Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (1,070)
  • Open Access

    ARTICLE

    Nanocelluloses from Eucalyptus Wood Pulp: A Morphological Comparison

    Antonio J. F. Carvalho

    Journal of Renewable Materials, Vol.2, No.2, pp. 118-122, 2014, DOI:10.7569/JRM.2014.634108

    Abstract Two nanocelluloses from eucalyptus, namely microfi brillated cellulose (MFC) and cellulose nanocrystals (CNC), were prepared and compared by transmission electron microscopy (TEM). The MFC fi bers are 20–30 nm wide and are composed of very homogeneous bundles of aligned regular elementary fi brils of 3–5 nm diameter. They show long straight portions and short fl exible zones, attributed to crystalline and amorphous zones, respectively. The needle-shaped CNC was approximately 200 nm long and 10 nm wide in the wider portion. A model for the MFC structure, whose fl exible zones are formed by alignment of More >

  • Open Access

    ARTICLE

    Physical and Mechanical Properties of Polymer Composite Materials Based on Olive Husk Flour

    Amar Boukerrou*, Dalila Hammiche, Djidjelli Hocine, Hassina Aouat

    Journal of Renewable Materials, Vol.2, No.4, pp. 249-257, 2014, DOI:10.7569/JRM.2014.634119

    Abstract The lack of compatibility between cellulose fi bers and some polymers, such as thermoplastics, is due on one hand to the hydrophilic nature of the vegetable fi bers and on the other hand to the hydrophobic character of the matrix. This incompatibility induces bad dispersion of the fi bers and the formation of a heterogeneous material with mechanical properties which are not very satisfactory. The scope of this article is to describe the possibility of using Olive Husk Flour (OHF) as reinforcement in the elaboration of a composite material based on polyvinyl chloride (PVC). In More >

  • Open Access

    ARTICLE

    Impact of selenium fertilization on the activity of detoxifying enzymes of H2O2 in bean plants

    Hermosillo-Cereceres MA1, E Sánchez1, E Muñoz-Márquez1, A Guevara-Aguilar1, M García-Bañuelos1, D Ojeda-Barrios2

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 347-352, 2014, DOI:10.32604/phyton.2014.83.347

    Abstract Selenium (Se) is an essential element for many organisms, although in high concentrations it may become toxic, leading to the generation of reactive oxygen species (ROS). In this study, bean plants received different application rates of Se (0, 10, 20, 40, 80, and 160 µM) in the form of selenite and selenate to evaluate the activity of the detoxifying enzymes of H2O2. The results indicated that the activity of these enzymes in bean plants depended on the chemical form of Se: selenite at rates of 20 µM or greater diminished biomass and yield, increasing the activity More >

  • Open Access

    ARTICLE

    Comparison of four DNA extraction methods on various tissues and types of Sechium edule ( Jacq.) Sw.

    Galindo-Tovar ME, VS Gasperin-Sanatta, JA Alejandre-Rosas, OR Leyva-Ovalle, J Murguía-González, HE Lee-Espinosa, I L,ero-Torres

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 307-310, 2014, DOI:10.32604/phyton.2014.83.307

    Abstract Sechium edule is an important crop in Southern Mexico and Central America, and México was the main producer, with 53% of the world production in 2012. This species presents high levels of morphological variation that have resulted in different types of varieties not clearly defined. However, morphological characteristics have not been sufficient to classify S. edule varieties, and it has been difficult to study the species genetic diversity. Because of it, there is a need to develop methods for studying the genetic diversity in S. edule. In this regard, the first step is to find a suitable DNA More >

  • Open Access

    ARTICLE

    Comparison of heat-unit methods to predict tomato anthesis

    Bouzo CA, JC Favaro

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 167-170, 2014, DOI:10.32604/phyton.2014.83.167

    Abstract The aim of this work was to compare methods to predict the time of anthesis in tomato (Solanum lycopersicum L.). Two independent experiments were carried out using seeds of the Tauro commercial hybrid. Daily maximum and minimum air temperatures were measured by means of an electronic thermometer with data storage; the photoperiod was calculated using a mathematical procedure. The moment at which each inflorescence presented 50% of its flowers in anthesis was recorded. The use of calendar days (CD) had a high dispersion, which was measured with a variation coefficient (VC) higher than 3.70% for all More >

  • Open Access

    ARTICLE

    Extension of postharvest shelf-life of tomato fruits using biocompatible synthetic latex

    Ramos G1, RH Lira1, RD Peralta2, GY Cortez2, A Cárdenas1

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 139-143, 2014, DOI:10.32604/phyton.2014.83.139

    Abstract Tomato fruits are perishable products that require treatments such as coating films to extend their shelf life. Because of this and to avoid use of synthetic chemicals to prevent physical deterioration during postharvest, we evaluated the effects of an edible coating polymer latex poly (vinyl acetate-co-vinyl alcohol), P (VAc-co-VA), at three concentrations (0, 50 and 100%) in tomato fruits. The trial was conducted at room temperature conditions (31 ± 4 °C; with RH of 30 ± 5%) and temperature-controlled (12 ± 1 °C; with RH of 75 ± 5%). Fruits coated with P (VAc-co-VA) at More >

  • Open Access

    ARTICLE

    Cytotoxicity assessment of a gold nanoparticle-chitosan nanocomposite as an effi cient support for cell immobilization: comparison with chitosan hydrogel and chitosan-gelatin

    Mohammad Reza RAMEZANI1, Hossein NADERI-MANESH1, *, Hossain-Ali RAFIEEPOUR2

    BIOCELL, Vol.38, No.1, pp. 11-16, 2014, DOI:10.32604/biocell.2014.38.011

    Abstract Cell-based biosensors have become a research hotspot in the biosensors and bioelectronics fields. The main feature of cell-based biosensors is immobilization of living cells on the surface of transducers. Different types of polymers which are used as scaffolds for cell growth should be biocompatible and should have reactive functional groups for further attachment of biomolecules. In this work, cell attachment and proliferation on chitosan hydrogel, chitosan-gelatin and gold nanoparticle-chitosan nanocomposite membranes was studied. Characterization of the membranes was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Cytotoxicity assessment on HEK293 More >

  • Open Access

    ARTICLE

    Optimization of Johnson-Cook Constitutive Model for Lead-free Solder Using Genetic Algorithm and Finite Element Simulations

    D.S.Liu1, C.L.Hsu1,2

    CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 165-178, 2014, DOI:10.3970/cmc.2014.040.165

    Abstract To ensure the reliability of microelectronics packages, the high strain rate deformation behavior of the solder joints must be properly understood. Accordingly, the present study proposes a hybrid experimental / numerical method for determining the optimal constants of the Johnson-Cook (J-C) constitutive model for 96.5Sn-3Ag-0.5Cu (SAC305) solder alloy. In the proposed approach, FEM simulations based on the J-C model are performed to describe the load-time response of an SAC305 ball solder joint under an impact velocity of 0.5 m/s. The optimal values of the constitutive model are then determined using an iterative Genetic Algorithm approach More >

  • Open Access

    ARTICLE

    Comparing the Effect of Uniaxial Cyclic Mechanical Stimulation and Chemical Factors on Myogenin and Myh2 Expression in Mouse Embryonic and Bone Marrow Derived Mesenchymal Stem Cells

    Norizadeh Abbariki Tannaz*,†, Shokrgozar Mohammad Ali†,‡, Haghighipour Nooshin*,§, Aghdami Nasser, Mahdian RezakII, Amanzadeh Amir*, Jazayeri Maryam*,†

    Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 19-37, 2014, DOI:10.3970/mcb.2014.011.019

    Abstract Background: Environmental factors affect stem cell differentiation. In addition to chemical factors, mechanical signals have been suggested to enhance myogenic differentiation of stem cells. Therefore, this study was undertaken to illustrate and compare the effect of chemical and mechanical stimuli on Myogenin (MyoG) and Myosin heavy chani 2 (Myh2) expression of mouse bone marrowderived mesenchymal stem cells (BMSCs) and embryonic stem cells (ESCs). Methods: After isolation and expansion of BMSCs and generation of embryoid bodies and spontaneous differentiation of ESCs, cells were examined in 4 groups: (1) control group: untreated cells; (2) chemical group: cells… More >

  • Open Access

    ARTICLE

    Comparison of Four Multiscale Methods for Elliptic Problems

    Y. T. Wu1, Y. F. Nie2, Z. H. Yang1

    CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.4, pp. 297-325, 2014, DOI:10.3970/cmes.2014.099.297

    Abstract Four representative multiscale methods, namely asymptotic homogenization method (AHM), heterogeneous multiscale method (HMM), variational multiscale (VMS) method and multiscale finite element method (MsFEM), for elliptic problems with multiscale coefficients are surveyed. According to the features they possess, these methods are divided into two categories. AHM and HMM belong to the up–down framework. The feature of the framework is that the macroscopic solution is solved first with the help of effective information computed in local domains, and then the multiscale solution is resolved in local domains using the macroscopic solution when necessary. VMS method andMsFEM fall More >

Displaying 861-870 on page 87 of 1070. Per Page