Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (197)
  • Open Access

    ARTICLE

    Oxidative stress in the hydrophilic medium of algae and invertebrates

    Gabriela MALANGA, Paula Mariela GONZÁLEZ, Juan Manuel OSTERA, Susana PUNTARULO*

    BIOCELL, Vol.40, No.1, pp. 35-38, 2016, DOI:10.32604/biocell.2016.40.035

    Abstract The harmful effects of the reactive species may be due to the increase in their steady state concentration either by the enhancement of their production rates and/or the decrease of their consumption rate by antioxidant activity. The ascorbyl radical (A ) can be considered as a final product of radical oxidative transformations of ascorbate (AH-). The ratio A content/AH- content (A /AH-) has been widely used as an interesting tool to estimate mild to moderate oxidative transformations, providing a quick and simple method of diagnosis of stress in the hydrophilic cellular medium. The aim of this work was More >

  • Open Access

    ARTICLE

    Superhydrophobic and Oleophobic UV-Curable Surface Engineering of Cellulose-Based Substrates

    José M. R. C. A. Santos*, Ana R. Sampaio, Joana Branquinho

    Journal of Renewable Materials, Vol.4, No.1, pp. 31-40, 2016, DOI:10.7569/JRM.2015.634123

    Abstract Cellulose-based materials are one of the most widely used materials provided by nature to mankind. In particular, cotton fi bers have been used for millennia to produce clothing items. This wide usage stems from the inherent properties of cotton fabrics such as hydrophilicity and permeability to water vapor. However, increasingly sophisticated uses for cotton-based clothing (e.g., technical textiles) demand specifi c properties such as hydrophobicity and oleophobicity for repellent functions. The current surface treatments used to attain these functionalities are based on thermally initiated polymerization reactions, using water-based formulations. Thus, the current technologies are energy-… More >

  • Open Access

    ARTICLE

    Biodegradable Copolyester Fibers by Solution Electrospinning

    Alvaro Iregui1, Lourdes Irusta1,*, Loli Martin2, Alba González1

    Journal of Renewable Materials, Vol.3, No.1, pp. 44-48, 2015, DOI:10.7569/JRM.2014.634128

    Abstract In this work, solution electrospinning technique was used to produce biodegradable fi bers using a commercially available polyester (Ecofl ex F Blend C1200). These materials (mats) could be of potential interest in tissue engineering. The effect of polymer concentration and the solvent nature on the obtained morphology was related to the wettability of the mat, characterized by water contact angle measurements. According to the results, the electrospun mats presented water contact angles characteristic of hydrophobic surfaces. More >

  • Open Access

    ARTICLE

    Tunable Hydrophilicity of Poly(ethyl lactate acrylate-coacrylic acid)

    M. Purushothaman1, P. Santhana Gopala Krishnan1,2,*, S. K. Nayak1,2

    Journal of Renewable Materials, Vol.3, No.4, pp. 292-301, 2015, DOI:10.7569/JRM.2015.634114

    Abstract Four copolymers of poly(ethyl lactate acrylate-co-acrylic acid) were prepared by the solution polymerization technique by varying the comonomer content from 0.2 to 0.8 mole percent. The copolymers were characterized by FT-IR, 1H-NMR and proton decoupled 13C-NMR spectroscopic techniques. The reactivity ratio of ethyl lactate acrylate (ELA) and acrylic acid (AA) was calculated using the Fineman-Ross method and the values were found to be 0.101 and 0.186, respectively, indicating the formation of an alternating copolymer. From the wide-angle X-ray diffraction studies (WAXD), the average molecular interchain spacing () was calculated from the 2θ value of amorphous halo at… More >

  • Open Access

    ARTICLE

    Contribution to knowledge of foliar anatomy on Mnesithea selloana (Hack.) de Koning & Sosef (Andropogoneae-Panicoideae-Poaceae)

    Moya ME1,2, AA Galussi1,2, MJ Gómez1,2, FG Marchese1,2

    Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 176-183, 2015, DOI:10.32604/phyton.2015.84.176

    Abstract The aim of the present work was to analyze the foliar anatomy in lamina transverse section an in epidermis superficial view of Mnesithea selloana. Epidermic preparations and transections were carried out of the medium leaf part of sterile innovations that were conditioned and observed with optic microscope (OM) and scanning electron microscope (SEM).The histofoliar characteristics observed were: epidermic, intercostal, subsidiary, suberose, silicea and bulliform cells; and also guard cells, hairs, waxes, mesophylls, Kranz sheath, vascular bundles, sclerenchyma, colourless parenchyma and leaf margin. Epidermic observations showed that M. selloana presents a panicoid type epidermis presenting silicic cells as More >

  • Open Access

    ARTICLE

    Numerical Simulation of Droplet Breakup, Splitting and Sorting in a Microfluidic Device

    Chekifi. T1,2, Dennai. B1, Khelfaoui. R1

    FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

    Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays More >

  • Open Access

    ARTICLE

    COMPUTATIONAL STUDIES OF SWIRL RATIO AND INJECTION TIMING ON ATOMIZATION IN A DIRECT INJECTION DIESEL ENGINE

    Renganathan Manimarana, Rajagopal Thundil Karuppa Rajb,*

    Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-9, 2014, DOI:10.5098/hmt.5.2

    Abstract Diesel engine combustion modeling presents a challenging task with the formation and breakup of spray into droplets. In this work, 3D-CFD computations are performed to understand the behaviour of spray droplet diameter and temperature during the combustion by varying the swirl ratio and injection timing. After the validation and grid and time independency tests, it is found that increase in swirl ratio from 1.4 to 4.1 results in peak pressure rise of 8 bar and an advancement of injection timing from 6 deg bTDC to 20 deg bTDC results in increase of peak pressure by More >

  • Open Access

    ARTICLE

    Simulations of Blood Drop Spreading and Impact for Bloodstain Pattern Analysis

    Chu Wang, Lucy T. Zhang1

    CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 41-67, 2014, DOI:10.3970/cmes.2014.098.041

    Abstract Bloodstain pattern analysis (BPA) in forensic science is an important tool to solve crime scenes. The complex dynamic behavior of blood drops poses great challenges for accurate fluid dynamic simulations. In this paper, we specifically focus on simulations of blood drop spreading and impact, which may involve contact line hysteresis and spattering of drops as they interact with solid surfaces. Here, we set up a numerical framework that combines (1) the connectivity-free front tracking (CFFT) method for modeling multiphase (air and liquid) flows and (2) a dynamic contact line model for modeling fluid-solid contact line.… More >

  • Open Access

    ARTICLE

    Simulation of Thermal Fluid-structure Interaction Phenomena in a Liquid Sodium Porous System

    Yan Shen1, Hong Zhang1,2,3, Hui Xu1, Tong Bai1, Ping Yu1

    FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 63-81, 2014, DOI:10.3970/fdmp.2014.010.063

    Abstract Single-unit and multi-unit models of porous media (metal felts) have been used to investigate thermal fluid-structure interaction phenomena in a liquid sodium system. Micro-scale aspects have been studied via numerical simulations. The permeability of metal felts has been measured experimentally to verify the reliability of the models used. This integrated approach has allowed a proper evaluation of the interdependencies among phenomena on different scales (including relevant information on skeleton deformation and pressure drop as a function of different parameters). Pressure drop generally increases with velocity and heat flux for both laminar and turbulent flows. The More >

  • Open Access

    ARTICLE

    Synthesis and Characterization of New Carbohydrate-based Polyureas

    Belén Begines, Francisca Zamora, M. Violante de Paz, Isaac Roffé, Manuel Mancera, Juan A. Galbis*

    Journal of Renewable Materials, Vol.1, No.3, pp. 212-221, 2013, DOI:10.7569/JRM.2013.634119

    Abstract A batch of linear [m,n]-type sugar-based polyureas was synthesized by polyaddition reaction in solution from hexamethylene diisocyanate or 4,4’-methylene-bis(phenyl isocyanate) with the acyclic 2,3,4-tri-O-methyl-1,5- diamino-alditols having L-arabino, or xylo confi guration or the bicyclic 1,6-diamino-1,6-dideoxy-2,4:3,5-diO-methylene-D-glucitol. The polymers were obtained in good yields and fair molecular weights. All these polyureas were semicrystalline materials showing well-defi ned melting transition within the 86−171°C range, with Tg s being dependent on the aliphatic or aromatic nature of the diisocyanate used, and on the cyclic or acyclic chemical structure of the sugar moiety. They were found to be stable up to around More >

Displaying 141-150 on page 15 of 197. Per Page