The Hamiltonian structure of a two-dimensional rigid circular cylinder interacting dynamically with N point vortices

This paper studies the dynamical fluid plus rigid-body system consisting of a two-dimensional rigid cylinder of general cross-sectional shape interacting with N point vortices. We derive the equations of motion for this system and show that, in particular, if the vortex strengths sum to zero and the rigid-body has a circular shape, the equations are Hamiltonian with respect to a Poisson bracket structure that is the sum of the rigid body Lie–Poisson bracket on Se(2)*, the dual of the Lie algebra of the Euclidean group on the plane, and the canonical Poisson bracket for the dynamics of N point vortices in an unbounded plane. We then use this Hamiltonian structure to study the linear and nonlinear stability of the moving Föppl equilibrium solutions using the energy-Casimir method

Non-invasive determination of external forces in vortex-pair-cylinder interactions

Expressions for the conserved linear and angular momenta of a dynamically coupled fluid + solid system are derived. Based on the knowledge of the flow velocity field, these expressions allow the determination of the external forces exerted on a body moving in the fluid such as, e.g., swimming fish. The verification of the derived conserved quantities is done numerically. The interaction of a vortex pair with a circular cylinder in various configurations of motions representing a generic test case for a dynamically coupled fluid + solid system is investigated in a weakly compressible Navier-Stokes setting using a Cartesian cut-cell method, i.e., the moving circular cylinder is represented by cut cells on a moving mesh. The objectives of this study are twofold. The first objective is to show the robustness of the derived expressions for the conserved linear and angular momenta with respect to bounded and discrete data sets. The second objective is to study the coupled dynamics of the vortex pair and a neutrally buoyant cylinder free to move in response to the fluid stresses exerted on its surface. A comparison of the vortex-body interaction with the case of a fixed circular cylinder evidences significant differences in the vortex dynamics. When the cylinder is fixed strong secondary vorticity is generated resulting in a repeating process between the primary vortex pair and the cylinder. In the neutrally buoyant cylinder case, a stable structure consisting of the primary vortex pair and secondary vorticity shear layers stays attached to the moving cylinder. In addition to these fundamental cases, the vortex-pair-cylinder interaction is studied for locomotion at constant speed and locomotion at constant thrust. It is shown that a similar vortex structure like in the neutrally buoyant cylinder case is obtained when the cylinder moves away from the approaching vortex pair at a constant speed smaller than the vortex pair translational velocity. Finally, the idealized symmetric settings are complemented by an asymmetric interaction of a vortex pair and a cylinder. This case is discussed for a fixed and a neutrally buoyant cylinder to show the validity of the derived relations for multi-dimensional body dynamics

The motion of the 2D hydrodynamic Chaplygin sleigh in the presence of circulation

We consider the motion of a planar rigid body in a potential flow with circulation and subject to a certain nonholonomic constraint. This model is related to the design of underwater vehicles. The equations of motion admit a reduction to a 2-dimensional nonlinear system, which is integrated explicitly. We show that the reduced system comprises both asymptotic and periodic dynamics separated by a critical value of the energy, and give a complete classification of types of the motion. Then we describe the whole variety of the trajectories of the body on the plane.Comment: 25 pages, 7 figures. This article uses some introductory material from arXiv:1109.321

The Dynamics of a Rigid Body in Potential Flow with Circulation

We consider the motion of a two-dimensional body of arbitrary shape in a planar irrotational, incompressible fluid with a given amount of circulation around the body. We derive the equations of motion for this system by performing symplectic reduction with respect to the group of volume-preserving diffeomorphisms and obtain the relevant Poisson structures after a further Poisson reduction with respect to the group of translations and rotations. In this way, we recover the equations of motion given for this system by Chaplygin and Lamb, and we give a geometric interpretation for the Kutta-Zhukowski force as a curvature-related effect. In addition, we show that the motion of a rigid body with circulation can be understood as a geodesic flow on a central extension of the special Euclidian group SE(2), and we relate the cocycle in the description of this central extension to a certain curvature tensor.Comment: 28 pages, 2 figures; v2: typos correcte

Identification of QTLs and candidate genes for high grain Fe and Zn concentration in sorghum [Sorghum bicolor (L.)Moench]

Sorghum is a major food crop in the semi-arid tropics of Africa and Asia. Enhancing the grain iron (Fe) and zinc (Zn) concentration in sorghum using genetic approaches would help alleviate micronutrient malnutrition in millions of poor people consuming sorghum as a staple food. To localize genomic regions associated with grain Fe and Zn, a sorghum F6 recombinant inbred line (RIL) population (342 lines derived from cross 296B PVK 801) was phenotyped in six environments, and genotyped with simple sequence repeat (SSR), DArT (Diversity Array Technology) and DArTSeq (Diversity Array Technology) markers. Highly significant genotype environment interactions were observed for both micronutrients. Grain Fe showed greater variation than Zn. A sorghum genetic map was constructed with 2088 markers (1148 DArTs, 927 DArTSeqs and 13 SSRs) covering 1355.52 cM with an average marker interval of 0.6 cM. Eleven QTLs (individual) and 3 QTLs (across) environments for Fe and Zn were identified. We identified putative candidate genes from the QTL interval of qfe7.1, qzn7.1, and qzn7.2 (across environments) located on SBI-07 involved in Fe and Zn metabolism. These were CYP71B34, and ZFP 8 (ZINC FINGER PROTEIN 8). After validation, the linked markers identified in this study can help in developing high grain Fe and Zn sorghum cultivars in sorghum improvement programs globally

Identification of QTLs and Underlying Candidate Genes Controlling Grain Fe and Zn Concentration in Sorghum [Sorghum bicolor (L).Moench]

Biofortification is one of sustainable options for combating micronutrient-malnutrition. For identifying genomic regions associated with grain Fe and Zn in sorghum, RIL population (342 individuals) from cross 296B × PVK 801 was phenotyped for two years at three locations and genotyped with SSRs and DArTs. Highly significant genotype×environment interactions were observed for both micronutrients; grain Fe showed greater variation than Zn. Sorghum genetic map was constructed with 2088 markers (1148 DArTs, 927 DArT Seqs and 13 SSRs) covering 1355.52 cM with an average marker interval of 0.6cM. A total of 18 QTLs controlling Fe and Zn were found stable across environments. Three QTLs for Fe and 15 for Zn were identified with phenotypic variance explained (PVE) values ranging from 3.94 to 5.09% and 3.17 to 9.42%, respectively. Of these 18 stable QTLs, 11 were located on chromosome SBI-07. Favorable alleles for 11 QTLs (co-located) for Fe and Zn on chromosome SBI-07 were contributed by parent PVK801-P23. QTLs were analyzed in-silico to identify underlying candidate genes, 62 candidate genes involved in Fe/Zn metabolism were identified within QTL interval; twenty-three were found in QTL with highest phenotypic effect (PVE 9.42%). Sorghum genes underlying Fe/Zn QTLs were used to analyze gene synteny with rice and maize. Synteny sequence level between sorghum-rice ranged from 44% to 97%, while sorghum-maize ranged from 49% to 99%. QTLs/candidate/novel genes along with the marker/genetic resources identified through this study can help in developing high Fe and Zn lines in cost-effective and efficient manner

ICHTHYODIVERSITY OF CHIKKLINGDALLI WATERBODY, WITH REFRENCE TO HYDROCHEMISTRY, KARANATAKA, INDIA

The present was carried out to document the diversity of fish fauna, economically important of fishes, status and Calculated Productivity Point CPP of fish species of Chikklingdalli water body Chincholli., India. A total number of fishes belonging to 5 families, 10 genus and 12 species were recorded. Highest 7 species recorded from family Cyprinidae, Siluridae 2 species, Channidae 01 species, Masticambidae 01 and Notopteridae 01 species. All the physic-chemical parameters are within the permissible limit. Present study suggests that the water temperature can positively correlated with, TDS, pH, total hardness

Synthesis of some newer analogues of substituted dibenzoyl phenol as potent anti-inflammatory agents

Benzoylation of hydroxybenzophenones 1a-f affords substituted benzoyl phenyl benzoates 3a-f, which on Fries rearrangement using microwave irradiation led to a facile synthesis of solely dibenzoyl phenols 4a-f in excellent yield. The newly synthesized compounds were screened for their anti-inflammatory activity and were compared with standard drugs. Out of the compounds studied, the compound 4e showed more potent activity than the standard drugs at all doses tested. (C) 2004 Elsevier Ltd. All rights reserved

PRIMARY PRODUCTIVITY AND PHYSICO-CHEMICAL PARAMETERS OF CHIKKLINGDALLI WATER BODY

The present study is carried out for estimation of primary productivity in relation to water quality of Chikklingadalli water body of Chinchollitaluk, Kalaburagi district, every month water samples were collected from the four different sampling sites of the water body from Feb 2016 to January 2018. Various water quality parameters including Atmospheric and water temperature, DO, Free CO2, Total alkalinity, Total hardness, Chloride, Nitrate, TDS etc. were estimated, whereas correlation and coefficient between parameters were analyzed. During the study period all the values of the physico-chemical parameters are within the permissible limit. Primary productivity values were recorded highest during summer season and   northeast monsoon season and lowest values recorded during the southwest monsoon season from study area. Data subjected to statistical analysis