Propagation Characterization and Analysis for 5G mmWave Through Field Experiments

The 5G network has been intensively investigated to realize the ongoing early deployment stage as an effort to match the exponential growth of the number of connected users and their increasing demands for high throughput, bandwidth with Quality of Service (QoS), and low latency. Given that most of the spectrums below 6 GHz are nearly used up, it is not feasible to employ the traditional spectrum, which is currently in use. Therefore, a promising and highly feasible effort to satisfy this insufficient frequency spectrum is to acquire new frequency bands for next-generation mobile communications. Toward this end, the primary effort has been focused on utilizing the millimeter-wave (mmWave) as the most promising candidate for the frequency spectrum. However, though the mmWave frequency band can fulfill the desired bandwidth requirements, it has been demonstrated to endure several issues like scattering, atmospheric absorption, fading, and especially penetration losses compared to the existing sub-6 GHz frequency band. Then, it is fundamental to optimize the mmWave band propagation channel to facilitate the practical 5G implementation for the network operators. Therefore, this study intends to investigate the outdoor channel characteristics of 26, 28, 36, and 38 GHz frequency bands for the communication infrastructure at the building to the ground floor in both Line of Sight (LOS) and Non-Line of Sight (NLOS) environments. The experimental campaign has studied the propagation path loss models such as Floating-Intercept (FI) and Close-In (CI) for the building to ground floor environment in LOS and NLOS scenarios. The findings obtained from the field experiments clearly show that the CI propagation model delivers much better performance in comparison with the FI model, thanks to its simple setup, accuracy, and precise function.     

Risk Governance of Emerging Technologies Demonstrated in Terms of its Applicability to Nanomaterials

Nanotechnologies have reached maturity and market penetration that require nano‐specific changes in legislation and harmonization among legislation domains, such as the amendments to REACH for nanomaterials (NMs) which came into force in 2020. Thus, an assessment of the components and regulatory boundaries of NMs risk governance is timely, alongside related methods and tools, as part of the global efforts to optimise nanosafety and integrate it into product design processes, via Safe(r)‐by‐Design (SbD) concepts. This paper provides an overview of the state‐of‐the‐art regarding risk governance of NMs and lays out the theoretical basis for the development and implementation of an effective, trustworthy and transparent risk governance framework for NMs. The proposed framework enables continuous integration of the evolving state of the science, leverages best practice from contiguous disciplines and facilitates responsive re‐thinking of nanosafety governance to meet future needs. To achieve and operationalise such framework, a science‐based Risk Governance Council (RGC) for NMs is being developed. The framework will provide a toolkit for independent NMs' risk governance and integrates needs and views of stakeholders. An extension of this framework to relevant advanced materials and emerging technologies is also envisaged, in view of future foundations of risk research in Europe and globally.     

A Learning Based Brain Tumor Detection System

Brain tumor is one of the most dangerous disease that causes due to uncontrollable and abnormal cell partition. In this paper, we have used MRI brain scan in comparison with CT brain scan as it is less harmful to detect brain tumor. We considered watershed segmentation technique for brain tumor detection. The proposed methodology is divided as follows: pre-processing, computing foreground applying watershed, extract and supply features to machine learning algorithms. Consequently, this study is tested on big data set of images and we achieved acceptable accuracy from K-NN classification algorithm in detection of brain tumor.     

Electrodeposition of silver (Ag) nanoparticles on MnO<Subscript>2</Subscript> nanorods for fabrication of highly conductive and flexible paper electrodes for energy storage application

Metal oxide based electrodes are attractive for energy storage applications with limited characteristics of flexibility due to inherent rigid structure. However, incorporation of flexible insulating matrix within metal oxide composites result in poor electrically conductive and energy storage characteristics. This study presents the fabrication of flexible MnO₂ based composite electrodes prepared by incorporation of lignocelluloses (LC) fibers, directly collected from a self-growing plant, Monochoria Vaginalis. Furthermore electrodeposition of silver (Ag) nanoparticles was performed on LC/MnO₂ in potentiostatic mode to address the electrically conductive characteristics. Morphology, structural, conductive and energy storage properties of fabricated electrodes are analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), impedance analyzer and potentiostat, respectively. SEM images clearly indicate the deposition of Ag nanoparticles on MnO₂ nanorods embedded in LC fibers whereas FTIR results confirm the bonding of the functional groups. Cyclic voltammetry measurements showed efficient kinetics of LC/MnO₂ after electrodeposition of Ag nanoparticles. The effects on electrical properties associated with blending MnO₂ nanorods in lignocelluloses fibers and Ag deposition on MnO₂ in LC/MnO₂ are explored in wide frequency range between 10 Hz and 5 MHz. However, deposition of Ag nanoparticles on MnO₂ nanorods surfaces acts as a conductive path and reduces the associated resistance. Incorporated flexibility in rigid structure of MnO₂ and further improvements in conductive and energy storage characteristics will open the possibilities to be used as electrode in modern bendable energy storage devices.     

In vitro antibacterial response of ZnO-MgO nanocomposites at various compositions

ZnO-MgO nanocomposites were prepared by a co-precipitation method and afterward compared with pristine ZnO and MgO accordingly. XRD and EDX spectra were used to confirm the crystal structure and crystallite size of these materials. X-ray diffraction analysis shows that antibacterial activity of ZnO:MgO composite enhances with crystallite size reduction ~1.34 times in comparison to pristine ZnO or MgO specimens, accompanied by domination of defect generation over defect annihilation activity. Besides, average particle sizes also reduce to ~2 times at 1:3 MgO/ZnO composite in comparison to MgO. The particle size of ZnO was substantially higher due to rod-like morphology. Moreover, the minimum inhibitory concentration outcomes also show that ZnO-MgO composites are more effective against gram-negative pathogens in appropriate ratios (ZnO:MgO) of 1:3 and 3:1 with the concentration of 15,000 µg/ml. Similarly, gram-positive pathogens were In contrast, ZnO and MgO separately or in 1:1 composite ratio does not prove considerably effective on all the five microbes (required higher >25,000 µg/ml) MIC to counter gram-negative pathogens. Additionally, lower doses of 3ZnO:1MgO and 1ZnO:3MgO ~5000 µg/ml composite nanoparticles are effective on gram-positive pathogens. Similarly, 3ZnO:1MgO composition proved highly productive at a much lower concentration, that is, 12500 ≤ X ≤ 15000 to counter gram-negative pathogens. Besides, 1ZnO:3MgO is effective against gram-negativepathogens at MIC ranging from 12500 ≤ X ≤ 15000 µg/ml.     

In vitro assessment of dual-network electrospun tubes from poly(1,4 cyclohexane dimethylene isosorbide terephthalate)/PVA hydrogel for blood vessel application

The fabrication of artificial blood vessel remains an ongoing challenge for cardiovascular tissue engineering. Full biocompatibility, proper physiological, and immediate availability have emerged as central issues. To address these issues, the dual-network composite scaffolds were fabricated by coating the electrospun nanofibers-based tubes with poly(vinyl alcohol) (PVA) hydrogel, which could increase the cell viability and show the potential for controlling the composition, structure, and mechanical properties of scaffolds. Herein, the tubular scaffolds having an inner diameter of 2 mm, were composed with poly(1,4 cyclohexane dimethylene isosorbide terephthalate)/PVA. The morphology examination showed that tubular structure was dimensionally stable and suitable for an artificial blood vessel. Fourier transform infrared spectra, wetting behavior, stress–strain behavior, and Thiazolyl Blue Tetrazolium Bromide (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) analysis also showed that the composite scaffolds have good chemical interactions between poly(1,4 cyclohexane dimethylene isosorbide terephthalate) (PICT) and PVA, blended PICT/PVA tubes showed the appropriate wetting behavior, it achieved the appropriate breaking strength and adequate pliability up to 47.5% and in vitro assessment showed that blended PICT/PVA scaffolds have the appropriate cell viability and nontoxic, respectively. On the basis of characterizations results, it was concluded that resultant scaffolds would be addressed to fulfill the requirements such as biocompatibility, dimensional stability, adequate elongation, breaking strength, immediate availability, and proper for physiologically. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47222.     

Laser-induced removal of a dye C.I. Acid Red 87 using n-type WO3 semiconductor catalyst

Water contamination by organic substances such as dyes is of great concern worldwide due to their utilization in many industrial processes and environmental concerns. To cater the needs for waste water treatment polluted with organic dyes, laser-induced photocatalytic process was investigated for removal of a dye derivative namely Acid Red 87 using n-type WO₃ semiconductor catalyst. The degradation was investigated in aqueous suspensions of tungsten oxide under different experimental conditions using laser instead of conventional UV lamp as an irradiation source. The degradation process was monitored by measuring the change in dye concentration as a function of laser irradiation time by employing UV spectroscopic analysis. The degradation of dye was studied by varying different parameters such as laser energy, reaction pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H₂O₂), and potassium bromate (KBrO₃). The degradation rates were found to be strongly dependent on all the above-mentioned parameters. Our experimental results revealed that the dye degradation process was very fast (within few minutes) under laser irradiation as compared to conventional setups using broad spectral lamps (hours or days) and this laser-induced photocatalytic degradation method could be an effective means to eliminate the pollutants present in liquid phase. The experience gained through this study could be beneficial for treatment of waste water contaminated with organic dyes and other organic pollutants.     

Planar measurements of soot volume fraction and OH in a JP-8 pool fire

The simultaneous measurement of soot volume fraction by laser induced incandescence (LII) and qualitative imaging of OH by laser induced fluorescence (LIF) was performed in a JP-8 pool fire contained in a 152 mm diameter pan. Line of sight extinction was used to calibrate the LII system in a laminar flame, and to provide an independent method of measuring average soot volume fraction in the turbulent flame. The presence of soot in the turbulent flame was found to be approximately 50% probable, resulting in high levels of optical extinction, which increased slightly through the flame from approximately 30% near the base, to approximately 50% at the tip. This high soot loading pushes both techniques toward their detection limit. Nevertheless, useful accuracy was obtained, with the LII measurement of apparent extinction in the turbulent flame being approximately 21% lower than a direct measurement, consistent with the influence of signal trapping. The axial and radial distributions of soot volume fraction are presented, along with PDFs of volume fraction, and new insight into the behavior of soot sheets in pool fires are sought from the simultaneous measurements of OH and LII.     

Neutronic and thermal hydraulic analysis for production of fission molybdenum-99 at Pakistan Research Reactor-1

Neutronic and thermal hydraulic analysis for the fission molybdenum-99 production at PARR-1 has been performed. Low enriched uranium foil (<20% ²³⁵U) will be used as target material. Annular target designed by ANL (USA) will be irradiated in PARR-1 for the production of 100 Ci of molybdenum-99 at the end of irradiation, which will be sufficient to prepare required ⁹⁹Mo/^99mTc generators at PINSTECH and its supply in the country. Neutronic and thermal hydraulic analysis were performed using various codes. Data shows that annular targets can be safely irradiated in PARR-1 for production of required amount of fission molybdenum-99.     

An improved numerical method to find parameters using experimental data

In this paper we describe a numerical method to determine adjustable parameters in a mathematical model using experimental data. This is basically an improvement over our earlier method which was based on the idea that the area under the experimental curve must be equal to the integral of the function used. The improvement used is the addition of an area correction factor which estimates the necessary difference that must exist between the numerically evaluated and the true area. This correction surprisingly eliminates the use of integral with the result that the two areas being equalized are both numerically evaluated, one using the experimental data points and the other using the fitted function values. It is shown that the application of the area correction factor significantly improves the accuracy of the adjusted parameters. The method has been compared with the well-known method of least squares for few selected cases involving variety of functions. It is seen that our method shows convergence for a wider range of initial guesses as compared to the method of least squares. The superiority of our method becomes evident when more than two non-linear parameters are involved.