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Tuesday, July 17, 2012

          In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and...
          Cement kilns are used for the pyroprocessing stage of manufacture of Portland and other types of hydraulic cement, in which calcium carbonatereacts with silica-bearing minerals to form a mixture of calcium silicates. Over a billion tonnes of cement are made per year, and cement kilns are the heart of this production process: their capacity usually define the...

Wednesday, July 11, 2012

          Building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is forthermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation (e.g. for vibrations caused by industrial applications). Often an insulation material will be chosen for its ability to...
         Silicon nitride has long been used in high-temperature applications. In particular, it was identified as one of the few monolithic ceramic materials capable of surviving the severe thermal shock and thermal gradients generated in hydrogen/oxygen rocket engines. To demonstrate this capability in a complex configuration, NASA scientists used advanced rapid prototyping technology to fabricate a one-inch-diameter,...

Monday, July 9, 2012

          A fire brick, firebrick, or refractory brick is a block of refractory ceramic material used in lining furnaces, kilns, fireboxes, and fireplaces. A refractory brick is built primarily to withstand high temperature, but will also usually have a low thermal conductivity for greater energy efficiency. Usually dense firebricks are used in applications with extreme mechanical, chemical, or thermal stresses, such as the inside of a wood-fired...
          Refractory metals are a class of metals that are extraordinarily resistant to heat and wear. The expression is mostly used in the context of materials science, metallurgy and engineering. The definition of which elements belong to this group differs. The most common definition includes five elements: two of the fifth period (niobium andmolybdenum) and three of the sixth period (tantalum, tungsten, and rhenium). They all share...

Sunday, July 8, 2012

Oil shale           Oil shale, also known as kerogen shale, is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons called shale oil (not to be confused with tight oil—crude oil occurring naturally in shales) can be produced. Shale oil is a substitute for conventional...
          All refractory require anchorage systems such as wire formed anchors, formed metal (for example, hexmetal) or ceramic tiles to support the refractory linings. The anchorage used for refractory on roofs and vertical walls are more critical as they must remain able to support the weight of refractory even at the elevated temperatures and operating conditions.           The commonly used anchorages have circular or rectangular cross-section. Circular cross-section are used for low...

Thursday, July 5, 2012

          A furnace is a device used for heating. The name derives from Latin fornax, oven. In American English and Canadian English, the term furnace on its own is generally used to describe household heating systems based on a central furnace (known either as a boiler or a heater in British English), and sometimes as a synonym...
          Plastic explosive is a specialised form of explosive material. It is a soft and hand moldable solid material. Plastic explosives are properly known as putty explosives within the field of explosives engineering. Common plastic explosives include Semtex and C-4. Plastic explosives are especially suited for explosive demolition as they can be easily formed...
          Putty is a generic term for a plastic material similar in texture to clay or dough typically used in domestic construction and repair as a sealant or filler.Painter's Putty is typically a linseed oil based product used for filling holes, minor cracks and defacements in wood only. Putties can also be madeintumescent, in which case they are used for firestopping as...
          Epoxy putty is a room-temperature-hardening substance used as a space-filling adhesive. It is stored until use as two components of clay-like consistency. Kneading the two components into each other creates an exothermic chemical reaction that activates the substance for use by catalyzing an epoxide polymerisation reaction. Unlike many other types of glues, an epoxy adhesive can fill gaps and even be molded into a structural part. Some makers claim in advertising that one can...

Wednesday, July 4, 2012

Adhesive           Adhesion is the tendency of dissimilar particles or surfaces to cling to one another (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories...
Hot melt adhesive         Hot melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly supplied in solid cylindrical sticks of various diameters, designed to be melted in an electric hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which may be pushed through the gun by a mechanical trigger mechanism, or directly by the user. The...