Comment and discussion on digital processing of PD pulses

Some of the more salient aspects of the digital processing technology of PD signals are examined. Most of the efforts in this field are concentrated on the application of digital analyzers for pulse height analysis, pattern recognition and identification of the physical phenomena. It is demonstrated that errors in the signal processing unit can lead to dominant mistakes in the interpretation of the test results     

Modeling of Diffusion in Capillary Porous Materials During the Drying Process

This paper presents a model of heterogenous diffusion in capillary porous materials during the process of drying. The governing heat and mass transfer equations have been established using the liquid as well as vapor flow. Two models have been presented. Model 1 does not consider the heat conduction while the model 2 has been established by considering the conduction. The developed models and the numerical solutions of the resulting differential equations can take into account the moisture and temperature dependent thermophysical properties of the product. All equations have been established in spherical coordinates but the programme written for the purpose of calculations can be used for other geometries also. Numerical calculations have been performed for gas concrete and tiles using model 1, while model 2 has been used for gas concrete only because of the lack of data for thermophysical properties of the tile. For gas concrete it was seen that conduction has only marginal effect on the drying process and the numerical predictions of the drying process were reasonably accurate.     

The effects of growth hormone in children with a GH deficiency: a report of 5 cases

The authors describe 5 cases, 3 boys and 2 girls, with idiopathic growth hormone deficiency in prepubertal age, treated with human growth hormone. In four of five cases the response to treatment with GH was relevant. Only in one case (F1) the response was negative. The results of this study confirm that rhGH is a safe and effective therapy in children with GHD.     

New method for assessing the global quality of energy systems

Comparisons of various energy systems are often made from partial, limited standpoints that do not take into due consideration the numerous factors involved in such systems. A more complete assessment of the global quality of energy systems must consider a wider range of characteristics, such as: conversion and transportation yields, energy potential, added value, risk of accidents during conversion and transportation, coefficients of transportability and storability, and polluting emissions (carbon monoxide, carbon dioxide, sulphur and nitrogen oxides, unburnt hydrocarbons, dust, radionuclides and dispersed heat).

This paper not only identifies and quantifies the parameters that allow the above qualities to be expressed, but also defines a tree-structured energy-quality index system which starts from the parameters identified and makes it possible to obtain a global summary index, through various intermediate levels of aggregation.

Our objective is to make an instrument available to professionals (engineers, policymakers and energy managers) which allows them to concentrate their attention each time, according to the specific needs in question, on particular aspects of the quality of the energy, or to obtain numerical indicators that briefly express quality in the broadest sense.

In addition, a sample application of the proposed method is presented, using data gathered mainly from the literature on alternative systems for power production and space heating by fossil fuels.     

Behavior of a vibrating wire near the liquid3He-vacuum interface and in a saturated3He-4He mixture

In this paper we describe the effect of the vicinity of a liquid³He-vacuum interface on the behavior of a vibrating wire viscometer. It was found that in the fluid near the liquid interface the quality factor is lower than in the bulk liquid. We further report on the observation of a doubling of the resonance peak of the wire in a saturated³He-⁴He mixture. The frequencies and amplitudes of the two peaks strongly depend on the distance between the phase boundary and the vibrating wire; the temperature and the velocity of the phase boundary have no significant influence on the peak frequencies. The observed peak doubling is attributed to the coupling of the vibrating wire with a standing second-sound wave in the dilute phase where the volume of the dilute phase can be regarded as a resonating cavity for second sound.     

Study of photosensitive mixtures of TMAE and helium, hydrocarbon or CF4-based carrier gases

Among the photocathodes used for particle identification based on the Cherenkov Ring Imaging technique, the TMAE molecule is still the best in terms of quantum efficiency. Despite the fact that TMAE gaseous photocathodes have already been used in a number of large experiments, one still seeks answers to many detailed questions. We present a systematic study of gaseous photocathodes based on TMAE mixed with helium, hydrocarbon and CF₄-based gases at normal pressure. The study includes a measurement of the electron drift velocity, gas quenching properties, single electron pulse height spectra and anode wire aging. The paper makes recommendations for carrier gas mixtures to obtain the best quenching, and suggests how to manage TMAE wire aging. This study was motivated by a specific particle identification detector proposal, the Fast Drift CRID proposed for the B-factory at SLAC.     

Cervical lymph nodes metastases from a pituitary carcinoma

Ipratropium bromide is a synthetic derivative of atropine with little absorption when used in inhalation, and therefore little secondary effects. The authors review its pharmacological properties and therapeutic efficacy in the treatment of asthma in children. Combined nebulized inhalation of ipratropium bromide and beta 2 sympathomimetic results in a more efficient and more sustained bronchodilatation than beta 2 sympathicomimetic alone in the treatment of acute asthma in children. Ipratropium bromide should be usefully introduced in the therapeutic scheme of acute asthma in children. Further studies will be necessary in order to determine its efficacy and tolerance in infants.