ABSTRACT
The purpose of this study was to investigate and assess how restrictive COVID-19 precautions affect air quality in Zonguldak, as well as to determine the relationship between air quality and meteorological variables under these conditions. Daily PM2.5, PM10, SO2, and NOx concentrations and meteorological data, from 1 March to 31 May 2018, 2019, and 2020 were collected for this research. During the 2020 restrictive COVID-19 precautions, it was determined that concentrations of air pollutants were different and low based on the 95% confidence interval by using paired t-test samples. Meteorological variables were found to be similar to previous years, and the correlation between them and air pollutants was found to be significant (P < 0.01) but low according to Pearson correlations. As a result, meteorological variables were determined to have no direct effect on the low concentrations of air quality emissions during the 2020 pandemic. The overall findings revealed that anthropogenic impact has a negative impact on air quality and the air quality had improved during the COVID pandemic. Furthermore, the restriction on the region's coalmines during the COVID-19 pandemic has significant impact on the improvement of air quality.
ABSTRACT
Ozone is a highly effective and broad-spectrum non-residual gas disinfectant.The global COVID-19 pandemic has significantly affected public safety and health, and low concentrations of ozone can inactivate the novel coronavirus.The negative ion generator is a safe and efficient method to generate ozone.Through corona discharge on the needle plate, an ion current can be formed between the needle-plate electrodes and a certain concentration of ozone can be released.In the research on the relationship between the electrode-to-plate distance and ozone release in the negative ion generator, different experimental observations show contradictory results, making the theoretical explanation very difficult and complicated.As the needle-to-plate electrode distance increases, the continuous exponential decreasing trend of ozone emission rate changes to a non-continuous step-wised decreasing pattern, which is defined as the Quantum Ozone Emission Effect (QOEE).The QOEE was observed in all negative ion generators when the plate material was aluminium, stainless steel, yellow brass, or copper.The observed quantum ozone emission effect in negative ion generators may be related to the gas ionization potential of the oxygen molecule and to the electron avalanche theory.The quantum effect of ozone emission is a manifestation of the quantum behavior of the microscopic electron world in the macroscopic world.The ozone emission quantum effect provides a novel technical method for measuring the microscopic properties and corona discharge characteristics of materials. © 2022, Editorial Department of Journal of Xidian University. All right reserved.
ABSTRACT
Rapid, selective, and highly sensitive microelectromechanical sensors are a promising technology for biosensing, medical recognition, and the detection of chemical hazards. At the same time, the surfaces of silicon microcantilevers cannot bond with thiols and cannot be functionalized without a bonding layer, such as gold. Therefore, in past literature, the surfaces of silicon microcantilevers have been coated with gold to facilitate their bonding with the thiol functional groups on the probe layers. However, gold coating produces thermal noise in the results owing to the metallic effect. Accordingly, this study aimed to modify the surface of silicon microcantilevers by patterning it using femtosecond laser (FSL) micromachining so that it could bond with the thiol functional groups with high sensitivity. The surface patterning of silicon microcantilevers enhances their physical, micromechanical, and chemical properties, increasing sensitivity by increasing the quality factor, specific surface area, and creating trapping areas on the microcantilever surfaces. The surfaces of the silicon microcantilever were patterned by microgrooves aligned from the free end to the bounded end, with each microgroove comprising submicrogrooves. To demonstrate their use in a biosensing applications, the modified microcantilevers were functionalized to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2;COVID-19) by immobilizing thiolated oligonucleotides on the surfaces, which worked as the probe layer. The modified biosensor was used to detect low concentrations of SSDNA sequence targets ranging from 300 nM down to 100 pM. The modified silicon-microcantilever sensors were directly functionalized without a joining layer, such as a gold layer. The results revealed a selective response to SARS-CoV-2 SSDNA down to a 9-nM concentration. To detect hazardous chemicals, the modified microcantilever was functionalized using reduced L-cysteine to detect Pb2+ at low concentrations down to 100 pM. The results revealed enhanced sensitivity and selectivity and demonstrated that the FSL patterning activated the microcantilevers to bond with probe layers through the interaction of the silanol created on the surface with the functional groups, such as the thiols, on the probe layers. The microcantilevers patterned with 10 microgrooves exhibited higher responses than those patterned with seven microgrooves. © 2022 John Wiley & Sons Ltd.
ABSTRACT
Systematic disinfection of the stethoscope diaphragm is required to ensure that it does not act as a vector for cross-transmission of health-related diseases. Thus, an antimicrobial latex film could be used as a cover to inhibit pathogenic bacteria from growing on its surface. The aim of this work is to determine the antimicrobial activity and mechanical properties of antimicrobial natural rubber (NR) latex films with different types of antimicrobial agents (mangosteen peel powder (MPP), zinc oxide nanoparticles (ZnO NP), and povidone-iodine (PVP-I)). The antimicrobial loading was varied from 0.5, to 1.0, and 2.0 phr to monitor the effective inhibition of Gram-negative bacteria and fungi growth. For MPP and PVP-I antimicrobial agents, a loading of 2.0 phr showed good antimicrobial efficacy with the largest zone of inhibition. Simultaneously, ZnO NP demonstrated excellent antimicrobial activity at low concentrations. The addition of antimicrobial agents shows a comparable effect on the mechanical properties of NR latex films. In comparison to control NR latex film (29.41 MPa, 48.49 N/mm), antimicrobial-filled films have significantly greater tensile and tear strengths (MPP (33.84 MPa, 65.21 N/mm), ZnO NP (31.79 MPa, 52.77 N/mm), and PVP-I (33.25 MPa, 50.75 N/mm). In conclusion, the addition of antimicrobial agents, particularly ZnO NP, can be a better choice for NR latex films because they will serve as both an activator and an antimicrobial. In a clinical context, with regard to frequently used medical equipment such as a stethoscope, such an approach offers significant promise to aid infection control.
ABSTRACT
COVID-19 is a SARS-CoV-2 virus infection that almost always damages a person's respiratory system. Moderate symptoms often include fever, low saturation, and soreness, which frequently lead to severe conditions. An individual with mild breathing difficulties will perhaps not know when to go to a hospital or need oxygen. This is why people must get accurate information about their current condition. Many patients with COVID-19, even if they feel well, have a low concentration of oxygen in their blood. Low oxygen saturation levels can be an early warning sign that emergency medical assistance is required. The four key indicators that medical and healthcare providers regularly track include body temperature, heartbeat, respiration, and blood pressure. As the number of patients is increasing rapidly, it has been difficult to provide treatment in hospitals due to the limited number of seats, especially in a third-world country like Bangladesh. So, COVID-19 patient treatment should not only be centralized in treatment centers and outpatient facilities, but it is also equally important to develop remote monitoring strategies to monitor and advise the patients remotely. The proposed device involves multiple sensors for the tracking of vital signs and the results of the sensor will be transmitted in the cloud, which will be made available to health professionals for comprehensive analysis. The paper proposes a solution for health status monitoring of patients using the Internet of Things (IoT) that could prove beneficial while battling the deadly virus. © 2021 IEEE.