A pulsed dipole magnet made from a hollow composite superconductor with a circulatory refrigeration system

When a superconducting dipole magnetic field is limited by a value of about 2.5 T using a ‘window frame’ type dipole, the design of such a magnet can be essentially simplified, and the superconducting winding volume can be decreased. If the winding is made of hollow composite superconductor, the cryostat construction is simplified and it is easy to handle with superconducting magnets.In order to estimate the prospects of using ‘window frame’ type dipole magnets with a circulatory refrigeration system for the Nuclotron Accelerator project, a dipole magnet with a length of about 0.4 m, a 5.5 cm aperture and a magnetic field of up to 2.5 T has been constructed and tested at the High Energy Laboratory, JINR. The superconducting cable of the magnet consists of a cupro-nickel pipe with an outer diameter of 5 mm and a wall thickness of 0.5 mm on which multifilament superconductors are cabled. The magnet construction with a two-phase helium circulating refrigeration system is described. The dependences are presented of the critical current degradation and of ac losses on the magnetic field inhomogeneity and hydraulic resistance.     

Nonisothermal flow of a non-Newtonian fluid in the slowly converging channel of a belt worm-conveyor pump under conditions of complex shear

The flow of an anomalously viscous fluid with an exponential rheological equation in the converging channel of the screw of a belt worm-conveyor pump is examined taking into account the circulatory flow of the fluid, the dissipation of mechanical energy, and the exchange of heat with the environment.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 6, pp. 1040–1046, June, 1976.     

Effect of carbohydrate load on the structuro-functional organization of cell membranes in patients with hypertension

Carbohydrate load induces in patients with essential hypertension reduction of the phospholipid fraction in the system blood plasma--surface-deep phospholipid pool of erythrocytic membranes, and the lowering of the levels of polyenic and dienic fatty acids.     

Dynamic kinetic capillary isoelectric focusing: a powerful tool for studying protein-DNA interactions

A new method called dynamic kinetic capillary isoelectric focusing (DK-CIEF) is presented for the study of protein-DNA interactions. The method is based on CIEF with laser-induced fluorescence-whole column imaging detection in which protein-DNA complexes are separated with spatial resolution while dissociations of the complexes are dynamically monitored using a CCD camera with temporal resolution. This method allows for the discrimination of different complexes and the measurement of the individual dissociation rate constants.     

Exhaustive removal of thorium and uranium traces from neodymium by liquid extraction

The Th content in commercially available Nd₂O₃ samples with the main substance content of 99.0–99.998% was found to be 2–8, and that of U, 3–230 ppb. Therefore, to obtain Nd meeting the requirements of the experiment on studying neutrinoless double β-decay, it should be purified to reduce the content of Th and U impurities by a factor of 10³–10⁴. To this end, the extraction of Nd, Th, and U from hydrochloric acid media with solutions of trioctylphosphine oxide (TOPO) in toluene was studied. The distribution ratios of Th increase with a decrease in the HCl concentration in the initial aqueous solution. With an increase in the Cl^? concentration in the aqueous phase, the U distribution ratios decrease, probably because of a decrease in the concentration of the free extractant due to the extraction of Nd and HCl. On the contrary, the distribution ratios of Th increase with an increase in the Cl^? concentration in the aqueous phase, with the slope of the straight line in the coordinates logD _Th-log[Cl^?]_aq close to 7, which may be due to coextraction of Th with Nd in the form of the complex ThNdCl₇. The enthalpies of formation of the extractable complexes of Th and U were determined from the temperature dependence of the extraction of Nd, Th, and U chlorides with a 0.1 M solution of TOPO in toluene. The optimal extraction system was chosen for Nd purification to remove traces of Th and U: organic phase, 0.1 M solution of TOPO in toluene; aqueous phase, 2.4 M NdCl₃ + 0.1 M HCl. From the initial aqueous solution contaning 574 ppt Th and 2837 ppt U, by single extraction with an equal volume of 0.1 M TOPO in toluene, an aqueous solution containing <10 ppt Th and 31 ppt U (detection limit 10 ppt) was obtained. By semicountercurrent extraction, from the initial aqueous NdCl3 solution containing 200 ppb Th, the raffinate containing <10 ppt Th was obtained in one extraction step. The results obtained confirm the possibility of exhaustive removal of Th and U impurities (to the level of ≤1 ppt) from Nd by extraction with TOPO solutions from chloride solutions.