While a gallium source is able to operate with elemental gallium, recently developed sources for gold, indium and bismuth use alloys which lower their melting points.

While Proust believed that chemical compounds are composed of a fixed ratio of their constituent elements irrespective of the methods of production, Berthollet believed that this ratio can change according to the ratio of the reactants initially taken.

While working toward his goal of improved insecticide, Schrader experimented with numerous compounds, eventually leading to the preparation of tabun.

While pure hydrocarbons undergo certain limited classes of reactions, many more reactions which organic compounds undergo are largely determined by functional groups.

While the etymology is Greek, the oldest extant record of the word itself is the New Latin form ontologia, which appeared in 1606, in the work Ogdoas Scholastica by Jacob Lorhard ( Lorhardus ) and in 1613 in the Lexicon philosophicum by Rudolf Göckel ( Goclenius ); see classical compounds for this type of word formation.

While there are natural sources for all of these species, the concentrations of chlorine and bromine have increased markedly in recent years due to the release of large quantities of man-made organohalogen compounds, especially chlorofluorocarbons ( CFCs ) and bromofluorocarbons.

While almost all reactions have integer-ratio stoichiometry in amount of matter units ( moles, number of particles ), some nonstoichiometric compounds are known that cannot be represented by a ratio of well-defined natural numbers.

While the trihalogen compounds can be obtained by reduction of the pentahalogenes with hydrogen, the dihalogen compounds do not exist.

While biodegradable simply means an object naturally falls apart into its base components, " compostable " makes the specific demand that the object break down into humus, organic compounds.

While these compounds have desirable effects in humans, they cannot be efficiently metabolized in many animals and can lead to cardiac and nervous system problems, and if consumed in high quantities, even lead to death.

While Scheele's experiments generated substances which have long since been found to be hazardous, the compounds and elements he used to start his experiments were dangerous to begin with, especially heavy metals.

While taurine is sometimes called an amino acid, and indeed is an acid containing an amino group, it is not an amino acid in the usual biochemical meaning of the term, which refers to compounds containing both an amino and a carboxyl group.

While this allowed for very little experimental characterization of its properties and possible compounds, theoretical calculations have resulted in many predictions, including some unexpected ones.

While harvesting grapes destined for sparkling wine, premium producers will take extra care to handle the grapes as gently as possible in order to minimize the extraction of harsh phenolic compounds from the skin.

While Emir is a common transliteration in English and other languages, the form Amir is found for numerous compounds ( e. g., admiral ) and names.

While the discovery of bromine and the preparation of many of its compounds was his most conspicuous piece of work, Balard was an industrious chemist on both the pure and applied sides.

While a lot of machine gun rounds and a fair amount of luck were needed to cause critical damage, a single cannon shell could instantly sever essential structural elements, penetrate armour or open up a fuel tank beyond what self sealing compounds could handle, even from a fairly long range.

While there are other compounds, such as silicone and urethane that are stronger and last longer, foam rubber is used because it is much easier to work with.

While still using a chemical preservative, this formulation contains no heavy-metal compounds.

While oxygenic phototrophs use water as an electron donor for phototrophy, Chloroflexus uses reduced sulfur compounds such as hydrogen sulfide, thiosulfate, or elemental sulfur.

While other compounds are used to attract pollinators or herbivores to spread ripe seeds.

While at the time, Hawaiians did wear sandals, it was only for traveling long distances or over heavy terrain, and the obviously Western Classical style of the shoes only compounds their inaccuracy.

" While compounds that produce estrogenic, androgenic, antiandrogenic, and antithyroid actions have been studied, less is known about interactions with other hormones.

While the clinic does offer conventional chemotherapy and ( via an associate center ) radiotherapy, it is best known for its " antineoplaston therapy ", a controversial pharmacological treatment using compounds called antineoplastons, devised by the clinic's founder Stanislaw Burzynski in the 1970s.

While this tendency decreased under his successors, it established the image of West Germany ( and later reunified Germany ) as a " chancellor democracy ".

While petroleum has decreased in importance in recent years due to depleting reserves and growth in other industries, it is still the mainstay of the economy.

While the association between serum blood levels of beta-cryptoxanthin and substantially decreased joint disease has been established, neither a convincing mechanism for such protection nor a cause-and-effect have been rigorously studied.

While there were 1, 655, 380 fixed lines in use by 1999, their number decreased to the current 994, 421.

While the working memory of the subjects decreased during and immediately after the exercise bouts, it was shown that the subjects ' working memory had an increase following recovery.

While profits plummeted the bewindhebbers only slightly decreased dividends from the earlier level.

While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a decreased appetite, some of which may be harmless, while others indicate a serious clinical condition or pose a significant risk.

While funding has decreased for these centres, and they have had to cut back, they have had a lower cost than the traditional fee-for-service approach.

While the air has already been dried by orographic lift before reaching the Great Basin as well as by subsidence from the upper atmosphere, the relative humidity of the air is further decreased as it descends from the high desert toward the coast, often falling below 10 percent.

While the local economy ’ s reliance on manufacturing has decreased in recent years, 20. 36 % of the labour force remains employed in the manufacturing sector.

While reading remains a favorite pastime of French youth today, surveys show that it has decreased in importance compared to music, television, sports and other activities.

While in 1936, Electra had well over 6, 000 residents, by the 1960s the population had decreased to a bit over 5, 000.

While the general signs for all types of shock are low blood pressure, decreased urine output, and confusion these may not always be present.

While it has been shown that lower levels of serotonin may be associated with ASPD, there has also been evidence that decreased serotonin function is highly correlated with impulsiveness and aggression across a number of different experimental paradigms.

While agricultural output increased as a result of the Green Revolution, the energy input into the process ( that is, the energy that must be expended to produce a crop ) has also increased at a greater rate, so that the ratio of crops produced to energy input has decreased over time.

While the emissions per barrel of bitumen produced decreased 26 % over the decade 1992 – 2002, total emissions were expected to increase due to higher production levels.

While the range may be decreased when using subsonic rounds, this may be acceptable for specialized situations, where the absolute minimum amount of noise is required.

While his government was credited with reforms such as those that led a multi-party political system in Ethiopia, introduction of private press in Ethiopia and decreased child mortality rates, his government was also accused of political repression and various human rights abuses, curbing freedom of press.

While it is clear that it now ( as of 2012 ) takes longer to reach the H-1B visa numerical cap, it is not clear whether this is a result of simple political pressure to put the program on " hold ", or a result of the decreased economic growth.

While the Bolshevik presence decreased overall following the repression of Socialist Party riots in Bucharest ( December 1918 ), it remained or was perceived as relatively strong in Iaşi and other Moldavian cities and towns.

While the Santa Anita meeting could still draw large crowds, attendance had decreased by a third.

While many private rollers still operate ( notables include Raymond W. Dillard, Tyler D. Tyson, Brad Ream, and Don Adams ), the vast introduction of commercial elongated machines into the marketplace in around 1985, following the introduction of the coin-operated penny press machine 1971, decreased the demand for private issues.

While nearing the Lesser Antilles upper-level winds decreased, allowing the depression to become Tropical Storm Hortense on September 7.

While Westchester residents successfully blocked a northward expansion of the airport, the increase in noise from jet takeoffs greatly decreased the desirability of the residential areas adjoining LAX.