Embedded gas sensing setup for air samples analysis

Spoilage Monitoring and Early Warning for Apples in Storage Using Gas Sensors and Chemometrics

In the process of storage and cold chain logistics, apples are prone to physical bumps or microbial infection, which easily leads to spoilage in the micro-environment, resulting in widespread infection and serious post-harvest economic losses. Thus, development of methods for monitoring apple spoilage and providing early warning of spoilage has become the focus for post-harvest loss reduction. Thus, in this study, a spoilage monitoring and early warning system was developed by measuring volatile component production during apple spoilage combined with chemometric analysis. An apple spoilage monitoring prototype was designed to include a gas monitoring array capable of measuring volatile organic compounds, such as CO2, O2 and C2H4, integrated with the temperature and humidity sensor. The sensor information from a simulated apple warehouse was obtained by the prototype, and a multi-factor fusion early warning model of apple spoilage was established based on various modeling methods. Simulated annealing-partial least squares (SA-PLS) was the optimal model with the correlation coefficient of prediction set (Rp) and root mean square error of prediction (RMSEP) of 0.936 and 0.828, respectively. The real-time evaluation of the spoilage was successfully obtained by loading an optimal monitoring and warning model into the microcontroller. An apple remote monitoring and early warning platform was built to visualize the apple warehouse's sensors data and spoilage level. The results demonstrated that the prototype based on characteristic gas sensor array could effectively monitor and warn apple spoilage.

A review of design approaches for the implementation of low-frequency noise measurement systems

Electronic noise has its roots in the fundamental physical interactions between matter and charged particles, carrying information about the phenomena that occur at the microscopic level. Therefore, Low-Frequency Noise Measurements (LFNM) are a well-established technique for the characterization of electron devices and materials and, compared to other techniques, they offer the advantage of being non-destructive and of providing a more detailed view of what happens in the matter during the manifestation of physical or chemical phenomena. For this reason, LFNM acquire particular importance in the modern technological era in which the introduction of new advanced materials requires in-depth and thorough characterization of the conduction phenomena. LFNM also find application in the field of sensors, as they allow to obtain more selective sensing systems even starting from conventional sensors. Performing meaningful noise measurements, however, requires that the background noise introduced by the measurement chain be much smaller than the noise to be detected and the instrumentation available on the market does not always meet the specifications required for reaching the ultimate sensitivity. Researchers willing to perform LFNM must often resort to the design of dedicated instrumentation in their own laboratories, but their cultural background does not necessarily include the ability to design, build, and test dedicated low noise instrumentation. In this review, we have tried to provide as much theoretical and practical guidelines as possible, so that even researchers with a limited background in electronic engineering can find useful information in developing or customizing low noise instrumentation.

Clinical studies of detecting COVID-19 from exhaled breath with electronic nose

The COVID-19 pandemic has attracted numerous research studies because of its impact on society and the economy. The pandemic has led to progress in the development of diagnostic methods, utilizing the polymerase chain reaction (PCR) as the gold standard for coronavirus SARS-CoV-2 detection. Numerous tests can be used at home within 15 min or so but of with lower accuracy than PCR. There is still a need for point-of-care tests available for mass daily screening of large crowds in airports, schools, and stadiums. The same problem exists with fast and continuous monitoring of patients during their medical treatment. The rapid methods can use exhaled breath analysis which is non-invasive and delivers the result quite fast. Electronic nose can detect a cocktail of volatile organic com-pounds (VOCs) induced by virus infection and disturbed metabolism in the human body. In our exploratory studies, we present the results of COVID-19 detection in a local hospital by applying the developed electronic setup utilising commercial VOC gas sensors. We consider the technical problems noticed during the reported studies and affecting the detection results. We believe that our studies help to advance the proposed technique to limit the spread of COVID-19 and similar viral infections.

Forecasting the Post-Pandemic Effects of the SARS-CoV-2 Virus Using the Bullwhip Phenomenon Alongside Use of Nanosensors for Disease Containment and Cure

The COVID-19 pandemic has the tendency to affect various organizational paradigm alterations, which civilization hasyet to fully comprehend. Personal to professional, individual to corporate, and across most industries, the spectrum of transformations is vast. Economically, the globe has never been more intertwined, and it has never been subjected to such widespread disruption. While many people have felt and acknowledged the pandemic's short-term repercussions, the resultant paradigm alterations will certainly have long-term consequences with an unknown range and severity. This review paper aims at acknowledging various approaches for the prevention, detection, and diagnosis of the SARS-CoV-2 virus using nanomaterials as a base material. A nanostructure is a material classification based on dimensionality, in proportion to the characteristic diameter and surface area. Nanoparticles, quantum dots, nanowires (NW), carbon nanotubes (CNT), thin films, and nanocomposites are some examples of various dimensions, each acting as a single unit, in terms of transport capacities. Top-down and bottom-up techniques are used to fabricate nanomaterials. The large surface-to-volume ratio of nanomaterials allows one to create extremely sensitive charge or field sensors (electrical sensors, chemical sensors, explosives detection, optical sensors, and gas sensing applications). Nanowires have potential applications in information and communication technologies, low-energy lightning, and medical sensors. Carbon nanotubes have the best environmental stability, electrical characteristics, and surface-to-volume ratio of any nanomaterial, making them ideal for bio-sensing applications. Traditional commercially available techniques have focused on clinical manifestations, as well as molecular and serological detection equipment that can identify the SARS-CoV-2 virus. Scientists are expressing a lot of interest in developing a portable and easy-to-use COVID-19 detection tool. Several unique methodologies and approaches are being investigated as feasible advanced systems capable of meeting the demands. This review article attempts to emphasize the pandemic's aftereffects, utilising the notion of the bullwhip phenomenon's short-term and long-term effects, and it specifies the use of nanomaterials and nanosensors for detection, prevention, diagnosis, and therapy in connection to the SARS-CoV-2.

Effect of Wearing Surgical Face Masks on Gas Detection from Respiration Using Photoacoustic Spectroscopy

Wearing surgical face masks is among the measures taken to mitigate coronavirus disease (COVID-19) transmission and deaths. Lately, concern was expressed about the possibility that gases from respiration could build up in the mask over time, causing medical issues related to the respiratory system. In this research study, the carbon dioxide concentration and ethylene in the breathing zone were measured before and immediately after wearing surgical face masks using the photoacoustic spectroscopy method. From the determinations of this study, the C₂H₄ was established to be increased by 1.5% after one hour of wearing the surgical face mask, while CO₂ was established to be at a higher concentration of 1.2% after one hour of wearing the surgical face mask, when the values were correlated with the baseline (control).

Advances in measurements and instrumentation leveraging embedded systems

The expression "embedded systems" is used in different contexts and with broad meanings, but in electronics, it refers to systems that contain peripherals and a firmware for local digital data processing, often on a single board. Embedded systems are often associated with the field of computer science, emphasizing the software and programming aspects of systems. However, the progress made on the hardware side cannot be ignored, and without such technological advances, embedded systems would not exist. In fact, the progress in the field of microelectronics drives a constant evolution of variegated digital platforms, which gradually become easier to program and configure, thus reducing the development and prototyping phase and causing a strong impact on different research and application fields.