Adiabatic Heavy Ion Fusion Potentials for Fusion at Deep Sub-barrier Energies

The fusion cross sections from well above barrier to extreme sub-barrier energies have been analysed using the energy (E) and angular momentum (L) dependent barrier penetration model ({\small{ELDBPM}}). From this analysis, the adiabatic limits of fusion barriers have been determined for a wide range of heavy ion systems. The empirical prescription of Wilzynska and Wilzynski has been used with modified radius parameter and surface tension coefficient values consistent with the parameterization of the nuclear masses. The adiabatic fusion barriers calculated from this prescription are in good agreement with the adiabatic barriers deduced from {\small{ELDBPM}} fits to fusion data. The nuclear potential diffuseness is larger at adiabatic limit, resulting in a lower $\hbar\omega$ leading to increase of "logarithmic slope" observed at energies well below the barrier. The effective fusion barrier radius and curvature values are anomalously smaller than the predictions of known empirical prescriptions. A detailed comparison of the systematics of fusion barrier with and without L-dependence has been presented.Comment: Revtex file of 6 pages and 3 eps figure

Entrance channel dependence in compound nuclear reactions with loosely bound nuclei

The measurement of light charged particles evaporated from the reaction 6,7Li+6Li has been carried out at extreme backward angle in the energy range 14 - 20 MeV. Calculations from the code ALICE91 show that the symmetry of the target-projectile combination and the choice of level density parameter play important roles in explaining the evaporation spectra for these light particle systems. In above barrier energy region the fusion cross-section is not suppressed for these loosely bound nuclei.Comment: 2 pages, 1 figur

Evaporation of alpha particles from 31^31P nucleus

The energy spectra of alpha particles have been measured in coincidence with the evaporation residues for the decay of the compound nucleus $^31$P produced in the reaction $^19$F (96 MeV) + $^12$C. The data have been compared with the predictions of the statistical model code CASCADE. It has been observed that significant deformation effect in the compound nucleus need to be considered in order to explain the shape of the evaporated alpha particle energy spectra.Comment: 4 pages, 3 figures, revtex, epsf styl

Role of the cluster structure of 7^7Li in the dynamics of fragment capture

Exclusive measurements of prompt $\gamma$-rays from the heavy-residues with various light charged particles in the $^7$Li + $^{198}$Pt system, at an energy near the Coulomb barrier (E/$V_b$ $\sim$ 1.6) are reported. Recent dynamic classical trajectory calculations, constrained by the measured fusion, $\alpha$ and $t$ capture cross-sections have been used to explain the excitation energy dependence of the residue cross-sections. These calculations distinctly illustrate a two step process, breakup followed by fusion in case of the capture of $t$ and $\alpha$ clusters; whereas for $^{6}$He + $p$ and $^{5}$He + $d$ configurations, massive transfer is inferred to be the dominant mechanism. The present work clearly demonstrates the role played by the cluster structures of $^7$Li in understanding the reaction dynamics at energies around the Coulomb barrier.Comment: 6 pages, 4 figures, Accepted for publication in Phys. Letts.

Coherent structures in numerically simulated jets with and without off-source heating

Direct numerical solutions of the incompressible Navier-Stokes equations, under the Boussinesq approximation, for the temporal evolution of a jet-like flow have been analyzed to educe coherent structures. The eduction procedure involved both conventional image processing and the application of the wavelet transform - here used as a spatially delimited filter to smooth out fine scale discontinuities and reveal the underlying order. Attention has been focussed on the vorticity and its components (azimuthal, radial and streamwise). It is found that the nature of the coherent motion is most strongly evident in the azimuthal component of the vorticity, and is revealed to consist of a toroidal base supporting a thin conical sheath; the interior of the structure is nearly devoid of azimuthal vorticity. There is some evidence of a secondary structure in the radial and streamwise components of the vorticity, which show strips of opposite sign close to each other, suggesting vortex pairs, possibly helically organized. With addition of volumetric heat after the (unheated) jet has achieved self-similarity, the structures tend to telescope into each other because of the acceleration produced by the heating, and the coherence present in the unheated jet is severely disrupted

Overlap syndrome of systemic lupus erythematosus and rheumatoid arthritis (“rhupus”) with systemic involvement – A rare case report

A 43 year old female, known hypothyroidism, presented with chest pain, breathlessness, without fever or rash, since 15 days. She had multiple joint pains since 11 months. Distal interphalyngeal joints were spared. She had hand deformities and tenderness in the metacarpophalyngeal and proximal interphalyngeal joints of all 10 fingers and both hips and knees. 2D-echo showed Pulmonary Hypertension. High resolution computed tomography of thorax showed non-specific interstitial pneumonia. She had anemia, raised C - reactive protein, positive indirect Coomb’s test. Her Anti-Nuclear antibody, rheumatoid factor, anti-Sm, anti-Sm/RNP and anti-Ro antibodies were positive. Her anti-Citrullinated peptide antibody was negative. As she satisfied the diagnostic criteria for both lupus and rheumatoid arthritis, she was diagnosed as a case of rhupus syndrome. She was treated with pulse injectable methylprednisolone for 3 days and then shifted to oral prednisone, along with hydroxychloroquine, oral methotrexate, sildenafil, pirfenidone and torsemide-spironolactone

TrueImage: A Machine Learning Algorithm to Improve the Quality of Telehealth Photos

Telehealth is an increasingly critical component of the health care ecosystem, especially due to the COVID-19 pandemic. Rapid adoption of telehealth has exposed limitations in the existing infrastructure. In this paper, we study and highlight photo quality as a major challenge in the telehealth workflow. We focus on teledermatology, where photo quality is particularly important; the framework proposed here can be generalized to other health domains. For telemedicine, dermatologists request that patients submit images of their lesions for assessment. However, these images are often of insufficient quality to make a clinical diagnosis since patients do not have experience taking clinical photos. A clinician has to manually triage poor quality images and request new images to be submitted, leading to wasted time for both the clinician and the patient. We propose an automated image assessment machine learning pipeline, TrueImage, to detect poor quality dermatology photos and to guide patients in taking better photos. Our experiments indicate that TrueImage can reject 50% of the sub-par quality images, while retaining 80% of good quality images patients send in, despite heterogeneity and limitations in the training data. These promising results suggest that our solution is feasible and can improve the quality of teledermatology care.Comment: 12 pages, 5 figures, Preprint of an article published in Pacific Symposium on Biocomputing \c{opyright} 2020 World Scientific Publishing Co., Singapore, http://psb.stanford.edu

Upper Bounds for the Average Error Probability of a Time-Hopping Wideband System

Abstract Ultra-wideband technology has been proposed as a viable solution for highspeed indoor short-range wireless communication systems because of its robustness to severe multipath and multi-user conditions, low cost, and low power implementation. Time-hopping combined with pulse position modulation was the original proposal for ultra-wideband systems. This paper proposes and analyzes a multiuser time-hopping system in which symbols are sent multiple times. A single-user receiver structure is proposed in which collisions with interfering users are discarded. Two formulas for the probability of error are derived. The first formula is a finite sum in which the number of terms grows with the number of symbol repetitions. The second formula is an integral that is well-suited to Chebyshev-Gauss quadrature as well as for allowing the derivation of bounds on the probability of error. Asymptotic formulas and upper bounds for the error probability are derived by letting various system parameters go to infinity. We evaluate the bounds numerically for some reasonable parameters and study their interplay with other parameters of interest