Reacceleration of Galactic Cosmic Rays Beyond the Knee at the Termination Shock of a Cosmic-Ray-Driven Galactic Wind

The origin of cosmic rays above the knee in the spectrum is an unsolved problem. We present a wind model in which interstellar gas flows along a non-rotating, expanding flux tube with a changing speed and cross-sectional area. Cosmic rays from Galactic sources, such as supernova remnants, which are coupled to the plasma via Alfv\'{e}n waves, provide the main pressure source for driving this outflow. These cosmic rays are then subject to diffusive shock reacceleration at the Galactic wind termination shock, which is located at a distance $\sim200\,{\rm kpc}$. Some of the highest-energy reaccelerated particles propagate upstream against the wind and can contribute to the PeV-EeV range of the spectrum. We analyze the conditions under which efficient reacceleration can occur and find that rigidities $\sim$ 10-40 PV can be obtained and that the termination shock may account for half of the proton spectrum measured in IceCube/IceTop experiment. The highest-energy particles that escape downstream from our termination shock, and similar shocks surrounding most galaxies, can be further accelerated by intergalactic shock fronts

Mental stress in infertility: a tertiary care hospital-based study

Background: Most of the couples suffering from infertility report it to be the most stressful and depressing period of their life, more so if it is a primary infertility. Studies regarding the prevalence and role of infertility-specific stress especially in eastern part of India is very limited. The objective of the present study was to estimate the prevalence of infertility-specific stress and its role in marital adjustment in women diagnosed with infertility.Methods: It was a cross-sectional study done on 80 married couple diagnosed with infertility (both primary and secondary) over 1 year from July 2016 to June,2017. Dyadic Adjustment Scale (DAS), "semi-structured questionnaire" compiled by the authors and "ICD-10 Classification of Mental and Behavioral Disorders (Clinical Descriptions and Diagnostic Guidelines)" were used for the evaluation. The analysis was done using SPSS (version 16) and Chi-square test.Results: Around 86% infertile women and 21% infertile men were found to suffer from mental stress. Infertility related stress were more in patients with primary infertility than in secondary one. Women mostly (56.5%) coped with stress by self-blaming whereas men (58.2%) by blaming the partner.Conclusions: Mental stress was significantly associated with infertility. In fact, maladjustment in marital relation caused by the stress adversely affected the conjugal life and thus also the fertility. Proper counselling of both partners might be helpful to solve this problem

Pregnancy with thalassemia: challenges and outcomes

Background: Thalassemia syndromes are autosomal recessive disorders and the most commonly inherited haemoglobinopathies in the world. HbE β is the most common type of thalassemia in eastern India. The objectives of the study include maternal outcome and complications like anemia, hypertensive disorders, gestational diabetes mellitus and also to study the neonatal outcome in terms of low birth weight, prematurity and other complications.Methods: A prospective longitudinal study carried out over a period of one year from July 2016 to June 2017 in Medical College, Kolkata. Fifty antenatal thalassemic mothers over 20 weeks of gestation during study period were enrolled in after institutional ethical clearance and consent from study subjects. All necessary investigations (complete haemogram, reticulocyte counts, Ultrasounds etc.) were done followed by statistical analysis.Results: Out of total 50 diagnosed thalassemic patients, maximum were HbE Beta Thal i.e. 54.0%. The mean level of iron in these women varied from 95.70±17.16µg/dl to 99.46±18.19µg/dl at the time of delivery and ferritin varied from 185.40±49.26µg/L vs 194.13±48.80µg/L. The mean blood transfusion done was 6.84 Units. Incidence of maternal complications were variable, PIH was found to be 26% whereas it was just 8% for GDM. The mean gestational age at delivery (Mean±SD) was 36.30±2.08 weeks. NICU admission was high (50%).Conclusions: Pregnancy with thalassemia is considered high risk, continuous pre-conceptional, antenatal and postpartum assessment should be done for favorable outcomes

A Hierarchical Framework for explaining the Cosmic Ray Spectrum using Diffusive Shock Acceleration

The hypothesis that the entire cosmic ray spectrum, from $\lesssim1\,{\rm GeV}$ to $\gtrsim100\,{\rm EeV}$ energy, can be accounted for by diffusive shock acceleration on increasingly large scales is critically examined. Specifically, it is conjectured that Galactic cosmic rays, up to $\sim3\,{\rm PeV}$, are mostly produced by local supernova remnants, from which they escape upstream. These cosmic rays initiate a powerful magnetocentrifugal wind, removing disk mass and angular momentum before passing through the Galactic Wind Termination Shock at a radius $\sim200\,{\rm kpc}$, where they can be re-accelerated to account for observed cosmic rays up to $\sim30\,{\rm PeV}$. The cosmic rays transmitted downstream from more powerful termination shocks associated with other galaxies can be further accelerated at Intergalactic Accretion Shocks to the highest energies observed. In this interpretation, the highest rigidity observed particles are protons; the highest energy particles are heavy nuclei, such as iron. A universal "bootstrap" prescription, coupling the energy density of the magnetic turbulence to that of the resonant cosmic rays, is proposed, initially for the highest energy particles escaping far ahead of the shock front and then scattering, successively, lower energy particles downstream. Observable implications of this general scheme relate to the spectrum, composition and sky distribution of Ultra-High-Energy Cosmic Rays, the extragalactic radio background, the Galactic halo magnetic field and Pevatrons.Comment: accepted for publication on Proceedings of Science for the 38th International Cosmic Ray Conference (ICRC2023

Role of shear stress in scratch deformation of soda-lime-silica glass

Various advance applications of glass demand high precision grinding and polishing of glass, a typical brittle material. The grinding and polishing are basically material removal by multiple scratches. In spite of the wealth of literature on soda-lime-silica glass, unfortunately however, the magnitudes of the maximum shear stresses generated beneath the moving indenter and the patterns of the shear stress contours are yet to be comprehensively understood. The stress beneath the indenter is required to be known to understand in a better way the damage evaluation processes as well as the material removal mechanisms as shear stress is the most important component of the stress tensor. Therefore, to develop a better understanding about the damage evolution and consequent material removal mechanisms the shear stress contours beneath the scratches made at four different normal loads of 2, 5, 10 and 15 N at scratching speed of 500 mu m/s were predicted using the Hertzian contact analysis. The extensive use of field emission scanning electron microscopy (FESEM) of the sub surface regions of the SLS glass revealed that three zones exist in the sub-surface region of the scratch grooves. The spatial extents of these three zones measured from the actual photomicrographs and the predictions were comparable. (C) 2012 Elsevier B.V. All rights reserved

Carbon Dots -A Turn-On Probe for Neurological Disorder

The creation of novel methods is essential for the early diagnosis and treatment of neurological illnesses (NDs). The blood-brain barrier (BBB), which can prevent substances from accessing the central nervous system, is the most difficult obstacle to overcome in the development of neural medication delivery systems (CNS). For several biological applications, carbon dots (CDs) have emerged as highly outstanding and promising agents, including the treatment of brain tumours, ND, and bioimaging research. Because of their great qualities, they have a lot of potential for a range of scientific disciplines due to their biocompatibility, tiny size, tunable optical properties, photostability, and straightforward fabrication processes. This article's goal is to provide a summary of current CD research and to make recommendations for future work on creating neural drug delivery systems that can penetrate the BBB and reach the central nervous system. The two main subjects of this review are CD toxicity and unique optical properties. For a variety of neurological illnesses, a unique CD-based drug delivery system is designed in detail. This study also explores the possible applications of CDs for neurodegenerative disease therapies and imaging of brain tumours. The final section provides a summary of present CD sensing applications and projected future developments

Novel combined scretch and nanoindentation experiments on soda-lime-silica glass

Many advanced applications of glass demand fabrication of engineering parts of utmost dimensional precision which require very accurate grinding and polishing that involves controlled removal of glass. Despite the wealth of literature, however; the mechanism of material removal in glass grinding and polishing is still far from well understood. For instance, it is not known at all to what extent the mechanical properties are compromised inside a scratch groove so as to optimize the machining parameters. Therefore, to develop better understanding about the mechanism of material removal, a series of combined nanoindentation and single pass scratch experiments were conducted on a commercially available soda-lime-silica glass as a function of various normal loads (2–20 N) and scratch speeds (0.1–1 mm/s). It was found that the nanohardness and Young’s modulus at the local microstructural length scale inside the scratch groove could decrease quite dramatically (~30% to 70%) depending on the combination of load and scratching speed. Further, the tribological properties, the severity and the spatial density of damage evolution were sensitive to the normal loads, scratching speeds, and tensile stresses. Extensive scanning electron microscopy leads to interesting observations on material removal mechanisms. These observations were explained by the theoretical predictions of a model for a brittle, microcracked solid