Lexikon

water generates electricity when it drops gravitationally, driving a turbine and generator. While most hydroelectricity is produced by water falling from dams, some is produced by water flowing down rivers (run-of-the-river electricity).

Conventionally, hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head. The amount of potential energy in water is proportional to the head. A large pipe (the "penstock") delivers water to the turbine.

Pumped-storage hydroelectric power plant produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand, excess generation capacity is used to pump water into the higher reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine. Pumped-storage schemes currently provide the most commercially important means of large-scale grid energy storage and improve the daily capacity factor of the generation system.

Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that the water coming from upstream must be used for generation at that moment, or must be allowed to bypass the dam.

A tidal power plant makes use of the daily rise and fall of ocean water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, can also be dispatchable to generate power during high demand periods. Less common types of hydro schemes use water's kinetic energy or undammed sources such as undershot waterwheels.

An underground power station makes use of a large natural height difference between two waterways, such as a waterfall or mountain lake. An underground tunnel is constructed to take water from the high reservoir to the generating hall built in an underground cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway.

Source: http://en.wikipedia.org/wiki/Hydroelectricity

hydrogen fuel cell vehicles (HFCVs) use a fuel cell to convert hydrogen fuel and oxygen from air into electricity which is used to run an electric motor. HFCVs are truly clean only if the hydrogen is produced by passing WWS-derived electricity through water (electrolysis). Several companies have prototype HFCVs, and California has about 200 HFCVs on the road (California Fuel Cell Partnership, 2009). Hydrogen fueling stations, though, are practically non-existent and most hydrogen today is produced by steam-reforming of natural gas, which is not as clean as that produced by WWS-electrolysis.

is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth's crust, (commonly in aquifers). The term geohydrology is often used interchangeably. Some make the minor distinction between a hydrologist or engineer applying themselves to geology (geohydrology), and a geologist applying themselves to hydrology (hydrogeology). (Source: Wikipedia)

EUGRIS defines hydrogeology as the study of the geological factors relating to the subsurface waters.

the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 g. It is considered a master gland. The pituitary gland secretes hormones regulating homeostasis, including tropic hormones that stimulate other endocrine glands. It is functionally connected to the hypothalamus by the median eminence.

International Agency for Research on Cancer

Inductively Coupled Plasma with Mass Spectrometry is a combined analytical tool that is highly sensitive and capable of the determination of a range of metals and some non-metals at a ppmppb concentration range. It is based on coupling together an inductively coupled plasma for ionising metals for the mass spectrometer, the tool for separation and detection of metal ions. ICP-MS is also capable of monitoring isotopic speciation for the ions of choice.

Internationalised Domain Names

igneous rocks are crystalline or glassy rocks formed by the cooling and solidification of molten magma. Magma is generated within the asthenosphere (the layer of partially molten rock underlying the Earth's crust) at a depth below about 60–100 kilometers (40–60 miles). Because magma is less dense than the surrounding solid rocks, it rises toward the surface. It may settle within the crust or erupt at the surface from a volcano as a lava flow. Rocks formed from the cooling and solidification of magma deep within the crust are distinct from those erupted at the surface mainly owing to the differences in conditions in the two environments. Within the Earth crust the temperatures and pressures are much higher than at its surface; consequently, the hot magma cools slowly and crystallizes completely. The slow cooling promotes the growth of minerals large enough to be identified visually without the aid of a microscope. On the other hand, magma erupted at the surface is chilled so quickly that the individual minerals have little or no chance to grow. As a result, the rock is either composed of minerals that can be seen only with the aid of a microscope or contains no minerals at all. Igneous rocks are classified on the basis of texture, mineralogy and chemistry. Texture is used to subdivide igneous rocks into two major groups: (1) plutonic igneous rocks, with mineral grain sizes that are visible to the naked eye, and (2) the volcanic extrusive rocks, which are usually too fine-grained or glassy for their mineral composition to be observed without the use of a microscope. Mineralogically, igneous rocks are classified according to QAPF diagram a double triangle diagram devised by the International Union of Geological Sciences (IUGS). The acronym, QAPF, stands for ”Quartz, Alkali feldspar, Plagioclase, Feldspathoid (Foid)". These are the mineral groups used for classification in QAPF diagram. Q, A, P and F percentages are normalized (recalculated so that their sum is 100%).QAPF diagrams are mostly used to classify plutonic igneous rocks but are also used to classify volcanic rocks if modal mineralogical compositions have been determined. Chemically, igneous rocks are classified in 3 groups according to saturation with respect to silica (SiO₂):

1. acidic (oversaturated) – SiO₂ content: 66–90%
2. neutral (saturated) – SiO₂ content: 48–66%
3. basic (unsaturated) – SiO₂ content: below 48%

Classification of igneous rocks is shown below:

see Institute for Health and Consumer Protection (IHCP)

immunogen is a specific type of antigen. An immunogen is defined as a substance that is able to provoke an adaptive immune response. We differentiate an immonogen from an antigen. The latter is able to combine with specifically with the antibody, the final products of the immune response.

impending death is term used in toxicity tests for the case when moribund state or death is expected prior to the next planned time of observation. Signs indicative of this state in rodents could include convulsions, lateral position, recumbence, and tremor.

impingement scrubbers are for handling insoluble solids or where high efficiency gas absorption is required. The venturi scrubbers can handle solids, but have a limited contact time, so gas absorption is not always complete. The impingement design uses multiple perforated plates in series to extend the contact time while handling solids.

This is a low energy device that offers an advantage of particulate collection, cooling, condensing and gas absorption all in a single unit. Gases enter the unit from the bottom and flow upward through a series of trays, each containing perforations designed to achieve the highest efficiency with minimum pressure drop. Scrubbing liquid is introduced above the top tray and cascades downward to the lower trays. As the gases accelerate through the perforations, a fluidized zone of liquid and gas is created. The turbulent mixing in each of these zones provides intimate contact where gas scrubbing and cooling occurs. Units are furnished with a final demister section to minimize liquid carry over problems before the cleaned gases are exhausted via the top outlet.

The type and number of trays is selected to meet the process requirements. Sieve or impingement or bubble cap type trays are incorporated with single or dual down comers to suit the application.

The CGS Impingement Wet Scrubber is particularly useful where particulate matter would foul a packed bed type scrubber, and on applications where gas absorption and/or sub-cooling is required.

Source: http://www.cgscgs.com/scrubber_i.htm

noise characterized by transient short-duration disturbances distributed essentially uniformly over the useful passband of a transmission system.

chemical oxidation typically involves reduction/oxidation redox reactions that chemically convert hazardous contaminants to nonhazardous or less toxic compounds that are more stable, less mobile, or inert. Redox reactions involve the transfer of electrons from one compound to another.

Specifically, one reactant is oxidized loses electrons and one is reduced gains electrons.

The oxidizing agents most commonly used for treatment of hazardous contaminants in soil are ozone, hydrogen peroxide, hypochlorites, chlorine, chlorine dioxide, potassium permanganate, and Fentons reagent hydrogen peroxide and iron.

Cyanide oxidation and dechlorination are examples of chemical treatment. This method may be applied in situ or ex situ, to soils, sludges, sediments, and other solids, and may also be applied for the in situ treatment of groundwater.

Source: US-EPA, ClU-In: http://www.clu-in.org/techfocus/default.focus/sec/In_Situ_Oxidation/cat/Overview/

soil flushing means the in situ washing of the unsaturated soil zone.

For in situ soil flushing, large volumes of water, at times supplemented with surfactants, cosolvents, or treatment compounds, are applied to the soil or injected into the groundwater to raise the water table into the contaminated soil zone. Injected water and treatment agents are isolated within the underlying aquifer and recovered together with flushed contaminants.

Source: US-EPA, Clu-In: http://www.clu-in.org/techfocus/default.focus/sec/In_Situ_Flushing/cat/Overview/

many different methods and combinations of techniques can be used to apply heat to polluted soil and/or groundwater in situ. The heat can destroy or volatilize organic chemicals. As the chemicals change into gases, their mobility increases, and the gases can be extracted via collection wells for capture and cleanup in an ex situ treatment unit. Thermal methods can be particularly useful for dense or light nonaqueous phase liquids (DNAPLs or LNAPLs). Heat can be introduced to the subsurface by electrical resistance heating, radio frequency heating, dynamic underground stripping, thermal conduction, or injection of hot water, hot air, or steam.

The main advantage of in situ thermal methods is that they allow soil to be treated without being excavated and transported, resulting in significant cost savings; however, in situ treatment generally requires longer time periods than ex situ treatment, and there is less certainty about the uniformity of treatment because of the variability in soil and aquifer characteristics and because the efficacy of the process is more difficult to verify.

ELECTRICAL RESISTANCE HEATING uses arrays of electrodes installed around a central neutral electrode to create a concentrated flow of current toward the central point. Resistance to flow in the soils generates heat greater than 100ºC, producing steam and readily mobile contaminants that are recovered via vacuum extraction and processed at the surface. Electrical resistance heating is an extremely rapid form of remediation with case studies of effective treatment of soil and groundwater in less than 40 days. Three-phase heating and six-phase soil heating are varieties of this technology.

INJECTION OF HOT AIR can volatilize organic contaminants (e.g., fuel hydrocarbons) in soils or sediments. With deeper subsurface applications, hot air is introduced at high pressure through wells or soil fractures. In surface soils, hot air is usually applied in combination with soil mixing or tilling, either in situ or ex situ.

INJECTION OF HOT WATER via injection wells heats the soil and ground water and enhances contaminant release. Hot water injection also displaces fluids (including LNAPL and DNAPL free product) and decreases contaminant viscosity in the subsurface to accelerate remediation through enhanced recovery.

INJECTION OF STEAM heats the soil and groundwater and enhances the release of contaminants from the soil matrix by decreasing viscosity and accelerating volatilization. Steam injection may also destroy some contaminants. As steam is injected through a series of wells within and around a source area, the steam zone grows radially around each injection well. The steam front drives the contamination to a system of ground-water pumping wells in the saturated zone and soil vapor extraction wells in the vadose zone.

RADIO FREQUENCY HEATING is an in situ process that uses electromagnetic energy to heat soil and enhance soil vapor extraction. The technique heats a discrete volume of soil using rows of vertical electrodes embedded in soil or other media. Heated soil volumes are bounded by two rows of ground electrodes with energy applied to a third row midway between the ground rows. The three rows act as a buried triplate capacitor. When energy is applied to the electrode array, heating begins at the top center and proceeds vertically downward and laterally outward through the soil volume. The technique can heat soils to over 300ºC.

THERMAL CONDUCTION (also referred to as electrical conductive heating or in situ thermal desorption) supplies heat to the soil through steel wells or with a blanket that covers the ground surface. As the polluted area is heated, the contaminants are destroyed or evaporated. Steel wells are used when the polluted soil is deep. The blanket is used where the polluted soil is shallow. Typically, a carrier gas or vacuum system transports the volatilized water and organics to a treatment system.

VITRIFICATION uses an electric current to melt contaminated soil at elevated temperatures (1,600 to 2,000ºC or 2,900 to 3,650ºF). Upon cooling, the vitrification product is a chemically stable, leach-resistant, glass and crystalline material similar to obsidian or basalt rock. The high temperature component of the process destroys or removes organic materials. Radionuclides and heavy metals are retained within the vitrified product. Vitrification can be conducted in situ or ex situ.

Source: US-EPA, Clu-In: http://www.clu-in.org/techfocus/default.focus/sec/Thermal_Treatment%3A_In_Situ/cat/Overview/

within a living organism or body. For example, some toxicity testing is done on whole animals, such as rats or mice, dogs or monkeys. In Europe new methods are under development for the exclusion of animal testing.

See also in vitro test

inch is a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot. A corresponding unit of area is the square inch and a corresponding unit of volume is the cubic inch. The inch is usually the universal unit of measurement in the United States, and is widely used in the United Kingdom, and Canada, despite the introduction of metric to the latter two in the 1960s and 1970s, respectively.

Conversion rate of inches to other length-, area- and volume-units are given in the table.

a complex in which one component (the host) forms a cavity or, in the case of a crystal, a crystal lattice containing spaces in the shape of long tunnels or channels in which molecular entities of a second chemical species (the guest) are located. There is no covalent bonding between guest and host, the attraction being generally due to van der Waals forces. If the spaces in the host lattice are enclosed on all sides so that the guest species is ‘trapped’ as in a cage, such compounds are known as clathrates or ‘cage’ compounds’. (Source: IUPAC Compendium of Chemical Terminology, 2nd Edition, 1997) In environmental risk reduction the inclusion complex formation is used for removal of contaminants, e.g. toxic metals from ground water by zeolites, and for enhancing the solubility and bioavailability of organic contaminants in soil by applying cyclodextrins (see: "sugar flushing" technology, cyclodextrin Technology).

indicator species maybe bacteria or other microorganisms, fungi, plant or animal species whose prescence, abundance, and health reveal the general condition of its habitat.

an inducible gene is a gene that is expressed in the presence of an inducer substance. This substance can control the expression of one or more genes (structural genes) involved in the metabolism of that substance. For example, lactose induces the expression of the lac genes that are involved in lactose metabolism. An certain antibiotic may induce the expression of a gene that leads to resistance to that antibiotic.

Induction is common in metabolic pathways that result in the catabolism of a substance and the inducer is normally the substrate for the pathway.

a method used in skin sensitization tests. The test animals are initially exposed to the test substance by intradermal injection and/or epidermal application (induction exposure). Following a rest period of 10 to 14 days, during which an immune response may develop.

a period of at least one week following an induction exposure during which a hypersensitive state may develop.

it is an external, sudden, unexpected, unintended event during the execution of industrial, mining, agricultural, transport, etc. activities which may lead to an industrial injury and damages in material , environment or man. The accident is a preceding "event" while the resulting damage, be it injury, fatality, material or environmental damages are all consequences of this event. Where the accidents involve multiple fatalities they are often referred to as industrial disasters

nn industrial injury is bodily damage resulting from working.

The most usual organs involved are the spine, hands, the head, lungs, eyes, skeleton, and skin. According to data from the National Institute for Occupational Safety and Health and the Bureau of Labor Statistics, an average of 15 workers die from traumatic injuries each day in the United States, and an additional 200 workers are hospitalized.

Common causes of industrial injury are poor ergonomics, manual handling of heavy loads, misuse or failure of equipment, exposure to general hazards, inadequate safety training and clothing, jewellery or long hair that becomes tangled in machinery.

General hazards in a work environment include electricity, explosive materials, fire, flammable gases, heat, height, high pressure gases and liquids, hot gases and liquids, powerful or sharp moving machinery, oxygen-free gases or spaces, poisonous gases, radiation, toxic materials, work on, near or under water, work on, near or under weak or heavy structures.

There are many methods of preventing or reducing industrial injuries, including anticipation of problems by risk assessment, safety training, control banding, personal protective equipment safety guards, mechanisms on machinery, and safety barriers. In addition, past problems can be analyzed to find their root causes by using a technique called root cause analysis.

Source: http://en.wikipedia.org/wiki/Industrial_injury