METHODOLOGY for ASSESSING the FINANCIAL SECURITY of ENTERPRISES in the POST-PANDEMIC PERIOD of DIGITAL ECONOMY

The article considers the approaches to assessing the financial security of enterprises presented in the literature, determines the rsistance of the textile industry of Uzbekistan to the negative impact of the coronavirus pandemic on the basis of statistical data, and reveals a significant differentiation of textile industry enterprises in terms of financial stability. Based on data on small enterprises in the textile industry of Uzbekistan, a method for assessing the financial security of an enterprise in the post-pandemic period is proposed and tested, taking into account the complex influence of non-financial parameters of economic security and assessing the deviations of the economic situation at a given enterprise from the patterns emerging in the relevant segment of the economy. In this research an econometric model was developed to determine the factors affecting the chemical industry and express their interrelationship, based on the conducted econometric analysis, the directions of development in our country were determined. According to the authors, it is necessary to continue these directions in order to ensure the economic security of industry enterprises in the country. © 2022 ACM.

Improving the Dissolution Rate and the Bioavailability of Favipiravir by Solid Dispersion with Curcumin

Favipiravir is an anti-viral agent that inhibits RNA-dependent RNA polymerase of several RNA viruses and is approved for the treatment of influenza in Japan. It has a role as an antiviral drug, an anti-coronaviral (COVID-19) agent but the poor solubility of the favipiravir in the aqueous media of the human body cause a reduction in the effectiveness and bioavailability. In the current work, the favipiravir was formulated for the first time as solid dispersed system with curcumin to improve dissolution property and antiviral activity during treatment of Covid-19. Binary and ternary mix of favipiravir and curcumin with/without soluplus were prepared and characterized by Differential Scanning Calorimetry (DSC), Powder X-ray Diffractometry (PXRD) and Fourier Transform Infrared Spec-troscopy (FTIR) and subjected to the dissolution test by apparatus I according to the European Pharma-copeia. The antiviral activity was measured by its cytotoxicity against A549-hACE2 cells. The results re-vealed that there was a reduction in the crystallinity of both binary and ternary mixtures with an en-hancement of the dissolution in comparison with the pure drug which accompanied by an improvement in the antiviral activity which is promising results that need further .Copyright © 2023, Colegio de Farmaceuticos de la Provincia de Buenos Aires. All rights reserved.

Atrial electromechanical delay in post-COVID-19 postural orthostatic tachycardia: Innocent bystander or pathologic factor.

BACKGROUND: Post-COVID-19 syndrome represents a wide range of ongoing symptoms that persist beyond weeks or even months, after recovery from the acute phase. Postural orthostatic tachycardia (POT) is one of these symptoms with a poorly recognized underlying pathophysiology. PURPOSE: We aimed to investigate atrial electromechanical delay (AEMD), demonstrated by electrocardiographic P wave dispersion (PWD) and tissue Doppler echocardiography (TDE) in patients with POST-COVID-19 POT (PCPOT). METHODS: 94 post-COVID-19 patients were enrolled and classified into two groups; PCPOT group, 34 (36.1%) patients, and normal heart rate (NR group), 60 (63.9%) patients. 31.9% of them were males and 68.1% were females, with a mean age of 35 ± 9 years. Both groups were compared in terms of PWD and AEMD. RESULTS: As compared to the NR group, the PCPOT group showed a significant increase in PWD (49 ± 6 versus 25.6 ± 7.8, p < 0.001), higher CRP (37 ± 9 versus 30 ± 6, p = 0.04), prolonged left-atrial EMD, right-atrial EMD and inter-atrial EMD at (p = 0.006, 0.001, 0.002 respectively). Multivariate logistic regression analysis revealed that P wave dispersion (ß 0.505, CI (0.224-1.138), p = 0.023), PA lateral (ß 0.357, CI (0.214-0.697), p = 0.005), PA septal (ß 0.651, CI. (0.325-0.861), p = 0.021), and intra-left atrial EMD (ß 0.535, CI (0.353-1.346) p < 0.012) were independent predictors of PCPOT. CONCLUSION: Atrial heterogenicity in the form of prolonged AEMD and PWD seems to be a reasonable underlying pathophysiology of PCPOT. This could provide a new concern during the management and novel pharmacological approaches in these patients.

Explaining Firm Performance During the COVID-19 With fsQCA: The Role of Supply Network Complexity, Inventory Turns, and Geographic Dispersion.

The COVID-19 pandemic has significantly affected firm performance. As a result, many studies have examined the significance of supply network complexity. Our paper uses the fuzzy set qualitative comparative analysis (fsQCA) method to investigate the causal relationships among the supply network complexity, geographic dispersion, inventory turns, and firm performance. Using a sample of 263 Chinese listed firms, we find that no single factor is necessary to achieve high firm performance during COVID-19 and reveal four paths to produce high performance: operational level driven, supply base complexity driven, and customer base complexity driven with supplier distance, and supply network complexity absence. Furthermore, our findings suggest that supply-based complexity-driven and customer-based complexity-driven can improve firm performance, but not all supply network complexity dimensions can improve firm performance. Hence, firms need to choose the suitable path based on their specific situations.

Bilateral Acute Iris Transillumination without Prior Systemic Antibiotics.

Purpose: To describe a case of bilateral acute iris transillumination (BAIT) with no history of systemic infections or antibiotics intake before the attack. Methods: This study included the review of the clinical record of the patient. Results: A 29-year-old male was referred to the glaucoma clinic with presumed bilateral acute iridocyclitis with refractory glaucoma. Ophthalmic examination revealed bilateral pigment dispersion, marked iris transillumination, dense pigment deposition in the iridocorneal angle, and high intraocular pressure. The patient was diagnosed with BAIT and was followed for 5 months. Conclusion: The diagnosis of BAIT can be elicited even without a prior history of systemic infection or antibiotics intake.

Numerical investigation of the impacts of environmental conditions and breathing rate on droplet transmission during dental service

Dental services are yet to return to a semblance of normality owing to the fear and uncertainty associated with the possible airborne transmission of diseases. The present study aims to investigate the impacts of environmental conditions [changes in ventilation location, ventilation rate, and relative humidity (RH)] and variations in dental patient's breathing rate on droplet transmission during dental service. Computational fluid dynamics simulation was performed based on our previous experimental study during ultrasonic scaling. The impacts of different factors were numerically analyzed by the final fate and proportion of emitted droplets in the dental surgery environment. The results revealed that about 85% of droplets deposited near the dental treatment region, where the patient's torso, face, and floor (dental chair) accounted for around 63%, 11%, and 8.5%, respectively. The change in the ventilation location had a small impact on the deposition of larger droplets (> 60 mu m), and a spatial region with high droplet mass concentration would be presented near the dental professional. The change in the ventilation rate from 5 to 8 ACH led to a 1.5% increment in the fraction of escaped droplets. 50% RH in dental environments was recommended to prevent droplets' fast evaporation and potential mold. Variations in the patient's breathing rate had little effect on the final fate and proportion of emitted droplets. Overall, environmental factors are suggested to maintain 50% RH and larger ACH in dental surgery environments. The findings can give policymakers insights into the role of environmental factors on infection control.

THREE-DIMENSIONAL ANALYTICAL SOLUTION OF THE ADVECTION-DIFFUSION EQUATION FOR AIR POLLUTION DISPERSION

We develop a new analytical solution of a three-dimensional atmospheric pollutant dispersion. The main idea is to subdivide vertically the planetary boundary layer into sub-layers, where the wind speed and eddy diffusivity assume average values for each sub-layer. Basically, the model is assessed and validated using data obtained from the Copenhagen diffusion and Prairie Grass experiments. Our findings show that there is a good agreement between the predicted and observed crosswind-integrated concentrations. Moreover, the calculated statistical indices are within the range of acceptable model performance.

Geographic dispersion and corporate resilience during the COVID-19 pandemic.

This study demonstrates the positive role of geographic dispersion in corporate resilience to the COVID-19 pandemic in the context of China. This association is more pronounced when firms are highly dependent on the domestic market, less likely to obtain enough financing, highly apply digital technology, and have low customer concentration. This association is attributable to the following three channels: a diversified portfolio, the maintenance of business relationships, and access to non-local resources. Overall, our findings provide a more nuanced picture of the potential impacts of corporate diversification on corporate resilience.

Development of Equipment for Air Decontamination in the Ventilation and Air Conditioning Systems of Public Buildings with the Use of the Photocatalysis and Plasmochemistry Methods

Introduction. Seasonal waves of SARS outbreaks, including COVID-19, necessitate the development of measures to create health-safe conditions in crowded places.Problem Statement. The existing supply and exhaust systems of the centralized heating, ventilation and air conditioning (HVAC) do not protect against infection, moreover, they serve as a source for the accumulation and spread of pathogenic microorganisms. Finding effective ways to clean the air in places of mass gathering of people as a component of anti-epidemic measures is an urgent task. Purpose. The purpose of this research is to develop and create equipment for cleaning and disinfecting air from airborne pathogenic microflora in the HVAC systems, which can be installed in the centralized ventilation systems of buildings without their reconstruction and modifications in technological parameters. Material and Methods. A complex of physical and chemical methods, which includes analytical and experimental techniques with the use of the theory of electrogas dynamics of dispersed systems and the raster scanning microscopy methods, and the methods for comparing the same quality indicators of specimens and initial samples have been used.Results. To study the efficiency of both the individual plasma-chemical , photocatalytic modules, as well as the equipment as a whole under the operating conditions that simulate those of the centralized ventilation system, an experimental stand has been created. The optimal technological parameters of the processes for raising the efficiency of air disinfection and purification in the HVAC systems by the plasma photocatalysis methods have been determined. Technical solutions for increasing the energy efficiency of the experimental stand for the complex air purification and disinfection from a wide class of air pollutants in the supply and exhaust ventilation systems of buildings have been proposed.ent, as well as to determine the required level of innova-tion factor by maximizing the hidden innovation capacity.Conclusions. Air disinfection by the method of combined plasma-photocatalytic effect on the air flow with a system for catalytic-thermal decomposition of excess ozone ensures effectively removing pollutants and allows reducing the microbiological contamination of the air to a safe level.

Influence of natural ventilation design on the dispersion of pathogen-laden droplets in a coach bus.

Natural ventilation is an energy-efficient design approach to reduce infection risk (IR), but its optimized design in a coach bus environment is less studied. Based on a COVID-19 outbreak in a bus in Hunan, China, the indoor-outdoor coupled CFD modeling approach is adopted to comprehensively explore how optimized bus natural ventilation (e.g., opening/closing status of front/middle/rear windows (FW/MW/RW)) and ceiling wind catcher (WCH) affect the dispersion of pathogen-laden droplets (tracer gas, 5 µm, 50 µm) and IR. Other key influential factors including bus speed, infector's location, and ambient temperature (Tref) are also considered. Buses have unique natural ventilation airflow patterns: from bus rear to front, and air change rate per hour (ACH) increases linearly with bus speed. When driving at 60 km/h, ACH is only 6.14 h-1 and intake fractions of tracer gas (IFg) and 5 µm droplets (IFd) are up to 3372 ppm and 1394 ppm with ventilation through leakages on skylights and no windows open. When FW and RW are both open, ACH increases by 43.5 times to 267.50 h-1, and IFg and IFd drop rapidly by 1-2 orders of magnitude compared to when no windows are open. Utilizing a wind catcher and opening front windows significantly increases ACH (up to 8.8 times) and reduces IF (5-30 times) compared to only opening front windows. When the infector locates at the bus front with FW open, IFg and IFd of all passengers are <10 ppm. More droplets suspend and further spread in a higher Tref environment. It is recommended to open two pairs of windows or open front windows and utilize the wind catcher to reduce IR in coach buses.

Spread of flushing-generated fecal aerosols in a squat toilet cubicle: Implication for infection risk.

Toilet flushing generates and spread fecal aerosols, potentially leading to infection transmission risk. Squat toilets are widely used in public restrooms in some Asian countries including China and India, and remain to be studied. Aerosol dispersion while flushing squat toilet in cubicle was visualized, while the aerosol concentrations were measured on different surfaces by monitoring fluorescence intensity through seeding simulated fluorescence feces. Flushing-generated fecal aerosols could spread to the breathing zone, deposit on floor, and partitions in squat toilet cubicles, and spread even beyond to the restroom lobby. A total of 0.24 % and 0.17 % of seeded fecal waste deposits on the floor and partition (lower than 0.20 m) for each flush. Aerosol concentration decays rapidly, with 86.8 ± 2.2 % reduction in the second minute after a previous flush compared to that in the first minute. Public toilet users are recommended to wait for 2 min after the early flush before entering the cubicle.

Numerical and experimental study of aerosol dispersion in the Do728 aircraft cabin.

The dispersion of aerosols originating from one source, the 'index' passenger, within the cabin of the aircraft Do728 is studied experimentally using an aerosol-exhaling thermal manikin and in Reynolds-averaged Navier-Stokes simulations (RANS). The overall aim of the present study is the experimental determination of the aerosol spreading for the state-of-the-art mixing ventilation (MV) and to evaluate the potential of alternative ventilation concepts for controlling the aerosol spreading in RANS. For MV, the experiments showed that the ratio of inhaled to exhaled aerosol particles drops below 0.06% (volume ratio) for distances larger than two seat rows from the source. However, within a single row, the observed ratio is higher. Further, the dispersion is much weaker for a standing than for a seated index passenger. High air exchange rates and a well-guided flow prevent a dispersion of the aerosols in high concentrations over larger distances. Additionally, the positive effect of a mask and an increased air flow rate, and especially their combination are shown. In the complementary conducted RANS, the advantages of floor-based cabin displacement ventilation (CDV) which is alternative ventilation concept to MV, regarding spreading lengths and the dwell time of the aerosols in the cabin were determined. The obtained results also underline the importance of the flow field for the aerosol dispersion. Further, additional unsteady RANS (URANS) simulations of the short-term process of the initial aerosol cloud formation highlighted that the momentum decay of the breathing and the evaporation processes take place within a few seconds only. Supplementary Information: The online version contains supplementary material available at 10.1007/s13272-023-00644-3.

Numerical simulation of social distancing of preventing airborne transmission in open space with lateral wind direction, taking into account temperature of human body and floor surface.

This paper presents the numerical results of particle propagation in open space, taking into account the temperature of the human body and the surface of the ground. And also, the settling of particles or droplets under the action of gravitational force and transport in the open air is taken into account, taking into account the temperature during the process of breathing and sneezing or coughing. The temperature of the body and the surface of the ground, different rates of particle emission from the mouth, such as breathing and coughing or sneezing, are numerically investigated. The effect of temperature, cross-inlet wind, and the velocity of particle ejection from a person's mouth on social distancing is being investigated using a numerical calculation. The variable temperature of the human body forms a thermal plume, which affects the increase in the trajectory of the particle propagation, taking into account the lateral air flow. The thermal plume affects the particles in the breathing zone and spreads the particles over long distances in the direction of the airflow. The result of this work shows that in open space, taking into account the temperature of the body and the surface of the ground, a 2-m social distance may be insufficient for the process of sneezing and social distance must be observed depending on the breathing mode.

Tourism De-Metropolisation but Not De-Concentration: COVID-19 and World Destinations

The current COVID-19 pandemic has caused a significant decline in human mobility during the past three years. This may lead to reconfiguring future tourism flows and resulting transformations in the geographic patterns of economic activities and transportation needs. This study empirically addresses the changes in tourism mobility caused by the pandemic. It focuses on the yet unexplored effects of the destination type on tourism volume change. To investigate this, 1426 metropolitan, urban/resort and dispersed destinations were delimited based on Airbnb offers. Airbnb reviews were used as the proxy for the changes in tourist visits in 2019–2022. Linear mixed-effects models were employed to verify two hypotheses on the differences between the effects of the pandemic on three kinds of tourism destinations. The results confirm the tourism de-metropolisation hypothesis: metropolitan destinations have experienced between −12.4% and −7.5% additional decreases in tourism visits compared to secondary cities and resorts. The second de-concentration hypothesis that urban/resort destinations are more affected than dispersed tourism destinations is not supported. The results also confirm that stricter restrictions and destination dependence on international tourism have negatively affected their visitation. The study sheds light on post-pandemic scenarios on tourism mobility transformations in various geographic locations.

Modeling of dispersion of aerosolized airborne pathogens exhaled in indoor spaces

Since the beginning of the COVID19 pandemic, there has been a lack of data to quantify the role played by breathing-out of pathogens in the spread of SARS-Cov-2 despite sufficient indication of its culpability. This work aims to establish the role of aerosol dispersion of SARS-Cov-2 virus and similar airborne pathogens on the spread of the disease in enclosed spaces. A steady-state fluid solver is used to simulate the air flow field, which is then used to compute the dispersion of SARS-Cov-2 and spatial probability distribution of infection inside two representative classrooms. In particular, the dependence of the turbulent diffusivity of the passive scalar on the air changes per hour and the number of inlet ducts has been given due consideration. By mimicking the presence of several humans in an enclosed space with a time-periodic inhalation-exhalation cycle, this study firmly establishes breathing as a major contributor in the spread of the pathogen, especially by superspreaders. Second, a spatial gradient of pathogen concentration is established inside the domain, which strongly refutes the well-mixed theory. Furthermore, higher ventilation rates and proximity of the infected person to the inlet and exhaust vents play an important role in determining the spread of the pathogen. In the case of classrooms, a ventilation rate equivalent to 9 air changes or more is recommended. The simulations show that the "one-meter distance rule"between the occupants can significantly reduce the risk of spreading infection by a high-emitter. © 2023 Author(s).

Computational study of 2D photonic crystal based biosensor for SARS-COV-2 detection

A computational study to design a 2D-photonic crystal (PC) structure with a fluorescence-based biosensor has been demonstrated for the detection of the severe acute respiratory syndrome corona virus 2 (SARS-COV-2) virus in the lungs. The proposed sensor can detect the different concentrations of the virus without any pretreatment of the sample. The virus detection is performed by measuring the mid-gap wavelength from the dispersion diagram and a redshift in the mid-gap wavelength has been observed as the concentration of virus increases in the lung tissue. The plane wave expansion method is used to determine the dispersion diagram of the proposed PC. The interaction of incident light with the proposed PC-based biosensor has been analyzed to evaluate the shift in the mid-gap wavelength. A maximum sensitivity of about 1459.3 nm/RIU is obtained for r/a = 0.45 with a mid-gap wavelength shift of 145.93 nm at n net = 1.49 concentration of SARS-COV-2. Moreover, a very small detection time has been observed with the proposed device as compared to conventional methods. This study provides a simple process to detect the presence of a virus within a short period and could be helpful in the development of a direct and easy-to-use portable detection kit in the future. © 2023 IOP Publishing Ltd.

Assessing Indoor Air Quality and Ventilation to Limit Aerosol Dispersion—Literature Review

The COVID-19 pandemic highlighted the importance of indoor air quality (IAQ) and ventilation, which researchers have been warning about for years. During the pandemic, researchers studied several indicators using different approaches to assess IAQ and diverse ventilation systems in indoor spaces. To provide an overview of these indicators and approaches in the case of airborne transmission through aerosols, we conducted a literature review, which covered studies both from before and during the COVID-19 pandemic. We searched online databases for six concepts: aerosol dispersion, ventilation, air quality, schools or offices, indicators, and assessment approaches. The indicators found in the literature can be divided into three categories: dose-, building-, and occupant-related indicators. These indicators can be measured in real physical spaces, in a controlled laboratory, or modeled and analyzed using numerical approaches. Rather than organizing this paper according to these approaches, the assessment methods used are grouped according to the following themes they cover: aerosol dispersion, ventilation, infection risk, design parameters, and human behavior. The first finding of the review is that dose-related indicators are the predominant indicators used in the selected studies, whereas building- and occupant-related indicators are only used in specific studies. Moreover, for a better understanding of airborne transmission, there is a need for a more holistic definition of IAQ indicators. The second finding is that although different design assessment tools and setups are presented in the literature, an optimization tool for a room's design parameters seems to be missing. Finally, to efficiently limit aerosol dispersion in indoor spaces, better coordination between different fields is needed. © 2023 by the authors.

Effects of COVID-19 infection on ECG parameters in outpatients

Objective: Covid-19 infection has been declared as a pandemic disease by the World Health Organization (WHO) and has been associated with increased morbidity and mortality. More than 400 million people diagnosed with the disease has been reported until February 2022 [1]. Covid-19 infection mostly progresses with lung involvement and pneumonia, however, its effects on the cardiovascular system are also well-known. Studies have reported that Covid 19 infection can trigger cardiac events such as acute myocardial damage, acute myocarditis, acute coronary syndrome (ACS), ventricular arrhythmias, cardiogenic shock, and cardiac arrest [2]. Electrocardiogram (ECG) is an important tool to diagnose cardiac involvement. QTc interval, QT dispersion, Tp-e interval, Tp-e/QTc ratio are defined as ventricular repolarization parameters and these parameters are associated with increased risk of ventricular arrhythmia [3,4]. In our study, we aimed to evaluate to predict ventricular arrhythmia by ECG in Covid-19 patients. Method(s): Our study is a single-center, cross-sectional study. Patients diagnosed with Covid-19 in our center between July and October 2020 were included. 408 patients with positive SARS-CoV2 PCR test were detected and the ECGs of the patients were recorded at admission and 15 days after symptomatic recovery. After the exclusion criteria, remained 91 patients were analyzed. Conduction parameters (PR and QRS durations) and repolarization parameters (QTc interval, QT dispersion, Tp-e interval and Tp-e/QTc ratio) were evaluated in 12-lead ECG recordings. Result(s): Ninety-one patients with Covid-19 infection were included. The group were consisted of 47 male (52%) and 44 female (48%). The mean age was 50.4 years. As a result of the statistical analysis, no significant difference was observed between the groups in terms of PR interval (142.2+/-21.4 ms vs. 140.1+/-19.0 ms;p=0.312). QRS duration was found significantly higher during active infection (91.4+/-12.2 ms vs. 88.8+/-10.9 ms;p=0.022). The mean QTc duration was detected longer in the first ECG, but no statistically significant difference was observed between the two groups (426.1+/-23.6 ms vs. 422.5+/-26.2 ms;p=0.237). QT dispersion (35.2+/-7.3 ms vs. 27.7+/-7.8 ms;p<0.001), Tp-e interval (86.7+/-10.1 ms vs. 76.1+/-9.9 ms;p<0.001) and Tp-e/QTc ratio (0.204+/-0.026 vs 0.180+/-0.025;p<0.001) were found significantly higher during active infection Conclusion(s): In our study, QRS complex, QT dispersion, Tp-e interval, Tpe/ QTc ratio were significantly higher during active infection. We considered these parameters as a contributor of the increased mortality by inducing ventricular arrhythmia and sudden death in Covid-19 patients during active infection.

Transmission of droplet aerosols in an elevator cabin: Effect of the ventilation mode.

The recent outbreak of COVID-19 has threatened public health. Owing to the relatively sealed environment and poor ventilation in elevator cabins, passengers are at risk of respiratory tract infection. However, the distribution and dispersion of droplet aerosols in elevator cabins remain unclear. This study investigated the transmission of droplet aerosols exhaled by a source patient under three ventilation modes. Droplet aerosols produced by nose breathing and mouth coughing were resolved using computational fluid dynamics (CFD) simulations. We adopted the verified renormalization group (RNG) k-ε turbulence model to simulate the flow field and the Lagrangian method to track the droplet aerosols. In addition, the influence of the ventilation mode on droplet transmission was evaluated. The results showed that droplet aerosols gathered in the elevator cabin and were difficult to discharge under the mixed and displacement ventilation modes with specific initial conditions. The inhalation proportion of droplet aerosols for air curtain was 0.016%, which was significantly lower than that for mixed ventilation (0.049%) and displacement ventilation (0.071%). The air curtain confined the transmission of droplet aerosols with the minimum ratios of inhalation, deposition, and suspension and is thus recommended to reduce the exposure risk.

A Novel IoT-Enabled Wireless Sensor Grid for Spatial and Temporal Evaluation of Tracer Gas Dispersion.

Current IoT applications in indoor air focus mainly on general monitoring. This study proposed a novel IoT application to evaluate airflow patterns and ventilation performance using tracer gas. The tracer gas is a surrogate for small-size particles and bioaerosols and is used in dispersion and ventilation studies. Prevalent commercial tracer-gas-measuring instruments, although highly accurate, are relatively expensive, have a long sampling cycle, and are limited in the number of sampling points. To enhance the spatial and temporal understanding of tracer gas dispersion under the influence of ventilation, a novel application of an IoT-enabled, wireless R134a sensing network using commercially available small sensors was proposed. The system has a detection range of 5-100 ppm and a sampling cycle of 10 s. Using Wi-Fi communication, the measurement data are transmitted to and stored in a cloud database for remote, real-time analysis. The novel system provides a quick response, detailed spatial and temporal profiles of the tracer gas level, and a comparable air change rate analysis. With multiple units deployed as a wireless sensing network, the system can be applied as an affordable alternative to traditional tracer gas systems to identify the dispersion pathway of the tracer gas and the general airflow direction.