Assessment of the indoor odour impact in a naturally ventilated room

Indoor air quality influences peopleâ\u80\u99s lives, potentially affecting their health and comfort. Nowadays, ventilation is the only technique commonly used for regulating indoor air quality. CO2 is the reference species considered in order to calculate the air exchange rates of indoor environments. Indeed, regarding air quality, the presence of pleasant or unpleasant odours can strongly influence the environmental comfort. In this paper, a case study of indoor air quality monitoring is reported. The indoor field tests were conducted measuring both CO2 concentration, using a photoacoustic multi-gas analyzer, and odour trends, using an electronic nose, in order to analyze and compare the information acquired. The indoor air monitoring campaign was run for a period of 20 working days into a university room. The work was focused on the determination of both CO2 and odour emission factors (OEF) emitted by the human activity and on the evaluation of the odour impact in a naturally ventilated room. The results highlighted that an air monitoring and recycling system based only on CO2 concentration and temperature measurements might be insufficient to ensure a good indoor air quality, whereas its performances could be improved by integrating the existing systems with an electronic nose for odour detection

QRsens:dual-purpose quick response code with built-in colorimetric sensors

QRsens represents a family of Quick Response (QR) sensing codes for in-situ air analysis with a customized smartphone application to simultaneously read the QR code and the colorimetric sensors. Five colorimetric sensors (temperature, relative humidity (RH), and three gas sensors (CO₂, NH₃ and H₂S)) were designed with the aim of proposing two end-use applications for ambient analysis, i.e., enclosed spaces monitoring, and smart packaging. Both QR code and colorimetric sensing inks were deposited by standard screen printing on white paper. To ensure minimal ambient light dependence of QRsens during the real-time analysis, the smartphone application was programmed for an effective colour correction procedure based on black and white references for three standard illumination temperatures (3000, 4000 and 5000 K). Depending on the type of sensor being analysed, this integration achieved a reduction of ∼71 – 87% of QRsens's dependence on the light temperature. After the illumination colour correction, colorimetric gas sensors exhibited a detection range of 0.7–4.1%, 0.7–7.5 ppm, and 0.13–0.7 ppm for CO2, NH3 and H2S, respectively. In summary, the study presents an affordable built-in multi-sensing platform in the form of QRsens for in-situ monitoring with potential in different types of ambient air analysis applications

QRsens: Dual-purpose quick response code with built-in colorimetric sensors

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.snb.2022.133001.QRsens represents a family of Quick Response (QR) sensing codes for in-situ air analysis with a customized smartphone application to simultaneously read the QR code and the colorimetric sensors. Five colorimetric sensors (temperature, relative humidity (RH), and three gas sensors (CO2, NH3 and H2S)) were designed with the aim of proposing two end-use applications for ambient analysis, i.e., enclosed spaces monitoring, and smart packaging. Both QR code and colorimetric sensing inks were deposited by standard screen printing on white paper. To ensure minimal ambient light dependence of QRsens during the real-time analysis, the smartphone application was programmed for an effective colour correction procedure based on black and white references for three standard illumination temperatures (3000, 4000 and 5000 K). Depending on the type of sensor being analysed, this integration achieved a reduction of ~71 – 87% of QRsens’s dependence on the light temperature. After the illumination colour correction, colorimetric gas sensors exhibited a detection range of 0.7–4.1%, 0.7–7.5 ppm, and 0.13–0.7 ppm for CO2, NH3 and H2S, respectively. In summary, the study presents an affordable built-in multi-sensing platform in the form of QRsens for in-situ monitoring with potential in different types of ambient air analysis applications.Spanish MCIN/AEI/10.13039/ 501100011033/ (Projects PID2019–103938RB-I00, ECQ2018–004937- P and grant IJC2020–043307-I)Junta de Andalucía (Projects B- FQM-243-UGR18, P18-RT-2961)European Regional Development Funds (ERDF)European Union NextGenerationEU/PRT

Air Quality Monitoring, Assessment and Management

Human beings need to breathe oxygen diluted in certain quantity of inert gas for living. In the atmosphere, there is a gas mixture of, mainly, oxygen and nitrogen, in appropriate proportions. However, the air also contains other gases, vapours and aerosols that humans incorporate when breathing and whose composition and concentration vary spatially. Some of these are physiologically inert. Air pollution has become a problem of major concern in the last few decades as it has caused negative effects on human health, nature and properties. This book presents the results of research studies carried out by international researchers in seventeen chapters which can be grouped into two main sections: a) air quality monitoring and b) air quality assessment and management, and serves as a source of material for all those involved in the field, whether as a student, scientific researcher, industrialist, consultant, or government agency with responsibility in this area

Development of Arduino-based portable systems for electroanalytical detection

This work presents the development of a multi-mode electroanalytical detection system based on Arduino microcontroller board. First, a multichannel impedance readout system is designed for alternating current electrokinetics (ACEK) based capacitive sensing. ACEK phenomena on 100μm interdigitated electrodes are observed via fluorescent particles as well as bioparticles, which illustrate the mechanisms of ACEK target enrichment for the capacitive sensing method. I2C multiplexer is applied to allow multiple impedance converters to work together providing continuous AC signals for ACEK capacitive sensing. Second, an electronic nose composed of three modules including a gas sensor array, a circuit for signal acquisition integrated with Arduino microcontroller board, and a PC for signal analysis is designed. A backpropagation neural network with one hidden layer and one output layer is trained to classify gas samples from binary and ternary mixtures of acetone, ethanol, and isopropyl alcohol. Three features are extracted from transient signals in a short time (as compared to steady-state signals), and the classification is done within 1 minute after gas reached the surface of the sensors. Third, a low-cost portable potentiometric sensing system for the detection of heavy metals in water is developed and assessed by testing with hand-fabricated all-solid-state Pb2+ and Cd2+ ion-selective electrodes (ISEs). To avoid the use of a multimeter, an extended-gate metal-oxide-semiconductor field-effect transistor (MOSFET) is applied to the readout circuit and integrated with an Arduino microcontroller board. ALD1106 matched MOSFET pair is chosen for differential sensing to overcome the possible drift problem of ISEs. With a threshold voltage of 0.7 V while operating at the subthreshold region, the MOSFET could be biased via a potentiometer to avoid the use of a voltage source. Last, the three different analytical detections are integrated into one multi-mode system in the design

Detection of liver dysfunction using a wearable electronic nose system based on semiconductor metal oxide sensors

The purpose of this exploratory study was to determine whether liver dysfunction can be generally classified using a wearable electronic nose based on semiconductor metal oxide (MOx) gas sensors, and whether the extent of this dysfunction can be quantified. MOx gas sensors are attractive because of their simplicity, high sensitivity, low cost, and stability. A total of 30 participants were enrolled, 10 of them being healthy controls, 10 with compensated cirrhosis, and 10 with decompensated cirrhosis. We used three sensor modules with a total of nine different MOx layers to detect reducible, easily oxidizable, and highly oxidizable gases. The complex data analysis in the time and non-linear dynamics domains is based on the extraction of 10 features from the sensor time series of the extracted breathing gas measurement cycles. The sensitivity, specificity, and accuracy for distinguishing compensated and decompensated cirrhosis patients from healthy controls was 1.00. Patients with compensated and decompensated cirrhosis could be separated with a sensitivity of 0.90 (correctly classified decompensated cirrhosis), a specificity of 1.00 (correctly classified compensated cirrhosis), and an accuracy of 0.95. Our wearable, non-invasive system provides a promising tool to detect liver dysfunctions on a functional basis. Therefore, it could provide valuable support in preoperative examinations or for initial diagnosis by the general practitioner, as it provides non-invasive, rapid, and cost-effective analysis results

A Scoping Review of Technological Approaches to Environmental Monitoring

Indoor environment quality (IEQ) can negatively affect occupant health and wellbeing. Air quality, as well as thermal, visual and auditory conditions, can determine how comfortable occupants feel within buildings. Some can be measured objectively, but many are assessed by interpreting qualitative responses. Continuous monitoring by passive sensors may be useful to identify links between environmental and physiological changes. Few studies localise measurements to an occupant level perhaps due to many environmental monitoring solutions being large and expensive. Traditional models for occupant comfort analysis often exacerbate this by not differentiating between individual building occupants. This scoping review aims to understand IEQ and explore approaches as to how it is measured with various sensing technologies, identifying trends for monitoring occupant health and wellbeing. Twenty-seven studies were reviewed, and more than 60 state-of-the-art and low-cost IEQ sensors identified. Studies were found to focus on the home or workplace, but not both. This review also found how wearable technology could be used to augment IEQ measurements, creating personalised approaches to health and wellbeing. Opportunities exist to make individuals the primary unit of analysis. Future research should explore holistic personalised approaches to health monitoring in buildings that analyse the individual as they move between environments

Environmental and health provisions for building products

ENVIRONMENTAL AND HEALTH PROVISIONS FOR BUILDING PRODUCTS Environmental and health provisions for building products (Rights reserved) ( -