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Aggregates
Kinds of Aggregates Terms modified by Aggregates Selected AbstractsEXAMINING THE ASYMMETRIC BEHAVIOUR OF MACROECONOMIC AGGREGATES IN ASIAN ECONOMIESPACIFIC ECONOMIC REVIEW, Issue 5 2008Paresh Kumar Narayan Abstract., The goal of this paper is to test for asymmetric behaviour of macroeconomic aggregates for three Asian economies; namely, Malaysia, Hong Kong and Korea. Whether macroeconomic aggregates can be characterised as asymmetric has important implications for policy-making and econometric modelling including forecasting. We examine two forms of asymmetries; specifically deepness, which arises when a detrended time series contains an asymmetric distribution, and steepness, which arises when the first difference of a series contains an asymmetric distribution. Overall, our findings suggest that for all three countries, the bulk of the series display asymmetry behaviour. [source] Scale, Congestion and GrowthECONOMICA, Issue 267 2000Theo Eicher This paper explores the relationship between aggregate and relativecongestion, returns to scale and economic growth. Aggregate congestionreduces the effective productivity of capital; relative congestion reducesthe effective productivity of labour. Both forms of congestion adverselyaffect the equilibrium growth rate, although their relative effects dependupon aggregate returns to scale. The two forms of congestion havecontrasting effects on the transitional dynamics. Relative congestionretards the rate of adjustment; aggregate congestion accelerates it. Theexternalities generated by congestion and non-optimal expenditure can befully corrected, both during the transition and in steady state, by atime-invariant income tax. [source] Commentary by Bun San Chong Chong BS, Pitt Ford TR, Hudson MB (2003) A prospective clinical study of Mineral Trioxide Aggregate and IRM when used as root-end filling materials in endodontic surgery.INTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2009International Endodontic Journal 3 No abstract is available for this article. [source] Ex vivo microscopic assessment of factors affecting the quality of apical seal created by root-end fillingsINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2007S. I. Tobón-Arroyave Abstract Aim, (i) To evaluate the incidence of microcracks around root-end preparations completed with ultrasonic tips and their relationship with the root filling technique and thickness of surrounding dentine. (ii) To investigate the effect of rapid exposure to a water-soluble dye of Intermediate Restorative Material (IRM), Super Ethoxybenzoic Acid (sEBA) and Mineral Trioxide Aggregate (MTA), on the marginal adaptation and microleakage of root-end fillings. (iii) To describe the microstructure of the surface of root-end filling materials. Methodology, Ninety-two single-rooted teeth were divided into two groups (n = 46) according to the root canal instrumentation/filling techniques. Group 1 consisted of specimens in which canal preparation was completed using a crown-down technique and then filled with the Thermafil system (TF group); Group 2 consisted of specimens in which canal preparation was completed using a step-back technique and lateral condensation (LC group). Following root-end resection and ultrasonic cavity preparation, the samples were further divided into three subgroups (n = 24) for root-end filling with IRM, sEBA or MTA. The ultrasonic preparation time was recorded. Eight teeth were kept as positive and 12 as negative controls. Following immersion in Indian ink for 7 days, all resected root surfaces were evaluated for the presence of microcracks and the cross-sectional area of root-end surface and root-end filling were measured to evaluate the thickness of the dentinal walls. Thereafter, the samples were sectioned longitudinally so as to assess the depth of dye penetration and marginal adaptation of root-end fillings. Negative controls longitudinally sectioned were used to describe microstructural characteristics of the root-end filling materials using scanning electron microscopic (SEM) techniques. Results, Although the thickness of dentinal walls between groups 1 and 2 was similar, the ultrasonic preparation time and number of microcracks were significantly higher (P < 0.001) in the TF group. Both groups had a significant correlation between microcracks and ultrasonic preparation time (P < 0.001). sEBA and IRM had better adaptation and less leakage compared with MTA. A SEM analysis displayed microstructural differences between the root-end filling materials. Conclusion, Microcracks can occur independently of the thickness of dentinal walls and may be associated with the prolonged ultrasonic preparation time required for the removal of the root filling during root-end cavity preparation. Although sEBA and IRM had better behaviour than MTA regarding microleakage and marginal adaptation, it is possible that exposure of MTA to a water-soluble dye before achieving full set and its porous microstructure contributed to the results. [source] A prospective clinical study of Mineral Trioxide Aggregate and IRM when used as root-end filling materials in endodontic surgeryINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2003B. S. Chong Abstract Aim, To assess the success rate of the root-end filling material, Mineral Trioxide Aggregate (MTA). Methodology, Referred adult patients were recruited using strict entry criteria and randomly allocated to receive MTA or IRM. A standardized surgical technique was employed: the root end was resected perpendicularly and a root-end cavity was prepared ultrasonically and filled. A radiograph taken immediately after surgery was compared with those taken at 12 and 24 months. Customised film holders and the paralleling technique were used; radiographs were assessed by two trained observers using agreed criteria. The results from 122 patients (58 in IRM group, 64 in MTA group) after 12 months and 108 patients (47 in IRM group, 61 in MTA group) for the 24-month review period were analysed using the ,2 test. Results, The highest number of teeth with complete healing at both times was observed when MTA was used. When the numbers of teeth with complete and incomplete (scar) healing, and those with uncertain and unsatisfactory healing were combined, the success rate for MTA was higher (84% after 12 months, 92% after 24 months) compared with IRM (76% after 12 months, 87% after 24 months). However, statistical analysis showed no significant difference in success between materials (P > 0.05) at both 12 and 24 months. Conclusions, In this study, the use of MTA as a root-end filling material resulted in a high success rate that was not significantly better than that obtained using IRM. [source] Photoluminescence effects on gold nano- particles modified by short single stranded DNA moleculesMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 4 2009O. Kysil Gold-Nanopartikel; Einzelstrang DNA; sichtbare Photolumineszenz; Photosensor Abstract The concept for a function of gold nanoparticle photosensor based on gold nanoparticle optical properties, depending on the size and architecture of their self , assemblies, is revised from the studies of modified by short ssDNA (5.4 nm length) selected gold nanoparticle (8.6 nm diameter) assembling in biosuspensions. Biosensing effect, collective photoluminescence in visible range of different size 2D, 3D assemblies from these nanoparticles, is revealed due to their controlled assembling in biosuspesions, dependent on ssDNA conformation, that changes gold core capping and therefore a force of interparticle interaction. Nanophotosensor is characterized by intensive photoluminescence maxima in two regions of visible range for tested biosuspensions due to detected difference in the self - assemblies' architecture of gold nanoparticles with different gold core capping by the ssDNA molecules. The emission maxima are 4.2x103 pps and 4.1x104 pps in (525,780) nm and (780,920) nm regions mainly for 2D assemblies as nanowires and 3D assemblies as circle holms, correspondently, in DNA buffer suspensions with different biomolecules. The results are explained addressing photoluminescence of gold nanoparticle assemblies to system of discrete electron states in valence and conductivity bands for gold nanoparticle model. Photolumineszenz-Effekt auf Gold Nanopartikel vermittelt durch kurze Einzelstrang DNA Moleküle Das Konzept für die Funktion der Goldpartikel Nanophotosensoren basiert auf den optischen Eigenschaften der Gold Nanopartikel abhängig von der Größe und Architektur ihrer ,Self-Assemblies", und wird auf Basis von Studien von kurzen ssDNA (5.4 nm Länge) mit ausgewählten sich in Biosuspensionen versammelnden Gold Nanopartikeln (8.6 nm Durchmesser) revidiert. Der Biosensoreffekt, sichtbar durch die gesammelte Photolumineszenz im sichtbaren Spektrum von verschieden großen 2D und 3D-Aggregaten von diesen Nanopartikeln, wird wegen ihrer kontrollierten Ansammlung in Biosuspensionen, welche in Abhängigkeit zu den kurzen ssDNA Konformation, dem Ändern der monomolekularen Bedeckungsschicht des Goldkerns und somit durch eine Kraft der Teilchen-Wechselwirkung offenbart. Der Nanophotosensor ist durch zwei intensive Photolumineszenz-Maxima im Bereich des sichtbaren Spektrums für derart geprüfte Biosuspensionen wegen des meßbaren Unterschieds in der Selbstanordnung von Gold Nanopartikeln mit dem verschiedenen Goldkernbedeckungen durch die ssDNA Stränge charakterisiert: Emissionsmaxima liegen bei 4.2x103 pps und 4.1x104 pps in den Wellenlängenbereichen von (525,780) nm und (780,920) nm, jeweils hauptsächlich für 2D-Aggregate als Nanodrähte und 3D-Aggregate in kreisförmiger Anordnung in DNA-Puffersuspendierungen mit verschiedenen Biomolekülen. Die Ergebnisse werden Mithilfe der Adressierung der Photolumineszenz von Gold Nanopartikel-Aggregaten zu System von getrennten Elektronzuständen in Valenz und Leitungsbändern entsprechend den Gold Nanopartikel-Modellen erklärt. [source] On Different Approaches to Estimate the Mass Fractal Dimension of Coal AggregatesPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 5 2005Jimmy Y. H. Liao Abstract Several methods to measure the structures of coal aggregates are compared. Loose and compact coal aggregates were generated through flocculation of ultrafine coal particles (mean volume diameter of 12,,m) under specific shearing conditions. Aggregate structure in terms of mass fractal dimension, Df, was determined using various methods; namely 2D and 3D image analysis, interpretation of intensity patterns from small angle light scattering, changes in aggregation state through light obscuration, and settling behavior. In this study, the measured values of Df ranged from 1.84,2.19 for coal aggregates with more open structures, and around 2.27,2.66 for the compact ones. All of these approaches could distinguish structural differences between aggregates, albeit with variation in Df values estimated by the different techniques. The discrepancy in the absolute values for fractal dimension is due to the different physical properties measured by each approach, depending on the assumptions used to infer Df from measurable parameters. In addition, image analysis and settling techniques are based on the examination of individual aggregates, such that a large number of data points are required to yield statistically representative estimations. Light scattering and obscuration measure the aggregates collectively to give average Df values of the particulate systems; consequently ignoring any structural variation between the aggregates, and leaving possible small contaminations undetected (e.g. by dust particles or air bubbles). Appropriate utilization of a particular method is thus largely determined by system properties and required data quality. [source] Chiralitätserkennung bei Menthol und Neomenthol: bevorzugte Bildung homokonfigurierter Aggregate,ANGEWANDTE CHEMIE, Issue 35 2010Merwe Albrecht Dr. Coole Chiralität:L -Menthol (siehe Kugel-Stab-Modell), einer der wichtigsten Aromastoffe, wurde hinsichtlich seiner Konformation, seiner selektiven Aggregation und des Sublimationsverhaltens untersucht. Es ergibt sich eine einheitliche Bevorzugung homokonfigurierter Aggregate. [source] Wechselwirkungen zwischen amyloidogenen Proteinen und Membranen: Modellsysteme liefern mechanistische EinblickeANGEWANDTE CHEMIE, Issue 33 2010Abstract Die Toxizität amyloidbildender Proteine ist mit ihrer Wechselwirkung mit Membranen korreliert. Bemerkenswerterweise führen Bindungsereignisse zwischen amyloidogenen Proteinen und Membranen beiderseits zu Strukturstörungen, die mit Toxizität assoziiert sind. Membranoberflächen vermitteln die Umwandlung amyloidbildender Proteine in toxische Aggregate, amyloidbildende Proteine wiederum beeinträchtigen die strukturelle Integrität der Zellmembran. Neuere Untersuchungen an künstlichen Modellmembranen haben eine bemerkenswerte Ähnlichkeit im Mechanismus der Membranpermeabilisierung von amyloidbildenden Proteinen, porenbildenden Toxinen und antimikrobiellen Peptiden aufgezeigt. [source] Phosphorus Ligand Imaging with Two-Photon Fluorescence Spectroscopy: Towards Rational Catalyst Immobilization,ANGEWANDTE CHEMIE, Issue 32 2010Fabrizio Marras Fleckenlose Katalysatoren: Die Ligandenimmobilisierung auf Trägern wurde durch Zweiphotonenfluoreszenzmikroskopie mit einem fluoreszierenden Nixantphos-Liganden als Sonde untersucht (siehe Bild). Im Immobilisierungsprozess bilden die Liganden Aggregate in Lösung und werden auf dem Träger abgeschieden, wo sie als helle Flecken im Fluoreszenzbild erscheinen. Indem man die Bildung der Aggregate verhindert, erhält man ,fleckenlose" Katalysatoren mit überlegenen Eigenschaften. [source] Facile Synthesis of Isomerically Pure Fullerenols and Formation of Spherical Aggregates from C60(OH)8,ANGEWANDTE CHEMIE, Issue 31 2010Gang Zhang Das Octahydroxyfulleren C60(OH)8 (siehe Bild) gehört zu einer Gruppe von isomerenreinen Fullerenolen mit zwei bis acht OH-Gruppen, die durch selektive Umwandlung von tert -Butylperoxogruppen in Peroxofullerenen hergestellt wurden. Weil alle OH-Gruppen auf der gleichen Kugelhälfte liegen, ist C60(OH)8 amphiphil und bildet stabile sphärische Aggregate in Wasser. [source] Multidimensional Structure,Activity Relationship of a Protein in Its Aggregated States,ANGEWANDTE CHEMIE, Issue 23 2010Lei Wang Gleich und doch sehr verschieden: Je nach den verwendeten chemischen, physikalischen und biologischen Bedingungen bildet ein einziges Protein fünf strukturell verschiedene Aggregate (siehe die Elektronenmikroskopiebilder, Maßstäbe: 500,nm), die alle das Kreuz-,-Faltblatt-Motiv enthalten. Die Aggregate unterscheiden sich in ihrer Affinität zu Adenosin-5,-triphosphat, Thioflavin,T, DNA und Membranmimetika sowie in ihrem Effekt auf die Zellgängigkeit. [source] Cages with Tetrahedron-Like Topology Formed from the Combination of Cyclotricatechylene Ligands with Metal Cations,ANGEWANDTE CHEMIE, Issue 16 2010Brendan Viel Platz: Anionische tetraedrische Aggregate, gebildet durch Kombination von Cyclotricatechylen-Anionen mit Übergangsmetallionen wie Vanadium (siehe Bild), umschließen große Hohlräume, die Alkalimetallionen und Lösungsmittelmoleküle aufnehmen können. Anionische Einheiten mit geeigneten Metallzentren lassen sich zu hoch symmetrischen Koordinationspolymeren verknüpfen (V,blau, O,rot, C,schwarz). [source] A Spherical 24,Butyrate Aggregate with a Hydrophobic Cavity in a Capsule with Flexible Pores: Confinement Effects and Uptake,Release Equilibria at Elevated Temperatures,ANGEWANDTE CHEMIE, Issue 43 2009Christian Schäffer Moleküle unter Zwang: Der Einschluss einer Anordnung aus 24,organischen Butyrat-Einheiten (siehe Bild), die mit 72,H-Atomen einen bemerkenswert großen hydrophoben Hohlraum umschließen, in einer porösen Kapsel führt zu interessanten Wechselwirkungen zwischen den eingesperrten Butyraten. Bei Temperaturerhöhung wird die ,Quarantäne" aufgehoben und die Gastspezies können leichter kommen und gehen. [source] Innentitelbild: Writing Self-Erasing Images using Metastable Nanoparticle "Inks" (Angew. Chem.ANGEWANDTE CHEMIE, Issue 38 200938/2009) Lichtempfindliche Tinten für selbstradierende Bilder wurden erzeugt, indem mit photoresponsiven Liganden umhüllte Metallnanopartikel (NPs) in einem Polymerfilm dispergiert wurden. Wie B.,A. Grzybowski und Mitarbeiter auf S.,7169,ff. schildern, bilden die NPs bei Bestrahlung mit UV-Licht metastabile Aggregate, deren Farbe vom Aggregationsgrad abhängt. Schaltet man das Licht aus, so zerfallen die Aggregate, und die Bilder radieren sich selbst aus. Mit nur einer NP-Tinte können sogar mehrfarbige Bilder erzeugt werden. [source] Crossing Party Lines: Volatility and Ticket Splitting in Mexico (1994,2000)BULLETIN OF LATIN AMERICAN RESEARCH, Issue 1 2005David Crow This article aims to amplify our portrait of the Mexican electorate by examining the ways in which Mexican electors distributed their votes among the parties during 1994,2000, both over successive elections (volatility) and in the same election (ballot splitting). Aggregate and survey data revealed that Mexicans engaged in these two forms of electoral behaviour frequently, indicators of an electorate in flux. Regression analysis indicated that, contrary to the expectation that the politically sophisticated differentiated their votes, virtually all parts of Mexican society were equally likely to switch parties and split tickets. [source] ChemInform Abstract: V4O10: Spectroscopic Fingerprint of a Well-Defined, Molecular Metaloxo Aggregate.CHEMINFORM, Issue 31 2008Christian Herwig Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] 3D Image Segmentation of Aggregates from Laser ProfilingCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2003Hyoungkwan Kim Automated scanners of different designs use cameras or lasers to obtain digital images of groups of aggregate particles. To accurately determine particle size and shape parameters, each particle region in the image must be isolated and processed individually. Here, a method for segmenting a particle image acquired from laser profiling is developed using a Canny edge detector and a watershed transformation. Canny edges with rigorous and liberal threshold values are used to outline particle boundaries on a binary image and to check the validity of watersheds, respectively. To find appropriate regional minima in the watershed transformation, a varying search window method is used, where the number of neighboring pixels being compared with the pixel of interest is determined from the height value of the pixel. Test results with this method are promising. When implemented in automated systems that are designed to rapidly assess size and shape characteristics of stone particles, this technique can not only reduce the amount of time required for aggregate preparation, but also increase the accuracy of analysis results. [source] Nodular fasciitis of parotid region: A pitfall in the diagnosis of pleomorphic adenomas on fine-needle aspiration cytologyDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2005Ph.D., Reda S. Saad M.D. Abstract Fine-needle aspiration cytology (FNAC) is routinely employed for the preoperative diagnosis of salivary gland lesions. Although most cases show morphologic features characteristic of specific entities, some lesions can be diagnostically challenging. We report two parotid aspirates, initially diagnosed as pleomorphic adenoma on FNA. The patients, a 33-yr-old white man, and a 24-yr-old white woman, presented with indurated lesions arising in the parotid gland region. The aspirates from both patients were markedly hypercellular. Smears showed a mixture of spindle cells with a well-demarcated cytoplasm showing occasional long cytoplasmic process; and cells with abundant cytoplasm with round to oval eccentric nuclei, giving the impression of plasmacytoid cells of pleomorphic adenoma. The nuclear chromatin was evenly distributed and finely granular with one or two occasional small nucleoli. Intermingled with the tumor cells were scattered neutrophils, eosinophils, and macrophages. Aggregates of spindle cells were also seen embedded in a mucoid background with occasional small tufts of a fibrillar mucoid stroma. These fibrillar tufts were magenta red in the Diff-Quik stain, giving the impression of matrix of pleomorphic adenoma. Both cases were later diagnosed on histologic examination as nodular fasciitis. Nodular fasciitis should be considered in the differential diagnosis of a mass arising in association with the parotid gland. Diagn. Cytopathol. 2005;33:191,194. © 2005 Wiley-Liss, Inc. [source] Visible and FTIR Microscopic Observation of Bisthiourea Ionophore Aggregates in Ion-Selective Electrode MembranesELECTROANALYSIS, Issue 22 2005Katherine Abstract Since conventional response models for ionophore-based ISEs are based on the assumption of a homogeneous membrane phase, they cannot accurately predict the response of membranes containing self-aggregating ionophores. However, meaningful conclusions about the relationship between ionophore structure and potentiometric responses can only be drawn if ionophore aggregation is properly recognized. This study demonstrates that dark field visible microscopy and FTIR microspectroscopy are valuable tools for the observation of such ionophore self-aggregation and, thereby, the development of new ionophore-based ISEs. Sulfate selective electrodes with solvent polymeric membranes containing bisthiourea ionophores that differ only by peripheral nonpolar substituents were shown to exhibit very different interferences from the sample pH. On one hand, optimized electrodes based on an ionophore with a phenyl substituent on each thiourea group (1) do not respond to pH at all and function well as sulfate-selective electrodes. On the other hand, membranes containing a more lipophilic ionophore with two additional hexyl-substituted adamantyl groups (2) exhibit severe pH interference at pH values as low as pH,5. The observation of membranes containing ionophore 2 with dark field visible microscopy and FTIR microspectroscopy shows supramolecular aggregation, and explains the startling difference between the potentiometric responses of the two types of electrodes. [source] A Novel Route to Thermosensitive Polymeric Core,Shell Aggregates and Hollow Spheres in Aqueous Media,ADVANCED FUNCTIONAL MATERIALS, Issue 4 2005Y. Zhang Abstract Poly(,-caprolactone)/poly(N -isopropylacrylamide) (PCL/PNIPAM) core,shell particles are obtained by localizing the polymerization of NIPAM and crosslinker methylene bisacrylamide around the surface of PCL nanoparticles. The resultant particles are converted to hollow PNIPAM spheres by simply degrading the PCL core with an enzyme. The hollow spheres are thermosensitive and display a reversible swelling and de-swelling at ,,32,°C. [source] Effect of an Ultrathin TiO2 Layer Coated on Submicrometer-Sized ZnO Nanocrystallite Aggregates by Atomic Layer Deposition on the Performance of Dye-Sensitized Solar CellsADVANCED MATERIALS, Issue 21 2010Kwangsuk Park An ultrathin TiO2 layer is successfully coated on the surface of sub-m-sized aggregates of ZnO nanocrystallites through the atomic layer deposition (ALD) technique. The ZnO core/TiO2 shell structure increases the open-circuit voltage, without impairing the photocurrent density and results in an increased power conversion efficiency from 5.2% to 6.3%. [source] Bioimaging with Two-Photon-Induced Luminescence from Triangular Nanoplates and Nanoparticle Aggregates of GoldADVANCED MATERIALS, Issue 22 2009Yuqiang Jiang Cell imaging with two-photon-induced photoluminescence is demonstrated using gold nanoparticles (either triangular nanoplates or nanosphere aggregates) as imaging agents. On being conjugated to yeast cells, gold nanoplates exhibit visible two-photon excited luminescence that can be detected by two-photon laser scanning microscopy. The cells can be either dried (in the air) or alive (in water). [source] Self-Assembled Multicomponent Chromophores: Conjugated Oligoelectrolyte/ssDNA Aggregates: Self-Assembled Multicomponent Chromophores for Protein Discrimination (Adv. Mater.ADVANCED MATERIALS, Issue 9 20099/2009) Guillermo Bazan and Huaping Li show on p. 964 that a range of optical reporters can be prepared by electrostatic interactions between a cationic conjugated oligoelectrolyte (COE) and dye-labeled single-stranded DNAs (ssDNA). Proteins perturb the optical properties of these aggregates and generate unique fluorescence resonance energy transfer (FRET) patterns that allow protein discrimination. Two different signatures can be obtained, depending on whether the fluorescence intensity of the COE or the ssDNAbound dye is observed. [source] Conjugated Oligoelectrolyte/ssDNA Aggregates: Self-Assembled Multicomponent Chromophores for Protein DiscriminationADVANCED MATERIALS, Issue 9 2009Huaping Li A range of optical reporters is prepared by electrostatic interactions between a cationic conjugated oligoelectrolyte (COE) and dye-labeled single-stranded DNAs (ssDNA). Proteins perturb the optical properties of these aggregates, and generate unique fluorescence resonance energy transfer (FRET) patterns that allow protein discrimination. Two different signatures can be obtained, depending on whether the fluorescence intensity of the COE or the ssDNA-bound dye is observed. [source] Highly Cooperative Behavior of Peptide Nucleic Acid-Linked DNA-Modified Gold-Nanoparticle and Comb-Polymer AggregatesADVANCED MATERIALS, Issue 6 2009Abigail K. R. Lytton-Jean PNA is used to assemble gold nanoparticles,DNA and polymer,DNA hybrids into highly cooperative aggregates with sharp melting transitions. The melting temperatures of these aggregates are found to increase with increasing salt concentrations, while the opposite trend is observed for unmodified PNA:DNA duplexes. This cooperative behavior is attributed to the presence of closely spaced duplexes inside the aggregate. [source] Influence of Microsilica Content on the Slag Resistance of Castables Containing Porous Corundum,Spinel AggregatesINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2008Wen Yan Corrosion of five corundum,spinel castables containing the same porous aggregates and different matrices by converter slag (C/S=3) was conducted using the static crucible test through the counting pixels method, XRD, SEM, EDAX, and so on. It was found that the corrosion and penetration resistance depend on the microsilica content. Microsilica content strongly affects liquid phase formation in the matrix, changes the porosity, pore size distribution of matrix, and viscosity of slag penetrated, and thus affects its corrosion and penetration resistance. Increasing microsilica, decreasing the porosity, or increasing the viscosity of the penetrating slag improves, whereas increasing the pore size or liquid content reduces the penetration and corrosion resistance. The penetration resistance increased abruptly with an increase of the microsilica content from 0.65 to 1.95 wt%, but changed slightly with increase of the microsilica content from 1.95 to 3.90 wt%. The corrosion resistance increased with an increase of the microsilica content from 0 to 2.60 wt%, but slightly decreased with a further increase of the microsilica content to 3.90 wt%. 1.95,2.60 wt% microsilica leads to a compromise between low corrosion and low penetration. [source] Multiply Shaped Silica Mediated by Aggregates of Linear Poly(ethyleneimine),ADVANCED MATERIALS, Issue 7 2005J.-J. Yuan A new method for biomimetic silica fabrication is reported. Organized poly(ethyleneimine) rapidly catalyzes and directs the shape of silica in the hydrolysis of tetramethoxysilane under ambient conditions. The resultant silica displays a diversity of controllable morphologies, such as flower, plate, bundle, leaf, and sphere (see Figure, scale bar represents 1,,m). [source] From Hollow to Dense Spheres: Control of Dipolar Interactions by Tailoring the Architecture in Colloidal Aggregates of Superparamagnetic Iron Oxide Nanocrystals,ADVANCED MATERIALS, Issue 6 2004P. Tartaj The synthesis of spherical colloidal aggregates (see Figure) of superparamagnetic iron oxide nanocrystals with different packing fractions is reported. Using a mean-field model, the magnitude of dipolar interactions between nanomagnets has been correlated with differences in their assembly. The results could help understanding of the magnetic behavior of magnetic liposomes and hollow capsules, which are promising for drug delivery. [source] Environmental Nursing Diagnoses for Aggregates and CommunityINTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 1 2001Pauline M. Green PhD PURPOSE. To describe the application of group-appropriate methods to derive actual nursing diagnoses for a community. METHODS. A triangulation method using multiple sources of data, including an environmental survey, fish consumption survey, government reports, publications, and community assessments FINDINGS. Three priority community environmental nursing diagnoses for aggregates within the community: Knowledge deficit among community residents related to lack of awareness of contaminants in the Anacostia River; "risk for adverse human health effects" among pregnant and nursing women and preschoolers related to consumption of chemically contaminated fish; and knowledge deficit among community residents related to lack of awareness of health effects of consuming chemically contaminated fish. CONCLUSIONS. The diagnoses serve as the basis for community education and other interventions. The methods are practical and useful for this type of research. PRACTICE IMPLICATIONS. The nursing profession is experiencing a growing awareness of the close relationship between environmental health and the health of individuals and communities. There is a need for diagnostic labels to describe the responses of aggregates and communities to environmental hazards and conditions. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||