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Sample records for volume flow production

  1. A MATHEMATICAL MODEL OF OPTIMIZATION OF THE VOLUME OF MATERIAL FLOWS IN GRAIN PROCESSING INTEGRATED PRODUCTION SYSTEMS

    OpenAIRE

    Baranovskaya T. P.; Loyko V. I.; Makarevich O. A.; Bogoslavskiy S. N.

    2014-01-01

    The article suggests a mathematical model of optimization of the volume of material flows: the model for the ideal conditions; the model for the working conditions; generalized model of determining the optimal input parameters. These models optimize such parameters of inventory management in technology-integrated grain production systems, as the number of cycles supply, the volume of the source material and financial flows. The study was carried out on the example of the integrated system of ...

  2. Productivity Analysis of Volume Fractured Vertical Well Model in Tight Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Jiahang Wang

    2017-01-01

    Full Text Available This paper presents a semianalytical model to simulate the productivity of a volume fractured vertical well in tight oil reservoirs. In the proposed model, the reservoir is a composite system which contains two regions. The inner region is described as formation with finite conductivity hydraulic fracture network and the flow in fracture is assumed to be linear, while the outer region is simulated by the classical Warren-Root model where radial flow is applied. The transient rate is calculated, and flow patterns and characteristic flowing periods caused by volume fractured vertical well are analyzed. Combining the calculated results with actual production data at the decline stage shows a good fitting performance. Finally, the effects of some sensitive parameters on the type curves are also analyzed extensively. The results demonstrate that the effect of fracture length is more obvious than that of fracture conductivity on improving production in tight oil reservoirs. When the length and conductivity of main fracture are constant, the contribution of stimulated reservoir volume (SRV to the cumulative oil production is not obvious. When the SRV is constant, the length of fracture should also be increased so as to improve the fracture penetration and well production.

  3. Flow and volume dependence of rat airway resistance during constant flow inflation and deflation.

    Science.gov (United States)

    Rubini, Alessandro; Carniel, Emanuele Luigi; Parmagnani, Andrea; Natali, Arturo Nicola

    2011-12-01

    The aim of this study was to measure the flow and volume dependence of both the ohmic and the viscoelastic pressure dissipations of the normal rat respiratory system separately during inflation and deflation. The study was conducted in the Respiratory Physiology Laboratory in our institution. Measurements were obtained for Seven albino Wistar rats of both sexes by using the flow interruption method during constant flow inflations and deflations. Measurements included anesthesia induction, tracheostomy and positioning of a tracheal cannula, positive pressure ventilation, constant flow respiratory system inflations and deflations at two different volumes and flows. The ohmic resistance exhibited volume and flow dependence, decreasing with lung volume and increasing with flow rate, during both inflation and deflation. The stress relaxation-related viscoelastic resistance also exhibited volume and flow dependence. It decreased with the flow rate at a constant lung volume during both inflation and deflation, but exhibited a different behavior with the lung volume at a constant flow rate (i.e., increased during inflations and decreased during deflations). Thus, stress relaxation in the rat lungs exhibited a hysteretic behavior. The observed flow and volume dependence of respiratory system resistance may be predicted by an equation derived from a model of the respiratory system that consists of two distinct compartments. The equation agrees well with the experimental data and indicates that the loading time is the critical parameter on which stress relaxation depends, during both lung inflation and deflation.

  4. Flow rate measurement in a volume

    Energy Technology Data Exchange (ETDEWEB)

    Galvez, Cristhian

    2018-04-17

    A system for measuring flow rate within a volume includes one or more transmission devices that transmit one or more signals through fluid contained within the volume. The volume may be bounded, at least in part, by an outer structure and by an object at least partially contained within the outer structure. A transmission device located at a first location of the outer structure transmits a first signal to a second location of the outer structure. A second signal is transmitted through the fluid from the second location to a third location of the outer structure. The flow rate of the fluid within the volume may be determined based, at least in part, on the time of flight of both the first signal and the second signal.

  5. 21 CFR 876.1800 - Urine flow or volume measuring system.

    Science.gov (United States)

    2010-04-01

    ... volume measuring system. (a) Identification. A urine flow or volume measuring system is a device that measures directly or indirectly the volume or flow of urine from a patient, either during the course of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urine flow or volume measuring system. 876.1800...

  6. The relationship between sap-flow rate and sap volume in dormant sugar maples

    Science.gov (United States)

    William J. Gabriel; Russell S. Walters; Donald W. Seegrist

    1972-01-01

    Sap-flow rate is closely correlated with the sap volume produced by dormant sugar maple trees (Acer saccharum Marsh.) and could be used in making phenotypic selections of trees for superior sap production.

  7. Entropy Production in Pipeline Flow of Dispersions of Water in Oil

    Directory of Open Access Journals (Sweden)

    Rajinder Pal

    2014-08-01

    Full Text Available Entropy production in pipeline adiabatic flow of water-in-oil emulsions is investigated experimentally in three different diameter pipes. The dispersed-phase (water droplets concentration of emulsion is varied from 0 to 41% vol. The entropy production rates in emulsion flow are compared with the values expected in single-phase flow of Newtonian fluids with the same properties (viscosity and density. While in the laminar regime the entropy production rates in emulsion flow can be described adequately by the single-phase Newtonian equations, a significant deviation from single-phase flow behavior is observed in the turbulent regime. In the turbulent regime, the entropy production rates in emulsion flow are found to be substantially smaller than those expected on the basis of single-phase equations. For example, the entropy production rate in water-in-oil emulsion flow at a dispersed-phase volume fraction of 0.41 is only 38.4% of that observed in flow of a single-phase Newtonian fluid with the same viscosity and density, when comparison is made at a Reynolds number of 4000. Thus emulsion flow in pipelines is more efficient thermodynamically than single-phase Newtonian flow.

  8. Flow dynamics of volume-heated boiling pools

    International Nuclear Information System (INIS)

    Ginsberg, T.; Jones, O.C.; Chen, J.C.

    1979-01-01

    Safety analyses of fast breeder reactors require understanding of the two-phase fluid dynamic and heat transfer characteristics of volume-heated boiling pool systems. Design of direct contact three-phase boilers, of practical interest in the chemical industries also requires understanding of the fundamental two-phase flow and heat transfer behavior of volume boiling systems. Several experiments have been recently reported relevant to the boundary heat-loss mechanisms of boiling pool systems. Considerably less is known about the two-phase fluid dynamic behavior of such systems. This paper describes an experimental investigation of the steady-state flow dynamics of volume-heated boiling pool systems

  9. Assessment and monitoring of flow limitation and other parameters from flow/volume loops.

    Science.gov (United States)

    Dueck, R

    2000-01-01

    Flow/volume (F/V) spirometry is routinely used for assessing the type and severity of lung disease. Forced vital capacity (FVC) and timed vital capacity (FEV1) provide the best estimates of airflow obstruction in patients with asthma, chronic obstructive pulmonary disease (COPD) and emphysema. Computerized spirometers are now available for early home recognition of asthma exacerbation in high risk patients with severe persistent disease, and for recognition of either infection or rejection in lung transplant patients. Patients with severe COPD may exhibit expiratory flow limitation (EFL) on tidal volume (VT) expiratory F/V (VTF/V) curves, either with or without applying negative expiratory pressure (NEP). EFL results in dynamic hyperinflation and persistently raised alveolar pressure or intrinsic PEEP (PEEPi). Hyperinflation and raised PEEPi greatly enhance dyspnea with exertion through the added work of the threshold load needed to overcome raised pleural pressure. Esophageal (pleural) pressure monitoring may be added to VTF/V loops for assessing the severity of PEEPi: 1) to optimize assisted ventilation by mask or via endotracheal tube with high inspiratory flow rates to lower I:E ratio, and 2) to assess the efficacy of either pressure support ventilation (PSV) or low level extrinsic PEEP in reducing the threshold load of PEEPi. Intraoperative tidal volume F/V loops can also be used to document the efficacy of emphysema lung volume reduction surgery (LVRS) via disappearance of EFL. Finally, the mechanism of ventilatory constraint can be identified with the use of exercise tidal volume F/V loops referenced to maximum F/V loops and static lung volumes. Patients with severe COPD show inspiratory F/V loops approaching 95% of total lung capacity, and flow limitation over the entire expiratory F/V curve during light levels of exercise. Surprisingly, patients with a history of congestive heart failure may lower lung volume towards residual volume during exercise

  10. Are urine flow-volume nomograms developed on Caucasian men optimally applicable for Indian men? Need for appraisal of flow-volume relations in local population

    Directory of Open Access Journals (Sweden)

    Mayank M Agarwal

    2010-01-01

    Full Text Available Introduction : Flow-volume nomograms and volume-corrected flow-rates (cQ are tools to correct uroflow rates (Q with varied voided volumes (VV of urine. We investigated the applicability of the available nomograms in our local population. Materials and Methods : Raw data of our previous study on variation in Q with voiding position (standing, sitting, and squatting in healthy adult men was reanalyzed. Additionally, the departmental urodynamic database of the last four years was searched for uroflow data of men with voiding symptoms (International Prostatic Symptom Score (IPSS > 7 and global quality of life score >2. These results were projected on the Liverpool and Siroky nomograms for men. The Q-VV relations were statistically analyzed using curve-estimation regression method to examine the current definition of corrected maximum flow rate (Qmax. Results : We found a cubic relation between Q and VV; based on this we developed novel equation for cQ [cQ=Q/(VV 1/3 ] and novel confidence-limit flow-volume nomograms. The imaginary 16 th percentile line of Liverpool nomogram, -1 standard-deviation line of Siroky nomogram and lower 68% confidence-limit line of our nomogram had sensitivity of 96.2%, 100% and 89.3%, and specificity of 75.3% 69.3% and 86.0%, respectively for Qmax-VV relations. Corresponding values for average flow rate (Qave-volume relations were 96.2%, 100% and 94.6%, and 75.2%, 50.4% and 86.0%, respectively. The area under curve of the receiver operating characteristics (ROC curve for cQmax and cQave was 0.954 and 0.965, respectively, suggesting significantly higher discriminatory power than chance (P = 0.0001. Conclusion : Flow-volume nomograms developed on Caucasian population may not be optimally applicable to the Indian population. We introduce flow-volume nomograms and cQ, which have high sensitivity and specificity.

  11. Real-time display of flow-pressure-volume loops.

    Science.gov (United States)

    Morozoff, P E; Evans, R W

    1992-01-01

    Graphic display of respiratory waveforms can be valuable for monitoring the progress of ventilated patients. A system has been developed that can display flow-pressure-volume loops as derived from a patient's respiratory circuit in real time. It can also display, store, print, and retrieve ventilatory waveforms. Five loops can be displayed at once: current, previous, reference, "ideal," and previously saved. Two components, the data-display device (DDD) and the data-collection device (DCD), comprise the system. An IBM 286/386 computer with a graphics card (VGA) and bidirectional parallel port is used for the DDD; an eight-bit microprocessor card and an A/D convertor card make up the DCD. A real-time multitasking operating system was written to control the DDD, while the DCD operates from in-line assembly code. The DCD samples the pressure and flow sensors at 100 Hz and looks for a complete flow waveform pattern based on flow slope. These waveforms are then passed to the DDD via the mutual parallel port. Within the DDD a process integrates the flow to create a volume signal and performs a multilinear regression on the pressure, flow, and volume data to calculate the elastance, resistance, pressure offset, and coefficient of determination. Elastance, resistance, and offset are used to calculate Pr and Pc where: Pr[k] = P[k]-offset-(elastance.V[k]) and Pc[k] = P[k]-offset-(resistance.F[k]). Volume vs. Pc and flow vs. Pr can be displayed in real time. Patient data from previous clinical tests were loaded into the device to verify the software calculations. An analog waveform generator was used to simulate flow and pressure waveforms that validated the system.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Estimation of soil properties and free product volume from baildown tests

    International Nuclear Information System (INIS)

    Zhu, J.L.; Parker, J.C.; Lundy, D.A.; Zimmerman, L.M.

    1993-01-01

    Baildown tests, involving measurement of water and free product levels in a monitoring well after bailing, are often performed at spill sites to estimate the oil volume per unit area -- which the authors refer to as ''oil specific volume.'' Spill volume is estimated by integrating oil specific volume over the areal domain of the spill. Existing methods for interpreting baildown tests are based on grossly simplistic approximations of soil capillary properties that cannot accurately describe the transient well response. A model for vertical equilibrium oil distributions based on the van Genuchten capillary model has been documented and verified in the laboratory and in the field by various authors. The model enables oil specific volume and oil transmissivity to be determined as functions of well product thickness. This paper describes a method for estimating van Genuchten capillary parameters, as well as aquifer hydraulic conductivity, from baildown tests. The results yield the relationships of oil specific volume and oil transmissivity to apparent product thickness, which may be used, in turn, to compute spill volume and to model free product plume movement and free product recovery. The method couples a finite element model for radial flow of oil and water to a well with a nonlinear parameter estimation algorithm. Effects of the filter pack around the well in the fluid level response are considered explicitly by the model. The method, which is implemented in the program BAILTEST, is applied to field data from baildown tests. The results indicate that hydrographs of water and oil levels are accurately described by the model

  13. Flow-induced vibration -- 1994. PVP-Volume 273

    International Nuclear Information System (INIS)

    Au-Yang, M.K.; Fujita, K.

    1994-01-01

    Flow-induced vibration is a subject of practical interest to many engineering disciplines, including the power generation, process, and petrochemical industries. In the nuclear industry, flow-induced vibration reaches a higher level of concern because of safety issues and the huge cost associated with down time and site repair. Not surprisingly, during the last 25 years a tremendous amount of effort has been spent in the study of flow-induced vibration phenomena related to nuclear plant components, notably nuclear steam generator tube banks and nuclear fuel bundles. Yet, in spite of this concentrated effort, the industry is still not free from flow-induced vibration-related problems. This explains why in this volume almost half of the papers address the issue of cross-flow induced vibration in tube bundles, with applications to the nuclear steam generator and nuclear fuel bundles in mind. Unlike 10 or 15 years ago, when flow-induced vibration studies almost always involved experimentation and empirical studies, the advent of high-speed computers has enabled numerical calculation and simulation of this complex phenomenon to take place. Separate abstracts were prepared for 27 papers in this volume

  14. A multicomponent tracer field experiment to measure the flow volume, surface area, and rectilinear spacing of fractures away from the wellbore

    Science.gov (United States)

    Cathles, L. M.; Sanford, W. E.; Hawkins, A.; Li, Y. V.

    2017-12-01

    The nature of flow in fractured porous media is important to almost all subsurface processes including oil and gas recovery, contaminant transport and remediation, CO2 sequestration, and geothermal heat extraction. One would like to know, under flowing conditions, the flow volume, surface area, effective aperture, and rectilinear spacing of fractures in a representative volume of rock away from the well bore, but no methods currently allow acquisition of this data. It could, however, be collected by deploying inert tracers with a wide range of aqueous diffusion constants (e.g., rapidly diffusing heat to non-diffusing nanoparticle) in the following fashion: The flow volume is defined by the heated volume measured by resistivity surveys. The fracture volume within this flow volume is indicate by the nanoparticle transit time. The average fracture spacing is indicated by the evolving thermal profile in the monitor and the production wells (measured by fiber optic cable), and by the retention of absorbing tracers. The average fracture aperture is determined by permeability measurements and the average fracture separation. We have proposed a field test to redundantly measure these fracture parameters in the fractured Dakota Sandstone where it approaches the surface in Ft Collins, Colorado. Five 30 m deep wells (an injection, production, and 3 monitor wells) cased to 20 m are proposed. The experiments will involve at least 9 different tracers. The planned field test and its potential significance will be described.

  15. Production performance laws of vertical wells by volume fracturing in CBM reservoirs

    Directory of Open Access Journals (Sweden)

    Liehui Zhang

    2017-05-01

    Full Text Available Volume fracturing technology has been widely applied in the development of coalbed methane (CBM reservoirs. As for the stimulated reservoir volume (SRV created by volume fracturing, the seepage laws of fluids are described more accurately and rationally in the rectangular composite model than in the traditional radial composite model. However, the rectangular composite model considering SRV cannot be solved using the analytical or semi-analytical function method, and its solution from the linear flow model has larger errors. In view of this, SRV areas of CBM reservoirs were described by means of dual-medium model in this paper. The complex CBM migration mechanisms were investigated comprehensively, including adsorption, desorption, diffusion and seepage. A well testing model for rectangular composite fracturing wells in CBM reservoirs based on unsteady-state diffusion was built and solved using the boundary element method combined with Laplace transformation, Stehfest numerical inversion and computer programming technology. Thus, production performance laws of CBM reservoirs were clarified. The flow regimes of typical well testing curves were divided and the effects on change laws of production performance from the boundary size of gas reservoirs, permeability of volume fractured areas, adsorption gas content, reservoir permeability and SRV size were analyzed. Eventually, CBM reservoirs after the volume fracturing stimulation were described more accurately and rationally. This study provides a theoretical basis for a better understanding of the CBM migration laws and an approach to evaluating and developing CBM reservoirs efficiently and rationally.

  16. Vector velocity volume flow estimation: Sources of error and corrections applied for arteriovenous fistulas

    DEFF Research Database (Denmark)

    Jensen, Jonas; Olesen, Jacob Bjerring; Stuart, Matthias Bo

    2016-01-01

    radius. The error sources were also studied in vivo under realistic clinical conditions, and the theoretical results were applied for correcting the volume flow errors. Twenty dialysis patients with arteriovenous fistulas were scanned to obtain vector flow maps of fistulas. When fitting an ellipsis......A method for vector velocity volume flow estimation is presented, along with an investigation of its sources of error and correction of actual volume flow measurements. Volume flow errors are quantified theoretically by numerical modeling, through flow phantom measurements, and studied in vivo...

  17. Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

    International Nuclear Information System (INIS)

    Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon

    2002-01-01

    To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

  18. Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon [Hallym University College of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

  19. Normal reference values for vertebral artery flow volume by color Doppler sonography in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Hyun Sook; Cha, Jang Gyu; Park, Seong Jin; Joh, Joon Hee; Park, Jai Soung; Kim, Dae Ho; Lee, Hae Kyung; Ahn, Hyun Cheol [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2003-09-15

    Vertebrobasilar ischemia has been attributed to a reduction of net vertebral artery flow volume. This study was to establish the reference values for the flow volume of the vertebral artery using color Doppler sonography in the normal Korea adults. Thirty five normal Korea adults without any underlying disease including hypertension, hyperlipidemia, diabetes, heart disease, obesity (body mas index>30), or carotid artery stenosis was included. There were 17 males and 18 females, age ranged from 20 to 53 years (average=32.86 years). Flow velocities and vessel diameters were recorded in the intertransverse (V2) segment, usually at C5-6 level, bilaterally. The flow volume (Q) was calculated. (Q=time averaged mean velocity x cross sectional area of vessel) A lower Flow velocity and smaller vessel diameter were measured on the right side compared to those of the left side, resulting in a lower flow volume. The calculated flow volumes using the equation were 77.0 +- 39.7 ml/min for the right side and 127.6 +- 71.0 ml/min for the left side (p=0.0001) while the net vertebral artery flow volume was 204.6 +- 81.8 ml/min. Decrease in the vertebral artery flow volume was statistically significant with advanced age. (r=-0.36, p=0.032). Vertebral artery blood flow volume was 191.20 +- 59.19 ml/min in male, and 217.28 +- 98.67 ml/min in female (p=0.6). The normal range for the net vertebral artery flow volume defined by the 5th to 95th percentiles was between 110.06 and 364.1 ml/min. The normal range for the net vertebral artery flow volume was between 110.06 and 364.1 ml/min. Vertebral artery flow volume decreased with the increase of age. However, gender did not affect the blood flow volume.

  20. Normal reference values for vertebral artery flow volume by color Doppler sonography in Korean adults

    International Nuclear Information System (INIS)

    Hong, Hyun Sook; Cha, Jang Gyu; Park, Seong Jin; Joh, Joon Hee; Park, Jai Soung; Kim, Dae Ho; Lee, Hae Kyung; Ahn, Hyun Cheol

    2003-01-01

    Vertebrobasilar ischemia has been attributed to a reduction of net vertebral artery flow volume. This study was to establish the reference values for the flow volume of the vertebral artery using color Doppler sonography in the normal Korea adults. Thirty five normal Korea adults without any underlying disease including hypertension, hyperlipidemia, diabetes, heart disease, obesity (body mas index>30), or carotid artery stenosis was included. There were 17 males and 18 females, age ranged from 20 to 53 years (average=32.86 years). Flow velocities and vessel diameters were recorded in the intertransverse (V2) segment, usually at C5-6 level, bilaterally. The flow volume (Q) was calculated. (Q=time averaged mean velocity x cross sectional area of vessel) A lower Flow velocity and smaller vessel diameter were measured on the right side compared to those of the left side, resulting in a lower flow volume. The calculated flow volumes using the equation were 77.0 ± 39.7 ml/min for the right side and 127.6 ± 71.0 ml/min for the left side (p=0.0001) while the net vertebral artery flow volume was 204.6 ± 81.8 ml/min. Decrease in the vertebral artery flow volume was statistically significant with advanced age. (r=-0.36, p=0.032). Vertebral artery blood flow volume was 191.20 ± 59.19 ml/min in male, and 217.28 ± 98.67 ml/min in female (p=0.6). The normal range for the net vertebral artery flow volume defined by the 5th to 95th percentiles was between 110.06 and 364.1 ml/min. The normal range for the net vertebral artery flow volume was between 110.06 and 364.1 ml/min. Vertebral artery flow volume decreased with the increase of age. However, gender did not affect the blood flow volume.

  1. Nonlinear flow model for well production in an underground formation

    Directory of Open Access Journals (Sweden)

    J. C. Guo

    2013-05-01

    Full Text Available Fluid flow in underground formations is a nonlinear process. In this article we modelled the nonlinear transient flow behaviour of well production in an underground formation. Based on Darcy's law and material balance equations, we used quadratic pressure gradients to deduce diffusion equations and discuss the origins of nonlinear flow issues. By introducing an effective-well-radius approach that considers skin factor, we established a nonlinear flow model for both gas and liquid (oil or water. The liquid flow model was solved using a semi-analytical method, while the gas flow model was solved using numerical simulations because the diffusion equation of gas flow is a stealth function of pressure. For liquid flow, a series of standard log-log type curves of pressure transients were plotted and nonlinear transient flow characteristics were analyzed. Qualitative and quantitative analyses were used to compare the solutions of the linear and nonlinear models. The effect of nonlinearity upon pressure transients should not be ignored. For gas flow, pressure transients were simulated and compared with oil flow under the same formation and well conditions, resulting in the conclusion that, under the same volume rate production, oil wells demand larger pressure drops than gas wells. Comparisons between theoretical data and field data show that nonlinear models will describe fluid flow in underground formations realistically and accurately.

  2. Identification of flow paths and quantification of return flow volumes and timing at field scale

    Science.gov (United States)

    Claes, N.; Paige, G. B.; Parsekian, A.

    2017-12-01

    Flood irrigation, which constitutes a large part of agricultural water use, accounts for a significant amount of the water that is diverted from western streams. Return flow, the portion of the water applied to irrigated areas that returns to the stream, is important for maintaining base flows in streams and ecological function of riparian zones and wetlands hydrologically linked with streams. Prediction of timing and volumes of return flow during and after flood irrigation pose a challenge due to the heterogeneity of pedogenic and soil physical factors that influence vadose zone processes. In this study, we quantify volumes of return flow and potential pathways in the subsurface through a vadose zone flow model that is informed by both hydrological and geophysical observations in a Bayesian setting. We couple a two-dimensional vadose zone flow model through a Bayesian Markov Chain Monte Carlo approach with time lapse ERT, borehole NMR datasets that are collected during and after flood irrigation experiments, and soil physical lab analysis. The combination of both synthetic models and field observations leads to flow path identification and allows for quantification of volumes and timing and associated uncertainties of subsurface return that stems from flood irrigation. The quantification of the impact of soil heterogeneity enables us to translate these results to other sites and predict return flow under different soil physical settings. This is key when managing irrigation water resources and predictions of outcomes of different scenarios have to be evaluated.

  3. Vector Volume Flow in Arteriovenous Fistulas

    DEFF Research Database (Denmark)

    Hansen, Peter Møller; Heerwagen, Søren; Pedersen, Mads Møller

    2013-01-01

    , but is very challenging due to the angle dependency of the Doppler technique and the anatomy of the fistula. The angle independent vector ultrasound technique Transverse Oscillation provides a new and more intuitive way to measure volume flow in an arteriovenous fistula. In this paper the Transverse...

  4. Influence of Gravity on Blood Volume and Flow Distribution

    Science.gov (United States)

    Pendergast, D.; Olszowka, A.; Bednarczyk, E.; Shykoff, B.; Farhi, L.

    1999-01-01

    In our previous experiments during NASA Shuttle flights SLS 1 and 2 (9-15 days) and EUROMIR flights (30-90 days) we observed that pulmonary blood flow (cardiac output) was elevated initially, and surprisingly remained elevated for the duration of the flights. Stroke volume increased initially and then decreased, but was still above 1 Gz values. As venous return was constant, the changes in SV were secondary to modulation of heart rate. Mean blood pressure was at or slightly below 1 Gz levels in space, indicating a decrease in total peripheral resistance. It has been suggested that plasma volume is reduced in space, however cardiac output/venous return do not return to 1 Gz levels over the duration of flight. In spite of the increased cardiac output, central venous pressure was not elevated in space. These data suggest that there is a change in the basic relationship between cardiac output and central venous pressure, a persistent "hyperperfusion" and a re-distribution of blood flow and volume during space flight. Increased pulmonary blood flow has been reported to increase diffusing capacity in space, presumably due to the improved homogeneity of ventilation and perfusion. Other studies have suggested that ventilation may be independent of gravity, and perfusion may not be gravity- dependent. No data for the distribution of pulmonary blood volume were available for flight or simulated microgravity. Recent studies have suggested that the pulmonary vascular tree is influenced by sympathetic tone in a manner similar to that of the systemic system. This implies that the pulmonary circulation is dilated during microgravity and that the distribution of blood flow and volume may be influenced more by vascular control than by gravity. The cerebral circulation is influenced by sympathetic tone similarly to that of the systemic and pulmonary circulations; however its effects are modulated by cerebral autoregulation. Thus it is difficult to predict if cerebral perfusion is

  5. Assessment of tidal volume and thoracoabdominal motion using volume and flow-oriented incentive spirometers in healthy subjects

    Directory of Open Access Journals (Sweden)

    V.F. Parreira

    2005-07-01

    Full Text Available The objective of the present study was to evaluate incentive spirometers using volume- (Coach and Voldyne and flow-oriented (Triflo II and Respirex devices. Sixteen healthy subjects, 24 ± 4 years, 62 ± 12 kg, were studied. Respiratory variables were obtained by respiratory inductive plethysmography, with subjects in a semi-reclined position (45º. Tidal volume, respiratory frequency, minute ventilation, inspiratory duty cycle, mean inspiratory flow, and thoracoabdominal motion were measured. Statistical analysis was performed with Kolmogorov-Smirnov test, t-test and ANOVA. Comparison between the Coach and Voldyne devices showed that larger values of tidal volume (1035 ± 268 vs 947 ± 268 ml, P = 0.02 and minute ventilation (9.07 ± 3.61 vs 7.49 ± 2.58 l/min, P = 0.01 were reached with Voldyne, whereas no significant differences in respiratory frequency were observed (7.85 ± 1.24 vs 8.57 ± 1.89 bpm. Comparison between flow-oriented devices showed larger values of inspiratory duty cycle and lower mean inspiratory flow with Triflo II (0.35 ± 0.05 vs 0.32 ± 0.05 ml/s, P = 0.00, and 531 ± 137 vs 606 ± 167 ml/s, P = 0.00, respectively. Abdominal motion was larger (P < 0.05 during the use of volume-oriented devices compared to flow-oriented devices (52 ± 11% for Coach and 50 ± 9% for Voldyne; 43 ± 13% for Triflo II and 44 ± 14% for Respirex. We observed that significantly higher tidal volume associated with low respiratory frequency was reached with Voldyne, and that there was a larger abdominal displacement with volume-oriented devices.

  6. MANAGING HIGH-END, HIGH-VOLUME INNOVATIVE PRODUCTS

    Directory of Open Access Journals (Sweden)

    Gembong Baskoro

    2008-01-01

    Full Text Available This paper discuses the concept of managing high-end, high-volume innovative products. High-end, high-volume consumer products are products that have considerable influence to the way of life. Characteristic of High-end, high-volume consumer products are (1 short cycle time, (2 quick obsolete time, and (3 rapid price erosion. Beside the disadvantages that they are high risk for manufacturers, if manufacturers are able to understand precisely the consumer needs then they have the potential benefit or success to be the market leader. High innovation implies to high utilization of the user, therefore these products can influence indirectly to the way of people life. The objective of managing them is to achieve sustainability of the products development and innovation. This paper observes the behavior of these products in companies operated in high-end, high-volume consumer product.

  7. Tracer responses and control of vessels with variable flow and volume

    International Nuclear Information System (INIS)

    Niemi, A.J.

    1990-01-01

    Continuous flow vessels which are subject to variation of flow and volume are characterized by time-variable parameters. It is shown that their residence time distributions and weighting functions obtained by tracer testing are made invariant with regard to the integrated flow variables which are introduced. Under variable flow but constant volume, one such integrated variable is sufficient. Under variable volume, two different variables are suggested for the residence time distribution and weighting function, while the appropriate variable of the perfect mixer differs distinctly from that of vessels with a distinct velocity profile. It is shown through a number of example cases, that an agreement with their mathematical models is reached. The approach is extended to include also arbitrary, non-analytic response functions obtained by tracer measurements. Applications of the derived models and their incorporation in automatic control algorithms is discussed. (orig.) [de

  8. Lung function in North American Indian children: reference standards for spirometry, maximal expiratory flow volume curves, and peak expiratory flow.

    Science.gov (United States)

    Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S

    1982-02-01

    Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.

  9. In vitro validation of a Pitot-based flow meter for the measurement of respiratory volume and flow in large animal anaesthesia.

    Science.gov (United States)

    Moens, Yves P S; Gootjes, Peter; Ionita, Jean-Claude; Heinonen, Erkki; Schatzmann, Urs

    2009-05-01

    To remodel and validate commercially available monitors and their Pitot tube-based flow sensors for use in large animals, using in vitro techniques. Prospective, in vitro experiment. Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied. Both the original and the remodelled sensor showed similar static flow-pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between -0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 +/- 0.2, range 5.91-6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity. The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia. This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia.

  10. Accuracy and Sources of Error for an Angle Independent Volume Flow Estimator

    DEFF Research Database (Denmark)

    Jensen, Jonas; Olesen, Jacob Bjerring; Hansen, Peter Møller

    2014-01-01

    This paper investigates sources of error for a vector velocity volume flow estimator. Quantification of the estima tor’s accuracy is performed theoretically and investigated in vivo . Womersley’s model for pulsatile flow is used to simulate velo city profiles and calculate volume flow errors....... A BK Medical UltraView 800 ultrasound scanner with a 9 MHz linear array transducer is used to obtain Vector Flow Imaging sequences of a superficial part of the fistulas. Cross-sectional diameters of each fistu la are measured on B-mode images by rotating the scan plane 90 degrees. The major axis...

  11. Volume of the steady-state space of financial flows in a monetary stock-flow-consistent model

    Science.gov (United States)

    Hazan, Aurélien

    2017-05-01

    We show that a steady-state stock-flow consistent macro-economic model can be represented as a Constraint Satisfaction Problem (CSP). The set of solutions is a polytope, which volume depends on the constraints applied and reveals the potential fragility of the economic circuit, with no need to study the dynamics. Several methods to compute the volume are compared, inspired by operations research methods and the analysis of metabolic networks, both exact and approximate. We also introduce a random transaction matrix, and study the particular case of linear flows with respect to money stocks.

  12. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    International Nuclear Information System (INIS)

    Meng, Yiqing; Lucas, Gary P

    2017-01-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas–water and oil–gas–water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the

  13. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    Science.gov (United States)

    Meng, Yiqing; Lucas, Gary P.

    2017-05-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water

  14. Fluid mechanics experiments in oscillatory flow. Volume 1

    International Nuclear Information System (INIS)

    Seume, J.; Friedman, G.; Simon, T.W.

    1992-03-01

    Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re max , Re W , and A R , embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation)

  15. Control volume based modelling of compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2004-01-01

    , and multidimensional effects must be calculated using empirical correlations; correlations for steady state flow can be used as an approximation. A transformation that assumes ideal gas is presented for transforming equations for masses and energies in control volumes into the corresponding pressures and temperatures......An approach to modelling unsteady compressible flow that is primarily one dimensional is presented. The approach was developed for creating distributed models of machines with reciprocating pistons but it is not limited to this application. The approach is based on the integral form of the unsteady...... conservation laws for mass, energy, and momentum applied to a staggered mesh consisting of two overlapping strings of control volumes. Loss mechanisms can be included directly in the governing equations of models by including them as terms in the conservation laws. Heat transfer, flow friction...

  16. Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates

    Science.gov (United States)

    Pedersen, G. B. M.; Belart, J. M. C.; Magnússon, E.; Vilmundardóttir, O. K.; Kizel, F.; Sigurmundsson, F. S.; Gísladóttir, G.; Benediktsson, J. A.

    2018-02-01

    Lava flow thicknesses, volumes, and effusion rates provide essential information for understanding the behavior of eruptions and their associated deformation signals. Preeruption and posteruption elevation models were generated from historical stereo photographs to produce the lava flow thickness maps for the last five eruptions at Hekla volcano, Iceland. These results provide precise estimation of lava bulk volumes: V1947-1948 = 0.742 ± 0.138 km3, V1970 = 0.205 ± 0.012 km3, V1980-1981 = 0.169 ± 0.016 km3, V1991 = 0.241 ± 0.019 km3, and V2000 = 0.095 ± 0.005 km3 and reveal variable production rate through the 20th century. These new volumes improve the linear correlation between erupted volume and coeruption tilt change, indicating that tilt may be used to determine eruption volume. During eruptions the active vents migrate 325-480 m downhill, suggesting rough excess pressures of 8-12 MPa and that the gradient of this excess pressure increases from 0.4 to 11 Pa s-1 during the 20th century. We suggest that this is related to increased resistance along the eruptive conduit.

  17. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine

    2000-10-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year ({delta}D) were significantly greater than in groups R and B (%TFV: 74.1{+-}0.07 vs 15.2{+-}0.03 vs 11.8{+-}0.04, p<0.01; {delta}D: 3.62{+-}0.82 vs 0 vs 0.58{+-}0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and {delta}D (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  18. Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs

    Directory of Open Access Journals (Sweden)

    Santiago Jr. A.T.

    1997-01-01

    Full Text Available We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon, perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight and controlled hemorrhage (up to a 50% drop in mean arterial pressure. Mean ileocolonic flow (N = 6 was gradually and significantly decreased during the expansion (17.1%, P<0.05 and expanded (44.9%, P<0.05 periods while mean ileal flow (N = 7 was significantly decreased only during the expanded period (38%, P<0.05. Mean colonic flow (N = 7 was decreased during expansion (12%, P<0.05 but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6 was not significantly modified. Mean ileocolonic flow (N = 10 was also decreased after hemorrhage (retracted period by 17% (P<0.05, but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively. The expansion effect was blocked by atropine (0.5 mg/kg, iv both on the ileocolonic (N = 6 and ileal (N = 5 circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.

  19. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki

    2000-01-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year (ΔD) were significantly greater than in groups R and B (%TFV: 74.1±0.07 vs 15.2±0.03 vs 11.8±0.04, p<0.01; ΔD: 3.62±0.82 vs 0 vs 0.58±0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and ΔD (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  20. Quantitative analysis of normal fetal brain volume and flow by three-dimensional power Doppler ultrasound

    Directory of Open Access Journals (Sweden)

    Ju-Chun Hsu

    2013-09-01

    Conclusion: 3D ultrasound can be used to assess the fetal brain volume and blood flow development quantitatively. Our study indicates that the fetal brain vascularization and blood flow correlates significantly with the advancement of GA. This information may serve as a reference point for further studies of the fetal brain volume and blood flow in abnormal conditions.

  1. Small volume target for F-18 production

    Science.gov (United States)

    Pellicioli, M.; Schuler, J.; Marchand, P.; Brasse, D.

    2017-05-01

    In order to reduce the volume of O-18 enriched water used for each F-18 production for research a small volume target of 1 ml has been designed at IPHC. The designed is derived from ACSI 3.8ml F-18 target and uses both water and Helium cooling. After one year of use production yield is reported.

  2. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    International Nuclear Information System (INIS)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D'Ippolito, Giuseppe; Colleoni, Ramiro

    2008-01-01

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  3. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

    2008-09-15

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  4. Connection between encounter volume and diffusivity in geophysical flows

    Science.gov (United States)

    Rypina, Irina I.; Smith, Stefan G. Llewellyn; Pratt, Larry J.

    2018-04-01

    Trajectory encounter volume - the volume of fluid that passes close to a reference fluid parcel over some time interval - has been recently introduced as a measure of mixing potential of a flow. Diffusivity is the most commonly used characteristic of turbulent diffusion. We derive the analytical relationship between the encounter volume and diffusivity under the assumption of an isotropic random walk, i.e., diffusive motion, in one and two dimensions. We apply the derived formulas to produce maps of encounter volume and the corresponding diffusivity in the Gulf Stream region of the North Atlantic based on satellite altimetry, and discuss the mixing properties of Gulf Stream rings. Advantages offered by the derived formula for estimating diffusivity from oceanographic data are discussed, as well as applications to other disciplines.

  5. High Volume Manufacturing and Field Stability of MEMS Products

    Science.gov (United States)

    Martin, Jack

    Low volume MEMS/NEMS production is practical when an attractive concept is implemented with business, manufacturing, packaging, and test support. Moving beyond this to high volume production adds requirements on design, process control, quality, product stability, market size, market maturity, capital investment, and business systems. In a broad sense, this chapter uses a case study approach: It describes and compares the silicon-based MEMS accelerometers, pressure sensors, image projection systems, and gyroscopes that are in high volume production. Although they serve several markets, these businesses have common characteristics. For example, the manufacturing lines use automated semiconductor equipment and standard material sets to make consistent products in large quantities. Standard, well controlled processes are sometimes modified for a MEMS product. However, novel processes that cannot run with standard equipment and material sets are avoided when possible. This reliance on semiconductor tools, as well as the organizational practices required to manufacture clean, particle-free products partially explains why the MEMS market leaders are integrated circuit manufacturers. There are other factors. MEMS and NEMS are enabling technologies, so it can take several years for high volume applications to develop. Indeed, market size is usually a strong function of price. This becomes a vicious circle, because low price requires low cost - a result that is normally achieved only after a product is in high volume production. During the early years, IC companies reduced cost and financial risk by using existing facilities for low volume MEMS production. As a result, product architectures are partially determined by capabilities developed for previous products. This chapter includes a discussion of MEMS product architecture with particular attention to the impact of electronic integration, packaging, and surfaces. Packaging and testing are critical, because they are

  6. Estimating the system price of redox flow batteries for grid storage

    Science.gov (United States)

    Ha, Seungbum; Gallagher, Kevin G.

    2015-11-01

    Low-cost energy storage systems are required to support extensive deployment of intermittent renewable energy on the electricity grid. Redox flow batteries have potential advantages to meet the stringent cost target for grid applications as compared to more traditional batteries based on an enclosed architecture. However, the manufacturing process and therefore potential high-volume production price of redox flow batteries is largely unquantified. We present a comprehensive assessment of a prospective production process for aqueous all vanadium flow battery and nonaqueous lithium polysulfide flow battery. The estimated investment and variable costs are translated to fixed expenses, profit, and warranty as a function of production volume. When compared to lithium-ion batteries, redox flow batteries are estimated to exhibit lower costs of manufacture, here calculated as the unit price less materials costs, owing to their simpler reactor (cell) design, lower required area, and thus simpler manufacturing process. Redox flow batteries are also projected to achieve the majority of manufacturing scale benefits at lower production volumes as compared to lithium-ion. However, this advantage is offset due to the dramatically lower present production volume of flow batteries compared to competitive technologies such as lithium-ion.

  7. Effective diffusion volume flow rates (Qe) for urea, creatinine, and inorganic phosphorous (Qeu, Qecr, QeiP) during hemodialysis.

    Science.gov (United States)

    Gotch, Frank A; Panlilio, Froilan; Sergeyeva, Olga; Rosales, Laura; Folden, Tom; Kaysen, George; Levin, Nathan

    2003-01-01

    In vivo solute clearances can be estimated from dialyzer blood (Qb) and dialysate (Qd) flow rates and a solute- and dialyzer-specific overall permeability membrane area product (KoA). However, these calculations require knowledge of the flow rate of the effective solute distribution volume in the flowing bloodstream (Qe) in order to calculate in vivo clearances and KoAs. We have determined Qe for urea, creatinine, and inorganic phosphorus from changes in concentrations across the blood compartment and mass balance between the blood and dialysate streams. We made four serial measurements over one dialysis in 23 patients and found that Qeu equals the total blood water flow rate, Qecr equals the plasma water flow rate plus 61% of red cell water flow rate, and QeiP is limited to the plasma water flow rate. Equations are derived to calculate Qe for each of these solutes from Qb and hematocrit and in vivo KoAs for each solute were calculated.

  8. Volume fraction prediction in biphasic flow using nuclear technique and artificial neural network

    International Nuclear Information System (INIS)

    Salgado, Cesar M.; Brandao, Luis E.B.

    2015-01-01

    The volume fraction is one of the most important parameters used to characterize air-liquid two-phase flows. It is a physical value to determine other parameters, such as the phase's densities and to determine the flow rate of each phase. These parameters are important to predict the flow pattern and to determine a mathematical model for the system. To study, for example, heat transfer and pressure drop. This work presents a methodology for volume fractions prediction in water-gas stratified flow regime using the nuclear technique and artificial intelligence. The volume fractions calculate in biphasic flow systems is complex and the analysis by means of analytical equations becomes very difficult. The approach is based on gamma-ray pulse height distributions pattern recognition by means of the artificial neural network. The detection system uses appropriate broad beam geometry, comprised of a ( 137 Cs) energy gamma-ray source and a NaI(Tl) scintillation detector in order measure transmitted beam whose the counts rates are influenced by the phases composition. These distributions are directly used by the network without any parameterization of the measured signal. The ideal and static theoretical models for stratified regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the network. The detector also was modeled with this code and the results were compared to experimental photopeak efficiency measurements of radiation sources. The proposed network could obtain with satisfactory prediction of the volume fraction in water-gas system, demonstrating to be a promising approach for this purpose. (author)

  9. Volume fraction prediction in biphasic flow using nuclear technique and artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Cesar M.; Brandao, Luis E.B., E-mail: otero@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The volume fraction is one of the most important parameters used to characterize air-liquid two-phase flows. It is a physical value to determine other parameters, such as the phase's densities and to determine the flow rate of each phase. These parameters are important to predict the flow pattern and to determine a mathematical model for the system. To study, for example, heat transfer and pressure drop. This work presents a methodology for volume fractions prediction in water-gas stratified flow regime using the nuclear technique and artificial intelligence. The volume fractions calculate in biphasic flow systems is complex and the analysis by means of analytical equations becomes very difficult. The approach is based on gamma-ray pulse height distributions pattern recognition by means of the artificial neural network. The detection system uses appropriate broad beam geometry, comprised of a ({sup 137}Cs) energy gamma-ray source and a NaI(Tl) scintillation detector in order measure transmitted beam whose the counts rates are influenced by the phases composition. These distributions are directly used by the network without any parameterization of the measured signal. The ideal and static theoretical models for stratified regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the network. The detector also was modeled with this code and the results were compared to experimental photopeak efficiency measurements of radiation sources. The proposed network could obtain with satisfactory prediction of the volume fraction in water-gas system, demonstrating to be a promising approach for this purpose. (author)

  10. Gated CT imaging using a free-breathing respiration signal from flow-volume spirometry

    International Nuclear Information System (INIS)

    D'Souza, Warren D.; Kwok, Young; Deyoung, Chad; Zacharapoulos, Nicholas; Pepelea, Mark; Klahr, Paul; Yu, Cedric X.

    2005-01-01

    Respiration-induced tumor motion is known to cause artifacts on free-breathing spiral CT images used in treatment planning. This leads to inaccurate delineation of target volumes on planning CT images. Flow-volume spirometry has been used previously for breath-holds during CT scans and radiation treatments using the active breathing control (ABC) system. We have developed a prototype by extending the flow-volume spirometer device to obtain gated CT scans using a PQ 5000 single-slice CT scanner. To test our prototype, we designed motion phantoms to compare image quality obtained with and without gated CT scan acquisition. Spiral and axial (nongated and gated) CT scans were obtained of phantoms with motion periods of 3-5 s and amplitudes of 0.5-2 cm. Errors observed in the volume estimate of these structures were as much as 30% with moving phantoms during CT simulation. Application of motion-gated CT with active breathing control reduced these errors to within 5%. Motion-gated CT was then implemented in patients and the results are presented for two clinical cases: lung and abdomen. In each case, gated scans were acquired at end-inhalation, end-exhalation in addition to a conventional free-breathing (nongated) scan. The gated CT scans revealed reduced artifacts compared with the conventional free-breathing scan. Differences of up to 20% in the volume of the structures were observed between gated and free-breathing scans. A comparison of the overlap of structures between the gated and free-breathing scans revealed misalignment of the structures. These results demonstrate the ability of flow-volume spirometry to reduce errors in target volumes via gating during CT imaging

  11. Inductive flow meter for measuring the speed of flow and gas volume contained in a flow of liquid metal

    International Nuclear Information System (INIS)

    Mueller, S.

    1980-01-01

    The speed of flow of the sodium is measured in two closely adjacent flow crossections using pairs of electrodes in the field of two disc-shaped permanent magnets made of AlNiCo 450, by means of measurements of running time of speed fluctuations. The result of the measurement is independent of the temperature of the sensor and the temperature of the sodium. The same arrangement makes it possible to determine the proportion by volume of the fission gas in sodium with a limiting freequency of several kHz. (DG) [de

  12. Blood flow and blood volume in a transplanted rat fibrosarcoma

    International Nuclear Information System (INIS)

    Tozer, G.M.; Morris, C.C.

    1990-01-01

    Blood flow measurements following i.v. infusion of iodi-antipyrine labelled with 14 C ( 14 C-IAP) and blood volume measurements following i.v. injection of 125 I human serum albumin and 51 Cr-labelled red blood cells were made in a transplanted rat fibrosarcoma for comparison with various normal tissues. The tumour-blood partition co-efficient for 14 C-IAP w as found to be 0.79 ± 0.07 which is similar to most of the normal tissues studied. The solubility of 14 C-IAP in plasma was found to be higher than that in whole blood. Blood flow to tumours 3 was found to be 17.9 ± 4.0 ml blood 100 g tissue -1 xmin -1 . These values were considered to be primarily measurements of nutritive flow. Blood in the tumours was found to occupy around 1% of the tissue space which was similar to that found for normal muscle and skin. There was no direct correlation between % blood volume and blood flow for the different tissues studied. Th haematocrit of blood contained in tumour tissue was calculated to be significantly lower than that of blood contained in the normal tissues. It was suspected that permeability of tumour blood vessel walls to 125 I-HSA could have accounted for this difference. (author). 41 refs.; 2 figs.; 3 tabs

  13. Measurement of volume and flow in the digestive tract

    International Nuclear Information System (INIS)

    Dixon, R.M.; Kennedy, P.M.; Milligan, L.P.

    1983-01-01

    Measurement of digesta volume and flow in the gastro-intestinal tract of ruminants may be achieved by either of two methods. The first involves total recovery of digesta through a cannula with gravimetric and physical (sieving) analysis. Alternatively, the flow of digesta may be estimated by reference to markers, with digesta samples taken through a T-shaped or re-entral intestinal cannula. The second approach assumes steady nutritional conditions, with the movement of digesta fractions estimated from the disappearance of specific markers. The adequacy of markers currently available for this purpose is discussed. Advantages of complementary techniques are emphasized. (author)

  14. Effects of Anti-VEGF on Predicted Antibody Biodistribution: Roles of Vascular Volume, Interstitial Volume, and Blood Flow

    Science.gov (United States)

    Boswell, C. Andrew; Ferl, Gregory Z.; Mundo, Eduardo E.; Bumbaca, Daniela; Schweiger, Michelle G.; Theil, Frank-Peter; Fielder, Paul J.; Khawli, Leslie A.

    2011-01-01

    Background The identification of clinically meaningful and predictive models of disposition kinetics for cancer therapeutics is an ongoing pursuit in drug development. In particular, the growing interest in preclinical evaluation of anti-angiogenic agents alone or in combination with other drugs requires a complete understanding of the associated physiological consequences. Methodology/Principal Findings Technescan™ PYP™, a clinically utilized radiopharmaceutical, was used to measure tissue vascular volumes in beige nude mice that were naïve or administered a single intravenous bolus dose of a murine anti-vascular endothelial growth factor (anti-VEGF) antibody (10 mg/kg) 24 h prior to assay. Anti-VEGF had no significant effect (p>0.05) on the fractional vascular volumes of any tissues studied; these findings were further supported by single photon emission computed tomographic imaging. In addition, apart from a borderline significant increase (p = 0.048) in mean hepatic blood flow, no significant anti-VEGF-induced differences were observed (p>0.05) in two additional physiological parameters, interstitial fluid volume and the organ blood flow rate, measured using indium-111-pentetate and rubidium-86 chloride, respectively. Areas under the concentration-time curves generated by a physiologically-based pharmacokinetic model changed substantially (>25%) in several tissues when model parameters describing compartmental volumes and blood flow rates were switched from literature to our experimentally derived values. However, negligible changes in predicted tissue exposure were observed when comparing simulations based on parameters measured in naïve versus anti-VEGF-administered mice. Conclusions/Significance These observations may foster an enhanced understanding of anti-VEGF effects in murine tissues and, in particular, may be useful in modeling antibody uptake alone or in combination with anti-VEGF. PMID:21436893

  15. High Production Volume Information System (HPVIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The High Production Volume Information System (HPVIS) provides access to select health and environmental effect information on chemicals that are manufactured in...

  16. Measurement of hepatic volume and effective blood flow with radioactive colloids: Evaluation of development in liver diseases

    International Nuclear Information System (INIS)

    Fujii, M.; Uchino, H.; Kyoto Univ.

    1982-01-01

    Changes in hepatic volume and the blood flow effectively perfusing the liver parenchyma were studied as an assessment of the severity of liver diseases. Hepatic effective blood flow was estimated as the hepatic fractional clearance of radioactive colloids, obtained from the disappearance rate multiplied by the fraction of injected dose taken up by the liver. The hepatic fractional clearance was normal or not markedly decreased in patients with acute hepatitis which had developed favorably, but was severely decreased in patients with fulminant hepatitis. In liver diseases, the ratio of hepatic volume to fractional clearance was found to increase as the clearance decreased. In subjects with normal clearance, hepatic fractional clearance was correlated significantly with liver volume, indicating that hepatic effective blood flow is proportional to parenchymal volume in an unanesthetized, resting state. In biopsied cases changes in volume and blood flow accorded well with changes indicated by morphological criteria. In chronic persistent hepatitis, effective hepatic blood flow is not diminished. However, hepatic blood flow were observed between the cirrhosis or chronic aggressive hepatitis, and normal control groups. Extension of chronic inflammatory infiltration into the parenchyma distinguishes chronic aggressive hepatitis from chronic persistent hepatitis. Architecture is often disturbed in the former. These changes should be accompanied by disturbance of microcirculation. The present study indicates that the decrease in effective hepatic blood flow in chronic hepatitis and cirrhosis has two aspects: one is a summation of microcirculatory disturbances, and the other is a decrease in liver cell mass. (orig.)

  17. Control-volume-based model of the steam-water injector flow

    Science.gov (United States)

    Kwidziński, Roman

    2010-03-01

    The paper presents equations of a mathematical model to calculate flow parameters in characteristic cross-sections in the steam-water injector. In the model, component parts of the injector (steam nozzle, water nozzle, mixing chamber, condensation wave region, diffuser) are treated as a series of connected control volumes. At first, equations for the steam nozzle and water nozzle are written and solved for known flow parameters at the injector inlet. Next, the flow properties in two-phase flow comprising mixing chamber and condensation wave region are determined from mass, momentum and energy balance equations. Then, water compression in diffuser is taken into account to evaluate the flow parameters at the injector outlet. Irreversible losses due to friction, condensation and shock wave formation are taken into account for the flow in the steam nozzle. In two-phase flow domain, thermal and mechanical nonequilibrium between vapour and liquid is modelled. For diffuser, frictional pressure loss is considered. Comparison of the model predictions with experimental data shows good agreement, with an error not exceeding 15% for discharge (outlet) pressure and 1 K for outlet temperature.

  18. Expiratory flow limitation and operating lung volumes during exercise in older and younger adults.

    Science.gov (United States)

    Smith, Joshua R; Kurti, Stephanie P; Meskimen, Kayla; Harms, Craig A

    2017-06-01

    We determined the effect of aging on expiratory flow limitation (EFL) and operating lung volumes when matched for lung size. We hypothesized that older adults will exhibit greater EFL and increases in EELV during exercise compared to younger controls. Ten older (5M/5W; >60years old) and nineteen height-matched young adults (10M/9W) were recruited. Young adults were matched for%predicted forced vital capacity (FVC) (Y-matched%Pred FVC; n=10) and absolute FVC (Y-matched FVC; n=10). Tidal flow-volume loops were recorded during the incremental exercise test with maximal flow-volume loops measured pre- and post-exercise. Compared to younger controls, older adults exhibited more EFL at ventilations of 26, 35, 51, and 80L/min. The older group had higher end-inspiratory lung volume compared to Y-matched%Pred FVC group during submaximal ventilations. The older group increased EELV during exercise, while EELV stayed below resting in the Y-matched%Pred FVC group. These data suggest older adults exhibit more EFL and increase EELV earlier during exercise compared to younger adults. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Biological hydrogen production by Clostridium acetobutylicum in an unsaturated flow reactor.

    Science.gov (United States)

    Zhang, Husen; Bruns, Mary Ann; Logan, Bruce E

    2006-02-01

    A mesophilic unsaturated flow (trickle bed) reactor was designed and tested for H2 production via fermentation of glucose. The reactor consisted of a column packed with glass beads and inoculated with a pure culture (Clostridium acetobutylicum ATCC 824). A defined medium containing glucose was fed at a flow rate of 1.6 mL/min (0.096 L/h) into the capped reactor, producing a hydraulic retention time of 2.1 min. Gas-phase H2 concentrations were constant, averaging 74 +/- 3% for all conditions tested. H2 production rates increased from 89 to 220 mL/hL of reactor when influent glucose concentrations were varied from 1.0 to 10.5 g/L. Specific H2 production rate ranged from 680 to 1270 mL/g glucose per liter of reactor (total volume). The H2 yield was 15-27%, based on a theoretical limit by fermentation of 4 moles of H2 from 1 mole of glucose. The major fermentation by-products in the liquid effluent were acetate and butyrate. The reactor rapidly (within 60-72 h) became clogged with biomass, requiring manual cleaning of the system. In order to make long-term operation of the reactor feasible, biofilm accumulation in the reactor will need to be controlled through some process such as backwashing. These tests using an unsaturated flow reactor demonstrate the feasibility of the process to produce high H2 gas concentrations in a trickle-bed type of reactor. A likely application of this reactor technology could be H2 gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

  20. Role of Doppler ultrasonography evaluation of superior mesenteric artery flow volume in the assessment of Crohn's disease activity

    Directory of Open Access Journals (Sweden)

    Fabiana Paiva Martins

    2013-09-01

    Full Text Available Objective To investigate superior mesenteric artery flow measurement by Doppler ultrasonography as a means of characterizing inflammatory activity in Crohn's disease. Materials and Methods Forty patients were examined and divided into two groups – disease activity and remission – according to their Crohn's disease activity index score. Mean superior mesenteric artery flow volume was calculated for each group and correlated with Crohn's disease activity index score. Results The mean superior mesenteric artery flow volume was significantly greater in the patients with active disease (626 ml/min ± 236 × 376 ml/min ± 190; p = 0.001. As a cut off corresponding to 500 ml/min was utilized, the superior mesenteric artery flow volume demonstrated sensitivity of 83% and specificity of 82% for the diagnosis of Crohn's disease activity. Conclusion The present results suggest that patients with active Crohn's disease have increased superior mesenteric artery flow volume as compared with patients in remission. Superior mesenteric artery flow measurement had a good performance in the assessment of disease activity in this study sample.

  1. Electrokinetic pumping and detection of low-volume flows in nanochannels

    NARCIS (Netherlands)

    Mela, P.; Tas, Niels Roelof; Berenschot, Johan W.; van Nieuwkasteele, Jan William; van den Berg, Albert

    2004-01-01

    Electrokinetic pumping of low-volume rates was performed on-chip in channels of small cross sectional area and height in the sub-m range. The flow was detected with the current monitoring technique by monitoring the change in resistance of the fluid in the channel upon the electroosmosis-driven

  2. Flow simulation of a Pelton bucket using finite volume particle method

    International Nuclear Information System (INIS)

    Vessaz, C; Jahanbakhsh, E; Avellan, F

    2014-01-01

    The objective of the present paper is to perform an accurate numerical simulation of the high-speed water jet impinging on a Pelton bucket. To reach this goal, the Finite Volume Particle Method (FVPM) is used to discretize the governing equations. FVPM is an arbitrary Lagrangian-Eulerian method, which combines attractive features of Smoothed Particle Hydrodynamics and conventional mesh-based Finite Volume Method. This method is able to satisfy free surface and no-slip wall boundary conditions precisely. The fluid flow is assumed weakly compressible and the wall boundary is represented by one layer of particles located on the bucket surface. In the present study, the simulations of the flow in a stationary bucket are investigated for three different impinging angles: 72°, 90° and 108°. The particles resolution is first validated by a convergence study. Then, the FVPM results are validated with available experimental data and conventional grid-based Volume Of Fluid simulations. It is shown that the wall pressure field is in good agreement with the experimental and numerical data. Finally, the torque evolution and water sheet location are presented for a simulation of five rotating Pelton buckets

  3. Fluid mechanics experiments in oscillatory flow. Volume 1: Report

    Science.gov (United States)

    Seume, J.; Friedman, G.; Simon, T. W.

    1992-01-01

    Results of a fluid mechanics measurement program in oscillating flow within a circular duct are presented. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re(sub max), Re(sub w), and A(sub R), embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radial components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and its reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. Volume 1 contains the text of the report including figures and supporting appendices. Volume 2 contains data reduction program listings and tabulated data (including its graphical presentation).

  4. A volume-filtered formulation to capture particle-shock interactions in multiphase compressible flows

    Science.gov (United States)

    Shallcross, Gregory; Capecelatro, Jesse

    2017-11-01

    Compressible particle-laden flows are common in engineering systems. Applications include but are not limited to water injection in high-speed jet flows for noise suppression, rocket-plume surface interactions during planetary landing, and explosions during coal mining operations. Numerically, it is challenging to capture these interactions due to the wide range of length and time scales. Additionally, there are many forms of the multiphase compressible flow equations with volume fraction effects, some of which are conflicting in nature. The purpose of this presentation is to develop the capability to accurately capture particle-shock interactions in systems with a large number of particles from dense to dilute regimes. A thorough derivation of the volume filtered equations is presented. The volume filtered equations are then implemented in a high-order, energy-stable Eulerian-Lagrangian framework. We show this framework is capable of decoupling the fluid mesh from the particle size, enabling arbitrary particle size distributions in the presence of shocks. The proposed method is then assessed against particle-laden shock tube data. Quantities of interest include fluid-phase pressure profiles and particle spreading rates. The effect of collisions in 2D and 3D are also evaluated.

  5. Applied multiphase flow in pipes and flow assurance oil and gas production

    CERN Document Server

    Al-Safran, Eissa M

    2017-01-01

    Applied Multiphase Flow in Pipes and Flow Assurance - Oil and Gas Production delivers the most recent advancements in multiphase flow technology while remaining easy to read and appropriate for undergraduate and graduate petroleum engineering students. Responding to the need for a more up-to-the-minute resource, this highly anticipated new book represents applications on the fundamentals with new material on heat transfer in production systems, flow assurance, transient multiphase flow in pipes and the TUFFP unified model. The complex computation procedure of mechanistic models is simplified through solution flowcharts and several example problems. Containing over 50 solved example problems and 140 homework problems, this new book will equip engineers with the skills necessary to use the latest steady-state simulators available.

  6. Can flow-volume loops be used to diagnose exerciseinduced laryngeal obstructions?

    DEFF Research Database (Denmark)

    Christensen, Pernille Melia; Maltbæk, Niels; Jørgensen, Inger M

    2013-01-01

    BACKGROUND: Pre- and post-exercise flow-volume loops are often recommended as an easy non-invasive method for diagnosing or excluding exercise-induced laryngeal obstructions in patients with exercise-related respiratory symptoms. However, at present there is no evidence for this recommendation...

  7. Measurement of regional pulmonary blood volume in patients with increased pulmonary blood flow or pulmonary arterial hypertension

    International Nuclear Information System (INIS)

    Wollmer, P.; Rozcovek, A.; Rhodes, C.G.; Allan, R.M.; Maseri, A.

    1984-01-01

    The effects of chronic increase in pulmonary blood flow and chronic pulmonary hypertension on regional pulmonary blood volume was measured in two groups of patients. One group of patients had intracardiac, left-to-right shunts without appreciable pulmonary hypertension, and the other consisted of patients with Eisenmenger's syndrome or primary pulmonary hypertension, i.e. patients with normal or reduced blood flow and severe pulmonary hypertension. A technique based on positron tomography was used to measure lung density (by transmission scanning) and regional pulmonary blood volume (after inhalation of /sup 11/CO). The distribution of pulmonary blood volume was more uniform in patients with chronic increase in pulmonary blood flow than in normal subjects. There were also indications of an absolute increase in intrapulmonary blood volume by about 15%. In patients with chronic pulmonary arterial hypertension, the distribution of pulmonary blood volume was also abnormally uniform. There was, however, no indication that overall intrapulmonary blood volume was substantially different from normal subjects. The abnormally uniform distribution of pulmonary blood volume can be explained by recruitment and/or dilatation of vascular beds. Intrapulmonary blood volume appears to be increased in patients with intracardiac, left-to-right shunts. With the development of pulmonary hypertension, intrapulmonary blood volume falls, which may be explained by reactive changes in the vasculature and/or obliteration of capillaries

  8. Relationship between spontaneous expiratory flow-volume curve pattern and air-flow obstruction in elderly COPD patients.

    Science.gov (United States)

    Nozoe, Masafumi; Mase, Kyoshi; Murakami, Shigefumi; Okada, Makoto; Ogino, Tomoyuki; Matsushita, Kazuhiro; Takashima, Sachie; Yamamoto, Noriyasu; Fukuda, Yoshihiro; Domen, Kazuhisa

    2013-10-01

    Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV(1) 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV(1)% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.

  9. Quantitative analysis of normal fetal medulla oblongata volume and flow by three-dimensional power Doppler ultrasound.

    Science.gov (United States)

    Shyu, Ing-Luen; Wang, Peng-Hui; Chen, Chih-Yao; Chen, Yi-Jen; Chang, Chia-Ming; Horng, Huann-Cheng; Yang, Ming-Jie; Yen, Ming-Shyen

    2016-06-01

    Assessment of the fetal medulla oblongata volume (MOV) and blood flow might be important in the evaluation of fetal brain growth. We used three-dimensional power Doppler ultrasound (3DPDUS) to assess the fetal MOV and blood flow index in normal gestation. The relationships between these parameters were further analyzed. We assessed the total volume and blood flow index of the fetal MO in normal pregnancies using a 3DPDUS (Voluson 730 Expert). The true sagittal plane over the fetal occipital area was measured by a 3D transabdominal probe to scan the fetal MO under the power Doppler mode. Then, we quantitatively assessed the total volume of the fetal MOV, mean gray area (MG), vascularization index (VI), and flow index (FI). A total of 106 fetuses, ranging from 19 weeks to 39 weeks of gestation, were involved in our study. The volume of the fetal MO was highly positively correlated with gestational age [correlation coefficient (r) = 0.686, p < 0.0001]. The MG was negatively correlated with gestational age [r = -0.544, p < 0.0001). VI and FI showed no significant correlation with gestational age (p = 0.123 and p = 0.219, respectively). 3DPDUS can be used to assess the fetal MOV and blood flow development quantitatively. Our study indicated that fetal MOV and blood flow correlated significantly with the advancement of gestational age. This information may serve as reference data for further studies of the fetal brain and blood flow under abnormal conditions. Copyright © 2016. Published by Elsevier B.V.

  10. High-Volume Production of Lightweight Multijunction Solar Cells

    Science.gov (United States)

    Youtsey, Christopher

    2015-01-01

    MicroLink Devices, Inc., has transitioned its 6-inch epitaxial lift-off (ELO) solar cell fabrication process into a manufacturing platform capable of sustaining large-volume production. This Phase II project improves the ELO process by reducing cycle time and increasing the yield of large-area devices. In addition, all critical device fabrication processes have transitioned to 6-inch production tool sets designed for volume production. An emphasis on automated cassette-to-cassette and batch processes minimizes operator dependence and cell performance variability. MicroLink Devices established a pilot production line capable of at least 1,500 6-inch wafers per month at greater than 80 percent yield. The company also increased the yield and manufacturability of the 6-inch reclaim process, which is crucial to reducing the cost of the cells.

  11. Prediction of gas volume fraction in fully-developed gas-liquid flow in a vertical pipe

    International Nuclear Information System (INIS)

    Islam, A.S.M.A.; Adoo, N.A.; Bergstrom, D.J.; Wang, D.F.

    2015-01-01

    An Eulerian-Eulerian two-fluid model has been implemented for the prediction of the gas volume fraction profile in turbulent upward gas-liquid flow in a vertical pipe. The two-fluid transport equations are discretized using the finite volume method and a low Reynolds number κ-ε turbulence model is used to predict the turbulence field for the liquid phase. The contribution to the effective turbulence by the gas phase is modeled by a bubble induced turbulent viscosity. For the fully-developed flow being considered, the gas volume fraction profile is calculated using the radial momentum balance for the bubble phase. The model potentially includes the effect of bubble size on the interphase forces and turbulence model. The results obtained are in good agreement with experimental data from the literature. The one-dimensional formulation being developed allows for the efficient assessment and further development of both turbulence and two-fluid models for multiphase flow applications in the nuclear industry. (author)

  12. Prediction of gas volume fraction in fully-developed gas-liquid flow in a vertical pipe

    Energy Technology Data Exchange (ETDEWEB)

    Islam, A.S.M.A.; Adoo, N.A.; Bergstrom, D.J., E-mail: nana.adoo@usask.ca [University of Saskatchewan, Department of Mechanical Engineering, Saskatoon, SK (Canada); Wang, D.F. [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

    2015-07-01

    An Eulerian-Eulerian two-fluid model has been implemented for the prediction of the gas volume fraction profile in turbulent upward gas-liquid flow in a vertical pipe. The two-fluid transport equations are discretized using the finite volume method and a low Reynolds number κ-ε turbulence model is used to predict the turbulence field for the liquid phase. The contribution to the effective turbulence by the gas phase is modeled by a bubble induced turbulent viscosity. For the fully-developed flow being considered, the gas volume fraction profile is calculated using the radial momentum balance for the bubble phase. The model potentially includes the effect of bubble size on the interphase forces and turbulence model. The results obtained are in good agreement with experimental data from the literature. The one-dimensional formulation being developed allows for the efficient assessment and further development of both turbulence and two-fluid models for multiphase flow applications in the nuclear industry. (author)

  13. Pre-compression volume on flow ripple reduction of a piston pump

    Science.gov (United States)

    Xu, Bing; Song, Yuechao; Yang, Huayong

    2013-11-01

    Axial piston pump with pre-compression volume(PCV) has lower flow ripple in large scale of operating condition than the traditional one. However, there is lack of precise simulation model of the axial piston pump with PCV, so the parameters of PCV are difficult to be determined. A finite element simulation model for piston pump with PCV is built by considering the piston movement, the fluid characteristic(including fluid compressibility and viscosity) and the leakage flow rate. Then a test of the pump flow ripple called the secondary source method is implemented to validate the simulation model. Thirdly, by comparing results among the simulation results, test results and results from other publications at the same operating condition, the simulation model is validated and used in optimizing the axial piston pump with PCV. According to the pump flow ripples obtained by the simulation model with different PCV parameters, the flow ripple is the smallest when the PCV angle is 13°, the PCV volume is 1.3×10-4 m3 at such operating condition that the pump suction pressure is 2 MPa, the pump delivery pressure 15 MPa, the pump speed 1 000 r/min, the swash plate angle 13°. At the same time, the flow ripple can be reduced when the pump suction pressure is 2 MPa, the pump delivery pressure is 5 MPa,15 MPa, 22 MPa, pump speed is 400 r/min, 1 000 r/min, 1 500 r/min, the swash plate angle is 11°, 13°, 15° and 17°, respectively. The finite element simulation model proposed provides a method for optimizing the PCV structure and guiding for designing a quieter axial piston pump.

  14. Studies concerning average volume flow and waterpacking anomalies in thermal-hydraulics codes

    International Nuclear Information System (INIS)

    Lyczkowski, R.W.; Ching, J.T.; Mecham, D.C.

    1977-01-01

    One-dimensional hydrodynamic codes have been observed to exhibit anomalous behavior in the form of non-physical pressure oscillations and spikes. It is our experience that sometimes this anomaloous behavior can result in mass depletion, steam table failure and in severe cases, problem abortion. In addition, these non-physical pressure spikes can result in long running times when small time steps are needed in an attempt to cope with anomalous solution behavior. The source of these pressure spikes has been conjectured to be caused by nonuniform enthalpy distribution or wave reflection off the closed end of a pipe or abrupt changes in pressure history when the fluid changes from subcooled to two-phase conditions. It is demonstrated in this paper that many of the faults can be attributed to inadequate modeling of the average volume flow and the sharp fluid density front crossing a junction. General corrective models are difficult to devise since the causes of the problems touch on the very theoretical bases of the differential field equations and associated solution scheme. For example, the fluid homogeneity assumption and the numerical extrapolation scheme have placed severe restrictions on the capability of a code to adequately model certain physical phenomena involving fluid discontinuities. The need for accurate junction and local properties to describe phenomena internal to a control volume often points to additional lengthy computations that are difficult to justify in terms of computational efficiency. Corrective models that are economical to implement and use are developed. When incorporated into the one-dimensional, homogeneous transient thermal-hydraulic analysis computer code, RELAP4, they help mitigate many of the code's difficulties related to average volume flow and water-packing anomalies. An average volume flow model and a critical density model are presented. Computational improvements due to these models are also demonstrated

  15. 640-slice DVCT multi-dimensionally and dynamically presents changes in bladder volume and urine flow rate

    Science.gov (United States)

    Su, Yunshan; Fang, Kewei; Mao, Chongwen; Xiang, Shutian; Wang, Jin; Li, Yingwen

    2018-01-01

    The present study aimed to explore the application of 640-slice dynamic volume computed tomography (DVCT) to excretory cystography and urethrography. A total of 70 healthy subjects were included in the study. Excretory cystography and urethrography using 640-slice DVCT was conducted to continuously record the motions of the bladder and the proximal female and male urethra. The patients' voiding process was divided into early, early to middle, middle, middle to late, and late voiding phases. The subjects were analyzed using DVCT and conventional CT. The cross-sectional areas of various sections of the male and female urethra were evaluated, and the average urine flow rate was calculated. The 640-slice DVCT technique was used to dynamically observe the urine flow rate and changes in bladder volume at all voiding phases. The urine volume detected by 640-slice DVCT exhibited no significant difference compared with the actual volume, and no significant difference compared with that determined using conventional CT. Furthermore, no significant difference in the volume of the bladder at each phase of the voiding process was detected between 640-slice DVCT and conventional CT. The results indicate that 640-slice DVCT can accurately evaluate the status of the male posterior urethra and female urethra. In conclusion, 640-slice DVCT is able to multi-dimensionally and dynamically present changes in bladder volume and urine flow rate, and could obtain similar results to conventional CT in detecting urine volume, as well as the status of the male posterior urethra and female urethra. PMID:29467853

  16. The management of subsurface uncertainty using probabilistic modeling of life cycle production forecasts and cash flows

    International Nuclear Information System (INIS)

    Olatunbosun, O. O.

    1998-01-01

    The subject pertains to the implementation of the full range of subsurface uncertainties in life cycle probabilistic forecasting and its extension to project cash flows using the methodology of probabilities. A new tool has been developed in the probabilistic application of Crystal-Ball which can model reservoir volumetrics, life cycle production forecasts and project cash flows in a single environment. The tool is modular such that the volumetrics and cash flow modules are optional. Production forecasts are often generated by applying a decline equation to single best estimate values of input parameters such as initial potential, decline rate, abandonment rate etc -or sometimes by results of reservoir simulation. This new tool provides a means of implementing the full range of uncertainties and interdependencies of the input parameters into the production forecasts by defining the input parameters as probability density functions, PDFs and performing several iterations to generate an expectation curve forecast. Abandonment rate is implemented in each iteration via a link to an OPEX model. The expectation curve forecast is input into a cash flow model to generate a probabilistic NPV. Base case and sensitivity runs from reservoir simulation can likewise form the basis for a probabilistic production forecast from which a probabilistic cash flow can be generated. A good illustration of the application of this tool is in the modelling of the production forecast for a well that encounters its target reservoirs in OUT/ODT situation and thus has significant uncertainties. The uncertainty in presence and size (if present) of gas cap and dependency between ultimate recovery and initial potential amongst other uncertainties can be easily implemented in the production forecast with this tool. From the expectation curve forecast, a probabilistic NPV can be easily generated. Possible applications of this tool include: i. estimation of range of actual recoverable volumes based

  17. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B., E-mail: otero@ien.gov.b, E-mail: cmnap@ien.gov.b, E-mail: brandao@ien.gov.b [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos

    2011-07-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  18. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    International Nuclear Information System (INIS)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B.

    2011-01-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  19. Hydraulic Fracturing and Production Optimization in Eagle Ford Shale Using Coupled Geomechanics and Fluid Flow Model

    Science.gov (United States)

    Suppachoknirun, Theerapat; Tutuncu, Azra N.

    2017-12-01

    With increasing production from shale gas and tight oil reservoirs, horizontal drilling and multistage hydraulic fracturing processes have become a routine procedure in unconventional field development efforts. Natural fractures play a critical role in hydraulic fracture growth, subsequently affecting stimulated reservoir volume and the production efficiency. Moreover, the existing fractures can also contribute to the pressure-dependent fluid leak-off during the operations. Hence, a reliable identification of the discrete fracture network covering the zone of interest prior to the hydraulic fracturing design needs to be incorporated into the hydraulic fracturing and reservoir simulations for realistic representation of the in situ reservoir conditions. In this research study, an integrated 3-D fracture and fluid flow model have been developed using a new approach to simulate the fluid flow and deliver reliable production forecasting in naturally fractured and hydraulically stimulated tight reservoirs. The model was created with three key modules. A complex 3-D discrete fracture network model introduces realistic natural fracture geometry with the associated fractured reservoir characteristics. A hydraulic fracturing model is created utilizing the discrete fracture network for simulation of the hydraulic fracture and flow in the complex discrete fracture network. Finally, a reservoir model with the production grid system is used allowing the user to efficiently perform the fluid flow simulation in tight formations with complex fracture networks. The complex discrete natural fracture model, the integrated discrete fracture model for the hydraulic fracturing, the fluid flow model, and the input dataset have been validated against microseismic fracture mapping and commingled production data obtained from a well pad with three horizontal production wells located in the Eagle Ford oil window in south Texas. Two other fracturing geometries were also evaluated to optimize

  20. Inlet Diameter and Flow Volume Effects on Separation and Energy Efficiency of Hydrocyclones

    Science.gov (United States)

    Erikli, Ş.; Olcay, A. B.

    2015-08-01

    This study investigates hydrocyclone performance of an oil injected screw compressor. Especially, the oil separation efficiency of a screw compressor plays a significant role for air quality and non-stop working hour of compressors has become an important issue when the efficiency in energy is considered. In this study, two separation efficiency parameters were selected to be hydrocyclone inlet diameter and flow volume height between oil reservoir surface and top of the hydrocyclone. Nine different cases were studied in which cyclone inlet diameter and flow volume height between oil reservoir surface and top were investigated in regards to separation and energy performance aspects and the effect of the parameters on the general performance appears to be causing powerful influence. Flow inside the hydrocyclone geometry was modelled by Reynolds Stress Model (RSM) and hydro particles were tracked by Discrete Phase Model (DPM). Besides, particle break up was modelled by the Taylor Analogy Breakup (TAB) model. The reversed vortex generation was observed at different planes. The upper limit of the inlet diameter of the cyclone yields the centrifugal force on particles to decrease while the flow becomes slower; and the larger diameter implies slower flow. On the contrary, the lower limit is increment in speed causes breakup problems that the particle diameters become smaller; consequently, it is harder to separate them from gas.

  1. Medication and volume delivery by gravity-driven micro-drip intravenous infusion: potential variations during "wide-open" flow.

    Science.gov (United States)

    Pierce, Eric T; Kumar, Vikram; Zheng, Hui; Peterfreund, Robert A

    2013-03-01

    Gravity-driven micro-drip infusion sets allow control of medication dose delivery by adjusting drops per minute. When the roller clamp is fully open, flow in the drip chamber can be a continuous fluid column rather than discrete, countable, drops. We hypothesized that during this "wide-open" state, drug delivery becomes dependent on factors extrinsic to the micro-drip set and is therefore difficult to predict. We conducted laboratory experiments to characterize volume delivery under various clinically relevant conditions of wide-open flow in an in vitro laboratory model. A micro-drip infusion set, plugged into a bag of normal saline, was connected to a high-flow stopcock at the distal end. Vertically oriented IV catheters (gauges 14-22) were connected to the stopcock. The fluid meniscus height in the bag was fixed (60-120 cm) above the outflow point. The roller clamp on the infusion set was in fully open position for all experiments resulting in a continuous column of fluid in the drip chamber. Fluid volume delivered in 1 minute was measured 4 times with each condition. To model resistive effects of carrier flow, volumetric infusion pumps were used to deliver various flow rates of normal saline through a carrier IV set into which a micro-drip infusion was "piggybacked." We also compared delivery by micro-drip infusion sets from 3 manufacturers. The volume of fluid delivered by gravity-driven infusion under wide-open conditions (continuous fluid column in drip chamber) varied 2.9-fold (95% confidence interval, 2.84-2.96) depending on catheter size and fluid column height. Total model resistance of the micro-drip with stopcock and catheter varied with flow rate. Volume delivered by the piggybacked micro-drip decreased up to 29.7% ± 0.8% (mean ± SE) as the carrier flow increased from 0 to 1998 mL/min. Delivery characteristics of the micro-drip infusion sets from 3 different manufacturers were similar. Laboratory simulation of clinical situations with gravity

  2. A finite volume method for density driven flows in porous media

    Directory of Open Access Journals (Sweden)

    Hilhorst Danielle

    2013-01-01

    Full Text Available In this paper, we apply a semi-implicit finite volume method for the numerical simulation of density driven flows in porous media; this amounts to solving a nonlinear convection-diffusion parabolic equation for the concentration coupled with an elliptic equation for the pressure. We compute the solutions for two specific problems: a problem involving a rotating interface between salt and fresh water and the classical but difficult Henry’s problem. All solutions are compared to results obtained by running FEflow, a commercial software package for the simulation of groundwater flow, mass and heat transfer in porous media.

  3. Blood flow and blood volume in the femoral heads of healthy adults according to age. Measurement with positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Kubo, Toshikazu; Kimori, Kokuto; Nakamura, Fuminori; Inoue, Shigehiro; Fujioka, Mikihiro; Ueshima, Keiichiro; Hirasawa, Yasusuke; Ushijima, Yo; Nishimura, Tsunehiko

    2001-01-01

    To deepen understanding of hemodynamics in the femoral head, i.e., the essential factor in clarifying pathogenesis of hip disorders, this study examined blood flow and blood volume in the femoral heads of healthy adults, and their changes with age, by using positron emission tomography (PET). In 16 healthy adult males (age: 20-78 years old, mean age: 42 years), blood flow was measured by means of the H 2 15 O dynamic study method, and blood volume was measured by means of the 15 O-labeled carbon monoxide bolus inhalation method. Blood flow was 1.68-6.47 ml/min/100 g (mean ±SD: 3.52±1.2), and blood volume was 1.67-6.03 ml/100 g (mean ±SD: 3.00±1.27). Blood flow significantly decreased (p<0.01) with age, and blood volume significantly increased (P<0.05). PET was useful in the measurement of blood flow and blood volume in the femoral heads. With age, physiological hemodynamic changes also increased in femoral heads. (author)

  4. Flow stagnation volume and abdominal aortic aneurysm growth: Insights from patient-specific computational flow dynamics of Lagrangian-coherent structures.

    Science.gov (United States)

    Joly, Florian; Soulez, Gilles; Garcia, Damien; Lessard, Simon; Kauffmann, Claude

    2018-01-01

    Abdominal aortic aneurysms (AAA) are localized, commonly-occurring dilations of the aorta. When equilibrium between blood pressure (loading) and wall mechanical resistance is lost, rupture ensues, and patient death follows, if not treated immediately. Experimental and numerical analyses of flow patterns in arteries show direct correlations between wall shear stress and wall mechano-adaptation with the development of zones prone to thrombus formation. For further insights into AAA flow topology/growth interaction, a workout of patient-specific computational flow dynamics (CFD) is proposed to compute finite-time Lyapunov exponents and extract Lagrangian-coherent structures (LCS). This computational model was first compared with 4-D phase-contrast magnetic resonance imaging (MRI) in 5 patients. To better understand the impact of flow topology and transport on AAA growth, hyperbolic, repelling LCS were computed in 1 patient during 8-year follow-up, including 9 volumetric morphologic AAA measures by computed tomography-angiography (CTA). LCS defined barriers to Lagrangian jet cores entering AAA. Domains enclosed between LCS and the aortic wall were considered to be stagnation zones. Their evolution was studied during AAA growth. Good correlation - 2-D cross-correlation coefficients of 0.65, 0.86 and 0.082 (min, max, SD) - was obtained between numerical simulations and 4-D MRI acquisitions in 6 specific cross-sections from 4 patients. In follow-up study, LCS divided AAA lumens into 3 dynamically-isolated zones: 2 stagnation volumes lying in dilated portions of the AAA, and circulating volume connecting the inlet to the outlet. The volume of each zone was tracked over time. Although circulating volume remained unchanged during 8-year follow-up, the AAA lumen and main stagnation zones grew significantly (8 cm 3 /year and 6 cm 3 /year, respectively). This study reveals that transient transport topology can be quantified in patient-specific AAA during disease progression

  5. High volume tidal or current flow harnessing system

    Energy Technology Data Exchange (ETDEWEB)

    Gorlov, A.M.

    1984-08-07

    Apparatus permitting the utilization of large volumes of water in the harnessing and extracting of a portion of the power generated by the rise and fall of ocean tides, ocean currents, or flowing rivers includes the provision of a dam, and a specialized single cavity chamber of limited size as compared with the water head enclosed by the dam, and an extremely high volume gating system in which all or nearly all of the water between the high and low levels on either side of the dam is cyclically gated through the single chamber from one side of the dam to the other so as to alternately provide positive air pressure and a partial vacuum within the single chamber. In one embodiment, the specialized chamber has a barrier at the bottom which divides the bottom of the chamber in half, large ports at the bottom of the chamber to permit inflow and outflow of high volumes of water, and ganged structures having a higher total area than that of corresponding ports, in which the structures form sluice gates to selectively seal off and open different sets of ports. In another embodiment, a single chamber is used without a barrier. In this embodiment, vertical sluice gates are used which may be activated automatically by pressures acting on the sluice gates as a result of ingested and expelled water.

  6. Numerical study on modeling of liquid film flow under countercurrent flow limitation in volume of fluid method

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Taro, E-mail: watanabe_t@qe.see.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita-shi, Osaka 565-7895 (Japan); Takata, Takashi, E-mail: takata.takashi@jaea.go.jp [Japan Atomic Energy Agency, 4002 Narita-chou, Oarai-machi, Higashi-Ibaraki-gun, Ibaraki 331-1393 (Japan); Yamaguchi, Akira, E-mail: yamaguchi@n.t.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, 2-22 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)

    2017-03-15

    Highlights: • Thin liquid film flow under CCFL was modeled and coupled with the VOF method. • The difference of the liquid flow rate in experiments of CCFL was evaluated. • The proposed VOF method can quantitatively predict CCFL with low computational cost. - Abstract: Countercurrent flow limitation (CCFL) in a heat transfer tube at a steam generator (SG) of pressurized water reactor (PWR) is one of the important issues on the core cooling under a loss of coolant accident (LOCA). In order to improve the prediction accuracy of the CCFL characteristics in numerical simulations using the volume of fluid (VOF) method with less computational cost, a thin liquid film flow in a countercurrent flow is modeled independently and is coupled with the VOF method. The CCFL characteristics is evaluated analytically in condition of a maximizing down-flow rate as a function of a void fraction or a liquid film thickness considering a critical thickness. Then, we have carried out numerical simulations of a countercurrent flow in a vertical tube so as to investigate the CCFL characteristics and compare them with the previous experimental results. As a result, it has been concluded that the effect of liquid film entrainment by upward gas flux will cause the difference in the experiments.

  7. 7 CFR 58.521 - Pasteurization and product flow.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Pasteurization and product flow. 58.521 Section 58.521... Procedures § 58.521 Pasteurization and product flow. (a) The skim milk used for the manufacture of cottage.... If held more than two hours between pasteurization and time of setting, the skim milk shall be cooled...

  8. Assessment of the adequacy of bronchial stenting by flow-volume loops

    Energy Technology Data Exchange (ETDEWEB)

    McLaren, Clare A.; Roebuck, Derek J. [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Pigott, Nick; Elliott, Martin J. [Great Ormond Street Hospital for Children, Cardiothoracic Unit, London (United Kingdom); Dunne, Catherine [Great Ormond Street Hospital for Children, Department of Physiotherapy, London (United Kingdom)

    2006-08-15

    Airway compression is a common problem in children with certain forms of congenital heart disease. Although various surgical approaches are available to overcome this form of airway obstruction, internal stenting is necessary in a minority of patients. It can be difficult to assess the success of stenting at the time of the procedure, and the interval to successful extubation is usually used as an outcome measure. Measurement of relevant parameters of respiratory physiology with flow-volume and volume-pressure loops permits immediate quantitative assessment of the adequacy of stenting. A 3-month-old infant who underwent bronchial stenting and physiological assessment at the time of the procedure is described. (orig.)

  9. Assessment of the adequacy of bronchial stenting by flow-volume loops

    International Nuclear Information System (INIS)

    McLaren, Clare A.; Roebuck, Derek J.; Pigott, Nick; Elliott, Martin J.; Dunne, Catherine

    2006-01-01

    Airway compression is a common problem in children with certain forms of congenital heart disease. Although various surgical approaches are available to overcome this form of airway obstruction, internal stenting is necessary in a minority of patients. It can be difficult to assess the success of stenting at the time of the procedure, and the interval to successful extubation is usually used as an outcome measure. Measurement of relevant parameters of respiratory physiology with flow-volume and volume-pressure loops permits immediate quantitative assessment of the adequacy of stenting. A 3-month-old infant who underwent bronchial stenting and physiological assessment at the time of the procedure is described. (orig.)

  10. Investigation results on water quality and volume of flowing-in water to the Yotsugi slag heap site. 2

    International Nuclear Information System (INIS)

    Naganuma, Masaki; Taki, Tomihiro; Takimoto, Sadao; Makita, A.

    2000-05-01

    Mining water flowing into the Yotsugi slag heap site at the Ningyo-toge Environment Technical Center is exhausted to a common river after carrying out the treatment of uranium and radium in the mining water at the previously settled mining water treatment facility and confirming it to be less than management target value on the river water within the site boundary regulated by the agreement on environmental conservation with Okayama prefecture and Kami-saihara mura. In order to elucidate some required treatment on every water system flowing-in the heap site as a part of reduction of flowing volume on taking action of the heap site, an investigation on its water quality and volume was carried out. As a result, it was confirmed on water quality that uranium values of every river were all less than their target values but radium values of them were all over their target values which necessitated conventional water treatment. And, on water volume, it was confirmed that flowing water volume from the exposed excavation site was reduced about 40% in comparison with same rain-fall before removing from rain water. (G.K.)

  11. Regional myocardial flow and capillary permeability-surface area products are nearly proportional.

    Science.gov (United States)

    Caldwell, J H; Martin, G V; Raymond, G M; Bassingthwaighte, J B

    1994-08-01

    Analyses of data on the transcapillary exchange and cellular uptake in the normal heart have generally been based on the assumption that local membrane conductances and volumes of distribution are everywhere the same. The question is whether such an assumption is justified in view of the marked (sixfold) heterogeneity of local blood flows per gram tissue. The method was to estimate both flow and capillary membrane permeability-surface area products (PS) locally in the heart. For each of five dogs running on a sloped treadmill, the deposition of tracer microspheres and of [131I]iodophenylpentadecanoic acid (IPPA), after left atrial injection, was determined in 256 pieces of left ventricular myocardium by killing the animals at approximately 100 s after radiotracer injection. A hydraulic occluder stopped the flow to a portion of the myocardium supplied by the left circumflex coronary artery 30 s before tracer injection. Regional flows ranged from 0.1 to 7.0 ml.g-1.min-1. IPPA extractions ranged from 20 to 49%. Using the known flows, we assumed the applicability of an axially distributed blood-tissue exchange model to estimate the PS for the capillary (PSc) and the parenchymal cell. It was impossible to explain the data if the PSc values for membrane transport were uniform throughout the organ. Rather, the only reasonable descriptors of the data required that local PSc values increase with local flow, almost in proportion. Current methods of analysis using data based on deposition methods need to be revised to take into account the near proportionality of PS to flow for at least some substrates.

  12. The effect of intralesional steroid injections on the volume and blood flow in periocular capillary haemangiomas.

    Science.gov (United States)

    Verity, David H; Rose, Geoffrey E; Restori, M

    2008-01-01

    To examine the effect of steroid therapy on the volume estimates and blood flow characteristics of childhood periorbital capillary haemangiomas. Children at risk of amblyopia due to periorbital haemangiomas were treated with intralesional steroid injections (between 1 and 4 courses) and serial assessment of the volume and blood-flow characteristics of the lesions measured using colour Doppler ultrasonography. The characteristics of the haemangiomas in these children were compared with a cohort of untreated cases. Eight of nine treated children were female, this proportion being significantly different from the equal sex distribution of an untreated cohort (p suppression persisting for several months (between 5 and 20) before the lesion later displays the cyclic fluctuations in volume and flow seen with untreated lesions. All treated haemangiomas had some residual vascular anomaly, detectable on ultrasonography, at last follow-up--this being despite absence of clinical signs in most cases. Periorbital capillary haemangiomas requiring steroid therapy for risk of amblyopia were significantly commoner in females, were larger lesions and presented at an earlier age. Intralesional steroids appear to cause a reduction of blood flow, with a transient reduction in volume and a suppression of the natural cyclic variation seen without treatment. The changes after a course of steroid therapy appear to last for between 5 and 20 months, this period of suppression of the lesion probably being particularly useful during infancy and early childhood when the child is at greatest risk of amblyopia.

  13. Dynamic Contrast-Enhanced Computed Tomography-Derived Blood Volume and Blood Flow Correlate With Patient Outcome in Metastatic Renal Cell Carcinoma

    DEFF Research Database (Denmark)

    Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre

    2017-01-01

    = 7). Using a prototype software program (Advanced Perfusion and Permeability Application, Philips Healthcare, Best, the Netherlands), blood volume (BV), blood flow (BF), and permeability surface area product (PS) were calculated for each tumor at baseline, week 5, and week 10. These parameters......OBJECTIVES: The aim was to explore the potential for using dynamic contrast-enhanced computed tomography as a noninvasive functional imaging biomarker before and during the early treatment of metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Dynamic contrast-enhanced computed...

  14. Effects of solution volume on hydrogen production by pulsed spark discharge in ethanol solution

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Y. B.; Sun, B., E-mail: sunb88@dlmu.edu.cn; Zhu, X. M.; Yan, Z. Y.; Liu, H.; Liu, Y. J. [College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026 (China)

    2016-07-15

    Hydrogen production from ethanol solution (ethanol/water) by pulsed spark discharge was optimized by varying the volume of ethanol solution (liquid volume). Hydrogen yield was initially increased and then decreased with the increase in solution volume, which achieved 1.5 l/min with a solution volume of 500 ml. The characteristics of pulsed spark discharge were studied in this work; the results showed that the intensity of peak current, the rate of current rise, and energy efficiency of hydrogen production can be changed by varying the volume of ethanol solution. Meanwhile, the mechanism analysis of hydrogen production was accomplished by monitoring the process of hydrogen production and the state of free radicals. The analysis showed that decreasing the retention time of gas production and properly increasing the volume of ethanol solution can enhance the hydrogen yield. Through this research, a high-yield and large-scale method of hydrogen production can be achieved, which is more suitable for industrial application.

  15. Solution of the square lid-driven cavity flow of a Bingham plastic using the finite volume method

    OpenAIRE

    Syrakos, Alexandros; Georgiou, Georgios C.; Alexandrou, Andreas N.

    2016-01-01

    We investigate the performance of the finite volume method in solving viscoplastic flows. The creeping square lid-driven cavity flow of a Bingham plastic is chosen as the test case and the constitutive equation is regularised as proposed by Papanastasiou [J. Rheol. 31 (1987) 385-404]. It is shown that the convergence rate of the standard SIMPLE pressure-correction algorithm, which is used to solve the algebraic equation system that is produced by the finite volume discretisation, severely det...

  16. Product ion diffusion in flowing afterglows

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M J; Stock, H M.P. [University Coll. of Wales, Aberystwyth (UK). Dept. of Physics

    1975-11-11

    An analysis of the variation of product ion signals in flowing after-glow experiments is presented. It is shown that under certain conditions the relative variation of a single product ion yields not only the total reaction rate coefficients but also the ambipolar diffusion coefficient of the product ion in the buffer gas. Theory is compared with experiment for a number of ion-molecule and Penning reactions.

  17. End-of-life flows of multiple cycle consumer products

    International Nuclear Information System (INIS)

    Tsiliyannis, C.A.

    2011-01-01

    Explicit expressions for the end-of-life flows (EOL) of single and multiple cycle products (MCPs) are presented, including deterministic and stochastic EOL exit. The expressions are given in terms of the physical parameters (maximum lifetime, T, annual cycling frequency, f, number of cycles, N, and early discard or usage loss). EOL flows are also obtained for hi-tech products, which are rapidly renewed and thus may not attain steady state (e.g. electronic products, passenger cars). A ten-step recursive procedure for obtaining the dynamic EOL flow evolution is proposed. Applications of the EOL expressions and the ten-step procedure are given for electric household appliances, industrial machinery, tyres, vehicles and buildings, both for deterministic and stochastic EOL exit, (normal, Weibull and uniform exit distributions). The effect of the physical parameters and the stochastic characteristics on the EOL flow is investigated in the examples: it is shown that the EOL flow profile is determined primarily by the early discard dynamics; it also depends strongly on longevity and cycling frequency: higher lifetime or early discard/loss imply lower dynamic and steady state EOL flows. The stochastic exit shapes the overall EOL dynamic profile: Under symmetric EOL exit distribution, as the variance of the distribution increases (uniform to normal to deterministic) the initial EOL flow rise becomes steeper but the steady state or maximum EOL flow level is lower. The steepest EOL flow profile, featuring the highest steady state or maximum level, as well, corresponds to skew, earlier shifted EOL exit (e.g. Weibull). Since the EOL flow of returned products consists the sink of the reuse/remanufacturing cycle (sink to recycle) the results may be used in closed loop product lifecycle management operations for scheduling and sizing reverse manufacturing and for planning recycle logistics. Decoupling and quantification of both the full age EOL and of the early discard flows is

  18. Implementation of Finite Volume based Navier Stokes Algorithm Within General Purpose Flow Network Code

    Science.gov (United States)

    Schallhorn, Paul; Majumdar, Alok

    2012-01-01

    This paper describes a finite volume based numerical algorithm that allows multi-dimensional computation of fluid flow within a system level network flow analysis. There are several thermo-fluid engineering problems where higher fidelity solutions are needed that are not within the capacity of system level codes. The proposed algorithm will allow NASA's Generalized Fluid System Simulation Program (GFSSP) to perform multi-dimensional flow calculation within the framework of GFSSP s typical system level flow network consisting of fluid nodes and branches. The paper presents several classical two-dimensional fluid dynamics problems that have been solved by GFSSP's multi-dimensional flow solver. The numerical solutions are compared with the analytical and benchmark solution of Poiseulle, Couette and flow in a driven cavity.

  19. Liver volume, portal vein flow, and clearance of indocyanine green and antipyrine in hyperthyroidism before and after antithyroid treatment

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Sonne, J; Court-Payen, M

    1999-01-01

    The aim of the study was to examine liver volume, portal vein flow, and indocyanine green (ICG) and antipyrine clearance in hyperthyroidism before and after antithyroid drug treatment.......The aim of the study was to examine liver volume, portal vein flow, and indocyanine green (ICG) and antipyrine clearance in hyperthyroidism before and after antithyroid drug treatment....

  20. Evaluation of Accordance of Magnetic Resonance Volumetric and Flow Measurements in Determining Ventricular Stroke Volume in Cardiac Patients

    International Nuclear Information System (INIS)

    Jeltsch, M.; Ranft, S.; Klass, O.; Aschoff, A.J.; Hoffmann, M.H.K.

    2008-01-01

    Background: Cardiovascular magnetic resonance imaging (CMR) has become an established noninvasive method for evaluating ventricular function utilizing three-dimensional volumetry. Postprocessing of volumetric measurements is still tedious and time consuming. Stroke volumes obtained by flow quantification across the aortic root or pulmonary trunk could be utilized to increase both speed of workflow and accuracy. Purpose: To assess accuracy of stroke volume quantification using MR volumetric imaging compared to flow quantification in patients with various cardiac diseases. Strategies for the augmentation of accuracy in clinical routine were deduced. Material and Methods: 78 patients with various cardiac diseases -excluding intra- or extracardiac shunts, regurgitant valvular defects, or heart rhythm disturbance -underwent cardiac function analysis with flow measurements across the aortic root and cine imaging of the left ventricle. Forty-six patients additionally underwent flow measurements in the pulmonary trunk and cine imaging of the right ventricle. Results: Left ventricular stroke volume (LVSV) and stroke volume of the aortic root (SVAo) correlated with r=0.97, and Bland-Altman analysis showed a mean difference of 0.11 ml and a standard error of estimation (SEE) of 4.31 ml. Ninety-two percent of the data were within the 95% limits of agreement. Right ventricular stroke volume (RVSV) and stroke volume of the pulmonary trunk (SVP) correlated with a factor of r=0.86, and mean difference in the Bland-Altman analysis was fixed at -2.62 ml (SEE 8.47 ml). For RVSV and SVP, we calculated r=0.82, and Bland-Altman analysis revealed a mean difference of 1.27 ml (SEE 9.89 ml). LVSV and RVSV correlated closely, with r=0.91 and a mean difference of 2.79 ml (SEE 7.17 ml). SVAo and SVP correlated with r=0.95 and a mean difference of 0.50 ml (SEE 5.56 ml). Conclusion: Flow quantification can be used as a guidance tool, providing accurate and reproducible stroke volumes of both

  1. Well balanced finite volume methods for nearly hydrostatic flows

    International Nuclear Information System (INIS)

    Botta, N.; Klein, R.; Langenberg, S.; Luetzenkirchen, S.

    2004-01-01

    In numerical approximations of nearly hydrostatic flows, a proper representation of the dominant hydrostatic balance is of crucial importance: unbalanced truncation errors can induce unacceptable spurious motions, e.g., in dynamical cores of models for numerical weather prediction (NWP) in particular near steep topography. In this paper we develop a new strategy for the construction of discretizations that are 'well-balanced' with respect to dominant hydrostatics. The classical idea of formulating the momentum balance in terms of deviations of pressure from a balanced background distribution is realized here through local, time dependent hydrostatic reconstructions. Balanced discretizations of the pressure gradient and of the gravitation source term are achieved through a 'discrete Archimedes' buoyancy principle'. This strategy is applied to extend an explicit standard finite volume Godunov-type scheme for compressible flows with minimal modifications. The resulting method has the following features: (i) It inherits its conservation properties from the underlying base scheme. (ii) It is exactly balanced, even on curvilinear grids, for a large class of near-hydrostatic flows. (iii) It solves the full compressible flow equations without reference to a background state that is defined for an entire vertical column of air. (iv) It is robust with respect to details of the implementation, such as the choice of slope limiting functions, or the particularities of boundary condition discretizations

  2. Monte Carlo Method with Heuristic Adjustment for Irregularly Shaped Food Product Volume Measurement

    Directory of Open Access Journals (Sweden)

    Joko Siswantoro

    2014-01-01

    Full Text Available Volume measurement plays an important role in the production and processing of food products. Various methods have been proposed to measure the volume of food products with irregular shapes based on 3D reconstruction. However, 3D reconstruction comes with a high-priced computational cost. Furthermore, some of the volume measurement methods based on 3D reconstruction have a low accuracy. Another method for measuring volume of objects uses Monte Carlo method. Monte Carlo method performs volume measurements using random points. Monte Carlo method only requires information regarding whether random points fall inside or outside an object and does not require a 3D reconstruction. This paper proposes volume measurement using a computer vision system for irregularly shaped food products without 3D reconstruction based on Monte Carlo method with heuristic adjustment. Five images of food product were captured using five cameras and processed to produce binary images. Monte Carlo integration with heuristic adjustment was performed to measure the volume based on the information extracted from binary images. The experimental results show that the proposed method provided high accuracy and precision compared to the water displacement method. In addition, the proposed method is more accurate and faster than the space carving method.

  3. Monte Carlo method with heuristic adjustment for irregularly shaped food product volume measurement.

    Science.gov (United States)

    Siswantoro, Joko; Prabuwono, Anton Satria; Abdullah, Azizi; Idrus, Bahari

    2014-01-01

    Volume measurement plays an important role in the production and processing of food products. Various methods have been proposed to measure the volume of food products with irregular shapes based on 3D reconstruction. However, 3D reconstruction comes with a high-priced computational cost. Furthermore, some of the volume measurement methods based on 3D reconstruction have a low accuracy. Another method for measuring volume of objects uses Monte Carlo method. Monte Carlo method performs volume measurements using random points. Monte Carlo method only requires information regarding whether random points fall inside or outside an object and does not require a 3D reconstruction. This paper proposes volume measurement using a computer vision system for irregularly shaped food products without 3D reconstruction based on Monte Carlo method with heuristic adjustment. Five images of food product were captured using five cameras and processed to produce binary images. Monte Carlo integration with heuristic adjustment was performed to measure the volume based on the information extracted from binary images. The experimental results show that the proposed method provided high accuracy and precision compared to the water displacement method. In addition, the proposed method is more accurate and faster than the space carving method.

  4. Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    Directory of Open Access Journals (Sweden)

    Arheden Håkan

    2011-04-01

    Full Text Available Abstract Background Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Methods Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Results Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Conclusion Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking

  5. Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    International Nuclear Information System (INIS)

    Töger, Johannes; Carlsson, Marcus; Söderlind, Gustaf; Arheden, Håkan; Heiberg, Einar

    2011-01-01

    Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR) can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking complements and provides incremental information compared to particle

  6. An unstructured finite volume solver for two phase water/vapour flows based on an elliptic oriented fractional step method

    International Nuclear Information System (INIS)

    Mechitoua, N.; Boucker, M.; Lavieville, J.; Pigny, S.; Serre, G.

    2003-01-01

    Based on experience gained at EDF and Cea, a more general and robust 3-dimensional (3D) multiphase flow solver has been being currently developed for over three years. This solver, based on an elliptic oriented fractional step approach, is able to simulate multicomponent/multiphase flows. Discretization follows a 3D full unstructured finite volume approach, with a collocated arrangement of all variables. The non linear behaviour between pressure and volume fractions and a symmetric treatment of all fields are taken into account in the iterative procedure, within the time step. It greatly enforces the realizability of volume fractions (i.e 0 < α < 1), without artificial numerical needs. Applications to widespread test cases as static sedimentation, water hammer and phase separation are shown to assess the accuracy and the robustness of the flow solver in different flow conditions, encountered in nuclear reactors pipes. (authors)

  7. 1D and 2D Numerical Modeling for Solving Dam-Break Flow Problems Using Finite Volume Method

    Directory of Open Access Journals (Sweden)

    Szu-Hsien Peng

    2012-01-01

    Full Text Available The purpose of this study is to model the flow movement in an idealized dam-break configuration. One-dimensional and two-dimensional motion of a shallow flow over a rigid inclined bed is considered. The resulting shallow water equations are solved by finite volumes using the Roe and HLL schemes. At first, the one-dimensional model is considered in the development process. With conservative finite volume method, splitting is applied to manage the combination of hyperbolic term and source term of the shallow water equation and then to promote 1D to 2D. The simulations are validated by the comparison with flume experiments. Unsteady dam-break flow movement is found to be reasonably well captured by the model. The proposed concept could be further developed to the numerical calculation of non-Newtonian fluid or multilayers fluid flow.

  8. 3D flow study in a mildly stenotic coronary artery phantom using a whole volume PIV method.

    Science.gov (United States)

    Brunette, J; Mongrain, R; Laurier, J; Galaz, R; Tardif, J C

    2008-11-01

    Blood flow dynamics has an important role in atherosclerosis initiation, progression, plaque rupture and thrombosis eventually causing myocardial infarction. In particular, shear stress is involved in platelet activation, endothelium function and secondary flows have been proposed as possible variables in plaque erosion. In order to investigate these three-dimensional flow characteristics in the context of a mild stenotic coronary artery, a whole volume PIV method has been developed and applied to a scaled-up transparent phantom. Experimental three-dimensional velocity data was processed to estimate the 3D shear stress distributions and secondary flows within the flow volume. The results show that shear stress reaches values out of the normal and atheroprotective range at an early stage of the obstructive pathology and that important secondary flows are also initiated at an early stage of the disease. The results also support the concept of a vena contracta associated with the jet in the context of a coronary artery stenosis with the consequence of higher shear stresses in the post-stenotic region in the blood domain than at the vascular wall.

  9. Cavitation and gas-liquid flow in fluid machinery and devices. FED-Volume 190

    International Nuclear Information System (INIS)

    O'Hern, T.J.; Kim, J.H.; Morgan, W.B.; Furuya, O.

    1994-01-01

    Cavitation and gas-liquid two-phase flow have remained important areas in many industrial applications and constantly provided challenges for academic researchers and industrial practitioners alike. Cavitation and two-phase flow commonly occur in fluid machinery such as pumps, propellers, and fluid devices such as orifices, valves, and diffusers. Cavitation not only degrades the performance of these machines and devices but deteriorates the materials. Gas-liquid two-phase flow has also been known to degrade the performance of pumps and propellers and can often induce an instability. The industrial applications of cavitation and two-phase flow can be found in power plants, ship propellers, hydrofoils, and aerospace equipment, to name but a few. The papers presented in this volume reflect the variety and richness of cavitation and gas-liquid two-phase flow in various flow transporting components and the increasing role they play in modern and conventional technologies. Separate abstracts were prepared for 35 papers in this book

  10. Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

    International Nuclear Information System (INIS)

    Sartipi, Sina; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge; Kapteijn, Freek

    2013-01-01

    Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors

  11. Six-flow operations for catalyst development in Fischer-Tropsch synthesis: Bridging the gap between high-throughput experimentation and extensive product evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sartipi, Sina, E-mail: S.Sartipi@tudelft.nl, E-mail: J.Gascon@tudelft.nl; Jansma, Harrie; Bosma, Duco; Boshuizen, Bart; Makkee, Michiel; Gascon, Jorge, E-mail: S.Sartipi@tudelft.nl, E-mail: J.Gascon@tudelft.nl; Kapteijn, Freek [Department of Chemical Engineering, Catalysis Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft (Netherlands)

    2013-12-15

    Design and operation of a “six-flow fixed-bed microreactor” setup for Fischer-Tropsch synthesis (FTS) is described. The unit consists of feed and mixing, flow division, reaction, separation, and analysis sections. The reactor system is made of five heating blocks with individual temperature controllers, assuring an identical isothermal zone of at least 10 cm along six fixed-bed microreactor inserts (4 mm inner diameter). Such a lab-scale setup allows running six experiments in parallel, under equal feed composition, reaction temperature, and conditions of separation and analysis equipment. It permits separate collection of wax and liquid samples (from each flow line), allowing operation with high productivities of C5+ hydrocarbons. The latter is crucial for a complete understanding of FTS product compositions and will represent an advantage over high-throughput setups with more than ten flows where such instrumental considerations lead to elevated equipment volume, cost, and operation complexity. The identical performance (of the six flows) under similar reaction conditions was assured by testing a same catalyst batch, loaded in all microreactors.

  12. Aerodynamics of the Large-Volume, Flow-Through Detector System. Final report

    International Nuclear Information System (INIS)

    Reed, H.; Saric, W.; Laananen, D.; Martinez, C.; Carrillo, R.; Myers, J.; Clevenger, D.

    1996-03-01

    The Large-Volume Flow-Through Detector System (LVFTDS) was designed to monitor alpha radiation from Pu, U, and Am in mixed-waste incinerator offgases; however, it can be adapted to other important monitoring uses that span a number of potential markets, including site remediation, indoor air quality, radon testing, and mine shaft monitoring. Goal of this effort was to provide mechanical design information for installation of LVFTDS in an incinerator, with emphasis on ability to withstand the high temperatures and high flow rates expected. The work was successfully carried out in three stages: calculation of pressure drop through the system, materials testing to determine surrogate materials for wind-tunnel testing, and wind-tunnel testing of an actual configuration

  13. Operating range, hold-up, droplet size and axial mixing of pulsed plate columns in highly disperse and low-continuity volume flows

    International Nuclear Information System (INIS)

    Schmidt, H.; Miller, H.

    Operating behavior, hold-up, droplet size and axial mixing are investigated in highly disperse and slightly continuous volume flows in a pulsed plate column. The geometry of the column of 4-m length and 10-cm inside diameter was held constant. The hole shape of the column bases was changed, wherby the cylindrical, sharp-edge drilled hole is compared with the punched, nozzle-shaped hole in their effects on the fluid-dynamic behavior. In this case we varied the volume flows, the ratio of volume flows, the pulse frequency and the operating temperature. The operation was held constant for the aqueous, the organic, the continuous and the disperse phases. The objective was to demonstrate the applicability of pulsed plate columns with very large differences between the organic disperse and the aqueous continuous volume flow, to obtain design data for such columns and to perform a scale-up to industrial reprocessing plant-size. 18 references, 11 figures, 3 tables

  14. Evaluation of plasma eosinophil count and mean platelet volume in patients with coronary slow flow

    Directory of Open Access Journals (Sweden)

    Mehmet Demir

    2014-01-01

    Full Text Available OBJECTIVE: The pathophysiology of coronary slow flow has not been clearly defined, although multiple abnormalities including arteritis, endothelial dysfunction, and atherothrombosis, have been reported. It is known that eosinophils play an important role in inflammation, endothelial dysfunction, and thrombosis. We aimed to compare the eosinophil counts of coronary slow flow patients versus healthy controls. METHODS: This study included 50 coronary slow flow patients (19 males, mean age 65.6±13.7 years and 30 healthy controls (10 males, mean age 57.86±11.6 years. These participants were evaluated using concurrent routine biochemical tests as well as neutrophil, lymphocyte, and eosinophil counts and mean platelet volume (MPV, which were obtained from the whole blood count. These parameters were compared between groups. RESULTS: The baseline characteristics of the study groups were comparable. The coronary slow flow patients had a higher mean platelet volume and eosinophil count than the control group (8.38±0.86 vs 6.28±1.6 fL and 0.31±0.42 vs 0.09±0.05; p<0.001 and 0.008, respectively. CONCLUSION: Our study demonstrated a relationship between eosinophil count and MPV in patients with coronary slow flow.

  15. Regional blood flow analysis and its relationship with arterial branch lengths and lumen volume in the coronary arterial tree

    International Nuclear Information System (INIS)

    Molloi, Sabee; Wong, Jerry T

    2007-01-01

    The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions (30-70% diameter stenosis) where it is difficult to determine whether a particular lesion is the cause of ischaemia. Therefore, a functional measure of stenosis severity is needed. The purpose of this study is to determine whether the expected maximum coronary blood flow in an arterial tree is predictable from its sum of arterial branch lengths or lumen volume. Using a computer model of a porcine coronary artery tree, an analysis of blood flow distribution was conducted through a network of millions of vessels that included the entire coronary artery tree down to the first capillary branch. The flow simulation results show that there is a linear relationship between coronary blood flow and the sum of its arterial branch lengths. This relationship holds over the entire arterial tree. The flow simulation results also indicate that there is a 3/4 er relation between coronary blood flow (Q) and the sum of its arterial lumen volume (V). Moreover, there is a linear relationship between normalized Q and normalized V raised to a power of 3/4 over the entire arterial tree. These results indicate that measured arterial branch lengths or lumen volumes can be used to predict the expected maximum blood flow in an arterial tree. This theoretical maximum blood flow, in conjunction with an angiographically measured blood flow, can potentially be used to calculate fractional flow reserve based entirely on angiographic data

  16. A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

    KAUST Repository

    Jagad, P. I.; Puranik, B. P.; Date, A. W.

    2018-01-01

    A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell

  17. Effect of cesium seeding on hydrogen negative ion volume production

    International Nuclear Information System (INIS)

    Bacal, M.; Balghiti-Sube, F. El; Elizarov, L. I.; Tontegode, A. J.

    1998-01-01

    The effect of cesium vapor partial pressure on the plasma parameters has been studied in the dc hybrid negative ion source ''CAMEMBERT III.'' The cesium vapor pressure was varied up to 10 -5 Torr and was determined by a surface ionization gauge in the absence of the discharge. The negative ion relative density measured by laser photodetachment in the center of the plasma extraction region increases by a factor of four when the plasma is seeded with cesium. However the plasma density and the electron temperature (determined using a cylindrical electrostatic probe) are reduced by the cesium seeding. As a result, the negative ion density goes up by a factor of two at the lowest hydrogen pressure studied. The velocity of the directed negative ion flow to the plasma electrode, determined from two-laser beam photodetachment experiments, appears to be affected by the cesium seeding. The variation of the extracted negative ion and electron currents versus the plasma electrode bias will also be reported for pure hydrogen and cesium seeded plasmas. The cesium seeding leads to a dramatic reduction of the electron component, which is consistent with the reduced electron density and temperature. The negative ion current is enhanced and a goes through a maximum at plasma electrode bias lower than 1 V. These observations lead to the conclusion that the enhancement of pure volume production occurs in this type of plasma. Possible mechanisms for this type of volume process will be discussed

  18. Nonlinear Effects in Osmotic Volume Flows of Electrolyte Solutions through Double-Membrane System

    NARCIS (Netherlands)

    Slezak, A.; Jasik-Slezak, J.; Grzegorczyn, S.; Slezak-Prochazka, I.

    The results of experimental study of volume osmotic flows in a double-membrane system are presented in this article. The double-membrane system consists of two membranes (M-u, M-d) oriented in horizontal planes and three identical compartments (u, m, d), containing unstirred binary or ternary ionic

  19. Control volume based modelling in one space dimension of oscillating, compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Carlsen, Henrik; Thomsen, Per Grove

    2006-01-01

    We present an approach for modelling unsteady, primarily one-dimensional, compressible flow. The conservation laws for mass, energy, and momentum are applied to a staggered mesh of control volumes and loss mechanisms are included directly as extra terms. Heat transfer, flow friction, and multidim...... are presented. The capabilities of the approach are illustrated with an example solution and an experimental validation of a Stirling engine model....

  20. A numerical model of two-phase flow at the micro-scale using the volume-of-fluid method

    Science.gov (United States)

    Shams, Mosayeb; Raeini, Ali Q.; Blunt, Martin J.; Bijeljic, Branko

    2018-03-01

    This study presents a simple and robust numerical scheme to model two-phase flow in porous media where capillary forces dominate over viscous effects. The volume-of-fluid method is employed to capture the fluid-fluid interface whose dynamics is explicitly described based on a finite volume discretization of the Navier-Stokes equations. Interfacial forces are calculated directly on reconstructed interface elements such that the total curvature is preserved. The computed interfacial forces are explicitly added to the Navier-Stokes equations using a sharp formulation which effectively eliminates spurious currents. The stability and accuracy of the implemented scheme is validated on several two- and three-dimensional test cases, which indicate the capability of the method to model two-phase flow processes at the micro-scale. In particular we show how the co-current flow of two viscous fluids leads to greatly enhanced flow conductance for the wetting phase in corners of the pore space, compared to a case where the non-wetting phase is an inviscid gas.

  1. A method for bubble volume calculating in vertical two-phase flow

    International Nuclear Information System (INIS)

    Wang, H Y; Dong, F

    2009-01-01

    The movement of bubble is a basic subject in gas-liquid two-phase flow research. A method for calculating bubble volume which is one of the most important characters in bubble motion research was proposed. A suit of visualized experimental device was designed and set up. Single bubble rising in stagnant liquid in a rectangular tank was studied using the high-speed video system. Bubbles generated by four orifice with different diameter (1mm, 2mm, 3mm, 4mm) were recorded respectively. Sequences of recorded high-speed images were processed by digital image processing method, such as image noise remove, binary image transform, bubble filling, and so on. then, Several parameters could be obtained from the processed image. Bubble area, equivalent diameter, bubble velocity, bubble acceleration are all indispensable in bubble volume calculating. In order to get the force balance equation, forces that work on bubble along vertical direction, including drag force, virtual mass force, buoyancy, gravity and liquid thrust, were analyzed. Finally, the bubble volume formula could be derived from the force balance equation and bubble parameters. Examples were given to shown the computing process and results. Comparison of the bubble volume calculated by geomettic method and the present method have shown the superiority of the proposed method in this paper.

  2. Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

    International Nuclear Information System (INIS)

    Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson; Schirru, Roberto; Silva, Ademir X.

    2007-01-01

    This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

  3. Study of volume fractions for stratified and annular regime in multiphase flows using gamma-rays and artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Cesar M.; Brandao, Luis Eduardo; Pereira, Claudio M.N.A.; Ramos, Robson [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: otero@ien.gov.br; brandao@ien.gov.br; cmnap@ien.gov.br; robson@ien.gov.br; Schirru, Roberto; Silva, Ademir X. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Energia Nuclear (PEN)]. E-mails: ademir@con.ufrj.br; schirru@lmp.ufrj.br

    2007-07-01

    This work presents methodology based on the use of nuclear technique and artificial intelligence for attainment of volume fractions in stratified and annular multiphase flow regime, oil-water-gas, very frequent in the offshore industry petroliferous. Using the principles of absorption and scattering of gamma-rays and an adequate geometry scheme of detection with two detectors and two energies measurement are gotten and they vary as changes in the volume fractions of flow regime occur. The MCNP-X code was used in order to provide the data training for artificial neural network that matched such information with the respective actual volume fractions of each material. (author)

  4. Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom

    International Nuclear Information System (INIS)

    Behrendt, Florian F.; Bruners, Philipp; Keil, Sebastian; Plumhans, Cedric; Mahnken, Andreas H.; Das, Marco; Ackermann, Diana; Guenther, Rolf W.; Muehlenbruch, Georg

    2010-01-01

    Purpose: To evaluate the influence of different saline chaser volumes and different saline chaser flow rates on the intravascular contrast enhancement in MDCT. Materials and methods: In a physiological flow phantom contrast medium (120 ml, 300 mgI/ml, Ultravist 300) was administered at a flow rate of 6 ml/s followed by different saline chaser volumes (0, 30, 60 and 90 ml) at the same injection rate or followed by a 30-ml saline chaser at different injection rates (2, 4, 6 and 8 ml/s). Serial CT-scans at a level covering the pulmonary artery, the ascending and the descending aorta replica were obtained. Time-enhancement curves were computed and both pulmonary and aortic peak enhancement and peak time were determined. Results: Compared to contrast medium injection without a saline chaser the pushing with a saline chaser (30, 60, and 90 ml) resulted in a statistically significant increased pulmonary peak enhancement (all p = 0.008) and prolonged peak time (p = 0.032, p = 0.024 and p = 0.008, respectively). Highest aortic peak enhancement values were detected for a saline chaser volume of 30 ml. A saline chaser flow rate of 8 ml/s resulted in the highest pulmonary peak enhancement values compared to flow rates of 2, 4 and 6 ml/s (all p = 0.008). Aortic peak enhancement showed the highest values for a flow rate of 6 ml/s. Conclusion: A saline chaser volume of 30 ml and an injection rate of 6 ml/s are sufficient to best improve vascular contrast enhancement in the pulmonary artery and the aorta in MDCT.

  5. Cyclotron production of radioactive gas from gaseous targets: inhomogeneity of the target activity - optimum flow rate of the carrier gas - cross sections

    International Nuclear Information System (INIS)

    Peters, J.-M.; Fiore, G. del; Quaglia, L.; Depresseux, J.-C.; Bartsch, P.

    1979-01-01

    When short-lived radioactive gases are produced by cyclotron-irradiated gaseous targets, the yield of activity, at the site of delivery, depends on the flow rate in the gas-carrying line. The authors improve a preliminarily published previous single model by the introduction of a supplementary hypothesis which takes into account the inhomogeneity of the activity in the gaseous target. By substituting the NTP volume of the gas in the irradiation cell Vsub(c) by a visible volume Vsub(a) depending on the flow rate and expressed by Vsub(a) = Vsub(infinity) +(V 0 - Vsub(infinity))exp(-kDsub(p)), they derive the following general expression for the optimum flow rate D which gives a maximum yield of production. D 2 -bD-bc-D 2 akexp(-kD)-abexp(-kD) = 0, a=lambda(V 0 -Vsub(infinity)), b = lambdaVsub(r), c = lambdaVsub(infinity), lambda = the decay constant of the radionuclide produced,Vsub(r) the inner volume of the gas-carrying line. The unknown parameters Vsub(r), Vsub(a), V 0 , Vsub(infinity), and k can be determined experimentally. The authors also suggest a new method for the determination of experimental cross sections with their gaseous target. (Auth.)

  6. Flow-through electroporation based on constant voltage for large-volume transfection of cells.

    Science.gov (United States)

    Geng, Tao; Zhan, Yihong; Wang, Hsiang-Yu; Witting, Scott R; Cornetta, Kenneth G; Lu, Chang

    2010-05-21

    Genetic modification of cells is a critical step involved in many cell therapy and gene therapy protocols. In these applications, cell samples of large volume (10(8)-10(9)cells) are often processed for transfection. This poses new challenges for current transfection methods and practices. Here we present a novel flow-through electroporation method for delivery of genes into cells at high flow rates (up to approximately 20 mL/min) based on disposable microfluidic chips, a syringe pump, and a low-cost direct current (DC) power supply that provides a constant voltage. By eliminating pulse generators used in conventional electroporation, we dramatically lowered the cost of the apparatus and improved the stability and consistency of the electroporation field for long-time operation. We tested the delivery of pEFGP-C1 plasmids encoding enhanced green fluorescent protein into Chinese hamster ovary (CHO-K1) cells in the devices of various dimensions and geometries. Cells were mixed with plasmids and then flowed through a fluidic channel continuously while a constant voltage was established across the device. Together with the applied voltage, the geometry and dimensions of the fluidic channel determined the electrical parameters of the electroporation. With the optimal design, approximately 75% of the viable CHO cells were transfected after the procedure. We also generalize the guidelines for scaling up these flow-through electroporation devices. We envision that this technique will serve as a generic and low-cost tool for a variety of clinical applications requiring large volume of transfected cells. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Treating network junctions in finite volume solution of transient gas flow models

    Science.gov (United States)

    Bermúdez, Alfredo; López, Xián; Vázquez-Cendón, M. Elena

    2017-09-01

    A finite volume scheme for the numerical solution of a non-isothermal non-adiabatic compressible flow model for gas transportation networks on non-flat topography is introduced. Unlike standard Euler equations, the model takes into account wall friction, variable height and heat transfer between the pipe and the environment which are source terms. The case of one single pipe was considered in a previous reference by the authors, [8], where a finite volume method with upwind discretization of the flux and source terms has been proposed in order to get a well-balanced scheme. The main goal of the present paper is to go a step further by considering a network of pipes. The main issue is the treatment of junctions for which container-like 2D finite volumes are introduced. The couplings between pipes (1D) and containers (2D) are carefully described and the conservation properties are analyzed. Numerical tests including real gas networks are solved showing the performance of the proposed methodology.

  8. Cost and price estimate of Brayton and Stirling engines in selected production volumes

    Science.gov (United States)

    Fortgang, H. R.; Mayers, H. F.

    1980-01-01

    The methods used to determine the production costs and required selling price of Brayton and Stirling engines modified for use in solar power conversion units are presented. Each engine part, component and assembly was examined and evaluated to determine the costs of its material and the method of manufacture based on specific annual production volumes. Cost estimates are presented for both the Stirling and Brayton engines in annual production volumes of 1,000, 25,000, 100,000 and 400,000. At annual production volumes above 50,000 units, the costs of both engines are similar, although the Stirling engine costs are somewhat lower. It is concluded that modifications to both the Brayton and Stirling engine designs could reduce the estimated costs.

  9. Analysis of one-dimensional nonequilibrium two-phase flow using control volume method

    International Nuclear Information System (INIS)

    Minato, Akihiko; Naitoh, Masanori

    1987-01-01

    A one-dimensional numerical analysis model was developed for prediction of rapid flow transient behavior involving boiling. This model was based on six conservation equations of time averaged parameters of gas and liquid behavior. These equations were solved by using a control volume method with an explicit time integration. This model did not use staggered mesh scheme, which had been commonly used in two-phase flow analysis. Because void fraction and velocity of each phase were defined at the same location in the present model, effects of void fraction on phase velocity calculation were treated directly without interpolation. Though non-staggered mesh scheme was liable to cause numerical instability with zigzag pressure field, stability was achieved by employing the Godunov method. In order to verify the present analytical model, Edwards' pipe blow down and Zaloudek's initially subcooled critical two-phase flow experiments were analyzed. Stable solutions were obtained for rarefaction wave propagation with boiling and transient two-phase flow behavior in a broken pipe by using this model. (author)

  10. Volume-heated boiling pool flow behavior and application to transition phase accident conditions

    International Nuclear Information System (INIS)

    Ginsberg, T.; Jones, O.C. Jr.; Chen, J.C.

    1978-01-01

    Observations of two-phase flow fields in volume-heated boiling pools are reported. Photographic observations, together with pool-average void fraction measurements are presented. Flow regime transition criteria derived from the measurements are discussed. The churn-turbulent flow regime was the dominant regime for superficial vapor velocities up to nearly five times the Kutateladze dispersal velocity. Within this range of conditions, a churn-turbulent drift flux model provides a reasonable prediction of the pool-average void fraction data. The results of the experiment and analyses are extrapolated to transition phase conditions. It is shown that intense pool boil-up could occur where the pool-average void fraction would be greater than 0.6 for steel vaporization rates equivalent to power levels greater than one percent of nominal LMFBR power density

  11. Implementation of Logic Flow in Planning and Production Control

    Directory of Open Access Journals (Sweden)

    Ulewicz Robert

    2016-03-01

    Full Text Available The article presents the results of analysis, the use of continuous flow of logic at the stage of production planning and control of the company producing furniture. The concept of continuous flow tends to regulate the flow of materials in a manner that provides the shortest flow path without unnecessary activities (Muda is a Japanese word meaning waste, a constant takt and defined throughput at constant resource requirements for the so-called transfer of material through the whole process. In the study Glenday’d sieve method was used to identify the correct area, which requires the value stream mapping, and areas called excessive complexity, which do not provide added value. The use of Glenday’s sieve method made it possible to identify areas in which it must be improve production capacity.

  12. Flow chemistry syntheses of natural products.

    Science.gov (United States)

    Pastre, Julio C; Browne, Duncan L; Ley, Steven V

    2013-12-07

    The development and application of continuous flow chemistry methods for synthesis is a rapidly growing area of research. In particular, natural products provide demanding challenges to this developing technology. This review highlights successes in the area with an emphasis on new opportunities and technological advances.

  13. Reconciling irrigated food production with environmental flows for Sustainable Development Goals implementation.

    Science.gov (United States)

    Jägermeyr, Jonas; Pastor, Amandine; Biemans, Hester; Gerten, Dieter

    2017-07-19

    Safeguarding river ecosystems is a precondition for attaining the UN Sustainable Development Goals (SDGs) related to water and the environment, while rigid implementation of such policies may hamper achievement of food security. River ecosystems provide life-supporting functions that depend on maintaining environmental flow requirements (EFRs). Here we establish gridded process-based estimates of EFRs and their violation through human water withdrawals. Results indicate that 41% of current global irrigation water use (997 km 3 per year) occurs at the expense of EFRs. If these volumes were to be reallocated to the ecosystems, half of globally irrigated cropland would face production losses of ≥10%, with losses of ∼20-30% of total country production especially in Central and South Asia. However, we explicitly show that improvement of irrigation practices can widely compensate for such losses on a sustainable basis. Integration with rainwater management can even achieve a 10% global net gain. Such management interventions are highlighted to act as a pivotal target in supporting the implementation of the ambitious and seemingly conflicting SDG agenda.

  14. Reconciling irrigated food production with environmental flows for Sustainable Development Goals implementation

    Science.gov (United States)

    Jägermeyr, Jonas; Pastor, Amandine; Biemans, Hester; Gerten, Dieter

    2017-07-01

    Safeguarding river ecosystems is a precondition for attaining the UN Sustainable Development Goals (SDGs) related to water and the environment, while rigid implementation of such policies may hamper achievement of food security. River ecosystems provide life-supporting functions that depend on maintaining environmental flow requirements (EFRs). Here we establish gridded process-based estimates of EFRs and their violation through human water withdrawals. Results indicate that 41% of current global irrigation water use (997 km3 per year) occurs at the expense of EFRs. If these volumes were to be reallocated to the ecosystems, half of globally irrigated cropland would face production losses of >=10%, with losses of ~20-30% of total country production especially in Central and South Asia. However, we explicitly show that improvement of irrigation practices can widely compensate for such losses on a sustainable basis. Integration with rainwater management can even achieve a 10% global net gain. Such management interventions are highlighted to act as a pivotal target in supporting the implementation of the ambitious and seemingly conflicting SDG agenda.

  15. Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

    International Nuclear Information System (INIS)

    Pitkaenen, M.A.; Hopewell, J.W.

    1985-01-01

    Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

  16. Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial

    Science.gov (United States)

    Kumar, Amaravadi Sampath; Augustine, Alfred Joseph; Pazhyaottayil, Zulfeequer Chundaanveetil; Ramakrishna, Anand; Krishnakumar, Shyam Krishnan

    2016-01-01

    Introduction Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. Aim To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. Materials and Methods A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni’s ‘t’-test. Exercise tolerance was analysed by Paired ‘T’-test. Results Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1st, 2nd and 3rd postoperative day when compared with preoperative day. On 4th and 5th postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group

  17. The Effect of the Volume Flow rate on the Efficiency of a Solar Collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    rates. Theoretically, a simplified model of the solar collector panel is built by means of the CFD (Computational Fluid Dynamics) code Fluent, where the geometry of the collector panel except the casing is fully modeled. Both lateral and longitudinal heat conduction in the absorber fins, the heat...... transfer from the absorber to the solar collector fluid and the heat loss from the absorber are considered. Flow and temperature distribution in the collector panel are investigated with buoyancy effect. Measurements are carried out with the solar collector panel. Collector efficiencies are measured......The flow distribution inside a collector panel with an area of 12.5 m² and with 16 parallel connected horizontal fins and the effect of the flow nonuniformity on the risk of boiling and on the collector efficiency have been theoretically and experimentally investigated for different volume flow...

  18. Multiple Flow Loop SCADA System Implemented on the Production Prototype Loop

    Energy Technology Data Exchange (ETDEWEB)

    Baily, Scott A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalmas, Dale Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wheat, Robert Mitchell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-16

    The following report covers FY 15 activities to develop supervisory control and data acquisition (SCADA) system for the Northstar Moly99 production prototype gas flow loop. The goal of this effort is to expand the existing system to include a second flow loop with a larger production-sized blower. Besides testing the larger blower, this system will demonstrate the scalability of our solution to multiple flow loops.

  19. Market projections of cellulose nanomaterial-enabled products-- Part 2: Volume estimates

    Science.gov (United States)

    John Cowie; E.M. (Ted) Bilek; Theodore H. Wegner; Jo Anne Shatkin

    2014-01-01

    Nanocellulose has enormous potential to provide an important materials platform in numerous product sectors. This study builds on previous work by the same authors in which likely high-volume, low-volume, and novel applications for cellulosic nanomaterials were identified. In particular, this study creates a transparent methodology and estimates the potential annual...

  20. A reliable and consistent production technology for high volume compacted graphite iron castings

    Directory of Open Access Journals (Sweden)

    Liu Jincheng

    2014-07-01

    Full Text Available The demands for improved engine performance, fuel economy, durability, and lower emissions provide a continual challenge for engine designers. The use of Compacted Graphite Iron (CGI has been established for successful high volume series production in the passenger vehicle, commercial vehicle and industrial power sectors over the last decade. The increased demand for CGI engine components provides new opportunities for the cast iron foundry industry to establish efficient and robust CGI volume production processes, in China and globally. The production window range for stable CGI is narrow and constantly moving. Therefore, any one step single addition of magnesium alloy and the inoculant cannot ensure a reliable and consistent production process for complicated CGI engine castings. The present paper introduces the SinterCast thermal analysis process control system that provides for the consistent production of CGI with low nodularity and reduced porosity, without risking the formation of flake graphite. The technology is currently being used in high volume Chinese foundry production. The Chinese foundry industry can develop complicated high demand CGI engine castings with the proper process control technology.

  1. Volume Measurement Algorithm for Food Product with Irregular Shape using Computer Vision based on Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Joko Siswantoro

    2014-11-01

    Full Text Available Volume is one of important issues in the production and processing of food product. Traditionally, volume measurement can be performed using water displacement method based on Archimedes’ principle. Water displacement method is inaccurate and considered as destructive method. Computer vision offers an accurate and nondestructive method in measuring volume of food product. This paper proposes algorithm for volume measurement of irregular shape food product using computer vision based on Monte Carlo method. Five images of object were acquired from five different views and then processed to obtain the silhouettes of object. From the silhouettes of object, Monte Carlo method was performed to approximate the volume of object. The simulation result shows that the algorithm produced high accuracy and precision for volume measurement.

  2. Long term monitoring of water production flow rates in boreholes in the Callovo-Oxfordian argillaceous rock

    International Nuclear Information System (INIS)

    Vinsot, A.; Delay, J.; La Vaissiere, R. de; Cruchaudet, M.

    2010-01-01

    Document available in extended abstract form only. Water production was observed in several boreholes in the Callovo-Oxfordian argillaceous rock (COx). These boreholes were implemented in 2005 in the Andra's Underground Research Laboratory (URL) at more than 400 m in depth. Despite the low COx permeability: close to 10-13 m/s, two original experimental setups made it possible to monitor water production flow rates ranging from 0.5 to 50 mL/day during 3 to 4 years in 4 boreholes. This contribution describes the water flow rate evaluation methods and the results obtained from several experimental phases which may be considered as a series of constant pressure production tests. The first experimental concept was based on seepage water collection. It consisted in filling with gas the interval of an ascending borehole at a pressure close to 1 bar and closing it. The hydraulic pressure in the rock surrounding the sealed interval was higher than 30 bars. Due to the hydraulic pressure difference between the interval and the surrounding rock, the interstitial water of the formation flowed into the interval, accumulated at its base by gravity and was pumped out at a controlled flow rate. The pumping rate was adjusted so that the water level would not exceed 40 cm inside the 5-meter-long interval. The water level was deduced from the difference between two absolute pressure measurements: one above the water surface in the gas phase and the other at the bottom of the water column. The total volume of the daily produced formation water was obtained by adding the water volume pumped out during the day and the water volume difference inside the interval between the beginning and the end of the day. This kind of experiment was performed in two boreholes. The second experimental concept was based on water circulation. It consisted in filling with water the interval of a descending borehole. Two water circulation lines and one pressure control line linked the test interval to

  3. Influence of shear flow on the specific volume and the crystalline morphology of isotactic polypropylene

    NARCIS (Netherlands)

    van der Beek, M.H.E.; Peters, G.W.M.; Meijer, H.E.H.

    2006-01-01

    The influence of shear flow on the temperature evolution of the specific volume and the crystalline morphology of two iPP's, differing in weight-averaged molar mass w, was investigated at nonisothermal conditions and elevated pressures, using a custom-designed dilatometer. These conditions are

  4. Linkages Among Water Vapor Flows, Food Production, and Terrestrial Ecosystem Services

    Directory of Open Access Journals (Sweden)

    Johan Rockström

    1999-12-01

    Full Text Available Global freshwater assessments have not addressed the linkages among water vapor flows, agricultural food production, and terrestrial ecosystem services. We perform the first bottom-up estimate of continental water vapor flows, subdivided into the major terrestrial biomes, and arrive at a total continental water vapor flow of 70,000 km3/yr (ranging from 56,000 to 84,000 km3/yr. Of this flow, 90% is attributed to forests, including woodlands (40,000 km3/yr, wetlands (1400 km3/yr, grasslands (15,100 km3/yr, and croplands (6800 km3/yr. These terrestrial biomes sustain society with essential welfare-supporting ecosystem services, including food production. By analyzing the freshwater requirements of an increasing demand for food in the year 2025, we discover a critical trade-off between flows of water vapor for food production and for other welfare-supporting ecosystem services. To reduce the risk of unintentional welfare losses, this trade-off must become embedded in intentional ecohydrological landscape management.

  5. FORMALIZING PRODUCT COST DISTORTION: The Impact of Volume-Related Allocation Bases on Cost Information

    Directory of Open Access Journals (Sweden)

    Johnny Jermias

    2003-09-01

    Full Text Available The purpose o f this study is to formally analyze product cost distortions resulting from the process of allocating costs to products based on Activity-Based Costing (ABC and the conventional product costing systems. The model developed in this paper rigorously shows the impact of treating costs that are not volume related as if they are. The model demonstrates that the source of product cost distortion is the difference between the proportion of driver used by each product in ABC and the proportion of the base used by the same product in the conventional costing systems. The difference arises because the conventional costing systems ignore the existence of batch-related and product-related costs. The model predicts a positive association between volume and size diversity with product cost distortions. When interaction between volume and size diversity exists, the distortion is either mitigated or exacerbated. The magnitude of the distortion is jointly determined by the size of the differences and the size of the total indirect costs.

  6. Study on a volume-production H- ion source

    International Nuclear Information System (INIS)

    Takama, S.

    1988-01-01

    H - ions formed by volume-production are extracted from a multicuspion source. By applying a large positive bias to the plasma electrode, the ratio I - /I e becomes 1/20. H - ion current of 0.4mA is extracted from a 0.3cm 2 circular aperture at an arc current of 10A. (author)

  7. A two-phase debris-flow model that includes coupled evolution of volume fractions, granular dilatancy, and pore-fluid pressure

    Science.gov (United States)

    George, David L.; Iverson, Richard M.

    2011-01-01

    Pore-fluid pressure plays a crucial role in debris flows because it counteracts normal stresses at grain contacts and thereby reduces intergranular friction. Pore-pressure feedback accompanying debris deformation is particularly important during the onset of debrisflow motion, when it can dramatically influence the balance of forces governing downslope acceleration. We consider further effects of this feedback by formulating a new, depth-averaged mathematical model that simulates coupled evolution of granular dilatancy, solid and fluid volume fractions, pore-fluid pressure, and flow depth and velocity during all stages of debris-flow motion. To illustrate implications of the model, we use a finite-volume method to compute one-dimensional motion of a debris flow descending a rigid, uniformly inclined slope, and we compare model predictions with data obtained in large-scale experiments at the USGS debris-flow flume. Predictions for the first 1 s of motion show that increasing pore pressures (due to debris contraction) cause liquefaction that enhances flow acceleration. As acceleration continues, however, debris dilation causes dissipation of pore pressures, and this dissipation helps stabilize debris-flow motion. Our numerical predictions of this process match experimental data reasonably well, but predictions might be improved by accounting for the effects of grain-size segregation.

  8. In-Vitro gas production technique as for feed evaluation: volume of gas production and feed degradability

    International Nuclear Information System (INIS)

    Asih Kurniawati

    2007-01-01

    In-vitro gas production technique can be used to predict feed quality. The effect of molasses supplementation as a source of degradable carbohydrate to protein source red clover silage has been done using this technique. Data showed there were positive correlation between total volume gas produced and feed degradability (r = 0.96), between total volume gas produced and microbial biomass (r = 0,96). Dry matter degradability, dry matter degraded, microbial biomass production and efficiency of nitrogen utilization, highly significant (P<0,01) increased due to increasing of degradable carbohydrate. The addition of 0.3 g molasses gave the best result whereas the addition of 0.15 g and 0.225 g have better effect than 0.0625 g molasses addition and red clover only. This result suggested that In-vitro production technique can be used as tool for feed evaluation. (author)

  9. Instantaneous equations for multiphase flow in porous media without length-scale restrictions using a non-local averaging volume

    International Nuclear Information System (INIS)

    Espinosa-Paredes, Gilberto

    2010-01-01

    The aim of this paper is to propose a framework to obtain a new formulation for multiphase flow conservation equations without length-scale restrictions, based on the non-local form of the averaged volume conservation equations. The simplification of the local averaging volume of the conservation equations to obtain practical equations is subject to the following length-scale restrictions: d << l << L, where d is the characteristic length of the dispersed phases, l is the characteristic length of the averaging volume, and L is the characteristic length of the physical system. If the foregoing inequality does not hold, or if the scale of the problem of interest is of the order of l, the averaging technique and therefore, the macroscopic theories of multiphase flow should be modified in order to include appropriate considerations and terms in the corresponding equations. In these cases the local form of the averaged volume conservation equations are not appropriate to describe the multiphase system. As an example of the conservation equations without length-scale restrictions, the natural circulation boiling water reactor was consider to study the non-local effects on the thermal-hydraulic core performance during steady-state and transient behaviors, and the results were compared with the classic local averaging volume conservation equations.

  10. TRPV4 activation mediates flow-induced nitric oxide production in the rat thick ascending limb

    Science.gov (United States)

    Garvin, Jeffrey L.

    2014-01-01

    Nitric oxide (NO) regulates renal function. Luminal flow stimulates NO production in the thick ascending limb (TAL). Transient receptor potential vanilloid 4 (TRPV4) is a mechano-sensitive channel activated by luminal flow in different types of cells. We hypothesized that TRPV4 mediates flow-induced NO production in the rat TAL. We measured NO production in isolated, perfused rat TALs using the fluorescent dye DAF FM. Increasing luminal flow from 0 to 20 nl/min stimulated NO from 8 ± 3 to 45 ± 12 arbitrary units (AU)/min (n = 5; P < 0.05). The TRPV4 antagonists, ruthenium red (15 μmol/l) and RN 1734 (10 μmol/l), blocked flow-induced NO production. Also, luminal flow did not increase NO production in the absence of extracellular calcium. We also studied the effect of luminal flow on NO production in TALs transduced with a TRPV4shRNA. In nontransduced TALs luminal flow increased NO production by 47 ± 17 AU/min (P < 0.05; n = 5). Similar to nontransduced TALs, luminal flow increased NO production by 39 ± 11 AU/min (P < 0.03; n = 5) in TALs transduced with a control negative sequence-shRNA while in TRPV4shRNA-transduced TALs, luminal flow did not increase NO production (Δ10 ± 15 AU/min; n = 5). We then tested the effect of two different TRPV4 agonists on NO production in the absence of luminal flow. 4α-Phorbol 12,13-didecanoate (1 μmol/l) enhanced NO production by 60 ± 11 AU/min (P < 0.002; n = 7) and GSK1016790A (10 ηmol/l) increased NO production by 52 ± 15 AU/min (P < 0.03; n = 5). GSK1016790A (10 ηmol/l) did not stimulate NO production in TRPV4shRNA-transduced TALs. We conclude that activation of TRPV4 channels mediates flow-induced NO production in the rat TAL. PMID:24966090

  11. Concentric Split Flow Filter

    Science.gov (United States)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  12. Radiation-induced parotid gland changes in oral cancer patients. Correlation between parotid volume and saliva production

    International Nuclear Information System (INIS)

    Teshima, Keiko; Murakami, Ryuji; Tomitaka, Etsuji

    2010-01-01

    The objective of this study was to evaluate whether saliva production reflects the parotid volume during the course of radiation therapy (RT) in patients with head-and-neck cancer. Twenty patients with advanced oral squamous cell carcinomas, who were treated with preoperative chemo-RT, underwent morphological assessment with CT or MRI and functional assessment with the Saxon test. For the Saxon test, saliva production was measured by weighing a gauze pad before and 2 min after chewing without swallowing; the low-normal value is 2 g. Saliva production and parotid volumes before and 2 weeks after RT were compared with the paired t-test, the Spearman rank correlation test and the Fisher exact test. After 30 Gy irradiation, mean saliva production was decreased from 4.2 to 1.0 g (P 3 (P<0.01); the post-RT: pre-RT parotid volume ratio ranged from 54% to 85% (mean 71%). Although the initial parotid volume was correlated with initial saliva production (r=0.47, P=0.04), no significant correlation was noted after RT (r=0.08, P=0.71), and there were considerable individual variations. The parotid volume ratio was inversely correlated with the saliva-reduction amount (r=-0.79, P<0.01). There was a correlation between decreased parotid gland volume and decreased saliva production in patients with head-and-neck cancer undergoing RT. Parotid volume reduction may predict parotid gland function. (author)

  13. The application of finite volume methods for modelling three-dimensional incompressible flow on an unstructured mesh

    Science.gov (United States)

    Lonsdale, R. D.; Webster, R.

    This paper demonstrates the application of a simple finite volume approach to a finite element mesh, combining the economy of the former with the geometrical flexibility of the latter. The procedure is used to model a three-dimensional flow on a mesh of linear eight-node brick (hexahedra). Simulations are performed for a wide range of flow problems, some in excess of 94,000 nodes. The resulting computer code ASTEC that incorporates these procedures is described.

  14. Improved brachial artery shear patterns and increased flow-mediated dilation after low-volume high-intensity interval training in type 2 diabetes.

    Science.gov (United States)

    Ghardashi Afousi, Alireza; Izadi, Mohammad Reza; Rakhshan, Kamran; Mafi, Farnoosh; Biglari, Soheil; Gandomkar Bagheri, Habibalah

    2018-06-22

    What is the central question of this study? Endothelial function is impaired because of increased oscillatory and retrograde shear in patients with type 2 diabetes. It is unclear whether low-volume high-intensity interval training and continuous moderate intensity exercise can modulate oscillatory and retrograde shear, blood flow and flow-mediated arterial dilation in these patients. What is the main finding and its importance? We found that low-volume high-intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow-mediated dilation and outward arterial remodelling in patients with type 2 diabetes. Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate intensity training (CMIT). Seventy five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85%-90% HR max and 2 min at 55%-60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max for 3 sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there were no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0

  15. Flow velocity and volume measurement of superior and inferior mesenteric artery with cine phase contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Cooper, T.G.; Jenner, G.; Potchen, E.J.; Ishigaki, Takeo.

    1994-01-01

    The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3±46.8 ml/min (mean±standard error) during the fasting state, and 714.7±207.7 ml/min, 339.2±85.7 ml/min, and 263.8±21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p<0.05). The corresponding flow measurements in the IMA were 63.1±11.2 ml/min, 67.6±11.2 ml/min, 57.9±8.6 ml/min, and 53.2±6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia. (author)

  16. Analysis of quality information flows in the product creation process of high-volume consumer products

    NARCIS (Netherlands)

    Sander, P.C.; Brombacher, A.C.

    2000-01-01

    It is recently realised that Quality and Reliability are not only a function of the product but also of the organisation realising the product. In spite of this very few companies are able to translate this into their business processes. The Maturity Index on Reliability (MIR) was developed to

  17. Study of geometry to obtain the volume fraction of multiphase flows using the MCNP-X code

    International Nuclear Information System (INIS)

    Peixoto, Philippe N.B.; Salgado, Cesar M.

    2015-01-01

    The gamma ray attenuation technique is used in many works to obtaining volume fraction of multiphase flows in the oil industry, because it is a noninvasive technique with good precision. In these studies are simulated various geometries with different flow regime, compositions of materials, source-detector positions and types of collimation for sources. This work aim evaluate the interference in the results of the geometry changes and obtaining the best measuring geometry to provide the volume fractions accurately by evaluating different geometries simulations (ranging the source-detector position, flow schemes and homogeneity Makeup) in the MCNP-X code. The study was performed for two types of biphasic compositions of materials (oil-water and oil-air), two flow regimes (annular and smooth stratified) and was varied the position of each material in relative to source and detector positions. Another study to evaluate the interference of homogeneity of the compositions in the results was also conducted in order to verify the possibility of removing part of the composition and make a homogeneous blend using a mixer equipment. All these variations were simulated with two different types of beam, divergent beam and pencil beam. From the simulated geometries, it was possible to compare the differences between the areas of the spectra generated for each model. The results indicate that the flow regime and the differences in the material's densities interfere in the results being necessary to establish a specific simulation geometry for each flows regime. However, the simulations indicate that changing the type of collimation of sources do not affect the results, but improving the counts statistics, increasing the accurate. (author)

  18. Study of geometry to obtain the volume fraction of multiphase flows using the MCNP-X code

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Philippe N.B.; Salgado, Cesar M., E-mail: phbelache@hotmail.com, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The gamma ray attenuation technique is used in many works to obtaining volume fraction of multiphase flows in the oil industry, because it is a noninvasive technique with good precision. In these studies are simulated various geometries with different flow regime, compositions of materials, source-detector positions and types of collimation for sources. This work aim evaluate the interference in the results of the geometry changes and obtaining the best measuring geometry to provide the volume fractions accurately by evaluating different geometries simulations (ranging the source-detector position, flow schemes and homogeneity Makeup) in the MCNP-X code. The study was performed for two types of biphasic compositions of materials (oil-water and oil-air), two flow regimes (annular and smooth stratified) and was varied the position of each material in relative to source and detector positions. Another study to evaluate the interference of homogeneity of the compositions in the results was also conducted in order to verify the possibility of removing part of the composition and make a homogeneous blend using a mixer equipment. All these variations were simulated with two different types of beam, divergent beam and pencil beam. From the simulated geometries, it was possible to compare the differences between the areas of the spectra generated for each model. The results indicate that the flow regime and the differences in the material's densities interfere in the results being necessary to establish a specific simulation geometry for each flows regime. However, the simulations indicate that changing the type of collimation of sources do not affect the results, but improving the counts statistics, increasing the accurate. (author)

  19. Nitric oxide, prostaglandins and angiotensin II in the regulation of renal medullary blood flow during volume expansion.

    Science.gov (United States)

    Moreno, Carol; Llinás, María T; Rodriguez, Francisca; Moreno, Juan M; Salazar, F Javier

    2016-03-01

    Regulation of medullary blood flow (MBF) is essential in maintaining renal function and blood pressure. However, it is unknown whether outer MBF (OMBF) and papillary blood flow (PBF) are regulated independently when extracellular volume (ECV) is enhanced. The aim of this study was to determine whether OMBF and PBF are differently regulated and whether there is an interaction between nitric oxide (NO), prostaglandins (PGs) and angiotensin II (Ang II) in regulating OMBF and PBF when ECV is enhanced. To achieve these goals, OMBF and PBF were measured by laser-Doppler in volume-expanded rats treated with a cyclooxygenase inhibitor (meclofenamate, 3 mg/kg) and/or a NO synthesis inhibitor (L-nitro-arginine methyl ester (L-NAME), 3 μg/kg/min) and/or Ang II (10 ng/kg/min). OMBF was unchanged by NO or PGs synthesis inhibition but decreased by 36 % (P blood flows to the outer medulla and renal papilla are differently regulated and showing that there is a complex interaction between NO, PGs and Ang II in regulating OMBF and PBF when ECV is enhanced.

  20. Determination of boron in natural water and products derived from grape using an automated flow injection analysis system with piezoelectric detection

    International Nuclear Information System (INIS)

    Jesus, Dosil P. de; Saito, Renata M.; Lago, Claudimir L. do

    2004-01-01

    An automated flow injection analysis system with piezoelectric detection is proposed as a sensitive and selective method for boron. The detector is an electrode-separated piezoelectric quartz crystal coated with N-methyl-D-glucamine-modified poly(epichlorohydrin). The film ability to retain boron allows the adjustment of the linear dynamic range and the sensitivity by varying the injected sample volume. In the present work, the sample volumes were varied from 0.5 to 5.0 mL. Among several ionic species, germanate is the only one that can interfere in the method. Nevertheless, it can be eliminated by addition of sulfide to the sample. The method was successfully applied to the determination of boron concentration in samples of natural water (from 1.71 to 309 μL -1 ) and products derived from grape juice (from 2.06 to 6.21 mg L -1 ). A pretreatment with hydrogen peroxide in alkaline medium was required due to the great amount of sugars in the grape products (author)

  1. Using Free Flow Energy Cumulation in Wind and Hydro Power Production

    Directory of Open Access Journals (Sweden)

    Lev Ktitorov

    2016-09-01

    Full Text Available When approaching a conventional wind turbine, the air flow is slowed down and widened. This results in a loss of turbine efficiency. In order to exploit wind or water flow power as effectively as possible, it was suggested that the turbine should be placed inside a shroud, which consists of 4 wing-shaped surfaces. Two internal airfoils improve the turbine performance by speeding up the flow acting on the turbine blades, two external wings create a field of low pressure behind the turbine, thus, helping to draw more mass flow to the turbine and avoid the loss of efficiency due to flow deceleration.  The system accumulates kinetic energy of the flow in a small volume where the smaller (and, therefore, cheaper turbine can be installed. A smaller system can be installed inside the bigger one, which would help to accumulate even more kinetic energy on the turbine. We call this method the kinetic energy summation with local flow redistribution. Both experiments and CFD simulations demonstrate a significant increase in velocity and generated mechanical power in comparison of those for a bare turbine.

  2. A simple and rational numerical method of two-phase flow with volume-junction model. 2. The numerical method for general condition of two-phase flow in non-equilibrium states

    International Nuclear Information System (INIS)

    Okazaki, Motoaki

    1997-11-01

    In the previous report, the usefulness of a new numerical method to achieve a rigorous numerical calculation using a simple explicit method with the volume-junction model was presented with the verification calculation for the depressurization of a saturated two-phase mixture. In this report, on the basis of solution method above, a numerical method for general condition of two-phase flow in non-equilibrium states is presented. In general condition of two-phase flow, the combinations of saturated and non-saturated conditions of each phase are considered in the each flow of volume and junction. Numerical evaluation programs are separately prepared for each combination of flow condition. Several numerical calculations of various kinds of non-equilibrium two-phase flow are made to examine the validity of the numerical method. Calculated results showed that the thermodynamic states obtained in different solution schemes were consistent with each other. In the first scheme, the states are determined by using the steam table as a function of pressure and specific enthalpy which are obtained as the solutions of simultaneous equations. In the second scheme, density and specific enthalpy of each phase are directly calculated by using conservation equations of mass and enthalpy of each phase, respectively. Further, no accumulation of error in mass and energy was found. As for the specific enthalpy, two cases of using energy equations for the volume are examined. The first case uses total energy conservation equation and the second case uses the type of the first law of thermodynamics. The results of both cases agreed well. (author)

  3. Estimated probabilities, volumes, and inundation areas depths of potential postwildfire debris flows from Carbonate, Slate, Raspberry, and Milton Creeks, near Marble, Gunnison County, Colorado

    Science.gov (United States)

    Stevens, Michael R.; Flynn, Jennifer L.; Stephens, Verlin C.; Verdin, Kristine L.

    2011-01-01

    During 2009, the U.S. Geological Survey, in cooperation with Gunnison County, initiated a study to estimate the potential for postwildfire debris flows to occur in the drainage basins occupied by Carbonate, Slate, Raspberry, and Milton Creeks near Marble, Colorado. Currently (2010), these drainage basins are unburned but could be burned by a future wildfire. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of postwildfire debris-flow occurrence and debris-flow volumes for drainage basins occupied by Carbonate, Slate, Raspberry, and Milton Creeks near Marble. Data for the postwildfire debris-flow models included drainage basin area; area burned and burn severity; percentage of burned area; soil properties; rainfall total and intensity for the 5- and 25-year-recurrence, 1-hour-duration-rainfall; and topographic and soil property characteristics of the drainage basins occupied by the four creeks. A quasi-two-dimensional floodplain computer model (FLO-2D) was used to estimate the spatial distribution and the maximum instantaneous depth of the postwildfire debris-flow material during debris flow on the existing debris-flow fans that issue from the outlets of the four major drainage basins. The postwildfire debris-flow probabilities at the outlet of each drainage basin range from 1 to 19 percent for the 5-year-recurrence, 1-hour-duration rainfall, and from 3 to 35 percent for 25-year-recurrence, 1-hour-duration rainfall. The largest probabilities for postwildfire debris flow are estimated for Raspberry Creek (19 and 35 percent), whereas estimated debris-flow probabilities for the three other creeks range from 1 to 6 percent. The estimated postwildfire debris-flow volumes at the outlet of each creek range from 7,500 to 101,000 cubic meters for the 5-year-recurrence, 1-hour-duration rainfall, and from 9,400 to 126,000 cubic meters for

  4. Rapid assay for cell age response to radiation by electronic volume flow cell sorting

    International Nuclear Information System (INIS)

    Freyer, J.P.; Wilder, M.E.; Raju, M.R.

    1987-01-01

    A new technique is described for measuring cell survival as a function of cell cycle position using flow cytometric cell sorting on the basis of electronic volume signals. Sorting of cells into different cell age compartments is demonstrated for three different cell lines commonly used in radiobiological research. Using flow cytometric DNA content analysis and [ 3 H]thymidine autoradiography of the sorted cell populations, it is demonstrated that resolution of the age compartment separation is as good as or better than that reported for other cell synchronizing techniques. Variation in cell survival as a function of position in the cell cycle after a single dose of radiation as measured by volume cell sorting is similar to that determined by other cell synchrony techniques. Advantages of this method include: (1) no treatment of the cells is required, thus, this method is noncytotoxic; (2) no cell cycle progression is needed to obtain different cell age compartments; (3) the cell population can be held in complete growth medium at any desired temperature during sorting; (4) a complete radiation age - response assay can be plated in 2 h. Applications of this method are discussed, along with some technical limitations. (author)

  5. System Development of Estimated Figures of Volume Production Plan

    Science.gov (United States)

    Brazhnikov, Maksim A.; Khorina, Irina V.; Minina, Yulia I.; Kolyasnikova, Lyudmila V.; Streltsov, Aleksey V.

    2016-01-01

    The relevance of this problem is primarily determined by a necessity of improving production efficiency in conditions of innovative development of the economy and implementation of Import Substitution Program. The purpose of the article is development of set of criteria and procedures for the comparative assessment of alternative volume production…

  6. Fluid mechanics experiments in oscillatory flow. Volume 2: Tabulated data

    Science.gov (United States)

    Seume, J.; Friedman, G.; Simon, T. W.

    1992-01-01

    Results of a fluid mechanics measurement program in oscillating flow within a circular duct are presented. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re sub max, Re sub w, and A sub R, embody the velocity amplitude, frequency of oscillation, and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radial components of ensemble-averaged velocity and rms velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and its reverse, were identified and sufficient data was gathered to propose the transition mechanism. Volume 2 contains data reduction program listings and tabulated data (including its graphics).

  7. Simulation of biological flow and transport in complex geometries using embedded boundary/volume-of-fluid methods

    International Nuclear Information System (INIS)

    Trebotich, David

    2007-01-01

    We have developed a simulation capability to model multiscale flow and transport in complex biological systems based on algorithms and software infrastructure developed under the SciDAC APDEC CET. The foundation of this work is a new hybrid fluid-particle method for modeling polymer fluids in irregular microscale geometries that enables long-time simulation of validation experiments. Both continuum viscoelastic and discrete particle representations have been used to model the constitutive behavior of polymer fluids. Complex flow environment geometries are represented on Cartesian grids using an implicit function. Direct simulation of flow in the irregular geometry is then possible using embedded boundary/volume-of-fluid methods without loss of geometric detail. This capability has been used to simulate biological flows in a variety of application geometries including biomedical microdevices, anatomical structures and porous media

  8. Finite volume model for two-dimensional shallow environmental flow

    Science.gov (United States)

    Simoes, F.J.M.

    2011-01-01

    This paper presents the development of a two-dimensional, depth integrated, unsteady, free-surface model based on the shallow water equations. The development was motivated by the desire of balancing computational efficiency and accuracy by selective and conjunctive use of different numerical techniques. The base framework of the discrete model uses Godunov methods on unstructured triangular grids, but the solution technique emphasizes the use of a high-resolution Riemann solver where needed, switching to a simpler and computationally more efficient upwind finite volume technique in the smooth regions of the flow. Explicit time marching is accomplished with strong stability preserving Runge-Kutta methods, with additional acceleration techniques for steady-state computations. A simplified mass-preserving algorithm is used to deal with wet/dry fronts. Application of the model is made to several benchmark cases that show the interplay of the diverse solution techniques.

  9. Effect of hysteroscopic adhesiolysis combined with growth hormone on endometrial blood flow and volume as well as Smad2/3 expression

    Directory of Open Access Journals (Sweden)

    Xing-Chan Li

    2016-10-01

    Full Text Available Objective: To study the effect of hysteroscopic adhesiolysis combined with growth hormone on endometrial blood flow and volume as well as Smad2/3 expression. Methods: A total of 64 patients with moderate or severe intrauterine adhesions who received hysteroscopic adhesiolysis in our hospital from May 2013 to October 2015 were selected as the research subjects and randomly divided into two groups who received different postoperative drug treatment, observation group received postoperative manual cycle intervention combined with growth hormone treatment and control group only received manual cycle intervention. Transvaginal ultrasonography was conducted after treatment to assess endometrial thickness, volume and blood flow, and endometrium was collected to determine Smad2, Smad3 and TGF- β1 levels. Results: After treatment, endometrial blood flow signal of observation group was more abundant than that of control group, ultrasound parameters RI and PI were significantly lower than those of control group, and VI, FI and VFI as well as endometrial thickness and endometrial cavity volume were significantly higher than those of control group; Smad2, Smad3 and TGF-β1 levels in endometrial tissue of observation group after treatment were significantly lower than those of control group. Conclusions: Hysteroscopic adhesiolysis combined with growth hormone therapy can promote endometrial repair and growth, increase endometrial blood flow and volume and also suppress the expression of Smad2/3 and TGF-β1 in patients with intrauterine adhesions.

  10. Evidence for P-Glycoprotein Involvement in Cell Volume Regulation Using Coulter Sizing in Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Jennifer Pasquier

    2015-06-01

    Full Text Available The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp. The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading, we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.

  11. Development and Application of a Low-Volume Flow System for Solution-State in Vivo NMR.

    Science.gov (United States)

    Tabatabaei Anaraki, Maryam; Dutta Majumdar, Rudraksha; Wagner, Nicole; Soong, Ronald; Kovacevic, Vera; Reiner, Eric J; Bhavsar, Satyendra P; Ortiz Almirall, Xavier; Lane, Daniel; Simpson, Myrna J; Heumann, Hermann; Schmidt, Sebastian; Simpson, André J

    2018-06-18

    In vivo nuclear magnetic resonance (NMR) spectroscopy is a particularly powerful technique, since it allows samples to be analyzed in their natural, unaltered state, criteria paramount for living organisms. In this study, a novel continuous low-volume flow system, suitable for in vivo NMR metabolomics studies, is demonstrated. The system allows improved locking, shimming, and water suppression, as well as allowing the use of trace amounts of expensive toxic contaminants or low volumes of precious natural environmental samples as stressors. The use of a double pump design with a sump slurry pump return allows algal food suspensions to be continually supplied without the need for filters, eliminating the possibility of clogging and leaks. Using the flow system, the living organism can be kept alive without stress indefinitely. To evaluate the feasibility and applicability of the flow system, changes in the metabolite profile of 13 C enriched Daphnia magna over a 24-h period are compared when feeding laboratory food vs exposing them to a natural algal bloom sample. Clear metabolic changes are observed over a range of metabolites including carbohydrates, lipids, amino acids, and a nucleotide demonstrating in vivo NMR as a powerful tool to monitor environmental stress. The particular bloom used here was low in microcystins, and the metabolic stress impacts are consistent with the bloom being a poor food source forcing the Daphnia to utilize their own energy reserves.

  12. Hybrid finite-volume/transported PDF method for the simulation of turbulent reactive flows

    Science.gov (United States)

    Raman, Venkatramanan

    A novel computational scheme is formulated for simulating turbulent reactive flows in complex geometries with detailed chemical kinetics. A Probability Density Function (PDF) based method that handles the scalar transport equation is coupled with an existing Finite Volume (FV) Reynolds-Averaged Navier-Stokes (RANS) flow solver. The PDF formulation leads to closed chemical source terms and facilitates the use of detailed chemical mechanisms without approximations. The particle-based PDF scheme is modified to handle complex geometries and grid structures. Grid-independent particle evolution schemes that scale linearly with the problem size are implemented in the Monte-Carlo PDF solver. A novel algorithm, in situ adaptive tabulation (ISAT) is employed to ensure tractability of complex chemistry involving a multitude of species. Several non-reacting test cases are performed to ascertain the efficiency and accuracy of the method. Simulation results from a turbulent jet-diffusion flame case are compared against experimental data. The effect of micromixing model, turbulence model and reaction scheme on flame predictions are discussed extensively. Finally, the method is used to analyze the Dow Chlorination Reactor. Detailed kinetics involving 37 species and 158 reactions as well as a reduced form with 16 species and 21 reactions are used. The effect of inlet configuration on reactor behavior and product distribution is analyzed. Plant-scale reactors exhibit quenching phenomena that cannot be reproduced by conventional simulation methods. The FV-PDF method predicts quenching accurately and provides insight into the dynamics of the reactor near extinction. The accuracy of the fractional time-stepping technique in discussed in the context of apparent multiple-steady states observed in a non-premixed feed configuration of the chlorination reactor.

  13. Study on influence of flow rates on voids in waxy crude oil subjected to dynamic and static cooling

    Directory of Open Access Journals (Sweden)

    Girma T. Chala

    2015-12-01

    Full Text Available The assumption of constant yield stress in the conventional restart pressure equation neglects the effects of thermal shrinkage and gas voids formation, which in turn resulted in an over-designed production piping systems. This paper presents a study on the effects of flow rates on the formation of voids in gelled waxy crude oil. A flow loop rig simulating offshore waxy crude oil transportation was used to produce a gel. A Magnetic Resonance Imaging (MRI was used to scan the gelled crude oil over the three planes. Waxy crude oil underwent both dynamic and static cooling to observe the effects of volume flow rates on the voids formed in wax-oil gel. Volume flow rate was found to have different influences on the intra-gel voids in the pipeline. A volume flow rate of 5 L/min resulted in a maximum total voids volume of 6.98% while 20 L/min produced a minimum total voids volume of 5.67% in the entire pipe. Slow flow rates resulted in a larger voids volume near the pipe wall. In contrast, faster flow rates produced insignificantly higher voids volume around pipe core. Generally, slower flow rates favoured the formation of higher total voids volume following sufficient steady time of wax crystal formation, producing larger voids areas in gelled waxy crude oil.

  14. Tree water storage and its diurnal dynamics related to sap flow and changes in stem volume in old-growth Douglas-fir trees.

    Science.gov (United States)

    Cermák, Jan; Kucera, Jiri; Bauerle, William L; Phillips, Nathan; Hinckley, Thomas M

    2007-02-01

    Diurnal and seasonal tree water storage was studied in three large Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees at the Wind River Canopy Crane Research site. Changes in water storage were based on measurements of sap flow and changes in stem volume and tissue water content at different heights in the stem and branches. We measured sap flow by two variants of the heat balance method (with internal heating in stems and external heating in branches), stem volume with electronic dendrometers, and tissue water content gravimetrically. Water storage was calculated from the differences in diurnal courses of sap flow at different heights and their integration. Old-growth Douglas-fir trees contained large amounts of free water: stem sapwood was the most important storage site, followed by stem phloem, branch sapwood, branch phloem and needles. There were significant time shifts (minutes to hours) between sap flow measured at different positions within the transport system (i.e., stem base to shoot tip), suggesting a highly elastic transport system. On selected fine days between late July and early October, when daily transpiration ranged from 150 to 300 liters, the quantity of stored water used daily ranged from 25 to 55 liters, i.e., about 20% of daily total sap flow. The greatest amount of this stored water came from the lower stem; however, proportionally more water was removed from the upper parts of the tree relative to their water storage capacity. In addition to lags in sap flow from one point in the hydrolic pathway to another, the withdrawal and replacement of stored water was reflected in changes in stem volume. When point-to-point lags in sap flow (minutes to hours near the top and stem base, respectively) were considered, there was a strong linear relationship between stem volume changes and transpiration. Volume changes of the whole tree were small (equivalent to 14% of the total daily use of stored water) indicating that most stored water came from

  15. An assessment of unstructured grid finite volume schemes for cold gas hypersonic flow calculations

    Directory of Open Access Journals (Sweden)

    João Luiz F. Azevedo

    2009-06-01

    Full Text Available A comparison of five different spatial discretization schemes is performed considering a typical high speed flow application. Flowfields are simulated using the 2-D Euler equations, discretized in a cell-centered finite volume procedure on unstructured triangular meshes. The algorithms studied include a central difference-type scheme, and 1st- and 2nd-order van Leer and Liou flux-vector splitting schemes. These methods are implemented in an efficient, edge-based, unstructured grid procedure which allows for adaptive mesh refinement based on flow property gradients. Details of the unstructured grid implementation of the methods are presented together with a discussion of the data structure and of the adaptive refinement strategy. The application of interest is the cold gas flow through a typical hypersonic inlet. Results for different entrance Mach numbers and mesh topologies are discussed in order to assess the comparative performance of the various spatial discretization schemes.

  16. Flow behavior of volume-heated boiling pools: implications with respect to transition phase accident conditions

    International Nuclear Information System (INIS)

    Ginsberg, T.; Jones, O.C. Jr.; Chen, J.C.

    1979-01-01

    Observations of two-phase flow fields in single-component volume-heated boiling pools were made. Photographic observations, together with pool-average void fraction measurements, indicate that the churn-turbulent flow regime is stable for superficial vapor velocities up to nearly five times the Kutateladze dispersal limit. Within this range of conditions, a churn-turbulent drift flux model provides a reasonable prediction of the pool-average void fraction data. An extrapolation of the data to transition phase accident conditions suggests that intense boilup could occur where the pool-average void fraction would be >0.6 for steel vaporization rates equivalent to power levels >1% of nominal liquid-metal fast breeder reactor power density. The extended stability of bubbly flow to unusually large vapor fluxes and void fractions, observed in some experiments, is a major unresolved issue

  17. Application of artificial neural networks for the prediction of volume fraction using spectra of gamma rays backscattered by three-phase flows

    Science.gov (United States)

    Gholipour Peyvandi, R.; Islami Rad, S. Z.

    2017-12-01

    The determination of the volume fraction percentage of the different phases flowing in vessels using transmission gamma rays is a conventional method in petroleum and oil industries. In some cases, with access only to the one side of the vessels, attention was drawn toward backscattered gamma rays as a desirable choice. In this research, the volume fraction percentage was measured precisely in water-gasoil-air three-phase flows by using the backscatter gamma ray technique andthe multilayer perceptron (MLP) neural network. The volume fraction determination in three-phase flows requires two gamma radioactive sources or a dual-energy source (with different energies) while in this study, we used just a 137Cs source (with the single energy) and a NaI detector to analyze backscattered gamma rays. The experimental set-up provides the required data for training and testing the network. Using the presented method, the volume fraction was predicted with a mean relative error percentage less than 6.47%. Also, the root mean square error was calculated as 1.60. The presented set-up is applicable in some industries with limited access. Also, using this technique, the cost, radiation safety and shielding requirements are minimized toward the other proposed methods.

  18. E-beam direct write versus reticle/stepper technology for ASICS in small volume production

    International Nuclear Information System (INIS)

    Wheeler, M.J.

    1987-01-01

    The pros and cons of using e-beam direct writing or reticles plus optical/UV steppers in fast prototyping and the small volume production of ASICs are discussed. The main conclusion is that fast prototyping is best achieved by e-beam direct write whereas small volume production of ASICs is best done via reticles and optical/UV stepping provided that the reticles are made in-house rather than by commercial maskhouses

  19. Analysis of poultry meat production volume in Serbia from 1984. to 2009

    Directory of Open Access Journals (Sweden)

    Glamočlija Nataša

    2013-01-01

    Full Text Available Poultry meat production has doubled in past 40 years in the world, with the tendency of constant growth, and its production volume exceeds beef, but is behind pork production. For poultry meat production it is typical that its annual increase exceeds pork as well as beef production. The biggest producers of poultry meat are Asia, North and South America and Europe. The most significant category of poultry is meat of young chicken (broilers. Cobb, Ross and Hubbard broiler provenance are most common in Serbia. The objective of this investigation was to analyse poultry meat production volume in Serbia, observed during three six-years periods - A (1984-1989, B (1994-1999 i C (2004-2009. For data processing there were used the data obtained from Statistical Yearbooks of Serbia from 1984. to 2009. It was found out that average poultry meat production in period A was 108,33 ± 7,00 thousand tonnes, than it statistically significantly decreased and in period B it was 76,67±5,54 thousand tonnes, and finally in period C it was 72,17± 5,78 thousand tonnes. [Projekat Ministarstva nauke Republike Srbije, br. TR 31034

  20. Numerical solution of viscous and viscoelastic fluids flow through the branching channel by finite volume scheme

    Science.gov (United States)

    Keslerová, Radka; Trdlička, David

    2015-09-01

    This work deals with the numerical modelling of steady flows of incompressible viscous and viscoelastic fluids through the three dimensional channel with T-junction. The fundamental system of equations is the system of generalized Navier-Stokes equations for incompressible fluids. This system is based on the system of balance laws of mass and momentum for incompressible fluids. Two different mathematical models for the stress tensor are used for simulation of Newtonian and Oldroyd-B fluids flow. Numerical solution of the described models is based on cetral finite volume method using explicit Runge-Kutta time integration.

  1. Simulation of corrosion product activity in pressurized water reactors under flow rate transients

    International Nuclear Information System (INIS)

    Mirza, Anwar M.; Mirza, Nasir M.; Mir, Imran

    1998-01-01

    Simulation of coolant activation due to corrosion products and impurities in a typical pressurized water reactor has been done under flow rate transients. Employing time dependent production and losses of corrosion products in the primary coolant path an approach has been developed to calculate the coolant specific activity. Results for 24 Na, 56 Mn, 59 Fe, 60 Co and 99Mo show that the specific activity in primary loop approaches equilibrium value under normal operating conditions fairly rapidly. Predominant corrosion product activity is due to Mn-56. Parametric studies at full power for various ramp decreases in flow rate show initial decline in the activity and then a gradual rise to relatively higher saturation values. The minimum value and the time taken to reach the minima are strong functions of the slope of linear decrease in flow rate. In the second part flow rate coastdown was allowed to occur at different flow half-times. The reactor scram was initiated at 90% of the normal flow rate. The results show that the specific activity decreases and the rate of decrease depends on pump half time and the reactor scram conditions

  2. Finite volume simulation of 2-D steady square lid driven cavity flow at high reynolds numbers

    Directory of Open Access Journals (Sweden)

    K. Yapici

    2013-12-01

    Full Text Available In this work, computer simulation results of steady incompressible flow in a 2-D square lid-driven cavity up to Reynolds number (Re 65000 are presented and compared with those of earlier studies. The governing flow equations are solved by using the finite volume approach. Quadratic upstream interpolation for convective kinematics (QUICK is used for the approximation of the convective terms in the flow equations. In the implementation of QUICK, the deferred correction technique is adopted. A non-uniform staggered grid arrangement of 768x768 is employed to discretize the flow geometry. Algebraic forms of the coupled flow equations are then solved through the iterative SIMPLE (Semi-Implicit Method for Pressure-Linked Equation algorithm. The outlined computational methodology allows one to meet the main objective of this work, which is to address the computational convergence and wiggled flow problems encountered at high Reynolds and Peclet (Pe numbers. Furthermore, after Re > 25000 additional vortexes appear at the bottom left and right corners that have not been observed in earlier studies.

  3. Information Flow Scheduling in Concurrent Multi-Product Development Based on DSM

    Science.gov (United States)

    Sun, Qing-Chao; Huang, Wei-Qiang; Jiang, Ying-Jie; Sun, Wei

    2017-09-01

    Multi-product collaborative development is adopted widely in manufacturing enterprise, while the present multi-project planning models don't take technical/data interactions of multiple products into account. To decrease the influence of technical/data interactions on project progresses, the information flow scheduling models based on the extended DSM is presented. Firstly, information dependencies are divided into four types: series, parallel, coupling and similar. Secondly, different types of dependencies are expressed as DSM units, and the extended DSM model is brought forward, described as a block matrix. Furthermore, the information flow scheduling methods is proposed, which involves four types of operations, where partitioning and clustering algorithm are modified from DSM for ensuring progress of high-priority project, merging and converting is the specific computation of the extended DSM. Finally, the information flow scheduling of two machine tools development is analyzed with example, and different project priorities correspond to different task sequences and total coordination cost. The proposed methodology provides a detailed instruction for information flow scheduling in multi-product development, with specially concerning technical/data interactions.

  4. A numerical investigation of the resin flow front tracking applied to the RTM process

    Directory of Open Access Journals (Sweden)

    Jeferson Avila Souza

    2011-09-01

    Full Text Available Resin Transfer Molding (RTM is largely used for the manufacturing of high-quality composite components and the key stage during processing is the resin infiltration. The complete understanding of this phenomenon is of utmost importance for efficient mold construction and the fast production of high quality components. This paper investigates the resin flow phenomenon within the mold. A computational application was developed to track the resin flow-front position, which uses a finite volume method to determine the pressure field and a FAN (Flow Analysis Network technique to track the flow front. The mass conservation problem observed with traditional FE-CV (Finite Element-Control Volume methods is also investigated and the use of a finite volume method to minimize this inconsistency is proposed. Three proposed case studies are used to validate the methodology by direct comparison with analytical and a commercial software solutions. The results show that the proposed methodology is highly efficient to determine the resin flow front, showing an improvement regarding mass conservation across volumes.

  5. 1995 national heat transfer conference: Proceedings. Volume 12: Falling films; Fundamentals of subcooled flow boiling; Compact heat exchanger technology for the process industry; HTD-Volume 314

    International Nuclear Information System (INIS)

    Sernas, V.; Boyd, R.D.; Jensen, M.K.

    1995-01-01

    The papers in the first section cover falling films and heat transfer. Papers in the second section address issues associated with heat exchangers, such as: plate-and-frame heat exchanger technology; thermal design issues; condensation; and single-phase flows. The papers in the third section deal with studies related to: the turbulent velocity field in a vertical annulus; the effects of curvature and a dissolved noncondensable gas on nucleate boiling heat transfer; the effects of flow obstruction on the onset of a Ledinegg-type flow instability; pool boiling from a large-diameter tube; and two-dimensional wall temperature distributions and convection in a single-sided heated vertical tube. Separate abstracts were prepared for most papers in this volume

  6. Membraneless laminar flow cell for electrocatalytic CO2 reduction with liquid product separation

    International Nuclear Information System (INIS)

    Monroe, Morgan M; Lobaccaro, Peter; Lum, Yanwei; Ager, Joel W

    2017-01-01

    The production of liquid fuel products via electrochemical reduction of CO 2 is a potential path to produce sustainable fuels. However, to be practical, a separation strategy is required to isolate the fuel-containing electrolyte produced at the cathode from the anode and also prevent the oxidation products (i.e. O 2 ) from reaching the cathode. Ion-conducting membranes have been applied in CO 2 reduction reactors to achieve this separation, but they represent an efficiency loss and can be permeable to some product species. An alternative membraneless approach is developed here to maintain product separation through the use of a laminar flow cell. Computational modelling shows that near-unity separation efficiencies are possible at current densities achievable now with metal cathodes via optimization of the spacing between the electrodes and the electrolyte flow rate. Laminar flow reactor prototypes were fabricated with a range of channel widths by 3D printing. CO 2 reduction to formic acid on Sn electrodes was used as the liquid product forming reaction, and the separation efficiency for the dissolved product was evaluated with high performance liquid chromatography. Trends in product separation efficiency with channel width and flow rate were in qualitative agreement with the model, but the separation efficiency was lower, with a maximum value of 90% achieved. (paper)

  7. An Analytical Model for Multilayer Well Production Evaluation to Overcome Cross-Flow Problem

    KAUST Repository

    Hakiki, Farizal; Wibowo, Aris T.; Rahmawati, Silvya D.; Yasutra, Amega; Sukarno, Pudjo

    2017-01-01

    One of the major concerns in a multi-layer system is that interlayer cross-flow may occur if reservoir fluids are produced from commingled layers that have unequal initial pressures. Reservoir would commonly have bigger average reservoir pressure (pore fluid pressure) as it goes deeper. The phenomenon is, however, not followed by the reservoir productivity or injectivity. The existence of reservoir with quite low average-pressure and high injectivity would tend experiencing the cross-flow problem. It is a phenomenon of fluid from bottom layer flowing into upper layer. It would strict upper-layer fluid to flow into wellbore. It is as if there is an injection treatment from bottom layer. The study deploys productivity index an approach parameter taking into account of cross-flow problem instead of injectivity index since it is a production well. The analytical study is to model the reservoir multilayer by addressing to avoid cross-flow problem. The analytical model employed hypothetical and real field data to test it. The scope of this study are: (a) Develop mathematical-based solution to determine the production rate from each layer; (b) Assess different scenarios to optimize production rate, those are: pump setting depth and performance of in-situ choke (ISC) installation. The ISC is acting as an inflow control device (ICD) alike that help to reduce cross-flow occurrence. This study employed macro program to write the code and develop the interface. Fast iterative procedure happens on solving the analytical model. Comparison results recognized that the mathematical-based solution shows a good agreement with the commercial software derived results.

  8. An Analytical Model for Multilayer Well Production Evaluation to Overcome Cross-Flow Problem

    KAUST Repository

    Hakiki, Farizal

    2017-10-17

    One of the major concerns in a multi-layer system is that interlayer cross-flow may occur if reservoir fluids are produced from commingled layers that have unequal initial pressures. Reservoir would commonly have bigger average reservoir pressure (pore fluid pressure) as it goes deeper. The phenomenon is, however, not followed by the reservoir productivity or injectivity. The existence of reservoir with quite low average-pressure and high injectivity would tend experiencing the cross-flow problem. It is a phenomenon of fluid from bottom layer flowing into upper layer. It would strict upper-layer fluid to flow into wellbore. It is as if there is an injection treatment from bottom layer. The study deploys productivity index an approach parameter taking into account of cross-flow problem instead of injectivity index since it is a production well. The analytical study is to model the reservoir multilayer by addressing to avoid cross-flow problem. The analytical model employed hypothetical and real field data to test it. The scope of this study are: (a) Develop mathematical-based solution to determine the production rate from each layer; (b) Assess different scenarios to optimize production rate, those are: pump setting depth and performance of in-situ choke (ISC) installation. The ISC is acting as an inflow control device (ICD) alike that help to reduce cross-flow occurrence. This study employed macro program to write the code and develop the interface. Fast iterative procedure happens on solving the analytical model. Comparison results recognized that the mathematical-based solution shows a good agreement with the commercial software derived results.

  9. Alaska's timber harvest and forest products industry, 2005

    Science.gov (United States)

    Jeff M. Halbrook; Todd A. Morgan; Jason P. Brandt; Charles E. Keegan; Thale Dillon; Tara M. Barrett

    2009-01-01

    This report traces the flow of timber harvested in Alaska during calendar year 2005, describes the composition and operations of the state's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, and sales of primary wood products....

  10. Leveraging Understanding of Flow of Variable Complex Fluid to Design Better Absorbent Hygiene Products

    Science.gov (United States)

    Krautkramer, C.; Rend, R. R.

    2014-12-01

    Menstrual flow, which is a result of shedding of uterus endometrium, occurs periodically in sync with a women's hormonal cycle. Management of this flow while allowing women to pursue their normal daily lives is the purpose of many commercial products. Some of these products, e.g. feminine hygiene pads and tampons, utilize porous materials in achieving their goal. In this paper we will demonstrate different phenomena that have been observed in flow of menstrual fluid through these porous materials, share some of the advances made in experimental and analytical study of these phenomena, and also present some of the unsolved challenges and difficulties encountered while studying this kind of flow. Menstrual fluid is generally composed of four main components: blood plasma, blood cells, cervical mucus, and tissue debris. This non-homogeneous, multiphase fluid displays very complex rheological behavior, e. g., yield stress, thixotropy, and visco-elasticity, that varies throughout and between menstrual cycles and among women due to various factors. Flow rates are also highly variable during menstruation and across the population and the rheological properties of the fluid change during the flow into and through the product. In addition to these phenomena, changes to the structure of the porous medium within the product can also be seen due to fouling and/or swelling of the material. This paper will, also, share how the fluid components impact the flow and the consequences for computer simulation, the creation of a simulant fluid and testing methods, and for designing products that best meet consumer needs. We hope to bring to light the challenges of managing this complex flow to meet a basic need of women all over the world. An opportunity exists to apply learnings from research in other disciplines to improve the scientific knowledge related to the flow of this complex fluid through the porous medium that is a sanitary product.

  11. Effect of gas quantity on two-phase flow characteristics of a mixed-flow pump

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    2016-04-01

    Full Text Available The inlet gas quantity has a great influence on the performance and inner flow characteristics of a mixed-flow pump. In this article, both numerical and experimental methods are used to carry out this research work. The effects under the steady gas volume fraction state and the transient gas quantity variation process on the mixed-flow pump are investigated and compared in detail. It could be concluded that the head of the mixed-flow pump shows slight decline at the low gas volume fraction state, while it decreases sharply at the high gas volume fraction state and then decreases with the increasing gas quantity. There is an obvious asymmetric blade vapor density on the blade suction side under each cavitation state. The cavities can be weakened obviously by increasing the inlet gas volume fraction within a certain range. It has little influence on the internal unsteady flow of the mixed-flow pump when the gas volume fraction is less than 10%, but the pump starts to operate with a great unsteady characteristic when the inlet gas volume fraction increases to 15%.

  12. An intravenous isotope method for measuring regional cerebral blood flow (rCBF) and volume (rCBV)

    International Nuclear Information System (INIS)

    Kuikka, J.; Ahonen, A.; Koivula, A.; Kallanranta, T.; Laitinen, J.

    1977-01-01

    The regional cerebal blood flow (rCBF), initial slope index (ISI), transfer time (t - sub(h)) and volume (rCBV) were measured simultaneously in 43 hospital patients using a 133 Xe intravenous injection method and quantitative dynamic 99 Tcsup(m) brain scintigraphy. The measurements were made with a gamma camera and the data processing interfaced with a small digital computer. The mean values and standard deviations were obtained from 50 control hemispheres standardized to the age of 40 years. Good agreement was found between the blood flow values determined from the intra-arterial and intravenous injection techniques. (author)

  13. Motion of water droplets in the counter flow of high-temperature combustion products

    Science.gov (United States)

    Volkov, R. S.; Strizhak, P. A.

    2018-01-01

    This paper presents the experimental studies of the deceleration, reversal, and entrainment of water droplets sprayed in counter current flow to a rising stream of high-temperature (1100 K) combustion gases. The initial droplets velocities 0.5-2.5 m/s, radii 10-230 μm, relative volume concentrations 0.2·10-4-1.8·10-4 (m3 of water)/(m3 of gas) vary in the ranges corresponding to promising high-temperature (over 1000 K) gas-vapor-droplet applications (for example, polydisperse fire extinguishing using water mist, fog, or appropriate water vapor-droplet veils, thermal or flame treatment of liquids in the flow of combustion products or high-temperature air; creating coolants based on flue gas, vapor and water droplets; unfreezing of granular media and processing of the drossed surfaces of thermal-power equipment; ignition of liquid and slurry fuel droplets). A hardware-software cross-correlation complex, high-speed (up to 105 fps) video recording tools, panoramic optical techniques (Particle Image Velocimetry, Particle Tracking Velocimetry, Interferometric Particle Imagine, Shadow Photography), and the Tema Automotive software with the function of continuous monitoring have been applied to examine the characteristics of the processes under study. The scale of the influence of initial droplets concentration in the gas flow on the conditions and features of their entrainment by high-temperature gases has been specified. The dependencies Red = f(Reg) and Red' = f(Reg) have been obtained to predict the characteristics of the deceleration of droplets by gases at different droplets concentrations.

  14. The morphology and evolution of the Stromboli 2002-2003 lava flow field--An example of a basaltic flow field emplaced on a steep slope

    Science.gov (United States)

    Lodato, Luigi; Harris, A.; Spampinato, L.; Calvari, Sonia; Dehn, J.; Patrick, M.

    2007-01-01

    The use of a hand-held thermal camera during the 2002–2003 Stromboli effusive eruption proved essential in tracking the development of flow field structures and in measuring related eruption parameters, such as the number of active vents and flow lengths. The steep underlying slope on which the flow field was emplaced resulted in a characteristic flow field morphology. This comprised a proximal shield, where flow stacking and inflation caused piling up of lava on the relatively flat ground of the vent zone, that fed a medial–distal lava flow field. This zone was characterized by the formation of lava tubes and tumuli forming a complex network of tumuli and flows linked by tubes. Most of the flow field was emplaced on extremely steep slopes and this had two effects. It caused flows to slide, as well as flow, and flow fronts to fail frequently, persistent flow front crumbling resulted in the production of an extensive debris field. Channel-fed flows were also characterized by development of excavated debris levees in this zone (Calvari et al. 2005). Collapse of lava flow fronts and inflation of the upper proximal lava shield made volume calculation very difficult. Comparison of the final field volume with that expecta by integrating the lava effusion rates through time suggests a loss of ~70% erupted lava by flow front crumbling and accumulation as debris flows below sea level. Derived relationships between effusion rate, flow length, and number of active vents showed systematic and correlated variations with time where spreading of volume between numerous flows caused an otherwise good correlation between effusion rate, flow length to break down. Observations collected during this eruption are useful in helping to understand lava flow processes on steep slopes, as well as in interpreting old lava–debris sequences found in other steep-sided volcanoes subject to effusive activity.

  15. Follicle vascularity coordinates corpus luteum blood flow and progesterone production.

    Science.gov (United States)

    de Tarso, S G S; Gastal, G D A; Bashir, S T; Gastal, M O; Apgar, G A; Gastal, E L

    2017-03-01

    Colour Doppler ultrasonography was used to compare the ability of preovulatory follicle (POF) blood flow and its dimensions to predict the size, blood flow and progesterone production capability of the subsequent corpus luteum (CL). Cows (n=30) were submitted to a synchronisation protocol. Follicles ≥7mm were measured and follicular wall blood flow evaluated every 12h for approximately 3.5 days until ovulation. After ovulation, cows were scanned daily for 8 days and similar parameters were evaluated for the CL. Blood samples were collected and plasma progesterone concentrations quantified. All parameters were positively correlated. Correlation values ranged from 0.26 to 0.74 on data normalised to ovulation and from 0.31 to 0.74 on data normalised to maximum values. Correlations between calculated ratios of both POF and CL in data normalised to ovulation and to maximum values ranged from moderate (0.57) to strong (0.87). Significant (Pprogesterone concentrations of the resultant CL. These findings indicate that follicle vascularity coordinates CL blood flow and progesterone production in synchronised beef cows.

  16. Improvement of productivity in low volume production industry layout by using witness simulation software

    Science.gov (United States)

    Jaffrey, V.; Mohamed, N. M. Z. N.; Rose, A. N. M.

    2017-10-01

    In almost all manufacturing industry, increased productivity and better efficiency of the production line are the most important goals. Most factories especially small scale factory has less awareness of manufacturing system optimization and lack of knowledge about it and uses the traditional way of management. Problems that are commonly identified in the factory are a high idle time of labour and also small production. This study is done in a Small and Medium Enterprises (SME) low volume production company. Data collection and problems affecting productivity and efficiency are identified. In this study, Witness simulation software is being used to simulate the layout and the output is focusing on the improvement of layout in terms of productivity and efficiency. In this study, the layout is rearranged by reducing the travel time from a workstation to another workstation. Then, the improved layout is modelled and the machine and labour statistic of both, original and improved layout is taken. Productivity and efficiency are calculated for both layout and then being compared.

  17. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  18. Hydropower Production and Fish Habitat Suitability: Impact and Effectiveness of Environmental Flow Prescriptions

    Science.gov (United States)

    Castellarin, A.; Galeati, G.; Ceola, S.; Pugliese, A.; Ventura, M.; Montanari, A.

    2017-12-01

    The anthropogenic alteration of the natural flow regime of a river for hydropower production can significantly modify the processes and functions associated with fluvial ecosystems. In order to preserve the fluvial habitat downstream of dams and diversion structures, environmental flows are commonly defined. Such environmental flows are generally computed from empirical methodologies, which are seldom based on site-specific studies, and may not be representative of local ecological and hydraulic conditions. Here we present the results of a quantitative analysis on the effectiveness of two alternative environmental flow scenarios prescribed in Central Italy (time-invariant experimental and empirically-based flow release versus time-variant hydrogeomorphologically-based flow release) and their impact on hydropower production and fish habitat suitability. The latter is examined by means of several models of habitat suitability curve, which is a well-known approach capable of analysing fluvial species preferences as a function of key eco-hydraulic features, such as water depth, flow velocity and river substrate. The results show an evident loss of hydropower production moving from the time-invariant experimental flow release to the hydrogeomorphological one (nearly 20% at the annual scale). Concerning the effects in terms of fish habitat suitability, our outcomes are less obvious, since they are species- and life stage-specific. The proposed analysis, which can be easily adapted to different riparian habitats and hydrological contexts, is a useful tool to guide the derivation of optimal water resource management strategies in order to ensure both hydropower production and fluvial ecosystem protection.

  19. Intention to Purchase Products under Volume Discount Scheme: A Conceptual Model and Research Propositions

    Directory of Open Access Journals (Sweden)

    Mohammad Iranmanesh

    2014-12-01

    Full Text Available Many standard brands sell products under the volume discount scheme (VDS as more and more consumers are fond of purchasing products under this scheme. Despite volume discount being commonly practiced, there is a dearth of research, both conceptual and empirical, focusing on purchase characteristics factors and consumer internal evaluation concerning the purchase of products under VDS. To attempt to fill this void, this article develops a conceptual model on VDS with the intention of delineating the influence of the purchase characteristics factors on the consumer intention to purchase products under VDS and provides an explanation of their effects through consumer internal evaluation. Finally, the authors discuss the managerial implications of their research and offer guidelines for future empirical research.

  20. Measurable inhomogeneities in stock trading volume flow

    Science.gov (United States)

    Cortines, A. A. G.; Riera, R.; Anteneodo, C.

    2008-08-01

    We investigate the statistics of volumes of shares traded in stock markets. We show that the stochastic process of trading volumes can be understood on the basis of a mixed Poisson process at the microscopic time level. The beta distribution of the second kind (also known as q-gamma distribution), that has been proposed to describe empirical volume histograms, naturally results from our analysis. In particular, the shape of the distribution at small volumes is governed by the degree of granularity in the trading process, while the exponent controlling the tail is a measure of the inhomogeneities in market activity. Furthermore, the present case furnishes empirical evidence of how power law probability distributions can arise as a consequence of a fluctuating intrinsic parameter.

  1. Can Wet Rocky Granular Flows Become Debris Flows Due to Fine Sediment Production by Abrasion?

    Science.gov (United States)

    Arabnia, O.; Sklar, L. S.; Bianchi, G.; Mclaughlin, M. K.

    2015-12-01

    Debris flows are rapid mass movements in which elevated pore pressures are sustained by a viscous fluid matrix with high concentrations of fine sediments. Debris flows may form from coarse-grained wet granular flows as fine sediments are entrained from hillslope and channel material. Here we investigate whether abrasion of the rocks within a granular flow can produce sufficient fine sediments to create debris flows. To test this hypothesis experimentally, we used a set of 4 rotating drums ranging from 0.2 to 4.0 m diameter. Each drum has vanes along the boundary ensure shearing within the flow. Shear rate was varied by changing drum rotational velocity to maintain a constant Froude Number across drums. Initial runs used angular clasts of granodiorite with a tensile strength of 7.6 MPa, with well-sorted coarse particle size distributions linearly scaled with drum radius. The fluid was initially clear water, which rapidly acquired fine-grained wear products. After each 250 m tangential distance, we measured the particle size distributions, and then returned all water and sediment to the drums for subsequent runs. We calculate particle wear rates using statistics of size and mass distributions, and by fitting the Sternberg equation to the rate of mass loss from the size fraction > 2mm. Abundant fine sediments were produced in the experiments, but very little change in the median grain size was detected. This appears to be due to clast rounding, as evidenced by a decrease in the number of stable equilibrium resting points. We find that the growth in the fine sediment concentration in the fluid scales with unit drum power. This relationship can be used to estimate fine sediment production rates in the field. We explore this approach at Inyo Creek, a steep catchment in the Sierra Nevada, California. There, a significant debris flow occurred in July 2013, which originated as a coarse-grained wet granular flow. We use surveys to estimate flow depth and velocity where super

  2. Nuclear assay of coal. Volume 6. Mass flow devices for coal handling

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The mass of coal entering the boiler per unit time is an essential parameter for determinig the total rate of heat input. The mass flow rate of coal on a conveyor belt is generally determined as a product of the instantaneous mass of material on a short section of the belt and the belt velocity. Belt loading could be measured by conventional transducers incorporating mechanical or electromechanical weighers or by gamma-ray attenuation gauge. This report reviews the state of the art in mass flow devices for coal handling. The various methods are compared and commented upon. Special design issues are discussed relative to incorporating a mass flow measuring device in a Continuous On-Line Nuclear Analysis of Coal (CONAC) system

  3. Montana's forest products industry and timber harvest, 2004

    Science.gov (United States)

    Timothy P. Spoelma; Todd A. Morgan; Thale Dillon; Alfred L. Chase; Charles E. Keegan; Larry T. DeBlander

    2008-01-01

    This report traces the flow of Montana's 2004 timber harvest through the primary wood-using industries; provides a description of the structure, capacity, and condition of Montana's primary forest products industry; and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as changes in harvest, production...

  4. Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Angelo; Byrne, James V. [ohn Radcliffe Hospital, Oxford Neurovascular and Neuroradiology Research Unit, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Rane, Neil; Kueker, Wilhelm; Cellerini, Martino; Corkill, Rufus [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom)

    2014-01-15

    This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. (orig.)

  5. A Finite-Volume approach for compressible single- and two-phase flows in flexible pipelines with fluid-structure interaction

    Science.gov (United States)

    Daude, F.; Galon, P.

    2018-06-01

    A Finite-Volume scheme for the numerical computations of compressible single- and two-phase flows in flexible pipelines is proposed based on an approximate Godunov-type approach. The spatial discretization is here obtained using the HLLC scheme. In addition, the numerical treatment of abrupt changes in area and network including several pipelines connected at junctions is also considered. The proposed approach is based on the integral form of the governing equations making it possible to tackle general equations of state. A coupled approach for the resolution of fluid-structure interaction of compressible fluid flowing in flexible pipes is considered. The structural problem is solved using Euler-Bernoulli beam finite elements. The present Finite-Volume method is applied to ideal gas and two-phase steam-water based on the Homogeneous Equilibrium Model (HEM) in conjunction with a tabulated equation of state in order to demonstrate its ability to tackle general equations of state. The extensive application of the scheme for both shock tube and other transient flow problems demonstrates its capability to resolve such problems accurately and robustly. Finally, the proposed 1-D fluid-structure interaction model appears to be computationally efficient.

  6. Wood Volume Production and Use of 10 Woody Species in Semiarid Zones of Northeastern Mexico

    Directory of Open Access Journals (Sweden)

    Rahim Foroughbakhch

    2012-01-01

    Full Text Available A research strategy was established to analyze the structure of timber trees in terms of forest productivity (volume and wood density of 10 species. The native species Acacia farnesiana, Acacia schaffneri, Bumelia celastrina, Cercidium macrun, Condalia hookeri, Ebenopsis ebano, Helietta parvifolia, and Prosopis laevigata and the exotic species Eucalyptus camaldulensis and Leucaena leucocephala were chosen due to their ecological and economic importance to the rural villages of northeastern Mexico. Measurements of different growth parameters and volume of trees were evaluated. The introduced species E. camaldulensis and L. leucocephala showed the best performance in wood volume production per tree and per hectare when compared to the native species. Likewise, among the native species, E. ebano, P. laevigata, C. hookeri, and A. farnesiana tended to show better characteristics in terms of wood volume production in comparison to H. parvifolia, A. schaffneri, C. macrum, and B. celastrina. Results showed a high diversity on the properties studied. The high biomass produced by most of the species considered in this study revealed their great energetic potential when used as wood and firewood or vegetal charcoal.

  7. Volume fraction calculation in multiphase system such as oil-water-gas using neutron

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mails: robson@ien.gov.br; brandao@ien.gov.br; otero@ien.gov.br; cmnap@ien.gov.br; Schirru, Roberto; Silva, Ademir Xavier da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mails: schirru@lmp.ufrj.br; ademir@con.ufrj.br

    2007-07-01

    Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic {sup 241}Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)

  8. Volume fraction calculation in multiphase system such as oil-water-gas using neutron

    International Nuclear Information System (INIS)

    Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da

    2007-01-01

    Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic 241 Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)

  9. Large-Scale, Continuous-Flow Production of Stressed Biomass (Desulfovibrio vulgaris Hildenborough)

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Jil T.; Borglin, Sharon E.; Fortney, Julian L.; Lam, Bonita R.; Hazen, Terry C.; Biggin, Mark D.

    2010-05-01

    The Protein Complex Analysis Project (PCAP, http://pcap.lbl.gov/), focuses on high-throughput analysis of microbial protein complexes in the anaerobic, sulfate-reducing organism, DesulfovibriovulgarisHildenborough(DvH).Interest in DvHas a model organism for bioremediation of contaminated groundwater sites arises from its ability to reduce heavy metals. D. vulgarishas been isolated from contaminated groundwater of sites in the DOE complex. To understand the effect of environmental changes on the organism, midlog-phase cultures are exposed to nitrate and salt stresses (at the minimum inhibitory concentration, which reduces growth rates by 50percent), and compared to controls of cultures at midlogand stationary phases. Large volumes of culture of consistent quality (up to 100 liters) are needed because of the relatively low cell density of DvHcultures (one order of magnitude lower than E. coli, for example) and PCAP's challenge to characterize low-abundance membrane proteins. Cultures are grown in continuous flow stirred tank reactors (CFSTRs) to produce consistent cell densities. Stressor is added to the outflow from the CFSTR, and the mixture is pumped through a plug flow reactor (PFR), to provide a stress exposure time of 2 hours. Effluent is chilled and held in large carboys until it is centrifuged. A variety of analyses -- including metabolites, total proteins, cell density and phospholipidfatty-acids -- track culture consistency within a production run, and differences due to stress exposure and growth phase for the different conditions used. With our system we are able to produce the requisite 100 L of culture for a given condition within a week.

  10. Globalisation of water resources: International virtual water flows in relation to international crop trade

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert; Hung, P.Q.

    2005-01-01

    The water that is used in the production process of a commodity is called the ‘virtual water’ contained in the commodity. International trade of commodities brings along international flows of virtual water. The objective of this paper is to quantify the volumes of virtual water flows between

  11. Evaluation of regional cerebral blood flow and volume of rapidly exchangeable water in man by positron emission tomography

    International Nuclear Information System (INIS)

    Depresseux, J.C.; Cheslet, J.P.; Hodiaumont, J.

    1982-01-01

    The present investigation uses bolus inhalation of C 15 O 2 and sequential positron emission tomography of the brain in view to simultaneously evaluate regional cerebral blood flow and regional cerebral volume of rapidly exchangeable water in normal human subjects. Arguments allow to infer that the cerebral distribution volume of radiowater does vary with time during the initial period of invasion of tissue by the indicator. Implications of this variation on the validity of classical data procedures is discussed and an alternative original method is proposed [fr

  12. Comments on H- volume production in Cs-seeded ion sources. Appendix I

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1986-01-01

    Considerable interest was generated at the IAEA Negative Ion Beam Workshop in Grenoble, France, in March, 1985, by a report from the Kurchatov Institute on the development of a 2-ampere steady-state H - ion source, in which the ions were volume-produced in a discharge in H 2 , seeded with Cs vapor. The mechanism primarily responsible for this remarkably high current from a volume production source was not yet understood, but it was tentatively presumed to involve the collisional energy transfer from electronically excited Cs 6p atoms into H 2 vibrations. In any case, it was apparently different from the surface-plasma interactions that have been assumed to control the H - production in the Dudnikov-Dimov type sources

  13. Effect of volume-oriented versus flow-oriented incentive spirometry on chest wall volumes, inspiratory muscle activity, and thoracoabdominal synchrony in the elderly.

    Science.gov (United States)

    Lunardi, Adriana C; Porras, Desiderio C; Barbosa, Renata Cc; Paisani, Denise M; Marques da Silva, Cibele C B; Tanaka, Clarice; Carvalho, Celso R F

    2014-03-01

    Aging causes physiological and functional changes that impair pulmonary function. Incentive spirometry is widely used for lung expansion, but the effects of volume-oriented incentive spirometry (VIS) versus flow-oriented incentive spirometry (FIS) on chest wall volumes, inspiratory muscle activity, and thoracoabdominal synchrony in the elderly are poorly understood. We compared VIS and FIS in elderly subjects and healthy adult subjects. Sixteen elderly subjects (9 women, mean ± SD age 70.6 ± 3.9 y, mean ± SD body mass index 23.8 ± 2.5 kg/m(2)) and 16 healthy adults (8 women, mean ± age 25.9 ± 4.3 y, mean ± body mass index 23.6 ± 2.4 kg/m(2)) performed quiet breathing, VIS, and FIS in randomized sequence. Chest wall kinematics (via optoelectronic plethysmography) and inspiratory muscle activity (via surface electromyography) were assessed simultaneously. Synchrony between the superior thorax and abdominal motion was calculated (phase angle). In the elderly subjects both types of incentive spirometry increased chest wall volumes similarly, whereas in the healthy adult subjects VIS increased the chest wall volume more than did FIS. FIS and VIS triggered similar lower thoracoabdominal synchrony in the elderly subjects, whereas in the healthy adults FIS induced lower synchrony than did VIS. FIS required more muscle activity in the elderly subjects to create an increase in chest wall volume. Incentive spirometry performance is influenced by age, and the differences between elderly and healthy adults response should be considered in clinical practice.

  14. Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

    International Nuclear Information System (INIS)

    Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

    2016-01-01

    A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

  15. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    International Nuclear Information System (INIS)

    Giovacchini, Giampiero; Bonwetsch, Robert; Theodore, William H.; Herscovitch, Peter; Carson, Richard E.

    2007-01-01

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR glu ) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR glu measurements also were obtained. Before PVC, regional values of CBF were significantly (p glu in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR glu , but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  16. Lean Production Control at a High-Variety, Low-Volume Parts Manufacturer

    NARCIS (Netherlands)

    Bokhorst, Jos A. C.; Slomp, Jannes

    2010-01-01

    Eaton Electric General Supplies, a parts manufacturing unit that supplies parts for Eaton's electrical business unit, implemented several lean control elements in its high-variety, low-volume production units. These control elements include a constant work-in-process mechanism to limit and control

  17. Unique Kutubu export system complete; production flowing

    International Nuclear Information System (INIS)

    McGovern, R.; Miller, G.

    1992-01-01

    First oil from near Lake Kutubu in Papua New Guinea began flowing in June through pipelines and marine facilities recently installed by Chevron Niugini Pty. Ltd. Production facilities were built near Lake Kutubu. The export pipeline was laid form the central production facility to landfall on the Kikori River - approximately 171 km (106 miles) away - and then another 56 miles to a platform in 66 ft of water in the gulf. From the platform, an oilspading line extends about 2.4 miles to the SPM in 83 ft of water where tankers will load oil at an initial design flowrate of 157,000 b/d

  18. Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

    Directory of Open Access Journals (Sweden)

    Donald P Bernstein

    2010-01-01

    Full Text Available Impedance cardiography (ICG is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV. As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC. By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω. Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t, which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t. ΔZ(t represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t, (i.e. dZ/dtmax, with the presumed units of Ω·s-1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t, Ωcm·s-1, and it is the peak rate of change of the blood resistivity variation dρb(t/dtmax (Ωcm·s-2 that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s-2, it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s-2 and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s-2

  19. A study of rumen water volume, rate of flow of water and rumen dry matter turnover time measurement by using 51Cr-labelled EDTA

    International Nuclear Information System (INIS)

    Krishna, G.; Ekern, A.

    1974-01-01

    Two fistulated adult sheep were infused with 100 μVi 51 Cr-EDTA, four hours after morning feeding, so as to calculate fumen water volume, and rate of flow of water from reticulo-rumen. The average figure of rumen water volume obtained was 2.191 litre, rate of flow of water expressed as volume per cent per hour was 7.55. The biological half-life of marker 51 Cr-EDTA in rumen was 9.34 hours. The percent recovery of infused dosage of 51 Cr-EDTA through faeces and urine was 66 and 5 during the period of four days after infusion. Dry matter turnover time in the rumen was 0.483 days. (author)

  20. Pollen- and seed-mediated transgene flow in commercial cotton seed production fields.

    Directory of Open Access Journals (Sweden)

    Shannon Heuberger

    Full Text Available BACKGROUND: Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt cotton is planted on millions of hectares annually and is a potential source of transgene flow. METHODOLOGY/PRINCIPAL FINDINGS: Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L. seed production fields (some transgenic for herbicide resistance, some not for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. CONCLUSIONS/SIGNIFICANCE: A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow.

  1. Splanchnic blood flow and hepatic glucose production in exercising humans

    DEFF Research Database (Denmark)

    Bergeron, R; Kjaer, M; Simonsen, L

    2001-01-01

    The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin-converti......The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin......-converting enzyme (ACE) blockade] or without (control) administration of the ACE inhibitor enalapril (10 mg iv). Splanchnic blood flow was estimated by indocyanine green, and splanchnic substrate exchange was determined by the arteriohepatic venous difference. Exercise led to an approximately 20-fold increase (P ...-blockade group vs. the control group, hormones, metabolites, VO(2), and RER followed the same pattern of changes in ACE-blockade and control groups during exercise. Splanchnic blood flow (at rest: 1.67 +/- 0.12, ACE blockade; 1.59 +/- 0.18 l/min, control) decreased during moderate exercise (0.78 +/- 0.07, ACE...

  2. Does helmet CPAP reduce cerebral blood flow and volume by comparison with Infant Flow driver CPAP in preterm neonates?

    Science.gov (United States)

    Zaramella, Patrizia; Freato, Federica; Grazzina, Nicoletta; Saraceni, Elisabetta; Vianello, Andrea; Chiandetti, Lino

    2006-10-01

    We compared neonatal helmet continuous positive airway pressure (CPAP) and the conventional nasal Infant Flow driver (IFD) CPAP in the noninvasive assessment of absolute cerebral blood flow (CBF) and relative cerebral blood volume changes (DeltaCBV) by near-infrared spectroscopy. A randomized crossover study in a tertiary referral NICU. Assessment of CBF and DeltaCBV in 17 very low birth weight infants with respiratory distress (median age 5 days) treated with two CPAP devices at a continuous distending pressure of 4 mbar. Neonates were studied for two consecutive 60-min periods with helmet CPAP and with IFD CPAP. Basal chromophore traces enabled DeltaCBV changes to be calculated. CBF was calculated in milliliters per 100 grams per minute from the saturation rise integral and rate of rise O(2)Hb-HHb. Median (range) CBF with helmet CPAP was 27.37 (9.47-48.20) vs. IFD CBF 34.74 (13.59-60.10)(p=0.049) and DeltaCBV 0.15 (0.09-0.28) with IFD and 0.13 (0.07-0.27) with helmet CPAP (NS). Using helmet and IFD CPAP, the neonates showed no difference in mean physiological parameters (transcutaneous carbon dioxide and oxygen tension, pulse oximetry saturation, heart rate, breathing rate, mean arterial blood pressure, desaturation rate, axillary temperature). Assessing CBF and DeltaCBV measured by near-infrared spectroscopy with two CPAP devices revealed no differences in relative blood volume, but CBF was lower with helmet CPAP. Greater active vasoconstriction and/or passive capillary and/or venous vessel compression seem the most likely reason, due to a positive pressure around the head, neck, and shoulders by comparison with the airway pressure.

  3. Fluid flow in gas condensate reservoirs. The interplay of forces and their relative strengths

    Energy Technology Data Exchange (ETDEWEB)

    Ursin, Jann-Rune [Stavanger University College, Department of Petroleum Engineering, PO Box 8002, Stavanger, 4068 (Norway)

    2004-02-01

    Natural production from gas condensate reservoirs is characterized by gas condensation and liquid dropout in the reservoir, first in the near wellbore volume, then as a cylindrical shaped region, dynamically developing into the reservoir volume. The effects of liquid condensation are reduced productivity and loss of production. Successful forecast of well productivity and reservoir production depends on detailed understanding of the effect of various forces acting on fluid flow in time and space. The production form gas condensate reservoirs is thus indirectly related to the interplay of fundamental forces, such as the viscosity, the capillary, the gravitational and the inertial force and their relative strengths, demonstrated by various dimensionless numbers. Dimensionless numbers are defined and calculated for all pressure and space coordinates in a test reservoir. Various regions are identified where certain forces are more important than others. Based on reservoir pressure development, liquid condensation and the numerical representation of dimensionless numbers, a conceptual understanding of a varying reservoir permeability has been reached.The material balance, the reservoir fluid flow and the wellbore flow calculations are performed on a cylindrical reservoir model. The ratios between fundamental forces are calculated and dimensionless numbers defined. The interplay of forces, demonstrated by these numbers, are calculated as function of radial dimension and reservoir pressure.

  4. Alaska’s timber harvest and forest products industry, 2011

    Science.gov (United States)

    Erik C. Berg; Charles B. Gale; Todd A. Morgan; Allen M. Brackley; Charles E. Keegan; Susan J. Alexander; Glenn A. Christensen; Chelsea P. McIver; Micah G. Scudder

    2014-01-01

    This report traces the flow of timber harvested in Alaska during calendar year 2011, describes the composition and operations of the state’s primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, export, sales of primary wood products,...

  5. A solution algorithm for fluid-particle flows across all flow regimes

    Science.gov (United States)

    Kong, Bo; Fox, Rodney O.

    2017-09-01

    Many fluid-particle flows occurring in nature and in technological applications exhibit large variations in the local particle volume fraction. For example, in circulating fluidized beds there are regions where the particles are close-packed as well as very dilute regions where particle-particle collisions are rare. Thus, in order to simulate such fluid-particle systems, it is necessary to design a flow solver that can accurately treat all flow regimes occurring simultaneously in the same flow domain. In this work, a solution algorithm is proposed for this purpose. The algorithm is based on splitting the free-transport flux solver dynamically and locally in the flow. In close-packed to moderately dense regions, a hydrodynamic solver is employed, while in dilute to very dilute regions a kinetic-based finite-volume solver is used in conjunction with quadrature-based moment methods. To illustrate the accuracy and robustness of the proposed solution algorithm, it is implemented in OpenFOAM for particle velocity moments up to second order, and applied to simulate gravity-driven, gas-particle flows exhibiting cluster-induced turbulence. By varying the average particle volume fraction in the flow domain, it is demonstrated that the flow solver can handle seamlessly all flow regimes present in fluid-particle flows.

  6. Transport volume in regions of the Czech Republic in relation to the production of waste

    OpenAIRE

    Pojkarová, Kateřina; Hruška, Roman

    2010-01-01

    The article deals with the transport volume in regions of the Czech Republic in relation to the production of waste. On the basis of waste statistics and transport statistics is researched the greatness of the relation between the transport volume and the production of waste in regions of the Czech Republic. The relation is illustrated graphically too. We have many kinds of waste which we can monitor. The most important kinds of waste are municipal waste, industrial waste, construction ...

  7. Practical application of game theory based production flow planning method in virtual manufacturing networks

    Science.gov (United States)

    Olender, M.; Krenczyk, D.

    2016-08-01

    Modern enterprises have to react quickly to dynamic changes in the market, due to changing customer requirements and expectations. One of the key area of production management, that must continuously evolve by searching for new methods and tools for increasing the efficiency of manufacturing systems is the area of production flow planning and control. These aspects are closely connected with the ability to implement the concept of Virtual Enterprises (VE) and Virtual Manufacturing Network (VMN) in which integrated infrastructure of flexible resources are created. In the proposed approach, the players role perform the objects associated with the objective functions, allowing to solve the multiobjective production flow planning problems based on the game theory, which is based on the theory of the strategic situation. For defined production system and production order models ways of solving the problem of production route planning in VMN on computational examples for different variants of production flow is presented. Possible decision strategy to use together with an analysis of calculation results is shown.

  8. Quantitative tomographic measurements of opaque multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O' HERN,TIMOTHY J.; CECCIO,STEVEN L.

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  9. Block-and-break generation of microdroplets with fixed volume

    Science.gov (United States)

    van Steijn, Volkert; Korczyk, Piotr M.; Derzsi, Ladislav; Abate, Adam R.; Weitz, David A.; Garstecki, Piotr

    2013-01-01

    We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets. PMID:24404013

  10. Engineering Mathematical Analysis Method for Productivity Rate in Linear Arrangement Serial Structure Automated Flow Assembly Line

    Directory of Open Access Journals (Sweden)

    Tan Chan Sin

    2015-01-01

    Full Text Available Productivity rate (Q or production rate is one of the important indicator criteria for industrial engineer to improve the system and finish good output in production or assembly line. Mathematical and statistical analysis method is required to be applied for productivity rate in industry visual overviews of the failure factors and further improvement within the production line especially for automated flow line since it is complicated. Mathematical model of productivity rate in linear arrangement serial structure automated flow line with different failure rate and bottleneck machining time parameters becomes the basic model for this productivity analysis. This paper presents the engineering mathematical analysis method which is applied in an automotive company which possesses automated flow assembly line in final assembly line to produce motorcycle in Malaysia. DCAS engineering and mathematical analysis method that consists of four stages known as data collection, calculation and comparison, analysis, and sustainable improvement is used to analyze productivity in automated flow assembly line based on particular mathematical model. Variety of failure rate that causes loss of productivity and bottleneck machining time is shown specifically in mathematic figure and presents the sustainable solution for productivity improvement for this final assembly automated flow line.

  11. Entropy analysis on non-equilibrium two-phase flow models

    International Nuclear Information System (INIS)

    Karwat, H.; Ruan, Y.Q.

    1995-01-01

    A method of entropy analysis according to the second law of thermodynamics is proposed for the assessment of a class of practical non-equilibrium two-phase flow models. Entropy conditions are derived directly from a local instantaneous formulation for an arbitrary control volume of a structural two-phase fluid, which are finally expressed in terms of the averaged thermodynamic independent variables and their time derivatives as well as the boundary conditions for the volume. On the basis of a widely used thermal-hydraulic system code it is demonstrated with practical examples that entropy production rates in control volumes can be numerically quantified by using the data from the output data files. Entropy analysis using the proposed method is useful in identifying some potential problems in two-phase flow models and predictions as well as in studying the effects of some free parameters in closure relationships

  12. Entropy analysis on non-equilibrium two-phase flow models

    Energy Technology Data Exchange (ETDEWEB)

    Karwat, H.; Ruan, Y.Q. [Technische Universitaet Muenchen, Garching (Germany)

    1995-09-01

    A method of entropy analysis according to the second law of thermodynamics is proposed for the assessment of a class of practical non-equilibrium two-phase flow models. Entropy conditions are derived directly from a local instantaneous formulation for an arbitrary control volume of a structural two-phase fluid, which are finally expressed in terms of the averaged thermodynamic independent variables and their time derivatives as well as the boundary conditions for the volume. On the basis of a widely used thermal-hydraulic system code it is demonstrated with practical examples that entropy production rates in control volumes can be numerically quantified by using the data from the output data files. Entropy analysis using the proposed method is useful in identifying some potential problems in two-phase flow models and predictions as well as in studying the effects of some free parameters in closure relationships.

  13. Synfuel program analysis. Volume 2: VENVAL users manual

    Science.gov (United States)

    Muddiman, J. B.; Whelan, J. W.

    1980-07-01

    This volume is intended for program analysts and is a users manual for the VENVAL model. It contains specific explanations as to input data requirements and programming procedures for the use of this model. VENVAL is a generalized computer program to aid in evaluation of prospective private sector production ventures. The program can project interrelated values of installed capacity, production, sales revenue, operating costs, depreciation, investment, dent, earnings, taxes, return on investment, depletion, and cash flow measures. It can also compute related public sector and other external costs and revenues if unit costs are furnished.

  14. Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

    Science.gov (United States)

    Ernst, M; Forkert, N D; Brehmer, L; Thomalla, G; Siemonsen, S; Fiehler, J; Kemmling, A

    2015-02-01

    In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume 50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. © 2015 by American Journal of Neuroradiology.

  15. Volume and Surface-Enhanced Volume Negative Ion Sources

    International Nuclear Information System (INIS)

    Stockli, M P

    2013-01-01

    H - volume sources and, especially, caesiated H - volume sources are important ion sources for generating high-intensity proton beams, which then in turn generate large quantities of other particles. This chapter discusses the physics and technology of the volume production and the caesium-enhanced (surface) production of H - ions. Starting with Bacal's discovery of the H - volume production, the chapter briefly recounts the development of some H - sources, which capitalized on this process to significantly increase the production of H - beams. Another significant increase was achieved in the 1990s by adding caesiated surfaces to supplement the volume-produced ions with surface-produced ions, as illustrated with other H - sources. Finally, the focus turns to some of the experience gained when such a source was successfully ramped up in H - output and in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source. (author)

  16. Should measurement of maximum urinary flow rate and residual urine volume be a part of a "minimal care" assessment programme in female incontinence?

    DEFF Research Database (Denmark)

    Sander, Pia; Mouritsen, L; Andersen, J Thorup

    2002-01-01

    OBJECTIVE: The aim of this study was to evaluate the value of routine measurements of urinary flow rate and residual urine volume as a part of a "minimal care" assessment programme for women with urinary incontinence in detecting clinical significant bladder emptying problems. MATERIAL AND METHODS....... Twenty-six per cent had a maximum flow rate less than 15 ml/s, but only 4% at a voided volume > or =200 ml. Residual urine more than 149 ml was found in 6%. Two women had chronic retention with overflow incontinence. Both had typical symptoms with continuous leakage, stranguria and chronic cystitis...

  17. Flow distribution in the accelerator-production-of-tritium target

    International Nuclear Information System (INIS)

    Siebe, D.A.; Spatz, T.L.; Pasamehmetoglu, K.O.; Sherman, M.P.

    1999-01-01

    Achieving nearly uniform flow distributions in the accelerator production of tritium (APT) target structures is an important design objective. Manifold effects tend to cause a nonuniform distribution in flow systems of this type, although nearly even distribution can be achieved. A program of hydraulic experiments is underway to provide a database for validation of calculational methodologies that may be used for analyzing this problem and to evaluate the approach with the most promise for achieving a nearly even flow distribution. Data from the initial three tests are compared to predictions made using four calculational methods. The data show that optimizing the ratio of the supply-to-return-manifold areas can produce an almost even flow distribution in the APT ladder assemblies. The calculations compare well with the data for ratios of the supply-to-return-manifold areas spanning the optimum value. Thus, the results to date show that a nearly uniform flow distribution can be achieved by carefully sizing the supply and return manifolds and that the calculational methods available are adequate for predicting the distributions through a range of conditions

  18. A finite volume solver for three dimensional debris flow simulations based on a single calibration parameter

    Science.gov (United States)

    von Boetticher, Albrecht; Turowski, Jens M.; McArdell, Brian; Rickenmann, Dieter

    2016-04-01

    Debris flows are frequent natural hazards that cause massive damage. A wide range of debris flow models try to cover the complex flow behavior that arises from the inhomogeneous material mixture of water with clay, silt, sand, and gravel. The energy dissipation between moving grains depends on grain collisions and tangential friction, and the viscosity of the interstitial fine material suspension depends on the shear gradient. Thus a rheology description needs to be sensitive to the local pressure and shear rate, making the three-dimensional flow structure a key issue for flows in complex terrain. Furthermore, the momentum exchange between the granular and fluid phases should account for the presence of larger particles. We model the fine material suspension with a Herschel-Bulkley rheology law, and represent the gravel with the Coulomb-viscoplastic rheology of Domnik & Pudasaini (Domnik et al. 2013). Both composites are described by two phases that can mix; a third phase accounting for the air is kept separate to account for the free surface. The fluid dynamics are solved in three dimensions using the finite volume open-source code OpenFOAM. Computational costs are kept reasonable by using the Volume of Fluid method to solve only one phase-averaged system of Navier-Stokes equations. The Herschel-Bulkley parameters are modeled as a function of water content, volumetric solid concentration of the mixture, clay content and its mineral composition (Coussot et al. 1989, Yu et al. 2013). The gravel phase properties needed for the Coulomb-viscoplastic rheology are defined by the angle of repose of the gravel. In addition to this basic setup, larger grains and the corresponding grain collisions can be introduced by a coupled Lagrangian particle simulation. Based on the local Savage number a diffusive term in the gravel phase can activate phase separation. The resulting model can reproduce the sensitivity of the debris flow to water content and channel bed roughness, as

  19. Reynolds-Stress and Triple-Product Models Applied to a Flow with Rotation and Curvature

    Science.gov (United States)

    Olsen, Michael E.

    2016-01-01

    Turbulence models, with increasing complexity, up to triple product terms, are applied to the flow in a rotating pipe. The rotating pipe is a challenging case for turbulence models as it contains significant rotational and curvature effects. The flow field starts with the classic fully developed pipe flow, with a stationary pipe wall. This well defined condition is then subjected to a section of pipe with a rotating wall. The rotating wall introduces a second velocity scale, and creates Reynolds shear stresses in the radial-circumferential and circumferential-axial planes. Furthermore, the wall rotation introduces a flow stabilization, and actually reduces the turbulent kinetic energy as the flow moves along the rotating wall section. It is shown in the present work that the Reynolds stress models are capable of predicting significant reduction in the turbulent kinetic energy, but triple product improves the predictions of the centerline turbulent kinetic energy, which is governed by convection, dissipation and transport terms, as the production terms vanish on the pipe axis.

  20. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  1. CFD analysis and flow model reduction for surfactant production in helix reactor

    NARCIS (Netherlands)

    Nikačević, N.M.; Thielen, L.; Twerda, A.; Hof, P.M.J. van den

    2014-01-01

    Flow pattern analysis in a spiral Helix reactor is conducted, for the application in the commercial surfactant production. Step change response curves (SCR) were obtained from numerical tracer experiments by three-dimensional computational fluid dynamics (CFD) simulations. Non-reactive flow is

  2. Endothelial surface glycocalyx can regulate flow-induced nitric oxide production in microvessels in vivo.

    Directory of Open Access Journals (Sweden)

    Wanyi Yen

    Full Text Available Due to its unique location, the endothelial surface glycocalyx (ESG at the luminal side of the microvessel wall may serve as a mechano-sensor and transducer of blood flow and thus regulate endothelial functions. To examine this role of the ESG, we used fluorescence microscopy to measure nitric oxide (NO production in post-capillary venules and arterioles of rat mesentery under reduced (low and normal (high flow conditions, with and without enzyme pretreatment to remove heparan sulfate (HS of the ESG and in the presence of an endothelial nitric oxide synthase (eNOS inhibitor, NG-monomethyl-L-arginine (L-NMMA. Rats (SD, 250-300 g were anesthetized. The mesentery was gently taken out from the abdominal cavity and arranged on the surface of a glass coverslip for the measurement. An individual post-capillary venule or arteriole was cannulated and loaded for 45 min with 5 μM 4, 5-Diaminofluorescein diacetate, a membrane permeable fluorescent indictor for NO, then the NO production was measured for ~10 min under a low flow (~300 μm/s and for ~60 min under a high flow (~1000 μm/s. In the 15 min after switching to the high flow, DAF-2-NO fluorescence intensity increased to 1.27-fold of its baseline, DAF-2-NO continuously increased under the high flow, to 1.53-fold of its baseline in 60 min. Inhibition of eNOS by 1 mM L-NMMA attenuated the flow-induced NO production to 1.13-fold in 15 min and 1.30-fold of its baseline in 60 min, respectively. In contrast, no significant increase in NO production was observed after switching to the high flow for 60 min when 1 h pretreatment with 50 mU/mL heparanase III to degrade the ESG was applied. Similar NO production was observed in arterioles under low and high flows and under eNOS inhibition. Our results suggest that ESG participates in endothelial cell mechanosensing and transduction through its heparan sulfate to activate eNOS.

  3. The SEA of the Future: Building the Productivity Infrastructure. Volume 3

    Science.gov (United States)

    Gross, Betheny, Ed.; Jochim, Ashley, Ed.

    2014-01-01

    "The SEA of the Future" is an education publication series examining how state education agencies can shift from a compliance to a performance-oriented organization through strategic planning and performance management tools to meet growing demands to support education reform while improving productivity. This volume, the third in the…

  4. A study of rumen water volume, rate of flow of water and rumen dry matter turnover time measurement by using /sup 51/Cr-labelled EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, G; Ekern, A [Agricultural University of Norway. Dept. of Animal Nutrition

    1974-06-01

    Two fistulated adult sheep were infused with 100 ..mu..Vi /sup 51/Cr-EDTA, four hours after morning feeding, so as to calculate rumen water volume, and rate of flow of water from reticulo-rumen. The average figure of rumen water volume obtained was 2.191 litre, rate of flow of water expressed as volume per cent per hour was 7.55. The biological half-life of marker /sup 51/Cr-EDTA in rumen was 9.34 hours. The percent recovery of infused dosage of /sup 51/Cr-EDTA through feces and urine was 66 and 5 during the period of four days after infusion. Dry matter turnover time in the rumen was 0.483 days.

  5. A lean production control system for high-variety/low-volume environments : a case study implementation

    NARCIS (Netherlands)

    Slomp, J.; Bokhorst, J.A.C.; Germs, R.

    2009-01-01

    Due to the success of lean manufacturing, many companies are interested in implementing a lean production control system. Lean production control principles include the levelling of production, the use of pull mechanisms and takt time control. These principles have mainly been applied in high volume

  6. Application of the finite volume method in the simulation of saturated flows of binary mixtures

    International Nuclear Information System (INIS)

    Murad, M.A.; Gama, R.M.S. da; Sampaio, R.

    1989-12-01

    This work presents the simulation of saturated flows of an incompressible Newtonian fluid through a rigid, homogeneous and isotropic porous medium. The employed mathematical model is derived from the Continuum Theory of Mixtures and generalizes the classical one which is based on Darcy's Law form of the momentum equation. In this approach fluid and porous matrix are regarded as continuous constituents of a binary mixture. The finite volume method is employed in the simulation. (author) [pt

  7. High Productivity DRIE solutions for 3D-SiP and MEMS Volume Manufacturing

    International Nuclear Information System (INIS)

    Puech, M; Thevenoud, J M; Launay, N; Arnal, N; Godinat, P; Andrieu, B; Gruffat, J M

    2006-01-01

    Emerging 3D-SiP technologies and high volume MEMS applications require high productivity mass production DRIE systems. The Alcatel DRIE product range has recently been optimised to reach the highest process and hardware production performances. A study based on sub-micron high aspect ratio structures encountered in the most stringent 3D-SiP has been carried out. The optimization of the Bosch process parameters has resulted in ultra high silicon etch rates, with unrivalled uniformity and repeatability leading to excellent process. In parallel, most recent hardware and proprietary design optimization including vacuum pumping lines, process chamber, wafer chucks, pressure control system, gas delivery are discussed. These improvements have been monitored in a mass production environment for a mobile phone application. Field data analysis shows a significant reduction of cost of ownership thanks to increased throughput and much lower running costs. These benefits are now available for all 3D-SiP and high volume MEMS applications. The typical etched patterns include tapered trenches for CMOS imagers, through silicon via holes for die stacking, well controlled profile angle for 3D high precision inertial sensors, and large exposed area features for inkjet printer heads and Silicon microphones

  8. Changes in the Flow-Volume Curve According to the Degree of Stenosis in Patients With Unilateral Main Bronchial Stenosis

    Science.gov (United States)

    Yoo, Jung-Geun; Yi, Chin A; Lee, Kyung Soo; Jeon, Kyeongman; Um, Sang-Won; Koh, Won-Jung; Suh, Gee Young; Chung, Man Pyo; Kwon, O Jung

    2015-01-01

    Objectives The shape of the flow-volume (F-V) curve is known to change to showing a prominent plateau as stenosis progresses in patients with tracheal stenosis. However, no study has evaluated changes in the F-V curve according to the degree of bronchial stenosis in patients with unilateral main bronchial stenosis. Methods We performed an analysis of F-V curves in 29 patients with unilateral bronchial stenosis with the aid of a graphic digitizer between January 2005 and December 2011. Results The primary diseases causing unilateral main bronchial stenosis were endobronchial tuberculosis (86%), followed by benign bronchial tumor (10%), and carcinoid (3%). All unilateral main bronchial stenoses were classified into one of five grades (I, ≤25%; II, 26%-50%; III, 51%-75%; IV, 76%-90%; V, >90% to near-complete obstruction without ipsilateral lung collapse). A monophasic F-V curve was observed in patients with grade I stenosis and biphasic curves were observed for grade II-IV stenosis. Both monophasic (81%) and biphasic shapes (18%) were observed in grade V stenosis. After standardization of the biphasic shape of the F-V curve, the breakpoints of the biphasic curve moved in the direction of high volume (x-axis) and low flow (y-axis) according to the progression of stenosis. Conclusion In unilateral bronchial stenosis, a biphasic F-V curve appeared when bronchial stenosis was >25% and disappeared when obstruction was near complete. In addition, the breakpoint moved in the direction of high volume and low flow with the progression of stenosis. PMID:26045916

  9. Information related to postal flows and big data analysis potential. The case of Spain

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Alvaro, O.; Nuñez Gonzalez, A.

    2016-07-01

    National Post Offices manage huge volumes of letters and parcels. Data associated to these flows are growing fast, with a great variety related to the diversity of postal products. The research described in this paper has classified all information flows of Correos, the Spanish National Post Office. In spite of the complexity of the current postal service portfolio, only four categories of matrices allow the classification of all postal information flows. Thanks to the migration towards new products, analyses with simple techniques will provide more and better information in the future, due to the structured nature of existing databases. (Author)

  10. Quantification of left ventricular volumes from cardiac cine MRI using active contour model combined with gradient vector flow

    International Nuclear Information System (INIS)

    Tanki, Nobuyoshi; Murase, Kenya; Kumashiro, Masayuki; Momoi, Risa; Yang, Xiaomei; Tabuchi, Takashi; Nagayama, Masako; Watanabe, Yuji

    2005-01-01

    We investigated the feasibility of combining the active contour model with gradient vector flow (Snakes-GVF) to estimate left ventricular (LV) volumes from cardiac cine magnetic resonance imaging (MRI). MRI data were acquired from 27 patients, including 14 adults (9 men, 5 women, 55.0±23.3 years) and 13 children (10 boys, 3 girls, 2.7±2.1 years) using Gyroscan Intera (1.5 Tesla, Philips Medical Systems). LV volumes were calculated by adding the areas surrounded by the contour extracted by Snakes-GVF and compared with volumes estimated by manual tracing. Those estimated by Snakes-GVF [y (mL)] correlated well with those estimated by manual tracing [x (mL)]. In adult cases, the regression equation and correlation coefficient were y=1.008x-0.517 and 0.996, respectively. In pediatric cases, they were y=1.174x-2.542 and 0.992, respectively. In conclusion, Snakes-GVF is a powerful and useful tool for quantifying LV volumes using cardiac MRI. (author)

  11. 77 FR 21065 - Certain High Production Volume Chemicals; Test Rule and Significant New Use Rule; Fourth Group of...

    Science.gov (United States)

    2012-04-09

    ... 2070-AJ66 Certain High Production Volume Chemicals; Test Rule and Significant New Use Rule; Fourth... an opportunity to comment on a proposed test rule for 23 high production volume (HPV) chemical... necessary, to prohibit or limit that activity before it occurs. The opportunity to present oral comment was...

  12. Phase-synchronisation in continuous flow models of production networks

    Science.gov (United States)

    Scholz-Reiter, Bernd; Tervo, Jan Topi; Freitag, Michael

    2006-04-01

    To improve their position at the market, many companies concentrate on their core competences and hence cooperate with suppliers and distributors. Thus, between many independent companies strong linkages develop and production and logistics networks emerge. These networks are characterised by permanently increasing complexity, and are nowadays forced to adapt to dynamically changing markets. This factor complicates an enterprise-spreading production planning and control enormously. Therefore, a continuous flow model for production networks will be derived regarding these special logistic problems. Furthermore, phase-synchronisation effects will be presented and their dependencies to the set of network parameters will be investigated.

  13. Finite volume approximation of the three-dimensional flow equation in axisymmetric, heterogeneous porous media based on local analytical solution

    KAUST Repository

    Salama, Amgad

    2013-09-01

    In this work the problem of flow in three-dimensional, axisymmetric, heterogeneous porous medium domain is investigated numerically. For this system, it is natural to use cylindrical coordinate system, which is useful in describing phenomena that have some rotational symmetry about the longitudinal axis. This can happen in porous media, for example, in the vicinity of production/injection wells. The basic feature of this system is the fact that the flux component (volume flow rate per unit area) in the radial direction is changing because of the continuous change of the area. In this case, variables change rapidly closer to the axis of symmetry and this requires the mesh to be denser. In this work, we generalize a methodology that allows coarser mesh to be used and yet yields accurate results. This method is based on constructing local analytical solution in each cell in the radial direction and moves the derivatives in the other directions to the source term. A new expression for the harmonic mean of the hydraulic conductivity in the radial direction is developed. Apparently, this approach conforms to the analytical solution for uni-directional flows in radial direction in homogeneous porous media. For the case when the porous medium is heterogeneous or the boundary conditions is more complex, comparing with the mesh-independent solution, this approach requires only coarser mesh to arrive at this solution while the traditional methods require more denser mesh. Comparisons for different hydraulic conductivity scenarios and boundary conditions have also been introduced. © 2013 Elsevier B.V.

  14. A Parallel, Finite-Volume Algorithm for Large-Eddy Simulation of Turbulent Flows

    Science.gov (United States)

    Bui, Trong T.

    1999-01-01

    A parallel, finite-volume algorithm has been developed for large-eddy simulation (LES) of compressible turbulent flows. This algorithm includes piecewise linear least-square reconstruction, trilinear finite-element interpolation, Roe flux-difference splitting, and second-order MacCormack time marching. Parallel implementation is done using the message-passing programming model. In this paper, the numerical algorithm is described. To validate the numerical method for turbulence simulation, LES of fully developed turbulent flow in a square duct is performed for a Reynolds number of 320 based on the average friction velocity and the hydraulic diameter of the duct. Direct numerical simulation (DNS) results are available for this test case, and the accuracy of this algorithm for turbulence simulations can be ascertained by comparing the LES solutions with the DNS results. The effects of grid resolution, upwind numerical dissipation, and subgrid-scale dissipation on the accuracy of the LES are examined. Comparison with DNS results shows that the standard Roe flux-difference splitting dissipation adversely affects the accuracy of the turbulence simulation. For accurate turbulence simulations, only 3-5 percent of the standard Roe flux-difference splitting dissipation is needed.

  15. Tamsulosin reduces nighttime urine production in benign prostatic hyperplasia patients with nocturnal polyuria: a prospective open-label long-term study using frequency-volume chart.

    Science.gov (United States)

    Kojima, Yoshiyuki; Sasaki, Shoichi; Imura, Makoto; Kubota, Yasue; Hayashi, Yutaro; Kohri, Kenjiro

    2012-01-01

    The effects of tamsulosin treatment on changes in frequency-volume chart (FVC) data, especially nighttime urine production, over time were assessed, and the mechanisms underlying the improvement of nocturia in benign prostatic hyperplasia (BPH) patients with nocturnal polyuria (NP) are discussed. A total of 104 patients with lower urinary tract symptoms secondary to BPH were enrolled. After enrollment in the study, the patients were treated with tamsulosin (0.2 mg) once daily. Visits were scheduled every 4 weeks until week 12 (month 3) after study entry, and then every 12 weeks subsequently. All patients completed the International Prostate Symptom Score (IPSS), quality of life (QOL) index, and 3-day FVC, and underwent uroflowmetry at enrollment and on each visit. Eighty-two patients (mean age: 70.9 ± 7.1 years) were analyzed for 24 months after treatment. Patients were divided into two groups, NP and nonNP, based on FVC outcome. The IPSS, QOL index, and maximum flow rate improved during the 24-month period after treatment in both groups. Mean daytime urine volume significantly increased in the NP group, but no changes were detected in the nonNP group. Mean nighttime urine frequency significantly decreased in the NP group over a 24-month period, and was associated with a significant decrease in nighttime urine volume that was not found in the nonNP group. Maximum voided volume increased most months after treatment in both groups. The present long-term prospective study using FVC demonstrated that tamsulosin reduced nighttime urine production in BPH patients with NP. Copyright © 2011 Wiley Periodicals, Inc.

  16. Design for Warehouse with Product Flow Type Allocation using Linear Programming: A Case Study in a Textile Industry

    Science.gov (United States)

    Khannan, M. S. A.; Nafisah, L.; Palupi, D. L.

    2018-03-01

    Sari Warna Co. Ltd, a company engaged in the textile industry, is experiencing problems in the allocation and placement of goods in the warehouse. During this time the company has not implemented the product flow type allocation and product placement to the respective products resulting in a high total material handling cost. Therefore, this study aimed to determine the allocation and placement of goods in the warehouse corresponding to product flow type with minimal total material handling cost. This research is a quantitative research based on the theory of storage and warehouse that uses a mathematical model of optimization problem solving using mathematical optimization model approach belongs to Heragu (2005), aided by software LINGO 11.0 in the calculation of the optimization model. Results obtained from this study is the proportion of the distribution for each functional area is the area of cross-docking at 0.0734, the reserve area at 0.1894, and the forward area at 0.7372. The allocation of product flow type 1 is 5 products, the product flow type 2 is 9 products, the product flow type 3 is 2 products, and the product flow type 4 is 6 products. The optimal total material handling cost by using this mathematical model equal to Rp43.079.510 while it is equal to Rp 49.869.728 by using the company’s existing method. It saves Rp6.790.218 for the total material handling cost. Thus, all of the products can be allocated in accordance with the product flow type with minimal total material handling cost.

  17. Blood products, volume control, and renal support in the coagulopathy of liver disease.

    Science.gov (United States)

    Argo, Curtis K; Balogun, Rasheed A

    2009-02-01

    Plasma-based products are commonly used in patients who have chronic liver disease to treat perceived coagulopathy despite unproven efficacy and potentially severe risks, such as transfusion-related acute lung injury, which carries a high mortality rate. Moreover, volume expansion may acutely worsen portal hypertension and increase bleeding from the collateral portal vascular bed. Although factor replacement therapy may be warranted in selected situations, its use should be restricted because of the limitations of target tests, such as international normalized ratio, which poorly reflects presence of bleeding diatheses in patients who have cirrhosis. Renal replacement therapies are frequent adjuncts in patients who have cirrhosis and are acutely decompensated, and may correct uremia-related bleeding diathesis and assist in controlling vascular volume, although they are generally limited to use as a bridge to liver transplantation. Novel extracorporeal therapies are emerging and may also have significant interaction with the hemostatic system. Volume contraction and blood conservation therapies are relatively new and promising approaches to reduce use of blood products in liver transplantation.

  18. Application of method of volume averaging coupled with time resolved PIV to determine transport characteristics of turbulent flows in porous bed

    Science.gov (United States)

    Patil, Vishal; Liburdy, James

    2012-11-01

    Turbulent porous media flows are encountered in catalytic bed reactors and heat exchangers. Dispersion and mixing properties of these flows play an essential role in efficiency and performance. In an effort to understand these flows, pore scale time resolved PIV measurements in a refractive index matched porous bed were made. Pore Reynolds numbers, based on hydraulic diameter and pore average velocity, were varied from 400-4000. Jet-like flows and recirculation regions associated with large scale structures were found to exist. Coherent vortical structures which convect at approximately 0.8 times the pore average velocity were identified. These different flow regions exhibited different turbulent characteristics and hence contributed unequally to global transport properties of the bed. The heterogeneity present within a pore and also from pore to pore can be accounted for in estimating transport properties using the method of volume averaging. Eddy viscosity maps and mean velocity field maps, both obtained from PIV measurements, along with the method of volume averaging were used to predict the dispersion tensor versus Reynolds number. Asymptotic values of dispersion compare well to existing correlations. The role of molecular diffusion was explored by varying the Schmidt number and molecular diffusion was found to play an important role in tracer transport, especially in recirculation regions. Funding by NSF grant 0933857, Particulate and Multiphase Processing.

  19. A comparative study of lattice Boltzmann and volume of fluid method for two dimensional multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seung Yeob [Korea Atomic Energy Research Institute (KAERI), Daejeon (Korea, Republic of); Ko, Sung Ho [Dept. of Mechanical Design Engineering, Chungnam National University, Daejeon (Korea, Republic of)

    2012-08-15

    The volume of fluid (VOF) model of FLUENT and the lattice Boltzmann method (LBM) are used to simulate two-phase flows. Both methods are validated for static and dynamic bubble test cases and then compared to experimental results. The VOF method does not reduce the spurious currents of the static droplet test and does not satisfy the Laplace law for small droplets at the acceptable level, as compared with the LBM. For single bubble flows, simulations are executed for various Eotvos numbers, Morton numbers and Reynolds numbers, and the results of both methods agree well with the experiments in the case of low Eotvos numbers. For high Eotvos numbers, the VOF results deviated from the experiments. For multiple bubbles, the bubble flow characteristics are related by the wake of the leading bubble. The coaxial and oblique coalescence of the bubbles are simulated successfully and the subsequent results are presented. In conclusion, the LBM performs better than the VOF method.

  20. Hybrid Multiscale Finite Volume method for multiresolution simulations of flow and reactive transport in porous media

    Science.gov (United States)

    Barajas-Solano, D. A.; Tartakovsky, A. M.

    2017-12-01

    We present a multiresolution method for the numerical simulation of flow and reactive transport in porous, heterogeneous media, based on the hybrid Multiscale Finite Volume (h-MsFV) algorithm. The h-MsFV algorithm allows us to couple high-resolution (fine scale) flow and transport models with lower resolution (coarse) models to locally refine both spatial resolution and transport models. The fine scale problem is decomposed into various "local'' problems solved independently in parallel and coordinated via a "global'' problem. This global problem is then coupled with the coarse model to strictly ensure domain-wide coarse-scale mass conservation. The proposed method provides an alternative to adaptive mesh refinement (AMR), due to its capacity to rapidly refine spatial resolution beyond what's possible with state-of-the-art AMR techniques, and the capability to locally swap transport models. We illustrate our method by applying it to groundwater flow and reactive transport of multiple species.

  1. Numerical study of cesium effects on negative ion production in volume sources

    Energy Technology Data Exchange (ETDEWEB)

    Fukumasa, Osamu; Niitani, Eiji [Yamaguchi Univ., Ube (Japan). Faculty of Engineering

    1997-02-01

    Effects of cesium vapor injection of H{sup -} production in a tandem negative ion source are studied numerically as a function of plasma parameters. Model calculation is done by solving a set of particle balance equations in a steady-state hydrogen discharge plasmas. Here, the results which focus on gas pressure and electron temperature dependences of H{sup -} volume production are presented and discussed. With including H{sup -} surface production processes caused by both H atoms and positive hydrogen ions, enhancement of H{sup -} production and pressure dependence of H{sup -} production observed experimentally are well reproduced in the model. To enhance H{sup -} production, however, so-called electron cooling is not so effective if plasma parameters are initially optimized with the use of magnetic filter. (author)

  2. Production polyphasique. Modélisation des écoulements à bouchons Multiphase Production Slug-Flow Modeling

    Directory of Open Access Journals (Sweden)

    Drouffe J. M.

    2006-11-01

    Full Text Available L'exploitation des hydrocarbures en mer reste une activité coûteuse et qui peut, même, se révéler, éventuellement dangereuse. Les concepts de production polyphasique tels que Poséidon permettent à la fois : - une réduction importante des coûts de production; - la suppression des risques humains liés à la présence permanente en mer d'équipes importantes. Les programmes de simulation des écoulements diphasiques actuellement disponibles pour la mise en oeuvre de ces concepts, sont tous basés sur une approche déterministeclassique. Cet article présente une nouvelle approche statistiquenon conventionnelle qui devrait nous permettre de mieux préciser les caractéristiques des écoulements à bouchons et donc de pouvoir mieux dimensionner et exploiter nos futures installations de production et transport polyphasique longue distance. Offshore hydrocarbon production remains a costly venture, and even one that might possibly be dangerous. Multiphase production concepts such as Poseidon make for both a considerable reduction in production costs and the elimination of human risks linked to the constant offshore presence of large crews. The two-phase flow simulation programs now available for implementing such concepts are all based on a standard deterministicapproach. This article describes a new and unconventional statisticalapproach that we feel more accurately describes the characteristics of slug flows and hence is more effecting for the sizing and operating of future production and long-distance pipelining installations.

  3. Finite volume multigrid method of the planar contraction flow of a viscoelastic fluid

    Science.gov (United States)

    Moatssime, H. Al; Esselaoui, D.; Hakim, A.; Raghay, S.

    2001-08-01

    This paper reports on a numerical algorithm for the steady flow of viscoelastic fluid. The conservative and constitutive equations are solved using the finite volume method (FVM) with a hybrid scheme for the velocities and first-order upwind approximation for the viscoelastic stress. A non-uniform staggered grid system is used. The iterative SIMPLE algorithm is employed to relax the coupled momentum and continuity equations. The non-linear algebraic equations over the flow domain are solved iteratively by the symmetrical coupled Gauss-Seidel (SCGS) method. In both, the full approximation storage (FAS) multigrid algorithm is used. An Oldroyd-B fluid model was selected for the calculation. Results are reported for planar 4:1 abrupt contraction at various Weissenberg numbers. The solutions are found to be stable and smooth. The solutions show that at high Weissenberg number the domain must be long enough. The convergence of the method has been verified with grid refinement. All the calculations have been performed on a PC equipped with a Pentium III processor at 550 MHz. Copyright

  4. Convex Bodies With Minimal Volume Product in R^2 --- A New Proof

    OpenAIRE

    Lin, Youjiang

    2010-01-01

    In this paper, a new proof of the following result is given: The product of the volumes of an origin symmetric convex bodies $K$ in R^2 and of its polar body is minimal if and only if $K$ is a parallelogram.

  5. The Combination of Micro Diaphragm Pumps and Flow Sensors for Single Stroke Based Liquid Flow Control.

    Science.gov (United States)

    Jenke, Christoph; Pallejà Rubio, Jaume; Kibler, Sebastian; Häfner, Johannes; Richter, Martin; Kutter, Christoph

    2017-04-03

    With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout-differential pressure based flow sensors and thermal calorimetric flow sensors-are evaluated for their suitability of combining them with mircopumps. Single stroke based calibration of the sensors was carried out with a new method, comparing displacement volumes and sensor flow volumes. Limitations of accuracy and performance for single stroke based flow control are described. Results showed that besides particle robustness of sensors, controlling resistive and capacitive damping are key aspects for setting up reproducible and reliable liquid dosing systems. Depending on the required average flow or defined volume, dosing systems with an accuracy of better than 5% for the differential pressure based sensor and better than 6.5% for the thermal calorimeter were achieved.

  6. Interstitial solute transport in 3D reconstructed neuropil occurs by diffusion rather than bulk flow.

    Science.gov (United States)

    Holter, Karl Erik; Kehlet, Benjamin; Devor, Anna; Sejnowski, Terrence J; Dale, Anders M; Omholt, Stig W; Ottersen, Ole Petter; Nagelhus, Erlend Arnulf; Mardal, Kent-André; Pettersen, Klas H

    2017-09-12

    The brain lacks lymph vessels and must rely on other mechanisms for clearance of waste products, including amyloid [Formula: see text] that may form pathological aggregates if not effectively cleared. It has been proposed that flow of interstitial fluid through the brain's interstitial space provides a mechanism for waste clearance. Here we compute the permeability and simulate pressure-mediated bulk flow through 3D electron microscope (EM) reconstructions of interstitial space. The space was divided into sheets (i.e., space between two parallel membranes) and tunnels (where three or more membranes meet). Simulation results indicate that even for larger extracellular volume fractions than what is reported for sleep and for geometries with a high tunnel volume fraction, the permeability was too low to allow for any substantial bulk flow at physiological hydrostatic pressure gradients. For two different geometries with the same extracellular volume fraction the geometry with the most tunnel volume had [Formula: see text] higher permeability, but the bulk flow was still insignificant. These simulation results suggest that even large molecule solutes would be more easily cleared from the brain interstitium by diffusion than by bulk flow. Thus, diffusion within the interstitial space combined with advection along vessels is likely to substitute for the lymphatic drainage system in other organs.

  7. Cross-Border Flows of People, Technology Diffusion and Aggregate Productivity

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Andersen, Thomas Barnebeck

    A number of empirical studies have investigated the hypothesis that cross-border flows of goods (international trade) and capital (FDI) lead to international technology diffusion. The contribution of the present paper consists in examining an as yet neglected vehicle for technology diffusion: cro......-border flows of people. We find that increasing the intensity of international travel, for the purpose of business and otherwise, by 1% increases the level of aggregate total factor productivity and GDP per worker by roughly 0.2%....

  8. Local Entropy Production in Turbulent Shear Flows: A Tool for Evaluating Heat Transfer Performance

    Institute of Scientific and Technical Information of China (English)

    H. HERWIG; F. KOCK

    2006-01-01

    Performance evaluation of heat transfer devices can be based on the overall entropy production in these devices.In our study we therefore provide equations for the systematic and detailed determination of local entropy production due to dissipation of mechanical energy and due to heat conduction, both in turbulent flows. After turbulence modeling has been incorporated for the fluctuating parts the overall entropy production can be determined by integration with respect to the whole flow domain. Since, however, entropy production rates show very steep gradients close to the wall, numerical solutions are far more effective with wall functions for the entropy production terms. These wall functions are mandatory when high Reynolds number turbulence models are used. For turbulent flow in a pipe with an inserted twisted tape as heat transfer promoter it is shown that based on the overall entropy production rate a clear statement from a thermodynamic point of view is possible. For a certain range of twist strength there is a decrease in overall entropy production compared to the case without insert. Also, the optimum twist strength can be determined. This information is unavailable when only pressure drop and heat transfer data are given.

  9. A Three-Dimensional, Immersed Boundary, Finite Volume Method for the Simulation of Incompressible Heat Transfer Flows around Complex Geometries

    Directory of Open Access Journals (Sweden)

    Hassan Badreddine

    2017-01-01

    Full Text Available The current work focuses on the development and application of a new finite volume immersed boundary method (IBM to simulate three-dimensional fluid flows and heat transfer around complex geometries. First, the discretization of the governing equations based on the second-order finite volume method on Cartesian, structured, staggered grid is outlined, followed by the description of modifications which have to be applied to the discretized system once a body is immersed into the grid. To validate the new approach, the heat conduction equation with a source term is solved inside a cavity with an immersed body. The approach is then tested for a natural convection flow in a square cavity with and without circular cylinder for different Rayleigh numbers. The results computed with the present approach compare very well with the benchmark solutions. As a next step in the validation procedure, the method is tested for Direct Numerical Simulation (DNS of a turbulent flow around a surface-mounted matrix of cubes. The results computed with the present method compare very well with Laser Doppler Anemometry (LDA measurements of the same case, showing that the method can be used for scale-resolving simulations of turbulence as well.

  10. Idaho's forest products industry and timber harvest, 2011

    Science.gov (United States)

    Eric A. Simmons; Steven W. Hayes; Todd A. Morgan; Charles E. Keegan; Chris Witt

    2014-01-01

    This report traces the flow of Idaho’s 2011 timber harvest through the primary industries; provides a description of the structure, capacity, and condition of Idaho’s industry; and quantifies volumes and uses of wood fiber. Historical wood products industry trends are discussed, as well as changes in harvest, production, employment, and sales.

  11. A parallel finite-volume finite-element method for transient compressible turbulent flows with heat transfer

    International Nuclear Information System (INIS)

    Masoud Ziaei-Rad

    2010-01-01

    In this paper, a two-dimensional numerical scheme is presented for the simulation of turbulent, viscous, transient compressible flows in the simultaneously developing hydraulic and thermal boundary layer region. The numerical procedure is a finite-volume-based finite-element method applied to unstructured grids. This combination together with a new method applied for the boundary conditions allows for accurate computation of the variables in the entrance region and for a wide range of flow fields from subsonic to transonic. The Roe-Riemann solver is used for the convective terms, whereas the standard Galerkin technique is applied for the viscous terms. A modified κ-ε model with a two-layer equation for the near-wall region combined with a compressibility correction is used to predict the turbulent viscosity. Parallel processing is also employed to divide the computational domain among the different processors to reduce the computational time. The method is applied to some test cases in order to verify the numerical accuracy. The results show significant differences between incompressible and compressible flows in the friction coefficient, Nusselt number, shear stress and the ratio of the compressible turbulent viscosity to the molecular viscosity along the developing region. A transient flow generated after an accidental rupture in a pipeline was also studied as a test case. The results show that the present numerical scheme is stable, accurate and efficient enough to solve the problem of transient wall-bounded flow.

  12. Experimental on two sensors combination used in horizontal pipe gas-water two-phase flow

    International Nuclear Information System (INIS)

    Wu, Hao; Dong, Feng

    2014-01-01

    Gas-water two phase flow phenomenon widely exists in production and living and the measurement of it is meaningful. A new type of long-waist cone flow sensor has been designed to measure two-phase mass flow rate. Six rings structure of conductance probe is used to measure volume fraction and axial velocity. The calibration of them have been made. Two sensors have been combined in horizontal pipeline experiment to measure two-phase flow mass flow rate. Several model of gas-water two-phase flow has been discussed. The calculation errors of total mass flow rate measurement is less than 5% based on the revised homogeneous flow model

  13. Analysis of renal blood flow and renal volume in normal fetuses and in fetuses with a solitary functioning kidney.

    Science.gov (United States)

    Hindryckx, An; Raaijmakers, Anke; Levtchenko, Elena; Allegaert, Karel; De Catte, Luc

    2017-12-01

    To evaluate renal blood flow and renal volume for the prediction of postnatal renal function in fetuses with solitary functioning kidney (SFK). Seventy-four SFK fetuses (unilateral renal agenesis [12], multicystic dysplastic kidney [36], and severe renal dysplasia [26]) were compared with 58 healthy fetuses. Peak systolic velocity (PSV), pulsatility index (PI), and resistance index (RI) of the renal artery (RA) were measured; 2D and 3D (VOCAL) volumes were calculated. Renal length and glomerular filtration rate (GFR) were obtained in SFK children (2 years). Compared with the control group, the PSV RA was significantly lower in nonfunctioning kidneys and significantly higher in SFK. Volume measurements indicated a significantly larger volume of SFK compared with healthy kidneys. All but 4 children had GFR above 70 mL/min/1.73 m 2 , and compensatory hypertrophy was present in 69% at 2 years. PSV RA and SFK volume correlated with postnatal renal hypertrophy. No correlation between prenatal and postnatal SFK volume and GFR at 2 years was demonstrated. Low PSV RA might have a predictive value for diagnosing a nonfunctioning kidney in fetuses with a SFK. We demonstrated a higher PSV RA and larger renal volume in the SFK compared with healthy kidneys. © 2017 John Wiley & Sons, Ltd.

  14. A Method of Flow-Shop Re-Scheduling Dealing with Variation of Productive Capacity

    Directory of Open Access Journals (Sweden)

    Kenzo KURIHARA

    2005-02-01

    Full Text Available We can make optimum scheduling results using various methods that are proposed by many researchers. However, it is very difficult to process the works on time without delaying the schedule. There are two major causes that disturb the planned optimum schedules; they are (1the variation of productive capacity, and (2the variation of products' quantities themselves. In this paper, we deal with the former variation, or productive capacities, at flow-shop works. When production machines in a shop go out of order at flow-shops, we cannot continue to operate the productions and we have to stop the production line. To the contrary, we can continue to operate the shops even if some workers absent themselves. Of course, in this case, the production capacities become lower, because workers need to move from a machine to another to overcome the shortage of workers and some shops cannot be operated because of the worker shortage. We developed a new re-scheduling method based on Branch-and Bound method. We proposed an equation for calculating the lower bound for our Branch-and Bound method in a practical time. Some evaluation experiments are done using practical data of real flow-shop works. We compared our results with those of another simple scheduling method, and we confirmed the total production time of our result is shorter than that of another method by 4%.

  15. Controllable Microdroplet Splitting via Additional Lateral Flow and its Application in Rapid Synthesis of Multi-scale Microspheres

    KAUST Repository

    Zhou, Bingpu

    2015-01-01

    In this paper, we demonstrate that controllable microdroplet splitting could be obtained via additional lateral flow with simplicity and high controllability. The volume ratio of the two splitting products can be flexibly regulated by adjusting the flow rate ratio between the main and additional lateral flows. The splitting phenomena under different main flow rates were investigated. A volume ratio up to 200 : 1 of the two daughter droplets under a relatively higher main flow rate was experimentally achieved based on our approach. In this case, we have successfully achieved uniform daughter droplets with a smallest diameter of ∼19.5 ± 1.6 μm. With such a design, we have synthesized uniform PEGDA hydrogel microspheres with diameters ranging from ∼30 μm to over hundred of micrometers simultaneously.

  16. Volatilization and reaction of fission products in flowing steam

    International Nuclear Information System (INIS)

    Johnson, I.; Steidl, D.V.; Johnson, C.E.

    1985-01-01

    The principal risk to the public from nuclear power plants derives from the highly radioactive atoms (fission products) generated as energy is produced in the nuclear fuel. The revolatilization of fission products from reactor system surfaces due to self-heating by radioactive decay has become a complicating factor in the source-term redefinition effort. It has had a major impact on calculations of fission product distributions in accident safety analyses. The focus of this research effort was to investigate the volatilization and transport of fission products and control rod materials in a flowing gaseous steam-hydrogen mixture. Fission product and control rod materials in various combinations were studied including CsI, CsOH, TeO 2 , SrO, Ag, In, Cd and Mn. The vaporization behavior of the deposits were characterized with respect to vaporization rates, chemical species and downstream transport behavior

  17. How shear increments affect the flow production branching ratio in CSDX

    Science.gov (United States)

    Li, J. C.; Diamond, P. H.

    2018-06-01

    The coupling of turbulence-driven azimuthal and axial flows in a linear device absent magnetic shear (Controlled Shear Decorrelation Experiment) is investigated. In particular, we examine the apportionment of Reynolds power between azimuthal and axial flows, and how the azimuthal flow shear affects axial flow generation and saturation by drift wave turbulence. We study the response of the energy branching ratio, i.e., ratio of axial and azimuthal Reynolds powers, PzR/PyR , to incremental changes of azimuthal and axial flow shears. We show that increasing azimuthal flow shear decreases the energy branching ratio. When axial flow shear increases, this ratio first increases but then decreases to zero. The axial flow shear saturates below the threshold for parallel shear flow instability. The effects of azimuthal flow shear on the generation and saturation of intrinsic axial flows are analyzed. Azimuthal flow shear slows down the modulational growth of the seed axial flow shear, and thus reduces intrinsic axial flow production. Azimuthal flow shear reduces both the residual Reynolds stress (of axial flow, i.e., ΠxzR e s ) and turbulent viscosity ( χzDW ) by the same factor |⟨vy⟩'|-2Δx-2Ln-2ρs2cs2 , where Δx is the distance relative to the reference point where ⟨vy⟩=0 in the plasma frame. Therefore, the stationary state axial flow shear is not affected by azimuthal flow shear to leading order since ⟨vz⟩'˜ΠxzR e s/χzDW .

  18. Energy flows of the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gorshkov, V.G.

    1980-01-01

    Mankind consumes more than 90% of the animal production of the world. The locking of a significant part of the biosphere energy flow onto the anthropogenic chain leads to the dislodging of natural forms of organisms of the biosphere, change of its functioning and self-regulation. For the maintenance of stable existence of a small set of cultivated plants and domestic animals not forming the complete set indispensable for reaction to the change of natural conditions, man is compelled to follow the path of auxiliary investments of energy and to compensate for the destruction of closed circulations of food substances by the flow of fertilizers extracted from natural deposits. Energy assessments show the lack of realism of many projects for increasing the global energy flow in the anthropogenic channel by increasing the full flow of energy of the biosphere. To obtain the net production of the contemporary plowed field in hotbed on the basis of hydroponics there is required 2 x 10/sup 14/ watts of additional energy. To provide for the inflow of such an amount of energy (and also vast volumes of fresh water) presents extremely complicated problems. According to the author's calculations, in a provisional conversion of all production of green plants, all gas and petroleum and edible food with an efficiency equal to 1%, it is possible to provide food reserves equal to one annual harvest of the plowed fields of the world of 2 x 10/sup 9/ tons.

  19. White Rose development plan amendment production volume increase

    International Nuclear Information System (INIS)

    2006-09-01

    In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada, submitted a Benefits Plan for the White Rose Development to the Canada- Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB). This revised document provided the case for requesting an increase in the facility maximum daily production rate and the average annual production rate for the White Rose field from 100,000 barrels per day (bpd) as stated in the approved White Rose Development Plan to 140,000 bpd. In order to determine the potential for increasing oil production through the Floating Production, Storage and Offloading (FPSO) vessel, two things were considered, namely the proper reservoir management of the White Rose field to ensure optimum resource recovery, and the capacity of the FPSO topsides processing system and supporting utilities to accommodate increased production. This document presented a detailed review of all the implications of increased production on the South White Rose Reservoir. In addition, the results from FPSO performance testing were reviewed, including a study of options for de-bottlenecking the process plant on the topsides and capacity testing of selected process streams and support systems. Vibration analysis was conducted before and during performance testing in July 2006 and a small number of areas addressed. The document also addressed flow metering, resource management, certifying authority review, safety plan revisions, environmental effects, as well as benefits to Canada and Newfoundland. 21 tabs., 60 refs

  20. Flow-volume loops measured with electrical impedance tomography in pediatric patients with asthma.

    Science.gov (United States)

    Ngo, Chuong; Dippel, Falk; Tenbrock, Klaus; Leonhardt, Steffen; Lehmann, Sylvia

    2018-05-01

    Electrical impedance tomography (EIT) provides information on global and regional ventilation during tidal breathing and mechanical ventilation. During forced expiration maneuvers, the linearity of EIT and spirometric data has been documented in healthy persons. The present study investigates the potential diagnostic use of EIT in pediatric patients with asthma. EIT and spirometry were performed in 58 children with asthma (average age ± SD: 11.86 ± 3.13 years), and 58 healthy controls (average age ± SD: 12.12 ± 2.9 years). The correlation between EIT data and simultaneously acquired spirometric data were tested for FEV 1 , FEV 0.5 , MEF 75 , MEF 50 , and MEF 25 . Binary classification tests were performed for the EIT-derived Tiffeneau index FEV 1 /FVC and the bronchodilator test index ΔFEV 1 . Average flow-volume (FV) loops were generated for patients with pathologic spirometry to demonstrate the feasibility of EIT for graphic diagnosis of asthma. Spirometry and global EIT-based FV loops showed a strong correlation (P  0.9 in FEV 1 and FEV 0.5 ). In all criteria, the binary classification tests yielded high specificity (>93%), a high positive predictive value (≥75%) and a high negative predictive value (>80%), while sensitivity was higher in ΔFEV 1 (86.67%) and lower in FEV 1 /FVC (25% and 35.29%). A typical concave shape of the EIT-derived average FV loops was observed for asthmatic children with improvement after bronchospasmolysis. Global FV loops derived from EIT correlate well with spirometry. Positive bronchospasmolysis can be observed in EIT-derived FV loops. Flow-volume loops originated from EIT have a potential to visualize pulmonary function. © 2018 Wiley Periodicals, Inc.

  1. Can Emergency Physicians Perform Common Carotid Doppler Flow Measurements to Assess Volume Responsiveness?

    Directory of Open Access Journals (Sweden)

    Stolz, Lori A.

    2015-02-01

    Full Text Available Introduction: Common carotid flow measurements may be clinically useful to determine volume responsiveness. The objective of this study was to assess the ability of emergency physicians (EP to obtain sonographic images and measurements of the common carotid artery velocity time integral (VTi for potential use in assessing volume responsiveness in the clinical setting. Methods: In this prospective observational study, we showed a five-minute instructional video demonstrating a technique to obtain common carotid ultrasound images and measure the common carotid VTi to emergency medicine (EM residents. Participants were then asked to image the common carotid artery and obtain VTi measurements. Expert sonographers observed participants imaging in real time and recorded their performance on nine performance measures. An expert sonographer graded image quality. Participants were timed and answered questions regarding ease of examination and their confidence in obtaining the images. Results: A total of 30 EM residents participated in this study and each performed the examination twice. Average time required to complete one examination was 2.9 minutes (95% CI [2.4-3.4 min]. Participants successfully completed all performance measures greater than 75% of the time, with the exception of obtaining measurements during systole, which was completed in 65% of examinations. Median resident overall confidence in accurately performing carotid VTi measurements was 3 (on a scale of 1 [not confident] to 5 [confident]. Conclusion: EM residents at our institution learned the technique for obtaining common carotid artery Doppler flow measurements after viewing a brief instructional video. When assessed at performing this examination, they completed several performance measures with greater than 75% success. No differences were found between novice and experienced groups. [West J Emerg Med. 2015;16(2:255–259.

  2. Entropy production in a cell and reversal of entropy flow as an anticancer therapy

    Institute of Scientific and Technical Information of China (English)

    Liao-fu LUO

    2009-01-01

    The entropy production rate of cancer cells is always higher than healthy cells in the case where no external field is applied. Different entropy production between two kinds of cells determines the direction of entropy flow among cells. The entropy flow is the carrier of information flow. The entropy flow from cancerous cells to healthy cells takes along the harmful information of cancerous cells, propagating its toxic action to healthy tissues. We demonstrate that a low-frequency and low- intensity electromagnetic field or ultrasound irradiation may increase the entropy production rate of a cell in normal tissue than that in cancer and consequently re- verse the direction of entropy current between two kinds of cells. The modification of the PH value of cells may also cause the reversal of the direction of entropy flow between healthy and cancerous cells. Therefore, the bio- logical tissue under the irradiation of an electromagnetic field or ultrasound or under the appropriate change of cell acidity can avoid the propagation of harmful infor- marion from cancer cells. We suggest that this entropy mechanism possibly provides a basis for a novel approach to anticancer therapy.

  3. Control volume based hydrocephalus research

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Wei, Timothy

    2008-11-01

    Hydrocephalus is a disease involving excess amounts of cerebral spinal fluid (CSF) in the brain. Recent research has shown correlations to pulsatility of blood flow through the brain. However, the problem to date has presented as too complex for much more than statistical analysis and understanding. This talk will highlight progress on developing a fundamental control volume approach to studying hydrocephalus. The specific goals are to select physiologically control volume(s), develop conservation equations along with the experimental capabilities to accurately quantify terms in those equations. To this end, an in vitro phantom is used as a simplified model of the human brain. The phantom's design consists of a rigid container filled with a compressible gel. The gel has a hollow spherical cavity representing a ventricle and a cylindrical passage representing the aquaducts. A computer controlled piston pump supplies pulsatile volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity, and volume change as functions of time. Independent pressure measurements and flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients.

  4. Effect of gas quantity on two-phase flow characteristics of a mixed-flow pump

    OpenAIRE

    Qiang Fu; Fan Zhang; Rongsheng Zhu; Xiuli Wang

    2016-01-01

    The inlet gas quantity has a great influence on the performance and inner flow characteristics of a mixed-flow pump. In this article, both numerical and experimental methods are used to carry out this research work. The effects under the steady gas volume fraction state and the transient gas quantity variation process on the mixed-flow pump are investigated and compared in detail. It could be concluded that the head of the mixed-flow pump shows slight decline at the low gas volume fraction st...

  5. Effects of Air Stacking Maneuver on Cough Peak Flow and Chest Wall Compartmental Volumes of Subjects With Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Sarmento, Antonio; Resqueti, Vanessa; Dourado-Júnior, Mario; Saturnino, Lailane; Aliverti, Andrea; Fregonezi, Guilherme; de Andrade, Armele Dornelas

    2017-11-01

    To assess the acute effects of air stacking on cough peak flow (CPF) and chest wall compartmental volumes of persons with amyotrophic lateral sclerosis (ALS) versus healthy subjects positioned at 45° body inclination. Cross-sectional study with a matched-pair design. University hospital. Persons (N=24) with ALS (n=12) and age-matched healthy subjects (n=12). CPF, chest wall compartmental inspiratory capacity, chest wall vital capacity, chest wall tidal volume and operational volumes, breathing pattern, and percentage of contribution of the compartments to the inspired volume were measured by optoelectronic plethysmography. Compared with healthy subjects, significantly lower CPF (P=.007), chest wall compartmental inspiratory capacity (Pprotocol in the healthy subjects, mainly because of end-inspiratory (P<.001) and abdominal volumes (P=.008). No significant differences were observed in percentage of contribution of the compartments to the inspired volume and end-expiratory volume of both groups. No significant differences were found in chest wall tidal volume, operational volume, and breathing pattern in persons with ALS. Air stacking is effective in increasing CPF, chest wall compartmental inspiratory capacity, and chest wall vital capacity of persons with ALS with no hyperinflation. Differences in compartmental volume contributions are probably because of lung and chest wall physiological changes. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. The Combination of Micro Diaphragm Pumps and Flow Sensors for Single Stroke Based Liquid Flow Control

    Directory of Open Access Journals (Sweden)

    Christoph Jenke

    2017-04-01

    Full Text Available With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout—differential pressure based flow sensors and thermal calorimetric flow sensors—are evaluated for their suitability of combining them with mircopumps. Single stroke based calibration of the sensors was carried out with a new method, comparing displacement volumes and sensor flow volumes. Limitations of accuracy and performance for single stroke based flow control are described. Results showed that besides particle robustness of sensors, controlling resistive and capacitive damping are key aspects for setting up reproducible and reliable liquid dosing systems. Depending on the required average flow or defined volume, dosing systems with an accuracy of better than 5% for the differential pressure based sensor and better than 6.5% for the thermal calorimeter were achieved.

  7. Theoretical and Computational Analyses of Bernoulli Levitation Flows

    International Nuclear Information System (INIS)

    Nam, Jong Soon; Kim, Gyu Wan; Kim, Jin Hyeon; Kim, Heuy Dong

    2013-01-01

    Pneumatic levitation is based upon Bernoulli's principle. However, this method is known to require a large gas flow rate that can lead to an increase in the cost of products. In this case, the gas flow rate should be increased, and the compressible effects of the gas may be of practical importance. In the present study, a computational fluid dynamics method has been used to obtain insights into Bernoulli levitation flows. Three-dimensional compressible Navier-Stokes equations in combination with the SST k-ω turbulence model were solved using a fully implicit finite volume scheme. The gas flow rate, work piece diameter,and clearance gap between the work piece and the circular cylinder were varied to investigate the flow characteristics inside. It is known that there is an optimal clearance gap for the lifting force and that increasing the supply gas flow rate results in a larger lifting force

  8. Theoretical and Computational Analyses of Bernoulli Levitation Flows

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jong Soon; Kim, Gyu Wan; Kim, Jin Hyeon; Kim, Heuy Dong [Andong Nat' l Univ., Andong (Korea, Republic of)

    2013-07-15

    Pneumatic levitation is based upon Bernoulli's principle. However, this method is known to require a large gas flow rate that can lead to an increase in the cost of products. In this case, the gas flow rate should be increased, and the compressible effects of the gas may be of practical importance. In the present study, a computational fluid dynamics method has been used to obtain insights into Bernoulli levitation flows. Three-dimensional compressible Navier-Stokes equations in combination with the SST k-{omega} turbulence model were solved using a fully implicit finite volume scheme. The gas flow rate, work piece diameter,and clearance gap between the work piece and the circular cylinder were varied to investigate the flow characteristics inside. It is known that there is an optimal clearance gap for the lifting force and that increasing the supply gas flow rate results in a larger lifting force.

  9. Tracer technology modeling the flow of fluids

    CERN Document Server

    Levenspiel, Octave

    2012-01-01

    A vessel’s behavior as a heat exchanger, absorber, reactor, or other process unit is dependent upon how fluid flows through the vessel.  In early engineering, the designer would assume either plug flow or mixed flow of the fluid through the vessel.  However, these assumptions were oftentimes inaccurate, sometimes being off by a volume factor of 100 or more.  The result of this unreliable figure produced ineffective products in multiple reaction systems.   Written by a pioneering researcher in the field of chemical engineering, the tracer method was introduced to provide more accurate flow data.  First, the tracer method measured the actual flow of fluid through a vessel.  Second, it developed a suitable model to represent the flow in question.  Such models are used to follow the flow of fluid in chemical reactors and other process units, like in rivers and streams, or solid and porous structures.  In medicine, the tracer method is used to study the flow of chemicals—harmful  and harmless—in the...

  10. Relation Between Pressure and Volume Unloading During Ramp Testing in Patients Supported with a Continuous-Flow Left Ventricular Assist Device

    DEFF Research Database (Denmark)

    Jung, Mette H; Hassager, Christian; Balling, Louise

    2015-01-01

    Pulmonary capillary wedge pressure (PCWP) is the key to describing left ventricular (LV) unloading, however, the relation between pressure and the echocardiography-derived surrogate of LV volume (left ventricular end-diastolic diameter (LVEDD)) as a function of pump speed (RPM) in continuous......-flow left ventricular assist device (CF-LVAD) patients is unknown. In this study the pressure-volume relationship as a function of RPM during ramp testing was investigated by simultaneously measuring PCWP by Swan-Ganz catheter and LVEDD by echocardiography. The ramp protocol started at usual pump setting...

  11. Recovery of Navy distillate fuel from reclaimed product. Volume II. Literature review

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, D.W.; Whisman, M.L.

    1984-11-01

    In an effort to assist the Navy to better utilize its waste hydrocarbons, NIPER, with support from the US Department of Energy, is conducting research designed to ultimately develop a practical technique for converting Reclaimed Product (RP) into specification Naval Distillate Fuel (F-76). This first phase of the project was focused on reviewing the literature and available information from equipment manufacturers. The literature survey has been carefully culled for methodology applicable to the conversion of RP into diesel fuel suitable for Navy use. Based upon the results of this study, a second phase has been developed and outlined in which experiments will be performed to determine the most practical recycling technologies. It is realized that the final selection of one particular technology may be site-specific due to vast differences in RP volume and available facilities. A final phase, if funded, would involve full-scale testing of one of the recommended techniques at a refueling depot. The Phase I investigations are published in two volumes. Volume 1, Technical Discussion, includes the narrative and Appendices I and II. Appendix III, a detailed Literature Review, includes both a narrative portion and an annotated bibliography containing about 800 references and abstracts. This appendix, because of its volume, has been published separately as Volume 2.

  12. Feasibility of commercial space manufacturing, production of pharmaceuticals. Volume 2: Technical analysis

    Science.gov (United States)

    1978-01-01

    A technical analysis on the feasibility of commercial manufacturing of pharmaceuticals in space is presented. The method of obtaining pharmaceutical company involvement, laboratory results of the separation of serum proteins by the continuous flow electrophoresis process, the selection and study of candidate products, and their production requirements is described. The candidate products are antihemophilic factor, beta cells, erythropoietin, epidermal growth factor, alpha-1-antitrypsin and interferon. Production mass balances for antihemophelic factor, beta cells, and erythropoietin were compared for space versus ground operation. A conceptual description of a multiproduct processing system for space operation is discussed. Production requirements for epidermal growth factor of alpha-1-antitrypsin and interferon are presented.

  13. Capacity Decay Mitigation by Asymmetric Positive/Negative Electrolyte Volumes in Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Park, Jong Ho; Park, Jung Jin; Park, O Ok; Yang, Jung Hoon

    2016-11-23

    Capacity decay in vanadium redox flow batteries during charge-discharge cycling has become an important issue because it lowers the practical energy density of the battery. The battery capacity tends to drop rapidly within the first tens of cycles and then drops more gradually over subsequent cycles during long-term operation. This paper analyzes and discusses the reasons for this early capacity decay. The imbalanced crossover rate of vanadium species was found to remain high until the total difference in vanadium concentration between the positive and negative electrolytes reached almost 1 mol dm -3 . To minimize the initial crossover imbalance, we introduced an asymmetric volume ratio between the positive and negative electrolytes during cell operation. Changing this ratio significantly reduced the capacity fading rate of the battery during the early cycles and improved its capacity retention at steady state. As an example, the practical energy density of the battery increased from 15.5 to 25.2 Wh L -1 simply after reduction of the positive volume by 25 %. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Nuclear assay of coal. Volume 6. Mass flow devices for coal handling. Final report

    International Nuclear Information System (INIS)

    Gozani, T.; Elias, E.; Bevan, R.

    1980-04-01

    The mass of coal entering the boiler per unit time is an essential parameter for determining the total rate of heat input. The mass flow rate of coal on a conveyor belt is generally determined as a product of the instantaneous mass of material on a short section of the belt and the belt velocity. Belt loading could be measured by conventional transducers incorporating mechanical or electromechanical weighers or by gamma-ray attenuation gauge. This report reviews the state of the art in mass flow devices for coal handling. The various methods are compared and commented upon. Special design issues are discussed relative to incorporating a mass flow measuring device in a Continuous On-Line Nuclear Analysis of Coal (CONAC) system

  15. Measurement of cerebral blood flow in normal subjects by phase contrast MR imaging

    International Nuclear Information System (INIS)

    Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Inoue, Yusuke; Osada, Hisato

    1994-01-01

    Global cerebral blood flow (CBF) was quantitatively measured with a two-dimensional phase contrast cine magnetic resonance (MR) imaging technique in 24 normal subjects (mean age, 38.6 years; range, 12-70 years). Cine transverse images of the upper cervical region (32 phases/cardiac cycle) were acquired with a 1.5 Tesla MR imaging unit. In five subjects, measurement of CBF was performed before and after intravenous administration of acetazolamide (DIAMOX, 15 mg/kg). Inter- and intra-observer variations in flow volume measurement were small (r=0.970, standard error of the estimate (SEE)=2.9 ml/min, n=8; r=0.963, SEE=4.6 ml/min, n=40, respectively). In measuring flow velocity, they were inferior to those of flow volume measurement. On a visually determined setting of region of interest (ROI), reproducibility of the measurement of flow velocity was not satisfactory in this study. Thus only the results of flow volume measurement are presented. Mean summed vertebral flow volume (171 ml/min, SD=40.6) was significantly less than mean summed internal carotid flow volume (523 ml/min, SD=111). Total blood flow volume showed a significant decline with age (r=-0.45, p<0.05). The mean proportions of carotid and vertebral flow volume to total flow volume were 75.3% and 24.7%, respectively, and showed no significant change with age. The left-to-right ratio of vertebral flow volume (1.39) was significantly higher than that of internal carotid flow volume (0.99, r=0.05). After DIAMOX i.v., the mean rate of increase in total flow volume was 157%. Mean rates of increase in carotid and vertebral flow volume were 154% and 166%, respectively, which were not significantly different. In conclusion, this method is useful for estimating carotid and vertebral flow volume. (author)

  16. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  17. Advanced Continuous Flow Platform for On-Demand Pharmaceutical Manufacturing.

    Science.gov (United States)

    Zhang, Ping; Weeranoppanant, Nopphon; Thomas, Dale A; Tahara, Kohei; Stelzer, Torsten; Russell, Mary Grace; O'Mahony, Marcus; Myerson, Allan S; Lin, Hongkun; Kelly, Liam P; Jensen, Klavs F; Jamison, Timothy F; Dai, Chunhui; Cui, Yuqing; Briggs, Naomi; Beingessner, Rachel L; Adamo, Andrea

    2018-02-21

    As a demonstration of an alternative to the challenges faced with batch pharmaceutical manufacturing including the large production footprint and lengthy time-scale, we previously reported a refrigerator-sized continuous flow system for the on-demand production of essential medicines. Building on this technology, herein we report a second-generation, reconfigurable and 25 % smaller (by volume) continuous flow pharmaceutical manufacturing platform featuring advances in reaction and purification equipment. Consisting of two compact [0.7 (L)×0.5 (D)×1.3 m (H)] stand-alone units for synthesis and purification/formulation processes, the capabilities of this automated system are demonstrated with the synthesis of nicardipine hydrochloride and the production of concentrated liquid doses of ciprofloxacin hydrochloride, neostigmine methylsulfate and rufinamide that meet US Pharmacopeia standards. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Adaptive mesh refinement for a finite volume method for flow and transport of radionuclides in heterogeneous porous media

    International Nuclear Information System (INIS)

    Amaziane, Brahim; Bourgeois, Marc; El Fatini, Mohamed

    2014-01-01

    In this paper, we consider adaptive numerical simulation of miscible displacement problems in porous media, which are modeled by single phase flow equations. A vertex-centred finite volume method is employed to discretize the coupled system: the Darcy flow equation and the diffusion-convection concentration equation. The convection term is approximated with a Godunov scheme over the dual finite volume mesh, whereas the diffusion-dispersion term is discretized by piecewise linear conforming finite elements. We introduce two kinds of indicators, both of them of residual type. The first one is related to time discretization and is local with respect to the time discretization: thus, at each time, it provides an appropriate information for the choice of the next time step. The second is related to space discretization and is local with respect to both the time and space variable and the idea is that at each time it is an efficient tool for mesh adaptivity. An error estimation procedure evaluates where additional refinement is needed and grid generation procedures dynamically create or remove fine-grid patches as resolution requirements change. The method was implemented in the software MELODIE, developed by the French Institute for Radiological Protection and Nuclear Safety (IRSN, Institut de Radioprotection et de Surete Nucleaire). The algorithm is then used to simulate the evolution of radionuclide migration from the waste packages through a heterogeneous disposal, demonstrating its capability to capture complex behavior of the resulting flow. (authors)

  19. Delivery of tidal volume from four anaesthesia ventilators during volume-controlled ventilation: a bench study.

    Science.gov (United States)

    Wallon, G; Bonnet, A; Guérin, C

    2013-06-01

    Tidal volume (V(T)) must be accurately delivered by anaesthesia ventilators in the volume-controlled ventilation mode in order for lung protective ventilation to be effective. However, the impact of fresh gas flow (FGF) and lung mechanics on delivery of V(T) by the newest anaesthesia ventilators has not been reported. We measured delivered V(T) (V(TI)) from four anaesthesia ventilators (Aisys™, Flow-i™, Primus™, and Zeus™) on a pneumatic test lung set with three combinations of lung compliance (C, ml cm H2O(-1)) and resistance (R, cm H2O litre(-1) s(-2)): C60R5, C30R5, C60R20. For each CR, three FGF rates (0.5, 3, 10 litre min(-1)) were investigated at three set V(T)s (300, 500, 800 ml) and two values of PEEP (0 and 10 cm H2O). The volume error = [(V(TI) - V(Tset))/V(Tset)] ×100 was computed in body temperature and pressure-saturated conditions and compared using analysis of variance. For each CR and each set V(T), the absolute value of the volume error significantly declined from Aisys™ to Flow-i™, Zeus™, and Primus™. For C60R5, these values were 12.5% for Aisys™, 5% for Flow-i™ and Zeus™, and 0% for Primus™. With an increase in FGF, absolute values of the volume error increased only for Aisys™ and Zeus™. However, in C30R5, the volume error was minimal at mid-FGF for Aisys™. The results were similar at PEEP 10 cm H2O. Under experimental conditions, the volume error differed significantly between the four new anaesthesia ventilators tested and was influenced by FGF, although this effect may not be clinically relevant.

  20. Artificial neural network and neutron application in a volume fraction calculation in annular and stratified multiphase system

    International Nuclear Information System (INIS)

    Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da

    2009-01-01

    Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a 241 Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)

  1. Mapping Global Flows of Chemicals: From Fossil Fuel Feedstocks to Chemical Products.

    Science.gov (United States)

    Levi, Peter G; Cullen, Jonathan M

    2018-02-20

    Chemical products are ubiquitous in modern society. The chemical sector is the largest industrial energy consumer and the third largest industrial emitter of carbon dioxide. The current portfolio of mitigation options for the chemical sector emphasizes upstream "supply side" solutions, whereas downstream mitigation options, such as material efficiency, are given comparatively short shrift. Key reasons for this are the scarcity of data on the sector's material flows, and the highly intertwined nature of its complex supply chains. We provide the most up to date, comprehensive and transparent data set available publicly, on virgin production routes in the chemical sector: from fossil fuel feedstocks to chemical products. We map global mass flows for the year 2013 through a complex network of transformation processes, and by taking account of secondary reactants and by-products, we maintain a full mass balance throughout. The resulting data set partially addresses the dearth of publicly available information on the chemical sector's supply chain, and can be used to prioritise downstream mitigation options.

  2. The Four Corners timber harvest and forest products industry, 2007

    Science.gov (United States)

    Steven W. Hayes; Todd A. Morgan; Erik C. Berg; Jean M. Daniels; Mike Thompson

    2012-01-01

    This report traces the flow of timber harvested in the "Four Corners" States (Arizona, Colorado, New Mexico, and Utah) during calendar year 2007, describes the composition and operations of the region's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as...

  3. Fluid dynamics following flow shut-off in bottle filling

    Science.gov (United States)

    Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman

    2012-11-01

    Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.

  4. Simulation of a multistage fractured horizontal well in a water-bearing tight fractured gas reservoir under non-Darcy flow

    Science.gov (United States)

    Zhang, Rui-Han; Zhang, Lie-Hui; Wang, Rui-He; Zhao, Yu-Long; Huang, Rui

    2018-06-01

    Reservoir development for unconventional resources such as tight gas reservoirs is in increasing demand due to the rapid decline of production in conventional reserves. Compared with conventional reservoirs, fluid flow in water-bearing tight gas reservoirs is subject to more nonlinear multiphase flow and gas slippage in nano/micro matrix pores because of the strong collisions between rock and gas molecules. Economic gas production from tight gas reservoirs depends on extensive application of water-based hydraulic fracturing of horizontal wells, associated with non-Darcy flow at a high flow rate, geomechanical stress sensitivity of un-propped natural fractures, complex flow geometry and multiscale heterogeneity. How to efficiently and accurately predict the production performance of a multistage fractured horizontal well (MFHW) is challenging. In this paper, a novel multicontinuum, multimechanism, two-phase simulator is established based on unstructured meshes and the control volume finite element method to analyze the production performance of MFHWs. The multiple interacting continua model and discrete fracture model are coupled to integrate the unstimulated fractured reservoir, induced fracture networks (stimulated reservoir volumes, SRVs) and irregular discrete hydraulic fractures. Several simulations and sensitivity analyses are performed with the developed simulator for determining the key factors affecting the production performance of MFHWs. Two widely applied fracturing models, classic hydraulic fracturing which generates long double-wing fractures and the volumetric fracturing aimed at creating large SRVs, are compared to identify which of them can make better use of tight gas reserves.

  5. Numerical investigation on compressible flow characteristics in axial compressors using a multi block finite-volume scheme

    International Nuclear Information System (INIS)

    Farhanieh, B.; Amanifard, N.; Ghorbanian, K.

    2002-01-01

    An unsteady two-dimensional numerical investigation was performed on the viscous flow passing through a multi-blade cascade. A Cartesian finite-volume approach was linked to Van-Leer's and Roe's flux splitting schemes to evaluate inviscid flux terms. To prevent the oscillatory behavior of numerical results and to increase the accuracy, Mon tonic Upstream Scheme for Conservation Laws was added to flux splitting schemes. The Baldwin-Lo max (B L) turbulence model was implemented to solve the turbulent case studies. Implicit solution was also provided using Lower and Upper (L U) decomposition technique to compare with explicit solutions. To validate the numerical procedure, two test cases are prepared and flow over a Na Ca 0012 airfoil was investigated and the pressure coefficients were compared to the reference data. The numerical solver was implemented to study the flow passing over a compressor cascade. The results of various combinations of splitting schemes and the Mon tonic Upstream Scheme for Conventional Laws limiter were compared with each other to find the suitable methods in cascade problems. Finally the convergence histories of implemented schemes were compared to each other to show the behavior of the solver in using various methods before implementation of them in flow instability studies

  6. Virtual water flows in the international trade of agricultural products of China.

    Science.gov (United States)

    Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

    2016-07-01

    With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Normal expiratory flow rate and lung volumes in patients with combined emphysema and interstitial lung disease: a case series and literature review.

    Science.gov (United States)

    Heathcote, Karen L; Cockcroft, Donald W; Fladeland, Derek A; Fenton, Mark E

    2011-01-01

    Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.

  8. Fed batch fermentation scale up in the production of recombinant streptokinase

    Directory of Open Access Journals (Sweden)

    Salvador Losada-Nerey

    2017-01-01

    Full Text Available Due to the high international demand of the recombinant streptokinase (Skr produced at the National Center for Bioproducts (BioCen, it was necessary to increase the production capacity of the drug, since the current production volume does not cover the demand. A scale up of the process of fermentation of the recombinant streptokinase was made using a fed batch culture, from the bank scale towards a 300L fermenter. The scaling criteria used were: the intensive variables of the process, the relationships of volumes of the fermentation medium and inoculum, the volumetric coefficient of oxygen transfer and air volume to liquid flow relationship which were kept constant. With this scale up procedure it was possible to reproduce the results obtained at the bank scale of and to double the biomass production volume with the same equipment, fulfilling all the quality requirements of the product and to cover the current demand of the market. Techno-economic indicators demonstrated the feasibility of this option.

  9. Regional Myocardial Blood Volume and Flow: First-Pass MR Imaging with Polylysine-Gd-DTPA

    Science.gov (United States)

    Wilke, Norbert; Kroll, Keith; Merkle, Hellmut; Wang, Ying; Ishibashi, Yukata; Xu, Ya; Zhang, Jiani; Jerosch-Herold, Michael; Mühler, Andreas; Stillman, Arthur E.; Bassingthwaighte, James B.; Bache, Robert; Ugurbil, Kamil

    2010-01-01

    The authors investigated the utility of an intravascular magnetic resonance (MR) contrast agent, poly-L-lysine-gadolinium diethylenetriaminepentaacetic acid (DTPA), for differentiating acutely ischemic from normally perfused myocardium with first-pass MR imaging. Hypoperfused regions, identified with microspheres, on the first-pass images displayed significantly decreased signal intensities compared with normally perfused myocardium (P < .0007). Estimates of regional myocardial blood content, obtained by measuring the ratio of areas under the signal intensity-versus-time curves in tissue regions and the left ventricular chamber, averaged 0.12 mL/g ± 0.04 (n = 35), compared with a value of 0.11 mL/g ± 0.05 measured with radiolabeled albumin in the same tissue regions. To obtain MR estimates of regional myocardial blood flow, in situ calibration curves were used to transform first-pass intensity-time curves into content-time curves for analysis with a multiple-pathway, axially distributed model. Flow estimates, obtained by automated parameter optimization, averaged 1.2 mL/min/g ± 0.5 [n = 29), compared with 1.3 mL/min/g ± 0.3 obtained with tracer microspheres in the same tissue specimens at the same time. The results represent a combination of T1-weighted first-pass imaging, intravascular relaxation agents, and a spatially distributed perfusion model to obtain absolute regional myocardial blood flow and volume. PMID:7766986

  10. Yellow cake product practice

    International Nuclear Information System (INIS)

    Bosina, B.

    1980-01-01

    The flow sheets of uranium ore processing plants at present operating throughout the world terminate with the production of yellow cake. The demands of the refineries on the quality of this commodity have become more stringent with time. The impurity content of yellow cake depends to a considerable extent on the nature of the technical operations preceding precipitation. As a rule the purity of the final product is greater when the uranium is precipitated from re-extractants or regenerators consisting of weakly basic resins. An analysis of 80 uranium precipitation flow sheets demonstrates the advantages of using ammonia, while to some extent use is made of caustic soda, magnesium oxide, hydrogen peroxide or calcium oxide; precipitation is carried out in one or two stages at high temperature. Use of a particular chemical is governed by its availability, price, effect on the environment, degree of filtrate utilization, etc. It may be anticipated that the perfecting of precipitation flow sheets will be directed towards achieving maximum concentration of uranium in the solutions before precipitation, reduction in the volume of liquid flows through the equipment, an improvement in the filtration qualities of the precipitate, etc. The paper gives the flow sheet for precipitation of uranium by means of gaseous ammonia from sulphate-carbonate solutions. For drying yellow cake use has been made of spray driers. The dry product is easily sampled and transported. (author)

  11. An Eulerian finite volume solver for multi-material fluid flows with cylindrical symmetry

    International Nuclear Information System (INIS)

    Bernard-Champmartin, Aude; Ghidaglia, Jean-Michel; Braeunig, Jean-Philippe

    2013-01-01

    In this paper, we adapt a pre-existing 2D cartesian cell centered finite volume solver to treat the compressible 3D Euler equations with cylindrical symmetry. We then extend it to multi-material flows. Assuming cylindrical symmetry with respect to the z axis (i.e. all the functions do not depend explicitly on the angular variable h), we obtain a set of five conservation laws with source terms that can be decoupled in two systems solved on a 2D orthogonal mesh in which a cell as a torus geometry. A specific up-winding treatment of the source term is required and implemented for the stationary case. Test cases will be presented for vanishing and non-vanishing azimuthal velocity uh. (authors)

  12. The Supply Chain Triangle: How Synchronisation, Stability, and Productivity of Material Flows Interact

    Directory of Open Access Journals (Sweden)

    Florian Klug

    2013-01-01

    Full Text Available Empirical evidence created a commonly accepted understanding that synchronisation and stability of material flows impact its productivity. This crucial link between synchronous and stable material flows by time and quantity to create a supply chain with the highest throughput rates is at the heart of lean thinking. Although this supply chain triangle has generally been acknowledged over many years, it is necessary to reach a finer understanding of these dynamics. Therefore, we will develop and study supply chains with the help of fluid dynamics. A multistage, continuous material flow is modelled through a conservation law for material density. Unlike similar approaches, our model is not based on some quasi steady-state assumptions about the stochastic behaviour of the involved supply chain but rather on a simple deterministic rule for material flow density. These models allow us to take into account the nonlinear, dynamical interactions of different supply chain echelons and to test synchronised and stable flow with respect to its potential impacts. Numerical simulations verify that the model is able to simulate transient supply chain phenomena. Moreover, a quantification method relating to the fundamental link between synchronisation, stability, and productivity of supply chains has been found.

  13. Recovery of Navy distillate fuel from reclaimed product. Volume I. Technical discussion

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, D.W.; Whisman, M.L.

    1984-11-01

    In an effort to assist the Navy to better utilize its waste hydrocarbons, NIPER, with support from the US Department of Energy, is conducting research designed to ultimately develop a practical technique for converting Reclaimed Product (RP) into specification Naval Distillate Fuel (F-76). The first phase of the project was focused on reviewing the literature and available information from equipment manufacturers. The literature survey has been carefully culled for methodology applicable to the conversion of RP into diesel fuel suitable for Navy use. Based upon the results of this study, a second phase has been developed and outlined in which experiments will be performed to determine the most practical recycling technologies. It is realized that the final selection of one particular technology may be site-specific due to vast differences in RP volume and available facilities. A final phase, if funded, would involve full-scale testing of one of the recommended techniques at a refueling depot. The Phase I investigations are published in two volumes. Volume 1, Technical Discussion, includes the narrative and Appendices I and II. Appendix III, a detailed Literature Review, includes both a narrative portion and an annotated bibliography containing about 800 referenvces and abstracts. This appendix, because of its volume, has been published separately as Volume 2. 18 figures, 4 tables.

  14. A multiphase flow meter for the on-line determination of the flow rates of oil, water and gas

    International Nuclear Information System (INIS)

    Roach, G.J.; Watt, J.S.

    1997-01-01

    Multiphase mixtures of crude oil, formation water and gas are carried in pipelines from oil wells to production facilities. Multiphase flow meters (MFMs) are being developed to determine the flow rates of each component of the heterogeneous mixture in the pipeline. CSIRO Minerals has developed and field tested a gamma-ray MFM for the on-line determination of the flow rates of heterogeneous mixtures of oil, water and gas in pipelines. It consists of two specialised gamma-ray transmission gauges, and pressure and temperature sensors, mounted on the pipeline carrying the full flow of the production stream. The MFM separately measures liquids and gas flow rates, and the volume ratio of water and liquids (water cut). The MFM has been trialled at three offshore production facilities in Australia. In each, the MFM was mounted on the pipeline between the test manifold and the test separator. The multiphase streams from the various wells feeding to the platform were sequentially routed past the MFM. The MFM and test separator outputs were compared using regression analysis. The flow rates of oil, water and gas were each determined to relative errors in the range of 5-10% . The MFM has been in routine use on the West Kingfish platform in the Bass Strait since November 1994. The MFM was recently tested over a wide range of flow conditions at a Texaco flow facility near Houston. Water cut, based on pre-trial calibration, was determined to 2% rms over the range 0-100% water cut. The liquids and gas flow results were interpreted based on slip correlations obtained from comparison of the MFM and Texaco flows. Using these, the relative errors were respectively 6.6% for liquid flow, 6.2% for gas, 8% for oil and 8% for water. The MFM is licensed to Kvaerner FSSL of Aberdeen. Kvaerner will supply the gamma-ray MFM for both platform and subsea use. Technology transfer commenced in December 1996, and Kvaerner completed the manufacture of the first MFM in August 1997

  15. Programming heterogeneous MPSoCs tool flows to close the software productivity gap

    CERN Document Server

    Castrillón Mazo, Jerónimo

    2014-01-01

    This book provides embedded software developers with techniques for programmingheterogeneous Multi-Processor Systems-on-Chip (MPSoCs), capable of executing multiple applications simultaneously. It describes a set of algorithms and methodologies to narrow the software productivity gap, as well as an in-depth description of the underlying problems and challenges of today’s programming practices. The authors present four different tool flows: A parallelism extraction flow for applications writtenusing the C programming language, a mapping and scheduling flow for parallel applications, a special mapping flow for baseband applications in the context of Software Defined Radio (SDR) and a final flow for analyzing multiple applications at design time. The tool flows are evaluated on Virtual Platforms (VPs), which mimic different characteristics of state-of-the-art heterogeneous MPSoCs.   • Provides a novel set of algorithms and methodologies for programming heterogeneous Multi-Processor Systems-on-Chip (MPSoCs)...

  16. Control volume based hydrocephalus research; a phantom study

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Madsen, Joseph; Wei, Timothy

    2009-11-01

    Hydrocephalus is a complex spectrum of neurophysiological disorders involving perturbation of the intracranial contents; primarily increased intraventricular cerebrospinal fluid (CSF) volume and intracranial pressure are observed. CSF dynamics are highly coupled to the cerebral blood flows and pressures as well as the mechanical properties of the brain. Hydrocephalus, as such, is a very complex biological problem. We propose integral control volume analysis as a method of tracking these important interactions using mass and momentum conservation principles. As a first step in applying this methodology in humans, an in vitro phantom is used as a simplified model of the intracranial space. The phantom's design consists of a rigid container filled with a compressible gel. Within the gel a hollow spherical cavity represents the ventricular system and a cylindrical passage represents the spinal canal. A computer controlled piston pump supplies sinusoidal volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity and volume change as functions of time. Independent pressure measurements and momentum flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients and normal individuals. Flow and pressure measurements on the flow phantom will be presented through the control volume framework.

  17. Dispersion strengthening of aluminium-aluminium-oxide products

    DEFF Research Database (Denmark)

    Hansen, Niels

    1970-01-01

    The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...... temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

  18. Controllable Microdroplet Splitting via Additional Lateral Flow and its Application in Rapid Synthesis of Multi-scale Microspheres

    KAUST Repository

    Zhou, Bingpu; Wang, Cong; Xiao, Xiao; Hui, Yu Sanna; Cao, Yulin; Wen, Weijia

    2015-01-01

    In this paper, we demonstrate that controllable microdroplet splitting could be obtained via additional lateral flow with simplicity and high controllability. The volume ratio of the two splitting products can be flexibly regulated by adjusting

  19. Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

    Directory of Open Access Journals (Sweden)

    Brito AF

    2014-12-01

    Full Text Available Aline de Freitas Brito,1 Caio Victor Coutinho de Oliveira,2 Maria do Socorro Brasileiro-Santos,1 Amilton da Cruz Santos1 1Physical Education Department, 2Research Laboratory for Physical Training Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Brazil Background: The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular resistance in hypertensive elderly subjects.Methods: The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m2 subjected to three experimental sessions, ie, a control session, exercise with a set (S1, and exercise with three sets (S3. For each session, the subjects were evaluated before and after intervention. In the pre-intervention period, blood pressure, forearm blood flow, and forearm vascular resistance were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same time period. Both S1 and S3 comprised a set of ten repetitions of ten exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (post-intervention in the supine position.Results: Post-exercise hypotension was greater in S3 than in S1 (systolic blood pressure, −26.5±4.2 mmHg versus −17.9±4.7 mmHg; diastolic blood pressure, −13.8±4.9 mmHg versus −7.7±5 mmHg, P<0.05. Similarly, forearm blood flow and forearm vascular resistance changed significantly in both sessions with an increase and decrease, respectively, that was more evident in S3 than in S1 (P<0.05.Conclusion: Resistance exercises with higher volume were more effective in causing post-exercise hypotension, being accompanied by an increase in forearm blood flow and a reduction of forearm vascular

  20. Quantitative Measurements using Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2016-01-01

    scanner for pulsating flow mimicking the femoral artery from a CompuFlow 1000 pump (Shelley Medical). Data were used in four estimators based on directional transverse oscillation for velocity, flow angle, volume flow, and turbulence estimation and their respective precisions. An adaptive lag scheme gave...... the ability to estimate a large velocity range, or alternatively measure at two sites to find e.g. stenosis degree in a vessel. The mean angle at the vessel center was estimated to 90.9◦±8.2◦ indicating a laminar flow from a turbulence index being close to zero (0.1 ±0.1). Volume flow was 1.29 ±0.26 mL/stroke...... (true: 1.15 mL/stroke, bias: 12.2%). Measurements down to 160 mm were obtained with a relative standard deviation and bias of less than 10% for the lateral component for stationary, parabolic flow. The method can, thus, find quantitative velocities, angles, and volume flows at sites currently...

  1. Artificial neural network and neutron application in a volume fraction calculation in annular and stratified multiphase system

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A., E-mail: robson@ien.gov.b, E-mail: brandao@ien.gov.b, E-mail: cmnap@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos; Schirru, Roberto; Silva, Ademir Xavier da, E-mail: schirru@lmp.ufrj.b, E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Dept.

    2009-07-01

    Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a {sup 241}Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)

  2. Two-Phase Quality/Flow Meter

    Science.gov (United States)

    Moerk, J. Steven (Inventor); Youngquist, Robert C. (Inventor); Werlink, Rudy J. (Inventor)

    1999-01-01

    A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components.ne dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors.The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.

  3. Animal health and production

    International Nuclear Information System (INIS)

    Kallfelz, F.A.; Lengemann, F.W.

    1984-01-01

    An outline review is presented of the use of radioisotopes and radiation in animal health and production research. Techniques covered are the qualitative localization of a radioisotope (static and dynamic measurements, detection procedures involving locating concentration sites of labelled toxins, parasites, abnormal blood cells, etc.), quantitative measurement of isotopes (absorption and excretion, transfer across membranes) comparator studies (determination of mass, volume or flow), isotope dilution and related studies (in vivo and in vitro applications, determination of total body red cell or plasma volume), dynamic systems (single compartmental systems such as rumen studies and the suckling lamb or calf, multiple exits from a compartment and multiple doses), stable isotopes and mass spectrometry, activation analysis and nuclear magnetic resonance, and the use of internal irradiation (sterile male technique, control of insects and parasites, production of attenuated vaccines etc.). (U.K.)

  4. Free surface flow with moving rigid bodies. Part 1. Computational flow model

    International Nuclear Information System (INIS)

    Gubanov, O.I.; Mironova, L.A.; Kocabiyik, S.

    2005-01-01

    This paper was motivated by the study of Hirt and Sicilian, where the 'differential form' of the governing equations for the inviscid fluid flow (FAVOR equations) were obtained. We utilize mainly generalized differentiation to extend the Reynolds transport theorem over a control volume containing fluid interface for deriving the 'integral form' of governing equations for the incompressible viscous flow problems. This is done following the work by Farassat and the use of generalized function theory made this derivation straightforward, systematic and rigorous. The resulting equations are discretized by a finite-volume method using a staggered grid, after making use of the coarse-scale approximation. The resulting governing equations are valid for a class of flows including free surface flows with arbitrarily moving bodies and are consistent with Hirt and Sicilian's formulation in the inviscid fluid flow case. (author)

  5. REORGANIZATION OF THE TECHNOLOGICAL FLOW AT CLOTHING COMPANY THROUGH THE PRODUCTION SCHEDULE

    Directory of Open Access Journals (Sweden)

    GHELBET Angela

    2017-05-01

    Full Text Available One of the main difficulties that light industry, namely clothing manufacturing sector faces today is inadequate organization of production processes. This is one of the most common and most serious obstacles in companies in the country, leading to low productivity. In order to reveal the causes of the problem and to develop solutions for change, it is proposed to conduct a study of a company facing difficulties in organizing the production process. It is important that the method/tool applied for the study is able to solve the problems occurring in the production process with minimum effort and maximum efficiency. The study was conducted within the process of manufacturing of a model of special clothing, namely clothing for doctors. The study was conducted within February-March 2016 at a clothing company of the Republic of Moldova. The study conducted shows that the transport issue in the technological flow can be solved by applying the production schedule, which eventually increases labor productivity by eliminating the time necessary to transport the labor object from one place of work to another, leading to economic growth considerable for the company. Following the assessments referring to the proposed improvements to organize the technological flow, there should be a 20% reduction in manufacturing time of a product, which will directly increase the revenue of the company by at least 10%.

  6. A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

    KAUST Repository

    Jagad, P. I.

    2018-04-12

    A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell-Centered Colocated Variables. Part I: Discretization, International Journal of Heat and Mass Transfer, vol. 48 (6), 1117-1127, 2005) is extended to include the solid-body stress analysis. The transport terms for a cell-face are evaluated in a structured grid-like manner. The Cartesian gradients at the center of each cell-face are evaluated using the coordinate transformation relations. The accuracy of the procedure is demonstrated by solving several benchmark problems involving different boundary conditions, source terms, and types of loading.

  7. Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI

    DEFF Research Database (Denmark)

    Gideon, P; Ståhlberg, F; Thomsen, C

    1994-01-01

    An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal...

  8. Production and delivery of polarized Xenon-129 for in vivo MRS/MRI.

    Science.gov (United States)

    Rosen, Matthew S.; Chupp, Timothy E.; Coulter, Kevin P.; Welsh, Robert C.; Swanson, Scott

    1998-05-01

    Laser polarized ^129Xe can be used as an entirely new magnetic tracer, and is a powerful enhancement to currently existing MRI techniques. Inert laser polarized ^129Xe is inhaled and transported via blood flow where it is detected using MR spectroscopy and imaging techniques. The time-dependent distribution patterns of ^129Xe signal intensity directly reflect local blood volume, blood flow rates, and the efficiency of perfusion and diffusive transport in tissues. We have developed a uniquely constructed laser polarized ^129Xe production and delivery system that is used in both our in vitro and in vivo imaging experiments with rats. This reliable, effective, and relatively simple production method for large volumes of laser polarized ^129Xe is the key to all other areas of research involving use of laser polarized gases.

  9. Operation control of fluids pumping in curved pipes during annular flow: a numerical evaluation

    Directory of Open Access Journals (Sweden)

    T Andrade

    2016-10-01

    Full Text Available To generate projects which provide significant volume recovery from heavy oils reservoirs and improve existing projects, is important to develop new production and transport technologies, especially in the scenario of offshore fields. The core-flow technique is one of new technologies used in heavy oil transportation. This core-flow pattern is characterized by a water pellicle that is formed close or adjacent to the inner wall of the pipe, functioning as a lubricant. The oil flows in the center of the pipe causing a reduction in longitudinal pressure drop. In this sense, this work presents a numerical study of heavy oil annular flow (core-flow assisted by computational tool ANSYS CFX® Release 12.0. It was used a three-dimensional, transient and isothermal mathematical model considered by the mixture and turbulence - models to address the water-heavy oil two-phase flow, assuming laminar flow for oil phase and turbulent flow for water phase. Results of the pressure, velocity and volume fraction distributions of the phases and the pressure drop for different operation conditions are presented and evaluated. It was observed that the oil core flowing eccentrically in the pipe and stops of the water flux considerably increases the pressure drop in the pipe after the restart of the pump.

  10. Accounting emergy flows to determine the best production model of a coffee plantation

    International Nuclear Information System (INIS)

    Giannetti, B.F.; Ogura, Y.; Bonilla, S.H.; Almeida, C.M.V.B.

    2011-01-01

    Cerrado, a savannah region, is Brazil's second largest ecosystem after the Amazon rainforest and is also threatened with imminent destruction. In the present study emergy synthesis was applied to assess the environmental performance of a coffee farm located in Coromandel, Minas Gerais, in the Brazilian Cerrado. The effects of land use on sustainability were evaluated by comparing the emergy indices along ten years in order to assess the energy flows driving the production process, and to determine the best production model combining productivity and environmental performance. The emergy indices are presented as a function of the annual crop. Results show that Santo Inacio farm should produce approximately 20 bags of green coffee per hectare to accomplish its best performance regarding both the production efficiency and the environment. The evaluation of coffee trade complements those obtained by contrasting productivity and environmental performance, and despite of the market prices variation, the optimum interval for Santo Inacio's farm is between 10 and 25 coffee bags/ha. - Highlights: → Emergy synthesis is used to assess the environmental performance of a coffee farm in Brazil. → The effects of land use on sustainability were evaluated along ten years. → The energy flows driving the production process were assessed. → The best production model combining productivity and environmental performance was determined.

  11. Accounting emergy flows to determine the best production model of a coffee plantation

    Energy Technology Data Exchange (ETDEWEB)

    Giannetti, B.F.; Ogura, Y.; Bonilla, S.H. [Universidade Paulista, Programa de Pos Graduacao em Engenharia de Producao, R. Dr. Bacelar, 1212 Sao Paulo SP (Brazil); Almeida, C.M.V.B., E-mail: cmvbag@terra.com.br [Universidade Paulista, Programa de Pos Graduacao em Engenharia de Producao, R. Dr. Bacelar, 1212 Sao Paulo SP (Brazil)

    2011-11-15

    Cerrado, a savannah region, is Brazil's second largest ecosystem after the Amazon rainforest and is also threatened with imminent destruction. In the present study emergy synthesis was applied to assess the environmental performance of a coffee farm located in Coromandel, Minas Gerais, in the Brazilian Cerrado. The effects of land use on sustainability were evaluated by comparing the emergy indices along ten years in order to assess the energy flows driving the production process, and to determine the best production model combining productivity and environmental performance. The emergy indices are presented as a function of the annual crop. Results show that Santo Inacio farm should produce approximately 20 bags of green coffee per hectare to accomplish its best performance regarding both the production efficiency and the environment. The evaluation of coffee trade complements those obtained by contrasting productivity and environmental performance, and despite of the market prices variation, the optimum interval for Santo Inacio's farm is between 10 and 25 coffee bags/ha. - Highlights: > Emergy synthesis is used to assess the environmental performance of a coffee farm in Brazil. > The effects of land use on sustainability were evaluated along ten years. > The energy flows driving the production process were assessed. > The best production model combining productivity and environmental performance was determined.

  12. Normal Expiratory Flow Rate and Lung Volumes in Patients with Combined Emphysema and Interstitial Lung Disease: A Case Series and Literature Review

    Directory of Open Access Journals (Sweden)

    Karen L Heathcote

    2011-01-01

    Full Text Available Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.

  13. A combined finite volume-nonconforming finite element scheme for compressible two phase flow in porous media

    KAUST Repository

    Saad, Bilal Mohammed; Saad, Mazen Naufal B M

    2014-01-01

    We propose and analyze a combined finite volume-nonconforming finite element scheme on general meshes to simulate the two compressible phase flow in porous media. The diffusion term, which can be anisotropic and heterogeneous, is discretized by piecewise linear nonconforming triangular finite elements. The other terms are discretized by means of a cell-centered finite volume scheme on a dual mesh, where the dual volumes are constructed around the sides of the original mesh. The relative permeability of each phase is decentred according the sign of the velocity at the dual interface. This technique also ensures the validity of the discrete maximum principle for the saturation under a non restrictive shape regularity of the space mesh and the positiveness of all transmissibilities. Next, a priori estimates on the pressures and a function of the saturation that denote capillary terms are established. These stabilities results lead to some compactness arguments based on the use of the Kolmogorov compactness theorem, and allow us to derive the convergence of a subsequence of the sequence of approximate solutions to a weak solution of the continuous equations, provided the mesh size tends to zero. The proof is given for the complete system when the density of the each phase depends on its own pressure. © 2014 Springer-Verlag Berlin Heidelberg.

  14. A combined finite volume-nonconforming finite element scheme for compressible two phase flow in porous media

    KAUST Repository

    Saad, Bilal Mohammed

    2014-06-28

    We propose and analyze a combined finite volume-nonconforming finite element scheme on general meshes to simulate the two compressible phase flow in porous media. The diffusion term, which can be anisotropic and heterogeneous, is discretized by piecewise linear nonconforming triangular finite elements. The other terms are discretized by means of a cell-centered finite volume scheme on a dual mesh, where the dual volumes are constructed around the sides of the original mesh. The relative permeability of each phase is decentred according the sign of the velocity at the dual interface. This technique also ensures the validity of the discrete maximum principle for the saturation under a non restrictive shape regularity of the space mesh and the positiveness of all transmissibilities. Next, a priori estimates on the pressures and a function of the saturation that denote capillary terms are established. These stabilities results lead to some compactness arguments based on the use of the Kolmogorov compactness theorem, and allow us to derive the convergence of a subsequence of the sequence of approximate solutions to a weak solution of the continuous equations, provided the mesh size tends to zero. The proof is given for the complete system when the density of the each phase depends on its own pressure. © 2014 Springer-Verlag Berlin Heidelberg.

  15. A non-statistical regularization approach and a tensor product decomposition method applied to complex flow data

    Science.gov (United States)

    von Larcher, Thomas; Blome, Therese; Klein, Rupert; Schneider, Reinhold; Wolf, Sebastian; Huber, Benjamin

    2016-04-01

    Handling high-dimensional data sets like they occur e.g. in turbulent flows or in multiscale behaviour of certain types in Geosciences are one of the big challenges in numerical analysis and scientific computing. A suitable solution is to represent those large data sets in an appropriate compact form. In this context, tensor product decomposition methods currently emerge as an important tool. One reason is that these methods often enable one to attack high-dimensional problems successfully, another that they allow for very compact representations of large data sets. We follow the novel Tensor-Train (TT) decomposition method to support the development of improved understanding of the multiscale behavior and the development of compact storage schemes for solutions of such problems. One long-term goal of the project is the construction of a self-consistent closure for Large Eddy Simulations (LES) of turbulent flows that explicitly exploits the tensor product approach's capability of capturing self-similar structures. Secondly, we focus on a mixed deterministic-stochastic subgrid scale modelling strategy currently under development for application in Finite Volume Large Eddy Simulation (LES) codes. Advanced methods of time series analysis for the databased construction of stochastic models with inherently non-stationary statistical properties and concepts of information theory based on a modified Akaike information criterion and on the Bayesian information criterion for the model discrimination are used to construct surrogate models for the non-resolved flux fluctuations. Vector-valued auto-regressive models with external influences form the basis for the modelling approach [1], [2], [4]. Here, we present the reconstruction capabilities of the two modeling approaches tested against 3D turbulent channel flow data computed by direct numerical simulation (DNS) for an incompressible, isothermal fluid at Reynolds number Reτ = 590 (computed by [3]). References [1] I

  16. Product differentiation during continuous-flow thermal gradient PCR.

    Science.gov (United States)

    Crews, Niel; Wittwer, Carl; Palais, Robert; Gale, Bruce

    2008-06-01

    A continuous-flow PCR microfluidic device was developed in which the target DNA product can be detected and identified during its amplification. This in situ characterization potentially eliminates the requirement for further post-PCR analysis. Multiple small targets have been amplified from human genomic DNA, having sizes of 108, 122, and 134 bp. With a DNA dye in the PCR mixture, the amplification and unique melting behavior of each sample is observed from a single fluorescent image. The melting behavior of the amplifying DNA, which depends on its molecular composition, occurs spatially in the thermal gradient PCR device, and can be observed with an optical resolution of 0.1 degrees C pixel(-1). Since many PCR cycles are within the field of view of the CCD camera, melting analysis can be performed at any cycle that contains a significant quantity of amplicon, thereby eliminating the cycle-selection challenges typically associated with continuous-flow PCR microfluidics.

  17. Unsteady force estimation using a Lagrangian drift-volume approach

    Science.gov (United States)

    McPhaden, Cameron J.; Rival, David E.

    2018-04-01

    A novel Lagrangian force estimation technique for unsteady fluid flows has been developed, using the concept of a Darwinian drift volume to measure unsteady forces on accelerating bodies. The construct of added mass in viscous flows, calculated from a series of drift volumes, is used to calculate the reaction force on an accelerating circular flat plate, containing highly-separated, vortical flow. The net displacement of fluid contained within the drift volumes is, through Darwin's drift-volume added-mass proposition, equal to the added mass of the plate and provides the reaction force of the fluid on the body. The resultant unsteady force estimates from the proposed technique are shown to align with the measured drag force associated with a rapid acceleration. The critical aspects of understanding unsteady flows, relating to peak and time-resolved forces, often lie within the acceleration phase of the motions, which are well-captured by the drift-volume approach. Therefore, this Lagrangian added-mass estimation technique opens the door to fluid-dynamic analyses in areas that, until now, were inaccessible by conventional means.

  18. Successful well test application of portable multi-phase flow meter for high gas-volume and high water-cut wells in east Kalimantan, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Kaura, Jiten D.; Finley, D.B. [PT Halliburton Indonesia, Jakarta (Indonesia); Sudradjat, Wangsa; Riyanto, Latief [Tota E and P Indonesie, Jakarta (Indonesia); Halverson, Martin [FlowSys AS, Bergen (Norway)

    2004-07-01

    Recently, testing was needed on production wells in East Kalimantan. The wells were in a mature field, and productivity from the wells field featured high water cut (WC) and extremely high gas-volume fractions (GVF). The WC and GVF ranged from 80 to 100% and 90 to 100%, respectively. Moreover, most of the wells are low productivity so they are very sensitive to back-pressure. The high WC, high GVF and low-productivity from these wells in this area present an extreme challenge for accurate production measurement. Barges are commonly used to perform well services in the swamp area of this marginal field, and production allocations from wells in this difficult area were previously monitored and measured with conventional well-test equipment on-board a well testing barge. The well test equipment traditionally used requires a large footprint, and the associated flaring presents an environmental situation in this sensitive swamp area. Hence, the MPFM solution was chosen. To better meet the challenges presented by the testing conditions, a portable multiphase flow meter (MPFM) was chosen to perform the testing from the well-testing barge. For comparative purposes, the MPFM was installed on the barge immediately upstream of the well testing equipment. Initial measurements with the MPFM yielded results that were {+-} 30% of the test separator reading. A slight modification was introduced to the MPFM system in the form of a gas knock-out (GKO) vessel. Subsequent measurements with the modified MPFM system yielded readings that were {+-}10% of the test separator reading. (author)

  19. The Four Corners timber harvest and forest products industry, 2012

    Science.gov (United States)

    Colin B. Sorenson; Steven W. Hayes; Todd A. Morgan; Eric A. Simmons; Micah G. Scudder; Chelsea P. McIver; Mike T. Thompson

    2016-01-01

    This report traces the flow of timber harvested in the "Four Corners" States (Arizona, Colorado, New Mexico, and Utah) during calendar year 2012, describes the composition and operations of the region’s primary forest products industry, and quantifies volumes and uses of wood fiber. Recent changes in the wood products industry are discussed, as well as trends...

  20. Bathyphotometer bioluminescence potential measurements: A framework for characterizing flow agitators and predicting flow-stimulated bioluminescence intensity

    Science.gov (United States)

    Latz, Michael I.; Rohr, Jim

    2013-07-01

    Bathyphotometer measurements of bioluminescence are used as a proxy for the abundance of luminescent organisms for studying population dynamics; the interaction of luminescent organisms with physical, chemical, and biological oceanographic processes; and spatial complexity especially in coastal areas. However, the usefulness of bioluminescence measurements has been limited by the inability to compare results from different bathyphotometer designs, or even the same bathyphotometer operating at different volume flow rates. The primary objective of this study was to compare measurements of stimulated bioluminescence of four species of cultured dinoflagellates, the most common source of bioluminescence in coastal waters, using two different bathyphotometer flow agitators as a function of bathyphotometer volume flow rate and dinoflagellate concentration. For both the NOSC and BIOLITE flow agitators and each species of dinoflagellate tested, there was a critical volume flow rate, above which average bioluminescence intensity, designated as bathyphotometer bioluminescence potential (BBP), remained relatively constant and scaled directly with dinoflagellate cell concentration. At supra-critical volume flow rates, the ratio of BIOLITE to NOSC BBP was nearly constant for the same species studied, but varied between species. The spatial pattern and residence time of flash trajectories within the NOSC flow agitator indicated the presence of dominant secondary recirculating flows, where most of the bioluminescence was detected. A secondary objective (appearing in the Appendix) was to study the feasibility of using NOSC BBP to scale flow-stimulated bioluminescence intensity across similar flow fields, where the contributing composition of luminescent species remained the same. Fully developed turbulent pipe flow was chosen because it is hydrodynamically well characterized. Average bioluminescence intensity in a 2.54-cm i.d. pipe was highly correlated with wall shear stress and

  1. Impact of Optimized Flow Pattern on Pollutant Removal and Biogas Production Rate Using Wastewater Anaerobic Fermentation

    Directory of Open Access Journals (Sweden)

    Ruyi Huang

    2015-06-01

    Full Text Available This paper introduces a new-type of antigravity mixing method, which was applied in the biogas production process, using organic wastewater fermentation. It was found that the digesters with two designs, a high-position, centralized pressure outlet and a high-position, dispersed pressure outlets, both lead to an increase in biogas production rates by 89% and 125%, respectively. The biogas production peak appeared 1 day and 7 days earlier, and the COD removal rates were raised by 27% and 42%, respectively. The results indicated that the optimized flow field had a significant impact. This work also explains the mechanism of flow field optimization using computational fluid dynamics (CFD software for the simulation of the flow field form in the hydraulic mixing.

  2. Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET

    DEFF Research Database (Denmark)

    IIda, H.; Law, I.; Pakkenberg, B.

    2000-01-01

    Limited spatial resolution of positron emission tomography (PET) can cause significant underestimation in the observed regional radioactivity concentration (so-called partial volume effect or PVE) resulting in systematic errors in estimating quantitative physiologic parameters. The authors have...... formulated four mathematical models that describe the dynamic behavior of a freely diffusible tracer (H215O) in a region of interest (ROI) incorporating estimates of regional tissue flow that are independent of PVE. The current study was intended to evaluate the feasibility of these models and to establish...... a methodology to accurately quantify regional cerebral blood flow (CBF) corrected for PVE in cortical gray matter regions. Five monkeys were studied with PET after IV H2(15)O two times (n = 3) or three times (n = 2) in a row. Two ROIs were drawn on structural magnetic resonance imaging (MRI) scans and projected...

  3. Numerical study of cesium effects on negative ion production in volume H-and D- ion sources

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Niitani, Eiji; Yoshino, Kyougo

    1997-01-01

    We present the results of model calculation on H - /D - isotope effects in the tandem volume source. The model includes the surface production due to cesium injection. On the electron density n e dependence of H - /D - production, we have observed an interesting phenomena. Namely D - production, i.e D - density, is higher than H - production in low n e , but in high n e H - production is higher than D - production. The atomic density plays an important role in the density inversion between H - and D - ions. (author)

  4. A finite-volume HLLC-based scheme for compressible interfacial flows with surface tension

    Energy Technology Data Exchange (ETDEWEB)

    Garrick, Daniel P. [Department of Aerospace Engineering, Iowa State University, Ames, IA (United States); Owkes, Mark [Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT (United States); Regele, Jonathan D., E-mail: jregele@iastate.edu [Department of Aerospace Engineering, Iowa State University, Ames, IA (United States)

    2017-06-15

    Shock waves are often used in experiments to create a shear flow across liquid droplets to study secondary atomization. Similar behavior occurs inside of supersonic combustors (scramjets) under startup conditions, but it is challenging to study these conditions experimentally. In order to investigate this phenomenon further, a numerical approach is developed to simulate compressible multiphase flows under the effects of surface tension forces. The flow field is solved via the compressible multicomponent Euler equations (i.e., the five equation model) discretized with the finite volume method on a uniform Cartesian grid. The solver utilizes a total variation diminishing (TVD) third-order Runge–Kutta method for time-marching and second order TVD spatial reconstruction. Surface tension is incorporated using the Continuum Surface Force (CSF) model. Fluxes are upwinded with a modified Harten–Lax–van Leer Contact (HLLC) approximate Riemann solver. An interface compression scheme is employed to counter numerical diffusion of the interface. The present work includes modifications to both the HLLC solver and the interface compression scheme to account for capillary force terms and the associated pressure jump across the gas–liquid interface. A simple method for numerically computing the interface curvature is developed and an acoustic scaling of the surface tension coefficient is proposed for the non-dimensionalization of the model. The model captures the surface tension induced pressure jump exactly if the exact curvature is known and is further verified with an oscillating elliptical droplet and Mach 1.47 and 3 shock-droplet interaction problems. The general characteristics of secondary atomization at a range of Weber numbers are also captured in a series of simulations.

  5. Waste-aware fluid volume assignment for flow-based microfluidic biochips

    DEFF Research Database (Denmark)

    Schneider, Alexander Rüdiger; Pop, Paul; Madsen, Jan

    2017-01-01

    complex Fluidic Units (FUs) such as switches, micropumps, mixers and separators can be constructed. When running a biochemical application on a FBMB, fluid volumes are dispensed from input reservoirs and used by the FUs. Given a biochemical application and a biochip, we are interested in determining...... the fluid volume assignment for each operation of the application, such that the FUs volume requirements are satisfied, while over- and underflow are avoided and the total volume of fluid used is minimized. We propose an algorithm for this fluid assignment problem. Compared to previous work, our method...

  6. CFD analysis and flow model reduction for surfactant production in helix reactor

    Directory of Open Access Journals (Sweden)

    Nikačević N.M.

    2015-01-01

    Full Text Available Flow pattern analysis in a spiral Helix reactor is conducted, for the application in the commercial surfactant production. Step change response curves (SCR were obtained from numerical tracer experiments by three-dimensional computational fluid dynamics (CFD simulations. Non-reactive flow is simulated, though viscosity is treated as variable in the direction of flow, as it increases during the reaction. The design and operating parameters (reactor diameter, number of coils and inlet velocity are varied in CFD simulations, in order to examine the effects on the flow pattern. Given that 3D simulations are not practical for fast computations needed for optimization, scale-up and control, CFD flow model is reduced to one-dimensional axial dispersion (AD model with spatially variable dispersion coefficient. Dimensionless dispersion coefficient (Pe is estimated under different conditions and results are analyzed. Finally, correlation which relates Pe number with Reynolds number and number of coils from the reactor entrance is proposed for the particular reactor application and conditions.

  7. Pyroclastic flows generated by gravitational instability of the 1996-97 lava dome of Soufriere Hills Volcano, Montserrat

    Science.gov (United States)

    Cole, P.D.; Calder, E.S.; Druitt, T.H.; Hoblitt, R.; Robertson, R.; Sparks, R.S.J.; Young, S.R.

    1998-01-01

    Numerous pyroclastic flows were produced during 1996-97 by collapse of the growing andesitic lava dome at Soufriere Hills Volcano, Montserrat. Measured deposit volumes from these flows range from 0.2 to 9 ?? 106 m3. Flows range from discrete, single pulse events to sustained large scale dome collapse events. Flows entered the sea on the eastern and southern coasts, depositing large fans of material at the coast. Small runout distance (Soufriere Hills Volcano, Montserrat. Measured deposit volumes from these flows range from 0.2 to 9??106 m3. Flows range from discrete, single pulse events to sustained large scale dome collapse events. Flows entered the sea on the eastern and southern coasts, depositing large fans of material at the coast. Small runout distance (<1 km) flows had average flow front velocities in the order of 3-10 m/s while flow fronts of the larger runout distance flows (up to 6.5 km) advanced in the order of 15-30 m/s. Many flows were locally highly erosive. Field relations show that development of the fine grained ash cloud surge component was enhanced during the larger sustained events. Periods of elevated dome pyroclastic flow productivity and sustained collapse events are linked to pulses of high magma extrusion rates.

  8. Environmental effects of energy production and utilization in the U.S. Volume I. Sources, trends, and costs of control

    International Nuclear Information System (INIS)

    Newkirk, H.W.

    1976-01-01

    Volume I deals with sources (what the emissions are and where they come from), trends (quantities of emissions and their dispersion with time), and costs of control (what it takes in time, energy, and money to meet minimum standards). Volume II concerns itself with the public health effects of energy production and utilization. Volume III summarizes the various techniques for controlling emissions, technological as well as economic, social, and political. Each volume is divided into sections dealing with the atmosphere, water, land, and social activities--each division indicating a particular sphere of man's environment affected by energy production and use. The sources of information that were used in this study included textbooks, journal articles, technical reports, memoranda, letters, and personal communications. These are cited in the text at the end of each subsection and on the applicable tables and figures

  9. A non-conformal finite element/finite volume scheme for the non-structured grid-based approximation of low Mach number flows

    International Nuclear Information System (INIS)

    Ansanay-Alex, G.

    2009-01-01

    The development of simulation codes aimed at a precise simulation of fires requires a precise approach of flame front phenomena by using very fine grids. The need to take different spatial scale into consideration leads to a local grid refinement and to a discretization with homogeneous grid for computing time and memory purposes. The author reports the approximation of the non-linear convection term, the scalar advection-diffusion in finite volumes, numerical simulations of a flow in a bent tube, of a three-dimensional laminar flame and of a low Mach number an-isotherm flow. Non conformal finite elements are also presented (Rannacher-Turek and Crouzeix-Raviart elements)

  10. Literature research on the production, loading, flow, and heat transfer of slush hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Moo [Dept. of Mechanical Engineering, Ajou University, Wonchon-dong san 5, Paldal-Gu, Suwon 442-749 (Korea, Republic of)

    2010-12-15

    This study summarizes the available information on slush hydrogen and answer pending engineering questions that arise in the design of slush hydrogen propellant systems. The four methods for the production of slush are discussed. For storage, slush hydrogen must be pressurized, free from impurities, and continuously upgraded. Slush flowing at low flow rates has a higher viscosity than the liquid, however at higher velocities it approaches the viscosity of neat liquid. For the entire range of natural convection and nucleate boiling, the heat transfer at the triple-point temperature and pressure is nearly the same for the liquid and slush. The natural convection from smooth surfaces for slush can be predicted using available correlations. However, for engineering analysis and design of a system involving a slush cryogenic propellant, reliable information is required on production, flow, heat transfer, and instrumentation of these fluids. Some relevant and important aspects of slush hydrogen which have not yet been fully answered are presented. (author)

  11. Study of volume fractions on biphasic stratified regime using gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, William L.; Brandão, Luis E.B., E-mail: william.otero@hotmail.com, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In the oil industries, interconnected pipelines are used to carry large quantities of petroleum and its byproducts. This modal has an advantage because they are more economical, eliminate a need for stocks and, in addition, great safety in operation minimizing a possibility of loss or theft when transported another way. In many cases, especially in the petrochemical industry, the same pipeline is used to carry more than one type of product. They are called poliduct. In the operation of a poliduct there is a sequence of products to be transported and during the exchange of the product, there are still fractions of the previous product and this generates contamination. It is therefore important to identify precisely this region in order to reduce the costs of reprocessing and treatment of discarded products. In this way, this work presents a methodology to evaluate the sensitivity of the gamma densitometry technique in a study of the calculation of volume fractions in biphasic systems, submitted to the stratified flow regime. Using computational simulations using the Monte Carlo Method with the MCNPX code measurement geometry was proposed that presented a higher sensitivity for the calculation of volume fractions. The relevant technical data to perform a simulation of the scintillator detectors were based on information obtained from the gammagraphy technique. The study had a theoretical validation through analytical equations, and the results show that it is possible to identify volume fractions equivalent to 3%. (author)

  12. Study of volume fractions on biphasic stratified regime using gamma ray

    International Nuclear Information System (INIS)

    Salgado, William L.; Brandão, Luis E.B.

    2017-01-01

    In the oil industries, interconnected pipelines are used to carry large quantities of petroleum and its byproducts. This modal has an advantage because they are more economical, eliminate a need for stocks and, in addition, great safety in operation minimizing a possibility of loss or theft when transported another way. In many cases, especially in the petrochemical industry, the same pipeline is used to carry more than one type of product. They are called poliduct. In the operation of a poliduct there is a sequence of products to be transported and during the exchange of the product, there are still fractions of the previous product and this generates contamination. It is therefore important to identify precisely this region in order to reduce the costs of reprocessing and treatment of discarded products. In this way, this work presents a methodology to evaluate the sensitivity of the gamma densitometry technique in a study of the calculation of volume fractions in biphasic systems, submitted to the stratified flow regime. Using computational simulations using the Monte Carlo Method with the MCNPX code measurement geometry was proposed that presented a higher sensitivity for the calculation of volume fractions. The relevant technical data to perform a simulation of the scintillator detectors were based on information obtained from the gammagraphy technique. The study had a theoretical validation through analytical equations, and the results show that it is possible to identify volume fractions equivalent to 3%. (author)

  13. 76 FR 1067 - Testing of Certain High Production Volume Chemicals; Second Group of Chemicals

    Science.gov (United States)

    2011-01-07

    ... Mfg & NOES (number based criteria based criteria significant chemicals (lbs) industrial of workers... 2070-AD16 Testing of Certain High Production Volume Chemicals; Second Group of Chemicals AGENCY... section 4(a)(1)(B) of the Toxic Substances Control Act (TSCA) to require manufacturers, importers, and...

  14. ICP curve morphology and intracranial flow-volume changes

    DEFF Research Database (Denmark)

    Unnerbäck, Mårten; Ottesen, Johnny T.; Reinstrup, Peter

    2018-01-01

    proposed to shape the ICP curve. This study tested the hypothesis that the ICP curve correlates to intracranial volume changes. METHODS: Cine phase contrast magnetic resonance imaging (MRI) examinations were performed in neuro-intensive care patients with simultaneous ICP monitoring. The MRI was set......BACKGROUND: The intracranial pressure (ICP) curve with its different peaks has been extensively studied, but the exact physiological mechanisms behind its morphology are still not fully understood. Both intracranial volume change (ΔICV) and transmission of the arterial blood pressure have been...

  15. Impact of Alternative Environmental Flow Prescriptions on Hydropower Production and Fish Habitat Suitability

    Science.gov (United States)

    Castellarin, A.; Ceola, S.; Pugliese, A.; Galeati, G. A.

    2015-12-01

    Anthropogenic activities along streams and rivers are increasingly recognized to be a major concern for fluvial ecosystems. The management of water resources, by means of e.g. flow diversions and dams, for industrial, agricultural, water-supply, hydropower production and flood protection purposes induces significant changes to the natural streamflow regime of a river. Indeed, the river flow regime is known to be a major abiotic factor influencing fluvial ecosystems. An established approach aimed at preserving the behaviour and distribution of fluvial species relies on the definition of minimum streamflow requirements (i.e., environmental flows) downstream of dams and diversion structures. Such environmental flows are normally identified through methodologies that have an empirical nature and may not be representative of local ecological and hydraulic conditions. While the effect of imposing a minimum discharge release is easily predictable in terms of e.g. loss of hydropower production, the advantages in terms of species preferences are often poorly understood and seldom assessed. To analyze the interactions between flow releases and the behaviour and distribution of fluvial species (i.e., from periphyton, to benthic invertebrate and fish), one may use a habitat suitability curve, which is a fundamental tool capable of describing species preferences influenced by any generic environmental variable. The outcomes of a real case study applied to several Italian rivers, located in the Marche administrative district in Central Italy (∽10000km2), in which we quantitatively assess the effects of alternative environmental flow scenarios on the existing hydropower network and on two fish species that are quite abundant in the study area (i.e., Leuciscus cephalus cabeda and Barbus barbus plebejus), will be presented and discussed. The proposed analysis, which can be easily adapted to different riparian habitats and hydrological contexts, is a useful tool to guide the

  16. Brief description of out-of-pile test facilities for study in corrosion and fission product behaviour in flowing sodium

    International Nuclear Information System (INIS)

    Iizawa, K.; Sekiguchi, N.; Atsumo, H.

    1976-01-01

    The experimental methods to perform tests for study in corrosion and fission products behaviour in flowing sodium are outlined. Flow diagrams for the activated materials and fission products behaviour test loop are given

  17. Quantitative agreement between [(15)O]H2O PET and model free QUASAR MRI-derived cerebral blood flow and arterial blood volume

    NARCIS (Netherlands)

    Heijtel, D. F. R.; Petersen, E. T.; Mutsaerts, H. J. M. M.; Bakker, E.; Schober, P.; Stevens, M. F.; van Berckel, B. N. M.; Majoie, C. B. L. M.; Booij, J.; van Osch, M. J. P.; van Bavel, E. T.; Boellaard, R.; Lammertsma, A. A.; Nederveen, A. J.

    2016-01-01

    The purpose of this study was to assess whether there was an agreement between quantitative cerebral blood flow (CBF) and arterial cerebral blood volume (CBVA) measurements by [(15)O]H2O positron emission tomography (PET) and model-free QUASAR MRI. Twelve healthy subjects were scanned within a week

  18. [The repercussions of pulmonary congestion on ventilatory volumes, capacities and flows].

    Science.gov (United States)

    Carmo, M M; Ferreira, T; Lousada, N; Bárbara, C; Neves, P R; Correia, J M; Rendas, A B

    1994-10-01

    To evaluate the effects of pulmonary congestion on pulmonary function. Prospective study performed in patients with left ventricular failure or mitral stenosis. Forty-eight hospitalized patients were included suffering from pulmonary congestion either from left ventricular failure or mitral stenosis. While in hospital all patients were submitted to right heart catheterization by the Swan-Ganz method and also to an echocardiographic examination. Within 48 hours after the patients were submitted to the following lung function studies: lung volumes and capacities by the multi-breath helium dilution method and airway flows by pneumotachography. Respiratory symptoms were evaluated by the Medical Research Council Questionnaire and the functional class classified according to the NYHA. Correlations were made between the functional and clinical data. Regarding the cardiac evaluation patients presented with a mean pulmonary wedge pressure of 19.9 +/- 8.6 mmHg, a cardiac index of 2.5 +/- 0.8 l/min/m2, an end diastolic dimension of the left ventricle of 65.9 +/- 10.1 mm, and end systolic dimension of 51.2 +/- 12.2 mm, with a shortening fraction of 21.8 +/- 9.5%. The pulmonary evaluation showed a restrictive syndrome with a reduction in the mean values of the following parameters: total pulmonary capacity 71 +/- 14.4% of the predicted value (pv), forced vital capacity (FVC) 69.8 +/- 20.5% pv, and forced expiratory volume (FEV1) of 64 +/- 21.8% vp. The index FEV1/FVC was within the normal value of 72.7 +/- 9.7%. These lung function results did not correlate significantly with either the clinical, the hemodynamic or echocardiographic findings. In these group of patients pulmonary congestion led to the development of a restrictive syndrome which failed to correlate in severity with the duration of the disease, the pulmonary wedge pressure and the left ventricular function.

  19. Theoretical and pragmatic modelling of governing equations for a two-phase flow in bubbly and annular flow regimes

    International Nuclear Information System (INIS)

    Bottoni, M.; Sengpiel, W.

    1992-01-01

    Starting from the rigorous formulation of the conservation equations for mass, momentum and enthalpy, derived for a two-phase flow by volume averaging microscopic balance equations over Eulerian control cells, the article discusses the formulation of the terms describing exchanges between the phases. Two flow regimes are taken into consideration, bubbly flow, applicable for small or medium void fractions, and annular flow, for large void fractions. When lack of knowledge of volume-averaged physical quantities make the rigorously formulated terms useless for computational purposes, modelling of these terms is discussed. 3 figs., 15 refs

  20. Flows and chemical reactions in heterogeneous mixtures

    CERN Document Server

    Prud'homme, Roger

    2014-01-01

    This book - a sequel of previous publications 'Flows and Chemical Reactions' and 'Chemical Reactions in Flows and Homogeneous Mixtures' - is devoted to flows with chemical reactions in heterogeneous environments.  Heterogeneous media in this volume include interfaces and lines. They may be the site of radiation. Each type of flow is the subject of a chapter in this volume. We consider first, in Chapter 1, the question of the generation of environments biphasic individuals: dusty gas, mist, bubble flow.  Chapter 2 is devoted to the study at the mesoscopic scale: particle-fluid exchange of mom

  1. Significant lung volume reduction with endobronchial valves in a patient despite the presence of microcollaterals masked by low-flow Chartis phenotype

    Directory of Open Access Journals (Sweden)

    Yin Y

    2016-11-01

    Full Text Available Yan Yin,1 Gang Hou,1 Felix J Herth,2 Xiao-bo Wang,1 Qiu-yue Wang,1 Jian Kang1 1Department of Respiratory Medicine, The First Hospital of China Medical University, Shenyang, People’s Republic of China; 2Department of Pneumology and Critical Care Medicine, Thoraxklinik, University of Heidelberg, Heidelberg, Germany Abstract: Satisfactory functional outcomes following bronchoscopic lung volume reduction (BLVR using endobronchial valves (EBVs depend on the absence of collateral ventilation (CV between the target and adjunct lobes. The Chartis system has proven to be useful for determining whether CV is present or absent, but this system can also erroneously indicate the absence of CV, which can lead to BLVR failure. Here, we describe low-flow Chartis phenotype in the target lobe resulted in difficult judgment of existence of CV. Consequently, BLVR with EBVs implanted into the right upper bronchus failed to reduce lung volume or induce atelectasis. Inserting another EBV into the right middle bronchus blocked the latent CV, which led to significant lung volume reduction in the right upper lobe (RUL and right middle lobe (RML and to improve the pulmonary function, 6-min walking distance, and St George respiratory questionnaire scores over a 2-week follow-up period. Low flow in the target lobe is a unique Chartis phenotype and represents the uncertainty of CV, which is a risk factor for the failure of BLVR using EBVs. Clinicians should be aware of this possibility and might be able to resolve the problem by blocking the RUL and RML between which the CV occurs. Keywords: COPD, bronchoscopic lung volume reduction, collateral ventilation, endobronchial valves, Chartis assessment

  2. Advances in gas-liquid flows 1990

    International Nuclear Information System (INIS)

    Kim, J.M.; Hashemi, A.

    1990-01-01

    Gas-liquid two-phase flows commonly occur in nature and industrial applications. Rain, clouds, geysers, and waterfalls are examples of natural gas-liquid flow phenomena, whereas industrial applications can be found in nuclear reactors, steam generators, boilers, condensers, evaporators, fuel atomization, heat pipes, electronic equipment cooling, petroleum engineering, chemical process engineering, and many others. The household-variety phenomena such as garden sprinklers, shower, whirlpool bath, dripping faucet, boiling tea pot, and bubbling beer provide daily experience of gas-liquid flows. The papers presented in this volume reflect the variety and richness of gas-liquid two-phase flow and the increasing role it plays in modern technology. This volume contains papers dealing with some recent development in gas-liquid flow science and technology, covering basic gas-liquid flows, measurements and instrumentation, cavitation and flashing flows, countercurrent flow and flooding, flow in various components and geometries liquid metals and thermocapillary effects, heat transfer, nonlinear phenomena, instability, and other special and general topics related to gas-liquid flows

  3. Erosion and deposition on a debris-flow fan

    Science.gov (United States)

    Densmore, A. L.; Schuerch, P.; Rosser, N. J.; McArdell, B. W.

    2011-12-01

    The ability of a debris flow to entrain or deposit sediment controls the downstream evolution of flow volume, and ultimately dictates both the geomorphic impact of the flow and the potential hazard that it represents. Our understanding of the patterns of, and controls on, such flow volume changes remains extremely limited, however, partly due to a poor mechanistic grasp of the interactions between debris flows and their bed and banks. In addition, we lack a good understanding of the cumulative long-term effects of sequences of flows in a single catchment-fan system. Here we begin to address these issues by using repeated terrestrial laser scanning (TLS) to characterize the detailed surface change associated with the passage of multiple debris flows on the Illgraben fan, Switzerland. We calculate surface elevation change along a 300 m study reach, and from this derive the downfan rate of flow volume change, or lag rate; for comparison, we also derive the spatially-averaged lag rate over the entire ~2 km length of the fan. Lag rates are broadly comparable over both length scales, indicating that flow behavior does not vary significantly across the fan for most flows, but importantly we find that flow volume at the fan head is a poor predictor of volume at the fan toe. The sign and magnitude of bed elevation change scale with local flow depth; at flow depths 2 m. On the Illgraben fan, this depth corresponds to a basal shear stress of 3-4 kPa. Because flow depth is in part a function of channel cross-sectional topography, which varies strongly both within and between flows, this result indicates that erosion and deposition are likely to be highly dynamic. The dependence of flow volume change on both the channel topography and the flow history may thus complicate efforts to predict debris-flow inundation areas by simple flow routing. We then apply a 2d numerical model of debris-flow fan evolution to explore the key controls on debris-flow routing and topographic

  4. Cost Analysis of an Air Brayton Receiver for a Solar Thermal Electric Power System in Selected Annual Production Volumes

    Science.gov (United States)

    1981-01-01

    Pioneer Engineering and Manufacturing Company estimated the cost of manufacturing and Air Brayton Receiver for a Solar Thermal Electric Power System as designed by the AiResearch Division of the Garrett Corporation. Production costs were estimated at annual volumes of 100; 1,000; 5,000; 10,000; 50,000; 100,000 and 1,000,000 units. These costs included direct labor, direct material and manufacturing burden. A make or buy analysis was made of each part of each volume. At high volumes special fabrication concepts were used to reduce operation cycle times. All costs were estimated at an assumed 100% plant capacity. Economic feasibility determined the level of production at which special concepts were to be introduced. Estimated costs were based on the economics of the last half of 1980. Tooling and capital equipment costs were estimated for ach volume. Infrastructure and personnel requirements were also estimated.

  5. The capability of radial basis function to forecast the volume fractions of the annular three-phase flow of gas-oil-water.

    Science.gov (United States)

    Roshani, G H; Karami, A; Salehizadeh, A; Nazemi, E

    2017-11-01

    The problem of how to precisely measure the volume fractions of oil-gas-water mixtures in a pipeline remains as one of the main challenges in the petroleum industry. This paper reports the capability of Radial Basis Function (RBF) in forecasting the volume fractions in a gas-oil-water multiphase system. Indeed, in the present research, the volume fractions in the annular three-phase flow are measured based on a dual energy metering system including the 152 Eu and 137 Cs and one NaI detector, and then modeled by a RBF model. Since the summation of volume fractions are constant (equal to 100%), therefore it is enough for the RBF model to forecast only two volume fractions. In this investigation, three RBF models are employed. The first model is used to forecast the oil and water volume fractions. The next one is utilized to forecast the water and gas volume fractions, and the last one to forecast the gas and oil volume fractions. In the next stage, the numerical data obtained from MCNP-X code must be introduced to the RBF models. Then, the average errors of these three models are calculated and compared. The model which has the least error is picked up as the best predictive model. Based on the results, the best RBF model, forecasts the oil and water volume fractions with the mean relative error of less than 0.5%, which indicates that the RBF model introduced in this study ensures an effective enough mechanism to forecast the results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

    2011-09-30

    The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE‘s bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and

  7. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn [General Electric Global Research, Niskayuna, NY (United States); Subramanian, Ramanathan [General Electric Global Research, Niskayuna, NY (United States); Rizeq, George [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); McDermott, John [General Electric Global Research, Niskayuna, NY (United States); Eiteneer, Boris [General Electric Global Research, Niskayuna, NY (United States); Ladd, David [General Electric Global Research, Niskayuna, NY (United States); Vazquez, Arturo [General Electric Global Research, Niskayuna, NY (United States); Anderson, Denise [General Electric Global Research, Niskayuna, NY (United States); Bates, Noel [General Electric Global Research, Niskayuna, NY (United States)

    2011-12-11

    The U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE's bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation

  8. Symposium on Turbulent Shear Flows, 7th, Stanford University, CA, Aug. 21-23, 1989, Proceedings. Volumes 1 ampersand 2

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Papers on turbulent shear flows are presented, covering topics such as the structure of pressure fluctuations, fossil two-dimensional turbulence in the ocean, turbulence production and eddy structure in wall turbulence, bypass transition in a heated boundary layer, a turbulent spot in plane Poiseuille flow, the evolution of an axisymmetric jet, plane mixing layer development, vortex models of a pseudoturbulent shear flow, numerical techniques for turbulence studies, Reynolds stress in the wall region of turbulent pipe flow, the turbulent structure of a momentumless wake, the near field of the transverse jet. Additional topics include a turbulent boundary layer disturbed by a cylinder, evolving mixing layers, flow analysis in a vortex flowmeter, ejections and bursts in pulsatile turbulent wall flow measurements, a flat plate oscillating in pitch, turbulent buoyant flows, isothermal lobed mixer flows, flow distortion on a turbulent scalar field, two phase flows. In addition, papers on the applications of turbulent shear flow studies are given, including air pollutant deposition, closures, oceanography, instrumentation, heat transfer, rotating flows, combustion, coherent structures, turbulence control, and scalar transport modeling

  9. Low parameter model to monitor bottom hole pressure in vertical multiphase flow in oil production wells

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi

    2016-09-01

    Full Text Available The importance of the flow patterns through petroleum production wells proved for upstream experts to provide robust production schemes based on the knowledge about flow behavior. To provide accurate flow pattern distribution through production wells, accurate prediction/representation of bottom hole pressure (BHP for determining pressure drop from bottom to surface play important and vital role. Nevertheless enormous efforts have been made to develop mechanistic approach, most of the mechanistic and conventional models or correlations unable to estimate or represent the BHP with high accuracy and low uncertainty. To defeat the mentioned hurdle and monitor BHP in vertical multiphase flow through petroleum production wells, inventive intelligent based solution like as least square support vector machine (LSSVM method was utilized. The evolved first-break approach is examined by applying precise real field data illustrated in open previous surveys. Thanks to the statistical criteria gained from the outcomes obtained from LSSVM approach, the proposed least support vector machine (LSSVM model has high integrity and performance. Moreover, very low relative deviation between the model estimations and the relevant actual BHP data is figured out to be less than 6%. The output gained from LSSVM model are closed the BHP while other mechanistic models fails to predict BHP through petroleum production wells. Provided solutions of this study explicated that implies of LSSVM in monitoring bottom-hole pressure can indicate more accurate monitoring of the referred target which can lead to robust design with high level of reliability for oil and gas production operation facilities.

  10. Simulation of flow in dual-scale porous media

    Science.gov (United States)

    Tan, Hua

    Liquid composite molding (LCM) is one of the most effective processes for manufacturing near net-shaped parts from fiber-reinforced polymer composites. The quality of LCM products and the efficiency of the process depend strongly on the wetting of fiber preforms during the mold-filling stage of LCM. Mold-filling simulation is a very effective approach to optimize the LCM process and mold design. Recent studies have shown that the flow modeling for the single-scale fiber preforms (made from random mats) has difficulties in accurately predicting the wetting in the dual-scale fiber preforms (made from woven and stitched fabrics); the latter are characterized by the presence of unsaturated flow created due to two distinct length-scales of pores (i.e., large pores outside the tows and small pores inside the tows) in the same media. In this study, we first develop a method to evaluate the accuracy of the permeability-measuring devices for LCM, and conduct a series of 1-D mold-filling experiments for different dual-scale fabrics. The volume averaging method is then applied to derive the averaged governing equations for modeling the macroscopic flow through the dual-scale fabrics. The two sets of governing equations are coupled with each other through the sink terms representing the absorptions of mass, energy, and species (degree of resin cure) from the global flow by the local fiber tows. The finite element method (FEM) coupled with the control volume method, also known as the finite element/control volume (FE/CV) method, is employed to solve the governing equations and track the moving boundary signifying the moving liquid-front. The numerical computations are conducted with the help of an in-house developed computer program called PORE-FLOW(c). We develop the flux-corrected transport (FCT) based FEM to stabilize the convection-dominated energy and species equations. A fast methodology is proposed to simulate the dual-scale flow under isothermal conditions, where flow

  11. Immersive volume rendering of blood vessels

    Science.gov (United States)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  12. Determinants of Pediatric Echocardiography Laboratory Productivity: Analysis from the Second Survey of the American Society of Echocardiography Committee on Echocardiography Laboratory Productivity.

    Science.gov (United States)

    Srivastava, Shubhika; Allada, Vivekanand; Younoszai, Adel; Lopez, Leo; Soriano, Brian D; Fleishman, Craig E; Van Hoever, Andrea M; Lai, Wyman W

    2016-10-01

    The American Society of Echocardiography Committee on Pediatric Echocardiography Laboratory Productivity aimed to study factors that could influence the clinical productivity of physicians and sonographers and assess longitudinal trends for the same. The first survey results indicated that productivity correlated with the total volume of echocardiograms. Survey questions were designed to assess productivity for (1) physician full-time equivalent (FTE) allocated to echocardiography reading (echocardiograms per physician FTE per day), (2) sonographer FTE (echocardiograms per sonographer FTE per year), and (3) machine utilization (echocardiograms per machine per year). Questions were also posed to assess work flow and workforce. For fiscal year 2013 or academic year 2012-2013, the mean number of total echocardiograms-including outreach, transthoracic, fetal, and transesophageal echocardiograms-per physician FTE per day was 14.3 ± 5.9, the mean number of echocardiograms per sonographer FTE per year was 1,056 ± 441, and the mean number of echocardiograms per machine per year was 778 ± 303. Both physician and sonographer productivity was higher at high-volume surgical centers and with echocardiography slots scheduled concordantly with clinic visits. Having an advanced imaging fellow and outpatient sedation correlated negatively with clinical laboratory productivity. Machine utilization was greater in laboratories with higher sonographer and physician productivity and lower for machines obtained before 2009. Measures of pediatric echocardiography laboratory staff productivity and machine utilization were shown to correlate positively with surgical volume, total echocardiography volumes, and concordant echocardiography scheduling; the same measures correlated negatively with having an advanced imaging fellow and outpatient sedation. There has been no significant change in staff productivity noted over two Committee on Pediatric Echocardiography Laboratory

  13. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    Energy Technology Data Exchange (ETDEWEB)

    Giovacchini, Giampiero [University Milano-Bicocca, Milan (Italy); Bonwetsch, Robert; Theodore, William H. [National Institute of Neurological Diseases and Strokes, Clinical Epilepsy Section, Bethesda, MD (United States); Herscovitch, Peter [National Institutes of Health, PET Department, Clinical Center, Bethesda, MD (United States); Carson, Richard E. [Yale PET Center, New Haven, CT (United States)

    2007-12-15

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR{sub glu}) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR{sub glu} measurements also were obtained. Before PVC, regional values of CBF were significantly (p<0.05) lower in TLE patients than in controls in all regions, except the fusiform gyrus contralateral to the epileptic focus. After PVC, statistical significance was maintained in only four regions: ipsilateral inferior temporal cortex, bilateral insula and contralateral amygdala. There was no significant difference between patients and controls in CBF asymmetry indices (AIs) in any region before or after PVC. In TLE patients, AIs for CBF were significantly smaller than for CMR{sub glu} in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR{sub glu}, but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  14. A data-driven approach for modeling post-fire debris-flow volumes and their uncertainty

    Science.gov (United States)

    Friedel, Michael J.

    2011-01-01

    This study demonstrates the novel application of genetic programming to evolve nonlinear post-fire debris-flow volume equations from variables associated with a data-driven conceptual model of the western United States. The search space is constrained using a multi-component objective function that simultaneously minimizes root-mean squared and unit errors for the evolution of fittest equations. An optimization technique is then used to estimate the limits of nonlinear prediction uncertainty associated with the debris-flow equations. In contrast to a published multiple linear regression three-variable equation, linking basin area with slopes greater or equal to 30 percent, burn severity characterized as area burned moderate plus high, and total storm rainfall, the data-driven approach discovers many nonlinear and several dimensionally consistent equations that are unbiased and have less prediction uncertainty. Of the nonlinear equations, the best performance (lowest prediction uncertainty) is achieved when using three variables: average basin slope, total burned area, and total storm rainfall. Further reduction in uncertainty is possible for the nonlinear equations when dimensional consistency is not a priority and by subsequently applying a gradient solver to the fittest solutions. The data-driven modeling approach can be applied to nonlinear multivariate problems in all fields of study.

  15. Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 8. Operational Logic Flow Diagrams for a Generic Advanced Air Traffic Management system

    Science.gov (United States)

    1974-02-01

    The volume presents a description of the services a generic Advanced Air Traffic Management System (AATMS) should provide to the useres of the system to facilitate the safe, efficient flow of traffic. It provides a definition of the functions which t...

  16. Effects of gas chamber geometry and gas flow on the neutron production in a fast plasma focus neutron source

    International Nuclear Information System (INIS)

    Tarifeño-Saldivia, Ariel; Soto, Leopoldo

    2014-01-01

    This work reports that gas chamber geometry and gas flow management substantially affect the neutron production of a repetitive fast plasma focus. The gas flow rate is the most sensitive parameter. An appropriate design of the gas chamber combined with a suitable flow-rate management can lead to improvements in the neutron production of one order of magnitude working in a fast repetitive mode. (paper)

  17. Comparison of Tidal Volumes at the Endotracheal Tube and at the Ventilator.

    Science.gov (United States)

    Kim, Paul; Salazar, Adler; Ross, Patrick A; Newth, Christopher J L; Khemani, Robinder G

    2015-11-01

    Lung protective ventilation for children with acute respiratory distress syndrome requires accurate assessment of tidal volume. Although modern ventilators compensate for ventilator tubing compliance, tidal volume measured at the ventilator may not be accurate, particularly in small children. Although ventilator-specific proximal flow sensors that measure tidal volume at the endotracheal tube have been developed, there is little information regarding their accuracy. We sought to test the accuracy of ventilator measured tidal volume with and without proximal flow sensors against a calibrated pneumotachometer in children. Prospective, observational. Tertiary care PICU. Fifty-one endotracheally intubated and mechanically ventilated children younger than 18 years. Tidal volumes were measured at the ventilator, using a ventilator-specific flow sensor, and a calibrated pneumotachometer connected to the SensorMedics 2600A Pediatric Pulmonary Function Cart. In a pressure control mode of ventilation: median tidal volume measured with the pneumotachometer (9.5 mL/kg [interquartile range, 8.2-11.7 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.2 mL/kg [7.1-9.6 mL/kg]) or at the proximal flow sensor (8.1 mL/kg [7.2-10.0 mL/kg]) (p tidal volume measured with the pneumotachometer (10.2 mL/kg [8.8-12.4 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.0 mL/kg [7.1-9.7 mL/kg]) or at the proximal flow sensor (8.5 mL/kg [7.3-10.4 mL/kg]) (p Tidal volume measured either at the endotracheal tube with a proximal flow sensor or at the ventilator with compensation for tubing compliance are both significantly lower than tidal volume measured with a calibrated pneumotachometer. This underestimation of delivered tidal volume may be particularly important when managing children with acute respiratory distress syndrome.

  18. MATHEMATICAL FRAMEWORK OF THE WELL PRODUCTIVITY INDEX FOR FAST FORCHHEIMER (NON-DARCY) FLOWS IN POROUS MEDIA

    KAUST Repository

    AULISA, EUGENIO

    2009-08-01

    Motivated by the reservoir engineering concept of the well Productivity Index, we introduced and analyzed a functional, denoted as "diffusive capacity", for the solution of the initial-boundary value problem (IBVP) for a linear parabolic equation.21 This IBVP described laminar (linear) Darcy flow in porous media; the considered boundary conditions corresponded to different regimes of the well production. The diffusive capacities were then computed as steady state invariants of the solutions to the corresponding time-dependent boundary value problem. Here similar features for fast or turbulent nonlinear flows subjected to the Forchheimer equations are analyzed. It is shown that under some hydrodynamic and thermodynamic constraints, there exists a so-called pseudo steady state regime for the Forchheimer flows in porous media. In other words, under some assumptions there exists a steady state invariant over a certain class of solutions to the transient IBVP modeling the Forchheimer flow for slightly compressible fluid. This invariant is the diffusive capacity, which serves as the mathematical representation of the so-called well Productivity Index. The obtained results enable computation of the well Productivity Index by resolving a single steady state boundary value problem for a second-order quasilinear elliptic equation. Analytical and numerical studies highlight some new relations for the well Productivity Index in linear and nonlinear cases. The obtained analytical formulas can be potentially used for the numerical well block model as an analog of Piecemann. © 2009 World Scientific Publishing Company.

  19. How to achieve synergy between volume replacement and filling products for global facial rejuvenation.

    Science.gov (United States)

    Raspaldo, Hervé; Aziza, Richard; Belhaouari, Lakhdar; Berros, Philippe; Body, Sylvie; Galatoire, Olivier; Le Louarn, Claude; Michaud, Thierry; Niforos, François; Rousseaux, Isabelle; Runge, Marc; Taieb, Maryna

    2011-04-01

    The objective of this paper is to provide an expert consensus regarding facial rejuvenation using a combination of volume replacement (Juvéderm(®) VOLUMA(®)), filling products (Juvéderm(®) Ultra product line) and botulinum toxin. The Juvéderm product line exploits innovative 3-D technology, producing a range of cohesive, homogenous gels that produce predictable, long-lasting and natural results. The products are easy to use by practitioners and are well-tolerated by patients, and used in combination can provide additional benefits not achieved with one product alone. An assessment of facial anatomy and consideration of the aging process, as well as available treatment options, are also addressed in determining the best combination of products to use. Outcomes from a questionnaire and workshop sessions focusing on specific aspects of use of the Juvéderm product line and botulinum toxin in daily clinical practice are discussed, and recommendations for product use following debate amongst the experts are provided.

  20. DEPOSITION OF FISSION PRODUCTS FROM HELIUM GAS FLOWING AT HIGH VELOCITIES

    Energy Technology Data Exchange (ETDEWEB)

    Abriss, A.; Ewing, R. A.; Sunderman, D. N.

    1963-11-15

    From American Nuclear Society Meeting, New York, Nov. 1963. Out-of- pile experiments simulating gas cooled reactor flow and temperature conditions were made to correlate by both empirical and theoretical considerations such parameters as Reynolds numbers, velocity, surface conditions, materials of construction, geometry, particulate matter, and fission product diffusion coefficients. It was concluded that all regions of flow disturbance are areas of buildup of activity. No selectivity in deposition among the elements studied, with the exception of I, Te, and Cs, was found. Relative abundances to each other of less volatile isotopes remained constant throughout any particular experiment. Data are tabulated. (P.C.H.)

  1. Environmental effects of energy production and utilization in the U. S. Volume I. Sources, trends, and costs of control

    Energy Technology Data Exchange (ETDEWEB)

    Newkirk, H.W. (comp.)

    1976-05-01

    Volume I deals with sources (what the emissions are and where they come from), trends (quantities of emissions and their dispersion with time), and costs of control (what it takes in time, energy, and money to meet minimum standards). Volume II concerns itself with the public health effects of energy production and utilization. Volume III summarizes the various techniques for controlling emissions, technological as well as economic, social, and political. (For abstracts of Vols. II and III, see ERDA Energy Research Abstracts, Vol. 2, Absts. 5764 and 5670, respectively) Each volume is divided into sections dealing with the atmosphere, water, land, and social activities--each division indicating a particular sphere of man's environment affected by energy production and use. The sources of information that were used in this study included textbooks, journal articles, technical reports, memoranda, letters, and personal communications. These are cited in the text at the end of each subsection and on the applicable tables and figures.

  2. Investigation of pore-scale flow physics in porous media burners

    Science.gov (United States)

    Sobhani, Sadaf; Muhunthan, Priyanka; Boigne, Emeric; Mohaddes, Danyal; Ihme, Matthias; Stanford University Team

    2017-11-01

    Porous media burners (PMBs) operate on the principle that the solid porous matrix serves as a means of internally recirculating heat from the combustion products upstream to the reactants, enabling a reduction of the lean-flammability limit, higher power dynamic range, and lower NOx and CO emissions as compared to conventional systems. Accurate predictions of the flow features and properties such as pressure loss in reticulated ceramic foams is an important step in the characterization and optimization of combustion in porous media. In this work, an integrated framework is proposed from obtaining the porous sample to performing a computational fluid dynamics simulation, including X-ray microtomography scanning, digital topology rendering, and volume meshing. Three-dimensional numerical simulations of the flow in the complex geometries of porous foams are obtained by solution of the Navier-Stokes equations using an unstructured, finite-volume solver. This capability enables the investigation of pore-scale flow physics in a wide range of porous materials used in PMBs. In this talk, results obtained at pore-scale Reynolds numbers of order 10 to 100 in a Silicone Carbide foam are presented to demonstrate this capability.

  3. Energy and materials flows in the fabrication of iron and steel semifinished products

    Energy Technology Data Exchange (ETDEWEB)

    Darby, J.B. Jr.; Arons, R.M.

    1979-08-01

    The flow of energy and materials in the fabrication of iron and steel semifinished products from molten metal is discussed. The focus is on techniques to reduce the amount of energy required to produce the typical products of integrated steel plants and iron and steel foundries. In integrated steel plants, if only 50% of the steel being cast were continuously cast, industry-wide energy consumption would be reduced by 6 to 15%. Further major energy savings could be achieved by increased use of by-product gases and regenerators in the various reheat operations. Finally, systems optimization studies to maintain the even flow of materials at full capacity should yield further improvements in energy efficiency. In foundry operations, alternate heating methods in forging operations and the use of no-bake molding and core materials should result in substantial energy savings. Studies of specific operations will suggest housekeeping changes to minimize wasted energy. These changes might include fixing heat leaks, reducing floor space requirements, improving temperature regulation, lowering working temperatures in some steel-forming operations, redesigning products, and minimizing scrap generation. There is also a need for new, energy conserving technologies. A good example would be the development of nondestructive testing to determine the existence, location, and size of defects in ingots at elevated temperatures. A second example is the need to reduce, through system studies, the large amount of scrap typical of foundry operations. Finally, computer control of steel mill operations (materials flow, furnace residence times, excessive heating or overheating, and full capacity utilization of all facilities at all times) deserves further study.

  4. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear

  5. Calf blood flow at rest evaluated by thermal measurement with tissue temperature and heat flow and 133Xe clearance

    International Nuclear Information System (INIS)

    Tamura, Toshiyo; Togawa, Tatsuo; Fukuoka, Masakazu; Kawakami, Kenji.

    1982-01-01

    The regional blood flow in the calf was determined simultaneously by thermal measurement and by 133 Xe clearance technique. Calf blood flow (Ft) by thermal measurement was accounted for by the equation of the form Ft=(CdT*d+Ho-Mb)/rho sub(b)c su b(D) (Ta-Td), where Cd is thermal capacitance of the calf compartment, T*d is the change of calf tissue temperature, Ta is arterila blood temperature, Td is calf tissue temperature, Ho is the heat dissipation from the compartment to the environment, Mb is estimated metabolism of the calf tissue and rho sub(b)c sub(b) is the product of density and specific heat of blood. The healthy men were chosen for the experiments. Total calf blood flow was 2.53+-1.31ml/(min-100ml calf), and muscle blood flow was 2.63+-1.69ml/(min- 100ml muscle) and skin blood flow 7.19+-3.83ml/(min-100ml skin) measured by 133 Xe clearance. On the basis of the results, an estimate has been made of the proportions of the calf volume which can be ascribed to skin and muscle respectively. Estimated muscle and skin blood flow were correlated with total calf blood flow(r=0.98). (author)

  6. Automating Mapping Production for the Enterprise: from Contract to Delivery

    Science.gov (United States)

    Uebbing, R.; Xie, C.; Beshah, B.; Welter, J.

    2012-07-01

    The ever increasing volume and quality of geospatial data has created new challenges for mapping companies. Due to increased image resolution, fusion of different data sources and more frequent data update requirements, mapping production is forced to streamline the work flow to meet client deadlines. But the data volume alone is not the only barrier for an efficient production work flow. Processing geospatial information traditionally uses domain and vendor specific applications that do not interface with each other, often leading to data duplication and therefore creating sources for error. Also, it creates isolation between different departments within a mapping company resulting in additional communication barriers. North West Geomatics has designed and implemented a data centric enterprise solution for the flight acquisition and production work flow to combat the above challenges. A central data repository containing not only geospatial data in the strictest sense such as images, vector layers and 3D point clouds, but also other information such as product specifications, client requirements, flight acquisition data, production resource usage and much more has been deployed at the company. As there is only one instance of the database shared throughout the whole organization it allows all employees, given they have been granted the appropriate permission, to view the current status of any project with a graphical and table based interface through its life cycle from sales, through flight acquisition, production and product delivery. Not only can users track progress and status of various work flow steps, but the system also allows users and applications to actively schedule or start specific production steps such as data ingestion and triangulation with many other steps (orthorectification, mosaicing, accounting, etc.) in the planning stages. While the complete system is exposed to the users through a web interface and therefore allowing outside customers to

  7. Quantifying the potential export flows of used electronic products in Macau: a case study of PCs.

    Science.gov (United States)

    Yu, Danfeng; Song, Qingbin; Wang, Zhishi; Li, Jinhui; Duan, Huabo; Wang, Jinben; Wang, Chao; Wang, Xu

    2017-12-01

    The used electronic product (UEP) has attracted the worldwide attentions because part of e-waste may be exported from developed countries to developing countries in the name of UEP. On the basis of large foreign trade data of electronic products (e-products), this study adopted the trade data approach (TDA) to quantify the potential exports of UEP in Macau, taking a case study of personal computers (PCs). The results show that the desktop mainframes, LCD monitors, and CRT monitors have more low-unit-value trades with higher trade volumes in the past 10 years, while the laptop and tablet PCs, as the newer technologies, owned the higher ratios of the high-unit-value trades. During the period of 2005-2015, the total mean exports for used laptop and tablet PCs, desktop mainframes, and LCD monitors were approximately 18,592, 79,957, and 43,177 units, respectively, while the possible export volume of used CRT monitors was higher, up to 430,098 units in 2000-2010. Noticed that these potential export volumes could be the lower bound because not all used PCs may be shipped using the PC trade code. For all the four kinds of used PCs, the majority (61.6-98.82%) of the export volumes have gone to Hong Kong, followed by Mainland China and Taiwan. Since 2011, there was no CRT monitor export; however, the other kinds of used PC exports will still exist in Macau in the future. The outcomes are helpful to understand and manage the current export situations of used products in Macau, and can also provide a reference for other countries and regions.

  8. The enormous Chillos Valley Lahar: An ash-flow-generated debris flow from Cotopaxi Volcano, Ecuador

    Science.gov (United States)

    Mothes, P.A.; Hall, M.L.; Janda, R.J.

    1998-01-01

    The Chillos Valley Lahar (CVL), the largest Holocene debris flow in area and volume as yet recognized in the northern Andes, formed on Cotopaxi volcano's north and northeast slopes and descended river systems that took it 326 km north-northwest to the Pacific Ocean and 130+ km east into the Amazon basin. In the Chillos Valley, 40 km downstream from the volcano, depths of 80-160 m and valley cross sections up to 337000m2 are observed, implying peak flow discharges of 2.6-6.0 million m3/s. The overall volume of the CVL is estimated to be ???3.8 km3. The CVL was generated approximately 4500 years BP by a rhyolitic ash flow that followed a small sector collapse on the north and northeast sides of Cotopaxi, which melted part of the volcano's icecap and transformed rapidly into the debris flow. The ash flow and resulting CVL have identical components, except for foreign fragments picked up along the flow path. Juvenile materials, including vitric ash, crystals, and pumice, comprise 80-90% of the lahar's deposit, whereas rhyolitic, dacitic, and andesitic lithics make up the remainder. The sand-size fraction and the 2- to 10-mm fraction together dominate the deposit, constituting ???63 and ???15 wt.% of the matrix, respectively, whereas the silt-size fraction averages less than ???10 wt.% and the clay-size fraction less than 0.5 wt.%. Along the 326-km runout, these particle-size fractions vary little, as does the sorting coefficient (average = 2.6). There is no tendency toward grading or improved sorting. Limited bulking is recognized. The CVL was an enormous non-cohesive debris flow, notable for its ash-flow origin and immense volume and peak discharge which gave it characteristics and a behavior akin to large cohesive mudflows. Significantly, then, ash-flow-generated debris flows can also achieve large volumes and cover great areas; thus, they can conceivably affect large populated regions far from their source. Especially dangerous, therefore, are snowclad volcanoes

  9. Isolation of monocytes from whole blood-derived buffy coats by continuous counter-flow elutriation.

    Science.gov (United States)

    Schwanke, Uwe; Nabereit, Anja; Moog, Rainer

    2006-10-01

    Monocytes (MOs) are the most commonly used precursors for the generation of dendritic cells (DCs) in vitro. Continuous counter-flow elutriation represents a promising tool to isolate MOs from white blood cell (WBC) products. Thirty whole blood-derived, AB0-identical buffy coats (BCs) were pooled using sterile technique (n = 5 experiments). For red blood cell (RBC) and polymorphonuclear cell (PMN) depletion, the BC pools were processed in a Cobe Spectra device (Gambro BCT) using the bone marrow program. Subsequently, continuous counter-flow elutriation in an Elutra device (Gambro BCT) was performed to enrich and purify MOs. BC pool volume averaged 1,260 +/- 14 ml containing 7.7 +/- 1.1 x 10(9) MOs. During 107 +/- 7 min, Cobe Spectra operation, the BC pools were processed for several times, and approximately 9,749 +/- 605 ml volume passed the device. Product volume and MO yield averaged 160 +/- 16 ml, and 4.3 +/- 1.3 x 10(9) cells, respectively. Elutra operation was performed within 59 +/- 0 min and yielded 2.5 +/- 0.9 x 10(9) MOs with a purity of 60 +/- 12%. Compared with the Cobe Spectra product cell count, MO recovery by Elutra averaged 59 +/- 10%. Elutriation of MOs from pooled BCs using Elutra exhibited comparatively low recovery and purity rates. This shortcoming may be due to the nature of the source material. Optimization of the elutriation procedure is necessary to improve MO enrichment from BCs.

  10. Water-vapor pressure control in a volume

    Science.gov (United States)

    Scialdone, J. J.

    1978-01-01

    The variation with time of the partial pressure of water in a volume that has openings to the outside environment and includes vapor sources was evaluated as a function of the purging flow and its vapor content. Experimental tests to estimate the diffusion of ambient humidity through openings and to validate calculated results were included. The purging flows required to produce and maintain a certain humidity in shipping containers, storage rooms, and clean rooms can be estimated with the relationship developed here. These purging flows are necessary to prevent the contamination, degradation, and other effects of water vapor on the systems inside these volumes.

  11. New flowing afterglow technique for determining products of dissociative recombination: CH5+ and N2H+

    International Nuclear Information System (INIS)

    Adams, Nigel G; Molek, Chris D; McLain, Jason L

    2009-01-01

    There are discrepancies in the literature for the product distributions of electron-ion (e-i) recombination when determined using different techniques. Because of this, a new technique has been developed. This is based on the flowing afterglow, with the product neutrals detected by electron impact ionization followed by mass spectrometric detection. However, in addition to the products of recombination, there are neutrals present from ion-molecule reactions and from the gases introduced into the flow tube to create the ion of interest, which often have much greater concentrations than the products. To distinguish these products, an electron attaching gas is pulsed into the flow to transiently attach the electrons, thus quenching e-i recombination. Then the difference between the attaching gas in and out yields the product distribution. Recombination products have been detected even when their signal is as much as ∼ 10 4 less than background. Here the details of the technique are described and the possible sources of error discussed. The viability of the technique is illustrated for the recombinations of CH 5 + and N 2 H + . The latter establishes the major product as N 2 + H (95 to 100%) correcting an error in the literature. In the former case, the major channel detected is CH 4 + H (95%) which is in disagreement with a storage ring (SR) result which gave CH 3 as the major channel (68%). Possible reasons for this are discussed.

  12. Intact nitric oxide production is obligatory for the sustained flow response during hypercapnic acidosis in guinea pig heart.

    Science.gov (United States)

    Heintz, Anke; Koch, Thea; Deussen, Andreas

    2005-04-01

    The mechanisms underlying hypercapnic coronary dilation remain unsettled. This study tests the hypothesis that flow dependent NO production is obligatory for the hypercapnic flow response. In isolated, constant pressure (CP) perfused guinea pig hearts a step change of arterial pCO(2) from 38.6 to 61.4 mm Hg induced a bi-phasic flow response with an early transient (maximum 60 s) and a consecutive persisting flow rise (121.6+/-6.6 (S.D.) % after 10 min). In contrast, when perfused with constant flow (CF), perfusion pressure only transiently (2 min) fell by 7.4+/-4.8 % following the step change of arterial pCO(2). In CP perfused hearts L-NAME (100 micromol/l) specifically abolished the delayed flow rise during hypercapnic acidosis (102.37+/-2.9% after 10 min), whereas the inhibitor had no effect on perfusion pressure response in CF perfused hearts. Under CP perfusion arterial hypercapnia resulted in a transient rise of coronary cGMP release (from 0.69+/-0.35 to 1.12+/-0.68 pmol/ml), which was abolished after L-NAME. Surprisingly, the K(+)ATP channel blocker glibenclamide did not have any significant effect on the hypercapnic flow response but largely blunted reactive hyperemia after a 20 s flow stop. The delayed steady state hypercapnic flow response in guinea pig heart requires intact NO production. The absence of a persisting decrease in coronary resistance under CF perfusion points to an important role of shear stress dependent NO production.

  13. Estimation of nitrogen and phosphorus flows in livestock production in Dianchi Lake basin, China.

    Science.gov (United States)

    Anzai, Hiroki; Wang, Lin; Oishi, Kazato; Irbis, Chagan; Li, Kunzhi; Kumagai, Hajime; Inamura, Tatsuya; Hirooka, Hiroyuki

    2016-01-01

    We assessed the nitrogen (N) and phosphorus (P) flows in intensified livestock production systems by investigating nutrient budgets and cycling in the basin of Dianchi Lake, one of the most eutrophic lakes in China. We conducted field surveys based on feed samplings and interviews of livestock farmers. The N and P in local and external feeds, animal body retentions, animal products and excretions were calculated at the individual level for dairy cattle, fattening pigs, breeding sows, broilers and laying hens. The N and P flows in the total livestock production system in the area were estimated by multiplying the individual N and P budgets by the number of animals. For the dairy and fattening pig productions, N and P supplied from local crops or by-products accounted for large parts of the inputs. For the other livestock categories, most of the N and P inputs depended on external resources. The N and P outputs through animal manure into the cropland were 287 and 66 kg/ha/year, respectively, which were higher than the N and P inputs into the livestock production systems from the cropland. The N and P loads from manure should be reduced for the establishment of sustainable agricultural production systems. © 2015 Japanese Society of Animal Science.

  14. Determination of fractional flow reserve (FFR) based on scaling laws: a simulation study

    International Nuclear Information System (INIS)

    Wong, Jerry T; Molloi, Sabee

    2008-01-01

    Fractional flow reserve (FFR) provides an objective physiological evaluation of stenosis severity. A technique that can measure FFR using only angiographic images would be a valuable tool in the cardiac catheterization laboratory. To perform this, the diseased blood flow can be measured with a first pass distribution analysis and the theoretical normal blood flow can be estimated from the total coronary arterial volume based on scaling laws. A computer simulation of the coronary arterial network was used to gain a better understanding of how hemodynamic conditions and coronary artery disease can affect blood flow, arterial volume and FFR estimation. Changes in coronary arterial flow and volume due to coronary stenosis, aortic pressure and venous pressure were examined to evaluate the potential use of flow and volume for FFR determination. This study showed that FFR can be estimated using arterial volume and a scaling coefficient corrected for aortic pressure. However, variations in venous pressure were found to introduce some error in FFR estimation. A relative form of FFR was introduced and was found to cancel out the influence of pressure on coronary flow, arterial volume and FFR estimation. The use of coronary flow and arterial volume for FFR determination appears promising

  15. Magnetic resonance imaging as a diagnostic method for assessing function. New procedures for the non-invasive quantification of cerebral blood volume and blood flow

    International Nuclear Information System (INIS)

    Gueckel, F.; Rempp, K.; Becker, G.; Koepke, J.; Loose, R.; Brix, G.

    1994-01-01

    This paper presents a brief introduction to the current status of cerebral blood volume and blood flow imaging with magnetic resonance imaging (MRI) techniques. A new method for the quantitative assessment of regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF) on the basis of the indicator dilution theory is described and preliminary quantitative results from healthy volunteers are presented. The mean values for the rCBV are 8,27±1,85 ml/100 g for grey matter and 3,78±1,34 ml/100 g for white matter. The mean values for the rCBF are 44,8±11,29 ml/min/100 g for the grey matter and 20,88±8,42 ml/min/100 g for the white matter. These results are in good agreement with PET results from the literature. (orig.) [de

  16. Reynolds-Stress and Triple-Product Models Applied to Flows with Rotation and Curvature

    Science.gov (United States)

    Olsen, Michael E.

    2016-01-01

    Predictions for Reynolds-stress and triple product turbulence models are compared for flows with significant rotational effects. Driver spinning cylinder flowfield and Zaets rotating pipe case are to be investigated at a minimum.

  17. Diels–Alder reactions of myrcene using intensified continuous-flow reactors

    Directory of Open Access Journals (Sweden)

    Christian H. Hornung

    2017-01-01

    Full Text Available This work describes the Diels–Alder reaction of the naturally occurring substituted butadiene, myrcene, with a range of different naturally occurring and synthetic dienophiles. The synthesis of the Diels–Alder adduct from myrcene and acrylic acid, containing surfactant properties, was scaled-up in a plate-type continuous-flow reactor with a volume of 105 mL to a throughput of 2.79 kg of the final product per day. This continuous-flow approach provides a facile alternative scale-up route to conventional batch processing, and it helps to intensify the synthesis protocol by applying higher reaction temperatures and shorter reaction times.

  18. NPR hazards review: (Phase 1, Production only appendixes). Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.R.; Trumble, R.E.

    1962-08-15

    The NPR Hazards Review is being issued in a series of volumes. Volume 1, which has already been published, was of the nature of an expanded summary. It included the results of hazards analyses with some explanatory material to put the results in context. Volume 2 presents results of reviews made after the preparation of Volume 1. It also contains supporting material and details not included in Volume 1. Volumes 1 and 2 together provide a nearly complete ``Design Hazards Review of the NPR.`` However, certain remaining problems still exist and are to be the subject of a continuing R&D program. These problems and programs are discussed in Appendix H. Neither Volume 1 nor Volume 2 treat operational aspects of reactor hazards in detail. This area of concern will be the primary subject of a third volume of the NPR Hazards Review. This third volume, to be prepared and issued at a later date, may also contain information supplementing Volumes 1 and 2.

  19. Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

    Science.gov (United States)

    Ko, Sae Hee; Bandyk, Dennis F; Hodgkiss-Harlow, Kelley D; Barleben, Andrew; Lane, John

    2015-06-01

    This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low (800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth 800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF 800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria

  20. Quantitative measurement of portal blood flow by magnetic resonance phase contrast. Comparative study of flow phantom and Doppler ultrasound in vivo

    International Nuclear Information System (INIS)

    Tsunoda, Masatoshi; Kimoto, Shin; Hamazaki, Keisuke; Takeda, Yoshihiro; Hiraki, Yoshio.

    1994-01-01

    A non-invasive method for measuring portal blood flow by magnetic resonance (MR) phase contrast was evaluated in a flow phantom and 20 healthy volunteers. In a flow phantom study, the flow volumes and mean flow velocities measured by MR phase contrast showed close correlations with those measured by electromagnetic flow-metry. In 20 healthy volunteers, the cross-sectional areas, flow volumes and mean flow velocities measured by MR phase contrast correlated well with those measured by the Doppler ultrasound method. Portal blood flow averaged during the imaging time could be measured under natural breathing conditions by using a large number of acquisitions without the limitations imposed on the Doppler ultrasound method. MR phase contrast is considered to be useful for the non-invasive measurement of portal blood flow. (author)

  1. The diagnostic utility of sonographic carotid flow time in determining volume responsiveness.

    Science.gov (United States)

    Shokoohi, Hamid; Berry, Grant W; Shahkolahi, Murteza; King, Jackson; King, Jordan; Salimian, Mohammad; Poshtmashad, Ameneh; Pourmand, Ali

    2017-04-01

    We aimed to predict volume responsiveness and to assess the diagnostic accuracy of carotid flow time (FTc) with the change in hydration status before and after a passive leg raise (PLR) maneuver. Participants who presented at a community health fair in a dehydrated state following a prolonged fast while observing the month of Ramadan were recruited. Sonographic FTc measurements were obtained in the semi-Fowler position and after a PLR maneuver while participants were in a fasting state and repeated approximately 3 hours after breaking their fast. In total, 123 participants with mean age of 47±14 years, 55% male, were enrolled. Participants had fasted for an average of 16.9 hours and consumed an average of 933 mL between the 2 ultrasound measurements. Mean FTc values were significantly lower in the fasting state compared with the nonfasting state (312±22 vs 345±25milliseconds, P value change in FTc of ≥5% provides a reliable diagnostic accuracy for predicting fluid status. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    Energy Technology Data Exchange (ETDEWEB)

    Cem Sarica; Holden Zhang

    2006-05-31

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The

  3. Numerical Simulation of single-stage axial fan operation under dusty flow conditions

    Science.gov (United States)

    Minkov, L. L.; Pikushchak, E. V.

    2017-11-01

    Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

  4. Material and energy flow analysis (MEFA – first step in eco-innovation approach to assessment of steel production

    Directory of Open Access Journals (Sweden)

    J. Korol

    2016-10-01

    Full Text Available The main goal of the study was to evaluate material and energy flow analysis (MEFA of steel production. The application of umberto universal software to devise MEFA for the steel production was presented. The material and energy flow analysis of steel production includes a range of technologies through each unit process in integrated steelmaking route in Poland. Modelling MEFA helps a high level of technology to be reached through the effective use of resources and energy.

  5. Mapping ENM from consumer products in solid waste flows in Denmark

    DEFF Research Database (Denmark)

    Heggelund, Laura Roverskov; Boldrin, Alessio; Hansen, Steffen Foss

    To address the challenges regarding management of waste from ENM-enabled consumer products, we mapped the flow of these products available online in Denmark and the EU. To do this, we used the Nanodatabase (www.nanodb.dk). A representative sample of products from the database was analyzed......, and placed into suitable waste material fractions. Subsequently, the distribution of ENM in the individual waste fractions, by number of products, was found. Overall, the results showed that nanosilver was present in seven of the eight identified waste material fractions, whereas other ENMs (e.g. CNTs...... and silicon) were only present in one or two fractions. Furthermore, the waste material fraction "dirty plastic" was the most diversified, containing five different ENMs. To our knowledge this type of analysis has not previously been performed, and the results hold promise for gaining a better understanding...

  6. Dynamic Model for the Stocks and Release Flows of Engineered Nanomaterials.

    Science.gov (United States)

    Song, Runsheng; Qin, Yuwei; Suh, Sangwon; Keller, Arturo A

    2017-11-07

    Most existing life-cycle release models for engineered nanomaterials (ENM) are static, ignoring the dynamics of stock and flows of ENMs. Our model, nanoRelease, estimates the annual releases of ENMs from manufacturing, use, and disposal of a product explicitly taking stock and flow dynamics into account. Given the variabilities in key parameters (e.g., service life of products and annual release rate during use) nanoRelease is designed as a stochastic model. We apply nanoRelease to three ENMs (TiO 2 , SiO 2 and FeO x ) used in paints and coatings through seven product applications, including construction and building, household and furniture, and automotive for the period from 2000 to 2020 using production volume and market projection information. We also consider model uncertainties using Monte Carlo simulation. Compared with 2016, the total annual releases of ENMs in 2020 will increase by 34-40%, and the stock will increase by 28-34%. The fraction of the end-of-life release among total release flows will increase from 11% in 2002 to 43% in 2020. As compared to static models, our dynamic model predicts about an order of magnitude lower values for the amount of ENM released from this sector in the near-term while stock continues to build up in the system.

  7. Evaluation of flow accelerated corrosion by coupled analysis of corrosion and flow dynamics (2), flow dynamics calculations for determining mixing factors and mass transfer coefficients

    International Nuclear Information System (INIS)

    Uehara, Yasushi; Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Koshizuka, Seiichi

    2009-01-01

    In order to predict and mitigate flow accelerated corrosion (FAC) of carbon steel piping in PWR and BWR secondary systems, computer program packages for evaluating FAC have been developed by coupling one through three dimensional (1-3D) computational flow dynamics (CFD) models and corrosion models. To evaluate corrosive conditions, e.g., oxygen concentration and electrochemical corrosion potential (ECP) along the flow path, flow pattern and temperature in each elemental volume were obtained with 1D computational flow dynamics (CFD) codes. Precise flow turbulence and mass transfer coefficients at the structure surface were calculated with 3D CFD codes to determine wall thinning rates. One of the engineering options is application of k-ε calculation as a 3D CFD code, which has limitation of detail evaluation of flow distribution at very surface of large scale piping. A combination of k-ε calculation and wall function was proposed to evaluate precise distribution of mass transfer coefficients with reasonable CPU volume and computing time and, at the same time, reasonable accuracy. (author)

  8. Production of free radical by magnetized sheet plasma with vertical gas-flow

    International Nuclear Information System (INIS)

    Tonegawa, Akira; Takatori, Masahiko; Kawamura, Kazutaka

    1995-01-01

    Free radicals play an important role in plasma processing, environment problem, and space plasma and so on because of their outstanding physical properties. Although much work has been done on the free radicals in the reactive plasma, very little is known about the production mechanism of the free radicals against various plasma parameters. To overcome this problem, we have proposed to do a new system of a magnetized sheet plasma with vertical gas-flow. The sheet plasma is a special type of strongly magnetized highly ionized slab plasma. This system is controlled to the parameters of radicals and plasma independently. Therefore, it is possible to make a quantitative analysis of free radicals as the simple one. In this paper, we describe the magnetized sheet plasma with vertical gas-flow system and report the preliminary results of production of the free radical. In particular, we show to produce and control the OH free radical which has been the most commonly studied combustion species

  9. Material flow enhancement in production assembly lines under application of zoned order picking systems

    Directory of Open Access Journals (Sweden)

    D. Živanić

    2014-10-01

    Full Text Available Introduced research work relates to the possibility of material flow enhancement in production systems, with the apostrophe on material order picking in production assembly lines. The paper presents basic rules and the results related to formed computer models of zoned order picking systems under the application of developed bound cavities method.

  10. A Production Planning Model for Make-to-Order Foundry Flow Shop with Capacity Constraint

    Directory of Open Access Journals (Sweden)

    Xixing Li

    2017-01-01

    Full Text Available The mode of production in the modern manufacturing enterprise mainly prefers to MTO (Make-to-Order; how to reasonably arrange the production plan has become a very common and urgent problem for enterprises’ managers to improve inner production reformation in the competitive market environment. In this paper, a mathematical model of production planning is proposed to maximize the profit with capacity constraint. Four kinds of cost factors (material cost, process cost, delay cost, and facility occupy cost are considered in the proposed model. Different factors not only result in different profit but also result in different satisfaction degrees of customers. Particularly, the delay cost and facility occupy cost cannot reach the minimum at the same time; the two objectives are interactional. This paper presents a mathematical model based on the actual production process of a foundry flow shop. An improved genetic algorithm (IGA is proposed to solve the biobjective problem of the model. Also, the gene encoding and decoding, the definition of fitness function, and genetic operators have been illustrated. In addition, the proposed algorithm is used to solve the production planning problem of a foundry flow shop in a casting enterprise. And comparisons with other recently published algorithms show the efficiency and effectiveness of the proposed algorithm.

  11. Flow-induced corrosion behavior of absorbable magnesium-based stents.

    Science.gov (United States)

    Wang, Juan; Giridharan, Venkataraman; Shanov, Vesselin; Xu, Zhigang; Collins, Boyce; White, Leon; Jang, Yongseok; Sankar, Jagannathan; Huang, Nan; Yun, Yeoheung

    2014-12-01

    The aim of this work was to study corrosion behavior of magnesium (Mg) alloys (MgZnCa plates and AZ31 stents) under varied fluid flow conditions representative of the vascular environment. Experiments revealed that fluid hydrodynamics, fluid flow velocity and shear stress play essential roles in the corrosion behavior of absorbable magnesium-based stent devices. Flow-induced shear stress (FISS) accelerates the overall corrosion (including localized, uniform, pitting and erosion corrosions) due to the increased mass transfer and mechanical force. FISS increased the average uniform corrosion rate, the localized corrosion coverage ratios and depths and the removal rate of corrosion products inside the corrosion pits. For MgZnCa plates, an increase of FISS results in an increased pitting factor but saturates at an FISS of ∼0.15Pa. For AZ31 stents, the volume loss ratio (31%) at 0.056Pa was nearly twice that (17%) at 0Pa before and after corrosion. Flow direction has a significant impact on corrosion behavior as more severe pitting and erosion corrosion was observed on the back ends of the MgZnCa plates, and the corrosion product layer facing the flow direction peeled off from the AZ31 stent struts. This study demonstrates that flow-induced corrosion needs be understood so that Mg-based stents in vascular environments can be effectively designed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. The impact of production capacity utilization on metallurgical companies financing

    Directory of Open Access Journals (Sweden)

    J. Kutáč

    2013-01-01

    Full Text Available The most important and the most problematic in-house sources of financing of metallurgical companies are profit and depreciations. In the event that the aggregate value of the economic result and depreciations goes over to negative values, then this kind of in-house financing ceases to increase Cash Flow of the company but, on the contrary, it will cause its reduction. It means that this type of financing is to some extent uncertain, particularly in times of crisis, when there are noticeable fluctuations in sales volumes, leading to a significant influence of the volume of production on the amount of profit. The article discusses the impact of production capacity utilization on metallurgical companies financing.

  13. Economic compensation standard for irrigation processes to safeguard environmental flows in the Yellow River Estuary, China

    Science.gov (United States)

    Pang, Aiping; Sun, Tao; Yang, Zhifeng

    2013-03-01

    SummaryAgriculture and ecosystems are increasingly competing for water. We propose an approach to assess the economic compensation standard required to release water from agricultural use to ecosystems while taking into account seasonal variability in river flow. First, we defined agricultural water shortage as the difference in water volume between agricultural demands and actual supply after maintaining environmental flows for ecosystems. Second, we developed a production loss model to establish the relationship between production losses and agricultural water shortages in view of seasonal variation in river discharge. Finally, we estimated the appropriate economic compensation for different irrigation stakeholders based on crop prices and production losses. A case study in the Yellow River Estuary, China, demonstrated that relatively stable economic compensation for irrigation processes can be defined based on the developed model, taking into account seasonal variations in river discharge and different levels of environmental flow. Annual economic compensation is not directly related to annual water shortage because of the temporal variability in river flow rate and environmental flow. Crops that have stable planting areas to guarantee food security should be selected as indicator crops in economic compensation assessments in the important grain production zone. Economic compensation may be implemented by creating funds to update water-saving measures in agricultural facilities.

  14. Excess molar volumes and isentropic compressibilities of binary ...

    Indian Academy of Sciences (India)

    Excess molar volume; binary liquid mixtures; isentropic compressibility; intermolecular interactions. ... mixtures are essential for fluid flow, mass flow and heat transfer processes in chemical ... Experimentally determined values of density(ρ).

  15. Determination of volume fraction in biphasic flows oil-gas and water-gas using artificial neural network and gamma densitometry

    International Nuclear Information System (INIS)

    Peixoto, Philippe Netto Belache

    2016-01-01

    This study presents a methodology based on the principles of gamma ray attenuation to identify volume fractions in biphasic systems composed of oil-gas-water and gas which are found in the offshore oil industry. This methodology is based on the acknowledgment counts per second on the photopeak energy using a detection system composed of a NaI (Tl) detector, a source of 137 Cs without collimation positioned at 180 ° relative to the detector on a smooth stratified flow regime. The mathematical modeling for computational simulation using the code MCNP-X was performed using the experimental measurements of the detector characteristics (energy resolution and efficiency), characteristics of the material water and oil (density and coefficient attenuation) and measurement of the volume fractions. To predict these fractions were used artificial neural networks (ANNs), and to obtain an adequate training the ANNs for the prediction of volume fractions were simulated a larger number of volume fractions in MCNP-X. The experimental data were used in the set data necessary for validation of ANNs and the data generated using the computer code MCNP-X were used in training and test sets of the ANNs. Were used ANNs of type feed-forward Multilayer Perceptron (MLP) and analyzed two functions of training, Levenberg-Marquardt (LM) and gradient descent with momentum (GDM), both using the Backpropagation training algorithm. The ANNs identified correctly the volume fractions of the multiphase system with mean relative errors lower than 1.21 %, enabling the application of this methodology for this purpose. (author)

  16. Micromachined pressure/flow-sensor

    NARCIS (Netherlands)

    Oosterbroek, R.E.; Lammerink, Theodorus S.J.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt; van den Berg, Albert

    1999-01-01

    The micromechanical equivalent of a differential pressure flow-sensor, well known in macro mechanics, is discussed. Two separate pressure sensors are used for the device, enabling to measure both, pressure as well as volume flow-rate. An integrated sensor with capacitive read-out as well as a

  17. Heat flow and radiogenic heat production in Brazil with implications for thermal evolution of continents

    International Nuclear Information System (INIS)

    Vitorello, I.

    1978-01-01

    Heat flow and heat production results are reported from nineteen widely spaced sites in eastern and central parts of Brazil. Three sites in the stable Sao Francisco Craton comprising rocks with Transamazonic ages (2600 to 1800 Ma) or older present an average heat flow of 41.8 +- 4.6 (standard error of the mean=sem) mW m -2 , typical of shield areas; eight sites located in the Late Precambrian Braziliane metamorphic belt have an average heat flow of 54.7 +- 3.8 (sem) mW m -2 ; and four sites in the Parana basin, locus of a Late Jurassic-Early Cretaceous basaltic volcanicity, have a mean heat flow of 70.1 +- 5.9 (sem) mW m -2 . Heat flow results from the Late Cretaceous-Early Tertiary alkalic intrusion of Pocos de Caldas have yielded a site mean of 55.3 mW m -2 . These results indicate a systematic decrease of heat flow with increasing age of the last tectonothermal event. As an explanation for this pattern, a model comprising three main heat flow components is advanced: radiogenic heat from the crust (40%), with the decrease of this contribution with time being achieved by erosional removal of radioactive material; a residual heat from a transient thermal perturbation associated with tectogenesis; and a uniform heat flow of about 28 mW m -2 from deeper sources. The Coastal Brazilian Shield is characterized by ordinary surface and reduced heat flow, but its heat production appears to be less concentrated near the surface, and distributed over a greater depth. Because of the variation in plate thickness, relative movements between the South American plate and the underlying mantle material are possibly constrained to depths exceeding 400 km

  18. Vital signs : twice-blessed by gains in both production volumes and prices

    International Nuclear Information System (INIS)

    Lunan, D.

    2000-01-01

    Canadian producers of oil and natural gas are taking advantage of the current high energy prices to run their productions at capacity and to expand their businesses. During the first half of 2000, producers reported huge revenue, earnings and cash flow gains and the trend is expected to continue for some time. This paper presented production statistics for natural gas and oil for each producing region in Canada. Natural gas and oil exports and consumption statistics for the past two decades were also included. Canadian natural gas production rose 1.4 per cent during the first four months of 2000. Oil exports also increased 14 per cent year-over-year in the January to April period. This trend is also expected to continue as demand for energy increases and U.S. production continues to lag. The U.S. has forecasted a double-digit growth in imports of Canadian gas for the coming year. 5 tabs

  19. INTRODUCTION AND STATIC ELECTRICITY, VOLUME 1.

    Science.gov (United States)

    KLAUS, DAVID J.; AND OTHERS

    THIS VOLUME, PART OF A TWO-VOLUME SET, PROVIDES AUTOINSTRUCTION IN PHYSICS. THE MATERIAL COVERS UNITS ON (1) STATIC ELECTRICITY AND ELECTRICAL CHARGES, (2) COULOMB'S LAW, (3) DISTRIBUTION OF CHARGE AND FLOW OF CURRENT, (4) DIFFERENCE OF POTENTIAL, (5) BATTERIES AND CIRCUITS, (6) RESISTANCE AND RESISTORS, (7) POTENTIAL DIVIDER AND WHEATSTONE…

  20. Effects of gas-flow structures on radical and etch-product density distributions on wafers in magnetomicrowave plasma etching reactors

    International Nuclear Information System (INIS)

    Ikegawa, Masato; Kobayashi, Jun'ichi; Fukuyama, Ryoji

    2001-01-01

    To achieve high etch rate, uniformity, good selectivity, and etch profile control across large diameter wafers, the distributions of ions, radicals, and etch products in magnetomicrowave high-etch-rate plasma etching reactors must be accurately controlled. In this work the effects of chamber heights, a focus ring around the wafer, and gas supply structures (or gas flow structures) on the radicals and etch products flux distribution onto the wafer were examined using the direct simulation Monte Carlo method and used to determine the optimal reactor geometry. The pressure uniformity on the wafer was less than ±1% when the chamber height was taller than 60 mm. The focus ring around the wafer produced uniform radical and etch-product fluxes but increased the etch-product flux on the wafer. A downward-flow gas-supply structure (type II) produced a more uniform radical distribution than that produced by a radial gas-supply structure (type I). The impact flow of the type II structure removed etch products from the wafer effectively and produced a uniform etch-product distribution even without the focus ring. Thus the downward-flow gas-supply structure (type II) was adopted in the design for the second-generation of a magnetomicrowave plasma etching reactor with a higher etching rate

  1. Topographic control of oceanic flows in deep passages and straits

    Science.gov (United States)

    Whitehead, J. A.

    1998-08-01

    Saddle points between neighboring deep ocean basins are the sites of unidirectional flow from one basin to the next, depending on the source of bottom water. Flow in these sites appears to be topographically controlled so the interface between the bottom water and the water above adjusts itself to permit bottom water flow from the basin that contains a source of bottom water into the next. Examples in the Atlantic include flow in the Romanche Fracture Zone, the Vema Channel, the Ceara Abyssal Plain, the Anegada-Jungfern passage, and the Discovery Gap, but there are many more. Theoretical predictions of volume flux using a method that requires only conductivity-temperature-depth data archives and detailed knowledge of bathymetry near the saddle point are compared with volume flux estimates using current meters and/or geostrophic estimates for seven cases. The ratio of prediction to volume flux estimate ranges from 1.0 to 2.7. Some ocean straits that separate adjacent seas are also found to critically control bidirectional flows between basins. Theory of the influence of rotation on such critical flows is reviewed. Predictions of volume flux in eight cases are compared with ocean estimates of volume flux from traditional methods.

  2. Fluid flow in panel radiator under various conditions - thermographic visualisation

    Directory of Open Access Journals (Sweden)

    Bašta Jiří

    2012-04-01

    Full Text Available Thermographic investigation of a heating panel radiator under various conditions, especially with various heating water volume flow rate is described in this article. For a radiator type 10-500x1000 TBOE and for two levels of inlet water temperature (75 and 55 °C a set of thermal images of surface temperature patterns for various values of heating water volume flow rate was taken. The initial value of flow rate was derived from nominal heating output and recalculated to real conditions. An increase of volume flow rate higher than 15 % over the nominal recalculated value is for the studied cases easily detectable on the resulting thermal images.

  3. Transverse-flow quasi-cw HF chemical laser: design and preliminary performance

    International Nuclear Information System (INIS)

    Gagne, J.M.; Mah, S.Q.; Conturie, Y.

    1974-01-01

    A small transverse-flow HF chemical laser has been constructed using a large volume microwave plasma generator for the production of F atoms. The F atoms react with hydrogen to form the lasing HF molecules. The active medium is about 5 cm long, and the maximum average laser power was found to be 560 mW for all lines. Three laser lines with wavelengths 2.61 μm, 2.64 μm, and 2.73 μm were observed. The time-varying laser transition profile closely resembles the density profile of the excited fluorine atoms in the plasma. Both profiles are greatly affected by changes in flow conditions

  4. Variable thickness transient ground-water flow model. Volume 3. Program listings

    International Nuclear Information System (INIS)

    Reisenauer, A.E.

    1979-12-01

    The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (OWNI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. Hydrologic and transport models are available at several levels of complexity or sophistication. Model selection and use are determined by the quantity and quality of input data. Model development under AEGIS and related programs provides three levels of hydrologic models, two levels of transport models, and one level of dose models (with several separate models). This is the third of 3 volumes of the description of the VTT (Variable Thickness Transient) Groundwater Hydrologic Model - second level (intermediate complexity) two-dimensional saturated groundwater flow

  5. Flow and axial dispersion in a sinusoidal-walled tube: Effects of inertial and unsteady flows

    Science.gov (United States)

    Richmond, Marshall C.; Perkins, William A.; Scheibe, Timothy D.; Lambert, Adam; Wood, Brian D.

    2013-12-01

    In this work, we consider a sinusoidal-walled tube (a three-dimensional tube with sinusoidally-varying diameter) as a simplified conceptualization of flow in porous media. Direct numerical simulation using computational fluid dynamics (CFD) methods was used to compute velocity fields by solving the Navier-Stokes equations, and also to numerically solve the volume averaging closure problem, for a range of Reynolds numbers (Re) spanning the low-Re to inertial flow regimes, including one simulation at Re=449 for which unsteady flow was observed. The longitudinal dispersion observed for the flow was computed using a random walk particle tracking method, and this was compared to the longitudinal dispersion predicted from a volume-averaged macroscopic mass balance using the method of volume averaging; the results of the two methods were consistent. Our results are compared to experimental measurements of dispersion in porous media and to previous theoretical results for both the low-Re, Stokes flow regime and for values of Re representing the steady inertial regime. In the steady inertial regime, a power-law increase in the effective longitudinal dispersion (DL) with Re was found, and this is consistent with previous results. This rapid rate of increase is caused by trapping of solute in expansions due to flow separation (eddies). One unsteady (but non-turbulent) flow case (Re=449) was also examined. For this case, the rate of increase of DL with Re was smaller than that observed at lower Re. Velocity fluctuations in this regime lead to increased rates of solute mass transfer between the core flow and separated flow regions, thus diminishing the amount of tailing caused by solute trapping in eddies and thereby reducing longitudinal dispersion. The observed tailing was further explored through analysis of concentration skewness (third moment) and its assymptotic convergence to conventional advection-dispersion behavior (skewness = 0). The method of volume averaging was

  6. 2nd International Conference on Multiphase Flow - ICMF '95

    CERN Document Server

    Fukano, T; Bataille, Jean

    1995-01-01

    There is increasing world-wide interest in obtaining an understanding of various multiphase flow phenomena and problems in terms of a common language of multiphase flow. This volume contains state-of-the-art papers which have been contributed from all over the world by experts working on all aspects of multiphase flows. The volume also highlights international technology-sharing in the fields of energy, environment and public health, in order to create a brighter and sustainable future for man and for all life in the next century. It is intended that this volume will serve as a major source of

  7. Constructal tree-shaped flow structures

    International Nuclear Information System (INIS)

    Bejan, A.; Lorente, S.

    2007-01-01

    This paper is an introduction to a new trend in the conceptual design of energy systems: the generation of flow configuration based on the 'constructal' principle that the global performance is maximized by balancing and arranging the various flow resistances (the irreversibilities) in a flow system that is free to morph. The paper focuses on distribution and collection, which are flows that connect one point (source, or sink) with an infinity of points (volume, area, curve). The flow configurations that emerge from this principle are tree-shaped, and the systems that employ them are 'vascularized'. The paper traces the most recent progress made on constructal vascularization. The direction is from large-scale applications toward microscales. The large-scale tree-shaped designs of electric power distribution systems and networks for natural gas and water are now invading small-scale designs such as fuel cells, heat exchangers and cooled packages of electronics. These flow configurations have several properties in common: freedom to morph, multiple scales, hierarchy, nonuniform (optimal) distribution of scales through the available volume, compactness and finite complexity

  8. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    Science.gov (United States)

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-02-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications.

  9. New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging

    Science.gov (United States)

    Qin, J. J.; Jones, M.; Shiota, T.; Greenberg, N. L.; Firstenberg, M. S.; Tsujino, H.; Zetts, A. D.; Sun, J. P.; Cardon, L. A.; Odabashian, J. A.; hide

    2000-01-01

    AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, Pmethods of real-time 3DE correlated well with reference standards for calculating LV volumes. Balancing accuracy and required time for these LV volume measurements, the apical six-plane method is recommended for clinical use.

  10. C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

    Energy Technology Data Exchange (ETDEWEB)

    Kamran, Mudassar; Byrne, James V. [University of Oxford, Nuffield Department of Surgical Sciences, Oxford (United Kingdom)

    2015-09-15

    C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

  11. C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

    International Nuclear Information System (INIS)

    Kamran, Mudassar; Byrne, James V.

    2015-01-01

    C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

  12. Effect of climate change on crop production patterns with implications to transport flows and inland waterways.

    Science.gov (United States)

    2011-12-01

    This project analyzed the demand for transportation capacity and changes in transportation flows on : inland waterways due to shifts in crop production patterns induced by climate change. Shifts in the crop : production mix have been observed in rece...

  13. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  14. Effective management of patients with acute ischemic stroke based on lean production on thrombolytic flow optimization.

    Science.gov (United States)

    Liang, Zhuoyuan; Ren, Lijie; Wang, Ting; Hu, Huoyou; Li, Weiping; Wang, Yaping; Liu, Dehong; Lie, Yi

    2016-12-01

    The efficacy of thrombolytic therapy for acute ischemic stroke (AIS) decreases when the administration of tissue plasminogen activator (tPA) is delayed. Derived from Toyota Production System, lean production aims to create top-quality products with high-efficiency procedures, a concept that easily applies to emergency medicine. In this study, we aimed to determine whether applying lean principles to flow optimization could hasten the initiation of thrombolysis. A multidisciplinary team (Stroke Team) was organized to implement an ongoing, continuous loop of lean production that contained the following steps: decomposition, recognition, intervention, reengineering and assessment. The door-to-needle time (DNT) and the percentage of patients with DNT ≤ 60 min before and after the adoption of lean principles were used to evaluate the efficiency of our flow optimization. Thirteen patients with AIS in the pre-lean period and 43 patients with AIS in the lean period (23 in lean period I and 20 patients in lean period II) were consecutively enrolled in our study. After flow optimization, we reduced DNT from 90 to 47 min (p < 0.001 ¤ ). In addition, the percentage of patients treated ≤60 min after hospital arrival increased from 38.46 to 75.0 % (p = 0.015 ¤ ). Adjusted analysis of covariance confirmed a significant influence of optimization on delay of tPA administration (p < 0.001). The patients were more likely to have a good prognosis (mRS ≤ 2 at 90 days) after the flow optimization (30.77-75.00 %, p = 0.012 ¤ ). Our study may offer an effective approach for optimizing the thrombolytic flow in the management of AIS.

  15. Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Maria Cecilia Bravo

    2006-06-30

    This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.

  16. Cerebral venography and flow quantification with MR

    International Nuclear Information System (INIS)

    Mattle, H.; Elelman, R.R.; Reis, H.H.; O'Reilly, G.V.; Wentz, K.V.; O'Leary, D.H.; Finn, J.P.; Longmaid, H.E.

    1989-01-01

    The authors describe an approach for creating projection venograms of the head and quantifying flow in the cerebral veins and sinuses. A series of two- dimensional flow-compensated gradient-echo images were acquired. Signal from arteries was eliminated by application of a 5-cm-thick presaturation slab to the neck. The images were postprocessed with use of a maximum intensity projection algorithm to produce projection venograms. In addition, flow directionally, flow velocity, and, in the superior sagittal sinus (SSS), flow volume was assessed by means of a dynamic bolus tracking technique. Flow velocities in the SSS ranged from 20.1 to 45.5 cm/sec, and flow volumes from 269 to 612 mL/min. This technique was able to identify cerebral venous thrombosis and partial SSS obstruction, cerebral venous angiomas, and venous drainage of arteriovenous malformations and to demonstrate patency of the SSS with falx meningiomas

  17. Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

    Science.gov (United States)

    Lund, Patricia E.; Naessens, Lauren C.; Seaman, Catherine A.; Reyes, Denise A.; Ritman, Erik L.

    2000-04-01

    Average myocardial perfusion is remarkably consistent throughout the heart wall under resting conditions and the velocity of blood flow is fairly reproducible from artery to artery. Based on these observations, and the fact that flow through an artery is the product of arterial cross-sectional area and blood flow velocity, we would expect the volume of myocardium perfused to be proportional to the cross-sectional area of the coronary artery perfusing that volume of myocardium. This relationship has been confirmed by others in pigs, dogs and humans. To test the body size-dependence of this relationship we used the hearts from rats, 3 through 25 weeks of age. The coronary arteries were infused with radiopaque microfil polymer and the hearts scanned in a micro- CT scanner. Using these 3D images we measured the volume of myocardium and the arterial cross-sectional area of the artery that perfused that volume of myocardium. The average constant of proportionality was found to be 0.15 +/- 0.08 cm3/mm2. Our data showed no statistically different estimates of the constant of proportionality in the rat hearts of different ages nor between the left and right coronary arteries. This constant is smaller than that observed in large animals and humans, but this difference is consistent with the body mass-dependence on metabolic rate.

  18. An open-source toolbox for multiphase flow in porous media

    Science.gov (United States)

    Horgue, P.; Soulaine, C.; Franc, J.; Guibert, R.; Debenest, G.

    2015-02-01

    Multiphase flow in porous media provides a wide range of applications: from the environmental understanding (aquifer, site-pollution) to industrial process improvements (oil production, waste management). Modeling of such flows involves specific volume-averaged equations and therefore specific computational fluid dynamics (CFD) tools. In this work, we develop a toolbox for modeling multiphase flow in porous media with OpenFOAM®, an open-source platform for CFD. The underlying idea of this approach is to provide an easily adaptable tool that can be used in further studies to test new mathematical models or numerical methods. The package provides the most common effective properties models of the literature (relative permeability, capillary pressure) and specific boundary conditions related to porous media flows. To validate this package, solvers based on the IMplicit Pressure Explicit Saturation (IMPES) method are developed in the toolbox. The numerical validation is performed by comparison with analytical solutions on academic cases. Then, a satisfactory parallel efficiency of the solver is shown on a more complex configuration.

  19. Macro-scale turbulence modelling for flows in porous media

    International Nuclear Information System (INIS)

    Pinson, F.

    2006-03-01

    - This work deals with the macroscopic modeling of turbulence in porous media. It concerns heat exchangers, nuclear reactors as well as urban flows, etc. The objective of this study is to describe in an homogenized way, by the mean of a spatial average operator, turbulent flows in a solid matrix. In addition to this first operator, the use of a statistical average operator permits to handle the pseudo-aleatory character of turbulence. The successive application of both operators allows us to derive the balance equations of the kind of flows under study. Two major issues are then highlighted, the modeling of dispersion induced by the solid matrix and the turbulence modeling at a macroscopic scale (Reynolds tensor and turbulent dispersion). To this aim, we lean on the local modeling of turbulence and more precisely on the k - ε RANS models. The methodology of dispersion study, derived thanks to the volume averaging theory, is extended to turbulent flows. Its application includes the simulation, at a microscopic scale, of turbulent flows within a representative elementary volume of the porous media. Applied to channel flows, this analysis shows that even within the turbulent regime, dispersion remains one of the dominating phenomena within the macro-scale modeling framework. A two-scale analysis of the flow allows us to understand the dominating role of the drag force in the kinetic energy transfers between scales. Transfers between the mean part and the turbulent part of the flow are formally derived. This description significantly improves our understanding of the issue of macroscopic modeling of turbulence and leads us to define the sub-filter production and the wake dissipation. A f - f - w >f model is derived. It is based on three balance equations for the turbulent kinetic energy, the viscous dissipation and the wake dissipation. Furthermore, a dynamical predictor for the friction coefficient is proposed. This model is then successfully applied to the study of

  20. Finite volume analysis of temperature effects induced by active MRI implants: 2. Defects on active MRI implants causing hot spots

    Directory of Open Access Journals (Sweden)

    Grönemeyer Dietrich HW

    2006-05-01

    investigations. The finite volume analysis calculates the time developing temperature maps for the model of a broken linear metallic wire embedded in tissue. Half of the total hot spot power loss is assumed to diffuse into both wire parts at the location of a defect. The energy is distributed from there by heat conduction. Additionally the effect of blood perfusion and blood flow is respected in some simulations because the simultaneous appearance of all worst case conditions, especially the absence of blood perfusion and blood flow near the hot spot, is very unlikely for vessel implants. Results The analytical solution as worst case scenario as well as the finite volume analysis for near worst case situations show not negligible volumes with critical temperature increases for part of the modeled hot spot situations. MR investigations with a high rf-pulse density lasting below a minute can establish volumes of several cubic millimeters with temperature increases high enough to start cell destruction. Longer exposure times can involve volumes larger than 100 mm3. Even temperature increases in the range of thermal ablation are reached for substantial volumes. MR sequence exposure time and hot spot power loss are the primary factors influencing the volume with critical temperature increases. Wire radius, wire material as well as the physiological parameters blood perfusion and blood flow inside larger vessels reduce the volume with critical temperature increases, but do not exclude a volume with critical tissue heating for resonators with a large product of resonator volume and quality factor. Conclusion The worst case scenario assumes thermal equilibrium for a hot spot embedded in homogeneous tissue without any cooling due to blood perfusion or flow. The finite volume analysis can calculate the results for near and not close to worst case conditions. For both cases a substantial volume can reach a critical temperature increase in a short time. The analytical solution, as absolute

  1. Entropy Production and the Pressure-Volume Curve of the Lung

    Directory of Open Access Journals (Sweden)

    Cláudio Lucas Oliveira

    2016-03-01

    Full Text Available We investigate analytically the production of entropy during a breathing cycle in healthy and diseased lungs. First, we calculate entropy production in healthy lungs by applying the laws of thermodynamics to the well-known transpulmonary pressure-volume (P-V curves of the lung under the assumption that lung tissue behaves as an entropy spring-like rubber. The bulk modulus, $B$, of the lung is also derived from these calculations. Second, we extend this approach to elastic recoil disorders of the lung such as occur in pulmonary fibrosis and emphysema. These diseases are characterized by particular alterations in the P-V relationship. For example, in fibrotic lungs B increases monotonically with disease progression, while in emphysema the opposite occurs. These diseases can thus be mimicked simply by making appropriate adjustments to the parameters of the P-V curve. Using Clausius's formalism, we show that entropy production, Delta_S, is related to the hysteresis area, Delta_A, enclosed by the P-V curve during a breathing cycle, namely, Delta_S = Delta_A/T, where T is the body temperature. Although Delta_A is highly dependent on the disease, such formula applies to healthy as well as diseased lungs, regardless of the disease stage. Finally, we use ansatzs to predict analytically the entropy produced by the fibrotic and emphysematous lungs.

  2. Effect of intravenous contrast agent volume on colorectal cancer vascular parameters as measured by perfusion computed tomography

    International Nuclear Information System (INIS)

    Goh, V.; Bartram, C.; Halligan, S.

    2009-01-01

    Aim: To determine the effect of two different contrast agent volumes on quantitative and semi-quantitative vascular parameters as measured by perfusion computed tomography (CT) in colorectal cancer. Materials and methods: Following ethical approval and informed consent, eight prospectively recruited patients with proven colorectal adenocarcinoma underwent two separate perfusion CT studies on the same day after (a) 100 ml and (b) 50 ml of a 340 mg/ml iodinated contrast medium, respectively. Quantitative (blood volume, blood flow, permeability surface area product) and semi-quantitative (peak enhancement, time to peak enhancement) tumour vascular parameters were determined using commercial software based on distributed parameter analysis and compared using t-testing. Results: Tumour blood volume, blood flow, and permeability surface area product were not substantially different following the injection of 100 ml and 50 ml contrast medium: 6.12 versus 6.23 ml/100 g tissue; 73.4 versus 71.3 ml/min/100 g tissue; 15.6 versus 15.3 ml/min/100 g tissue for 100 and 50 ml, respectively; p > 0.05. Tumour peak enhancement and time to peak were significantly greater following the injection of 100 ml versus 50 ml contrast medium: 41.2 versus 28.5 HU; 16.1 versus 11.8 s for 100 ml and 50 ml, respectively; p = 0.002; p = 0.0003. Conclusion: Quantitative parameters do not appear to change substantially with a higher contrast agent volume suggesting a combined diagnostic staging-perfusion CT study following a single injection is feasible for colorectal cancer

  3. Calibration of a large volume argon-41 gas-effluent monitor

    International Nuclear Information System (INIS)

    Wilson, William E.; Lovas, Thomas A.

    1976-01-01

    In September of 1975, a large volume Argon-41 sampler was calibrated using a series connected calibration chamber of known sensitivity and a constant flow of activated Argon gas. The calibration included analysis of the effects of flow rate through the large volume sampler and yielded a calibration constant of 2.34 x 10 -8 μc/cm 3 /CPM. (author)

  4. Modeling Approach for Estimating Co-Produced Water Volumes and Saltwater Disposal Volumes in Oklahoma

    Science.gov (United States)

    Murray, K. E.

    2016-12-01

    Management of produced fluids has become an important issue in Oklahoma because large volumes of saltwater are co-produced with oil and gas, and disposed into saltwater disposal wells at high rates. Petroleum production increased from 2009-2015, especially in central and north-central Oklahoma where the Mississippian and Hunton zones were redeveloped using horizontal wells and dewatering techniques that have led to a disproportional increase in produced water volumes. Improved management of co-produced water, including desalination for beneficial reuse and decreased saltwater disposal volumes, is only possible if spatial and temporal trends can be defined and related to the producing zones. It is challenging to quantify the volumes of co-produced water by region or production zone because co-produced water volumes are generally not reported. Therefore, the goal of this research is to estimate co-produced water volumes for 2008-present with an approach that can be replicated as petroleum production shifts to other regions. Oil and gas production rates from subsurface zones were multiplied by ratios of H2O:oil and H2O:gas for the respective zones. Initial H2O:oil and H2O:gas ratios were adjusted/calibrated, by zone, to maximize correlation of county-scale produced H2O estimates versus saltwater disposal volumes from 2013-2015. These calibrated ratios were then used to compute saltwater disposal volumes from 2008-2012 because of apparent data gaps in reported saltwater disposal volumes during that timeframe. This research can be used to identify regions that have the greatest need for produced water treatment systems. The next step in management of produced fluids is to explore optimal energy-efficient strategies that reduce deleterious effects.

  5. Pattern recognition techniques for horizontal and vertically upward multiphase flow measurement

    Science.gov (United States)

    Arubi, Tesi I. M.; Yeung, Hoi

    2012-03-01

    The oil and gas industry need for high performing and low cost multiphase meters is ever more justified given the rapid depletion of conventional oil reserves that has led oil companies to develop smaller and marginal fields and reservoirs in remote locations and deep offshore, thereby placing great demands for compact and more cost effective solutions of on-line continuous multiphase flow measurement for well testing, production monitoring, production optimisation, process control and automation. The pattern recognition approach for clamp-on multiphase measurement employed in this study provides one means for meeting this need. High speed caesium-137 radioisotope-based densitometers were installed vertically at the top of a 50.8mm and 101.6mm riser as well as horizontally at the riser base in the Cranfield University multiphase flow test facility. A comprehensive experimental campaign comprising flow conditions typical of operating conditions found in the Petroleum Industry was conducted. The application of a single gamma densitometer unit, in conjunction with pattern recognition techniques to determine both the phase volume fractions and velocities to yield the individual phase flow rates of horizontal and vertically upward multiphase flows was investigated. The pattern recognition systems were trained to map the temporal fluctuations in the multiphase mixture density with the individual phase flow rates using statistical features extracted from the gamma counts signals as their inputs. Initial results yielded individual phase flow rate predictions to within ±5% relative error for the two phase airwater flows and ±10% for three phase air-oil-water flows data.

  6. [Evaluation of tidal volume delivered by ventilators during volume-controlled ventilation].

    Science.gov (United States)

    Zhou, Juan; Yan, Yong; Cao, Desen

    2014-12-01

    To study the ways which ensure the delivery of enough tidal volume to patients under various conditions close to the demand of the physician. The volume control ventilation model was chosen, and the simulation lung type was active servo lung ASL 5000 or Michigan lung 1601. The air resistance, air compliance and lung type in simulation lungs were set. The tidal volume was obtained from flow analyzer PF 300. At the same tidal volume, the displaying values of tidal volume of E5, Servo i, Evital 4, and Evital XL ventilators with different lung types of patient, compliance of gas piping, leakage, gas types, etc. were evaluated. With the same setting tidal volume of a same ventilator, the tidal volume delivered to patients was different with different lung types of patient, compliance of gas piping, leakage, gas types, etc. Reducing compliance and increasing resistance of the patient lungs caused high peak airway pressure, the tidal volume was lost in gas piping, and the tidal volume be delivered to the patient lungs was decreased. If the ventilator did not compensate to leakage, the tidal volume delivered to the patient lungs was decreased. When the setting gas type of ventilator did not coincide with that applying to the patient, the tidal volume be delivered to the patient lungs might be different with the setting tidal volume of ventilator. To ensure the delivery of enough tidal volume to patients close to the demand of the physician, containable factors such as the compliance of gas piping, leakage, and gas types should be controlled.

  7. Finding Elephant Flows for Optical Networks

    NARCIS (Netherlands)

    Fioreze, Tiago; Oude Wolbers, Mattijs; van de Meent, R.; Pras, Aiko

    2007-01-01

    Optical networks are fast and reliable networks that enable, amongst others, dedicated light paths to be established for elephant IP flows. Elephant IP flows are characterized by being small in number, but long in time and high in traffic volume. Moving these flows from the general IP network to

  8. Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

    Science.gov (United States)

    Roque, Fernanda R.; Soci, Ursula Paula Renó; De Angelis, Katia; Coelho, Marcele A.; Furstenau, Cristina R.; Vassallo, Dalton V.; Irigoyen, Maria Claudia; Oliveira, Edilamar M.

    2011-01-01

    OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C) and trained (T). An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05). RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 5′-nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion. PMID:22189737

  9. Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

    Directory of Open Access Journals (Sweden)

    Fernanda R. Roque

    2011-01-01

    Full Text Available OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C and trained (T. An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05. RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59- nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.

  10. Comparative Simulation Study of Production Scheduling in the Hybrid and the Parallel Flow

    Directory of Open Access Journals (Sweden)

    Varela Maria L.R.

    2017-06-01

    Full Text Available Scheduling is one of the most important decisions in production control. An approach is proposed for supporting users to solve scheduling problems, by choosing the combination of physical manufacturing system configuration and the material handling system settings. The approach considers two alternative manufacturing scheduling configurations in a two stage product oriented manufacturing system, exploring the hybrid flow shop (HFS and the parallel flow shop (PFS environments. For illustrating the application of the proposed approach an industrial case from the automotive components industry is studied. The main aim of this research to compare results of study of production scheduling in the hybrid and the parallel flow, taking into account the makespan minimization criterion. Thus the HFS and the PFS performance is compared and analyzed, mainly in terms of the makespan, as the transportation times vary. The study shows that the performance HFS is clearly better when the work stations’ processing times are unbalanced, either in nature or as a consequence of the addition of transport times just to one of the work station processing time but loses advantage, becoming worse than the performance of the PFS configuration when the work stations’ processing times are balanced, either in nature or as a consequence of the addition of transport times added on the work stations’ processing times. This means that physical layout configurations along with the way transport time are including the work stations’ processing times should be carefully taken into consideration due to its influence on the performance reached by both HFS and PFS configurations.

  11. Continuous-Flow Production of Injectable Liposomes via a Microfluidic Approach

    Science.gov (United States)

    Zizzari, Alessandra; Bianco, Monica; Perrone, Elisabetta; Amato, Francesco; Maruccio, Giuseppe; Rendina, Filippo; Arima, Valentina

    2017-01-01

    Injectable liposomes are characterized by a suitable size and unique lipid mixtures, which require time-consuming and nonstraightforward production processes. The complexity of the manufacturing methods may affect liposome solubility, the phase transition temperatures of the membranes, the average particle size, and the associated particle size distribution, with a possible impact on the drug encapsulation and release. By leveraging the precise steady-state control over the mixing of miscible liquids and a highly efficient heat transfer, microfluidic technology has proved to be an effective and direct methodology to produce liposomes. This approach results particularly efficient in reducing the number of the sizing steps, when compared to standard industrial methods. Here, Microfluidic Hydrodynamic Focusing chips were produced and used to form liposomes upon tuning experimental parameters such as lipids concentration and Flow-Rate-Ratios (FRRs). Although modelling evidenced the dependence of the laminar flow on the geometric constraints and the FRR conditions, for the specific formulation investigated in this study, the lipids concentration was identified as the primary factor influencing the size of the liposomes and their polydispersity index. This was attributed to a predominance of the bending elasticity modulus over the vesiculation index in the lipid mixture used. Eventually, liposomes of injectable size were produced using microfluidic one-pot synthesis in continuous flow. PMID:29232873

  12. Controlled release fertilizer and container volumes in the production of Parapiptadenia rigida (Benth. Brenan seedlings

    Directory of Open Access Journals (Sweden)

    Ezequiel Gasparin

    2015-10-01

    Full Text Available Growing demand for native tree seedlings will require improvements in quality standards of production processes through the use of more efficient cultivation techniques. This study evaluated the effects of different doses of controlled release fertilizer (CRF and different container volumes in the production of Parapiptadenia rigida seedlings. We examined the effects of five different concentrations (0, 3, 6, 9 and 12 g L-1 substrate of CRF (18-5-9 NPK and three different container volumes (50, 110 and 180 cm3 on seedling height (H and collar diameter (CD measured monthly for seven months and then calculated H/CD ratios. After 210 days of growth, the dry masses of the aerial portions, root systems, and total masses were determined, as well as the concentrations of macro- and micronutrients in the aerial portions of the seedlings. In general, the dose 9 g L-1 substrate combined with the 180 cm3 cultivation tubes demonstrated the best results in terms of the morphological variables analyzed, resulting in consistent quality seedlings for field planting.

  13. Numerical simulation of nanofluid flow over diamond-shaped elements in tandem in laminar and turbulent flow

    Directory of Open Access Journals (Sweden)

    Hamed Safikhani

    2017-07-01

    Full Text Available In this paper, the Al2O3-water nanofluid flow in laminar and turbulent flows inside tubes fitted with diamond-shaped turbulators is numerically modeled. The nanofluid flow is modeled by employing a two-phase mixture method and applying the constant heat flux boundary condition at tube walls. In the results, the effects of different parameters such as the geometry of turbulators, volume fraction and diameter of nanoparticles, etc. on the flow field in the tubes have been investigated. The obtained results indicate that, with the reduction of tail length ratio (TR and increase of vertex angle of turbulators (θ, the heat transfer coefficient as well as the wall shear stress increase. Similarly, with the reduction of TR and increase of θ, the amount of secondary flows, vortices and the turbulent kinetic energy increase. Moreover, the increase in the volume fraction of nanoparticles and the reduction of nanoparticles diameter lead to the increase of the heat transfer coefficient and wall shear stress.

  14. High production volume chemical Amine Oxide [C8-C20] category environmental risk assessment

    DEFF Research Database (Denmark)

    Sanderson, Hans; Tibazarwa, Caritas; Greggs, William

    2009-01-01

    and personal care products. Given the lack of persistence or bioaccumulation, and the low likelihood of these chemicals partitioning to soil, the focus of the environmental assessment is on the aquatic environment. In the United States, the E-FAST model is used to estimate effluent concentrations in the United......An environmental assessment of amine oxides has been conducted under the OECD SIDS High Production Volume (HPV) Program via the Global International Council of Chemical Associations (ICCA) Amine Oxides Consortium. Amine oxides are primarily used in conjunction with surfactants in cleaning...... States from manufacturing facilities and from municipal facilities resulting from consumer product uses. Reasonable worst-case ratios of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) range from 0.04 to 0.003, demonstrating that these chemicals are a low risk...

  15. Lung volumes, ventricular function and pulmonary arterial flow in children operated on for left-sided congenital diaphragmatic hernia: long-term results

    International Nuclear Information System (INIS)

    Abolmaali, Nasreddin; Koch, Arne; Goetzelt, Knut; Vogelberg, Christian; Hahn, Gabriele; Fitze, Guido

    2010-01-01

    To compare MRI-based functional pulmonary and cardiac measurements in the long-term follow-up of children operated on for left-sided congenital diaphragmatic hernia (CDH) with age- and body size-matched healthy controls. Twelve children who received immediate postnatal surgery for closure of isolated left-sided CDH were included and received basic medical examinations, pulmonary function testing and echocardiography. MRI included measurement of lung volume, ventricular function assessment and velocity-encoded imaging of the pulmonary arteries and was compared with the data for 12 healthy children matched for age and body size. While patients' clinical test results were not suspicious, comparison between the MRI data for patients and those for healthy controls revealed significant differences. In patients, the volumes of the left lungs were increased and the tidal volume was larger on the right side. While the stroke volumes of both ventricles were reduced, heart rate and ejection fraction were increased. Flow, acceleration time and cross-sectional area of the left pulmonary artery were reduced. Functional MRI detected pulmonary and cardiac findings in the late follow-up of CDH children which may be missed by standard clinical methods and might be relevant for decisions regarding late outcome and treatment. (orig.)

  16. Lung volumes, ventricular function and pulmonary arterial flow in children operated on for left-sided congenital diaphragmatic hernia: long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Abolmaali, Nasreddin; Koch, Arne [Dresden University of Technology, OncoRay - Molecular and Biological Imaging, Medical Faculty Carl Gustav Carus, Dresden (Germany); Goetzelt, Knut; Vogelberg, Christian [University Clinics Carl Gustav Carus, Dresden University of Technology, Clinic and Policlinic for Pediatrics - Pediatric Pulmonology, Dresden (Germany); Hahn, Gabriele [University Clinics Carl Gustav Carus, Dresden University of Technology, Institute and Policlinic for Radiology - Pediatric Radiology, Dresden (Germany); Fitze, Guido [University Clinics Carl Gustav Carus, Dresden University of Technology, Clinic and Policlinic for Pediatric Surgery, Dresden (Germany)

    2010-07-15

    To compare MRI-based functional pulmonary and cardiac measurements in the long-term follow-up of children operated on for left-sided congenital diaphragmatic hernia (CDH) with age- and body size-matched healthy controls. Twelve children who received immediate postnatal surgery for closure of isolated left-sided CDH were included and received basic medical examinations, pulmonary function testing and echocardiography. MRI included measurement of lung volume, ventricular function assessment and velocity-encoded imaging of the pulmonary arteries and was compared with the data for 12 healthy children matched for age and body size. While patients' clinical test results were not suspicious, comparison between the MRI data for patients and those for healthy controls revealed significant differences. In patients, the volumes of the left lungs were increased and the tidal volume was larger on the right side. While the stroke volumes of both ventricles were reduced, heart rate and ejection fraction were increased. Flow, acceleration time and cross-sectional area of the left pulmonary artery were reduced. Functional MRI detected pulmonary and cardiac findings in the late follow-up of CDH children which may be missed by standard clinical methods and might be relevant for decisions regarding late outcome and treatment. (orig.)

  17. Lung volumes, ventricular function and pulmonary arterial flow in children operated on for left-sided congenital diaphragmatic hernia: long-term results.

    Science.gov (United States)

    Abolmaali, Nasreddin; Koch, Arne; Götzelt, Knut; Hahn, Gabriele; Fitze, Guido; Vogelberg, Christian

    2010-07-01

    To compare MRI-based functional pulmonary and cardiac measurements in the long-term follow-up of children operated on for left-sided congenital diaphragmatic hernia (CDH) with age- and body size-matched healthy controls. Twelve children who received immediate postnatal surgery for closure of isolated left-sided CDH were included and received basic medical examinations, pulmonary function testing and echocardiography. MRI included measurement of lung volume, ventricular function assessment and velocity-encoded imaging of the pulmonary arteries and was compared with the data for 12 healthy children matched for age and body size. While patients' clinical test results were not suspicious, comparison between the MRI data for patients and those for healthy controls revealed significant differences. In patients, the volumes of the left lungs were increased and the tidal volume was larger on the right side. While the stroke volumes of both ventricles were reduced, heart rate and ejection fraction were increased. Flow, acceleration time and cross-sectional area of the left pulmonary artery were reduced. Functional MRI detected pulmonary and cardiac findings in the late follow-up of CDH children which may be missed by standard clinical methods and might be relevant for decisions regarding late outcome and treatment.

  18. An analytical model to predict the volume of sand during drilling and production

    Directory of Open Access Journals (Sweden)

    Raoof Gholami

    2016-08-01

    Full Text Available Sand production is an undesired phenomenon occurring in unconsolidated formations due to shear failure and hydrodynamic forces. There have been many approaches developed to predict sand production and prevent it by changing drilling or production strategies. However, assumptions involved in these approaches have limited their applications to very specific scenarios. In this paper, an elliptical model based on the borehole shape is presented to predict the volume of sand produced during the drilling and depletion stages of oil and gas reservoirs. A shape factor parameter is introduced to estimate the changes in the geometry of the borehole as a result of shear failure. A carbonate reservoir from the south of Iran with a solid production history is used to show the application of the developed methodology. Deriving mathematical equations for determination of the shape factor based on different failure criteria indicate that the effect of the intermediate principal stress should be taken into account to achieve an accurate result. However, it should be noticed that the methodology presented can only be used when geomechanical parameters are accurately estimated prior to the production stage when using wells and field data.

  19. Determination of the equation parameters of carbon flow curves and estimated carbon flow and CO2 emissions from broiler production.

    Science.gov (United States)

    Henn, J D; Bockor, L; Borille, R; Coldebella, A; Ribeiro, A M L; Kessler, A M

    2015-09-01

    The objective of this study was to determine the equation parameters of carbon (i.e., C) flow curves and to estimate C flow and carbon dioxide (i.e., CO2) emissions from the production of 1- to 49-day-old broilers from different genetic strains. In total, 384 1-day-old chicks were used, distributed into 4 groups: high-performance males (Cobb-M) and females (Cobb-F), and intermediate-performance males (C44-M) and females (C44-F), with 6 replicates/treatment according to a completely randomized study design. Carbon intake and retention were calculated based on diet and body C composition, and expired C was stoichiometrically estimated as digestible C intake-C retention-C in the urine. Litter C emission was estimated as initial litter C+C in the excreta-final litter C. Carbon flow curves were determined fitting data by nonlinear regression using the Gompertz function. Expired CO2 was calculated based on expired C. The applied nonlinear model presented goodness-of-fit for all responses (R2>0.99). Carbon dioxide production was highly correlated with growth rate. At 42 d age, CO2 expiration (g/bird) was 3,384.4 for Cobb-M, 2,947.9 for Cobb-F, 2,512.5 for C44-M, and 2185.1 for C44-F. Age also significantly affected CO2 production: to achieve 2.0 kg BW, CO2 expiration (g/bird) was 1,794.3 for Cobb-M, 2,016.5 for Cobb-F, 2617.7 for C44-M, and 3,092.3 for C44-F. The obtained equations present high predictability to estimate individual CO2 emissions in strains of Cobb and C44 broilers of any weight, or age, reared between 1 and 49 d age. © 2015 Poultry Science Association Inc.

  20. ACFAC: a cash flow analysis code for estimating product price from an industrial operation

    International Nuclear Information System (INIS)

    Delene, J.G.

    1980-04-01

    A computer code is presented which uses a discountted cash flow methodology to obtain an average product price for an industtrial process. The general discounted cash flow method is discussed. Special code options include multiple treatments of interest during construction and other preoperational costs, investment tax credits, and different methods for tax depreciation of capital assets. Two options for allocating the cost of plant decommissioning are available. The FORTRAN code listing and the computer output for a sample problem are included

  1. Rotating flow

    CERN Document Server

    Childs, Peter R N

    2010-01-01

    Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows. Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries. Traditional fluid and flow dynamics titles offer the essential background but generally include very sparse coverage of rotating flows-which is where this book comes in. Beginning with an accessible introduction to rotating flow, recognized expert Peter Childs takes you through fundamental equations, vorticity and vortices, rotating disc flow, flow around rotating cylinders and flow in rotating cavities, with an introduction to atmospheric and oceanic circul...

  2. Surveillance of Hemodialysis Vascular Access with Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Brandt, Andreas Hjelm; Olesen, Jacob Bjerring; Lindskov Hansen, Kristoffer

    2015-01-01

    -functioning vascular access with as few complications as possible and preferred vascular access is an AVF. Dysfunction due to stenosis is a common complication, and regular monitoring of volume flow is recommended to preserve AVF patency. UDT is considered the gold standard for volume flow surveillance, but VFI has...... proven to be more precise, when performing single repeated instantaneous measurements. Three patients with AVF were monitored with UDT and VFI monthly for five months. A commercial ultrasound scanner with a 9 MHz linear array transducer with integrated VFI was used to obtain data. UDT values were...... be used for surveillance of volume flow....

  3. Frequency of Poison Center Exposures for Pediatric Accidental Unsupervised Ingestions of Acetaminophen after the Introduction of Flow Restrictors.

    Science.gov (United States)

    Brass, Eric P; Reynolds, Kate M; Burnham, Randy I; Green, Jody L

    2018-04-02

    To assess the temporal association of flow restrictor introduction and the rate of accidental unsupervised ingestions (AUIs) of liquid acetaminophen products. The National Poison Data System was used to identify AUIs of single ingredient acetaminophen in patients aged poison centers obtained additional information using a structured telephone survey. Pediatric AUIs involving acetaminophen averaged 30 000 exposures per year between 2007 and 2012. From 2012 to 2015, after flow restrictor introduction, exposures steadily decreased at a rate of 2400 fewer exposures annually, reaching 21 877 exposures in 2015. Normalized to sales volume, exposures involving liquid acetaminophen products decreased by 40% from 2010 to 2015. Exposures involving products with flow restrictors tended to have a lower estimated ingestion per exposure, fewer exposures exceeding a 150 mg/kg acetaminophen threshold, and were associated with lower rates of hospital admissions when compared with products without restrictors. Caregivers reported improper storage and child confusion of the medicine with treats as common contributing factors to exposures. The introduction of flow restrictors was associated with a decrease in pediatric AUIs of liquid acetaminophen products. Decreases in the dose ingested and risk of hospital admission per exposure may also have resulted. Efforts to optimize flow restrictors and increase their use with medicines associated with high pediatric overdose risk should be encouraged. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Microsphere estimates of blood flow: Methodological considerations

    International Nuclear Information System (INIS)

    von Ritter, C.; Hinder, R.A.; Womack, W.; Bauerfeind, P.; Fimmel, C.J.; Kvietys, P.R.; Granger, D.N.; Blum, A.L.

    1988-01-01

    The microsphere technique is a standard method for measuring blood flow in experimental animals. Sporadic reports have appeared outlining the limitations of this method. In this study the authors have systematically assessed the effect of blood withdrawals for reference sampling, microsphere numbers, and anesthesia on blood flow estimates using radioactive microspheres in dogs. Experiments were performed on 18 conscious and 12 anesthetized dogs. Four blood flow estimates were performed over 120 min using 1 x 10 6 microspheres each time. The effects of excessive numbers of microspheres pentobarbital sodium anesthesia, and replacement of volume loss for reference samples with dextran 70 were assessed. In both conscious and anesthetized dogs a progressive decrease in gastric mucosal blood flow and cardiac output was observed over 120 min. This was also observed in the pancreas in conscious dogs. The major factor responsible for these changes was the volume loss due to the reference sample withdrawals. Replacement of the withdrawn blood with dextran 70 led to stable blood flows to all organs. The injection of excessive numbers of microspheres did not modify hemodynamics to a greater extent than did the injection of 4 million microspheres. Anesthesia exerted no influence on blood flow other than raising coronary flow. The authors conclude that although blood flow to the gastric mucosa and the pancreas is sensitive to the minor hemodynamic changes associated with the microsphere technique, replacement of volume loss for reference samples ensures stable blood flow to all organs over a 120-min period

  5. U3O8 production cost analysis study. Sandstone deposit mine model EA-730, Volume 1

    International Nuclear Information System (INIS)

    1978-08-01

    Objective was the development and testing of a model for estimating the production cost of conventional uranium mining. The model used evolved from a base case underground mine of 1000 tons per day output at a nominal depth of 900 feet, and from base-case open pit mines of 2000 tons per day output at 30-, 120-, and 240-foot depths. In addition, an alternate production method employing heap leaching was partially investigated, to be merged with similar work performed by another contractor. The model was internally structured into component submodels capable of reflecting the contributory factors which aggregate into the computed production cost. A financial submodel based on last-quarter 1976 prices used conventional accounting practices to generate a cash flow and profit-and-loss record over the mine life. From this a selling price was obtained based on a desired discounted cash flow return on equity. This submodel is also capable of accepting input inflation rates so that costs in current dollars for future years can be estimated. A Monte Carlo method of the analysis of variance was applied to 50 model runs to obtain a statistical estimate for the expected variance in production cost

  6. Effect of Water Volume and Biogas Volumetric Flowrate in Biogas Purification Through Water Scrubbing Method

    Directory of Open Access Journals (Sweden)

    Hendry Sakke Tira

    2016-05-01

    Full Text Available Energy supply is a crucial issue in the world in the last few years. The increase in energy demand caused by population growth and resource depletion of world oil reserves provides determination to produce and to use renewable energies. One of the them is biogas. However, until now the use of biogas has not yet been maximized because of its poor purity. According to the above problem, the research has been carried out using the method of water absorption. Under this method it is expected that the rural community is able to apply it. Therefore, their economy and productivity can be increased. This study includes variations of absorbing water volume (V and input biogas volume flow rate (Q. Raw biogas which is flowed into the absorbent will be analyzed according to the determined absorbing water volume and input biogas volume rate. Improvement on biogas composition through the biogas purification method was obtained. The level of CO2 and H2S was reduced significantly specifically in the early minutes of purification process. On the other hand, the level of CH4 was increased improving the quality of raw biogas. However, by the time of biogas purification the composition of purified biogas was nearly similar to the raw biogas. The main reason for this result was an increasing in pH of absorbent. It was shown that higher water volume and slower biogas volume rate obtained better results in reducing the CO2 and H2S and increasing CH4 compared to those of lower water volume and higher biogas volume rate respectively. The purification method has a good promising in improving the quality of raw biogas and has advantages as it is cheap and easy to be operated.

  7. Effect of Water Volume and Biogas Volumetric Flowrate in Biogas Purification Through Water Scrubbing Method

    Directory of Open Access Journals (Sweden)

    Hendry Sakke Tira

    2014-10-01

    Full Text Available Energy supply is a crucial issue in the world in the last few years. The increase in energy demand caused by population growth and resource depletion of world oil reserves provides determination to produce and to use renewable energies. One of the them is biogas. However, until now the use of biogas has not yet been maximized because of its poor purity. According to the above problem, the research has been carried out using the method of water absorption. Under this method it is expected that the rural community is able to apply it. Therefore, their economy and productivity can be increased. This study includes variations of absorbing water volume (V and input biogas volume flow rate (Q. Raw biogas which is flowed into the absorbent will be analyzed according to the determined absorbing water volume and input biogas volume rate. Improvement on biogas composition through the biogas purification method was obtained. The level of CO2 and H2S was reduced significantly specifically in the early minutes of purification process. On the other hand, the level of CH4 was increased improving the quality of raw biogas. However, by the time of biogas purification the composition of purified biogas was nearly similar to the raw biogas. The main reason for this result was an increasing in pH of absorbent. It was shown that higher water volume and slower biogas volume rate obtained better results in reducing the CO2 and H2S and increasing CH4 compared to those of lower water volume and higher biogas volume rate respectively. The purification method has a good promising in improving the quality of raw biogas and has advantages as it is cheap and easy to be operated.

  8. Aqueous Productivity: An enhanced productivity indicator for water

    Science.gov (United States)

    Ritzema, Randall S.

    2014-09-01

    Increasing demand for scarce water supplies is fueling competition between agricultural production and other municipal and environmental demands, and has heightened the need for effective indicators to measure water performance and support water allocation and planning processes. Water productivity (WP), defined as the ‘ratio of the net benefits from crop, forestry, fishery, livestock, and mixed agricultural systems to the amount of water required to produce those benefits', is one such indicator that has gained prominence, particularly in research-for-development efforts in the developing world. However, though WP is a framework well-suited to systems where water use is directly attributable, particularly via depletion, to definitive benefits, the suitability of the approach becomes questionable when these conditions are not met, such as in multiple use systems with high re-use and non-depleting uses. These factors furthermore make WP highly scale-dependent, complicating comparative studies across scales and systems. This research forwards ‘aqueous productivity' (AP) as an alternative indicator that addresses some inherent limitations in the WP approach and enhances productivity estimates for water in integrated systems. Like WP, AP is expressed as a ratio of benefit to water volume. However, AP uses a systems approach and is based on the concept that elements within a hydrologic system are linked via water flow interactions, and that those elements either ‘extract' value from associated water flows or ‘infuse' value into them. The AP method therefore calculates the ‘aqueous productivity', a ratio indicating the ‘dissolved' production-related economic value of all downstream uses of an individual water flow, for each inter-element and cross-boundary flow in the system. The AP conceptual framework and analytical methodology are presented. The method is then applied to two example hydroeconomic systems and compared to equivalent WP analysis. Discussion

  9. Flow characteristics of metallic powder grains for additive manufacturing

    Directory of Open Access Journals (Sweden)

    Peters Bernhard

    2017-01-01

    Full Text Available Directed energy deposition technologies for additive manufacturing such as laser selective melting (SLM or electron beam melting (EBM is a fast growing technique mainly due to its flexibility in product design. However, the process is a complex interaction of multi-physics on multiple length scales that are still not entirely understood. A particular challenging task are the flow characteristics of metallic powder ejected as jets from a nozzle and shielded by an inert turbulent gas flow. Therefore, the objective is to describe numerically the complex interaction between turbulent flow and powder grains. In order to include both several physical processes and length scales an Euler-Lagrange technology is applied. Within this framework powder is treated by the Discrete-Element-Method, while gas flow is described by Euler approaches as found in classical Computational Fluid Dynamics (CFD. The described method succeeded in delivering more accuracy and consistency than a standard approach based on the volume averaging technique and therefore, is suited for the solution of problems within an engineering framework.

  10. Integration of a turbine expander with an exothermic reactor loop--Flow sheet development and application to ammonia production

    International Nuclear Information System (INIS)

    Greeff, I.L.; Visser, J.A.; Ptasinski, K.J.; Janssen, F.J.J.G.

    2003-01-01

    This paper investigates the direct integration of a gas turbine power cycle with an ammonia synthesis loop. Such a loop represents a typical reactor-separator system with a recycle stream and cold separation of the product from the recycle loop. The hot reaction products are expanded directly instead of raising steam in a waste heat boiler to drive a steam turbine. Two new combined power and chemicals production flow sheets are developed for the process. The flow sheets are simulated using the flow sheet simulator AspenPlus (licensed by Aspen Technology, Inc.) and compared to a simulated conventional ammonia synthesis loop. The comparison is based on energy as well as exergy analysis. It was found that the pressure ratio over the turbine expander plays an important role in optimisation of an integrated system, specifically due to the process comprising an equilibrium reaction. The inlet temperature to the reactor changes with changing pressure ratio, which in turn determines the conversion and consequently the heat of reaction that is available to produce power. In terms of the minimum work requirement per kg of product a 75% improvement over the conventional process could be obtained. The work penalty due to refrigeration needed for separation was also accounted for. Furthermore this integrated flow sheet also resulted in a decrease in exergy loss and the loss was more evenly distributed between the various unit operations. A detailed exergy analysis over the various unit operations proved to be useful in explaining the overall differences in exergy loss between the flow sheets

  11. Production and loss of H- and D- in the volume of a plasma

    International Nuclear Information System (INIS)

    Hamilton, G.W.; Bacal, M.

    1981-01-01

    The study of the production and loss of negative ions, H - and D - , in the volume of a plasma has received considerable attention since the measurement of anomalously high densities of H - in 1977. The most probable mechanism for production is dissociative attachment (DA) to vibrationally highly-excited hydrogen molecules. New diagnostics developed for this purpose are photodetachment and the extension of coherent anti-Stokes Raman scattering (CARS) systems to the sensitivity required for low-pressure gases. Measurements and calculations indicate that the important loss mechanisms are diffusion to the walls at low densities and collisional destruction of several types at plasma densities above 10 10 cm -3 . Production mechanisms must be highly efficient to compete with the losses. It appears to be straightforward to extrapolate measurements and theory to the densities above 10 12 cm -3 that are required for an intense source of D - for neutral beam injection into magnetically-confined fusion devices

  12. Essays on innovation, productivity and knowledge flows: evidence for Spanish firms

    OpenAIRE

    Goya Carrillo, Esther

    2015-01-01

    This dissertation aims to further understand the relationship between innovation and productivity in Spain taking into account the impact of knowledge flows. To this end, Spanish firms from both manufacturing and services sectors are considered. This thesis consists of three empirical studies. The first study analyses the impact that R&D expenditures and intra- and inter-industry externalities have on Spanish firms’ performance considering the firm’s technology level. A Cobb-Douglas produ...

  13. Maximizing the productivity of the microalgae Scenedesmus AMDD cultivated in a continuous photobioreactor using an online flow rate control.

    Science.gov (United States)

    McGinn, Patrick J; MacQuarrie, Scott P; Choi, Jerome; Tartakovsky, Boris

    2017-01-01

    In this study, production of the microalga Scenedesmus AMDD in a 300 L continuous flow photobioreactor was maximized using an online flow (dilution rate) control algorithm. To enable online control, biomass concentration was estimated in real time by measuring chlorophyll-related culture fluorescence. A simple microalgae growth model was developed and used to solve the optimization problem aimed at maximizing the photobioreactor productivity. When optimally controlled, Scenedesmus AMDD culture demonstrated an average volumetric biomass productivity of 0.11 g L -1  d -1 over a 25 day cultivation period, equivalent to a 70 % performance improvement compared to the same photobioreactor operated as a turbidostat. The proposed approach for optimizing photobioreactor flow can be adapted to a broad range of microalgae cultivation systems.

  14. FLOW PHYSICS OF 3-BLADED STRAIGHT CHORD H-DARRIEUS WIND TURBINE

    Directory of Open Access Journals (Sweden)

    Rajat Gupta

    2013-06-01

    Full Text Available Steady-state two-dimensional Computational Fluid Dynamics (CFD simulations were performed using Fluent 6.0 software to analyze the flow physics of 3-bladed straight chord H-Darrieus wind turbine having blade twist of 300 for 10% of its chord at the trailing ends. The flow was simulated using finite volume method coupled with moving mesh technique to solve mass and momentum conservation equations. The standard k-ε turbulence model with enhanced wall condition was used. Second-order upwind discretization scheme was adopted for pressure-velocity coupling of the flow. Flow physics of the turbine was analyzed with the help of pressure and velocity contours. It was found that velocity magnitude decreases from upstream to downstream side across the turbine, which will cause overall lift for the turbine. Further, blade twist at the trailing ends creates circulations that interact with the blades in a direction opposite to the direction of rotation of the turbine which would enhance power production for the three bladed turbine.

  15. FLOW PHYSICS OF 3-BLADED STRAIGHT CHORD H- DARRIEUS WIND TURBINE

    Directory of Open Access Journals (Sweden)

    Rajat Gupta

    2013-01-01

    Full Text Available Steady-state two-dimensional Computational Fluid Dynamics (CFD simulations were performed using Fluent 6.0 software to analyze the flow physics of 3-bladed straight chord H-Darrieus wind turbine having blade twist of 300 for 10% of its chord at the trailing ends. The flow was simulated using finite volume method coupled with moving mesh technique to solve mass and momentum conservation equations. The standard k- ε turbulence model with enhanced wall condition was used. Second-order upwind discretization scheme was adopted for pressure-velocity coupling of the flow. Flow physics of the turbine was analyzed with the help of pressure and velocity contours. It was found that velocity magnitude decreases from upstream to downstream side across the turbine, which will cause overall lift for the turbine. Further, blade twist at the trailing ends creates circulations that interact with the blades in a direction opposite to the direction of rotation of the turbine which would enhance power production for the three bladed turbine.

  16. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  17. CADDIS Volume 2. Sources, Stressors and Responses: Flow Alteration - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the flow alteration module, when to list flow alteration as a candidate cause, ways to measure flow alteration, simple and detailed conceptual model diagrams for flow alteration, flow alteration module references and literature reviews.

  18. Rapid MR measurements of contrast medium dilution kinetics (gadolinium-DTPA) in a flow phantom

    International Nuclear Information System (INIS)

    Boeck, J.C.; Sander, B.; Frank, J.; Schoerner, W.

    1991-01-01

    We studied first-pass MRI-contrast dilution to compute flow and volume of distribution in a realistic flow phantom. Pulsatile flow was provided by a one-chamber artificial heart. Physiological stroke volume, rate, pressure, and flow were adjustable. An elastic tube with dimensions similar to that of the human aorta was imaged at a rate of 2.4 Hz. After contrast injection, an initial increase in signal intensity was followed by a decrease. Signal-intensity-time plots demonstrated slightly skewed curves as expected from dispersion theory. After calibration at different gadolinium-DTPA concentrations, signal intensities were converted into true gadolinium concentrations, and flow was calculated from the concentration-time curves. Flow was varied between 2.5 and 10.0 l/min and a significant correlation was found between the MRI-estimate and true flow. Volume of distribution between injection and detection site was reliably estimated. This study demonstrates rapid 2-D imaging of a paramagnetic contrast bolus in a realistic flow phantom. Reliable estimates of flow and volume are obtained. (orig.) [de

  19. Sensors, Volume 4, Thermal Sensors

    Science.gov (United States)

    Scholz, Jorg; Ricolfi, Teresio

    1996-12-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

  20. Delivered volumes of enteral nutrition exceed prescribed volumes.

    Science.gov (United States)

    Walker, Renee Nichole; Utech, Anne; Velez, Maria Eugenia; Schwartz, Katie

    2014-10-01

    Enteral nutrition (EN) provisions are typically calculated based on a 24-hour infusion period. However, feedings are often interrupted for daily activities, procedures, or gastrointestinal intolerance. The study's objective was to determine the delivered EN quantities provided to stable hospitalized patients, using cellular time and measured volumes to verify our EN calculation adjustment. A supply of consecutively numbered ready-to-hang (RTH) EN product was delivered to the bedside of 26 inpatients with established EN tolerance at goal rates on various types of nursing units. The dietitian weighed the volume remaining in the infusing product and recorded the measurement time. On the following days, the dietitian continued to weigh the infusing RTH product and the empty RTH bottles saved by nursing. The primary outcome was the difference between the prescribed and delivered EN provisions, which was calculated with a paired t test. Patients received significantly more calories in the delivered enteral feeding (mean [SD], 1678 [385] kcal) than prescribed calories in the EN order (1489 [246 kcal]; t = 3.736, P = .001), adjusting for observed time. No significant differences were found between nursing units, product, and rate. EN delivered may actually exceed ordered amounts by 5%–21% (mean, 12%) with feeding pump inaccuracy as the primary contributing factor. This differs from what others have found. Our findings support using a volume-based ordering system vs a rate-based ordering system for more accurate EN delivery.

  1. Transient regimes during high-temperature deformation of a bulk metallic glass: A free volume approach

    International Nuclear Information System (INIS)

    Bletry, M.; Guyot, P.; Brechet, Y.; Blandin, J.J.; Soubeyroux, J.L.

    2007-01-01

    The homogeneous deformation of a zirconium-based bulk metallic glass is investigated in the glass transition range. Compression and stress-relaxation tests have been conducted. The stress-strain curves are modeled in the framework of the free volume theory, including transient phenomena (overshoot and undershoot). This approach allows several physical parameters (activation volume, flow defect creation and relaxation coefficient) to be determined from a mechanical experiment. This model is able to rationalize the dependency of stress overshoot on relaxation time. It is shown that, due to the relationship between flow defect concentration and free volume model, it is impossible to determine the equilibrium flow defect concentration. However, the relative variation of flow defect is always the same, and all the model parameters depend on the equilibrium flow defect concentration. The methodology presented in this paper should, in the future, allow the consistency of the free volume model to be assessed

  2. An assessment of software for flow cytometry analysis in banana plants

    Directory of Open Access Journals (Sweden)

    Renata Alves Lara Silva

    2014-02-01

    Full Text Available Flow cytometry is a technique that yields rapid results in analyses of cell properties such as volume, morphological complexity and quantitative DNA content, and it is considered more convenient than other techniques. However, the analysis usually generates histograms marked by variations that can be produced by many factors, including differences between the software packages that capture the data generated by the flow cytometer. The objective of the present work was to evaluate the performance of four software products commonly used in flow cytometry based on quantifications of DNA content and analyses of the coefficients of variation associated with the software outputs. Readings were obtained from 25 ‘NBA’ (AA banana leaf samples using the FACSCalibur (BD flow cytometer, and 25 histograms from each software product (CellQuest™, WinMDI™, FlowJo™ and FCS Express™ were analyzed to obtain the estimated DNA content and the coefficient of variation (CV of the estimates. The values of DNA content obtained from the software did not differ significantly. However, the CV analysis showed that the precision of the WinMDI™ software was low and that the CV values were underestimated, whereas the remaining software showed CV values that were in relatively close agreement with those found in the literature. The CellQuest™ software is recommended because it was developed by the same company that produces the flow cytometer used in the present study.

  3. Emulation and Control of Slugging Flows in a Gas-Lifted Offshore Oil Production Well Through a Lab-sized Facility

    DEFF Research Database (Denmark)

    Jepsen, Kasper Lund; Hansen, Leif; Mai, Christian

    2013-01-01

    flow and pressures in the production well system, which is referred to as the slugging flow problem. This instability is mainly due to the casing-heading mechanism. This work investigates the possibility to use a feedback control for stabilizing the production operation without sacrificing...... the production capability. A labsized production well system is constructed in an economic manner. Afterwards, a simple nonlinear model is derived according to physical principles and then verified with the experimental facility. A observer-based state feedback control is designed to handle the potential...... slugging problem. The developed controller manipulates the openness degree of the production choke based on feedback a number of pressure measurements. The current simulation results showed satisfactory control performances by stabilizing the system operation at some relatively large production rate which...

  4. Continuous-Flow Production of Injectable Liposomes via a Microfluidic Approach

    Directory of Open Access Journals (Sweden)

    Alessandra Zizzari

    2017-12-01

    Full Text Available Injectable liposomes are characterized by a suitable size and unique lipid mixtures, which require time-consuming and nonstraightforward production processes. The complexity of the manufacturing methods may affect liposome solubility, the phase transition temperatures of the membranes, the average particle size, and the associated particle size distribution, with a possible impact on the drug encapsulation and release. By leveraging the precise steady-state control over the mixing of miscible liquids and a highly efficient heat transfer, microfluidic technology has proved to be an effective and direct methodology to produce liposomes. This approach results particularly efficient in reducing the number of the sizing steps, when compared to standard industrial methods. Here, Microfluidic Hydrodynamic Focusing chips were produced and used to form liposomes upon tuning experimental parameters such as lipids concentration and Flow-Rate-Ratios (FRRs. Although modelling evidenced the dependence of the laminar flow on the geometric constraints and the FRR conditions, for the specific formulation investigated in this study, the lipids concentration was identified as the primary factor influencing the size of the liposomes and their polydispersity index. This was attributed to a predominance of the bending elasticity modulus over the vesiculation index in the lipid mixture used. Eventually, liposomes of injectable size were produced using microfluidic one-pot synthesis in continuous flow.

  5. Energy Production by Means of Pumps As Turbines in Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Mauro Venturini

    2017-10-01

    Full Text Available This paper deals with the estimation of the energy production by means of pumps used as turbines to exploit residual hydraulic energy, as in the case of available head and flow rate in water distribution networks. To this aim, four pumps with different characteristics are investigated to estimate the producible yearly electric energy. The performance curves of Pumps As Turbines (PATs, which relate head, power, and efficiency to the volume flow rate over the entire PAT operation range, were derived by using published experimental data. The four considered water distribution networks, for which experimental data taken during one year were available, are characterized by significantly different hydraulic features (average flow rate in the range 10–116 L/s; average pressure reduction in the range 12–53 m. Therefore, energy production accounts for actual flow rate and head variability over the year. The conversion efficiency is also estimated, for both the whole water distribution network and the PAT alone.

  6. Indefinite inner product spaces, Schur analysis, and differential equations a volume dedicated to Heinz Langer

    CERN Document Server

    Kirstein, Bernd

    2018-01-01

    This volume, which is dedicated to Heinz Langer, includes biographical material and carefully selected papers. Heinz Langer has made fundamental contributions to operator theory. In particular, he has studied the domains of operator pencils and nonlinear eigenvalue problems, the theory of indefinite inner product spaces, operator theory in Pontryagin and Krein spaces, and applications to mathematical physics. His works include studies on and applications of Schur analysis in the indefinite setting, where the factorization theorems put forward by Krein and Langer for generalized Schur functions, and by Dijksma-Langer-Luger-Shondin, play a key role. The contributions in this volume reflect Heinz Langer’s chief research interests and will appeal to a broad readership whose work involves operator theory.  .

  7. Virtual water flows and water-footprint of agricultural crop production, import and export: A case study for Israel.

    Science.gov (United States)

    Shtull-Trauring, E; Bernstein, N

    2018-05-01

    Agriculture is the largest global consumer of freshwater. As the volume of international trade continues to rise, so does the understanding that trade of water-intensive crops from areas with high precipitation, to arid regions can help mitigate water scarcity, highlighting the importance of crop water accounting. Virtual-Water, or Water-Footprint [WF] of agricultural crops, is a powerful indicator for assessing the extent of water use by plants, contamination of water bodies by agricultural practices and trade between countries, which underlies any international trade of crops. Most available studies of virtual-water flows by import/export of agricultural commodities were based on global databases, which are considered to be of limited accuracy. The present study analyzes the WF of crop production, import, and export on a country level, using Israel as a case study, comparing data from two high-resolution local databases and two global datasets. Results for local datasets demonstrate a WF of ~1200Million Cubic Meters [MCM]/year) for total crop production, ~1000MCM/year for import and ~250MCM/year for export. Fruits and vegetables comprise ~80% of Export WF (~200MCM/year), ~50% of crop production and only ~20% of the imports. Economic Water Productivity [EWP] ($/m 3 ) for fruits and vegetables is 1.5 higher compared to other crops. Moreover, the results based on local and global datasets varied significantly, demonstrating the importance of developing high-resolution local datasets based on local crop coefficients. Performing high resolution WF analysis can help in developing agricultural policies that include support for low WF/high EWP and limit high WF/low EWP crop export, where water availability is limited. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effects of reduced return activated sludge flows and volume on anaerobic zone performance for a septic wastewater biological phosphorus removal system.

    Science.gov (United States)

    Magro, Daniel; Elias, Steven L; Randall, Andrew Amis

    2005-01-01

    Enhanced biological phosphorous removal (EBPR) performance was found to be adequate with reduced return-activated sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller-than-typical anaerobic zone volume (1.08 hours hydraulic retention time [HRT]). Three identical parallel biological nutrient removal pilot plants were fed with strong, highly fermented (160 mg/L volatile fatty acids [VFAs]), domestic and industrial wastewater from a full-scale wastewater treatment facility. The pilot plants were operated at 100, 50, 40, and 25% RAS (percent of available RAS) flows to the anaerobic tank, with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours) and increased hydraulic loading (35% increase) were examined. The study was divided into four phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusion was that returning part of the RAS to the anaerobic zone did not decrease EBPR performance; instead, it changed the location of phosphorous release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic phosphorus release and increased anoxic phosphorus release (or decreased anoxic phosphorus uptake). Equally important is that, with VFA-rich influent wastewater, excessive anaerobic volume was shown to hurt overall phosphorus removal, even when it resulted in increased anaerobic phosphorus release.

  9. Cpuf: Chirped-Pulse Microwave Spectroscopy in Pulsed Uniform Supersonic Flows

    Science.gov (United States)

    Suits, Arthur; Abeysekera, Chamara; Zack, Lindsay N.; Joalland, Baptiste; Ariyasingha, Nuwandi M.; Park, Barratt; Field, Robert W.; Sims, Ian

    2015-06-01

    Chirped-pulse Fourier-transform microwave spectroscopy has stimulated a resurgence of interest in rotational spectroscopy owing to the dramatic reduction in spectral acquisition time it enjoys when compared to cavity-based instruments. This suggests that it might be possible to adapt the method to study chemical reaction dynamics and even chemical kinetics using rotational spectroscopy. The great advantage of this would be clear, quantifiable spectroscopic signatures for polyatomic products as well as the possibility to identify and characterize new radical reaction products and transient intermediates. To achieve this, however, several conditions must be met: 1) products must be thermalized at low temperature to maximize the population difference needed to achieve adequate signal levels and to permit product quantification based on the rotational line strength; 2) a large density and volume of reaction products is also needed to achieve adequate signal levels; and 3) for kinetics studies, a uniform density and temperature is needed throughout the course of the reaction. These conditions are all happily met by the uniform supersonic flow produced from a Laval nozzle expansion. In collaboration with the Field group at MIT we have developed a new instrument we term a CPUF (Chirped-pulse/Uniform Flow) spectrometer in which we can study reaction dynamics, photochemistry and kinetics using broadband microwave and millimeter wave spectroscopy as a product probe. We will illustrate the performance of the system with a few examples of photodissociation and reaction dynamics, and also discuss a number of challenges unique to the application of chirped-pulse microwave spectroscopy in the collisional environment of the flow. Future directions and opportunities for application of CPUF will also be explored.

  10. R 12 two-phase flow in throttle capillaries in critical flow conditions

    International Nuclear Information System (INIS)

    Petry, G.

    1983-01-01

    In this dissertation, the state of knowledge on two phase flow, its use and measurement processes are given from an extensive search of the literature. In the experimental part of the work, a continuously working experimental circuit was built up, by which single component two phase flow can be examined in critical flow conditions. Using the maintenance equations, a system of equations was produced, by which the content of steam flow, the content of steam volume and the slip between the phases at the end corssection of the capillary can be determined. The transfer of the experimental results into the Baker diagram shows that the experimental values lie in the region of mist, bubble and foam flow. (orig.) [de

  11. KINEMATIC STUDY OF THE AIR FLOW PRODUCED BY SOME SPRAYERS USED IN “TENDONE” VINEYARDS

    Directory of Open Access Journals (Sweden)

    Simone Pascuzzi

    2008-09-01

    Full Text Available A computerized measuring system to analyse the vector field of the air velocities in a volume surrounding the fan of air assisted sprayers usually used in tendone vineyards was designed and built. The performance of three different sprayers was tested: the first, a traditional air-convection sprayer, the other two, suitably designed for treatments in tendone vineyards. The air flow which exited through the discharge diffusers and moving towards the target sucked air from the surrounding environment that enlarged the flow rate on the target. The available flow was that which reached the vegetative and productive area, placed in a horizontal position respectively at 1.8 m and 2.0 m from the ground plane. The pneumatic sprayer produced an air flow clearly directed towards the top of the vines.

  12. Detection of fission products in carbon dioxide by instantaneous ion collection

    International Nuclear Information System (INIS)

    Le Meur, R.; Lorin, A.

    1968-01-01

    This report describes a fission product detector with instantaneous electric collection, capable of analyzing carbon dioxide up to a pressure of 60 bars and at a temperature of 200 C. In contrast to delayed collection detectors, this apparatus makes it possible to collect rubidium and cesium ions as soon as they are formed; this avoids losses due to recombination. The detector has been tested with a fission product source made up of a uranium oxide sample subjected to a neutron flux. The activity of the ions collected as a function of an electric field has been measured for different parameters: pressure, temperature, CO 2 gas flow rate, and the volume of the ion-formation chamber. The sensitivity of this apparatus is compared to that of other fission product detectors. For a low volume-flow rate, e.g. 100 cm 3 sec -1 , its sensitivity for krypton 88 is better than that of a delayed collection detector. An apparatus of this type could be used as a can rupture detector on a reactor with a large number of channels, with a low gas sampling rate per channel. The equipment will be included in the can rupture detector installations in the Fessenheim reactor. (authors) [fr

  13. Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

    Science.gov (United States)

    Eu, Byung Chan

    2008-09-07

    In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

  14. Generalized Kutta–Joukowski theorem for multi-vortex and multi-airfoil flow with vortex production — A general model

    Directory of Open Access Journals (Sweden)

    Bai Chenyuan

    2014-10-01

    Full Text Available By using a special momentum approach and with the help of interchange between singularity velocity and induced flow velocity, we derive in a physical way explicit force formulas for two-dimensional inviscid flow involving multiple bound and free vortices, multiple airfoils, and vortex production. These force formulas hold individually for each airfoil thus allowing for force decomposition, and the contributions to forces from singularities (such as bound and image vortices, sources, and doublets and bodies out of an airfoil are related to their induced velocities at the locations of singularities inside this airfoil. The force contribution due to vortex production is related to the vortex production rate and the distance between each pair of vortices in production, thus frame-independent. The formulas are validated against a number of standard problems. These force formulas, which generalize the classic Kutta–Joukowski theorem (for a single bound vortex and the recent generalized Lagally theorem (for problems without a bound vortex and vortex production to more general cases, can be used to identify or understand the roles of outside vortices and bodies on the forces of the actual body, optimize arrangement of outside vortices and bodies for force enhancement or reduction, and derive analytical force formulas once the flow field is given or known.

  15. The impact of hydraulic flow unit & reservoir quality index on pressure profile and productivity index in multi-segments reservoirs

    Directory of Open Access Journals (Sweden)

    Salam Al-Rbeawi

    2017-12-01

    Full Text Available The objective of this paper is studying the impact of the hydraulic flow unit and reservoir quality index (RQI on pressure profile and productivity index of horizontal wells acting in finite reservoirs. Several mathematical models have been developed to investigate this impact. These models have been built based on the pressure distribution in porous media, depleted by a horizontal well, consist of multi hydraulic flow units and different reservoir quality index. The porous media are assumed to be finite rectangular reservoirs having different configurations and the wellbores may have different lengths. Several analytical models describing flow regimes have been derived wherein hydraulic flow units and reservoir quality index have been included in addition to rock and fluid properties. The impact of these two parameters on reservoir performance has also been studied using steady state productivity index.It has been found that both pressure responses and flow regimes are highly affected by the existence of multiple hydraulic flow units in the porous media and the change in reservoir quality index for these units. Positive change in the RQI could lead to positive change in both pressure drop required for reservoir fluids to move towards the wellbore and hence the productivity index.

  16. Flow regime effects on mature Populus fremontii (Fremont cottonwood) productivity on two contrasting dryland river floodplains

    Science.gov (United States)

    Andersen, Douglas C.

    2016-01-01

    I compared riparian cottonwood (Populus fremontii) productivity-discharge relationships in a relictual stand along the highly regulated Green River and in a naturally functioning stand along the unregulated Yampa River in semiarid northwest Colorado. I used multiple regression to model flow effects on annual basal area increment (BAI) from 1982 to 2011, after removing any autocorrelation present. Each BAI series was developed from 20 trees whose mean size (67 cm diameter at breast height [DBH]) was equivalent in the two stands. BAI was larger in the Yampa River stand except in 2 y when defoliating leaf beetles were present there. I found no evidence for a Yampa flood-magnitude threshold above which BAI declined. Flow variables explained ∼45% of residual BAI variability, with most explained by current-year maximum 90-d discharge (QM90) in the Yampa River stand and by a measure of the year-to-year change in QM90 in the Green River stand. The latter reflects a management-imposed ceiling on flood magnitude—Flaming Gorge Dam power plant capacity—infrequently exceeded during the study period. BAI in the relictual stand began to trend upward in 1992 when flows started to mimic a natural flow regime. Mature Fremont cottonwoods appear to be ecologically resilient. Their productivity along regulated rivers might be optimized using multiyear environmental flow designs.

  17. Automotive Manufacturing Assessment System : Volume 1. Master Product Schedules.

    Science.gov (United States)

    1999-11-01

    Volume I is part of a four volume set documenting areas of research resulting from the development of the Automotive Manufacturing Assessment System (AMAS) for the DOT/Transportation Systems Center. AMAS was designed to assist in the evaluation of in...

  18. Enhancement of the anaerobic hydrolysis and fermentation of municipal solid waste in leachbed reactors by varying flow direction during water addition and leachate recycle

    Energy Technology Data Exchange (ETDEWEB)

    Uke, Matthew N., E-mail: cnmnu@leeds.ac.uk [Department of Civil Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Stentiford, Edward [Department of Civil Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2013-06-15

    Highlights: ► Combined downflow and upflow water addition improved hydraulic conductivity. ► Upflow water addition unclogged perforated screen leading to more leachate flow. ► The volume of water added and transmitted positively correlated with hydrolysis process. ► Combined downflow and upflow water addition increased COD production and yield. ► Combined downflow and upflow leachate recycle improved leachate and COD production. - Abstract: Poor performance of leachbed reactors (LBRs) is attributed to channelling, compaction from waste loading, unidirectional water addition and leachate flow causing reduced hydraulic conductivity and leachate flow blockage. Performance enhancement was evaluated in three LBRs M, D and U at 22 ± 3 °C using three water addition and leachate recycle strategies; water addition was downflow in D throughout, intermittently upflow and downflow in M and U with 77% volume downflow in M, 54% volume downflow in U while the rest were upflow. Leachate recycle was downflow in D, alternately downflow and upflow in M and upflow in U. The strategy adopted in U led to more water addition (30.3%), leachate production (33%) and chemical oxygen demand (COD) solubilisation (33%; 1609 g against 1210 g) compared to D (control). The total and volatile solids (TS and VS) reductions were similar but the highest COD yield (g-COD/g-TS and g-COD/g-VS removed) was in U (1.6 and 1.9); the values were 1.33 and 1.57 for M, and 1.18 and 1.41 for D respectively. The strategy adopted in U showed superior performance with more COD and leachate production compared to reactors M and D.

  19. Optimization of material flow in the nuclear fuel cycle using a cyclic multi-stage production-to-inventory model

    International Nuclear Information System (INIS)

    DePorter, E.L.

    1977-01-01

    The nuclear fuel cycle is modelled as a cyclic, multi-stage production-to-inventory system. The objective is to meet a known deterministic demand for energy while minimizing acquisition, production, and inventory holding costs for all stages of the fuel cycle. The model allows for cyclic flow (feedback) of materials, material flow conversion factors at each stage, production lag times at each stage, and for escalating costs of uranium ore. It does not allow shortages to occur in inventories. The model is optimized by the application of the calculus of variations and specifically through recently developed theorems on the solution of functionals constrained by inequalities. The solution is a set of optimal cumulative production trajectories which define the stagewise production rates. Analysis of these production rates reveals the optimal nuclear fuel cycle costs and that inventories (stockpiles) occur in uranium fields, enriched uranium hexafluoride, and fabricated fuel assemblies. An analysis of the sensitivity of the model to variation in three important parameters is performed

  20. Flow Forecasting in Drainage Systems with Extrapolated Radar Rainfall Data and Auto Calibration on Flow Observations

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Grum, M.; Rasmussen, Michael R.

    2011-01-01

    Forecasting of flows, overflow volumes, water levels, etc. in drainage systems can be applied in real time control of drainage systems in the future climate in order to fully utilize system capacity and thus save possible construction costs. An online system for forecasting flows and water levels......-calibrated on flow measurements in order to produce the best possible forecast for the drainage system at all times. The system shows great potential for the implementation of real time control in drainage systems and forecasting flows and water levels.......Forecasting of flows, overflow volumes, water levels, etc. in drainage systems can be applied in real time control of drainage systems in the future climate in order to fully utilize system capacity and thus save possible construction costs. An online system for forecasting flows and water levels...... in a small urban catchment has been developed. The forecast is based on application of radar rainfall data, which by a correlation based technique, is extrapolated with a lead time up to two hours. The runoff forecast in the drainage system is based on a fully distributed MOUSE model which is auto...