Liouville soliton surfaces obtained using Darboux transformations

We construct parametric Liouville surfaces corresponding to parametric soliton solutions of the Liouville equation and Darboux-transformed counterparts. We also use a modified variation of parameters method together with the elliptic functions method to obtain the traveling wave solutions to Liouville equation and express the centroaffine invariant in terms of the soliton Hamiltonian

Type IIA Orientifold Limit of M-Theory on Compact Joyce 8-Manifold of Spin(7)-Holonomy

We show that M-theory compactified on a compact Joyce 8-manifold of $Spin(7)$-holonomy, which yields an effective theory in $D = 3$ with $\N$ = 1 supersymmetry, admits at some special points in it moduli space a description in terms of type IIA theory on an orientifold of compact Joyce 7-manifold of $G_2$-holonomy. We find the evidence in favour of this duality by computing the massless spectra on both M-thory side and type IIA side. For the latter, we compute the massless spectra by going to the orbifold limit of the Joyce 7-manifold.Comment: 26 pages, 2 eps figures, Latex file, two references and one footnote added, corrected some typo

Kahler Independence of the G2-MSSM

The G2-MSSM is a model of particle physics coupled to moduli fields with interesting phenomenology both for colliders and astrophysical experiments. In this paper we consider a more general model - whose moduli Kahler potential is a completely arbitrary G2-holonomy Kahler potential and whose matter Kahler potential is also more general. We prove that the vacuum structure and spectrum of BSM particles is largely unchanged in this much more general class of theories. In particular, gaugino masses are still supressed relative to the gravitino mass and moduli masses. We also consider the effects of higher order corrections to the matter Kahler potential and find a connection between the nature of the LSP and flavor effects.Comment: Final version, matches the version published in JHE

Glyoxylate as a reducing agent for manganese(III) in salen scaffold: a kinetics and mechanistic study

The kinetics of oxidation of glyoxylic acid (HGl) by MnIII(salen)(OH2)2+ ((H2salen = N,N′- bis(salicylidene)ethane-1,2-diamine) is investigated at 30.0–45.0°C, 1.83 ≤ pH ≤ 6.10, I = 0.3 mol dm−3(NaClO4). The products are identified as formic acid, CO2 and MnII with the reaction stoichiometry, |Δ[MnIII]/Δ[HGl]| = 2. The overall reaction involves fast equilibrium pre-association of MnIII(salen)(OH2)2+ with HGl and its conjugate base Gl− forming the corresponding inner sphere complexes (both HGl and Gl- being the monohydrate gem-diol forms) followed by the slow electron transfer steps. In addition, the second order electron transfer reactions involving the inner-sphere complexes and HGl/Gl- are also observed. The rate, equilibrium constants and activation parameters for various steps are presented. MnIII(salen)(OH2)(Gl) is virtually inert to intra molecular electron transfer while the process is facile for MnIII(salen)(OH2)(HGl)+ (105ket = 2.8 ± 0.3 s-1 at 35.0°C) reflecting the involvement of proton coupled electron transfer mechanism in the latter case. A computational study of the structure optimization of the complexes, trans-MnIII(salen)(OH2)2+, trans-MnIII(salen)(OH2)(Gl), and trans- MnIII(salen)(OH2)(HGl)+ (all high spin MnIII(d4) systems), reveals strongest axial distortion for the (aqua)(Gl) complex ; HGl bound to MnIII centre by the C=O function of the carboxyl group in the (aqua)(HGl) complex facilitates the formation of a hydrogen bond between the proton of the carboxyl group and the coordinated phenoxide moiety ((O-H. . .O hydrogen bond distance 1.745 Å) and the gem-diols are not involved in H-bonding in either case. A rate comparison for the second order paths: MnIII(salen)(OH2)(HGl)/Gl),+/0+ HGl/Gl- → products, shows that HGl for the (aqua)(HGl) complex is a better reducing agent than Gl- for the (aqua)(Gl) complex (kHG ~ 5 kGl). The high values of activation enthalpy (ΔH≠ = 93–119 kJ mol−1) are indicative of substantial reorganization of the bonds as expected for inner-sphere ET process

Binary and ternary complexes of nickel(II) with 2-aminomethylbenzimidazole and salicylaldehyde: kinetic and equilibrium studies

The complexation of NiII with 2-aminomethylbenzimidazole (L) has been investigated at 20–40 °C, I= 0.30 mol dm-3. Both monoprotonated and unprotonated ligands bind the metal ion to form [NiL]2+. and the rate and activation parameters for the formation and acid-catalysed dissociation of this chelate are calculated. In the presence of Salicylaldehyde (Hsal), a mixed-ligand complex. [NiL(sal)]+, is also formed as an intermediate which further condenses to the Schiff-base complex, [NiL']+[HL'=N-(benzimidazol-2-ylmethyl)salicylideneimine]. The kinetics of the fast ternary complex formation and its slow intramolecular transformation to the Schifi base complex have been investigated at 25 °C. The presence of L in the co-ordination sphere of Ni2+ enhances the dissociation of [NiL(sal)]+ to [NiL]2+ and sal– with respect to [Ni(Sal)]+, as evidenced by the stability constants of [NiL(sal)]+ and [Ni(sal)]+. Calculations based on the values of ΔS° for the ionisation of H2L2+ and the formation of [NiL]2+combined with S [> with combining macron]aq°(H+) and S[> with combining macron]aq°(Ni2+) data yielded the values S[> with combining macron]aq°(H2L2+)–S[> with combining macron]aq°(L)= 110, S[> with combining macron]aq°(L)–S[> with combining macron]aq°(HL+)=–116 and S[> with combining macron]aq°([NiL]2+)–S[> with combining macron]aq°(L)=–294 J K−1 mol−1, which presumably reflect the varying solvent-ordering effects of L, HL+, H2L2+ and [NiL]2+

Measuring gender norms about relationships in early adolescence : results from the global early adolescent study

Introduction: Gender norms are increasingly recognized as drivers of health and wellbeing. While early adolescence constitutes a critical window of development, there is limited understanding about how adolescents perceive gender relations across different cultural settings. This study used a mixed-method approach, grounded in the voices of young people around the world, to construct and test a cross-cultural scale assessing the perceptions of gender norms regulating romantic relationships between boys and girls in early adolescence. Methods: The study draws on the Global Early Adolescent study (GEAS), a study focusing on gender norms and health related outcomes over the course of adolescence in urban poor settings worldwide. In-depth interviews were first conducted among approximately 200 adolescents between 10-14 years in seven sites across 4 continents to identify common scripts guiding romantic relations in early adolescence. These scripts were then transformed into a multidimensional scale. The scale was tested among 120 adolescents in each of 14 GEAS sites, followed by a second pilot among 75 adolescents in six sites. We evaluated the psychometric criteria of each subscale using principal component analysis, and parallel analysis, followed by exploratory factor analysis to guide the selection of a more parsimonious set of items. Results: Results suggested a two-factor structure, consisting of an "adolescent romantic expectations" subscale and a "Sexual Double Standard" subscale. Both subscales yielded high internal validity in each site, with polychoric Cronbach alpha values above 0.70 with the exception of Kinshasa for the adolescent romantic expectations scale (0.64) and Hanoi for the sexual double standard scale (0.61). Conclusion: This study reveals common perceptions of gendered norms about romantic engagement in early adolescence, normative for both sexes, but socially valued for boys while devaluated for girls. The findings illustrate that social hierarchies of power in romantic relationships form early in adolescence, regardless of cultural setting

Role of Mineralogy, Mineral Chemistry and Geochemistry in Mineral Processing : A case study for High Phosphorous manganese ores of Nishikhal, South Orissa, India

Conformable manganese ore bands are present in the khond-alite suite of rocks belonging to the Eastern Ghats Complex of South Orissa,India. The ores cart be classified as high-grade, siliceous and ferruginous. Cryptomelane, romanechite, pyrolusite, jacobsite, hausmannite, braunite, lithiophorite, birnessite and pyrophanite represent the manganese minerals. Goethite, limonite, graphite, hematite, magnetite are the associated opaque gangue minerals while quartz,orthoclase, hyalophane, garnet, kaolinite, apatite, collophane,. fibrolite,zircon, biotite and muscovite are the silicate gangue minerals recorded in these ores. Optical microscopic and Electron Probe Microanalysis studies revealed that the phosphorous, in these ores, present in the form of (i) apatite inclusions within qua-rtz, orthoclase and garnet, (ii) amorphous calcium phos-phate (collophane) within the voids of garnet, (iii) ads-orbed component within the manganese oxide and silicate phases as well as in the iron oxide phase (goethite) Geochemical studies indicated that high amount of phos-phorous is linked with ferruginous manganese ores. Regression analysis of the geochemical data suggests a strong positive correlation between P-Fe and P-Mn. Magnetic separation studies on low- and off- grade bulk manganese samples, indicated that the phosphorous contributed by apatite is relatively low (4.44 to 17.76%) compared to the phosphorous held in adsorption(82.24 to 95.56%), while the contribution of phosphorous by collophane is insignificant.The above studies confirm that the association of phosphorous in Nishikhal ores is very complex. Since most of the phosphorous is in adsorption, these low and off grade ores are expected to respond well to dephosphorisation by reduction roasting followed by magnetic separation or roast alkali leaching method

Complex formation between nickel(II) and some pentamine (substituted salicylato)cobalt(III) ions

The kinetics of reversible complexation of NiII with pentamine(substituted salicylato)cobalt(III) ions, [Co(N5){O2CC6H3(X)OH}]2+[N5= 5NH3, (en)2(NH3)(cis isomer, en = ethane-1,2-diamine) or tetren (tetraethylenepentamine), X = 3-NO2; N5= 5NH3, X = 5-NO2], was investigated by the stopped-flow technique at 15–35 °C, pH 5.70–6.90 and I= 0.30 mol dm−3(ClO4−). The formation of [(Co(N5){O2CC6H3(X)O}Ni]3+ occurs via the reaction of [Ni(OH2)6]2+ with the phenoxide form of the cobalt(III) substrates. The rate and activation parameters have been determined for the formation and dissociation of the binuclear species in which nickel(II) is chelated by the salicylate moiety. The data are consistent with and Id mechanism. The rate constant for spontaneous dissociation of the binuclear species to the reacting partners is sensitive to the nature of the pentamine moiety and decreases in the sequence tetren > (en)2(NH3)− 5NH3. The acid-catalysed dissociation of cis-[(en)2(NH3)Co{O2CC6H3(NO2−3)O}Ni]3+ conforms to a two-step process

Kinetics & Mechanism of Oxidation of Benzoin & Its Derivatives by Tl(III) in Aqueous Acetic Acid

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