Impact of frozen storage on polyacetylene content, texture and colour in carrots disks

This study investigated the effect of freezing method (slow or blast freezing) with or without blanching during storage at −20 °C on the levels of three polyacetylenes, falcarinol (FaOH), falcarindiol (FaDOH), falcarindiol-3-acetate (FaDOAc) in carrot disks. The quality of the carrot disks was also assessed using instrumental texture and colour measurements. Blast frozen carrot disks retained higher amounts of polyacetylenes compared to their slow frozen counterparts. Whilst the levels of retention of total polyacetylenes was higher in unblanched than blanched disks prior to freezing there was a sharp decrease in the levels of polyacetylenes in unblanched frozen carrots during the storage period for 60 days at −20 °C. FaDOH was observed to be the most susceptible to degradation during frozen storage of unblanched carrot disks, followed by FaOH and FaDOAc. The changes in the level of polyacetylenes during storage were adequately described by using Weibull model. The texture and colour were also found to decrease during frozen storage compared to fresh carrots.     

Bioactive Carbohydrates and Peptides in Foods: An Overview of Sources,Downstream Processing Steps and Associated Bioactivities

Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these.     

Physical Model Based Method to Generate Channel Coefficients for Nakagami-m Distribution

In this paper, we discuss physical model based method to generate channel coefficients for Nakagami-m distribution. We consider the phase envelope joint distribution so that the phase of the faded signal is also considered. Mainly, the coefficients are generated by exploring the physical model that relates the Nakagami-m fading distribution with Gaussian and gamma distributions for which generation of coefficients is available in commonly used simulation tools. The empirical probability density function (PDF) of generated coefficients are compared with the theoretical values and they are found in excellent agreements. The empirical PDFs for envelope and phase of the generated coefficients are validated using the Kolmogorov–Smirnov test.

     

Static and dynamic analysis of organic and hybrid inverter circuits

This paper explores the possibility of organic-inorganic inverter circuits starting with independent designs of organic thin film transistors. Simulated I–V characteristics of all p/n devices are compared with experimental results that yield an average error of 0.8 % and 4.3 % for threshold voltage and mobility, respectively. Furthermore, static and dynamic responses of different inverters are compared, using CuPc–F₁₆CuPc, pentacene–C₆₀, pentacene–ZnO, pentacene–a-Si:H and pentacene–pentacene as driver and load combinations to address the effect of various materials and configurations. Analytical results for switching threshold and propagation delay have also been provided to validate the circuit simulation. Observations illustrate good balancing between pull up and pull down operation of pentacene with C₆₀, a-Si:H and ZnO due to the comparable mobility of p and n-type transistors. Moreover, pentacene–C₆₀ and all p-organic inverters demonstrate 38 % and 45 % reduction in propagation delay, respectively, even at smaller W/L ratios, as compared to CuPc–F₁₆CuPc combination, due to lower mobilities of CuPc and F₁₆CuPc devices. Although, pentacene–ZnO hybrid combination shows almost 35 % higher propagation delay as compared to a-Si:H, but still it is preferable due to several advantages related to fabrication, such as low process temperature.     

Comparative Evaluation of Two Neural Network Based Techniques for the Classification of Microcalcifications in Digital Mammograms

This paper investigates two neural network based techniques for the classification of microcalcifications in digital mammograms. Both techniques extract suspicious areas containing microcalcifications from digital mammograms and classify them into two categories: whether they contain benign or malignant clusters. The centroids and radii provided by expert radiologists are being used to locate and extract suspicious areas. Two neural networks based on iterative and non-iterative training methods are used to classify them into benign or malignant. The proposed techniques have been implemented in C++ on the SP2 supercomputer. The database from the Department of Radiology at the University of Nijmegen has been used for the experiments. The comparative results are very interesting and promising. Some of them are included in this paper.     

Modeling Soil Water Uptake by Plants Using Nonlinear Dynamic Root Density Distribution Function

Water uptake by plants is one of the major components of water balance of the vadose zone that greatly influences the contaminant and moisture movement in variably saturated soils. In this study, a nonlinear macroscopic root water uptake model that includes the impact of soil moisture stress is developed. The model incorporates the spatial and temporal variation of root density in addition to the dynamic root depth considerations. The governing moisture flow equation coupled with the water extraction by plants term is solved numerically by an implicit finite-difference method. The simulation is performed for various physical scenarios subjected to different boundary conditions. The model is tested first without considering the water uptake and results are compared with observed data available in the literature for two cases. A nonlinear water uptake term is subsequently incorporated in the model which is then simulated for corn crop for constant root depth under various characteristic moisture availability environments. Results show that the water extraction rate is closely related to the soil moisture availability in addition to the root density. The plants are observed to extract moisture mainly from the upper root dense soil profile when water content is in an optimal range, otherwise, the peak of the uptake moves to other soil layers where the moisture is easily available. Finally, the model is applied to a corn field and simulated results are validated with field data. The simulated moisture content for 2 months of crop growing season shows a reasonably good agreement with the observed data.