57 research outputs found
Microwave-Assisted Synthesis of Some 1H-1,2,4-Triazol-3-one Derivatives
4-Amino-5-(methyl/ethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one were synthesized from the reaction of (methyl/ethyl)-ester ethoxycarbonyl hydrazone with hydrazine hydrate and then, converted to corresponding Schiff bases using 9H-fluorene- 3-carbaldehyde. Ester, hydrazide and oxadiazole derivatives were synthesized starting from Schiff bases in three steps. All reactions occurred under conventional conditions and microwave irradiation. The obtained results were compared.KEYWORDS Triazole, oxadiazole, hydrazine hydrate, microwave irradiation
Transformations between WISE, 2MASS, SDSS and BVRI photometric systems: I. Transformation equations for dwarfs
We present colour transformations for the conversion of the W1 and W2
magnitudes of WISE photometric system to the Johnson-Cousins' BVRI, SDSS (gri),
and 2MASS (JHK_s) photometric systems, for dwarfs. The W3 and W4 magnitudes
were not considered due to their insufficient signal to noise ratio (S/N). The
coordinates of 825 dwarfs along with their BVRI, gri, and JHK_s data, taken
from Bilir et al. (2008) were matched with the coordinates of stars in the
preliminary data release of WISE (Wright et al., 2010) and a homogeneous dwarf
sample with high S/N ratio have been obtained using the following constraints:
1) the data were dereddened, 2) giants were identified and excluded from the
sample, 3) sample stars were selected according to data quality, 4)
transformations were derived for sub samples of different metallicity range,
and 5) transformations are two colour dependent. These colour transformations,
coupled with known absolute magnitudes at shorter wavelenghts, can be used in
space density evaluation for the Galactic (thin and thick) discs, at distances
larger than the ones evaluated with JHK_s photometry.Comment: 16 pages, including 5 figures and 7 tables, accepted for publication
in MNRA
Classical r-matrix of the su(2|2) SYM spin-chain
In this note we straightforwardly derive and make use of the quantum R-matrix
for the su(2|2) SYM spin-chain in the manifest su(1|2)-invariant formulation,
which solves the standard quantum Yang-Baxter equation, in order to obtain the
correspondent (undressed) classical r-matrix from the first order expansion in
the ``deformation'' parameter 2 \pi / \sqrt{\lambda}, and check that this last
solves the standard classical Yang-Baxter equation. We analyze its bialgebra
structure, its dependence on the spectral parameters and its pole structure. We
notice that it still preserves an su(1|2) subalgebra, thereby admitting an
expression in terms of a combination of projectors, which spans only a subspace
of su(1|2) \otimes su(1|2). We study the residue at its simple pole at the
origin, and comment on the applicability of the classical Belavin-Drinfeld type
of analysis.Comment: 14 pages, LaTeX, no figures; corrections made, further analysis of
the residue and references adde
Emotional Labor in Mathematics: Reflections on Mathematical Communities, Mentoring Structures, and EDGE
Terms such as "affective labor" and "emotional labor" pepper feminist
critiques of the workplace. Though there are theoretical nuances between the
two phrases, both kinds of labor involve the management of emotions; some acts
associated with these constructs involve caring, listening, comforting,
reassuring, and smiling. In this article I explore the different ways academic
mathematicians are called to provide emotional labor in the discipline, thereby
illuminating a rarely visible component of a mathematical life in the academy.
Underlying this work is my contention that a conceptualization of labor
involved in managing emotions is of value to the project of understanding the
character, values, and boundaries of such a life. In order to investigate the
various dimensions of emotional labor in the context of academic mathematics, I
extend the basic framework of Morris and Feldman [33] and then apply this
extended framework to the mathematical sciences. Other researchers have mainly
focused on the negative effects of emotional labor on a laborer's physical,
emotional, and mental health, and several examples in this article align with
this framing. However, at the end of the article, I argue that mathematical
communities and mentoring structures such as EDGE help diminish some of the
negative aspects of emotional labor while also accentuating the positives.Comment: Revised version to appear in the upcoming volume A Celebration of
EDGE, edited by Sarah Bryant, Amy Buchmann, Susan D'Agostino, Michelle
Craddock Guinn, and Leona Harri
Synthesis and In Vitro Urease Inhibition of Some Novel Benzimidazole-based Hydrazones
WOS: 000479700000001A novel series of N '-(substituted benzylidene)-2-(5,6-dichloro-2-methyl-1H-benzimidazol-1-yl)acetohydrazides and N '-(1-(substituted phenyl)ethylidene)-2-(5,6-dichloro-2-methyl-1H-benzimidazol-1-yl)acetohydrazides were synthesized and then studied for their urease inhibitory activities using thiourea as a standard drug. All newly synthesized compounds were found to exhibit potent inhibitory properties against urease enzyme in the range of IC50 = 0.0155 +/- 0.0039-0.0602 +/- 0.0071 mu M, when compared with the thiourea as standard (IC50 = 0.5115 +/- 0.0233 mu M). All target molecules were characterized by H-1-NMR, C-13-NMR, IR, and electrospray ionization mass spectrometry
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