Basics 3 min read
Nuclear Technology
The energy released by the change in the nucleus of atoms is known as nuclear energy. The changes in the…
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Basics 3 min read
Ocean Technology
More than 70 percent of the Earth’s area is covered by water (water in Oceans) and it is a great…
Basics 3 min read
Nanotechnology
Nanotechnology or simply ‘nanotech’ is the engineering of matter on an atomic, molecular, and supramolecular scale. The credit of propagation…
Basics 3 min read
Biotechnology
Biotechnology is that branch of science which gained popularity in the 1970s. This is a Science which through different biological…
Material Science 7 min read
Types of Polymers/plastics
Thermosetting plastics (thermosets) are polymer materials that cure, through the addition of energy, to a stronger form. The energy may be in the form of heat (generally above 200 degrees Celsius), through a chemical reaction (two-part epoxy, for example), or irradiation. Thermoset materials are usually liquid, powder, or malleable prior to curing, and designed to be molded into their final form, or used as adhesives. The curing process transforms the resin into a plastic or rubber by a cross-linking process. Energy and/or catalysts are added that cause the molecular chains to react at chemically active sites (unsaturated or epoxy sites, for example), linking into…
Material Science 4 min read
Applications and Processing of Polymers/ Plastics
Plastic covers a range of synthetic or semisynthetic polymerization products. They are composed of organic condensation or addition polymers and may contain other substances to improve performance or economics. There are few natural polymers generally considered to be “plastics”. Plastics can be formed into objects or films or fibers. Their name is derived from the fact that many are malleable, having the property of plasticity. Plastic can be classified in many ways but most commonly by their polymer backbone (polyvinyl chloride, polyethylene, acrylic, silicone, urethane, etc.). Other classifications include thermoplastic vs. thermoset, elastomer, engineering plastic, addition or condensation, and Glass transition temperature or Tg. A lot of plastics are partially crystalline and partially amorphous in molecular structure, giving them both a melting point (the temperature at which the attractive intermolecular forces are overcome) and one or more glass transitions (temperatures at which the degree of cross-linking is substantially reduced). Plastics are polymers: long chains of atoms bonded to one another. These chains are made up of many repeating molecular units, or “monomers”. The vast majority of plastics are composed of polymers of carbon alone or with oxygen, nitrogen, chlorine…
Basics 4 min read
Space Science echnology
In this chapter, we will discuss what is Space Science and how technology influences Space Science. We will focus more…
Material Science 3 min read
Fabrication and processing of ceramics
Ceramic Synthesis Our expertise and capabilities in synthesizing ceramics are based onchemical solution techniques. Chemical solution or sol-gel approaches have beendeveloped to fabricate powders, films, and porous bodies. Materials of interest range from silica to complex, multicomponent electronic ceramics. The complexity inherent in fabricating materials with structured nanoporosity or complex chemistries requires a fundamental understanding of these chemical solution approaches. Fabrication of unique precursors for complex oxides is being done with novel metal alkoxide chemistry to produce powders and thin-film materials with carefully controlled properties. Our ability to synthesize materials with complex structures, chemistries, or both, is at the heart of numerous research and development efforts at Sandia. Ceramic Processing Sandia’s fabrication of ceramic components and devices is based on a strong ceramic-processing capability. We recently have demonstrated the ability to characterize and model the powder- compaction process in detail, and to address and control density gradients in powder compacts that cause shape distortion and differential shrinkage. Proprietary 3D, finite-element code packing and compaction models, and process-control tools are now available to improve the production of ceramic components. Sandia has capabilities in the areas of hydrostatic and triaxial compaction testing to characterize materials properties, and x-ray radiography, ultrasound, and computed tomography for density characterization. In addition, expertise in slurry processing has enabled the…
Basics 3 min read
Communication Technology
Communication is the exchange of information through different mediums. It is an activity that started even before the civilization of…
Material Science 3 min read
Portland Cement
Portland cement is a closely controlled chemical combination of calcium, silicon, aluminum, iron and small amounts of other compounds, to which gypsum is added in the final grinding process to regulate the setting time of the concrete. Some of the raw materials used to manufacture cement are limestone, shells, and chalk or marl, combined with shale, clay, slate or blast furnace slag, silica sand, and iron ore. Lime and silica make up approximately 85 percent of the mass The term “Portland” in Portland cement originated in 1824 when an English mason obtained a patent for his product, which he named Portland Cement. This was because his cement blend produced concrete that resembled the color of the natural limestone quarried on the Isle of Portland in the English Channel. Different types of Portland cement are manufactured to meet different physical and chemical requirements for specific purposes. Common Examples Structural clay products Brick, sewer pipe, roofing tile, clay floor and wall tile (i.e., quarry…
Basics 2 min read
Artificial Intelligence
Artificial Intelligence or simply AI is an experimental science being developed with the purpose to understand the nature of intelligent…
Material Science 11 min read
Types and applications of ceramics
Ceramics offer a high temperature range. However, ceramics are not very strong. To compensate for their lack of strength ceramics are usually combined with some other material to form a ceramic composite. 1) Glasses and glass ceramics- The glasses are a familiar group of ceramics; containers, windows, lenses and fiberglass represent typical applications. The properties of standard vitrified products are insufficient for architectural applications and structural building components, insulation or other specialized applications. Yet there is an effective way to improve these properties without major alterations to the process itself – the introduction of a controlled crystallization process through a subsequent heat treatment, i.e. by forming a glass-ceramic. Production of Glass-Ceramics Glass-ceramic articles may be produced by three routes: • The heat treatment of solid glass (the traditional route) • The controlled cooling of a molten glass, known as the petrurgic method • The sintering and crystallisation of glass powders. In the latter case, the powders are densified at relatively low temperatures by exploiting a viscous flow sintering mechanism. After densification, the material is subjected to a crystallisation heat- treatment to obtain the required glass-ceramic microstructure. Alternatively, both densification and crystallisation may take place during a single sintering step. Along with the economic advantage of using relatively low processing temperatures, the powder technology route is…
