26 research outputs found
Rheological Modelling and Simulations of Dilute Polyelectrolyte Solutions in Complex Geometries
No full textDilute polyelectrolyte solutions show viscoelastic behaviour different from solutions of uncharged polymers by virtue of the additional stiffness provided by the repulsion between charges on the polymer chain and screening of the charged sites by ionic species in the system. Experiments report an increase in chain extensions and polymeric viscosities due to the charged nature of the polymers. These effects impact the macroscopic flow behaviour of polyelectrolytes in complex geometries. In this work, we have developed a theoretical model describing the viscoelastic behavior of dilute polyelectrolyte (PE) solutions using Onsager’s variational principle. The PE molecules are described as finitely extensible charged dumbbells suspended in a solvent containing ionic species which screen the charged sites on the macromolecules. We first formulate the rheological model in a conformation tensor formalism and couple it to the steady Stokes equations to simulate the flow of dilute polyelectrolyte solutions in confined geometries. Our results indicate an increase in the drag experienced by the bodies in a flowing PE solution, increased pressure drops and normal stresses with increasing molecular charge density. Next, the model is reformulated to consider stress induced inhomogeneities in the system and the effect of counterion fluctuations on molecular migration of polyelectrolytes is investigated. We conclude that our model based on a simple charged dumbbell with counterion screening, together with Onsager’s variational principle is a powerful tool to investigate the dynamics of dilute polyelectrolyte solutions and the effects of the polyelectrolyte charge and solvent salinity
A comparative study of dexamethasone ointment along with triamcinolone acetonide in treatment of recurrent aphthous stomatitis
No full textAim: To assess and compare the efficacy of dexamethasone ointment with triamcinolone acetonide, the gel form, in the treatment of minor recurrent aphthous stomatitis (RAS). Materials and Methods: This was a randomized clinical trial of 60 patients of either sex with clinically diagnosed RAS who were randomly divided into two groups—the dexamethasone ointment group (Group I) and the triamcinolone acetonide gel group (Group II). Patients were asked to apply the gel three times a day on each ulcer. Estimation of the efficacy of gel was done based on the time required for regression in pain, size, and number of ulcers. Results: The results showed there was a significant difference in size, pain, number, and duration of ulcers in Group I and Group II within 7 days. However, in both groups, no significant difference was noted in the treatment of RAS. Conclusion: Dexamethasone ointment was found to be efficient in this treatment and was safe as evaluated using clinical assessments
Short-chain n-alkanes in benthic mats and mosses from the Larsemann Hills, East Antarctica
No full textVariation in leaf colour (green, red and grey) of mosses and lake benthic mats in Antarctica is often linked to water stress and ultraviolet light (UV-B) exposure. Changes in the abundance of organic compounds, such as pectin and phenols, are associated with mechanisms protecting against desiccation and UV radiation. However, the function of n-alkanes, especially against UV radiation, is rarely examined. Here, gas chromatography–mass spectrometry and Fourier-transform infrared spectroscopy analyses were performed to study the variation in n-alkanes in freshwater lake benthic mats and mosses collected from the Larsemann Hills in East Antarctica. Stable isotopes of organic carbon and nitrogen, environmental DNA characterisation and microscopy-based analyses are used to estimate the presence of cyanobacteria, algae and diatoms in moss and benthic mat consortia. Variation in the short-chain (n-C17 to n-C20) versus long-chain (n-C21 to n-C30) n-alkanes in the mosses and benthic mats with their colour were noted. The research links the relative abundance of short-chain n-alkanes to the UV-B exposure and proposes that Antarctic mosses and benthic mats synthesise short-chain n-alkanes for protection against UV-B.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Sanitary Engineerin
Application of Genetic Fuzzy System for Damage Identification in Cantilever Beam Structure
No full textAbstractThe performance of the system consisting of beam structures is very much affected by identification of faults or damage in it's structural integrity. The consistent and secure operation can be well ensured in an engineering system by effectively identifying the damage in the structures. The conventional techniques are rendered to few limitations due to the unreliable mathematical simulation used for actual scenario. Therefore, hybrid artificial techniques (AI) would be more sophisticated tool for damage identification in beam structures. The combination of Fuzzy inference system and Genetic algorithms (GAs) can be employed to obtain effective solutions for many systems. In the current research, GA-Fuzzy controller has been considered for identification of damage in steel cantilever beam in transverse direction subjected to natural vibration. The results obtained from the proposed technique have been in very good agreement with the experimental results
Evaluation of mass transfer effect and response surface optimization for abatement of phenol and cyanide using immobilized carbon alginate beads in a fixed bio‐column reactor
No full textData-driven optimization of manufacturing processes Advances in civil and industrial engineering (ACIE) book series./ [edited by] Kanak Kalita, Ranjan Kumar Ghadai, Xiao-Zhi Gao.
No full text"Premier Reference Source" -- Cover.Includes bibliographical references and index."This book is a compilation of chapters on the application of state-of-the-art computational intelligence techniques from both predictive modeling and optimization, offering both soft computing approaches and machining processes"--Data-driven optimization of manufacturing processes / Kanak Kalita, Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, India, Ranjan Ghadai, Sikkim Manipal Institute of Technology, India, Xiao-Zhi Gao, University of Eastern Finland, Finland -- Non-traditional machining process selection -- A holistic approach from customer standpoint / Manish Roy, Sikkim Manipal Institute of Technology, India, Partha Das, Sikkim Manipal Institute of Technology, India, Premchand Mahto, Sikkim Manipal Institute of Technology, India, Ankit Singh, Indian Institute of Science, India, Manish Oraon, Birla Institute of Technology, Mesra, India -- Optimization of drilling parameters for composite laminate using genetic algorithm / Subham Pal, Indian Institute of Engineering Science and Technology, Shibpur, India, Salil Haldar, Indian Institute of Engineering Science and Technology, India.1 online resource (xvi, 298 pages)
Drug Promotional Literatures – a critical appraisal of their adherence to global guidelines
No full textBackground: Drug promotional literatures (DPL) distributed by various pharmaceutical companies are frequently reported to be inaccurate and not adhering to the relevant guidelines. The objective of the study was to evaluate various drug promotional literatures using criteria advocated by various national and global guidelines. Methods: This observational study was conducted with diverse DPLs collected from various OPDs using the World Health Organization and other guidelines. Results: Out of total 560 DPLs evaluated, majority of them were found to be lacking in adequate and accurate information with regard to various criteria like dosage, dosage schedule, adjuvants used, safety information and pharmaceutical safety data. Conclusion: Majority of the DPLs did not adhere to the ethical guidelines issued by any company and requires strict administrative monitoring. Prescribers also need to exercise utmost caution in believing those claims mentioned and judiciously incorporate information mentioned in DPLs
Infectious mononucleosis due to epstein-barr virus infection in children: A profile from eastern India
No full textObjective: The objective of this study is to delineate the clinical and laboratory profile of infectious mononucleosis due to Epstein-Barr virus (EBV) infection in children admitted to tertiary care teaching hospitals. Materials and Methods: Retrospective observational multicentric analysis of clinical and laboratory features of children between 1 month to 12 years with a diagnosis of infectious mononucleosis due to EBV infection confirmed by positive serology over a 12-month period after seeking approval from the Institutional Ethics Committee. Results: Out of 66 children screened, 53 were included in final analysis. The majority were aged between 5 and 8 years with male: female ratio of 1.2:1. Most presentations were during the monsoon months. The common clinical features were fever (100%), splenomegaly (86.7%), and cervical lymphadenopathy (73.5%) in contrast to the classical triad of fever, sore throat, and generalized lymphadenopathy described in the literature. There were no age differences in clinical findings except for generalized and cervical lymphadenopathy and hepatomegaly which were commoner in 9–12 years age band. Although the incidence of common findings matched with previously published studies, there were some notable differences. While frequencies of upper eyelid edema, epitrochlear lymphadenopathy, and splenomegaly were more, those of rash and sore throat were less. Lymphocytosis and presence of atypical lymphocytes were relatively less common in our series. All children recovered. Conclusions: This multicentric study on profiling childhood infectious mononucleosis, possibly first of its kind from Eastern India, has documented clinical and laboratory features associated with this condition. These data can serve as a reference for future studies
