In this study, a nanocomposite of reduced graphene oxide (RGO) nanofiller-reinforcement poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG) matrix was prepared via the melt blending method. The flexibility of PLA was improved by blending the polymer with a PEG plasticizer as a second polymer. To enhance the electromagnetic interference shielding properties of the nanocomposite, different RGO wt % were combined with the PLA/PEG blend. Using Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM) and X-ray diffraction, the structural, microstructure, and morphological properties of the polymer and the RGO/PLA/PEG nanocomposites were examined. These studies showed that the RGO addition did not considerably affect the crystallinity of the resulting nanomaterials. Thermal analysis (TGA) reveals that the addition of RGO highly improved the thermal stability of PLA/PEG nanocomposites. The dielectric properties and electromagnetic interference shielding effectiveness of the synthesized nanocomposites were calculated and showed a higher SE total value than the target value (20 dB). On the other hand, the results showed an increased power loss by increasing the frequency and conversely decreased with an increased percentage of filler.
The Metaverse is all about expanding connectivity amongst users and objects and seamlessly delivering information and services to the right user at the right time. Its potential advantages are virtually limitless, and its applications are progressively changing the way we live, and are opening new opportunities for innovation and growth. It is crystal clear that the Metaverse can enable fully immersive experience, elements of fantasy, and new degrees of freedom. However, it is still considered controversial since it will also open up opportunities for misconduct and crime. Furthermore, the industry lacks the capacity to carry out a comprehensive study of the potential risks that will come along. This paper highlights the current and envisioned Metaverse applications along with the main concerns and challenges faced by the Metaverse stakeholders. Furthermore, it examines the strengths, weakness, opportunities and threats of the Metaverse technology. Finally, the paper presents the future directions and highlights the most important recommendations for developing the Metaverse systems.
1 April 2016 in American Journal of Engineering and Applied Sciences
Globally, there is a great need for portable, inexpensive diagnostic tools that can provide quick, accurate results using relatively small sample volumes. Point-Of-Care (POC) measurements of human saliva, sweat and/or blood capable of detecting glucose levels, foreign pathogens such as bacteria, fungi and many different viruses (HIV, Ebola, Influenza, etc.) that use microfluidics and optofluidics are close to commercial availability. These diagnostic tools use both optical and electrical methods for the detection and analysis of single biomolecules. The applications extend beyond healthcare and can be used for pathogen detection in aquatic environments such as drinking water. Additional research in handheld Optical Coherence Tomography (OCT) offers the possibility for inexpensive diagnosis and treatment of tissue like middle ear infection and breast cancer. Finally, microscopes are also getting smaller and cheaper, with an inexpensive plastic florescence microscope that can quantify white blood cell levels and a suitcase sized microscope that can look at a single drop of blood for a million biomarkers, searching for signs of sepsis and infectious disease. POC devices such as these will provide medical care to poor, remote areas that can be administered by junior physicians or even used for self-diagnosis. In this study, a review of advances in POC devices reported in recent literature is conducted, in order to provide the reader with a thorough description of new diagnostic techniques that have taken place in the last couple of years.
Pressure ulcers (PU) are deep scars on the skin that cause pain, infections and severe health complications. Most movement-impaired subjects are vulnerable to PU, leading to permanent and irreversible skin damage. The system proposed in this paper aims to prevent PU formation with the design and implementation of a wirelessly controlled device that predicts PUs before their occurrence and attempts to prevent it using therapeutic feedback. A flexible pad that consists of multiple types of sensors is used, theses sensors continuously and non-invasively monitor ulcer-related vital signs in vulnerable areas, and uses these data to predict PU with a decision-making process. When PU is detected an electrical stimulation (ES) unit is automatically activated. Stimulation prevents PU formation by increasing local blood flow to the simulated area and eliminating the main factor that leads to PU formation. The system successfully monitored and predicted PU; tests were performed on three healthy volunteers and one volunteer with sacral ulcers. Results including readings of blood oxygenation, force, humidity and temperature were recorded as graphs to monitor decay/increase in values more efficiently.
Radiofrequency fields in the 1–28 GHz range are ubiquitous in the modern world, giving rise to numerous studies of potential health risks such as cancer, neurological conditions, reproductive risks and electromagnetic hypersensitivity. However, results are inconsistent due to a lack of precision in exposure conditions and vastly differing experimental models, whereas measured RF effects are often indirect and occur over many hours or even days. Here, we present a simplified RF exposure protocol providing a single 1.8 GHz carrier frequency to human HEK293 cell monolayer cultures. A custom-built exposure box and antenna maintained in a fully shielded anechoic chamber emits discrete RF signals which can be precisely characterized and modelled. The chosen amplitudes are non-thermal and fall within the range of modern telecommunication devices. A critical feature of the protocol is that cell cultures are exposed to only a single, short (15 min) RF exposure period, followed by detection of immediate, rapid changes in gene expression. In this way, we show that modulation of genes implicated in oxidative stress and ROS signaling is among the earliest cellular responses to RF exposure. Moreover, these genes respond in complex ways to varying RF signal amplitudes consistent with a hormetic, receptor-driven biological mechanism. We conclude that induction of mild cellular stress and reactive oxygen species (ROS) is a primary response of human cells to RF signals, and that these responses occur at RF signal amplitudes within the range of normal telecommunications devices. We suggest that this method may help provide a guideline for greater reliability and reproducibility of research results between labs, and thereby help resolve existing controversy on underlying mechanisms and outcomes of RF exposure in the general population.
Internet of Things (IoT) systems are becoming increasingly safety-critical as the "Things" become an integral part of everyday life and are given control over life-sustaining processes. As such, these products will need safety-aware analysis during the software development life cycle to ensure they operate successfully without harming users. Objective: The overall objective of this study is to construct an approach for conducting safety analysis on the IoT systems in the design phase of the Software Development Life Cycle. Problem: The increasing complexity of the IoT raises concerns with respect to properly assuring IoT safety, since more interaction among components and tighter coupling may result in increased logical errors, posing new safety risks. To show the effect of these problems, we have analyzed several medical systems using our proposed methodology. Method: In this study, we present a methodology to implement IoT systems which takes into account errors and potential hazards at design time. To increase the adoptability of our approach, we use standardized languages/model to represent errors. Several medical use cases are analyzed to prove the viability of the suggested approach. Results: The results of our study show that tracing errors via our method leads to the discovery of hazards in IoT architectures without requiring specialized domain knowledge. The results also are validated based on the traceability criteria. Conclusion: By providing a new hazard analysis method based on early design knowledge and validating early in the Software Development Life Cycle, we discover more hazards and safety constraints to ensure the success of safety critical IoT systems.