1.
Laboratory centrifuge
–
A laboratory centrifuge is a piece of laboratory equipment, driven by a motor, which spins liquid samples at high speed. There are various types of centrifuges, depending on the size, like all other centrifuges, laboratory centrifuges work by the sedimentation principle, where the centripetal acceleration is used to separate substances of greater and lesser density. There are different providers of laboratory centrifuges like Eppendorf, Thermo-Heraeus, Thermo-Sorvall, Hettich, Beckmann-Coulter, MSE, Sigma, centrifuge tubes are precision-made, high-strength tubes of glass or plastic made to fit exactly in rotor cavities. They may vary in capacity from 50 mL down to much smaller capacities used in microcentrifuges used extensively in biology laboratories. They can be cleaned like other laboratory glassware, and can be sterilized by autoclaving and they must be handled with care, since small scratches can cause failure under the strong forces imposed during a run. Glass tubes are inserted into soft rubber sleeves to cushion them during runs, plastic centrifuge tubes, especially tend to be less expensive and, with care, can be just as durable as glass. Water is preferred when plastic centrifuge tubes are used and they are more difficult to clean thoroughly, and are usually inexpensive enough to be considered disposable. Disposable plastic microlitre tubes of 0. 5ml to 2ml are commonly used in microcentrifuges and they are molded from a flexible transparent plastic similar to polythene, are semi-conical in shape, with integral, hinged sealing caps. Larger samples are spun using centrifuge bottles, which range in capacity from 250 to 1000 millilitres, although some are made of heavy glass, centrifuge bottles are usually made of shatterproof plastics such as polypropylene or polycarbonate. Sealing closures may be used for added leak-proof assurance, the load in a laboratory centrifuge must be carefully balanced. This is achieved by using a combination of samples and balance tubes which all have the weight or by using various balancing patterns without balance tubes. Small differences in mass of the load can result in a force imbalance when the rotor is at high speed. This force imbalance strains the spindle and may result in damage to the centrifuge or personal injury, some centrifuges have an automatic rotor imbalance detection feature that immediately discontinues the run when an imbalance is detected. Before starting a centrifuge, a check of the rotor. Centrifuge rotors should never be touched while moving, because a spinning rotor can cause serious injury, modern centrifuges generally have features that prevent accidental contact with a moving rotor as the main lid is locked during the run. Centrifuge rotors have tremendous kinetic energy during high speed rotation, rotor failure, caused by mechanical stress from the high forces imparted by the motor, can occur due to manufacturing defects, routine wear and tear, or improper use and maintenance. Such a failure can be catastrophic failure, especially with larger centrifuges, uncontained rotor failures have shattered laboratory windows and destroyed refrigerators and cabinetry. Another potential hazard is the aerosolization of hazardous samples during centrifugation, to prevent contamination of the laboratory, rotor lids with special aerosol-tight gaskets are available
2.
Nanoparticle
–
Nanoparticles are particles between 1 and 100 nanometers in size. In nanotechnology, a particle is defined as an object that behaves as a whole unit with respect to its transport. Particles are further classified according to diameter, scientific research on nanoparticles is intense as they have many potential applications in medicine, physics, optics, and electronics. The U. S. National Nanotechnology Initiative offers government funding focused on nanoparticle research, the term nanoparticle is not usually applied to individual molecules, it usually refers to inorganic materials. However, during the 1990s before the National Nanotechnology Initiative was launched in the USA, nanoparticles can exhibit size-related properties significantly different from those of either fine particles or bulk materials. Nanoclusters have at least one dimension between 1 and 10 nanometers and a size distribution. Nanopowders are agglomerates of ultrafine particles, nanoparticles, or nanoclusters, nanometer-sized single crystals, or single-domain ultrafine particles, are often referred to as nanocrystals. Although nanoparticles are associated with science, they have a long history. In modern times, pottery from the Middle Ages and Renaissance often retains a distinct gold- or copper-colored metallic glitter and this luster is caused by a metallic film that was applied to the transparent surface of a glazing. The luster can still be visible if the film has resisted atmospheric oxidation, the luster originates within the film itself, which contains silver and copper nanoparticles dispersed homogeneously in the glassy matrix of the ceramic glaze. These nanoparticles are created by the artisans by adding copper and silver salts and oxides together with vinegar, ochre, the object is then placed into a kiln and heated to about 600 °C in a reducing atmosphere. In the heat the glaze softens, causing the copper and silver ions to migrate into the layers of the glaze. There the reducing atmosphere reduced the ions back to metals, which came together forming the nanoparticles that give the color. Luster technique showed that ancient craftsmen had an empirical knowledge of materials. The technique originated in the Muslim world, as Muslims were not allowed to use gold in artistic representations, they sought a way to create a similar effect without using real gold. The solution they found was using luster, michael Faraday provided the first description, in scientific terms, of the optical properties of nanometer-scale metals in his classic 1857 paper. The result is white light is now freely transmitted, reflection is correspondingly diminished. Uncontrolled agglomeration of powders due to van der Waals forces can also give rise to microstructural heterogeneity
3.
Energy
–
In physics, energy is the property that must be transferred to an object in order to perform work on – or to heat – the object, and can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton. Mass and energy are closely related, for example, with a sensitive enough scale, one could measure an increase in mass after heating an object. Living organisms require available energy to stay alive, such as the humans get from food. Civilisation gets the energy it needs from energy resources such as fuels, nuclear fuel. The processes of Earths climate and ecosystem are driven by the radiant energy Earth receives from the sun, the total energy of a system can be subdivided and classified in various ways. It may also be convenient to distinguish gravitational energy, thermal energy, several types of energy, electric energy. Many of these overlap, for instance, thermal energy usually consists partly of kinetic. Some types of energy are a mix of both potential and kinetic energy. An example is energy which is the sum of kinetic. Whenever physical scientists discover that a phenomenon appears to violate the law of energy conservation. Heat and work are special cases in that they are not properties of systems, in general we cannot measure how much heat or work are present in an object, but rather only how much energy is transferred among objects in certain ways during the occurrence of a given process. Heat and work are measured as positive or negative depending on which side of the transfer we view them from, the distinctions between different kinds of energy is not always clear-cut. In contrast to the definition, energeia was a qualitative philosophical concept, broad enough to include ideas such as happiness. The modern analog of this property, kinetic energy, differs from vis viva only by a factor of two, in 1807, Thomas Young was possibly the first to use the term energy instead of vis viva, in its modern sense. Gustave-Gaspard Coriolis described kinetic energy in 1829 in its modern sense, the law of conservation of energy was also first postulated in the early 19th century, and applies to any isolated system. It was argued for years whether heat was a physical substance, dubbed the caloric, or merely a physical quantity. In 1845 James Prescott Joule discovered the link between mechanical work and the generation of heat and these developments led to the theory of conservation of energy, formalized largely by William Thomson as the field of thermodynamics
4.
Pigment
–
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors and it must be stable in solid form at ambient temperatures. For industrial applications, as well as in the arts, permanence, pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food, and other materials. Most pigments used in manufacturing and the arts are dry colorants. This powder is added to a binder, a neutral or colorless material that suspends the pigment. A distinction is made between a pigment, which is insoluble in its vehicle, and a dye, which either is itself a liquid or is soluble in its vehicle. A colorant can act as either a pigment or a dye depending on the vehicle involved, in some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt. The resulting pigment is called a lake pigment, the term biological pigment is used for all colored substances independent of their solubility. In 2006, around 7.4 million tons of inorganic, organic, asia has the highest rate on a quantity basis followed by Europe and North America. By 2020, revenues will have risen to approx, the global demand on pigments was roughly US$20.5 billion in 2009, around 1. 5-2% up from the previous year. It is predicted to increase in a growth rate in the coming years. The worldwide sales are said to increase up to US$24.5 billion in 2015, pigments appear the colors they are because they selectively reflect and absorb certain wavelengths of visible light. White light is an equal mixture of the entire spectrum of visible light with a wavelength in a range from about 375 or 400 nanometers to about 760 or 780 nm. When this light encounters a pigment, parts of the spectrum are absorbed by the molecules or ions of the pigment, in organic pigments such as diazo or phthalocyanine compounds the light is absorbed by the conjugated systems of double bonds in the molecule. Some of the inorganic pigments such as vermilion or cadmium yellow absorb light by transferring an electron from the ion to the positive ion
5.
Water treatment
–
Water treatment is any process that makes water more acceptable for a specific end-use. The end use may be drinking, industrial supply, irrigation, river flow maintenance, water recreation or many other uses. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. Substances that are removed during the process of drinking water treatment include suspended solids, bacteria, algae, viruses, fungi, measures taken to ensure water quality not only relate to the treatment of the water, but to its conveyance and distribution after treatment. It is therefore common practice to keep residual disinfectants in the water to kill bacteriological contamination during distribution. World Health Organization guidelines are a set of standards intended to apply where better local standards are not implemeted. More rigorous standards apply across Europe, the USA and in most other developed countries, followed throughout the world for drinking water quality requirements. Disinfection for killing bacteria viruses and other pathogens, technologies for potable water and other uses are well developed, and generalized designs are available from which treatment processes can be selected for pilot testing on the specific source water. In addition, a number of companies provide patented technological solutions for treatment of specific contaminants. Automation of water and waste-water treatment is common in the developed world, source water quality through the seasons, scale and environmental impact can dictate capital costs and operating costs. End use of the treated water dictates the necessary quality monitoring technologies, biological processes can be employed in the treatment of wastewater and these processes may include, for example, aerated lagoons, activated sludge or slow sand filters. To be effective, sewage must be conveyed to a treatment plant by appropriate pipes and infrastructure, some wastewaters require different and sometimes specialized treatment methods. At the simplest level, treatment of sewage and most wastewaters is carried out through separation of solids from liquids, by progressively converting dissolved material into solids, usually a biological floc, which is then settled out, an effluent stream of increasing purity is produced. Two of the processes of industrial water treatment are boiler water treatment. A lack of water treatment can lead to the reaction of solids and bacteria within pipe work. Steam boilers can suffer from scale or corrosion when left untreated, scale deposits can lead to weak and dangerous machinery, while additional fuel is required to heat the same level of water because of the rise in thermal resistance. Poor quality dirty water can become a ground for bacteria such as Legionella causing a risk to public health. With the proper treatment, a significant proportion of industrial on-site wastewater might be reusable, corrosion in low pressure boilers can be caused by dissolved oxygen, acidity and excessive alkalinity
6.
Crystallization
–
Crystallization is the process where a solid forms where the atoms or molecules are highly organized in a structure known as a crystal. Some of the ways which crystals form are through precipitating from a solution, crystallization is also a chemical solid–liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid crystalline phase occurs. In chemical engineering crystallization occurs in a crystallizer, crystallization is therefore related to precipitation, although the result is not amorphous or disordered, but a crystal. The crystallization process consists of two events, nucleation and crystal growth which are driven by thermodynamic properties as well as chemical properties. These stable clusters constitute the nuclei, therefore, the clusters need to reach a critical size in order to become stable nuclei. Such critical size is dictated by different factors. The crystal growth is the subsequent size increase of the nuclei that succeed in achieving the critical cluster size, crystal growth is a dynamic process occurring in equilibrium where solute molecules or atoms precipitate out of solution, and dissolve back into solution. Supersaturation is one of the forces of crystallization, as the solubility of a species is an equilibrium process quantified by Ksp. Depending upon the conditions, either nucleation or growth may be predominant over the other, many compounds have the ability to crystallize with some having different crystal structures, a phenomenon called polymorphism. Each polymorph is in fact a different thermodynamic solid state and crystal polymorphs of the compound exhibit different physical properties, such as dissolution rate, shape, melting point. For this reason, polymorphism is of importance in industrial manufacture of crystalline products. Additionally, crystal phases can sometimes be interconverted by varying factors such as temperature, there are many examples of natural process that involve crystallization. Geological time scale process examples include, Natural crystal formation, Stalactite/stalagmite, usual time scale process examples include, Snow flakes formation, Honey crystallization. Crystal formation can be divided into two types, where the first type of crystals are composed of a cation and anion, also known as a salt, the second type of crystals are composed of uncharged species, for example menthol. The formation of a solution does not guarantee crystal formation. A typical laboratory technique for crystal formation is to dissolve the solid in a solution in which it is partially soluble, the hot mixture is then filtered to remove any insoluble impurities. The filtrate is allowed to slowly cool, crystals that form are then filtered and washed with a solvent in which they are not soluble, but is miscible with the mother liquor. The process is repeated to increase the purity in a technique known as recrystallization
