Measurement of Plasma Parameters of Calcium and Silicon in a Rock Sample Using Laser Induced Breakdown Spectroscopy

Laser Induced Breakdown Spectroscopic(LIBS)technique was used to detect calcium and silicon in an unknown sample.In this method plasma was generated by Nd∶YAG laser of wavelength 1 064 nm with energy 400 mJ and pulse duration between 5~10ns.The method was applied for the qualitative as well as quantitative analysis.In the qualitative analysis,the electron number density(Ne)of plasma containing calcium and silicon is determined showing that Neof neutral particles is equivalent to 1016(cm-3)whereas for ionized particles it is 1017(cm-3).Plasma temperature is measured using Boltzmann plot method which must be greater than 10 000 k.Intensity ratio method is used for the quantitative analysis shows various elements in abundance with calcium and silicon in majority.

Experimental Study of Parameters of a Plasma Antenna

A plasma column excited by a surface wave can act as a plasma antenna. Experiments are carried out to study the current and conductivity distributions, field, power patterns, directivity and efficiency of such a plasma antenna. In addition, an equivalent metallic copper antenna is built up and its antenna parameters are compared with that of the plasma antenna. Our findings indicate that the power content in the harmonics of the plasma antenna is more prominent as compared to the copper antenna （which only generates a fundamental frequency）. However, the power patterns for both antennae are quite similar. To provide a more qualitative understanding regarding the generation of harmonics in the field of the plasma antenna, a bi-spectral analysis is performed to study the nonlinear interactions in the current fluctuations. Some specific features of the plasma antenna are investigated in our study, which may enhance the application prospect of the plasma antenna with respect to the conventional metallic antenna.

Modeling Approach and Analysis of the Structural Parameters of an Inductively Coupled Plasma Etcher Based on a Regression Orthogonal Design

The geometry of an inductively coupled plasma （ICP） etcher is usually considered to be an important factor for determining both plasma and process uniformity over a large wafer. During the past few decades, these parameters were determined by the ＂trial and error＂ method, resulting in wastes of time and funds. In this paper, a new approach of regression orthogonal design with plasma simulation experiments is proposed to investigate the sensitivity of the structural parameters on the uniformity of plasma characteristics. The tool for simulating plasma is CFD-ACE＋, which is commercial multi-physical modeling software that has been proven to be accurate for plasma simulation. The simulated experimental results are analyzed to get a regression equation on three structural parameters. Through this equation, engineers can compute the uniformity of the electron number density rapidly without modeling by CFD-ACE＋. An optimization performed at the end produces good results.

Plasma brain natriuretic peptide, platelet parameters, and cardiopulmonary function in chronic obstructive pulmonary disease

BACKGROUND Chronic obstructive pulmonary disease(COPD)is a chronic respiratory disease with worldwide occurrence and high disability and mortality rate.It occurs mostly in the elderly population with pulmonary heart disease,type II respiratory failure,and other serious complications.AIM To investigate the correlation of plasma brain natriuretic peptide(BNP)and platelet parameters with cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease.METHODS From June 2016 to June 2019,52 patients with COPD-pulmonary heart disease(pulmonary heart disease group),30 patients with COPD(COPD group),and 30 healthy individuals(control group)in our hospital were enrolled in the study.The pulmonary heart disease group was further divided into subgroups according to cardiac function classification and pulmonary artery pressure.Plasma BNP and platelet parameters were estimated and compared among each group and subgroup.The correlation of plasma BNP and platelet parameters with cardiac function classification and pulmonary artery pressure was then analyzed.RESULTS In the pulmonary heart disease group,the COPD group,and the control group,the levels of plasma BNP,platelet distribution width(PDW),and mean platelet volume(MPV)showed a decreasing trend(P<0.05),while an increasing trend was found in platelet count(PLT)and plateletcrit(PCT)levels among the three groups(P<0.05).In the pulmonary hypertension mild,moderate,and severe subgroups,the levels of plasma BNP,PDW,and MPV showed an increasing trend(P<0.05),while a decreasing trend was observed in PLT levels(P<0.05);however,PCT levels showed no significant difference among the three subgroups(P>0.05).In the cardiac function grade I,II,III,and IV subgroups,the levels of plasma BNP,PDW,and MPV showed an increasing trend(P<0.05),while a decreasing trend was noted in PLT and PCT levels among the four subgroups(P<0.05).Correlation analysis showed that the levels of plasma BNP,PDW,and MPV in patients with pulmonary heart disease were positively correlated with their pulmonary artery pressure(P<0.05),while PLT was negatively correlated with their pulmonary artery pressure(P<0.05).Moreover,plasma BNP,PDW,and MPV levels were positively correlated with cardiac function grade(P<0.05)of these patients,while PLT and PCT levels were negatively correlated with their cardiac function grade(P<0.05).CONCLUSION Plasma BNP and PLT parameters are significantly correlated with the cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease,indicating that these parameters have high clinical relevance in reflecting the health condition of these patients and for guiding their treatment.

Influence of process parameters on microstructure of reactive plasma cladding TiC-Fe-Cr coating

A certain amount of Ti was added to the plasma cladding Fe-Cr-C coating in the early stage in order to improve the quality and properties of the coating.Ti-Fe-Cr-C composite powder was prepared by precursor carbonization-composition process.In situ synthesized TiC-Fe-Cr coatings were fabricated on substrate of Q235 steel by plasma cladding process with the composite powder.Microstructures of the coatings with different process parameters,including cladding current,cladding speed,number of overlapping cladding layers,were analyzed by scanning electron microscope.The results show that the structure of the TiC-Fe-Cr coating is greatly affected by the cladding current,the cladding speed and the overlapping cladding process.In this test,when the cladding current of 300 A and the cladding process parameter of the cladding speed of 50 mm/min are clad with three layers,a well-formed and well-structured TiC-Fe-Cr coating can be obtained in this test.TiC-Fe-Cr coating has good wear resistance and good load characteristics under dry sliding wear test conditions.

Influence of processing parameters and heat treatment on phase composition and microstructure of plasma sprayed hydroxyapatite coatings

Air plasma spraying process was employed to fabricate various hydroxyapatite(HA)coatings on titanium substrates.The influence of processing parameters on the phase composition and the microstructure of the obtained coatings was investigated.The effect of heat treatment on as-sprayed coating in terms of the crystallinity and microstructure was also studied.The phase composition of coatings was analyzed by X-ray diffraction(XRD)and FTIR.The surface and cross-section morphologies and microstructure of coatings as well as the morphology of feedstock were evaluated using scanning electron microscope(SEM).The crystallization temperature of amorphous HA phase in as-sprayed coating was examined by using differential thermal analysis(DTA). The results suggest that phase composition and microstructure of as-sprayed HA coatings strongly depend on the spraying parameters,and heat treatment at 760 ℃for 2 h is one of effective means for increasing the crystallinity and improvement in microstructure of as-sprayed HA coatings.

Simulation of Plasma Parameters for HCSB-DEMO by a 1.5D Plasma Transport Code

Simulation of the core plasma parameters of HCSB-DEMO （helium-cooled solid breeder, HCSB）, by using a 1.5D plasma transport code, was carried out. The study includes investigations of operational scenarios, temperature and density profiles of both ions and electrons, fusion and radiated power, distribution of the safety factor, sensitivity analyses for some input parameters as well as a primary estimate of the divertor heating load. The results indicate that the following fusion reactor parameters can be properly set for HCSB-DEMO, namely major radius of 7.2 m, aspect ratio of 3.4, elongation of 1.85, triangularity of 0.45, plasma current of 14.8 MA, normalized beta of 4.4, toroidal field （TF） of 6.86 T, average electron density of 1.5× 10^20 m^-3, average electron temperature of 14.5 keV, fusion power of 2.55 GW, neutron wall loading of 2.3 MW.m^-2 and fusion multiplication factor of 35.

Research on resonance parameters matching based on partitioned operation method of atmospheric pressure plasma reactor array

Matching optimization of resonant parameters among the high power inverters,low power transformers and plasma reactors have significant effects on the performance and output of the reactor array when applying the partitioned operation method.In this paper,the Matlab/Simulink electrical model was established based on the method of partitioned operation.The matching relation between resonant parameters is analyzed on the basis of experimental result.As a consequence,transformer leakage inductance and working frequency are the important parameters influencing the operational efficiency of system,leakage inductance of transformer should be adjusted based on the equivalent capacitance of plasma reactor to realize the matching optimization of resonant parameters.

Measurement of Ion Parameters by Ion Sensitive Probe in ECR Plasma

Ion parameters in electron cyclotron resonance （ECR） microwave plasma were measured by ion sensitive probe and were compared with the electron parameters obtained by double Langmuir probe. The effects of gas pressure and microwave power on the ion temperature and density were analyzed. The spatial distribution of the ion parameters was also investigated by the ion sensitive probes with a tunable radial depth installed on different probe windows along the chamber axis. Results showed that the ion density measured by the ion sensitive probe was in good agreement with the electron density measured by the double Langmuir probe. The influ- ence of gas pressure on the ion parameters was stronger than that of microwave power. With the increase in working pressure, the ion temperature decreased monotonously with a decreasing rate larger than that at higher pressure. The ion density first increased to a peak （42.3~ 101~ cm-3） at 1 Pa and then decreased. The ion temperature and density increased little with the increase in the microwave power from 400 W to 800 W, The plasma far away from the resonant point is found to be radially uniform.

Effects of the Standardized Ileal Digestible Lysine to Metabolizable Energy Ratio on Performance,Nutrient Digestibility,and Plasma Parameters of 10 to 28 kg Pigs

A total of 480 nursery pigs （Duroc x Landrace x Large White） were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine （SID- Lys） to metabolizable energy （ME） ratio on the performance, nutrient digestibility, plasma urea nitrogen （PUN） ,and plasma free amino acids of 10 to 28 kg pigs. In Exp. 1, 192 pigs （ 10.58 kg） were assigned to one of four treatments. The treatments consisted of diets with a ME content of 3.2, 3.25, 3.3, or 3.35 Mcal/kg with a constant SID-Lys：ME ratio of 3.7 g/Mcal. The experiment lasted 28 days. Pigs which were fed the diets containing 3.3 and 3.35 Mcal/kg ME had lower feed intakes （ P 〈 0.05）than those fed 3.2 Mcal/kg. Feed efficiency was linearly improved with increasing dietary ME （ P 〈0.05）. Increasing the dietary ME level also increased （P 〈0.05 ） dry matter and energy digestibility. Therefore,3.3 Mcal/kg ME was selected for Exp. 2 in which 288 pigs （ 10.60 kg） were assigned to one of six treatments. Treatments consisted of SID-Lys： ME ratios of 3.1,3.3,3.5,3.7,3.9, or 4.1 g/Mcal with all diets providing 3.3 Mcal of ME/kg. Weight gain and feed efficiency were increased （P 〈0.05 ） as the SID-Lys：ME ratio in diet increased. Based on a straight broken-line model ,the estimated SID-Lys：ME ratio to maximize weight gain was 3.74.

Effectiveness of Apricots (<i>Prunus armeniaca</i>), Pomegranate (<i>Punica granatum</i>) Juice and Lactic Acid Fermented Sobya on Plasma Levels of Lipid Profile Parameters and Total Homocysteine among Egyptian Adults

Objectives: The aim of this study was to investigate the effectiveness of dietary intervention with apricots, pomegranate juice or lactic acid fermented sobya on improving the plasma levels of lipid profile parameters and total plasma homocysteine (tHcy) among healthy adults. Design of the study: Thirty-five men and women (28.9 ± 3.0 years) with mean body mass index of 23.5 ± 1.2 kg/m2 were randomly assigned to a dietary intervention study. During the pre-feeding study records of 24-hour food intake, anthropometric measurements and blood sampling were collected for biochemical investigations. Thereafter the volunteers were divided into five groups: a control group (C);the other four groups received daily one of the following supplements: 200 g of deep yellow apricots (Prunus armeniaca) (AF);250 g pomegranate (Punica granatum) juice (PJ);mixture of 100 g (PJ) and 150 g of fermented sobya (FS), (PJ-FS) or 165 g (FS). After completing the three-week dietary intervention, blood samples were collected and blood indices were again evaluated. Biochemical analysis of total lipids (TL), total glycerides (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) and tHcy were completed. The low density lipoprotein-cholesterol level and three indices of risk factors were calculated using the appropriate equations. Results: Three-week dietary intervention improved the levels of lipid profile parameters TG, TC, HDL-C and LDL-C as compared to the respective baseline levels and the response of the control group that did not receive any supplement. Consuming (PJ-FS) had a synergistic beneficially added value on some of the above mentioned lipid profile parameters. The mean plasma tHcy concentrations;a marker for occlusive vascular disease was reduced significantly following the three week consumption of (PJ) or (FS), compared with the respective pre-feeding levels. Conclusion: Pomegranate juice (PJ) or lactic acid fermented sobya (FS) or mixture of both are potential natural agents in lowering the plasma levels of lipid profile parameters and tHcy among apparently healthy young women and men, without dyslipidemic symptoms.

Dependence of Plasma Parameters on Plate Separation and Filament Location in a Double Plasma Device

A pair of stainless steel (ss) plates separates the source and target regions of a double plasma device. Two sets of tungsten filaments, placed at different distances from the ss plates, are then used to produce plasma alternately and the plasma parameters in the source and target regions for different discharge voltage, discharge current and plate separation are measured using Langmuir probes. It is found that plasma density and electron temperature are considerably affected and respond differently to changes in the plate separations and the position of the filaments.

Diagnostics of Optical Characteristics and Parameters of Gas-Discharge Plasma Based on Mercury Diiodide and Helium Mixture

The results of diagnostics of spectral, temporal and energy characteristics of the radiation of gas-discharge plasma in a mixture of mercury diiodide vapor with helium in the spectral range of 350 - 900 nm, and the plasma parameters in the range of reduced electric field E/N = 1 - 100 Td are presented. The plasma is created in the barrier discharge device with a cylindrical aperture. The electrodes are placed 0.2 m in length at a distance of 0.015 m. The amplitude of the pump pulse, the duration and frequency were 20 - 30 kV, 150 ns and 1 - 20 kHz, respectively. Radiation in the visible region of the spectrum of mercury monoiodide exciplex molecule is revealed. Regu larities in the optical characteristics of the plasma, depending on the partial pressures of the components of the mixture, the electron energy distribution function, mean electron energy, specific losses of discharge power on the process of dissociative excitation of mercury monoiodide (state B2Σ+1/2) molecules as well as the rate constant of dissociative excitation of mercury monoiodide molecules in working mixture depending on the given reduced electric field are established.

Study of the influence of discharge loop parameters on anode side on generation characteristics of metal plasma jet in a pulsed vacuum discharge

In a pulsed vacuum discharge,the ejection performance of a metal plasma jet can be effectively improved by preventing charged particles from moving to the anode.In this paper,the effects of resistance and capacitance on the anode side on the discharge characteristics and the generation characteristics of plasma jet are investigated.Results show that the existence of a resistor on the anode side can increase the anode potential,thereby preventing charged particles from entering the anode and promoting the ejection of charged particles along the axis of the insulating sleeve nozzle.The application of a capacitor on the anode side can not only absorb electrons at the initial stage of discharge,increasing the peak value of the cathode hump potential,but also prevent charged particles from moving to the anode,thereby improving the ejection performance of the plasma jet.In addition,the use of a larger resistance and a smaller capacitance can improve the blocking effect on charged particles and further improve the ejection performance of the plasma jet.Results of this study will provide a reference for the improvement of the ejection performance of plasma jets and their applications.

Spectrometric Measurement of Plasma Parameters Utilizing the Target Ambient Gas O I &N I Atomic Lines in LIBS Experiment

In this article, we shall report the results of the spectroscopic measurements of the plasma parameters utilizing the spectral lines emitted from the air atoms surrounding plasma (O I line at 777.19 nm and N I at 746.83 nm). The plasma was created via irradiation of plane solid aluminum target in open air by a high peak power Nd: YAG laser pulses at fundamental wavelength of 1064 nm. The emission spectra were recorded using Echelle type spectrograph in conjunction with a time gated ICCD camera at different delay time from 1 to 5 μs and at a fixed gate time of 1 μs. The plasma electron density was measured utilizing the Stark broadening of the N I and O I lines and then compared to the reference density as deduced from the optically thin Hα-line at 656.27 nm appeared in the same emission spectra. The results show that under our experimental conditions the air lines are subjected to moderate absorption. The plasma electron temperature was measured utilizing the relative spectral intensity of the air (O I to N I) lines after correcting their spectral radiance against absorption. The standard temperature was measured utilizing the Al II ionic lines. A comparison to the reference temperatures shows a very close agreement after correcting the emission spectral radiance of the air lines against self absorption, which emphasizes the importance of correction process.

Analysis of Langmuir Probe Characteristics for Measurement of Plasma Parameters in RF Discharge Plasmas

A simple method for measuring RF plasma parameters by means of a DC-biased Langmuir probe is developed. The object of this paper is to ensure the reliability of this method by using the other methods with different principles. First, Langmuir probe current response on RF voltage superimposed to DC biased probe was examined in DC plasmas. Next, probe current response of DC biased probe in RF plasmas was studied and compared with the first experiment. The results were confirmed by using an emissive prove method, an ion acoustic wave method, and a square pulse response method. The method using a simple Langmuir probe is useful and convenient for measuring electron temperature , electron density , time-averaged space potential , and amplitude of space potential oscillation in RF plasmas with a frequency of the order of .

Study of the Parameters of a Magnetic DC Plasma Jet

A Magnetic DC plasma torch has been developed. Magnetic field distributions of solenoid coils have been calculated electrodynamically. For Ar +H2 plasma, the effects of an akial magnetic field and gas flow rate on the characttristics of the plasma jet were studied. Electron temperature, density and plasma velocity at 80 mm from the nozzle have been measured using a floating double probe and a Mach probe. The values of the heat fluxes to substrate were derived from experimental data.

The Study of the Grit-blasting Parameters and Their Effects on the Adhesive Strength of the Plasma Sprayed Coatings

Surface Preparation is very important in adhesive b on ding of spray coatings to the surface of a work piece. The common practice is gr it-blasting of the surface before subjecting it to the spray coating process. In this study, grit-blasting of an AISI 4130 steel (of different heat treatmen ts) with Al 2O 3 particles was studied. Various grit-blasting parameters such as blasting particle size, the distance between blasting nozzle and the work pi ece (25, 30 and 40 cm.), blasting pressure (3,4,5,6 and 7 bars), blasting time ( 3, 6 and 10 seconds), and the blasting angle (45° and 90°) were examined in or der to find the optimum roughness. The mean roughness (Ra) of the grit-blasted surfaces were measured and the vari ations of the roughness with respect to the above mentioned variables were studi ed. The results show that by increasing blasting time, surface roughness increas es up to a maximum and then slightly decreases it with further duration of t he process. On the other hand a lengthy blasting causes some undesirable results such as an increase in residual particles between surface irregularities. There fore an optimum blasting time is of great importance. Increasing the blasting pr essure also provides a rougher surface, but in grit blasting of harder specimens the surface roughness decreases when the pressure reaches a certain limit. About the blasting angle, it was noticed that an angle of 45° results in less r esidual particles between the surface irregularities, in comparison to the angle of 90°. After grit-blasting, the specimens were plasma spray coated with 80% ZrO 2-20 % Y 2O 3 powder. The adhesive strength of the coating to the substrate was the n measured according to the DIN 50160 standard. The results show that for a certain base metal, the adhesive strength is directl y related to the surface roughness of the base material. Residual particles afte r grit-blasting the surface of the specimens can also have a strong deteriorati ng effect on adhesive strength. Finally, it was shown that the hardness of the b ase material had a direct effect on the adhesive strength of the sprayed coating s.

Processing parameters for Cu nanopowders prepared by anodic arc plasma

Copper nanopowders were successfully prepared by anodic arc discharging plasma method with home-made experimental apparatus.The effects of various processing parameters on the particle size of Cu nanopowders were investigated in the process,and the optimum processing parameters were obtained.In addition,the morphology,crystal structure,particle size distribution of the nanopowders were characterized via X-ray diffraction(XRD),transmission electron microscopy(TEM)and the corresponding selected area electron diffraction(SAED).The experimental results show that the crystal structure of the samples is the same fcc structure as that of the bulk materials.The processing parameters play a major role in controlling the particle size.The particle size increases with the increase of the arc current or gas pressure.

Effect of Spraying Parameters on the Microstructure and Mechanical Properties of Micro-Plasma Sprayed Alumina-Titania Coatings

Electrical property of a micro-plasma spray system with different working-gas feed- ing schemes was tested to optimize the plasma spray process. The arc voltage with an integrated gas injection mode is higher than that with radial injection or axial injection modes. Thus, an integrated gas injection mode with an excellent electrical characteristic was adopted to deposit alumina-titania coating. The microstructure, bonding strength and hardness of the plasma sprayed alumina-titania coating, as a function of the spraying parameters, e.g., plasma current, gas flow rate and gas pressure, were studied. It was shown that the spraying parameters affected remarkably on the microstructure of the coating. Different tendencies in bonding strength and hardness were also shown for different spraying parameters. At an arc current of 250 A, a gas flow rate of 20 L/min and a gas pressure of 0.5 MPa, the bonding strength and micro-hardness of the coatings reach 40.6 MPa and HV1406.1, respectively.