An Invariant Dual-beam Snowflake Antenna for Future 5G Communications

A broadband snowflake antenna for future 5G and millimeter-wave communications is presented. The proposed antenna has a size of 8 × 5 mm 2 . The antenna consists of a central hexagon surrounded by a series of symmetrically placed smaller hexagons around it, resulting in broadband characteristics. The impedance bandwidth of the proposed antenna ranges from 25.284-29.252 GHz. The antenna has a gain of 3.12 dBi at 28 GHz and is more than 98% efficient. A distinct feature of the proposed antenna is its dual-beam radiation pattern. The two beams remain fixed at ±50° even if the frequency is varied with in its operating band. The proposed antenna is modelled on thin Rogers substrate which makes it very useful for future 5G smart phones

Compact Polarization Diversity Antenna for 28/38 GHz Bands

In this paper, design and analysis of a millimeter wave dual- and dual-polarized antenna for 5G millimeter communications system is presented. The proposed design has a compact structure with size of 5 × 5 mm 2 . It consists of a rectangular patch with a crossed-slot etched off in the patch to reduce the interference between the two targeted 5G bands of 28 and 38 GHz. To achieve dual polarization performance, the radiating patch is fed by two different 50-Ω microstrip transmission lines. The antenna has -10dB impedance bandwidths of 2.6GHz (26.8-29.4 GHz) and 2.5GHz (37.7-40.2GHz) to cover 28/38 GHz mobile communication bands respectively. The antenna has the merits of miniaturized dimensions, stable broadside radiation patterns with high gains and low cross polarization in both bands of operation

Geographical area network-structural health monitoring utility computing model

In view of intensified disasters and fatalities caused by natural phenomena and geographical expansion, there is a pressing need for a more effective environment logging for a better management and urban planning. This paper proposes a novel utility computing model (UCM) for structural health monitoring (SHM) that would enable dynamic planning of monitoring systems in an efficient and cost-effective manner in form of a SHM geo-informatics system. The proposed UCM consists of networked SHM systems that send geometrical SHM variables to SHM-UCM gateways. Every gateway is routing the data to SHM-UCM servers running a geo-spatial patch health assessment and prediction algorithm. The inputs of the prediction algorithm are geometrical variables, environmental variables, and payloads. The proposed SHM-UCM is unique in terms of its capability to manage heterogeneous SHM resources. This has been tested in a case study on Qatar University (QU) in Doha Qatar, where it looked at where SHM nodes are distributed along with occupancy density in each building. This information was taken from QU routers and zone calculation models and were then compared to ideal SHM system data. Results show the effectiveness of the proposed model in logging and dynamically planning SHM.This publication was made possible by NPRP grant # 8-1781-2-725 from the Qatar National Research Fund (a member of Qatar Foundation). The publication of this article was funded by the Qatar National Library

MoO3 altered ZnO: A suitable choice for the photocatalytic removal of chloro-acetic acids in natural sunlight exposure

The MoO3 coated ZnO photocatalysts were synthesized for the optimum harvesting of the absorbed ultraviolet sunlight photons by initially permeating Mo6+ ions at the surface of pre-synthesized ZnO and finally transformed to MoO3 by thermal treatment in the air. The absorption spectra of the synthesized powders revealed the extension of the absorption edge in the visible region whereas, the photoluminescence spectroscopy established the supporting role of the MoO3 coating in gradually plummeting the excitons recombination. The growth of additional peaks in Raman as well as X-ray photoelectron spectra and the appearance of the corresponding low-intensity reflection substantiated the surface prevalence of MoO3. The absence of the individual particles of MoO3 in FESEM and the verification of coated layer by HRTEM images validated the authenticity of the adopted synthetic route. The electrochemical evaluation of the synthesized powders under illumination revealed the complete elimination of photocorrosion and the synergic role of the MoO3 layer for improved trap and transfer of charge carriers. The evaluation of the flat-band potentials of the coated powders by Mott-Schottky analysis revealed the suitability of the conduction band edges for the generation of superoxide anion radicals. The photocatalytic activity of the synthesized powders was assessed for the removal of chloro derivatives (mono-, di-, trichloroacetic acids) in comparison to pure acetic acid. A significant effect of the stability, polarity and stereochemical structure of the substrate on the photocatalytic removal process was observed and discussed. The experimental evidences from the time-scale chemical analysis were interpreted for the identification of the reactive oxygen species (ROS) involved in the degradation/mineralization process. The validation of the Langmuir-Hinshelwood kinetic model was also examined. Efforts were made to estimate the plausible route of the degradation/mineralization process

The evaluation of the photocatalytic activity of magnetic and non-magnetic polymorphs of Fe2O3 in natural sunlight exposure: a comparison of photocatalytic activity

The non-magnetic and magnetic polymorphs of iron oxide (Fe2O3) namely: alpha-Fe2O3 (hematite) and gamma-Fe2O3 (maghemite) respectively, were synthesized by a facile surfactant aided hydrogel route. The synthesized polymorphs were characterized by diffuse reflectance, photoluminescence and raman spectroscopy for optical properties whereas the morphological, structural, chemical and electronic state evaluation were performed by FESEM, HRTEM, XRD, and XPS. The charge transport and the stability of the materials were examined electrochemically. The photocatalytic activity of the synthesized polymorphs was evaluated for the degradation of 2-chlorophenol and 2-nitrophenol in the exposure of the visible region and complete spectrum natural sunlight. Both the polymorphs exhibited a significantly high activity for the degradation of the phenolic substrate in the exposure of the complete spectrum of sunlight, however, the activity in the visible region of the sunlight was relatively lower. A substantial increase in the activity in the visible region was noticed when the polymorphs were exposed to complete spectrum sunlight prior to the photocatalytic experiments. The comparison of the exposed and unexposed samples revealed the induction of defects that served as traps for the excited electrons and increased activity of the polymorphs. (C) 2018 Elsevier B.V. All rights reserved

Transition metal doped CeO2 for photocatalytic removal of 2-chlorophenol in the exposure of indoor white light and antifungal activity

Besides natural sunlight and expensive artificial lights, economical indoor white light can play a significant role in activating a catalyst for photocatalytic removal of organic toxins from contaminated water. In the current effort, CeO2 has been modified with Ni, Cu, and Fe through doping methodology to study the removal of 2-chlorophenol (2-CP) in the illumination of 70 W indoor LED white light. The absence of additional diffractions due to the dopants and few changes such as reduction in peaks’ height, minor peak shift at 2θ (28.525°) and peaks’ broadening in XRD patterns of modified CeO2 verifies the successful doping of CeO2. The solid-state absorption spectra revealed higher absorbance of Cu-doped CeO2 whereas a lower absorption response was observed for Ni-doped CeO2. An interesting observation regarding the lowering of indirect bandgap energy of Fe-doped CeO2 (∼2.7 eV) and an increase in Ni-doped CeO2 (∼3.0 eV) in comparison to pristine CeO2 (∼2.9 eV) was noticed. The process of e-– h+ recombination in the synthesized photocatalysts was also investigated through photoluminescence spectroscopy. The photocatalytic studies revealed the greater photocatalytic activity of Fe-doped CeO2 with a higher rate (∼3.9 × 10−3 min-1) among all other materials. Moreover, kinetic studies also revealed the validation of the Langmuir-Hinshelwood kinetic model (R2 = 0.9839) while removing 2-CP in the exposure of indoor light with a Fe-doped CeO2 photocatalyst. The XPS analysis revealed the existence of Fe3+, Cu2+ and Ni2+ core levels in doped CeO2. Using the agar well-diffusion method, the antifungal activity was assessed against the fungus M. fructicola and F. oxysporum. Compared to CeO2, Ni-doped CeO2, and Cu-doped CeO2 nanoparticles, the Fe-doped CeO2 nanoparticles have outstanding antifungal properties

Study protocol of DIVERGE, the first genetic epidemiological study of major depressive disorder in Pakistan

INTRODUCTION: Globally, 80% of the burdenof major depressive disorder (MDD) pertains to low- and middle-income countries. Research into genetic and environmental risk factors has the potential to uncover disease mechanisms that may contribute to better diagnosis and treatment of mental illness, yet has so far been largely limited to participants with European ancestry from high-income countries. The DIVERGE study was established to help overcome this gap and investigate genetic and environmental risk factors for MDD in Pakistan. METHODS: DIVERGE aims to enrol 9000 cases and 4000 controls in hospitals across the country. Here, we provide the rationale for DIVERGE, describe the study protocol and characterise the sample using data from the first 500cases. Exploratory data analysis is performed to describe demographics, socioeconomic status, environmental risk factors, family history of mental illness and psychopathology. RESULTS AND DISCUSSION: Many participants had severe depression with 74% of patients who experienced multiple depressive episodes. It was a common practice to seek help for mental health struggles from faith healers and religious leaders. Socioeconomic variables reflected the local context with a large proportion of women not having access to any education and the majority of participants reporting no savings. CONCLUSION: DIVERGE is a carefully designed case-control study of MDD in Pakistan that captures diverse risk factors. As the largest genetic study in Pakistan, DIVERGE helps address the severe underrepresentation of people from South Asian countries in genetic as well as psychiatric research