We compared the plasma characteristics of asymmetric bipolar pulsed-dc discharges at
100 kHz to those produced by a radio frequency (rf) source. The electrical discharges were monitored by a computer-controlled Langmuir probe operating in time-resolved mode. The acquisition system provided the intensity-voltage (I-V) characteristics with a time resolution of 1 mu s. This facilitated the discussion of the variation in plasma parameters within a pulse cycle as a function of the pulse waveform and the peak voltage. The electron distribution was clearly divided into high- and low-energy Maxwellian populations of electrons (a bi-Maxwellian population) at the beginning of the negative voltage region of the pulse. We ascribe selleck inhibitor this
to intense stochastic heating due to the rapid advancing of the sheath edge. The hot population had an electron temperature T-e(hot) of over 10 eV and an initial low density n(e)(hot) which decreased to zero. Cold electrons of temperature T-e(cold)similar to 1 eV represented STAT inhibitor the majority of each discharge. The density of cold electrons n(e)(cold) showed a monotonic increase over time within the negative pulse, peaking at almost 7×10(10) cm(-3), corresponding to the cooling of the hot electrons. The plasma potential V-p of similar to 30 V underwent a smooth increase during the pulse and fell at the end of the negative region. Different rates of CH4 conversion were calculated from the DLC deposition rate. These were explained in terms of the specific activation energy E-a and the conversion factor x(dep) associated with the plasma processes. The work deepens our understanding of the advantages of using pulsed power supplies for the PECVD of hard metallic and protective coatings for industrial applications (optics, biomedicine, and YH25448 purchase electronics).”
“In this work, a new microwave resonant cavity was developed to completely preheat a poly(ethylene terephthalate) preform efficiently for a stretch blow molding process. Microwave power
simulation software was used to design the microwave resonant cavity. An investigation of the inside and outside Surface temperature profile along the preform and free inflation experimentation indicated that a cylindrical resonant cavity could efficiently preheat a poly(ethylene terephthalate) preform with the advantages of reduced time and increased energy savings versus a conventional infrared heating system. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1670-1679, 2009″
“Objective-To evaluate the use of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) concentrations in pooled serum samples for herd-based detection of subclinical ketosis (SCK) in dairy cows after calving.
Design-Cross-sectional study.
Animals-1,100 dairy cows from 110 herds.
Procedures-Blood samples were collected from 10 healthy cows/herd in the first week after parturition. Aliquots of serum were mixed to create a pooled sample.