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Alzheimer's disease (AD) is one of the prominent causes for disability and lowered quality of life worldwide in elderly population. It has fostered immense burden to AD patients, families and society. Burgeoning progress in the field of pathogenesis over last two decades has persuaded the investigation of novel pharmacological therapeutics that focuses towards the pathophysiological events of AD. Miscellaneous clinical trials, development and testing of interventions aimed at various targets, such as anti‐tau and anti‐amyloid interventions, neurotransmitter modification, neuroprotection and anti‐neuroinflammation interventions, cognitive enhancement and interventions to palliate behavioural symptoms have been carried out. Despite massive efforts to find disease‐modifying therapies, there lingers a vital need for continuing the advancement in progress of the AD research. This review features the new developments of small molecule compounds that will be beneficial in evolution of new AD therapies. In particular, this review briefly describes summary of mechanistic causes chiefly associated with AD and focuses on medicinal approach via small molecule inhibitors that can manage cognitive impairment and dysfunction and may combat Alzheimer's development. [ABSTRACT FROM AUTHOR]

Among several known zeolites, silicoaluminophosphate (SAPO)‐34 zeolite exhibits a distinct chemical structure, unique pore size distribution, and chemical, thermal, and ion exchange capabilities, which have recently attracted considerable research attention. Global carbon dioxide (CO2) emissions are a serious environmental issue. Current atmospheric CO2 level exceeds 414 parts per million (ppm), which greatly influences humans, fauna, flora, and the ecosystem as a whole. Zeolites play a vital role in CO2 removal, recycling, and utilization. This review summarizes the properties of the SAPO‐34 zeolite and its role in CO2 capture and separation from air and natural gas. In addition, due to their high thermal stability and catalytic nature, CO2 conversions into valuable products over single metal, bi‐metallic, and tri‐metallic catalysts and their oxides supported on SAPO‐34 were also summarized. Considering these accomplishments, substantial problems related to SAPO‐34 are discussed, and future recommendations are offered in detail to predict how SAPO‐34 could be employed for greenhouse gas mitigation. [ABSTRACT FROM AUTHOR]

CO2 emission from anthropogenic sources has raised worldwide environmental concerns and hence proficient energy paradigm has tilted towards CO2 capture. Membrane technology is one of the efficient technologies for CO2 separation since it is environmentally friendly, inexpensive, and offers high surface areas. Various approaches are discussed to improve membrane performance focusing mainly on permeability and selectivity parameters. Different types of fillers are incorporated to reach the Robeson's upper bound curve. In this review, polymer‐inorganic nanocomposite membranes for the separation of CO2, CH4, and N2 from various gas mixtures are comprehensively discussed. Metal organic frameworks (MOFs) and ionic liquid (ILs) mixed‐matrix membranes are also considered. Membrane technology is considered as an efficient, environmentally friendly, and inexpensive technology for CO2 separation. Various approaches to improve membrane performance are reviewed with the focus on permeability and selectivity parameters. Polymer‐inorganic nanocomposite membranes, metal organic frameworks, and ionic liquid mixed‐matrix membranes are also discussed and evaluated. [ABSTRACT FROM AUTHOR]

Summary: Visible light communication (VLC) is the branch of optical wireless communications that uses light‐emitting diodes for the dual purpose of illumination and very‐high‐speed data communication. The main motivation behind the current work is finding alternatives to the saturated radio frequency spectrum, radio frequency security issue, and vulnerability to interferences. The current work is aimed at developing a module for the physical layer of a VLC‐based ad hoc network in network simulation 3. The VLC physical layer module is developed by using the optical signal modules available in the network simulator. The work also includes modelling of VLC‐based transmitter, wireless optical channel, and the optical receiver. Furthermore, the implementation and evaluation of the VLC‐based physical layer is carried out over a typical ad hoc network under different performance metrics. The designed ad hoc network is also tested under Wi‐Fi module followed by its comparison with corresponding ad hoc network under VLC module. The comparison is based on bit error rate curves, system throughput, and gain in received signal‐to‐noise ratio mainly. Finally, the suitability of different modulation schemes is also investigated in the current work for both Wi‐Fi– and VLC‐based ad hoc networks. [ABSTRACT FROM AUTHOR]

Abstract: This letter presents the design and analysis of a smart and low profile Ultra‐Wideband Slotted Planar Inverted Cone Antenna. The proposed slotted PICA has low profile (0.4 λ mm2 × 0.4 λ mm2) as compared to other existing designs and its operational bandwidth is from 3 GHz to 18 GHz. The simulated and measured results concur with acceptable return loss of better than 10 dB throughout the operational bandwidth. The radiation pattern of the antenna is omnidirectional and it has maximum Gain of 3.2 dB when placed close to human body, making it compatible for WBAN applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Mixed matrix membranes (MMMs) containing fluorinated-sulfonated poly(ether ether ketone) (F-SPEEK) and zeolite 4A filler, were prepared by solution casting. F-SPEEK with a fixed degree of sulfonation (40%) was used for membrane synthesis. The SEM pictures showed good interfacial adhesion between filler particles and polymer, which was also confirmed by the increase in glass transition temperature of MMMs with increase in filler particles. Pure and mixed gas permeation experiments were carried out to investigate the potential of this membrane material. The results revealed that addition of zeolite 4A fillers enhanced both permeability and selectivity owing to the intrinsic nature of polymer and modified membrane morphology due to filler. The highest permeability obtained for CO2 at 30% filler loading was 49.2 Barrer, while highest selectivities obtained for CO2/CH4 and CO2/N2 were 55 and 58 compared to 47 and 51 for the unfilled polymer, respectively. Intrinsic CO2 solubility of F-SPEEK was observed to be decreased from 10.7 to 1.9 (10−2) cm3 (STP)/cm3 cmHg with the addition of Zeolite 4A. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45952. [ABSTRACT FROM AUTHOR]

ABSTRACT This study is focused on the development of ionic liquids (ILs) based polymeric membranes for the separation of carbon dioxide (CO2) from methane (CH4). The advantage of ILs in selective CO2 absorption is that it enhances the CO2 selective separation for the ionic liquid membranes (ILMs). ILMs are developed and characterized with two different ILs using the solution-casting method. Three different blend compositions of ILs and polysulfone (PSF) are selected for each ILMs 10, 20, and 30 wt %. Effect of the different types of ILs such as triethanolamine formate (TEAF) and triethanolamine acetate (TEAA) are investigated on PSF-based ILMs. Field emission scanning electron microscopy analysis of the membranes showed reasonable homogeneity between the ILs and PSF. Thermogravimetric analysis showed that by increasing the ILs loading thermal stability of the membranes improved. Mechanical analysis on developed membranes showed that ILs phase reduced the amount of plastic flow of the PSF phase and therefore, fracture takes place at gradually lower strains with increasing ILs content. Gas permeation evaluation was carried out on the developed membranes for CO2/CH4 separation between 2 bar to 10 bar feed pressure. Results showed that CO2 permeance increases with the addition of ILs 10-30 wt % in ILMs. With 20-30 wt % TEAF-ILMs and TEAA-ILMs, the highest selectivity of a CO2/CH4 53.96 ± 0.3, 37.64 ± 0.2 and CO2 permeance 69.5 ± 0.6, 55.21 ± 0.3 is observed for treated membrane at 2-10 bar. The selectivity using mixed gas test at various CO2/CH4 compositions shows consistent results with the ideal gas selectivity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45395. [ABSTRACT FROM AUTHOR]

This study concerns wide angular sector (higher order) null synthesis in planar irregular sparse antenna arrays when aperture distributed sub-arrays are used to reduce the computational load. A hybrid optimisation tool has been used to find array element excitations to achieve as low as possible sector nulls for the desired sector width. Performance comparisons have been made for three sub-array configurations based on the obtained numerical results. Various interference jamming scenarios have been considered including single and dual sectors for single-dimensional (θ) (1D) and two-dimensional (θ, ϕ) (2D) nulls. The proposed optimisation scheme has shown to be successful for the synthesis of 1D and 2D sector nulls with depths as low as -100 dB for the given configuration with reduced computational time when compared with the full array. The comparison of achieved null depths for different sub-array sizes and convergence time has also been presented and discussed. [ABSTRACT FROM AUTHOR]

Various gas permeation models including Maxwell model, Bruggeman model, Lewis-Nielson model and Pal model were compared via a modelling approach with the relative permeance of CO2 against published experimental data on silica filled polysulfone/polyimide (PSF/PI) mixed matrix membranes (MMMs). However, none of the tested models were able to predict the data with good accurately. A closer look at the cross-sectional image by scanning electron microscopy (SEM) indicated that the fillers were actually prolate ellipsoids dispersed within the matrix. Maxwell-Wagner-Sillar model was then employed to investigate the prolate effect and it was observed that the optimization curves of maximum packing ( φm) and shape factor (n) showed least deviations. The percentage average absolute relative error (AARE %) value for fitted shape factor (nf) was found to be in the range of 1.12-2.17 at 2-10 bar pressure which showed its robustness. A further evaluation from SEM image showed that the shape factor along z-direction (nz) displayed a minimum deviation of 17.52 % for prolates at 0.102 ± 0.01. By using nz as upper limit and estimated shape factor ne through generalization, the error was reduced to 6.01 %. The AAR % deviation was found in the order of nf e < nz,which indicated the importance of shape factor parameter for estimating true CO2 permeance. [ABSTRACT FROM AUTHOR]

ABSTRACT Reduced size dual band patch antenna is designed on pulp fibers-based substrate, obtained from a self-growing plant, Typha angustifolia. The proposed design is low cost and has <10 dB return loss at 2.4 and 5.7 GHz, with 6.9 dBi antenna gain and also has potential for conformal designs. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2146-2148, 2016 [ABSTRACT FROM AUTHOR]

Sparse antenna arrays with irregularly spaced elements are increasingly being used in large array applications such as radio astronomy and radar. These antenna arrays may consist of hundreds of elements and therefore optimisation of these arrays becomes computationally expensive. This study proposes a novel solution to the problem of null synthesis in such arrays, where nulls are formed in prescribed locations for two-dimensional irregular sparse antenna arrays. The technique is based on a subarray and hybrid synthesis solution, where each subarray spans the entire antenna aperture. Single and multiple null formations with array gain maximisation are considered. The technique's effectiveness is demonstrated using evolutionary optimisation algorithms; however, the basic technique can be used with other optimisation methods. The simulation results presented compare the null synthesis performance with and without subarraying and it has shown that the use of subarray results in improved convergence compared with a direct full array synthesis. Furthermore the technique is appropriate for ready application to parallel computer architectures. [ABSTRACT FROM AUTHOR]

A dual narrow band wearable antenna is proposed to operate in the range of 2.4-2.5 GHz and 5.7-5.9 GHz for WLAN and telemedicine applications. The proposed design is achieved by simple modification to the rectangular patch antenna. The antenna design is low profile and easy to integrate with the fabric. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:916-918, 2014 [ABSTRACT FROM AUTHOR]

The objective of this work is to study the effect of grain orientation on the thermal grooving by surface diffusion. Hackl et al. [1] have presented a finite element model for thermal grooving in three‐dimensions. This variational model involves surface energy, grain boundary energy, external and internal triple line energy. In this study, We use an orientation dependent surface energy. For {1 0 0} grain orientation in the normal direction, we have self‐similar groove profiles for increasing extent of anisotropy of the surface energy. For {1 1 0} and {1 1 1} orientations, there are formation of facets for critical anisotropic cases. These formations are due to so‐called missing orientations concerning the shape of an unconstrained crystal in equilibrium. The rate of grooving varies with change in the extent of surface free energy anisotropy. Flux along the triple line is also important in determining the groove root shape. Triple line energy and its mobility lead to deviate from a typical t1/4 scaling law. For all theses simulations, grain boundary energies are constant, satisfying Herring's relation. Comparisons are made for different values of mobilities for groove shape and its growth rate, using different grain orientations. [ABSTRACT FROM AUTHOR]

Summary: Quadrifilar helix antenna (QHA) has its applications in satellite communications. This paper presents the performance optimisation of input and radiation characteristics of QHA in the presence of infinite and finite metallic ground planes. For the infinite ground plane, it has been observed that input parameters such as impedance and voltage standing wave ratio (VSWR) are stable, and the antenna has broader half power beamwidth (HPBW). Smaller metallic platforms that act as finite ground planes produce better 3‐dB axial ratio beamwidth and boresight axial ratio. Deployment of QHA on smaller metallic platforms such as nanosatellites and CubeSats enhances the circularly polarised beamwidth of the antenna with improved boresight axial ratio. However, on large low earth orbit (LEO) satellites, stable input characteristics and broader HPBW have been achieved at the cost of narrow circularly polarised beamwidth and degraded boresight axial ratio. [ABSTRACT FROM AUTHOR]

Abstract: The Polycrystalline materials grain boundary structure, crystalline texture and grain surface morphology, each plays an important role in interface transport. Among the different surface evolution phenomenas, the objective of the current work is to study the kinetics of grooving by surface diffusion only. Most of the existing theoretical and computational models use two dimensional grooving with one dimensional surface evolution. Hackl, et al. [2] have presented a novel variational model of surface motion using a thermodynamic extremum principle for grooving and wetting under diffusion. This model is further extended to a three dimensional grain structure using two dimensional surface evolution [1].In this paper, the kinetics of grooving for a periodic polycrystalline aggregate is studied. An ansatz function for grain boundary energy is defined as a functional of grain orientation and boundary inclination. For such orientation dependent grain boundary energy, Herring's relation must be satisfied locally at each triple point of intersecting boundaries thus we have four equations at each node in a representative volume element(RVE). Such an overdetermined system is solved using a non‐linear optimization method with weak constraints for the grain boundary energies. The evolution of surface grooves is studied with isotropic surface energy and mobility. The effect of line mobility on surface evolution is also studied for the chosen RVE. A comparison is made between orientation dependent grain boundary energies and isotropic grain boundary energies. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]