This study reports preparation of glass composition (54.50 wt.%) SiO2, (10.80 wt.%) B2O3, (14.20 wt.%) Na2O, (1.20 wt.%) K2O, (6.00 wt.%) CaO, (4.00 wt.%) Fe2O3 and (9.30 wt.%) TiO2 by melt quenching method using direct microwave heating and conventional resistive heating. Study of dielectric loss factor of the glass as function of temperature illustrated increasing loss factor above 370 ℃, 550 ℃, 650 ℃ and 900 ℃, indicating enhanced microwave absorption by the glass at above these temperatures. Chemical analysis results of both the glasses depicted more volatilization loss of volatile ingredients in conventional heating. The study of chemical durability was performed from leachate analysis describing less leaching of Na2O, K2O and other constituents from glass melted in microwave furnace. Glass transition temperatures (Tg) were found to be 576.3 ℃ and 569.5 ℃ for glass melted in conventional and microwave heating route, respectively. Laboratory experiment of glass melting utilizing microwave energy as an alternate heating source demonstrated 70%-75% electrical power saving. 相似文献
Estimation of the direct radiative forcing (DRF) by atmospheric particles is uncertain to a large extent owing to uncertainties in their morphology (shape and size), mixing states, and chemical composition. A region-specific database of the aforementioned physico-chemical properties (at individual particle level) is necessary to improve numerically-estimated optical and radiative properties. Till date, there is no detailed observation of the above mentioned properties over Kanpur in the Indo-Gangetic Plain (IGP). To fill this gap, an experiment was carried out at Kanpur (IITK; 26.52°N, 80.23°E, 142 m msl), India from April to July, 2011. Particle types broadly classified as (a) Cu-rich particles mixed with carbon and sulphur (b) dust and clays mixed with carbonaceous species (c) Fe-rich particles mixed with carbon and sulfur and (d) calcite (CaCO3) particles aged with nitrate, were observed. The frequency distributions of aspect ratio (AR; indicator of extent of particle non-sphericity) of total 708 particles from April to June reveal that particles with aspect ratio range >1.2 to ≤1.4 were abundant throughout the experiment except during June when it was found to shift to high AR range, >1.4 to ≤1.6 (followed with another peak of AR i.e. >2 to ≤2.4) due to dust storm conditions enhancing the occurrence of more non-spherical particles over the sampling site. The spherical particles (and close to spherical shape; AR range, 1.0 to ≤1.2) were found to be <20% throughout the experiment with a minimum (11.5%) during June. Consideration of Homogeneous Equivalent Sphere Approximation (HESA) in the optical/radiative model over the study region is found to be irrelevant during the campaign. 相似文献
The dependence of the width of void-denuded zones (VDZs) on grain boundary (GB) characters was investigated in Cu irradiated with He ions at elevated temperature. Dislocation loops and voids formed near GBs during irradiation were characterized by transmission electron microscopy, and GB misorientations and normal planes were determined by electron back-scatter diffraction. The VDZ widths at Σ3〈1 1 0〉 tilt GBs ranged from 0 to 24 nm and increased with the GB plane inclination angle. For non-Σ3 GBs, VDZ widths ranged from 40 to 70 nm and generally increased with misorientation angle. Nevertheless, there is considerable scatter about this general trend, indicating that the remaining crystallographic parameters also play a role in determining the sink efficiencies of these GBs. In addition, the VDZ widths at two sides of a GB show different values for certain asymmetrical GBs. Voids were also observed within GB planes and their density and radius also appeared to depend on GB character. We conclude that GB sink efficiencies depend on the overall GB character, including both misorientation and GB plane orientation. 相似文献
In the present work, morphology, microstructure, and electrochemical behavior of Zn coatings containing non-toxic additives have been investigated. Zn coatings were electrodeposited over mild steel substrates using Zn sulphate baths containing four different organic additives: sodium gluconate, dextrose, dextrin, and saccharin. All these additives are “green” and can be derived from food contents. Morphological and structural characterization using electron microscopy, x-ray diffraction, and texture co-efficient analysis revealed an appreciable alteration in the morphology and texture of the deposit depending on the type of additive used in the Zn plating bath. All the Zn coatings, however, were nano-crystalline irrespective of the type of additive used. Polarization and electrochemical impedance spectroscopic analysis, used to investigate the effect of the change in microstructure and morphology on corrosion resistance behavior, illustrated an improved corrosion resistance for Zn deposits obtained from plating bath containing additives as compared to the pure Zn coatings. 相似文献
Prediction of stock index remains a challenging task of the financial time series prediction process. Random fluctuations in the stock index make it difficult to predict. Usually the time series prediction is based on the observations of past trend over a period of time. In general, the curve the time series data follows has a linear part and a non-linear part. Prediction of the linear part with past history is not a difficult task, but the prediction of non linear segments is difficult. Though different non-linear prediction models are in use, but their prediction accuracy does not improve beyond a certain level. It is observed that close enough data positions are more informative where as far away data positions mislead prediction of such non linear segments. Apart from the existing data positions, exploration of few more close enough data positions enhance the prediction accuracy of the non-linear segments significantly. In this study, an evolutionary virtual data position (EVDP) exploration method for financial time series is proposed. It uses multilayer perceptron and genetic algorithm to build this model. Performance of the proposed model is compared with three deterministic methods such as linear, Lagrange and Taylor interpolation as well as two stochastic methods such as Uniform and Gaussian method. Ten different stock indices from across the globe are used for this experiment and it is observed that in majority of the cases performance of the proposed EVDP exploration method is better. Some stylized facts exhibited by the financial time series are also documented.
Soy meal-based biodegradable blends were prepared by melt extrusion process. The effects of denaturants, i.e., urea and sodium
sulfite and plasticizer (glycerol) and polyester type (polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate)
on tensile strength and elongation at break were investigated using a Taguchi experimental design approach. The results showed
that the sodium sulfite had little or no effect on final properties of the blends. Also, biodegradable polyester type had
significant effect on the tensile strength and elongation at break of the blends prepared. The predicted values and experimental
were found to be in tune with each other. The chemical structure and morphology of the optimum sample was probed by FT-IR
spectroscopy and scanning electron microscopy (SEM). Also, the results provided an insight into how important the plasticization
and destructurization of soy protein to obtain the blends with desired mechanical properties. 相似文献
Effect of ultrasound pretreatment on yield and functional properties of taro starch was investigated. A three-factor two-level factorial design was employed with treatment time (5 and 10 min), treatment cycle (0.5 and 1), and amplitude of ultrasound (50 and 100 %). Starch yield from ultrasonic treatment varied from 17.45 to 18.97 % compared to 15.29 % in conventional method. The highest yield of 18.97 % was obtained with treatment time 10 min, treatment cycle 0.5, and amplitude 50 %. A significant increase in swelling, solubility, pasting, and texture properties of the ultrasonically extracted starch was observed. A slight decrease in clarity of the starch pastes was also observed after ultrasonic pretreatment, but the differences were not much significant. Freeze-thaw stability of the ultrasonically extracted starches was found to be better compared to starch extracted using conventional method, making them suitable for foods subjected to refrigeration. The whiteness of the ultrasonically extracted starch powders was lower compared to conventionally extracted starch, but the differences were not statistically significant. 相似文献
Wireless Personal Communications - Balancing energy consumption of sensor nodes to extend the network lifetime is a major concern for the energy constrained wireless sensor network. Improper load... 相似文献