Artículos de revistas: "Liquid aerosol filtration"

1

Frising, T., V. Gujisait, D. Thomas, S. Callé, D. Bémer, P. Contal y D. Leclerc. "Filtration of solid and liquid aerosol mixtures". Filtration & Separation 41, n.º 2 (marzo de 2004): 36. http://dx.doi.org/10.1016/s0015-1882(04)00075-8.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Frising, T., V. Gujisaite, D. Thomas, S. Callé, D. Bémer, P. Contal y D. Leclerc. "Filtration of solid and liquid aerosol mixtures". Filtration & Separation 41, n.º 2 (marzo de 2004): 37–39. http://dx.doi.org/10.1016/s0015-1882(04)00076-x.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Lecoq, Marie, Soleiman Bourrous, Dominique Thomas, Jean-Christophe Appert-Collin, Fabien Floc’Hlay y Mathieu Barrault. "Investigation of the Possibility of Application of Metal Fibrous Media in the Process of Filtration of Liquid Aerosols". Atmosphere 13, n.º 10 (7 de octubre de 2022): 1633. http://dx.doi.org/10.3390/atmos13101633.

Texto completo

Resumen

This manuscript presents a study of the possibility of applying metallic fibre filter media made of stainless steel for the filtration process of liquid aerosols. To perform the experiment, three types of filters were used: single layer and symmetric or non-symmetric multi-layered filters. Filters have been loaded with DEHS (Di-Ethyl-Hexyl-Sebacate) aerosol while the pressure drop and the collection efficiency were monitored. The impact of the filtration velocity on the saturation pressure drop has been quantified for monolayer filters. The building of a draining film on the free surface of the multi-layered filters has been studied and the impact of this phenomenon on the filtration performances and saturation ratio of the medium are discussed. For multilayer filters, the clogging dynamic, occurring by a successive loading of the draining layers, is highlighted in this work. Finally, propositions are made to evaluate the behaviour of metallic multi-layered filters for liquid aerosol filtration applications.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Crosswhite, Mark R., Lena N. Jeong, Patrick C. Bailey, J. Brian Jameson, Anastasia Lioubomirov, David Cook, Clarissa Yang, Adam Ozvald, Matthew Lyndon y I. Gene Gillman. "Non-Targeted Chemical Characterization of JUUL-Menthol-Flavored Aerosols Using Liquid and Gas Chromatography". Separations 9, n.º 11 (11 de noviembre de 2022): 367. http://dx.doi.org/10.3390/separations9110367.

Texto completo

Resumen

The aerosol constituents generated from JUUL Menthol pods with 3.0% and 5.0% nicotine by weight (Me3 and Me5) are characterized by a non-targeted approach, which was developed to detect aerosol constituents that are not known to be present beforehand or that may be measured with targeted methods. Three replicates from three production batches (n = 9) were aerosolized using two puffing regimens (intense and non-intense). Each of the 18 samples were analyzed by gas chromatography electron ionization mass spectrometry and by liquid chromatography electrospray ionization high-resolving power mass spectrometry. All chemical constituents determined to differ from control were identified and semi-quantified. To have a complete understanding of the aerosol constituents and chemistry, each chemical constituent was categorized into one of five groups: (1) flavorants, (2) harmful and potentially harmful constituents, (3) leachables, (4) reaction products, and (5) chemical constituents that were unable to be identified or rationalized (e.g., chemical constituents that could not be categorized in groups (1–4). Under intense puffing, 74 chemical constituents were identified in Me3 aerosols and 68 under non-intense puffing, with 53 chemical constituents common between both regimens. Eighty-three chemical constituents were identified in Me5 aerosol using an intense puffing regimen and seventy-five with a non-intense puffing regimen, with sixty-two chemical constituents in common. Excluding primary constituents, reaction products accounted for the greatest number of chemical constituents (approximately 60% in all cases, ranging from about 0.05% to 0.1% by mass), and flavorants—excluding menthol—comprised the second largest number of chemical constituents (approximately 25%, ranging consistently around 0.01% by mass). The chemical constituents detected in JUUL aerosols were then compared to known constituents from cigarette smoke to determine the relative chemical complexities and commonalities/differences between the two. This revealed (1) a substantial decrease in the chemical complexity of JUUL aerosols vs. cigarette smoke and (2) that there are between 55 (Me3) and 61 (Me5) unique chemical constituents in JUUL aerosols not reported in cigarette smoke. Understanding the chemical complexity of JUUL aerosols is important because the health effects of combustible cigarette smoke are related to the combined effect of these chemical constituents through multiple mechanisms, not just the effects of any single smoke constituent.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Warren, J. Jasper, Anushree Mohan, Juan Hinestroza y Roger Barker. "Degradation Processes in Corona-Charged Electret Filter-Media with Exposure to Ethyl Benzene". Journal of Engineered Fibers and Fabrics 2, n.º 4 (diciembre de 2007): 155892500700200. http://dx.doi.org/10.1177/155892500700200401.

Texto completo

Resumen

The degradation of filtration performance for corona-charged electret filter media exposed to ethyl benzene was assessed. Nonwoven corona-charged polypropylene fiber mats were exposed to ethyl-benzene using a custom made apparatus. Evaluated scenarios included ethyl-benzene vapor and liquid exposures. The filtration performance was evaluated using DOP as a test aerosol to measure filtration performance. It was observed that significant filtration degradation occurred only when liquid ethyl benzene came into direct contact with the filter media. No significant changes in the pressure drop or filtration efficiency was observed for any of the exposure scenarios in which the fibers were only exposed to ethyl benzene in the vapor phase.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Zhu, Ping, Wang Sun y Yunchun Liu. "Improvement of Aerosol Filtering Performance of PLLA/PAN Composite Fiber with Gradient Structure". Nanomaterials 12, n.º 22 (20 de noviembre de 2022): 4087. http://dx.doi.org/10.3390/nano12224087.

Texto completo

Resumen

Since commercial non-woven air filtering materials have unstable filtering efficiency and poor moisture permeability for the abundant condensed aerosol particles in the highly humid atmospheric environment, the PLLA/PAN composite fiber material with a hydrophobic and hydrophilic gradient structure is designed and prepared by using electrode sputtering electro spinning technology. By characterizing and testing the filtrating effect of SEM, XRD, FTIR, wettability, mechanical property, N2 adsorption isotherm, and BET surface area, NaCl aerosol of PLLA fiber, PAN fiber, and PLLA/PAN composite fiber membranes, the study found that the electrode sputtering electrospinning is fine, the fiber mesh is dense, and fiber distribution is uniform when the diameter of the PAN fiber is 140–300 nm, and the PLLA fiber is 700–850 nm. In this case, PLLA/PAN composite fiber materials gather the hydrophobicity of PLLA fiber and the hydrophilicity of PAN fiber; its electrostatic effect is stable, its physical capturing performance is excellent, it can realize the step filtration of gas-solid liquid multiphase flow to avoid the rapid increase of air resistance in a high-humidity environment, and the filtrating efficiency η of NaCl aerosol particles with 0.3 μm reaches 99.98%, and the quality factor QF 0.0968 Pa−1. The manufacturing of PLLA/PAN composite fiber material provides a new method for designing and developing high-performance air filtration materials and a new technical means for the large-scale production of high-performance, high-stability, and low-cost polylactic acid nanofiber composites.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Hao, Junli, Saptarshi Chattopadhyay y Gregory C. Rutledge. "Chemical separation in a binary liquid aerosol by filtration using electrospun membranes". Chemical Engineering Journal 382 (febrero de 2020): 122924. http://dx.doi.org/10.1016/j.cej.2019.122924.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Jin, Xiaohong C., Regina M. Ballentine, William P. Gardner, Matt S. Melvin, Yezdi B. Pithawalla, Karl A. Wagner, Karen C. Avery y Mehran Sharifi. "Determination of Formaldehyde Yields in E-Cigarette Aerosols: An Evaluation of the Efficiency of the DNPH Derivatization Method". Separations 8, n.º 9 (13 de septiembre de 2021): 151. http://dx.doi.org/10.3390/separations8090151.

Texto completo

Resumen

Recent reports have suggested that (1) formaldehyde levels (measured as a hydrazone derivative using the DNPH derivatization method) in Electronic Nicotine Delivery Systems (ENDS) products were underreported because formaldehyde may react with propylene glycol (PG) and glycerin (Gly) in the aerosol to form hemiacetals; (2) the equilibrium would shift from the hemiacetals to the acetals in the acidic DNPH trapping solution. In both cases, neither the hemiacetal nor the acetal would react with DNPH to form the target formaldehyde hydrazone, due to the lack of the carbonyl functional group, thus underreporting formaldehyde. These reports were studied in our laboratory. Our results showed that the aerosol generated from formaldehyde-fortified e-liquids provided a near-quantitative recovery of formaldehyde in the aerosol, suggesting that if any hemiacetal was formed in the aerosol, it would readily hydrolyze to free formaldehyde and, consequently, form formaldehyde hydrazone in the acidic DNPH trapping solution. We demonstrated that custom-synthesized Gly and PG hemiacetal adducts added to the DNPH trapping solution would readily hydrolyze to form the formaldehyde hydrazone. We demonstrated that acetals of PG and Gly present in e-liquid are almost completely transferred to the aerosol during aerosolization. The study results demonstrate that the DNPH derivatization method allows for an accurate measurement of formaldehyde in vapor products.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Gac, Jakub M., Anna Jackiewicz-Zagórska, Łukasz Werner y Szymon Jakubiak. "Numerical modeling of solid deposits reorganization during consecutive solid-liquid aerosol filtration: Influence on the dynamics of filtration efficiency". Journal of Aerosol Science 119 (mayo de 2018): 13–21. http://dx.doi.org/10.1016/j.jaerosci.2018.02.008.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Allison, J. R., C. Dowson, K. Pickering, G. Červinskytė, J. Durham, N. S. Jakubovics y R. Holliday. "Local Exhaust Ventilation to Control Dental Aerosols and Droplets". Journal of Dental Research 101, n.º 4 (10 de noviembre de 2021): 384–91. http://dx.doi.org/10.1177/00220345211056287.

Texto completo

Resumen

Dental procedures produce aerosols that may remain suspended and travel significant distances from the source. Dental aerosols and droplets contain oral microbes, and there is potential for infectious disease transmission and major disruption to dental services during infectious disease outbreaks. One method to control hazardous aerosols often used in industry is local exhaust ventilation (LEV). The aim of this study was to investigate the effect of LEV on aerosols and droplets produced during dental procedures. Experiments were conducted on dental mannequins in an 825.4-m3 open-plan clinic and a 49.3-m3 single surgery. Ten-minute crown preparations were performed with an air-turbine handpiece in the open-plan clinic and 10-min full-mouth ultrasonic scaling in the single surgery. Fluorescein was added to instrument irrigation reservoirs as a tracer. In both settings, optical particle counters (OPCs) were used to measure aerosol particles between 0.3 and 10.0 µm, and liquid cyclone air samplers were used to capture aerosolized fluorescein tracer. In addition, in the open-plan setting, fluorescein tracer was captured by passive settling onto filter papers in the environment. Tracer was quantified fluorometrically. An LEV device with high-efficiency particulate air filtration and a flow rate of 5,000 L/min was used. LEV reduced aerosol production from the air-turbine handpiece by 90% within 0.5 m, and this was 99% for the ultrasonic scaler. OPC particle counts were substantially reduced for both procedures and air-turbine settled droplet detection reduced by 95% within 0.5 m. The effect of LEV was substantially greater than suction alone for the air-turbine and was similar to the effect of suction for the ultrasonic scaler. LEV reduces aerosol and droplet contamination from dental procedures by at least 90% in the breathing zone of the operator, and it is therefore a valuable tool to reduce the dispersion of dental aerosols.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Semeraro, Sabrina, Anastasia Serena Gaetano, Luisa Zupin, Carlo Poloni, Elvio Merlach, Enrico Greco, Sabina Licen et al. "Operative Protocol for Testing the Efficacy of Nasal Filters in Preventing Airborne Transmission of SARS-CoV-2". International Journal of Environmental Research and Public Health 19, n.º 21 (23 de octubre de 2022): 13790. http://dx.doi.org/10.3390/ijerph192113790.

Texto completo

Resumen

Background: Standardized methods for testing Viral Filtration Efficiency (VFE) of tissues and devices are lacking and few studies are available on aerosolizing, sampling and assessing infectivity of SARS-CoV-2 in controlled laboratory settings. NanoAg-coated endonasal filters appear a promising aid for lowering viable virus inhalation in both adult and younger populations (e.g., adolescents). Objective: to provide an adequate method for testing SARS-CoV-2 bioaerosol VFE of bio-gel Ag nanoparticles endonasal filters, by a model system, assessing residual infectivity as cytopathic effect and viral proliferation on in vitro cell cultures. Methods: A SARS-CoV-2 aerosol transmission chamber fed by a BLAM aerosol generator produces challenges (from very high viral loads (105 PFU/mL) to lower ones) for endonasal filters positioned in a Y shape sampling port connected to a Biosampler. An aerosol generator, chamber and sampler are contained in a class II cabinet in a BSL3 facility. Residual infectivity is assessed from aliquots of liquid collecting bioaerosol, sampled without and with endonasal filters. Cytopathic effect as plaque formation and viral proliferation assessed by qRT-PCR on Vero E6 cells are determined up to 7 days post inoculum. Results: Each experimental setting is replicated three times and basic statistics are calculated. Efficiency of aerosolization is determined as difference between viral load in the nebulizer and in the Biosampler at the first day of experiment. Efficiency of virus filtration is calculated as RNA viral load ratio in collected bioaerosol with and without endonasal filters at the day of the experiment. Presence of infectious virus is assessed by plaque forming unit assay and RNA viral load variations. Conclusions: A procedure and apparatus for assessing SARS-CoV-2 VFE for endonasal filters is proposed. The apparatus can be implemented for more sophisticated studies on contaminated aerosols.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Starnoni, M. y C. Manes. "A multiphase multicomponent flow and transport model for liquid aerosol filtration in coalescing fibrous filters". Separation and Purification Technology 266 (julio de 2021): 118574. http://dx.doi.org/10.1016/j.seppur.2021.118574.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Charvet, A., Y. Gonthier, E. Gonze y A. Bernis. "Experimental and modelled efficiencies during the filtration of a liquid aerosol with a fibrous medium". Chemical Engineering Science 65, n.º 5 (marzo de 2010): 1875–86. http://dx.doi.org/10.1016/j.ces.2009.11.037.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Charvet, A., S. Rolland Du Roscoat, M. Peralba, J. F. Bloch y Y. Gonthier. "Contribution of synchrotron X-ray holotomography to the understanding of liquid distribution in a medium during liquid aerosol filtration". Chemical Engineering Science 66, n.º 4 (febrero de 2011): 624–31. http://dx.doi.org/10.1016/j.ces.2010.11.008.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Crosswhite, Mark R., Patrick C. Bailey, Lena N. Jeong, Anastasia Lioubomirov, Clarissa Yang, Adam Ozvald, J. Brian Jameson y I. Gene Gillman. "Non-Targeted Chemical Characterization of JUUL Virginia Tobacco Flavored Aerosols Using Liquid and Gas Chromatography". Separations 8, n.º 9 (24 de agosto de 2021): 130. http://dx.doi.org/10.3390/separations8090130.

Texto completo

Resumen

The chemical constituents of JUUL Virginia Tobacco pods with 3.0% and 5.0% nicotine by weight (VT3 and VT5) were characterized by non-targeted analyses, an approach to detect chemicals that are not otherwise measured with dedicated methods or that are not known beforehand. Aerosols were generated using intense and non-intense puffing regimens and analyzed by gas chromatography electron ionization mass spectrometry and liquid chromatography electrospray ionization high resolving power mass spectrometry. All compounds above 0.7 µg/g for GC–MS analysis or above 0.5 µg/g for LC–HRMS analysis and differing from blank measurements were identified and semi-quantified. All identifications were evaluated and categorized into five groups: flavorants, harmful and potentially harmful constituents, extractables and/or leachables, reaction products, and compounds that could not be identified/rationalized. For VT3, 79 compounds were identified using an intense puffing regimen and 69 using a non-intense puffing regimen. There were 60 compounds common between both regimens. For VT5, 85 compounds were identified with an intense puffing regimen and 73 with a non-intense puffing regimen; 67 compounds were in common. For all nicotine concentrations, formulations and puffing regimens, reaction products accounted for the greatest number of compounds (ranging from 70% to 75%; 0.08% to 0.1% by mass), and flavorants comprised the second largest number of compounds (ranging from for 15% to 16%; 0.1 to 0.2% by mass). A global comparison of the compounds detected in JUUL aerosol to those catalogued in cigarette smoke indicated an approximate 50-fold decrease in chemical complexity. Both VT3 and VT5 aerosols contained 59 unique compounds not identified in cigarette smoke.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Kerner, Maximilian, Kilian Schmidt, Stefan Schumacher, Christof Asbach y Sergiy Antonyuk. "Electret Filters—From the Influence of Discharging Methods to Optimization Potential". Atmosphere 12, n.º 1 (4 de enero de 2021): 65. http://dx.doi.org/10.3390/atmos12010065.

Texto completo

Resumen

Electret filters are electrostatically charged nonwovens which are commonly used in aerosol filtration to remove fine particles from gases. It is known that the charge and thus also the filtration efficiency can degrade over time. Thus, many testing standards require to remove the charge by treatment with liquid isopropanol (IPA) or IPA-saturated air. However, the parameters influencing this discharge have not been completely clarified yet. The aim of this work was, on the one hand, to experimentally investigate the influence of the IPA treatment on different electret filters and, on the other hand, to show the optimization potential of electret filters with respect to efficiency and long-term stability by numerical simulations. The experiments revealed that the air permeability is a central influencing parameter. Small pores lead to a reduced discharge efficiency using liquid IPA, while both treatment methods are suitable for larger pores. The simulations showed that a homogeneous charge distribution within the filter depth is advantageous for the initial performance. In contrast, charge penetrating deeper in the filter medium delays the charge decay and thus increases the operating time, with the trade-off of a lower initial performance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Anttila, Piia, Tuulia Hyötyläinen, Anu Heikkilä, Matti Jussila, Johan Finell, Markku Kulmala y Marja-Liisa Riekkola. "Determination of organic acids in aerosol particles from a coniferous forest by liquid chromatography-mass spectrometry". Journal of Separation Science 28, n.º 4 (marzo de 2005): 337–46. http://dx.doi.org/10.1002/jssc.200401931.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Jung, Seojin y Jooyoun Kim. "Advanced Design of Fiber-Based Particulate Filters: Materials, Morphology, and Construction of Fibrous Assembly". Polymers 12, n.º 8 (30 de julio de 2020): 1714. http://dx.doi.org/10.3390/polym12081714.

Texto completo

Resumen

With increasing air pollution and sporadic outbreaks of epidemics, there is ramping attention on the filtration devices. The main constituents of airborne pollutants are particulate matters of solid particles, liquid aerosol, bioaerosol/bio-droplets, and gas/vapor. With the growing demand for high-performance filters, novel materials and functionalities are being developed applying advanced technologies. In this paper, recent developments of fiber-based particulate filters are reviewed, with a focus on the important performance parameters and material properties. Trends in technology and research activities are briefly reviewed, and the evaluative measures of filtration performance are reported. Recent studies on the advanced filter materials are reviewed in the aspect of polymers and the fabrication process of fibrous assembly. The characterization method including 3D modeling and simulation is also briefly introduced. Multifunctional filters such as antimicrobial filter and gas and particulate filters are briefly introduced, and efforts for developing environmentally sustainable filters are noted.

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Ismayilov, G. G., E. Kh Iskenderov, V. M. Fataliyev y F. B. Ismayilova. "The maintenance of stable operation of a pipeline keeping natural gas in disperse state". Azerbaijan Oil Industry, n.º 08 (15 de agosto de 2022): 35–40. http://dx.doi.org/10.37474/0365-8554/2022-08-35-40.

Texto completo

Resumen

Despite the initial seperation and preperation of the transported well output from the gas and gas-condensate fields, several complications occur during the transportation of the production to the stations of refining or to the customer. These complications during the transportation lead to the serious issues, therefore their solution and management are of great importance. The paper reviews the reasons for formation of liquid phase in a pipeline, analyzes its physical-thermodynamic essence and negative effect on the operation of pipeline as well. To eliminate the pressure pulses while filtration of multi-phase systems, the ways of keeping the natural gas in aerosol-disperse state were studied. With this purpose, a special pipeline construction is considered and the efficiency of proposed pipeline element is experimentally justified.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Brouwers, J. J. H. "Separation and Disinfection of Contagious Aerosols from the Perspective of SARS-CoV-2". Separations 8, n.º 10 (15 de octubre de 2021): 190. http://dx.doi.org/10.3390/separations8100190.

Texto completo

Resumen

An assessment was performed on methods of separating and disinfecting airborne droplet nuclei containing viruses, such as SARS-CoV-2. The droplet nuclei originate from evaporating aerosols emitted by the coughing, singing, sneezing, etc. of infected humans. Based on empirical data and theoretical analysis, we successively determined: (i) the particle number distribution of nuclei versus the nucleus diameter, (ii) the statistical distribution of the viral content in the droplet nuclei starting from a uniform random distribution of viruses in the mucus, (iii) the particle number distribution of droplet nuclei containing at least one virus particle, and (iv) the effectiveness of methods for removing and disinfecting nuclei containing one or more virus particles from indoor air; viz., ventilation with fresh air, filtering with porous media, such as HEPA, and centrifugal separation and simultaneous disinfection, particularly with a rotational particle separator (RPS). Indoor aerosol removal with RPS supplemented with HEPA to arrest tiny volumes of very small particles was found to be the most effective. It is as good as particle removal through ventilation with clean air over long periods of time. An RPS facilitates direct elimination of viruses in the collected nuclei by flushing with a disinfection liquid. The components of an RPS are recyclable. Combining HEPA with an RPS extends the service time of HEPA by almost two orders of magnitude compared to the relatively short service time of stand-alone HEPA filters.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Mustonen, Kimmo, Toma Susi, Antti Kaskela, Patrik Laiho, Ying Tian, Albert G. Nasibulin y Esko I. Kauppinen. "Influence of the diameter of single-walled carbon nanotube bundles on the optoelectronic performance of dry-deposited thin films". Beilstein Journal of Nanotechnology 3 (17 de octubre de 2012): 692–702. http://dx.doi.org/10.3762/bjnano.3.79.

Texto completo

Resumen

The optoelectronic performance of thin films of single-walled carbon nanotubes (SWCNTs) was studied with respect to the properties of both individual nanotubes and their bundles. The SWCNTs were synthesized in a hot wire generator aerosol reactor, collected by gas filtration and dry-transferred onto various substrates. By thus completely avoiding liquid dispersion steps, we were able to avoid any artifacts from residual surfactants or sonication. We found that bundle lengths determined the thin-film performance, as would be expected for highly resistive bundle–bundle junctions. However, we found no evidence that contact resistances were affected by the bundle diameters, although they did play a secondary role by simply affecting the absorption. The individual SWCNT diameters and their graphitization level as gauged by the Raman D band intensity did not show any clear correlation with the overall performance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Rubow, Kenneth, Benjamin Liu y Donald Grant. "Characteristics of Ultra-High Efficiency Membrane Filters in Gas Applications". Journal of the IEST 31, n.º 3 (1 de mayo de 1988): 26–30. http://dx.doi.org/10.17764/jiet.1.31.3.a20003860165wlj5.

Texto completo

Resumen

The particle collection characteristics of ultra-high efficiency polyvinylidene fluoride (PVDF) membrane filter media has been evaluated. This media is typical of PVDF and polytetrafluoroethylene (PTFE) media used for process gas filtration in the semiconductor industry. Testing was performed using specially prepared ultra-thin membrane samples since the penetration through the standard production media is less than current detection limits. The data obtained were used to predict the performance of the standard membrane. The calculated aerosol penetration through the standard media ranges between 6 × 10-32 and 4 × 10-23 for face velocities of 5 to 50 cm/sec. The most penetrating particle size was found in the 0.035 to 0.045 μm size range. The effect of particle loading on particle penetration was also studied. The penetration was found to decrease as the filter media was loaded with either liquid or solid particles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Bergman, Michael S., Dennis J. Viscusi, Brian K. Heimbuch, Joseph D. Wander, Anthony R. Sambol y Ronald E. Shaffer. "Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators". Journal of Engineered Fibers and Fabrics 5, n.º 4 (diciembre de 2010): 155892501000500. http://dx.doi.org/10.1177/155892501000500405.

Texto completo

Resumen

Disposable N95 filtering facepiece respirators (FFRs) certified by the National Institute for Occupational Safety and Health (NIOSH) are widely used by healthcare workers to reduce exposures to infectious biological aerosols. There is currently major concern among public health officials about a possible shortage of N95 FFRs during an influenza pandemic. Decontamination and reuse of FFRs is a possible strategy for extending FFR supplies in an emergency; however, the NIOSH respirator certification process does not currently include provisions for decontamination and reuse. Recent studies have investigated the laboratory performance (filter aerosol penetration and filter airflow resistance) and physical integrity of FFRs following one-cycle (1X) processing of various decontamination treatments. The studies found that a single application of some methods did not adversely affect laboratory performance. In the event that healthcare facilities experience dramatic shortages of FFR supplies, multiple decontamination processing may become necessary. This study investigates three-cycle (3X) processing of eight different methods: ultraviolet germicidal irradiation, ethylene oxide, hydrogen peroxide gas plasma, hydrogen peroxide vapor, microwave-oven-generated steam, bleach, liquid hydrogen peroxide, and moist heat incubation (pasteurization). A four-hour 3X submersion of FFR in deionized water was performed for comparison (control). Following 3X treatment by each decontamination and control method, FFRs were evaluated for changes in physical appearance, odor, and laboratory filtration performance. Only the hydrogen peroxide gas plasma treatment resulted in mean penetration levels > 5% for four of the six FFR models; FFRs treated by the seven other methods and the control samples had expected levels of filter aerosol penetration (< 5%) and filter airflow resistance. Physical damage varied by treatment method. Further research is still needed before any specific decontamination methods can be recommended.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Arvelo, Ilan, Frank Pagone, Jacob Persky, Carlos E. Carpio, Phil Arnold y Nicholas Clements. "Decay rates of two tracer gases compared to DNA-tagged liquid aerosol tracer particles: Impact of varying dilution rate and filtration". Building and Environment 212 (marzo de 2022): 108819. http://dx.doi.org/10.1016/j.buildenv.2022.108819.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Socia, Adam, Yong Liu, Yuejie Zhao, Andreas Abend y W. Peter Wuelfing. "Development of an ultra‐high‐performance liquid chromatography‐charged aerosol detection/UV method for the quantitation of linear polyethylenimines in oligonucleotide polyplexes". Journal of Separation Science 43, n.º 20 (3 de septiembre de 2020): 3876–84. http://dx.doi.org/10.1002/jssc.202000414.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Dragunova, Anastasiya V., Mikhail S. Morkin y Vladimir V. Perevezentsev. "Features of methods for monitoring the fuel cladding tightness in lead-cooled fast breeder reactors". Nuclear Energy and Technology 7, n.º 4 (17 de diciembre de 2021): 319–25. http://dx.doi.org/10.3897/nucet.7.78372.

Texto completo

Resumen

To timely detect failed fuel elements, a reactor plant should be equipped with a fuel cladding tightness monitoring system (FCTMS). In reactors using a heavy liquid-metal coolant (HLMC), the most efficient way to monitor the fuel cladding tightness is by detecting gaseous fission products (GFP). The article describes the basic principles of constructing a FCTMS in liquid-metal-cooled reactors based on the detection of fission products and delayed neutrons. It is noted that in a reactor plant using a HLMC the fuel cladding tightness is the most efficiently monitored by detecting GFPs. The authors analyze various aspects of the behavior of fission products in a liquid-metal-cooled reactor, such as the movement of GFPs in dissolved and bubble form along the circuit, the sorption of volatile FPs in the lead coolant (LC) and on the surfaces of structural elements, degassing of the GFPs dissolved in the LC, and filtration of cover gas from aerosol particles of different nature. In addition, a general description is given of the conditions for the transfer of GFPs in a LC environment of the reactor being developed. Finally, a mathematical model is presented that makes it possible to determine the calculated activity of reference radionuclides in each reactor unit at any time after the fuel element tightness failure. Based on this model, methods for monitoring the fuel cladding tightness by the gas activity in the gas volumes of the reactor plant will be proposed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Lan, Jing, Gelin Wu, Linlin Wu, Haibin Qu, Ping Gong, Yongjian Xie, Peng Zhou y Xingchu Gong. "Development of a Quantitative Chromatographic Fingerprint Analysis Method for Sugar Components of Xiaochaihu Capsules Based on Quality by Design Concept". Separations 10, n.º 1 (26 de diciembre de 2022): 13. http://dx.doi.org/10.3390/separations10010013.

Texto completo

Resumen

Background: Xiaochaihu capsule is composed of seven traditional Chinese medicines. The pharmacopoeia only focuses on the quantitative detection of baicalin, which cannot fully reflect the quality of the preparation. Some medium polar components were used to establish the fingerprint of Xiaochaihu capsule, but there was no report on the strong polar components. Methods: A high performance liquid chromatography-corona charged aerosol detection technology was used to establish a fingerprint analysis method for Xiaochaihu capsules following an analytical quality by design approach. Definitive screening designed experiments were used to optimize the method parameters. A stepwise regression method was used to build quantitative models. The method operable design region was calculated using the experimental error simulation method. Plackett–Burman designed experiments were carried out to test robustness. Results: The contents of four components were simultaneously determined. There were seven common peaks in the fingerprint. The common peak area accounted for 91.72%. Both fingerprint and quantitative analysis methods were validated as applicable in the methodology study. The quantitative fingerprint analysis method for sugar components can fill the gap in the detection of strong polar components in the existing methods. It provides a new technology for the comprehensive overall evaluation of Xiaochaihu capsule.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Elster, J., R. J. Delmas, J. R. Petit y K. Řeháková. "Composition of microbial communities in aerosol, snow and ice samples from remote glaciated areas (Antarctica, Alps, Andes)". Biogeosciences Discussions 4, n.º 3 (19 de junio de 2007): 1779–813. http://dx.doi.org/10.5194/bgd-4-1779-2007.

Texto completo

Resumen

Abstract. Taxonomical and ecological analyses were performed on micro-autotrophs (cyanobacteria and algae together with remnants of diatom valves), micro-fungi (hyphae and spores), bacteria (rod, cocci and red clusters), yeast, and plant pollen extracted from various samples: Alps snow (Mt. Blank area), Andean snow (Illimani, Bolivia), Antarctic aerosol filters (Dumont d'Urville, Terre Adélie), and Antarctic inland ice (Terre Adélie). Three methods for ice and snow sample's pre-concentration were tested (filtration, centrifugation and lyophilisation). Afterwards, cultivation methods for terrestrial, freshwater and marine microorganisms (micro-autotrophs and micro-fungi) were used in combination with liquid and solid media. The main goal of the study was to find out if micro-autotrophs are commonly transported by air masses, and later stored in snow and icecaps around the world. The most striking result of this study was the absence of culturable micro-autotrophs in all studied samples. However, an unusual culturable pigmented prokaryote was found in both alpine snow and aerosol samples. Analyses of many samples and proper statistical analyses (PCA, RDA- Monte Carlo permutation tests) showed that studied treatments highly significantly differ in both microbial community and biotic remnants composition F=9.33, p=0.001. In addition, GLM showed that studied treatments highly significantly differ in numbers of categories of microorganisms and remnants of biological material F=11.45, p=0.00005. The Antarctic aerosol samples were characterised by having red clusters of bacteria, the unusual prokaryote and yeasts. The high mountain snow from the Alps and Andes contained much more culturable heterotrophs. The unusual prokaryote was very abundant, as were coccoid bacteria, red clusters of bacteria, as well as yeasts. The Antarctic ice samples were quite different. These samples had higher numbers of rod bacteria and fungal hyphae. The microbial communities and biological remnants of analysed samples comprises two communities, without a sharp boundary between them: i) the first community includes ubiquitous organisms including contaminants, ii) the second community represents individuals frequently occurring in remote terrestrial cold or hot desert/semi-desert and/or marginal soil-snow-ice ecosystems.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Huang, Chun Xiang, Xia Liling y Sergiy Ryzhkov. "DEVELOPMENT OF PHOTOCATALYTIC AND ULTRASONIC EQUIPMENT TO PREVENT THE SPREAD OF CORONAVIRUS SARS-COV-2. PHOTOCATALYTIC SAMPLE OF SEPARATION STAGE". Management of Development of Complex Systems, n.º 48 (20 de diciembre de 2021): 165–72. http://dx.doi.org/10.32347/2412-9933.2021.48.165-172.

Texto completo

Resumen

The Full-scale experimental photocatalytic sample of separator consists of 5 equal purification modules. Each of the modules consists of separation elements for increasing of purification level. The equipment is designed for air volume G = 50… 150 m3 / hour, should reduce the degree of microbial contamination of the air to the required level (capture particles of 0.1 μm) and help reduce the risk of airborne diseases. Project considers solving an important scientific and technical problem of creating and development of photocatalytic and ultrasonic heat and mass transfer separation equipment for air clean from dust and viruses (coronavirus SARS-COV-2). Filtration is a quite economical and efficient method of improving air-conditioning system, the air filtration systems represent a good solution for the improvement of Indoor Air Quality (IAQ), and the Antimicrobial treatments (coronavirus SARS-COV-2 prevention) of filters may be a solution to these problems. It is possible to prevent the accumulation and dispersion of microorganisms by adding anti-microbial agents on the surfaces of filter, which contributes to the improvement of air quality. Purification from dust and viruses and liquid media smaller than 1 μm requires development of air-purifying separation equipment able to capture particles of this size with implementation of resource-saving features base on photocatalytic and ultrasonic equipment. Development of photocatalytic and ultrasonic heat and mass transfer separation equipment for air clean from dust and viruses (coronavirus SARS-COV-2 prevention) is based on multilevel gradient aerosol technologies, as well as research of methods of their control, is their joint use in the presence of substantial gradients of the hydrodynamic and thermophysical parameters (temperature, pressure, velocity, density, etc.).

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Burić, Nina y Simona Stojanović. "Occupational hazard for Dental staff exposed to the SARS-CoV-2 virus during Dental procedures". Acta stomatologica Naissi 36, n.º 81 (2020): 1995–2006. http://dx.doi.org/10.5937/asn2081995b.

Texto completo

Resumen

Introduction: The dental profession is a high-risk profession, considering the aspect of a possible 100% infection from patients who are carriers of bacterial, viral and fungal diseases during dental interventions. Aim: To perform the analysis of all data that explain the possibility of a SARS-CoV-2 virus infection in dental practice. Material and Methods: The literature data on the presence of SARS-CoV-2 virus, and its characteristics and behavior in the external environment and in living tissues was analyzed. Databases from the Medline, Cochrane Library, Science-Direct, EMBASE, and Google scholar libraries were used, as well as other sources of literature information about this virus. Results: SARS-CoV-2 is an RNA virus, which has a submicron size and the ability to survive in various environments. The retention of SARS-CoV-2 virus in air / aerosol lasts an average of 3 hours, while the half-life of this virus is 5 to 6 hours on stainless steel and 6 to 8 hours on plastic. Infected patients with SARS-CoV-2 virus develop COVID-19 disease, which manifests itself through presymptomatic, symptomatic and post-symptomatic periods of the disease. Conclusion: The SARS-CoV-2 virus can be found in aerosols generated by dental equipment, which uses compressed air for its work. Protection of dentists and staff from infection with the virus is possible by wearing an N95 respiratory mask with protection levels 2 and 3, which has a filtration efficiency, i.e. retention of submicron particles with an efficiency of ≥ 98%. Waterproof goggles with a protective visor or a special industrially designed facial visor in the form of a full face mask, which has its own motor for the supply of filtered air to the mask, and which prevents the contamination of the mucous membranes of the eyes, nose and mouth from liquid or solid aerosol in the air, need to be used. Other disposable protective equipment also must be waterproof. Korona virus izaziva prehladu kod ljudi, koja ima uobičajne simptome prehlade gornjih respiratornih puteva; zahvata nosnu šupljinu,a ponekad se širi i na ždrelo, larinks i sinuse 5,6,7 . Sa druge strane, SARS-CoV-2 virus, koji je izazivač masovne/globalne virusne infekcije, ima sličnosti sa druga dva korona virusa -beta korona virusom (SARS-CoV-1) i virusom srednjeistočnog respiratonog sindroma (MERS-CoV).

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Qiu, Jiangbing, Elliott J. Wright, Krista Thomas, Aifeng Li, Pearse McCarron y Daniel G. Beach. "Semiquantitation of Paralytic Shellfish Toxins by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry Using Relative Molar Response Factors". Toxins 12, n.º 6 (16 de junio de 2020): 398. http://dx.doi.org/10.3390/toxins12060398.

Texto completo

Resumen

Paralytic shellfish toxins (PSTs) are a complex class of analogs of the potent neurotoxin saxitoxin (STX). Since calibration standards are not available for many PSTs, including C-11 hydroxyl analogs called M-toxins, accurate quantitation by liquid chromatography–mass spectrometry (LC-MS) can be challenging. In the absence of standards, PSTs are often semiquantitated using standards of a different analog (e.g., STX), an approach with a high degree of uncertainty due to the highly variable sensitivity between analytes in electrospray ionization. Here, relative molar response factors (RMRs) were investigated for a broad range of PSTs using common LC-MS approaches in order to improve the quantitation of PSTs for which standards are unavailable. First, several M-toxins (M1-M6, M9 and dcM6) were semipurified from shellfish using preparative gel filtration chromatography and quantitated using LC-charged aerosol detection (LC-CAD). The RMRs of PST certified reference materials (CRMs) and M-toxins were then determined using selective reaction monitoring LC-MS/MS and full scan LC-high-resolution MS (LC-HRMS) methods in positive and negative electrospray ionization. In general, RMRs for PSTs with similar chemical structures were comparable, but varied significantly between subclasses, with M-toxins showing the lowest sensitivity. For example, STX showed a greater than 50-fold higher RMR than M4 and M6 by LC-HRMS. The MS instrument, scan mode and polarity also had significant impacts on RMRs and should be carefully considered when semiquantitating PSTs by LC-MS. As a demonstration of their utility, the RMRs determined were applied to the semiquantitation of PSTs in contaminated mussels, showing good agreement with results from calibration with CRMs.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Chen, Xin, Patrick C. Bailey, Clarissa Yang, Bryant Hiraki, Michael J. Oldham y I. Gene Gillman. "Targeted Characterization of the Chemical Composition of JUUL Systems Aerosol and Comparison with 3R4F Reference Cigarettes and IQOS Heat Sticks". Separations 8, n.º 10 (3 de octubre de 2021): 168. http://dx.doi.org/10.3390/separations8100168.

Texto completo

Resumen

Aerosol constituent yields have been reported from a wide range of electronic nicotine delivery systems. No comprehensive study has been published on the aerosol constituents generated from the JUUL system. Targeted analyses of 53 aerosol constituents from the four JUUL products currently on the US market (Virginia Tobacco and Menthol flavored e-liquids in both 5.0% and 3.0% nicotine concentration by weight) was performed using non-intense and intense puffing regimens. All measurements were conducted by an ISO 17025 accredited contract research organization. JUUL product aerosol constituents were compared to published values for the 3R4F research cigarette and IQOS Regular and Menthol heated tobacco products. Across the four JUUL products and two puffing regimes, only 10/53 analytes were quantifiable, including only two carbonyls (known propylene glycol or glycerol degradants). The remaining analytes were primary ingredients, nicotine degradants and water. Average analyte reductions (excluding primary ingredients and water) for all four JUUL system aerosols tested were greater than 98% lower than 3R4F mainstream smoke, and greater than 88% lower than IQOS aerosol. In summary, chemical characterization and evaluation of JUUL product aerosols demonstrates a significant reduction in toxicants when compared to mainstream cigarette smoke from 3R4F reference cigarettes or aerosols from IQOS-heated tobacco products.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Tay, Li-Lin, Shawn Poirier, Ali Ghaemi y John Hulse. "Inkjet-printed paper-based surface enhanced Raman scattering (SERS) sensors for the detection of narcotics". MRS Advances 7, n.º 9 (7 de marzo de 2022): 190–96. http://dx.doi.org/10.1557/s43580-022-00257-8.

Texto completo

Resumen

AbstractRecent advances in inkjet-printing of advanced materials have provided a versatile platform for the rapid development and prototyping of sensor devices. We have recently demonstrated inkjet-printed surface enhanced Raman scattering (SERS) sensors on flexible substrates for the detection of variety of small molecules [Tay et al. in Front Chem 9:680556 (2021); Tay et al. in J Raman Spectrosc 52:563 (2020)]. These flexible SERS sensors have many advantages for performing point-of-sampling testing, among them liquid or aerosol filtration and swabbing capabilities. These simple sampling and separation features make these inkjet-printed paper-based sensors ideal for field applications. SERS detection of molecules with poor binding affinity towards the plasmonic surfaces of the sensors tends to be inefficient. A surface functionalization approach has been applied to SERS sensors to improve the molecule affinity and hence their detection sensitivity. In this paper, we investigate the optimization of SERS sensor fabrication to achieve optimal performance. Three performance criteria: diffuse reflectance, SERS background intensity from the as-printed blank sensors and SERS performance of sensors exposed to the benzenethiol reporter molecule, are characterized carefully to derive the optimal inkjet-printing conditions for producing the best performing SERS sensors. Additionally, we demonstrate the use of a simple potassium iodide functionalization scheme to improve the detection sensitivity for narcotics such as fentanyl by two orders of magnitude. Graphical abstract

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Panfilov, Ivan, Alexey N. Beskopylny y Besarion Meskhi. "Numerical Simulation of Heat Transfer and Spread of Virus Particles in the Car Interior". Mathematics 11, n.º 3 (3 de febrero de 2023): 784. http://dx.doi.org/10.3390/math11030784.

Texto completo

Resumen

The epidemic caused by the coronavirus infection SARS-CoV-2 at the beginning of 2022 affected approximately 500 million people in all countries. The source of infection is the particles of the virus, which, when breathing, talking, and coughing, are released with the respiratory droplets and aerosol dust of an infected person. Actions aimed at combating and minimizing the consequences of coronavirus infection led to taking measures in scientific areas to investigate the processes of the spread of viral particles in the air, in ventilation, and air conditioning systems of premises and transport, filtration through masks, the effect of partitions, face shields, etc. The article presents a mathematical model of the spread of viral particles in technological transport. Air intake diverters and the operator’s respiratory tract are the sources of the virus. The Euler–Lagrange approach was used to simulate liquid droplets in a flow. Here, the liquid phase is considered as a continuous medium using Navier–Stokes equations, the continuity equation, the energy equation, and the diffusion equation. Accounting for diffusion makes it possible to explicitly model air humidity and is necessary to consider the evaporation of droplets (changes in the mass and size of particles containing the virus). Liquid droplets are modeled using the discrete-phase model (DPM), in which each particle is tracked in a Lagrange coordinate system. The DPM method is effective, since the volume fraction of particles is small relative to the total volume of the medium, and the interaction of particles with each other can be neglected. In this case, the discrete and continuous phases are interconnected through the source terms in the equations. The averaged RANS equations are solved numerically using the k-ω turbulence model in the Ansys Fluent package. The task was solved in a static form and in the time domain. For a non-stationary problem, the stabilization time of the variables is found. The simulation results are obtained in the form of fields of pressures, velocities, temperatures and air densities, and the field of propagation of particles containing the virus. Various regimes were studied at various free flow rates and initial velocities of droplets with viral particles. The results of trajectories and velocities of particles, and particle concentrations depending on time, size, and on the evaporability of particles are obtained.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Dinkele, Ryan, Sophia Gessner, Andrea McKerry, Bryan Leonard, Ronnett Seldon, Anastasia S. Koch, Carl Morrow et al. "Capture and visualization of live Mycobacterium tuberculosis bacilli from tuberculosis patient bioaerosols". PLOS Pathogens 17, n.º 2 (1 de febrero de 2021): e1009262. http://dx.doi.org/10.1371/journal.ppat.1009262.

Texto completo

Resumen

Interrupting transmission is an attractive anti-tuberculosis (TB) strategy but it remains underexplored owing to our poor understanding of the events surrounding transfer of Mycobacterium tuberculosis (Mtb) between hosts. Determining when live, infectious Mtb bacilli are released and by whom has proven especially challenging. Consequently, transmission chains are inferred only retrospectively, when new cases are diagnosed. This process, which relies on molecular analyses of Mtb isolates for epidemiological fingerprinting, is confounded by the prolonged infectious period of TB and the potential for transmission from transient exposures. We developed a Respiratory Aerosol Sampling Chamber (RASC) equipped with high-efficiency filtration and sampling technologies for liquid-capture of all particulate matter (including Mtb) released during respiration and non-induced cough. Combining the mycobacterial cell wall probe, DMN-trehalose, with fluorescence microscopy of RASC-captured bioaerosols, we detected and quantified putative live Mtb bacilli in bioaerosol samples arrayed in nanowell devices. The RASC enabled non-invasive capture and isolation of viable Mtb from bioaerosol within 24 hours of collection. A median 14 live Mtb bacilli (range 0–36) were isolated in single-cell format from 90% of confirmed TB patients following 60 minutes bioaerosol sampling. This represented a significant increase over previous estimates of transmission potential, implying that many more organisms might be released daily than commonly assumed. Moreover, variations in DMN-trehalose incorporation profiles suggested metabolic heterogeneity in aerosolized Mtb. Finally, preliminary analyses indicated the capacity for serial image capture and analysis of nanowell-arrayed bacilli for periods extending into weeks. These observations support the application of this technology to longstanding questions in TB transmission including the propensity for asymptomatic transmission, the impact of TB treatment on Mtb bioaerosol release, and the physiological state of aerosolized bacilli.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Agranovski, Igor E. y Roger D. Braddock. "Filtration of liquid aerosols on wettable fibrous filters". AIChE Journal 44, n.º 12 (diciembre de 1998): 2775–83. http://dx.doi.org/10.1002/aic.690441218.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Agranovski, Igor E. y Roger D. Braddock. "Filtration of liquid aerosols on nonwettable fibrous filters". AIChE Journal 44, n.º 12 (diciembre de 1998): 2784–90. http://dx.doi.org/10.1002/aic.690441219.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Charvet, A., Y. Gonthier, A. Bernis y E. Gonze. "Filtration of liquid aerosols with a horizontal fibrous filter". Chemical Engineering Research and Design 86, n.º 6 (junio de 2008): 569–76. http://dx.doi.org/10.1016/j.cherd.2007.11.008.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Zhen, Huajun, Taewon Han, Donna E. Fennell y Gediminas Mainelis. "Release of Free DNA by Membrane-Impaired Bacterial Aerosols Due to Aerosolization and Air Sampling". Applied and Environmental Microbiology 79, n.º 24 (4 de octubre de 2013): 7780–89. http://dx.doi.org/10.1128/aem.02859-13.

Texto completo

Resumen

ABSTRACTWe report here that stress experienced by bacteria due to aerosolization and air sampling can result in severe membrane impairment, leading to the release of DNA as free molecules.Escherichia coliandBacillus atrophaeusbacteria were aerosolized and then either collected directly into liquid or collected using other collection media and then transferred into liquid. The amount of DNA released was quantified as the cell membrane damage index (ID), i.e., the number of 16S rRNA gene copies in the supernatant liquid relative to the total number in the bioaerosol sample. During aerosolization by a Collison nebulizer, theIDofE. coliandB. atrophaeusin the nebulizer suspension gradually increased during 60 min of continuous aerosolization. We found that theIDof bacteria during aerosolization was statistically significantly affected by the material of the Collison jar (glass > polycarbonate;P< 0.001) and by the bacterial species (E. coli>B. atrophaeus;P< 0.001). WhenE. coliwas collected for 5 min by filtration, impaction, and impingement, itsIDvalues were within the following ranges: 0.051 to 0.085, 0.16 to 0.37, and 0.068 to 0.23, respectively; when it was collected by electrostatic precipitation, theIDvalues (0.011 to 0.034) were significantly lower (P< 0.05) than those with other sampling methods. Air samples collected inside an equine facility for 2 h by filtration and impingement exhibitedIDvalues in the range of 0.30 to 0.54. The data indicate that the amount of cell damage during bioaerosol sampling and the resulting release of DNA can be substantial and that this should be taken into account when analyzing bioaerosol samples.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Brochocka, Agnieszka. "Filtration Properties of Nonwoven Structures with Superabsorbents for Respiratory Protective Devices". Fibres and Textiles in Eastern Europe 25 (30 de junio de 2017): 62–67. http://dx.doi.org/10.5604/01.3001.0010.1691.

Texto completo

Resumen

The paper presents a study of the protective and functional properties of nonwoven structures, such as penetration by solid and liquid aerosols, airflow resistance, and air moisture sorption capacity. Nonwovens were modified by the introduction of electrostatic charges in the structure of polymer fibers and by the addition of a superabsorbent polymeric (SAP) directly to the fiber-forming area in a melt-blown process. The resulting materials (outer nonwovens containing SAP of different grain sizes and filtering nonwovens with and without electrostatic charges) had varied morphological structures. The materials developed were characterised by high filtering efficiency at low airflow resistance and good moisture sorption ability. The study proved the possibility to apply nonwoven structures containing SAP in respiratory protective equipment used in harsh work environments at high temperature and relative humidity. The materials fabricated were found to improve hygienic comfort.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Huang, Hsiao-Lin, Da-Ming Wang, Se-Tsung Kao, Shinhao Yang y Yi-Chin Huang. "Removal of monodisperse liquid aerosols by using the polysulfone membrane filters". Separation and Purification Technology 54, n.º 1 (marzo de 2007): 96–103. http://dx.doi.org/10.1016/j.seppur.2006.08.012.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Bredin, Arne y Benjamin J. Mullins. "Influence of flow-interruption on filter performance during the filtration of liquid aerosols by fibrous filters". Separation and Purification Technology 90 (abril de 2012): 53–63. http://dx.doi.org/10.1016/j.seppur.2012.02.009.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Majchrzycka, Katarzyna, Małgorzata Okrasa, Agnieszka Brochocka y Wiesława Urbaniak-Domagała. "Influence of Low-Temperature Plasma Treatment on The Liquid Filtration Efficiency of Melt-Blown PP Nonwovens in The Conditions of Simulated Use of Respiratory Protective Equipment". Chemical and Process Engineering 38, n.º 2 (27 de junio de 2017): 195–207. http://dx.doi.org/10.1515/cpe-2017-0015.

Texto completo

Resumen

Abstract Filtering nonwovens produced with melt-blown technology are one of the most basic materials used in the construction of respiratory protective equipment (RPE) against harmful aerosols, including bio- and nanoaerosols. The improvement of their filtering properties can be achieved by the development of quasi-permanent electric charge on the fibres. Usually corona discharge method is utilized for this purpose. In the presented study, it was assumed that the low-temperature plasma treatment could be applied as an alternative method for the manufacturing of conventional electret nonwovens for the RPE construction. Low temperature plasma treatment of polypropylene nonwovens was carried out with various process gases (argon, nitrogen, oxygen or air) in a wide range of process parameters (gas flow velocity, time of treatment and power supplied to the reactor electrodes). After the modification, nonwovens were evaluated in terms of filtration efficiency of paraffin oil mist. The stability of the modification results was tested after 12 months of storage and after conditioning at elevated temperature and relative humidity conditions. Moreover, scanning electron microscopy and ATR-IR spectroscopy were used to assess changes in surface topography and chemical composition of the fibres. The modification of melt-blown nonwovens with nitrogen, oxygen and air plasma did not result in a satisfactory improvement of the filtration efficiency. In case of argon plasma treatment, up to 82% increase of filtration efficiency of paraffin oil mist was observed in relation to untreated samples. This effect was stable after 12 months of storage in normal conditions and after thermal conditioning in (70 ± 3)°C for 24 h. The use of low-temperature plasma treatment was proven to be a promising improvement direction of filtering properties of nonwovens used for the protection of respiratory tract against harmful aerosols.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Carroll, B. J. "Deposition of Liquid Drops on a Long Cylindrical Fiber". Textile Research Journal 58, n.º 9 (septiembre de 1988): 495–500. http://dx.doi.org/10.1177/004051758805800901.

Texto completo

Resumen

The way in which the deposition of drops from a dispersion onto the surface of a collecting fiber varies with system parameters is discussed, using as a starting point previously published analyses of the properties of a single drop deposited on a fiber. The deposition of drops may involve coalescence with either the fiber alone or with drops already attached to the fiber, and marked differences are predicted for the rate of variation of the drop/fiber contact area for the two cases. The relative predominance of a particular deposition mechanism depends on the stage of the overall process, and stages are identified where the contact area changes are insensitive to the contact angle. The effects of drop size polydispersity and the presence of surfactant in the system are discussed. While increasing the complexity of the problem, neither of these influences poses insuperable obstacles to the theoretical interpretation of the processes. Possible applications of this work include filtration and deposition on fibers from aerosols or emulsions. Deposition onto an optical fiber as a means of monitoring particle concentrations in dispersed systems is also considered.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Brochocka, Agnieszka, Aleksandra Nowak, Rafał Panek y Wojciech Franus. "The Effects of Textural Parameters of Zeolite and Silica Materials on the Protective and Functional Properties of Polymeric Nonwoven Composites". Applied Sciences 9, n.º 3 (2 de febrero de 2019): 515. http://dx.doi.org/10.3390/app9030515.

Texto completo

Resumen

Zeolites are micro- and mesoporous aluminosilicate minerals (both natural and industrially produced) widely used as catalysts and sorbents in domestic and commercial water purification and separation technologies. Their ability to selectively adsorb gases (i.e., water vapor, carbon dioxide, and sulfur dioxide removal) from an air stream makes them suitable for applications in odor reducing media used in filtering facepiece respirators (FFRs). FFRs are multilayer products in which the most important role is played by high-performance melt-blown electret nonwovens modified with activated carbon to adsorb malodorous compounds. Replacing carbon sorbents with zeolites could increase the efficiency of odor abatement, thus alleviating work-related hazards for individuals exposed to malodorous substances with adverse effects on human well-being. The objective of the present work was to analyze the influence of the textural parameters of zeolite and mesoporous silica materials on the protective and functional properties of polymeric nonwoven composites containing them. In our experiments, the longest breakthrough time against ammonia vapor was found for a nonwoven composite containing the inorganic mesoporous silica material type MCM-41. It was also characterized by high filtration efficiency against aerosols with solid and liquid dispersed phases (97% and 99% for sodium chloride and paraffin oil mist, respectively) at an airflow resistance of approximately 330 Pa. In turn, the composites containing the molecular sieve (SM-zeolite ZSM-5) exhibited the longest breakthrough time for acetone and cyclohexane vapors at the maximum allowable concentrations of 235 ppm and 81 ppm, respectively. Basic filtration tests showed that the composite was 97% effective against both test aerosols at an airflow resistance of 283.5 Pa.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Yu, Kuo-Pin, Yen-Ping Chen, Jia-You Gong, Yen-Chi Chen y Chih-Ching Cheng. "Improving the collection efficiency of the liquid impinger for ultrafine particles and viral aerosols by applying granular bed filtration". Journal of Aerosol Science 101 (noviembre de 2016): 133–43. http://dx.doi.org/10.1016/j.jaerosci.2016.08.002.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Denis, Bemer. "Granular bed filtration of a liquid aerosol". Powder Technology, septiembre de 2021. http://dx.doi.org/10.1016/j.powtec.2021.09.023.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Sokolović, Dunja, Thomas Laminger, Gerd Mauschitz y Wilhelm Hoeflinger. "Novel coalescer with bed of waste polymer fibers for liquid aerosol separation". Separation and Purification Technology, diciembre de 2020, 118187. http://dx.doi.org/10.1016/j.seppur.2020.118187.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

"Pipette filter tips block out liquid and aerosol contaminants". Filtration + Separation 56, n.º 6 (noviembre de 2019): 9. http://dx.doi.org/10.1016/s0015-1882(20)30173-7.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Wang, Yongxiang, Zhongping Lin, Wanyi Zhang y Bin Xu. "Effects of solid particles with various charging states and oil aerosols on the filtration characteristics of electret media". Indoor and Built Environment, 15 de junio de 2020, 1420326X2093220. http://dx.doi.org/10.1177/1420326x20932209.

Texto completo

Resumen

In this study, electret media were loaded with neutralized and charged potassium chloride (KCl) to examine the effect of charged solid particles on loading behaviour. The media were then loaded with diethylhexyl sebacate (DEHS), dipropylene glycol (DPG) and glycerol to obtain a correlation between the efficiency degradation and liquid aerosol. The results indicated that the efficiency of electret media decreased from 72% to 46% under the neutralized KCl loading whilst the efficiency decreased from 96% to 82% under the positively charged KCl loading. Particle charging increased the initial efficiency and also effectively minimized the efficiency degradation. Given the increase in efficiency via chargers, the deposition morphology of the solid particles on the fibres was changed to mitigate the efficiency degradation. With respect to electret media loaded with DEHS, DPG and glycerol, the decrease in efficiency was associated with the solubility difference between the fibres and oil aerosols. Given sufficient affinity between the oil particles and fibres, oil molecules permeated the chain segments of the fibres and produced swelling that damaged the charge traps and decreased efficiency. The results of this study can guide practical electret filter operations and provide a better indoor environment.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Liquid aerosol filtration"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros