4,546 research outputs found
Oxidative dealkylation of a hindered phenol catalyzed by copper (II) bis benzimidazole diamide complex
No full textThe oxidative dealkylation of 2,4,6-tri-tert-butylphenol (TTBP) has been investigated using molecular oxygen and Cu(NO3(GBHA)(NO3) as catalyst, where GBHA is N,N′-bis((benzimidazol-2-yl)methyl)hexanediamide (a) M. Gupta, P. Mathur, R.J. Butcher, Inorg. Chem. 40 (2001) 878; (b) M. Gupta, S.K. Das, P. Mathur, A.W. Cordes, Inorg. Chim. Acta 353 (2003) 197; (c) S. Tehlan, M.S. Hundal, P. Mathur, Inorg. Chem. 43 (2004) 6589; (d) F. Afreen, P. Mathur, A. Rheingold, Inorg. Chim. Acta 358 (2005) 1125.. X-ray structural characterization of complex Cu(NO3)(GBHA)(NO3)·CH3OH confirms that the Cu (II) ion is in a distorted square pyramidal geometry (τ=0.168). The TTBP oxidation reaction proceeds via tri-tert-butylphenoxyl radical producing two products 2,6-di-tert-butyl-1,4-benzoquinone (A) and 4,6-di-tert-butyl-1,2-benzoquinone (B). Both A and B have been well characterized by 1H NMR, 13C NMR, UV–Vis and mass data
Absolute and Conditional Convergence: Its Speed for Selected Countries for 1961--2001
No full textThe study gives the theoretical justification for the per capita growth equations using Solovian model(1956) and its factor accumulation assumptions. The different forms of the per capita growth equation is used to test for 'absolute convergence' and 'conditional convergence' hypotheses and also work out the speed of absolute and conditional convergence for selected countries from 1961-2001.Only EU and East Asian countries together have shown uniform evidence of absolute convergence in all periods. While EU as a region has shown significant evidence of absolute convergence in two periods, 1961-2001 and 1970-2001, there is no convincing statistical evidence in favor of absolute convergence in the last two periods: 1980-2001 and 1990-2001. The speed of absolute convergence in the four periods range between 0.99-2.56 % p.a. (2% for the EU was worked out by Barro and Xavier Sala-i-Martin, 1995, for European regions) for EU while it ranges between 0.57-1.16 % p.a. for the countries in East Asia and EU regions together. However, there is no evidence of convergence among the South Asian countries in all periods and some major CIS republics since 1966.There is however tendency for absolute convergence among countries of South Asia, East Asia and European Union together particularly after the 1980s. Conditional convergence is prevalent among almost all pairs of regions in our sample except East Asian and South Asian nations together. Speed of conditional convergence ranges from 0.2 % in an year to 22%.In the European nations, the speed of conditional convergence works out be nearly 20 % unlike the speed of absolute convergence which hovered around 2 %.Such results would mean that countries in Europe are converging very quickly to their own potential level of incomes per capita but not so quickly to a common potential level of income per capita.Growth equation; absolute convergence; conditional convergence; speed of absolute and conditional convergence; elasticity of output with respect to capital; half life of convergence
Data for "First-principles-based Machine Learning Models for Phase Behavior and Transport Properties of CO2"
No full textThis dataset contains example input files, training data sets and potential files related to the publication "First-principles-based Machine Learning Models for Phase Behavior and Transport Properties of CO2." by Mathur et al (2023). In this work, we developed machine learning models for CO2 based on different exchange-correlation DFT functionals. We assessed their performance on liquid densities, vapor-liquid equilibrium and transport properties.DPMDCO2readme.txt
DPMD-CO2-dataspace.tar.g
Nanoscale magnetoelectric effects revealed by imaging
No full textWe review our work on continuous Ni films coupled via strain to ferroelectric substrates of BaTiO3 (BTO) and 0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (PMN-PT). We show that magnetic force microscopy (MFM) and photoemission electron microscopy (PEEM) of the Ni films (during or after electrical treatment) permit to reveal nanoscale converse magnetoelectric effects (CMEs) that are novel and elude macroscopic measurements. As examples, we discuss magnetization reversal without applied field in multilayer capacitors (MLCs), shear-strain-mediated CMEs in thin Ni films on PMN-PT and reversible switching of perpendicular magnetization from out-of-plane to in-plane in Ni films on BTO. In this latter case, we show that PEEM can be used to measure both magnetic and ferroelectric domains, thus providing key mechanistic insight in the magnetoelectric coupling mechanism
An Analytical Criterion for Centrifugal Instability in Non-Axisymmetric Vortices
No full textNon-axisymmetric vortices are ubiquitous in nature; examples include polar vortices in planets, the giant red spot in Jupiter, tornadoes and cyclones on Earth, mesoscale eddies in the ocean. Turbulent flows are furthermore known to be dominated by small- and large-scale vortex structures. Owing to the wide range of applications, knowledge of conditions under which a given vortex becomes unstable is beneficial. Here, the centrifugal instability of two-dimensional, non-axisymmetric vortices in the presence of an axial flow and a background rotation is studied using the local stability approach. The local stability approach, based on geometric optics and similar in formulation to the rapid distortion theory \cite{bib:godeferd2001}, considers the evolution of shortwavelength perturbations along streamlines in the base flow. This approach, developed by Lifschitz Hameiri \cite{bib:lifschitz1991}, is particularly useful for base flows for which a global stability analysis is computationally expensive. A sufficient criterion for centrifugal instability in an axisymmetric vortex with and is first derived by analytically solving the local stability equations for wave vectors that are periodic upon evolution around a closed streamline. This criterion is then heuristically extended to non-axisymmetric vortices and written in terms of integral quantities on a streamline. The criterion is then shown to be accurate in describing centrifugal instability over a reasonably large range of parameters that specify Stuart vortices and Taylor-Green vortices
Not Available
No full textPublished in book entitled as Trends in Livestock Research (Ed. S.K. Kaushish) M/S Agrobios (India), Behind Nasrani Cinema, Chopasani Road, JodhpurNot AvailableNot Availabl
Surprises from a deep ASCA spectrum of the broad absorption line quasar PHL 5200
No full textWe present a deep (similar to 85 ks) ASCA observation of the prototype broad absorption line quasar (BALQSO) PHL 5200. This is the best X-ray spectrum of a BALQSO yet. We find the following: (1) The source is not intrinsically X-ray weak. (2) The line-of-sight absorption is very strong, with N-H = 5 x 10(23) cm(-2). (3) The absorber does not cover the source completely; the covering fraction is approximate to 90%. This is consistent with the large optical polarization observed in this source, implying multiple lines of sight. The most surprising result of this observation is that (4) the spectrum of this BALQSO is not exactly similar to other radio-quiet quasars. The hard X-ray spectrum of PHL 5200 is steep, with the power-law spectral index alpha approximate to 1.5. This is similar to the steepest hard X-ray slopes observed so far. At low redshifts, such steep slopes are observed in narrow-line Seyfert 1 (NLS1) galaxies, believed to be accreting at a high Eddington rate. This observation strengthens the analogy between BALQSOs and NLS1 galaxies and supports the hypothesis that BALQSOs represent an early evolutionary state of quasars. It is well accepted that the orientation to the line of sight determines the appearance of a quasar; age seems to play a significant role as well
Observations of the γ-ray-emitting narrow-line Seyfert 1, SBS 0846+513, and its host galaxy
No full textThe γ-ray-emitting galaxy SBS 0846+513 has been classified as a narrow-line Seyfert 1 (NLS1) from its spectroscopy, and on that basis would be thought likely to have a small central black hole hosted in a spiral galaxy. However, very few of the γ-ray NLS1s have high-resolution imaging of their hosts, so it is unknown how the morphology expectation holds up for the γ-emitting class. We have observed this galaxy in the J band with the Large Binocular Telescope's LUCI1 camera and the ARGOS adaptive optics system. We estimate its black hole mass to lie between , using the correlation with bulge luminosity, or using the correlation with Sérsic index. Our favoured estimate is 4.2 × 107 M⊙, putting its mass at the high end of the NLS1 range in general but consistent with others that are γ-ray emitters. These estimates are independent of the broad-line region viewing geometry and avoid any underestimates due to looking down the jet axis. Its host shows evidence of a bulge + disc structure, from the isophote shape and residual structure in the nuclear-subtracted image. This supports the idea that γ-ray NLS1 may be spiral galaxies, like their non-jetted counterparts
XPEEM and MFM Imaging of Ferroic Materials
No full textThe authors describe and compare two complementary techniques that are habitually used to image ferromagnetic and ferroelectric materials with sub-micron spatial resolutions (typically 50 nm, at best 10 nm). The first technique is variable-temperature photoemission electron microscopy with magnetic/antiferromagnetic/polar contrast from circularly/linearly polarized incident X-rays (XPEEM). The second technique is magnetic force microscopy (MFM). Focusing mainly on the authors' own work, but not exclusively, published/unpublished XPEEM and MFM images of ferroic domains and complex magnetic textures (involving vortices and phase separation) are presented. Highlights include the use of two XPEEM images to create 2D vector maps of in-plane (IP) magnetization, and the use of imaging to detect electrically driven local reversals of magnetization. The brief and simple descriptions of XPEEM and MFM should be useful for beginners seeking to employ these techniques in order to understand and harness ferroic materials
Antibiotic treatment of pediatric infections in primary healthcare setting: evaluation and comparison of 80 national treatment guidelines with the WHO AWaRe book recommendations
No full textBackground: Antibiotic recommendations for pediatric infections in national standard treatment guidelines (STGs) vary widely, particularly for Access and Watch antibiotics. The WHO AWaRe book recommends Access antibiotics as first-line treatment for over 80% of common infections managed in primary healthcare. This study aims to evaluate the agreement between first and second-line antibiotics in national STGs with AWaRe book recommendations and the inclusion of these antibiotics in Essential Medicine Lists (EMLs). Methods: National STGs of 80 countries were systematically collected from databases and grey literature (up to May 2025). Antibiotic recommendations for the ten most common primary healthcare infections in children were compared with the WHO AWaRe book (2022), the WHO Essential Medicines List for children (EMLc) and national Essential Medicines Lists (nEMLs) where available. Findings: A median of eight STGs per country were collected, with higher numbers in LMICs due to guidelines for cholera and enteric fever. A total of 1124 first-line and 841 second-line antibiotic recommendations were identified. Over 70% of first-line recommended treatments were Access antibiotics, while Watch antibiotics accounted for more than 50% of second-line recommended treatments. First-line recommendations showed strong agreement with WHO guidance, whereas second-line treatments exhibited lower agreement and greater variability across regions. More than 80% of first-line antibiotics were included in the EMLc and nEMLs, although some high-income countries lacked nEMLs. Interpretation: First-line antibiotic recommendations in national pediatric STGs largely align with the WHO AWaRe book guidance focusing on Access antibiotic use. In contrast, second-line treatments vary considerably, commonly recommending Watch antibiotics. Strengthening the evidence base of national STGs and aligning second-line recommendations with the WHO AWaRe book could help meet the 79th UNGA High-Level Meeting on AMR target, which aims for 70% of all human antibiotic use to come from the Access group. Funding: PRIN 2022 “A Cluster randomized clinical trial to change Antibiotic Prescribing behavior in Outpatient pediatric primary care setting in Italy (CAPO project)", funded in the framework of the National Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment 1.1, funded by the European Union–Next Generation EU, Project 2022A7LA2W, CUP C53D23006050006
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