3610 results about "Partial pressure" patented technology

A method of fabricating a long carbon nanotube yarn includes the following steps: (1) providing a flat and smooth substrate; (2) depositing a catalyst on the substrate; (3) positioning the substrate with the catalyst in a furnace; (4) heating the furnace to a predetermined temperature; (5) supplying a mixture of carbon containing gas and protecting gas into the furnace; (6) controlling a difference between the local temperature of the catalyst and the furnace temperature to be at least 50° C.; (7) controlling the partial pressure of the carbon containing gas to be less than 0.2; (8) growing a number of carbon nanotubes on the substrate such that a carbon nanotube array is formed on the substrate; and (9) drawing out a bundle of carbon nanotubes from the carbon nanotube array such that a carbon nanotube yarn is formed.

A method and apparatus for the transcutaneous monitoring of blood gases generally comprises a blood gas data acquisition device, a vacuum source and a blood gas transducer unit. The blood gas transducer unit is adapted for application to a patient's skin and administration of a local vacuum at the area of patient application. It further comprises an electrochemical blood gas transducer, well known to those of ordinary skill in the art, which is disposed entirely within the local vacuum at the area of patient application. The vacuum source is placed in fluid communication with the blood gas transducer unit, through a hydrophobic membrane filter for safety purposes, in order to induce a condition of hyperperfusion in the locality of the electrochemical blood gas transducer. Under the control of a microcontroller, or equivalent means, the blood gas acquisition device is then utilized to capture a measure of skin surface oxygen or carbon dioxide pressure. The microcontroller can then utilize this measure to arrive at an estimate of arterial partial pressure of oxygen or carbon dioxide, accordingly. Because vacuum induced perfusion produces the requisite condition of hyperperfusion without local heating and, therefore, without acceleration of the local metabolic function, the present invention results in more accurate than previously available estimates of partial pressure blood gas pressures and does so while eliminating a significant risk for injury to the patient.

A III-V nitride homoepitaxial microelectronic device structure comprising a III-V nitride homoepitaxial epi layer on a III-V nitride material substrate, e.g., of freestanding character. Various processing techniques are described, including a method of forming a III-V nitride homoepitaxial layer on a corresponding III-V nitride material substrate, by depositing the III-V nitride homoepitaxial layer by a VPE process using Group III source material and nitrogen source material under process conditions including V/III ratio in a range of from about 1 to about 105, nitrogen source material partial pressure in a range of from about 1 to about 103 torr, growth temperature in a range of from about 500 to about 1250 degrees Celsius, and growth rate in a range of from about 0.1 to about 500 microns per hour. The III-V nitride homoepitaxial microelectronic device structures are usefully employed in device applications such as UV LEDs, high electron mobility transistors, and the like.

A method and apparatus for measuring the consumption of reactants includes a partial pressure sensor for measuring the partial pressure of a reactant in a reactant stream. The partial pressure sensor includes a first pressure sensor that has a first sensitivity to the composition of the gas stream and a second pressure sensor that has a second sensitivity to the composition of the reactant stream, the second sensitivity being greater than the first sensitivity. A control unit is configured to compare a first pressure signal from the first pressure sensor to a second pressure signal from the second pressure sensor to determine the partial pressure of the reactant in the reactant stream.

High-deposition rate methods for forming transparent ashable hardmasks (AHMs) that have high plasma etch selectivity to underlying layers are provided. The methods involve placing a wafer on a powered electrode such as a powered pedestal for plasma-enhanced deposition. According to various embodiments, the deposition is run at low hydrocarbon precursor partial pressures and/or low process temperatures. Also provided are ceramic wafer pedestals with multiple electrode planes embedded with the pedestal are provided. According to various embodiments, the pedestals have multiple RF mesh electrode planes that are connected together such that all the electrode planes are at the same potential.

Methods are provided herein for forming thin films comprising oxygen by atomic layer deposition. The thin films comprising oxygen can be deposited by providing higher concentration water pulses, a higher partial pressure of water in the reaction space, and/or a higher flow rate of water to a substrate in a reaction space. Thin films comprising oxygen can be used, for example, as dielectric oxides in transistors, capacitors, integrated circuits, and other semiconductor applications.

Etching of nitride and oxide layers with reactant gases is modulated by etching in different process regimes. High etch selectivity to silicon nitride is achieved in an adsorption regime where the partial pressure of the etchant is lower than its vapor pressure. Low etch selectivity to silicon nitride is achieved in a condensation regime where the partial pressure of the etchant is higher than its vapor pressure. By controlling partial pressure of the etchant, very high etch selectivity to silicon nitride may be achieved.

A Si-free C-containing film having filling capability is deposited by forming a viscous polymer in a gas phase by striking an Ar, He, or N₂ plasma in a chamber filled with a volatile hydrocarbon precursor that can be polymerized within certain parameter ranges which define mainly partial pressure of precursor during a plasma strike, and wafer temperature.

A high-throughput method of forming a semiconductor precursor layer by use of a chalcogen-containing vapor is disclosed. In one embodiment, the method comprises forming a precursor material comprising group IB and/or group IIIA particles of any shape. The method may include forming a precursor layer of the precursor material over a surface of a substrate. The method may further include heating the particle precursor material in a substantially oxygen-free chalcogen atmosphere to a processing temperature sufficient to react the particles and to release chalcogen from the chalcogenide particles, wherein the chalcogen assumes a liquid form and acts as a flux to improve intermixing of elements to form a group IB-IIIA-chalcogenide film at a desired stoichiometric ratio. The chalcogen atmosphere may provide a partial pressure greater than or equal to the vapor pressure of liquid chalcogen in the precursor layer at the processing temperature.

A process to produce terephthalic acid is provided, the process including the steps of: providing a feed stream comprising a dialkyl substituted aromatic and in an organic acid solvent: contacting the feed stream with an oxidant, the oxidant containing at least 50% by volume oxygen and at an oxygen partial pressure of at least 1 psia, at a temperature between about 80 DEG C. and about 130 DEG C., in the presence of a catalyst system comprising zirconium and cobalt, wherein the contacting is done in a stirred tank reactor; removing from the stirred tank reactor a vapor stream comprising the organic acid, water vapor and unreacted oxidant; condensing at least a portion of the organic acid and water from the vapor stream; separating at least a portion of the water from the organic acid back to the stirred tank reactor; returning at least a portion of the condensed organic acid back to the stirred tank reactor; continuously recovering from the stirred tank reactor a product comprising a diacid substituted aromatic; isolating solid crystals of diacid substituted aromatic from the reactor product; and recovering from the solid crystals a diacid substituted aromatic having a purity of preferably at least 97% by weight.

This invention relates to a process to produce a polyalpha-olefin comprising: 1) contacting one or more alpha-olefin monomers having 3 to 24 carbon atoms with an unbridged substituted bis cyclopentadienyl transition metal compound having: 1) at least one non-isoolefin substitution on both cyclopentadientyl rings, or 2) at least two substitutions on at least one cyclopentadienyl ring, a non-coordinating anion activator, and optionally an alkyl-aluminum compound, where the molar ratio of transition metal compound to activator is 10:1 to 0.1:1, and if the alkyl aluminum compound is present then the molar ratio of alkyl aluminum compound to transition metal compound is 1:4 to 4000:1, under polymerization conditions wherein: i) hydrogen is present at a partial pressure of 0.1 to 50 psi, based upon the total pressure of the reactor or the concentration of the hydrogen is from 1 to 10,000 ppm or less by weight; ii) wherein the alpha-olefin monomer(s) having 3 to 24 carbon atoms are present at 10 volume % or more based upon the total volume of the catalyst/activator/alkylaluminum compound solutions, monomers, and any diluents or solvents present in the reaction; iii) the residence time of the reaction is at least 5 minutes; iv) the productivity of the process is at least 43,000 grams of total product per gram of transition metal compound; v) the process is continuous or semi-continuous, and vi) the temperature in the reaction zone does not rise by more than 10° C. during the reaction; and vii) ethylene is not present at more than 30 volume % of the monomers entering the reaction zone; and 2) obtaining a polyalpha-olefin (PAO), optionally hydrogenating the PAO, wherein the PAO comprises at least 50 mole % of a C3 to C24 alpha-olefin monomer, and wherein the PAO has a kinematic viscosity at 100° C. of 20 cSt or less.

Power plants and process for lowering CO₂ emissions generally includes extracting a portion of the recirculated CO₂-rich flue gas mid-way through the compression pathway of a gas turbine and removing the CO₂ in a separation unit. The remaining portion of the CO₂ rich flue gas (i.e., the portion of the recirculated flue gas that was not fed to the separation unit) is mixed with fresh air coming from an additional compressor-expander and then fed back to the compression pathway. As a result, flue gas recirculation increases the CO₂ concentration within the working fluid, leading to an additional increase in CO₂ partial pressure. As the concentration and partial pressure of CO₂ is increased, a lower energy penalty is observed to remove the CO₂. Moreover, a reduced volume is fed to the CO₂ separation unit during operation. Consequently, the size of the separation equipment can be reduced as well as the energy required for the separation process.

A III-V nitride homoepitaxial microelectronic device structure comprising a III-V nitride homoepitaxial epi layer of improved epitaxial quality deposited on a III-V nitride material substrate, e.g., of freestanding character. Various processing techniques are described, including a method of forming a III-V nitride homoepitaxial layer on a corresponding III-V nitride material substrate, by depositing the III-V nitride homoepitaxial layer by a VPE process using Group III source material and nitrogen source material under process conditions including V/III ratio in a range of from about 1 to about 10<5>, nitrogen source material partial pressure in a range of from about 1 to about 10<3 >torr, growth temperature in a range of from about 500 to about 1250 degrees Celsius, and growth rate in a range of from about 0.1 to about 10<2 >microns per hour. The III-V nitride homoepitaxial microelectronic device structures are usefully employed in device applications such as UV LEDs, high electron mobility transistors, and the like.

A production method of a thin film transistor including an active layer including an amorphous oxide semiconductor film, wherein a step of forming the active layer includes a first step of forming the oxide film in an atmosphere having an introduced oxygen partial pressure of 1×10⁻³ Pa or less, and a second step of annealing the oxide film in an oxidative atmosphere after the first step.

An apparatus to measure cardiac output (Q) and other parameters such as alveolar ventilation (VA), minute CO₂ elimination from the lung (VCO₂ ), minute oxygen consumption (VO₂), oxygenated mixed venous partial pressure of CO₂, (PvCO₂-oxy), true mixed venous partial pressure of CO₂(PvCO₂), PaCO₂, mixed venous oxygen saturation (SvO₂), pulmonary shunt, and anatomical dead space, consisting of: a) a breathing circuit with characteristics that: i. on exhalation, exhaled gas is kept substantially separate from inhaled gas; ii. oninhalation, when V_E is greater than FGS flow, the subject inhales FGS first and then inhales a gas that is substantially SGS, for the balance of inhalation; b) gas sensor means for monitoring gas concentrations at the patient-circuit interface c) a first gas set (FGS), and a second gas set (SGS), said second gas set which may comprise previously exhaled gases or exogenous gases or both d) a gas flow control means for controlling the rate of FGS flow into the breathing circuit e) means to identify phase of breathing, said means may consist of pressure sensors or analysis of signal generated by gas sensors or other means known to those skilled in the art; f) machine intelligence consisting of a computer or logic circuit capable of controlling the gas flow control means, receiving the output of the gas sensor means and means to identify phased of breathing, and performing the calculations for measuring cardiac output and other parameters as outlined in the disclosure.

There is provided a process for converting methanol and/or dimethyl ether to a product containing C2 to C4 olefins which comprises the step of contacting a feed which contains methanol and/or dimethyl ether with a catalyst comprising a porous crystalline material, said contacting step being conducted in the presence of an aromatic compound under conversion conditions including a temperature of 350 DEG C. to 480 DEG C. and a methanol partial pressure in excess of 10 psia (70 kPa), said porous crystalline material having a pore size greater than the critical diameter of the aromatic compound and the aromatic compound being capable of alkylation by the methanol and/or dimethyl ether under said conversion conditions.

There is provided a catalyst and a process for converting methanol or dimethyl ether to a product containing C2 to C4 olefins. The catalyst comprises a porous crystalline material having a Diffusion Parameter for 2,2-dimethylbutane of about 0.1-20 sec-1 when measured at a temperature of 120 DEG C. and a 2,2-dimethylbutane pressure of 60 torr (8 kPa). In addition, the catalyst is characterized by a hydrothermal stability such that, after steaming the catalyst at 1025 DEG C. for 45 minutes in 1 atmosphere steam, the catalyst exhibits a methanol conversion activity of at least 50% when contacted with methanol at a methanol partial pressure of 1 atmosphere, a temperature of 430 DEG C. and 0.5 WHSV. The porous crystalline material is preferably a medium-pore zeolite, particularly ZSM-5, which contains phosphorus and has been severely steamed at a temperature of at least 950 DEG C.

An onboard fuel separation apparatus separates a material fuel (gasoline) into a high-octane fuel having a higher octane value than the material fuel and a low-octane fuel having a lower octane value than the material fuel using a separation membrane which selectively allows high-octane value components (such as aromatic components) permeate through the membrane. The apparatus increases the ratio of the amount of the high-octane value components permeating through the membrane to the amount of the high-octane value components contained in the material fuel by, (A) Controlling the temperature of the material fuel supplied to the membrane (B) Increasing partial pressure of the low-octane value components on the high-octane fuel side of the membrane and removing volatiles from the permeate, and (C) Bypassing volatiles in the material feed around the membrane.

A method and apparatus for monitoring and controlling reactive sputter deposition, particularly useful for depositing insulating compounds (e.g., metal-oxides, metal-nitrides, etc.). For a given nominal cathode power level, target material, and source gases, the power supplied to the cathode (target) is controlled to stabilize the cathode (target) voltage at a specified value or within a specified range corresponding to a partial pressure or relative flow rate value or range of the reactive gas. Such an operating point or range, characterized by a specified voltage value or range and corresponding reactive gas relative-flow/partial-pressure value or range, may be determined empirically based on measuring the cathode voltage as a function of reactive gas relative-flow/partial-pressure for the given nominal power. This relationship is typically a hysteresis curve, and preferably the operation point is selected at or near the hysteresis transition edge to provide high rate deposition of high quality films, including insulating or dielectric films using a metallic target.