A method and apparatus are provided for planarizing a material layer on a substrate. In one aspect, a method is provided for processing a substrate including forming a passivation layer on a substrate surface, polishing the substrate in an electrolyte solution, applying an anodic bias to the substrate surface, and removing material from at least a portion of the substrate surface. In another aspect, an apparatus is provided which includes a partial enclosure, polishing article, a cathode, a power source, a substrate carrier movably disposed above the polishing article, and a computer based controller to position a substrate in an electrolyte solution to form a passivation layer on a substrate surface, to polish the substrate in the electrolyte solution with the polishing article, and to apply an anodic bias to the substrate surface or polishing article to remove material from at least a portion of the substrate surface.

Planarization of substrates using electrochemical mechanical polishing

A method of plugging a fracture in a subterranean formation which includes placing into the fracture a composition comprising microspheres or microbeads, wherein the microspheres are created by surface crosslinking of droplets in a water-in-water emulsion. Such microspheres may form a filter cake in the formation. The microspheres may include a chemical agent to be released when the microspheres dissolve.

Polymeric Microspheres As Degradable Fluid Loss Additives In Oilfield Applications

This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.

Polymer delivery in well treatment applications

A thickened oil emulsifying viscosity reducer consists of anion surface activator, non-ionic-anion surface activator, demulsifier and water in proportion by 1:0.1-50:0.01-20 and water content is 0.2-5000 times of the sum of a, b and c. Anion surface activator comprises sodium salt and calcium salt of petroleum sulfoacid salt methyl condensate and sulfonated lignin; non-ionic-anion surface activator is chosen organic phosphate salt, sulfuric ester salt , carboxylate and sulfosalt of alkylphenol or fatty alcohol-polyoxyethylene ether; demulsifier is copolymer of alkyl ammonium halide cation demulsifier, polyethylene glycol polyoxytrimethylene polylol ether non-ionic demulsifier or polyethylene glycol polyoxytrimethylene polyethylene polyamines block. It has strong emulsifying ability and low thickened oil viscosity,

Inspissated oil emulsion viscidity reducer

A thickened aqueous composition is delivered to a subterranean location accessible via a wellbore by steps of i. providing a biphasic aqueous mixture comprising two aqueous solutions which, at surface temperature and pressure, are able to co-exist as separate aqueous phases in contact with each other, ii. pumping said biphasic aqueous system down the wellbore to the subterranean location, and iii. converting the biphasic mixture below ground so that its phases combine into a single aqueous phase which is more viscous than the biphasic mixture. The two phases of the aqueous biphasic mixture contain dissolved solutes which segregate between the two phases such that at least one first solute is present at a greater concentration in the first aqueous phase than in the second aqueous phase while at least one second solute is present at a greater concentration in the second aqueous phase than in the first aqueous phase. The solute in the first phase may be a thickening polymer or other thickening material such as viscoelastic surfactant. The solute in the second phase may be a different polymer, surfactant or salt. Conversion to a single phase may be carried out in various ways including dilution, change in pH, change in salinity, increase in temperature and adsorption of one solute onto formation rock.

Provision of viscous compositions below ground

A process for supporting facings and the associated groundwater in advance working systems, especially with shields operated by earth pressure for the construction of tunnels and for micro-tunnelling, in which the worked soil in the earth pressure chamber is mixed with a fluidising medium (I) and a pressure opposing the groundwater pressure is created by taking off the mixture. Medium (I) is a gel which reduces the permeability of the soil, and the soli/gel mixture is obtained by mixing and agitating in the working space or the feed screw.

Process for preparation and use of gels as additives for mechanical shield driving

A hydrocolloid (mixture) comprising water-soluble biopolymer(s) (I) and water-insoluble biopolymer(s) (II), is used as ancillary for drilling applications, especially as foam-generating or foam-stabilising component in tunnel construction by the shield drive technique, especially the shield system with thrust drive. Preferably the mixture also contains a surfactant, especially non-ionic, anionic, cationic and/or amphoteric surfactant(s), more especially non-ionic surfactant(s) or a mixture with anionic, cationic or amphoteric surfactant(s). Surfactants based on renewable raw materials, especially non-ionic surfactants of the alkylpolyglycoside type, are especially suitable, particularly alkylpolyglycoside with 4-30C alkyl chains.

Hydrocolloids and hydrocolloid mixtures as additives for underground construction eg tunnels construction

Hydrokolloide und Hydrokolloidabmischungen als Hilfsmittel für den Tunnelbau mit Schildvortriebssystemen

Verfahren zum Stutzen der Ortsbrust und des anstehenden Grundwassers bei Vortriebssystemen, insbesondere mit Erddruckschilden betriebenen Schildsystemen fur den Tunnelbau im begehbaren und nichtbegehbaren Bereich sowie Microtunnelling bei dem der abgebaute Boden in der Erddruckkammer mit einem fluidisierenden Medium vermischt und durch gezieltes Abfuhren des Gemisches in der Erddruckkammer ein dem Erddruck und dem Grundwasserdruck entgegenwirkender Druck erzeugt wird, wobei, das das dem abgebauten Boden zugefuhrte fluidisierende Medium ein die Durchlassigkeit des Bodens verringerndes Gel ist und das durch Mischen und Verruhren im Abbauraum oder der Forderschnecke ein Gemisch aus Boden und Gel hergestellt wird.

Verfahren zur Herstellung sowie Verwendung von Gelen als Additive für einen mechanischen Schildvortrieb

We document incentive effects of the evaluation deadlines in the UK’s performance-based research funding system. Studying 3,597,272 publications by UK researchers, we find that publications just before assessment deadlines obtain substantially fewer citations and are published in venues with lower impact factors. These trends reverse abruptly after the deadlines. We discuss different factors that contribute to this observation and provide evidence that evaluation deadlines are likely to set incentives against investment in research quality and long-term topics. We conclude that where such shifts in research incentives are not intended, they might require balancing by additional incentives for exploratory, long-term oriented research. 

Thomas Dr. Voigt

Papers

Process for preparation and use of gels as additives for mechanical shield driving

Hydrocolloids and hydrocolloid mixtures as additives for underground construction eg tunnels construction

Hydrokolloide und Hydrokolloidabmischungen als Hilfsmittel für den Tunnelbau mit Schildvortriebssystemen

Verfahren zur Herstellung sowie Verwendung von Gelen als Additive für einen mechanischen Schildvortrieb

Short-term incentives of research evaluations: Evidence from the UK Research Excellence Framework