Abstract: A process for forming large-grain polycrystalline films from amorphous films for use as photovoltaic devices. The process operates on the amorphous film and uses the driving force inherent to the transition from the amorphous state to the crystalline state as the force which drives the grain growth process. The resultant polycrystalline film is characterized by a grain size that is greater than the thickness of the film.A thin amorphous film is deposited on a substrate. The formation of a plurality of crystalline embryos is induced in the amorphous film at predetermined spaced apart locations and nucleation is inhibited elsewhere in the film. The crystalline embryos are caused to grow in the amorphous film, without further nucleation occurring in the film, until the growth of the embryos is halted by imgingement on adjacently growing embryos. The process is applicable to both batch and continuous processing techniques.
Type:
Grant
Filed:
October 16, 1981
Date of Patent:
April 5, 1983
Assignee:
Massachusetts Institute of Technology
Inventors:
Andreas M. Glaeser, John S. Haggerty, Stephen C. Danforth
Abstract: Method and apparatus for the simultaneous automatic analysis and sequential displaying in digital form of a plurality of parameters of whole or hemolyzed blood samples, such as total hemoglobin, percent oxyhemoglobin, percent carboxyhemoglobin, percent methemoglobin (in each case percent meaning percentage of total hemoglobin) and oxygen content. The apparatus is an electro-optical instrument including a servo-controlled spectral line source, such as a hollow cathode lamp, a laser etc., a ratiometric logarithmic amplifier of minimized dynamic range, a fluid-flow system of improved design that combine to measure the absorbances of blood samples at a plurality of wavelengths defined and generated by the spectral line source, to calculate the above parameters based on the absorbances by the use of a micro-computer and associated circuitry absorbances, to display automatically and digitally one of the parameters, and then to display digitally seriatim the remaining parameters responsive to operator intervention.
Type:
Grant
Filed:
March 16, 1977
Date of Patent:
January 16, 1979
Assignee:
Instrumentation Laboratory Inc.
Inventors:
Leslie J. Brown, Bruno DeGironimo, Charles F. Mountain, Richard B. Stevens, Fernando M. Vasconcelos
Abstract: A continuous automatic calibration system and fault detection method for analytical instruments of the kind used for measuring constituents of a fluid sample which system includes a memory for storing reference information, a comparator circuit for continuously comparing the instrument output to the stored reference information, and a sample-and-hold circuit charged positive or negative by the comparator, depending whether or not the instrument output exceeds the value of the reference information. The output of the sample-and-hold circuit in turn is coupled to the instrument continuously to adjust its output to correct value. Where the maximum allowed corrective range of the sample-and-hold circuit is exceeded by the signal from the comparator circuit beyond a predetermined time period, the system displays fault, warning the operator.