Carbon Dioxide Plasma Research Articles

Optical emission spectroscopy of plasma generated by a waveguide-supplied microwave plasma source operated at 915 MHz

In this paper we present the results of an optical emission spectroscopic study of an atmospheric pressure microwave (915 MHz) nitrogen and nitrogen with carbon dioxide (1%) plasma at high working gas flow rate. This study was aimed at determining rotational Trot and vibrational Tvib temperatures of N2+ ions and N2, CN molecules. The plasma was generated in a waveguide-supplied cavity-resonant type microwave plasma source. All experimental tests were performed with working gas flow rates QN2 between 80 and 320 l min−1 and a power PA absorbed by the plasma microwave varied from 1.5 to 3 kW. The Trot and Tvib temperatures of selected heavy species were determined by comparing the measured and simulated spectra. The measured temperatures of N2+ ions and N2, CN molecules were 6800 to 7500 K (± 250 K), 5000 to 5200 K (± 150 K) and 6100 to 6600 K (± 100 K), respectively, depending on the PA.

Decomposition of tetrodotoxin using multi-gas plasma jet

In this study, non-thermal multi-gas plasma treatments were performed for Tetrodotoxin (TTX) solution, and TTX decomposition was analyzed by liquid chromatography coupled with electrospray time-of-flight mass spectrometry. The TTX mass spectrum signal was reduced by plasma irradiations to different levels by using various gas species. Nitrogen plasma exhibited the optimal capability for TTX decomposition, followed by oxygen, argon, and carbon dioxide plasmas. The TTX concentration decreased 100-fold by nitrogen plasma treatment for 10 min.

Venous hemogasometry and blood electrolytes in Mangalarga Marchador mares submitted to aerobic training

The Mangalarga Marchador (MM) breed, valued for its marcha pace, has been excelling in functional activities such as marcha course. Considering the lack of information about sports physiology of the marcha horses, the development of training protocols and physical testing becomes essential and, in this context, the concentrations of blood gases and electrolytes provide additional information for the monitoring of metabolic changes induced by exercise. The goal of the study was to assess the hemogasometric responses and blood electrolyte concentration in MM mares during maximal effort treadmill tests carried out before and after training (trial 1) and between a maximal effort treadmill test and an incremental field test (trial 2). The trials assessed plasma lactate concentration, blood pH, oxygen and carbon dioxide blood pressures, and blood concentrations of the ions bicarbonate, sodium (Na+), potassium (K+), and calcium (Ca++). The study followed a randomized block in a split-plot design. In the first trial, the distances walked by the equines in the tests before and after training caused decrease (p<0.05) in pH and Ca++ concentration and increase in the concentrations of K+ and Na+. In the second trial, the influence of the type of test and the ambient temperature caused decrease (p<0.05) in pH and increase in the concentrations of K+ and Ca++. After training, MM mares had greater changes in pH and electrolyte concentrations.

Influence of O2 and CO2 plasma treatment on the deposition of chitosan onto polyethylene terephthalate (PET) surfaces

Oxygen and carbon dioxide plasma treatments were applied in order to study their influences on chitosan adhesion onto PET foils. Modification of the surface and the adsorption of chitosan were monitored by the determination of XPS spectra, titrations, zeta potential, contact angles, and AFM.The plasma treatment resulted in hydrophilization of the surface through the introduction of new polar oxygen-containing groups. The treatment also yielded binding-sites for amino groups of chitosan. This led to a decrease in accessible protonated amino groups after chitosan binding onto plasma-activated foils in comparison with the plasma-non-activated ones. Consequently, the layer of chitosan adsorbed after plasma treatment was less antimicrobially active in the case of O2-treated foils. Surprisingly, the layer of chitosan adsorbed after CO2 plasma treatments were, in general, more active as antimicrobial agents than those of the non-plasma treated PET surfaces.

Plasmatron for simulation of re-entry conditions in a planetary atmosphere

The characteristics of segmented plasmatron are presented. The arc is sustained in argon plasma and in plasma stream, argon, nitrogen and carbon-dioxide are introduced. The numerical simulation of argon electric arc and plasma stream is carried out and the temperatures and densities of electron and heavy particles are presented. Experimental and theoretical investigations determine and explain the influence of natural gas and flow rate injected into plasma stream on working plasmatron conditions. The anode voltage drop analysis shows that in plasmatron working at a current between 40 and 340 A, gas flow rate between 0.4 and 2 g/s and pressure from 5 to 100 kPa, this drop changes from negative to positive, influencing arc voltage value. The gas injection into plasma stream results in anode spot dynamic. Electric breakdowns accompanied by high voltage fluctuations are observed when argon or nitrogen is introduced while carbon dioxide eliminates this type of breakdown reducing the voltage fluctuations and ablation of electrodes.

Effects of carbon dioxide plasma immersion ion implantation on the electrochemical properties of AZ31 magnesium alloy in physiological environment

Plasma immersion ion implantation (PIII) is conducted to improve the intrinsically poor corrosion properties of biodegradable AZ31 magnesium alloy in the physiological environment. Carbon dioxide is implanted into the samples and X-ray photoelectron spectroscopy and scanning electron microscopy are used to characterize the materials. The corrosion properties are systematically studied by potentiodynamic polarization tests in two simulated physiological environments, namely simulated body fluids and cell culture medium. The plasma-implanted materials exhibit a lower initial corrosion rate. Being a gaseous ion PIII technique, conformal ion implantation into an object with a complex shape such as an orthopedic implant can be easily accomplished and CO2 PIII is a potential method to improve the biological properties of magnesium and its alloys in clinical applications.

Oxidation of SiC in low-pressure CO2 plasma: Formation of silica nano-needles

Samples of silicon carbide were exposed to carbon dioxide plasma at high temperature to study thermal and chemical degradation, as well as the evolution of surface morphology. Scanning electron microscope images revealed that the samples remained fairly intact up to a temperature of approximately 1700 K, when surface modification and degradation started to occur. The oxidation at high temperature caused the formation of liquid silica droplets that were several μm in diameter at a temperature exceeding 1800 K. Sharp nano-needles were found that stretched perpendicularly from the surface at this temperature. Increases in temperature resulted in increased density of the droplets with nano-needles until the entire surface was covered with the nano-needles at a temperature of approximately 1850 K. Further increases of temperature caused rapid degradation of material and loss of the nano-needles. These results are explainable by the particularities of passive oxidation of SiC upon treatment with plasma particles.

Oligopeptide Production from Alanine Monomer by Pulsed Corona Discharge Plasma in Ambient and Supercritical Argon

Supercritical carbon dioxide and electric discharge plasma could be one of reaction or extraction media for green chemical processes. Supercritical fluid is an attractive solvent due to its unique characteristic and transport physical properties. Taking advantage of these characteristics, this has been extensively investigated for extraction and chemical conversion technology. Although density of a supercritical fluid is high like a liquid, it is mobile like a gas because of low viscosity. On the other hand, the electron energy generated by electric discharge plasma in high pressure and a high-density domain generally serves as an index depending on the field intensity and medium density which were supplied to electric discharge space. From the above-mentioned viewpoint, the synergistic effect of combining electric pulsed plasma and supercritical fluids is expected as a new reaction process which may be able to enhance chemical reaction without using any catalysts. In this research, production of protein-like substance by pulse electric discharge plasma was carried out using amino acid in supercritical carbon dioxide. Moreover, nano pulse electric discharge plasma was also formed in supercritical fluids; reaction of amino acid was also observed. Aiming at establishment of a new reaction field, we did fusion research of supercritical fluids and electric discharge plasma. In this experiment, argon at the pressurized state was used as a reaction medium. Initially, alanine aqueous solution of 0.1 mol/L was loaded to a plasma reactor (inner volume: 600 mL) and reached under the desired conditions (290-308 K and 1-10.8 MPa). They were then analyzed by high-performance liquid chromatography (HPLC) and matrix-assisted laser desorption time of flight mass spectroscopy (MALDI TOF-MS). The possibility of polymerization of alanine was realized from the compound after electric pulsed discharge plasma processing.

A Novel Route to Polycaprolactone Scaffold for Vascular Tissue Engineering

Polycaprolactone biocomposite scaffolds were prepared by a novel process of precoagulationevaporation and subsequent gelatin immobilization. Water was used as the additive for partial coagulation of the polycaprolactone-chloroform solution. The subsequent coating of the precoagulated solution on a glass surface followed by drying provided a tubular scaffold with regular porosity. The dried scaffolds were treated with carbon dioxide plasma in order to introduce functional groups for enhancing hydrophilicity of the scaffold. Subsequently, gelatin was immobilised on the scaffold by dip coating. Both chemical and morphological changes took place during plasma treatment and gelatin immobilization. The scaffolds were porous and turned out to be hydrophilic. The surfaces were characterized by scanning electron microscopy, atomic force microscopy, tensile measurements and contact angle measurements. These scaffolds were found to offer excellent surfaces for the growth of progenitor-derived endothelial cells.

Podocyte-specific overexpression of human angiotensin-converting enzyme 2 attenuates diabetic nephropathy in mice

Angiotensin-converting enzyme 2 (ACE2) degrades angiotensin II to angiotensin-(1–7) and is expressed in podocytes. Here we overexpressed ACE2 in podocytes in experimental diabetic nephropathy using transgenic methods where a nephrin promoter drove the expression of human ACE2. Glomeruli from these mice had significantly increased mRNA, protein, and activity of ACE2 compared to wild-type mice. Male mice were treated with streptozotocin to induce diabetes. After 16 weeks, there was no significant difference in plasma glucose levels between wild-type and transgenic diabetic mice. Urinary albumin was significantly increased in wild-type diabetic mice at 4 weeks, whereas albuminuria in transgenic diabetic mice did not differ from wild-type nondiabetic mice. However, this effect was transient and by 16 weeks both transgenic and nontransgenic diabetic mice had similar rates of proteinuria. Compared to wild-type diabetic mice, transgenic diabetic mice had an attenuated increase in mesangial area, decreased glomerular area, and a blunted decrease in nephrin expression. Podocyte numbers decreased in wild-type diabetic mice at 16 weeks, but were unaffected in transgenic diabetic mice. At 8 weeks, kidney cortical expression of transforming growth factor-β1 was significantly inhibited in transgenic diabetic mice as compared to wild-type diabetic mice. Thus, the podocyte-specific overexpression of human ACE2 transiently attenuates the development of diabetic nephropathy.

Brain edema in diseases of different etiology

Cerebral edema is a potentially life-threatening complication shared by diseases of different etiology, such as diabetic ketoacidosis, acute liver failure, high altitude exposure, dialysis disequilibrium syndrome, and salicylate intoxication. Pulmonary edema is also habitually present in these disorders, indicating that the microcirculatory disturbance causing edema is not confined to the brain. Both cerebral and pulmonary subclinical edema may be detected before it becomes clinically evident. Available evidence suggests that tissue hypoxia or intracellular acidosis is a commonality occurring in all of these disorders. Tissue ischemia induces physiological compensatory mechanisms to ensure cell oxygenation and carbon dioxide removal from tissues, including hyperventilation, elevation of red blood cell 2,3-bisphosphoglycerate content, and capillary vasodilatation. Clinical, laboratory, and necropsy findings in these diseases confirm the occurrence of low plasma carbon dioxide partial pressure, increased erythrocyte 2,3-bisphosphoglycerate concentration, and capillary vasodilatation with increased vascular permeability in all of them. Baseline tissue hypoxia or intracellular acidosis induced by the disease may further deteriorate when tissue oxygen requirement is no longer matched to oxygen delivery resulting in massive capillary vasodilatation with increased vascular permeability and plasma fluid leakage into the interstitial compartment leading to edema affecting the brain, lung, and other organs. Causative factors involved in the progression from physiological adaptation to devastating clinical edema are not well known and may include uncontrolled disease, malfunctioning adaptive responses, or unknown factors. The role of carbon monoxide and local nitric oxide production influencing tissue oxygenation is unclear

Detection of Various Performance Enhancing Substances in Specimens Collected from Race Horses in Illinois: A Five-Year Experience

In order to protect the integrity of horse racing in Illinois, a complex testing of urine and blood specimens collected post-race from winning and special designation horses is continuously conducted. The initial screening by immunoassays was followed by the confirmation on presumptive positive samples. Instrumental screening was also conducted. Perimortem and postmortem specimens and special exhibits (syringes, needles, etc.) were also analyzed. The administration of alkalinizing agents was detected by measuring the total plasma carbon dioxide concentration. The laboratory analyzed specimens collected post race from winning horses and special designation horses at eight race tracks in the State of Illinois over the five-year time period (2004-2009). The total number of specimens collected was 91,808, comprising 45,210 urine specimens and 46,598 blood specimens. The total number of violations was 413 (0.45% of the total number of specimens analyzed); 207 were blood specimens (0.44% of the total blood specimens analyzed), and 206 were urine specimens (0.45% of the total urine specimens analyzed). A total of 220 violations were reported for harness horses, and 193 were reported for Thoroughbred horses. The number of reported violations of the total tested specimens in Illinois was small, but a wide variety of performance-enhancing drugs was shown.

Pseudohypobicarbonatemia Caused by an Endogenous Assay Interferent: A New Entity

Serum total carbon dioxide, measured using a chemistry analyzer, and gas panel-derived plasma bicarbonate, calculated from the pH and partial pressure of carbon dioxide, often are used interchangeably for clinical purposes. When they disagree, there is a tendency to accept total carbon dioxide and discredit gas panel-derived plasma bicarbonate values. We report a patient who, during a 5-month hospitalization, had persistently low total carbon dioxide levels (12.4 ± 2.7 [standard deviation] mEq/L [12.4 ± 2.7 mmol/L]), measured using an enzymatic/photometric assay, and a high anion gap (19.2 ± 3.1 mEq/L [19.2 ± 3.1 mmol/L]), suggesting high-anion-gap metabolic acidosis, but who had gas panel-derived plasma bicarbonate (24.0 ± 0.9 mEq/L [24.0 ± 0.9 mmol/L]) and arterial pH values in the reference range. Organic anion levels in blood and urine were unremarkable. Negative interference with the enzymatic assay by the patient's serum was shown by the findings that total carbon dioxide level was 7.0 ± 0.1 mEq/L (7.0 ± 0.1 mmol/L) higher when measured using the electrode-based method than using the enzymatic method (P < 0.01), and the patient's serum, but not control serum, altered the reaction kinetics of the enzymatic assay by producing turbidity, resulting in an initial increase in absorbance and a falsely low total carbon dioxide value. The turbidity may have resulted from precipitation of 1 of 2 paraproteins in the patient's serum or an endogenous antibody binding with an animal protein included in the assay reagents. In summary, a discrepancy between total carbon dioxide level measured using an enzymatic assay and gas panel-derived plasma bicarbonate level was found to be the result of turbidity caused by an endogenous interferent with the total carbon dioxide assay, a novel artifact. When total carbon dioxide and gas panel-derived plasma bicarbonate values disagree, measurement error in total carbon dioxide level should be considered.

Hydrophobic Modification of PVDF

For preparation of an architecture membrane with hydrophobic properties, a method combining supercritical carbon dioxide (scCO2 ) and low temperature plasma treatment was used. The effects of treating time, pressure and temperature in scCO2 fluid on surface hydrophobic property were studied. The results showed that the contact angle of the membrane that was firstly modified by low temperature plasma and then treated in scCO2 fluid was up to 141°from 80°. In addition, the optimal hydrophobic modification conditions in scCO2 were 100°C、25MPa and 6h, and the hydrophobic property of the membrane that treated by plasma improved, the most suitable time was 300s.

Surface bioactivity modification of titanium by CO 2 plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

Secondary Responses to Altered Acid-Base Status

Each of the four canonical acid-base disorders expresses as a primary change in carbon dioxide tension or plasma bicarbonate concentration followed by a secondary response in the countervailing variable. Quantified empirically, these secondary responses are directional and proportional to the primary changes, run a variable time course, and tend to minimize the impact on body acidity engendered by the primary changes. Absence of an appropriate secondary response denotes the coexistence of an additional acid-base disorder. Here we address the expected magnitude of the secondary response to each cardinal acid-base disorder in humans and offer caveats for judging the appropriateness of each secondary response.

Alternative instrumentation for the analysis of total carbon dioxide (TCO2) in equine plasma

The analysis of total carbon dioxide (TCO(2)) in equine plasma is conventionally done in Australia and elsewhere using Beckman Synchron EL-ISE(R) analysers. This instrument is no longer being manufactured and has not been supported by the supplier since December 2008. For testing for TCO(2) to continue, it is necessary to evaluate and commission alternative instrumentation. In this paper, we compare the Beckman Synchron EL-ISE, the Beckman Synchron CX5, the Beckman UniCel DxC 600 and the Randox Daytona instruments. Results indicate that all four instruments perform in accordance with the manufacturer's specifications. The Beckman CX 5, DxC 600 and Randox Daytona instruments are therefore all suitable alternatives for routine screening in a laboratory environment. Only the Randox Daytona instrument is sufficiently 'portable', i.e. it can be readily transported and used on-site at a racecourse (typically in a purpose-built modest-size laboratory vehicle). The three Beckman instruments are suitable for 'confirmatory analysis' using the quality-accredited method (Racing Science Centre), but the principle of operation of the Randox Daytona instrument may preclude its use in confirmatory analysis. Instrument costs may affect purchase decisions.

Effects of exposure to calves persistently infected with bovine viral diarrhea virus type 1b and subsequent infection with Mannheima haemolytica on clinical signs and immune variables: Model for bovine respiratory disease via viral and bacterial interaction1,2

The objective was to determine effects of an intratracheal Mannheimia haemolytica challenge after 72-h exposure to bovine viral diarrhea virus type 1b (BVDV1b) persistently infected (PI) calves on serum antibody production, white blood cell count (WBC), cytokine concentrations, and blood gases in feedlot steers. Twenty-four steers (initial BW = 314 +/- 31 kg) were randomly allocated to 1 of 4 treatments (6 steers/treatment) arranged as a 2 x 2 factorial. Treatments were 1) steers not exposed to steers PI with BVDV nor challenged with M. haemolytica (control; CON); 2) steers exposed to 2 steers PI with BVDV for 72 h (BVD); 3) steers intratracheally challenged with M. haemolytica (MH); and 4) steers exposed to 2 steers PI with BVDV for 72 h and challenged with M. haemolytica (BVD+MH). There were 12 h between exposure to PI steers and challenge with M. haemolytica. Rectal temperature was increased (P < 0.001) for MH and BVD+MH during the initial 24 h after the M. haemolytica challenge. For MH and BVD+MH, total WBC count was increased (P < 0.01) at 36 h post M. haemolytica challenge compared with CON, whereas in BVD steers, WBC count was decreased (P < 0.01). Total lymphocyte count was increased (P = 0.004) during the initial 72 h post BVDV exposure for the BVD and BVD+MH groups compared with MH and CON, and this difference remained at 96 h post M. haemolytica challenge. An increased (P < 0.001) total neutrophil count was observed during the initial 36 h for the MH group and at 72 h for the BVD+MH challenge group. Interleukin 1beta, IL-6, and tumor necrosis factor alpha (TNFalpha) concentrations were greater (P <or= 0.04) in BVD steers than steers not exposed to BVDV, and interferon gamma, IL-1beta, and TNFalpha were greater (P <or= 0.02) in MH steers than in steers not challenged with M. haemolytica. There were BVD x MH interactions (P <or= 0.04) for plasma carbon dioxide, carbonic acid, and sodium bicarbonate concentrations. Challenge with M. haemolytica decreased carbon dioxide, carbonic acid, and sodium bicarbonate concentrations to a greater extent when steers were not exposed to PI steers compared with steers exposed to BVDV. We conclude that the challenge model was successful at inducing bovine respiratory disease (BRD) associated with BVDV and M. haemolytica. Understanding the physiological changes in morbid animals will lead to improved strategies for decreasing severity and economic losses associated with BRD.

S1904-1-4 炭酸ガスアークプラズマフリージェット流中の炭化ケイ素材料の加熱実験(大気突入・減速技術(1),社会変革を技術で廻す機械工学)

S1904-1-4 炭酸ガスアークプラズマフリージェット流中の炭化ケイ素材料の加熱実験(大気突入・減速技術(1),社会変革を技術で廻す機械工学)

The use of new technologies in coloration of textile fibers

Textile coloration is a wet process that uses dyes, chemicals, and large volume of water. The chemical wet processing of textiles continues to expand each year using new technologies. The driving force being the need for cleaner, cost-effective, and value-added textile products. This review will provide a summary of recent developments in the coloration of textile fiber. Emphasis will be paid to the new technologies, in particular those based on physicochemical means such as nanotechnology, electrochemistry, supercritical carbon dioxide coloration, plasma, ultrasonic and microwave, and their uses in the coloration of textile fibers.