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1.
Nanotechnology ; 27(1): 015501, 2016 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-26595669

RESUMEN

Different types of crystalline carbon nanomaterials were used to reinforce polyaniline for use in electromechanical bilayer bending actuators. The objective is to analyze how the different graphitic structures of the nanocarbons affect and improve the in situ polymerized polyaniline composites and their subsequent actuator behavior. The nanocarbons investigated were multiwalled carbon nanotubes, nitrogen-doped carbon nanotubes, helical-ribbon carbon nanofibers and graphene oxide, each one presenting different shape and structural characteristics. Films of nanocarbon-PAni composite were tested in a liquid electrolyte cell system. Experimental design was used to select the type of nanocarbon filler and composite loadings, and yielded a good balance of electromechanical properties. Raman spectroscopy suggests good interaction between PAni and the nanocarbon fillers. Electron microscopy showed that graphene oxide dispersed the best, followed by multiwall carbon nanotubes, while nitrogen-doped nanotube composites showed dispersion problems and thus poor performance. Multiwall carbon nanotube composite actuators showed the best performance based on the combination of bending angle, bending velocity and maximum working cycles, while graphene oxide attained similarly good performance due to its best dispersion. This parallel testing of a broad set of nanocarbon fillers on PAni-composite actuators is unprecedented to the best of our knowledge and shows that the type and properties of the carbon nanomaterial are critical to the performance of electromechanical devices with other conditions remaining equal.

2.
Plant Dis ; 96(7): 990-996, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30727214

RESUMEN

The effectiveness of a combination of soil solarization and poultry manure (raw or pelletized) amendments for the control of root-knot nematode (Meloidogyne incognita) was tested in carnation (Dianthus caryophyllus) crops grown in in-ground beds under plastic-covered greenhouse conditions in southern Spain. Our trials demonstrated that soil solarization alone did not provide sufficient control of root-knot nematode, because the carnation growing season in this region only partly coincides with the most effective period for solarization, resulting in an insufficient duration of treatment during a key period for effectiveness. Chemical fumigation with 1,3-dichloropropene + chloropicrin prior to planting was effective in reducing nematode population densities in soil. Its effects spanned 9 months after planting, resulting in acceptable crop yields. In comparison, the combination of soil solarization and raw or pelletized poultry manure was slightly less effective than chemical fumigation for control of this pathogen but crop yields after 9 months were similar. However, the higher root gall indices observed after 9 months, in comparison with chemically fumigated plots, indicated the need for a reapplication of the organic manure treatment at the start of each successive growing season.

3.
Int Angiol ; 26(4): 378-84, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18091707

RESUMEN

AIM: Clinical and capillaroscopic evaluation of an association of Ruscus aculeatus, hesperidin methylchalcone (HMC) and ascorbic acid in chronic venous insufficiency METHODS: A prospective, multicenter and open clinical study. Chronic venous insufficiency patients were studied using clinical, etiological, anatomical, physiological classification (CEAP) symptom scale. Symptomatology, CEAP scale, and baseline, 2-, 4-, 6- and 8-week skin capillaroscopy were assessed. Treatment consisted of two capsules per day of Ruscus aculeatus 150 mg/HMC 150 mg/ascorbic acid 100 mg during 8 weeks. RESULTS: A total of 124 patients were studied, 109 female (89.28%), with a mean age of 52.5 (33-80+9.8). Initial intense reports were 79% pain, 85% heaviness, 74% cramps, 82% edema, decreasing to 20%, 12%, 8% and 14%, respectively, within two weeks, and symptomatology being absent at the end of treatment. Capillaroscopy changes at treatment completion were: 98% to 20% inter-capillary fluid decrease; 80% to 20% efferent loop thickening; 5% to 2% peri-capillary bed, and 5% to 4% mega-capillaries. CONCLUSION: Severe symptom decrease started from the second week until there were no symptoms at the end of treatment. It is the first time morphologic changes were observed in chronic venous insufficiency through capillaroscopy following a pharmacological intervention. Capillary-level effect was proportional to symptom decrease. Improvement was seen from the second week of treatment.


Asunto(s)
Antioxidantes/uso terapéutico , Ácido Ascórbico/uso terapéutico , Chalconas/uso terapéutico , Hesperidina/análogos & derivados , Fitoterapia , Extractos Vegetales/uso terapéutico , Ruscus , Insuficiencia Venosa/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Femenino , Hesperidina/uso terapéutico , Humanos , Pierna/irrigación sanguínea , Masculino , Angioscopía Microscópica , Persona de Mediana Edad , Insuficiencia Venosa/complicaciones , Insuficiencia Venosa/patología
4.
Nano Lett ; 7(8): 2220-6, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17658866

RESUMEN

Novel coaxial structures consisting of nitrogen-doped carbon nanotube (MWNTs-CNx) cores with external concentric shells of pure carbon were produced by the pyrolysis of toluene over Fe-coated MWNTs-CNx. These materials were thoroughly characterized by SEM, HRTEM, X-ray diffraction, and TGA; a possible growth scenario for their formation is also proposed. In addition, these coaxial structures were able to form 2D and 3D covalent networks that mainly exhibited T-, Y-, and on-type morphologies. The two-step technique presented here could be further developed to fully control the growth of these new coaxial structures, study of individual junctions, and it could be used to create periodic nanotube networks, in which the heterocable structure could find applications in nanoelectronics.


Asunto(s)
Cristalización/métodos , Nanotecnología/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestructura , Nitrógeno/química , Conductividad Eléctrica , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de Superficie
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