Spectrophotometric Studies on the Vanadium(V)-Chelates with N-Arylhydroxamic Acids. A Superior Method for the Extraction and Spectrophotometric Determination of Vanadium in Steels

The reaction of 18 N-arylhydroxamic acids ·with V{V) in different acidities and under varying experimental conditions have been investigated. In concentrated HCl an intensely violet chelate of V(V), which is readily extracted into chloroform, is formed. The substitution in the hydroxamic acid functional grouping affects the hue and spectral characteristics of the V(V)-chelates. It is inferred that N-p-Cl-phenyl-p-methoxybenzohydroxamic acid retains all the useful features of N-phenylbenzohydroxamic acid as a reagent for V(V) but surpasses it in sensitivity and selectivity of the reaction. With this quick method vanadium has been determined in analysed steels without the recourse of masking agents or prior separations. The excellent results obtained on these samples are taken as a proof of the reliability, precision and accuracy of the method

Far Infrared Observations of the Galactic Star Forming Regions associated with IRAS 00338+6312 and RAFGL 5111

Two Galactic star forming regions, one in a very early phase of evolution and another evolved one, associated with the IRAS sources 00338+6312 and 03595+5110 (RAFGL 5111) respectively have been studied in detail. These sources have been mapped simultaneously in two far infrared bands at 143 & 185 \micron), with about 1.5 arcmin angular resolution, using the TIFR 100 cm balloon borne telescope. The HIRES processed IRAS maps at 12, 25, 60 & 100 \micron, have been used for comparison. Whereas IRAS 00338+6312 is resolved only in the TIFR bands, RAFGL 5111 is very well resolved in both the TIFR bands, as well as in at least 3 IRAS bands. The neighbouring fainter source IRAS 04004+5114 has also been resolved in the TIFR bands. Taking advantage of the identical beams in the two TIFR bands at 143 & 185 \micron, dust colour temperature, $T(143/185)$, and optical depth, $\tau_{150}$, maps have been generated for RAFGL 5111. These maps show interesting structural details. Radiative transfer modelling in spherical geometry has been carried out for individual sources. The best fit models are in good agreement with the observed spectral energy distribution (SED), radio continuum data etc. Another scheme of radiative transfer through the interstellar dust-gas cloud including the heavier elements has been used to predict ionic nebular line emission, which are in reasonable agreement with the measurements for RAFGL 5111. An important conclusion from the present study is that, for all the three sources (IRAS 00338+6312; 03595+5110; and 04004+5114, a faint source in the neighbourhood of RAFGL 5111), the best fit to the observed SED is obtained for a uniform density ($n(r) \sim r^0$) cloud

Fermionic description of spin-gap states of antiferromagnetic Heisenberg ladders in a magnetic field

Employing the Jordan-Wigner transformation on a unique path and then making a mean-field treatment of the fermionic Hamiltonian, we semiquantitatively describe the spin-gap states of Heisenberg ladders in a field. The appearance of magnetization plateaux is clarified as a function of the number of legs.Comment: 2 pages, 3 figures embedded, J. Phys. Soc. Jpn. Vol. 71, No. 6, 1607 (2002

GASP XVIII: Star formation quenching due to AGN feedback in the central region of a jellyfish galaxy

We report evidence for star formation quenching in the central 8.6 kpc region of the jellyfish galaxy JO201 which hosts an active galactic nucleus, while undergoing strong ram pressure stripping. The ultraviolet imaging data of the galaxy disk reveal a region with reduced flux around the center of the galaxy and a horse shoe shaped region with enhanced flux in the outer disk. The characterization of the ionization regions based on emission line diagnostic diagrams shows that the region of reduced flux seen in the ultraviolet is within the AGN-dominated area. The CO J$_{2-1}$ map of the galaxy disk reveals a cavity in the central region. The image of the galaxy disk at redder wavelengths (9050-9250 \overset{\lower.5em\circ}{\mathrm{A}}) reveals the presence of a stellar bar. The star formation rate map of the galaxy disk shows that the star formation suppression in the cavity occurred in the last few 10$^8$ yr. We present several lines of evidence supporting the scenario that suppression of star formation in the central region of the disk is most likely due to the feedback from the AGN. The observations reported here make JO201 a unique case of AGN feedback and environmental effects suppressing star formation in a spiral galaxy.Comment: Author's accepted manuscrip

Prevalence of vitamin B12 deficiency among individuals with type 2 diabetes mellitus in a South Indian rural community

Background: To estimate the prevalence of vitamin B12 deficiency in a rural south Indian community and to evaluate the association between metformin use and prevalent vitamin B12 deficiency in people with T2DM stratified by oral vitamin B12 supplementation.Methods: Using a cross sectional study design, a random sample of people with T2DM (N=438) was recruited from a rural community. Vitamin B12 deficiency was defined as serum B12 ≤200pg/ml. Data on metformin dose, duration of use, oral vitamin B12 supplementation, and diet were collected. Laboratory measurements included complete blood count, tests for hepatic, renal, and thyroid function, as well as serum vitamin B12 levels and HbA1c.Results: The prevalence of vitamin B12 deficiency in people with T2DM was 11.2% (95% Confidence Interval (CI) 8.2%-14.1%). The odds of vitamin B12 deficiency in patients receiving a metformin dose of 2 grams/day were 4 times higher compared to those receiving ≤1 gram/day, after adjusting for oral B12 supplementation (odds ratio 4.2;95% CI 1.5-11.8). The odds of vitamin B12 deficiency in those taking metformin and receiving oral vitamin B12 supplementation were lower compared to those on metformin and not receiving vitamin B12 supplementation (adjusted odds ratio 0.20; 95% CI 0.06-0.70).Conclusions: Vitamin B12 deficiency affects 1 in 10 people with T2DM, is associated with higher dose metformin use, and oral vitamin B12 supplementation mitigates B12 deficiency in this group

Transforming Steel Domain Green through Innovative Waste Management - A Jindal Approach

The paper summarises the various innovative approaches taken at the COREX process based integrated steel plant of M/s Jindal Vijaynagar Steel Limited. The economics of res-ource recyling has also been described

Effects of magnetic field induced chiral-spin interactions on quasi-one-dimensional spin systems

It is known that in certain non-bipartite quasi-one dimensional spin systems in a magnetic field, in addition to the usual Pauli coupling of the spins to the field, new parity breaking three spin interactions, i.e. chiral spin interactions, are induced at higher order due to virtual processes involving the intrinsic electronic nature of the underlying spins. The strenght of these interactions depend strongly on the orientation of the field, a feature which can be exploited to detect chiral effects experimentally. In many spin systems, these chiral interactions are generated and should be taken into account before any comparison with experiments can be made. We study the effect of the chiral interactions on certain quasi-one-dimensional gapped spin half systems and show that they can potentially alter the physics expected from the Pauli coupling alone. In particular, we demonstrate that these terms alter the universality class of the C-IC transition in spin-tubes. More interestingly, in weakly coupled XX zig-zag ladders, we find that the field induced chiral term can close the singlet gap and drive a second order transition in the non-magnetic singlet sector, which manifests itself as a two component Luttinger liquid-like behaviour in the spin correlation functions. Finally, we discuss the relevance of our results to experiments.Comment: RevTex, 11 pages, 3 figure

Frustrated trimer chain model and Cu3Cl6(H2O)2 2H8C4SO2 in a magnetic field

Recent magnetization and susceptibility measurements on Cu3Cl6(H2O)2 2H8C4SO2 by Ishii et.al. [J. Phys. Soc. Jpn. 69, 340 (2000)] have demonstrated the existence of a spin gap. In order to explain the opening of a spin gap in this copper-trimer system, Ishii et.al. have proposed a frustrated trimer chain model. Since the exchange constants for this model have not yet been determined, we develop a twelfth-order high-temperature series for the magnetic susceptibility and fit it to the experimentally measured one. We find that some of the coupling constants are likely to be ferromagnetic. The combination of several arguments does not provide any evidence for a spin gap in the parameter region with ferromagnetic coupling constants, but further results e.g. for the magnetization process are in qualitative agreement with the experimental observations.Comment: 9 pages REVTeX, 4 PostScript figures included using psfig.sty; for series and supplementary material see http://www.tu-bs.de/~honecker/3mer/ or http://www.itp.phys.ethz.ch/staff/laeuchli/3mer ; substantial reorganization including shifting part of the discussion to WWW pages with "supplementary material"; new appendix shows that antiferromagnetic J_i > 0 are not compatible with the experimental data for the magnetic susceptibilit