3,323 research outputs found

    Response of Gaussian-modulated guided wave in aluminum: An analytical, numerical, and experimental study

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    The application of guided-wave ultrasonic testing in structural health monitoring has been widely accepted. Comprehensive experimental works have been performed in the past but their validation with possible analytical and numerical solutions still requires serious efforts. In this paper, behavior and detection of the Gaussian-modulated sinusoidal guided-wave pulse traveling in an aluminum plate are presented. An analytical solution is derived for sensing guided wave at a given distance from the actuator. This solution can predict the primary wave modes separately. Numerical analysis is also carried out in COMSOL® Multiphysics software. An experimental setup comprising piezoelectric transducers is used for the validation. Comparison of experimental results with those obtained from analytical and numerical solutions shows close agreement

    Synthesis, characterization, POM analyses and biological evaluation of n-[(2-methoxy-5- nitrophenyl)]-4-oxo-4-[oxy] butenamide based zinc(II) carboxylate complexes

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    ABSTRACT. The aim of medicinal chemistry is to links many scientific disciplines and allows the scientists in researching and developing new drugs with enhance and targeted properties. In this article we are exploring the preparation of four new zinc(II) carboxylate complexes based on N-[(2-methoxy-5-nitrophenyl)]-4-oxo-4-[oxy]butenamide which were characterized through FT-IR and EDX studies. The DNA binding ability and binding type of complexes were assessed by spectroscopic (UV-Visible) and viscosity measurements, exhibiting an intercalative pattern of interaction. The synthesized compounds were also assessed to know theoretically about their nature by molecular docking studies resulting also in intercalation mode. Analysis of the complexes for biological applications such as anti-microbial, anti-leishmanial, cytotoxicity and DNA damage activities showed that these complexes carries good anti-microbial, anti-leishmanial activity with no toxicity to human blood thyrocytes and DNA. The bioavailability prediction and drug likeness score has also been evaluated through Insilco studies.                     KEY WORDS: Zn(II) carboxylate complex, DNA binding, Anti-leishmanial activity, Cytotoxicity, Docking study   Bull. Chem. Soc. Ethiop. 2021, 35(2), 365-380. DOI: https://dx.doi.org/10.4314/bcse.v35i2.1

    Analysis of Unsteady Axisymmetric Squeezing Fluid Flow with Slip and No-Slip Boundaries Using OHAM

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    In this manuscript, An unsteady axisymmetric flow of nonconducting, Newtonian fluid squeezed between two circular plates is studied with slip and no-slip boundaries. Using similarity transformation, the system of nonlinear partial differential equations is reduced to a single fourth order ordinary differential equation. The resulting boundary value problems are solved by optimal homotopy asymptotic method (OHAM) and fourth order explicit Runge-Kutta method (RK4). It is observed that the results obtained from OHAM are in good agreement with numerical results by means of residuals. Furthermore, the effects of various dimensionless parameters on the velocity profiles are investigated graphically

    Fabrication, physicochemical characterization and preliminary efficacy evaluation of a W/O/W multiple emulsion loaded with 5% green tea extract

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    Emulsões múltiplas complexas possuem excelente habilidade de agregar grandes quantidades de agentes cosméticos funcionais. Este estudo teve por objetivo encapsular grandes volumes de chá verde em uma emulsão múltipla clássica e comparar sua estabilidade com a emulsão múltipla sem o extrato do chá verde. Emulsões múltiplas são desenvolvidas usando cetil dimeticona copoliol como emulsificante lipofílico e o clássico polissorbato-80 como emulsificante hidrofílico. As emulsões múltiplas foram avaliadas por meio de vários aspectos fisico-químicos como condutividade, pH, análise microscópica e reologia. Estas características foram observadas por um período de 30 dias sob diferentes condições de armazenamento. Testes de proteção da pele in vivo e in vitro foram realizados para ambos os tipos de emulsões testadas, i.e. com o ativo em estudo (MeA) e sem ativo (MeB). Ambas as formulações apresentaram características comparáveis no que diz respeito aos diferentes fatores físico-químicos avaliados sob diferentes condições de armazenamento. A análise reológica mostrou que as formulações apresentaram comportamento pseudo-plástico sob contínuo estresse de cisalhamento. Os resultados dos testes in vivo e in vitro sobre a proteção da pele revelaram que a formulação ativa promoveu efeitos comparáveis à formulação controle. Nossos dados mostraram que emulsões múltiplas estáveis poderiam ser escolhas promissoras para a aplicação tópica do chá verde. Entretanto, a fórmula das emulsões múltiplas apresentadas neste estudo precisam ser melhoradas no que diz respeito ao pH, condutividade e viscosidade aparente.Complex multiple emulsions have an excellent ability to fill large volumes of functional cosmetic agents. This study was aimed to encapsulate large volume of green tea in classical multiple emulsion and to compare its stability with a multiple emulsion without green tea extract. Multiple emulsions were developed using Cetyl dimethicone copolyol as lipophilic emulsifier and classic polysorbate-80 as hydrophilic emulsifier. Multiple emulsions were evaluated for various physicochemical aspects like conductivity, pH, microscopic analysis, rheology and these characteristics were followed for a period of 30 days in different storage conditions. In vitro and in vivo skin protection tests were also performed for both kinds of multiple emulsions i.e. with active (MeA) and without active (MeB). Both formulations showed comparable characteristics regarding various physicochemical characteristics in different storage conditions. Rheological analysis showed that formulations showed pseudo plastic behavior upon continuous shear stress. Results of in vitro and in vivo skin protection data have revealed that the active formulation has comparable skin protection effects to that of control formulation. It was presumed that stable multiple emulsions could be a promising choice for topical application of green tea but multiple emulsions presented in this study need improvement in the formula, concluded on the basis of pH, conductivity and apparent viscosity data

    Effects of Aluminium Exposures on Growth, Photosynthetic Efficiency, Lipid Peroxidation, Antioxidant Enzymes and Artemisinin Content of Artemisia annua L.

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    Acid soils are widely distributed at a global scale; under acidic conditions, the solubility of aluminium (Al) increases and the elevated concentration of toxic Al3+ in soil solution seriously limits crop production. There is no information on the effects of aluminium (Al) on Artemisia annua L., which is a most important antimalarial plant in the recent time being artemisinin; responsible for its antimalarial activity. In this report, we describe the effects of Al contamination on growth, photosynthetic efficiency, membrane damage, antioxidant enzyme activities and changes in artemisinin content in A. annua. Al addition to the soil medium significantly reduced the yield and growth of the plants. Lower values of net photosynthetic rate, stomatal conductance, internal CO2 and total chlorophyll content were observed as a result of different Al concentrations applied. The activities of nitrate reductase (NR) and carbonic anhydrase (CA) were also found to be hampered by Al exposure to the plants. Al enhanced lipid peroxidation rate (TBRAS content) and activated the activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes in the treated plants. The elicitation in the endogenous ROS levels, due to the Al treatments, was also noticed in the present study. Furthermore, enhanced artemisinin content and yield was obtained at 0.10mM concentration of soil applied Al. Our study provides evidence that excess Al in soil hamper the growth and yield, slow down the activities of NR and CA, induce lipid peroxidation and antioxidant enzymes but a low level of Al-toxicity can induce artemisinin content in A. annua plants.Key words: Aluminium (Al); Artemisia annua L.; Artemisinin; Lipid peroxidation; Reactive oxygen species (ROS)Tariq Aftab et al. Effects of Aluminium Exposures on Growth, Photosynthetic Efficiency, Lipid Peroxidation, Antioxidant Enzymes and Artemisinin Content of Artemisia annua L. J Phytol 2/8(2010) 23-37

    Analysis of Metal Content of Samples of Gloriosa Superba L (Colchicaceae) Collected from Two Different Locations in Pakistan

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    Purpose: To determine the metallic content of different parts of Gloriosa superba collected from two different locations in Pakistan, and also to assess their nutritious values and toxic levels.Methods: The plant material and soil were collected from two different locations - polluted and unpolluted. Wet digestion method was used for the preparation of samples (whole plant and soil) followed by analysis using flame atomic absorption spectrophotometer (for micronutrients) and flame photometry (for macronutrients).Results: Of the detected micronutrients, high concentrations of Zn, Fe and Mn were noted for samples collected from both areas. These values were within permissible limits. Samples collected from the polluted area contained Cu (7.5 – 13.0 ppm), Cr (1.4 − 1.9 ppm) and Ni (0.3 − 2.0 ppm), all of which exceeded acceptable limits; the same nutrients were mostly within acceptable limits for samples collected from the unpolluted area. Significant presence of macronutrients - Ca, Na and K - were observed in samples obtained from both areas.Conclusion: Proper validation of medicinal plants used for therapeutic purposes should be mandatory on safety grounds to protect consumers from contaminants.Keywords: Gloriosa superba, Micronutrients, Macronutrients, Toxicity, Metal ions, Medicinal plant

    Estimation of Para Red Dye in Chilli Powder and Tomato Sauces by a Simple Spectrophotmetric Method followed by Thin layer Chromatography

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    A number of grinded chilli powder samples and tomato sauce samples were collected from various localities of Karachi city. All the samples were estimated for the presence of para red which is an azo dye and more specifically belongs from the group of sudan dyes. According to the regulation of various governmental agencies its use in food is strictly prohibited because of its ability to form carcinogenic compounds. Although there were a number of sophisticated chromatographic methods for the estimation of this dye but we developed here a simple, convenient, expeditious spectrophotometric method followed by thin layer chromatography technique and compared the results by single point and multiple point external standard methods. On the basis of these results we also specify the localities of Karachi city where the contamination is more prominent. © JASE

    Progressive Class-Wise Attention (PCA) Approach for Diagnosing Skin Lesions

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    Skin cancer holds the highest incidence rate among all cancers globally. The importance of early detection cannot be overstated, as late-stage cases can be lethal. Classifying skin lesions, however, presents several challenges due to the many variations they can exhibit, such as differences in colour, shape, and size, significant variation within the same class, and notable similarities between different classes. This paper introduces a novel class-wise attention technique that equally regards each class while unearthing more specific details about skin lesions. This attention mechanism is progressively used to amalgamate discriminative feature details from multiple scales. The introduced technique demonstrated impressive performance, surpassing more than 15 cutting-edge methods including the winners of HAM1000 and ISIC 2019 leaderboards. It achieved an impressive accuracy rate of 97.40% on the HAM10000 dataset and 94.9% on the ISIC 2019 dataset

    Sustainable digital economy and trade adjusted carbon emissions: Evidence from China's provincial data

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    The importance of the digital economy and trade adjusted emissions is of great importance to study, especially in case of China. Since China is the leading exporter of the world and achieving high economic growth consecutively for the last 2-3 decades, this study, unlike past studies, evaluates the importance of digital economy, exports, imports and gross domestic product on trade adjusted carbon emissions for China. This is the only study that incorporates the importance of digital economy on trade adjusted carbon emissions for provincial data of China. This study determines whether the digital economy is a viable source of green economy. Research and development will simply replace a physical resource, flows through energy and transportation networks? This question is answered by using updated data, especially for digital economy. This study uses panel data for the Chinese provinces to investigate the impact of the digital economy in limiting CO2 emissions, taking into account GDP, exports and imports as control variables. Using method of moments quantile regression, we find a negative impact of digital economy and exports on consumption-based carbon emissions. Moreover, we find that GDP, and imports amplify consumption-based carbon emissions. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
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