Verification of electromagnetic calorimeter concept for the HADES spectrometer

The HADES spectrometer currently operating on the beam of SIS18 accelerator in GSI will be moved to a new position in the CBM cave of the future FAIR complex. Electromagnetic calorimeter (ECAL) will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 A GeVon the beam of the new accelerator SIS100. Calorimeter will be based on 978 massive lead glass modules read out by photomultipliers and a novel front-end electronics. Secondary gamma beam with energies ranging from 81 MeV up to 1399 MeV from MAMI-C Mainz facility was used to verify selected technical solutions. Relative energy resolution was measured using modules with three different types of photomultipliers. Two types of developed front-end electronics as well as energy leakage between neighbouring modules under parallel and declined gamma beams were studied in detail

The effects of cow genetic group on the density of raw whole milk

peer reviewedThe density of milk is dependent upon various factors including temperature, processing conditions, and animal breed. This study evaluated the effect of different cow genetic groups, Jersey, elite Holstein Friesians (EHF), and national average Holstein Friesians (NAHF) on the compositional and physicochemical properties of milk. Approximately 1,040 representative (morning and evening) milk samples (~115 per month during 9 mo) were collected once every 2 wk. Milk composition was determined with a Bentley Dairyspec instrument. Data were analysed with a mixed linear model that included the fixed effects of sampling month, genetic group, interaction between month and genetic group and the random effects of cow to account for repeated measures on the same animal. Milk density was determined using three different analytical approaches – a portable and a standard desktop density meter and 100 cm3 calibrated glass pycnometers. Milk density was analysed with the same mixed model as for milk composition but including the analytical method as a fixed effect. Jersey cows had the greatest mean for fat content (5.69 ± 0.13%), followed by EHF (4.81 ± 0.16%) and NAHF (4.30 ± 0.15%). Milk density was significantly higher (1.0313 g/cm³ ± 0.00026, P < 0.05) for the milk of Jersey breed when compared to the EHF (1.0304 ± 0.00026 g/cm³) and NAHF (1.0303 ± 0.00024 g/cm³) genetic groups. The results from this study can be used by farmers and dairy processors alike to enhance accuracy when calculating the quantity and value of milk solids depending upon the genetic merit of the animal/herd, and may also improve milk payment systems through relating milk solids content and density

Interaction of laser beam with rocks

Interaction between laser beam and rocks was studied. Two types of laser beam was used in experiment. Continuous laser with high power and pulsing laser with low power

The model of product distortion in AWJ cutting

V článku uvedeno Libor M. HlaváčThe abrasive water jet (AWJ) retardation inside the cut material, the characteristic phenomenon of the AWJ cutting, causes declination of the kerf sidewalls especially in corners and curvatures. This paper is aimed at a description of the origin of these negative consequences of jet retardation. The model for calculation of the limit traverse speed from both the jet parameters and material properties has been derived using laws of conservation. The equation expressing dependence of the angle between the tangent to the striation curve and the impinging jet axis on the depth of jet penetration into material has been used for evaluation of the product distortion in the cutting process. Proposed model has been applied for setting up the tilting angle of the cutting head during the AWJ cutting process to reduce the product shape distortion. The model was supplemented by geometrical analysis of curved parts of cut trajectories. The resulting equation makes possible to calculate the shift of the jet trajectory at the outlet side of the workpiece from its regular position determined by projection of the trajectory at the inlet side of the workpiece along the jet axis. The model is capable to determine the appropriate tilting angles of the cutting head for compensation of the jet retardation and the taper. The experimental data measured on metal samples seem to be in a good accordance with the proposed model.Web of Science621-416615

Study of anthranilate cyclisation to 2-hydroxymethyl-2,3- dihydroquinazolin-4(1H)-ones and an alternative synthetic route

Applicability of the previously described rearrangement of 2-oxo-2-phenylethyl 2-amino-benzoate leading to 2-phenyl-2-hydroxymethyl-2,3-dihydroquinazolin-4(1H)-one has been studied. To test the limits of the reaction, various starting compounds such as 2-oxopropyl 2-aminobenzoate, 2-oxo-2-phenylethyl 2-aminobenzoate and 3,3-dimethyl-2-oxobutyl 2- aminobenzoate as well as some of their corresponding N-methyl and N-phenyl analogues were used. The structure-reactivity dependence was observed giving the expected products only in specific cases and in limited yields. Structure of the dihydroquinazolin-4(1H)-one skeleton was unambiguously confirmed with use of X-ray analysis of two selected compounds. Finally, an alternative way for the preparation of the desired derivatives was developed