Information Theory and Neural Networks for Managing Uncertainty in Flood Routing

This paper presents an approach for handling uncertainties arising mainly from ignored or misrepresented processes in physically based models. The approach is based on the application of a parallel artificial neural network (ANN) model that uses state variables, input and output data, and previous model errors at specific time steps to predict the errors of a physically based model. Concepts from information theory are used to discover the relationships between the variables and the model errors, which also serves as a mechanism to detect the predictability of the errors. The resulting information is used to select the best related input data for the error prediction model. The error prediction model is then trained and applied to improve the forecasts made by the physically based model. This approach was applied to a routing model of a 70 km reach of the River Wye, United Kingdom. The results demonstrate that errors from the physically based model show a consistent trend governed by some dynamics of their own, which can be modeled with learning algorithms. Errors were forecasted at different lead times. In all cases the forecasts made by the combined application of both models were more accurate than those made by the physically based model alone. From this it was concluded that, along with proper information analysis techniques, the use of ANN models to predict the forecast errors of physically based models can help to improve significantly the prediction and therefore to reduce the associated uncertainty.     

Effects of a titanate coupling agent on the mechanical and thermo‐physical properties of talc‐reinforced polyethylene compounds

An experimental study was carried out to investigate the effects of a titanate coupling agent on the mechanical properties, moisture absorption, and thermal conductivity of talc‐filled high‐density polyethylene (HDPE). Talc (0–35 wt %) was used as reinforcement particulate filler in an HDPE matrix and samples were prepared in a micro‐compounder and an injection molding machine. Isopropyl tri(dioctyl)phosphate titanate (0.5 wt %) was used as coupling agent. Composites with and without coupling agent were evaluated for changes in mechanical and thermo‐physical properties, morphology, and void content. Addition of the titanate coupling agent most often resulted in an increase in stiffness and tensile strength. Furthermore, both the void content and the elongation at break of composites were reduced. Results also showed that the coupling agent had no effects on the thermal conductivity, thermal diffusivity, and specific heat capacity of the composites. In addition, it was observed that the coupling agent was more effective at low concentrations of filler. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40449.     

Electrochemical reduction of CO2: Two- or three-electrode configuration

Electrocatalytical conversion of CO₂ into various chemicals like hydrocarbons and CO is regarded as a promising approach to mitigate carbon emission and, meanwhile, to provide sustainable energy and value-added chemicals. Two different reactors are used in this work. One is based upon the two-electrode configuration powered by a DC power supply or Si solar cell, which is suitable for practical applications. Another is three-electrode one powered by a potentiostat, which is feasible to study the electrode performance. Polycrystalline Cu electrode is used as the cathode, and hematite is the anode. Performance of CO₂ reduction using the two- and three-electrode configurations is studied by measuring electrode potential, cell voltage, current density, Faradaic efficiency, and reduction selectivity of CO₂. Cu cathode used here exhibits a low overpotential for CO₂ reduction, specifically for the cell with two-electrode configuration. No obvious difference can be observed between the two types of configurations at a low bias like −0.3 and −0.4 V; while the reactor with two-electrode configuration exhibits better performance at a high bias like −0.8 V than the one with three-electrode configuration. Thus, the reactors with two-electrode configuration are desirable for practical applications, specifically considering solar cells can be used as the power source to provide green and sustainable energy.     

Impact of pre-treatment (soaking or germination) on nutrient and anti-nutrient contents,cooking time and acceptability of cooked red dry bean (Phaseolus vulgaris L.) and chickpea (Cicer arietinum L.) grown in Ethiopia

Pulses are processed in diverse ways prior to consumption. Soaking and germination are among the most common traditional, household-level food processing strategies. This study was carried out to determine the effects of soaking, germination, cooking and their combinations on the contents of selected nutrients and anti-nutrients of red dry bean and chickpea. In addition, the effects of pre-treatment on cooking time and the acceptability of dishes prepared from red dry bean and chickpea were determined. The nutrient compositions (zinc, iron and calcium) of most soaked-cooked and germinated-cooked red dry bean and chickpea samples were not significantly different than those of respective controls. However, soaking and germination pre-treatments significantly lowered the phytate and tannin contents of the red dry bean and chickpea samples, with a few exceptions, and overall, polyphenol contents were lower after soaking-cooking than after germination-cooking. Most scores for sensory attributes of bean-based and chickpea-based dishes prepared from soaked or germinated samples were not significantly different than those of the controls. For most red dry bean and chickpea samples, longer germination times yielded superior results in terms of reductions in cooking time, tannin content, and phytate:zinc and phytate:iron molar ratio.     

Loss mechanisms in single-mode fiber tapers

The onset of transmission loss in four single-mode tapers is shown to coincide with the taper slope exceeding the critical slope angle at which fundamental mode cutoff occurs. This implies that the primary loss mechanism in single-mode fiber tapers is cutoff of the fundamental mode from the core. A secondary loss mechanism of coupling to the modes of a coaxial outer waveguide is also observed and modeled. Implications for fused fiber couplers are discussed.     

Current-voltage characteristics from an asymptotic analysis of the MOSFET equations

Phenomenological formulae for the current-voltage characteristics of a MOSFET are derived by extending the asymptotic method of Ward. Practical methods for combining the perturbation approximations and numerically implementing the Ward equations are developed. A detailed comparison with real MOSFET data is presented and the model is shown to be effective over a range of device geometries.     

Assessment of iron bioavailability from twenty elite late‐maturing tropical maize varieties using an in vitro digestion/Caco‐2 cell model

An in vitro digestion/Caco‐2 cell model was used to assess iron bioavailability of twenty elite late‐maturing tropical maize varieties grown in three diverse agroecologies in West and Central Africa (WCA). Kernel‐iron concentration of the varieties, averaged across locations, varied from 19.2 to 24.4 mg kg^?1, while mean kernel‐zinc concentration ranged between 19.4 and 24.6 mg kg^?1. Significant differences in iron bioavailability were observed among varieties, but the environment had no significant effect. Mean bioavailable iron ranged between 14% below and 43% above the reference control variety, TZB‐SR. Variety DMR‐LSR‐Y with the highest concentrations of kernel‐iron and ‐zinc of 24–25 mg kg^?1 across the three locations had a similar quantity of bioavailable iron as the reference control, TZB‐SR. In the long run this variety could be potentially effective in reducing iron deficiency because of its high kernel‐iron. The most promising varieties were Mid‐altitude STR synthetic and ACR91SUWAN‐1‐SRC1. They had kernel‐iron and ‐zinc levels of 22–24 mg kg^?1 and bioavailable iron 24–36% higher than the reference control, TZB‐SR. Additional research is necessary to determine if the increases in kernel‐iron concentration and bioavailable iron observed in this study can significantly improve the iron status of individuals in WCA at risk for iron deficiency. Copyright © 2004 Society of Chemical Industry     

Classification of rose flowers based on Fourier descriptors and color moments

Multimedia Tools and Applications - In this paper, a rose-flower variety classification scheme, using color and shape features is presented. The first three statistical moments of the R, G, and B...     

Dietary and bioactive properties of the berries and leaves from the underutilized Hippophae salicifolia D. Don grown in Northeast India

Food Science and Biotechnology - The physico-chemical, polyphenols, antioxidant and antibacterial properties of berries and mixture of male and female leaves of Hippophae salicifolia were...