Acid spun carbon nanotube (CNT) fibers were investigated for their field emission properties and performance was determined to be dependent on fiber morphology. The fibers were fabricated by wet-spinning of pre-made CNTs. Fiber morphology was controlled by a fabrication method and processing conditions, as well as purity, size, and type of the CNT starting material. The internal fiber structure consisted of CNT fibrils held together by van der Waals forces. Alignment and packing density of the CNTs affects the fiber's electrical and thermal conductivity. Fibers with similar diameters and differing morphology were compared, and those composed of the most densely packed and well aligned CNTs were the best field emitters as exhibited by a lower turn-on voltage and a larger field enhancement factor. Fibers with higher electrical and thermal conductivity demonstrated higher maximum current before failure and longer lifetimes. A stable emission current at 3 mA was obtained for 10 h at a field strength of <1 V μm(-1). This stable high current operation makes these CNT fibers excellent candidates for use as low voltage electron sources for vacuum electronic devices.

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The rotation of the angular correlation between the 7-group at about 820 keV and the 80 keV radiation in the decay of Tm l~ has been observed in an external magnetic field of 20300 gauss.The result : coR.r = 0,485 4-0,o5t yields for the gR-factor of the 80 keV state of Erl~The evaluation includes a paramagnetic correction factor of: /~= 7,26, (Belt =~ " Bext).The angular correlation is slightly attenuated by internal fields. For a liquid source of Tm (NO~)~ solved in 3 n HNO 3, a measurement of the differential angular correlation as a function of the delay time gave:X~(LS• 9 107sec -1, assuming A~(t)=A2(O) 9 e-;.2"t.The half life of the 80 keV state was found to be:2"1/2 = (t,92 :k 0,04) 9 I0 _9 sec in agreement with earlier measurements.

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PrT-Nets are usefull as an instrument of inference. The article will give a short introduction in the PrT-Net theory and shows on same example how to transfer the work process in a PrT-Net structure. 2 Introduction Processes are changes of state in systems. For planning and controlling by using of expertsystems they have to he represented in it with their structures, their relations and their behaviour. The logical relation of the real system concerning all relevant exogenous, and mostly stochastical conditions have to be found in the model. An expert, system needs an inference instrument connecting user, real system and data base management system. This inference instrument has to settle following conditions: • to represents the real structures and relations • to represent the behaviour of the real system