摘要:
An apparatus for the analysis of carbon products enables air reactivity, CO.sub.2 reactivity, soot index and coefficient of thermal expansion of the carbon products to be determined in one analysis operation. The apparatus includes vertical and/or horizontal tube furnaces, each of which is provided with devices for weighing, temperature registration and/or registration dilation. Introduction of gas takes place via one end of each of the tube furnaces. Each of the furnaces is connected to a joint processing unit which checks the various instruments and registers the various instruments and registers and processes the analytical data.
摘要:
A method for the manufacture of an improved sensor element for determining the amount of oxygen in a sample, comprises the steps of: (a) mixing a fluorescent reagent with a silicone oil which has a molecular weight of 6,700 to 80,000 and most preferably in the range of between 15,000 and 30,000; (b) heating the mixture at a temperature in the range of between 150.degree. to 350.degree. C. and (c) adding an optical insulating material forming an optical insulating layer onto the fluorescent reagent. Optionally, a crosslinking agent is incorporated. In order to increase the efficiency of fluorescence, an additionally layer of light scattering material is inserted between the fluorescent reagent layer and that of the insulator.
摘要:
The concentration of molecular fluorine in a mixed gas such as an excimer laser gas can be determined easily, quickly and accurately by passing the mixed gas through a column packed with an alkali metal or alkaline earth metal compound which has no halogen atom and reacts with fluorine to form a solid fluoride together with molecular oxygen and/or carbon dioxide and measuring the concentration of oxygen or carbon dioxide in the fluorine-free gas flowed out of the packed column. If the mixed gas initially contains molecular oxygen or carbon dioxide, its concentration is measured separately after fixing fluorine in another column packed with an element which forms a fluoride. This analyzing method can be used in a feedback control system for controlling the concentration of fluorine in an excimer laser gas during operation of the laser to thereby stabilize the laser output power.
摘要:
Colorimetric, fiber optic sensors for measuring pH, PCO.sub.2 and/or other chemical parameters of the blood. The sensors are fabricated using a single optical fiber, which is provided with a chamber at its distal end containing a pH sensitive dye. Located distal to the chamber is a white reflective surface located within 0.04" from the end of the optical fiber, which enhances the performance of the sensor.
摘要:
The concentration of molecular fluorine in a mixed gas such as an excimer laser gas can be determined easily, quickly and accurately by passing the mixed gas through a column packed with an alakli metal or alkaline earth metal compound which has no halogen atom and reacts with fluorine to form a solid fluoride together with molecular oxygen and/or carbon dioxide and measuring the concentration of oxygen or carbon dioxide in the fluorine-free gas flowed out of the packed column. If the mixed gas initially contains molecular oxygen or carbon dioxide, its concentration is measured separately after fixing fluorine in another column packed with an element which forms a fluoride. This analyzing method can be used in a feedback control system for controlling the concentration of fluorine in an excimer laser gas during operation of the laser to thereby stabilize the laser output power.
摘要:
A sensor for determining the partial pressure of carbon dioxide in a liquid, which comprises a carbon dioxide - permeable, liquid and ion-impermeable membrane enveloping an aqueous medium containing an absorber, a fluorescer and a source of bicarbonate ions, which medium exhibits variations in pH as a function of the partial pressure of dissolved carbon dioxide, the ratio of absorber to fluorescer and the characteristics of the absorption spectrum of the absorber and the excitation and emission spectra of the fluorescer being such that the partial pressure of carbon dioxide in the liquid may be determined from the pH of the aqueous medium as measured by the intensity of the fluorescent emission of the fluorescer.
摘要:
A novel system and method for treating ischemic neurologic tissue is disclosed wherein an oxygenated nutrient emulsion is circulated through at least a portion of the cerebospinal pathway. The nutrient emulsion contains an oxygenatable non-aqueous component, an aqueous nutrient component, an emulsification component, and other components which render physiologic acceptability of the nutrient emulsion. Methods for producing the nutrient emulsion and a system for delivering that emulsion to the crebrospinal pathway are also disclosed. Additionally, novel diagnostic methods for diagnosing the physiologic state of hypoxic-ischemic and other diseased neurologic tissue during treatment are provided.
摘要:
A fluorescence-based optical sensor includes a membrane immobilized fluorophor secured to one end of a bifurcated fiber optic channel for exposure to the sample to be analyzed. The fiber optic channel also has an input end coupled to a radiation source arranged to supply radiation at two different wavelengths and an output end coupled to a bandwidth limited photosensor. The radiation source alternately excites the fluorophor at a first wavelength that excites an acid form of the fluorophor and at a second wavelength that excites a base form of the fluorophor, and a ratio of the resulting fluorescence intensities is taken as a measure of a characteristic of the sample being analyzed.
摘要:
A method and an arrangement for measuring the concentration of gases in a sample includes the generation of a monochromatic light beam having predetermined color characteristic. An indicator generates light signals indicative of the concentration of the gases in a sample to be measured and includes a light-transmissive surface positioned to be impinged by the monochromatic light beam, a diffusion membrane adapted to be placed in the proximity of a sample and being permeable to a selected gas component thereof, and an indicating substance positioned to be impinged by the monochromatic light beam penetrating the light-transmissive surface and by the gas component penetrating the diffusion membrane. The indicating substance reacts when illuminated by the incident monochromatic light by emitting a resultant light beam having an emitted component which has a color characteristic different from the predetermined color characteristic of the monochromatic light beam. The resultant light beam is conducted away from the indicating substance through the light-transmissive surface. Finally, the emitted component is discriminated from the resultant light beam so that the change in the color characteristic of the indicating substance can be measured and correlated with the concentration of gases in the sample.
摘要:
Process for analyzing anions in a liquid by means of an ion exchanger and by complex formation with specific anions by addition of polyhydric alcohol. Sensitivity is increased owing to the fact that the complex of specific anions with polyhydric alcohol has a high activity as acid.