Understanding NO2 Concentration Dynamics within Tema Metropolitan Area of Ghana Using Generalized Linear Model

The concentration of nitrogen dioxide (NO2) is worsening across the globe alongside growth in industrial and general anthropogenic activities. Due to its serious health implications with long-term exposure, studies on NO2 concentration have gained space in the academic literature. In this study, awareness is created on the levels of NO2 across four (4) locations within the Tema Metropolitan area, with specific interest in selecting locations and periods significantly saturated with NO2 within the study area. NO2 was measured using RKI Eagle, an instrument with a built-in sensor for a specific gas measurement. Measurements were taken day and night at sampling points around 100 meters apart in each location. Data collection was performed over a nine (9)-month period. The Generalized Linear model is explored for selecting locations and periods significantly affected by NO2. From the results, the fourth week (26th–31st) of July 2020, the fourth week (27th–31st) of December 2020, the first week (1st–7th) of January 2021, and the fourth week (24th–31st) of January 2021 recorded severe concentrations of NO2. Additionally, the lives of residents in the Oil Jetty and the VALVO hospital areas were found to be the most endangered, as they recorded significantly high concentrations of NO2. In a developing country such as Ghana, this study is useful for monitoring NO2 concentrations in similar areas to inform decision making and environmental policy formulation.

A Portable Device of Air Pollution Measurement Due to Highway Exhaust Emissions Using LabVIEW Programming

A multisensory gas device integrated with myRIO module to measure air pollution has been established. This device is programmed using the LabVIEW programming language and can measure CO2, CO, NOX, and HC pollution on roads due to motor vehicle exhaust emissions. The device and the display system are made separately using wireless network communication to make this tool portable. Exhaust Gas Analyzer (EGA) was chosen for device calibration, obtaining 3.62% on the average error after performing 30 tests. The tests for measuring CO, CO2, NOX, and HC gas levels were conducted in several locations in Padang City and performed in the morning, afternoon, and evening. The result showed that the system properly measured CO2, CO, NOX and HC pollution in parks and highways in real-time in parts per million (ppm). It also displayed varied gas measurement results in terms of time and test location with a range of CO gas values at 0.034 – 0.15 ppm, CO2 151.3 – 815.2 ppm, NOX 0.0001 – 0.004 ppm, and HC 0.04 – 0.65 ppm. In addition, the system could perform well in providing warnings by automatically activating the air indicator alert at several measurement places when the gas content on one of the gas elements and compounds at a particular location has exceeded the threshold for the clean air category. Thus, this device can be used as initial research to build a real-time air pollution measurement system using the Internet of Things (IoT).

The Effect of Mechanical Tongue Cleaning on Oral Malodor and Tongue Coating

Background: Mechanical tongue cleaning is an important oral hygiene procedure; it is known that a significant cause of volatile sulfur compounds (VSCs), a major component of bad breath, is due to the bacteria coating the tongue. This study was conducted to identify the effect of mechanical tongue cleaning on reducing bad breath and tongue coating. Methods: Various mechanical tongue-cleaning methods were studied, including removing tongue coating using a toothbrush, removing tongue coating using a tongue scraper, and removing tongue coating using a toothbrush and a tongue scraper together. The results were as follows. Results: First, the organic bad breath measurement value after cleaning the tongue significantly decreased in the group using only the toothbrush, the group using only the tongue scraper, and the group using both the toothbrush and the tongue scraper. However, there was no difference between the groups. Second, after cleaning the tongue, the measured values of the tongue coating in the values of WTCI (Winkel’s tongue coating index) and Qray view were significantly reduced in all three groups, and there was no difference between the groups. Third, the gas measurement value in the oral cavity using a machine significantly decreased only the H2S value of the group using the tongue scraper immediately after the mechanical tongue cleaning. Conclusions: From these results, it can be confirmed that mechanical tongue cleaning is effective at reducing bad breath and tongue coating. However, in this study, there was no difference in the reduction effect according to the tools (groups) used for mechanical tongue cleaning. It can therefore be seen that wiping accurately from the rear of the tongue to the front is more effective at reducing bad breath and tongue coating.

Blood Gas Analyses in Hyperbaric and Underwater Environments: A Systematic Review

Background: Pulmonary gas exchange during diving or in a dry hyperbaric environment is affected by increased breathing gas density and possibly water immersion. During free diving there is also the effect of apnea. Few studies have published blood gas data in underwater or hyperbaric environments: this review summarizes the available literature and was used to test the hypothesis that arterial PO2 under hyperbaric conditions can be predicted from blood gas measurement at 1 atmosphere assuming a constant arterial/alveolar PO2 ratio (a:A). Methods: A systematic search was performed on traditional sources including arterial blood gases obtained on humans in hyperbaric or underwater environments. The a:A was calculated at 1 atmosphere absolute (ATA). For each condition, predicted PaO2 at pressure was calculated using the 1 ATA a:A, and the measured PaO2 was plotted against the predicted value with Spearman correlation coefficients. Results: Of 3640 records reviewed, 30 studies were included: 25 were reports describing values obtained in hyperbaric chambers, and the remaining were collected while underwater. Increased inspired O2 at pressure resulted in increased PaO2, although underlying lung disease in patients treated with hyperbaric oxygen attenuated the rise. PaCO2 generally increased only slightly. In breath-hold divers, hyperoxemia generally occurred at maximum depth, with hypoxemia after surfacing. The a:A adequately predicted the PaO2 under various conditions: dry (r=0.993, p< 0.0001); rest vs. exercise (r=0.999, p< 0.0001); and breathing mixtures (r=0.995, p< 0.0001). Conclusion: Pulmonary oxygenation under hyperbaric conditions can be reliably and accurately predicted from 1 ATA a:A measurements.

Assessment of professional Argentine football players using the UNCa test

Objective: To evaluate the maximum oxygen consumption (VO2max) and the Maximum Aerobic Speed (MAS) with direct and portable measurement in field, in professional soccer players using the UNCa test. Material and method: 9 professional soccer players (age: 26.8±5.12 years, mass: 78.7±5.8 kg, height: 177.3±5.8 cm), belonging to the first and promotion categories of AFA soccer league, were measured in the field with the UNCa test using direct gas measurement. A subsample of 3 players was also measured on treadmill. On treadmill and in the field, the same Medgraphics® VO2000 gas analyzer was used. Results: In the field, a VO2max of 52.18±5.86 ml/kg/min, and a MAS of 14.8±1.3 km/h were found. Also, a correlation between VO2max and MAS of r = 0.75, and between MAS and the final speed reached (FSR) r=0.91. In the subsample, no differences were found between treadmill and field in VO2max; 46.6±1.4 ml/kg/min and 48.1±2.2 ml/kg/min (p <0.001) respectively. Differences between MAS are shown; 17.0±0.0 km/h for the treadmill and 13.7±1.5 km/h for the field (p <0.001) replicating the protocol. Conclusion: If professional players of the Argentine Football Association (AFA) were measured directly and in the field, applying the UNCa test for the first time. The VO2max and MAS values were slightly lower than those published in the bibliography

Study on Gas-Generating Property of Lithium-Ion Batteries

A main cause of fires and explosions in lithium-ion batteries is the generation of combustible gases by them, and when a large number of batteries are densely packed, like in an Energy Storage System, there is a high risk of thermal runaway and fire propagation. Currently, many studies are being conducted worldwide to predict and prevent the generation of combustible gases, and thermal runaway in lithium-ion batteries, but they are still in progress. Therefore, in this study, we analyzed the gases generated before and after thermal runaway in lithium ion batteries, to prepare a basis for reducing the risk of thermal runaway. We aimed to establish the basis for prevention by early detection in the event of thermal runaway, by understanding the type and characteristics of the generated gases. For the experiment, lithium ion batteries were classified in terms of appearance (cylindrical, prismatic, pouch type), and cathode materials (NCM, NCA, LFP). The gases generated was measured against time. An FT-IR analyzer was used for gas measurement, and a separate hydrogen sensor was installed in the chamber to analyze changes in the types of gas, and measure the mass of the lithium ion battery over time. In the experiment, CO2 and CO were generated the most during thermal runaway in all lithium-ion batteries. Thereafter, CO2 increased, and CO decreased in the prismatic and pouch types, and both CO2 and CO increased in the cylindrical type. HF (a toxic gas), and H2 having a wide explosive range, were also generated, and the concentrations of these gases were inversely proportional to each other.

Regulatory Requirements for Accuracy in Flare Gas Measurement – Synergizing Software Method Advancement to assist the Hardware Technology to meet Accuracy Demands

Over the years, the industry has been so used to the hard logic of utilizing flare gas meters (notably the ultrasonic flare gas meters) in the measurement of stranded flare gas. This is because it has been a workable solution for years with minimal challenges due to the broader range of accuracy required by regulatory bodies. Usually, companies are either constrained to either utilize the associated gas from the oil and gas facilities as fuel gas to power up the unit or reinject in the reservoir to serve as pressure maintenance agent that pushes the oil towards the reservoir, or stored in the reservoir and/or flare the gas (which in most cases, have been deployed by operators despite the penalties by the regulatory organization). With the recent steer in carbon capture, natural gas utilization, climate change and energy transition, accuracy level demands has been made more stringent with some countries including Nigeria requesting for 2.5 – 3% accuracy level of measurement from operators in a bid to monitor and curb the essence flue gases that are unaccounted for. This can only be for gases flared during routine conditions which does include when process upsets give rise to shut down and blowdown of gases through the flare header to the flare tip. The high demand of measurement accuracy has opened windows for OEM to produce calibrated meters that are bespoke with a longer timeline for recalibration as most of the hardware in critical operations could require a process shutdown to either maintain, repair, calibrate or even replace. With this growing concerns in the industry and the surging growth of digitalization involving AI, data analytics etc in other areas, the software method would be a potential source of synergy to assist the failing hardware which are being impacted by time as calibration issues continue to resurface throughout the life of the meters, giving rise to wider accuracy measurement in the region 5 – 10%, hence attracting the hammer from the regulators. This paper is intended to produce a deep dive of the current regulatory requirements for gas measurement in Nigeria by the regulators (DPR), the impact of the recent 3% accuracy requirements as it impacts both large and medium size operators, the role of gas measurement software for bridging the gaps and shortfalls of the hardware components. A case study of newly developed flare gas measurement software and its impact in assisting operators in gas performance reporting, production allocation and flare penalties where applicable

Novel gas measurement based on pressure triggered release cycles for biochemical methane potential tests

This study aims to present a novel gas counter and to demonstrate its suitability for biochemical methane potential tests. In this system, the gas to be measured is collected in a chamber enclosed with two one-way solenoid valves and the absolute pressure is continuously monitored. After a trigger pressure is reached, a portion of the gas is released and the amount of the released gas is calculated according to ideal gas law and recorded. Three iterations of the supervisory control and data acquisition unit were constructed and tested for BMP measurement. Although it can be further improved and variations are possible, the presented final version works with eight reactors simultaneously and the recommended maximum gas flow is 1.24 mL/min. For those reactors, the measured/theoretical BMP ratio was 65.3% with 4.2% standard uncertainty, which is subjectively acceptable. Therefore, it can be concluded that the concept is valid and applicable to BMP tests.

UL 9540A Installation Level Tests with Outdoor Lithium-ion Energy Storage System Mockups

This report covers results of experiments conducted to obtain data on the fire and deflagration hazards from thermal runaway and its propagation through energy storage systems (ESS). The UL 9540A test standard provides a systematic evaluation of thermal runaway and propagation in energy storage system at cell, module, unit, and installation levels. The data from this testing may be used to design fire and explosion protection systems needed for safe siting and installation of ESS. In addition to temperature, pressure, and gas measurement instruments installed inside of the container, fire service portable gas monitors were placed at locations inside and outside the storage container during the experiments to assess their ability to detect products of thermal runaway and inform fire service size-up decisions. Review section 2.2.3 Fire Service Size-up Equipment to learn more. This research demonstrates a clear need for responding firefighters to have early access to data from instrumentation installed within an ESS, particularly gas measurement instrumentation, available through a monitoring panel. Additionally, it highlights the importance of communication between responding firefighters and personnel responsible for management of the ESS, who can aid in complete evaluation of system data to develop a more clear picture of system status and potential hazards.