Revisiting Low Resource Status of Indian Languages in Machine Translation

Indian language machine translation performance is hampered due to the lack of large scale multi-lingual sentence aligned corpora and robust benchmarks. Through this paper, we provide and analyse an automated framework to obtain such a corpus for Indian language neural machine translation (NMT) systems. Our pipeline consists of a baseline NMT system, a retrieval module, and an alignment module that is used to work with publicly available websites such as press releases by the government. The main contribution towards this effort is to obtain an incremental method that uses the above pipeline to iteratively improve the size of the corpus as well as improve each of the components of our system. Through our work, we also evaluate the design choices such as the choice of pivoting language and the effect of iterative incremental increase in corpus size. Our work in addition to providing an automated framework also results in generating a relatively larger corpus as compared to existing corpora that are available for Indian languages. This corpus helps us obtain substantially improved results on the publicly available WAT evaluation benchmark and other standard evaluation benchmarks.Comment: 10 pages, few figures, Preprint under revie

An ab initio study of muscovite mica and formation energy of ions in liquid water

Fest/Flüssig Grenzflächen sind maßgebend für zahlreiche elektrochemische Prozesse und Anwendungen, wie etwa Batterien, Brennstoffzellen, Energiewandlung, Korrosion und viele mehr. Eine Voraussetzung für die erkenntnisorientierte Entwicklung und Verbesserung dieser Prozesse ist ein tiefgehendes Verständnis der elementaren Prozesse, welche an der Grenzfläche ablaufen. In der vorliegenden Arbeit werden Elektronenstrukturrechnungen verwendet, um Grundlegende Fragen zur Fest/Flüssig Grenzfläche, am Beispield der Wasser/Mica Grenzfläche, zu untersuchen. Die Genauigkeit welche benötigt wird, um die individuellen Bestandteile (Mica, Wasser und Ionen in Wasser) zu beschreiben, ist mittels Dichtefunktionaltheorieberechnungen mit verschiedenen Funktionalen bewertet worden. Eine Methode zur Berechnung von Ionenformationsenergien und Übergangsniveaus ist anhand repräsentativer Kationen (Zn, Mg) und Anionen (Cl, Br, I) erläutert

Probing the Effect of Aliphatic Ionic Liquids on Asphaltene Aggregation Using Classical Molecular Dynamics Simulations

One of the major constituents of heavy oil is asphaltenes. They are responsible for numerous problems in petroleum downstream and upstream processes, such as catalyst deactivation in heavy oil processing and blocking pipes while transporting crude oil. Probing the efficiency of new nonhazardous solvents in separating asphaltenes from crude oil is key to avoid conventional volatile and hazardous solvents by replacing these conventional solvents with new ones. In this work, we have investigated the efficiency of ionic liquids to separate asphaltenes from organic solvents (such as toluene and hexane) using molecular dynamics simulations. Triethylammonium-dihydrogen-phosphate and triethylammonium acetate ionic liquids are considered in this work. Various structural and dynamical properties are calculated, such as radial distribution function, end-to-end distance, trajectory density contour, and diffusivity of asphaltene in the ionic liquid-organic solvent mixture. Our results explain the role of anions, i.e., dihydrogen-phosphate and acetate ions, in separating asphaltene from toluene and hexane. Our study provides an important revelation about the dominant role played by the IL anion in intermolecular interactions which depends on the type of solvent (i.e., toluene or hexane) in which the asphaltene is present. The anion induces enhanced aggregation in the asphaltene-hexane mixture compared to the asphaltene-toluene mixture. The molecular insights obtained within this study on the role played by ionic liquid anion in asphaltene separation are key for the preparation of new ionic liquids for asphaltene precipitation applications.</p

Electric Field Induced Patterning of Thin Coatings on Fiber Surfaces

We explore the electric field induced instabilities of a thin liquid film coated on a fiber surface. Thin liquid films on the curved surfaces spontaneously self-organize into interesting patterns such as a string of beads/droplets when the destabilizing radial curvature force dominate over the stabilizing in plane curvature. Application of an external electrostatic field in such a situation opens up the added possibility of fabricating ridge like structures issuing outward from the film surface when electric field dominates over the curvature forces. With the help of a general linear stability analysis and long-wave nonlinear simulations, the study uncovers the conditions under which the ridges and beads form on the fiber surface. In particular, we show that the ridges are favored morphologies when electric field is stronger because of higher film to air filling ratio in between the electrodes, higher applied voltage, and larger fiber radius. The beads and the ridges are found to coexist when the destabilizing forces are equally dominant whereas only beads are formed when the radial curvature force is the dominant destabilizing force. The analysis also shows that tuning the voltage, fiber radius, and film thickness, length scales ranging from a few hundred nanometers to a few micrometers can be achieved for all these morphologies. The results reported can potentially be exploited in the applications related to the field-induced microfabrication on the curved surfaces

Mathematical modelling of a single tethered aerostat using longitudinal stability derivatives

Abstract Lighter-than-air (LTA) aerial vehicles such as airships and aerostats can be found in various strategic and commercial applications, primarily due to their capability to hover and stealth. The mathematical model of these vehicles helps in understanding their complex dynamics and designing and developing proper stabilisation systems for them. Stability derivatives have been used for developing mathematical models for heavier-than-air aerial vehicles since their introduction. This paper presents a methodology to develop a mathematical model of an aerostat based on stability derivatives. One of the major contributions of this study is the estimation of aerostat’s added mass terms expressed as longitudinal stability derivatives due to acceleration of the longitudinal motion variables. A longitudinally decoupled linear mathematical model of a single-tethered aerostat using stability derivatives is investigated in this study. A computational fluid dynamics (CFD)-based analysis of the 3D model of the vehicle is used to obtain the stability derivatives. The methodology presented considers the aerostat and tether models separately before coupling them to create the full model. The stability derivative analysis is carried out using ANSYS Fluent, and the coupled tethered aerostat model is investigated using MATLAB 2020. The negative pitch angle of the aerostat is caused by the selection of the pitching centre as the aerostat centre of volume instead of the tether confluence point. The tension force on the tether, which is proportional to the wind velocity, and aerostat velocity components are found to be stabilised within 200–400 s

Status of the brain antioxidant system at different growing periods after prenatal stress and N -acetyl cysteine administration

Prenatal stress-induced neurobehavioral deficits observed in offspring are multifactorial, including oxidative stress in the developing brain. The time by which the developing brain acquires self-defense against oxidative stress is not clear. Hence in the present study we aimed to evaluate the brain antioxidant status during different developing periods. Further the study also evaluates the role of the glutathione precursor, N-acetyl cysteine (NAC) on the brain antioxidant status. Pregnant rats were subjected to restraint stress during an early or late gestational period. Another set of rats received NAC during the entire gestational period along with early or late gestational stress. The study parameters included several antioxidant studies directly from rat brain homogenate on postnatal day 24 or 48. Early or late gestational stress has caused severe oxidative stress in the developing brain on postnatal day 24 in all the parameters studied. However, brain reduced glutathione (GSH), superoxide dismutase (SOD) and total antioxidant activity (TAO) were not affected by either early or late gestational stress on postnatal day 48, but the brain malondialdehyde (MDA) level remained high and brain glutathione reductase (GSS-Rd) level remained low on postnatal day 48. Prenatal NAC treatment has reversed the oxidative damage in all the parameters on postnatal day 24 and also the brain MDA level and GSS-Rd level on postnatal day 48. This study confirms that the growing brain acquires antioxidant capacity over time but during early postnatal development it is vulnerable to oxidative stress and related neurological consequences. N-acetyl cysteine treatment during the prenatal period as an antioxidant supplement exerted a beneficiary effect in this study. Hence glutathione supplement in the nutritional source would be an idealistic approach to prenatal stress-induced neurological comorbidities in children

Stability Derivatives of Various Lighter-than-Air Vehicles: A CFD-Based Comparative Study

An aerostat with a single tether is proposed for the application of wind measurements at low altitudes. In the current study, the aerodynamic model parameters (stability derivatives) of the aerostat are investigated based on a CFD-based approach. The static, as well as the dynamic stability derivatives of the aerostats are presented. The calculation of the dynamic stability derivatives involves the simulation of the oscillations of the aerostats in their axial direction (surge), the vertical direction (heave) and angular motions with respect to the lateral direction (pitch). A forced sinusoidal oscillation is used for the simulation of the aerostat, and one stable period of oscillation is taken for the derivatives’ extraction. Four different aerostats are considered for the current study with four different angles of attack. The Zhiyuan aerostat, HAA aerostat, NPL aerostat and GNVR aerostat are the aerostats considered for this study. The stability derivative results obtained for the four aerostats are analyzed and compared with respect to their geometrical features. From the static aerodynamic characteristics, the Zhiyuan aerostat shows better performance than the other aerostats in terms of the lift–drag ratio. The dynamic stability derivatives of the Zhiyuan aerostat suggest its application as the proposed low-altitude wind measurement system

Role of Choline-Docosahexaenoic acid and Trigonella foenum graecum Seed Extract on Ovariectomy Induced Dyslipidemia and Oxidative Stress in Rat Model

Background: Menopause is characterized by the deficiency of ovarian hormones, mainly estrogen. The decline in estrogen hormone is contributing the cardiovascular disorders in women. Hormone replacement therapy has disadvantages especially a higher risk of breast, ovarian and endometrial cancers upon chronic use. Phytoestrogens may be used as an alternative to hormone replacement therapy. Aim and Objectives: This study was designed to scientifically evaluate the role of Choline- Docosahexaenoic Acid (DHA) and Trigonella foenum graecum (TFG) seed extract on Ovariectomy (OVX) induced dyslipidemia and oxidative stress in rat model. Material and Methods: Female Wistar rats were allocated into four groups (n=6):1) Sham control, 2) ovariectomized, 3) ovariectomized+ choline-DHA and 4) ovariectomized + choline-DHA+TFG. After 30 days of treatment, fasting blood samples and liver tissues were collected. Serum was analyzed for lipid profile and liver homogenates were used for assessment of oxidative stress and antioxidant activity. Results: Ovariectomized rats showed significantly increased (P<0.05) Total Cholesterol (TC), Low Density Lipoprotein (LDL) levels and decreased High Density Lipoprotein (HDL) levels. Treating ovariectomized rats with choline-DHA and TFG seed extract significantly lowered (P<0.05) total cholesterol, LDL and markedly increased the HDL. Significantly increased (P≤0.01) Thiobarbituric Acid Reactive Substances (TBARS) and reduced (P<0.05) glutathione levels were observed in OVX group. The synergetic effect of choline-DHA and fenugreek showed a significant reduction ((P≤0.01) in TBARS levels. Conclusion: These results showed that choline-DHA with TFG supplementation have a favorable effect on OVX induced hyperlipidemia and oxidative stress. Therefore, these components may be a therapeutic agent for treating the menopause induced hyperlipidemia or oxidative stress

Role of Ionic Liquid in Asphaltene Dissolution: A Combined Experimental and Molecular Dynamics Study

The role of ionic liquid in asphaltene dissolution is studied using experimental characterization techniques, such as optical microscopic imaging analysis, 13C nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectroscopy, along with molecular insights achieved using classical molecular dynamics (MD) simulations. The dissolution behavior of the asphaltenes in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) ionic liquid along with organic solvents, i.e., toluene and hexane, is investigated using optical images. The behavior of asphaltene aggregates in the solvent plus ionic liquid mixture is probed using FTIR and 13C NMR spectroscopic techniques. The structural and dynamical properties of the asphaltene aggregates mainly end-to-end distance, the diffusion coefficient of the asphaltene molecules, and the trajectory density contour of the asphaltene in the solvent plus ionic liquid mixture are probed using MD simulations. It is concluded from our combined experimental-MD study that the ionic liquid plays a key role in asphaltene separation from organic solvents under study.</p

Ahmed glaucoma valve in post-penetrating-keratoplasty glaucoma: A critically evaluated prospective clinical study

Aim: The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG). Materials and Methods: In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5 < IOP < 21 mmHg and qualified success as 5 < IOP < 21 mmHg with medications or minor procedures. Results: The mean IOP decreased from 42.95 ± 10.24 to 17.69 ± 3.64 mmHg (P < 0.001) and the use of medications dropped from 2.92 to 0.39 (P < 0.001) after AGV implantation. The absolute success was achieved in 11 eyes and qualified success in 9. There was no significant change in best corrected visual acuity, graft clarity, or graft thickness. Six device-related complications occurred after AGV implantations which were successfully managed with medical or minor surgical therapy. Conclusions: Postkeratoplasty refractory glaucoma managed by AGV implantation revealed a satisfactory outcome up to 6 months of follow-up