CO2 Monitoring Research Articles

Carbon dioxide and trace oxygen concentrations impact growth and product formation of the gut bacterium Phocaeicola vulgatus

BackgroundThe promising yet barely investigated anaerobic species Phocaeicola vulgatus (formerly Bacteroides vulgatus) plays a vital role for human gut health and effectively produces organic acids. Among them is succinate, a building block for high-value-added chemicals. Cultivating anaerobic bacteria is challenging, and a detailed understanding of P. vulgatus growth and metabolism is required to improve succinate production. One significant aspect is the influence of different gas concentrations. CO2 is required for the growth of P. vulgatus. However, it is a greenhouse gas that should not be wasted. Another highly interesting aspect is the sensitivity of P. vulgatus towards O2. In this work, the effects of varying concentrations of both gases were studied in the in-house developed Respiratory Activity MOnitoring System (RAMOS), which provides online monitoring of CO2, O2, and pressure under gassed conditions. The RAMOS was combined with a gas mixing system to test CO2 and O2 concentrations in a range of 0.25-15.0 vol% and 0.0-2.5 vol%, respectively.ResultsChanging the CO2 concentration in the gas supply revealed a CO2 optimum of 3.0 vol% for total organic acid production and 15.0 vol% for succinate production. It was demonstrated that the organic acid composition changed depending on the CO2 concentration. Furthermore, unrestricted growth of P. vulgatus up to an O2 concentration of 0.7 vol% in the gas supply was proven. The viability decreased rapidly at concentrations larger than or equal to 1.3 vol% O2.ConclusionsThe study showed that P. vulgatus requires little CO2, has a distinct O2 tolerance and is therefore well suited for industrial applications.

Signal propagation from portable active seismic source (PASS) to km‐scale borehole DAS for continuous monitoring of CO2 storage site

AbstractWe have developed a portable active seismic source (PASS) to monitor CO2 storage reservoirs at a depth of approximately 1 km. Despite its small size, stacking the signals generated by the PASS improves the signal‐to‐noise ratio of the seismometer data far from the source. The smaller size and lower cost of the PASS enables its permanent deployment in many locations to continuously monitor CO2 storage reservoirs. To achieve continuous monitoring, distributed acoustic sensing (DAS) is also a vital technology. Based on DAS, we can continuously record the signal from the PASS in an extensive area, including within boreholes and offshore fields. Here we report application of the PASS for the borehole DAS system. We confirmed the PASS signal propagation to a depth of ∼1 km when we used a PASS with 630N at 50 Hz close to the wellhead and recorded the signal by the borehole fiber optic cable. The ability of the system to propagate the PASS signal to a depth of ∼1 km enables continuous monitoring of most CO2 storage reservoirs with high temporal resolution. Furthermore, deploying multiple PASS systems could improve the spatial resolution of monitoring results. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

Implementation of a long range-based monitoring system for environmental remote safety schemes

<p>The effects of poor air quality on people are profound. Air pollution and health issues are linked to millions of deaths. The World Health Organization (WHO)and the environmental protection agency (EPA)have produced several regulations and guidelines to control and enhanceair quality. Several authors have recently suggested low-cost tools for instantly assessing air quality. the abundance of inexpensive ways to assess air quality and collect sensor data. The design and employment of remote safety monitoring for humidity, temperature, and carbon monoxide has been merged into a single tool in this work. The results findings can be observed on the actual measured instrument’s organic light-emitting diode (OLED)show and the liquid crystal display (LCD)remote monitoring system. This device uses ESP32 microcontroller with long range (LoRa)wireless communication technology.The DHT22 sensor is used to detect humidity and temperature, while the MQ-7 sensor is used to monitor carbon monoxide levels. Testing measurements are calibrated using instruments that meet industrial standards (AS8700A CO meter and 4,000 NV weather tracker) used in environmental station. If the abnormalities in the recorded parameters are detected, then alert will be triggered. This instrument can help patients and workers to check their surroundings and provide remote monitoring to health service providers.</p>

Development and Baseline Comparison of a New Pulsed-Neutron Spectroscopy Tool for Carbon- Oxygen Analysis and Three-Phase Saturation Monitoring

A new slim multidetector pulsed-neutron wireline-logging tool has been developed for openhole or casedhole formation evaluation saturation analysis and time-lapse monitoring. With a greater neutron source output and high-spectral resolution gamma ray detectors, the tool can be operated with reduced uncertainty or faster logging speeds. New, fully programable digital electronics provide a range of acquisition modes optimized for specific formation evaluation objectives. Neutrons are generated from a high-output pulsed-neutron generator, which propagates radially outward, passing through the borehole, completion material, and into the formation. Energy is lost through scattering, and neutrons are absorbed by the surrounding material. Gamma rays are emitted from scattering and absorption interactions at discrete energies, which can be measured by one of three spectral gamma scintillation detectors. The energy distribution of these incident gamma rays by inelastic and capture interactions is affected by the elemental composition of the material. A salinity-independent oil-water saturation assessment begins with the deconvolution of neutron-induced gamma ray inelastic spectra into constituent elemental components. Carbon-oxygen ratios (C/O) of elemental yields are then compared to a reference model to determine the relative saturation and porosity-filled volume of oil and water. In PNC (pulsed-neutron capture) acquisition mode, a salinity-dependent oil-water saturation assessment is determined from neutron capture cross section (sigma) measurements, which are compared to formation and porosity fluids using a mass balance approach. Gas saturation assessment is determined from gas-sensitive inelastic (RIN13) and capture (RATO13) ratios. Gas ratios are compared to a reference model to assess the relative saturation of fluids, typically distinguishing gas from water or gas from oil. Gas saturation is not limited to hydrocarbon components and can also be used for saturation analysis of H2, He, CO2, N2, and other non-hydrocarbon-bearing components. A new Omni-mode acquisition combining simultaneous PNC and C/O measurements was also developed. This acquisition mode provides advantages in reducing multipass logging typically required from separate PNC and C/O acquisitions. By including PNC neutron capture sigma, gas-sensitive neutron capture and inelastic measurements, and C/O inelastic measurements, the simultaneous Omni-mode (PNC+C/O) acquisition is specifically optimized for three-phase saturation analysis applications, including baseline CO2 sequestration evaluation for carbon capture, utilization, and storage (CCUS) CO2 and steamflood time-lapse monitoring. Results from a field example are presented to demonstrate the new technology with spectral C/O saturation analysis compared to traditional windows C/O analysis and to compare the performance of the next-generation tool to the legacy tool. Multiphase saturations from C/O and RIN13 measurements and compatibility with legacy interpretations for time-lapse saturation monitoring are also presented.

Measuring Carbon Dioxide Emissions From Liquefied Natural Gas (LNG) Terminals With Imaging Spectroscopy

AbstractThe rapid growth of liquefied natural gas (LNG) exports underscores the importance of CO2 monitoring for LNG export terminals. We present a method for measuring LNG terminal CO2 emissions using remote sensing imaging spectroscopy. The method is first validated using 47 power plant emission events with in situ measured data, then applied to 22 emission events in Sabine Pass and Cameron. The power plant data set shows a robust correlation between our estimates and in situ data, with R2 0.9146 and the average error −2%. At Sabine Pass, eight point sources are identified with emission rates from 219.69 ± 54.95 to 1,083.22 ± 308.06 t/hr. At Cameron, three point sources are identified with emission rates from 91.64 ± 25.81 to 265.61 ± 67.80 t/hr. The liquefaction carbon intensity estimates also align with past study ranges. This illustrates that remote sensing can validate environmental reporting and CO2 inventories for industrial facilities.

Remote Carbon Monoxide Capture via REDCap: Evaluation of an Integrated Mobile Application.

To improve the feasibility of remote biochemical verification of smoking status, our team developed "COast," a mobile app integrated with REDCap that allows a research participant to complete self-report research assessments and provide a breath sample via the iCOQuit Smokerlyzer for the purposes of carbon monoxide (CO) testing. The aims of the present study were to examine (1) the validity of remote CO data capture using COast as compared to gold-standard approaches (salivary cotinine, stand-alone CO monitor) and (2) the feasibility of remote CO data capture using COast as applied to both daily and weekly CO collection schedules. Participants (N = 143, 59% Female), including recently quit (n = 36) and current (n = 107) smokers, completed a baseline video session to capture validity data, and then were randomized to daily or weekly CO monitoring for a period of 1 month. Balancing both sensitivity and specificity, optimal cut-points for defining abstinence using the COast system were <4 parts per million (ppm) with salivary cotinine as the referent (Sensitivity = 100%, Specificity = 92.8%) and <8 ppm with the stand-alone CO monitor as the referent (Sensitivity = 100%, Specificity = 88.9%). Compliance across groups with CO monitoring was high with average compliance of 74% for the daily group and 84% for the weekly group. Self-reported feasibility and acceptability of using the system were strong. Pairing the iCOQuit with REDCap via the COast app was both valid and feasible among a sample of adults who smoke cigarettes enrolled remotely. This integration may help to improve the rigor of decentralized smoking cessation trials. With increasing prevalence of decentralized trial designs, innovative methods are needed to remotely capture biomarkers. Methods that leverage existing widely available research data capture platforms may be particularly useful for promoting adoption. The COast app, which integrates a Bluetooth-enabled CO monitor with REDCap, is a fitting, valid, and feasible solution to remotely biochemically verify smoking status.

Utilising BC observations to estimate CO contributions from fossil fuel and biomass burning in the Central Himalayan region

The Himalayan region is adversely affected by the increasing anthropogenic emissions from the adjacent Indo-Gangetic plain. However, source apportionment studies for the Himalayan region that are crucial for estimating CO concentration, are grossly insufficient, to say the least. It is in this context that our study reported here assumes significance. This study utilizes five years (2014–2018) of ground-based observations of eBC and multiple linear regression framework (MLR) to estimate CO and segregate its fossil fuel and biomass emission fractions at a high-altitude (1958 m) site in the Central Himalayas. The results show that MERRA2 always underestimates the observed CO; MOPITT has a high monthly difference ranging from −32% to +57% while WRF-Chem simulations underestimate CO from February to June and overestimate in other months. In contrast, CO estimated from MLR replicates diurnal and monthly variations and estimates CO with an r2 > 0.8 for 2014–2017. The CO predicted during 2018 closely follows the observed variations, and its mixing ratios lie within ±17% of the observed CO. The results reveal a unimodal diurnal variation of CO, COff (ff: fossil fuel) and CObb (bb: biomass burning) governed by the boundary layer evolution and upslope winds. COff has a higher diurnal amplitude (39.1–67.8 ppb) than CObb (5.7–33.5 ppb). Overall, COff is the major contributor (27%) in CO after its background fraction (58%). CObb fraction reaches a maximum (28%) during spring, a period of increased agricultural and forest fires in Northern India. In comparison, WRF-Chem tracer runs underestimate CObb (−38% to −98%) while they overestimate the anthropogenic CO during monsoon. This study thus attempts to address the lack of continuous CO monitoring and the need to segregate its fossil fuel and biomass sources, specifically over the Central Himalayas, by employing a methodology that utilizes the existing network of eBC observations.

Relationship between red blood cell lifespan and endogenous carbon monoxide in the common bottlenose dolphin and beluga.

Certain deep-diving marine mammals [i.e., northern elephant seal (Mirounga angustirostris), Weddell seal (Leptonychotes weddellii)] have blood carbon monoxide (CO) levels that are comparable with those of chronic cigarette smokers. Most CO produced in humans is a byproduct of heme degradation, which is released when red blood cells (RBCs) are destroyed. Elevated CO can occur in humans when RBC lifespan decreases. The contribution of RBC turnover to CO concentrations in marine mammals is unknown. Here, we report the first RBC lifespans in two healthy marine mammal species with different diving capacities and heme stores, the shallow-diving bottlenose dolphin (Tursiops truncatus) and deep-diving beluga whale (Delphinapterus leucas), and we relate the lifespans to the levels of CO in blood and breath. The belugas, with high blood heme stores, had the longest mean RBC lifespan compared with humans and bottlenose dolphins. Both cetacean species were found to have three times higher blood CO content compared with humans. The estimated CO production rate from heme degradation indicates some marine mammals may have additional mechanisms for CO production, or delay CO removal from the body, potentially from long-duration breath-holds.NEW & NOTEWORTHY This is the first study to determine the red blood cell lifespan in a marine mammal species. High concentrations of carbon monoxide (CO) were found in the blood of bottlenose dolphins and in the blood and breath of belugas compared with healthy humans. Red blood cell turnover accounted for these high levels in bottlenose dolphins, but there may be alternative mechanisms of endogenous CO production that are contributing to the CO concentrations observed in belugas.

Characteristics and prediction of traffic-related PMs and CO2 at the urban neighborhood scale

Accurate portrayal of the spatial-temporal distribution of traffic-related pollutants at the neighborhood scale contributes to refined management for the urban air environment. This study conducted mobile monitoring of traffic-related particulate matters (TRPMs, including PM10, PM2.5, and BC) and CO2 on urban roads in a neighborhood-scale area of Xi'an. Random forest land-use regression (RF-LUR) models for TRPMs and CO2 were developed to quantify the contributions of relevant influencing factors. Finally, the accuracy of the LUR and RF-LUR prediction models was evaluated and compared. The results showed that the pollutants in the neighborhood-scale regions had significant spatial-temporal heterogeneity. The concentrations of TRPMs and CO2 were significantly higher in the morning peak than in the evening peak. BC and CO2 hotspots mostly appeared on arterial roads, while PM10 and PM2.5 exhibited considerably greater spatial variability and more widely dispersed hotspots. The prediction models demonstrated that the RF-LUR model outperforms the LUR model in all evaluation indicators. Specifically, the RF-LUR model displays a higher degree of explanatory power, as evidenced by R2 values of 0.784, 0.871, 0.533, and 0.551 for PM10, PM2.5, BC, and CO2, respectively. Further analysis of the contributions of various factors showed that the concentrations of PM10 and PM2.5, which reflect the background concentrations, were the main influencing factors, with explanatory powers of 57.72% and 78.27%, respectively. Additionally, meteorological factors explained TRPMs and CO2 to a greater extent than did different land use types. Our results showed that RF-LUR can be effectively applied to the prediction of neighborhood scale traffic pollutants.

Abstract 12421: Guided Advanced Cardiovascular Life Support Mobile App Improves Trainee Experience and Performance During Simulated Cardiac Arrest: A Randomized Controlled Trial

Introduction: Leading hospital code teams is stressful for resident physicians, and variability in training and experience may result in inconsistent care and outcomes. Nearly all bedside aids like AHA advanced cardiovascular life support (ACLS) pocket cards and third-party ACLS mobile apps lack step-by-step guidance or reminders. Our team designed a guided ACLS mobile app to help trainees lead more effective hospital resuscitations and conducted a randomized controlled trial to assess user experience and performance according to 2020 AHA ACLS guidelines. Hypothesis: A guided ACLS app will improve subjective user experience and adherence to AHA ACLS guidelines. Methods: The ACLS mobile app was developed using Swift UIKit. Internal Medicine, Emergency Medicine, Surgery, and Anesthesia residents (N = 46) were randomized to lead a simulated code for cardiac arrest due to massive pulmonary embolism using either AHA pockets cards (N = 22) or the ACLS app (N = 24). User experience was assessed via surveys. Code outcomes, guideline adherence, and errors were analyzed from video recordings. A focus group of 22 residents provided feedback. Statistical analysis was conducted using R software and included two-sided t-tests and Fisher exact tests. Results: App users showed significantly increased confidence (1.0 vs 0.3; p = 0.005), backboard use (96% vs 27%; p &lt;0.001), end-tidal CO2 monitoring (58% vs 27%; p = 0.042), correct thrombolytic administration (54% vs 23%; p = 0.035), and achieving return of spontaneous circulation (50% vs 18%; p = 0.032) compared to controls. Focus group results showed that 100% of the participants would use the app and that 82% preferred the guided app to AHA pocket cards. Conclusions: The guided app improves user confidence and adherence to AHA ACLS guidelines and addresses the need for greater standardization in hospital code management. Validation studies are necessary to confirm its effectiveness in clinical practice.

The Role of Red Blood Cell Lifespan Testing in the Evaluation of Patients with Paroxysmal Nocturnal Hemoglobinuria

Objective To explore the role of red blood cell(RBC) lifespan testing in the evaluation of patients with paroxysmal nocturnal hemoglobinuria (PNH). Methods The endogenous breath carbon monoxide (CO) test was used to detect the RBC lifespan of PNH patient with the treatment of crovalimab（ Roche） or iptacopan（ Novartis.），for comparison of different hemolysis indices in the assessment of patients' condition. Results Nine patients have been enrolled in the study at our centre from June to December 2021, 4 with the treatment of crovalimab and 5 with iptacopan. The median lifespan in the untreated patients was 17 (range 12-38) days, median hemoglobin(Hb) 83(69-94) g/l, median lactic dehydrogenase（LDH）590.8(446.1-935.5)U/L, median PNH clones 96.0(33.2-99.9)%. By 6 months post-treatment, 8 patients achieved hematologic improvement without breakthrough hemolysis. In all patients, LDH levels decreased rapidly and stabilized at lower levels after starting treatment. But the degree of Hb recovery varied，median 60(20-85)g/L. Analyzing the correlation between different hemolytic indices (LDH, RBC lifespan, total bilirubin, indirect bilirubin, etc.) and Hb changes, RBC lifespan showed good correlation（P=0.002，R=0.867）. In the crovalimab group, three patients presented with a positive Coombs test and the negative patient didn't obtain hematologic improvement. No patients with a positive Coombs test were seen in the iptacopan group. Conclusion Different (upstream/downstream) complement inhibitors have different effects on the condition of PNH patients, and different indicators can reflect different results; LDH responds to intravascular hemolysis, and red blood cell lifespan also quantifies extravascular hemolysis, and is applied to monitor hemolysis. The application of RBC lifespan testing can provide an accurate scientific basis for the assessment of PNH conditions. Keywords: red blood cell lifespa, paroxysmal nocturnal hemoglobinuria ,red blood cell lifespan,lactic dehydrogenase

Perinatal Hemolytic Disorders and Identification Using End Tidal Breath Carbon Monoxide.

Hemolytic disorders can cause severe morbidity or can be life-threatening. Before the re-cent development of practical and inexpensive testing for hemolysis by quantifying carbon monox-ide in end-tidal breath, some hemolytic disorders in perinatal patients were not detected until se-verely problematic hyperbilirubinemia and/or anemia occurred. Here we review studies aimed at es-tablishing the normal reference intervals for end tidal breath carbon monoxide (ETCO) in various perinatal populations. We also review reports, and new theories, about using this methodology to diagnose and quantify hemolytic disorders in term and premature neonates, anemic pregnant wom-en, and fetuses in utero. The purposes of making these measurements are to; (1) identify patients who have hemolytic disorders, (2) characterize the severity of the hemolysis in each hemolytic pa-tient, and (3) predict and prevent co-morbidities, thereby improving outcomes.

Wireless CO2 and Ozone Monitoring with IoT Technology for Indoor Air Quality

This article presents the development of a wireless sensing and control system for indoor air quality by measuring gases such as carbon dioxide, as well as the use of ozone as a biocide agent for environmental control in real time, respecting concentrations allowed by national and international environmental health standards. The developed system uses cutting edge technology such as the Internet of Things and Cloud Computing that allows remote access to air quality measurements through mobile devices with the installation of the developed App, which has the capacity for registration and controlled access to users, auto-configuration of devices and data visualization in real time and historical record. The use of ozone as a biocide agent for environmental control was effective against the use of chemicals or other substances since it does not leave hazardous residues, inhibiting the generation of new colonies and keeping the areas under a disinfection control.

Does end-tidal carbon dioxide monitoring in gastrointestinal endoscopy have a clinical advantage?

Aims: In current guidelines recommended CO2 monitoring for patient safety and comfort in sedation for gastrointestinal endoscopy. We aimed to investigate whether carbon dioxide monitoring, which was developed for the early detection of adverse respiratory events shows the expected benefit in its clinical use.&#x0D; Methods: Asa I-II patients, average age 48±15, were divided into two groups, standard monitoring was performed on Group S (n=30), and EtCO2, Integrated Pulmonary Index measurements were added to the Group K (n=30). Patients received Fentanyl 1µgr/kg, propofol 1 mg/kg and propofol 10-30 mg in a bolus by providing BIS to be 60-85. Adverse respiratory events were recorded. The time to Fast-tracking score being 14 was recorded and patients with two consecutive Fast-tracking scores of 14 were discharged. Patient satisfaction was questioned the next day.&#x0D; Results: There is no difference between groups in heart rate and mean arterial pressure, and decreased during the procedure compared to baseline in both groups. While EtCO2 was similar at all times, IPI was lower than baseline. While the processing time was 21±6 in Group S, it was 38±11 in Group K. No adverse respiratory events occurred. Recovery heart rates, peripheral oxygen saturation, mean arterial pressure and scores were similar. There was no difference in patient satisfaction.&#x0D; Conclusions: There wasn’t a clinical advantage with measuring EtCO2 added to the standard monitoring in gastrointestinal tract endoscopy. We believe that more studies are needed on optimum monitoring during moderate sedation in patients with less clinical risk.

Intelligent pointing increases the fraction of cloud-free CO2 and CH4 observations from space

For most CO2 and CH4 satellites, only a small percentage (∼10%) of observations yield successful retrievals, with the remaining ∼90% rejected, primarily due to the effects of clouds. Discarding this large fraction of data is an inefficient strategy worth reconsidering due to the costs involved in developing, launching and operating the satellites to make these observations. However, if real-time cloud data are available together with pointing capability, cloud data can guide the instrument pointing in an “intelligent pointing” strategy for cloud avoidance. In this work, multiple intelligent pointing simulations were conducted, demonstrating the significant advantages of this approach for satellites in a highly elliptical orbit (HEO), from which nearly the whole Earth disk can be observed. Multiple factors are shown to contribute to intelligent pointing efficiency such as the size and shape (or aspect ratio) of the field of view (FOV). For the current baseline orbit and Imaging Fourier Transform Spectrometer (IFTS) observing characteristics for the proposed Arctic Observing Mission (AOM), the monthly fraction of cloud-free observations is roughly a factor of 2 (ranging from ∼1.5–2.5) more than obtained with standard pointing (in which cloud information is not used). A similar efficiency is expected in a geostationary orbit (GEO) with an IFTS, however, for a dispersive instrument in HEO or GEO, the gain is more modest. This result is primarily attributed to the ∼1:1 aspect ratio of the IFTS FOV, since it is more efficient for cloud avoidance and scanning irregularly-shaped land masses than the long and narrow slit projection of a typical dispersive spectrometer. These results have implications for the design of future CO2 or CH4 monitoring satellites and constellation architectures, as well as other fields of satellite earth observation in which clouds significantly impact observations.

Improving CO2 sensing and p-n conductivity transition under UV light by chemo-resistive sensor based on ZnO nanoparticles

Chemo-resistive gas sensors for CO2 detection were fabricated using ZnO nanoparticles synthesized by the hydrothermal method. The CO2 sensors were activated by thermal and/or UV light exposure. While the resistance changes of sensors exposed to CO2 at high temperatures (150–300 °C) exhibited noise, those activated by UV light remained stable, indicating that UV light can improve CO2 sensing. Good response, short response time (<10 s), stability, a linear calibration curve, and high sensitivity were obtained under UV light. Therefore, the UV-activated sensor could be applied in practical environments for CO2 monitoring. Furthermore, the measurements for CO2 also showed that the p-n transition was observed with changes in temperature. The CO2 sensor acted as p-type at RT, while it acted as n-type at 80 °C. The p-type conductivity of ZnO at RT, which can be attributed to Zn vacancies acting as acceptors, was confirmed through PL and EDX spectra, as well as Hall Effect measurements. It should be noted that the p-n transition in sensors based on undoped materials under UV irradiation at low temperatures (<100 °C) has been less reported. The n-p transition could offer intriguing opportunities to customize the electronic properties of the nanostructured devices.

P084 Characteristics of sleep hypoventilation during polysomnography in a large Australian clinical sleep laboratory cohort.

Abstract BACKGROUND Sleep hypoventilation complicates a range of neurological and respiratory conditions. However, robust definitions are based mainly on expert consensus, and clinically significant thresholds remain unclear. This study thus aims to provide a descriptive analysis of capnography results in a large clinical cohort of patients referred for overnight polysomnography (PSG). METHODS Retrospective clinical audit of overnight in-lab PSGs, between Jan 2015 and June 2023, at a tertiary hospital housing the State-wide referral centre for chronic domiciliary ventilation. Diagnostic PSGs with transcutaneous CO2 (PTcCO2) monitoring and without supplemental oxygen were included. The following data will be extracted from each PSG: Patient demographics: -Primary and secondary clinical diagnoses -PTcCO2 values (e.g. Mean, Minimum and Maximum PTcCO2 in Wake, Sleep, NREM and REM) -Sleep fragmentation measures -Sleep macro-architecture measures -AHI -SpO2 values Data analysis will be performed with IBM SPSS Statistics software, version 26 (Armonk, NY: IBM Corp) PROGRESS TO DATE 525 PSGs meeting initial criteria have been identified. Currently processing PSG data files to extract parameters and complete exploratory data cleaning and analysis. INTENDED OUTCOME AND IMPACT We aim to explore and clarify: -Differences in patterns of hypoventilation between different diagnostic groups. -Relationships between awake hypoventilation, sleep hypoventilation and REM-isolated hypoventilation. -Effects of applying differing criteria for hypoventilation available in the literature. -Relationships between measures of sleep fragmentation, AHI, SpO2 and hypoventilation parameters. The results of this study will also support and inform future research into associations between severity, duration and patterns of hypoventilation and clinically significant outcomes including morbidity and mortality.

CO2 monitoring associated with the quality of soybean grains stored in different moisture contentes

The objective of this study was to quantify the levels of CO2 produced by soybeans stored at room temperature in a prototype silo, with initial moisture contents of 12, 14, and 16% (w.b.), as well as to evaluate the quality of the product over storage. Analyses of the moisture content, ash, proteins, lipids, color, germination, and electrical conductivity were performed. In the atmosphere in the silos, the amount of CO2, relative humidity, and temperature were monitored every hour using a CO2 meter data logger. Grain quality evaluations took place at four storage times (0, 30, 60, and 90 days). Analyses were performed in triplicate, and data were analyzed using analysis of variance and regression, adopting the 5% level of significance. The moisture contents, protein, lipids, germination, and color were reduced over time, resulting in a loss of grain quality. Soybeans initially stored with 16% (w.b.) of initial moisture content showed greater losses associated with the rise in the levels of CO2. The rise in CO2 emission in the internal atmosphere of the silo signals the beginning of grain deterioration and can be used as a decision-making tool, aiming at preventing and reducing losses in product quality over storage.

An ultra-small integrated CO2 infrared gas sensor for wearable end-tidal CO2 monitoring

Human physiological metabolic status can be obtained by monitoring exhaled CO2 concentration, but current CO2 sensors have disadvantages such as large size, high power consumption, and slow response time, which limit their application in wearable devices and portable instruments. In this article, we report a small size, good performance, and large range CO2 infrared gas sensor that integrates a high emissivity MEMS emitter chip, a high detectivity thermopile chip, and a high coupling efficiency optical chamber to achieve high efficiency optical-thermal-electrical conversion. Compared with typical commercial sensors, the size of the sensor can be reduced by approximately 80% to only 10mm×10mm×6.5mm, with the advantages of low power consumption and fast response speed. Further, a monitoring system for end-tidal CO2 concentration installed on a mask was developed using this sensor, and good results were achieved.

Multi-Scale Seismic Measurements for Site Characterization and CO2 Monitoring in an Enhanced Oil Recovery/Carbon Capture, Utilization, and Sequestration Project, Farnsworth Field, Texas

To address the challenges of climate change, significantly more geologic carbon sequestration projects are beginning. The characterization of the subsurface and the migration of the plume of supercritical carbon dioxide are two elements of carbon sequestration that can be addressed through the use of the available seismic methods in the oil and gas industry. In an enhanced oil recovery site in Farnsworth, TX, we employed three separate seismic techniques. The three-dimensional (3D) surface seismic survey required significant planning, design, and processing, but produces both a better understanding of the subsurface structure and a three-dimensional velocity model, which is essential for the second technique, a timelapse vertical seismic profile, and the third technique, cross-well seismic tomography. The timelapse 3D Vertical Seismic Profile (3D VSP) revealed both significant changes in the reservoir between the second and third surveys and geo-bodies that may represent the extent of the underground carbon dioxide. The asymmetry of the primary geo-body may indicate the preferential migration of the carbon dioxide. The third technique, cross-well seismic tomography, suggested a strong correlation between the well logs and the tomographic velocities, but did not observe changes in the injection interval.