Cl‐Doped ZnO Nanowire Arrays on 3D Graphene Foam with Highly Efficient Field Emission and Photocatalytic Properties

An environmentally friendly, low‐cost, and large‐scale method is developed for fabrication of Cl‐doped ZnO nanowire arrays (NWAs) on 3D graphene foam (Cl‐ZnO NWAs/GF), and investigates its applications as a highly efficient field emitter and photocatalyst. The introduction of Cl‐dopant in ZnO increases free electrons in the conduction band of ZnO and also leads to the rough surface of ZnO NWAs, which greatly improves the field emission properties of the Cl‐ZnO NWAs/GF. The Cl‐ZnO NWAs/GF demonstrates a low turn‐on field (≈1.6 V μm⁻¹), a high field enhancement factor (≈12844), and excellent field emission stability. Also, the Cl‐ZnO NWAs/GF shows high photocatalytic efficiency under UV irradiation, enabling photodegradation of organic dyes such as RhB within ≈75 min, with excellent recyclability. The excellent photocatalytic performance of the Cl‐ZnO NWAs/GF originates from the highly efficient charge separation efficiency at the heterointerface of Cl‐ZnO and GF, as well as improved electron transport efficiency due to the doping of Cl. These results open up new possibilities of using Cl‐ZnO and graphene‐based hybrid nanostructures for various functional devices.     

A Novel Artificial Intelligence Based Timing Synchronization Scheme for Smart Grid Applications

The smart grid control applications necessitate real-time communication systems with time efficiency for real-time monitoring, measurement, and control. Time-efficient communication systems should have the ability to function in severe propagation conditions in smart grid applications. The data/packet communications need to be maintained by synchronized timing and reliability through equally considering the signal deterioration occurrences, which are propagation delay, phase errors and channel conditions. Phase synchronization plays a vital part in the digital smart grid to get precise and real-time control measurement information. IEEE C37.118 and IEC 61850 had implemented for the synchronization communication to measure as well as control the smart grid applications. Both IEEE C37.118 and IEC 61850 experienced a huge propagation and packet delays due to synchronization precision issues. Because of these delays and errors, measurement and monitoring of the smart grid application in real-time is not accurate. Therefore, it has been investigated that the time synchronization in real-time is a critical challenge in smart grid applications, and for this issue, other errors raised consequently. The existing communication systems are designed with the phasor measurement unit (PMU) along with communication protocol IEEE C37.118 and uses the GPS timestamps as the reference clock stamps. The absence of GPS increases the clock offsets, which surely can hamper the synchronization process and the full control measurement system that can be imprecise. Therefore, to reduce this clock offsets, a new algorithm is needed which may consider any alternative reference timestamps rather than GPS. The revolutionary Artificial Intelligence (AI) enables the industrial revolution to provide a significant performance to engineering solutions. Therefore, this article proposed the AI-based Synchronization scheme to mitigate smart grid timing issues. The backpropagation neural network is applied as the AI method that employs the timing estimations and error corrections for the precise performances. The novel AIFS scheme is considered the radio communication functionalities in order to connect the external timing server. The performance of the proposed AIFS scheme is evaluated using a MATLAB-based simulation approach. Simulation results show that the proposed scheme performs better than the existing system.

     

Metal–Ligand Based Mechanophores Enhance Both Mechanical Robustness and Electronic Performance of Polymer Semiconductors

The backbone of diketopyrrolopyrrole-thiophene-vinylene-thiophene-based polymer semiconductors (PSCs) is modified with pyridine (Py) or bipyridine ligands to complex Fe(II) metal centers, allowing the metal–ligand complexes to act as mechanophores and dynamically crosslink the polymer chains. Mono- and bi-dentate ligands are observed to exhibit different degrees of bond strengths, which subsequently affect the mechanical properties of these Wolf-type-II metallopolymers. The counter ion also plays a crucial role, as it is observed that Py-Fe mechanophores with non-coordinating BPh₄^– counter ions (Py-FeB) exhibit better thin film ductility with lower elastic modulus, as compared to the coordinating chloro ligands (Py-FeC). Interestingly, besides mechanical robustness, the electrical charge carrier mobility can also be enhanced concurrently when incorporating Py-FeB mechanophores in PSCs. This is a unique observation among stretchable PSCs, especially that most reports to date describe a decreased mobility when the stretchability is improved. Next, it is determined that improvements to both mobility and stretchability are correlated to the solid-state molecular ordering and dynamics of coordination bonds under strain, as elucidated via techniques of grazing-incidence X-ray diffraction and X-ray absorption spectroscopy techniques, respectively. This study provides a viable approach to enhance both the mechanical and the electronic performance of polymer-based soft devices.     

Enhanced ultraviolet sensitivity of zinc oxide nanoparticle photoconductors by surface passivation

Zinc oxide nanoparticles were created by a top-down wet-chemical etching process and then coated with polyvinyl-alcohol (PVA), exhibiting sizes ranging from 10 to 120 nm with an average size approximately 80 nm. The PVA layer provides surface passivation of zinc oxide nanoparticles. As a result of PVA coating, enhancement in ultraviolet emission and suppression of parasitic green emission is observed. Photoconductors fabricated using the PVA coated zinc oxide nanoparticles exhibited a ratio of ultraviolet photo-generated current to dark current as high as 4.5 × 10⁴, 5 times better than that of the devices fabricated using uncoated ZnO nanoparticles.     

The time of our lives: Life span development of timing and event tracking.

Life span developmental profiles were constructed for 305 participants (ages 4-95) for a battery of paced and unpaced perceptual-motor timing tasks that included synchronize-continue tapping at a wide range of target event rates. Two life span hypotheses, derived from an entrainment theory of timing and event tracking, were tested. A preferred period hypothesis predicted a monotonic slowing of a preferred rate (tempo) of event tracking across the life span. An entrainment region hypothesis predicted a quadratic profile in the range of event rates that produced effective timing across the life span; specifically, age-specific entrainment regions should be narrower in childhood and late adulthood than in midlife. Findings across tasks provide converging support for both hypotheses. Implications of these findings are discussed for understanding critical periods in development and age-related slowing of event timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design and Evaluation of a Multihoming-Based Mobility Management Scheme to Support Inter Technology Handoff in PNEMO

Wireless Personal Communications - Handoff management is an indispensable component in supporting network mobility. The handoff situation raises while the Mobile Router (MR) or Mobile Node (MN)...     

Effect of pseudomonas lipase enzyme on the degradation of polycaprolactone/polycaprolactone-polyglycolide fiber blended nanocomposites

This study describes the interaction resulting from adding pseudomonas lipase (PS) enzyme to polycaprolactone-based composites designed for orthopedic applications. The biopolymer composite evaluated in this study consists of electrospun polycaprolactone (PCL)/polyglycolide (PGA) blended fibers impregnated with double stranded deoxyribonucleic acid wrapped single-walled carbon nanotubes encapsulated by a PCL matrix. PS enzyme was used to catalyze the degradation of PCL-based biocomposites. PCL present in the biocomposites showed considerable degradation in 4 weeks in the presence of the enzyme, exhibiting a contrast to hydrolytic degradation which lasts several years. PGA-consisting fibers degraded completely within one week of exposure to the enzyme.     

A Novel HGBBDSA-CTI Approach for Subcarrier Allocation in Heterogeneous Network

Telecommunication Systems - In recent times, Heterogeneous Network (HetNet) achieves the capacity and coverage for indoors through the deployment of small cells i.e. femtocells (HeNodeBs). These...     

Influence of polycaprolactone/polyglycolide blended electrospun fibers on the morphology and mechanical properties of polycaprolactone

Polycaprolactone (PCL) and polyglycolide (PGA) are two biopolymers that have been used as in situ biomedical devices for various applications. The obstacle of creating a composite that captures the benefit of PCL's long degradation time, while acquiring the strength from PGA is overcoming the lack of surface adhesion between the two biopolymers for stress transfer to occur. This study investigates the use of miscible PCL‐PGA blended fibers, created by electrospinning, to increase the interfacial bonding of fibers to the PCL matrix of the polymer–polymer composite. The use of the blended fibers will thereby create the ability of load transfer from the long‐term PCL matrix to the stronger PCL‐PGA fiber reinforcement. The incorporation of the PCL‐PGA fibers was able to increase the tensile yield strength and Young's modulus over that of the bulk PCL, while decreasing the percent elongation at break. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40224.