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impregnation meaning in science

Impregnation The treatment of castings with a sealing medium to stop pressure leaks, such as soaking under pressure with or without prior evacuation and either with hot or cold application. Tension control is not a trivial matter, especially not at relatively low levels and in combination with variable speed. 2. saturation . Human fertilization is the union of a human egg and sperm, occurring in the ampulla of the fallopian tube. WAKEMAN, C.D. From: New and Future Developments in Catalysis, 2013, C. SOHL, in Comprehensive Composite Materials, 2000. 6.2. A variety of standard machines are available from a small number of suppliers. En toxicologie et écotoxicologie, l’imprégnation est le résultat du dosage d’une toxine ou d’un polluant (ou des métabolites de leur dégradation) dans l’organisme. Direct impregnation with multi feed configuration: 1: Outer liner, 2: Inner liner, 3: Guiding tool, 4: Fibers axial, 5: Fibers circumferential. The act of making pregnant; fertilization. See more. In incipient wetness impregnation, high drug concentrations or repeated impregnations are required in order to achieve high loading degrees. Provided by an external single extruder, the melted polymer is pressed through a heated impregnation unit, for example a porous ring consisting of sintered metal, and the fibers are impregnated with matrix. During drying, the drug located in the solution outside the pores is driven inside the pores by diffusion. Dictionary entry overview: What does impregnation mean? Thus you can have a sponge that absorbs (soaks up) water. In addition, the probability of harmful reactions between the porous material and the payload molecules is increased at elevated temperatures. Simple increases in pressure, during direct-melt impregnation for example, are likely to be counter-productive since this will also reduce the transverse permeability of the fibre bundles. Important in science, microtomes are used in microscopy, allowing for the preparation of samples for observation under transmitted light or electron radiation. Mechanisms of the impregnation method There are two mechanisms according to type of the impregnation method. J. Mack, R. Schledjewski, in Manufacturing Techniques for Polymer Matrix Composites (PMCs), 2012. With a variable impregnation length the winding speed can be adjusted to the required winding velocity. The key issue in impregnation of graphite and porous metals is penetration of dispersion into the pores. Learn more. The raw material costs (fibers and polymer) are equal for all processes but further processing steps are not necessary. Chemical Engineering Science A theoretical study is presented dealing with the impregnation of one or two active species on a porous support, in order to predict the internal concentration as a function of the process parameters. through a medium or substance. Impregnation meaning The act of making pregnant; fertilization. The advantage is that there are no rollers on which the filaments could coil up on. Similar wet-impregnation methods are reported for SBA-15 [98] and SBA-15-like plugged hexagonally templated silica (PHTS). Impregnation - Science topic. The protection of human body by the impregnated carbons involves adsorption as in the case of chloropicrin, chemical reactions with the impregnant such as neutralization, complex formation, hydrolysis as in the case of phosgene and hydrogen cyanide, and catalytic reactions such as oxidation in the case of arsine. Because of their good tensile strength and further expected positive properties, e.g., high energy absorption capacity, biocompatibility, and chemical resistance, PE/PE composites are interesting for special applications, e.g., ballistic protection or as implant materials for artificial joints. • IMPREGNATION (noun) The noun IMPREGNATION has 3 senses:. There is often an associated increase in product cost with increasing homogeneity2. Melt impregnation results in low penetration of matrix into a bundle. The applications of impregnated metal and graphite parts are in heat exchangers and bearings where impervious properties are required. In the case of glass fiber, polished hard chrome or ceramic performs well, whereas carbon fiber will produce less fuzz on a “rougher” surface, i.e., sandblasted steel plated with hard chrome (Mitsubishi Chemical Corporation) (Figure 8). The process of fertilization involves a sperm fusing with an ovum. In the Incipient wetness impregnation method capillary action draws the solution into the pores. An example is when winding a large diameter compared to length at a low angle; it is often efficient to use pinrings instead of a turnaround on a dome. Learn more. It can be used with all fiber types, fiber damage is minimal, and winding can performed with a minimum amount of excess resin, securing not only a high composite quality but also a cleaner working environment. However, it can be difficult to control the amount of payload on the external surface of the material (Salonen et al., 2008). The unique features on a winding machine are the software, the impregnation bath, the delivery eye, and the tensioning system. Oxygen Reduction Catalysts on Nanoparticle Electrodes. How to use impregnate in a sentence. Word of the day God's acre 6.2)1. What does impregnation mean? Impregnation can be carried out in a number of ways. Schematic illustrations of a few new scalable production methods of shape-controlled ORR catalysts: (A) impregnation-reduction method, (B) droplet-based microreactor, and (C) conveyor transport system. M D WAKEMAN, J-A E MÅNSON, in Design and Manufacture of Textile Composites, 2005. Among them, carbon-supported PtNi catalysts showed a superior ORR performance. Casting impregnation is the process of removing air from the pores of leakage paths in a casting and replacing it with resin that is specifically formulated to cure in the pores so that the casting becomes pressure tight. KARL SCHULTE, FRANK VON LACROIX, in Comprehensive Composite Materials, 2000. Direct impregnation thermoplastic winding processes have some advantages compared to winding technologies which use semi-finished products. Spun yarn could contain up to 5% cotton for production industrial packing. They are available in a number of forms, which can be coated. (geology) An ore deposit, with indefinite boundaries, consisting of rock impregnated with ore. quotations ▼ The machines have 2–5 axes of motion and 1–10 spindles. After impregnation, the mixture is typically calcined to remove any volatile components of the impregnation solution that are left over (surface nitrates in the Cr(NO3)3 case) and stabilize the active surface species in their final state. Akin could have had some assistant or intern look it up in minutes via Google Scholar or PubMed, as a … Notably for lower viscosity systems, capillary pressure can play a role in the spontaneous wetting of fibres as low external pressure may be applied. Impregnate definition, to make pregnant; get with child or young. Looking for the abbreviation of Vacuum Pressure Impregnation? After dipping, the asbestos is dried in an oven (80–90°C) followed by calendaring to smooth the surface. Resin pickup is directly related to roving tension, i.e., as the roving tension increases, the resin pickup decreases. Resin pick-up is difficult to control (the amount of excess resin will be high). Impregnation has traditionally been used to load catalytic species into porous materials, but it is also suitable for loading porous materials for biomedical applications (Campanati et al., 2003; Mellaerts et al., 2008). Material routes, preform types and final moulding processes for aligned fibre thermoplastic composites. Figure 8. Fig 7.12. Due to a limited market it is like buying a low-precision lathe for wood at the price of a high-precision lathe for metal. (geology) An ore deposit, with indefinite boundaries, consisting of rock impregnated with ore. 1. creation by the physical union of male and female gametes; of sperm and ova in an animal or pollen and ovule in a plant In general, each step is similar to the corresponding step for coating glass cloth. This is accomplished by placing the dipping operation in a vacuum chamber. The solution impregnation technique and impregnation in a suspension solve the impregnation problems.

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