scholarly journals A High Electrical Field Effect to Ultrafine Particle Filter Performance on Motor Vehicle Exhaust

2020 ◽  
Vol 9 (3S) ◽  
pp. 220-223
Keyword(s):  
Electric Field ◽  
Direct Current ◽  
Ultrafine Particles ◽  
Particle Concentration ◽  
Motor Vehicle ◽  
Ultrafine Particle ◽  
Vehicle Exhaust ◽  
Electrical Field ◽  
Filter Performance ◽  
High Electrical Field

In this study, a high electric field generated by direct current was applied to an electrode filter on the motor vehicle exhaust to reduce the ultrafine particle emission. A standard motor vehicle engine in an idle condition with the engine rotation of 1000 rpm was used as the particle source. The aluminum plates with a thickness of 0.15 mm were used as the positive and negative electrodes. They were placed onto an acrylic filter frame and installed on the exhaust. A signal generator producing a high stable voltage (direct current) was applied on the electrodes to produce an electric field. The influence of the applied electrical field on the filter to reduce ultrafine particles was investigated by the reduction of the concentration before and after passing through the filter. The particle concentration was measured using a TSI P-Trak 8525. The experiment result shows that applying a high electrical field on the filter affects to reduce the ultrafine particle concentration with an efficiency of 5% to 47%.

Corona Ions from Overhead Transmission Voltage Powerlines: Effect on Direct Current Electric Field and Ambient Particle Concentration Levels

2010 ◽  
Vol 44 (1) ◽  
pp. 526-531 ◽  
Author(s):  
Folasade J-Fatokun ◽  
Rohan Jayaratne ◽  
Lidia Morawska ◽  
David Birtwhistle ◽  
Rihandanu Rachman ◽  
...  
Keyword(s):  
Electric Field ◽  
Direct Current ◽  
Particle Concentration ◽  
Direct Current Electric Field ◽  
Ambient Particle ◽  
Current Electric Field ◽  
Concentration Levels

scholarly journals Ultrafine particle formation in the inland sea breeze airflow in Southwest Europe

2010 ◽  
Vol 10 (19) ◽  
pp. 9615-9630 ◽  
Author(s):  
R. Fernández-Camacho ◽  
S. Rodríguez ◽  
J. de la Rosa ◽  
A. M. Sánchez de la Campa ◽  
M. Viana ◽  
...  
Keyword(s):  
Urban Areas ◽  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Sea Breeze ◽  
Ambient Air ◽  
Exhaust Emissions ◽  
Particle Formation ◽  
New Particle Formation ◽  
Vehicle Exhaust ◽  
Number Of Particles

Abstract. Studies on ultrafine particles (diameter < 100nm) and air quality have mostly focused on vehicle exhaust emissions and on new particle formation in "clean" ambient air. Here we present a study focused on the processes contributing to ultrafine particle concentrations in a city (Huelva, SW Spain) placed close to a coastal area where significant anthropogenic emissions of aerosol precursors occur. The overall data analysis shows that two processes predominantly contribute to the number of particles coarser than 2.5 nm: vehicle exhaust emissions and new particle formation due to photo-chemical activity. As typically occurs in urban areas, vehicle exhaust emissions result in high concentrations of black carbon (BC) and particles coarser than 2.5 nm (N) during the morning rush hours. The highest N concentrations were recorded during the 11:00–17:00 h period, under the sea breeze regime, when low BC concentrations were registered and photochemical activity resulted in high O3 levels and in new particle formation in the aerosol precursors' rich inland airflow. In this period, it is estimated that about 80% of the number of particles are linked to sulfur dioxide emissions. The contributions to N of "carbonaceous material and those compounds nucleating/condensing immediately after emission" and of the "new particle formation processes in air masses rich gaseous precursors (e.g. SO2)" were estimated by means of a relatively novel method based on simultaneous measurements of BC and N. A comparison with two recent studies suggests that the daily cycles of "new particle formation" during the inland sea breeze is blowing period seem to be a feature of ultrafine particles in coastal areas of South-west Europe.

scholarly journals Ultrafine particle formation in the inland sea breeze airflow in Southwest Europe

2010 ◽  
Vol 10 (7) ◽  
pp. 17753-17788 ◽  
Author(s):  
R. Fernández-Camacho ◽  
S. Rodríguez ◽  
J. de la Rosa ◽  
A. M. Sánchez de la Campa ◽  
M. Viana ◽  
...  
Keyword(s):  
Urban Areas ◽  
Ultrafine Particles ◽  
Ultrafine Particle ◽  
Sea Breeze ◽  
Ambient Air ◽  
Exhaust Emissions ◽  
Particle Formation ◽  
New Particle Formation ◽  
Vehicle Exhaust ◽  
Number Of Particles

Abstract. Studies on ultrafine particles and air quality have mostly focused on vehicle exhaust emissions and on new particle formation in "clean" ambient air. Here we present a study of the processes contributing to ultrafine particle concentrations in an urban coastal area (Huelva, SW Spain) where significant anthropogenic emissions of aerosol precursors occur. The overall data analysis shows that two processes predominantly contribute to the number of particles coarser than 2.5 nm: vehicle exhaust emissions and new particle formation due to photo-chemical activity. As typically occurs in urban areas, vehicle exhaust emissions result in high concentrations of black carbon (BC) and particles coarser than 2.5 nm (N) during the morning rush hours. The highest N concentrations were recorded during the 11–17 h period, under the sea breeze regime, when photochemical activity resulted in high O3 levels and new particle formation in the aerosol precursors' rich inland airflow. In this period, it is estimated that about 80% of the number of particles are linked to sulfur dioxide emissions. The contributions to N of "carbonaceous material and those compounds nucleating/condensing immediately after emission" and of the "new particle formation processes in air masses rich gaseous precursors (e.g. SO2)" were estimated by means of a relatively novel method based on simultaneous measurements of BC and N. A comparison with two recent studies suggests that the daily cycles of "new particle formation" during the period when the inland sea breeze is blowing period seem to be a feature of ultrafine particles in coastal areas of South-west Europe.

scholarly journals The Impact of Cross-Linking Effect on the Space Charge Characteristics of Cross-Linked Polyethylene with Different Degrees of Cross-Linking under Strong Direct Current Electric Field

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1149 ◽  
Author(s):  
Shuchao Wang ◽  
Quan Zhou ◽  
Ruijin Liao ◽  
Lai Xing ◽  
Nengcheng Wu ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Space Charge ◽  
Direct Current ◽  
Cross Linking ◽  
Average Charge ◽  
Electrical Field ◽  
Electrical Field Strength ◽  
The Cross ◽  
The Impact

Cross-linked polyethylene (XLPE) obtained by the crossing-linking reaction of polyethylene (PE) can greatly enhance the mechanical properties and other properties of PE, which makes XLPE widely applied in the field of electric power engineering. However, the space charges can distort the distribution of the electrical field strength in the XLPE applied in the insulation materials, which can shorten the service life of the insulation materials. Therefore, the space charge characteristics of XLPE under the strong direct current (DC) electric field have been the focus of scholars and engineers all over the world. This article has studied the impact of the cross-linking effect on the space charge characteristics of XLPE with different degrees of cross-linking. For this issue, we used dicumyl peroxide (DCP) as the cross-linking agent and low-density polyethylene (LDPE) as the base material for the preparation of samples. Besides, the space charge distribution was measured by the pulsed electro-acoustic method (PEA). In addition, the average charge density as a characteristic parameter was introduced into the experiment, which was used to quantitatively analyze the impact of the cross-linking effect on the space charge characteristics of XLPE with different degrees of cross-linking. Meanwhile, we also explained the impact of the cross-linking effect on XLPE with different degrees of cross-linking from a microscopic point of view. Ultimately, some important conclusions can be obtained. For instance, the cross-linking effect significantly increases the threshold electrical field strength of XLPE, and as the content of cross-linking agent increases, the threshold electrical field strength increases at first and then decreases, and the threshold electrical field strength reaches the maximum value when the content of the cross-linking agent is 1.0% or 2.1%. Besides, the cross-linking effect introduces negative charge traps into the LDPE and increases the densities of the deeper charge traps, and so on. In addition, we have also analyzed the average charge density, and we have summarized the theoretical model of the average charge decay, namely, Q ( t ) = Q 0 + α e − t β , which is very effective for explaining the dissipation characteristics (more conclusive contents can be seen in the conclusion section of this article).

scholarly journals Impact on Ultrafine Particles Concentration and Turbulent Fluxes of SARS-CoV-2 Lockdown in a Suburban Area in Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 407
Author(s):  
Antonio Donateo ◽  
Adelaide Dinoi ◽  
Gianluca Pappaccogli
Keyword(s):  
Ultrafine Particles ◽  
Particle Number ◽  
Ultrafine Particle ◽  
Turbulent Fluxes ◽  
Number Concentration ◽  
Suburban Area ◽  
Observation Site ◽  
Meteorological Forcing ◽  
Restrictive Measures ◽  
Measurement Area

In order to slow the spread of SARS-CoV-2, governments have implemented several restrictive measures (lockdown, stay-in-place, and quarantine policies). These provisions have drastically changed the routines of residents, altering environmental conditions in the affected areas. In this context, our work analyzes the effects of the reduced emissions during the COVID-19 period on the ultrafine particles number concentration and their turbulent fluxes in a suburban area. COVID-19 restrictions did not significantly reduce anthropogenic related PM10 and PM2.5 levels, with an equal decrement of about 14%. The ultrafine particle number concentration during the lockdown period decreased by 64% in our measurement area, essentially due to the lower traffic activity. The effect of the restriction measures and the reduction of vehicles traffic was predominant in reducing concentration rather than meteorological forcing. During the lockdown in 2020, a decrease of 61% in ultrafine particle positive fluxes can be observed. At the same time, negative fluxes decreased by 59% and our observation site behaved, essentially, as a sink of ultrafine particles. Due to this behavior, we can conclude that the principal particle sources during the lockdown were far away from the measurement site.

scholarly journals Electrical Field-Assisted Gene Delivery from Polyelectrolyte Multilayers

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 133
Author(s):  
Yu-Che Cheng ◽  
Shu-Lin Guo ◽  
Kun-Da Chung ◽  
Wei-Wen Hu
Keyword(s):  
Gene Delivery ◽  
Electric Field ◽  
Treatment Time ◽  
Transfection Efficiency ◽  
Polyelectrolyte Multilayers ◽  
Aqueous Environment ◽  
Layer By Layer ◽  
Electrical Field ◽  
Lbl Assembly ◽  
Electric Field Treatment

To sustain gene delivery and elongate transgene expression, plasmid DNA and cationic nonviral vectors can be deposited through layer-by-layer (LbL) assembly to form polyelectrolyte multilayers (PEMs). Although these macromolecules can be released for transfection purposes, their entanglement only allows partial delivery. Therefore, how to efficiently deliver immobilized genes from PEMs remains a challenge. In this study, we attempt to facilitate their delivery through the pretreatment of the external electrical field. Multilayers of polyethylenimine (PEI) and DNA were deposited onto conductive polypyrrole (PPy), which were placed in an aqueous environment to examine their release after electric field pretreatment. Only the electric field perpendicular to the substrate with constant voltage efficiently promoted the release of PEI and DNA from PEMs, and the higher potential resulted in the more releases which were enhanced with treatment time. The roughness of PEMs also increased after electric field treatment because the electrical field not only caused electrophoresis of polyelectrolytes and but also allowed electrochemical reaction on the PPy electrode. Finally, the released DNA and PEI were used for transfection. Polyplexes were successfully formed after electric field treatment, and the transfection efficiency was also improved, suggesting that this electric field pretreatment effectively assists gene delivery from PEMs and should be beneficial to regenerative medicine application.

Direct measurement of the characteristic three-body electron attachment time in the atmospheric air in direct current electric field

2013 ◽  
Vol 103 (3) ◽  
pp. 034106 ◽  
Author(s):  
A. V. Shutov ◽  
I. V. Smetanin ◽  
A. A. Ionin ◽  
A. O. Levchenko ◽  
L. V. Seleznev ◽  
...  
Keyword(s):  
Electric Field ◽  
Direct Measurement ◽  
Direct Current ◽  
Electron Attachment ◽  
Atmospheric Air ◽  
Direct Current Electric Field ◽  
Three Body ◽  
Current Electric Field

Combustion of ethanol fuel droplet in vertical direct current electric field

2011 ◽  
Vol 33 (2) ◽  
pp. 2005-2011 ◽  
Author(s):  
O. Imamura ◽  
B. Chen ◽  
S. Nishida ◽  
K. Yamashita ◽  
M. Tsue ◽  
...  
Keyword(s):  
Electric Field ◽  
Direct Current ◽  
Fuel Droplet ◽  
Ethanol Fuel ◽  
Direct Current Electric Field ◽  
Current Electric Field

scholarly journals Multiscale Coupling of Transcranial Direct Current Stimulation to Neuron Electrodynamics: Modeling the Influence of the Transcranial Electric Field on Neuronal Depolarization

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Edward T. Dougherty ◽  
James C. Turner ◽  
Frank Vogel
Keyword(s):  
Electric Field ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Three Dimensional ◽  
Human Head ◽  
Multiscale Model ◽  
Medical Intervention ◽  
Medical Community ◽  
Computational Grids ◽  
Direct Current Stimulation

Transcranial direct current stimulation (tDCS) continues to demonstrate success as a medical intervention for neurodegenerative diseases, psychological conditions, and traumatic brain injury recovery. One aspect of tDCS still not fully comprehended is the influence of the tDCS electric field on neural functionality. To address this issue, we present a mathematical, multiscale model that couples tDCS administration to neuron electrodynamics. We demonstrate the model’s validity and medical applicability with computational simulations using an idealized two-dimensional domain and then an MRI-derived, three-dimensional human head geometry possessing inhomogeneous and anisotropic tissue conductivities. We exemplify the capabilities of these simulations with real-world tDCS electrode configurations and treatment parameters and compare the model’s predictions to those attained from medical research studies. The model is implemented using efficient numerical strategies and solution techniques to allow the use of fine computational grids needed by the medical community.

Sign in / Sign up

Export Citation Format

Share Document