-- Although there was some variation in results which must be attributed either to trace impurities or to variation in wall effects, the photochemical exchange in the gas phase was sufficiently reproducible so that it seemed meaningful to compare the reaction rates in different series of reaction tubes for the purpose of obtaining information on the effect of chlorine concentration and of carbon tetrachloride concentration on the reaction rate.

Although heterocyclic compounds may be inorganic, most contain at least one carbon.

Although neon is a very common element in the universe and solar system ( it is fifth in cosmic abundance after hydrogen, helium, oxygen and carbon ), it is very rare on Earth.

Although similar to alcohols, phenols have unique properties and are not classified as alcohols ( since the hydroxyl group is not bonded to a saturated carbon atom ).

Although almost any low-fire glaze can be used, potters often use specially formulated glaze recipes that " crackle " or craze ( present a cracked appearance ), because the crazing lines take on a dark color from the carbon.

Although the volcano is quiescent at the present time, at the current active crater ( there are several former craters on Nea Kameni ), steam and carbon dioxide are given off.

Although the patent described several ways of creating the carbon filament including " cotton and linen thread, wood splints, papers coiled in various ways ", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1, 200 hours.

Although Taiwan's per capita energy use is on part with neighboring Asian countries, in July 2005 the Ministry of Economic Affairs announced plans to cut 170 million-tons of carbon dioxide emissions by 2025.

Although the hyperfilament is constructed from " continuous pseudo-one-dimensional diamond crystal ", Clarke later expressed his belief that another type of carbon, Buckminsterfullerene, would play the role of hyperfilament in a real space elevator.

Although the latter was the most common type used in the past, cooks tend to be divided on whether carbon steel or cast iron woks are superior.

Although an excellent conductor of heat, it has somewhat inferior volumetric heat capacity as cast iron or carbon steel, it loses heat to convection much faster than carbon steel, and it may be constructed much thinner than cast iron.

Although diamond s ( top left ) and graphite ( top right ) are identical in chemical composition — being both pure carbon — X-ray crystallography revealed the arrangement of their atoms ( bottom ) accounts for their different properties.

Although wood hulls are still in production, the most common construction material is fibreglass, followed by aluminium, steel, carbon fibre, and ferrocement ( rarer because of insurance difficulties ).

Although carbon dioxide levels have changed naturally over the past several thousand years, human emissions of carbon dioxide into the atmosphere exceed natural fluctuations.

Although often depicted with alternating double and single bonds, phenyl groups are chemically aromatic and show nearly equal bond lengths between carbon atoms in the ring.

Although there is a claim that the segment of the cloth used in the 1988 carbon dating was from a patch repaired during the Middle Ages, this is disputed by experts.

Although silicones contain silicon atoms, they also include carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have different physical and chemical properties than elemental silicon.

Although not as strong or as rigid as carbon fiber, it is much cheaper and significantly less brittle.

Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive.

Although burning biomass for fuel releases carbon dioxide, sulfur compounds, and nitrogen compounds into the atmosphere, a major concern in a sustainable lifestyle, the amount that is released is sustainable ( it will not contribute to a rise in carbon dioxide levels in the atmosphere ).

Although the material has changed from sheet aluminium to carbon fibre, this remains today the standard technique for building top-level racing cars.

Although there are conflicting dates as to when they met ( some sources state that they met in January 1989 at the Satyricon nightclub ), Love stated that the two first encountered one another in January 1988 at a Dharma Bums show where she was doing a spoken word performance, and Erlandson stated that both he and Love were formally introduced to Cobain in a parking lot after a Butthole Surfers concert at the Hollywood Paladium in 1991.

Although much of Chinese philosophy begins in the Warring States period, elements of Chinese philosophy have existed for several thousand years ; some can be found in the Yi Jing ( the Book of Changes ), an ancient compendium of divination, which dates back to at least 672 BCE.

Although the Nihon Shoki states that Nintoku ruled from 313 – 399, modern research suggests those dates are likely inaccurate.

Although new publication dates were repeatedly announced, the book never appeared.

Although the use of the term infantry in English dates from the 15th century ( from French Infanterie, itself from the Italian Infanteria ), the foot troops of the previous eras in history who fought with a variety of weapons before the introduction of the firearms are also referred to as infantry.

Although recorded Luxembourgian history dates back to Roman times, the history of Luxembourg proper is considered to begin in 963.

Although some books ( in particular guidebooks ) suggest that the mazes on cathedral floors served as substitutes for pilgrimage paths, the earliest attested use of the phrase " chemin de Jerusalem " ( path to Jerusalem ) dates to the late 18th century when it was used to describe mazes at Reims and Saint-Omer.

Although lutes were in widespread use in Europe at least since the 13th century, and documents mention numerous early performers and composers, the earliest surviving music for the instrument dates from the late 15th century.

Although the latter is a soup, it is considered as a dish in itself and is served as such or with dates especially during the month of Ramadan.

Although the practice of selling " Chametz " dates back many years, some contemporary rabbinical authorities have come to regard it with disdain – since the supposed " new owner " never takes actual possession of the goods.

Although the concept of offering hospitality to the traveler dates back to early cultures ( notably ancient Greece: xenia and Viking Age Scandinavia ), the idea of applying it specifically to Esperanto speakers began in 1966 in Argentina when Ruben Feldman-Gonzalez started the Programo Pasporto.

Although paper had been known as a wrapping and padding material in China since the 2nd century BC, the first documented use of toilet paper in human history dates back to the 6th century AD, in early medieval China.

Although derived from a text written more than a century later, it is thought by some historians that the earliest Scots verse written in Scotland dates from this time: Quhen Alexander our kynge was dede, That Scotland lede in lauche and le, Away was sons of alle and brede, Of wyne and wax, of gamyn and gle. Our gold was changit into lede. Christ, born in virgynyte, Succoure Scotland, and ramede, That stade is in perplexite.

Although Caesarean sections were performed in Roman times, no classical source records a mother surviving such a delivery, – the earliest recorded survival dates to 1500 AD – and Caesar's mother Aurelia Cotta lived to serve him as an advisor in his adulthood.

Although this system dates to the later 5th century BC, it was slow to take root, as it does not appear in official documents until the late 2nd century BC and was not common until the time of Sulla, right before the Empire.

Although the Bermuda sloop is often described as a development of the narrower-beamed Jamaica sloop, which dates from the 1670s, the high, raked masts and triangular sails of its Bermuda rig are rooted in a tradition of Bermudian boat design dating from the early 17th century.

Although contemporary professional use of the term ' urban design ' dates from the mid-20th century, urban design as such has been practiced throughout history.

Although the study of ethnic conflict has a long history, genuine interest in ethnic conflict beyond the comparative political science subfield dates from the collapse of the Soviet Union and Yugoslavia, both of which were followed by ethnic conflicts that escalated to violence and civil war.

Although the proliferation of costumes is of twentieth-century origin, the occasional use of costumes dates back almost to the date of casting, the oldest costume on display in the City Museum being of seventeenth-century origin.

Although first LGBTQ festival in Slovenia dates in 1984, namely the Ljubljana Gay and Lesbian Film Festival, the first pride parade was only organized in 2001 as a result of an incident in a Ljubljana cafe where a gay couple was asked to leave for being homosexual.

Although Winston Churchill, had proposed the creation of an airborne force to assault behind the Germans lines in 1917, the first modern operation dates to late 1918.

Although the subtitle states that the book comprises " 103 Good Things, 5 Bad Kings and 2 Genuine Dates ", the book's preface mentions that originally four dates were planned, but last-minute research revealed that two of them were not memorable.

Although playing mostly locations the band had not previously visited, The Datsuns still managed to sell out the majority of the European dates.

Although The Choir had essentially ceased touring, the overwhelmingly positive response to this one-off concert led to a short series of tour dates to support O How the Mighty Have Fallen in the early part of 2006.

Although its origin and purpose is unknown, the imiut fetish dates as far back as to the First Dynasty ( 3100-2890 BC ).