Abstract:
One embodiment of the disclosure relates to a method of cleaning silica-based soot or an article made of silica-based soot, the method comprising the step of treating silica-based soot or the article made of silica-based soot with at least one of the following compounds: (i) a mixture of CO and C1 2 in a carrier gas such that the total concentration of CO and C1 2 in the mixture is greater than 10 % (by volume, in carrier gas) and the ratio of CO:C1 2 is between 0.25 and 5; (ii) CC1 4 in a carrier gas, such that concentration CC1 4 is greater than 1 % (by volume, in carrier gas). Preferably, the treatment by CC1 4 is performed at temperatures between 600 °C, and 850 °C. Preferably, the treatment with the CO and Cl mixture is performed at temperatures between 900 °C and 1200 °C. The carrier gas may be, for example, He, Ar, N 2 , or the combination thereof.
Abstract:
L'invention concerne une chambre de combustion d'une turbomachine, comprenant au moins une bougie d'allumage (11 ) portée par un carter extérieur et s'étendant dans des moyens de guidage (14) portés par une paroi de révolution (3) de la chambre, ces moyens de guidage (14) comprenant un guide tubulaire (16) traversé axialement par la bougie (11 ) et monté avec un jeu axial (j1 ) et transversal (j2) sur une cheminée (15) fixée sur la paroi de révolution (3) de la chambre et débouchant dans celle- ci, le guide (16) comportant une collerette annulaire (19) engagée avec jeu (j1, j2) dans une gorge annulaire interne (20) de la cheminée (15). La collerette annulaire (19) est sollicitée en appui sur une paroi (24) de la gorge (20) par un organe élastique (25) monté dans la gorge (20).
Abstract:
A method and apparatus for consolidating an optical fiber preform, wherein the optical fiber preform is located in a furnace comprising a muffle tube, said muffle tube comprising an inner section and an outer section surrounding the inner section. The inner and outer sections are comprised of different materials, and the preform is exposed to a pressure less than 0.8 atm while simultaneously exposing said preform to a temperature of at least 1000 C.
Abstract:
The invention relates to the use of a cross-linkable composition with controlled cross-linking, preferably delayed cross-linking, as a material for fixing and thermally insulating tubes used for casing in drill holes, especially oil drill holes, during exploitation operations, such as oil extraction, in the hole.
Abstract:
An apparatus for downwardly drawing glass ribbon comprises edge directors, wherein an outer portion defining a first pair of surfaces and a second pair of surfaces. In one example, the first and second pair of surfaces of each edge director includes a glass wettability with a static contact angle within a range of from about 30° to about 60°. In another example, the outer portion comprises a platinum alloy including from about 0.05 weight % tin to about 5 weight % tin. Methods for forming glass include the step of providing the edge director with a desired glass wettability and/or a desired platinum alloy.
Abstract:
A method and apparatus for making an optical fiber preform. The apparatus has an outer wall and an inner wall. The outer wall surrounds the inner wall and the inner wall surrounds an inner cavity of the apparatus. A core rod is deposited in the inner cavity after which particulate glass material, such as glass soot, is deposited in the inner cavity around the core rod. The core rod has at least 10 percent of the final cladding soot already applied thereto. A radially inward pressure is applied against the particulate glass material to pressurize the particulate glass material against the core rod.
Abstract:
The infunnelion relates to the combustion chamber of a turbine engine, comprising at least one spark plug (11) borne by an outer casing and extending inside guiding means (14) borne by a rotating wall (3) of the chamber, said guiding means (14) including a tubular guide (16) traversed axially by the spark plug (11) and mounted with axial (j1) and transverse (j2) clearance on a funnel (15) secured to, and opening at, the rotating wall (3) of the chamber. In addition, the guide (16) comprises a flange ring (19) inserted with clearance (j1, j2) into an inner annular groove (20) in the funnel (15). The flange ring (19) is urged against a wall (24) of the groove (20) by an elastic member (25) mounted in the groove (20).
Abstract:
A method of preparing an optical preform includes the steps of: a) etching an optical preform to remove a portion of an oxide material deposited on the preform by using a gas comprising an etchant gas containing fluorine at a sufficient temperature and gas concentration to create a redeposited germanium containing compounds contamination such as GeO x in the remaining oxide material; and b) cleaning the etched preform using a cleaning gas containing at least one halogen gas at a sufficient temperature and gas concentration to remove the redeposited germanium containing compound contamination without any substantial further contamination of the remaining deposited oxide material. Preferably the halogen is either chlorine or bromine.
Abstract:
Paroi annulaire pour chambre de combustion de turbomachine, comprenant une rangée annulaire d'orifices de dilution comprenant des orifices (40) de plus grande superficie et des orifices (62) de plus petite superficie, ainsi qu'une multiperforation formée de micro-perforations (46) réparties en une rangée amont (48), une rangée aval (50) et au moins une rangée intercalaire (52) interrompue par lesdits orifices, un rapport géométrique étant défini comme le quotient de la division de l'écartement maximal L entre deux points quelconques du bord de cet orifice selon une direction parallèle à un axe de ladite paroi par l'écartement maximal L entre deux points quelconques du bord de cet orifice mesuré selon une direction perpendiculaire audit axe, ledit rapport géométrique desdits orifices de plus grande superficie étant supérieur ou égal à 1, et ledit rapport géométrique desdits orifices de plus petite superficie étant supérieur à celui desdits orifices de plus grande superficie.
Abstract:
A method and apparatus for making an optical fiber preform, is claimed using an apparatus which has an outer wall and an inner wall. The outer wall surrounds the inner wall and the inner wall surrounds an inner cavity of the apparatus. A consolidated glass rod is deposited in the inner cavity after which particulate glass material, such as glass soot, is deposited in the inner cavity around the glass rod. A radially inward pressure is applied against the particulate glass material to pressurize the particulate glass material against the glass rod.