsions and foams in food and cosmetic industries. Polymers, such as proteins, are surface active and tend to adsorb at the interface, where they can change conformation and influence the interfacial properties. Natural surfactants like asphaltenes and resins stabilize water- oil emulsions in crude oil applications, and by understanding their behavior the crude oil separation process can be enhanced.
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Continuous foam separation is a chemical process closely related to foam fractionation in which foam is used to separate components of a solution when they differ in surface activity. In any solution, surface active components tend to adsorb to gas-liquid interfaces while surface inactive components stay within the bulk solution. When a solution is foamed, the most surface active components collect in the foam and the foam can be easily extracted. This process is commonly used in large-scale projects such as water waste treatment due to a continuous gas flow in the solution.
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They concluded Janus particles are both surface-active and amphiphilic, whereas homogeneous particles are only surface-active. Twenty years later, a plethora of Janus particles of different sizes, shapes and properties, with applications in textile, sensors, stabilization of emulsions, and magnetic field imaging have been reported. Variety of janus particles in sizes 10um to 53um in diameter are currently commercially available from Cospheric, who holds a patent on Hemispherical Coating Method for Microelements United States Patent 8,501,272 Lipovetskaya , et al. 6 August 2013 \----Hemispherical coating method for micro-elements .
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The presence of surface active elements such as oxygen and sulfur will have a large impact on the measurements obtained with this technique. Surface active elements will exist in larger concentrations at the surface than in the bulk of the liquid, meaning that the total levels of these elements must be carefully controlled to a very low level. For example, the presence of only 50 ppm sulphur in liquid iron will reduce the surface tension by approximately 20%.Seshadri Seetharaman: Fundamentals of metallurgy, Woodhead Publishing in Materials, Cambridge, 2005.
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Some of the chemical properties of activated carbon have been attributed to presence of the surface active carbon double bond. The Polyani adsorption theory is a popular method for analyzing adsorption of various organic substances to their surface.
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Many food and non-food systems require stabilization of mixtures of oil and water in order to prevent phase separation. Therefore, additives are used to provide stability. Lactylates are such additives. Lactylates are surface active and are therefore surfactants.
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However, as a finite droplet exists on the tip of the needle, following the depletion of surface-active analytes, the remaining components in the droplet can then be ionized and observed. This can result in the production of distinctively different mass spectra from a single sample over the application of the high voltage for just a few seconds. This effect offers a particular advantage in the analysis of analytes suffering from ion suppression effects. The presence of surface-active analytes or charged solvent additives can result in the suppressed ionization of analytes of interest, resulting in low sensitivity or the complete absence of the analyte.
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Another theory presumes that microscopic bubble nuclei always exist in aqueous media, including living tissues. These bubble nuclei are spherical gas phases that are small enough to remain in suspension yet strong enough to resist collapse, their stability being provided by an elastic surface layer consisting of surface-active molecules which resists the effect of surface tension.
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It created a research division in 1961. In the early 1960s the site researched colloid chemistry, surface active phenomena, rheology of dispersions, surface chemistry, fluorescence of dyestuffs, adsorbed films on liquids, germicides, timber technology (for West Africa), and paper chromatography. Organic chemists, physical chemists and physicists worked there. In the 1960s the site was run by Unilever Research.
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In gram-positive bacteria, these are exotoxins or enterotoxins, which may vary depending on the species of bacteria. These are divided into three types. Type I, cell surface-active toxins, disrupt cells without entering, and include superantigens and heat-stable enterotoxins. Type II, membrane-damaging toxins, destroy cell membranes in order to enter and includeF hemolysins and phospholipases.
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These are microbial-synthesized surface-active substances that allow for more efficient microbial biodegradation of hydrocarbons in bioremediation processes. There are two ways by which biosurfactants are involved in bioremediation. (1) Increase the surface area of hydrophobic water-insoluble substrates. Growth of microbes on hydrocarbons can be limited by available surface area of the water-oil interface.
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Generally a defoamer is insoluble in the foaming medium and has surface active properties. An essential feature of a defoamer product is a low viscosity and a facility to spread rapidly on foamy surfaces. It has affinity to the air-liquid surface where it destabilizes the foam lamellas. This causes rupture of the air bubbles and breakdown of surface foam.
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The hooded scaly-foot feeds predominantly on surface-active arthropods. Insects are the main prey type, while it is also noted to feed on spider egg sacks and scorpions. The species has been observed to actively search for prey. Once caught, larger prey is crushed and disabled as the hooded scaly-foot rotates its body rapidly, in a crocodile-roll fashion.
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Ustilagic acid is an organic compound with the formula C36H64O18. The acid is a cellobiose lipid produced by the corn smut fungus Ustilago maydis under conditions of nitrogen starvation. The acid was discovered in 1950 and was proved to be an amphipathic glycolipid with surface active properties. The name comes from Latin ustus which means burnt and refers to the scorched appearance of the smut fungi.
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In pharmaceutical chemistry, numerous methods exist to help solubilize poorly water-soluble drugs for use in treatment. These methods include cosolvency, hydrotropism, complexation, ionization, and using surface active agents. The most pervasive is the application of non-toxic cosolvents with water to produce formulations that can dissolve hydrophobic molecules while maintaining cohesion with biological systems. Common cosolvents for this purpose are ethanol, propylene glycol, glycerine, glycofural, and polyethylene glycols.
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High concentration of surfactants (surface- active substances) produced by phytoplanktons can result higher Marangoni stress in converging regions in LC. Numerical simulation suggest that such Marangoni stress due to surfactant can increase the size of vortical structures, vertical velocity and remixing of water and biological/chemical components in the local region compared to that without surfactant. Finally, more theoretical and experimental investigations are needed to confirm the significance of LC.
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Bashkortostan is one of the major raw materials bases for Russia non-ferrous metallurgy. The republic has good deposits of lignite with a high degree of bitumen. This lignite can be used for obtaining a variety of different chemical products like resins, surface-active substances, gummy fertilizers, and other stimulants for plants growth. Mining-chemical raw materials (rock salt, lime, phosphorites, barytes, etc.) are quite substantial, and are utilized in the republic economy.
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In the gizzard, strong muscular contractions grind the food with the help of mineral particles ingested along with the food. Once through the gizzard, food continues through the intestine for digestion. The intestine secretes pepsin to digest proteins, amylase to digest polysaccharides, cellulase to digest cellulose, and lipase to digest fats. Earthworms use, in addition to the digestive proteins, a class of surface active compounds called drilodefensins, which help digest plant material.
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The Japanese forest rat snake can be found surface active at any hour, but they most often show crepuscular activity patterns. It may completely cease surface activity from mid-late summer when conditions become too hot and/or dry. Principal prey items are small rodents, and the snakes often use the rodent burrows for shelter. As the Japanese common name suggests, this species is fossorial, and is normally associated with forested areas.
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Several conditions are needed to produce foam: there must be mechanical work, surface active components (surfactants) that reduce the surface tension, and the formation of foam faster than its breakdown. To create foam, work (W) is needed to increase the surface area (ΔA): : W = \gamma \Delta A \,\\! where γ is the surface tension. One of the ways foam is created is through dispersion, where a large amount of gas is mixed with a liquid.
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A female North Atlantic right whale with her calf. During the mating season, which can occur at any time in the North Atlantic, right whales gather into "surface-active groups" made up of as many as 20 males consorting a single female. The female has her belly to the surface while the males stroke her with their flippers or keep her underwater. The males do not compete as aggressively against each other as male humpbacks.
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Because of the pressure and temperature on the polymers, it is easier to break them down. Because of this, the drag reducing agent is re- injected after points like pumps and turns, where the pressure and temperature can be extra high. To safeguard against degradation at high temperature, a different class of drag reducing agents are at times used, namely, surfactants. Surfactant is a very convenient contraction of the term Surface- active agent.
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Alveoli are the spherical outcroppings of the respiratory bronchioles. Pulmonary surfactant is a surface-active lipoprotein complex (phospholipoprotein) formed by type II alveolar cells. The proteins and lipids that make up the surfactant have both hydrophilic and hydrophobic regions. By adsorbing to the air-water interface of alveoli, with hydrophilic head groups in the water and the hydrophobic tails facing towards the air, the main lipid component of surfactant, dipalmitoylphosphatidylcholine (DPPC), reduces surface tension.
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Surfactant enhanced recovery increases the mobility and solubility of the contaminants absorbed to the saturated soil matrix or present as dense non-aqueous phase liquid. Surfactant-enhanced recovery injects surfactants (surface-active agents that are primary ingredient in soap and detergent) into contaminated groundwater. A typical system uses an extraction pump to remove groundwater downstream from the injection point. The extracted groundwater is treated aboveground to separate the injected surfactants from the contaminants and groundwater.
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A microemulsion is a stable isotropic dispersion of 2 immiscible liquids consisting of nanosized domains of one or both liquids in the other stabilized by an interfacial film of surface-active molecules. Microemulsions may be categorized further as oil-in-water (o/w) or water-in-oil (w/o), depending on the dispersed and continuous phases. Water-in-oil is more popular for synthesizing many kinds of nanoparticles. The water and oil are mixed with an amphiphillic surfactant.
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The dilute nature of the pelagic marine environment promotes large diffusive losses and renders the efficiency of the normal siderophore-based iron uptake strategies problematic. However, many heterotrophic marine bacteria do produce siderophores, albeit with properties different from those produced by terrestrial organisms. Many marine siderophores are surface-active and tend to form molecular aggregates, for example aquachelins. The presence of the fatty acyl chain renders the molecules with a high surface activity and an ability to form micelles.
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Phospholipids are important natural surfactant lipids Anti-asthmatic combinations comprising surface active phospholipids used in enhancing penetration and bioavailability.PHOSPHOLIPID-BASED INHALATION SYSTEM Phospholipids act by reducing the high surface tension forces at the air-water interface within the alveoli, thereby reducing the pressure needed to expand the lungs, Thus, commercially available formulations of phospholipids have been designed to spread rapidly over an air-aqueous interface, thereby reducing what is otherwise a very high surface tension of water.
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Sedimentation is the opposite phenomenon of creaming and normally observed in water-in-oil emulsions. Sedimentation happens when the dispersed phase is denser than the continuous phase and the gravitational forces pull the denser globules towards the bottom of the emulsion. Similar to creaming, sedimentation follows Stoke's law. An appropriate "surface active agent" (or "surfactant") can increase the kinetic stability of an emulsion so that the size of the droplets does not change significantly with time.
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A long-term (12-year) study continuing the work of Sattler and Reichenbach (1998) was conducted to assess population trends on a larger time scale. The same treatment sites and study methods were used. Two years after timbering, the numbers of surface-active animals on the clearcut sites had dropped to 25% of levels before timbering. The population did not begin to recover until five years after timbering, and finally stabilized at only 55% of before-timbering levels.
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While the actual foam activity of beer depends on the presence of carbon dioxide, it is the surface-active materials like amphipathic polypeptides from malt that determine size, shape and length of the foam. Beer foam consists of polypeptides of five different classifications, divided by their relative hydrophobicity. As the hydrophobicity of the polypeptide groups increases, so does the stability of the foam. Carbonation occurs when carbon dioxide is dissolved in water or an aqueous solution.
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It connotes an organic molecule or an unformulated compound having surface-active properties. All three classes of surfactants, namely, anionic, cationic and nonionic surfactants, have been successfully tried as drag-reducing agents. Knowing what will create the ideal drag reducer is key in this process. Ideal molecules have a high molecular weight, shear degradation resistance, are quick to dissolve in whatever is in the pipe, and have low degradation in heat, light, chemicals, and biological areas.
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For nonpolar ligands, van der Waals forces instead play a larger role in sorption interactions. Hydrogen bonding does also occur, but is not a part of the adsorption process itself. Due to these factors, the soil quality influences the retention and depletion of nutrients, pollutants, and other ligands that perform sorption with the soil. Generally, the charged surface of a metallic ion can become charged via crystalline imperfections, chemical reactions at the surface, or sorption at the surface-active ion.
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The lungs make a surfactant, a surface-active lipoprotein complex (phospholipoprotein) formed by type II alveolar cells. It floats on the surface of the thin watery layer which lines the insides of the alveoli, reducing the water's surface tension. The surface tension of a watery surface (the water-air interface) tends to make that surface shrink. When that surface is curved as it is in the alveoli of the lungs, the shrinkage of the surface decreases the diameter of the alveoli.
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Foam fractionation is a chemical process in which hydrophobic molecules are preferentially separated from a liquid solution using rising columns of foam. It is commonly used, albeit on a small scale, for the removal of organic waste from aquariums; these units are known as "protein skimmers". However it has much broader application in the chemical process industry and can be used for the removal of surface active contaminants from waste water streams in addition to the enrichment of bio-products.
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Gas bubbles with a radius greater than 1 micron should float to the surface of a standing liquid, whereas smaller ones should dissolve rapidly due to surface tension. The Tiny Bubble Group has been able to resolve this apparent paradox by developing and experimentally verifying a new model for stable gas nuclei. According to the varying-permeability model, gas bubble nuclei are simply stable microbubbles. The stability of these microbubbles is due to elastic skins or membranes consisting of surface-active molecules.
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A significant characteristic of Janus nanoparticles is the capability of having both hydrophilic and hydrophobic parts. Many research groups have investigated the surface activities of nanoparticles with amphiphilic properties. In 2006, Janus nanoparticles, made from gold and iron oxides, were compared with their homogeneous counterparts by measuring the ability of the particles to reduce the interfacial tension between water and n-hexane. Experimental results indicated Janus nanoparticles are considerably more surface-active than homogeneous particles of comparable size and chemical nature.
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Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and are often the source of flares and Coronal Mass Ejections due to the intense magnetic field present. Active regions produce 82% of the total coronal heating energy. Coronal holes are open field lines located predominantly in the polar regions of the Sun and are known to be the source of the fast solar wind.
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Additionally it inhibits the formation of error-causing bubbles. A surfactant (surface active agent), such as hand-dishwashing liquid detergent, can be added to the water to significantly lower the surface tension of the water. This liquid solution will flow more easily and more rapidly in the tube than plain water, so operation of the device will be more precise, repeatable, and responsive – particularly when using a small-diameter tube. Also, this liquid solution can be emptied from a small-diameter tube more easily than plain water.
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The Brooks Range is visible at the bottom. (June 2001) Within the North Slope, only a surface "active layer" of the tundra thaws each season; most of the soil is permanently frozen year-round. On top of this permafrost, water flows to sea via shallow, braided streams or settles into pools and ponds. Along the bottom of the Landsat 7 image on the right, the rugged terrain of the Brooks Range mountains is snow-covered in places (blue areas) and exposed (pink areas) in others.
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The life history of E. rosaliae is virtually unknown (Price 1990b). The species seems to be nocturnal or crepuscular and may be surface active during daylight hours under suitable conditions (Ottley and Jacobsen 1983). Nothing is known about reproduction or growth except that clutches with an unspecified number of eggs have been laid in captivity (Price 1990b). The few data on diet and behavior are based on captive specimens and are difficult to interpret in the absence of data on this snake under field conditions.
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Vacuum MD contains an air gap channel configuration. Once it has passed through the membrane, the vapour is sucked out of the permeate channel and condenses outside the module as with SWGMD. VCMD and SWGMD can be applied for the separation of volatile substances from a watery solution or for the generation of pure water from concentrated salt water. One advantage of this method is that undissolved inert gasses blocking the membrane pores are sucked out by the vacuum, leaving a larger effective membrane surface active.
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It is necessary that the mucoadhesive device has features or properties that favor both chemical and mechanical interactions for the macromolecular interpenetration theory to take place. Molecules that can present mucoadhesive properties are molecules with hydrogen bond building groups, high molecular weight, flexible chains, and surface active properties. It is perceived that increase in adhesion force is associated with the degree of penetration of polymer chains. Literature states that the degree of penetration required for efficient bioadhesive bonds lies in the range of 0.2-0.5μm.
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Surfactant is a surface-active lipoprotein complex formed by type II alveolar cells. The proteins and lipids that comprise surfactant have both a hydrophilic region and a hydrophobic region. By absorbing to the air-water interface of alveoli with the hydrophilic head groups in the water and the hydrophobic tails facing towards the air, the main lipid component of surfactant, dipalmitoylphosphatidylcholine, reduces surface tension. It also means the rate of shrinking is more regular because of the stability of surface area caused by surfactant.
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When in the form of a bar, cake or moulded shape, such soap is classified under subheading 3401.11, which provides for Soap and organic surface-active products and preparations, in the form of bars, cakes, moulded pieces or shapes, and paper, wadding, felt and nonwovens, impregnated, coated or covered with soap or detergent: For toilet use (including medicated products). Conversely, liquid personal hygiene soap is classified under either 3401.20, which provides for Soap in other forms, or 3401.30, which provides for Organic surface-active products and preparations for washing the skin, in the form of liquid or cream and put up for retail sale, whether or not containing soap. An example of a product classified according to its function is a carbon monoxide (CO) detector. If the CO detector captures and displays gas measurements, then it is properly classified under subheading 9027.10, which provides for Instruments and apparatus for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus; instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes.
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DPPC is the main phospholipid of pulmonary surfactant, and it is surface-active due to its amphipathic behaviour and its adsorption capacity. However, adsorption is not optimal at human body temperature for DPPC alone, because at 37 °C it is found in a gel phase. The presence of some unsaturated phospholipids (such as dioleoylphosphatidylcholine [DOPC] or phosphatidylglycerol) and cholesterol increases the surfactant's fluidity, so it can adsorb oxygen more efficiently. When this mixture contacts water, for example, it accumulates at the water-air interface and forms a thin superficial pellicule of surfactant.
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A bottle of olive oil used in food An oil is any nonpolar chemical substance that is a viscous liquid at ambient temperatures and is both hydrophobic (does not mix with water, literally "water fearing") and lipophilic (mixes with other oils, literally "fat loving"). Oils have a high carbon and hydrogen content and are usually flammable and surface active. Most oils are unsaturated lipids that are liquid at room temperature. The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses.
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Bacteria in the surface microlayer of the ocean, called bacterioneuston, are of interest due to practical applications such as air-sea gas exchange of greenhouse gases, production of climate-active marine aerosols, and remote sensing of the ocean. Of specific interest is the production and degradation of surfactants (surface active materials) via microbial biochemical processes. Major sources of surfactants in the open ocean include phytoplankton,Ẑutić, V., Ćosović, B., Marčenko, E., Bihari, N. and Kršinić, F. (1981) "Surfactant production by marine phytoplankton". Marine Chemistry, 10(6): 505–520. .
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Musim Mas merchandises and distributes its products via its marketing arm, Inter-Continental Oil and Fats Pte. Ltd. (ICOF). Based in Singapore, ICOF serves all the major markets in the world, offering a comprehensive range of tropical oils and derivative products. Maschem B.V., a wholly owned subsidiary of the Musim Mas Group, has developed a state-of-the-art Ethoxylation Facility at the site of Dow Benelux B.V. in Terneuzen. The facility will produce surface active agents or more commonly known as surfactants based on alcohols, oils, esters, fatty acids and amines.
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This does two things: it flattens the tape to allow a smoother shot, and it also makes the blade of the stick stickier, which helps hockey players control the puck for stick-handling, passing, and shooting purposes. Also the wax acts as a surfactant, also called surface- active agent, to aid moisture dispersion from the blade during ice hockey sessions. In addition, some goaltenders rub the wax on the shaft of the stick to help them hold the stick when it is struck by hard shots, some of which exceed 100 MPH.
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Ceragenix Pharmaceuticals logo Ceragenix Pharmaceuticals, Inc. is a biopharmaceutical company headquartered in Denver, Colorado that develops prescription therapies based on a platform of proprietary surface active technologies—skin Barrier Repair Technology (BRT) and Cerageninis, a new class of broad spectrum anti-infectives. The company discovers, develops and commercializes anti-infective drugs based on its proprietary class of compounds, Ceragenins. Active against a range of gram positive and gram negative bacteria, these agents are being developed as anti-infective medical device coatings and as therapeutics for antibiotic-resistant organisms.
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The structure elements are combined in structural systems. The majority of everyday load-bearing structures are section-active structures like frames, which are primarily composed of one-dimensional (bending) structures. Other types are Vector-active structures such as trusses, surface-active structures such as shells and folded plates, form-active structures such as cable or membrane structures, and hybrid structures. Load-bearing biological structures such as bones, teeth, shells, and tendons derive their strength from a multilevel hierarchy of structures employing biominerals and proteins, at the bottom of which are collagen fibrils.
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The value of the CMC for a given dispersant in a given medium depends on temperature, pressure, and (sometimes strongly) on the presence and concentration of other surface active substances and electrolytes. Micelles only form above critical micelle temperature. For example, the value of CMC for sodium dodecyl sulfate in water (without other additives or salts) at 25 °C, atmospheric pressure, is 8x10−3 mol/L.Ana Domínguez, Aurora Fernández, Noemí González, Emilia Iglesias, and Luis Montenegro "Determination of Critical Micelle Concentration of Some Surfactants by Three Techniques", Journal of Chemical Education, Vol.
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Top to Bottom: Increasing concentration of surfactant in water first leads to the formation of a layer on the surface. After reaching the CMC micelles begin forming. Notice that the existence of micelles does not preclude the existence of individual surfactant molecules in solution. Upon introducing surfactants (or any surface active materials) into a system, they will initially partition into the interface, reducing the system free energy by: # lowering the energy of the interface (calculated as area times surface tension), and # removing the hydrophobic parts of the surfactant from contact with water.
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Their free-floating characteristic sets TEPs aside from other extracellular polymeric substance subgroups where exopolymers exists as cell coating, dissolved slime or as part of biofilm matrices. The formation of Transparent Exopolymer Particles(TEP) is mainly due to the abiotic coagulation of dissolved carbohydrates, which is secreted by the phytoplankton communities. Transparent Exopolymer Particles ((TEP) have the ability to form larger aggregates because of their strong surface active properties or “stickiness”. This particular property of TEP allows them to perform as a glue matrix for other solid particles including detritus.
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Dioctyl sodium sulfosuccinate has been approved by the US FDA as a "generally recognized as safe" (GRAS) additive. It is used in a variety of food products, as a surface active agent, stabilizer, thickener, wetting agent, processing aid, solubilizing agent, emulsifier, and dispersant. The highest amount found in food products is 0.5% by weight, which include pasteurized cheese spreads, cream cheeses and salad dressings. The FDA also approved its use as a wetting agent or solubilizer for flavoring agents in carbonated and non-carbonated drinks at levels up to 10 parts per million.
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Moreover, multiple biopsies using double tetracycline labelling are necessary for the same patient to assess treatment response or disease progression. Another drawback is that the iliac crest may not provide a true measurement of changes in bone metabolism at the lumbar spine or hip as considerable differences in regional bone metabolism estimates are observed at different skeletal sites. Revell et al. describes the measurement of various parameters such as trabecular bone volume, osteoid volume, osteoid surface, active osteoblastic surface, resorption surface, osteoclastic resorption surface, mineralization front, osteoid index, appositional rate, and osteoclastic index via histomorphometric analysis of bone samples.
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Pulsating combustion was also used to generate hot gas for heating purposes and to fire boilers. The principle was tested in the eighties at the SKET Institute in Weimar to determine the suitability of pulsating combustion as a unit for performing thermal, material-modifying processes. The unit was already being referred to as a pulsation reactor by the Institute at that time. As well as the process of cement clinker firing, the manufacture of polishing agents from iron oxalate for the optical industry and the manufacture of surface-active catalyst substrates from gibbsite were also investigated.
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Or when used with materials such as soft copper, it may have extra additives to prevent stone loading, or metal deactivators to prevent staining of copper containing alloys. To achieve maximum cutting rates and abrasive life with petroleum (mineral) based machining oils when honing difficult materials like stainless steel, a higher level of surface active lubricity agents are combined with sulfur extreme pressure additives. Industrial honing oil is typically available in: 5 gal pails, 55 gal drums, 275 gal and 330 gal totes, while home knife honing oils are typically available in 1 oz, 4 oz, and 12 oz. bottles.
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Gilbert and his coworkers then revealed the mechanism for initiation in emulsion polymerisation by the entry of radicals into particles—in terms of fundamental thermodynamic and kinetic precepts—in a theory that clarifies the process as being through production of surface-active species in the water phase. This model produced various qualitative predictions. One prediction, that of the independence of the entry-rate coefficient of the size and surface properties of particles, was widely seen as counterintuitive because of the deep-rooted belief in models that he had shown to be wrong. Subsequently, this prediction was experimentally verified by Gilbert and others.
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Air entrainment is the intentional creation of tiny air bubbles in concrete. A concrete maker introduces the bubbles by adding to the mix an air entraining agent, a surfactant (surface-active substance, a type of chemical that includes detergents). The air bubbles are created during mixing of the plastic (easy flowing, not hardened) concrete, and most of them survive to be part of the hardened concrete. The primary purpose of air entrainment is to increase the durability of the hardened concrete, especially in climates subject to freeze-thaw; the secondary purpose is to increase workability of the concrete while in a plastic state in concrete.
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Eugene Rosenberg working in his laboratory Rosenberg’s early work in Israel focused on myxobacteriology, hydrocarbon microbiology, surface-active polymers from Acinetobacter, and bioremediation. In collaboration with his department colleagues Eliora Z. Ron and David Gutnik, he introduced the pioneering use of microorganisms and bioemulsifiers to treat oil pollution in oil tankers, pipelines and on beaches In later years he collaborated with Yossi Loya (Zoology Dept., Tel Aviv University) to research coral disease. They demonstrated for the first time that coral bleaching is the result of an infectious disease and that a rise in temperature due to global warming causes pathogenic micro organisms to be more active and cause infectious epidemic diseases.
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Twelve sites were used, with four sites each randomly assigned to one of three treatments: clearcut (complete canopy removal), shelterwood (partial canopy removal), and reference (no timbering). Population baselines were established the year before timbering began, by conducting night mark/recapture surveys of surface-active animals. Establishing a baseline is a vital step in studying timbering effects, as salamander distribution and dispersal patterns may be clumped, and without a preliminary reference point, it may not be possible to separate dispersal effects and individual site differences from timbering effects. Subsequent surveys were conducted in the next year, after timbering was complete and the year following.
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Foams have been used in many forms in the history of cooking, for example: whipped cream, ice cream, cakes, meringue, soufflés, mousse and marshmallow. It has a unique light texture because of the tiny air bubbles and/or a different mouthfeel. In most of these products, proteins are the main surface active agents that help in the formation and stabilization of the dispersed gas phase. To create a protein- stabilized foam, it usually involves bubbling, whipping or shaking a protein solution and its foaming properties refers to its capacity to form a thin tenacious film at the gas-liquid interface for large amounts of gas bubbles to become incorporated and stabilized.
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The strain hardening modulus is calculated over the entire strain hardening region in the true stress strain curve. The strain hardening region of the stress-strain curve is considered to be the homogeneously deforming part well above the natural draw ratio, which is determined by presence of the neck propagation, and below the maximum elongation. The strain hardening modulus when measured at 80℃ is sensitive to the same molecular factors that govern slow crack resistance in HDPE as measured by an accelerated ESCR test where a surface active agent is used. The strain hardening modulus and ESCR values for polyethylene have been found to be strongly correlated with each others.
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Iron oxide and cobalt nanoparticles can be loaded onto various surface active materials like alumina to convert gases such as carbon monoxide and hydrogen into liquid hydrocarbon fuels using the Fischer-Tropsch process. Much research on nanomaterial-based catalysts has to do with maximizing the effectiveness of the catalyst coating in fuel cells. Platinum is currently the most common catalyst for this application, however, it is expensive and rare, so a lot of research has been going into maximizing the catalytic properties of other metals by shrinking them to nanoparticles in the hope that someday they will be an efficient and economic alternative to platinum. Gold nanoparticles also exhibit catalytic properties, despite the fact that bulk gold is unreactive.
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Employing a sit-and-wait hunting technique, painted dragons will use their keen vision to detect most of their prey by the telltale movement they make. Accordingly, their diets consist largely of surface- active, mobile prey resulting in them consuming a range of arthropods. A strange feature of the family Agamidae is that ants, which are often avoided by other lizards, feature prominently in the diets of many of its species. While it is believed that this is more of a reflection on availability than preference, it still remains to be explained why they take ants at all when so many other lizards actively avoid them due to the formic acid they contain.
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Reference site levels of P. hubrichti varied from 0.19 to 0.35 surface-active salamanders/m2 during the course of the study, with a complete oscillation over an 11-year period around a mean of 0.28/m2. Had the study been shorter, the population would have appeared to decline overall instead of varying. With this variation at reference sites as a comparison, clearcuts evidently have a significant negative impact on Peaks of Otter salamander populations, with no signs of complete recovery even 12 years after timbering. While shelterwood cuts do not leave the population completely unscathed, they are not harmful in the long term, and if applied judiciously they may be used in allopatric areas where populations of P. hubrichti are otherwise stable.
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This decompression model was developed by D.E. Yount and others at the University of Hawaii to model laboratory observations of bubble formation and growth in both inanimate and in vivo systems exposed to pressure variations. It presumes that microscopic bubble nuclei always exist in aqueous media, including living tissues. These bubble nuclei are spherical gas phases that are small enough to remain in suspension yet strong enough to resist collapse, their stability being provided by an elastic surface layer consisting of surface-active molecules with variable gas permeability. These skins resist the effect of surface tension, as surface tension tends to collapse a small bubble by raising internal pressure above ambient so that the partial pressure gradient favours diffusion out of the bubble in inverse proportion to the radius of the surface.
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The process of mechanical alloying involves the production of a composite powder particles by: # Using a high energy mill to favor plastic deformation required for cold welding and reduce the process times # Using a mixture of elemental and master alloy powders (the latter to reduce the activity of the element, since it is known that the activity in an alloy or a compound could be orders of magnitude less than in a pure metal) # Eliminating the use of surface-active agents which would produce fine pyrophoric powder as well as contaminate the powder # Relying on a constant interplay between welding and fracturing to yield a powder with a refined internal structure, typical of very fine powders normally produced, but having an overall particle size which was relatively coarse, and therefore stable. Narrow particle size distribution.
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Equilibrium of forces on the surface is required for a bubble to exist. The sum of the Ambient pressure and pressure due to tissue distortion, exerted on the outside of the surface, with surface tension of the liquid at the interface between the bubble and the surroundings must be balanced by the pressure on the inside of the bubble. This is the sum of the partial pressures of the gases inside due to the net diffusion of gas to and from the bubble. The force balance on the bubble may be modified by a layer of surface active molecules which can stabilise a microbubble at a size where surface tension on a clean bubble would cause it to collapse rapidly, and this surface layer may vary in permeability, so that if the bubble is sufficiently compressed it may become impermeable to diffusion.
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These bubble nuclei are spherical gas phases that are small enough to remain in suspension yet strong enough to resist collapse, their stability being provided by an elastic surface layer consisting of surface-active molecules which resists the effect of surface tension. Once a micro-bubble forms it may continue to grow if the tissues are sufficiently supersaturated. As the bubble grows it may distort the surrounding tissue and cause damage to cells and pressure on nerves resulting in pain, or may block a blood vessel, cutting off blood flow and causing hypoxia in the tissues normally perfused by the vessel. If a bubble or an object exists which collects gas molecules this collection of gas molecules may reach a size where the internal pressure exceeds the combined surface tension and external pressure and the bubble will grow.
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Lung surfactant (LS) is a surface-active material produced by most air-breathing animals for the purpose of reducing the surface tension of the water layer where gas exchange occurs in the lungs, given that the movements due to inhalation and exhalation may cause damage if there is not enough energy to sustain alveolar structural integrity. The monolayer formed by the LS on the interface is composed primarily of phospholipids (80%), in addition to proteins (12%) and neutral lipids (8%). Among the phospholipids, the most prevalent one is phosphatidylcholine (PC, or lecithin) (70–85%), which in turn is the basis of a pool of similar diacylphophatidylcholines of which 50% is dipalmitoylphosphatidylcholine or DPPC. While DPPC itself already has the ability to reduce the surface tension of the alveolar liquid, the proteins and other lipids in the surfactant further facilitate the adsorption of oxygen into the air-liquid interface.
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In 2012, the bilateral trade turnover between the countries was 1.3 billion dollars, a growth of 49.1% in comparison to 2011. The total export of Ukraine was 922.5 million dollars (796.4 in products and 126.1 in services). The import reached the amount of 364.2 million dollars (266.8 in goods and 97.4 in services). The main exports from Ukraine to Israel in 2012 were: grain (50.6%), non-precious metal (18.2%), aircraft (6.9%), food industry byproducts (5.8%), oil seeds and oleaginous fruits (3.3%), fats and oils of animal or vegetable origin (1.5%), electrical machinery (1.2%), nuclear reactors, boilers, machinery (1.1%). The main Israeli imports to Ukraine in 2012 were: mineral fuels, mineral oils and products of their distillation (42.4%, various chemical products (9.0%), plastics (7.0%), goods purchased in ports (5.5%), pharmaceutical products (4.8%), electrical machinery (4.4%), nuclear reactors, boilers, machinery (4.1%), fruits and nuts (3.1%), optical: photographic equipment (2.2%), soap: organic surface-active substances (1.9%), synthetic or artificial (1.7%), vegetables (1.6%), essential oils (1.5%).
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1,4-butanesultone reacts smoothly with nucleophiles such as ammonia to form the corresponding zwitterionic, usually very water-soluble sulfobutylbetaines. Synthese von 4-Aminobutan-1-sulfonsäure aus 1,4-Butansulton Sulfobetaines with longer alkyl chains (CnH2n+1 mit n > 10) show interesting properties as surface-active compounds (surfactants, detergents) with antimicrobial properties. Synthese eines Alkylpiperidinsulfobetains-Surfactants In the reaction of N-N- butylimidazole with 1,4-Butansultone in Toluene in a 98% yield is formed 1-butylimidazolium-3-(n-butylsulfonate) Synthese von ionischen Flüssigkeiten vom Chlorbutylsulfonat-Typ 1-Butylimidazolium-3-(n-butylsulfonate) catalyses as a component of multifunctional catalysts the reaction of platform chemicals from biomass (for example levulinic acid or itaconic acid) into the corresponding lactones, diols or cyclic ethers. Aminoalkylphosphonic acids (such as aminomethane diphosphonic acid, accessible from phosphorus trichloride, formamide and phosphonic acid) form with 1,4-butanesultone N-(sulfobutyl)aminomethane diphosphonic acids: Synthese von N-(Sulfobutyl)aminomethandiphosphonsäure-Komplexbildnern N-(sulfobutyl)aminomethane diphosphonic acid is characterized by very high water solubility (< 1000 g·l−1) and a strong capability as complexing agent and water softener.
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Lampropeltis zonata pulchra is an infrequently observed, secretive, cryptozooic snake, the life history of which is still only partly understood. The San Diego mountain kingsnake typically emerges from overwintering sites in March and may remain near-surface active through November, but it is particularly conspicuous near the surface from roughly mid-March to mid-May (Klauber 1931, McGurty 1988, Hubbs 2004), during which time it is active during the warmer daylight hours (pers. observ.). Later in the season, it may be active after dark, which is probably related to the fact that, like most snakes, it has a relatively low temperature preferendum and a relatively low critical thermal maximum (42.5 °C: data provided for L. zonata, subspecies not specified; Brattstrom 1965). Based on wild-caught captive individuals, mating probably takes place in May and eggs are usually laid in June or early July (McGurty 1988; pers. observ.). Females lay 4-9 moderate-sized (averages 36 mm long x 16 mm wide), bone white, leathery-shelled eggs that if similar to eggs incubated in captivity, require at least 2 months to develop before hatching (McGurty 1988).
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