The ZnxCd1-xTe films with x = 0 ÷ 0.97 are grown by vacuum deposition in quasiequilibrium conditions on single crystal Si (111) substrates. The details of the growth process were analyzed. The ...possibilities of the quasi-closed volume method for producing high quality homogeneous layers of solid solutions were evaluated. It is shown that this method is very effective for the production of films with x < 0.1 and may be implemented at condensation temperatures up to ∼ 300°C. Studies of electrical and photovoltaic properties showed high quality of ZnxCd1-xTe layers and structures in general. This is, in particular, evidenced by increasing photosensitivity in the region of absorption of the film material, and of the structure as a whole, increasing integral sensitivity with zinc doping, a significant reduction in nonideality factor in solid solution films as compared with CdTe films. We have established an increase of mechanical stability of the structure with increasing Zn content, expressed in maintaining the strength during repeated thermal cycling. As a result, the manufactured Si ZnxCd1-xTe heterostructures can serve as a basis for fabrication of multijunction solar energy converters.
The Gigaton Volume Detector in Lake Baikal Avrorin, A.; Aynutdinov, V.; Belolaptikov, I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
639, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The objective of the Baikal Project is the creation of a kilometer-scale high-energy neutrino observatory: the Gigaton Volume Detector (GVD) in Lake Baikal. Basic elements of the GVD – new optical ...modules, FADC readout units, and underwater communication systems – were investigated and tested in Lake Baikal with prototype strings in 2008–2010. We describe the results of prototype strings operation and review the preliminary design and expected sensitivity of the GVD telescope.
The Baikal neutrino experiment Avrorin, A.; Aynutdinov, V.; Balkanov, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2011, Letnik:
626
Journal Article
Recenzirano
Odprti dostop
We review the status of the Lake Baikal Neutrino Experiment. Preparation towards a km
3-scale Gigaton Volume Detector (GVD) in Lake Baikal is currently a central activity. As an important milestone, ...a km
3-prototype string comprising of 12 optical modules and based on a completely new technology, has been installed and was put in operation together with NT200+ in April, 2009. We also present recent results from the long-term operation of NT200, including an improved limit on the diffuse astrophysical neutrino flux.
The operation of large underwater neutrino telescopes requires the precise knowledge of the water parameters governing light absorption and scattering, as well as a continuous monitoring of these ...parameters. For this purpose, a stationary underwater device, ASP-15, has been developed by the Baikal collaboration. We describe the basic assumptions and formulae behind ASP-15, the methods how absorption length, scattering length and phase functions are determined, the design of the device, and give some results obtained over many years of operation in conjuction with the Baikal telescope NT200.
The work is devoted to the computing unite of a mobile computer vision system and developing his algorithmic software. We developed hardware-implemented the convolutional neural networks on a field ...programmable gate array. A study of the performance and power consumption of variants of the computing unite.
Excessive amounts of heavy metals (e.g. Zn, Cu, Mn, Cr) are accumulated in river bottom sediments (RBS), being available to humans and animals along food chains. Increased exposure of mammals to ...certain metals (Cr, Cu) induces immunosuppresion, due to DNA damage and decreased survival of lymphoid cells. By contrast, excess of Zn and Cd causes inhibition of apoptosis thus suggesting increased survival of genetically mutated cells and higher cancer risks in exposed populations. Rat thymic lymphocytes represent a well-established model for apoptosis testing. The primary goal of our study was to assess the degree of apoptosis modulation with a number of RBS extracts differing in their metal contents. A series of freshly deposited RBS was collected at nine sampling stations along the Elbe River. All sediments were rich in Fe, Mn and Zn. The contents of Cu, Cr, Ni, Cd, Hg, Pb and As were much lower and interrelated. The short-term cytotoxicity of aqueous sediment extracts was assessed, using the following criteria: total cell counts; incidence of apoptosis and necrosis (morphological detection by fluorescent microscopy); and nuclear chromatin decay (by DNA flow cytometry). RBS extracts produced both apoptosis and necrosis of thymocytes. High contents of zinc and other heavy metals in the samples correlated with decreased thymocyte apoptosis (
r=−0.543 to −0.608,
P<0.01). The rates of thymocyte damage showed a distinct dependence on the time and region of sampling. Apoptosis modulation was also tested with pure salts of Mn(II), Zn(II), Cu(II), Cr(III) and Cd(II), at the test concentrations of 1, 10 and 100 μM. Cu(II) and Cr(III) proved to induce marked dose-related apoptosis, whereas Zn(II) ions caused significant suppression of apoptosis. These effects were similar to those trends observed with metal-rich sediments. In the present study, DNA flow cytometry proved to be a less sensitive index of cell death than morphological assay of apoptosis and/or necrosis. In summary, inhibition of lymphocyte apoptosis by RBS extracts and pure metals is associated with excess of zinc and, probably, cadmium. The proposed model of lymphoid cell apoptosis is a promising tool for screening cytotoxic effects of complex environmental samples.
The Zn x Cd1-x Te films with x = 0 ÷ 0.97 are grown by vacuum deposition in quasiequilibrium conditions on single crystal Si (111) substrates. The details of the growth process were analyzed. The ...possibilities of the quasi-closed volume method for producing high quality homogeneous layers of solid solutions were evaluated. It is shown that this method is very effective for the production of films with x < 0.1 and may be implemented at condensation temperatures up to ∼ 300°C. Studies of electrical and photovoltaic properties showed high quality of Zn x Cd1-x Te layers and structures in general. This is, in particular, evidenced by increasing photosensitivity in the region of absorption of the film material, and of the structure as a whole, increasing integral sensitivity with zinc doping, a significant reduction in nonideality factor in solid solution films as compared with CdTe films. We have established an increase of mechanical stability of the structure with increasing Zn content, expressed in maintaining the strength during repeated thermal cycling. As a result, the manufactured Si/Zn x Cd1-x Te heterostructures can serve as a basis for fabrication of multijunction solar energy converters.
PDF
