Electrical impedance string probes for two-phase void and velocity measurements

An instrumentation system was developed to measure two-phase flow velocity and void fraction. The principle of operation of this system was based on the measurement of the electrical impedance of two-phase mixtures. Two-phase velocity is estimated by time-of-flight analysis of signals from two spatially separated sensors. A technique involving measurement of both the capacitance and the conductance of the mixture was used to determine void fraction and correct for the effect of liquid distribution. The string probe instrumentation proved to be durable in air/water and steam/water flows and demonstrated an ability to measure a wide range of flow velocities (1–17 m/s) and void fractions (0.25?0.99+).     

Investigations in the field of radiation-induced solid state polymerization-XXXI

Binary systems of N-vinyl succinimide and endomethylene tetrahydrophtalic acid monoallyl ester with some additives were studied. It was established that the amount and nature of the quasi-eutectic structure could be regulated to the desired extent only when crystallization was performed under nearly isothermal conditions. In the present conditions for heat transfer, one component of the binary system should have a maximum linear crystallization rate low enough to produce a maximum linear crystallization rate of the quasi-eutectic structure less than 1 × 10^?2 mm/sec. In many cases, kinetic results could definitely be connected with qualitative and quantitative changes in the quasi-eutectic structure. Some phenomena suggested the roles of certain structural features and the phase conditions of the ternary system formed by the polymer produced.     

Properties of the lighest known caesium isotopes 114–118Cs

Neutron-deficient caesium isotopes with mass numbers from 114 to 118 have been studied at the ISOLDE facility. Half-lives have been determined from counting of β-particles, β-delayed protons, and γ-rays. A short-lived isomer ($\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 0.7}\text{sec}$) in ¹¹⁶Cs has been observed and the new delayed-particle precursors ¹¹⁶Cs (protons and α-particles), ¹¹⁵Cs (protons), and ¹¹⁴Cs (protons and α-particles) have been identified. Coincidences between delayed particles and γ-rays have been measured for ¹¹⁸Cs (pγ and αγ) and ¹¹⁶Cs (pγ). A search for the possible proton-radioactive isotope ¹¹³Cs has been performed and an upper limit for its production yield is given.     

Factorization in certain Cayley rings

There are, up to isomorphism, three rings of integral elements of the Cayley algebra over the rationals which contain the naive Cayley ring as a proper subring. This paper studies factorizations in each of these rings in a manner analogous to that in an earlier study by Pall and Taussky.     

A new delayed proton precursor: Chromium-45

The new $\text{T}{}_{\mathrm{z}}\text{= ?}\text{3}\text{2}$ isotope, ⁴⁵Cr, has been produced by the ³²S(¹⁶O, 3n)⁴⁵ Cr reaction. Its half-life was measured to be 50 ± 6 ms. A single β-delayed proton group with center-of-mass energy 2.10 ± 0.05 MeV was observed, corresponding to the decay of the lowest $\text{T}{}_{\mathrm{z}}\text{=}\text{3}\text{2}$ state in ⁴⁵V.     

Beam propagation through parabolic-index waveguides with distorted optical axis

An integral expression is derived for the fields in parabolic-index waveguides with distorted optical axis. It is based on well-known ray matrix techniques and generalized Huygens integrals. The distortions give rise to beam oscillations which in turn are identified as the excitation mechanism for radiation modes. The model gives some better understanding of the transition regions between waveguides. On leave from the Department of Electronics onthe Weizmann Institute of Science, Rehovot, Israel     

Delicious not siliceous: expanded carbohydrates as renewable separation media for column chromatography

Expansion of native corn starch produces a high surface area mesoporous material capable of acting as a novel stationary phase for separating various mixtures of compounds.