In this paper it was shown that pulsed electron irradiation forms in the surface layer of the Ni3Al intermetallic compound samples a columnar crystal structure oriented perpendicular to the ...irradiated surface. The dimensions of the crystals of the columnar structure and the depth of the surface layer modification depend on the power density and the duration of the irradiation pulses - with power density increasing, the dispersion of the columnar structure increases, with increasing duration of irradiation pulses, the depth of the surface layer structure modification increases. Modification of the surface layer structure improves the strength properties of Ni3Al intermetallic compound samples.
The aim of our study was to evaluate the clinical-anamnestic, serological, immunological and biochemical tests used for early diagnostics of gastric cancer associated with Helicobacter pylori ...infection in the adult population of the Krasnoyarsk Territory. Materials and methods. The control group consisted of 104 apparently healthy blood donors, the comparison group – 97 patients with chronic atrophic gastritis as well as a group of patients with early gastric cancer comprising 98 subjects. Assessment of monocyte and neutrophil spontaneous and induced chemiluminescence (CL) was carried out on a 36-channel biochemiluminometer BLM-3607. Phagocytosis was measured by using a Beckman Coulter FC 500 flow cytometer. A Varian Cary Eclipse spectrofluorometer was used to study lipid peroxidation and factors of the antioxidant defense system. Results and discussion. While studying the phagocytic arm of immunity, it was found that all patients with early gastric cancer were reported to have parameters of the maximum intensity for neutrophil spontaneous CL from 17 831 c.u. and lower, whereas induced CL reached at least 30 000 c.u. Phagocytic activity of neutrophilic granulocytes in patients with early gastric cancer was 36% or less. While studying the indicators of monocytes, it was found that spontaneous and induced CL decreased from 454 c.u. and 1186 c.u., respectively, in the patients with early gastric cancer. Monocytic activity in early gastric cancer was 34% or less. In the study of lipid peroxidation, an antioxidant defense in patients with chronic atrophic gastritis and gastric cancer had increased malondialdehyde (MDA) level. Patients with gastric cancer had decreased activity of the enzyme catalase (CAT), whereas subjects with chronic atrophic gastritis had reduced glutathione peroxidase (GPO) level. In contrast, patients with early gastric cancer were featured with increased GPO activity. We have proposed coefficients for assessing the factors of the antioxydant defence system in patients: the ratio for superoxide dismutase to catalase activity (SOD/CAT) as well as the ratio for superoxide dismutase to glutathione peroxidase activity (SOD/GPO). Conclusion. During the study, threshold values of parameters were obtained for assigning groups at high risk of developing early gastric cancer, which can be used for screening in adult population.
Event reconstruction in the RICH detector of the CBM experiment at FAIR Adamczewski, J.; Becker, K.-H.; Belogurov, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2014, Volume:
766
Journal Article
Peer reviewed
The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net-baryon densities and moderate temperatures. One of the key signatures ...will be di-leptons emitted from the hot and dense phase in heavy-ion collisions. Measuring di-electrons, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). In order to access the foreseen rare probes, the detector and the data acquisition have to handle interaction rates up to 10 MHz. Therefore, the development of fast and efficient event reconstruction algorithms is an important and challenging task in CBM. In this contribution event reconstruction and electron identification algorithms in the RICH detector are presented. So far they have been developed on simulated data but could already be tested on real data from a RICH prototype testbeam experiment at the CERN-PS. Efficient and fast ring recognition algorithms in the CBM-RICH are based on the Hough Transform method. Due to optical distortions of the rings, an ellipse fitting algorithm was elaborated to improve the ring radius resolution. An efficient algorithm based on the Artificial Neural Network was implemented for electron identification in RICH. All algorithms were significantly optimized to achieve maximum speed and minimum memory consumption.
Due to conceptual difference between geometry descriptions in Computer-Aided Design (CAD) systems and particle transport Monte Carlo (MC) codes direct conversion of detector geometry in either ...direction is not feasible. The paper presents an update on functionality and application practice of the CATIA-GDML geometry builder first introduced at CHEP2010. This set of CATIAv5 tools has been developed for building a MC optimized GEANT4/ROOT compatible geometry based on the existing CAD model. The model can be exported via Geometry Description Markup Language (GDML). The builder allows also import and visualization of GEANT4/ROOT geometries in CATIA. The structure of a GDML file, including replicated volumes, volume assemblies and variables, is mapped into a part specification tree. A dedicated file template, a wide range of primitives, tools for measurement and implicit calculation of parameters, different types of multiple volume instantiation, mirroring, positioning and quality check have been implemented. Several use cases are discussed.
The CBM experiment at the future FAIR facility will explore nuclear matter at high net-baryon densities. One of the key observables is di-leptons as they penetrate the created matter without further ...strong interactions. A gaseous RICH detector in a standard projective geometry using spherical mirrors is one of two detector elements for the required electron identification. The mirror system consists of about 72 trapezoidal mirror tiles. Any misalignment between the tiles relative to the nominal common spherical surface leads to reduction of the reconstruction efficiency of Cherenkov rings and deterioration of their resolution. To determine tolerances in mirror misalignment extensive simulation and measurement studies were carried out. Pure CO sub(2) will be used as radiator gas. Gas contamination, mainly moisture and Oxygen, reduces the number of detected photons per ring and worsens the quality of reconstructed Cherenkov rings. Therefore a study was carried out to determine tolerances in radiator gas contamination.
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