2,527 research outputs found

    From fusion to total disassembly: global stopping in heavy-ion collisions

    Full text link
    Using the quantum molecular dynamics model, we aim to investigate the emis- sion of light complex particles, and degree of stopping reached in heavy-ion colli- sions. We took incident energies between 50 and 1000 MeV/nucleon. In addition, central and peripheral collisions and different masses are also considered. We ob- serve that the light complex particles act in almost similar manner as anisotropic ratio. In other words, multiplicity of light complex particles is an indicator of global stopping in heavy-ion collisions. We see that maximum light complex particles and stopping is obtained for heavier masses in central collisions

    Understanding the agglomeration behavior of nickel laterite and gold ores using statistical design of experiments

    Get PDF
    pre-printThe drum agglomeration of nickel laterite and gold ores has been optimized through the design of experiments (DOE) using a Taguchi L16 (45) orthogonal array to determine the optimum conditions for maximizing average agglomerate size and minimizing the amount of fines. The effects of controllable operating factors including moisture content (nickel laterite ore: 34-37%; gold ore: 7-10%), retention time (2-3.5 min), drum speed (15-45% critical speed), drum load (nickel laterite ore: 8-32 %; gold ore: 6-22%) and acid concentration (150-600 g/L) on the performance of the agglomeration process were studied. For nickel laterite ore, maximum average agglomerate size and minimum percent fines (-1 mm) occurred under the following conditions: drum load (23.7%), moisture (36.5%), time (3 min), drum speed (30% critical speed) and acid concentration (150 g/L). Under the studied nickel laterite ore conditions, the most effective parameters for maximizing average agglomerate size and minimizing the amount of fines were found to be drum load and acid concentration, respectively. Drum speed had a statistically significant effect on minimizing the amount of fines. Maximum average agglomerate size and minimum percent fines (-1 mm) for gold ore occurred under the following conditions: drum load (19.3%), moisture (8.5%), time (2 min 15 s) and drum speed (40% critical). The most significant factors for maximizing average agglomerate size and minimizing the amount of fines for gold ore were found to be drum load, time and moisture

    A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass

    Full text link
    Using the Very Long Baseline Array, we have measured a trigonometric parallax for the micro quasar GRS 1915+105, which contains a black hole and a K-giant companion. This yields a direct distance estimate of 8.6 (+2.0,-1.6) kpc and a revised estimate for the mass of the black hole of 12.4 (+2.0,-1.8) Msun. GRS 1915+105 is at about the same distance as some HII regions and water masers associated with high-mass star formation in the Sagittarius spiral arm of the Galaxy. The absolute proper motion of GRS 1915+105 is -3.19 +/- 0.03 mas/y and -6.24 +/- 0.05 mas/y toward the east and north, respectively, which corresponds to a modest peculiar speed of 22 +/-24 km/s at the parallax distance, suggesting that the binary did not receive a large velocity kick when the black hole formed. On one observational epoch, GRS 1915+105 displayed superluminal motion along the direction of its approaching jet. Considering previous observations of jet motions, the jet in GRS 1915+105 can be modeled with a jet inclination to the line of sight of 60 +/- 5 deg and a variable flow speed between 0.65c and 0.81c, which possibly indicates deceleration of the jet at distances from the black hole >2000 AU. Finally, using our measurements of distance and estimates of black hole mass and inclination, we provisionally confirm our earlier result that the black hole is spinning very rapidly.Comment: 20 pages; 2 tables; 6 figure

    PMD28 CHALLENGES FOR MODEL-BASED ECONOMIC EVALUATIONS OF GLAUCOMA AND OCULAR HYPERTENSION TREATMENTS

    Get PDF

    IN VIVO RADIOPROTECTIVE EFFECTS OF WHEATGRASS (TRITICUM AESTIVUM) EXTRACT AGAINST X-IRRADAITION-INDUCED OXIDATIVE STRESS AND APOPTOSIS IN PERIPHERAL BLOOD LYMPHOCYTES IN RATS

    Get PDF
     Objectives: The present study was undertaken to investigate the possible protective potential of wheatgrass extract against radiation-induced toxicity in peripheral lymphocytes of rats exposed to a fractionated dose of X-rays.Methods: Effects of the X-irradiation with and without wheatgrass were studied on various parameters in peripheral lymphocytes including antioxidant defense system and apoptosis. Male Sprague-Dawley rats were divided into four different groups: Normal control group, X-ray-irradiated group (21 Gy over a span of 7 days), wheatgrass-treated group (80 mg/100 g bodyweight for 2 weeks), and X-rays-irradiated + wheatgrass-treated group. All the biochemical indices which included lipid peroxidation (LPO), reduced glutathione, reactive oxygen species (ROS), and activities of antioxidant enzymes were investigated in lymphocytes. Terminal deoxynucleotidyl transferase dUTP nick-end labeling assay was carried out to assess the apoptosis in lymphocytes following whole-body X-irradiation.Results: Whole-body X-irradiation to rats resulted in significant increase in LPO with concomitant depression of antioxidant enzymes activities, namely, superoxide dismutase, catalase, and glutathione peroxidise (GPx) in lymphocytes. Further, the present study witnessed a significant increase in the number of apoptotic lymphocytes in the X-irradiated animals. However, wheatgrass supplementation lowered the LPO levels, restored cellular antioxidant status, and provided significant protection against radiation-induced apoptosis.Conclusions: Based on these observations, the present study suggests that wheatgrass extract has the potential to be used as an effective radioprotectant against radiation-induced oxidative stress and apoptosis in peripheral lymphocytes of whole-body X-ray-exposed rats

    Development of nano-structured titanium oxide thin films using a gas carving technique

    Get PDF
    A method is developed for producing nano-structured titanium oxide thin films using H2 gas interaction with titanium thin film at a high temperature. These nano-structured thin films have been formed on a quartz crystal substrate. Titanium (Ti) thin films were deposited on the quartz crystal using a RF magnetron sputterer. The samples were placed in the oven at 500-800°C for 5 hours. The gas mixture of 1% H2 in N2 was introduced in the oven. The process of Ti annealing in the presence of H2 carves Ti films into nano-structure shapes. The process is a gas-solid interaction. Thin films were characterised using Scanning Electron Microscopes (SEM) and X-Ray Diffraction (XRD) technique. The nano structures formed have dimensions in a range of 25nm - 150nm obtained after gas carving

    Effect of plant and animal protein sources on the growth, gonadal maturity and proximate composition of Labeo rohita (Hamilton, 1822)

    Get PDF
    The aim of the present study was to evaluate the effect of plant and animal sources in the diet of Labeo rohita with an overall goal of gaining sustainable fish and egg production. Fishes with an initial weight of 310-323 g were fed with five different isocaloric (3Kcalg-1) diets viz. D1 ( control diet- 30% rice bran + 70% groundnut meal), D2 (30% rice bran + 50% groundnut meal + 20% fish meal), D3 (30% rice bran + 50% groundnut meal + 20% mustard meal), D4 (30% rice bran + 30% groundnut meal + 20% mustard meal + 20 % fish meal) and D5 (30% rice bran + 30% soybean meal + 20% mustard meal + 20 % fish meal) @ 3% of fish biomass for 270 days. Significantly higher weight gain and better gonadal maturity was recorded in fishes fed with diet containing fish meal than other. Among diets containing fish meal (D2, D4, D5), fish fed on diet D2 resulted in higher somatic growth (35.67, 42.80, 28.10 and 18.48% higher net weight gain than D1, D3, D4 and D5, respectively) and better gonadal development (43.20, 50.08, 22.59 and 23.25% higher absolute fecundity than D1, D3, D4 and D5,respectively) in L. rohita. Hence, Our study revealed that for higher growth and better broodstock development, L. rohita may be fed on diet formulated with 30% rice bran, 50% groundnut meal and 20% fish meal

    Switching Language Modes: Complementary Brain Patterns for Formulaic and Propositional Language

    Get PDF
    © John J. Sidtis et al. 2018. Language has been modeled as a rule governed behavior for generating an unlimited number of novel utterances using phonological, syntactic, and lexical processes. This view of language as essentially propositional is expanding as a contributory role of formulaic expressions (e.g., you know, have a nice day, how are you?) is increasingly recognized. The basic features of the functional anatomy of this language system have been described by studies of brain damage: left lateralization for propositional language and greater right lateralization and basal ganglia involvement for formulaic expressions. Positron emission tomography (PET) studies of cerebral blood flow (CBF) have established a cortical-subcortical pattern of brain activity predictive of syllable rate during phonological/lexical repetition. The same analytic approach was applied to analyzing brain images obtained during spontaneous monologues. Sixteen normal, right-handed, native English speakers underwent PET scanning during several language tasks. Speech rate for the repetition of phonological/lexical items was predicted by increased CBF in the left inferior frontal region and decreased CBF in the head of the right caudate nucleus, replicating previous results. A complementary cortical-subcortical pattern (CBF increased in the right inferior frontal region and decreased in the left caudate) was predictive of the use of speech formulas during monologue speech. The use of propositional language during the monologues was associated with strong left lateralization (increased CBF at the left inferior frontal region and decreased CBF at the right inferior frontal region). Normal communication involves the integration of two language modes, formulaic and novel, that have different neural substrates

    Stability of the fragments and thermalization at peak center-of-mass energy

    Full text link
    We simulate the central reactions of nearly symmetric, and asymmetric systems, for the energies at which the maximum production of IMFs occurs (Ec.m.peak_{c.m.}^{peak}).This study is carried out by using hard EOS along with cugnon cross section and employing MSTB method for clusterization. We study the various properties of fragments. The stability of fragments is checked through persistence coefficient and gain term. The information about the thermalization and stopping in heavy-ion collisions is obtained via relative momentum, anisotropy ratio, and rapidity distribution. We find that for a complete stopping of incoming nuclei very heavy systems are required. The mass dependence of various quantities (such as average and maximum central density, collision dynamics as well as the time zone for hot and dense nuclear matter) is also presented. In all cases (i.e., average and maximum central density, collision dynamics as well as the time zone for hot and dense nuclear matter) a power law dependence is obtained.Comment: 21 Pages, 8 Figure

    Pomegranate Peel Extract Decreases Plaque Necrosis and Advanced Atherosclerosis Progression in Apoe(-/-) Mice

    Get PDF
    Atherosclerosis is a chronic lipid-driven inflammatory condition of the arteries and is a leading cause of stroke, myocardial infarction, and other peripheral arterial diseases. Plant products rich in polyphenols such as pomegranate juice and peel extract are known to have beneficial effects in suppressing atherogenesis. However, the mechanism of action and its effect on advanced atherosclerosis progression which results in adverse clinical outcomes are not well understood. Herein, we use a standardized hydroethanolic extract of Punica granatum (pomegranate) peel in the Apoe ( -/- ) a murine model of advanced atherosclerosis. It was observed that the pomegranate peel extract fed mice have decreased plaque necrosis and elevated lesional collagen content which was associated with a favorable metabolic profile including lowering of blood glucose, cholesterol, and triglyceride. The decrease in plaque necrosis was linked with increased lesional macrophage efferocytosis efficiency which was associated with enhanced expression of the efferocytosis receptor Mertk. Using in vitro studies, we show that pomegranate peel extract blocks the shedding of Mertk and preserves macrophage efferocytosis efficiency. These data identify a novel mechanism by which pomegranate peel extract promotes the resolution of inflammation in atherosclerosis
    • …
    corecore