nyuuzyou/wikis huggingface dataset:
Dichroism

== Description ==
An optical effect in which a material shows two different colors under different lighting conditions. For example, under plane polarized light, calcite crystals will change colors from blue to pink when viewed at different angles. Some materials, such as alexandrite, cobalt yellow, and chlorophyll solutions, exhibit different colors when viewed in reflected versus transmitted light. A dichroic mirror is designed to reflect some wavelengths while transmitting others. 
See also anisotropic, and birefringence.
== Synonyms and Related Terms ==
Dichroismus (Deut.); dicroïsme (Fr.); dichroic light
==Resources and Citations==
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972
* Richard C. Wolbers, Nanette T. Sterman, Chris Stavroudis, Notes for Workshop on New Methods in the Cleaning of Paintings, J.Paul Getty Trust, Los Angeles, 1990
* Wikipedia: http://en.wikipedia.org/wiki/Dichroic (Accessed Nov. 9, 2005)
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
Category:Materials database
Dichromatism

== Description ==
A material that can appear two different colors. This is a broad term that covers color variations dependent on any of the following physical conditions: 1) illumination direction (dichroism), 2) illumination wavelength, 3) concentration or thickness of the material, 4) temperature (liquid crystals), 5) physical orientation (suede effect), or 6) chemical environment (pH indicators).
== Synonyms and Related Terms ==
dichromatisme (Fr.);
Category:Materials database
Dicotyledon

== Description ==
A large class of flowering plants and trees whose seeds have two cotyledons or leaves. Examples of this type of plant are: cotton, flax, hemp, rubber tree. and most hardwood trees.
== Synonyms and Related Terms ==
dicotylédon (Fr.); dicotiledónea (Esp., Port.); dicotiledone (It.)
==Resources and Citations==
* Mary-Lou Florian, Dale Paul Kronkright, Ruth E. Norton, The Conservation of Artifacts Made from Plant Materials, The Getty Conservation Institute, Los Angeles, 1990
* Wikipedia: http://en.wikipedia.org/wiki/Dicotyledon (accessed Dec. 15, 2004)
Category:Materials database
Dicyclohexyl amine nitrite

== Description ==
A white crystalline solid. Dicyclohexyl amine nitrite is used as a vapor phase corrosion inhibitor for silver, steel, and aluminum. It forms a thin protective layer on the surface of the metal which minimizes the transmission of moisture and oxygen. Dicyclohexyl amine nitrite is marketed as VPI 260 by Shell. It is used in antitarnish wrapping papers.
== Synonyms and Related Terms ==
VPI 260 [Shell]; dicyclohexyl ammonium nitrite; dicyclohexylamine nitrite
== Risks ==
* Skin irritant. 
* Strong oxidizer.
* Sigma Aldrich: SDS
==Physical and Chemical Properties==
* Vapor pressure = 0.00013 at 21C
* pH of condensate = 10.0
Composition 	(C6H11)2NH-HNO2
CAS 	3129-91-7
Melting Point	182-183 C
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p.67
* L. Selwyn, 'Historical Silver: Storage, Display and Tarnish Removal', J.IIC-GC, 15, 1990
Category:Materials database
Dicyclohexyl phthalate

== Description ==
A nonvolatile, white solid used as a plasticizer in polymers such as cellulose nitrate, ethyl cellulose, chlorinated rubber, polyvinyl acetate, and polyvinyl chloride.
== Synonyms and Related Terms ==
DCHP, Morflex 150
== Risks ==
* Combustible.
* NIH: Information sheet
== Physical and Chemical Properties ==
Soluble in most organic solvents. Insoluble in water.
Composition 	C20H26O4
Melting Point	62-65 C
Density 	1.20 g/ml
Category:Materials database
Dieldrin

== Description ==
A chlorinated hydrocarbon formerly used as an insecticide, fungicide and wood preservative. First used in 1948, dieldrin was an effective contact insecticide against cockroaches and termites with persistent residual action. However, because of its high chemical stability and high toxicity to birds and fish, dieldrin had drastic long-term environmental effects. It is no longer manufactured or used in the United States and its use is banned in most countries.
== Synonyms and Related Terms ==
HEOD; insecticide no. 457; Octalox; Dieldrx; Dieldrite; Alvit: Quintox; Illoxol; Panoram D-31; Dorytox; Compound 497
== Risks ==
* Extremely toxic by skin absorption, ingestion and inhalation. LD50 = 46 mg/kg. 
* Carcinogen. 
* Severe environmental hazard. 
* ChemService: SDS
==Physical and Chemical Properties==
Soluble in most organic solvents. Insoluble in water.
Composition 	C12H8OCl6
CAS 	60-57-1
Melting Point 	176-177 C
Molecular Weight	mol. wt. = 381
==Resources and Citations==
* Encyclopedia Britannica, http://www.britannica.com Comment: agriculture, history of [Accessed March 26, 2002] for date of introduction
* Lynda A. Zycherman, J.Richard Schrock, A Guide to Museum Pest Control, FAIC and Association of Systematics Collections, Washington DC, 1988
* Stephen R. Edwards, Bruce M. Bell, Mary Elizabeth King, Pest Control in Museums: a Status Report 1980, Association of Systematics Collections, Washington DC, 1980
* Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002
* G.Caneva, M.P.Nugari, O.Salvadori, Biology in the Conservation of Works of Art, ICCROM, Rome, 1991
Category:Materials database
Dielectric

== Description ==
A substance that resists the conduction of electricity, such as an insulator. A dielectric material with a high dielectric strength can be exposed to a large electric field without losing any of its insulating ability. Common example of dielectric materials are glass, rubber, wood, paper, and hydrocarbon oils.
== Synonyms and Related Terms ==
dielectric material
==Resources and Citations==
* Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
Category:Materials database
Dielectric constant

== Description ==
The capacity of a material to resist the transmission of a electricity. The dielectric constant is the ratio of a material's dielectric strength to an electric field in a vacuum (which is set at 1 as a standard). To measure the dielectric constant, an electric field is generated by placing a positive electrode on one side of a material with the negative electrode on the other. A high dielectric constant indicates that a material passes electricity well. A low dielectric constant indicates that a material is a good insulator. Glass has a dielectric constant of 3, while water has a dielectric constant of 81.
== Synonyms and Related Terms ==
constante diélectrique (Fr.); Dielektrizitâtskonstante (Deut.)
Category:Materials database
Diethanolamine

== Description ==
A colorless, viscous liquid surface active agent (surfactant) with a pungent odor. Diethanolamine is used in liquid nonionic detergents, shampoos, cleaners, and polishes. Diethanolamine is also used as an emulsifier, dispersant, and plasticizer in some polymers. 
See also monoethanolamine, and triethanolamine.
[[[SliderGallery rightalign|diethanolamine.jpg~Chemical structure]]]
== Synonyms and Related Terms ==
DEA; di(2-hydroxyethyl)amine; 2,2'-iminodiethanol; diethylolamine; bis(hydroxyethyl)amine
== Risks ==
* Combustible. Flash point = 134C. 
* Skin irritant. 
* Toxic by inhalation and ingestion. 
* ThermoFisher: SDS
==Physical and Chemical Properties==
Miscible in water, methanol, acetone. Slightly soluble in ether.
Composition 	NH(CH2CH2OH)2
CAS 	111-42-2
Melting Point 	28.0 C
Density 	1.088-1.092 g/ml
Molecular Weight	mol. wt. = 105.2
Boiling Point 	270 C
 
==Resources and Citations==
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
* Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
* The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 3156
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Teri Hensick, contributed information, 1998
Category:Materials database
Diethyl ether

== Description ==
A volatile, sweet smelling liquid that was formerly used as an anesthetic. Commonly known as ether, diethyl ether is a strong solvent that dissolves most oils, fats, waxes, and polymers. Although listed in earlier references and recipes for etching grounds and removing wax, ether is no longer used because of its hazards.
== Synonyms and Related Terms ==
ether; ethyl ether; ethoxyethane; sulfuric ether; ethyloxide; diethyl oxide
== Risks ==
* Highly flammable. Forms explosive peroxides. 
* Nervous system depressant by inhalation or skin absorption. 
* Millipore Sigma: SDS
* EPA lists diethyl ether as hazardous waste; concentrations over 10% must be disposed of appropriately
==Physical and Chemical Properties==
Miscible in ethanol, chloroform, benzene, naphtha and oils. Slightly soluble in water.
Composition 	(C2H5)2O
CAS 	60-29-7
Melting Point 	-116.3 C
Density 	0.7147 g/ml
Molecular Weight	mol. wt. = 74.1
Refractive Index	1.352
Boiling Point 	34.6 C
== Comparisons ==
==Resources and Citations==
* R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986
* Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
* CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. index=1.352
Category:Materials database
Diethylaminoethanol

== Description ==
Colorless, hygroscopic liquid base that is used as a vapor phase corrosion inhibitor. Diethylaminoethanol (DEAE) is added to the water in boilers in steam humidification systems to minimize pipe corrosion. It is also used as an alkalizing agent in HVAC systems to neutralize carbonic acids. When DEAE is used in an open ventilation system, it can deposit on all available surfaces including works of art. DEAE produces an oily residue that can soften varnishes.
== Synonyms and Related Terms ==
DEAE; 2-diethylaminoethanol; beta-diethylaminoethyl alcohol; 2-hydroxytriethyl amine; N,N-diethylethanolamine; diethyl ethanolamine
[[[SliderGallery rightalign|diethylaminoethanol.jpg~Chemical structure]]]
== Risks ==
* Combustible. Flash point = 52 C. 
* Toxic by ingestion and skin absorption. 
* Contact causes irritation. 
* Millipore Sigma: SDS
==Physical and Chemical Properties==
Soluble in water, ethanol, ether, benzene.
Composition 	(C2H5)2NCH2CH2OH
CAS 	100-37-8
Melting Point 	-70 C
Density 	0.88-0.89 g/ml
Molecular Weight	mol. wt.=117.2
Refractive Index	1.4389
Boiling Point 	161-163 C
==Resources and Citations==
* The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry #3092
* Robert Fournier, Illustrated Dictionary of Practical Pottery, Chilton Book Company, Radnor, PA, 1992
* Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002
* Monona Rossol, The Artist's Complete Health and Safety Guide, Allworth Press, New York, 1994
Category:Materials database
Diethylbenzene

== Description ==
A colorless aromatic hydrocarbon liquid. Diethylbenzene has similar solvating properties to toluene and xylenes but it evaporates slower. Diethylbenzene has been used as a solvent for Acryloid B-72; when used as a consolidant, the slow drying properties of diethylbenzene allow the polymer greater penetration time (Welsh 1980).
== Synonyms and Related Terms ==
DEB; o-diethylbenzene
== Risks ==
* Fire risk. Flammable. Flash point = 55 C. 
* Moderately toxic. 
* Inhalation, ingestion and skin contact cause irritation and pain. 
* ThermoFisher SDS
==Physical and Chemical Properties==
Soluble in ethanol, benzene, carbon tetrachloride, ether. Insoluble in water.
Composition 	C6H4(C2H5)2
CAS 	25340-17-4
Melting Point 	-31 C
Density 	0.865 g/ml
Molecular Weight	mol. wt.=134.2
Boiling Point 	179.8-184.8 C
== Resources and Citations ==
* E. Welsh, "A Consolidation Treatment for Powdery Matte Paint" in Preprints for AIC Meeting in SanFancisco, May 1980, p. 141-150.
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Conservation Materials Ltd., Catalog
Category:Materials database
Diethylene glycol

== Description ==
A colorless, thick, hygroscopic liquid that is used as a finishing agent for fabrics (wool, cotton, rayon, and silk), tobacco, leather, sponges, paper products, and cork. As a finishing agent, diethylene glycol prevents materials from drying out and becoming stiff or hard. Diethylene glycol is used as a lubricant, plasticizer, surfactant, and solvent in many types of polymers, adhesives, varnishes, paints, inks, and dyes. 
See also ethylene glycol
== Synonyms and Related Terms ==
2,2'-oxybisethanol; dihydroxydiethyl ether; diglycol; DEG; oxydiethanol
== Risks ==
* Toxic by ingestion. Skin contact may cause redness. 
* Reacts strongly with oxidants. 
* Combustible. Flash point = 124C 
* ThermoFisher: SDS
==Physical and Chemical Properties==
Miscible with water, ethanol, ether, acetone, ethylene glycol. Insoluble in benzene, toluene and carbon tetrachloride.
Composition 	C4H10O3
CAS 	111-46-6
Melting Point 	-6.5 C
Density 	1.118 g/ml
Molecular Weight	mol. wt. = 106.1
Refractive Index	1.445
Boiling Point 	244-245 C
== Comparisons ==
==Resources and Citations==
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 303
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979 Comment: flash point = 140C
* Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
* The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983
* Photographic chemicals: www.jetcity.com/~mrjones/chemdesc.htm 
* CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. index= 1.445
Category:Materials database
Diethylzinc

== Description ==
A colorless, volatile liquid that was the first known organometallic compound. In the preservation of archival materials, vapor phase diethylzinc has been used to neutralize acids and deposit an alkaline reserve. As diethylzinc will ignite on contact with air, any treatment must be carried out in specially designed chambers. In the commercial process used by the Library of Congress, the pre-dried books were placed in a vacuum chamber. The air was evacuated and diethylzinc was released. After a 12-15 hour exposure, the chamber was re-evacuated to remove excess diethylzinc, then flushed with moist carbon dioxide. Any zinc oxide left in the paper is converted to zinc carbonate to provide an alkaline reserve. The treatment also acts as a fungistat to control mold growth (Paper Catalog, 1984).
== Synonyms and Related Terms ==
diethyl zinc; zinc diethyl; ethyl zinc; zinc ethyl; DEZ
== Risks ==
* Fire hazard: Ignites spontaneously on contact with air.
* ThermoFisher: SDS
==Physical and Chemical Properties==
Miscible with ether, ligroin, benzene and other hydrocarbons. 
Slight garlic-like odor.
Composition 	Zn(C2H5)2
CAS 	557-20-0
Melting Point 	-28 C
Density 	1.2065 g/ml
Molecular Weight	mol. wt. = 123.50
Boiling Point 	118 C
==Resources and Citations==
* Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
* A Glossary of Paper Conservation Terms, Margaret Ellis (ed.), Conservation Center of the Institute of Fine Arts, New York City, 1998
* Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989
Category:Materials database
Differential gravimetric analysis

== Description ==
A technique used to measure changes in weight of a material as the temperature of its external environment is increased by a controlled temperature program. Differential gravimetric analysis (DGA) can be used to provide quantitative information on additives such as solvents, oxidation, or the release of decomposition products.
== Synonyms and Related Terms ==
DGA; Thermogravimetrie (Deut.); analyse gravimétrique différentielle (Fr.);
Category:Materials database
Differential scanning calorimetry

== Description ==
A technique used to measure changes in energy of a material as the temperature of its external environment is increased by a controlled temperature program. Differential scanning calorimetry (DSC) measures the energy of the material and compares it to a standard reference as a function of temperature. The absorbed energy (endotherms) or released energy (exotherms) may be related to physical changes in the material such as melting, crystallization, resin curing, ceramic firing temperature, glass transition or solvent lost.
== Synonyms and Related Terms ==
DSC
==Resources and Citations==
* Wikipedia: Differential scanning calorimetry
* A.Burmester, "Investigation of Paint Media by Differential Scanning Calorimetry" Studies in Conservation, 37:73-81, 1991.
* National Gallery of Art, Scientific Research: Glossary of Conservation Terminology
Category:Materials database
Differential thermal analysis

== Description ==
A technique used to measure the ability of a material to absorb heat as the temperature of its external environment is increased by a controlled temperature program. differential thermal analysis (DTA) can recognize the presence of additives in a material, such as solvents. DTA also provides information about heat capacity.
== Synonyms and Related Terms ==
DTA; Differentialthermoanalyse (Deut.); analyse thermique différentielle (Fr.);
Category:Materials database
Diffraction

== Description ==
The change or deflection in a wave pattern of light or sound. Diffraction occurs when light waves pass through an opening or past an opaque barrier. The light is deflected, or bent, toward the obscuring side of the opening or barrier. Shorter wavelengths are deflected less than longer wavelengths. The overlap of the wavelengths can cause interference and in some cases produce a diffraction pattern of light and dark bands.
== Synonyms and Related Terms ==
diffraktion (Dan.); Beugung (Deut.); Diffraktion (Deut.); difracción (Esp.); diffraction (Fr.); diffractie (Ned.); dyfrakcja (Pol); difração (Port.);
==Resources and Citations==
* R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
* Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
* Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972
* John Stacy, submitted communication, 2001.
* Wikipedia: http://en.wikipedia.org/wiki/Diffraction (Accessed Sept. 20, 2005)
* Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
Category:Materials database
Diffuse reflection

== Description ==
A type of reflection in which a beam of light is reflected as numerous angles from an uneven or granular surface. Diffuse reflection is nonspecular. It occurs when light illuminates matte paint, powders, or any other non-shiny surface. Diffuse reflectance is the measured quantity of diffusely reflected light.
== Synonyms and Related Terms ==
Diffuse Reflexion (Deut.); réflexion diffuse; réflexion (Fr.); non spéculaire (Fr.); nonspecular reflection; diffuse reflectance
==Resources and Citations==
* Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972
* M.Derrick, D.Stulik, J.Landry, Infrared Spectroscopy in Conservation Science, in Scientific Tools for Conservation series, Getty Conservation Institute, Los Angeles, 1999
* Wikipedia: http://en.wikipedia.org/wiki/Diffuse_reflection (Accessed Sept. 20, 2005)
* Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
Category:Materials database
Diffuser

== Description ==
1) A material or device that diffuses radiation, whether it is light, sound or heat. Heating and air conditioning vents may place a diffuser unit at duct outlets to direct and disperse air evenly. Photographic lights may have a diffuser placed over the bulb to scatter and soften the illumination. 
2) A device placed on a nozzle to slow and disperse a pressurized stream of gas or liquid.
== Synonyms and Related Terms ==
Strahler (Deut.); diffuseur (Fr.);
==Resources and Citations==
* Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
Category:Materials database
Diffusion

== Description ==
The spontaneous movement of energy or matter from a region of high concentration to a region of lower concentration that continues until a uniform mixture is obtained. Diffusion occurs from the random movement of molecules and thus happens fastest in gases, more slowly in liquids and slowest in solids. The rate of diffusion of a gas through a barrier material is a function of the permeability of the material and the concentration of the gas on each side of the barrier. The rate increases with increasing temperature and pressure. Examples of diffusion are: a solid dissolves in a liquid; the mixture of two gases; osmosis in plant and animals cells; the intermixing of molecules in some adjacent metals over long periods of time.
== Synonyms and Related Terms ==
Diffusion (Deut.); diffusion (Fr.);
Category:Materials database
Diffusion tube

== Description ==
A device used to passively measure pollutant levels. Diffusion tubes contain a sorbent material treated with a chemical to produce a pollutant-specific colorimetric reaction. When the pollutant is absorbed, the chemical reacts to form a colored product. A reference chart is provided for comparison of the color intensity with approximate pollutant concentrations. Diffusion tubes are available for sulfur dioxide, nitrogen dioxide, formic acid and acetic acid. In general, diffusion tubes are inexpensive and easy to use but their detection limits are relatively high for museum environments. They may be useful for initial screenings of high pollutant levels in closed environments.
== Synonyms and Related Terms ==
Diffusionsröhre (Deut.); tube à diffusion (Fr.);
== Risks ==
* Multiple pollutants may cause inaccurate results.
==Resources and Citations==
* P. Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002.
Category:Materials database