Optical and Mass Spectrometric Measurements of the CH-CO Dry Reforming Process in a Low Pressure, Very High Density, and Purely Inductive Plasma.

This paper presents a study of a CH-CO plasma-reforming process carried out in a high power density (5-50 W/cm), using toroidal transformer-coupled plasma, and operated at low pressure (0.2-0.7 Torr).

Nonlocal effect of plasma resonances on the electron energy-distribution function in microwave plasma columns.

Spatially resolved trace rare gases optical emission spectroscopy was used to analyze the electron energy-distribution function (EEDF) in low-pressure argon plasma columns sustained by surface waves. At frequencies >1 GHz, in the microwave-sustained region, the EEDF departs from a Maxwellian, characterized by a depletion of low-energy electrons and a high-energy tail, whereas in the field-free zone, the EEDF is Maxwellian. Abnormal behavior of the EEDF results from the acceleration of low-energy electrons due to the conversion of surface waves into volume plasmons at the resonance point where the plasma frequency equals the wave frequency and their absorption by either collisional or Landau damping.

Recombination reactions of oxygen atoms on an anodized aluminum plasma reactor wall, studied by a spinning wall method.

We have studied the recombination of O atoms on an anodized Al surface in an oxygen plasma, using a new "spinning wall" technique. With this method, a cylindrical section of the wall of the plasma reactor is rotated and the surface is periodically exposed to an oxygen plasma and then to a differentially pumped mass spectrometer (MS). By varying the substrate rotation frequency (r), we vary the reaction time (t(r)), that is, the time between exposure of the surface to O atoms in the plasma and MS detection of desorbing O(2) (t(r) = 1/2r).

Plasma-surface reactions at a spinning wall.

We report a new method for studying surface reactions and kinetics at moderately high pressures (<10 Torr) in near real time. A cylindrical substrate in a reactor wall is rotated at up to 200,000 rpm, allowing the surface to be periodically exposed to a reactive environment and then analyzed by a triple-differentially pumped mass spectrometer in as little as 150 micros thereafter. We used this method to study oxygen plasma reactions on anodized aluminum.

Nanopantography: a new method for massively parallel nanopatterning over large areas.

We report a radically different approach to the versatile fabrication of nanometer-scale preselected patterns over large areas. Standard lithography, thin film deposition, and etching are used to fabricate arrays of ion-focusing microlenses (e.g.

Trace rare gases optical emission spectroscopy: nonintrusive method for measuring electron temperatures in low-pressure, low-temperature plasmas.

Trace rare gases optical emission spectroscopy (TRG-OES) is a new, nonintrusive method for determining electron temperatures (T(e)) and, under some conditions, estimating electron densities (n(e)) in low-temperature, low-pressure plasmas. The method is based on a comparison of atomic emission intensities from trace amounts of rare gases (an equimixture of He, Ne, Ar, Kr, and Xe) added to the plasma, with intensities calculated from a model. For Maxwellian electron energy distribution functions (EEDFs), T(e) is determined from the best fit of theory to the experimental measurements.

Social support and its relationship to immunization status in preschool children.

Many children are at risk for developing serious and costly health problems because they are not adequately immunized. This descriptive correlational study explored the relationship between social support, parental knowledge of vaccine-preventable diseases, and the immunization status of preschool children. A convenience sample of 153 parents and guardians of children aged 6 to 24 months completed Procidano and Heller's Perceived Social Support Scales, a questionnaire on immunization knowledge, and a demographics questionnaire.