Influence of Exposure Time,Shear Stress,and Surfactants on Detachment of <Emphasis Type="Italic">Escherichia coli</Emphasis> O157:H7 from Fresh Lettuce Leaf Surfaces During Washing Process

Washing and sanitation of fresh produce are critical for detachment and inactivation of pathogenic and spoilage microorganisms. The overall goal of this study was to evaluate the influence of processing conditions such as washing time, shear stress, and a food grade surfactant on the detachment of Escherichia coli O157:H7 from lettuce leaf surfaces during a simulated washing process. A benchtop scale rotating disk washing device was designed to simulate the processing conditions used in commercial washing systems. Numerical simulations were carried out to calculate the flow profile and shear stress near the leaf surface. Removal of E. coli O157:H7 as a function of processing conditions in the rotating disk washing device was evaluated by enumeration of bacterial population using plate counting and changes in bioluminescence intensity and further confirmed by bioluminescence imaging. The results showed that shear stress was necessary to remove attached bacteria from inoculated leaf samples and simple incubation of inoculated leaves with wash water was not effective. Furthermore, detachment of bacteria from inoculated leaf samples increased with increasing shear stress and incubation time. Shear stress values in the range of 0 – 300 mPa were adequate to induce removal of approximately 1.5 log CFU/cm² of bacteria from inoculated samples. The addition of a surfactant increased the removal of bacteria from inoculated leaf samples by 0.5 log CFU/cm². Overall, these results may guide the design of new produce wash systems as well as current industrial practice related to flow conditions and use of surfactants during washing of fresh produce.     

Comparative studies on the nutritive and anti-nutritive properties of fruits in selected Berberis species of West Himalaya, India

Nutritional and anti-nutritional factors of five Berberis species, widely known for their wild edible fruits and medicinal properties, were investigated in the Indian west Himalaya. These fruits contained high content of fiber (pulp 7.0-8.1%; seeds 4.4-5.3%), protein (pulp 4.7-7.2%; seeds 5.9-8.5%) and fat (pulp 2.6-4.0%; seeds 4.6-5.3%) as compared to most of the known wild edibles in the region. They, however, contained reasonably lower food energy, largely due to low carbohydrate content. All the five species emerged as good source of minerals, especially Ca and K. The values of various nutrient and mineral elements varied significantly among species, which implies potential of different species can be harnessed for diverse attributes. The fruits, however, possessed anti-nutritional factors like tannins and phytic acid, which need to be tackled appropriately while considering these fruits for value addition as health food.     

An improved vertical-axis water-current turbine incorporating a channelling device

Water-Current Turbines (WCTs) are non-polluting electricity generation plants that harness the kinetic energy of natural water courses, using several kinds of rotors. At the School of Engineering of the University of Buenos Aires, researchers are developing a WCT whose particular characteristics improve technical and economic performance. A channelling device, integrated into the flotation system, is used to modify flow conditions in the neighbourhood of the rotor. This system was developed from theoretical modelling and small-scale model testing in a hydrodynamic test canal. The principal advantages of this kind of machine include reduced need for fixed civil works, ease of transport and relocation and autonomous, self-regulated operation, and it is expected to be a low-cost and long-lifetime system.     

Hybrid system for handling premature convergence in GA – Case of grammar induction

Grammar induction (also known as grammar inference or language learning) is the process of learning grammar from training data. This paper presents hybrid genetic algorithm (GA) Tool for handling premature convergence for the case of grammar induction. The tool is developed in Java and the results are tested for the set of 20 languages. It is an effort towards introduction of a hybrid GA system where the collection of more than one type of reproduction methods is used for the grammar induction. Paper also includes the discussion on the various approaches used by author for handling the premature convergence problem in using GA.     

Response Time in Data Broadcast Systems: Mean,Variance and Tradeoff

Data broadcast has been suggested as a promising method of information dissemination [2,33]. In such an environment, the information server cannot afford to serve the requests from a large population of users individually. Instead, the server uses a broadcast channel to deliver information to all users. A single transmission of a data item satisfies all pending requests for that item. The response time of a request depends on the broadcast time of the desired data item, which is scheduled by the server according to the overall demands for various data items. Therefore, the response time may vary in a large range. We argue that, in addition to mean response time, the variance of response time should also be taken into account by the broadcast scheduler. In this paper, we address the issue of variance optimization in regard to response time. Building on our previous research on mean response time optimization, we propose an algorithm which can minimize the variance of response time. Furthermore, we evaluate an algorithm that facilitates a tradeoff between the mean and variance of response time. Numerical examples that illustrate the performance of our algorithms are also presented.     

Hierarchical Delay Test Generation

Delay testing is used to detect timing errors in a digital circuit.In this paper, we report a tool called MODET forautomatic test generation for path delay faults in modular combinational circuits. Our technique usesprecomputed robust delay tests for individual modules to computerobust delay tests for the module-level circuit. We present alongest path theorem at the module level ofabstraction which specifies the requirements for path selectionduring delay testing. Based on this theorem, we propose a pathselection procedure in module-level circuits and report efficientalgorithms for delay test generation. MODET hasbeen tested against a number of hierarchical circuits with impressivespeedups in relation to gate-level test generation.     

ESTIMATION OF ACTIVITY COEFFICIENTS AT INFINITE DILUTION OF HALOCARBONS IN WATER AND ORGANIC COMPOUNDS IN HYDROFLUOROPARAFFINS USING NEURAL NETWORKS

Infinite dilution activity coeffcents ( 1) of 19 halocarbons in water and 18 organic compounds in 5 hydrofluoroparaffins over a temperature range of 291 333K have been estimated by the method of neural nets. The network was trained using 351 data points covering 18 halocarbons in water and 17 organic compounds in 4 hydrofluoroparaffins, and generalization test was carried out using the remaining 92 data points covering one halocarbon in water, 17 organic compounds in a hydrofluroparaffin, and an organic compound in 5 hydrofluoroparaffins. Seven inputs are included in the network, namely the temperature, dipole moment, molar refraction and critical pressure of the solute and solvent. The network represented the data with an overall average absolute deviation of 11.8% estimated on the basis of the values of 1. The result obtained could be considered reasonable in view of the wide variations in the values of the input properties and 1 values and the varied nature and size of compounds treated. Among the several variables studied, dipole moment contributed to the correlation the most, followed by the critical pressure. Further study on the applicability of MLR (multilinear regression) method revealed the overwhelming superiority of the neural network over MLR.     

Analytical modeling of Junctionless Accumulation Mode Cylindrical Surrounding Gate MOSFET (JAM‐CSG)

This paper presents physics based analytical model for center potential, electric field and subthreshold drain current of Junctionless Accumulation Mode Cylindrical Surrounding Gate MOSFET (JAM‐CSG). The expressions are derived from Poisson's equation in cylindrical co‐ordinate system based on parabolic potential approximation (PPA). The influence of technology parameter variations such as gate length, silicon pillar diameter and oxide thickness on electrical characteristics is studied in detail. Developed analytical model results are validated through the good agreement with simulated data obtained from ATLAS 3D simulator. Copyright © 2016 John Wiley & Sons, Ltd.