Ethyl 4-(phenyl­sulfon­yl)piperazine-1-carboxyl­ate

In the title compound, C13H18N2O4S, the piperazine ring adopts a chair conformation. The dihedral angle between the least-squares planes through the piperazine and benzene rings is 73.23 (10)°. In the crystal, there are no classical hydrogen bonds but stabilization is provided by weak C—H⋯π inter­actions

Screening for Ascochyta Blight Resistance in Chickpea (Cicer arietinum L.)

Ten chickpea lines CM1966/93, CMC77S, CM843/98, CM1223/98, CM1441/98, CM2070/98, CC 104/99, CC106/99, CC124/00 were found highly resistant to Ascochyta blight with disease rating of 2 followed by 34 lines that were resistant and 21 lines were tolerant. None was found immune to blight. The highly resistant lines have exhibited higher level of resistance against blight as compared to earlier released varieties (CM72, CM88 and CM2000)

Adsorption and inhibitive properties of Tryptophan on low alloy steel corrosion in acidic media

AbstractThe inhibition efficiency of Tryptophan (Trp) has been studied for the corrosion of low alloy steel ASTM A213 grade T22 in sulfamic (HSO3NH2) and hydrochloric (HCl) acid solutions.Corrosion inhibition was studied using electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM) and weight loss measurements. The influence of inhibitor concentration, solution temperature, and immersion time on the corrosion resistance of low alloy steel (LAS) has been investigated. Trp proved to be a very good inhibitor for low alloy steel acid corrosion. EFM measurements showed that Trp is a mixed type inhibitor. Trp behaved better in 0.6M HCl than in 0.6M HSO3NH2. Moreover, it was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and immersion time. The associated activation energy (Ea) has been determined. The values of Ea indicate that the type of adsorption of Trp on the steel surface in both acids belongs to physical adsorption. The adsorption process was tested using Temkin adsorption isotherm

Diaqua­bis­(hydrogen tartrato)copper(II) dihydrate

The title complex, [Cu(C4H5O6)2(H2O)2]·2H2O, contains a CuII ion lying on an inversion centre. The coordination geometry of the CuII ion is a distorted octa­hedron with four O atoms from two hydrogen tartrate ions occupying the equatorial positions and two O atoms from two coordinated water mol­ecules occupying the axial positions. In the crystal structure, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

Screening for Ascochyta blight resistance in chickpea (Cicer arietinum L.)

Ten chickpea lines CM1966/93, CMC77S, CM843/98, CM1223/98, CM1441/98, CM2070/98, CC 104/99, CC106/99, CC107/99, CC124/00 were found highly resistant to Ascochyta blight with disease rating of 2 followed by 34 lines that were resistant and 21 lines were tolerant. None was found immune to blight. The highly resistant lines have exhibited higher level of resistance against blight as compared to earlier released varieties (CM72, CM88 and CM2000)

Production of Lambda and Sigma^0 hyperons in proton-proton collisions

This paper reports results on simultaneous measurements of the reaction channels pp -> pK+\Lambda and pp -> pK+\Sigma^0 at excess energies of 204, 239, and 284 MeV (\Lambda) and 127, 162, and 207 MeV (\Sigma^0). Total and differential cross sections are given for both reactions. It is concluded from the measured total cross sections that the high energy limit of the cross section ratio is almost reached at an excess energy of only about 200 MeV. From the differential distributions observed in the overall CMS as well as in the Jackson and helicity frames, a significant contribution of interfering nucleon resonances to the \Lambda production mechanism is concluded while resonant \Sigma^0-production seems to be of lesser importance and takes place only through specific partial waves of the entrance channel. The data also indicate that kaon exchange plays a minor role in the case of \Lambda- but an important role for \Sigma^0-production. Thus the peculiar energy dependence of the \Lambda-to-\Sigma^0 cross section ratio appears in a new light as its explanation requires more than mere differences between the p\Lambda and the p\Sigma^0 final state interaction. The data provide a benchmark for theoretical models already available or yet to come.Comment: 18 pages, 10 figures; accepted by The European Physical Journal A (EPJ A

Determination of Leptoquark Properties in Polarized eγe\gamma Collisions

We study leptoquark production using polarized $e\gamma$ colliders for the center of mass energies $\sqrt s=500$~GeV and 1~TeV. We show that using polarization asymmetries the ten different types of leptoquarks listed by Buchm\"uller, R\"uckl and Wyler can be distinquished from one another for leptoquark masses essentially up to the kinematic limit of the respective colliders. Thus, if a leptoquark were discovered an $e\gamma$ collider could play a crucial role in determining its origins.Comment: 10 pages (plus 10 postscript figures submitted separately), OCIP/C 94-