Electrical,optical and hole transport mechanism in thin films of poly(3-octylthiophene-co-3-hexylthiophene): Synthesis and characterization

The present study demonstrates the designing of copolymer poly(3-octylthiophene-co-3-hexylthiophene) (P3OT-HT) and study of the hole transport mechanism in it. Detailed structural, optical and thermal studies of P3OT-HT discuss its synthesis aspects. Current density–voltage characteristics have been studied at different temperatures (290–110 K) to understand the mechanism of hole transport in P3OT-HT. It has been established that current density in P3OT-HT thin films is governed by space charge limited conduction with traps distributed exponentially in energy and space. Hole mobility is both temperature and electric field dependent arising due to substituent functional groups attached the polymer backbone.     

Forming-free bipolar resistive switching in nonstoichiometric ceria films

The mechanism of forming-free bipolar resistive switching in a Zr/CeO _x /Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrO _y layer at the Zr/CeO _x interface. X-ray diffraction studies of CeO _x films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeO _x film and in the nonstoichiometric ZrO _y interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).     

Investigation of water vapor permeability and antimicrobial property of zinc oxide nanoparticles‐loaded chitosan‐based edible film

This study is focused on the investigation of moisture uptake properties of chitosan films. The GAB isotherm model is found to fit well to the experimental moisture uptake data obtained at 10, 25, and 37°C. The water vapor permeability is found to increase with temperature. The use of plasticizer enhances the water vapor permeability. Finally, the films have been loaded with ZnO nanoparticles and characterized by X‐ray diffraction, differential scanning calorimetry, surface plasma resonance, and scanning electron microscopic analyses. The crystal size as determined using Scherrer's equation is found to be around 15 nm. The films have shown excellent antibacterial action against the model bacterium Escherichia coli. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Diversity in seed and flour properties in field pea (Pisum sativum) germplasm

The genetic diversity in agronomic, seeds (physicochemical, hydration, textural and cooking) and flour (pasting and gel texture) characteristics amongst 71 field pea lines was studied. L∗-, a∗-, b∗-values, seed weight, density, hydration capacity, swelling capacity and cooking time ranged between 43.6 and 67.1, −2.3 and 6.2, 5.8 and 17.4, 4.26 and 25.65 g/100 seeds, 0.55 and 2.01 g/ml, 0.05 and 0.31 g/seed, 0.02 and 0.76 ml/seed and 45 and 81 min, respectively. Amylose content of starch ranged between 21.4% and 58.3%. Pasting temperature, peak viscosity, breakdown, final viscosity and setback of flours from different lines ranged from 73.5 to 81.5 °C, 533 to 3000, 8 to 187, 121 to 2276, and 183 to 998 cP, respectively. The frequency distribution and principal component analysis revealed significant variation in quality traits amongst the 71 field pea lines.     

Jitter performance in ethernet passive optical networks

Ethernet passive optical networks (EPONs) have emerged as one of the most promising access network technologies. Propelled by rapid price declines in fiber optics and Ethernet components, these architectures combine the latest in optical and electronic advances and are poised to become the dominant means of delivering gigabit broadband connectivity to homes over a unified single platform. As this technology matures, related quality of service (QoS) issues are becoming a key concern. This paper proposes a novel dynamic scheduling algorithm, termed hybrid granting protocol (HGP), to support different QoS in EPON. Specifically, the proposed dynamic scheduling algorithm minimizes packet delay and jitter for delay and delay-variation sensitive traffic (e.g., voice transmissions) by allocating bandwidth in a grant-before-report (GBR) fashion. This considerably improves their performance without degrading QoS guarantees for other service types. Detailed simulation experiments are presented to validate the effectiveness of the proposed algorithm.     

A dynamic lot sizing problem with multiple customers: customer-specific shipping and backlogging costs

This paper considers a dynamic lot sizing problem faced by a producer who supplies a single product to multiple customers. Characterized by their backorder costs as well as shipping costs, a customer with a high backorder cost has a greater need for the product than a customer with a low backorder cost. We show that the general problem with time-varying customer-dependent backlogging and shipping costs is NP-hard in the strong sense. We then develop an efficient dynamic programming algorithm for an important instance of the problem when there is no speculative motive for backlogging. We also establish forecast horizon results for the case of stationary production and shipping costs, which help the decision maker determine a proper forecast horizon in a rolling-horizon planning process.     

Selective adsorption of precious metals from hydrochloric acid solutions using porous carbon prepared from barley straw and rice husk

Porous carbon was prepared by carbonization from agro-waste such as rice husk and barley straw to evaluate the adsorption of precious and base metals from metal solutions. The effects of hydrochloric acid concentration, metal ion concentration, and contact time on adsorption were examined. Rice husk carbon was found to be highly selective for Au(III) and inert to Pt(IV), Pd(II) and other base metals. Barley straw carbon adsorbed these three precious metal ions, but was inert to base metal ions such as Cu(II), Fe(III) and Ni(II). The maximum adsorption capacity of rice husk carbon for Au(III) was 0.76 mol/kg and the maximum adsorption capacity of barley straw carbon for Au(III), Pt(IV) and Pd(II) was 1.47, 0.39 and 0.64 mol/kg, respectively. The effectiveness of recovery of precious metals from industrial solution was also tested and barley straw carbon was found to be highly efficient and selective for the targeted metal ions in the presence of excess of other metal ions. Rice husk and barley straw carbon are thus potential alternatives to commercially available activated carbon as they have high selectivity and are efficient with low production costs.     

REFLECTION OF GENERALIZED THERMOELASTIC WAVES FROM THE BOUNDARY OF A HALF-SPACE

We investigated the problem of thermoelastic wave reflection from the insulated and isothermal stress-free as well as rigidly fixed boundaries of homogeneous isotropic solid half-spaces in the context of various linear theories of thermoelasticity, namely, Lord-Shulman, Green-Lindsay, Green-Nagdhi, coupled thermoelasticity, and uncoupled thermoelasticity. The ratios of reflection coefficients to that of incident coefficients are obtained for P- and SV-wave incidence cases. The results for partition of the energy for various values of the angle of incidence are computed numerically and presented graphically for aluminum-epoxy composite material in case of incident P- and SV-waves from the stress-free and rigidly fixed thermally insulated boundaries. The results obtained are discussed and compared in various models of thermoelasticity.     

Segmented patching broadcasting protocol for video data

In adaptive segment-based patching scheme, the video is divided into fixed number of segments, which are transmitted over the server channels. For efficient transmission of the video segments, the server channels are classified into two types – regular and patching channels. A regular channel generally transmits fixed number of segments and a patching channel helps transmitting those segments that cannot be provided by any regular channel to the users. The number of segments transmitted by the first regular channel is decided by the number of regular channels that are allocated to the video by the video server. Other regular channels transmit pre-specified number of segments. This scheme estimates the bandwidth of the patching channels based on the requests received at the video server in terms of fixed time intervals, called time slots. The bandwidth estimation in this scheme is less accurate because for multiple requests received in a time slot more than one patching channels are used. Second, the probability distribution considered in this scheme does not satisfy the basic rule, i.e., the sum of all probabilities is not 1. In this paper, we address these issues and propose a new protocol named as Segmented Patching Broadcasting Protocol for Video Data. The average server bandwidth allocated to the patching channels is much less as compared to the adaptive segment-based patching scheme because only one patching channel is sufficient for any number of requests received in a time slot.     

Water Management for a Megacity: National Capital Territory of Delhi

Urban and regional demand for freshwater in National Capital Territory of Delhi has grown significantly over the last few decades. The National Capital Territory, Delhi is one of the most rapidly growing urban centers of the world, with a population of about 15 million people, a high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, the government is focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of Rupees. Environmental, economic and social policies associated with water management are largely inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socio-economic conditions of a population living in one of the largest urban agglomerations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far. The aim of this paper is to provide an overview of the urban water use with a view to enhance the understanding of the factors influencing urban water demand for residential, commercial and industrial sectors in National Capital Territory of Delhi. The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices to become sustainable. Other measures such as public education and information/awareness will be necessary to achieve desired rationalization in water consumption, especially in the residential and commercial sectors.