scholarly journals Passive Vaping from Sub-Ohm Electronic Cigarette Devices

2021 ◽  
Vol 18 (21) ◽  
pp. 11606
Author(s):  
Maurizio Manigrasso ◽  
Carmela Protano ◽  
Matteo Vitali ◽  
Pasquale Avino
Keyword(s):  
Electric Power ◽  
First Generation ◽  
Particle Number ◽  
Electronic Cigarettes ◽  
High Volume ◽  
Heat Fluxes ◽  
Main Mode ◽  
Decomposition Products ◽  
Aerosol Emissions ◽  
Volume Size

To investigate passive vaping due to sub-ohm electronic cigarettes (e-cigs), aerosol number size distribution measurements (6 nm–10 µm) were performed during volunteer-vaping sessions. E-liquids, with vegetable glycerin (VG) and propylene glycol (PG), with a VG/PG ratio of 50/50 (with nicotine) and 80/20 (without nicotine), were vaped with a double-coil, single aerosol exit hole at 25–80 W electric power, corresponding to 130–365 kW m−2 heat fluxes and with an octa-coil, four aerosol exit holes atomizers, at 50–150 W electric power, corresponding to 133–398 kW m−2 heat fluxes. At the lowest heat flux, lower particle number concentrations (NTot) were observed for the nicotine-liquid than for the nicotine-free liquid, also due to its higher content of PG, more volatile than VG. For the octa-coil atomizer, at 265 and 398 kW m−2, NTot decreased below the first-generation e-cig, whereas volume concentrations greatly increased, due to the formation of super micron droplets. Higher volume concentrations were observed for the 80/20 VG/PG liquid, because of VG vaporization and of its decomposition products, greater than for PG. For the double coil atomizer, increasing the electric power from 40 W (208 kW m−2) to 80 W (365 kW m−2) possibly led to a critical heat flow condition, causing a reduction of the number concentrations for the VG/PG 50/50 liquid, an increase for the 80/20 VG/PG liquid and a decrease of the volume concentrations for both of them. Coherently, the main mode was at about 0.1 µm on both metrics for both liquids. For the other tests, two main modes (1 and 2 µm) were observed in the volume size distributions, the latter becoming wider at 100 and 150 W (265 and 398 kW m−2), suggesting the increased emission of light condensable decomposition products. The lower aerosol emissions observed at 150 W than at 100 W suggest the formation of gas-phase decomposition products. The observation of low-count high-volume aerosols addresses the relevance of the volume metric upon measuring the second-hand concentration of the aerosols released by sub-ohm e-cigarettes.

scholarly journals Influence of trace H2O and O2 on SF6 decomposition products under arcing conditions in electric power equipment

2019 ◽  
Vol 2019 (16) ◽  
pp. 1774-1777 ◽  
Author(s):  
Ren Yang ◽  
Mengyuan Xu ◽  
Chen Guan ◽  
Jing Yan ◽  
Yingsan Geng
Keyword(s):  
Electric Power ◽  
Power Equipment ◽  
Decomposition Products ◽  
Sf6 Decomposition

scholarly journals From the Deeming Rule to JUUL—US News Coverage of Electronic Cigarettes, 2015–2018

2020 ◽  
Vol 22 (10) ◽  
pp. 1816-1822 ◽  
Author(s):  
Olivia A Wackowski ◽  
Jennah M Sontag ◽  
Binu Singh ◽  
Jessica King ◽  
M Jane Lewis ◽  
...  
Keyword(s):  
News Media ◽  
Electronic Cigarettes ◽  
News Coverage ◽  
High Volume ◽  
The United States ◽  
Online News ◽  
Future Research ◽  
The Public ◽  
News Sources ◽  
Over Time

Abstract Introduction News media may influence public perceptions and attitudes about electronic cigarettes (e-cigarettes), which may influence product use and attitudes about their regulation. The purpose of this study is to describe trends in US news coverage of e-cigarettes during a period of evolving regulation, science, and trends in the use of e-cigarettes. Methods We conducted a content analysis of e-cigarette topics and themes covered in US news articles from 2015 to 2018. Online news databases (Access World News, Factiva) were used to obtain US news articles from the top 34 circulating newspapers, four national wire services, and five leading online news sources. Results The number of articles increased by 75.4% between 2015 and 2018 (n = 1609). Most articles focused on policy/regulation (43.5%) as a main topic, followed by health effects (22.3%) and prevalence/trends (17.9%). Discussion about flavor bans quadrupled (6.1% to 24.6%) and discussion of youth e-cigarette use was most prevalent (58.4%) in 2018, coinciding with an increase in coverage about JUUL. JUUL was mentioned in 50.8% of 2018 articles. Across years, articles more frequently mentioned e-cigarette risks (70%) than potential benefits (37.3%). Conclusions E-cigarettes continue to be a newsworthy topic, with coverage both reflecting numerous changes and events over time, and providing repeated opportunities for informing the public and policymakers about these novel products. Future research should continue to track how discourse changes over time and assess its potential influence on e-cigarette perceptions and policy changes. Implications E-cigarette news coverage in the United States increased between 2015 and 2018 and predominantly focused on policy and regulation. Notable spikes in volume were associated with some but not all major e-cigarette events, including the FDA’s deeming rule, Surgeon General’s report, and release of the National Youth Tobacco Survey data in 2018. Coverage of the 2018 National Academy of Medicine, Engineering, and Sciences report on the Public Health Consequences of E-cigarettes received minimal news coverage. The high volume in 2018 was driven in large part by coverage of the e-cigarette brand JUUL; over half of news articles in 2018 referenced JUUL specifically.

scholarly journals Application of Flower-Like ZnO Nanorods Gas Sensor Detecting Decomposition Products

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Shudi Peng ◽  
Gaolin Wu ◽  
Wei Song ◽  
Qian Wang
Keyword(s):  
Electric Power ◽  
Gas Sensor ◽  
Sulfur Hexafluoride ◽  
Zno Nanorods ◽  
State Assessment ◽  
Electric Power System ◽  
Decomposition Products ◽  
Long Term Stability ◽  
Response And Recovery

Gas insulated switchgear (GIS) is an important electric power equipment in a substation, and its running state has a significant relationship with stability, security, and reliability of the whole electric power system. Detecting and analyzing the decomposition byproducts of sulfur hexafluoride gas (SF6) is an effective method for GIS state assessment and fault diagnosis. This paper proposes a novel gas sensor based on flower-like ZnO nanorods to detect typical SF6decompositions. Flower-like ZnO nanoparticles were synthesized via a simple hydrothermal method and characterized by X-ray powder diffraction and field-emission scanning electron microscopy, respectively. The gas sensor was fabricated with a planar-type structure and applied to detect SF6decomposition products. It shows excellent sensing properties to SO2, SOF2, and SO2F2with rapid response and recovery time and long-term stability and repeatability. Moreover, the sensor shows a remarkable discrimination among SO2, SOF2, and SO2F2with high linearity, which makes the prepared sensor a good candidate and a wide application prospect detecting SF6decomposition products in the future.

scholarly journals Comparison of Urinary Biomarkers of Exposure in Humans Using Electronic Cigarettes, Combustible Cigarettes, and Smokeless Tobacco

2018 ◽  
Vol 21 (9) ◽  
pp. 1228-1238 ◽  
Author(s):  
Pawel Lorkiewicz ◽  
Daniel W Riggs ◽  
Rachel J Keith ◽  
Daniel J Conklin ◽  
Zhengzhi Xie ◽  
...  
Keyword(s):  
Smokeless Tobacco ◽  
First Generation ◽  
Disease Risk ◽  
Electronic Cigarettes ◽  
Cardiovascular Disease Risk ◽  
Urinary Metabolites ◽  
Cigarette Use ◽  
Tobacco Products ◽  
Urinary Levels ◽  
Methylhippuric Acid

Abstract Background Cigarette smoking is associated with an increase in cardiovascular disease risk, attributable in part to reactive volatile organic chemicals (VOCs). However, little is known about the extent of VOC exposure due to the use of other tobacco products. Methods We recruited 48 healthy, tobacco users in four groups: cigarette, smokeless tobacco, occasional users of first generation e-cigarette and e-cigarette menthol and 12 healthy nontobacco users. After abstaining for 48 h, tobacco users used an assigned product. Urine was collected at baseline followed by five collections over a 3-h period to measure urinary metabolites of VOCs, nicotine, and tobacco alkaloids. Results Urinary levels of nicotine were ≃2-fold lower in occasional e-cigarette and smokeless tobacco users than in the cigarette smokers; cotinine and 3-hydroxycotinine levels were similar in all groups. Compared with nontobacco users, e-cigarette users had higher levels of urinary metabolites of xylene, cyanide, styrene, ethylbenzene, and benzene at baseline and elevated urinary levels of metabolites of xylene, N,N-dimethylformamide, and acrylonitrile after e-cigarette use. Metabolites of acrolein, crotonaldehyde, and 1,3-butadiene were significantly higher in smokers than in users of other products or nontobacco users. VOC metabolite levels in smokeless tobacco group were comparable to those found in nonusers with the exception of xylene metabolite—2-methylhippuric acid (2MHA), which was almost three fold higher than in nontobacco users. Conclusions Smoking results in exposure to a range of VOCs at concentrations higher than those observed with other products, and first generation e-cigarette use is associated with elevated levels of N,N-dimethylformamide and xylene metabolites. Implications This study shows that occasional users of first generation e-cigarettes have lower levels of nicotine exposure than the users of combustible cigarettes. Compared with combustible cigarettes, e-cigarettes, and smokeless tobacco products deliver lower levels of most VOCs, with the exception of xylene, N,N-dimethylformamide, and acrylonitrile, whose metabolite levels were higher in the urine of e-cigarette users than nontobacco users. Absence of anatabine in the urine of e-cigarette users suggests that measuring urinary levels of this alkaloid may be useful in distinguishing between users of e-cigarettes and combustible cigarettes. However, these results have to be validated in a larger cohortcomprised of users of e-cigarettes of multiple brands.

scholarly journals Dust events in Beijing, China (2004–2006): comparison of ground-based measurements with columnar integrated observations

2009 ◽  
Vol 9 (18) ◽  
pp. 6915-6932 ◽  
Author(s):  
Z. J. Wu ◽  
Y. F. Cheng ◽  
M. Hu ◽  
B. Wehner ◽  
N. Sugimoto ◽  
...  
Keyword(s):  
Optical Properties ◽  
Particle Number ◽  
Size Distributions ◽  
Particle Volume ◽  
Coarse Mode ◽  
Dust Events ◽  
Beijing China ◽  
Volume Size

Abstract. Ambient particle number size distributions spanning three years were used to characterize the frequency and intensity of atmospheric dust events in the urban areas of Beijing, China in combination with AERONET sun/sky radiometer data. Dust events were classified into two types based on the differences in particle number and volume size distributions and local weather conditions. This categorization was confirmed by aerosol index images, columnar aerosol optical properties, and vertical potential temperature profiles. During the type-1 events, dust particles dominated the total particle volume concentration (<10 μm), with a relative share over 70%. Anthropogenic particles in the Aitken and accumulation mode played a subordinate role here because of high wind speeds (>4 m s−1). The type-2 events occurred in rather stagnant air masses and were characterized by a lower volume fraction of coarse mode particles (on average, 55%). Columnar optical properties showed that the superposition of dust and anthropogenic aerosols in type-2 events resulted in a much higher AOD (average: 1.51) than for the rather pure dust aerosols in type-1 events (average AOD: 0.36). A discrepancy was found between the ground-based and column integrated particle volume size distributions, especially for the coarse mode particles. This discrepancy likely originates from both the limited comparability of particle volume size distributions derived from Sun photometer and in situ number size distributions, and the inhomogeneous vertical distribution of particles during dust events.

scholarly journals A Prototypical First-Generation Electronic Cigarette Does Not Reduce Reports of Tobacco Urges or Withdrawal Symptoms among Cigarette Smokers

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Arit M. Harvanko ◽  
Catherine A. Martin ◽  
Richard J. Kryscio ◽  
William W. Stoops ◽  
Joshua A. Lile ◽  
...  
Keyword(s):  
First Generation ◽  
Electronic Cigarettes ◽  
Electronic Cigarette ◽  
Withdrawal Symptoms ◽  
Cigarette Smokers ◽  
Deprivation Period ◽  
Nicotine Concentration ◽  
Tobacco Cigarette ◽  
Within Subjects

It is unknown whether first-generation electronic cigarettes reduce smoking urges and withdrawal symptoms following a 24 h deprivation period. This study tested whether a first-generation electronic cigarette reduces smoking urges and withdrawal symptoms in cigarette smokers. Following 24 h of tobacco deprivation, using a within-subjects design, eight nontreatment seeking tobacco cigarette smokers (3 females) administered 10 puffs from a conventional cigarette or a first-generation electronic cigarette containing liquid with 0, 8 or 16 mg/ml nicotine. Conventional cigarettes ameliorated smoking urges and electronic cigarettes did not, regardless of nicotine concentration. First-generation electronic cigarettes may not effectively substitute for conventional cigarettes in reducing smoking urges, regardless of nicotine concentration.

scholarly journals Biomass burning aerosol emissions from vegetation fires: particle number and mass emission factors and size distributions

2009 ◽  
Vol 9 (4) ◽  
pp. 17183-17217 ◽  
Author(s):  
S. Janhäll ◽  
M. O. Andreae ◽  
U. Pöschl
Keyword(s):  
Particle Number ◽  
Combustion Efficiency ◽  
Emission Factors ◽  
Fuel Type ◽  
Vegetation Fires ◽  
Fitting Procedures ◽  
Median Diameter ◽  
Count Median Diameter ◽  
Biomass Burning Aerosol ◽  
Aerosol Emissions

Abstract. Aerosol emissions from vegetation fires have a large impact on air quality and climate. In this study, we use published experimental data and different fitting procedures to derive dynamic particle number and mass emission factors (EFPN, EFPM) related to the fuel type, burning conditions and the mass of dry fuel burned, as well as characteristic CO-referenced emission ratios (PN/CO, PM/CO). Moreover, we explore and characterize the variability of the particle size distribution of fresh smoke, which is typically dominated by a lognormal accumulation mode with count median diameter around 120 nm (depending on age, fuel and combustion efficiency), and its effect on the relationship between particle number and mass emission factors. For the particle number emission factor of vegetation fires, we found no dependence on fuel type and obtained the following parameterization as a function of modified combustion efficiency (MCE): EFPN=34·1015×(1-MCE) kg−1±1015 kg−1 with regard to dry fuel mass (d.m.). For the fine particle mass emission factors (EFPM) we obtained (86–85×MCE) g kg−1±3 g kg−1 as an average for all investigated fires; (93–90×MCE) g kg

scholarly journals A Study on Mobile Networks and Their Generations

2021 ◽  
pp. 201-205
Author(s):  
Dr. Kiran B Malagi ◽  
Adarsh K M ◽  
Brijesh Reddy ◽  
Anusha T R ◽  
Bindhu R
Keyword(s):  
Mobile Phones ◽  
Mobile Networks ◽  
High Speed ◽  
First Generation ◽  
Data Transfer ◽  
High Volume ◽  
Fourth Generation ◽  
High Speed Data ◽  
Telecommunications Services ◽  
Manufacturing Technologies

The main purpose of this paper is to provide detailed and comprehensive research on the emergence of various cell phone manufacturing technologies in wireless communication. In this paper we focus on studying mobile generations from 1G to 5G and future mobile phones. The first generation has fulfilled the basic needs of the voice, and the second generation has delivered a high volume and a large amount of integration. The third generation included high-speed data transfer which gave its users a ‘mobile broadband experience’. The fourth generation will provide access to a variety of telecommunications services, including advanced mobile services, supported by mobile networks and fixed networks. We have compared all the mobile phones that have been created so far based on their technology.

scholarly journals Model Calculations of Aerosol Transmission and Infection Risk of COVID-19 in Indoor Environments

2020 ◽  
Vol 17 (21) ◽  
pp. 8114 ◽  
Author(s):  
Jos Lelieveld ◽  
Frank Helleis ◽  
Stephan Borrmann ◽  
Yafang Cheng ◽  
Frank Drewnick ◽  
...  
Keyword(s):  
High Efficiency ◽  
High Volume ◽  
Infection Risk ◽  
Published Data ◽  
Indoor Environments ◽  
Model Calculations ◽  
Viral Loads ◽  
The Individual ◽  
Aerosol Emissions

The role of aerosolized SARS-CoV-2 viruses in airborne transmission of COVID-19 has been debated. The aerosols are transmitted through breathing and vocalization by infectious subjects. Some authors state that this represents the dominant route of spreading, while others dismiss the option. Here we present an adjustable algorithm to estimate the infection risk for different indoor environments, constrained by published data of human aerosol emissions, SARS-CoV-2 viral loads, infective dose and other parameters. We evaluate typical indoor settings such as an office, a classroom, choir practice, and a reception/party. Our results suggest that aerosols from highly infective subjects can effectively transmit COVID-19 in indoor environments. This “highly infective” category represents approximately 20% of the patients who tested positive for SARS-CoV-2. We find that “super infective” subjects, representing the top 5–10% of subjects with a positive test, plus an unknown fraction of less—but still highly infective, high aerosol-emitting subjects—may cause COVID-19 clusters (>10 infections). In general, active room ventilation and the ubiquitous wearing of face masks (i.e., by all subjects) may reduce the individual infection risk by a factor of five to ten, similar to high-volume, high-efficiency particulate air (HEPA) filtering. A particularly effective mitigation measure is the use of high-quality masks, which can drastically reduce the indoor infection risk through aerosols.

scholarly journals Toxic Metals in Liquid and Aerosol from Pod-Type Electronic Cigarettes

2020 ◽  
Author(s):  
Naudia Gray ◽  
Mary Halstead ◽  
Liza Valentin-Blasini ◽  
Clifford Watson ◽  
R Steven Pappas
Keyword(s):  
Electronic Cigarettes ◽  
Potential Health ◽  
Metal Concentrations ◽  
High Background ◽  
Nickel Copper ◽  
Metal Levels ◽  
Zinc Cadmium ◽  
Copper Zinc ◽  
Aerosol Emissions ◽  
Metal Delivery

Abstract High-quality, accurate data on liquid contents and aerosol emissions from electronic nicotine delivery systems (ENDS, e.g., e-cigarettes) are crucial to address potential health concerns as these devices evolve and mature. Metals are an important class of ENDS constituents that merit attention as they have various health implications. Proper sampling, handling and aerosol trapping materials are essential to generate accurate quantitative metal data and to reduce the likelihood of inaccurate results originating from inappropriate collection vessels and materials that contribute to high background levels. Published methods that meet these criteria were applied to the analyses of chromium, nickel, copper, zinc, cadmium, tin and lead in liquid and aerosol from mint/menthol and tobacco flavors of currently popular pod-based devices from three manufacturers. Metal concentrations from pods that had not been used for generating aerosol ranged from below our lowest reportable level to 0.164 µg/g for Cr, 61.3 µg/g for Ni, 927 µg/g for Cu, 14.9 µg/g for Zn, 58.2 µg/g for Sn and 2.56 µg/g for Pb. Cadmium was included in our analyte panel and was not present above detection limits in liquid or aerosol. Aerosol metal concentrations (using a 55-mL puff) ranged from below our lowest reportable level to 29.9 ng/10 puffs for Cr, 373 ng/10 puffs for Ni, 209 ng/10 puffs for Cu, 4,580 ng/10 puffs for Zn, 127 ng/10 puffs for Sn and 463 ng/10 puffs for Pb. Our results showed some metal delivery from all the products examined and highly variable metal levels between manufacturer, brand and package.

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