Jodbestimmung im Varec

Ohne ZusammenfassungHierzu Fig. 1 auf Taf. V.     

Ueber Titriren des Zinks mittels Schwefelnatriums

Ohne Zusammenfassung     

Electrical Signal Induced by a Chemical Reaction in pts

Abstract

Single crystals of monomeric pTS (bis-p-toluene-sulphonate of 2,4-hexadiyne 1,6-diol), when isothermally annealed at 350 K, were found to generate an electrical signal peaking at a time corresponding to that of a maximum conversion rate. The measurements reported here were carried out in the current mode, i.e. the samples were shortcir-cuited through the electrometer insistance (usually 10¹⁰ ohms). The measured signals were of the order of 10^?12 10¹¹ A, and — although differing in details — were found to be satisfactorily reproducible in general features.

It is shown that a steady-state polarization of the order of 10^?4 C/m2 is built into the pTS samples during the polymerization. The effect is probably associated with non-compensated dipolar defects created on polymerizing pTS crystals, and possibly also accounting for the pyroelectricity of poly-pTS, reported earlier in the literature.     

An experiment for the measurement of the bound- β-decay of the free neutron

The hyperfine-state population of hydrogen after the bound-β-decay of the neutron directly yields the neutrino left-handedness or a possible right-handed admixture and possible small scalar and tensor contributions to the weak force. Using the through-going beam tube of a high-flux reactor, a background free hydrogen rate of ca. 3s^-1 can be obtained. The detection of the neutral hydrogen atoms and the analysis of the hyperfine states is accomplished by Lamb shift source type quenching and subsequent ionization. The constraints on the neutrino helicity and the scalar and tensor coupling constants of the weak interaction can be improved by a factor of ten.     

Possibility of plasma density diagnostics using Langmuir-wave-caused dips observed in dense laser plasmas

A systematic study of the Langmuir-wave-caused dips (L dips) observed in profiles of the Al Ly γ line emitted from laser irradiated sandwich targets indicates that these fine spectral features can be used as a tool for density diagnostics in intermediately coupled plasmas. The spectroscopic data required for a reliable identification of L dips were collected by a vertical-geometry Johann spectrometer providing high spectral and spatial resolution. The electron densities deduced from the evolution of the L dips along the laser target axis compare well with those derived from hydrosimulations and from measurements of the line widths and shifts.     

Studies of degradation enhancement of polystyrene by flame retardant additives

Experimental methods as well as thermodynamic modeling techniques were utilized to explore potential gas and condensed-phase contributions of various flame retardant (FR) additives with polystyrene polymer. FR additives investigated include hexabromocyclododecane (HBCD), triphenyl phosphine oxide (TPPO), triphenyl phosphate (TPP), triphenyl phosphine sulfide (TPPS), and sulfur. Flame studies of fundamental FR activity were also employed using molecular beam mass spectrometry analysis of FR active species directly in a flame system. The flame studies show direct evidence for active bromine (HBr, Br) species for HBCD and active phosphorous species (HPO₂, PO, PO₂ HPO₃) species for TPPO and TPP which provide high potential for gas-phase activity for these FR additives. Various experimental measurements were also done to assess the degradation species and the degree of degradation of polystyrene by the FR additives. These studies support enhanced degradation of the base polystyrene polymer by the FR additive as a major pathway for condensed FR activity for HBCD and sulfur FR additives. Phosphorous based structures appear to show little enhancement of polystyrene degradation.