Hybrid R&D

We develop a model of R&D competition and collaborationin which individual firms carry out independent in-house researchand also undertake joint research projects with other firms. Weexamine the impact of collaboration on in-house research andexplore the circumstances under which a hybrid organization ofR&D which combines the two is optimal for firms andsociety. We find that investments in independent research and injoint research are complementary: an increase in the number ofjoint projects also increases in-house research. Firm profits arehighest under a hybrid organization if the number of firms issmall (less than 5) while they are highest with pure in-houseresearch if the number of firms is large (5 or more). However,social welfare is maximized under a hybrid organization of R&D inall cases. Our analysis also yields new results on the role ofcooperative R&D. We find that non-cooperative decision making byfirms leads to larger R&D investments and higher social welfarethan fully cooperative decision making. However, a hybrid form ofdecision making where there is bilateral cooperation in jointprojects and non-cooperative decision making in in-house researchyields the highest level of welfare in concentrated industries.

Search for β+\beta^+EC and ECEC processes in 112^{112}Sn

Limits on $\beta^+$EC (here EC denotes electron capture) and ECEC processes in $^{112}$Sn have been obtained using a 380 cm$^3$ HPGe detector and an external source consisting of 53.355 g enriched tin (94.32% of $^{112}$Sn). A limit with 90% C.L. on the $^{112}$Sn half-life of $4.7\times 10^{20}$ y for the ECEC(0$\nu$) transition to the $0^+_3$ excited state in $^{112}$Cd (1871.0 keV) has been established. This transition is discussed in the context of a possible enhancement of the decay rate by several orders of magnitude given that the ECEC$(0\nu)$ process is nearly degenerate with an excited state in the daughter nuclide. Prospects for investigating such a process in future experiments are discussed. The limits on other $\beta^+$EC and ECEC processes in $^{112}$Sn were obtained on the level of $(0.6-8.7)\times 10^{20}$ y at the 90% C.L.Comment: 14 pages, 4 figure

Effect of an electric field on superfluid helium scintillation produced by alpha-particle sources

We report a study of the intensity and time dependence of scintillation produced by weak alpha particle sources in superfluid helium in the presence of an electric field (0 - 45 kV/cm) in the temperature range of 0.2 K to 1.1 K at the saturated vapor pressure. Both the prompt and the delayed components of the scintillation exhibit a reduction in intensity with the application of an electric field. The reduction in the intensity of the prompt component is well approximated by a linear dependence on the electric field strength with a reduction of 15% at 45 kV/cm. When analyzed using the Kramers theory of columnar recombination, this electric field dependence leads to the conclusion that roughly 40% of the scintillation results from species formed from atoms originally promoted to excited states and 60% from excimers created by ionization and subsequent recombination with the charges initially having a cylindrical Gaussian distribution about the alpha track of 60 nm radius. The intensity of the delayed component of the scintillation has a stronger dependence on the electric field strength and on temperature. The implications of these data on the mechanisms affecting scintillation in liquid helium are discussed.Comment: 17 pages, 23 figure

The Role of Plastic Flow in Processes of High-speed Sintering of Ceramic Materials under Pressure

A model to describe the kinetics of the compaction of conductive nitride ceramics using electropulse technologies is developed. The relationship between density and pressure is established on the basis of three components of the geometric, plastic and stressed state, which is affects the contact area between the particles. The model takes into account the change in the relative area of the interpartial contacts under the action oftwo mechanisms of mass transfer-diffusion and plastic flow. It is shown that a decrease in the particle size of the powder leads to an in-crease in the diffusion contribution and a decrease in the plastic flow, at all other conditions being equal. And for the case of nano-sized particles, diffusion mass transfer is predominant.Increasing in the heating rate leads to a decrease in the contribution of dif-fusion mass transfer at equal temperatures, as well as to an increase in the temperature of the beginning of shrinkage.The processes of plasma-plasma sintering, high-voltage electro-pulsed consolidation and hot pressing control the same mechanisms, plastic flow and diffusion mass transfer, which do not require, in the first approximation, the influence of the electric current on the properties of materials. Keywords: spark-plasma sintering, high-voltage electrodischarge consolidation, sintering kinetic

Evaluation of detoxication arsenic salt solution by humates by biotesting

We investigated, toxicity and detoxification of model solutions of arsenic salts (Na3AsO4) by biotesting. Decreasing the toxicity of arsenic using humic substances («Powhumus», «Lignohumate», and «Humate-80») is shown. The possibility of use of humic substances to detoxify arsenic contamination, in model experiments is studied. To study the possibility of detoxification model contamination by salt of arsenic we used humic substances Powhumus (humate from leonardite «Humintech Ltd», Germany), Humate-80 (potassium, humate LLC «Agricultural Technology») and. Lignohumate (potassium, humate «SPA «RET»). As test objects seeds of Lepidium. sativum. L. (JSC «Irkutsk seeds») and. algae (Scenedesmus quadricauda (Turp.) Breb.) were taken. Toxicity was evaluated by effect on seed germination and. root length of L. sativum, the change in intensity of chlorophyll fluorescence of algae cells S. quadricauda. The significance of differences was determined, by Student's test. The table shows the mean values and. standard deviations for p > 0,95. Sodium arsenite at a concentration, of 8 mg/cdm inhibited seed germination of cress to 70,1 ± 6,9 %. The content of 9 mg/cdm. Na3AsO4 reduced, the number of germinated seeds to 75,1 ± 6,6 %. LC50 for this method was equal 5,7 mg/cdm. In applying the HS in a concentration, of 0,2 g/cdm a decrease toxicity of sodium arsenite to 25,3 ± 2,7 % was observed. The most effective model in reducing the toxicity of arsenic contamination was observed at a concentration of Powhumus 1,0 g/dm3 - the number of germinated, seeds was 90,1 ± 8,7 %. The next stage was the bioassay using the registration reducing chlorophyll fluorescence of algae cells S. quadricauda. Value of LC50 for this method was 1,5 mg/cdm. The concentration of sodium arsenite 1,8 and 1,5 mg/ cdm suppressed, levels of chlorophyll fluorescence by more than 30 % (the level of chlorophyll fluorescence was 26,4 ± 3,2 % and. 54,5 ± 6,1 % respectively). Powhumus in concentration of 0,05 g/cdm reduced toxicity of samples for 36,7 ± 3,9 % and. 31,8 ± 3,4 %, respectively. Bioassay method of changing the intensity of chlorophyll fluorescence of cells of algae S. quadricauda showed greater sensitivity and. speed of the response than the method of assessing the impact on seed, germination. and seedling root length of L. sativum

Hybrid R&D

We develop a model of R&D competition and collaboration in which individual firms carry out independent in-house research and also undertake joint research projects with other firms. We examine the impact of collaboration on in-house research and explore the circumstances under which a hybrid organization of R&D which combines the two is optimal for firms and society. We find that investments in independent research and in joint research are complementary. Firm profits are highest under a hybrid organization if the number of firms is small; otherwise they are highest with pure in-house research. However, social welfare is maximized under a hybrid organization of R&D in all cases. Our analysis also yields new results on the role of cooperative R&D. Non-cooperative firm decision making leads to more R&D and higher social welfare than fully cooperative decision making. However, bilateral cooperation in joint projects and non-cooperative decision making in in-house research yields the highest level of welfare in concentrated industries