Curing kinetics of medium reactive unsaturated polyester resin used for liquid composite molding process

The cure kinetics of medium reactivity unsaturated polyester resin formulated for Liquid Composite Molding process simulation was studied by Differential Scanning Calorimetry (DSC) under isothermal conditions over a specific range of temperature. For isothermal curing reactions performed at 100, 110, and 120°C, several influencing factors were evaluated using the heat evolution behavior of curing process. We propose two‐ and three‐parameter kinetic models to describe the cure kinetics of thermoset resins. Comparisons of the model solutions with our experimental data showed that the three‐parameter model was the lowest parameter model capable of capturing both the degree of cure and the curing rate qualitatively and quantitatively. The model parameters were evaluated by a non‐linear multiple regression method and the temperature dependence of the kinetic rate constants thus obtained has been determined by fitting to the Arrhenius equation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study of the biodegradation behavior of soy protein‐grafted polyethylene by the soil burial method

In this article, we report on the biodegradation of soy‐protein‐grafted polyethylene, which was successfully synthesized by a graft copolymerization method with benzoyl peroxide as the radical initiator. The biodegradation behavior of the grafted polyethylene was ascertained by a soil burial test. The weight‐loss percentage was measured as a function of the number of days, and it was observed that the percentage weight loss increased with increasing number of days. To further substantiate the degradation, microanalysis of the soil containing the samples was carried out. An increase in microorganism colonies was observed with increasing number of days. The hydrolysis of the samples taken from the soil after a specified number of days also corroborated the findings and revealed a continuous loss of weight. The effect of the degradation of the grafted samples on the growth of plants (wheat and soybean) was studied, and we observed that the products of degradation were not harmful to the growth of the plants. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Appropriate bleaching technique for coconut fiber

Recipes for bleaching of coconut fiber at both ambient and elevated temperature were investigated using appropriate statistical design of experiments using hydrogen peroxide with essential bleaching assisting auxiliaries. The statistical tool is also being utilized to suggest optimized recipe for the treatments considering mainly whiteness index, yellowness index, and tenacity. Statistical computation affirmed need of higher amount of bleaching chemicals in elevated temperature than ambient bleaching. Both the bleaching treatments were resulting in small mass loss essentially of noncellulosic nature including lignin and thus result in improved mechanical properties. The change in whiteness and yellowness index of the bleached fiber under the shed storage condition for duration of 2 years was found to be negligible.     

An Improved Method for Load Taxonomy Using Sample Shifting Technique and Signature Analysis

This paper illustrates an improved method of classification of electrical appliances, particularly for domestic loads, to construct load taxonomy on the basis of their signature analysis. Each electrical load is characterized by its own distinct signature and hence load signature analysis is useful in monitoring the health of the equipment, power quality, in determining individual energy usage etc. type of services. On the other hand, load taxonomy classifies these loads in several clusters on the basis of some features extracted from their signatures. In traditional methods of construction of load taxonomy, different signature patterns based on power metrics, V-I trajectories, Eigen vectors, etc. In this proposed method, with the adoption of sample shifting technique the required number of feature extraction is reduced to a lower value to find out various signature patterns than those are required in traditional load taxonomies. Moreover, a better taxonomy, having well separated groups of loads is achieved with lower number of extracted features.     

Human Platelet Membrane Functionalized Microchips with Plasmonic Codes for Cancer Detection

The possibility of functional roles played by platelets in close alliance with cancer cells has inspired the design of new biomimetic systems that exploit platelet–cancer cell interactions. Here, the role of platelets in cancer diagnostics is leveraged to design a microfluidic platform capable of detecting cancer‐derived extracellular vesicles (EVs) from ultrasmall volumes (1 µL) of human plasma samples. Further, the captured EVs are counted by direct optical coding of plasmonic nanoprobes modified with EV‐specific antibodies. Owing to the inherent properties of platelets for multifaceted interaction with cancer cells, the microfluidic chip equipped with a biologically interfaced platelet membrane‐cloaked surface (denoted “PLT‐Chip”) can capture a significantly higher number of EVs from multiple types of cancer cell lines (prostate, lung, bladder, and breast) than the normal cell‐derived EVs. Furthermore, this chip allows the monitoring of the growth of tumor spheroids (100 µm–2.5 mm) and clearly distinguishes the plasma of cancer patients from that of normal healthy controls. This robust, multifaceted, and cancer‐specific binding affinity, coupled with excellent biocompatibility, is a unique feature of platelet membrane‐cloaked surfaces, which therefore represent promising alternatives to antibodies for application in EVs‐based cancer theranostics.     

Design of a compact protrudent‐shaped ultra‐wideband multiple‐input‐multiple‐output/diversity antenna with band‐rejection capability

In this endeavor, a new multiple‐input‐multiple‐output antenna with a sharp rejection at wireless local area network (WLAN) band is designed and practically examined for portable wireless ultra‐wideband applications. The intended diversity antenna possess a small size of 15 mm × 26 mm and two inverted L‐strip are loaded over the conventional rectangular patch antenna to form protrudent‐shaped radiator that acts as a radiating element. The sharp band‐rejection capability at WLAN is established by incising the L‐shaped slits at the decoupling structure. More than ?21 dB isolation is accomplished for the complete working band (ie, 2.87 ‐17 GHz). Degradation in the antenna efficiency at the center frequency of band rejection corroborates the good interference rejection capability. The working capabilities of the intended antenna are tested by using the isolation between the ports, total efficiency, gain, envelope correlation coefficient, radiation pattern, mean effective gain, and total active reflection coefficient.     

Analysis of three-dimensional transient seepage into ditch drains from a ponded field

An analytical solution in the form of infinite series is developed for predicting time-dependent three-dimensional seepage into ditch drains from a flat, homogeneous and anisotropic ponded field of finite size, the field being assumed to be surrounded on all its vertical faces by ditch drains with unequal water level heights in them. It is also assumed that the field is being underlain by a horizontal impervious barrier at a finite distance from the surface of the soil and that all the ditches are being dug all the way up to this barrier. The solution can account for a variable ponding distribution at the surface of the field. The correctness of the proposed solution for a few simplified situations is tested by comparing predictions obtained from it with the corresponding values attained from the analytical and experimental works of others. Further, a numerical check on it is also performed using the Processing MODFLOW environment. It is noticed that considerable improvement on the uniformity of the distribution of the flow lines in a three-dimensional ponded drainage space can be achieved by suitably altering the ponding distribution at the surface of the soil. As the developed three-dimensional ditch drainage model is pretty general in nature and includes most of the common variables of a ditch drainage system, it is hoped that the drainage designs based on it for reclaiming salt-affected and water-logged soils would prove to be more efficient and cost-effective as compared with designs based on solutions developed by making use of more restrictive assumptions. Also, as the developed model can handle three-dimensional flow situations, it is expected to provide reliable and realistic drainage solutions to real field situations than models being developed utilizing the two-dimensional flow assumption. This is because the existing two-dimensional solutions to the problem are actually valid not for a field of finite size but for an infinite one only.