Potential of PTH-Fe3O4 Based Nanomaterial for the Removal of Pb (II), Cd (II), and Cr (VI) Ions

Journal of Inorganic and Organometallic Polymers and Materials - In this work, polythiophene and Fe3O4 nanoparticles (PTh-Fe3O4) based hybrid nanomaterial was utilized for the adsorption based...     

Mesoporous bragg stack color tunable sensors

Herein we report a novel self-assembly synthesis, structural and optical characterization of mesoporous Bragg stacks (MBS) composed of spin-coated multilayer stacks of mesoporous TiO(2) and mesoporous SiO(2). Investigation of the optical response of MBS to the infiltration of alcohols and alkanes into its pores reveals better sensitivity and selectivity than conventional Bragg reflectors. Furthermore, we demonstrate that the chemical sensing ability can be tuned via layer thickness, composition and surface properties.     

A study on the performance and emission of a diesel engine fueled with Jatropha biodiesel oil and its blends

Biodiesel either in neat form or as a mixture with diesel fuel is widely investigated to solve the twin problem of depletion of fossil fuels and environmental degradation. The main objective of the present study is to compare performance, emission and combustion characteristics of biodiesel derived from non edible Jatropha oil in a dual fuel diesel engine with base line results of diesel fuel. The performance parameters evaluated were: brake thermal efficiency, brake specific fuel consumption, power output. As a part of combustion study, in-cylinder pressure, rate of pressure rise and heat release rates were evaluated. The emission parameters such as carbon monoxide, carbon dioxide, un-burnt hydrocarbon, oxides of nitrogen and smoke opacity with the different fuels were also measured and compared with base line results. The different properties of Jatropha oil after transestrification were within acceptable limits of standards as set by many countries. The brake thermal efficiency of Jatropha methyl ester and its blends with diesel were lower than diesel and brake specific energy consumption was found to be higher. However, HC, CO and CO₂ and smoke were found to be lower with Jatropha biodiesel fuel. NO_x emissions on Jatropha biodiesel and its blend were higher than Diesel. The results from the experiments suggest that biodiesel derived from non edible oil like Jatropha could be a good substitute to diesel fuel in diesel engine in the near future as far as decentralized energy production is concerned. In view of comparable engine performance and reduction in most of the engine emissions, it can be concluded and biodiesel derived from Jatropha and its blends could be used in a conventional diesel engine without any modification.     

Low-energy Formulations of Support Vector Machine Kernel Functions for Biomedical Sensor Applications

Although physiologically-indicative signals can be acquired in low-power biomedical sensors, their accurate analysis imposes several challenges. Data-driven techniques, based on supervised machine-learning methods provide powerful capabilities for potentially overcoming these, but the computational energy is typically too severe for low-power devices. We present a formulation for the kernel function of a support-vector machine classifier that can substantially reduce the real-time computations involved. The formulation applies to kernel functions employing polynomial transformations. Using two representative biomedical applications (EEG-based seizure detection and ECG-based arrhythmia detection) employing clinical patient data, we show that the polynomial transformation yields accuracy performance comparable to the most powerful available transformation (i.e., the radial-basis function), and the proposed formulation reduces the energy by over 2500× in the arrhythmia detector and 9.3-198× in the seizure detector (depending on the patient).     

Shape memory polymer based self-healing syntactic foam: 3-D confined thermomechanical characterization

In this study, the thermomechanical behavior of a shape memory polymer (SMP) based syntactic foam under three-dimensional (3-D) confinement was investigated through strain-controlled programming and fully confined shape recovery tests. The 3-D confinement was created by encasing the foam in circular confining tubes and subjecting the foam cylinder to uniaxial compression. The parameters investigated included two programming temperatures, three types of confining tubes with varying lateral confinements, three prestrain levels, and one fully-confined recovery condition. A three-layer plane-stress analytical model was also developed to estimate the volume change of the specimen by prestressing. It is found that the stress recovery ratio is the highest with rubber liner and the recovered stress is the highest with nylon liner. The stress recovered in the foam specimen which is confined by the nylon liner is as high as 26 MPa, making it possible as actuators. While volume reduction during programming is the key for the foam to self-close cracks, the volume reduction must be within a certain limit; otherwise, the foam loses its shape memory functionality.     

Microfluidic devices harboring unsealed reactors for real-time isothermal helicase-dependent amplification

High-throughput microchip devices used for nucleic-acid amplification require sealed reactors. This is to prevent evaporative loss of the amplification mixture and cross-contamination, which may occur among fluidically connected reactors. In most high-throughput nucleic-acid amplification devices, reactor sealing is achieved by microvalves. Additionally, these devices require micropumps to distribute amplification mixture into an array of reactors, thereby increasing the device cost, and adding complexity to the chip fabrication and operation processes. To overcome these limitations, we report microfluidic devices harboring open (unsealed) reactors in conjunction with a single-step capillary based flow scheme for sequential distribution of amplification mixture into an array of reactors. Concern about evaporative loss in unsealed reactors have been addressed by optimized reactor design, smooth internal reactor surfaces, and incorporation of a localized heating scheme for the reactors, in which isothermal, real-time helicase-dependent amplification (HDA) was performed.     

Design,implementation, and evaluation of a Programmable Bandwidth Aggregation System for home networks

Bandwidth aggregation is a promising technology that can speed up access to the Internet by bandwidth sharing and multi-path communication. Current Bandwidth Aggregation Systems (BASs) deployed in public networks provide limited performance and flexibility when they are directly used in home networking environments. To reap the full performance benefits of BASs in home networks, they need to be easily and dynamically programmable by home network users. We present the design and implementation of a Programmable Bandwidth Aggregation System (PBAS) that can provide home network users improved performance when sharing bandwidth for activities that access the Internet. We also present an empirical performance evaluation of the system and we demonstrate the superior efficiency of our proposed PBAS over a traditional BAS in terms of computational overheads, loadable code, throughput performance, and programmability.     

Dry sliding wear behaviour of AA 6351-ZrB2 in situ composite at room temperature

In the present work, AA 6351-xZrB₂ [x = 0, 3, 6 and 9 weight percentage (wt.%)] in situ composites have been prepared by the reaction of mixture of K₂ZrF₆ and KBF₄ with molten aluminium alloy at a reaction temperature of 850 °C. The in situ prepared composites were characterized by using scanning electron microscope (SEM), X-ray diffractometer (XRD), and microhardness analysis. The sliding wear properties of the prepared composite at room temperature were estimated by a pin-on-disc wear testing equipment using the composite material; the pins were machined according to standard sizes, and the tests were conducted as per the standards recommended by the ASTM G99-95a designation of different weighing percentage at room temperature. The wear characteristics of the composite in the as-cast, the solutionized and the solutionized-aged conditions were studied by conducting sliding wear test at the load of 9.81 N. The results indicated that the wear rate was decreased with an increase in the weight percentage of ZrB₂ and the wear resistance was increased with an increase in the fraction of ZrB₂ particulates in composite before and after heat treatment.     

Effect of Gd3+ substitution on physicochemical properties of superparamagnetic Fe3O4 nanoparticles

Journal of Materials Science: Materials in Electronics - The present study depicts physicochemical characteristics of Gd3+ modified Fe3O4 nanoparticles synthesized via the sol-gel combustion...