Ppbv-level mid-infrared photoacoustic sensor for mouth alcohol test after consuming lychee fruits

Photoacoustics, Journal Year: 2023, Volume and Issue: 33, P. 100559 - 100559

Published: Sept. 20, 2023

A ppbv-level mid-infrared photoacoustic spectroscopy sensor was developed for mouth alcohol tests. compact CO2 laser with a sealed waveguide and integrated radio frequency (RF) power supply used. The emission wavelength is ∼9.3 µm of 10 W. detection limit ∼18 ppbv (1σ) ethanol gas an integration 1 s achieved. performed linear dynamic range R square value ∼0.999. breath measurement experiment after consuming lychees conducted. signal amplitude decreased the quality lychee consumed, confirming existence residual in mouth. During continuous measurement, < min when 30 g fruits, proving that detected exhaled originated from oral cavity rather than bloodstream. This work provided valuable information on distinction alcoholism crime.

Language: Английский

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On the Chemical Pathways Influencing the Effective Global Warming Potential of Commercial Hydrofluoroolefin Gases

ChemSusChem, Journal Year: 2024, Volume and Issue: unknown

Published: April 5, 2024

Abstract The enforcement of a global hydrofluorocarbon (HFC) refrigerant phase down led to the introduction hydrofluoroolefins (HFOs) as low Global Warming Potential (GWP) substitute, given their atmospheric lifetime. However, this date it is not fully clear long‐term fate HFOs primary degradation products: trifluoro acetaldehyde (TFE), acetyl fluoride (TFF), and trifluoroacetic acid (TFA). It particularly concerns possibility forming HFC‐23, potent warming agent. Although reaction networks TFE, TFF, TFA have fair level complexity, relevant chemical pathways are well characterized in literature, enabling comprehensive hazard assessment HFC‐23 formation secondary HFO breakdown product diverse scenarios. A lower bound effective GWP baseline scenario found above regulatory thresholds. While further research crucial refine climate risk assessments, existing evidence suggests non‐negligible associated with HFOs.

Language: Английский

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E-Nose-Driven Advancements in Ammonia Gas Detection: A Comprehensive Review from Traditional to Cutting-Edge Systems in Indoor to Outdoor Agriculture

Sustainability, Journal Year: 2023, Volume and Issue: 15(15), P. 11601 - 11601

Published: July 27, 2023

Ammonia (NH3) represents a perilous gas that poses substantial hazard to both human well-being and the environment, particularly within agricultural regions. Agricultural activities constitute primary source of ammonia emissions. Thus, effective monitoring measurement sources in agriculture are imperative for mitigating its adverse impact. However, not all existing detection methods suitable discerning low concentrations typically encountered volatilizing (ranging from 0.01 5 parts per million). Consequently, curtailing volatilization farmland assumes paramount importance, with real-time serving as crucial mechanism assessing environmental contamination minimizing losses. Deploying appropriate methodologies ensures requisite measures taken safeguard health environment deleterious repercussions exposure. The present paper introduces comprehensive approach detecting analyzing settings. It elucidates merits demerits conventional indoor outdoor methods, juxtaposing them innovative technology Electronic nose (E-nose). Within paper, seven widely employed scrutinized compared against traditional techniques. Additionally, constructional aspects distinct components E-nose meticulously delineated appraised. Ultimately, culminates comparative analysis encompassing aforementioned methodologies, elucidating potential limitations facilitating endeavors contexts.

Language: Английский

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Facile Fabrication of Oxygen‐Enriched MXene‐Based Sensor and Their Ammonia Gas‐Sensing Enhancement

Advanced Materials Interfaces, Journal Year: 2023, Volume and Issue: 10(16)

Published: April 18, 2023

Abstract Various sensing materials have been demonstrated to increase the precision of technology. Nevertheless, this complicates fabrication process for integration obtain devices that can simultaneously accommodate various gas detectors, like electronic nose. The study here focuses on exploring response different functionalization specific provide an alternative way achieve selective multiple gases. Triethoxysilylpropyl succinic anhydride silane (TESPSA) was introduced 2D material MXene‐Ti 3 C 2 T x form carboxylic acid terminated MXene (COOH‐Ti ) and alternately coated with polyaniline /PANI). This modification doubled up binding sites improved strength Ti surface NH molecules. 5CC‐COOH‐Ti /PANI sensor prepared from five coating cycles showed highest sensitivity (214.70 %) fast rate at 80 ppm (1.75 % s ‐1 ). Therefore, signal responses same will allow possible array fingerprint‐like map recognition in presence mixed

Language: Английский

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Determination of Ozone Concentration Levels in Urban Environments Using a Laser Spectroscopy System

Environments, Journal Year: 2024, Volume and Issue: 11(1), P. 9 - 9

Published: Jan. 2, 2024

In urban areas, there has been a recent rise in ground-level ozone. Given its toxicity to both humans and the environment, investigation of ozone pollution demands attention should not be overlooked. Therefore, we conducted study on concentration three distinct locations within city Magurele, Romania. This considered variations structure location during spring summer seasons, specifically at breathing level 1.5 m above ground. Our analysis aimed explore impact different meteorological variables levels. The measurement points were strategically positioned diverse settings: city, forest, an industrial area. For these measurements, used laser spectroscopy system determine system’s sensitivity selectivity influence humidity detection ambient air, which is mixture trace gases water vapor. During March–August campaign, mean values measuring 24.45 ± 16.44 ppb, 11.96 3.80 95.01 37.11 ppb. peak concentrations observed season. A diurnal revealed that atmospheric levels higher latter part day compared earlier part. These measurements suggest temperature plays significant role tropospheric production. Additionally, such as wind speed direction found concentration. Remarkably, despite substantial traffic, remained consistently low throughout entire period forested observation may remarkable ability trees mitigate

Language: Английский

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Copper-Substituted Calcium Orthophosphate (CaxCu1-x)HPO4.nH2O for Humidity Detection

Crystals, Journal Year: 2025, Volume and Issue: 15(2), P. 153 - 153

Published: Feb. 1, 2025

Calcium orthophosphate material (Ca1-xCux)HPO4.nH2O (0.4 ≤ x 1) with the gradual replacement of Ca2+ Cu2+ ions were synthesized by a chemical precipitation technique. Samples characterized X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission (TEM). Then, prepared powders deposited onto an alumina substrate interdigitated Pt electrodes spin coating method polyvinyl alcohol (PVA) as binder. Successively, sensors investigated from 0% to 90% at room temperature under various conditions, including humidity, nitrogenous oxide, methane, carbon dioxide ammonia. The results evidenced that RH, sensitivity significantly increased increase in Cu content. Moreover, exhibited good repeatability and, after 1 year aging, sensor response was equal 34% freshly sensor. Finally, there no interference presence other gases (nitrogenous oxide 2.5 ppm, methane 10 500 ppm ammonia 4 ppm).

Language: Английский

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Infrared to terahertz identification of chemical substances used for the production of IEDs

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2024, Volume and Issue: 312, P. 124055 - 124055

Published: Feb. 23, 2024

Language: Английский

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Temporal Variations in Urban Air Pollution during a 2021 Field Campaign: A Case Study of Ethylene, Benzene, Toluene, and Ozone Levels in Southern Romania

Sustainability, Journal Year: 2024, Volume and Issue: 16(8), P. 3219 - 3219

Published: April 11, 2024

This study focused on quantifying the gas concentrations of ethylene, benzene, toluene, and ozone within an urban area in southern region Romania. The sampling campaign, conducted between March August 2021, took place three different locations from point view architectural structure, height was 1.5 m. Sampling occurred weekdays (Monday through Friday) during daylight hours, with subsequent concentration analysis employing descriptive statistics, diurnal cycles, seasonal assessments. A highly sensitive selective detector, laser photoacoustic spectroscopy, utilized to monitor pollutants. average (±Standard Deviation) were determined as follows: ethylene at 116.82 ± 82.37 parts per billion (ppb), benzene 1.13 0.32 ppb, toluene 5.48 3.27 154.75 68.02 peak levels observed summer months. Diurnal patterns observable for exhibiting higher early hours day followed by a decrease towards evening. In contrast, peaked evening compared part day. Thus, perceptible effects demonstrated result influence meteorological variables. Moreover, high toluene/benzene ratio indicated traffic industrial emissions primary sources these Of four gases monitored, exceeded regulatory limits, particularly season, highlighting concerns regarding air quality studied environment.

Language: Английский

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Measurement Report: Urban Ammonia and Amines in Houston, Texas

Published: May 7, 2024

Abstract. Ammonia and amines play critical roles in secondary aerosol formation, especially urban environments. However, fast measurements of ammonia the atmosphere are very scarce. We measured with a chemical ionization mass spectrometer (CIMS) at center Houston, Texas, fourth most populated site United States, during October 2022. concentrations were on average 4 parts per billion volume (ppbv), while concentration an individual amine ranged from several trillion (pptv) to hundreds pptv. These reduced nitrogen compounds more abundant weekdays than weekends correlated CO concentrations, implying they mostly emitted pollutant sources. Both showed distinct diurnal cycle, higher warmer afternoon, indicating dominant gas-to-particle conversion processes taking place changing ambient temperatures. Studies have shown that dimethylamine is for new particle formation (NPF), but currently, there no emission inventories global climate models (as opposed ammonia). Our observations show general positively ammonia, it reasonable use scaled-down (e.g., 0.1 %) as proxy simulate NPF processes.

Language: Английский

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Bio-Based Colorimetric Sensors for Detecting Ammonia in the Air

IEEE Sensors, Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 29, 2023

Sustainable ammonia colorimetric sensors made from bio-based compounds prepared agricultural waste are developed. The operate at room temperature two important concentration scales: an accident scale $(> 50$ ppm NH3 in the air) and a health safety (1 – 50 air). color change of reacting to can be followed by naked eye quantified with homemade device smartphone. sensors' response time high concentrations (>50 ppm) is minutes, making them useful for applications, such as fast detection leakages accidents or alarming workplace.

Language: Английский

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