No abstract available

[en] A method of polarizing nuclei having a long relaxation time in a solid in a high dc magnetic field is described. The solid also contains nuclei having a short relaxation time. The method involves the step of applying a high dc magnetic field to the solid. Then the solid is swept with a radio frequency field which excites the nuclei with a short relaxation time; there results the polarization of the nuclei having a long relaxation time. 1 figure, 1 table

No abstract available

No abstract available

No abstract available

No abstract available

[en] Nanofiltration is a membrane separation pro where the driving force is the difference of pressure on both sides of the membrane. In membrane separation is input stream separated into permeate (the part of the mixture that passes through the membrane) and retentate (a portion of the mixture retained above the inlet surface of the membrane - concentrate). The model dye Acid blue 80 was selected for this work, which was removed from the aqueous solutions by nanofiltration. It is a blue anthraquinone dye used for dyeing wool and polyamide [1]. During experiments attention was paid to the dependences of permeate flow intensity per time with different concentrations and the overall dependence of the permeate flow on the pressure, from where we could find the ideal pressure for operation, whether rejection is sufficient and whether this process can be affected by pH. (authors)

[en] 1Abbreviations: cyt, cytochrome; cyt bL, low potential b cytochrome; cyt bH, high potential b cytochrome; DBMIB, 2,5-dibromo-3-methyl-6-isopropylbenzoquinone; DMSO, dimethylsulfoxide; DNP-INT, 2'-iodo-6-isopropyl-3-methyl-2',4,4'-trinitrodiphenylether; EPR, electron paramagnetic resonance; HEPES, n-(2-hydroxyethyl)piperazine-n'-(2-ethanesulfonic acid); NQNO, 2-nonyl-4-hydroxyquinoline n-oxide; ISP, iron-sulfur protein; MOA, E-b-methoxyacrylate; pmf, proton motive force; PC, plastocyanin; PQ, plastoquinone; PQH2, plastoquinol; PS, photosystem; Qi, quinol reductase; Qo, quinol oxidase; UHDBT, 5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole

[en] Past studies demonstrate that complexation will limit abiotic and biotic U(VI) reduction rates and the overall extent of reduction. However, the underlying basis for this behavior is not understood and presently unpredictable across species and ligand structure. The central tenets of these investigations are: (1) reduction of U(VI) follows the electron-transfer (ET) mechanism developed by Marcus; (2) the ET rate is the rate-limiting step in U(VI) reduction and is the step that is most affected by complexation; and (3) Marcus theory can be used to unify the apparently disparate U(VI) reduction rate data and as a computational tool to construct a predictive relationship

[en] In a unicellular cyanobacterium, the mobile fraction of phycobilisome (PBS) was found to be maximum at a particular redox value of Q_A (i.e., 0.52). An upward or downward shift in the redox value leads to a decrease in this mobile fraction of PBS. Furthermore, the regulatory effect of the redox state of Q_A on PBS mobility was found to be independent of the effect exerted by the plastoquinone pool. These findings indicate for the first time that PBS mobility is regulated by the Q_A redox state in cyanobacteria. A possible working mechanism underlying this control is discussed.