In order to study Ne diffusion into glasses, we measured noble gas concentrations in obsidian samples which were degassed in a vacuum at 800°C and subsequently heated in air at various temperatures and heating times. Neon was concentrated in samples which were kept at room temperature, indicating that Ne is easily diffused into obsidians from the atmosphere even at room temperature. We also measured noble gas concentrations in five size-separated fractions of the obsidian (ME1) (>250, 149-250, 74-149, 46-74 and <46 ?m fractions) and in three size-separated fractions of tektite (TE6) (>250 and 149-250 ?m fractions and powdered fraction) to examine the degassing effect on noble gases by crushing. (more…)
Structural and quantitative effects of different electron scavenger concentrations on the free radical formation in the nucleotide thymidine-5′-monophosphate (TMP) and in deoxyribonucleic acid (DNA) after X-irradiation in frozen aqueous solution and glasses (BeF2/H2O for TMP and LiCl/H2O for DNA) at 77 K are investigated. At the highest concentration used (100 mmol dmm3) about 80% (TMP) and 70% (DNA) of the radicals are scavenged compared with the control in both matrices. In TMP, allyl radicals form the major population of radicals left unscavenged at 77 K. These are shown to transform into a quintet pattern upon annealing (S 220 K). Analysis of various substrates for quintet formation shows that a sugar-group and a C4-carbonyl group are necessary structural prerequisites. (more…)
Glasse Parent Description
Glasses of the BaO — Nb.sub.2 O.sub.5 — GeO.sub.2, SrO — Nb.sub.2 O.sub.5 — GeO.sub.2 and PbO — Nb.sub.2 O.sub.5 — GeO.sub.2 system in selected proportions have been found to have desirable properties from the standpoint of transparency and stability and are useful for a wide variety of purposes. Of particular interest is the finding that these glasses can be heat treated to produce transparent glass-ceramics having an index of refraction higher than that of the glass and which specifically may be in excess of 2.000. The glass-ceramics which are capable of being formed from glasses within the above-described glass system have high dielectric constants; e.g. in excess of 50 and low dissipation factors; e.g. about 3.5% or less. Both transparent and non-transparent or opaque glass-ceramics may be obtained in accordance with this invention possessing the aforementioned desirable properties. (more…)
The mobility of an organic volatile probe (1-n-propanol), incorporated in two types of amorphous carbohydrate glasses, was evaluated by measuring probe retention as a function of time. Retention was found to depend on temperature, moisture content and the degree of matrix collapse. In sucrose glasses, crystallization and probe release occur simultaneously and both crystallization and release depend on the temperature above Tg, as predicted by the William-Landel-Ferry (WLF) equation. (more…)
Nineteen current makes of sports glasses and six older types of sunglasses were tested for spectral UV transmission. Transmissions in the UVB range (280–320 nm) were less than 10^-4; all glasses therefore offered 100% protection against keratitis. (more…)
Glasse Parent Case Text
REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending application Ser. No. 349,152 filed Apr. 9, 1973 now abandoned; which in turn is a division of copending application Ser. No. 241,448 filed Apr. 5, 1972 now U.S. Pat. No. 3,852,077, the entire disclosures of both copending applications are relied on herein. (more…)
We present the experimental results on the effects of hydrogen doping on the superconducting and paramagnetic properties of zirconium-rich (x > 0.66) Zrx3d1-x metallic glasses. Zr0.70Cu0.30, Zr0.67Ni0.33 and Zr0.67Co0.33 are superconductors with a superconducting transition temperature in the vicinity of 2 K, while Zr0.68Fe0.32 is a paramagnet down to very low temperatures because of pronounced spin-fluctuations. (more…)
High-magnetostriction Fe-rich metallic glasses in the form of ribbons presenta magnetoelastic resonance characterized by the frequency of the longitudinal vibrational mode ofthe sample, /spl omega//sub r/, which is a function of the applied static field, H. This value of/spl omega//sub r/ can be used to recognize different objects or the position of a single object ina field gradient, that is as a carrier of information. (more…)
United States Patent 3935019
Rapp January 27, 1976
Glasses Patent Abstract
Thermally crystallizable glasses are disclosed of the system: wherein RO is a BaO or SrO. Also disclosed are thermally crystallizable glasses of the system PbO — Nb.sub.2 O.sub.5 — GeO.sub.2. Glass-ceramics made from these glass systems have high dielectric constants and low dissipation factors or loss tangents, which glasses and glass-ceramics are suitable for use as capacitors and dielectrics, and particularly for thick-film dielectric pastes utilized in the manufacture of micro-electronic printed circuits. (more…)
We investigate dynamical systems of gauge symmetric Ising spin glasses usingthe method of the gauge transformation. Several exact relations are derived among dynamicalquantities such as the equilibrium auto-correlation function and the non-equilibrium remanentmagnetization. The same result as in the static case is obtained in terms of the equivalence of theferromagnetic and the spin glass order (more…)