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Impregnation
Terms modified by Impregnation Selected AbstractsPyridine Carboxylate Complexes of MoII as Active Catalysts in Homogeneous and Heterogeneous PolymerizationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2007Maria Vasconcellos-Dias Abstract New lamellar materials intercalated with molybdenum(II) complexes with potential catalytic properties were prepared by a stepwise procedure. The lamellar material was first calcined at 823 K for four hours to eliminate all the carbonate ions; the layered structure was reconstructed after treatment with a solution of either pycH (pyridine-2-carboxylic acid) or pydcH2 (pyridine-2,6-dicarboxylic acid) in a KOH solution of dmf at 343 K. Impregnation with a solution of the organometallic precursor [Mo(CO)3I2(NCCH3)2] led to substitution of the nitrile groups by two pyridine ligands. All the materials were characterized by powder X-ray diffraction, FTIR, and 13C CP MAS and 27Al MAS solid-state NMR spectroscopy. Similar MoII complexes were also prepared by using pycH or pydcH2 and characterized by elemental analysis as well as FTIR and 1H and 13C solution NMR spectroscopy. These new materials and the complexes of pyc or pydc ligands containing 4.54 wt.-% and 6.33 wt.-% of Mo respectively, catalyze the ring-opening-metathesis polymerization of norbornene and the polymerization of styrene at 333 K, their performance increasing upon the addition of methylalumoxane (MAO) as cocatalyst.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Deproteinized bovine bone and gentamicin as an adjunct to GTR in the treatment of intrabony defects: a randomized controlled clinical studyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2003A. Stavropoulos Abstract Objectives: To evaluate whether Bio-Oss® used as an adjunct to guided tissue regeneration (GTR) improves the healing of 1- or 2-wall intrabony defects as compared with GTR alone, and to examine whether impregnation of Bio-Oss® with gentamicin may have an added effect. Material and methods: Sixty patients, with at least one interproximal intrabony defect with probing pocket depth (PPD) 7 mm and radiographic evidence of an intrabony component (IC) 4 mm, were treated at random with either a resorbable membrane (GTR), a resorbable membrane in combination with Bio-Oss® impregnated with saline (DBB,), a resorbable membrane in combination with Bio-Oss® impregnated with gentamicin (DBB+), or with flap surgery (RBF). Results: All treatment modalities resulted in statistically significant clinical improvements after 1 year. Defects treated with GTR alone presented a probing attachment level (PAL) gain of 2.9 mm, a residual PPD (PPD12) of 4.9 mm, a radiographic bone level (RBL) gain of 3.1 mm, and a residual IC (IC12) of 2.7 mm. GTR combined with Bio-Oss® did not improve the healing outcome (PAL gain: 2.5 mm; PPD12: 4.9 mm; RBL gain: 2.8 mm; IC12: 3.3 mm). Impregnation of the Bio-Oss® with gentamicin 2% mg/ml resulted in clinical improvements (PAL gain: 3.8 mm; PPD12: 4.2 mm; RBL gain: 4.7 mm; IC12: 2.1 mm), superior to those of the other treatment modalities, but the difference was not statistically significant. Defects treated with only flap surgery showed the most inferior clinical response (PAL gain: 1.5 mm; PPD12: 5.1 mm; RBL gain: 1.2 mm; IC12: 4.2 mm) of all groups. Conclusion: The results failed to demonstrate an added effect of Bio-Oss® implantation in combination with GTR on the healing of deep interproximal 1- or 2-wall, or combined 1- and 2-wall intrabony defects compared with GTR alone. Local application of gentamicin, on the other hand, improved the treatment outcome but not to an extent that it was statistically significant. Zusammenfassung Von Proteinen befreiter boviner Knochen und Gentamycin als Adjuvans der GTR bei der Behandlung von infraalveolären Knochentaschen. Eine randomisierte kontrollierte klinische Studie. Ziele: Die Evaluation ob, Bio-Oss® welches als Adjuvans zur GTR verwendet wird, die Heilung von 1- oder 2-wandigen Knochentaschen im Vergleich zu alleiniger GTR verbessert. Sowie die Untersuchung, ob die Imprägnierung von Bio-Oss® mit Gentamycin einen zusätzlichen Effekt haben könnte. Material und Methoden: 60 mit wenigstens einer approximalen Knochentasche mit Sondierungstiefe (PPD) ,7 mm und röntgenologischem Nachweis einer infraalveolären Komponente (IC) von ,4 mm, wurden randomisiert entweder mit einer resorbierbaren Membran (GTR), einer resorbierbaren Membran in Kombination mit Bio-Oss® welche mit Kochsalzlösung imprägniert war (DBB-), einer resorbierbaren Membran in Kombination mit Bio-Oss® welche mit Gentamycin imprägniert war (DBB+) oder mit Lappen-OP (RPF) behandelt. Ergebnisse: Nach einem Jahr hatten alle Behandlungsweisen eine statistisch signifikante klinische Verbesserung zum Ergebnis. Defekte, die mit alleiniger GTR behandelt wurden zeigten einen Gewinn an klinischem Attachmentniveau (PAL) von 2,9 mm, einer PPD (PPD12) von 4,9 mm, einem Gewinn an röntgenologischem Knochenniveau (RBL) von 3,1 mm und einer IC (IC12) von 2,7 mm. GTR in Kombination mit Bio-Oss® verbesserte das Ergebnis der Heilung nicht (PAL Gewinn: 2,5 mm; PPD12: 4,9; RBL Gewinn: 2,8 mm; IC12: 3,3 mm). Die Imprägnierung von Bio-Oss® mit Gentamycin 2% mg/ml hatte klinische Verbesserungen zum Ergebnis (PAL Gewinn: 3,8 mm; PPD12: 4,2 mm; RBL Gewinn: 4,7 mm; IC12: 2,1 mm), die größer waren als die der anderen Behandlungsweisen, jedoch waren die Unterschiede nicht statistisch signifikant. Defekte, die nur mit Lappen-OP behandelt wurden zeigten das schlechteste klinische Ergebnis von allen Gruppen (PAL Gewinn: 1,5 mm; PPD12: 5,1 mm; RBL Gewinn: 1,2 mm; IC12: 4,2 mm). Schlussfolgerung: Die Ergebnisse konnten im Vergleich mit alleiniger GTR keinen zusätzlichen Effekt der Bio-Oss®-Implantation in Kombination mit GTR hinsichtlich der Heilung von tiefen approximalen 1- oder 2-wandigen oder kombinierten 1- oder 2-wandigen Knochentaschen aufzeigen. Auf der anderen Seite verbessert die lokale Applikation von Gentamycin das Behandlungsergebnis, jedoch war das Ausmaß nicht statistisch signifikant. Résumé Os bovin déprotéiné et gentamicine comme adjuvant à la RTG pour le traitement des lésions intra-osseuses. Une étude clinique contrôlée et randomisée. Objectifs: Evaluer si Bio-Oss® utilisé comme adjuvant de la RTG améliore la cicatrisation des lésions intra-osseuses par rapport à la RTG seule et examiner si l'imprégnation de Bio-Oss® avec de la gentamicine pourrait avoir un effet supplémentaire. Matériels et Méthodes: 60 patients, présentant au moins une lésion intra-osseuse interproximale avec une profondeur de poche au sondage (PPD) ,7 mm et la présence avérée radiologiquement d'une composante intra-osseuse (IC) ,4 mm, ont été traités au hasard avec soit une membrane résorbable (GTR), une membrane résorbable en combinaison avec du Bio-Oss® imprégné de solution saline (DBB-), une membrane résorbable en combinaison avec du Bio-Oss® imprégné de gentamicine (DBB+), ou par chirurgie à lambeau (RBF). Résultats: Toutes les modalités de traitement entraînaient des améliorations cliniques significatives statistiquement après un an. Les lésions traitées par RTG seule présentaient un gain d'attache de 2.9 mm, une PPD résiduelle (PPD12) de 4.9 mm, un gain de niveau osseux radiographique (RBL) de 3.1 mm, et un IC résiduel (IC12) de 2.7 mm. La RTG combinée avec le Bio-Oss® n'améliorait pas le devenir de la cicatrisation. (gain de PAL: 2.5 mm; PPD12: 4.9; gain de RBL: 2.8 mm; IC12: 3.3 mm). L'imprégnation du Bio-Oss®avec la gentamicine (2% mg/ml) apportait des améliorations cliniques (gain de PAL: 3.8 mm; PPD12: 4.2 mm; gain de RBL: 4.7 mm; IC12: 2.1 mm), supérieurs à ceux des autres modalités de traitement, mais la différence n'était pas significative. Le traitement des lésions par lambeaux seulement entraînait la réponse clinique la moins bonne (gain de PAL: 1.5 mm; PPD12: 5.1 mm; gain de RBL: 1.2 mm; IC12: 4.2 mm). Conclusion: Ces résultats ne pouvaient démontrer un effet supplémentaire, sur la cicatrisation de lésions profondes interproximales avec une ou deux parois, de l'implantation de Bio-Oss® en combinaison avec la RTG par rapport à la RTG seule. L'application locale de gentamicine, par contre, améliorait le devenir du traitement mais pas suffisamment pour être statistiquement significatif. [source] Mass Balances in Porous Foods ImpregnationJOURNAL OF FOOD SCIENCE, Issue 9 2001V. Roa ABSTRACT: A simple model based on mass balance equations is proposed for prediction of the final mass and composition of products subjected to vacuum impregnation. It was applied to some tropical fruits in a fruit-sucrose solution system. The phenomenon can be described in terms of volumetric fraction of impregnating solution as the basic modeling parameter, instead of effective porosity. To use the equations of the model, only routine laboratory equipment and simple experiments are required. Prediction of the final weight of impregnated fruit was accomplished with an average absolute error of 2 to 3%, while in final composition of the fruit (total solids), it was 5.7 %. [source] Glutamate AMPA/kainate receptors, not GABAA receptors, mediate estradiol-induced sex differences in the hypothalamusDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2007Brigitte J. Todd Abstract Sex differences in brain morphology underlie physiological and behavioral differences between males and females. During the critical perinatal period for sexual differentiation in the rat, gonadal steroids act in a regionally specific manner to alter neuronal morphology. Using Golgi-Cox impregnation, we examined several parameters of neuronal morphology in postnatal day 2 (PN2) rats. We found that in the ventromedial nucleus of the hypothalamus (VMN) and in areas just dorsal and just lateral to the VMN that there was a sex difference in total dendritic spine number (males greater) that was abolished by treating female neonates with exogenous testosterone. Dendritic branching was similarly sexually differentiated and hormonally modulated in the VMN and dorsal to the VMN. We then used spinophilin, a protein that positively correlates with the amount of dendritic spines, to investigate the mechanisms underlying these sex differences. Estradiol, which mediates most aspects of masculinization and is the aromatized product of testosterone, increased spinophilin levels in female PN2 rats to that of males. Muscimol, an agonist at GABAA receptors, did not affect spinophilin protein levels in either male or female neonates. Kainic acid, an agonist at glutamatergic AMPA/kainate receptors, mimicked the effect of estradiol in females. Antagonizing AMPA/kainate receptors with NBQX prevented the estradiol-induced increase in spinophilin in females but did not affect spinophilin level in males. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] An optimal method of DNA silver staining in polyacrylamide gelsELECTROPHORESIS, Issue 8 2007Yun-Tao Ji Abstract A silver staining technique has widely been used to detect DNA fragments with high sensitivity on polyacrylamide gels. The conventional procedure of the silver staining is tedious, which takes about 40,60,min and needs five or six kinds of chemicals and four kinds of solutions. Although our previous improved method reduced several steps, it still needed six kinds of chemicals. The objective of this study was to improve further the existing procedures and develop an optimal method for DNA silver staining on polyacrylamide gels. The novel procedure could be completed with only four chemicals and two solutions within 20,min. The steps of ethanol, acetic acid, and nitric acid precession before silver impregnation have been eliminated and the minimal AgNO3 dose has been used in this up-to-date method. The polyacrylamide gel of the DNA sliver staining displayed a golden yellow and transparent background with high sensitivity. The minimum 0.44 and 3.5,ng of DNA amount could be detected in denaturing and nondenaturing polyacrylamide gel, respectively. This result indicated that our optimal method can save time and cost, and still keep a high sensitivity for DNA staining in polyacrylamide gels. [source] Efficient and sensitive method of DNA silver staining in polyacrylamide gelsELECTROPHORESIS, Issue 1 2005Lujiang Qu Abstract DNA silver staining is widely used to detect DNA fragment in polyacrylamide gel with high sensitivity. Conventional procedures of the silver staining involve several steps, which take about 40 min to 2 h in total. To improve the efficiency of DNA silver staining, a more efficient protocol is developed in this study. The procedure comprises only four steps including impregnating, rinsing, developing, and stopping, and could be completed within 20 min. Nitric acid and ethanol in the silver-impregnation step of the new procedure eliminates the need for prior treatment of gels with a fixing solution and following rinse prior to impregnation with silver. The procedure has high sensitivity and long storage lifetime. The minimum detectable mass of DNA is 0.44 and 3.5 ng in denaturing and nondenaturing polyacrylamide gel, respectively. [source] Ultra-Fast Atomic Transport in Severely Deformed Materials,A Pathway to Applications?,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Sergiy Divinski Abstract Severe plastic deformation of pure Cu and Cu-rich alloys was found to create a hierarchical combination of fast and ultra-fast diffusion paths ranging from non-equilibrium grain boundaries to non-equilibrium triple junctions, vacancy clusters, nano- and micro-pores, and finally to general high-angle grain boundaries. Under certain conditions, a percolating network of porosity can be introduced in the ultra-fine grained materials by a proper mechanical and thermal treatment. This network may offer promising opportunities for creating materials with tailor-made properties, including combinations of improved mechanical performance with a possibility of self repair using "vascular structures" for atom transport. Applications in such areas as drug eluting bioimplants and lead or polymer eluting materials for reduction of friction based on impregnation of porosity networks with these agents are also envisaged. [source] Fire performance of wood (Pinus radiata) treated with fire retardants and a wood preservativeFIRE AND MATERIALS, Issue 6 2008D. C. O. Marney Abstract In this work, we co-formulated an oil-borne copper naphthenate/permethrin wood preservative system with synthetic polymer-based fire-retardant additives prior to the impregnation of Pinus radiata sapwood. We evaluated what effect, if any, the preservative had upon the fire performance properties of the fire retardants and whether the fire retardants impacted on the fungicidal and termiticidal efficacy of the preservative. The fire retardants included halogenated and phosphorus-based systems. A mass loss calorimeter, in conjunction with a thermopile, was used to measure the time to ignition and the peak heat release rate (PHRR) from which the fire performance index (FPI) was determined. The preservative properties were evaluated using termite and soil-block decay bioassays. In summary, we found that the rate of fire growth was reduced when the fire retardants were used in combination with the wood preservative. We also found that the PHRR was a better determinant of fire performance than the FPI. The performance of the wood preservative was enhanced against fungal decay and termite attack when used in combination with the fire retardants. The fire retardants also demonstrated some wood preservative properties of their own. Copyright © 2008 John Wiley & Sons, Ltd. [source] High Mechanical Performance Composite Conductor: Multi-Walled Carbon Nanotube Sheet/Bismaleimide NanocompositesADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Qunfeng Cheng Abstract Multi-walled carbon nanotube (MWNT)-sheet-reinforced bismaleimide (BMI) resin nanocomposites with high concentrations (,60,wt%) of aligned MWNTs are successfully fabricated. Applying simple mechanical stretching and prepregging (pre-resin impregnation) processes on initially randomly dispersed, commercially available sheets of millimeter-long MWNTs leads to substantial alignment enhancement, good dispersion, and high packing density of nanotubes in the resultant nanocomposites. The tensile strength and Young's modulus of the nanocomposites reaches 2,088,MPa and 169,GPa, respectively, which are very high experimental results and comparable to the state-of-the-art unidirectional IM7 carbon-fiber-reinforced composites for high-performance structural applications. The nanocomposites demonstrate unprecedentedly high electrical conductivity of 5,500,S cm,1 along the alignment direction. Such unique integration of high mechanical properties and electrical conductance opens the door for developing polymeric composite conductors and eventually structural composites with multifunctionalities. New fracture morphology and failure modes due to self-assembly and spreading of MWNT bundles are also observed. [source] Compact Inverse-Opal Electrode Using Non-Aggregated TiO2 Nanoparticles for Dye-Sensitized Solar CellsADVANCED FUNCTIONAL MATERIALS, Issue 7 2009Eun Sik Kwak Abstract Compact inverse-opal structures are constructed using non-aggregated TiO2 nanoparticles in a three-dimensional colloidal array template as the photoelectrode of a dye-sensitized solar cell. Organic-layer-coated titania nanoparticles show an enhanced infiltration and a compact packing within the 3D array. Subsequent thermal decomposition to remove the organic template followed by impregnation with N-719 dye results in excellent inverse-opal photoelectrodes with a photo-conversion efficiency as high as 3.47% under air mass 1.5 illumination. This colloidal-template approach using non-aggregated nanoparticles provides a simple and versatile way to produce efficient inverse-opal structures with the ability to control parameters such as cavity diameter and film thickness. [source] The Large Electrochemical Capacitance of Microporous Doped Carbon Obtained by Using a Zeolite Template,ADVANCED FUNCTIONAL MATERIALS, Issue 11 2007O. Ania Abstract A novel microporous templated carbon material doped with nitrogen is synthesized by using a two-step nanocasting process using acrylonitrile (AN) and propylene as precursors, and Na,Y zeolite as a scaffold. Liquid-phase impregnation and in,situ polymerization of the nitrogenated precursor inside the nanochannels of the inorganic scaffold, followed by gas-phase impregnation with propylene, enables pore-size control and functionality tuning of the resulting carbon material. The material thereby obtained has a narrow pore-size distribution (PSD), within the micropore range, and a large amount of heteroatoms (i.e., oxygen and nitrogen). In addition, the carbon material inherits the ordered structure of the inorganic host. Such features simultaneously present in the carbon result in it being ideal for use as an electrode in a supercapacitor. Although presenting a moderately developed specific surface area (SBET,=,1680,m2,g,1), the templated carbon material displays a large gravimetric capacitance (340,F,g,1) in aqueous media because of the combined electrochemical activity of the heteroatoms and the accessible porosity. This material can operate at 1.2,V in an aqueous medium with good cycleability,-beyond 10,000,cycles,and is extremely promising for use in the development of high-energy-density supercapacitors. [source] Inorganic Macroporous Films from Preformed Nanoparticles and Membrane Templates: Synthesis and Investigation of Photocatalytic and Photoelectrochemical Properties,ADVANCED FUNCTIONAL MATERIALS, Issue 10 2003D.G. Shchukin Abstract Colloidal dispersions of titania, zirconia, tin oxide, indium oxide, and ceria have been successfully used to impregnate membrane templates and form the respective metal oxide (MO) porous films. The use of alumina and iron oxide sols in the same procedure, however, resulted in compact structures. By mixing different nanoparticle solutions before impregnation, final inorganic films containing two metal oxides, of variable metal oxide ratios, were obtained. The porous inorganic materials were analyzed in terms of surface area, pore size, film thickness, and crystallinity. The mechanism of nanoparticle infiltration and particle adsorption to the template walls is proposed based on the stability of the inorganic film and a study of the influence of either the sol concentration or washing times on the amount of inorganic substance incorporated in the hybrid material. The photocatalytic decomposition of an organic pollutant, 2-chlorophenol, was demonstrated for the porous titania material along with the structures containing mixtures of titania with zirconia, indium oxide, and tin oxide. A ratio of 9:1 TiO2/MO gave the highest photocatalytic activity, which was higher than the activity of Degussa P25 for the TiO2/In2O3 and TiO2/SnO2 systems under the same conditions. The titania films have also been attached to substrates,glass or indium tin oxide (ITO) surfaces,and the photoelectrochemical properties of the porous film attained. A comparison with a spin-coated titania film (prepared from the same colloidal dispersion) showed that the structured porous inorganic film has two times the photoelectrochemical efficiency as the spin-coated film. [source] Running induces widespread structural alterations in the hippocampus and entorhinal cortexHIPPOCAMPUS, Issue 11 2007Alexis M. Stranahan Abstract Physical activity enhances hippocampal function but its effects on neuronal structure remain relatively unexplored outside of the dentate gyrus. Using Golgi impregnation and the lipophilic tracer DiI, we show that long-term voluntary running increases the density of dendritic spines in the entorhinal cortex and hippocampus of adult rats. Exercise was associated with increased dendritic spine density not only in granule neurons of the dentate gyrus, but also in CA1 pyramidal neurons, and in layer III pyramidal neurons of the entorhinal cortex. In the CA1 region, changes in dendritic spine density are accompanied by changes in dendritic arborization and alterations in the morphology of individual spines. These findings suggest that physical activity exerts pervasive effects on neuronal morphology in the hippocampus and one of its afferent populations. These structural changes may contribute to running-induced changes in cognitive function. © 2007 Wiley-Liss, Inc. [source] The structure of dentine in the apical region of human teethINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2001I. A. Mjör Abstract Aim To study the structure of the apical region of human teeth with emphasis on dentinal tubules and their branches. Methodology This descriptive histological study employed demineralized stained sections for light microscopy, demineralized unstained sections for scanning electron microscopy, and undemineralized, acid-etched specimens for confocal tandem scanning microscopy. Results The apical portion of human teeth showed marked variations in structure, including accessory root canals, areas of resorption and repaired resorptions, occasional attached, embedded and free pulp stones, varied amounts of irregular secondary dentine, and even cementum-like tissue lining the apical root canal wall. The apex often deviated from the long axis of the root canal. Primary dentinal tubules were irregular in direction and density. Some areas were devoid of tubules. Conclusions The irregular and variable structure of the apical region of human teeth represent special challenges during endodontic therapy. Obturation techniques based on the penetration of adhesives into dentinal tubules are unlikely to be successful and adhesive techniques must depend on impregnation of a hybrid layer. [source] Immobilization of Porphyrinatocopper Nanoparticles onto Activated Multi-Walled Carbon Nanotubes and a Study of its Catalytic Activity as an Efficient Heterogeneous Catalyst for a Click Approach to the Three-Component Synthesis of 1,2,3-Triazoles in WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Hashem Sharghi Abstract An efficient, regioselective, one-pot and two-step synthesis of ,-hydroxy 1,4-disubstituted 1,2,3-triazoles from a wide range of non-activated terminal alkynes and epoxides and sodium azide by way of a three-component click reaction using a catalytic amount of [meso -tetrakis(o -chlorophenyl)porphyrinato]copper(II) (5,mol%) in excellent isolated yields is described. The reactions were performed in water as a green solvent at ambient temperature without any additives. By performing two reaction steps in one pot and purifying only at the final step, this procedure excludes any interim purification of in situ generated organic azide intermediates, which significantly improves the overall yield and reduces the reaction time. To benefit from the recovery and reuse of the catalyst, a new heterogeneous catalyst was prepared by simple and successful impregnation of the catalyst onto activated multi-walled carbon nanotubes (AMWCNT). The heterogeneous catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic forced microscopy (AFM), and thermogravimetric (TG) analysis to estimate the amount of nitrogen adsorption, and Raman and FT-IR spectroscopy. Leaching experiments after ten successive cycles showed that the catalyst is most strongly anchored to the AMWCNT support. Mechanistically, porphyrinatocopper catalyzes each step of the reaction in different ways as a bifunctional catalyst including epoxide ring opening by azide delivery to epoxide, forming in situ generated 2-azido alcohols followed by activation of the CC triple bond of the starting terminal alkynes by forming a porphyrinatocopper-acetylide intermediate and thereby promoting the [3+2]-cycloaddition reaction as the key step to form the triazole framework. [source] Numerical simulation of the microscale impregnation in commingled thermoplastic composite yarnsADVANCES IN POLYMER TECHNOLOGY, Issue 2 2010R. Gennaro Abstract The impregnation of a glass woven fabric with an amorphous polyethylene terephthalate copolymer (PET- g) matrix was investigated using a finite element (FE) model for interbundle and intrabundle flow of the matrix. Micrographs of samples obtained by film stacking of PET- g to impregnate the glass fabric have confirmed the occurrence of interbundle and intrabundle flow, taking place as separate steps. On the basis of this evidence, two different mechanisms for the fiber impregnation were postulated. The first flow process is associated with a macroscale interbundle impregnation, whereas the second is associated with microscale intrabundle impregnation. Two different FE models were developed to simulate the microscopic and macroscopic flow of the matrix, considering a large number of different random fiber arrangements. Both models could account for the non-Newtonian rheological behavior of the thermoplastic matrix. The microscale impregnation of fibers was simulated by using randomly spaced and nonoverlapping unidirectional filaments. The effect of the number of filaments and the number of random distributions necessary to achieve an adequate accuracy of the method was assessed. The results obtained from the simulation showed that at low pressures, the polymer melt exhibits Newtonian behavior, which makes it possible to predict the tow permeability by the Darcy law. A more difficult situation arises at high pressures because of the non-Newtonian behavior of the melt. This requires the introduction of a value for the permeability that is also dependent on the rheological properties of the melt. The same non-Newtonian behavior of the matrix was observed for macroscale impregnation of bundles. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:122,130, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20179 [source] Microstructural studies of PMMA impregnated mortarsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010Priya Nair Abstract Studies on cement concrete microstructures are carried out to explain experimentally observed phenomenon and for modeling of concrete at the macroscopic level. In this article, the preparation of polymer impregnated mortar (PIC) is carried out by partially or fully replacing the pores in the cement mortars (OPC) by PMMA. The effect of this polymer impregnation on density and morphology of the cement matrix is studied. The microstructural changes in the mortar, on exposure of these specimens to hydrochloric acid and sea water for 7 and 28 days, are also investigated in this article. The above studies indicated that the polymer addition decreased the voids in the mortar thereby preventing leaching of water soluble salts present in the OPC. It was observed that the polymer also prevented the external chemical media from permeating into the cement matrix and undergoing interactions with it. It is concluded that the durability and chemical resistance properties of the PIC are better compared with OPC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Morphology and thermal and dielectric behavior of cycloaliphatic epoxy/trimethacrylate interpenetrating polymer networks for vacuum-pressure-impregnation electrical insulationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Jingkuan Duan Abstract Vacuum pressure impregnation has been known as the most advanced impregnation technology that has ever been developed for large and medium high-voltage electric machines and apparatuses. We developed one new type of vacuum-pressure-impregnation resin with excellent properties by means of a novel approach based on in situ sequential interpenetrating polymer networks resulting from the curing of trimethacrylate monomer [trimethylol-1,1,1-propane trimethacrylate (TMPTMA)] and cycloaliphatic epoxy resin (CER). In this study, the influence of the concentrations of the components and their microstructures on their thermal and dielectric behaviors were investigated for the cured CER/TMPTMA systems via atomic force microscopy, dynamic mechanical analysis, thermogravimetric analysis, and dielectric analysis. The investigation results show that the addition of TMPTMA to the CER,anhydride system resulted in the formation of a uniform and compact microstructure in the cured epoxy system. This led the cured CER/TMPTMA systems to show much higher moduli in comparison with the pure CER,anhydride system. The thermogravimetric analysis results show that there existed a decreasing tendency in the maximum thermal decomposition rates of the cured CER/TMPTMA systems, which implies that the thermal stability properties improved to some extent. The dielectric analysis results show that the cured CER/TMPTMA systems displayed quite different dielectric behaviors in the wide frequency range 0.01 Hz,1 MHz and in the wide temperature range 27,250°C compared with the cured CER,anhydride system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Impact of impregnation chemical on surface glossiness of synthetic, acrylic, polyurethane, and water-based varnishesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Hakan Keskin Abstract This study was performed to determine the effects of impregnation chemical on surface glossiness of some varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods according to ASTM D 358 were impregnated with Imersol-Aqua according to ASTM D 1413 and producer's definition by short-term (S), medium-term (M), and long-term (L) of dipping methods and coated by synthetic (Sv), acrylic (Ac), water-based (Wb), and polyurethane (Pu) varnishes according to ASTM D 3023. After the varnishing process, the surface glossiness parallel to fibers was determined according to TS 4318. Consequently, among the nonimpregnated wood samples, surface glossiness parallel to fibers was found to be the highest in Oriental spruce and the lowest in European oak. As for the period of dipping, the highest surface glossiness was obtained in medium-term dipping and the lowest in long-term dipping. As for the varnish types, the surface glossiness was found to be the highest in polyurathane varnish and the lowest in water-based varnish. Considering the interaction of wood type, period of impregnation, and type of varnish, surface glossiness was the highest in Uludag fir, long-term dipping, and polyurathane varnish (103.9 gloss) and the lowest in Oriental beech, long-term dipping, and water-based varnish (67.78 gloss). In consequence, in the massive constructions and furniture elements the surface glossiness parallel to fibers after the impregnation with Imersol-Aqua is of great concern, long-term impregnation of Uludag fir materials could be recommended. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Biomarkers as biological indicators of xenobiotic exposureJOURNAL OF APPLIED TOXICOLOGY, Issue 4 2001Fernando Gil Abstract The presence of a xenobiotic in the environment always represents a risk for living organisms. However, to talk about impregnation there is a need to detect toxicity in the organism, and the concept of intoxication is related to specific organ alterations and clinical symptoms. Moreover, the relationship between the toxic levels within the organism and the toxic response is rather complex and has a difficult forecast because it depends on several factors, namely toxicokinetic and genetic factors. One of the methods to quantify the interaction with xenobiotics and its potential impact on living organisms, including the human being, is monitoring by the use of the so-called biomarkers. They can provide measures of the exposure, toxic effect and individual susceptibility to environmental chemical compounds and may be very useful to assess and control the risk of long-term outcomes associated with exposure to xenobiotic (i.e. heavy metals, halogenated hydrocarbons, pesticides). Copyright © 2001 John Wiley & Sons, Ltd. [source] Capacity of activated carbon derived from pistachio shells by H3PO4 in the removal of dyes and phenolicsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2003Amina A Attia Abstract Two activated carbons were obtained from pistachio shells by impregnation with H3PO4 under standard conditions of acid concentration (50 wt%) and heat treatment at 773 K for 2 h. The soaking time was 24 and 72 h for the two samples before thermal pyrolysis. Analysis of the N2/77 K adsorption isotherms proved that both were highly adsorbing carbons with considerable microporosity, and that the prolonged contact with activant enhanced total porosity (surface area and pore volume) and increased the amount of mesoporosity. Adsorption isotherms of probe molecules, viz methylene blue (MB), rhodamine B (RB), phenol (P) and p -nitrophenol (PNP), were determined at room temperature, from aqueous solutions. Both the Langmuir and Freundlich model adsorption equations show satisfactory fit to experimental data. Both carbons exhibit similar adsorption parameters irrespective of their porosity characteristics. The sequence of uptake per unit weight was: PNP > MB > RB > P. Low affinity towards phenol may be associated with its competition with water molecules which are more favourably attracted to the acid surface which has a high oxygen functionality. Preferred adsorption in the order PNP > MB > RB is proposed to be a function of carbon porosity, related to the increased molecular dimensions of the solutes. Adsorption from a binary mixture of equal concentrations of MB and RB showed reduced uptake for both sorbates in comparison to the single component experiments. RB removal surpasses that of MB in the binary test and may be attributed to lower water solubility and higher molecular dimensions. Copyright © 2003 Society of Chemical Industry [source] Deproteinized bovine bone and gentamicin as an adjunct to GTR in the treatment of intrabony defects: a randomized controlled clinical studyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2003A. Stavropoulos Abstract Objectives: To evaluate whether Bio-Oss® used as an adjunct to guided tissue regeneration (GTR) improves the healing of 1- or 2-wall intrabony defects as compared with GTR alone, and to examine whether impregnation of Bio-Oss® with gentamicin may have an added effect. Material and methods: Sixty patients, with at least one interproximal intrabony defect with probing pocket depth (PPD) 7 mm and radiographic evidence of an intrabony component (IC) 4 mm, were treated at random with either a resorbable membrane (GTR), a resorbable membrane in combination with Bio-Oss® impregnated with saline (DBB,), a resorbable membrane in combination with Bio-Oss® impregnated with gentamicin (DBB+), or with flap surgery (RBF). Results: All treatment modalities resulted in statistically significant clinical improvements after 1 year. Defects treated with GTR alone presented a probing attachment level (PAL) gain of 2.9 mm, a residual PPD (PPD12) of 4.9 mm, a radiographic bone level (RBL) gain of 3.1 mm, and a residual IC (IC12) of 2.7 mm. GTR combined with Bio-Oss® did not improve the healing outcome (PAL gain: 2.5 mm; PPD12: 4.9 mm; RBL gain: 2.8 mm; IC12: 3.3 mm). Impregnation of the Bio-Oss® with gentamicin 2% mg/ml resulted in clinical improvements (PAL gain: 3.8 mm; PPD12: 4.2 mm; RBL gain: 4.7 mm; IC12: 2.1 mm), superior to those of the other treatment modalities, but the difference was not statistically significant. Defects treated with only flap surgery showed the most inferior clinical response (PAL gain: 1.5 mm; PPD12: 5.1 mm; RBL gain: 1.2 mm; IC12: 4.2 mm) of all groups. Conclusion: The results failed to demonstrate an added effect of Bio-Oss® implantation in combination with GTR on the healing of deep interproximal 1- or 2-wall, or combined 1- and 2-wall intrabony defects compared with GTR alone. Local application of gentamicin, on the other hand, improved the treatment outcome but not to an extent that it was statistically significant. Zusammenfassung Von Proteinen befreiter boviner Knochen und Gentamycin als Adjuvans der GTR bei der Behandlung von infraalveolären Knochentaschen. Eine randomisierte kontrollierte klinische Studie. Ziele: Die Evaluation ob, Bio-Oss® welches als Adjuvans zur GTR verwendet wird, die Heilung von 1- oder 2-wandigen Knochentaschen im Vergleich zu alleiniger GTR verbessert. Sowie die Untersuchung, ob die Imprägnierung von Bio-Oss® mit Gentamycin einen zusätzlichen Effekt haben könnte. Material und Methoden: 60 mit wenigstens einer approximalen Knochentasche mit Sondierungstiefe (PPD) ,7 mm und röntgenologischem Nachweis einer infraalveolären Komponente (IC) von ,4 mm, wurden randomisiert entweder mit einer resorbierbaren Membran (GTR), einer resorbierbaren Membran in Kombination mit Bio-Oss® welche mit Kochsalzlösung imprägniert war (DBB-), einer resorbierbaren Membran in Kombination mit Bio-Oss® welche mit Gentamycin imprägniert war (DBB+) oder mit Lappen-OP (RPF) behandelt. Ergebnisse: Nach einem Jahr hatten alle Behandlungsweisen eine statistisch signifikante klinische Verbesserung zum Ergebnis. Defekte, die mit alleiniger GTR behandelt wurden zeigten einen Gewinn an klinischem Attachmentniveau (PAL) von 2,9 mm, einer PPD (PPD12) von 4,9 mm, einem Gewinn an röntgenologischem Knochenniveau (RBL) von 3,1 mm und einer IC (IC12) von 2,7 mm. GTR in Kombination mit Bio-Oss® verbesserte das Ergebnis der Heilung nicht (PAL Gewinn: 2,5 mm; PPD12: 4,9; RBL Gewinn: 2,8 mm; IC12: 3,3 mm). Die Imprägnierung von Bio-Oss® mit Gentamycin 2% mg/ml hatte klinische Verbesserungen zum Ergebnis (PAL Gewinn: 3,8 mm; PPD12: 4,2 mm; RBL Gewinn: 4,7 mm; IC12: 2,1 mm), die größer waren als die der anderen Behandlungsweisen, jedoch waren die Unterschiede nicht statistisch signifikant. Defekte, die nur mit Lappen-OP behandelt wurden zeigten das schlechteste klinische Ergebnis von allen Gruppen (PAL Gewinn: 1,5 mm; PPD12: 5,1 mm; RBL Gewinn: 1,2 mm; IC12: 4,2 mm). Schlussfolgerung: Die Ergebnisse konnten im Vergleich mit alleiniger GTR keinen zusätzlichen Effekt der Bio-Oss®-Implantation in Kombination mit GTR hinsichtlich der Heilung von tiefen approximalen 1- oder 2-wandigen oder kombinierten 1- oder 2-wandigen Knochentaschen aufzeigen. Auf der anderen Seite verbessert die lokale Applikation von Gentamycin das Behandlungsergebnis, jedoch war das Ausmaß nicht statistisch signifikant. Résumé Os bovin déprotéiné et gentamicine comme adjuvant à la RTG pour le traitement des lésions intra-osseuses. Une étude clinique contrôlée et randomisée. Objectifs: Evaluer si Bio-Oss® utilisé comme adjuvant de la RTG améliore la cicatrisation des lésions intra-osseuses par rapport à la RTG seule et examiner si l'imprégnation de Bio-Oss® avec de la gentamicine pourrait avoir un effet supplémentaire. Matériels et Méthodes: 60 patients, présentant au moins une lésion intra-osseuse interproximale avec une profondeur de poche au sondage (PPD) ,7 mm et la présence avérée radiologiquement d'une composante intra-osseuse (IC) ,4 mm, ont été traités au hasard avec soit une membrane résorbable (GTR), une membrane résorbable en combinaison avec du Bio-Oss® imprégné de solution saline (DBB-), une membrane résorbable en combinaison avec du Bio-Oss® imprégné de gentamicine (DBB+), ou par chirurgie à lambeau (RBF). Résultats: Toutes les modalités de traitement entraînaient des améliorations cliniques significatives statistiquement après un an. Les lésions traitées par RTG seule présentaient un gain d'attache de 2.9 mm, une PPD résiduelle (PPD12) de 4.9 mm, un gain de niveau osseux radiographique (RBL) de 3.1 mm, et un IC résiduel (IC12) de 2.7 mm. La RTG combinée avec le Bio-Oss® n'améliorait pas le devenir de la cicatrisation. (gain de PAL: 2.5 mm; PPD12: 4.9; gain de RBL: 2.8 mm; IC12: 3.3 mm). L'imprégnation du Bio-Oss®avec la gentamicine (2% mg/ml) apportait des améliorations cliniques (gain de PAL: 3.8 mm; PPD12: 4.2 mm; gain de RBL: 4.7 mm; IC12: 2.1 mm), supérieurs à ceux des autres modalités de traitement, mais la différence n'était pas significative. Le traitement des lésions par lambeaux seulement entraînait la réponse clinique la moins bonne (gain de PAL: 1.5 mm; PPD12: 5.1 mm; gain de RBL: 1.2 mm; IC12: 4.2 mm). Conclusion: Ces résultats ne pouvaient démontrer un effet supplémentaire, sur la cicatrisation de lésions profondes interproximales avec une ou deux parois, de l'implantation de Bio-Oss® en combinaison avec la RTG par rapport à la RTG seule. L'application locale de gentamicine, par contre, améliorait le devenir du traitement mais pas suffisamment pour être statistiquement significatif. [source] KINETICS OF OSMOTIC DEHYDRATION IN ORANGE AND MANDARIN PEELSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2001M. CHÁFER ABSTRACT The nutritional and health properties of some citrus peel components such as pectin, flavonoids, carotenoids or limonene make interesting developing processing methods to obtain peel stable products, maintaining its quality attributes, increasing its sweetness and improving its sensory acceptability. In this sense, osmotic dehydration represents a useful alternative by using sugar solutions at mild temperature. Kinetics of osmotic treatments of orange and mandarin peels carried out at atmospheric pressure and by applying a vacuum pulse at the beginning of the process were analysed at 30, 40 and 50C, in 65 °Brix sucrose, 55 °Brix glucose and 60 °Brix rectified grape must. Vacuum pulse greatly affected mass transfer behavior of peels due to the greatly porous structure of albedo. So, PVOD treatments greatly accelerate the changes in the product composition in line with an increase in the peel sample thickness. In osmotic processes at atmospheric pressure, sample impregnation occurs coupled with osmotic process, but much longer treatments are required to achieve a reasonable concentration degree which assures sample stability. Low viscosity osmotic solutions seems recommendable in order to promote both diffusional and hydrodynamic transport, in vacuum pulsed pretreatments at mild temperatures. [source] COLOR and CHLOROPHYLL CONTENT CHANGES of MINIMALLY PROCESSED KIWIFRUITJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2000MARÍA ASUNCIÓN LEUNDA A combined factors preservation technology involving blanching and vacuum solutes (sucrose, potassium sorbate, ascorbic and citric acids, zinc chloride) impregnation was proposed to minimize color changes in minimally processed kiwifruit slices during one month storage. Atmospheric impregnation was also studied in order to compare both impregnation techniques. A Box-Behnken design was adopted and second order polynomial models were computed for different storage times to relate some process variables (blanching time, zinc content, storage temperature) to a color function (Brown Index). As the storage time increased, the response surfaces for vacuum treated fruits were vertically displaced to greater Brown Index values while the response surface behavior for atmospheric impregnated fruits were less dependent on storage time. For vacuum treated fruits, combinations of blanching and addition of zinc chloride improved the color of the finished product at all storage temperatures assayed, but these treatments were detrimental for atmospheric impregnated fruits, increasing significantly the Brown Index values. After storage, total chlorophyll had been degraded between 70 and 90% depending on the pretreatments. There did not appear to be any consistent relation between the changes which occurred in the total chlorophyll content and color. [source] Effects of High-Pressure Pretreatment and Calcium Soaking on the Texture Degradation Kinetics of Carrots during Thermal ProcessingJOURNAL OF FOOD SCIENCE, Issue 5 2004D.N. Sila ABSTRACT: Carrots (Daucus carota) pretreated under different high-pressure conditions were thermally processed at temperatures in the range of 90°C to 110°C. Texture degradation (hardness) was monitored objectively using a texture analyzer. For a given thermal treatment, the rate constant (k-value) decreased with increasing pretreatment pressure. A high-pressure pretreatment (200 to 500 MPa) at 60°C for 15 min resulted in a more pronounced texture improvement compared with the same pretreatment at 20°C and 40°C, respectively. Calcium impregnation conferred more beneficial effects when applied immediately after the high-pressure pretreat-ment. The observed changes in texture characteristics were associated with the degree of methylation of carrot pectins, which is dependent on pectinmethylesterase (PME) activity. [source] Mass Balances in Porous Foods ImpregnationJOURNAL OF FOOD SCIENCE, Issue 9 2001V. Roa ABSTRACT: A simple model based on mass balance equations is proposed for prediction of the final mass and composition of products subjected to vacuum impregnation. It was applied to some tropical fruits in a fruit-sucrose solution system. The phenomenon can be described in terms of volumetric fraction of impregnating solution as the basic modeling parameter, instead of effective porosity. To use the equations of the model, only routine laboratory equipment and simple experiments are required. Prediction of the final weight of impregnated fruit was accomplished with an average absolute error of 2 to 3%, while in final composition of the fruit (total solids), it was 5.7 %. [source] Enhancing high water content biomass gasification with impregnated Ca in fuel dryingAICHE JOURNAL, Issue 10 2006Guangwen Xu Abstract In view of energy conversion efficiency, the gas production from high water content (>60 wt.%) biomass via gasification is necessarily conducted with fuel drying in advance. In regard to this kind of processes, the present study was devised to impregnate Ca onto fuel during fuel drying and thereby to increase fuel's gasification reactivity to raise the gas production efficiency with minimal additional cost. By employing wet coffee grounds as a model biomass fuel and slurry dewatering in kerosene as the adopted drying technology, the Ca impregnation was implemented through dosing Ca(OH)2 into a fuel-kerosene slurry and in turn treating the slurry in the same way as for the case without Ca addition. The resulting Ca (4.0 wt.% load in CaO base) exhibited high dispersion through the fuel matrix in both SEM-EDX image and XRD spectrum. Gasification of the fuel in a pilot dual fluidized gasification setup further demonstrated that the fuel possessed distinctively high reaction reactivity. This led it to show C and H conversions of 91% and 138%, respectively, at a reaction temperature of about 1083 K, whereas these conversions were only 70% and 92% for the fuel with a similar amount of physically mixed CaO. The catalytic effect of the impregnated Ca manifested also on hydrocarbon reforming and water gas shift, making the resulting product gas evidently rich in H2 and lean in CO and hydrocarbons. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Porous anodic alumina microreactors for production of hydrogen from ammoniaAICHE JOURNAL, Issue 4 2004Jason C. Ganley Abstract The synthesis and properties are described of a ruthenium-impregnated anodic aluminum catalyst for use in microreactors for the production of hydrogen from an ammonia feed. The catalyst structure was synthesized using microelectric discharge machining to create a series of 300 × 300-,m posts on an aluminum substrate. The posts were anodized to yield a 60-,m covering of anodic alumina, with an average surface area of 16 m2/gm and an average pore size of 50 nm. Ruthenium metal was dispersed on the alumina using conventional wet impregnation. A 0.9 × 0.9-cm reactor containing 250 posts decomposed 95% of anhydrous ammonia at 650°C to yield 15 sccm of hydrogen. A possible application of these microreactor fabrication methods is hydrogen generation for fuel cells in mobile power production. 2004 American Institute of Chemical Engineers AIChE J, 50:829,834, 2004 [source] Structure and drug release in a crosslinked poly(ethylene oxide) hydrogelJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2007Boris Y. Shekunov Abstract Hydrogels are a continuously expanding class of pharmaceutical polymers designed for sustained or controlled drug release. The structure and intermolecular interactions in such systems define their macroscopic properties. The aim of this study was to investigate the mechanism of swelling, drug impregnation, and drug release from poly(ethylene oxide) (PEO) gel crosslinked by urethane bonds. A combination of SAXS/WAXS/SANS techniques enabled us to determine the phase transition between lamellar and extended gel network, and to apply different descriptions of crystallinity, based on lamellar and crystal lattice structures. It is shown that even low (1,7% w/w) loading of model drugs acetaminophen and caffeine, produced significant disorder in the polymer matrix. This effect was particularly pronounced for acetaminophen due to its specific ability to form complexes with PEO. The drug-release profiles were analyzed using a general cubic equation, proposed for this work, which allowed us to determine the gel hydration velocity. The results indicate that the release profiles correlate inversely with the polymer crystallinity. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 1320,1330, 2007 [source] Quantification of soil structural changes induced by cereal anchorage failure: Image analysis of thin sectionsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2007Sacha J. Mooney Abstract Cereal anchorage failure, or lodging, is the permanent displacement of a crop from the vertical and results in significant annual yield losses globally. Several factors have been identified as contributors to this phenomenon but the precise mechanisms of failure are still largely unknown because of difficulties in observing these processes as they occur in situ. To identify potential soil management practices to minimize losses associated with cereal root failure, an understanding of the nature of root-soil interactions attributed to lodging is needed. An experiment was conducted that involved field impregnation and subsequent thin sectioning of lodged and unlodged root-soil complexes from contrasting soils, cereal crops, and management practices to elucidate the effects of lodging on soil structure and porous architecture. Using image analysis, size and distribution of pores in soils were quantified at both meso- (100,30 ,m) and microscales (<30 ,m). A significant effect of lodging on porosity was recorded whereby lodging reduced total porosity through compaction created by movement of the stem base, although this was variable among soil types. Pore-size distributions comprehensively supported these trends since alteration in the relative frequency of pores within specific size classes was clearly observed. The effects of lodging were more pronounced at the mesoscale because the data were more susceptible to variations created by natural soil heterogeneity at the microscale. These data suggested that sideways movement of the subterranean stem within the soil is a significant factor which is likely to affect the propensity for a cereal plant to lodge, indicating soil strength in the upper part of the soil profile is crucial. [source] | ||||||||||||||||||||||||||||||||||||||||