摘要:
There is provided a novel class of additives, specifically coals, which are useful in zinc extraction processes involving one or more pressure leach stages carried out at temperatures above the melting point of sulphur. Such processes may include those incorporating a single stage pressure leach, a process involving two stage countercurrent or cocurrent pressure leaches or a multistage leach process for recovering zinc, lead and silver from zinc bearing sulphidic materials which also contain lead and silver.
摘要:
There is provided a novel hydrometallurgical process for the extraction of copper from sulphidic concentrates involving an oxidizing pressure leach using dilute sulphuric acid and a carbonaceous additive. The leaching step is carried out preferably at temperatures above the melting point of sulphur but below about 200.degree. C.
摘要:
There is provided a novel class of additives, specifically coals, which are useful in zinc extraction processes involving one or more pressure leach stages carried out at temperatures above the melting point of sulphur. Such processes may include those incorporating a single stage pressure leach, a process involving two stage countercurrent or cocurrent pressure leaches or a multistage leach process for recovering zinc, lead and silver from zinc bearing sulphidic materials which also contain lead and silver.
摘要:
A method and apparatus for controlling the electrical power applied to an electrically driven oxygen separation device having one or more composite membrane elements to separate oxygen from an oxygen containing feed. The composite membrane elements have a resistance increasing during the operation thereof that would act to reduce oxygen output if applied voltage were held constant. In order to increase the time interval for renewing the composite membrane elements, the electrical potential difference is controlled such that the electric current drawn by the elements remains at a substantially constant level by increasing the electrical potential difference as the resistance increases until a predetermined voltage level is reached. Once this level is obtained, the electrical potential difference is maintained at a constant level and the electric current being drawn and the oxygen output is allowed to decay to a predetermined low level after which the element or elements are replaced.
摘要:
Methods are presented that detect and classify mass-like regions exhibiting spiculated and/or dense characteristics with high sensitivity and at acceptable false positive rates. One or more suspicious masses are identified in medical imagery of the breast. In certain embodiments, a quantitative measure of spiculation and quantitative measure of density are computed for each suspicious mass located. At least one classification scheme, developed using true and false positives with similar quantitative measures, is then selected for each suspicious mass according to both quantitative measures. In certain other embodiments, a measure of breast location is computed for each suspicious mass. In one embodiment, the location determines whether a suspicious mass appears inside or outside of the parenchyma region of the breast.
摘要:
Lenses are designed using the corneal topography or wavefront measurements of the eye derived by subtracting the optical power of the eye after orthokeratology treatment from the optical power before orthokeratology treatment.
摘要:
The present invention provides an electrically driven oxygen separation assembly and method of applying an electrical potential thereto in which one or more tubular membrane elements are provided having an anode layer, a cathode layer, an electrolyte layer and two current collector layers adjacent to and in contact with the anode layer and the cathode layer and situated on the inside and outside of the at least one tubular membrane element. The potential is applied to one of the two current collector layers at two central spaced locations of the at least one tubular membrane element and to the other of the two current collector layers at least at opposite end locations thereof. As a result the electric current flow through the tubular membrane element is divided into two parts flowing between the two central spaced locations and the opposite end locations.
摘要:
A driver for a white LED string or a display is provided. The driver includes a boost converter that is arranged to provide an output voltage from a source voltage. Also, the driver includes a sense resistor that is coupled between the output voltage and a feedback voltage. The sense resistor is coupled in series with the white LED string or the display. Further, the boost converter uses the sense voltage across the sense resistor to regulate the output voltage. In one embodiment, the boost converter includes a level shifter that converts the sense voltage into a comparison signal that is referenced to ground. In another embodiment, the converter employs a reference voltage that is referenced to the output voltage.
摘要:
A method and system that provides users with additional information regarding imagery analyzed by computer-aided detection (CAD) systems is described. A user selects a region of the analyzed imagery. Information is then derived from computational measurements of the region obtained during CAD processing. The region selected by the user does not necessarily have to include a displayed CAD system detection. The information includes a description of the computational measurement and the value of the measurement, both of which are provided in clinically relevant terms.
摘要:
A sample for NMR measurement of moisture and fat and oil contents is disclosed. The sample includes an organic portion containing at least some fats and oils, a pad that is substantially transparent to microwave radiation and is free of atoms that would interfere with or mask the NMR response of the protons in the fats and oils in the sample, and a sheet material that is free of atoms that would interfere with or mask the NMR response of the protons in the fats and oils in the sample, with the sheet material being wrapped around the organic portion and the pad.