Directional mass transport in an atmospheric pressure surface barrier discharge

In an atmospheric pressure surface barrier discharge the inherent physical separation between the plasma generation region and downstream point of application reduces the flux of reactive chemical species reaching the sample, potentially limiting application efficacy. This contribution explores the impact of manipulating the phase angle of the applied voltage to exert a level of control over the electrohydrodynamic forces generated by the plasma. As these forces produce a convective flow which is the primary mechanism of species transport, the technique facilitates the targeted delivery of reactive species to a downstream point without compromising the underpinning species generation mechanisms. Particle Imaging Velocimetry measurements are used to demonstrate that a phase shift between sinusoidal voltages applied to adjacent electrodes in a surface barrier discharge results in a significant deviation in the direction of the plasma induced gas flow. Using a two-dimensional numerical air plasma model, it is shown that the phase shift impacts the spatial distribution of the deposited charge on the dielectric surface between the adjacent electrodes. The modified surface charge distribution reduces the propagation length of the discharge ignited on the lagging electrode, causing an imbalance in the generated forces and consequently a variation in the direction of the resulting gas flow

Detection and Processing Techniques of FECG Signal for Fetal Monitoring

Fetal electrocardiogram (FECG) signal contains potentially precise information that could assist clinicians in making more appropriate and timely decisions during labor. The ultimate reason for the interest in FECG signal analysis is in clinical diagnosis and biomedical applications. The extraction and detection of the FECG signal from composite abdominal signals with powerful and advance methodologies are becoming very important requirements in fetal monitoring. The purpose of this review paper is to illustrate the various methodologies and developed algorithms on FECG signal detection and analysis to provide efficient and effective ways of understanding the FECG signal and its nature for fetal monitoring. A comparative study has been carried out to show the performance and accuracy of various methods of FECG signal analysis for fetal monitoring. Finally, this paper further focused some of the hardware implementations using electrical signals for monitoring the fetal heart rate. This paper opens up a passage for researchers, physicians, and end users to advocate an excellent understanding of FECG signal and its analysis procedures for fetal heart rate monitoring system

Control of Phomopsis Blight of Egg Plant through Fertilizer and Fungicide Management

The experiments were conducted at Laboratory of the Department of Plant Pathology and in the farm of Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh during Rabi season of the year 2007-2008. Four fungicides viz. Bavistin 50 WP (Carbendazim), Tilt 250 EC (Propiconazole), Cupravit 50 WP (Copperoxychloride) and Dithane M-45 (Mancozeb) and micronutrients (Gypsum, ZnO and Boric acid) were evaluated against Phomopsis vexans causing Phomopsis blight and fruit rot of eggplant. The fungicides and micronutrients either applied individually or in combination showed significant effect in terms of per cent leaf infection, fruit infection, leaf area diseased and fruit area diseased in comparison to control. Effect of each fungicide applied in combination with micronutrients always showed better performance in reducing disease incidence and disease severity than the fungicides applied alone. Among the fungicides, Bavistin 50 WP (0.1%) proved to be effective arresting the spore germination and mycelia growth of Phomopsis vexans assayed in in vitro test. Reduction of leaf area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 58.17, 67.37, 78.41 and 85.25%, respectively at preflowering, post-flowering, fruiting and fruit ripening stages while Bavistin 50 WP (0.1%) alone reduced by 52.22, 58.67, 74.19 and 83.09%, respectively at those stages. Similarly reduction of fruit area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 57.93 and 79.79%, respectively at fruiting and fruit ripening stages while Bavistin 50WP (0.1%) alone reduced by 56.93 and 76.14%, respectively at those stages. Micronutrients had little effect against the disease but significantly better than control.Int. J. Agril. Res. Innov. & Tech. 3 (1): 66-72, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1609

Computational model of the interaction of a helium atmospheric-pressure jet with a dielectric surface

Using a time-dependent two-dimensional axisymmetric fluid model the interaction of a plasma jet with a dielectric surface has been studied. The model is solved for two consecutive periods of a positive unipolar pulsed waveform. The study concentrates on determining the fluxes of the main oxygen ion species, $\text{O}_{2}^{+}$ , $\text{O}_{2}^{-}$ and the total accumulated charge on the surface. Approaching the dielectric surface, the streamer head is seen to divert its direction of propagation, spreading out radially approximately 0.2 mm above the dielectric surface. For $\text{O}_{2}^{+}$ generated near the streamer head, this leads to a maximum in their flux to the surface which moves radially outwards with the streamer propagation, driven by the applied electric field in pulse on-time. In the off-time, the flux of $\text{O}_{2}^{+}$ drops by at least two orders of magnitude. As a result, the total number of $\text{O}_{2}^{+}$ ions arriving at the surface over one entire pulse period (fluence) has an annular shape limited by the effective contact area of the streamer on the surface. In contrast $\text{O}_{2}^{-}$ ions generated in the pulse on-time do not reach the surface due to the direction of the applied electric field. In the off-time, $\text{O}_{2}^{-}$ ions generated at the edges of the deformed streamer are pushed by the accumulated surface charge outwards. As a result, the $\text{O}_{2}^{-}$ fluence has an annular structure with its maximum being outside the area of the dielectric surface covered by the plasma channel. Solving for the second pulse period shows small changes in the predicted fluences, with largest difference seen with $\text{O}_{2}^{-}$ . We see that increasing the flow rate (by a factor of three) shifts the position of the maximum fluence of $\text{O}_{2}^{+}$ outwards, and decreasing the $\text{O}_{2}^{-}$ fluence in the second pulse period

Modeling the thermalization of electrons in conditions relevant to atmospheric pressure He-O-2 nanosecond pulsed discharges

The electron thermalization process is significant in nanosecond pulsed discharges due to the applied voltage pulse’s short duration and rapid rise and fall times. In this contribution a comparison was made between two approaches to modeling the electron kinetics of electron thermalization in atmospheric pressure helium plasma with an oxygen admixture. Modeling based on the direct solution of the local time-dependent electron Boltzmann equation was compared with modeling based on the commonly used but less general local mean energy approximation. For modeling based on the local time-dependent electron Boltzmann equation, a temporary faster decay in the population of electrons in the high energy tail, and a slower decay in the population of intermediate energy electrons was observed while the electron swarm cooled from an average energy of above 8 eV, without an electric field present. During that period, the electron impact reaction rate coefficients of helium direct ionization and electronic excitation decreased by more than 3 orders of magnitude as compared to the modeling based on the local mean energy approximation. Global modeling of the evolution of plasma species densities in response to an electric field typical of atmospheric pressure pulsed discharges was performed with the two approaches to electron kinetics. Differences in the species densities were observed between the two approaches, with an 100% increase in the maximum density of electrons found with the modeling based on the local mean energy approximation.info:eu-repo/semantics/publishedVersio

Retrospective study of the effect of disease progression on patient reported outcomes in HER-2 negative metastatic breast cancer patients

<p>Abstract</p> <p>Background</p> <p>This retrospective study evaluated the impact of disease progression and of specific sites of metastasis on patient reported outcomes (PROs) that assess symptom burden and health related quality of life (HRQoL) in women with metastatic breast cancer (mBC).</p> <p>Methods</p> <p>HER-2 negative mBC patients (n = 102) were enrolled from 7 U.S. community oncology practices. Demographic, disease and treatment characteristics were abstracted from electronic medical records and linked to archived Patient Care Monitor (PCM) assessments. The PCM is a self-report measure of symptom burden and HRQoL administered as part of routine care in participating practices. Linear mixed models were used to examine change in PCM scores over time.</p> <p>Results</p> <p>Mean age was 57 years, with 72% of patients Caucasian, and 25% African American. Median time from mBC diagnosis to first disease progression was 8.8 months. Metastasis to bone (60%), lung (28%) and liver (26%) predominated at initial metastatic diagnosis. Results showed that PCM items assessing fatigue, physical pain and trouble sleeping were sensitive to either general effects of disease progression or to effects associated with specific sites of metastasis. Progression of disease was also associated with modest but significant worsening of General Physical Symptoms, Treatment Side Effects, Acute Distress and Impaired Performance index scores. In addition, there were marked detrimental effects of liver metastasis on Treatment Side Effects, and of brain metastasis on Acute Distress.</p> <p>Conclusions</p> <p>Disease progression has a detrimental impact on cancer-related symptoms. Delaying disease progression may have a positive impact on patients' HRQoL.</p