Gotowe bibliografie tematyczne / Plasma volume measurement technique

Gotowa bibliografia na temat „Plasma volume measurement technique”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 7 lutego 2022

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Artykuły w czasopismach na temat "Plasma volume measurement technique"

Rehm, Markus, Mathias Haller, Victoria Orth, Uwe Kreimeier, Mathias Jacob, Holger Dressel, Sabine Mayer, Heinz Brechtelsbauer i Udilo Finsterer. "Changes in Blood Volume and Hematocrit during Acute Preoperative Volume Loading with 5% Albumin or 6% Hetastarch Solutions in Patients before Radical Hysterectomy". Anesthesiology 95, nr 4 (1.10.2001): 849–56. http://dx.doi.org/10.1097/00000542-200110000-00011.

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Background The impact of acute preoperative volume loading with colloids on blood volume has not been investigated sufficiently. Methods Before surgery, in 20 patients undergoing major gynecologic procedures, volume loading was performed during anesthesia by infusing approximately 20 ml/kg of colloid at a rate of 90 ml/min (group I: 5% albumin solution; group II: 6% hetastarch solution; n = 10 each). Plasma volume (indocyanine green dilution technique), erythrocyte volume (labeling erythrocytes with fluorescein), hematocrit, total protein, and hetastarch plasma concentrations (group II) were measured before and 30 min after the end of infusion. Results More than 1,350 ml of colloid (approximately 50% of the baseline plasma volume) were infused within 15 min. Thirty minutes after the infusion had been completed, blood volume was only 524 +/- 328 ml (group I) and 603 +/- 314 ml (group II) higher than before volume loading. The large vessel hematocrit (measured by centrifugation) dropped more than the whole body hematocrit, which was derived from double-label measurements of blood volume. Conclusions The double-label measurements of blood volume performed showed that 30 min after the infusion of approximately 20 ml/kg of 5% albumin or 6% hetastarch solution (within 15 min), only mean 38 +/- 21% and 43 +/- 26%, respectively, of the volume applied remained in the intravascular space. Different, i.e., earlier or later, measuring points, different infusion volumes, infusion rates, plasma substitutes, or possibly different tracers for plasma volume measurement might lead to different results concerning the kinetics of fluid or colloid extravasation.

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Hinghofer-Szalkay, H. "Volume and density changes of biological fluids with temperature". Journal of Applied Physiology 59, nr 6 (1.12.1985): 1686–89. http://dx.doi.org/10.1152/jappl.1985.59.6.1686.

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High-precision (10(-5) g/ml) mass density measurements on human blood, plasma, plasma ultrafiltrate (using PM-10 membranes), and erythrocyte concentrate samples were performed with the mechanical oscillator technique. Measurement temperatures varied between 4 and 48 degrees C and were accurate to +/- 1 X 10(-2) K. The coefficient of thermal expansion (beta), defined as relative volume change with temperature, was calculated. It was shown that beta increases with temperature in these fluid samples over the entire temperature range investigated; the magnitude of this increase declines with increasing temperature; beta increases with density at temperatures below 40 degrees C but is independent of density above 40 degrees C; and the beta of the intracellular fluid has about twice the value of the beta for extracellular fluid at low (4–10 degrees C) temperatures but is equal for both fluids at greater than or equal to 40 degrees C. The mechanical oscillator technique provides data with an accuracy sufficient to perform precise (10(-5) K) calculations of beta of small volumes of biological fluids.

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Kelly, Kevin Lawrence, Alex R. Carlson, Bradley B. Cierzan, Jennifer Isautier, Wayne L. Miller i Bruce D. Johnson. "3092 Measuring Fluid Compartments Before and After Rapid Saline Infusion". Journal of Clinical and Translational Science 3, s1 (marzec 2019): 48–49. http://dx.doi.org/10.1017/cts.2019.115.

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OBJECTIVES/SPECIFIC AIMS: To evaluate the ability of various techniques to track changes in body fluid volumes before and after a rapid infusion of saline. METHODS/STUDY POPULATION: Eight healthy participants (5M; 3F) completed baseline measurements of 1) total body water using ethanol dilution and bioelectrical impedance analysis (BIA) and 2) blood volume, plasma volume and red blood cell (RBC) volume using carbon monoxide rebreathe technique and I-131 albumin dilution. Subsequently, 30mL saline/kg body weight was administered intravenously over 20 minutes after which BIA and ethanol dilution were repeated. RESULTS/ANTICIPATED RESULTS: On average, 2.29±0.35 L saline was infused with an average increase in net fluid input-output (I/O) of 1.56±0.29 L. BIA underestimated measured I/O by −3.4±7.9%, while ethanol dilution did not demonstrate a measurable change in total body water. Carbon monoxide rebreathe differed from I-131 albumin dilution measurements of blood, plasma and RBC volumes by +0.6±2.8%, −5.4±3.6%, and +11.0±4.7%, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: BIA is capable of tracking modest changes in total body water. Carbon monoxide rebreathe appears to be a viable alternative for the I-131 albumin dilution technique to determine blood volume. Together, these two techniques may be useful in monitoring fluid status in patients with impaired fluid regulation.

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Jacob, Matthias, Peter Conzen, Udilo Finsterer, Alexander Krafft, Bernhard F. Becker i Markus Rehm. "Technical and physiological background of plasma volume measurement with indocyanine green: a clarification of misunderstandings". Journal of Applied Physiology 102, nr 3 (marzec 2007): 1235–42. http://dx.doi.org/10.1152/japplphysiol.00740.2006.

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The indocyanine green (ICG) dilution technique (DT) is frequently used for plasma volume (PV) measurement. However, because of inadequate knowledge about the properties of this dye, lack of accuracy has been attributed to the method. The aim of this report is to provide physiological background information about the ICG-DT to avoid some profound misunderstandings. When performing tracer dilution, one has to consider the tracer's distribution space before interpreting the result. For ICG, the distribution space is the total PV, i.e., circulating + noncirculating PV, fixed within the endothelial glycocalyx. The distribution space of red blood cells and large molecules, in contrast, is only the circulating part of PV. Therefore, it is erroneous to compare directly PV derived from different tracer dilution methods. The transcapillary escape rate of ICG should not relevantly influence measured PV if the method is performed properly, i.e., if a short time window of measurement is subjected to monoexponential extrapolation. A major problem of PV measurement in general is that the target itself is very inconstant. Thus, checking for constancy of ICG-DT with two consecutive measurements is unreliable. Nevertheless, the ICG-DT is a useful tool for determining PV, provided it is well understood by the investigator to enable correct interpretation of the results.

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Burczynski, F. J., K. L. Pushka, D. S. Sitar i C. V. Greenway. "Hepatic plasma flow: accuracy of estimation from bolus injections of indocyanine green". American Journal of Physiology-Heart and Circulatory Physiology 252, nr 5 (1.05.1987): H953—H962. http://dx.doi.org/10.1152/ajpheart.1987.252.5.h953.

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Experiments were performed to determine the validity of the indocyanine green (ICG) clearance technique, with and without allowances for incomplete hepatic extraction, as an estimate of hepatic plasma flow. This technique was compared with that of directly measured hepatic blood flow using a hepatic venous long-circuit preparation in the anesthetized cat. This preparation allowed direct measurement and alteration of hepatic blood flow and collection of arterial, portal, and hepatic venous blood samples without depletion of the animal's blood volume. Measurements of ICG by spectrophotometry and high-pressure liquid chromatography (HPLC) were equally accurate, but the HPLC was 100 times more sensitive and allowed smaller sample volumes. It was determined that systemic clearance of ICG after a bolus dose (1.3 mumol/kg) was much smaller than hepatic blood flow. Allowance must be made for the incomplete extraction. When the clearance was multiplied by extraction, mean estimated hepatic plasma flow exceeded the measured flow values by 20-30%, and this difference was attributed to temporary extrahepatic distribution. In all experiments estimated hepatic plasma flows were highly variable, and reasons for this are discussed. In hepatectomized cats ICG was found to be distributed into extrahepatic tissues.

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Zohoori, F. Vida, Anne Maguire, E. Angeles Martinez-Mier, Marília Afonso Rabelo Buzalaf, Roy Sanderson i George J. Eckert. "A Comparison of Simple Analytical Methods for Determination of Fluoride in Microlitre-Volume Plasma Samples". Caries Research 53, nr 3 (8.10.2018): 275–83. http://dx.doi.org/10.1159/000492339.

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The aim was to compare potential methods for fluoride analysis in microlitre-volume plasma samples containing nano-gram amounts of fluoride. Methods: A group of 4 laboratories analysed a set of standardised biological samples as well as plasma to determine fluoride concentration using 3 methods. In Phase-1, fluoride analysis was carried out using the established hexamethyldisiloxane (HMDS)-diffusion method (1 mL-aliquot/analysis) to obtain preliminary measurement of agreement between the laboratories. In Phase-2, the laboratories analysed the same samples using a micro-diffusion method and known-addition technique with 200 µL-aliquot/analysis. Coefficients of Variation (CVs) and intra-class correlation coefficients (ICCs) were estimated using analysis of variance to evaluate the amount of variation within- and between-laboratories. Based on the results of the Phase-2 analysis, 20 human plasma samples were analysed and compared using the HMDS-diffusion method and known-addition technique in Phase-3. Results: Comparison of Phase-1 results showed no statistically significant difference among the laboratories for the overall data set. The mean between- and within-laboratory CVs and ICCs were < 0.13 and ≥0.99, respectively, indicating very low variability and excellent reliability. In Phase-2, the overall results for between-laboratory variability showed a poor CV (1.16) and ICC (0.44) for the micro-diffusion method, whereas with the known-addition technique the corresponding values were 0.49 and 0.83. Phase-3 results showed no statistically significant difference in fluoride concentrations of the plasma samples measured with HMDS-diffusion method and known- addition technique, with a mean (SE) difference of 0.002 (0.003) µg/mL. In conclusion, the known-addition technique could be a suitable alternative for the measurement of fluoride in plasma with microlitre-volume samples.

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Biswas, MA Karim, MA Shayed, RD Hund i Ch Cherif. "Surface modification of Twaron aramid fiber by the atmospheric air plasma technique". Textile Research Journal 83, nr 4 (9.11.2012): 406–17. http://dx.doi.org/10.1177/0040517512464291.

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Twaron aramid fibers (AFs) were modified by atmospheric air dielectric barrier discharge plasma with various parameters. The wettability of plasma-treated AF was observed by means of contact angle and surface free energy measurement. Surface roughness was investigated with the help of scanning electron microscopy. Energy-dispersive X-ray analysis was used to measure the chemical composition of AF in volume with one micrometer dimension. The tensile test of AF roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the adhesion effect with matrix material. Lower contact angles, increase of oxygen concentration at the fiber surface, surface roughness and increase of pull-out force with the rubber matrix were observed after the air plasma treatment.

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Molitoris, Bruce A., Anthony G. George, Patrick T. Murray, Daniel Meier, Erinn S. Reilly, Erin Barreto, Ruben M. Sandoval, Dana V. Rizk, Andrew D. Shaw i W. Frank Peacock. "A Novel Fluorescent Clinical Method to Rapidly Quantify Plasma Volume". Cardiorenal Medicine 9, nr 3 (2019): 168–79. http://dx.doi.org/10.1159/000496480.

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Objectives: To determine the performance of a rapid fluorescent indicator technique for measuring plasma volume (PV). Methods: This was an open-label, observational evaluation of a two-component intravenous visible fluorescent dye technique to rapidly measure PV in 16 healthy subjects and 16 subjects with chronic kidney disease (8 stage 3 and 8 stage 4 CKD), at 2 clinical research sites. The method consisted of a single intravenous injection of 12 mg of a large 150-kDa carboxy-methyl dextran conjugated to a fluorescent rhodamine-derived dye as the PV marker (PVM), and 35 mg of a small 5-kDa carboxy-methyl dextran conjugated to fluorescein, the renal clearance marker. Dye concentrations were quantified 15 min after the injections for initial PV measurements using the indicator-dilution principle. Additional samples were taken over 8 h to evaluate the stability of the PVM as a determinant of PV. Blood volumes (BV) were calculated based on PV and the subject’s hematocrit. Pharmacokinetic parameters were calculated from the plasma concentration data taken over several days using noncompartmental methods (Phoenix WinNonlin®). Linear correlation and Bland-Altman plots were used to compare visible fluorescent injectate-measured PV compared to Nadler’s formula for estimating PV. Finally, 8 healthy subjects received 350 mL infusion of a 5% albumin solution in normal saline over 30 min and a repeat PV determination was then carried out. Results: PV and BV varied according to weight and body surface area, with PV ranging from 2,115 to 6,234 mL and 28.6 to 41.9 mL/kg when weight adjusted. Both parameters were stable for > 6 h with repeated plasma measurements of the PVM. There was no difference between healthy subjects and CKD subjects. Overall, there was general agreement with Nadler’s estimation formula for the mean PV in subjects. A 24-h repeat dose measurement in 8 healthy subjects showed PV variability of 98 ± 121 mL (mean = 3.8%). Additionally, following an intravenous bolus of 350 mL of a 5% albumin solution in normal saline in 8 healthy subjects, the mean (SD) measured increase in PV was 356 (±50.0) mL post-infusion. There were no serious adverse events reported during the study. Conclusions: This minimally invasive fluorescent dye approach safely allowed for rapid, accurate, and reproducible determination of PV, BV, and dynamic monitoring of changes following fluid administration.

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Gillen, C. M., A. Takamata, G. W. Mack i E. R. Nadel. "Measurement of plasma volume in rats with use of fluorescent-labeled albumin molecules". Journal of Applied Physiology 76, nr 1 (1.01.1994): 485–89. http://dx.doi.org/10.1152/jappl.1994.76.1.485.

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We describe a method for measuring plasma volume (PV) in small animals that allows small sample sizes but does not require the use of radioisotopes and thus is a convenient approach for making repeated measurements. Texas Red covalently bound to albumin (TR-A) was used in a typical indicator-dilution technique to measure PV. The relative fluorescent intensity of TR-A is linear to its concentration (up to 0.15 mg/ml) at an excitation lambda of 590 nm and an emission lambda of 610 nm. Catheters were inserted through the right jugular vein of anesthetized rats and threaded into the vena cava. A 0.5-ml control blood sample was taken, a measured quantity of TR-A was injected, and the catheter was flushed with saline. A 0.5-ml postinjection sample was taken 5 min after TR-A injection. PV was calculated by comparing the difference between the relative fluorescent intensity of control and postinjection plasma samples to a standard. The PV of 22 rats [362 +/- 14 (SE) g] was 14.1 +/- 0.4 ml (39.6 +/- 0.9 ml/kg body wt) measured by the TR-A method and 12.8 +/- 0.4 ml (35.9 +/- 1.0 ml/kg body wt) measured by a standard radioiodinated albumin method. There was a strong correlation between PV measured by both methods in the same rat (r = 0.90, P < 0.01). Infusion experiments indicated that the TR-A method can detect acute changes in PV, and repeated measurements of PV made on a chronically instrumented rat demonstrated that the method can reliably measure PV on consecutive days.

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Kasireddy, Nithya, Jeremy C. Orie i Damir Khismatullin. "Resonant Acoustic Tweezing Spectroscopy for Small-Volume Noncontact Assessment of Blood Coagulation". Blood 132, Supplement 1 (29.11.2018): 3785. http://dx.doi.org/10.1182/blood-2018-99-117902.

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Abstract Introduction: Measurement and interpretation of mechanical properties of whole blood and blood plasma are important diagnosis and treatment monitoring of various conditions like coagulopathy, hemophilia, sickle cell disease and many cardiovascular disorders. Many of the current techniques like thromboelastography, micro-viscometry or microfluidic devices used for this purpose require a large sample volume and/or may be prone to measurement errors due to sample contact with device walls. To address these issues, we developed a single-drop non-contact method for blood rheological analysis, referred to as "acoustic tweezing rheometry". With sample volume as small as 4 μL, our innovative technology has been successfully applied for assessment of whole blood and blood plasma coagulation. Here, we present the extension of this technology to resonant spectroscopic measurement of blood viscoelasticity. Materials and Methods: The schematic of the acoustic tweezing device is shown in (Figure 1A). The standing acoustic wave field between the transducer and reflector generates the acoustic radiation force on the biological sample that traps it in a host fluid (e.g., air). Sample tweezing (force-induced deformation and translational motion of the trapped sample) is achieved by amplitude modulation of the acoustic tweezing signal at high frequency and then decrease the frequency continuously until the lower limit for sample trapping is reached. During this frequency sweep, shape changes of the sample were recorded (Figure 1B) by a photodetector and a high-speed camera (Figure 1A). The amplitude-frequency response of the sample was obtained from raw data analysis, with the amplitude being the maximum deflection of the sample height from its equilibrium value. Dynamic (shear) viscosity and elasticity of the sample were assessed from the quality factor of the amplitude-frequency response (Figure 1C) and the resonance frequency, respectively. Results and Discussion: The quality factor analysis predicted that the dynamic viscosity of commercial normal control blood plasma was 1.5 mPa·s at room temperature, which agreed with previous large-sample-volume measurements. Once re-calcified, the resonance frequency of blood plasma and thus its shear elasticity increased due to clot formation until reaching a plateau in 5 min (Figure 1D). Using this graphical output (referred to as "tweezograph"), the following coagulation parameters can be extracted: clot initiation time, clotting rate, clotting time, and maximum clot elasticity. Conclusions: Resonant acoustic tweezing spectroscopy can accurately measure dynamic viscosity and elasticity of whole blood and blood plasma with a small drop of the sample and without artefacts or measurement errors due to sample contact with device walls. This technique can be applied for rapid assessment of whole blood and blood plasma coagulation. Acknowledgments: This study has been supported by U.S. National Science Foundation grant 1438537, American Heart Association Grant-in-Aid 13GRNT17200013, and Tulane University intramural grants. The acoustic tweezing technology is protected by pending patents PCT/US14/55559 and PCT/US2018/014879. Disclosures Khismatullin: Levisonics Inc: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

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Rozprawy doktorskie na temat "Plasma volume measurement technique"

Gordon, Christopher, i res cand@acu edu au. "Hydrostatic and thermal influences on intravascular volume determination during immersion: quantification of the f-cell ratio". Australian Catholic University. School of Exercise Science, 2001. http://dlibrary.acu.edu.au/digitaltheses/public/adt-acuvp4.14072005.

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Previous data have shown that the most prevalent, indirect plasma volume (PV) measurement technique, which utilises changes in haematocrit (Hct) and haemoglobin concentration ([Hb]), underestimates actual PV changes during immersion, when compared to a direct tracer-dilution method. An increase in the F-cell ratio (whole-body haematocrit (Hctw) to large-vessel haematocrit (Hctv) ratio) has been purported as a possible explanation, probably due to hydrostatic and thermally-mediated changes during water immersion. Previous investigators have not quantified the F-cell ratio during immersion. Therefore, this study sought to determine the effect of the F-cell ratio on the indirect method during both, thermoneutral and cold-water immersions. Seven healthy males were tested three times, seated upright in air (control: 21.2°C SD ±1.1), and during thermoneutral (34.5oC SD ±0.2) and cold-water immersion (18.6oC SD ±0.2), immersed to the third intercostal space for 60 min. Measurements during the immersion tests included PV (Evans blue dye column elution, Evans blue dye computer programme, and Hct [Hb]), red cell volume (RCV; sodium radiochromate), cardiac frequency (fc) and rectal temperature (Tre). Plasma volume during the control trial remained stable, and equivalent across the three tests. There was a hydrostatically-induced increase in PV during thermoneutral immersion, when determined by the Evans blue dye method (16.2%). However, the Hct/[Hb] calculation did not adequately reflect this change, and underestimated the relative PV change by 43%. In contrast, PV decreased during cold immersion when determined using the Evans blue dye method by 17.9% and the Hct/[Hb] calculation by 8.0%, respectively, representing a 52% underestimation by the latter method. There was a non-significant decline in RCV during both immersions. Furthermore, an increase (8.6%) and decrease (-14.4%) in blood volume (BV) was observed during thermoneutral and cold-water immersions, respectively. The decline in RCV during thermoneutral immersion attenuated the BV expansion. Despite the disparity between the PV methods, there was no increase in the F-cell ratio during either immersion. In contrast, there was a significant decline in the F-cell ratio during the control: air and thermoneutral immersion, which may indicate that other, undefined variables may impact on the stability of the red cell compartment. The current study is the first to show that the Hct/[Hb] method clearly underestimates PV changes during both thermoneutral and cold-water immersion. Furthermore, RCV was shown, for the first time, to decline during both immersions. However, the changes in the F-cell ratio during this study, did not account for the underestimation of PV change using the Hct/[Hb] method.

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Viré, Axelle. "Study of the dynamics of conductive fluids in the presence of localised magnetic fields: application to the Lorentz force flowmeter". Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210062.

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When an electrically conducting fluid moves through a magnetic field, fluid mechanics and electromagnetism are coupled.

This interaction is the object of magnetohydrodynamics, a discipline which covers a wide range of applications, from electromagnetic processing to plasma- and astro-physics.

In this dissertation, the attention is restricted to turbulent liquid metal flows, typically encountered in steel and aluminium industries. Velocity measurements in such flows are extremely challenging because liquid metals are opaque, hot and often corrosive. Therefore, non-intrusive measurement devices are essential. One of them is the Lorentz force flowmeter. Its working principle is based on the generation of a force acting on a charge, which moves in a magnetic field. Recent studies have demonstrated that this technique can measure efficiently the mean velocity of a liquid metal. In the existing devices, however, the measurement depends on the electrical conductivity of the fluid.

In this work, a novel version of this technique is developed in order to obtain measurements that are independent of the electrical conductivity. This is particularly appealing for metallurgical applications, where the conductivity often fluctuates in time and space. The study is entirely numerical and uses a flexible computational method, suitable for industrial flows. In this framework, the cost of numerical simulations increases drastically with the level of turbulence and the geometry complexity. Therefore, the simulations are commonly unresolved. Large eddy simulations are then very promising, since they introduce a subgrid model to mimic the dynamics of the unresolved turbulent eddies.

The first part of this dissertation focuses on the quality and reliability of unresolved numerical simulations. The attention is drawn on the ambiguity that may arise when interpretating the results. Owing to coarse resolutions, numerical errors affect the performances of the discrete model, which in turn looses its physical meaning. In this work, a novel implementation of the turbulent strain rate appearing in the models is proposed. As opposed to its usual discretisation, the present strain rate is in accordance with the discrete equations of motion. Two types of flow are considered: decaying turbulence located far from boundaries, and turbulent flows between two parallel and infinite walls. Particular attention is given to the balance of resolved kinetic energy, in order to assess the role of the model.

The second part of this dissertation deals with a novel version of Lorentz force flowmeters, consisting in one or two coils placed around a circular pipe. The forces acting on each coil are recorded in time as the liquid metal flows through the pipe. It is highlighted that the auto- or cross-correlation of these forces can be used to determine the flowrate. The reliability of the flowmeter is first investigated with a synthetic velocity profile associated to a single vortex ring, which is convected at a constant speed. This configuration is similar to the movement of a solid rod and enables a simple analysis of the flowmeter. Then, the flowmeter is applied to a realistic three-dimensional turbulent flow. In both cases, the influence of the geometrical parameters of the coils is systematically assessed.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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Tattersall, James Erskine. "Atrial natriuretic peptide : its measurement in plasma and role in blood volume homeostasis". Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338515.

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Lee, Chi Shing. "A comparison of body density determinations using residual volume and total lung capacity in underwater weighing technique". HKBU Institutional Repository, 1998. http://repository.hkbu.edu.hk/etd_ra/147.

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Jarl, Gustav. "Accuracy and precision of a technique to assess residual limb volume with a measuring-tape". Thesis, Jönköping University, HHJ, Dep. of Rehabilitation, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-1247.

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Transtibial stump volume can change dramatically postoperatively and jeopardise prosthetic fitting. Differences between individuals make it hard to give general recommendations of when to fit with a definitive prosthesis. Measuring the stump volume on every patient could solve this, but most methods for volume assessments are too complicated for clinical use.

The aim of this study was to evaluate accuracy and intra- and interrater precision of a method to estimate stump volume from circumferential measurements. The method approximates the stump as a number of cut cones and the tip as a sphere segment.

Accuracy was evaluated theoretically on six scanned stump models in CAPOD software and manually on six stump models. Precision was evaluated by comparing measurements made by four CPOs on eight stumps. Measuring devices were a wooden rule and a metal circumference rule. The errors were estimated with intraclass correlation coefficient (ICC), where 0,85 was considered acceptable, and a clinical criterion that a volume error of ±5% was acceptable (5% corresponds to one stocking).

The method was accurate on all models in theory but accurate on only four models in reality. The ICC was 0,95-1,00 for intrarater precision but only 0,76 for interrater precision. Intra- and interrater precision was unsatisfying when using clinical criteria. Variations between estimated tip heights and circumferences were causing the errors.

The method needs to be developed and is not suitable for stumps with narrow ends. Using a longer rule (about 30 cm) with a set square end to assess tip heights is recommended to improve precision. Using a flexible measuring-tape (possible to disinfect) with a spring-loaded handle could improve precision of the circumferential measurements.

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Wilson, Austin T. "Measurement of Nanoparticle Size Distributions and Number of Nanoparticles Per Volume by Inductively Coupled Plasma Mass Spectrometry". The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1471823411.

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Outif, Ahmed M. "Measurement of limb vascular volume using nuclear medicine technique : A new physiological approach to the diagnosis of peripheral arterial occlusive disease". Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310638.

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Zhang, Hongyuan. "Fonctionnalisation et caractérisation multi-échelle de films minces de chitosane : vers une utilisation en ingénierie tissulaire". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0366/document.

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Ce travail porte sur la fonctionnalisation en volume et/ou en surface et la caractérisation multi-échelle de films minces de chitosane utilisés en ingénierie tissulaire. L’ajout des nanoliposomes à base de lécithine naturelle (végétale ou marine) et un traitement plasma sont employés pour réaliser ces deux fonctionnalisations. De nombreuses analyses des caractéristiques physico-chimiques et « structurales » de films minces ont montré que lorsqu’on ajoute 10 % de nanoliposomes dans les films de chitosane, l’hydrophobicité de la surface s’améliore de 18 à 36 %, ce fait est attribué à la présence de composants polaires. La cristallinité est légèrement augmentée ; à 37 °C, le module d’Young diminue de 6 GPa environ jusqu’à près de 4 GPa ; aucune nouvelle liaison ne se crée entre le chitosane et les nanoliposomes ; une diminution de degré de déacétylation est observée, qui pourrait être associée à la conformation des nanoliposomes ajoutés en volume aux films de chitosane. Le traitement plasma a réussi à modifier la structure de surface du chitosane seul et du chitosane mélangé aux nanoliposomes par greffe de groupements actifs (groupes amine, C-O, COOH, -OH). En revanche, dans notre cas, les liaisons hydrogène entre les groupes polaires créés par le traitement plasma peuvent être éliminées partiellement après un temps donné, ce qui limite l’application du traitement. Ensuite, des études préliminaires sur la biocompatibilité in vitro et la biodégradabilité in vitro sont réalisées pour les films de chitosane et du chitosane mélangé aux nanoliposomes. Les cellules souches mésenchymateuses sont utilisées pour l’étude de la première, et une solution de PBS contenant 10 mg/L de lysozyme pour la seconde. Les propriétés physico-chimiques des films de chitosane mélangé aux nanoliposomes marines, leur faible cytotoxicité aux cellules et leur stabilité dans la solution de PBS contenant du lysozyme leur permettent d’être utilisés comme matrice de support dans le domaine de la médecine régénérative
This work focused on functionalized chitosan thin films in the bulk and/or on the surface by nanoliposomes based on natural lecithin (plant and marine) and plasma treatment. Various techniques were used for physicochemical properties analysis of functionalized thin films. The results showed that by adding the nanoliposomes into the chitosan scaffold, the surface wettability of thin films increased from 18 % to 36 %. The crystallinity degree was slightly improved in blend thin films. Any new bond was determined by fourier transform infrared spectroscopy (FTIR), which confirmed that there is no chemical interaction between the nanoliposomes and chitosan. The Young’s modulus of blend thin films deceased from 6 GPa to 5 GPa. The morphological, nanomechanical properties and adhesion force of each scaffold system determined by Scanning Probe Microscopy (HarmoniXTM mode) showed that the fish nanoliposomes/chitosan thin film had the most similar properties compared to the pure chitosan thin film. The surface of chitosane films and nanoliposomes/chitosane blend films were modified by the plasma treatment. Functional groups (amine groups, C-O, COOH, -OH) are grafted onto the surface enhancing thus the surface energy of the films. But the hydrogen bonds between the polar groups introduced by the treatment can be destroyed after a given time; the author proposed that the functionalization in the bulk by adding of nanoliposomes provided more stable and greater possibility of new materials producing than the functionalization at the surface by plasma treatment for potential tissue engineering application. Then, in vitro biocompatibility preliminary study was carried using human mesenchymal stem cells (hMSCs); and in vitro biodegradability study was tested in the phosphate buffered saline (PBS) mixed with 10 mg/L lysozyme. The films of chitosan functionalized by salmon nanoliposomes showed more interesting as matrix extracellular for regenerative medicine applications because of their physico-chemical properties, low cytotoxicity and the stability inside the PBS and lysozyme solutions

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Morandi, Pierre. "Développement d'une technique de tomographie par découpage optique rotatif pour la mesure résolue en temps de champs cinématiques 3D par corrélation d'images volumiques". Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2324/document.

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Pour l'étude d'une structure solide ou d'un matériau, l'analyse expérimentale permet d'obtenir des grandeurs mécaniques qui permettent de comprendre leurs comportements ou encore de valider des résultats issus d'une simulation numérique. Ces grandeurs peuvent être de différentes natures (contraintes, déformations...) et être localisées de différentes manières dans l'espace (2D, 3D) et dans le temps (statique, dynamique). Le bilan des techniques actuelles d'analyse expérimentale en mécanique des solides révèle un besoin concernant l'acquisition d'une structure en tous points avec une résolution élevée à la fois spatialement et temporellement. L'objectif des travaux menés au cours de cette thèse est le développement d'une nouvelle technique d'acquisition capable d'acquérir un volume de matière de quelques centimètres de côté en moins d'une seconde avec une précision spatiale inférieure à 0.1mm. Les volumes obtenus doivent avoir une qualité suffisamment élevée pour être couplés à la technique de Corrélation d'Images Volumiques (DVC) permettant d'obtenir les déplacements ainsi que le tenseur des déformations de Green-Lagrange complet au coeur de la matière. Un nouveau procédé d'acquisition baptisé Optical Rotating Scanning Tomography (ORST) et basé sur le découpage optique a été développé. Après l'avoir décrit mathématiquement, un système spécifique synchronisé avec une caméra rapide a été conçu. La méthode a été appliquée sur deux essais mécaniques : traction continue et contact entre un galet roulant et un bloc. L'analyse des résultats a montré que l'ORST est capable d'analyser l'évolution des champs de déformations à la fois au coeur du volume et résolue en temps
To study of a solid structure or a material, an experimental analysis can be used to get mechanical fields in order to understand the mechanical behaviour or to validate simulation results. Different kind of fields can be obtained (stress, strain) in different spatial (2D, 3D) or temporal referential (static, dynamic). Current techniques are not able to acquire the whole volume of a structure with a high spatial and temporal resolution. The objective of this work is to develop a new volume acquisition technique able to capture a volume with a characteristic edge size of several centimetres in less than 1 second with a spatial accuracy less than 0.1mm. Reconstructed volumes need to have a good quality to be used with the Digital Volume Correlation (DVC) in order to provide displacement fields and the full Green-Lagrange tensor in the whole volume. A new acquisition technique called Optical Rotating Scanning Tomography (ORST) based on the optical scanning technique has been developed. A mathematical description has been achieved and then a special device has been manufactured. This device is synchronized with a high speed CCD camera in order to perform time-resolved acquisition. This new technique has been used to study two mechanical tests. The first is a traction test with a continuous loading, and the second concerns a wheel rolling over a solid bloc. Experimental results of these applications show that ORST technique is able to analyse displacement and strain fields in the whole volume and in a time-resolved way

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Quéméneur, Jean. "Etude des forces à l'origine du déplacement d'un arc électrique dans un disjoncteur basse-tension". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30040/document.

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Le Disjoncteur Basse-Tension (DBT) est un appareil classique de la distribution électrique depuis plus de cinquante ans. Mais aujourd'hui, avec l'arrivée de produits bas-coût fabriqués dans les pays émergents, les industriels sont soumis à une forte pression pour développer de nouveaux systèmes moins encombrants, utilisant d'autres matériaux, ou incorporant davantage de fonctionnalités. Cette recherche est très compliquée dans la mesure où le DBT est un système hautement multi-physique (mécanique, thermique, physique des matériaux, physique des plasmas, ...). De fait, le développement de nouveaux produits passe par un processus empirique long et coûteux. Cet effort pourrait être réduit par l'utilisation de modèles prédictifs permettant d'arriver plus vite à un système fonctionnel. De nos jours, avec l'augmentation des moyens de résolution numérique, de plus en plus de travaux portent sur la description multi-physique en 3D du DBT et notamment sur la chambre de coupure ou l'arc électrique est amorcé, se déplace et doit être éteint, l'objet de nôtre étude. Le travail de cette thèse se divise en deux axes complémentaires : le développement d'un modèle fluide 3D en méthode des volumes finis simulant l'arc électrique et son déplacement dans la chambre de coupure; ainsi que la mise en place d'un dispositif expérimental permettant d'analyser le phénomène physique en œuvre. Pour ces deux points la problématique est abordée dans une configuration simplifiée de DBT où l'arc se déplace entre deux rails parallèles dans une chambre parallélépipédique. Basé sur le savoir-faire du groupe AEPPT, un modèle numérique est établi pour simuler le plasma thermique. Les particularités de ce modèle, du fait de l'application, sont la nécessité d'une résolution précise du champ magnétique en utilisant le calcul de Biot & Savart pour les conditions limites ainsi que l'utilisation de méthodes permettant le déplacement et la commutation de l'arc. La validation de ce modèle se fera à géométrie similaire par confrontation avec l'expérience. En s'inspirant de précédents travaux nous avons réalisé une maquette expérimentale composée d'un réacteur faisant office de chambre de coupure et d'un mécanisme permettant l'amorçage de l'arc dans le réacteur par ouverture rotative du contact à vitesse contrôlée. D'autres paramètres modifiables sont la taille du réacteur ainsi que les matériaux qui le constituent. Les diagnostiques disponibles en plus de la mesure de courant et de tension sont l'imagerie rapide et la mesure de pression en différents points de la chambre de coupure. Notre expérience est utile pour la réalisation d'études paramétriques en découplant facilement les paramètres. En outre, par la mise en évidence des phénomènes prépondérants, notre maquette aide à la mise en place du modèle en plus de permettre sa validation expérimentale. Cette thèse est donc une étape cruciale vers la mise en place d'un modèle prédictif
Low-Voltage Circuit Breakers (LVCB) are classical apparatuses of electrical distribution since more than fifty years. But nowadays, with the outbreak of low-cost products from the developing countries, industry is under a strong stress in order to improve their devices by making them more compact, using different materials or to implement new functionalities. This research is harsh since LVCB are highly multiphysics systems (mechanics, thermal properties, materials, plasma physics, ...). Therefore, developing new products goes through a long and expensive empirical process. Those efforts could be reduced by using predictive models allowing to get faster to a functional device. With the improvements of the numerical solution capacity, there are more and more works toward the 3D multiphysical description of the LVCB, especially on the extinction chamber where the electrical arc is ignited, moved and must be quenched. This is the subject of our work. The study described here is divided in two complementary parts: development of a 3D fluid model with finite volume method simulating the electrical arc and its movement inside the arc extinction chamber; and the set-up of experimental means to analyse this physical phenomenon. For those two points, we use a simplified LVCB configuration with an arc moving between two parallel rails inside a rectangular box chamber. Based on AEPPT's know-how, a numerical model is established to simulate thermal plasma. Particularities on this model, due to the application, are the resolution of Biot&Savart law to calculate precisely the magnetic field for the boundary condition and the development of methods to model the arc roots movement and commutation of the arc from the moving contact to the rail. Validation of this model will be done with the same geometry by confrontation with the experiment. Inspired by precedent works we designed a test apparatus with a reactor representing the extinction chamber of the LVCB and an opening mechanism allowing arc ignition by contact opening at a specified speed. Other parameters such as size of the chamber and materials can be modified. Measurements will include high speed imaging and pressure acquisition in several points of the reactor in addition to the classical current and voltage measurements. This experiment is useful for parametric studies with its easy uncoupling of the parameters. Moreover, by highlighting the dominating phenomena for arc movement, this set-up helps in the build-up of the model over and above the experimental validation

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Książki na temat "Plasma volume measurement technique"

Chojnacky, David C. Dryland forest volume: Another look at the visual segmentation technique. [Ogden, UT]: U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1992.

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Chojnacky, David C. Dryland forest volume: Another look at the visual segmentation technique. Ogden, UT]: U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1992.

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Cavity-Ringdown Spectroscopy. An Ultratrace-Absorption Measurement Technique (ACS Symposium Series, Volume 720). American Chemical Society, 1999.

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F. B. Dunning (Series Editor) i Randall G. Hulet (Series Editor), red. Atomic, Molecular, and Optical Physics: Atoms and Molecules, Volume 29B: Volume 29B: Atomic, Molecular, And Optical Physics (Experimental Methods in the Physical Sciences). Academic Press, 1996.

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Kent, Ostrander Gary, red. Techniques in Aquatic Toxicology, Volume 2. Boca Raton, Fla: Lewis Publishers, 1996.

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An estimated residual volume: Influence on the measurement of body density by the hydrostatic weighing technique. 1991.

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An estimated residual volume: Influence on the measurement of body density by the hydrostatic weighing technique. 1988.

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Techniques in Aquatic Toxicology, Volume 2. CRC, 2005.

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(Editor), B. Siefert, H. J. van de Wiel (Editor), B. Dodet (Editor) i I. K. O'Neill (Editor), red. Environmental Carcinogens: Methods of Analysis and Exposure Measurement Volume 12: Indoor Air (DISCONTINUED (IARC Scient Pub)). IARC Scientific Publications, 1994.

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Części książek na temat "Plasma volume measurement technique"

Kudryavtsev, Y., i J. Kleiman. "Ultrasonic Technique and Equipment for Residual Stresses Measurement". W Engineering Applications of Residual Stress, Volume 8, 55–66. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-0225-1_8.

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Jaecks, D. H., D. H. Crandall i R. H. McKnight. "Measurement of Differential Charge-Transfer Cross Sections and Probabilities by Photon-Particle Coincidence Technique". W Springer Series on Atomic, Optical, and Plasma Physics, 447–50. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4613-0187-5_25.

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Chen, Terry Yuan-Fang, i Ren-Shaung Lu. "Hybrid Infrared Image Correlation Technique to Deformation Measurement of Composites". W Advancement of Optical Methods in Experimental Mechanics, Volume 3, 115–19. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-41600-7_13.

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Buyukozturk, Selda, Alexander K. Landauer i Christian Franck. "Development of an Interferometer and Schlieren Based Measurement Technique for Resolving Cavitation Pressure Fields". W Dynamic Behavior of Materials, Volume 1, 137–40. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95089-1_24.

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Liu, Yihao, Hongjian Gao, James Zhuge i Jeff Zhao. "Research of Under-Sampling Technique for Digital Image Correlation in Vibration Measurement". W Shock & Vibration, Aircraft/Aerospace, Energy Harvesting, Acoustics & Optics, Volume 9, 49–58. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54735-0_6.

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Masui, Kenta, Kaoru Kiyomitsu, Keiko Ogawa i Norimichi Tsumura. "Visualization Technique for Change of Edema Condition by Volume Measurement Using Depth Camera". W Lecture Notes in Computer Science, 526–33. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-94211-7_57.

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Allahdadian, Saeid, Michael Döhler, Carlos E. Ventura i Laurent Mevel. "On the Influence of Sample Length and Measurement Noise on the Stochastic Subspace Damage Detection Technique". W Structural Health Monitoring, Damage Detection & Mechatronics, Volume 7, 35–46. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29956-3_4.

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Brown, Eric N. "Inverse Measurement of Stiffness by the Normalization Technique for J-Integral Fracture Toughness". W Challenges in Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials, Volume 2, 17–21. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-4241-7_3.

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Le, Minh, Zhaoyang Wang i Hieu T. Nguyen. "Some Practical Considerations in High-Speed 3D Shape and Deformation Measurement Using Single-Shot Fringe Projection Technique". W Advancement of Optical Methods in Experimental Mechanics, Volume 3, 357–62. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06986-9_42.

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Ismonov, S., i S. R. Daniewicz. "Study of an On-Line Crack Compliance Technique for Residual Stress Measurement Using 2D Finite Element Simulations of Fatigue Crack Growth". W Fatigue and Fracture Mechanics: 38th Volume, 136–56. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2012. http://dx.doi.org/10.1520/stp49545t.

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Streszczenia konferencji na temat "Plasma volume measurement technique"

Shan, Hua, i Yu-Tai Lee. "Numerical Study of Dielectric Barrier Discharge Plasma Actuation". W ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21108.

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There has been an increasing interest in dielectric barrier discharge (DBD) plasma actuation for flow control in the past decade. Compared to other means of active flow controls, the DBD plasma actuations have several advantages, including absence of moving parts, a fast time response for unsteady applications, a very low mass of the device, no cavities or holes on control surfaces, and possibly low energy consumption. These features are especially important for applications with high g-loads, such as turbomachinery blades rotating at high speed. A computational method has been developed to couple a DBD electro-hydrodynamic (EHD) body force model with the Reynolds averaged Navier-Stokes (RANS) model for incompressible flows. The EHD body force model is based on solving the electrostatic equations for the electric potential due to applied voltage and the net charge density due to ionized air. The boundary condition for charge density on the dielectric surface is obtained from a Space-Time Lumped-Element (STLE) circuit model that accounts for time and space dependence of the air ionization on the input voltage amplitude, frequency, electrode geometry, and dielectric properties. Alternatively, an empirical formulation representing a Gaussian distribution of charge density on the dielectric surface can also be used. The EHD body force is calculated using the solutions obtained from solving the electric potential and the net charge density equations. As a comparison, a much simpler Linearized Electric Body Force (LEBF) model is also used to directly specify the spatial distribution of the averaged EHD body force. The coupled computational models have been implemented using a multiple-domain approach. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. All equations are discretized in space using a cell-centered finite volume method. Parallel computation is implemented using domain-decomposition and message passing interface (MPI). Due to a large disparity in time scales between the electric discharge and the flow, a multiple sub-cycle technique is used in coupling the plasma solver and the flow solver. The DBD plasma induced flow in quiescent air is used as a test case and the computational results are validated against experimental measurement. A comparison between different EHD body force models is also presented. Then, the effect of driving duty-cycles with different waveforms and input voltage amplitudes is investigated in terms of electrical power, EHD thrust, and kinetic energy of induced flow.

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Maor, D., M. Meron, B. M. Johnson, K. W. Jones, A. Agagu i B. L. Hu. "Measurement of plasma production and neutralization in gas neutralizers". W AIP Conference Proceedings Volume 158. AIP, 1987. http://dx.doi.org/10.1063/1.36585.

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Shan, Hua, Shawn Aram i Yu-Tai Lee. "Application of an Integrated Flow and DBD Plasma Actuation Model to a High-Lift Airfoil: Part I — RANS". W ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-14213.

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An integrated numerical simulation tool that couples the Reynolds averaged Navier-Stokes (RANS) or the large eddy simulation (LES) solver for incompressible flows with the dielectric barrier discharge (DBD) electro-hydrodynamic (EHD) body force model has been developed. The EHD body force model is based on solving the electrostatic equations for the electric potential due to applied voltage and the net charge density due to ionized air. The boundary condition for the charge density on the dielectric surface is obtained from a Space-Time Lumped-Element (STLE) circuit model that accounts for the time and space dependence of air ionization on the input voltage amplitude, frequency, electrode geometry, and dielectric properties. The development of the numerical simulation tool is based on the framework of NavyFOAM using a multi-domain approach. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. All equations are discretized in space using the cell-centered finite volume method. Parallel computation is implemented using domain-decomposition and message passing interface (MPI). Due to a large disparity in time scales between the electric discharge and the flow, a multiple sub-cycle technique is used in coupling the plasma solver and the flow solver. This paper focuses on its application to numerical simulation of flow separation and control over a high-lift flapped airfoil at a Reynolds number of 240,000. The 2-D unsteady RANS simulation utilized the Wilcox k-ω, the SST k-ω, and the k-kl-ω turbulence models. For the baseline case, in comparison with the measurement, the k-kl-ω model captures the feature of the unsteadiness of flow field associated with flow separation and shedding of vortices, better than the Wilcox k-ω and SST k-ω models. In the RANS simulations for flow separation control with DBD plasma actuation, the actuator is driven by voltage signals of a continuous or an amplitude-modulated sine waveform with a range of voltage amplitudes. The numerical results indicate that the modulated forcing is more effective than the continuous forcing for a certain range of applied voltages. The electrical power consumption calculated by the plasma model fits to a parabolic curve as a function of the root-mean-square of applied voltage.

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Ngo, C. C., N. M. Brown i F. C. Lai. "Electrohydrodynamic (EHD) Pump in a Square Channel". W ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55185.

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The electrohydrodynamics (EHD) technique has shown promising results in enhancing heat transfer and mass transport. It has endless potential in industrial applications such as drying technology, design of evaporators, condensers, electrostatic precipitator, plasma actuator, and micropumps in microfluidic, chip-integrated cooling, and drug delivery systems. In recent years, a significant amount of research has been directed to design EHD micropumps as researchers realize their attractive features (e.g., no moving part, simple fabrication process) are most suitable in the aforementioned microelectro-mechanical systems (MEMS). This paper evaluates the performance of an EHD pump in a vertical square (4 × 4 inch) channel with a non-intrusive wire-electrode configuration. The voltage and current characteristics of the EHD pump are measured such that numerical simulations can be carried out. Measurements were taken from the corona threshold voltage to the occurrence of sparkover with a 1 kV increment. Due to the corona wind generated, the average volume flow rate in the channel was as high as 10 liter per second subjected to a voltage difference of 25 kV.

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Martínez, D. S., E. Pescini, F. Marra, M. G. De Giorgi i A. Ficarella. "Analysis of the Performance of Plasma Actuators Under Low-Pressure Turbine Conditions Based on Experiments and URANS Simulations". W ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64867.

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The present work is focused on the investigation of an alternate current driven single dielectric barrier discharge plasma actuator (AC-SDBDPA) for the control of separated flow at Reynolds numbers up to 2·104. Laminar boundary layer separation typically occurs on the suction surface of the low pressure turbines (LPT) blades when operating at high altitude cruise conditions, as the Reynolds number can drop below 2.5·104. In this context, the implementation of an active boundary layer control system able to operate in suppressing separation — only at the critical Reynolds numbers — is of great interest. The SDBDPA was manufactured by means of the photolithographic technique, which ensured a thin metal deposition with high manufacturing reliability control. Actuator operation under sinusoidal voltage at 8 kV amplitude and 2 kHz frequency was considered. Investigations were performed in a closed loop wind tunnel. A curved plate with a shape designed to reproduce the suction surface of a LPT was mounted directly over the bottom wall of the test section. The SDBDPA was inserted in a groove made at the middle of the curved plate, located at the front side of the adverse pressure gradient region. The flow pattern and velocities in absence of actuation were experimentally measured by a two-dimensional (2-D) particle image velocimetry (PIV) system and a laser Doppler velocimetry (LDV) system. PIV measurements were performed in presence of actuation. Simultaneously to the velocity measurements, the voltage applied to the AC-SDBDPA and the discharge current flowing through the circuit were acquired in order to determine the power dissipated by the device. The experimental data were supported by computational fluid dynamics (CFD) simulations based on the finite volume method. In order to deeply investigate the effect of flow separation control by the AC-SDBDPA on the LPT blade performances, the viscous and unsteady Reynolds-averaged Navier-Stokes equations were solved to predict the characteristics of the flow with and without actuation. The actuation effect was modelled as a time-constant body force calculated prior to the fluid flow simulations by using the dual potential algebraic model. The experimental data were used to calibrate and successfully validate the numerical model. An unsteady RANS (URANS) approach, using the k-ω Lam and Bremhorst Low-Reynolds turbulence model was employed, accounting with the main transient flow structures. Results showed that the mixing action of the streamwise fluid with higher momentum and the boundary layer fluid with the lower momentum -due to the AC-SDBDPA-led, depending on the tested Reynolds number, to the alleviation or suppression of the boundary layer flow separation which occurred on the suction surface of the LPT blade. The validated numerical model will allow expanding the study of the actuation effect including different locations and multiple devices, saving considerably experimental efforts.

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Cordova-Fraga, T. "Volume Measurement in Solid Objects Using Artificial Vision Technique". W MEDICAL PHYSICS: Eighth Mexican Symposium on Medical Physics. AIP, 2004. http://dx.doi.org/10.1063/1.1811843.

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Schley, R. S., D. H. Hurley i Z. A. Hua. "Optical fiber technique for in-reactor mechanical properties measurement". W REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: VOLUME 32. AIP, 2013. http://dx.doi.org/10.1063/1.4789246.

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Devi, N. Vishnu, i R. Naveeth Kumar. "Lung air volume measurement from x-ray images using DSA technique". W 2015 Online International Conference on Green Engineering and Technologies (IC-GET). IEEE, 2015. http://dx.doi.org/10.1109/get.2015.7453812.

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Konstantinopoulos, T., A. Lagoyannis, S. Harissopulos, A. Dewald, W. Rother, G. Ilie, P. Jones i in. "128Xe Lifetime Measurement Using the Coulex‐Plunger Technique in Inverse Kinematics". W REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION VOLUME 29. American Institute of Physics, 2008. http://dx.doi.org/10.1063/1.2939335.

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Miakonkikh, A., i K. Rudenko. "Measurement of polymerizing fluorocarbon plasma parameters: dynamic Langmuir probe technique application". W SPIE Proceedings, redaktorzy Kamil A. Valiev i Alexander A. Orlikovsky. SPIE, 2006. http://dx.doi.org/10.1117/12.677021.

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