7,376 research outputs found
Author response: India and China in Africa: a comparative perspective of the oil industry by Raj Verma
No full textEarlier this month Ian Taylor reviewed India and China in Africa, a new book about Asian engagement in the West African oil industry. Here, the book’s author Raj Verma responds to Taylor’s comments, outlining the rationale and evidence for the framework used in the study. India and China in Africa: A comparative perspective of the oil industry. Raj Verma. London: Routledge. 2017
New discrimination and classification diagrams for igneous rocks and application to geothermal fiels /\ua0propuesta de tesis que para opter por el grado de Doctor en Ingeniería presenta Sanjeet Kumar Verma ; tutor Dr. Surendra P. Verma
No full text272 páginas :\ua0ilustracionesDoctor en Ingeniería\ua0Universidad Nacional Autónoma de México,\ua02012\ua0Programa de Maestría y Doctorado en Ingenierí
Some properties of generalized reduced Verma modules over -graded modular Lie superalgebras
No full textsummary:We study some properties of generalized reduced Verma modules over -graded modular Lie superalgebras. Some properties of the generalized reduced Verma modules and coinduced modules are obtained. Moreover, invariant forms on the generalized reduced Verma modules are considered. In particular, for -graded modular Lie superalgebras of Cartan type we prove that generalized reduced Verma modules are isomorphic to mixed products of modules
Lactarius kanadii Verma K., Mehmood, Uniyal & Sharma Y. P. 2022, sp. nov.
No full textLactarius kanadii Verma K., Mehmood, Uniyal & Sharma Y.P. sp. nov. 2 Figs. 5, 6. Mycobank:— MB842104 GenBank:— OL 691266 (holotype), OL 691518 (Paratype) Diagnosis:—Basidiocarps with greyish brown to dark brown pileus; abundant watery white latex which changes to yellowish orange; globose to subglobose basidiospores with winged ornamentations ≥ 2 μm high. Etymology:—In honor of Dr Kanad Das for his invaluable contribution to the systematics of Russulaceae in the Indian Himalayan Region. Typification:— INDIA. Jammu and Kashmir: Kathua district, Samanamanj, 1750m, N 32 o 42.997ʹ E 075 o 25.931ʹ, 01 August 2020, Komal Verma, LK-011 (CAL 1868, holotype). Description:— Pileus 65–80 mm diam., initially convex, plano-convex at maturity, at times infundibuliform with depressed centre; surface velvety, greyish brown (6F3-4) to dark brown (6F7); margin undulate, decurved. Lamellae 4–5 mm broad, subdecurrent to decurrent, cream white (1A2) to greyish yellow (4B4), staining light brown (5C5) to brownish orange (5D5) after 15–20 minutes, crowded (10–12/cm), edges concolorous, staining yellowish brown (5D8) when damaged; lamellulae plentiful, unevenly distributed, 8–9 lengths. Stipe 60–80 × 10–18 mm, cylindric, slightly tapered towards apex, surface smooth, concolorous with pileus. Context brittle, white to cream white (5D8), staining light orange (6A4–5) on exposure, stuffed in stipe; not staining with FeSO4 and KOH, brownish red (8D7–8) in guaiacol. Latex abundant, watery white (1A1), changing to light orange (6A4–5) or yellowish orange (6A5–6) on lamellae. Taste mild. Odour pleasant. Spore deposit not obtained. Basidiospores 6.8–8.17–9.5 × 6.0–7.8–9.0 μm, (n = 40, Q = 1.01–1.05–1.13), globose to subglobose, ornamentation composed of 1.5–2 μm high, winged, thick ridges and conical warts, short ridges between the larger ridges, forming an incomplete reticulum; plage inamyloid. Basidia 32–48 × 10–17 μm, subclavate, 2- or 4-spored; sterigmata 4.5–6 × 0.3–0.5 μm. Pleurocystidia absent. Pseudocystidia abundant, 7–9 μm diam., emergent up to 17–37 μm, unbranched. Cheilocystidia absent. Gill edges sterile. Cheiloleptocystidia abundant, 27–52 × 5–8 μm, emergent up to 10–25 μm, cylindric to clavate, apices round, with one to two cells at the base. Marginal cells 10–18 × 5–8 μm, cylindric to subclavate, often multiseptate, thin-walled, with brown intracellular pigmentation. Hymenophoral trama composed of abundant lactifers, up to 4–7 μm diam. Pileipellis a trichopalisade, 75–125 μm thick; suprapellis 40–55 μm deep, composed of cylindric to subclavate cells with brown intracellular pigmentation; subpellis 30–50 μm thick, composed of cylindrical to almost rounded cells. Stipitipellis a palisade to a trichopalisade, 38–55 μm thick; hyphae 6–8 μm diam., terminal cells with intracellular brown pigment. Habit and habitat: — Scattered, under Quercus sp. and Pinus roxburghii in subtemperate mixed forest. Additional specimens examined:— INDIA. Jammu and Kashmir, Kathua, Samanamanj, 1749 m, N 32º42.996ʹ E 075º25.931ʹ, 08 August 2020 K. Verma LK-021; Kathua, Garh 1700 m, 10 August 2020, K. Verma, LK-023. Notes:—Phylogenetically, Lactarius fuliginosus (98 % identity for 98–100 % query coverage using BLAST) and Lactarius picinus (98 % identity for 99–100 % query coverage using BLAST) are closest to Lactarius kanadii and these species could be confused in the field due to their similar macromorphology (basidiome shape, colors of pileus and lamellae). However, Lactarius picinus can be differentiated by its fuscous to brownish olive or sepia-coloured pileus, scant white latex which stains the lamellae salmon to reddish brown, slightly smaller, globose to broadly ellipsoid basidiospores, and its association with Picea sp. Lactarius fuliginosus, which is also close to Lactarius kanadii, can be differentiated by its velvety, greyish brown pileus, globose to broadly ellipsoid basidiospores with an almost complete reticulum, a pileipellis as a trichoepithelium, and its occurrence in coniferous and deciduous forests (Heilmann-Clausen et al. 1998, Stubbe & Verbeken 2012). Lactarius atromarginatus can be differentiated from Lactarius kanadii by its marginate lamellae, abundant watery white latex that turns pale lilac and basidiospores with ornamentation forming a complete reticulum (Verbeken & Horak 2000, Lee et al. 2018). In the context of Indian representatives of L. subg. Plinthogalus, Lactarius nodulisporus and L. singeri could be confused with Lactarius kanadii due to the dark colored basidiomes. However, Lactarius nodulisporus can be segregated from Lactarius kanadii by its white latex, adnexed, distant lamellae and presence of nodulose ornamentation on the basidiospores (Uniyal et al. 2018). Lactarius singer differs from Lactarius kanadii in having a strongly rugose pileus with white context that remains unchanged on exposure, a palisadic pileipellis, a stipitipellis as a trichoderm and occurrence with Quercus sp. and Abies sp. (Uniyal et al. 2018).Published as part of Verma, Komal, Mehmood, Tahir, Uniyal, Priyanka & Sharma, Yash Pal, 2022, Lactarius indoevosmus and L. kanadii (Russulaceae), two new species from the northwestern Himalayas, India, inferred from morphology and molecular data, pp. 165-177 in Phytotaxa 541 (2) on pages 172-175, DOI: 10.11646/phytotaxa.541.2.6, http://zenodo.org/record/638874
Verma and simple modules for quantum groups at non-abelian groups
No full textThe Drinfeld double D of the bosonization of a finite-dimensional Nichols algebra B(V) over a finite non-abelian group G is called a quantum group at a non-abelian group. We introduce Verma modules over such a quantum group D and prove that a Verma module has simple head and simple socle. This provides two bijective correspondences between the set of simple modules over D and the set of simple modules over the Drinfeld double D(G). As an example, we describe the lattice of submodules of the Verma modules over the quantum group at the symmetric group S3 attached to the 12-dimensional Fomin–Kirillov algebra, computing all the simple modules and calculating their dimensions.Fil: Pogorelsky, Barbara. Universidade Federal do Rio Grande do Sul; BrasilFil: Vay, Cristian Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentin
Sweeping has no effect on renormalized turbulent viscosity
No full textWe perform renormalization group analysis (RG) of the Navier-Stokes equation in the presence of constant mean velocity field , and show that the renormalized viscosity is unaffected by , thus negating the ``sweeping effect", proposed by Kraichnan [Phys. Fluids {\bf 7}, 1723 (1964)] using random Galilean invariance. Using direct numerical simulation, we show that the correlation functions for and differ from each other, but the renormalized viscosity for the two cases are the same. Our numerical results are consistent with the RG calculations
A Unified Shell model for Buoyancy-Driven Turbulence
No full textWe construct a unified shell model for stably stratified and convective turbulence. Shell model simulation of stably stratified flow in turbulent regime exhibit Bolgiano-Obukhbov (BO) scaling in which the kinetic energy spectrum varies as . However, simulation of convective turbulence shows Kolmogorov's spectrum. These results are consistent with the direct numerical simulations of Kumar {\em et al.} [Phys. Rev. E {\bf 90}, 023016 (2014)]. We also observe a dual scaling ( and ) for a limited range of parameters in stably stratified flow
Energy transfers in small-scale and large-scale dynamos
No full textWe study energy transfers during magnetic energy growth in small-scale and large-scale dynamos. We perform direct numerical simulations for magnetic Prandtl number Pm =20 and 0.2 in a periodic box on 1024^3 grid. Energy fluxes and shell-to-shell energy transfers indicate that in small-scale dynamo for Pm =20, the magnetic energy growth takes place due to a non-local energy transfer from large-scale velocity field to small-scale magnetic field. On the other hand, in large-scale dynamo for Pm =0.2, local energy transfers from large-scale velocity field to large-scale magnetic field takes place
Role of the strain-rate tensor in turbulent scalar-transport modeling
No full textWe examine the geometric orientation of the subfilter-scale scalar-flux vector in homogeneous isotropic turbulence. Vector orientation is determined using the eigenframe of the resolved strain-rate tensor. The Schmidt number is kept sufficiently large so as to leave the velocity field, and hence, the strain-rate tensor, unaltered by filtering in the viscous-convective subrange. Strong preferential alignment is observed for the case of Gaussian and box filters, whereas the sharp-spectral filter leads to close to a random orientation. The orientation angle obtained with the Gaussian and box filters is largely independent of the filter-width and the Schmidt number. It is shown that the alignment direction observed numerically using these two filters is predicted very well by the tensor-diffusivity model. Further a-priori tests indicate poor alignment of the Smagorinsky and stretched vortex model predictions with the exact subfilter flux
Systems of Differential Operators and Generalized Verma Modules
No full textIn this paper we close the cases that were left open in our earlier works on the study of conformally invariant systems of second-order differential operators for degenerate principal series. More precisely, for these cases, we find the special values of the systems of differential operators, and determine the standardness of the homomorphisms between the generalized Verma modules, that come from the conformally invariant systems.The author was supported by the Global COE program at the Graduate School of Mathematical
Sciences, the University of Tokyo, Japan. He would like to be thankful for the referees for their
careful reading and invaluable comments
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