The Influence of Graphene Oxide on Nanoparticle Emissions during Drilling of Graphene/Epoxy Carbon-Fiber Reinforced Engineered Nanomaterials

Graphene oxide (GO) nanoparticles are increasingly being used to tailor industrial composites. However, despite the advantages, GO has shown conceivable health risks and toxicity to humans and the environment if released. This study investigates the influence that GO concentrations have on nanoparticle emissions from epoxy-reinforced carbon fiber hybrid composites (EP/CF) during a lifecycle scenario, that is, a drilling process. The mechanical properties are investigated and an automated drilling methodology in which the background noise is eliminated is used for the nanoparticle emissions measurements. Real-time measurements are collected using a condensation particle counter (CPC), a scanning mobility particle sizer spectrometer (SMPS), a real-time fast mobility particle spectrometer (DMS50) and post-test analytical methods. The results observe that all three nanoparticle reinforced samples demonstrated a statistically significant difference of up to a 243% increase in mean peak particle number concentration in comparison to the EP/CF sample. The results offer a novel set of data comparing the nanoparticle release of GO with varying filler weight concentration and correlating it the mechanical influence of the fillers. The results show that the release characteristics and the influence in particle number concentration are primarily dependent on the matrix brittleness and not necessarily the filler weight concentration within the nanocomposite.

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Effect of Electrocautery Settings on Particulate Concentrations in Surgical Plume during Tonsillectomy

Otolaryngology ◽

10.1177/0194599820914275 ◽

2020 ◽

Vol 162 (6) ◽

pp. 867-872 ◽

Cited By ~ 5

Author(s):

Michele M. Carr ◽

Vijay A. Patel ◽

Jhy-Charm Soo ◽

Sherri Friend ◽

Eun Gyung Lee

Keyword(s):

Particle Number ◽

Medical Center ◽

Health Hazard ◽

Number Concentration ◽

Particle Number Concentration ◽

Breathing Zone ◽

Operating Room Personnel ◽

Cross Sectional ◽

Significant Difference ◽

Smoke Evacuation

Objectives To describe the effect of monopolar electrocautery (EC) settings on surgical plume particulate concentration during pediatric tonsillectomy. Study Design Cross-sectional study. Setting Tertiary medical center. Subjects and Methods During total tonsillectomy exclusively performed with EC, air was sampled with a surgeon-worn portable particle counter. The airborne mean and maximum particle concentrations were compared for tonsillectomy performed with EC at 12 W vs 20 W, with smoke evacuation system (SES) and no smoke evacuation (NS). Results A total of 36 children were included in this analysis: 9 cases with EC at 12 W and SES (12SES), 9 cases with EC at 20 W and SES (20SES), 9 cases with EC at 12 W without SES (12NS), and 9 cases with EC at 20 W without SES (20NS). Mean particle number concentration in the breathing zone during tonsillectomy was 1661 particles/cm3 for 12SES, 5515 particles/cm3 for 20SES, 8208 particles/cm3 for 12NS, and 78,506 particles/cm3 for 20NS. There was a statistically significant difference in the particle number concentrations among the 4 groups. The correlation between the particle number concentration and EC time was either moderate (for 12SES) or negative (for remaining groups). Conclusion Airborne particle concentrations during tonsillectomy are over 9.5 times higher when EC is set at 20 W vs 12 W with NS, which is mitigated to 3.3 times with SES. Applying lower EC settings with SES during pediatric tonsillectomy significantly reduces surgical plume exposure for patients, surgeons, and operating room personnel, which is a well-known occupational health hazard.

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Commuter Exposure to Black Carbon, Fine Particulate Matter and Particle Number Concentration in Ferry and at the Pier in Istanbul

Atmosphere ◽

10.3390/atmos10080439 ◽

2019 ◽

Vol 10 (8) ◽

pp. 439 ◽

Cited By ~ 1

Author(s):

Onat ◽

Şahin ◽

Uzun ◽

Akın ◽

Özkaya ◽

...

Keyword(s):

Standard Deviation ◽

Black Carbon ◽

Particle Number ◽

Fine Particulate Matter ◽

Road Transport ◽

Number Concentration ◽

Particle Number Concentration ◽

Total Exposure ◽

Significant Difference ◽

Commuter Exposure

This paper presents measurements and analyses of the concentrations of black carbon (BC), particle number concentration (PNC), and PM2.5 (≤2.5 μm) while commuting by ferries in Istanbul. In this context, exposures to the mentioned pollutants were estimated for car ferry, fast ferry, and at the piers, and for two travel routes, for a total of 89 trips. BC, PNC, and PM2.5 measurements were simultaneously performed in a ferry and at the piers, and the correlation between pollutant concentrations, meteorological parameters, and environmental factors were analyzed. The mean concentrations for all pollutants in car ferry were lower than the average concentrations in fast ferry. The concentration ratios of fast ferry to car ferry for BC, PNC, and PM2.5 were 6.4, 1.2, and 1.3, respectively. High variability in the concentrations was observed at the piers and in ferry during berthing. The highest mean concentrations (±standard deviation) of BC (14.3 ± 10.1 µg m−3) and PNC (42,005 ± 30,899 pt cm−3) were measured at Yalova pier. The highest mean concentration (±standard deviation) of PM2.5 (26.1 ± 11.5) was measured at Bostancı pier. It was observed that the main external sources of BC, PNC, and PM2.5 at the piers were road transport, residential heating, and shipping activity. There were no significant correlations between BC, PNC, and PM2.5 in fast ferry, while BC was positively correlated with PNC (r = 0.61, p < 0.01) and PM2.5 (r = 0.76, p < 0.01) in car ferry. At the piers, significant relations between pollutants and meteorological variables were observed. It was noticed that there was no significant difference between summer and winter in ferry and at the pier concentrations of BC, PNC, and PM2.5 except for Yenikapı pier and Bakırköy pier. The highest total exposure to PNC and PM2.5 was in car ferry mode, while the highest total exposure to BC was in fast ferry mode.

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Exposure assessment of nanotitanium oxide powder handling using real-time size-selective particle number concentration measurements and X-ray fluorescence spectrometry —The possibility of exposure to nonagglomerated nanomaterials during the handling of nanomaterial fine powders—

Industrial Health ◽

10.2486/indhealth.2021-0110 ◽

2021 ◽

Author(s):

Mitsutoshi TAKAYA ◽

Maromu YAMADA ◽

Kenichi KOBAYASHI ◽

Ichiro HIGASHIKUBO ◽

Masayoshi HAGIWARA ◽

...

Keyword(s):

Exposure Assessment ◽

Real Time ◽

Particle Number ◽

Number Concentration ◽

Oxide Powder ◽

Fluorescence Spectrometry ◽

Particle Number Concentration ◽

X Ray ◽

Fine Powders ◽

Concentration Measurements

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Influence of particle charging on TEOM measurements in the presence of an electrostatic precipitator

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-1-435-2008 ◽

2008 ◽

Vol 1 (1) ◽

pp. 435-449

Author(s):

N. K. Meyer ◽

A. Lauber ◽

T. Nussbaumer ◽

H. Burtscher

Keyword(s):

Real Time ◽

Mass Concentration ◽

Particle Number ◽

Electrostatic Precipitator ◽

Number Concentration ◽

Particle Number Concentration ◽

Wood Combustion ◽

Particle Charging ◽

Combustion Emissions ◽

Electrostatic Effect

Abstract. The efficiency of an electrostatic precipitator (ESP) for reducing wood combustion emissions was investigated. Real-time measurements were conducted by directly reading the change in frequency of the tapered element in a Thermo Scientific 1400a TEOM. The measurements have been shown to be influenced by the charge on the aerosols reaching the tapered element such that the TEOM overestimates mass concentration. This electrostatic effect was cross-checked with particle number concentration measurements where no influence was observed. Placing a radioactive neutraliser prior to the TEOM leads to agreement between observed ESP efficiencies as measured by both the TEOM and a CPC.

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