Investigation of a capacitively coupled atmospheric pressure RF excited glow discharge in He-water mixtures by molecular beam mass spectroscopy

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Electron kinetics in radio-frequency atmospheric-pressure microplasmas

The kinetic study of three radio-frequency atmospheric-pressure helium microdischarges indicates that the electron energy probability function is far from equilibrium, and three electron groups with three distinct temperatures are identified. The relative population of electrons in different energy regions is strongly time modulated and differs significantly from values recently reported from fluid analyses. It is also shown that a flux of energetic electrons (epsilon > 5 eV) that comprises up to 50% of the total electron flux can reach the electrodes. This energetic electron flux provides a new means of delivering energy to the electrodes and tuning the surface chemistry in atmospheric-pressure discharges. The three electron groups and the engineering of an energetic electron flux might open up a new paradigm in plasma-surface chemistry that has not been considered up until now.open11159sciescopu

High Hepatitis E Seroprevalence Among Displaced Persons in South Sudan.

AbstractLarge protracted outbreaks of hepatitis E virus (HEV) have been documented in displaced populations in Africa over the past decade though data are limited outside these exceptional settings. Serological studies can provide insights useful for improving surveillance and disease control. We conducted an age-stratified serological survey using samples previously collected for another research study from 206 residents of an internally displaced person camp in Juba, South Sudan. We tested serum for anti-HEV antibodies (IgM and IgG) and estimated the prevalence of recent and historical exposure to the virus. Using data on individuals' serostatus, camp arrival date, and state of origin, we used catalytic transmission models to estimate the relative risk of HEV infection in the camp compared with that in the participants' home states. The age-adjusted seroprevalence of anti-HEV IgG was 71% (95% confidence interval = 63-78), and 4% had evidence of recent exposure (IgM). We estimated HEV exposure rates to be more than 2-fold (hazard ratio = 2.3, 95% credible interval = 0.3-5.8) higher in the camp than in the participants' home states, although this difference was not statistically significant. HEV transmission may be higher than previously appreciated, even in the absence of reported cases. Improved surveillance in similar settings is needed to understand the burden of disease and minimize epidemic impact through early detection and response

Atmospheric glow discharges from the high-frequency to very high-frequency bands

Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the authors and the American Institute of Physics. This article appeared in the journal, Applied Physics Letters, and may be found at: http://link.aip.org/link/?APPLAB/93/251502/1This letter reports an experimental investigation of an atmospheric glow discharge in both the high-frequency (HF) band of 3–30 MHz and the very high frequency band of 30–300 MHz. At constant input power, increased frequency is found to change little the electron density and to reduce slightly the electron excitation temperature. Significantly, an eightfold frequency increase from 20 to 80 MHz leads to a 20-fold increase in the maximum plasma power without plasma constriction. The maximum power density of 355 W/cm3 achieved at 80 MHz is far greater than those reported in the HF band

The complex behavior of El Niño winter 2015-2016

This paper examines the outstanding characteristics of the strong 2015-2016 El Nino (EN) winter and its impact over the European region through the stratosphere. Despite being classified as a strong eastern Pacific (EP) EN event, our analysis reveals an anomalous behavior, with some signatures that are more typical of central Pacific (CP) EN events instead. They include (i) a record-breaking value of the CP index, (ii) a stronger polar vortex in early and midwinter, due to reduced upward wave activity and a weakened Aleutian low, and (iii) the occurrence of one of the earliest stratospheric final warmings (SFWs) on record, which are more prone to occur during CP-EN. Following the SFW, a stratospheric influence on the Euro-Atlantic sector is reported in spring, with persistent Greenland blocking resulting in extreme precipitation over some southern European regions. Results highlight the importance of considering early SFWs as mediators of El Nino teleconnections

Forensic Odontology and its applicability in processing crime scenes and other catastrophic events

En los últimos años la odontología forense alcanza a nivel mundial fundamental importancia, consiguiendo, mediante determinados procedimientos, estimar hora y fecha de muerte de una persona, facilitando la resolución de múltiples y complicados casos de muerte. Los procedimientos empleados también permiten el levantamiento de huellas aplicando técnicas para queiloscopía, mordidas, registro de rugas palatinas, brindando de esta forma un gran aporte en la investigación criminal en su primera fase indagatoria, dentro de la cual el procesamiento de la escena busca colectar indicios y evidencias vinculantes al hecho, que posteriormente a través de una cadena de custodia se trasladarán al laboratorio donde los indicios y evidencias serán estudiados, pasando a ser medios de prueba pericial para poder identificar el hecho y la autoria de un acto presuntamente criminal. Se presenta así una recopilacion de literatura concerniente al tema que busca informar al odontólogo de practica general sobre terminología, procedimientos y demás relacionados a las ciencias forenses, con el propósito de informar y actualizar sus conocimientos al respecto.In recent years, forensic dentistry reaches critical importance worldwide, getting through certain procedures to estimate, time and date of death of a person, facilitating the resolution of multiple and complicated cases of death. The procedures employed also allow the lifting of fingerprints by applying techniques; Queiloscopía, Biting, Registration Rugas Palatine, providing thus a great contribution in the Criminal Investigation in its first phase Inquest, within which the processing of the scene seeks to collect evidence and binding evidence the fact that subsequently through a chain of custody is transferred to the laboratory where the evidence and evidence will be studied, becoming media expert evidence to identify the fact and authorship of an allegedly criminal act, thus presents a collection of literature concerning the subject that seeks to inform the general practice dentist on terminology, procedures and other related forensic sciences in order to inform and update their knowledge about it

Particle-in-cell simulations of rf breakdown

Breakdown voltages of a capacitively coupled radio frequency argon discharge at 27 MHz are studied. We use a one-dimensional electrostatic PIC code to investigate the effect of changing the secondary emission properties of the electrodes on the breakdown voltage, particularly at low pd values. Simulation results are compared with the available experimental results and a satisfactory agreement is found.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

The mechanism of striation formation in plasma display panels

This article was published in the journal, Journal of applied physics [© American Institute of Physics] and is also available at: http://jap.aip.orgDespite the high pressure employed in plasma display panels, the energy balance of low-energy electrons is found to be dominated by inelastic collisions, and the resulting nonlocal electron kinetics plays a key role in the striation formation. Surface charge accumulation on the anode dielectric, however, is also needed for striations to form. It is the combined effect of surface charges and nonlocal electron kinetics that results in the striation formation in plasma display panel cells. Two-dimensional fluid simulations, which assume local electron kinetics, and two-dimensional particle-in-cell Monte Carlo collision simulations with a bare conducting anode show that striations do not form if either the nonlocal electron kinetics or the surface charge accumulation is not considered