摘要:
THIS INVENTION RELATES TO HIGH STRENGTH GLASS, GLASSCERAMIC, OR GLASS AND GLASS-CERAMIC LAMINATES HAVING SUBSURFACE FORTIFICATION WHEREBY A CRACK RESULTING FROM THE FRACTURE OF AN OUTER COMPRESSIVELY STRESSED LAYER OF THE LAMINATE IS PREVENTED FROM PROPAGATING THROUGHOUT THE ENTIRE CROSS SECTION OF THE LAMINATE BY A SUBSURFACE FORTIFI-
CATION COMPRISING AT LEAST ONE INTERNAL COMPRESSIVELY STRESSED LAYER.
摘要:
This invention relates to a Colpitts oscillator circuit for a radio capsule of the type adapted to be swallowed by a patient for investigating a condition of the gastrointestinal tract. The circuit includes a transistor as the active element and a parallel resonant LC circuit including the series combination of a variable capacitance diode and first and second capacitors, the capacitance of the second capacitor being the larger of the two in order to provide the minimum amount of positive feedback required to cause stable oscillation. The capacitance of the first capacitor, which is connected between the diode and the transistor emitter, approximates that of the diode at the lowest voltage applied to the diode by a sensor device.
摘要:
THIS INVENTION RELATES TO HIGH STRENGTH GLASS, GLASSCERAMIC, OR GLASS AND GLASS-CERAMIC LAMINATED ARTICLES WHICH ARE PRODUCED THROUGH A CONTINUOUS HOT-FORMING PROCESS WHEREIN GLASS BATCHES ARE MELTED FOR THE INDIVIDUAL LAMINAE AND THESE LAMINAE ARE ESSENTIALLY SIMULTANEOUSLY FUSED TOGETHER AND SHAPED INTO A LAMINATED STRUCTURE OF A DESIRED CONFIGURATION. WHERE A GLASS-CERAMIC LAMINA IS SOUGHT, THE INITIALLY-FORMED LAMINATED GLASS ARTICLE IS SUBSEQUENTLY HEAT TREATED IN A PARTICULARLY-DEFINED MANNER TO CAUSE THE GLASS TO CRYSTALLIZE IN SITU. THE PRESENT INVENTION IS SPECIFICALLY CONCERNED WITH VISCOSITY RELATIONSHIPS OBTAINED IN THE MELTS UTILIZED IN FORMING THE INDIVIDUAL LAMINAE.
摘要:
THIS INVENTION RELATES TO THE PRODUCTION OF GLASS-CERAMIC ARTICLES EXHIBITING VERY LOW COEFFICIENTS OF THERMAL EXPANSION AND EXCELLENT RESISTANCE TO CREEP AT TEMPERATURES UP TO 1000*C. MORE SPECIFICALLY, THIS INVENTION IS CONCERNED WITH GLASS-CERAMIC ARTICLES CONTAINING BETASPODUMENE SOLID SOLUTION AS THE PRINCIPAL CRYSTAL PHASE WHICH ARE CRYSTALLIZED IN SITU FROM GLASS COMPOSITIONS IN THE LI2O-AL2O3-SIO2 FIELD BUT WHICH ALSO CONTAIN MINOR, BUT NECESSARY, AMOUNTS OF SRO, Y2O3, LA2O3, AND/OR TA2O5.
摘要:
THIS INVENTION RELATES TO THE PRODUCTION OF TETRASILICIC FLUORINE MICA GLASS-CERAMIC ARTICLES FROM THE CONTROLLED HEAT TREATMENT OF CRYSTALLIZABLE GLASSES CONTAINING, IN WEIGHT PERCENT ON THE OXIDE BASIS, 45-70% SIO2, 8-20% MGO, 8-15% MGF2, A TOTAL OF 5-35% (R2O+RO), WHEREIN R2O RANGES FROM ABOUT 5-25% AND CONSISTS OF ONE OR MORE OXIDES SELECTED IN THE INDICATED PROPORTIONS FROM THE GROUP CONSISTING OF 0-20% K2O, 0-23% RB2O AND 0-25% CS2O, AND WHEREIN RO RANGES FROM 0-20% AND CONSISTS OF ONE OR MORE OXIDES SELECTED FROM THE GROUP CONSISTING OF SRO, BAO AND CDO, A TOTAL OF 0-10% OF OXIDES SELECTED FROM THE GROUP CONSISTING OF AS2O5 AND SB2O5, AND TO ABOUT 5% OF GLASS COLORANTS. THESE TETRASILICIC MICA PRODUCTS EXHIBIT GOOD MACHINABILITY WITH STEEL TOOLS, GOOD MECHANICAL STRENGTH, MODERATE THERMAL EXPANSION AND GOOD CHEMICAL DURABILITY. THE USE OF THE OPTIONAL CONSTITUENTS AS2O5, SB2O5 AND THE GLASS COLORANTS PERMITS THE PRODUCTION OF TRANSLUCENT GLASS-CERAMICS AND GLASS-CERAMICS HAVING THE APPEARANCE OF MARBLE.
摘要:
The surface characteristics of as=drawn glass sheet are provided with improved flatness uniformity by positioning such sheet between a pair of precision ground fused silica slabs and subjecting such assembly to controlled radiant heat energy for a predetermined period so as to compressibly sag the sheet between the fused silica slabs and thereby provide improved surface flatness not heretofore obtainable.
摘要:
This invention relates to the manufacture of dense, fine-grained glass-ceramic articles having compositions within the Na2O and/or K2O-Al2O3-SiO2 field which are nucleated with TiO2 and/or ZrO2 and/or SnO2 and wherein the principal crystal phase is a nepheline-type crystal, i.e., a nepheline and/or kaliophilite solid solution.
摘要:
Method of removing SO2 and NO2 or SO2 alone from gaseous mixtures passing the gaseous mixtures through a molten bath of sodium hydroxide and/or potassium hydroxide.
摘要:
In X-ray emission spectrometry a quantitative chemical analysis of the elements in an unknown sample is obtained. A standard, or standards, whose composition has previously been accurately established is used to determine the first order approximation to the original intensity of the most efficient excitation energy for each element being determined. The most efficient excitation energy is defined as that energy which is just greater than the energy of the absorption edge of the characteristic X-ray emission line employed in the analysis. Using the computed original intensity of the most efficient excitation energy for each element in the standard(s), the observed X-ray intensities measured on the unknown, and an assumed chemical composition of the unknown, the expected characteristic X-ray intensity for each element in the unknown is computed. The assumed chemical composition of the unknown is then adjusted by a self-consistent iterative procedure until the expected and observed X-ray intensities for each element being determined agree. In this manner the best estimate of the chemical composition of the unknown is determined.