Observation of leading particles in pp interactions with large transverse momentum secondaries at the CERN-ISR

Events with a positive particle of large transverse momentum emitted at medium angles have been studied using the split field magnet spectrometer at the CERN-ISR at a c.m. energy of √s = 52.5 GeV. Positive particles with large longitudinal momentum, |x| > 0.5, i.e., leading particles, associated to large p_T events, are analysed.     

Nachweis von Pflanzenschutzwirkstoffen in Mischung miteinander mit Hilfe der Infrarot-Spektrographie

Summary It is shown, that each component of a mixture of several pesticides can be recognized by the IR-spectrum of the mixture in certain ranges of concentration. For this purpose a special diagram was elaborated for 16 pesticides. The procedure is illustrated by the example of a 3-component mixture.

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Die Arbeit wurde mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.     

On longitudinal impact IV

Summary A survey is given of common pile-driving formulae, and special attention is paid to the so-called dynamic formulae whose characteristic features are compiled in a table and a diagram. The well-known situation that these formulae are fairly reliable for drop-hammers (heavy rams) but quite unreliable for double-acting compressed air hammers (light rams) is analyzed and illustrated by means of an example from the literature. An alternative method of computing the dynamic resistance of the ground by means of the measured set and the data of the hammer is presented, and evidence is given that it can be expected to apply equally well to light rams as to heavy ones. It is based on the graphodynamical method of treating longitudinal impact according to the complete pulse solution of the one-dimensional wave equation which was presented and developed in the previous articles of this series. One important parameter of this computing method is the elastic property of the ground. Suggestions are given for the experimental determination of this parameter. Contrary to common opinion this theory leads to the conclusion that high efficiency may well be obtained with light rams (compressed air hammers). In order to give best results, ram, capblock, helmet etc. should be constructed according to the demands of the pulse theory, and if this is done, a reduction of pile stresses can sometimes be obtained. Examples show that the assumptions of current dynamic formulae are better valid for heavy rams (short piles) than for light rams (long piles). Suggestions are given for further theoretical and experimental development of the new method.     

The determination of bromide,chloride and lead in airborne particulate matter by stripping voltammetry

Cathodic and anodic stripping voltammetry are proposed for the simultaneous determination of chloride, bromide and lead in atmospheric particulate matter. Particulate matter collected on Nucleopore membrane filters with high-volume pumps is digested in a dilute nitric acid wash at elevated temperature and pressure for 1 h. The sample is then removed to the electrochemical cell and analyzed directly for chloride and bromide by cathodic stripping and for lead by anodic stripping. The total amount of halide is first determined and then, by changing the deposition potential, the amount of bromide only is determined. The chloride is found indirectly by difference. Analysis time for the three elements is approximately 20 min beginning with a prepared sample.