scholarly journals Miniaturizing wet scrubbers for aerosolized droplet capture

2021 ◽  
Author(s):  
Ulri N Lee ◽  
Tammi L van Neel ◽  
Fang Yun Lim ◽  
Jian Wei Khor ◽  
Jiayang He ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Ease Of Use ◽  
Droplet Growth ◽  
Aerosol Sampling ◽  
Sampling Device ◽  
Industrial Systems ◽  
Adverse Health Effects ◽  
Personal Exposures ◽  
Wet Scrubbers ◽  
Particulate Matter Pollution

Particles dispersed and transmitted through the air (e.g., particulate matter pollution, bioaerosols) are ubiquitous and one of the leading causes of adverse health effects and disease transmission. A variety of sampling methods (e.g., filters, cyclones, impactors) have been developed to assess personal exposures. However, a gap still remains in the accessibility and ease-of-use of these technologies for people without experience or training in collecting airborne samples. Additionally, wet scrubbers (large non-portable industrial systems) utilize liquid sprays to remove particles from the air; the goal is to "scrub" (i.e., clean) the exhaust of industrial smoke stacks, not collect the particles for analysis. Inspired by wet scrubbers, we developed a device fundamentally different from existing portable air samplers by using aerosolized microdroplets to capture airborne particles in personal spaces (e.g., homes, offices, schools). Our aerosol-sampling device is the size of a pint of ice cream (0.5 L), can be operated without specialized training, and features a winding flow path in a supersaturated relative humidity environment enabling droplet growth. The integrated open mesofluidic channels shuttle coalesced droplets to a collection chamber for subsequent sample analysis. Here, we present the experimental demonstration of aerosol capture into water droplets. Iterative study optimized the non-linear flow manipulating baffles and enabled us to retain 83% of the aerosolized microdroplets in the confined volume of our device. As a proof-of-concept for bioaerosol capture into the liquid medium, 0.5-3 μm model particles were used to evaluate aerosol capture efficiency.

scholarly journals Evaluation of the efficacy of two methods for direct extraction of DNA from Mycobacterium tuberculosis sputum

2018 ◽  
Vol 12 (12) ◽  
pp. 1067-1072
Author(s):  
Victor Ndhlovu ◽  
Wilson Mandala ◽  
Derek Sloan ◽  
Mercy Kamdolozi ◽  
Maxine Caws ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Single Molecule ◽  
Disease Transmission ◽  
Extraction Efficiency ◽  
Ease Of Use ◽  
Clinical Samples ◽  
Direct Extraction ◽  
Significant Difference ◽  
Ctab Method ◽  
Dna Purity

Introduction: Whole genome sequencing (WGS) has shown superiority over other bacterial typing methods and can be used to monitor disease transmission. The long culture period hinders use of WGS as a diagnostic tool for TB. The ideal situation would be to efficiently sequence directly from clinical specimens such as sputum. Attempts to sequence directly from Mtb clinical samples have achieved very low coverage (less than 0.7X). We compared DNA extraction methods for direct extraction from Mycobacterium tuberculosis positive sputum and assessed their suitability for Single Molecule Real Time sequencing. Methodology: We evaluated the extraction efficiency of the PrimeXtract kit and an in-house CTAB method by extracting DNA from Mtb sputum. We evaluated the methods on these parameters: ease of use, efficiency (quantity and purity) and the cost per extraction. Results: The PrimeXtract kit was able to isolate 5.93 µg/mL ± 0.94, (Mean ± SEM) concentration of DNA and a yield of 0.2975 µg ± 0.04723, (Mean ± SEM). Comparatively, the CTAB method isolated 1.88 µg/mL ± 0.38 DNA and a yield of 0.09 µg ± 0.02. Both concentration and yield from the kit were significantly (p = 0.0002) higher than those from CTAB. The PrimeXtract kit had a DNA purity ratio of 1.69 ± 0.09 compared to the CTAB’s 1.73 ± 0.14 and this difference was not statistically different. Conclusion: PrimeXtract kit has a superior extraction efficiency than the CTAB method on Mtb sputum in terms of DNA yield although no significant difference by DNA purity was seen.

A PROPOSED SAMPLING DEVICE FOR PERSONAL EXPOSURES

AIHAJ ◽  
1992 ◽  
Vol 53 (8) ◽  
pp. 527-527 ◽  
Author(s):  
Paul T. Chien
Keyword(s):  
Sampling Device ◽  
Personal Exposures

scholarly journals Hierarchical Superhydrophobic Copper for Sustained Dropwise Condensation

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Xuemei Chen ◽  
Justin A. Weibel
Keyword(s):  
Growth Dynamics ◽  
Time Lapse ◽  
Droplet Surface ◽  
Droplet Growth ◽  
Environmental Scanning ◽  
Dropwise Condensation ◽  
Droplet Motion ◽  
Surface Design ◽  
Industrial Systems ◽  
The Hill

Engineering surfaces that sustain continuous dropwise condensation, and are composed of materials commonly employed in heat transfer applications, are of great interest for scaled-up industrial systems. We fabricate hierarchical micro/nano-structured superhydrophobic surfaces on copper substrates. Condensate droplet growth dynamics on the as-fabricated samples were investigated using an environmental scanning electron microscope (ESEM; FEI Quanta 3D, ~6 torr, ~3 °C stage). Time-lapse ESEM images show that the condensate droplets preferentially nucleate at the bases of the hill-shaped microstructures (40 s). The droplets at the microstructure bases coalesce; merged droplets rise and appear to be suspended atop adjacent microstructures (180-220 s). These droplets, when triggered by coalescence, can gain sufficient kinetic energy by a reduction in droplet surface area/energy to spontaneously depart from the substrate. This droplet motion sweeps additional droplets in the trajectory and exposes fresh space for formation of new droplets (220-250 s). These droplet growth and departure dynamics are facilitated by the combination of microscale and nanoscale roughness features on the surface, and the behavior provides important insight into surface design requirements for sustaining dropwise condensation in thermal management applications.

scholarly journals Factors Affecting the Adoption of Blockchain Technology in the Complex Industrial Systems: Data Modeling

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yu Chengyue ◽  
M. Prabhu ◽  
Mahendar Goli ◽  
Anoop Kumar Sahu
Keyword(s):  
Technology Acceptance ◽  
Survey Data ◽  
Structural Equation ◽  
Positive Impact ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Theoretical Research ◽  
Equation Modeling ◽  
Industrial Systems ◽  
Blockchain Technology

Nowadays, Blockchain Technology (BCT) is contributing toward addressing the challenges of complex industrial systems (CISs). The BCT reduces the complexity of cash data storage as well as retrieval system of finance, marketing, supply chain, inventory, and other departments. The objective of the present study is to investigate the factors, which affect the intention of professionals to adapt the BCT in the CISs by using an extension of the technology acceptance model. To fulfill the research objective, a theoretical research model is constituted by multiple hypotheses (H1–H6), i.e., perceived usefulness, perceived ease of use, perceived innovativeness, knowledge, risk, and trust after conducting the relevant literature survey in the context of BCT. Next, each hypothesis is tested by exploring the survey data of a sample of 287 professionals of different BCT user’s companies such as retailing, e-commerce, manufacturing, and construction. Survey data is analyzed by executing the structural equation modeling with AMOS software. The factors and latent constructs loadings, reliability, convergent, discriminant, model fit-measurement, structural model, and the path analysis are conducted. The results reveal that the H1, H2, and H4–H6 dropped the positive impact and effect on professionals’ intention to use the BCT in CISs. But, H3 has no effect for enhancing the intention of professionals to use BCT.

scholarly journals Estimation of Dust Downfall Time in Dusty Days using the Correlation between PM<sub>10</sub> and Sunphotometer Data

2017 ◽  
Author(s):  
Samira Zolfaghari Nikanjam ◽  
Hamid Reza Khalesifard ◽  
Yousefali Abedini
Keyword(s):  
Remote Sensing ◽  
Air Pollution ◽  
Correlation Coefficient ◽  
Aerosol Optical Depth ◽  
Urban Air Pollution ◽  
Urban Air ◽  
Aerosol Sampling ◽  
Measurement Instruments ◽  
Sampling Device ◽  
Vertical Column

Abstract. Urban air pollution has become a serious challenge in all societies. Nowadays, pollutants are measured by various tools and devices, including local particulate measurement instruments and ground-based remote sensing devices. This paper aims to estimate dust downfall time in dusty days of Zanjan city using the data obtained from ground-based aerosol sampling device and sunphotometer. The particulates with the size of less than 10 micrometers (PM10) were measured by ground-based measurement device in the height of 3 meters above the ground, while aerosol optical depth (AOD), which represents the amount of aerosols in vertical column of atmosphere, was measured by sunphotometer. According to correlation coefficient diagram, PM10 and AOD reached a maximum of 2, 6, 3 and 3 hours in dusty days of 9, 10, 24 and 25 June 2010. In other words, dust downfall took 2, 6, 3 and 3 hours respectively in the aforementioned days. Keywords: Downfall, dust, sunphotometer, correlation

scholarly journals Ion-Selective Electrodes for Detection of Lead (II) in Drinking Water: A Mini-Review

Environments ◽  
2018 ◽  
Vol 5 (9) ◽  
pp. 95 ◽  
Author(s):  
Xiaochao Tang ◽  
Po-Yen Wang ◽  
Gabrielle Buchter
Keyword(s):  
Drinking Water ◽  
Low Cost ◽  
Analytical Techniques ◽  
Ease Of Use ◽  
Lead Contamination ◽  
Superior Performance ◽  
Adverse Health Effects ◽  
Lead Detection ◽  
Skilled Operator ◽  
Near Term

Despite the fact that the adverse health effects due to the intake of lead have been well studied and widely recognized, lead contamination in drinking water has been reoccurring worldwide, with some incidents escalating into a public drinking water crisis. As lead contamination is often related to lead-based pipes close to or inside homes, it is not realistic, at least in the near term, to remove and replace all lead connection pipes and lead-based plumbing. Effective monitoring of lead concentration at consumers’ water taps remains critical for providing consumers with first-hand information and preventing potential wide-spread lead contamination in drinking water. This review paper examines the existing common technologies for laboratory testing and on-site measuring of lead concentrations. As the conventional analytical techniques for lead detection require using expensive instruments, as well as a high time for sample preparation and a skilled operator, an emphasis is placed on reviewing ion-selective electrode (ISE) technology due to its superior performance, low cost, ease of use, and its promising potential to be miniaturized and integrated into standalone sensing units. In a holistic way, this paper reviews and discusses the background, different types of ISEs are reviewed and discussed, namely liquid-contact ISEs and solid-contact ISEs. Along with the potential opportunities for further research, the limitations and unique challenges of ISEs for lead detection are also discussed in detail.

scholarly journals Development of a novel self-sanitizing mask prototype to combat the spread of infectious disease and reduce unnecessary waste

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthew J. Crawford ◽  
Sepehr Ramezani ◽  
Roghaie Jabbari ◽  
Pawan Pathak ◽  
Hyoung J. Cho ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Mycobacterium Tuberculosis ◽  
Exposure Time ◽  
Disease Transmission ◽  
H1n1 Influenza ◽  
Ease Of Use ◽  
Infectious Disease Transmission ◽  
The Face ◽  
Ultraviolet C ◽  
Mitigation Techniques

AbstractWith the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR). ARMOR is a novel, reusable face covering that can be quickly disinfected using an array of ultraviolet C lamps contained within a wearable case. A nanomembrane UVC sensor was used to quantify the intensity of germicidal radiation at 18 different locations on the face covering and determine the necessary exposure time to inactivate SARS-CoV-2 in addition to other viruses and bacteria. After experimentation, it was found that ARMOR successfully provided germicidal radiation to all areas of the mask and will inactivate SARS-CoV-2 in approximately 180 s, H1N1 Influenza in 130 s, and Mycobacterium tuberculosis in 113 s, proving that this design is effective at eliminating a variety of pathogens and can serve as an alternative to traditional waste-producing disposable face masks. The accessibility, ease of use, and speed of sanitization supports the wide application of ARMOR in both clinical and public settings.

scholarly journals Development of a Novel Self-Sanitizing Mask Prototype to Combat the Spread of Infectious Disease and Reduce Unnecessary Waste

2021 ◽  
Author(s):  
Matthew J. Crawford ◽  
Sepehr Ramezani ◽  
Roghaie Jabbari ◽  
Pawan Pathak ◽  
Hyong Jin Cho ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Mycobacterium Tuberculosis ◽  
Exposure Time ◽  
Disease Transmission ◽  
H1n1 Influenza ◽  
Ease Of Use ◽  
Infectious Disease Transmission ◽  
The Face ◽  
Ultraviolet C ◽  
Mitigation Techniques

Abstract With the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR). ARMOR is a novel, reusable face covering that can be quickly disinfected using an array of ultraviolet C lamps contained within a wearable case. A nanomembrane UVC sensor was used to quantify the intensity of germicidal radiation at 18 different locations on the face covering and determine the necessary exposure time to inactivate SARS-CoV-2 in addition to other viruses and bacteria. After experimentation, it was found that ARMOR successfully provided germicidal radiation to all areas of the mask and will inactivate SARS-CoV-2 in approximately 180 seconds, H1N1 Influenza in 130 seconds, and Mycobacterium tuberculosis in 113 seconds, proving that this design is effective at eliminating a variety of pathogens and can serve as an alternative to traditional waste-producing disposable face masks. The accessibility, ease of use, and speed of sanitization supports the wide application of ARMOR in both clinical and public settings.

scholarly journals Growth of respiratory droplets in cold and humid air

2020 ◽  
Author(s):  
Chong Shen Ng ◽  
Kai Leong Chong ◽  
Rui Yang ◽  
Mogeng Li ◽  
Roberto Verzicco ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Disease Transmission ◽  
Liquid Droplet ◽  
Quantitative Agreement ◽  
Droplet Growth ◽  
Liquid Droplets ◽  
Ambient Conditions ◽  
Ambient Temperatures ◽  
Saturated Vapour ◽  
Respiratory Droplets

The ambient conditions surrounding liquid droplets determine their growth or shrinkage. However, the precise fate of a liquid droplet expelled from a respiratory puff as dictated by its surroundings and the puff itself has not yet been fully quantified. From the view of airborne disease transmission, such as SARS-CoV-2, knowledge of such dependencies are critical. Here we employ direct numerical simulations (DNS) of a turbulent respiratory vapour puff and account for the mass and temperature exchange with respiratory droplets and aerosols. In particular, we investigate how droplets respond to different ambient temperatures and relative humidity (RH) by tracking their Lagrangian statistics. We reveal and quantify that in cold and humid environments, as there the respiratory puff is supersaturated, expelled droplets can first experience significant growth, and only later followed by shrinkage, in contrast to the monotonic shrinkage of droplets as expected from the classical view by William F. Wells (1934). Indeed, cold and humid environments diminish the ability of air to hold water vapour, thus causing the respiratory vapour puff to super-saturate. Consequently, the super-saturated vapour field drives the growth of droplets that are caught and transported within the humid puff. To analytically predict the likelihood for droplet growth, we propose a model for the axial RH based on the assumption of a quasi-stationary jet. Our model correctly predicts super-saturated RH conditions and is in good quantitative agreement with our DNS. Our results culminate in a temperature-RH map that can be employed as an indicator for droplet growth or shrinkage.Significance StatementInfluence of environmental conditions on airborne diseases transmission is an important issue, especially during the pandemic of COVID-19. Human-to-human transmission is mediated by the transport of virus-laden respiratory droplets. Here we investigate the problem from a fluid mechanics perspective by conducting numerical simulations to quantify the fate of respiratory droplets in a warm humid coughing puff under different ambient conditions. We reveal a non-intuitive regime with considerable growth of respiratory droplets, dominated by a super-saturated vapour field, preferentially occurring in cold and humid environments. We further propose a theoretical model that accurately predicts the condition for droplet growth. Our work should inform socializing policies and ventilation strategies for controlling indoor ambient conditions to mitigate dispersion of droplets from asymptomatic individuals.

Morphogenetic machines revealed: Microscopy of living cells in the embryo of the frog, Xenopus laevis

1993 ◽  
Vol 51 ◽  
pp. 172-173
Author(s):  
Ray Keller
Keyword(s):  
Image Processing ◽  
Fluorescent Dyes ◽  
Cell Movement ◽  
Living Cells ◽  
Ease Of Use ◽  
Low Light ◽  
Amphibian Embryo ◽  
Large Populations ◽  
Light Fluorescence ◽  
Video Image Processing

The amphibian embryo offers advantages of size, availability, and ease of use with both microsurgical and molecular methods in the analysis of fundamental developmental and cell biological problems. However, conventional wisdom holds that the opacity of this embryo limits the use of methods in optical microscopy to resolve the cell motility underlying the major shape-generating processes in early development.These difficulties have been circumvented by refining and adapting several methods. First, methods of explanting and culturing tissues were developed that expose the deep, nonepithelial cells, as well as the superficial epithelial cells, to the view of the microscope. Second, low angle epi-illumination with video image processing and recording was used to follow patterns of cell movement in large populations of cells. Lastly, cells were labeled with vital, fluorescent dyes, and their behavior recorded, using low-light, fluorescence microscopy and image processing. Using these methods, the details of the cellular protrusive activity that drives the powerful convergence (narrowing)

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