Normally cavities or voids included in electrical insulation are filled with gases, which have lower breakdown strength than the surrounding insulation. Under the normal working conditions of the insulation system, the voltage across the cavity may exceed the breakdown value of the filling gas and cause a breakdown in the cavity. This phenomenon is called Partial Discharge (PD). This research is focused on methods using basically detection and quantification of PD charge per the voltage pulses in charge sensitive amplifier. Two different principles of processing PD events are used - analog and digital technique. This method is useful for non-destructive and non-invasive on- line diagnostic systems.

The paper reports on the investigation and simulation about the influence on the Digital Down Conversion (DDC) output signal of (i) the Σ∆ modulator, (ii) the pipelined ADC architecture and (iii) some relevant non-idealities of their model such as the sampling jitter, thermal noise and finite gain of the operational amplifier. The investigation is performed in the case that the digital filters of the DDC are in accordance with the GSM mask.

Internal wave with a soliton-like, large amplitudes within several kilometers, is frequently observed in the sea surface caused by tidal rectification due to sill or rough topographic changes. Internal waves can perturb current and density field, initiate bottom sediment re-suspension and mix nutrients to photic zone. Previous studies indicate that the appearance of internal wave in the Lombok Strait have been detected in SAR image data. This paper studies effect of internal wave in the Lombok Strait on distribution of chlorophyll in the surrounded areas using SeaWiFS and ERS SAR images data during 1996-2001 period. The preliminary result concludes that the internal waves presumably affect chlorophyll distribution spreading southeastward in the coast off Bali Island.

The switching between channels when performing multi-channel data acquisition originates errors in the result of the analog to digital conversion due to the non-ideal behavior of multiplexers. Here we discuss the test methods required to quantify those errors, presenting the shortcomings of existing ones and proposing new testing procedures.

In this paper an extension of a previously developed and well-proven technique for the estimate of the INL of an ADC via spectral analysis methods is presented and discussed. Until now the authors applied this technique only to estimate the static INL, but further in-depth analyses show that it can be used to measure the ADC response to a sine wave even if the dynamic nonlinearity cannot be neglected (i.e. when the frequency of the input signal is higher than a given limit). To prove the validity of the method the authors compare their results with those obtained by the a time-consuming but certainly accurate method, i.e. direct comparison of the average of many output records with the input sine wave.