2,598 research outputs found

    Spin-String Interaction in QCD Strings

    Full text link
    I consider the question of the interaction between a QCD string and the spin of a quark or an antiquark on whose worldline the string terminates. The problem is analysed from the point of view of a string representation for the expectation value of a Wilson loop for a spin-half particle. A string representation of the super Wilson loop is obtained starting from an effective string representation of a Wilson Loop. The action obtained in this manner is invariant under a worldline supersymmetry and has a boundary term which contains the spin-string interaction. For rectangular loops the spin-string interaction vanishes and there is no spin-spin term in the resulting heavy quark potential. On the other hand if an allowance is made for the finite intrinsic thickness of the flux-tube, by assuming that the spin-string interaction takes place not just at the boundary of the string world-sheet but extends to a distance of the order of the intrinsic thickness of the flux tube, then we do obtain a spin-spin interaction which falls as the fifth power of the distance. Such a term was previously suggested by Kogut and Parisi in the context of a flux-tube model of confinement.Comment: 19 pages, 1 figure; Published version with added discussion and references in section

    Free Response of Shells on Flexible Foundation

    Get PDF
    Free response of axisymmetric shells resting on flexible foundation in their asymmetric modes is studied using Finite Elements based on harmonic formulation. Influence of various parameters, such as subgrade modulus, proximity of boundary, density ratio, shear wave velocity, embedment of structure and depth of flexible foundation., on free response is studied. Axisymmetric interface element with harmonic functions is developed and introduced between the raft slab and foundation media

    Heavy Quark Potential from Gauge/Gravity Duality: A Large D Analysis

    Full text link
    The heavy-quark potential is calculated in the framework of gauge/gravity duality using the large-D approximation, where D is the number of dimensions transverse to the flux tube connecting a quark and an antiquark in a flat D+2-dimensional spacetime. We find that in the large-D limit the leading correction to the ground-state energy, as given by an effective Nambu-Goto string, arises not from the heavy modes but from the behavior of the massless modes in the vicinity of the quark and the antiquark. We estimate this correction and find that it should be visible in the near-future lattice QCD calculations of the heavy-quark potential.Comment: 22 pages, 5 Figures. v2: references added, typos corrected and, Sec. 4 rewritten with an expanded non-perturbative discussion of the corrections to the Arvis potential arising from the massless modes near the boundary of the qcd strin

    Phyllanthus Niruri: A magic Herb

    Get PDF
    Medicinal herbs are significant source of pharmaceutical drugs. Latest trends have shown increasing demand of phytodrugs and some medicinal herbs have proven hepatotprotective potential. Inflammation describes a coordinated series of molecular, cellular, tissue, organ, and systemic responses that drive the pathology of various diseases Inflammation is a finely tuned, dynamic, highly-regulated process that is not inherently detrimental, but rather required for immune surveillance, optimal post-injury tissue repair, and regeneration. The inflammatory response is driven by cytokines and chemokines and is partially propagated by damaged tissue-derived products (Damage-associated Molecular Patterns; DAMP’s). DAMPs perpetuate inflammation through the release of proinflammatory cytokines, but may also inhibit anti-inflammatory cytokines

    Changing trends in fetomaternal outcome in COVID-19 in pregnancy

    Get PDF
    Background: This study is to provide an overview of the clinical course and outcome of COVID in pregnancy in both first wave and second wave, to study about different parameters affected significantly in both waves.Methods: This is a retrospective comparative study that was conducted by dividing the patients into group 1 and group 2. Group 1 was treated in 2020 (wave 1) whereas group 2 in 2021 (wave 2). A laboratory confirmed positive cases of COVID-19 infection in pregnant women were included. All the patients were further categorized into mild, moderate and severe subgroups according to the ICMR criteria. Results: The study of the first (2020) and second (2021) wave of COVID-19. In group 1 and group 2, there were a total of 359 cases and 145 cases respectively. In group 1, there were 54/359 (15.04%) moderate cases and in group 2 there were 17/145 (11.72%) moderate cases. While there were 101/359 (28.13%) and 106/145 (73.10%) severe cases in group 1 and group 2 respectively. Most of severe cases of second group associated with breathlessness, tachypnoea and fall in oxygen saturation level ended with mechanical ventilation by O2 mask (7.54%), NRBM (8.49%), HFNC (14.15%), BIPAP (12.26%), invasive ventilation (22.64%). Conclusions: The results of study show that hospitalized patients in the second wave were younger, required hospitalization, and had higher mortality rates

    Study of various treatment modalities of caesarean scar pregnancy

    Get PDF
    Background: Caesarean scar pregnancy (CSP) can be defined as the implantation of the gestational sac within the scar of a previous caesarean surgery. Incidence of CSP is 1 in 1800 pregnancies.Methods: It is a retrospective study based on clinical diagnosis and management of CSP of women who presented to the obstetrics and gynaecology department SVP hospital from January 2008 to August 2021. Total number of cases of CSP were 28. Incidence, gestational age, ultrasound findings, serum β-human chorionic gonadotropin (β-hCG) levels, flow profiles of color Doppler, and different methods of treatment were recorded. Diagnosis was confirmed by ultrasound.Results: In this study, all 28 cases of CSP considered were offered definitive management. In present study 5 cases (17.88%) showed torrential haemorrhage during dilatation and evacuation (D and E) which was treated by various methods like 1 (3.57%) Foley’s tamponade, 1 (3.57%) uterine artery embolization (UAE) and 3 (10.71%) hysterectomy. Hysterotomy was performed in 13 cases (46.42%) and (7.69%) of heterotrophic CSP (HCSP). One case (3.84%) of CSP presented at 26 weeks of gestation with haemorrhagic shock, underwent obstetric hysterectomy.Conclusions: There is a rise in the incidence of CSP because of increase in the global rate of caesarean sections and early transvaginal USG in pregnancy. Transvaginal sonography is the best diagnostic tool. Medical management can be offered when diagnosis is made at gestational age of 7 weeks of gestational age. Surgical management has an advantage of shorter follow up.

    Random matrix ensemble with random two-body interactions in presence of a mean-field for spin one boson systems

    Full text link
    For mm number of bosons, carrying spin (SS=1) degree of freedom, in Ω\Omega number of single particle orbitals, each triply degenerate, we introduce and analyze embedded Gaussian orthogonal ensemble of random matrices generated by random two-body interactions that are spin (S) scalar [BEGOE(2)-S1S1]. The embedding algebra is U(3)GG1SO(3)U(3) \supset G \supset G1 \otimes SO(3) with SO(3) generating spin SS. A method for constructing the ensembles in fixed-(mm, SS) space has been developed. Numerical calculations show that the form of the fixed-(mm, SS) density of states is close to Gaussian and level fluctuations follow GOE. Propagation formulas for the fixed-(mm, SS) space energy centroids and spectral variances are derived for a general one plus two-body Hamiltonian preserving spin. In addition to these, we also introduce two different pairing symmetry algebras in the space defined by BEGOE(2)-S1S1 and the structure of ground states is studied for each paring symmetry.Comment: 22 pages, 6 figure
    corecore