Browse Items (11810 total)
Sort by:
-
Optimization and sensitivity analysis of heat transport of hybrid nanoliquid in an annulus with quadratic Boussinesq approximation and quadratic thermal radiation
The quadratic convective flow of hybrid nanoliquid in an annulus subjected to quadratic thermal radiation is studied for the first time. The impact of suction/injection and the uniform movement of the rings are considered. Nonlinear equations are handled numerically by adopting the shooting technique. An optimization procedure is performed by using response surface methodology. The maximum heat transport is observed for chosen values of effective parameters (thermal radiation parameter (5 ? Rt? 15) , temperature ratio parameter (1.1 ? ?w? 5.1) and nanoparticle volume fraction of copper (1 % ? ?Cu? 3 %)) at three different levels (low(? 1), middle(0) and high(+ 1)). In addition, a slope of the data point is evaluated for the friction coefficient and the Nusselt number. The results showed that the impact of quadratic thermal radiation on velocity and temperature distributions is more significant than linear thermal radiation. Further, an increase in quadratic convection and quadratic thermal radiation leads to an improvement in the friction coefficient of the skin on the inner surface of the outer annulus. Furthermore, the sensitivity of the friction coefficient is positive for the appearance of quadratic thermal radiation. 2020, SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature. -
An efficient methodology for resolving uncertain spatial references in text documents
In recent decades, all the documents maintained by the industries are getting transformed into soft copies in either structured documents or as an e-copies. In text document processing, there is a number of ways available to extract the raw data. As the accuracy in finding the spatial data is crucial, this domain invites various research solutions that provide high accuracy. In this article, the Fuzzy Extraction, Resolving, and Clustering (FERC) architecture is proposed which uses fuzzy logic techniques to identify and cluster uncertain textual spatial reference. When the text corpus is queried with a spatial-keyword, FERC returns a set of relevant documents sorted in view of the fuzzy pertinence score. Any two documents may be compared in light of the spatial references that exist in them and their fuzzy similarity score is presented. This enables finding the degree to which the two documents speak about a specified location. The proposed architecture provides a better result set to the user, unlike a Boolean search where the document is either rated relevant or irrelevant. Copyright 2020, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. -
Synthesis of emeraldine PANI polymer-reduced graphene and its use as polyelectrolyte
Abstract: Reduced graphene oxide (rGO)/polyaniline (PANI) composites grabbed the interest of researcher towards the development of electrolyte material. In present research work, we have focused on the synthesis of rGO and PANI by chemical method. The composites are prepared using different amounts of rGO/PANI and lithium carbonate. The main objective is to enhance structural and electrochemical properties of polymer composites. It is observed that proper interface of polymer composites leads towards the desired chargedischarge capacity and cyclic stability with the diffusion of electrons and electrolyte ions. This particular study can be further used for the development of electrochemical device applications. Graphic abstract: [Figure not available: see fulltext.]. 2019, Springer-Verlag GmbH Germany, part of Springer Nature. -
A Statistical Search for Star-Planet Interaction in the Ultraviolet Using GALEX
Most (?82%) of the over 4000 confirmed exoplanets known today orbit very close to their host stars, within 0.5 au. Planets at such small orbital distances can result in significant interactions with their host stars, which can induce increased activity levels in them. In this work, we have searched for statistical evidence for star-planet interactions in the ultraviolet (UV) using the largest sample of 1355 Galaxy Evolution Explorer (GALEX) detected host stars with confirmed exoplanets and making use of the improved host-star parameters from Gaia DR2. From our analysis, we do not find any significant correlation between the UV activity of the host stars and their planetary properties. We further compared the UV properties of planet host stars to that of chromospherically active stars from the RAdial Velocity Experiment (RAVE) survey. Our results indicate that the enhancement in chromospheric activity of host stars due to star-planet interactions may not be significant enough to reflect in their near- and far-UV broadband flux. 2020. The American Astronomical Society. All rights reserved.. -
Analyzing and optimizing the usability of website access
The world wide web (WWW) plays a significant role in information sharing and distribution. In web-based information access, the speed of information retrieval plays a critical role in shaping the web usability and determining the user satisfaction in accessing webpages. To deal with this problem, web caching is used. The problem with the present web caching system is that it is very hard to recognize webpages that are to be accessed and then to be cached. This is forced by the fact that there are broad categories of users and each one having their own preferences. Hence, it is decided to propose a novel approach for web access pattern generation by analyzing the web log file present in the proxy server. Further, it tries to propose a novel hybrid policy called popularity-aware modified least frequently used (PMLFU) that best suits for the current proxy-based web caching environment. It combines features such as frequency, recency, popularity, and user page count in decision-making policy. The performance of the proposed system is observed using real-time datasets, empirically using IRCACHE datasets. 2020, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. -
Old Monk: The Resurrection of a Heritage Brand
This case is developed to discuss options related to strategy in general and marketing strategy in particular that were implemented by an iconic brandOld Monkin the compelling attempt to revive the its brand value and relevance. The protagonist in the case is Mr Hemanth Mohan, the Director of this brand who is faced with serious challenges in resurrecting the brand in a hypercompetitive, ever-changing lifestyle alcoholic beverages market in India. The most significant of the challenges faced by Mr Mohan are changing tastes and preferences of the consumer, new foreign brands entering into the market, strong regulation, close monitoring from the government, and the monopoly of state-managed liquor retail chains. This case addresses and provides for the evaluation of various strategic options available for the brand in terms of repositioning itself in the relevant markets. The case presents questions related to how effectively a traditional brand can carry forward the legacy to redeem its brand value in the light of changing tastes and customer preferences. The case proposes to bring to light the importance of strategic decisions to be made around managing brand extensions in addressing the dilemma of brand value being spread too thin versus capitalizing on the past glory of the brand in finding life for the newly launched products under the known umbrella. This case is developed with an intent to be discussed among students pursuing undergraduate and/or graduate education in management discipline. The case is well aligned to be relevant for discussing concepts related to brand management, marketing strategy, strategic management, and consumer behavior. The content of this case is designed to be discussed and delivered in a typical 90-min class session, allowing students 120 min of pre-reading time and 120 min of post-discussion report preparation. 2020 K.J. Somaiya Institute of Management Studies and Research. -
Dynamic route scheduler in vehicular ad hoc network for smart crowd control
Revenue generated by tourism is positively correlated with the development of any city. In recent years, tourism is getting peak focus among the government, local bodies, and researchers. This has led to increase in initiatives to grow tourism in and across the country. Being one of the most flourishing sectors, tourism in India shows bold signals of emerging as a strong participant in the world of tourism. In addition to safeguarding its culture and deep-rooted traditional values, tourism provides a way to increase employment opportunities as well as increase the foreign exchange within the country. There are many open research problems arising in the domain, which need the attention of researchers. City traffic management is one among the major concern for cities around the world. Scheduling dynamic travel plans for tourists with crowd and traffic awareness has high scope for research. In this paper, a system is proposed which connects the vehicles to a centralized sink for getting the optimal routes. Route scheduling is done based on a prediction model. Different parameters were collected from the environment that includes crowd, traffic, and schedule of other vehicles. The system has modules like static nodes, mobile nodes, host nodes, and sink node for the control and management. Selection of path and protocol is a primary strategy to design any VANET systems. Hence, performance analysis of routing protocols for the proposed system is done as a major step in selection of protocols. Packet delivery ratio, jitter, and throughput are common measures used for the comparison of protocols. 2019, Springer-Verlag London Ltd., part of Springer Nature. -
New results on upper domatic number of graphs
For a graph G = (V, E), a partition ? = {V1, V2,..., Vk} of the vertex set V is an upper domatic partition if Vi dominates Vj or Vj dominates Vi or both for every Vi, Vj ? ?, whenever i 6= j. The upper domatic number D(G) is the maximum order of an upper domatic partition of G. We study the properties of upper domatic number and propose an upper bound in terms of clique number. Further, we discuss the upper domatic number of certain graph classes including unicyclic graphs and power graphs of paths and cycles. 2020 Azarbaijan Shahid Madani University -
Surface water detection and delineation using remote sensing images: a review of methods and algorithms
Multispectral and hyperspectral images captured by remote sensing satellites or airborne sensors contain abundant information that can be used to study and analyze objects of interest on the surface of earth and their properties. The potential of remotely sensed images for studying natural resources like water has been studied by researchers over the past many years. As water is an important natural resource that needs to be conserved, such studies have been of great interest to the scientific community. By employing appropriate digital image processing techniques on images taken from remote sensing satellites or airborne sensors, an effective system can be developed to study the quantitative and qualitative changes happening to surface water bodies over a period of time. Surface water detection and mapping is a crucial and necessary step in such studies and different automated and semi-automated methods have been developed over the years for mapping water in remotely sensed images. Remote sensing sensors capture images at multiple bands corresponding to different wavelength ranges in the EM spectrum. Digital image processing based techniques for water mapping falls predominantly into four categories; (i) single band based methods, (ii) spectral index based methods, (iii) machine learning based methods and (iv) spectral mixture analysis based methods. This paper presents a review of techniques, methods, algorithms and the sensors/satellites that have been developed and experimented with to perform surface water body detection and delineation from remote sensing images. 2020, Springer Nature Switzerland AG. -
Restrained domination in signed graphs
A signed graph ? is a graph with positive or negative signs attatched to each of its edges. A signed graph ? is balanced if each of its cycles has an even number of negative edges. Restrained dominating set D in ? is a restrained dominating set of its underlying graph where the subgraph induced by the edges across ?[D: V\D] and within V\D is balanced. The set D having least cardinality is called minimum restrained dominating set and its cardinality is the restrained domination number of ? denoted by ?r(?). The ability to communicate rapidly within the network is an important application of domination in social networks. The main aim of this paper is to initiate a study on restrained domination in the realm of different classes of signed graphs. 2020 Anisha Jean Mathias et al., published by Sciendo 2020. -
Significance of thickness of paraboloid of revolution and buoyancy forces on the dynamics of EryingPowell fluid subject to equal diffusivity kind of quartic autocatalysis
The flows of non-Newtonian fluid over upper horizontal surfaces of rockets, over bonnets of cars, and pointed surfaces of aircraft are of great importance to the experts in the field of space sciences, automobile construction, and aerodynamic industry where efficiency is dependent on the thickness of paraboloid of revolution, buoyancy, and autocatalysis. The purpose of this study is to present not only the nonlinear governing equation which models the transport phenomenon, but also to analyze the non-Newtonian EryingPowell fluid flow within a thin layer formed on an object which is neither a perfect horizontal nor a vertical, and neither an inclined surface nor a cone/wedge. The governing equation suitable to model the transport phenomenon above for the case of equal diffusivity during quartic autocatalytic kind of chemical reaction was non-dimensionalized and solved numerically. The velocity of the flow along x?direction can be enhanced when thickness increases negligible but buoyancy forces increase significantly. The rate of increase in the velocity of the flow along the y?direction from the wall to the free stream is optimal when the thickness of the paraboloid of revolution is zero (objects with a uniform thickness) and buoyancy force is sufficiently large. The concentration of EryingPowell fluid at the wall G(0) is a decreasing function of Prandtl number but an increasing property of Schmidt number. 2020 Elsevier B.V. -
Employing bioactive compounds derived from Ipomoea obscura (L.) to evaluate potential inhibitor for SARS-CoV-2 main protease and ACE2 protein
Angiotensin converting enzyme 2 (ACE2) and main protease (MPro) are significant target proteins, mainly involved in the attachment of viral genome to host cells and aid in replication of severe acute respiratory syndrome-coronaviruses or SARS-CoV genome. In the present study, we identified 11 potent bioactive compounds from ethanolic leaf extract of Ipomoea obscura (L.) by using GC-MS analysis. These potential bioactive compounds were considered for molecular docking studies against ACE2 and MPro target proteins to determine the antiviral effects against SARS-COV. Results exhibits that among 11 compounds from I. obscura (L.), urso-deoxycholic acid, demeclocycline, tetracycline, chlorotetracycline, and ethyl iso-allocholate had potential viral inhibitory activity. Hence, the present findings suggested that chemical constitution present in I. obscura (L.) will address inhibition of corona viral replication in host cells. 2020 The Authors. Food Frontiers published by NCU, NWU, JSU, ZJU & FAFU and John Wiley & Sons Australia, Ltd. -
Convection in a horizontal layer of water with three diffusing components
Triple diffusive convection in water is modelled with properties like density, specific heat, thermal conductivity, thermal diffusivity and thermal expansion, modified in the presence of salts. The GinzburgLandau equation is derived to study heat and mass transports of different combinations of salts in water. A table is prepared documenting the actual values of thermophysical properties of water with different salts and the critical Rayleigh number is calculated. This information is used in the estimation of Nusselt and Sherwood numbers and their relative magnitudes are commented upon. A detailed study on different single, double and triple diffusive systems is done and comparison is made of the results. The local nonlinear stability analysis made via a GinzburgLandau model mimics many properties of the original governing equations, namely, Hamiltonian character and a bounded solution. 2020, Springer Nature Switzerland AG. -
A novel approach for the synthesis of functionalized hydroxylamino derivative of dihydroquinazolinones
A new metal-free and modular approach for the synthesis of various functionalized dihydroquinazolinones has been developed from isatoic anhydride, amines, 4-chloro-N-hydroxybenzimidoylchloride to yield up to 71%. The reaction has been screened in various bases, solvents at different temperatures. The substrate scope of the reaction has been studied with various amines and the possible reaction mechanism for this reaction has also been proposed. 2020, 2020 Taylor & Francis Group, LLC. -
Rational design of bifunctional catalyst from KF and ZnO combination on alumina for cyclic urea synthesis from CO2 and diamine
This study is mainly focused on the design of stable, active and selective catalyst for direct synthesis of 2-imidazolidinone (cyclic urea) from ethylenediamine and CO2. Based on the rationale for the catalyst properties needed for this reaction, KF, ZnO and Al2O3 combination was selected to design the catalyst. ZnO/KF/Al2O3 catalyst was prepared by stepwise wet-impregnation followed by the removal of physisorbed KF from the surface. High product yield could be achieved by tuning acid-base sites by varying the composition and calcination temperature. The catalysts were characterized by various techniques like XRD, N2-sorption, NH3-TPD, CO2-TPD, TEM, XPS and FT-IR measurements. It is shown that acidic and basic properties of the solvent can influence the activity and product selectivity for this reaction. Under optimized condition; 180 C, 10 bar and 10 wt.% catalyst in batch mode, 96.3 % conversion and 89.6 % selectivity towards the 2-imidazolidinone were achieved. 2020 Elsevier B.V. -
Bacterial biofilm inhibition activity of ethanolic extract of hemidesmus indicus
Multi-drug resistance is one of the biggest nightmares in the field of healthcare today. Adding on to this, some bacteria like Staphylococcus aureus and Pseudomonas aeruginosa have the ability to form biofilms. These essentially are large colonies of bacteria that are held together by polysaccharides and other biomolecules which in turn facilitate in their adherence to solid substrate both natural and synthetic. This further creates a life-threatening implication leading to nosocomial infections like pneumonia, Urinary tract infections (UTI), etc. increasing the co-morbidities and mortality of critically-ill patients. The combination of antimicrobial resistance, ability to form biofilms and threat of nosocomial infections calls for a need to investigate newer, safer alternatives. Plant based medicaments have been used for centuries and they are a great alternative to synthetic drugs. In the present study, ethanolic extracts of Hemidesmus indicus was evaluated against clinically-important multi-drug resistant organisms. Percentage biofilm inhibition of plant extracts of Hemidesmus indicus by crystal violet assay method. Triplicate analysis was done and data obtained was statistically interpreted using Microsoft Excel. Alcoholic extracts of Hemidesmus indicus exhibited significant biofilm inhibitory activity against the common bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. Further, isolation of the chief active constituent responsible for Anti-biofilm activity is in process. 2020, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved. -
A novel free space communication system using nonlinear InGaAsP microsystem resonators for enabling power-control toward smart cities
Nowadays, the smart grid has demonstrated a great ability to make life easier and more comfortable given recent advances. This paper studies the above issue from the perspective of two important and very useful smart grid applications, i.e., the advanced metering infrastructure and demand response using the instrumentality of a set of well-known scheduling algorithms, e.g., best-channel quality indicator, log rule, round robin, and exponentialproportional fairness to validate the performance. To increase the data transmission bandwidth, a new concept of optical wireless communication known as free-space optical communication (FSO) system based on microring resonator (MRR) with the ability to deliver up to gigabit (line of sight) transmission per second is proposed for the two studied smart grid applications. The range between 374.7 and 374.79THz frequency band was chosen for the generation of 10 successive-carriers with a free spectral range of 8.87GHz. The ten multi-carriers were produced through drop port of the MRR. The results show up to 10 times bandwidth improvement over the radius as large as 600m and maintain receive power higher than the minimum threshold (? 20dBm) at the controller/users, so the overall system is still able to detect the FSO signal and extract the original data without detection. 2019, Springer Science+Business Media, LLC, part of Springer Nature. -
Effective atomic number and electron density of some biologically important lipids for electron, proton, alpha particle and photon interactions
X-ray, ?-ray and charged particle interaction parameters of biomolecules are useful in medical diagnosis and radiation therapy as exposure to radiations can cause energy of photons and charged particles to be deposited in body through various interaction processes. With this in view, the effective atomic number (Zeff) and electron density (Neff) of some biologically important lipids for X-ray, ?-ray and charged particle interactions were studied in the energy range 10 keV500 MeV using logarithmic interpolation method. A non-monotonic variation in Zeff values was observed for protons and alpha particles in low and intermediate energy regions respectively whereas a sudden increase in Zeff was observed for electron interaction in higher energy region. Zeff values were maximum in higher energy region for total electron interactions whereas maximum values of Zeff for total alpha particle interactions were at relatively lower energies. Highest Zeff values were found at lower energy region of photoelectric absorption dominance for photon interactions. Variation in Neff seems to be similar to variation in Zeff as they are inter-related. 2020 Elsevier Ltd -
Study on the influence of modified chitosan on the preservation of tiger prawn penaeus monodon
Native chitosan, irradiated chitosan (5kGy and 10 kGy) and grafted chitosan was characterized and employed for the preservation of sea food Penaeus monodon. The grafting of metha acrylate onto natural native polymer chitosan was executed and the configuration and arrangement of covalent bonds in the grafted chitosan was demonstrated by performing, SEM, XRD, FTIR, TG and DSC analyses. The modified chitosan conferred antioxidant and antibacterial potential equivalent to or better than that of the unmodified chitosan in the stored Penaeus monodon. Modified chitosan treated Penaeus monodon produced less TBARS and TVB values than the control group. 2020 Slovak University of Agriculture. -
Further Discussion on the Significance of Quartic Autocatalysis on the Dynamics of Water Conveying 47nm Alumina and 29nm Cupric Nanoparticles
Improvement of product performance, efficiency, and reliability is a major concern of experts, scientists, and technologists dealing with the dynamics of water conveying nanoparticles on objects with nonuniform thickness either coated or sprayed with the catalyst. However, little is known on the significance of quartic autocatalysis as it affects the dynamics of water conveying alumina and cupric nanoparticles. In this study, comparative analysis between the dynamics of water conveying 29nm CuO and 47nm Al 2O 3 on an upper horizontal surface of a paraboloid of revolution is modeled and presented. In the transport phenomena, migration of nanoparticles due to temperature gradient, the haphazard motion of nanoparticles, and diffusion of motile microorganisms were incorporated into the mathematical models. Due to the inherent nature of the thermophysical properties of the two nanofluids, viscosity, density, thermal radiation, and heat capacity of the two nanofluids were incorporated in the mathematical model. The nonlinear partial differential equations that model the transport phenomenon were transformed, non-dimensionalized and parameterized. The corresponding boundary value problems were converted to an initial value problem using the method of superposition and solved numerically. The concentration of the catalyst increases significantly with buoyancy at a larger magnitude of space-dependent internal heat source in the flow of 29nm CuOwater nanofluid. Negligible migration of nanoparticles due to temperature gradient decreases the concentration of the fluid throughout the domain. 2020, King Fahd University of Petroleum & Minerals.