Lexikon

noise consequences on human health consist in loss of hearing and psychological effects.

the total of measures and devices implemented to preserve persons from harm to the faculty of perceiving sound.

hectare is a unit of area, defined as 10,000 square metres, and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare ("hecto-" + "are") was thus 100 ares or 1/100 km². Data in the table supports conversion of different area units.

highly toxic substances are defined by U.S. OSHA as the following:

1. A chemical substance that has a median lethal dose (LD₅₀) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.
2. A chemical substance that has a median lethal dose (LD₅₀) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each.
3. A chemical substance that has a median lethal concentration (LC₅₀) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.

In case of the use of highly toxic substances, standard operating procedures (SOP's) for working with each highly toxic material is obligatory! This written procedure must include knowing the physical properties of the material as well as symptoms of exposure and first aid procedures. Never work with highly toxic materials while alone!

High Performance Liquid Chromatography

high performance liquid chromatography/electrospray tandem mass spectrometry

High Production Volume Chemicals.
is a term that was used in previous European chemicals legislation for substances manufactured annually in volumes of more than 1,000 tonnes. The term is no longer relevant under REACH regulation, but it is currently still use for the global risk assessment of chemicals e.g. by the Organisation for Economic Co-operation and Development OECD.

Source: REACH Glossary

Home Theatre PC

human toxicology aims to give the dose-response relation between hazardous chemical substances and human responses. As these associations cannot be tested in well designed, statistically relevant human population, human toxicity of chemical substances is mainly based on the results of animal toxicity tests. In these tests the information on the effect of chemical substances comes from animal experimentation, which from an extrapolation is possible to man, supposing that the properly selected animal species’ response is analogous to human body’s response and the test-method, the applied test scenario perfectly models real human exposure. The main methodology for extrapolation for example from rat to man, is the application of a safety factor, based on experience. The default for the interspecies safety factor is EC50 (human)/EC50 (animal) = 0.1, because drugs and toxic chemical substances are ten times more potent in humans based on existing pharmacological and toxicological data.

Animal data are suitable to establish the dose or the concentration of the chemical substance that would cause adverse effect, damage or death, and based on these tests we can determine or calculate the lowest effect and the highest no effect concentrations or doses, which are manageable limit values.

Animal testing has many subclasses, according to the applied animal taxon (fish, bird, mouse, rat, dog, monkey, etc.), the type of exposure (acute, repeated or chronic exposure), exposure routes (inhalation, peroral, cutaneous, mixed routes), aim of the test method (toxicity, mutagenicity, reprotoxicity, neurotoxicity testing) and according to the measured endpoint such as death, immobilization, changes in behavior, irritation, corrosion, organ-toxicity (cardiac-, ophthalmic-, cutaneous-, muscle-, bone-, or hepatotoxicity), cellular toxicity (cell death, mitochondrial, perixosome, cellular tight junctions, reactive oxygen species, glutathione and glutathione-transferase, metabolomics, DNA-changes, chemokines, etc.) toxicity on endocrine system, immuntoxicity, phototoxicity, photoallergy.

a fluid supplied for use in hydraulic systems. Low viscosity and low pour-point are desirable characteristics. hydraulic fluids may be of petroleum or non-petroleum origin. Earlier polychlorinated biphenyles (PCB) were used as hydraulic fluids.

molecules that consist only of hydrogen and carbon atoms. hydrocarbons can be found in raw oil (petroleum hydrocarbons), gas and coal. hydrocarbons can be aliphatic hydrocatrbons with methane as the simplest and aromatics with benzene as the basic unit. The aliphatic hydrocarbons can be divided into alkanes, alkenes and alkines depending on the carbon-carbon bond.

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.

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.

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)

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

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/

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.