Source of polarised deuterons

The proposed project assumes the development of a universal high-intensity source of polarized deuterons (protons) using a charge-exchange plasma ionizer. The design output current of the source will be up to 10mA for ↑ D⁺(↑ H⁺) and polarization will be up to 90% of the maximal vector (±1) and tensor (+1,−2) polarization. The project is based on the equipment which was supplied within the framework of an agreement between JINR and IUCF (Bloomington, USA). The project will be realized in close cooperation with INR (Moscow, Russia). The source will be installed in the linac hall (LU-20) and polarization of beams will be measured at the output of LU-20. The main purpose of the project is to increase the intensity of the accelerated polarized beams at the JINR Accelerator Complex up to 10¹⁰ d/pulse. Calculations and first accelerator runs have shown that the depolarization resonances are absent for the deuteron beam in the entire energy range of the NUCLOTRON. The source could be transformed into a source of polarized negative ions if necessary. The period of reliable operation without participation of the personnel should be within 1000 hours. The project should be implemented within two to two and a half years from the start of funding.     

The stress-related production of the activePhotinus pyralis and luciolaMingrelica firefly luciferases inEscherichia coli

The kinetics ofPhotinus pyralis andLuciola mingrelica luciferase gene expression was studied on plasmids with the thermoinducible λP_r promoter inEscherichia coli by SDS-gel electrophoresis of cell lysates to follow luciferase protein-synthesized, enzyme immunoassay (EIA) to follow native enzyme conformer, and the luciferase activity assay.E. coli cells were cultivated at temperature schemes 28–42–21°C or 28–21°C, or at alkali pH shift. In the cases of thermoinduction and pH shift, the luciferase expressions have similar features. The 3-h thermoinduction (42°C) followed by the incubation at 21°C, for 10 h resulted in the maximal amount of the luciferase protein of 4–5% of the total cell proteins. The yield did not change further. The amount of native luciferase conformer and the luciferase activity started to grow after incubation for 10 h at 21°C and reached the maximum after 50–60 h when the synthesized luciferase protein adopted the native-like conformation. At the same time, only 50% of the latter appeared to be catalytically active. An increase in the enzymatic activity correlates with an increase in the intracellular pH and ATP content. Intracellular metabolic reactions were shown to play a role in the conformational changes of the enzyme in a postthermoinduction period, and a possible mechanism of this effect is proposed.     

A Cell for Measuring Shear Strength of Powdered Disperse Systems

The design of a cell is described for shear thixotrometers allowing to measure the shear strength of powdered materials under compression loads of up to 1 MPa.     

Status of the polarized ions source for the JINR accelerator complex

The project assumes the design and construction of a universal high-intensity source of polarized deuterons (protons) using a charge-exchange plasma ionizer. The output D ⁺↑ (H ⁺↑) current of the source is expected to be at a level of 10 mA. The polarization will be up to 90% of the maximal vector (±1) for D ⁺↑ (H ⁺↑) and tensor (+1, ?2) for D ⁺↑ polarization. Realization of the project is carried out in close cooperation with INR of the RAS (Moscow). The equipment available from the CIPIOS ion source (IUCF, Bloomington, USA) is partially used for the Dubna setup. The new source at the JINR Nuclotron accelerator facility will make it possible to increase the polarized deuteron beam intensity up to the level of 10¹⁰ d/pulse. The first results of the source of polarized atoms testing are presented.     

Synthesis of 6‐Aminopropyl‐6H‐indolo[2,3‐b]quinoxaline Derivatives

A series of 6‐(3‐aminopropyl)‐6H‐indolo[2,3‐b]quinoxalines were synthesized with high yields by the reaction of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline and corresponding amines in presence of tetrabutylammonium iodide in boiling toluene or dimethylformamide at room temperature. It was found that boiling of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline in acetone with sodium iodide or in acetic acid lead to intramolecular cyclization product.     

High‐temperature mass spectrometric study of the vaporization processes of V2O3 and vanadium‐containing slags

A Knudsen effusion mass spectrometric method was used to study the vaporization processes and thermodynamic properties of pure V₂O₃ and 14 samples of vanadium‐containing slags in the CaO‐MgO‐Al₂O₃‐SiO₂ system in the temperature range 1875–2625 K. The system was calibrated using gold in the liquid state as the standard. Vaporization was carried out from double tungsten effusion cells. First it was shown that, in vapor over V₂O₃ and the vanadium‐containing slags in the temperature range 1875–2100 K, the following vapor species were present: VO₂, VO, O, WO₃ and WO₂, with the latter two species being formed as a result of interaction with the tungsten crucibles. The temperature dependencies of the partial pressures of these vapor species were obtained over V₂O₃ and the slags. The ion current comparison method was used for the determination of the V₂O₃ activities in slags as a function of temperature with solid V₂O₃ as a reference state. The V₂O₃ activity coefficients in the slags under investigation indicated positive deviations from ideality at 1900 K and a tendency to ideal behavior at 2100 K. It was shown that the V₂O₃ activity as a function of the slag basicity decreased at 1900 K and 2000 K and was practically constant in the slag melts at 2100 K. The results are expected to be valuable in the optimization of slag composition in high‐alloy steelmaking processes as well as for their environmental implications. Copyright © 2010 John Wiley & Sons, Ltd.     

Variation of the reactivity of flax fiber cellulose in the course of flax ripening

Carboxymethyl cellulose ethers were prepared from flax fibers of various degrees of ripeness. The influence exerted by the degree of ripeness of flax fibers on their reactivity in carboxymethylation was examined. The rheological properties of aqueous solutions of the synthesized carboxymethyl cellulose were studied.     

1-chloroacetyloxindole(isatin) in reactions with some <Emphasis Type="Italic">N</Emphasis>-nucleophiles. Unexpetedly easy cleavage of chloroacetyl group

Reactions of 1-chloroacetyloxindole and 1-chloroacetylisatin with some secondary amines, Girard’s reagent T and thiourea were studied. All investigated reactions proceeded via cleavage of the acyl group to form 3-substituted isatin or oxindole derivatives.