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991.
Gagan Kumar Ritu Rani Sucheta Sharma Khalid M. Batoo M. Singh 《Ceramics International》2013,39(5):4813-4818
Cobalt substituted Mg–Mn nanoferrites with formulae Mg0.9Mn0.1CoxFe2?xO4, x=0.0, 0.1, 0.2 and 0.3, have been synthesized for the first time by the solution combustion technique. The effects of Co2+ ions on the dc resistivity, dielectric constant and dielectric loss tangent of Mg–Mn nanoferrites at room temperature are presented in this paper. X-ray diffraction confirmed the formation of a single phase spinel structure. Particle size was found to increase, 20.9–23.9 nm, with increasing Co2+ concentration. The dc resistivity was increased by two order of magnitude with substitution of Co2+ ions while the dielectric constant was found to be decreasing with the increasing concentration of cobalt ions. The value of dc resistivity obtained for Mg0.9Mn0.1Fe2O4 nanoferrite in our work is greater than the value obtained for the same composition prepared by the conventional ceramic technique. Further, the dielectric constant and dielectric loss tangent were observed to be decreasing with the increase in frequency. 相似文献
992.
In this paper, the theory on the translation of a measured chord length distribution (CLD) into its particle size distribution (PSD), which was developed in the first part of this study [Li and Wilkinson, 2005. Determination of non-spherical particle size distribution from chord length measurements. Part 1: theoretical analysis. Chemical Engineering Science 60, 3251-3265], has been validated using experimental results. CLDs were measured using the Lasentec focused beam reflectance measurement (FBRM) with three different materials, spherical ceramic beads and non-spherical plasma aluminium and zinc dust particles. Meanwhile, the particle shape and PSD of each material were also investigated by image analysis (IA). Comparison of the retrieved PSDs with the measured PSDs by IA shows that the PSD can be retrieved from a measured CLD successfully using the proposed iterative nonnegative least squares (NNLS) method based on the PSD-CLD model. 相似文献
993.
Srinivasan Srikanth Ajay Kumar Ray Amitava Bandopadhyay Bandari Ravikumar Animesh Jha 《Journal of the American Ceramic Society》2005,88(9):2396-2401
The phase constitution during the sintering of pure red mud and red mud–fly ash mixtures was studied in the temperature range of 900°–1250°C. The phases formed at different sintering temperatures were analyzed by X-ray powder diffraction. The phases that are likely to form at equilibrium at any isotherm were predicted using the Gibbs free energy minimization technique and the databases provided in the FactSage software. Although the thermodynamic prediction is in reasonable agreement with the experimental results for the major phases, there is some disagreement regarding the minor phases, especially the more complex phases. The major limitation of the thermodynamic approach presently is the non-availability of thermodynamic data for several complex and multi-component solution phases. 相似文献
994.
A half‐fraction, two‐level, four‐factor factorial experimental design was used to study the effects of the acetic anhydride concentration, reaction temperature, reaction time, and sulfuric acid concentration on the degree of substitution, intrinsic viscosity, and yield of oxidized cellulose acetate (OCA). Oxidized cellulose containing 20% (w/w) carboxylic acid was used as the starting material. The data were fitted by multiple regression analysis with SAS software. The correlation coefficients obtained from plots of the predicted and observed values for the degree of substitution, intrinsic viscosity, and yield were 0.985, 0.993, and 0.991, respectively. Residual normal plots of the regression models showed a linear relationship. Lenth and main‐factor‐effect plots revealed an increase in the degree of substitution of OCA with an increasing concentration of acetic anhydride. The latter had no effect on the intrinsic viscosity and yield of OCA. An increase in the reaction temperature led to an increase in the degree of substitution and a decrease in the intrinsic viscosity and yield of OCA. The influence of the reaction time on the degree of substitution and intrinsic viscosity followed a trend similar to that observed with the reaction temperature, but the yield of OCA was unaffected. Increasing the concentration of sulfuric acid reduced the degree of substitution, intrinsic viscosity, and yield of OCA. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 696–705, 2005 相似文献
995.
Nanobelts are a new class of semiconducting metal oxide nanowires. The ribbon-like nanobelts are chemically pure and structurally uniform single crystals, with clean, sharp, smooth surfaces, and rectangular cross-sections. Positive and negative dielectrophoresis (DEP) was demonstrated for the first time on semiconducting oxide nanobelts. This effect was then used for the fabrication of a nanodevice, which consisted of SnO2 nanobelts attached to castellated gold electrodes defined on a glass substrate, and covered by a microchannel. The SnO2 nanobelts (width ∼ 100-300 nm, thickness ∼ 30-40 nm) were suspended in ethanol and introduced into the microchannel. An alternating (AC) voltage of ∼9.8 V peak to peak, with variable frequency, was applied between the electrodes (minimum electrode gap ∼ 20 μm), which corresponds to an average electric field strength of less than 2.5 × 105 V/m. In the 10 Hz-1 kHz range, repulsion between the nanobelts and the electrodes occurred, while in the 1-10 MHz range, attraction was observed. Once the nanobelts touched the electrodes, those that were sufficiently long bridged the electrode gaps. The device was characterized and can potentially be used as a nanosensor. 相似文献
996.
The use of polymeric materials for the administration of pharmaceuticals, and as biomedical devices has increased dramatically. This review focuses on synthetic biodegradable polymers of current interest for medical use, based on ester and anhydride bonds. Special attention is given to factors affecting biodegradation, including: polymer structure, morphology, molecular weight, radiation, and chemical treatment, as well as the effects of drugs and plasticizers added to the polymer mass. The toxicity and biocompatibility of the polymers and their current and future applications in medicine are also briefly reviewed. 相似文献
997.
998.
Silicon - In this review, we discussed highly sensitive biosensor devices which is having a more attractive, wide scope and development in the sensing field. Biosensor devices can detect the... 相似文献
999.
Silicon - Recycling and reutilization of industrial waste is one way to minimize land pollution to attain green environment. In this research waste SiC grinding wheel was ball milled to powder form... 相似文献
1000.
Wighmal Kosheen Peddi Giridhar Apoorva Kumar Naveen Amin S. Intekhab Anand Sunny 《SILICON》2022,14(11):5951-5959
Silicon - Through this paper, we discuss how Tunnel Field Effect Transistors can be utilized for the detection of biomaterials hence acting as a biosensor. The device proposed is a 3-D Doping less... 相似文献