A note on information retrieval models and theories

To improve tightness of a pinch or press seal (2a; 13a, 13b) between a molybdenum foil and quartz or similar hard glass of an electric lamp, typically a halogen incandescent lamp or metal halide discharge lamp, an intermediate melt glass layer in form of a strip is applied to the sealing foil, which has the following main components: SiO2: 60-70% Al2O3: 3-20% K2O: 12-18, all percentages by weight, the glass being, except for trace contaminants, free from Na2O. In a preferred form, the main components are: SiO2: 66% Al2O3: 18% K2O: 15%, all percentages by weight.