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Bioethanol's importance as a renewable energy carrier led to the development of new devices for the high-throughput screening (HTS) of ethanol-producing microorganisms, monitoring ethanol production, and process optimization. This study developed two devices based on measuring CO2 evolution (an equimolar byproduct of microbial ethanol fermentation) to allow for a fast and robust HTS of ethanol-producing microorganisms for industrial purposes. First, a pH-based system for identifying ethanol producers (Ethanol-HTS) was established in a 96-well plate format where CO2 emission is captured by a 3D-printed silicone lid and transferred from the fermentation well to a reagent containing bromothymol blue as a pH indicator. Second, a self-made CO2 flow meter (CFM) was developed as a lab-scale tool for real-time quantification of ethanol production. This CFM contains four chambers to simultaneously apply different fermentation treatments while LCD and serial ports allow fast and easy data transfer. Applying ethanol-HTS with various yeast concentrations and yeast strains displayed different colors, from dark blue to dark and light green, based on the amount of carbonic acid formed. The results of the CFM device revealed a fermentation profile. The curve of CO2 production flow among six replications showed the same pattern in all batches. The comparison of final ethanol concentrations calculated based on CO2 flow by the CFM device with the GC analysis showed 3% difference which is not significant. Data validation of both devices demonstrated their applicability for screening novel bioethanol-producer strains, determining carbohydrate fermentation profiles, and monitoring ethanol production in real time. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has emphasized the need for infection risk analysis and assessment of ventilation systems in indoor environments based on air quality criteria. In this context, simulations and direct measurements of CO2 concentrations as a proxy for exhaled air can help to shed light on potential aerosol pathways. While the former typically lack accurate boundary conditions as well as spatially and temporally resolved validation data, currently existing measurement systems often probe rooms in non-ideal, single locations. Addressing both of these issues, a large and flexible wireless array of 50 embedded sensor units is presented that provides indoor climate metrics with configurable spatial and temporal resolutions at a sensor response time of 20 s. Augmented by an anchorless self-localization capability, three-dimensional air quality maps are reconstructed up to a mean 3D Euclidean error of 0.21 m. Driven by resolution, ease of use, and fault tolerance requirements, the system has proven itself in day-to-day use at ETH Zurich, where topologically differing auditoria (at-grade, sloped) were investigated under real occupancy conditions. The corresponding results indicate significant spatial and temporal variations in the indoor climate rendering large sensor arrays essential for accurate room assessments. Even in well-ventilated auditoria, cleanout time constants exceeded 30 min. [ABSTRACT FROM AUTHOR]

The estimates of anthropogenic CO2 emissions in the megacity of St. Petersburg per square kilometer and for the entire area of the city (integral emissions), obtained on the basis of ground-based measurements of the CO2 content within the city limits, are presented. To determine emissions, the inverse problem was solved using the results of comparison between the measured and calculated data (ODIAC dataset) of the anthropogenic contribution to the CO2 content from the city. Two approaches were applied. In the first, the tomographic method was used and the anthropogenic emissions of three city districts per square kilometer were determined. In the second, all available measurements were used to find the average correction factor R and estimates of the integral CO2 emissions of the entire megacity and its central part. The emissions per square kilometer for the south of the city are in the range of 32.7–48.3 kt/km2 year; for the center, 69.0–97.5 kt/km2 year; and for the north, 78.2 kt/km2 year. The integral CO2 emissions from the central part and the entire metropolis are 39.8 and 65.3 Mt/year, respectively. Inaccuracies in the estimate reach 20–40%. The estimates of the CO2 anthropogenic emissions in St. Petersburg are higher by approximately two times than earlier results. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) are attracting considerable attention because they can produce renewable energy from organic matter. To extract useable energy from MFCs, a suitable energy harvester is needed that can store energy in a capacitor and increase the output voltage of the MFC. We present an u ltra-low- p ower e nergy harvester specially designed for M FCs (UPEM) which can extract energy even from extremely low-power, inexpensive, and single MFCs. The minimum required input power from an MFC to UPEM for charging a supercapacitor to 3.3 V is only 2.09 μW, and this value is two orders of magnitude lower than any input power reported for any energy harvester till date. UPEM is the first harvester that succeeded in obtaining almost real-time measurements of temperature and humidity, CO2 sensing, iBeacon™ transmission, and long-range wireless data transmission (>5 km) with a LoRa module at intervals shorter than 3 h, using a single MFC with a maximum power of 0.52 mW. These results show that UPEM can enable the realization of various applications of MFCs, such as their use in MFC-driven autonomous environmental sensing devices to measure greenhouse gases in remote off-grid locations. Image 1 • A novel energy harvester was specially designed for low-power and inexpensive MFCs. • The harvester can charge a supercapacitor to 3.3 V using only 2 μW of MFC output. • The power required for charging is lowest among any reported values thus far. • A CO 2 sensor module was driven using an MFC for the first time. • A LoRa module for long-range wireless transmission was driven. [ABSTRACT FROM AUTHOR]

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[Display omitted] • A capillary sensor doped with O 2 indicator RuDP, pH and CO 2 indicator HPTS is designed for detecting pH, O 2 , and CO 2. • The multifunctional sensor can be excited at the same wavelength and realize the monitoring of multiple analyte at the different sensing position. • The fluorescent capillary sensor exhibits favorable stability, low-cost and real-time monitoring. • The optical multi-analyte fluorescent capillary sensor possesses a sensitive fluorescence response to pH, O 2 and CO 2. A fluorescent capillary sensor for detecting the bioanalytically and biologically relevant analytes pH, O 2 , and CO 2 has been designed. The sensor is based on single capillary tube with 2 mm inner diameter, which is simultaneous doped with emissive O 2 -sensitive indicator Ru(dpp) 3 (PF6) 2 (RuDP), pH-sensitive and CO 2 -sensitive indicator 8-hydroxypyrene-1, 3,6-trisulfonic acid trisodium salt (HPTS). The multifunctional sensor can be excited at the same wavelength and realize multi-parameter optical monitoring at the different sensing position. Studies in phosphate-buffered solutions display the excellent feasibility of the capillary sensor for fluorescence detection of pH, O 2 , and CO 2. Overall, the multifunctional capillary sensor exhibits great potential in real-time blood gas analysis, and clinical application of multi-parameter biological detection. [ABSTRACT FROM AUTHOR]

Seed companies increasingly need to obtain reliable results on seed vigor. Therefore, the objective was to verify the efficiency of the respiratory activity measurement, by the CO2 released, to classify the vigor of okra seed lots. For this, five seed lots of okra cv. "Santa Cruz 47" were used. In order to determine seed physiological quality, the following tests were performed: germination, seedling emergence, emergence speed index, shoot length, total dry matter, potassium leaching, electrical conductivity and respiratory activity. Mean values of germination and vigor were compared by Tukey's test. Respiratory activity was correlated with germination and other vigor tests by the Pearson's correlation. The results indicate that CO2 measurement is a promising method to identify vigor differences between okra seed lots.

Abstract The quest for a sustainable environment and combating global warming, carbon capture, and storage (CCS) has become the primary resort. A complete shift from non-renewable resources to renewable resources is currently impossible due to its major share in energy generation; making CCS an imperative need of the time. This study, therefore, aims to examine the reckoning of carbon dioxide (CO 2), measurement methods, and its efficient capture and storage technologies with an ambition to combat global warming and achieve environmental sustainability. Conventionally, physical, geological and biological proxies are used to measure CO 2. The recent methods for CO 2 analyses are spectrometry, electrochemical gas sensors, and gas chromatography. Various procedures such as pre, post, and oxyfuel combustion, and use of algae, biochar, and charcoal are the promising ways for CO 2 sequestration. However, the efficient implementation of CCS lies in the application of nanotechnology that, in the future, could provide a better condition for the environment and economic outlooks. The captured carbon can be stored in the earth crust for trillions of years, but its leakage during storage can raise many issues including its emissions in the atmosphere and soil acidification. Therefore, global and collective efforts are required to explore, optimize and implement new techniques for CCS to achieve high environmental sustainability and combat the issues of global warming. Graphical abstract Image 1 Highlights • Climate change is a serious threat to all living creatures on the planet Earth. • Deforestation and intensive use of fossil fuels have exacerbated global warming. • Several technologies can be used for CO 2 capture and storage (CCS). • Nanotechnology has a promising role in carbon sequestration. • Captured carbon can be stored for million years under Earth crust and deep oceans. [ABSTRACT FROM AUTHOR]

Background: Assessment of asthma outside of the hospital using a patient independent device is highly in demand due to the limitation of existing devices, which are manual and unreliable if patients are not cooperative.Objective: The study aims to verify the use of newly developed human respiration, carbon dioxide (CO2) measurement device for the management of asthma outside of the hospital.Method: The data were collected from 60 subjects aged between 18-35 years via convenience sampling method reported in UTM Health Center using the device. Furthermore, the data were normalized and analyzed using descriptive statistics, t-test, and area (Az) under receiver operating characteristic curve (ROC).Result: Findings revealed that the normalized mean values of end-tidal carbon dioxide (EtCO2), Hjorth Activity (HA), and respiratory rate (RR) were lower in asthmatic compared with healthy subjects with minimum deviation from the mean. In addition, each parameter was found to significantly differ statistically for asthma and non-asthma with p< 0.05. Furthermore, the Az shows the strong association for the screening of asthma and non-asthma with an average of 0.71 (95% CI: 0.57-0.83), 0.77 (95% CI: 0.64-0.90), and 0.83 (95% CI: 0.73-0.94) for RR, EtCO2, and HA, respectively.Conclusions: This study demonstrates that the newly developed handheld human respiration CO2 measurement device may possibly be used as an effort-independent asthma management method outside of the hospital. [ABSTRACT FROM AUTHOR]

In light of concerns over climate changes, extensive scientific research is ongoing in the field of CO2 separation [1-5]. No definitive determination has yet been made as to which separation technology should be selected and efforts are continuing to find new methods [6-11]. This paper presents preliminary results of measurements of the disturbance of the uniformity of a nitrogen and CO2 mixture inside a thermoacoustic tube. Transversely to the tube axis, a detection path was placed to identify disturbance of the CO2 and nitrogen content. The tube was filled with a uniform mixture of nitrogen and CO2. An acoustic standing wave was induced inside the tube and the readings of the mixture uniformity disturbance detection system were recorded. More data were recorded from an internal microphone, enabling detection of the standing wave. The results were processed numerically and the computations resulted in a series of curves in the time and frequency domains, illustrating the behavior of the mixture inside the tube. [ABSTRACT FROM AUTHOR]

Abstract: The development of reduced tillage in cropping systems raises the question of adaptation of N fertilization of crops in response to changes in the chemical, physical and biological soil caused by the cessation of ploughing. The purpose of the work was to investigate the fate of fertilizer 15N applied in spring to a winter wheat crop (Triticum aestivum L.) under minimum tillage (MT) and conventional tillage (CT) and to examine the hypothesis that in MT systems plants face stronger microbial competition for N. The experiment was conducted in Northern France on a silt loam in two different rotations [sugar beet (Beta vulgaris L.)–winter wheat–maize (Zea mays L.)–winter wheat and seed flax (Linum usitatissimum L.)–winter wheat–pea (Pisum sativum L.)–winter wheat] from which we selected two crop sequences, pea–wheat and maize–wheat. At the beginning of stem elongation, 15N labelled fertilizer was applied at the rates of 100kgNha−1 for wheat after pea and 120kgNha−1 for wheat after maize. The dynamics of fertilizer 15N in soil and plant was assessed at six dates between N application and wheat harvest. In addition, soil respiration was monitored continuously on the maize–wheat CT and MT plots as a way of assessing heterotrophic microbial activity. The type of tillage (MT vs CT) had little effect on fertilizer N dynamics in the soil. The amount of labelled N immobilized was low with values ranging from 3.5 to 11.9% of applied 15N. Plant 15N recovery (above ground biomass+roots) amounted to 59–63% at flowering and harvest. The 15N balance at harvest time (i.e. the sum of 15N recovered from all plant and soil compartments) indicates that approximately 29% of the fertilizer N applied was lost whichever the tillage considered. The type of rotation (i.e. the nature of the preceding crop) had more influence on wheat N uptake than the type of tillage. The lack of observed effect of tillage on the dynamics of nitrogen fertilizer and plant recovery is in agreement with most published results obtained in other soil and climate conditions. [Copyright &y& Elsevier]