A Gas Scintillation Proportional Counter for the X-Ray Astronomy Satellite SAX

A driftless gas scintillation proportional counter is described. The instrument has several advantages over conventional GSPCs especially for applications at low x-ray energies (~0.l - 30 keV) and small dimensions such as imaging focal plane detectors for x-ray telescopes or concentrators. The x-ray astronomy satellite project SAX has such a requirement and an imaging GSPC of this configuration is presented in this context.     

A simple and novel method for measuring the chirp parameter of anintensity modulated light source

A new and simple method of measuring the chirp parameter α of a modulated light source is presented. The technique involves modulating the optical source in a particular manner, and then directly examining the resulting optical spectrum. This experimental measurement technique allows us to directly measure the phase of the optical signal in the frequency domain. In addition, the method is very easy and accurate. Experimental results demonstrate the use of this measurement technique for measuring the chirp parameter of a source modulated at 10 GHz     

The influence of the concentration of the quench gas on the count rate effect in proportional counters

The count rate dependent shift of pulse height in cylindrical proportional counters has been measured for Kr/iso-pentane, and Kr/cyclohexane mixtures. The effect of various concentrations of quench vapour on this shift has been investigated. A very rapid decrease of this shift has been found for a concentration of the admixture c ～ 1.5% in comparison with a smaller concentration. The theoretical explanation for this dependence is also presented.     

Ultrasonic-Assisted Osmotic Dehydration of Carrot Followed by Convective Drying with Continuous and Intermittent Heating

The aim of the studies was to analyze the effect of ultrasound action on osmotic pretreatment and then on drying kinetics in continuous and intermittent drying conditions, and on the final product quality. This article presents the results of intermittent-convective drying of carrot preceded by ultrasonic assisted osmotic dehydration in fructose aqueous solutions. The theoretical drying kinetics developed from the numerical solution of mathematical model is validated using the experimental data. It has been shown that combination of ultrasonic assisted osmosis with intermittent-convective drying accelerates the drying process and improves the quality of dried biomaterial. A good adherence of the numerically determined kinetic curves confirms the usefulness of the presented model and its possible application to construction of controlled and optimized drying processes.     

US-Assisted Convective Drying of Biological Materials

The aim of this work is to promote ultrasound as an energy source that is suitable for the enhancement of drying processes, and in particular of biological materials. The study aims at a more profound recognition of the interaction between ultrasonic (US) waves and the tissues of fruits and vegetables, which may contribute to an intensification of moisture removal during their drying. Absorption of acoustic energy causes heating and structural changes of the drying material due to a series of rapid material compressions and decompressions. The research hypothesis is based on the expectation that the ultrasound waves may enhance moisture removal from the fruits and vegetables during drying due to a special “heating effect,” “vibration effect,” and “synergistic effect.” Convective ultrasonic-assisted drying tests were conducted experimentally on a new hybrid dryer with ultrasonic equipment, and the effects of ultrasonic enhancement by drying are presented based on a drying model and assessed numerically.     

Is rumen development in newborn calves affected by different liquid feeds and small intestine development?

The objective of the study was to determine the effect of different liquid feeds on calf small intestine and rumen development. Twenty-one bull calves (5 ± 1 d old) were randomly allocated to 3 groups and fed whole milk (WM), milk replacer (MR; 22% CP and 17.5% fat), or MR supplemented with sodium butyrate (MR+SB; 0.3% as fed). Liquid feed dry matter intake was equal between treatments and amounted to 1% of BW at the beginning of the trial. Starter diet was offered ad libitum. Animals were slaughtered at 26 (±1) d of age. Calves fed WM had higher average daily gain in the whole trial and higher starter diet dry matter intake between d 15 to 21 of the trial as compared with calves fed MR and MR+SB. Calves fed MR lost on average 1.4 kg of BW within first 14 d of the trial and their BW tended to be lower at d 7, 14, and 21 of the study as compared with calves fed MR+SB. The empty jejunum and ileum weight, crypt depth, mitotic index in the middle jejunum were higher, and apoptotic index tended to be lower in calves fed WM as compared with calves fed MR and MR+SB. Calves fed WM also had higher aminopeptidase N activity in the middle jejunum and tended to have higher maltase activity in the distal jejunum as compared with calves fed MR and MR+SB. The mitotic index was higher and apoptotic index was lower in the middle jejunum, and aminopeptidase A activity tended to be higher in the distal jejunum of calves fed MR+SB as compared with those fed MR. Calves fed WM had greater papillae length and width, and tended to have greater muscle layer thickness as compared with calves fed MR and MR+SB. Reticulorumen weight, reticulorumen weight expressed as percent of whole stomach weight, and papillae length and width were higher in calves fed MR+SB as compared with those fed MR. Additionally, calves fed WM had higher plasma glucose and urea in the whole trial period as compared with calves fed MR and MR+SB, and plasma glucose was higher in calves fed MR+SB as compared with those fed MR. Significant positive Pearson correlations were found between small intestine and reticulorumen weights as well as between activity of brush border lactase, maltase, aminopeptidase A, and aminopeptidase N and reticulorumen weight. Different liquid feeds affect small intestine development, animal growth, solid feed intake and metabolic status of calves and this effect can indirectly influence the development of forestomachs.