Y
Y. Symbol for yttrium. yeast artificial chromosome (YAC). Con-
structed from yeast DNA, it is a vector used to clone
large DNA fragments; a method for cloning very
YAC. Abbreviation for yeast artificial chromo-
large fragments of DNA. Genomic DNA in frag-
some.
ments of 200-500 kb are linked to sequences which
allow them to propagate in yeast as a mini-chromo-
Yankee machine. A papermaking machine
some (including telomeres, a centromere, and an
similar to a fourdrinier but with much shorter wire. It
ARS—an autonomous replication sequence). This
is designed for lightweight papers such as toilet and
technique is used to clone large genes and intergenic
facial tissues and operates at comparatively high
regions, and for chromosome walking.
speeds. It has a specialized cylindrical drying roll
See cloning vector; cosmid.
that effects drying of the web much more efficiently
than felts.
“Yellotone” [Ashland].
See fourdrinier.
CAS: 7704-34-9. TM for a sulfur product.
Use: As a rubber vulcanizing agent, insecticide, and
“Yarmor” [Aqualon]. TM for series of pine
fungicide.
oils for widely varied uses. Total terpene alcohol
contents from 55 to 91%.
yellow AB. (1-(phenylazo)-2-naphthylamine;
Use: Disinfectants, textile specialties, wetting and
CI 11380).
flotation agents, special solvents, household and
CAS: 85-84-7. C
6
H
5
N
2
C
10
H
6
NH
2
.
industrial cleaners, odorants.
Properties: Orange or red platelets. Mp 102–104C.
Insoluble in water; soluble in alcohol and oils.
Yb. Symbol for ytterbium.
Hazard: Consult regulations before using in food
products.
Use: Biological stain.
Y chromosome. One of the two sex chromo-
somes, X and Y.
See X chromosome; sex chromosome.
yellow brass. A brass containing 34–37% zinc;
it has excellent fabrication properties and corrosion
resistance.
yeast. (barm). Unicellular organisms known as
Use: Structural and decorative purposes.
saccharomycetaceae. The following description ap-
See brass.
plies to the cultured commercial product and not to
various wild varieties.
yellowcake. See uranium dioxide.
Properties: Yellowish-white, viscid liquid or soft
mass, flakes, or granules, consisting of cells and
spores of Saccharomyces cerevisiae.
yellow enzyme. See flavin enzyme.
Derivation: A ferment obtained in brewing. Yeasts
induce fermentation by enzymes (zymases) that
yellow glass. A soda-lime glass.
convert glucose and other carbohydrates into carbon
dioxide and water in the presence of oxygen or into
yellow lake. Any of several pigments made by
alcohol and carbon dioxide (or lactic acid) in the
precipitating soluble yellow dyes on an aluminum
absence of oxygen.
hydrate base. They are transparent in oil and lacquer
Grade: Technical, brewers’, cooking, compressed
vehicles and are used for metal decorating.
(contains about 74% moisture), dried, NF (contains
no starch or filler, not more than 7% moisture nor
more than 8% ash). Also graded according to vita-
yellow OB.
(1-o-tolueneazonaphthylamine-2;
min B
1
content.
CI 11390).
Use: Fermentation of sugars, molasses, and cereals
CAS: 131-79-3. CH
3
C
6
H
4
N
2
C
10
H
6
NH
2
.
for alcohol; brewing; baking; food supplement; pro-
Properties: Orange or yellow powder. Mp
tein biosynthesis from many carbonaceous and ni-
122–125C. Insoluble in water; soluble in alcohol
trogenous materials, including petroleum; source of
and oils.
vitamins, enzymes, nucleic acids, etc.; biochemical
Hazard: Consult regulations before using in food
research.
products.
See bacteria; fermentation.
Use: Biological stain.
yeast adenylic acid. See adenylic acid. yellow phosphorus. See phosphorus.
1338
1339 YTTRIUM ARSENIDE
yellow precipitate. See mercuric oxide, Derivation: Reduction of the oxide with lanthanum
yellow. or misch metal.
Grade: Regular high purity (ingots and lumps).
Use: Lasers, dopant for garnets, portable X-ray
yellow prussiate of potash. See potassium
source, chemical research.
ferrocyanide.
ytterbium chloride. YbCl
3
6H
2
O.
yellow prussiate of soda. See sodium fer-
Properties: Green crystals. D 2.575, loses 6H
2
Oat
rocyanide.
180C, mp 865C. Very soluble in water; hygro-
scopic.
yellow rain. See mycotoxin.
ytterbium fluoride. YbF
3
.
yellow salt. See uranyl nitrate.
Properties: Solid. Mp 1157C, bp 2200C. Insoluble
in water; hygroscopic.
-yl. The suffix of univalent radicals derived from
Hazard: TLV: 2.5 mg(F)/m
3
.
aromatic hydrocarbons or heterocyclic compounds
by the removal of one hydrogen atom from the ring.
ytterbium oxide. (ytterbia). Yb
2
O
3
.
Properties: Colorless mass when free of thulia, tint-
ylang ylang oil. An essential, yellowish, vola-
ed brown or yellow when containing thulia. D 9.2,
tile oil distilled from the flowers of Cananga odora-
mp 2346C. The weakest base of the yttrium group,
ta. Strongly levorotatory.
except scandia and lutetia. Slightly hygroscopic,
Use: Perfumery.
absorbs water and carbon dioxide from the air. Solu-
See cananga oil.
ble in hot, dilute acids; less so in cold acids.
Use: Special alloys, dielectric ceramics, carbon rods
ylid. A substance in which a carbanion is attached
for industrial lighting, catalyst, special glasses.
to a heteratom with a high degree of positive charge,
i.e., >C
-X
+
. It is similar to a zwitterion and related to
ytterbium sulfate. Yb
2
(SO
4
)
3
8H
2
O.
the Wittig reaction.
Properties: Crystalline solid. D 3.286. Soluble in
water.
-ylidene. (-ylidyne). A suffix for bivalent or tri-
valent radicals derived from saturated hydrocarbons
yttria. See yttrium oxide.
by the removal of two or three hydrogen atoms from
the same carbon atom.
yttrium.
CAS: 7440-65-5. Y. Metallic element of atomic
-ylidyne. See -ylidene.
number 39, group IIIB of the periodic table, aw
88.9059, valence of 3; no stable isotopes.
yohimbine. (aprodine; corynine; quebrachine).
Properties: Dark-gray metal. D 4.47, mp 1500C, bp
CAS: 146-48-5. C
21
H
26
O
3
N
2
.
2927C. Soluble in dilute acids and potassium hy-
Properties: Glistening, needlelike alkaloid, mp
droxide solution; decomposes water. Known only in
234C, soluble in alcohol and ether, very slightly
the tripositive state. Low neutron capture cross sec-
soluble in water.
tion.
Derivation: By extraction from the bark of Coryn-
Source: See rare-earth metals.
anthe yohimbe, found in the Cameroons.
Derivation: Reduction of the fluoride with calcium.
Hazard: Said to be an aphrodisiac. Toxic by inges-
Grade: Regular high purity (ingots, lumps, turnings),
tion.
metallurgical, low-oxygen, crystal sponge, powder.
Hazard: Flammable in finely divided form. TLV: 1
-yohimbine hydrochloride.
mg(Y)/m
3
.
CAS: 75444-63-2. mf: C
21
H
26
N
2
O
3
ClH.
Use: Nuclear technology, iron and other alloys, deox-
Hazard: A poison by ingestion.
idizer for vanadium and other nonferrous metals,
microwave ferrites, coating on high-temperature al-
Young’s modulus. See modulus of elas-
loys, special semiconductors.
ticity.
yttrium acetate. Y(C
2
H
3
O
2
)
3
9H
2
O.
ytterbium.
Properties: Colorless crystals. Soluble in water.
CAS: 7440-64-4. Yb. A metallic element. A rare-
Derivation: Action of acetic acid on yttrium oxide.
earth metal of yttrium subgroup, atomic number 70,
Use: Analytical chemistry.
aw 173.04, valence of 2, 3; exists in and forms,
the latter being semiconductive at pressures above
yttrium antimonide. YSb. A high-purity bina-
16,000 atm. There are seven natural isotopes.
ry semiconductor.
Properties: Metallic luster, malleable. Mp 824C, bp
1427C, d 7.01. Reacts slowly with water; soluble in
dilute acids and liquid ammonia.
yttrium arsenide. YAs. A high-purity binary
Source: See rare-earth metals. semiconductor.
1340YTTRIUM BROMIDE
Hazard: Highly toxic. Use: Phosphors for color TV tubes (alloy with euro-
pium), yttrium-iron garnets for microwave filters,
stabilizer for high-temperature service materials
yttrium bromide. YBr
3
9H
2
O.
(zirconia and silicon nitride refractories).
Properties: Colorless crystals. Hygroscopic, mp (an-
hydrous) 904C. Soluble in water; slightly soluble in
alcohol; insoluble in ether.
yttrium phosphide. YP.
Use: High-purity binary semiconductor.
yttrium chloride.
CAS: 10361-92-9. YCl
3
6H
2
O.
yttrium sulfate. Y
2
(SO
4
)
3
8H
2
O.
Properties: Reddish-white, transparent, deliques-
Properties: Small, reddish-white, monosymmetric
cent prisms. D 2.18, decomposes at 100C. Soluble in
crystals. D 2.558, loses 8H
2
O at 120C, decomposes
water and alcohol; insoluble in ether.
700C. Soluble in concentrated sulfuric acid; spar-
Derivation: By the action of hydrochloric acid on
ingly soluble in water; insoluble in alkalies.
yttrium oxide.
Derivation: Action of sulfuric acid on monazite
Grade: Purities to 99%.
sand.
Use: Analytical chemistry.
Method of purification: Fractional crystallization.
Use: Reagent.
yttrium oxide. (yttria).
CAS: 1314-36-9. Y
2
O
3
.
Properties: Yellowish-white powder. D 4.84, mp
yttrium vanadate. YVO
4
.
2410C. Soluble in dilute acids; insoluble in water. Properties: White, crystalline solid.
Derivation: By the ignition of yttrium nitrate. Use: With europium vanadate as red phosphor in
Grade: Purities to 99.8%, electronic grade 99.999%. color television tubes.