Study of thermal stability in Se90Sb10-xAgx glassy alloys

Alloys of Se100-xSb10-xAgx (x=2, 4 &8) glassy system have been obtained by quenching technique. Kinetic parameters, which represent thermal stability, have been determined from differential scanning calorimetric technique. The rate of crystallization decreases with Ag concentration and is lowest for glassy Se90Sb2Ag8 alloy. Thermal stability (Tc-Tg), Hruby criterion Hr , Saad Poulain ‘S’ have been found to increase with Ag concentration and are maximum for Se90Sb2Ag8. Thus, one can conclude that the rate of crystallization is related to the thermal stability. The reduced glass transition temperature for Se90Sb10-xAgx is found to be 2/3, which shows that these glassy alloys are suitable for phase change optical memories

Analysis of ankle alignment abnormalities as a risk factor for pediatric flexible flat foot

Majority of paediatric flat feet are flexible and asymptomatic;less than 0.1% of all flat feet are rigid. If these can be diagnosed and managed early, then various complications can be prevented and they will remain asymptomatic. This study was conducted to analyse the ankle rotational malalignments in the natural course of flexible flat foot in children. Seventy-six patients of flexible flat foot and one hundred controls were included in this study. The height of foot arches was judged clinically by inspecting the height of the medial arch and by measuring the arch index on weight-bearing podograms. Tibial torsion and bimalleolar angle were assessed in all subjects. Tibial torsion was assessed in the first twenty subjects (ten cases and ten controls) both by clinical methods (foot-thigh angle) and CT. As no statistical difference in the two methods was observed, tibial torsion was measured by clinical methods only in the remaining subjects. Bimalleolar angle was measured on weight-bearing podograms in all subjects. For a minimum of two years, cases were followed up regularly with a standard conservative protocol and the height of the arches observed. Majority of cases of flexible flat foot were found to have increased tibial torsion and increased foot-bimalleolar angle (high talar spin). The severity of collapse of the medial arch and the response to conservative treatment was found to correlate with these rotational mal-alignments of the ankle. Ankle rotational mal-alignments were seen to make these flexible flat foot deformities more complex and less responsive to conservative treatment.KEY WORDS: Flat foot; Pediatric flat feet; Flexible flat fee

Intensity interferometry of thermal photons from relativistic heavy ion collisions

Intensity interferometry of thermal photons, having transverse momenta $k_T \approx$ 0.1 -- 2.0 GeV, produced in relativistic collision of heavy nuclei is studied. It is seen to provide an accurate information about the temporal and spatial structure of the interacting system. The source dimensions and their $k_T$ dependence revealed by the photon interferometry, display a richness not seen in pion interferometry. We attribute this to difference in the source functions, the fact that photons come out from every stage of the collision and from every point in the system, and the fact that the rate of production of photons is different for the quark-gluon plasma, which dominates the early hot stage, and the hadronic matter which populates the last phase of the collision dynamics. The usefulness of this procedure is demonstrated by an application to collision of lead nuclei at the CERN SPS. Prediction for the transverse momentum dependence of the sizes for SPS, RHIC, and LHC energies are given.Comment: 16 pages, 11 figures. Added discussions and references. To appear in Phys. Rev.

Fingertip reconstruction: study of functional and cosmetic results of various local flaps and grafting techniques in patients attending a tertiary care center in North India

Background: Finger injuries are becoming more common with the increasing use of mechanical, industrial, and household appliances. There are six main types of repair for this injury. The replacement of skin loss in digital injuries, particularly on the volar aspects, is an important part of hand-injury management. It would be of value to know the best type of cover, especially for sensory reinnervation as well as for subjective evaluation, cosmetic appearance and freedom from complications. The objective of this study was to measure incidence of age, sex, site, pattern of injury as well as to evaluate and compare the functional and cosmetic results of the various local flap and grafting techniques in finger reconstruction distal to metacarpophalangeal joint.Methods: In a prospective study between May 2014 to October 2018 consisting of 50 patients (43 males, 7 females), aged between 2 years and 54 years, with soft tissue loss distal to metacarpophalangeal joint were treated with either free split-thickness skin grafts, palmar flaps, cross-finger flap or pedicle flaps from the abdomen. The follow-up period ranged from 10 days to 15 months from the date of surgery. Subjective and objective evaluation was done and graded as excellent, good, fair and poor.Results: In this series there were 2 good and 6 fair results for split skin grafting; 9 good and 6 fair results for v-y plasty; 5 excellent, 12 good and 4 fair results for cross finger flap; 1 good and 1 fair result for radial artery based flap; 1 excellent and 1 good for first metacarpal artery based flap and 2 good results for abdominal flap. Overall 6(12%) had excellent, 27(54%) had good and 17(34%) had fair results. None of them had poor results.Conclusions: The group of patients with cross-finger flaps had less subjective complaints and more normal objective testing results than the other groups. When an extensive tactile pad avulsion exists, the cross-finger pedicle flap offers the best long-term result with fewer secondary problems. The exclusive use of any one method cannot be advocated since each serves an useful purpose under proper conditions

Indications and effectiveness of arthroscopic lavage and debridement in osteoarthritis knee

Background: Degenerative joint disease will afflict most of the people if they live long enough. The majority of patients with osteoarthritis present to orthopaedic surgeons seeking relief of pain and associated restoration of function. Various intraarticular and periarticular structures may be the cause of pain. Improvement in osteoarthritis by arthroscopic lavage and debridement is seen due to various mechanisms.Methods: In a prospective study from July 2016 to December 2018, 35 patients with primary osteoarthritis knee were assessed for effectiveness of arthroscopic lavage and debridement in relieving symptoms of osteoarthritis of knee and to determine the indications of arthroscopy in osteoarthritis of knee. Assessment was done using variables as age of the patient, body mass index, varus deformity, radiographic grading and arthroscopic grading.Results: A declining trend was seen on follow up over time; 91.4% excellent to good results seen at one month follow up, 76.1% at six months, 49.93% at twelve months, 37.5%, at eighteen months, 23.07% at twenty-four months and 28.5% at thirty months. Results at six month follow up when compared, were better for age less than 50 years (88.8% Vs 73.1% in >50 years age), normal weight patients with BMI 18.5 to 25(94.5% Vs 58.5% in overweight), varus angulation 100), radiological grade I and II (95-100% Vs 45-50% in grade III and IV) and arthroscopic grade I and II (94-100% Vs 0-77% in grade III and IV).Conclusions: Arthroscopic lavage and debridement is an effective method of treatment for osteoarthritis knee in patients with grade I and grade II osteoarthritis having symptoms of pain and locking due to loose bodies or degenerative meniscal tears

Structural and magnetic phenomena in Ni53Mn25Al22 thin film prepared by rf magnetron sputtering

Magnetic and structural properties of Ni–Mn–Al thin films are investigated. It is demonstrated that the annealed film shows L21 phase at room temperature. Magnetometry measurements reveal that the annealed film is ferromagnetic and a first order transition in magnetization versus temperature measurement confirms that the martensite to austenite transition occurs around room temperature. Transmission electron microscopy measurements confirm that this structural change occurs just below room temperature. The splitting of Mn 2p3/2 level in x-ray photoelectron spectroscopy core level spectra of the annealed Ni–Mn–Al film, confirms that the origin of magnetism is definitely correlated with the local magnetic moment at the Mn atoms

Modeling and optimal control of dengue disease with screening and information

This study presents a mathematical model for dengue transmission which quantifies two very important aspects: one, the impact of information-based behavioural response, and the other, the segregation of infected human population into two subclasses, ‘detected’ and ‘undetected’. For the proposed model, the sensitivity analysis is conducted to identify the key model parameters which not only influence the basic reproduction number, but also regulate the transmission of dengue. Further, in order to find the optimal pathways for suitable control interventions that reduce the dengue prevalence and economic burden, an optimal control problem is proposed by considering information-induced behavioural change, quarantine, screening, use of repulsive measures and culling of mosquitoes as control interventions. A weighted sum of various costs incurred in applied controls and the cost due to dengue disease (productivity loss) is incorporated in the proposed cost functional. The analysis of control system using Pontryagin’s maximum principle leads the existence of the optimal control profiles. Further, an exhaustive comparative study for seven different control strategies is conducted numerically. Our findings emphasize that every individual control strategy has their own impact on reducing the cumulative count of infection as well as cost. The combined impact of all control interventions is highly effective and economically viable in controlling the prevalence of dengue. We also investigated the effect of the basic reproduction number on the designed control strategies and observed that the comprehensive use of controls keeps a strong tab on the infective even if the severity of epidemic is high

Unexplored photoluminescence from bulk and mechanically exfoliated few layers of Bi2Te3

We report the exotic photoluminescence (PL) behaviour of 3D topological insulator Bi2Te3 single crystals grown by customized self-flux method and mechanically exfoliated few layers (18 plus minus 2 nm)/thin flakes obtained by standard scotch tape method from as grown Bi2Te3 crystals.The experimental PL studies on bulk single crystal and mechanically exfoliated few layers of Bi2Te3 evidenced a broad red emission in the visible region. These findings are in good agreement with our theoretical results obtained using the ab initio density functional theory framework.Comment: Main MS (17 Pages text including 4 Figs): Suppl. info. (4 pages); Accepted Scientific Report

Spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites

Correlation-induced spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites are calculated with realistic parameters in order to provide a quantitative comparison with experimental results for spin stiffness, magnon dispersion, magnon damping, anomalous zone-boundary magnon softening, and Curie temperature. The role of orbital degeneracy, orbital ordering, and orbital correlations on spin dynamics in different doping regimes is highlighted.Comment: 19 pages, 9 figure