Artigos de revistas: "Lits fluidisé"

1

Miháltz, P., Zs Csikor, P. Chatellier e B. Siklódi. "Optimisation de la concentration de biomasse dans un réacteur à lit fluidisé". Revue des sciences de l'eau 14, n.º 2 (12 de abril de 2005): 131–45. http://dx.doi.org/10.7202/705413ar.

Texto completo da fonte

Resumo:

Une étude expérimentale de la dénitrification a été réalisée sur des bioréacteurs à lits fluidisés alimentés avec un effluent dont la teneur en nitrates peut atteindre 900 mg N-NO3- /l. Des mesures ont montré, qu'à ces concentrations, il n'y a pas d'inhibition des substrats (NO3- et éthanol). Le flux de nitrates éliminé par le réacteur a atteint 10 kg N-NO3- /m3j avec pratiquement 100 % d'élimination des nitrates. Ce flux semble toutefois dépendre de la quantité de biomasse dénitrifiante sur le support de sable. Pour le contrôle optimal du procédé, il est indispensable de pouvoir - déterminer facilement la concentration massique (G) de la biomasse - éviter les valeurs extrêmes conduisant à une expansion trop importante du lit et à des limitations diffusionnelles. Une étude préalable des auteurs a servi comme base pour établir la corrélation entre le gradient de pression dans le lit, exprimé en fonction de l'écart de masse volumique (Cp), et les valeurs de G. Une corrélation a été déterminée et les constantes validées pour une gamme de G allant jusqu'à 100 mg MVS/g support. La concentration volumique de biomasse (X) a été ensuite établie à l'aide de paramètres caractérisant le comportement hydrodynamique du lit fluidisé. Dans le cas du système étudié, la valeur maximale de X est de 19 - 20 g MVS/l. Ceci correspond à des valeurs de G de 80-100 mg MVS/g support. Les corrélations obtenues peuvent servir pour le dimensionnement ainsi que pour l'optimisation de l'épaississeur du biofilm dans la conduite du réacteur.

Estilos ABNT, Harvard, Vancouver, APA, etc.

2

Dufour, I., A. Maali, Y. Amarouchene, C. Ayela, B. Caillard, A. Darwiche, M. Guirardel et al. "The Microcantilever: A Versatile Tool for Measuring the Rheological Properties of Complex Fluids". Journal of Sensors 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/719898.

Texto completo da fonte

Resumo:

Silicon microcantilevers can be used to measure the rheological properties of complex fluids. In this paper, two different methods will be presented. In the first method, the microcantilever is used to measure the hydrodynamic force exerted by a confined fluid on a sphere that is attached to the microcantilever. In the second method, the measurement of the microcantilever's dynamic spectrum is used to extract the hydrodynamic force exerted by the surrounding fluid on the microcantilever. The originality of the proposed methods lies in the fact that not only may the viscosity of the fluid be measured, but also the fluid's viscoelasticity, that is, both viscous and elastic properties, which are key parameters in the case of complex fluids. In both methods, the use of analytical equations permits the fluid's complex shear modulus to be extracted and expressed as a function of shear stress and/or frequency.

Estilos ABNT, Harvard, Vancouver, APA, etc.

3

Ruvalcaba, J. Ramiro Rodriguez, Brigitte Caussat, Merhdji Hemati e Jean-Pierre Couderc. "Étude hydrodynamique des lits fluidisés sous vide et sous haute température". Canadian Journal of Chemical Engineering 77, n.º 1 (fevereiro de 1999): 35–44. http://dx.doi.org/10.1002/cjce.5450770107.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

4

Chehbouni, A., J. Chaouki, C. Guy e D. Klvana. "Description et modélisation des structures globale et locale des lits fluidisés en régime turbulent". Chemical Engineering Journal and the Biochemical Engineering Journal 61, n.º 2 (fevereiro de 1996): 73–82. http://dx.doi.org/10.1016/0923-0467(95)03029-8.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

5

King, Danielle, Hakan Başağaoğlu, Hoa Nguyen, Frank Healy, Melissa Whitman e Sauro Succi. "Effects of Advective-Diffusive Transport of Multiple Chemoattractants on Motility of Engineered Chemosensory Particles in Fluidic Environments". Entropy 21, n.º 5 (4 de maio de 2019): 465. http://dx.doi.org/10.3390/e21050465.

Texto completo da fonte

Resumo:

Motility behavior of an engineered chemosensory particle (ECP) in fluidic environments is driven by its responses to chemical stimuli. One of the challenges to understanding such behaviors lies in tracking changes in chemical signal gradients of chemoattractants and ECP-fluid dynamics as the fluid is continuously disturbed by ECP motion. To address this challenge, we introduce a new multiscale numerical model to simulate chemotactic swimming of an ECP in confined fluidic environments by accounting for motility-induced disturbances in spatiotemporal chemoattractant distributions. The model accommodates advective-diffusive transport of unmixed chemoattractants, ECP-fluid hydrodynamics at the ECP-fluid interface, and spatiotemporal disturbances in the chemoattractant concentrations due to particle motion. Demonstrative simulations are presented with an ECP, mimicking Escherichia coli (E. coli) chemotaxis, released into initially quiescent fluids with different source configurations of the chemoattractants N-methyl-L-aspartate and L-serine. Simulations demonstrate that initial distributions and temporal evolution of chemoattractants and their release modes (instantaneous vs. continuous, point source vs. distributed) dictate time histories of chemotactic motility of an ECP. Chemotactic motility is shown to be largely determined by spatiotemporal variation in chemoattractant concentration gradients due to transient disturbances imposed by ECP-fluid hydrodynamics, an observation not captured in previous numerical studies that relied on static chemoattractant concentration fields.

Estilos ABNT, Harvard, Vancouver, APA, etc.

6

Sabiri, Nour-Eddine, e Jacques Comiti. "Ecoulement de fluides newtoniens et non newtoniens à travers des lits fixes stratifiés". Canadian Journal of Chemical Engineering 75, n.º 6 (dezembro de 1997): 1030–37. http://dx.doi.org/10.1002/cjce.5450750605.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

7

Duravac. "Vacuum publications Duravac Vacuum Fluids 1986 Price List". Vacuum 36, n.º 10 (outubro de 1986): 748. http://dx.doi.org/10.1016/0042-207x(86)90543-9.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

8

Major, Laura. "“There Were Some Things That Did Not Change”: Postcolonial Reckonings with Gender in The No. 1 Ladies’ Detective Agency Series". College Literature 51, n.º 1 (janeiro de 2024): 84–105. http://dx.doi.org/10.1353/lit.2024.a917865.

Texto completo da fonte

Resumo:

Abstract: Though seemingly romanticized, Alexander McCall Smith’s popular No. 1 Ladies’ Detective Agency series reckons with the gendered realities of postcolonial Botswana by creating a paradox that resists a simple reading of gender and feminism in the locale it inhabits. The series’ heroine, though traditional, defies gender roles, practicing a situated and culturally specific version of women’s empowerment. Indeed, when discussing gender in postcolonial Africa, we should not apply Western notions of feminism. Homi Bhabha’s notion of hybridity, which recognizes locality, fluidity, and mutual influence in the construction of postcolonial identity, is a useful lens through which to understand the series’ paradoxes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

9

Wang, Jie, Ming Jun Xu, Lin Li Shi, Qi Shi, Yong Chao Wang e Yi Xiang Duan. "A Computer-Controlled In Situ Analysis Instrument Based on Laser Induced Breakdown Spectroscopy". Applied Mechanics and Materials 556-562 (maio de 2014): 561–66. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.561.

Texto completo da fonte

Resumo:

A portable LIBS device capable of analyzing material component especially for drilling fluids in the drilling site was designed and assembled. A position adjustable apparatus was developed, which permits the applications in outdoor environments. The alkali metal elements such as potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), aluminum (Al), have been detected in the drilling fluids using the newly developed portable LIBS device. The results show that the device well performs qualitative analysis, and also has potential predominance for the quantitative analysis in-situ.

Estilos ABNT, Harvard, Vancouver, APA, etc.

10

Esen, Oğul, Miroslav Grmela, Hasan Gümral e Michal Pavelka. "Lifts of Symmetric Tensors: Fluids, Plasma, and Grad Hierarchy". Entropy 21, n.º 9 (18 de setembro de 2019): 907. http://dx.doi.org/10.3390/e21090907.

Texto completo da fonte

Resumo:

Geometrical and algebraic aspects of the Hamiltonian realizations of the Euler’s fluid and the Vlasov’s plasma are investigated. A purely geometric pathway (involving complete lifts and vertical representatives) is proposed, which establishes a link from particle motion to evolution of the field variables. This pathway is free from Poisson brackets and Hamiltonian functionals. Momentum realizations (sections on T * T * Q ) of (both compressible and incompressible) Euler’s fluid and Vlasov’s plasma are derived. Poisson mappings relating the momentum realizations with the usual field equations are constructed as duals of injective Lie algebra homomorphisms. The geometric pathway is then used to construct the evolution equations for 10-moments kinetic theory. This way the entire Grad hierarchy (including entropic fields) can be constructed in a purely geometric way. This geometric way is an alternative to the usual Hamiltonian approach to mechanics based on Poisson brackets.

Estilos ABNT, Harvard, Vancouver, APA, etc.

11

Harmon, Russell S. "Laser-Induced Breakdown Spectroscopy in Mineral Exploration and Ore Processing". Minerals 14, n.º 7 (22 de julho de 2024): 731. http://dx.doi.org/10.3390/min14070731.

Texto completo da fonte

Resumo:

Laser-induced breakdown spectroscopy (LIBS) is a type of optical emission spectroscopy capable of rapid, simultaneous multi-element analysis. LIBS is effective for the analysis of atmospheric gases, geological fluids, and a broad spectrum of minerals, rocks, sediments, and soils both in and outside the traditional laboratory setting. With the recent introduction of commercial laboratory systems and handheld analyzers for use outside the laboratory for real-time in situ analysis in the field, LIBS is finding increasing application across the geosciences. This article first overviews the LIBS technique and then reviews its application in the domain of mineral exploration and ore processing, where LIBS offers some unique capabilities.

Estilos ABNT, Harvard, Vancouver, APA, etc.

12

Botton, R. "Lits fluidisés pour l'industrie chimique. Extrapolation et amélioration des catalyseurs. Première partie : Etudes et modèles. Enseignements issus des pilotes". Oil & Gas Science and Technology 54, n.º 5 (setembro de 1999): 619–40. http://dx.doi.org/10.2516/ogst:1999052.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

13

Ćosić, Bernhard, Dominik Waßmer e Franklin Genin. "Integration of Fluidic Nozzles in the New Low Emission Dual Fuel Combustion System for MGT Gas Turbines". Fluids 6, n.º 3 (21 de março de 2021): 129. http://dx.doi.org/10.3390/fluids6030129.

Texto completo da fonte

Resumo:

Fluidic oscillators have proven their capabilities and advantages in terms of the generation of oscillating jets without moving parts for many years, mainly in experimental studies. In this paper, the design, development, and integration of fluidic atomizers into the liquid-fuel system of the dual-fuel low NOX Advanced Can Combustion (ACC) system of the MAN Gas Turbines (MGT) are presented. The two-stage system comprises a pressure-swirl nozzle as a pilot stage and an assembly of four main premixed nozzles, based on fluidic technology. The design and the features of the pilot nozzle are briefly presented, whereas the focus lies on the functionality and layout of the fluidic nozzles. The complete integration, validation, and verification of this innovative liquid-fuel injection unit are presented. The final system features fast fuel-switchovers, low complexity, high reliability, and dry low emissions in liquid-fuel operation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

14

Knoepflmacher, U. C. "A Victorianist Looks Back: Fluidity vs. Fragmentation". Victorian Literature and Culture 47, n.º 1 (7 de dezembro de 2018): 137–53. http://dx.doi.org/10.1017/s1060150318001407.

Texto completo da fonte

Resumo:

InMiddlemarch,when Mr. Brooke asks Edward Casaubon how he arranges his documents, the pedantic would-be author of “The Key to All Mythologies” replies with a “startled air of effort” that he puts them into “pigeon-holes mostly.” Dorothea's uncle is baffled. He complains that his own scattered gatherings became much too “mixed in pigeon-holes: I never know whether a paper is in A or Z.” Embarrassed, his niece volunteers to sort out his papers: “I would letter them all, and then make a list of subjects under each letter.” Her offer catches Mr. Casaubon's attention. Commending Mr. Brooke for having such “an excellent secretary at hand,” he gravely smiles his approval. But the befuddled gentleman whose mind remains full of disconnected “fragments” bluntly rejects Dorothea's offer: “‘No, no,’ said Mr. Brooke: ‘I cannot let young ladies meddle with my documents. Young ladies are too flighty.’”

Estilos ABNT, Harvard, Vancouver, APA, etc.

15

Zhang, Mengye. "Classification and Research Progress of Fracturing Fluids". International Journal of Energy 3, n.º 1 (26 de junho de 2023): 73–74. http://dx.doi.org/10.54097/ije.v3i1.10659.

Texto completo da fonte

Resumo:

As one of the important technical means to increase production in oil and gas fields, the success or failure of fracturing construction and the effect of increasing production depend largely on the performance of the fracturing fluid used. This paper analyzes the fracturing fluid systems used in different coal seams at home and abroad, and lists the research progress of several fracturing fluid systems, which plays a guiding role in the selection of fracturing fluids in the development of oil seams.

Estilos ABNT, Harvard, Vancouver, APA, etc.

16

Geng, Changyou, Xinli Lu, Hao Yu, Wei Zhang, Jiaqi Zhang e Jiansheng Wang. "Theoretical Study of a Novel Power Cycle for Enhanced Geothermal Systems". Processes 10, n.º 3 (4 de março de 2022): 516. http://dx.doi.org/10.3390/pr10030516.

Texto completo da fonte

Resumo:

As obtained geofluids from enhanced geothermal systems usually have lower temperatures and contain chemicals and impurities, a novel power cycle (NPC) with a unit capacity of several hundred kilowatts has been configured and developed in this study, with particular reference to the geofluid temperature (heat source) ranging from 110 °C to 170 °C. Using a suitable CO2-based mixture working fluid, a transcritical power cycle was developed. The novelty of the developed power cycle lies in the fact that an increasing-pressure endothermic process was realized in a few-hundred-meters-long downhole heat exchanger (DHE) by making use of gravitational potential energy, which increases the working fluid’s pressure and temperature at the turbine inlet and, hence, increases the cycle’s power output. The increasing-pressure endothermic process in the DHE has a better match with the temperature change of the heat source (geofluid), as does the exothermic process in the condenser with the temperature change of the sink (cooling water), which reduces the heat transfer irreversibility and improves the cycle efficiency. Power cycle performance has been analyzed in terms of the effects of mass fraction of the mixture working fluids, the working fluid’s flowrate and its DHE inlet pressure, geofluid flowrate, and the length of the DHE. Results show that, for a given geofluid’s temperature and mass flowrate, the cycle’s net power output is a strong function of the working-fluid’s flowrate, as well as of its DHE inlet pressure. Too high or too low of a DHE inlet pressure results in a lower power output. When geofluid temperature is 130 °C, the optimum DHE inlet pressure is found to be 11 MPa, corresponding to an optimum working-fluid flowrate of 6.5 kg/s. The longer the DHE, the greater the corresponding working-fluid flowrate and the higher the net power output. For geofluid temperature ranging from 110 °C to 170 °C, the developed NPC has a better thermodynamic performance than the conventional ORC. The advantage of using the developed NPC becomes obvious when geofluid temperature is low. The maximum net power output difference between the NPC and the ORC happens when the geofluid temperature is 130 °C and NPC’s working fluid mass fraction (R32/CO2) is 0.5/0.5.

Estilos ABNT, Harvard, Vancouver, APA, etc.

17

Angulo Sibaja, Andrés A., Rodrigo Alvarado Marín e Mauricio Vargas Obando. "Cosmological exact solutions of Petrov type D. A mixture of two fluids: dark energy and radiation". Revista de Matemática: Teoría y Aplicaciones 29, n.º 2 (30 de junho de 2022): 225–38. http://dx.doi.org/10.15517/rmta.v29i2.46390.

Texto completo da fonte

Resumo:

In this paper, two exact solutions of the Einstein’s equations are obtained for an anisotropic and homogeneous symmetry of Petrov Type D, the difference between both solutions lies in how relevant is the expansion that is presented initially, either on an axis or on a perpendicular plane. Both solutions represent a mixture of two fluids with minimum interaction: dark energy (P = −µ) and radiation (P = µ/3). The singularities and the influence that these fluids have on this metric are studied; the Hubble parameters, the deceleration parameter and the role that these fluids represent on them are determined and analyzed. Additionally, their temperature and the role that both play on this magnitude are determined.

Estilos ABNT, Harvard, Vancouver, APA, etc.

18

Olesen, Henrik, David Cowan, Rafael De La Torre, Ivan Bruunshuus, Morten Rohde e Desmond Kenny. "Properties and units in the clinical laboratory sciences. Part XII. Properties and units in clinical pharmacology and toxicology (Technical Report) (IFCC-IUPAC 1999)". Pure and Applied Chemistry 72, n.º 3 (1 de janeiro de 2000): 479–552. http://dx.doi.org/10.1351/pac200072030479.

Texto completo da fonte

Resumo:

The term designating a substance being an active ingredient of a drug may be a generic name, a nonproprietary name, a registered trade name, a fantasy name, or other. This causes difficulties in the transmission of requests and reports on properties for such substances in biological fluids to and from the clinical laboratories, and in the collating of this information from different sources.The document comprises a list of properties of drugs in biological fluids for use in electronic transmission systems. Systematic names are presented together with a code value for each.

Estilos ABNT, Harvard, Vancouver, APA, etc.

19

Semenov, Ivan, e Kirill Boychuk. "SIMULATION OF THE PROCESS OF RECTIFICATION OF VACUUM DISTILLATE HYDROGENATE". Modern Technologies and Scientific and Technological Progress 2023, n.º 1 (4 de maio de 2023): 55–56. http://dx.doi.org/10.36629/2686-9896-2023-1-55-56.

Texto completo da fonte

Resumo:

The primary analysis of the operation of the process for the rectification of vacuum distillate hydrogenate was carried out. The list of initial data necessary for creating a mathematical simulation of the process was determined. It is planned to change the unit work regime to produce hydrocarbon bases of drilling fluids

Estilos ABNT, Harvard, Vancouver, APA, etc.

20

Gerulová, Kristína, Eva Buranská e Maroš Soldán. "Human Health Concenrs of Metalworking Fluid Components". Research Papers Faculty of Materials Science and Technology Slovak University of Technology 25, n.º 40 (1 de junho de 2017): 25–32. http://dx.doi.org/10.1515/rput-2017-0003.

Texto completo da fonte

Resumo:

Abstract Exploration of 209 available Material safety data sheets of 85 straight oils, 46 emulsions, 51 semi-synthetics and 27 synthetics was carried out to provide a report on the most widely used components defined as dangerous substances. As many as 217 of different substances of which 15 were identified as biocides, 17 as corrosion inhibitors or neutralizing agent, 17 were lubricity improvers and 38 different base fluids, lubricity solvents or surfactants, while 93 substances were not identified specifically and 37 substances occurred only once. This article is focused on the list of base fluids in straight oils and their possible health effects.

Estilos ABNT, Harvard, Vancouver, APA, etc.

21

Leon Escalante, S. G., G. Dominguez e G. Touchard. "Phénomènes électrostatiques dans les lits fluidisés et nouvelle méthode pour la mesure de la vitesse minimale de fluidisation dans les matériaux pulvérulents". Journal of Electrostatics 60, n.º 1 (janeiro de 2004): 1–13. http://dx.doi.org/10.1016/s0304-3886(03)00106-2.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

22

Zhang, Tongyu. "Research on the Low-Temperature Stability of Anode and Electrolyte of Lithium-ion Battery". E3S Web of Conferences 553 (2024): 01001. http://dx.doi.org/10.1051/e3sconf/202455301001.

Texto completo da fonte

Resumo:

With the acceleration of technological progress, lithium-ion batteries (LIBs) have become one of the indispensable forms of energy in modern life and play a crucial role. However, its performance degradation in low-temperature environments remains a key factor restricting its further development. In particular, as the core components of LIBs, the stability of electrodes and electrolytes at low temperatures directly determines the overall performance of the battery. Specifically, the fluidity of the electrolyte is significantly reduced at low temperatures, while lithium-ions at the negative electrode are more easily precipitated, leading to the formation of lithium dendrites, which together affect the safety and life of the battery. This paper systematically analyses the latest advances in structure regulation and design of anode materials and electrolytes through an in-depth study of the low-temperature stability of LIBs. Modification methods for these key materials are described in detail, including strategies for optimising electrolyte additives and their positive effects on enhancing battery performance at low temperatures. In addition, the article discusses potential directions for future research in this area, aiming to provide guidance and reference for improving the performance of LIBs for applications in low-temperature environments.

Estilos ABNT, Harvard, Vancouver, APA, etc.

23

Cunliffe, Ann L., e Karen Locke. "Working With Differences in Everyday Interactions through Anticipational Fluidity: A Hermeneutic Perspective". Organization Studies 41, n.º 8 (15 de abril de 2019): 1079–99. http://dx.doi.org/10.1177/0170840619831035.

Texto completo da fonte

Resumo:

This paper sheds light on an issue we all face, how to work with differences encountered in our everyday interactions with each other when the outcome of the exchange is not simply up to us. Our contribution lies in proposing the notion of anticipational fluidity, of finding ways of relating and responding to others as we orient ourselves to each other and to what might happen next within the moment of conversation. Situated in a hermeneutic lens that highlights the interplay of interpretations in unfolding responsive moments, we integrate the work of Shotter and Ricoeur with our interpretation of empirical texts generated from an ethnographic inquiry of academic/practitioner collaboration. We suggest that anticipational fluidity encompasses open work, difference-making and tentative intentionality, and elaborate these sensitizing resources by putting readers within unfolding moments of a meeting where differences are addressed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

24

Bouchendouka, Abdellah, Zine El Abiddine Fellah, Zakaria Larbi, Zineeddine Louna, Erick Ogam, Mohamed Fellah e Claude Depollier. "Fractal Analysis of a Non-Newtonian Fluid Flow in a Rough-Walled Pipe". Materials 15, n.º 10 (22 de maio de 2022): 3700. http://dx.doi.org/10.3390/ma15103700.

Texto completo da fonte

Resumo:

The fully developed laminar flow of a viscous non-Newtonian fluid in a rough-walled pipe is considered. The fluid rheology is described by the power–law model (covering shear thinning, Newtonian, and shear thickening fluids). The rough surface of the pipe is considered to be fractal, and the surface roughness is measured using surface fractal dimensions. The main focus of this study lies in the theoretical investigation of the influence of the pipe surface roughness on the velocity profile and the Darcy friction factor of an incompressible non-Newtonian fluid. The plotted results demonstrate that shear thinning fluids are the most sensitive to the surface roughness compared with Newtonian and shear thickening fluids. For a particular value of the surface fractal dimension, there exists an intersection point where shear thinning, Newtonian, and shear thickening fluids behave the same way regarding the amplitude of the velocity profile and the friction factor. This approach has a variety of potential applications, for instance fluid dynamics in hydrology, blood flow in the cardiovascular system, and many industrial applications.

Estilos ABNT, Harvard, Vancouver, APA, etc.

25

Allerdissen, Merle, Rinaldo Greiner e Andreas Richter. "Microfluidic Microchemomechanical Systems". Advances in Science and Technology 81 (setembro de 2012): 84–89. http://dx.doi.org/10.4028/www.scientific.net/ast.81.84.

Texto completo da fonte

Resumo:

The lab-on-a-chip (LOC) technology was expected to influence our every day live in a similarly fundamental way as integrated circuits have. Unfortunately, this demand has not been met yet. The cause therefore lies in the complexity of microelectromechanical systems (MEMS), which form the base of the current LOC technology. We present a new concept of LOC which are based on fluidic microchemomechanical systems (μCMS). During the fabrication process, these μCMS are preprogrammed by monolithic integration of special active components. These active components are holding chemical energy that can be transformed at least once into mechanical energy and thus provide a timed and quantitative exactly defined fluidic function. With our simple and inexpensive fabrication method combined with the above mentioned advantages of the invented μCMS, new and better LOC technology can be developed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

26

El Hassan, Mouhammad. "Numerical Characterization of the Flow Dynamics and COP Estimation of a Binary Fluid Ejector Ground Source Heat Pump Cooling System". Fluids 7, n.º 7 (20 de julho de 2022): 250. http://dx.doi.org/10.3390/fluids7070250.

Texto completo da fonte

Resumo:

Ejector-based refrigeration systems can make direct use of many forms of thermal energy, such as solar thermal, waste heat, biogas, or natural gas. The present paper describes the estimation of the thermal coefficient of performance (COP) of a binary fluid ejector ground source heat pump (BFE GSHP) cooling system. A method for fluid selection was defined based on the favorable thermo-physical properties of the working fluids. A short list of fluid pairs were selected based on their favorable properties for the BFE GSHP cooling system. Computational Fluid Dynamics (CFD) investigation was conducted for the selected fluid pairs and a suitable ejector geometry is proposed for the high compression ratios encountered in the GSHP applications. The mixing between primary and secondary fluids was investigated using physical analysis of the CFD results. The effect of the fluids’ thermo-physical properties on the system performance was also discussed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

27

Zhang, Hong Xu, Yu Jie Zhao, Jia Zhuang, Hai Yang Qin e Han Ling Zhang. "Modified Mechanism and Properties of Water-Soluble Sodium Silicate for Oil and Gas Field". Materials Science Forum 814 (março de 2015): 220–29. http://dx.doi.org/10.4028/www.scientific.net/msf.814.220.

Texto completo da fonte

Resumo:

With an analysis on the structure of water-soluble sodium silicate and its polymerization, it was found that the poor stability of silicate drilling fluids lies in the relevance between the inherent nature and the pH value of sodium silicate. The modification of water-soluble sodium silicate in this paper was to improve its stability and keep the inhibitive property simultaneously. The a-olefin sulfonate (AOS) was employed as the modifer agent acted on the water-soluble sodium silicate monomer and oligomers. Furthermore, the modification mechanism was discussed through FTIR, Laser particle size, Zeta potential and SEM. A stable sodium silicate drilling fluids with better inhibitive property was obtained by the comparison of modified sodium silicate and unmodified ones.

Estilos ABNT, Harvard, Vancouver, APA, etc.

28

Rammohan, Shruthi, Basavaraj Bhandare, Adarsh E. e Satyanarayana V. "The prescribing pattern for the management of dengue fever in pediatric patients of a tertiary care hospital: an observational study". International Journal of Basic & Clinical Pharmacology 7, n.º 12 (24 de novembro de 2018): 2384. http://dx.doi.org/10.18203/2319-2003.ijbcp20184851.

Texto completo da fonte

Resumo:

Background: Dengue fever is a mosquito borne viral infection which has become a global health hazard, especially in tropical and subtropical areas. Children have higher risk of developing severe forms of dengue fever, however, studies show that paediatric complications/fatalities from dengue fever are potentially avoidable by proper management. Data about drug usage patterns for dengue are particularly lacking, especially in the paediatric age group, therefore this study will help facilitate the rational use of drugs and aid in establishing a more specific management for dengue fever. The objective of the present study was to identify the prescribing pattern of dengue fever in paediatric inpatients admitted to RajaRajeswari Medical College and Hospital and assess according to the WHO core prescribing indicatorsMethods: This prospective observational study took place from March 2017 to September 2017 in the paediatric general wards. Data was collected from case files of NS1 positive patients of both genders between 1-18years. Data was analysed using descriptive statistics and expressed as percentages, means and standard deviations. The prescription pattern was analysed using the prescribing indicators mentioned in the World Health Organization core drug use indicators.Results: Total of 300 drugs were prescribed for 110 prescriptions that were analysed excluding IV fluids and blood products. Mean number of drugs prescribed was 2.7±0.8. Drugs prescribed by a generic name was 7.33%. Patients prescribed an antibiotic was 12.73%. Patients prescribed with an injection was 62.72% Majority of drugs prescribed in this study come from essential medicines list created by regulatory bodies. Intravenous fluids were administered to all patients with majority receiving normal saline (60.9%).Conclusions: Mainstay of treatment of dengue fever for paediatric patients is symptomatic along with focus on fluid management. Majority of drugs prescribed are from essential medicines lists formed by regulatory bodies. With dengue infections being a worldwide health hazard, more studies are needed to facilitate rational use of drugs in this disease.

Estilos ABNT, Harvard, Vancouver, APA, etc.

29

Trimble, Jennifer. "Why are our Jar Lids Crumbling?" Biodiversity Information Science and Standards 2 (13 de junho de 2018): e25928. http://dx.doi.org/10.3897/biss.2.25928.

Texto completo da fonte

Resumo:

Glass jars and lids used to house fluid preserved specimens in Natural History Museums are arguably one of the most important factors needed to ensure the long term conservation of the specimens in their collections. Additionally these jars are used to display specimens in exhibits, and are the first, and often the only line of defense against damage caused by evaporation of the fluids used to preserve specimens. The Harvard Museum of Natural History (HMNH) was established as the public face of the Museum of Comparative Zoology (MCZ) which opened its doors in 1859. Often, the Museum of Comparative Zoology loans fluid preserved invertebrates to the Museum of Natural History at Harvard for display. Of specific interest to this project is a permanent arthropod exhibit displaying a variety of specimens in jars ranging from 4 oz to 1 gallon in size. During a 7-year public exhibition loan, lids began to deteriorate while on display. Visually, these lids became cracked and webbed, and upon physical manipulation the plastic crumpled into pieces. Notably, this problem has not been observed in research collections where the specimens are permanently stored. Possible factors affecting lid stability include temperature and light, and other unknowns. Given the potential impact of this issue on all collections we investigated the possible causes of lid degradation and wish to bring attention to this issue. Photography was used to document the physical problem and MicroCT was used to investigate both cracked and new lids. The resulting images are displayed here. Although the composition of lids are explored, and other jar methods outlined, flint jars remain the most consistent, and sturdy option for a student oriented museum.

Estilos ABNT, Harvard, Vancouver, APA, etc.

30

Kuroda, Keigo, Takayuki Komori, Hirofumi Saito, Ryuta Ikoma, Yota Kimura, Hiroki Komatsuzaki, Kenta Suzuki et al. "Improved Performances of All-Polyimide Fluidic Devices Using Thermal Nanoimprinting". Applied Mechanics and Materials 300-301 (fevereiro de 2013): 1360–63. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.1360.

Texto completo da fonte

Resumo:

Flexible micropumps are important components for advanced microfluidic systems. Here, polyimide (PI) for flexible micropumps was focused on. This is because PI has many advantageous properties such as good biocompatibility, high thermal stability, and superior mechanical strength. However, the difficulty in realizing an all-PI micropump lies in fabricating microstructures on PI film surfaces. In this paper, we present improved performances of a flexible all-PI micropump fabricated using high-temperature hot embossing above 320 oC that is considerably higher than its glass transition temperature of 275 oC. The fabricated micropump had diffuser/nozzle valves and a chamber with 5 mm diameter, and it was functioned by vibrating a 2-µm-thick PI diaphragm with alternating air pressures outside of the diaphragm. The flow rate of deionized water in the micropump reached to 110 μl/min at 3 Hz.

Estilos ABNT, Harvard, Vancouver, APA, etc.

31

Suresh, Vignesh, Ong Qunya, Bera Lakshmi Kanta, Lee Yeong Yuh e Karen S. L. Chong. "Non-invasive paper-based microfluidic device for ultra-low detection of urea through enzyme catalysis". Royal Society Open Science 5, n.º 3 (março de 2018): 171980. http://dx.doi.org/10.1098/rsos.171980.

Texto completo da fonte

Resumo:

This work describes the design, fabrication and characterization of a paper-based microfluidic device for ultra-low detection of urea through enzyme catalysis. The microfluidic system comprises an entry port, a fluidic channel, a reaction zone and two electrodes (contacts). Wax printing was used to create fluidic channels on the surface of a chromatography paper. Pre-conceptualized designs of the fluidic channel are wax-printed on the paper substrate while the electrodes are screen-printed. The paper printed with wax is heated to cause the wax reflow along the thickness of the paper that selectively creates hydrophilic and hydrophobic zones inside the paper. Urease immobilized in the reaction zone catalyses urea into releasing ions and, thereby, generating a current flow between the electrodes. A measure of current with respect to time at a fixed potential enables the detection of urea. The methodology enabled urea concentration down to 1 pM to be detected. The significance of this work lies in the use of simple and inexpensive paper-based substrates to achieve detection of ultra-low concentrations of analytes such as urea. The process is non-invasive and employs a less cumbersome two-electrode assembly.

Estilos ABNT, Harvard, Vancouver, APA, etc.

32

Nellis, W. J. "The unusual magnetic fields of Uranus and Neptune". Modern Physics Letters B 29, n.º 01 (10 de janeiro de 2015): 1430018. http://dx.doi.org/10.1142/s021798491430018x.

Texto completo da fonte

Resumo:

Voyager 2 discovered the unusual non-dipolar and non-axisymmetric magnetic fields of Uranus and Neptune (U/N) in the 1980s. The cause of the unique fields of U/N has been a major scientific question since then. The answer lies in physical properties of fluids that generate planetary magnetic fields by a dynamo: convecting, electrically-conducting fluids at high pressures P and temperatures T in planetary interiors. Fluids in planets at finite temperatures are degenerate condensed matter because of high densities: T/T F ≪1, where T F is Fermi temperature. For metallic fluid H , T/T F ≈0.015. The vast majority of measured properties of fluids at planetary P/Ts were made under dynamic compression to few 100 GPa (1 Mbar) and few 1000 K. Fluids in U/N are discussed in terms of experimental data. Major conclusions: (i) Magnetic fields of U/N are made by metallic fluid H at outer planetary radii in the vicinity of the crossover from insulating fluid H 2 to metallic fluid H . (ii) Because those fields are made near outer surfaces, it is reasonable to observe non-dipolar non-axisymmetric fields. (iii) A proposed mechanism for the existence of those fields is decoupling of global rotation of U/N from convective motions in their dynamos, unlike Earth with a dipolar field.

Estilos ABNT, Harvard, Vancouver, APA, etc.

33

Ying-Kai, Xiao, Liao Bu-Yong, Liu Wei-Guo, Xiao Yun e Swihart George H. "Ion Exchange Extraction of Boron from Aqueous Fluids by Amber-lite IRA 743 Resin". Chinese Journal of Chemistry 21, n.º 8 (26 de agosto de 2010): 1073–79. http://dx.doi.org/10.1002/cjoc.20030210819.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

34

Huang, Lei, e Yang Cui. "Numerical Analysis of Flow and Heat Transfer Characteristics on Micro Couette Flow". Advanced Materials Research 960-961 (junho de 2014): 551–54. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.551.

Texto completo da fonte

Resumo:

In this paper, Couette flow is mainly discussed by studying the general flow behaviour mechanism and importing the velocity slip and temperature jump boundary condition. By analyzing velocity, temperature and pressure profiles at different Knudsen numbers, we concluded that Couette flow is driven by shear stress. The shear stress lies in stream direction. Viscous heat causes the increasing of the fluid’s temperature. With the increasing of Knudsen numbers, the increasing speed increases. It’s in the beginning of transition region that the heat flux has the maximum.

Estilos ABNT, Harvard, Vancouver, APA, etc.

35

Steinhausen, C., V. Gerber, A. Preusche, A. Dreizler, B. Weigand e G. Lamanna. "Feasibility Analysis On Transient Speed Of Sound Investigations Using Laser-Induced Thermal Acoustics In Evaporating Droplets". Proceedings of the International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics 20 (11 de julho de 2022): 1–12. http://dx.doi.org/10.55037/lxlaser.20th.75.

Texto completo da fonte

Resumo:

The development of combustion processes to achieve higher efficiencies has led to a continuous increase in operating pressures that exceed the critical point of the injected fluids. Especially for supercritical atmospheric conditions with respect to the injected fluid, the fundamental physics of the occurring mixing and evaporation processes are not fully understood. In particular, quantitative data for the validation of numerical simulations as well as analytical models remain sparse. Laser-induced thermal acoustic (LITA) is a seedless, non-intrusive measurement technique capable of detecting speed of sound data within these mixing processes. Until now, the feasibility of time-resolved LITA measurements in complex fluid dynamic processes has not been proven. Therefore, a feasibility analysis on transient speed of sound investigations using laser-induced thermal acoustics in evaporating droplets has been conducted. LITA has hereby been applied in the wake of a free-falling acetone droplet evaporating in a nitrogen atmosphere at nearcritical conditions. To the authors’ best knowledge, this is the first-time transient LITA measurements investigating macroscopic fluid phenomena, such as fluid injection and evaporation processes, have been conducted. The evaporation of the droplet has been simultaneously visualised using shadowgraphy, whereas time-resolved speed of sound data have been directly detected by a high-speed LITA system with a high-repetition rate excitation laser source.

Estilos ABNT, Harvard, Vancouver, APA, etc.

36

ZHOU, SHIQI. "EXTENDING SIMPLE WEIGHTED DENSITY APPROXIMATION FOR HARD SPHERE FLUID TO LENNARD–JONES FLUID (I): TEST". International Journal of Modern Physics B 19, n.º 32 (30 de dezembro de 2005): 4701–21. http://dx.doi.org/10.1142/s0217979205033078.

Texto completo da fonte

Resumo:

A theoretical formalism which can be combined with any hard sphere density functional approximations (DFA) to construct DFA for non-hard sphere fluids with a hard or soft core subjected to diverse external potentials is proposed. To show validity and power of the present formalism, we employ a simple weighted density approximation as an illustrating example. It is found that the resultant DFA for Lennard–Jones fluid under influences of diverse extenal potentials is in generally satisfactory agreement with corresponding simulational results even though the co-existence bulk fluid in the particle reservoir with which the non-uniform fluid under consideration is connected, is situated at "dangerous" regions. The significance of the present formalism lies in that it can be combined with any other hard sphere DFAs to construct DFAs for any non-hard sphere fluids with a hard or soft core.

Estilos ABNT, Harvard, Vancouver, APA, etc.

37

Abubacker, S., A. Attia e C. Alcock. "547 QUALITY IMPROVEMENT PROJECT IN PRESCRIBING THICKENERS POST STROKE". Age and Ageing 50, Supplement_2 (junho de 2021): ii1—ii4. http://dx.doi.org/10.1093/ageing/afab117.03.

Texto completo da fonte

Resumo:

Abstract Introduction One of the therapies that Speech and Language Therapy SALT) provide is a level to which fluids must be thickened to ensure a safe swallow. The thickening agent should be supplied by the hospital to the patient on discharge. This requires the thickening agent to be added to the electronic discharge letter (EDL) and, ‘To Take Out’ (TTO) medication list by ward doctors. Method samples of 10-20 EDLs, taken from SALT list of stroke patients between interventions. Cycle 1: SALT were initially attempting to contact the physicians responsible for writing the EDL Cycle 2: SALT kept a register of patients that they had seen the recommended thickener prescription. This list was kept in the doctor’s office. This list was mentioned in handover every morning for doctors to update EDL Cycle 3: The aforementioned list was continued, and responsibility for transfer onto EDLs was delegated to the on call Senior House Officer (SHO) Cycle 4: In addition to the above measures, custom made stickers were added to the prescription chart as an indicator to add thickener to the TTO. Results Cycle 1: 20% Prescribed (n = 10) Cycle 2: 78% Prescribed n = 18) Cycle 3: 93% Prescribed (n = 14) Cycle 4: 100% Prescribed (n = 10). Conclusion This project has built up a multidisciplinary system to a multidisciplinary problem. Through repeated cycles and system improvement, we have seen and demonstrated a collaborative effort resulting in consistent and improving results.

Estilos ABNT, Harvard, Vancouver, APA, etc.

38

Nevstruyev, Viktor, e Olga Kozlova. "Geodynamic and structural factors of porphyritic objects localization in Sikhote-Alin". E3S Web of Conferences 56 (2018): 04020. http://dx.doi.org/10.1051/e3sconf/20185604020.

Texto completo da fonte

Resumo:

Ore bearing porphyritic systems of Sikhote-Alin form linear zones in Cretaceous volcanic belt. They are limited to zones of tectonic disturbances at Moho depths of 19-25 mi (30-40 km). Pacific slab lies at around 340 miles (548 km) below the volcanic belt, which matches the slab depth of porphyritic deposits formation belts in the Andes and Indonesia-Tonga region. Formation of porphyry copper systems is linked to the processes of metalliferous fluids intrusion at slab destruction areas near asthenosphere.

Estilos ABNT, Harvard, Vancouver, APA, etc.

39

Mazzeo, M. D., M. Ricci e C. Zannoni. "The Linked Neighbour List (LNL) method for fast off-lattice Monte Carlo simulations of fluids". Computer Physics Communications 181, n.º 3 (março de 2010): 569–81. http://dx.doi.org/10.1016/j.cpc.2009.11.006.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

40

Estes, Joel D. "Imperfection in Paradise: Reading Genesis 2 through the Lens of Disability and a Theology of Limits". Horizons in Biblical Theology 38, n.º 1 (19 de abril de 2016): 1–21. http://dx.doi.org/10.1163/18712207-12341313.

Texto completo da fonte

Resumo:

Genesis 2 has been interpreted from many angles, but rarely through the lens of disability studies. Such a reading, however, provides a necessary corrective to interpretations that import into the text idealistic notions of bodily perfection and thereby inadvertently disenfranchise those with disabilities. By attending to the range of bodily experiences and the fluidity of embodied existence, this article seeks to shed new light on Genesis 2 and on the wider task of theological anthropology. More specifically, reading Genesis 2 with and for those with disabilities lifts up three essential themes in the text that all express human limitation as a good aspect of God’s creation: embodiment, imperfection, and relationship.

Estilos ABNT, Harvard, Vancouver, APA, etc.

41

Tijjani Lawal Hassan, Abdul Rahman Mohd Kasim e Mohd Haziezan Hassan. "A Comparative Analysis on Single and Two Phase Casson Fluid under Aligned Magnetic Field Effect and Newtonian Heating". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 110, n.º 2 (15 de dezembro de 2023): 206–18. http://dx.doi.org/10.37934/arfmts.110.2.206218.

Texto completo da fonte

Resumo:

This research investigates the impact of aligned magnetic fields and Newtonian heating on single and two-phase Casson fluid (a mixture of Casson fluid and dust particles), addressing a notable knowledge gap in comparing the two fluid models under the same effect. The problem of this study lies in the need to understand the similarities or differences in the reaction of these fluids to external forces. To achieve this, the governing equations for both fluids were formulated using a boundary layer approximation and numerical solutions were obtained utilizing the 'bvp4c' function within MATLAB software. The analysis revealed comparable trends in flow and thermal behaviour between the two fluids, it also showed that the magnetic field exerted a more pronounced influence on flow properties compared to forces such as buoyancy and inertia. Conversely, Newtonian heating conditions had a more significant impact on thermal properties compared to the magnetic field. Additionally, the single-phase Casson fluid showed higher velocity and temperature profiles than the two-phase Casson fluid phases. These findings suggest that the presence of dust particles reduces the velocity and temperature magnitudes of the Casson fluid.

Estilos ABNT, Harvard, Vancouver, APA, etc.

42

Ali, Rehab Abd Al Hussin, Hashim Ali Yusr e Soudad S. Bassam. "The magnetic switch manufacturing by using ferrofluid and ferrofluid doped copper nanoparticles". Iraqi Journal of Physics (IJP) 18, n.º 46 (30 de agosto de 2020): 39–45. http://dx.doi.org/10.30723/ijp.v18i46.511.

Texto completo da fonte

Resumo:

The splendor of ferrofluid lies on two important facts. It is a natural fluid that flows and at the same time responds to the external magnetic field. Unlike other conventional fluids. Through this study it can be said that if a substance (ferroeluid) is placed in an effective external magnetic field, the response of the substance depends on two important factors. The intensity of the light falling on the material as well as the purity of the substance (ferrofluid) therefore affect the results (hysteres loop) resulting.

Estilos ABNT, Harvard, Vancouver, APA, etc.

43

Dong, Jin Xin, Xie Zhao Lin e Ji Ying. "Coupled Electrostatic-Structures-Fluidic Analysis of a Nozzle/Diffuser Diaphragm Micropump". Advanced Materials Research 317-319 (agosto de 2011): 1609–13. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1609.

Texto completo da fonte

Resumo:

Micropump is the key component in the micro total analytical system. The major technical impediment in improving the performance of this micro-device lies in the lack of understanding the physical phenomena and their interactions of electric, mechanical, and fluidic fields for performing their intended functions. Because of the complexity of the micropump, the full coupled numerical analysis is extremely needed. This paper presents for the results of such fully coupled simulations. CFDRC® was used for the transient analysis of an electrostatically actuated micropump. The results show that the dynamic characteristics of fluid in the micropump and the vibration of flexible diaphragm are highly interactive each other. The flow rectification of the nozzle/diffuser will work only after the pressure difference between the two ends of valve have reached at a critical value. In the pump chamber, the fluidic press distribution almost independent of the space variation. Due to the increasing demands for accuracy, the nonlinear features of viscous loss of the fluid can no longer be neglected or simplified, but have to be taken into account in detail.

Estilos ABNT, Harvard, Vancouver, APA, etc.

44

Senga, Mikiko, Alpha Koi, Lina Moses, Nadia Wauquier, Philippe Barboza, Maria Dolores Fernandez-Garcia, Etsub Engedashet et al. "Contact tracing performance during the Ebola virus disease outbreak in Kenema district, Sierra Leone". Philosophical Transactions of the Royal Society B: Biological Sciences 372, n.º 1721 (10 de abril de 2017): 20160300. http://dx.doi.org/10.1098/rstb.2016.0300.

Texto completo da fonte

Resumo:

Contact tracing in an Ebola virus disease (EVD) outbreak is the process of identifying individuals who may have been exposed to infected persons with the virus, followed by monitoring for 21 days (the maximum incubation period) from the date of the most recent exposure. The goal is to achieve early detection and isolation of any new cases in order to prevent further transmission. We performed a retrospective data analysis of 261 probable and confirmed EVD cases in the national EVD database and 2525 contacts in the Contact Line Lists in Kenema district, Sierra Leone between 27 April and 4 September 2014 to assess the performance of contact tracing during the initial stage of the outbreak. The completion rate of the 21-day monitoring period was 89% among the 2525 contacts. However, only 44% of the EVD cases had contacts registered in the Contact Line List and 6% of probable or confirmed cases had previously been identified as contacts. Touching the body fluids of the case and having direct physical contact with the body of the case conferred a 9- and 20-fold increased risk of EVD status, respectively. Our findings indicate that incompleteness of contact tracing led to considerable unmonitored transmission in the early months of the epidemic. To improve the performance of early outbreak contact tracing in resource poor settings, our results suggest the need for prioritized contact tracing after careful risk assessment and better alignment of Contact Line Listing with case ascertainment and investigation. This article is part of the themed issue ‘The 2013–2016 West African Ebola epidemic: data, decision-making and disease control’.

Estilos ABNT, Harvard, Vancouver, APA, etc.

45

Botton, R. "Lits fluidisés pour l'industrie chimique. Extrapolation et amélioration des catalyseurs. Deuxième partie : Stratégie n'utilisant que des expériences de laboratoire. Troisième partie : Etudes théoriques, réalités expérimentales, suggestions". Oil & Gas Science and Technology 55, n.º 1 (janeiro de 2000): 87–121. http://dx.doi.org/10.2516/ogst:2000005.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

46

HUKE, B., M. LÜCKE, P. BÜCHEL e CH JUNG. "Stability boundaries of roll and square convection in binary fluid mixtures with positive separation ratio". Journal of Fluid Mechanics 408 (10 de abril de 2000): 121–47. http://dx.doi.org/10.1017/s0022112099007648.

Texto completo da fonte

Resumo:

Rayleigh–Bénard convection in horizontal layers of binary fluid mixtures heated from below with realistic horizontal boundary conditions is studied theoretically using multi-mode Galerkin expansions. For positive separation ratios the main difference between the mixtures and pure fluids lies in the existence of stable three-dimensional patterns near onset in a wide range of the parameter space. We evaluated the stationary solutions of roll, crossroll, and square convection and we determined the location of the stability boundaries for many parameter combinations thereby obtaining the Busse balloon for roll and square patterns.

Estilos ABNT, Harvard, Vancouver, APA, etc.

47

Haciislamoglu, M., e J. Langlinais. "Non-Newtonian Flow in Eccentric Annuli". Journal of Energy Resources Technology 112, n.º 3 (1 de setembro de 1990): 163–69. http://dx.doi.org/10.1115/1.2905753.

Texto completo da fonte

Resumo:

A common assumption for annular flow used in the petroleum industry is that the inner pipe is concentrically located inside the flow geometry; however, this is rarely the case, even in slightly deviated wells. Considering the increasing number of directional and horizontal wells, the flow behavior of drilling fluids and cement slurries in eccentric annuli is becoming particularly important. In this paper, the governing equation of laminar flow is numerically solved using a finite differences technique to obtain velocity and viscosity profiles of yield-power law fluids (including Bingham plastic and power law fluids). Later, the velocity profile is integrated to obtain flow rate. Results show that the velocity profile is substantially altered in the annulus when the inner pipe is no longer concentric. Stagnant regions of flow were calculated in the low side of the hole. Viscosity profiles predicted for an eccentric annulus show how misleading the widely used single-value apparent viscosity term can be for non-Newtonian fluids. Profiles of velocity and viscosity in concentric and varying eccentric annuli are presented in 3-D and 2-D contour plots for a better visualization of annular flow. Frictional pressure loss gradient versus flow rate relationship data for power law fluids is generated using the computer program. Later, this data is fitted to obtain a simple equation utilizing regressional analysis, allowing for a quick calculation of friction pressure losses in eccentric annuli. For a given flow rate, frictional pressure loss is reduced as the inner pipe becomes eccentric. In most cases, about a 50-percent reduction in frictional pressure loss is predicted when the inner pipe lies on the low side.

Estilos ABNT, Harvard, Vancouver, APA, etc.

48

Spagnoli, Federico, Teresa Romeo, Franco Andaloro, Simonepietro Canese, Valentina Esposito, Marco Grassi, Erik Delos Biscotti, Patrizia Giordano e Giovanni Bortoluzzi. "Seeps and Tectonic Structure of the Hydrothermal System of the Panarea Volcanic Complex (Aeolian Islands, Tyrrhenian Sea)". Geosciences 14, n.º 3 (23 de fevereiro de 2024): 60. http://dx.doi.org/10.3390/geosciences14030060.

Texto completo da fonte

Resumo:

High-definition bathymetry mapping, combined with the measurement of dissolved benthic fluxes and water column biogeochemical properties, allows for a description of new biogeochemical processes around the Panarea Volcanic island. Investigations focused on the CO2 releases from the bottom sea on the east of the Panarea volcanic complex provided insights into the geological setup of the marine area east and south of the Panarea Island. Between the Panarea Island and the Basiluzzo Islet lies a SW-NE-stretching graben structure where a central depression, the Smoking Land Valley, is bounded by extensional faults. Abundant acidic fluids rich in dissolved inorganic Carbon are released on the edges of the graben, along the extensional faults, either diffusely from the seafloor, from hydrothermal chimneys, or at the center of craters of different sizes. The precipitation of iron dissolved in the acidic fluids forms Fe-oxyhydroxides bottom sea crusts that act as a plug, thus preventing the release of the underlying gases until their mounting pressure generates a bursting release. This process is cyclic and results in intermittent gas release from the bottom, leaving extinct craters and quiescent chimneys. The measurement of dissolved benthic fluxes allowed us to estimate the volcanic DIC venting at 15 Mt of CO2 over the past 10,000 years. The fluxes are not distributed homogeneously but rather concentrate along fractures and fault planes, which facilitate their rise to the seafloor. The acidic fluids released affect the chemical properties and structure of the water column through the formation of layers with a lower pH under the pycnocline, which can limit volcanic CO2 release to the atmosphere. Further and continuous monitoring and investigation of the area are needed in order to complete a thorough picture of the variations in fluid releases through time and space. The importance of such monitoring lies in the development of a new method for detecting and quantifying the diffusive dissolved benthic fluxes on a volcanic sea bottom affected by hydrothermal seeps.

Estilos ABNT, Harvard, Vancouver, APA, etc.

49

Siddiqui, A. M., Ahsan Walait, T. Haroon e Hameed Ashraf. "On the study of stationary points and uniform thickness of PTT fluid film on a vertically upward moving belt". Canadian Journal of Physics 94, n.º 10 (outubro de 2016): 982–91. http://dx.doi.org/10.1139/cjp-2014-0591.

Texto completo da fonte

Resumo:

This paper investigates the thin film flow of Phan-Thien Tanner (PTT) fluid on a vertically moving belt. Three different models, namely, the upper convected Maxwell model (UCM), linear version of Phan-Thien Tanner model (LPTT), and exponential version of Phan-Thien Tanner model (EPTT), are taken into consideration. Exact expressions for velocity profiles, flow rates, average velocities, film thicknesses, shear stresses, and normal stresses are obtained. Special consideration is given to the predictions of stationary points in withdrawal of these fluids from the belt. It is observed that the stationary point of the UCM model lies closer to the free surface and the stationary point of the LPTT model lies in the middle of the stationary points of UCM and EPTT models. It is also observed that the stationary points tend to move towards the belt with the increase in Stokes number, Deborah number, and elongational parameter. Graphical results are also presented for various dimensionless flow parameters.

Estilos ABNT, Harvard, Vancouver, APA, etc.

50

Rishi, Dewan. "Artificial lift methods in petroleum industry - a review". i-manager’s Journal on Future Engineering and Technology 17, n.º 3 (2022): 34. http://dx.doi.org/10.26634/jfet.17.3.18925.

Texto completo da fonte

Resumo:

Artificial lift system adds energy to the fluid column in the wellbore to start and improve production from a hydrocarbon well. It is necessary when natural drives of the reservoir do not support satisfactory rates or make fluids to flow by any means at times. It is one of the main techniques to improve oil production from wells. These are intended to overcome bottom hole pressure to enable a well to deliver at the ideal rate. This includes either utilizing a pump or infusing gas to lessen its hydrostatic pressure to give extra lift pressure down hole. Different types of artificial lifts are used in the petroleum industry. Their use depends on their design, formation type and various reservoir conditions. This paper has a detailed description of various types of artificial lifts, their design and application. The advantages and disadvantages that are associated with each artificial lift system play a crucial role in the decision of selection of the most convenient system in a particular reservoir.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Artigos de revistas sobre o tema "Lits fluidisé"

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos