Consulta: subjectFacets:"Polymers"
Registros recuperados: 11
Data/hora: 09/06/2024 12:27:32

Contribution à l'étude du couplage entre diffusion d'eau et contrainte mécaniques dans les matériaux marins hautes performances
Provedor de dados: 5
Autores: Humeau, Corentin.
The aim of the study was to understand the impact of coupling on water diffusion and mechanical stress on marine installations. Moreover, we identified the key phenomena involved during this type of exposure. When we look to these type of applications we can distinguish two type of materials used: one for the structure and another for mooring facilities. The best performing structural materials appear to be composites, while the most effective mooring devices are made with synthetic ropes. Therefore, we decided to investigate both materials with the same method: first the properties uncoupled, second, as semi-coupled behaviours and finally as one coupled phenomenon. The present work highlights the divergences between uncoupled, semi-coupled and coupled...
Tipo: Text
Palavras-chave: Couplage; Diffusion d’eau; Contrainte mécanique; Vieillissement; Polymères; Cordages synthétiques; Composites; Coupling; Water diffusion; Mechanical stress; Ageing; Polymers; Synthetic ropes; Composites.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00499/61023/64424.pdf

Delamination behaviour of very high modulus carbon/epoxy marine composites
Provedor de dados: 5
Autores: Baral, N; Davies, Peter; Baley, C; Bigourdan, Benoit.
This paper presents a study of the delamination resistance Of unidirectional carbon fibre reinforced epoxy composites manufactured from prepreg for racing yacht mast applications. Fibre modulus has been varied from 290 to 640 GPa. Two manufacturing methods, oven cure under vacuum and autoclave, were used to produce samples. Results show that delamination resistance tinder mode I and mixed mode loading decreases as fibre modulus increases. The manufacturing route affects G, values by modifying interlaminar layer geometry but does not change the trend of lower toughness with increasing fibre modulus. For the pitch composites crack propagation is observed within the fibres, in addition to more usual matrix and interface cracking. For the very high modulus...
Tipo: Text
Palavras-chave: Mixed mode; Fracture toughness; Polymers; Carbon fibres; Delamination.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3772.pdf

Effect of xanthan on the growth of sulphate-reduction bacteria in marine sediments.
Provedor de dados: 5
Autores: Battersby, N; Stewart, D; Sharma, A.
Chemical additives are used extensively in the offshore oil industry. For secondary oil recovery, the biopolymer xanthan has been recommended as a viscosifying agent but its use may provoke microbial problems. The effect of adding xanthan to marine sediments on the growth and metabolic activity of sulphate-reducing bacteria (SRB) was studied. In all instances, its addition resulted in an increasing in SRB numbers of up to 250-fold. This was accompanied by a marked increase in the electron transport activity of the sediments when these were incubated under either aerobic or anaerobic conditions. The products formed as a result of the biodegradation of the polymer by indigenous heterotrophic bacteria in these sediments appear to have acted as suitable...
Tipo: Text
Palavras-chave: Bacteria; Growth; Additives; Pollution effects; Oil recovery; Biodegradation; Polymers; Sediment pollution; Sulfate reduction.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1015.pdf

Facility for Growing Plants in Test Tubes at ICRISAT
Provedor de dados: 30
Autores: O.P.
Palavras-chave: Rhizobium; Chickpeas; Pigeonpeas; Root nodulation; Temperature; Nitrogen fixation; Polymers; Iron; Tropical zones; Quality.
Ano: 1984
URL: http://agropedia.iitk.ac.in/openaccess/?q=node/4025

Ten Myths about Tannins in Sorghums
Provedor de dados: 30
Autores: Rooney, L.
Palavras-chave: Organic acids; Sorghum; Antioxidants; Pigments; Phenols; Linseed; Aromatic compounds; HPLC; Bakery products; Polymers.
Ano: 2005
URL: http://agropedia.iitk.ac.in/openaccess/?q=node/3264

Effect of harvest timing and postharvest storage conditions on aflatoxin contamination in groundnuts harvested from the Wonogiri regency in Indonesia
Provedor de dados: 30
Autores: Rahmianna,A.A.
Palavras-chave: Mycotoxins; Groundnuts; ELISA; Polymers; Retail marketing; Sampling; Storage; Harvesting; Fungi; Quality.
Ano: 2007
URL: http://agropedia.iitk.ac.in/openaccess/?q=node/3358

Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
Provedor de dados: 42
Autores: FERNANDES-DE-LIMA,VERA M.; KOGLER,JOÃO E.; BENNATON,JOCELYN; HANKE,WOLFGANG.
The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Intrinsic optic signals; Volume phase transitions; Polymers; Spreading depression; Central gray matter; Extracellular matrix.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000300006

Experimental acrylonitrile butadiene styrene and polyamide evisceration implant: a rabbit clinical and histopathology study
Provedor de dados: 45
Autores: Gomes Júnior,D.C.; Nassar,E.J.; Dórea Neto,F.A.; Lima,A.E.; Martins Filho,E.F.; Oriá,A.P.
ABSTRACT The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS) and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rabbits; Ocular prosthesis; Polymers.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352016000501168

Characterisation of Cassava Bagasse and Composites Prepared by Blending with Low-Density Polyethylene
Provedor de dados: 52
Autores: Farias,Fabiane Oliveira; Jasko,Ariana Crasnhak; Colman,Tiago André Denck; Pinheiro,Luís Antônio; Schnitzler,Egon; Barana,Ana Cláudia; Demiate,Ivo Mottin.
The main objective of this study was to characterise the cassava bagasse and to evaluate its addition in composites. Two cassava bagasse samples were characterised using physicochemical, thermal and microscopic techniques, and by obtaining their spectra in the mid-infrared region and analysing them by using x-ray diffraction. Utilising sorption isotherms, it was possible to establish the acceptable conditions of temperature and relative humidity for the storage of the cassava bagasse. The incorporation of cassava bagasse in a low-density polyethylene (LDP) matrix was positive, increasing the elasticity modulus values from 131.90 for LDP to 186.2 for 70% LDP with 30% SP bagasse. These results were encouraging because cassava bagasse could serve as a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Manihot esculenta Crantz; Residue; Polymers.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000600821

Flocculation of fine fluorite particles with Corynebacterium xerosis and commercial long chain polymers
Provedor de dados: 58
Autores: Rigo,Lisandra N.; Pinto,Angela Maria; Denardin,Norimar D'Avila; Schneider,Ivo André H.
This work aimed to study, comparatively, the flocculation of fluorite particles with Corynebacterium xerosis cells and three commercial long chain polymers. Best flocculation results were obtained with cells of C. xerosis and with an anionic polyacrylamide. Both were effective in solids removal and water clarification, although flocculation with C. xerosis cells requires a higher dosage of reagent per mass unit of processed ore.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Corynebacterium xerosis; Flocculation; Fluorite; Polymers.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000400010

Pharmaceutical films made from the waste material from the preparation of propolis extracts: development and characterization
Provedor de dados: 60
Autores: Toledo,Lucas de Alcântara Sica de; Bavato,Maíra Isabeli; Rosseto,Hélen Cássia; Cortesi,Rita; Bruschi,Marcos Luciano.
abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP) from the preparation of propolis extracts. Films were produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose) and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation), water vapour permeability (WVP), moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR) were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Propolis/byproducts; Propolis/use of waste material/films development; Films/propolis byproducts/physicochemical properties; Polymers; Ethylcellulose; Gelatin.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502015000400847