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Size Control (size + control)

Distribution by Scientific Domains
Polymers and Materials Science36%
Life Sciences18%
Chemistry18%

Selected Abstracts

Particle Size Control of Nanocrystalline Anatase TiO2 Synthesized by Hydrolysis of Titanyl Organic Compounds

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 12 2008
X.-Q. Chen
Abstract The global nanocrystalline anatase TiO2 particle can be obtained by hydrolysis of titanyl organic compounds. Its particle size is mostly influenced by the titanyl organic compounds' concentration, nitric acid (HNO3) concentration, reaction time and temperature, and especially the HNO3 concentration. The formation of nanocrystalline TiO2 with bigger size can be accelerated by a higher temperature, thick solution of reactant (titanyl organic compounds), and HNO3. Vice versa, in order to gain smaller particles, such as 6 nm, the reaction conditions should be set at a thin reactant solution, low temperature, and low HNO3 concentration. The reason lies in the hydrolyzing mechanism of titanyl organic compounds, which is strongly influenced by the temperature and pH. [source]

ChemInform Abstract: Size Control of Catalytic Reaction Space by Intercalation of Alkylcarboxylate Anions into Ni,Zn Mixed Basic Salt Interlayer: Application for Knoevenagel Reaction in Water.

CHEMINFORM, Issue 32 2010
Takayoshi Hara
Abstract The interlayer space of layered Ni-Zn mixed basic salt can be controlled precisely by the intercalation of various carboxylate anions. [source]

Single-layered microscale linear-gradient PDLC material for electro-optics

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2009
Y. G. Marinov
Abstract We report on single-layered optical material of linear-gradient microscale polymer-dispersed liquid crystal (PDLC). E7/NOA65 composite films formed by pulsed UV laser photopolymerization-induced phase separation exhibit two morphology types, namely a bipolar and a hybrid alignment of liquid crystal droplets. The specific structural properties of the produced PDLC layers, such as the droplet shape uniformity and alignment, as well as the droplet size control through the film thickness, facilitate the efficient control on the electro-optical (EO) response, thus being of practical interest for EO device applications. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Hot Deformation Mechanisms and Microstructural Control in High-Temperature Extruded AZ31 Magnesium Alloy,

ADVANCED ENGINEERING MATERIALS, Issue 7 2007

A Processing map has been developed for Magnesium alloy AZ31 extruded at 450,°C which revealed that the extruded rods may be further processed into components industrially at 400,°C and at a strain rate of 10,s,1. If processed at lower strain rates in the vicinity of 0.1,s,1, unusual grain size variations with temperature and strain rate are observed, suggesting that grain size control will be difficult. [source]

Photosensitization of TiO2 Nanostructures with CdS Quantum Dots: Particulate versus Tubular Support Architectures

ADVANCED FUNCTIONAL MATERIALS, Issue 5 2009
David R. Baker
Abstract TiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons. [source]

Highly Sensitive, Mechanically Stable Nanopore Sensors for DNA Analysis

ADVANCED MATERIALS, Issue 27 2009
Bala Murali Venkatesan
Highly sensitive, mechanically robust Al2O3 nanopores are fabricated and characterized. These sensors allow for size control with sub-nanometer precision, chemical modification, and exhibit superior noise performance and increased lifetime over their solid-state counterparts. This new class of nanopore sensor is used in dsDNA studies and finds broad application in bio-nanotechnology. [source]

Supercritical Fluid,Liquid,Solid (SFLS) Synthesis of Si and Ge Nanowires Seeded by Colloidal Metal Nanocrystals,

ADVANCED MATERIALS, Issue 5 2003
T. Hanrath
Abstract Semiconductor nanowires, 5 to 20 nm in diameter and micrometers in length, appear to be promising candidates for a variety of new technologies, including computing, memory, and sensor applications. Suitable for these applications, silicon (Si) and germanium (Ge) nanowires ranging from 4 to 30 nm in diameter and micrometers in length can be produced in high temperature supercritical fluids by thermally degrading organosilane or organogermane precursors in the presence of organic-monolayer-protected gold nanocrystals. Although gas phase vapor,liquid,solid (VLS) methods can be used to produce a variety of different nanowire materials, high temperature supercritical fluids provide wire size control through nanocrystal size selection prior to synthesis, and high product yields due to the high precursor solubility. [source]

Using Difference-Based Methods for Inference in Regression with Fractionally Integrated Processes

JOURNAL OF TIME SERIES ANALYSIS, Issue 6 2007
Wen-Jen Tsay
Abstract., This paper suggests a difference-based method for inference in the regression model involving fractionally integrated processes. Under suitable regularity conditions, our method can effectively deal with the inference problems associated with the regression model consisting of nonstationary, stationary and intermediate memory regressors, simultaneously. Although the difference-based method provides a very flexible modelling framework for empirical studies, the implementation of this method is extremely easy, because it completely avoids the difficult problems of choosing a kernel function, a bandwidth parameter, or an autoregressive lag length for the long-run variance estimation. The asymptotic local power of our method is investigated with a sequence of local data-generating processes (DGP) in what Davidson and MacKinnon [Canadian Journal of Economics. (1985) Vol. 18, pp. 38,57] call ,regression direction'. The simulation results indicate that the size control of our method is excellent even when the sample size is only 100, and the pattern of power performance is highly consistent with the theoretical finding from the asymptotic local power analysis conducted in this paper. [source]

Correlation between leaf growth variables suggest intrinsic and early controls of leaf size in Arabidopsis thaliana

PLANT CELL & ENVIRONMENT, Issue 11 2005
SARAH J. COOKSON
ABSTRACT Leaf development is affected by both internal (genetic) and external (environmental) regulatory factors. The aim of this work was to investigate how leaf growth variables are related to one another in a range of environments. The leaf growth variables of wild-type Arabidopsis thaliana and leaf development mutants (ang4, ron2-1, elo1, elo2 and elo4) were studied under different incident light treatments (light and shade). The leaves studied were altered in various leaf development variables, such as the duration of expansion, relative and absolute expansion rates, epidermal cell size, epidermal cell number and initiation rate. Final leaf area was correlated to maximal absolute leaf expansion rate and cell number, but not to duration of leaf expansion or cell size. These relationships were common to all studied genotypes and light conditions, suggesting that leaf size is determined early in development. In addition, the early variables involved in leaf development were correlated to one another, and initial relative expansion rate was negatively correlated to the duration of expansion. These relationships between the leaf development variables were used to construct a conceptual model of leaf size control. [source]

Adaptive finite element procedures for elastoplastic problems at finite strains

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
A. Koch Dipl.-Ing.
A major difficulty in the context of adaptive analysis of geometrically nonlinear problems is to provide a robust remeshing procedure that accounts both for the error caused by the spatial discretization and for the error due to the time discretization. For stability problems, such as strain localization and necking, it is essential to provide a step,size control in order to get a robust algorithm for the solution of the boundary value problem. For this purpose we developed an easy to implement step,size control algorithm. In addition we will consider possible a posteriori error indicators for the spatial error distribution of elastoplastic problems at finite strains. This indicator is adopted for a density,function,based adaptive remeshing procedure. Both error indicators are combined for the adaptive analysis in time and space. The performance of the proposed method is documented by means of representative numerical examples. [source]

A standard panel of microsatellites for Asian seabass (Lates calcarifer)

ANIMAL GENETICS, Issue 2 2010
Z. Y. Zhu
Summary Microsatellites are the most popular markers for parentage assignment and population genetic studies. To meet the demand for international comparability for genetic studies of Asian seabass, a standard panel of 28 microsatellites has been selected and characterized using the DNA of 24 individuals from Thailand, Malaysia, Indonesia and Australia. The average allele number of these markers was 10.82 ± 0.71 (range: 6,19), and the expected heterozygosity averaged 0.76 ± 0.02 (range: 0.63,1.00). All microsatellites showed Mendelian inheritance. In addition, eight standard size controls have been developed by cloning a set of microsatellite alleles into a pGEM-T vector to calibrate allele sizes determined by different laboratories, and are available upon request. Seven multiplex PCRs, each amplifying 3,5 markers, were optimized to accurately and rapidly genotype microsatellites. Parentage assignment using 10 microsatellites in two crosses (10 × 10 and 20 × 20) demonstrated a high power of these markers for revealing parent-sibling connections. This standard set of microsatellites will standardize genetic diversity studies of Asian seabass, and the multiplex PCR sets will facilitate parentage assignment. [source]