Abstract: The invention provides (1) a method of increasing the thermal stability of an oleaginous liquid containing a high surface area silica viscosifier therein by adding a water soluble biopolymer thereto; and (2) a drilling, completion, workover, or well servicing fluid comprising an oleaginous liquid, a water soluble biopolymer, and a high surface area silica viscosifier.

Abstract: A protein from Group B Streptococcus is shown to be an outer surface protein and is a useful target for antimicrobial therapy.

Abstract: A UV screening composition comprising particles which are capable of absorbing UV light so that electrons and positively charged holes are formed within the particles, characterised in that the particles are adapted to minimise migration to the surface of the particles of the electrons and/or the positively charged holes when said particles are exposed to UV light in an aqueous environment.

Abstract: The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and citric acid in an amount sufficient to increase the low shear rate viscosity of the fluids. The invention further provides a method of increasing the low shear rate viscosity of fluids which contain a water soluble polymer and a calcined magnesia bridging agent which has an Activity Index greater than about 800 seconds.

Abstract: According to the present invention, a series of genes are identified in Group B Streptococcus, the products of which may be associated with the outer surface of the organism. The genes, or functional fragments thereof, may be useful in the preparation of therapeutics, e.g. vacaccines to immunize a patient against microbial infection.

Abstract: A process for preparing phosphor particles of a host oxide doped with a rare earth or manganese which comprises: preparing an aqueous solution of salts of the host ion and of the dopant ion and a water soluble compound which decomposes under the reaction conditions to convert said salts into hydroxycarbonate, heating the solution so as to cause said compound to decompose, recovering the resulting precipitate and calcining it at a temperature of at least 500° C. Substantially monocrystalline particles can be obtained by this process.

Abstract: There is disclosed a biosensor comprising a conducting surface, a layer of dielectric material overlying the conducting surface, a plurality of micro electrodes constituted by a plurality of pores extending through the thickness of said dielectric layer, a biopolymer positioned on the conducting surface in said pores, and a counter electrode arranged such that electrical connection can be made between it and at least part of said conducting surface by a fluid to be assessed. Such a device can be made using a method comprising the steps of providing a conducting surface; providing a layer of dielectric material adjacent to said conducting surface, said dielectric material comprising a plurality of pores extending through the thickness of the dielectric layer; providing a biopolymer on the conducting surface in said pores; and providing a counter electrode insulated from said conducting surface.

Abstract: Phosphor compositions are prepared by treating metal oxides or mixed-metal oxides with refractory metals to form cathodoluminescent phosphors stimulatable by electrons of very low energy. The phosphors comprise 90% to 100% of a mixed metal oxide Mx,TyOz (where M is a metal selected from Zn, Sn, In, Cu, and combinations thereof; T is a refractory metal selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and combinations thereof; and O is Oxygen, x, y, and z being chosen such that z is at most stoichiometric for MxTyOz) and 0% to 10% of a dopant comprising a substance selected from a rare earth element of the lanthanide series, Mn, Cr, and combinations thereof, or stoichiometrically excess Zn, Cu, Sn, or In. A blue-light-emitting phosphor based on ZnO treated with Ta2O5 or Ta to form Ta2Zn3O8 is characterized by CIE 1931 chromaticity values x and y, where x is between about 0.14 and 0.20 and y is between about 0.05 and 0.15.

Abstract: A process is disclosed for preparing phosphor particles of a doped host oxide which comprises: preparing an aqueous solution of salts of the host ion and of the dopant ion which is a rare earth, thorium, titanium, silicon, bismuth, copper, silver, tungsten or chromium and a water soluble compound, which decomposes under the reaction conditions to convert said salts into hydroxycarbonate, heating the solution so as to cause said compound to decompose, recovering the resulting precipitate and calcining it at a temperature of at least 500° C.

Abstract: A UV screening composition comprising particles which are capable of absorbing UV light so that electrons and positively charged holes are formed within the particles, characterised in that the particles are adapted to minimise migration to the surface of the particles of the electrons and/or the positively charged holes when said particles are exposed to UV light in an aqueous environment.

Abstract: Compounds having the formula Z2O3:Zx+ where Z is a rare earth metal and x is from 2 to 4, and nanoparticles thereof together with a process for their production and their uses are disclosed.

Abstract: A protein from Group B Streptococcus is shown to be an outer surface protein and is a useful target for antimicrobial therapy.

Abstract: The light emitter is fabricated from a silicon substrate (2) that has a layer of porous silicon (3) on its upper surface. A hole transporter (4) is applied to the upper surface of the porous silicon (2) and penetrates the channels (3′) formed within the porous silicon. An upper semitransparent p-type material such as NiO is used as the upper contact (5) to the hole transporter and a further contact is formed on the base of the silicon wafer (2). The penetration of the hole transporter into the interstices between the silicon particles significantly improves the efficiency of the light emitter by up to two orders of magnitude. The light emitter is particularly suited to use in VLSI and display applications.

Abstract: Metal quantum dots are produced from a solution of the metal salt when the solution is passed through an electrostatic capillary nozzle (3) into a chamber (7). The nozzle (3) produces an aerosol of droplets (4) of the solution which is then irradiated using laser light (8). The solution evaporates from the droplets to form quantum dots of the metal element on a substrate 5 in the chamber 7.

Abstract: Quantum dots of a metal or metal compound are made by a method of providing a solution in an evaporable solvent at a predetermined concentration of a chosen metal and forming droplets of the solution of a substantially uniform predetermined size. The droplets are thereafter brought into contact with a gas phase reagent thereby forming the metal or metal compound quantum dots desired. The solvent may be removed before, during or after the contacting of the droplets with the gas phase reagent. The metal or metal compound quantum dots so formed are deposited on a substrate. The quantum dots may be contained within a polymer as a film. By control of the concentration of the solution and the size of the droplets the size of the quantum dots may be closely controlled.