Conducting polymers inducing catalysis: Enhanced formic acid electro-oxidation at a Pt/polyaniline nanocatalyst

Research is moving rapidly to sustain convenient energy resources fulfilling the global climate legislations. Herein, a novel catalyst of platinum nanoparticles (PtNPs) dispersed onto polyaniline (PANi) is recommended for formic acid electro-oxidation (FAO); the fundamental anodic reaction in direct formic acid fuel cells (DFAFCs). The catalyst's preparation scheme allows a sequential electrodeposition of fibril PANi and spherical PtNPs (ca. 65 nm in size) on a glassy carbon (GC) substrate and permits a precise control over the deposition sequence and loading. Interestingly, incorporation of PANi into the catalyst's ingredients can significantly (ca. 16 times) improve the catalytic activity of the catalyst towards FAO by shifting the mechanism towards the desirable dehydrogenation pathway and mitigating the undesirable poisoning dehydration pathway. The catalytic efficiency is tuned by manipulating the deposition order and loading of different catalyst's ingredients. Several techniques are employed to confirm the successful deposition of the catalyst and to evaluate its morphology, composition and crystal structure. While PtNPs are essential for FA adsorption, PANi improves the dispersion of PtNPs and mediates FAO to facilitate the charge transfer and mitigate CO poisoning. A promising catalytic stability is achieved in a long continuous (150 CVs) electrolysis experiment.     

Backstepping-based cooperative and adaptive tracking control design for a group of underactuated AUVs in horizontal plan

In this paper, we investigate new implementable cooperative adaptive backstepping controllers for a group of underactuated autonomous vehicles that are communicating with their local neighbours to track a time-varying virtual leader of which the relative position may only be available to a portion of the team members. At the kinematic cooperative control level of the autonomous underwater vehicle, the virtual cooperative controller is basically designed on a proportional and derivative consensus algorithm presented in Ren (2010) Ren, W. (2010). Consensus tracking under directed interaction topologies: Algorithms and experiments. IEEE Transactions on Control Systems Technology, 18, 230–237.[Crossref], [Web of Science ®] , [Google Scholar], which involves velocity information from local neighbours. In this paper, we propose a new design algorithm based on singular perturbation theory that precludes the use of the neighbours’ velocity information in the cooperative design. At the dynamic cooperative control level, calculation of the partial derivatives of some stabilising functions which in turn will contain velocity information from the local neighbours is required. To facilitate the implementation of the cooperative controllers, we propose a command filter approach technique to avoid analytic differentiation of the virtual cooperative control laws. We show how Lyapunov-based techniques and graph theory can be combined together to yield a robust cooperative controller where the uncertain dynamics of the cooperating vehicles and the constraints on the communication topology which contains a directed spanning tree are explicitly taken into account. Simulation results with a dynamic model of underactuated autonomous underwater vehicles moving on the horizontal plane are presented and discussed.     

Peripheral mRNA Expression and Prognostic Significance of Emotional Stress Biomarkers in Metastatic Breast Cancer Patients

Emotional stress is believed to be associated with increased tumor progression. Stress-induced epigenetic modifications can contribute to the severity of disease and poor prognosis in cancer patients. The current study aimed to investigate the expression profiles along with the prognostic significance of psychological stress-related genes in metastatic breast cancer patients, to rationalize the molecular link between emotional stress and cancer progression. We profiled the expression of selected stress-associated genes (5-HTT, NR3C1, OXTR, and FKBP5) in breast cancer including the stress evaluation of all participants using the Questionnaire on Distress in Cancer Patients–short form (QSC-R10). A survival database, the Kaplan–Meier Plotter, was used to explore the prognostic significance of these genes in breast cancer. Our results showed relatively low expressions of 5-HTT (p = 0.02) and OXTR (p = 0.0387) in metastatic breast cancer patients as compared to the non-metastatic group of patients. The expression of NR3C1 was low in tumor grade III as compared to grade II (p = 0.04). Additionally, the expression of NR3C1 was significantly higher in patients with positive estrogen receptor status. However, no significant difference was found regarding FKBP5 expression in breast cancer. The results suggest a potential implication of these genes in breast cancer pathology and prognosis.     

Estimation of fog utility pricing: a bio-inspired optimisation techniques' perspective

ABSTRACT

Due to the limited data storage capacity available to Internet service providers and large-scale enterprises, the concept of resource sharing arises. The services can be given on lease to enterprises through Service Level Agreements. Being the extension of the cloud computing, fog computing architecture brings the resources near end users. In order to get the services on lease, the enterprises are supposed to pay for the resources or services which are being used by them. In this paper, four nature inspired algorithms are analysed in order to determine the efficient management of services or resources so that the cost of resources can be reduced and the billing can be attained through calculation of the utilised resources. Pigeon inspired optimization, enhanced differential evolution, binary bat algorithm and simple human learning optimization are used to evaluate the energy consumed by the edge nodes or cloudlets that in turn can be used for estimating the bill through the Time of Use pricing variable. We evaluate the aforementioned techniques to analyse their performance regarding the bill calculation on the basis of fog servers usage. Simulation results demonstrate that BAT algorithm gives significantly better results than other three algorithms in terms of resource utilisation and bill reduction.     

Theoretical Investigations of Magnetic Properties and Mechanical Stability of Quaternary Heusler Compounds FeYCrZ (Z = Al,Ga, Ge,and Si): a Spin Gapless Semiconductor

Journal of Superconductivity and Novel Magnetism - In this work, full potential linearized augmented plane wave (FP-LAPW) method is used to determine the electronic, magnetic, and mechanical...     

Aptitude of Graphene Oxide–Silver in Advance Polymer Nanocomposite: A Review

This is a state-of-the art overview on polymer/graphene oxide–silver nanoparticle nanocomposite. Different polymer/graphene oxide–silver nanoparticle categories have been elucidated using polyethersulfone, polyimides, polyindole, poly(vinylidene fluoride), polyaniline, polyvinyl pyrrolidone, and poly(3,4-ethylenedioxythiophene). In situ reduction of silver salt and particle decoration on graphene oxide surface were effective to develop interaction between nanoparticles. Essential features of polymer/graphene oxide–silver nanoparticle revealed several advance technical applications. Conducting polymer/graphene oxide–silver nanoparticle is promising material for sensor, supercapacitor, and electrodes. Polymer/graphene oxide–silver nanoparticle possesses relevance in cancer treatment, gene transfection, cellular probing, imaging, antibacterial action, etc. Polyimide/graphene oxide–silver nanoparticle can also effectively prevent membrane bifouling. Catalytic activity of composites was also detected toward oxygen reduction in energy devices.     

Interfacial performance and durability of textile reinforced concrete

The aim of this work is to understand the bonding characteristics between various yarn structures and cement matrix which was studied by yarn pull out test. In this work, the effect of accelerated ageing under alkaline environment for different types of fibers i.e. Basalt, Polypropylene, Polyester, and Jute is studied in order to comparatively evaluate their weight loss and reduction of tensile strength. SEM images are also used for studying the morphology of alkali degraded fibers. Material characterization can also be done by FTIR, XRD, ICP, Zeta potential, and UV spectrometer.