Design of a Compressive Sensing Based Fall detection System for Elderly Using WSN

Wireless Personal Communications - Recent researches have pointed out that one third persons are aged 65 and above requires special health care. As the number of elderly person is increasing, home...     

A Flexi-PEGDA Upconversion Implant for Wireless Brain Photodynamic Therapy

Near-infrared (NIR) activatable upconversion nanoparticles (UCNPs) enable wireless-based phototherapies by converting deep-tissue-penetrating NIR to visible light. UCNPs are therefore ideal as wireless transducers for photodynamic therapy (PDT) of deep-sited tumors. However, the retention of unsequestered UCNPs in tissue with minimal options for removal limits their clinical translation. To address this shortcoming, biocompatible UCNPs implants are developed to deliver upconversion photonic properties in a flexible, optical guide design. To enhance its translatability, the UCNPs implant is constructed with an FDA-approved poly(ethylene glycol) diacrylate (PEGDA) core clad with fluorinated ethylene propylene (FEP). The emission spectrum of the UCNPs implant can be tuned to overlap with the absorption spectra of the clinically relevant photosensitizer, 5-aminolevulinic acid (5-ALA). The UCNPs implant can wirelessly transmit upconverted visible light till 8 cm in length and in a bendable manner even when implanted underneath the skin or scalp. With this system, it is demonstrated that NIR-based chronic PDT is achievable in an untethered and noninvasive manner in a mouse xenograft glioblastoma multiforme (GBM) model. It is postulated that such encapsulated UCNPs implants represent a translational shift for wireless deep-tissue phototherapy by enabling sequestration of UCNPs without compromising wireless deep-tissue light delivery.     

Design of energy-efficient precoders in MIMO cognitive two-way relay network

This paper addresses the energy efficiency (EE) maximization problem for a multi-input multi-output cognitive two-way relay network. The secondary system, comprises of a two-way amplify-and-forward (AF) relay and two transceivers, co-exists with the licensed primary user (PU). The secondary transceivers communicate through the two-way AF relay. We jointly design the precoders for the secondary transceivers and the AF relay with the aim to maximize the EE while satisfying the transmit power constraints at the secondary transceivers and the relay, quality-of-service constraints at the secondary transceivers, and interference constraints at the PU. The resulting maximization problem is a non-convex fractional programming problem with three unknown precoder matrices. This problem is first simplified and converted into a vector valued problem using singular value decomposition. Further, the tools of iterative optimization scheme and the fractional programming theory are employed to solve the simplified problem. The computational complexity and convergence behaviour of the proposed solution are analysed. Numerical results are presented to illustrate the effectiveness of the proposed design in terms of the achievable EE and the probability of feasibility.

     

A simple procedure for selection and sizing of indirect passive solar heating systems

Equivalent sol-air temperatures have been defined for four indirect gain passive solar heating concepts, namely, mass wall, water wall, Trombe wall and solarium. Steady state thermal efficiencies have also been defined as a measure of the ability of each system to deliver heat into the living space.

Design curves have been developed which relate the average instantaneous solar radiation incident on the passive element to thermal efficiency for different values of ambient temperature. These curves are useful in selection of an appropriate passive heating concept for a particular location.

It is inferred that a solarium is most effective at very low levels of incident radiation and low ambient temperature. Water walls and Trombe walls are most efficient at higher levels of incident radiation.

A simple procedure has been developed for a first approximation of sizing the selected system using these design curves and a minimum of meteorological information, namely, monthly average of daily global solar radiation, monthly average maximum and minimum ambient temperatures.     

Photophysical and charge-transporting properties of the copolymer SuperYellow

Conjugated copolymers are important materials for organic light-emitting diodes. Here, an investigation of the photophysical and charge-transporting properties of the prototypical poly(p-phenylene vinylene) based copolymer SuperYellow (SY) is reported. The study also investigated the effect of processing conditions by comparing the properties of spin-coated and solution-cast films. For both types of films, the results of time-resolved fluorescence and photoluminescence quantum yield measurements are similar. The high photoluminescence quantum yield of 60% and its independence of processing conditions shows the effectiveness of the bulky side groups in preventing concentration quenching of fluorescence. Time of flight measurements of charge mobility in both spin-coated and solution-cast films also showed similar results, with mobilities in the range 10^?6–10^?7 cm²/V s for both films. These results provide important information about a widely used copolymer and show that a good polymer light-emitting diode material can have low mobility.     

Rapid Quantification of Low-Viscosity Acetyl-Triacylglycerols Using Electrospray Ionization Mass Spectrometry

Acetyl‐triacylglycerols (acetyl‐TAG) possess an sn‐3 acetate group, which confers useful chemical and physical properties to these unusual triacylglycerols (TAG). Current methods for quantification of acetyl‐TAG are time consuming and do not provide any information on the molecular species profile. Electrospray ionization mass spectrometry (ESI–MS)‐based methods can overcome these drawbacks. However, the ESI–MS signal intensity for TAG depends on the aliphatic chain length and unsaturation index of the molecule. Therefore response factors for different molecular species need to be determined before any quantification. The effects of the chain length and the number of double‐bonds of the sn‐1/2 acyl groups on the signal intensity for the neutral loss of short chain length sn‐3 groups were quantified using a series of synthesized sn‐3 specific structured TAG. The signal intensity for the neutral loss of the sn‐3 acyl group was found to negatively correlated with the aliphatic chain length and unsaturation index of the sn‐1/2 acyl groups. The signal intensity of the neutral loss of the sn‐3 acyl group was also negatively correlated with the size of that chain. Further, the position of the group undergoing neutral loss was also important, with the signal from an sn‐2 acyl group much lower than that from one located at sn‐3. Response factors obtained from these analyses were used to develop a method for the absolute quantification of acetyl‐TAG. The increased sensitivity of this ESI–MS‐based approach allowed successful quantification of acetyl‐TAG in various biological settings, including the products of in vitro enzyme activity assays.     

The Yeast ATF1 Acetyltransferase Efficiently Acetylates Insect Pheromone Alcohols: Implications for the Biological Production of Moth Pheromones

Many moth pheromones are composed of mixtures of acetates of long‐chain (≥10 carbon) fatty alcohols. Moth pheromone precursors such as fatty acids and fatty alcohols can be produced in yeast by the heterologous expression of genes involved in insect pheromone production. Acetyltransferases that subsequently catalyze the formation of acetates by transfer of the acetate unit from acetyl‐CoA to a fatty alcohol have been postulated in pheromone biosynthesis. However, so far no fatty alcohol acetyltransferases responsible for the production of straight chain alkyl acetate pheromone components in insects have been identified. In search for a non‐insect acetyltransferase alternative, we expressed a plant‐derived diacylglycerol acetyltransferase (EaDAcT) (EC 2.3.1.20) cloned from the seed of the burning bush (Euonymus alatus) in a yeast system. EaDAcT transformed various fatty alcohol insect pheromone precursors into acetates but we also found high background acetylation activities. Only one enzyme in yeast was shown to be responsible for the majority of that background activity, the acetyltransferase ATF1 (EC 2.3.1.84). We further investigated the usefulness of ATF1 for the conversion of moth pheromone alcohols into acetates in comparison with EaDAcT. Overexpression of ATF1 revealed that it was capable of acetylating these fatty alcohols with chain lengths from 10 to 18 carbons with up to 27‐ and 10‐fold higher in vivo and in vitro efficiency, respectively, compared to EaDAcT. The ATF1 enzyme thus has the potential to serve as the missing enzyme in the reconstruction of the biosynthetic pathway of insect acetate pheromones from precursor fatty acids in yeast.     

Alginate gel particles–A review of production techniques and physical properties

The application of hydrocolloid gel particles is potentially useful in food, chemical, and pharmaceutical industries. Alginate gel particles are one of the more commonly used hydrocolloid gel particles due to them being biocompatible, nontoxic, biodegradable, cheap, and simple to produce. They are particularly valued for their application in encapsulation. Encapsulation in alginate gel particles confers protective benefits to cells, DNA, nutrients, and microbes. Slow release of flavors, minerals, and drugs can also be achieved by encapsulation in gel particles. The particle size and shape of the gel particles are crucial for specific applications. In this review, current methods of producing alginate gel particles will be discussed, taking into account their advantages, disadvantages, scalability, and impact on particle size. The physical properties of alginate gel particles will determine the effectiveness in different application conditions. This review will cover the current understanding of the alginate biopolymer, gelation mechanisms and factors affecting release properties, gel strength, and rheology of the alginate gel particle systems.     

Numerical and experimental study on the three-dimensional extrusion of square section from square billet through a polynomial shaped curved die

The geometry of die profile plays a major role in reducing the extrusion pressure and ensuring the smooth flow of material. In general, the extrusion process is mostly affected by billet geometry, die geometry, and interface frictional force at the die billet geometry. In the present investigation, an analysis using three-dimensional upper bound method using fifth-order die profile function has been carried out for extrusion of square sections from square billet. The extrusion pressure and optimum die length have been computed by multivariable optimization technique. The present die shape profile is found to be superior to many other profiles. The results obtained will help in design of optimum die profile and investigation of its performance.     

Performance analysis of two‐hop decode‐amplify‐forward relayed system in different fading conditions

Recent advances in the field of wireless communication have proven the importance of diversity in combating channel fading and improving the bit error rates (BERs). In this report, a dual‐hop decode‐amplify‐forward (DAF) transmission system over Nakagami‐m fading channel is studied. The DAF relay system is a hybrid of decode‐and‐forward and amplify‐and‐forward relay systems that shows the benefits of both decode‐and‐forward and amplify‐and‐forward relay systems and is also called hybrid relay system or hybrid DAF relay system. Signal‐to‐noise ratios and BERs for various system models with varying number of transmit and receive antennas have been discussed. The diversity is achieved in two ways: firstly, by the use of relay and secondly, by the use of multiple antennas at both the transmitter and the receiver. Dual‐hop relaying gives better trunking efficiency and with single antenna at the relay site acquisition and antenna structures are much less expensive. The variations in the performance levels when the relay is moved to different locations within the line of sight of the transmitter and the receiver have also been analyzed. BERs with respect to variations in the fading parameter ‘m’ have also been presented and discussed. Copyright © 2013 John Wiley & Sons, Ltd.