Dynamic simulation of an electrorheological fluid

International Nuclear Information System (INIS)

Bonnecaze, R.T.; Brady, J.F.

1992-01-01

A molecular-dynamics-like method is presented for the simulation of a suspension of dielectric particles in a nonconductive solvent forming an electrorheological fluid. The method accurately accounts for both hydrodynamic and electrostatic interparticle interactions from dilute volume fractions to closest packing for simultaneous shear and electric fields. The hydrodynamic interactions and rheology are determined with the Stokesian dynamics methodology, while the electrostatic interactions, in particular, the conservative electrostatic interparticle forces, are determined from the electrostatic energy of the suspension. The energy of the suspension is computed from the induced particle dipoles by a method previously developed [R. T. Bonnecaze and J. F. Brady, Proc. R. Soc. London, Ser. A 430, 285 (1990)]. Using the simulation, the dynamics can be directly correlated to the observed macroscopic rheology of the suspension for a range of the so-called Mason number, Ma, the ratio of viscous to electrostatic forces. The simulation is specifically applied to a monolayer of spherical particles of areal fraction 0.4 with a particle-to-fluid dielectric constant ratio of 4 for Ma=10 -4 to ∞. The effective viscosity of the suspension increases as Ma -1 or with the square of the electric field for small Ma and has a plateau value at large Ma, as is observed experimentally. This rheological behavior can be interpreted as Bingham plastic-like with a dynamic yield stress. The first normal stress difference is negative, and its magnitude increases as Ma -1 at small Ma with a large Ma plateau value of zero. In addition to the time averages of the rheology, the time traces of the viscosities are presented along with selected ''snapshots'' of the suspension microstructure

Electrorheology of a zeolite/silicone oil suspension under dc fields

International Nuclear Information System (INIS)

Tian, Yu; Meng, Yonggang; Wen, Shizhu

2001-01-01

The electrorheology of electrorheological (ER) fluids based on zeolite and silicone oil under dc fields was investigated at room temperature. ER fluids with volume fractions of 27% and 30% were prepared and tested. When a 5 kV/mm dc field was applied, shear yield stress of 26.7 kPa was obtained for the latter. The ER fluid with a higher volume fraction of zeolite had a higher current density and a higher shear yield stress under the same electric field. Compared with other ER fluids based on zeolite particles with low shear yield stress, the zeolite employed by us was found to have high dielectric constant and conductivity. The high permittivity mismatch and the high conductivity mismatch of the components of the fluids were considered responsible for the high shear yield stress. [copyright] 2001 American Institute of Physics

State of the art of medical devices featuring smart electro-rheological and magneto-rheological fluids

Directory of Open Access Journals (Sweden)

Jong-Seok Oh

2017-10-01

Full Text Available Recently, smart fluids have drawn significant attention and growing a great interest in a broad range of engineering applications such as automotive and medical areas. In this article, two smart fluids called electro-rheological (ER fluid and magneto-rheological (MR fluid are reviewed in terms of medical applications. Especially, this article describes the attributes and inherent properties of individual medical and rehabilitation devices. The devices surveyed in this article include multi-degree-of-freedom haptic masters for robot surgery, thin membrane touch panels for braille readers, sponge-like tactile sensors to feel human tissues such as liver, rehabilitation systems such as prosthetic leg, and haptic interfaces for dental implant surgery. The operating principle, inherent characteristics and practical feasibility of each medical device or system are fully discussed in details.

Temperature-dependent electrorheological effect and its description with respect to dielectric spectra

Czech Academy of Sciences Publication Activity Database

Plachý, T.; Sedlačík, M.; Pavlínek, V.; Stejskal, Jaroslav; Pedro Graça, M.; Cadillon Costa, L.

2016-01-01

Roč. 27, č. 7 (2016), s. 880-886 ISSN 1045-389X. [International Conference on Electrorheological Fluids and Magnetorheological Suspensions /14./ - ERMR2014. Granada, 07.07.2014-11.07.2014] R&D Projects: GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : electrorheology * aniline oligomers * carbonization Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.255, year: 2016

Characteristics of an electro-rheological fluid valve used in an inkjet printhead

Science.gov (United States)

Lee, C. Y.; Liao, W. C.

2000-12-01

The demand for non-impact printers has grown considerably with the advent of personal computers. For entry-level mass production, two drop-on-demand techniques have dominated the market - piezoelectric impulse and thermal-bubble types. However, the high cost of the piezoelectric printhead and the thermal problems encountered by the thermal-bubble jet printhead have restrained the use of these techniques in an array-type printhead. In this study, we propose a new design of printhead with an electro-rheological (ER) fluid acting as a control medium. The ER fluid valve controls the ink ejection. As a first step toward developing this new printhead, the characteristics of an ER fluid valve which controls the deflection of the elastic diaphragm are investigated. First, the response of a prototype is tested experimentally to prove the feasibility of using this ER valve for the inkjet printhead. Then, the discretized governing equation of the ER valve is derived. Finally, the prototype of the ER valve is fabricated. The experimental measurement based on the sinusoidal response verifies both the theoretical analysis and the controllability of the response of the ER valve by the applied electric field.

PREFACE: 13th International Conference on Electrorheological Fluids and Magnetorheological Suspensions (ERMR2012)

Science.gov (United States)

Unal, Halil Ibrahim

2013-02-01

Conference photograph The 13th International Conference on Electrorheological Fluids and Magnetorheological Suspensions (ERMR2012) was held in Ankara, Turkey at Gazi University in the Architect Kemaleddin historical hall on 2-6 July 2012. The first International Conference on Electrorheological Fluids and Magnetorheological Suspensions took place nearly 25 years ago and this conference continued the same tradition by providing an arena for researchers around the world to present their new research findings in these fields, and gave them the opportunity to learn about the latest research and technology and to renew their acquaintances. The meeting brought together scientists and engineers in multidisciplinary areas such as chemical engineering, mechanical engineering, materials science and engineering, physics, chemistry and polymer science and technology, to explore the state-of-art technology, identify key areas to be focused on and discuss their problems/issues. All oral presentations were held in a single session to enhance the interactions between the scientists and engineers. The ERMR2012 Conference included plenary lectures given by prominent leaders in their respective fields. About 130 participants from more than 50 organizations attended the conference and 15 plenary speeches, 64 oral presentations and 57 poster presentations took place in the following areas: (i) synthesis, characterization and processing of novel ER/MR materials, (ii) dynamics, chain and structure formation of ER/MR materials, (iii) ER/MR elastomers, ferrogels and their characterizations, (iv) rheological techniques and measurements of ER/MR materials, (v) modeling and simulations of ER/MR materials, (vi) device development and control techniques and (vii) applications of ER/MR materials. The ERMR2012 International Conference began with Turkish classical music performed by the musicians of the Ministry of Culture and Tourism. Rector Professor Dr R Ayhan welcomed the participants and the

Comparison of electrorheological measurements using different geometries in two commercial rotational rheometers

Czech Academy of Sciences Publication Activity Database

Peer, Petra; Filip, Petr; Stěnička, M.; Pavlínek, V.

2017-01-01

Roč. 2, č. 1 (2017), s. 20-24 ISSN 2405-4658 Institutional support: RVO:67985874 Keywords : Anton Paar MCR 501 * electrocells * electrorheology * Gemini CVOR 150 * rheological characteristics Subject RIV: BK - Fluid Dynamics OBOR OECD: Fluids and plasma physics (including surface physics)

Desenvolvimento de fluidos aquosos com bentonita para perfuração de poços de petróleo onshore Development of aqueous fluids with bentonite clay for drilling of onshore oil wells

Directory of Open Access Journals (Sweden)

R. C. A. M Nascimento

2010-06-01

Full Text Available Devido aos grandes desafios encontrados na perfuração de poços, há a necessidade de se desenvolver fluidos com propriedades adequadas e capazes de atender todas as exigências da perfuração, como elevada capacidade de carreamento de sólidos e alta lubricidade, como também fluidos ambientalmente corretos. O grau de impacto dos fluidos de perfuração no meio ambiente depende especialmente do tipo de fluido utilizado, se de base aquosa, oleosa, sintética ou mesmo de base ar. Portanto, é de fundamental importância o desenvolvimento de fluidos com características específicas em cada etapa da perfuração. Sendo assim, este trabalho objetivou o desenvolvimento de fluidos aquosos, com baixo teor de sólidos e propriedades reológicas, de filtração e lubricidade adequadas à perfuração de poços de petróleo onshore. Os fluidos foram formulados utilizando em sua composição bentonita sódica industrializada, aditivos poliméricos e lubrificantes, em diferentes concentrações. O estudo reológico, de filtração e lubricidade mostrou que os fluidos apresentam comportamento pseudoplástico e que os aditivos selecionados desempenham com êxito suas funções de modificadores reológicos, redutores de filtrado e agente lubrificante. Além disto, ficou evidenciada a necessidade de aditivos lubrificantes em fluidos aquosos contendo argila bentonítica e polímeros. A adição de 1% de lubrificante no fluido é suficiente para adequar a capacidade lubrificante dos fluidos.Due to challenges encountered in drilling wells, there is a need to develop fluids that have properties suitable and able to meet all the requirements of drilling, such as, high capacity for carrying of solid and high lubricity. Besides that, they need to be environmentally friend. The degree of impact of drilling fluids in the environment depends on the type of fluid used, if water or oil or synthetic or air based. It is therefore of fundamental importance to develop

Design and dynamic modeling of electrorheological fluid-based variable-stiffness fin for robotic fish

Science.gov (United States)

Bazaz Behbahani, Sanaz; Tan, Xiaobo

2017-08-01

Fish actively control their stiffness in different swimming conditions. Inspired by such an adaptive behavior, in this paper we study the design, prototyping, and dynamic modeling of compact, tunable-stiffness fins for robotic fish, where electrorheological (ER) fluid serves as the enabling element. A multi-layer composite fin with an ER fluid core is prototyped and utilized to investigate the influence of electrical field on its performance. Hamilton's principle is used to derive the dynamic equations of motion of the flexible fin, and Lighthill's large-amplitude elongated-body theory is adopted to estimate the hydrodynamic force when the fin undergoes base-actuated rotation. The dynamic equations are then discretized using the finite element method, to obtain an approximate numerical solution. Experiments are conducted on the prototyped flexible ER fluid-filled beam for parameter identification and validation of the proposed model, and for examining the effectiveness of electrically controlled stiffness tuning. In particular, it is found that the natural frequency is increased by almost 40% when the applied electric field changes from 0 to 1.5× {10}6 {{V}} {{{m}}}-1.

Electrorheology of graphene oxide.

Science.gov (United States)

Zhang, Wen Ling; Liu, Ying Dan; Choi, Hyoung Jin; Kim, Sang Guk

2012-04-01

Novel polarizable graphene oxide (GO) particles with oxidized groups on their edge and basal planes were prepared by a modified Hummers method, and their electro-responsive electrorheological (ER) characteristics when dispersed in silicone oil were examined with and without an electric field applied. The fibrillation phenomenon of this GO-based electro-responsive fluid was also observed via an optical microscope under an applied electric field. Both flow curves and dielectric spectra of the ER fluid were measured using a rotational rheometer and a LCR meter, respectively. Its viscoelastic properties of both storage and loss moduli were also examined using a vertical oscillation rheometer equipped with a high voltage generator, finding that the GO-based smart ER system behaves as a viscoelastic material under an applied electric field.

Electrorheological properties of suspensions of polypyrrole coated titanate nanorods

Czech Academy of Sciences Publication Activity Database

Mrlík, M.; Pavlínek, V.; Saha, P.; Quadrat, Otakar

2011-01-01

Roč. 21, č. 5 (2011), 52365_1-52365_7 ISSN 1430-6395 R&D Projects: GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : polypyrrole * nanorods * electrorheology Subject RIV: BK - Fluid Dynamics Impact factor: 1.000, year: 2011

Torque Measurement of 3-DOF Haptic Master Operated by Controllable Electrorheological Fluid

Directory of Open Access Journals (Sweden)

Oh Jong-Seok

2015-02-01

Full Text Available This work presents a torque measurement method of 3-degree-of-freedom (3-DOF haptic master featuring controllable electrorheological (ER fluid. In order to reflect the sense of an organ for a surgeon, the ER haptic master which can generate the repulsive torque of an organ is utilized as a remote controller for a surgery robot. Since accurate representation of organ feeling is essential for the success of the robot-assisted surgery, it is indispensable to develop a proper torque measurement method of 3-DOF ER haptic master. After describing the structural configuration of the haptic master, the torque models of ER spherical joint are mathematically derived based on the Bingham model of ER fluid. A new type of haptic device which has pitching, rolling, and yawing motions is then designed and manufactured using a spherical joint mechanism. Subsequently, the field-dependent parameters of the Bingham model are identified and generating repulsive torque according to applied electric field is measured. In addition, in order to verify the effectiveness of the proposed torque model, a comparative work between simulated and measured torques is undertaken.

Concentrações de FSH, LH, estradiol, progesterona e histamina no soro, no fluido peritoneal e no fluido folicular de mulheres com e sem endometriose FSH, LH, estradiol, progesterone, and histamine concentrations in serum, peritoneal fluid and follicular fluid of women with and without endometriosis

Directory of Open Access Journals (Sweden)

Andréa Pereira de Lima

2006-11-01

Full Text Available OBJETIVOS: relatos da literatura mostram que não há dados conclusivos sobre a associação entre a endometriose e as concentrações de hormônios envolvidos no controle da reprodução. Este estudo foi realizado para determinar as concentrações de FSH, LH, estradiol (E, progesterona (P e histamina (Hi no soro, no fluido peritoneal e no fluido folicular de mulheres com e sem endometriose. MÉTODOS: a extensão da doença foi estadiada de acordo com a American Fertility Society classification (1997. Para a coleta de soro e de fluido peritoneal foram selecionadas 28 mulheres com endometriose submetidas à laparoscopia diagnóstica (18 mulheres inférteis com endometriose I-II e dez mulheres inférteis com endometriose III-IV. Para o grupo controle, foram selecionadas 21 mulheres férteis submetidas à laparoscopia para esterilização tubárea. O fluido folicular foi obtido de 39 mulheres inférteis submetidas a fertilização in vitro (21 mulheres com endometriose e 18 mulheres sem endometriose. RESULTADOS: as concentrações de FSH e LH no soro, no fluido peritoneal e no fluido folicular não diferiram significativamente entre os grupos. As concentrações de E e P no fluido peritoneal foram significativamente mais baixas em mulheres inférteis com endometriose (E: 154,2±15,3 para estágios I-II e 89,3±9,8 ng/mL para estágios III-IV; P: 11,2±1,5 para estágios I-II e 7,6±0,8 ng/mL para estágios III-IV em comparação com mulheres controle (E: 289,1±30,1; P: 32,8±4,1 ng/mL (Testes de Kruskal-Wallis/Dunn; pPURPOSE: literature reports show that there are no conclusive data about the association between endometriosis and the concentrations of hormones involved in the control of reproduction. Thus, the present study was undertaken to determine FSH, LH, estradiol (E, progesterone (P, and histamine (Hi concentrations in serum, peritoneal fluid and follicular fluid of women with and without endometriosis. METHODS: the extent of the disease

An effect of carbonization on the electrorheology of poly(p-phenylenediamine)

Czech Academy of Sciences Publication Activity Database

Plachý, T.; Sedlačík, M.; Pavlinek, V.; Morávková, Zuzana; Hajná, Milena; Stejskal, Jaroslav

2013-01-01

Roč. 63, November (2013), s. 187-195 ISSN 0008-6223 R&D Projects: GA ČR GA202/09/1626 Institutional support: RVO:61389013 Keywords : carbonization * electrorheology * poly(p-phenylenediamine) Subject RIV: BK - Fluid Dynamics Impact factor: 6.160, year: 2013

Influence of liquid phase on nanoparticle-based giant electrorheological fluid.

Science.gov (United States)

Gong, Xiuqing; Wu, Jinbo; Huang, Xianxiang; Wen, Weijia; Sheng, Ping

2008-04-23

We show that the chemical structures of silicone oils can have an important role in the giant electrorheological (GER) effect. The interaction between silicone oils and solid nanoparticles is found to significantly influence the ER effect. By increasing the kinematic viscosity of silicone oils, which is a function of siloxane chain length, sol-like, gel-like and clay-like appearances of the constituted ER fluids were observed. Different functional-group-terminated silicone oils were also employed as the dispersing media. Significant differences of yield stress were found. We systematically study the effect of siloxane chain lengths on the permeability of oils traveling through the porous spaces between the particles (using the Washburn method), oils adsorbed on the particles' surface (using FT-IR spectra), as well as their particle size distribution (using dynamic light scattering). Our results indicate the hydrogen bonds are instrumental in linking the silicone oil to GER solid particles, and long chain lengths can enhance the agglomeration of the GER nanoparticles to form large clusters. An optimal oil structure, with hydroxyl-terminated silicone oil and a suitable viscosity, was chosen which can create the highest yield stress of ∼300 kPa under a 5 kV mm(-1) DC electric field.

Modeling and Design of an Electro-Rheological Fluid Based Haptic System for Tele-Operation of Space Robots

Science.gov (United States)

Mavroidis, Constantinos; Pfeiffer, Charles; Paljic, Alex; Celestino, James; Lennon, Jamie; Bar-Cohen, Yoseph

2000-01-01

For many years, the robotic community sought to develop robots that can eventually operate autonomously and eliminate the need for human operators. However, there is an increasing realization that there are some tasks that human can perform significantly better but, due to associated hazards, distance, physical limitations and other causes, only robot can be employed to perform these tasks. Remotely performing these types of tasks requires operating robots as human surrogates. While current "hand master" haptic systems are able to reproduce the feeling of rigid objects, they present great difficulties in emulating the feeling of remote/virtual stiffness. In addition, they tend to be heavy, cumbersome and usually they only allow limited operator workspace. In this paper a novel haptic interface is presented to enable human-operators to "feel" and intuitively mirror the stiffness/forces at remote/virtual sites enabling control of robots as human-surrogates. This haptic interface is intended to provide human operators intuitive feeling of the stiffness and forces at remote or virtual sites in support of space robots performing dexterous manipulation tasks (such as operating a wrench or a drill). Remote applications are referred to the control of actual robots whereas virtual applications are referred to simulated operations. The developed haptic interface will be applicable to IVA operated robotic EVA tasks to enhance human performance, extend crew capability and assure crew safety. The electrically controlled stiffness is obtained using constrained ElectroRheological Fluids (ERF), which changes its viscosity under electrical stimulation. Forces applied at the robot end-effector due to a compliant environment will be reflected to the user using this ERF device where a change in the system viscosity will occur proportionally to the force to be transmitted. In this paper, we will present the results of our modeling, simulation, and initial testing of such an

Comparison of electrorheological characteristics obtained for two geometries: parallel plates and concentric cylinders

Czech Academy of Sciences Publication Activity Database

Peer, Petra; Filip, Petr; Stěnička, M.; Pavlínek, V.

2014-01-01

Roč. 59, č. 3 (2014), s. 221-235 ISSN 0001-7043 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : electrorheology * parallel plates * concentric cylinders * silicone oil * PANI powders Subject RIV: BK - Fluid Dynamics

Spontaneous electrorheological effect in nematic liquid crystals under Taylor-Couette flow configuration

Science.gov (United States)

Dhar, Jayabrata; Chakraborty, Suman

2017-09-01

Electrorheological (ER) characteristics of Nematic Liquid Crystals (NLCs) have been a topic of immense interest in the field of soft matter physics owing to its rheological modulation capabilities. Here we explore the augmentation in rheological characteristics of the nematic fluid confined within the annular region of the concentric cylindrical space with an Electrical Double Layer (EDL) induced at the fluid-substrate interface due to certain physico-chemical interactions. Using a Taylor-Couette flow configuration associated with an EDL induced at the inner cylinder wall, we show that a spontaneous electrorheological effect is generated owing to the intrinsic director anisotropy and structural order of complex nematic fluids. We seek to find the enhancement in torque transfer capability due to the inherent electrorheological nature of the nematic medium, apart from exploiting the innate nature of such homogeneous media to remain free of coagulation, a fact which makes it an excellent candidate for the applications in microfluidic environment. Our analysis reveals that with stronger induced charge density within the EDL, the apparent viscosity enhances, which, in turn, augments torque transfer across the concentric cylinder. The velocity profile tends to flatten in comparison to the classical circular Couette flow in annular geometry as one increases the surface charge density. We further observe a more pronounced ER effect for the nematic medium having larger electrical permittivity anisotropy. Besides the torque transfer qualifications, we also explore the distinct scenarios, wherein the same NLC medium exhibits shear thinning and shear thickening characteristics. The present configuration of the efficient torque transfer mechanism may be proficiently downscaled to micro-level and is relevant in the fabrication of micro-clutch and micro-dampers.

An electrorheological investigation of PVB solutions in connection with their electrospinning qualities

Czech Academy of Sciences Publication Activity Database

Peer, Petra; Stěnička, M.; Pavlínek, V.; Filip, Petr; Kuřitka, I.; Brus, Jiří

2014-01-01

Roč. 39, October (2014), s. 115-121 ISSN 0142-9418 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 ; RVO:61389013 Keywords : electrospinning * nanofibres * polyvinylbutyral * electrorheology * polymer solution Subject RIV: BK - Fluid Dynamics; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.240, year: 2014

Electrorheological Properties of Suspensions Prepared from Polystyrene- Block- Polyisoprene Copolymer

OpenAIRE

YAVUZ, Mustafa

2014-01-01

Considerable scientific and industrial interest is currently being focused on a class of materials known as electrorheological (ER) fluids, which display remarkable rheological behaviour, being able to convert rapidly and repeatedly from a liquid to solid when an electric field (E) is applied or removed. In this article, the synthesis, characterization, partial hydrolysis and ER properties of polystyrene- block}-polyisoprene copolymer (COP) were investigated. The block copolymer was ...

Investigation de fluides électrorhéologiques sur la base des matériaux hybrides

OpenAIRE

Marins , Jéssica Alves ,

2014-01-01

Electrorheology is an area has been exploring the application of these organic-inorganic hybrid compounds, to obtain better performance in electrorheological properties. Electro-rheological fluids consist of a colloidal dispersion, where the liquid is non-conductive and the particles dispersed in the fluid are able of polarized at presence of electric field. When the fluids ER are subjected to an external electric field the rheological properties change, and may increase or decrease the appar...

Comparison of electrorheological measurements based on different methods of electric field generation

Czech Academy of Sciences Publication Activity Database

Peer, Petra; Stěnička, M.; Filip, Petr; Pavlinek, V.

2014-01-01

Roč. 24, č. 4 (2014), 42875-1-42875-4 ISSN 1430-6395 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : rheology * electrorheology * rheometry * PANI powder * silicone oil Subject RIV: BK - Fluid Dynamics Impact factor: 1.078, year: 2014 http://www.ar.ethz.ch/TMPPDF/24394938472.192/ApplRheol_24_42875.pdf

Proposal to neutralize acid fluids from wells in the Los Humeros, Pue., geothermal field; Propuesta para la neutralizacion de fluidos acidos provenientes de pozos del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Flores Armenta, Magaly del Carmen; Ramirez Montes, Miguel; Garcia Cuevas, Juan Manuel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

2009-07-15

Neutralizing an acidic fluid consists of adding a sodium hydroxide solution to neutralize the H group of acids, therefore increasing the pH. The injection of sodium hydroxide has to be continuous and at a proper depth inside the well to protect against the corrosion of casing and surface equipment. Neutralization is a common practice used in geothermal fields, such as at The Geysers in the US and Miravalles in Costa Rica-places where aggressive fluids cause problems for extracting and using geothermal fluids commercially. A zone surrounding wells H-4, H-16 and H-29 in the northern section of the Los Humeros, Pue., geothermal field, known as the Colapso Central, has shown evidence of aggressively acidic fluids. Several wells drilled in the area had to be repaired, thus plugging and isolating the deepest production zones. Well H-43 was drilled two years ago in the northern zone of the field, and even though it is not located in the aggressive-fluid zone, the well presents mineralogical features possibly indicating the presence of acidic fluids. Therefore, before producing this well it has been proposed we install a neutralization system with general characteristics presented in this paper. The system will prevent corrosion that up to now has prevented exploitation of the deep portion of Colapso Central, helping to develop the field in a more profitable way. [Spanish] Neutralizar un fluido acido consiste en agregarle una solucion de hidroxido de sodio. Esto neutraliza el grupo de acidos H y en consecuencia aumenta el pH. La inyeccion de hidroxido de sodio se realiza de manera continua y a una profundidad adecuada dentro del pozo para proteger a la tuberia y a todo el equipo superficial contra la corrosion. La neutralizacion es una practica comun que se viene realizando en campos como Los Geysers en Estados Unidos y en Miravalles, Costa Rica, donde la presencia de fluidos agresivos causa problemas en la extraccion y aprovechamiento del fluido geotermico con fines

Polyaniline in electrorheology

Czech Academy of Sciences Publication Activity Database

Quadrat, Otakar; Stejskal, Jaroslav

2006-01-01

Roč. 12, č. 3 (2006), s. 352-361 ISSN 1226-086X R&D Projects: GA ČR GA202/06/0419 Institutional research plan: CEZ:AV0Z40500505 Keywords : electrorheology * suspensions of polyaniline * polyaniline derivatives Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.957, year: 2006

Polyaniline Coated Core-Shell Typed Stimuli-Responsive Microspheres and Their Electrorheology

Directory of Open Access Journals (Sweden)

Yu Zhen Dong

2018-03-01

Full Text Available Functional core-shell-structured particles have attracted considerable attention recently. This paper reviews the synthetic methods and morphologies of various electro-stimuli responsive polyaniline (PANI-coated core-shell-type microspheres, including PANI-coated Fe3O4, SiO2, Fe2O3, TiO2, poly(methyl methacrylate, poly(glycidyl methacrylate, and polystyrene along with their electrorheological (ER characteristics when prepared by dispersing these particles in an insulating medium. In addition to the various rheological characteristics and their analysis, such as shear stress and yield stress of their ER fluids, this paper summarizes some of the mechanisms proposed for ER fluids to further understand the responses of ER fluids to an externally applied electric field.

Two-phase characteristics of the feeding fluid of Cerro Prieto IV wells (Mexico) obtained by gas equilibrium; Caracteristicas bifasicas del fluido de alimentacion de pozos de Cerro Prieto IV (Mexico), obtenidas por equilibrio gaseoso

Energy Technology Data Exchange (ETDEWEB)

Barragan-Reyes, Rosa Maria; Arellano-Gomez, Victor Manuel; Portugal-Marin, Enrique [Instituto de Investigaciones Electricas (Mexico); De Leon-Vivar, Jesus [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)

2008-10-15

The gas composition of fluids produced by CP IV geothermal wells from the Cerro Prieto field was studied in order to identify different types of fluids entering the wells by estimating their temperature and excess steam. A method based on the Fischer Tropsch reaction and H2S equilibrium with pyrite-pyrrhotite as mineral buffer (FTHSH3) was used. The results for the reservoir natural state indicated the presence of fluids with heterogeneous reservoir temperature (between 275 and 310 degrees Celsius) and excess steam values, which were found from negative (boiled liquid that has lost steam when flowing to the well) to one (steam phase with zero liquid saturation). The study for individual wells in which boiling processes were identified, showed that through time, the feeding fluids consist of a two-phase mixture with different liquid/steam proportions. Also, the results suggested that a steam phase could occur at CP IV which is added to the feeding fluid, depending on the operation conditions of the wells. The origin of this steam could be the boiling of the deeper liquid due to a pressure drop. [Spanish] Se estudio la composicion gaseosa de los fluidos producidos por pozos geotermicos del sector CP IV del campo de Cerro Prieto para tratar de distinguir aportes de fluidos diferentes mediante la estimacion de su temperatura de yacimiento y del exceso de vapor. Se utilizo un metodo de equilibrio gaseoso basado en la reaccion de Fischer Tropsch y el equilibrio combinado pirita-pirrotita (FT-HSH3). Los resultados obtenidos indican que en el estado inicial del yacimiento existen fluidos que muestran heterogeneidad en los valores de temperatura de yacimiento (entre 275 y 310 grados Celsius), asi como en el exceso de vapor con valores desde negativos (liquido que despues de ebullir ha perdido vapor en su trayecto hacia el pozo) hasta uno (vapor con cero saturacion de liquido). El estudio individual de los pozos con fenomenos de ebullicion muestra que a traves del tiempo

Electrorheological suspensions of laponite in oil: rheometry studies.

Science.gov (United States)

Parmar, K P S; Méheust, Y; Schjelderupsen, Børge; Fossum, J O

2008-03-04

We have studied the effect of an external direct current (DC) electric field ( approximately 1 kV/mm) on the rheological properties of colloidal suspensions consisting of aggregates of laponite particles in a silicone oil. Microscopy observations show that, under application of an electric field greater than a triggering electric field Ec approximately 0.6 kV/mm, laponite aggregates assemble into chain- and/or columnlike structures in the oil. Without an applied electric field, the steady-state shear behavior of such suspensions is Newtonian-like. Under application of an electric field larger than Ec, it changes dramatically as a result of the changes in the microstructure: a significant yield stress is measured, and under continuous shear the fluid is shear-thinning. The rheological properties, in particular the dynamic and static shear stress, were studied as a function of particle volume fraction for various strengths (including null) of the applied electric field. The flow curves at constant shear rate can be scaled with respect to both the particle fraction and electric field strength onto a master curve. This scaling is consistent with simple scaling arguments. The shape of the master curve accounts for the system's complexity; it approaches a standard power-law model at high Mason numbers. Both dynamic and static yield stresses are observed to depend on the particle fraction Phi and electric field E as PhibetaEalpha, with alpha approximately 1.85 and beta approximately 1 and 1.70 for the dynamic and static yield stresses, respectively. The yield stress was also determined as the critical stress at which there occurs a bifurcation in the rheological behavior of suspensions that are submitted to a constant shear stress; a scaling law with alpha approximately 1.84 and beta approximately 1.70 was obtained. The effectiveness of the latter technique confirms that such electrorheological (ER) fluids can be studied in the framework of thixotropic fluids. The method

Electrorheology of aniline oligomers

Czech Academy of Sciences Publication Activity Database

Mrlík, M.; Sedlačík, M.; Pavlínek, V.; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav; Sáha, P.

2013-01-01

Roč. 291, č. 9 (2013), s. 2079-2086 ISSN 0303-402X R&D Projects: GA ČR GA202/09/1626 Institutional support: RVO:61389013 Keywords : anilin e oligomers * polyaniline * electrorheology Subject RIV: JI - Composite Materials Impact factor: 2.410, year: 2013

Chemical changes in well fluids from the Los Humeros geothermal field: Evidences for deep recharge; Cambios quimicos en fluidos de pozos del campo geotermico de Los Humeros: Evidencia de recarga profunda

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Flores Armenta, Magaly [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Tovar Aguado, Rigoberto [Comision Federal de Electricidad (Mexico)

2008-07-15

Fluid (water and steam) chemical changes over time were studied in 20 wells in the Los Humeros, Mexico, geothermal field for the purpose of correlating such changes with physical processes occurring in the reservoir due to exploitation. Most wells (except well H-1) produce high-enthalpy fluids with almost no liquid, making gas geochemistry important in this field. Liquid-phase studies include fluid classification, determination of water-rock equilibrium state, and reservoir-temperature estimates. Changes in gas composition through time were studied using the Fischer-Tropsch (FT) reaction and the combined balance pyrite-hematite-magnetite (HSH2) as the buffer controlling H{sub 2}S fluid concentration. Data for most wells from 1987-1995 and 2000-2005 indicate the presence of deeper-fluid recharge, with maximum temperatures occurring in 1994-95 and 2005. The estimated temperature in well H-1 in 1994 was 305 degrees Celsius and the estimated temperature in well H-7 was 338 degrees Celsius in 1995. Temperature estimations from 2005 data were 222 degrees Celsius in well H-1D and 350 degrees Celsius in well H-7. These results are considered caused by the entrance of deeper fluids due to the increase of secondary permeability, which in turn is related to the seismicity increase in the zone. At the same time, re-injection returns in the steam phase were identified in well discharges during 1995-2000 by means of the FT-HSH2 diagram. [Spanish] Se realizo un estudio de los cambios quimicos ocurridos en fluidos (liquido y vapor) de veinte pozos del campo geotermico de Los Humeros, Pue., Mexico, con objeto de investigar la ocurrencia de procesos del yacimiento relacionados con la explotacion. La mayoria de los pozos (excepto el pozo H-1) se caracterizan por producir descargas de alta entalpia con escasa produccion de liquido, por lo que en este campo la geoquimica de gases juega un papel importante. El estudio de la fase liquida incluyo la clasificacion de los fluidos, la

Geochemical and isotopic behavior of fluids from wells in Los Humeros geothermal field, Puebla, Mexico; Comportamiento geoquimico e isotopico del fluido de los pozos del campo geotermico Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Tovar Aguado, Rigoberto; Lopez Romero, Oscar [Comision Federal de Electricidad, Los Humeros, Puebla (Mexico)

1999-12-01

In general the wells in Los Humeros geothermal fields produce sodium bicarbonate water with a low salinity because the fluids are produced from the shallow part of the reservoir. The fluids in wells H-33 and H-6 are sodium chloride: the first influenced by fluids from deep levels in the reservoir and the second by fluids coming only from the deeps part of the reservoir. Fluid mixture for other wells depends on operating conditions. To date, it has been difficult with the geothermetric temperatures to establish the underground flow directions and whether or not an infiltration of shallow low-temperature fluids occurs. Well H-16 has the lowest-temperature fluid in the liquid phase, which suggests infiltration of shallow local fluids-a result corroborated by an isotopic study. Using the methodology of Giggenbach and Goguel, we found that the gases are in equilibrium with the liquid phase at temperatures between 275 and 325 Celsius degrees. The maximum temperature is measured in wells H-12 and H-9, where good agreement exists between this temperature and those calculated with a geothermometer of CO{sub 2}/H{sub 2} . Isotopic results show, in general, that the wells with the highest levels of oxygen-18 are those with the highest geothermetric temperatures (CO{sub 2}/H{sub 2})- both in the north (H-35 and H-9) and in the south (H-6 and H-12)-results that agree with the temperatures measured in the field. The initial thermodynamic conditions of the wells show that they produce fluids from the liquid region. This fact, together with the low salinity, permit the application of the D' Amore methodology, with which the estimations of vapor fractions in the reservoir are relatively low. [Spanish] En general, los pozos del campo geotermico de Los Humeros producen agua del tipo bicarbonato sodico con baja salinidad. Esto se debe a que extraen fluidos de la parte somera del yacimiento. Los pozos H-33 y H-6 son clorurados sodicos; el primero por cierta influencia de la zona

Graphene oxide nanocomposites and their electrorheology

International Nuclear Information System (INIS)

Zhang, Wen Ling; Liu, Ying Dan; Choi, Hyoung Jin

2013-01-01

Graphical abstract: - Highlights: • GO-based PANI, NCOPA and PS nanocomposites are prepared. • The nanocomposites are adopted as novel electrorheological (ER) candidates. • Their critical ER characteristics and dielectric performance are analyzed. • Typical ER behavior widens applications of GO-based nanocomposites. - Abstract: Graphene oxide (GO), a novel one-atom carbon system, has become one of the most interesting materials recently due to its unique physical and chemical properties in addition to graphene. This article briefly reviews a recent progress of the fabrication of GO-based polyaniline, ionic N-substituted copolyaniline and polystyrene nanocomposites. The critical electrorheological characteristics such as flow response and yield stress from rheological measurement, relaxation time and achievable polarizability from dielectric analysis are also analyzed

Effects of confinement & surface roughness in electrorheological flows

Science.gov (United States)

Helal, Ahmed; Telleria, Maria J.; Wang, Julie; Strauss, Marc; Murphy, Mike; McKinley, Gareth; Hosoi, A. E.

2014-11-01

Electrorheological (ER) fluids are dielectric suspensions that exhibit a fast, reversible change in rheological properties with the application of an external electric field. Upon the application of the electric field, the material develops a field-dependent yield stress that is typically modeled using a Bingham plastic model. ER fluids are promising for designing small, cheap and rapidly actuated hydraulic devices such as rapidly-switchable valves, where fluid flowing in a microchannel can be arrested by applying an external electric field. In the lubrication limit, for a Bingham plastic fluid, the maximum pressure the channel can hold, before yielding, is a function of the field-dependent yield stress, the length of the channel and the electrode gap. In practice, the finite width of the channel and the surface roughness of the electrodes could affect the maximum yield pressure but a quantitative understanding of these effects is currently lacking. In this study, we experimentally investigate the effects of the channel aspect ratio (width/height) and the effects of electrode roughness on the performance of ER valves. Based on this quantitative analysis, we formulate new performance metrics for ER valves as well as design rules for ER valves that will help guide and optimize future designs.

Initial isotopic geochemistry ({delta} 18 O, {delta} D) of fluids from wells of the Los Humeros, Pue., geothermal field; Geoquimica isotopica ({delta} 18 O, {delta} D) inicial de fluidos de pozos del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Ramirez Montes, Miguel; Tovar Aguado, Rigoberto [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

2010-01-15

Isotopic data ({delta} 18 O, {delta} D) from fluids from production wells at the Los Humeros, Pue., geothermal field were analyzed to investigate the possible origin of these fluids and the dominant processes of the reservoir at its initial state. According to pre-exploitation data, it is suggested the Los Humeros reservoir fluids are made of a mixture of meteoric water of very light isotopic composition (paleo-fluids) and andesitic water. The relationship {delta} D vs {delta} 18 O from pre-exploitation data indicates the produced fluids are composed of a mixture of (at least) two fluids with distinct isotopic compositions. At the more enriched end of the mixing relationship are the isotopic compositions of the wells H-23 and H-18 (located in the southern area of the field), while the lighter fluids were found in well H-16 (originally) and then in well H-16 (repaired). It was found that the liquid phases of deep wells are more enriched in {delta} 18 O while the shallow wells present lower values, suggesting a convection process at the initial state. Based on this isotopic profile, it is considered that even the production depths of the wells H-1, H-12 and H-16 (repaired) are just about the same, but their respective isotopic compositions are quite different. The {delta} 18 O value for well H-16 (repaired) seems to be that of condensate steam, while the corresponding values for wells H-1 and H-12 fall within the value interval of the deep wells (H-23). This suggests wells H-1 and H-12 are collecting very deep fluids enriched in {delta} 18 O. These results could be useful in creating a conceptual model of the reservoir. [Spanish] Se analizaron datos isotopicos ({delta}18 O, {delta}D) de los fluidos de pozos productores del campo geotermico de Los Humeros, Pue., para investigar el posible origen de los fluidos asi como los procesos dominantes del yacimiento en su estado inicial. De acuerdo con datos previos a la explotacion, se plantea que los fluidos del yacimiento

One-pot synthesis of polyaniline-doped in mesoporous TiO2 and its electrorheological behavior

International Nuclear Information System (INIS)

Wei Chuan; Zhu Yihua; Yang Xiaoling; Li Chunzhong

2007-01-01

A class of hybrid organic-inorganic composite for application in electrorheological (ER) fluid was prepared by using a simple one-pot method. Transmission electron microscopy (TEM) image shows that the synthesized material had a mesoporous structure. X-ray diffraction (XRD) further proves that the pore size is about 7.4 nm with an anatase TiO 2 framework. Fourier transform infrared (FT-IR) and nitrogen sorption curve reveal polyaniline (PANI) is doped in mesochannels. The ER behaviors of PANI/TiO 2 in silicone oil are invesigated with different doping degrees under different electric fields. The results obtained provide more insight into the role of proper doping in ER fluid

Estudo da reologia e espessura do reboco de fluidos de perfuração: influência de dispersantes e umectante aniônicos Study of rheology and filter-cake thickness of drilling fluids: influence of anionic dispersants and surfactant

Directory of Open Access Journals (Sweden)

K. V. Farias

2006-12-01

Full Text Available Este trabalho teve como objetivo avaliar a influência de aditivos dispersantes e umectante aniônicos nas viscosidades aparente (VA e plástica (VP, no volume de filtrado (VF e na espessura do reboco (ER de fluidos de perfuração á base de água e argila bentonítica. Os fluidos foram preparados com 4,86% em massa de argila bentonítica e os aditivos estudados nas concentrações de 0,025 g a 0,300 g/24,3 g de argila seca para os dispersantes e de 0,005 g a 0,300 g/24,3 g de argila seca para o umectante aniônico. Os resultados mostraram que a espessura do reboco foi significativamente reduzida pela presença do umectante aniônico, sem, contudo, alterar as taxas de filtração dos fluidos estudados. Como era esperado, observou-se a redução nos valores de VA e VP após a aditivação dos fluidos com os aditivos dispersantes. Além disso, a mudança brusca nos valores de VA, VP e ER dos fluidos aditivados com o umectante aniônico na concentração de 0,100 g/24,3 g de argila seca evidenciou que esta é muito provavelmente a concentração micelar crítica deste aditivo.The aim of this work is to evaluate the influence of dispersants additives and anionic surfactants in the apparent viscosity (AV, plastic viscosity (PV, water loss (WL and filter-cake thickness (FT of the water based drilling fluids with bentonite clay. The fluids were prepared with 4.86 wt % of bentonite clay and the additives studied in the concentrations of 0.025 g to 0.300 g/24.3 g of dry clay for the dispersants and 0.005 g to 0.300 g/24.3 g of dry clay for the anionic surfactant. The results had shown the filter-cake thickness was significantly reduced by the presence of the anionic surfactant, without, however, to modify the taxes of filtration of studied fluids. As it was waited, it was observed the reduction in the values of AV and PV after treating the fluids with dispersants addictives. Also, the abrupt change in the values of AV, PV and FT of fluids treated with

A haptic sensor-actor-system based on ultrasound elastography and electrorheological fluids for virtual reality applications in medicine.

Science.gov (United States)

Khaled, W; Ermert, H; Bruhns, O; Boese, H; Baumann, M; Monkman, G J; Egersdoerfer, S; Meier, A; Klein, D; Freimuth, H

2003-01-01

Mechanical properties of biological tissue represent important diagnostic information and are of histological relevance (hard lesions, "nodes" in organs: tumors; calcifications in vessels: arteriosclerosis). The problem is, that such information is usually obtained by digital palpation only, which is limited with respect to sensitivity. It requires intuitive assessment and does not allow quantitative documentation. A suitable sensor is required for quantitative detection of mechanical tissue properties. On the other hand, there is also some need for a realistic mechanical display of those tissue properties. Suitable actuator arrays with high spatial resolution and real-time capabilities are required operating in a haptic sensor actuator system with different applications. The sensor system uses real time ultrasonic elastography whereas the tactile actuator is based on electrorheological fluids. Due to their small size the actuator array elements have to be manufactured by micro-mechanical production methods. In order to supply the actuator elements with individual high voltages a sophisticated switching and control concept have been designed. This haptic system has the potential of inducing real time substantial forces, using a compact lightweight mechanism which can be applied to numerous areas including intraoperative navigation, telemedicine, teaching, space and telecommunication.

Composição de argilas organofílicas obtida com tensoativo não-iônico para fluidos de perfuração base orgânica Compositions of organoclays obtained with nonionic surfactant for organic base drilling fluids

Directory of Open Access Journals (Sweden)

F. K. A. Sousa

2011-06-01

Full Text Available Este trabalho tem como objetivo o estudo do efeito da composição de misturas de argilas bentoníticas organofílicas na reologia de fluidos de perfuração base orgânica. As composições foram estudadas por meio de delineamento de misturas, viscosidade aparente, plástica e limite de escoamento e dos testes recomendados pelo Instituto Americano de Petróleo, API (peso específico, estabilidade elétrica e volume de filtrado. Os resultados foram comparados aos obtidos com fluido padrão utilizado pela Petrobrás. Dentre as composições desenvolvidas, duas apresentaram potencial de utilização em fluidos de perfuração base orgânica, atendendo a maioria das propriedades. Foram desenvolvidas composições contendo as argilas de qualidade "inferior" (Bofe e verde-lodo em maior quantidade e o mínimo da argila Chocolate UBM, considerada como a melhor argila da região das minas de Boa Vista, PB, para uso em fluidos de perfuração.This paper aims to study the effect of compositions of bentonite organoclays for drilling fluids containing organic base. The compositions were studied using the mixture design of experiment methodology and their performance evaluated by rheological behavior (flow curves, the initial gel, final gel apparent viscosity, plastic, and flow limit and the tests recommended by API (specific gravity, electrical stability and filtrate volume. Results were compared to those obtained with standard fluid used by Petrobrás. The results showed that among the developed compositions, two compositions showed promising potential for use in organic drilling fluids, achieving most of the limits of the normalization. Compositions containing high amount of low quality clays (Bofe and verde-lodo and a minimum of high quality clay (Chocolate of the mines of Boa Vista PB were developed for using in drilling fluids operation.

Recession in a linear stepper motor based on piezoelectric actuator and electrorheological clampers

International Nuclear Information System (INIS)

Li, Cuihong; Meng, Yonggang; Tian, Yu

2012-01-01

A linear inchworm-type stepper motor based on piezoelectric actuator and comb shape electrorheological (ER) clampers was developed and tested. A recession phenomenon in the movement of the motor was found and was significantly affected by the driving voltage of the piezoelectric actuator and ER fluids. A dynamic model to analyze the mechanism of the recession was established. The force ratio of the viscoelastic clamping force (applied high electric field) to the viscous damping force (zero field) of ER fluids is the critical factor which determines the recession. The ratio is also affected by the extension or contraction rate of the actuator during movement, which is affected by the charging and discharging processes. With a relatively large distance between the clamper electrodes and a small displacement activated by the extension of the piezoelectric actuator, the instantaneous shear rate might not be sufficiently high, preventing ER fluids from attaining a shear-thickened and high-strength state. The ratio of yield strength to the viscous strength of ER fluids during movement should be as large as possible to reduce the recession displacement. (paper)

Materiales de la asignatura Mecánica de Fluidos (curso 2011-2012)

OpenAIRE

Salcedo Díaz, Raquel; Martín Gullón, Ignacio

2012-01-01

En este material están contenidos los conceptos básicos del curso de Mecánica de fluidos, de tercer curso de la titulación de Ingeniero Químico de la Universidad de Alicante. En dicho curso se aborda el flujo interno de fluidos, el flujo externo sólido-fluido y las operaciones de separación basadas en el flujo de fluidos.

Fabrication of poly(o-anisidine) coated silica core-shell microspheres and their electrorheological response

Science.gov (United States)

Lee, Chul Joo; Choi, Hyoung Jin

2017-11-01

In this work, silica/poly(o-anisidine) (POA) core-shell structured microspheres were synthesized by coating the silica core surface with POA with a help of a chemical grafting agent, N-[(3-trimethoxylsilyl)-propyl] aniline. The synthesized silica microspheres were then applied as a polymer/inorganic composite particle-based electrorheological (ER) fluid. The morphology of the silica/POA microspheres was examined by using both transmission electron microscopy and scanning electron microscopy, while their thermal properties and chemical structure were checked by thermogravimetric analysis and Fourier-transform infrared spectroscopy, respectively. The ER properties of the silica/POA particle-based ER fluid were examined by using a Couette-type rotational rheometer equipped with a high-voltage power supplier and analyzed by the Bingham model and modified Mason number. In order to obtain additional information about the electrical polarization properties, the dielectric spectra were measured by an LCR meter and fitted by using the Cole-Cole equation. Furthermore, suspension stability of the ER fluid was tested using Turbiscan.

Supersonic flutter suppression of electrorheological fluid-based adaptive panels resting on elastic foundations using sliding mode control

International Nuclear Information System (INIS)

Hasheminejad, Seyyed M; Nezami, M; Aryaee Panah, M E

2012-01-01

Brief reviews on suppressing panel flutter vibrations by various active control strategies as well as utilization tunable electrorheological fluids (ERFs) for vibration control of structural systems are presented. Active suppression of the supersonic flutter motion of a simply supported sandwich panel with a tunable ERF interlayer, and coupled to an elastic foundation, is subsequently investigated. The structural formulation is based on the classical beam theory along with the Winkler–Pasternak foundation model, the ER fluid core is modeled as a first-order Kelvin–Voigt material, and the quasi-steady first-order supersonic piston theory is employed to describe the aerodynamic loading. Hamilton’s principle is used to derive a set of fully coupled dynamic equations of motion. The generalized Fourier expansions in conjunction with the Galerkin method are then employed to formulate the governing equations in the state space domain. The critical dynamic pressures at which unstable panel oscillations (coalescence of eigenvalues) occur are obtained via the p-method for selected applied electric field strengths (E = 0,2,4 kV mm −1 ). The classical Runge–Kutta time integration algorithm is subsequently used to calculate the open-loop aeroelastic response of the system in various basic loading configurations (i.e. uniformly distributed blast, gust, sonic boom, and step loads), with or without an interacting soft/stiff elastic foundation. Finally, a sliding mode control synthesis (SMC) involving the first six natural modes of the structural system is set up to actively suppress the closed-loop system response in supersonic flight conditions and under the imposed excitations. Simulation results demonstrate performance, effectiveness, and insensitivity with respect to the spillover of the proposed SMC-based control system. Limiting cases are considered and good agreements with the data available in the literature as well as with the computations made by using the

Electrorheological effect of Ti-bearing blast furnace slag with different TiC contents at 1500°C

Science.gov (United States)

Yue, Hong-rui; Jiang, Tao; Zhang, Qiao-yi; Duan, Pei-ning; Xue, Xiang-xin

2017-07-01

The electrorheological properties of CaO-SiO2-Al2O3-MgO-TiO2-TiC slags were investigated to enhance understanding of the effect of TiC addition on the viscosity, yield stress, and fluid pattern of Ti-bearing slags in a direct-current electric field. The viscosities and shear stresses of 4wt% and 8wt% TiC slags were found to increase substantially with increasing electric field intensity, whereas virtually no rheological changes were observed in the 0wt% TiC slag. The Herschel-Bulkley model was applied to demonstrate that the fluid pattern of the 4wt% TiC slag was converted from that of a Newtonian fluid to that of a Bingham fluid in response to the applied electric field; and the static yield stress increased linearly with the square of the electric field intensity.

Uso de fluidos dieléctricos a base de aceites en maquinado por descargas eléctricas por penetración/Case Study for the use of Vegetable Dielectric Fluid in Die-Sink Electro Discharge Machining (EDM.

Directory of Open Access Journals (Sweden)

Mauro Suarez Paipa

2012-12-01

Full Text Available En procesos de mecanizado por descarca eléctrica EDM (Electro Dischage Machining el fluido dieléctrico normalmente está compuesto por derivados del petróleo. El objetivo de este trabajo es evaluar fluidos alternativos a los tradicionales. En este contexto, fueron analizados 5 fluidos dieléctricos de origen vegetal, comparándolos con el desempeño de kerosene y aceite mineral. El material mecanizado fue acero rápido M2, usando parámetros de desbaste para electrodos de cobre y grafito. Fueron medidas las tasas de remoción de material (TMR, el desgaste de los electrodos, la rugosidad y la morfología de la superficie mecanizada. Los dieléctricos de origen vegetal presentaron un desempeño competitivo usando electrodos de cobre y grafito.EDM process commoly use petroleum based died fluids.The aim of this work is to evaluate alternative fluidsto traditional mineral ones. It was analyzed 5 different dielectric fluids derived of seeds. They were comparedwith kerosene and a mineral oil. The workpiece was speed-steel M2. The machining parameters were preestablished for working with copper and graphite electrodes. The material removal rate, the wear rate ofthe electrodes, the finishing and morphology of machined surface were all measured. Vegetable based oils showed a competitive performance using cooper and graphite electrodes when compared with mineral based oils.

The electrorheological properties of nano-sized SiO2 particle materials doped with rare earths

International Nuclear Information System (INIS)

Liu Yang; Liao Fuhui; Li Junran; Zhang Shaohua; Chen Shumei; Wei Chenguan; Gao Song

2006-01-01

Electrorheological (ER) materials of pure SiO 2 and SiO 2 doped with rare earths (RE = Ce, Gd, Y) (non-metallic glasses (silicates)) were prepared using Na 2 SiO 3 and RECl 3 as starting materials. The electrorheological properties are not enhanced by all rare earth additions. The material doped with Ce exhibits the best ER performance

Tema 1. Mecánica de sólidos y fluidos (Curso 2009-2010)

OpenAIRE

Caballero Caballero, María Teresa; Miret Marí, Juan José; Espinosa Tomás, Julián; Pérez Rodríguez, Jorge

2009-01-01

Sólidos, líquidos y gases: densidad; Elasticidad en sólidos: tensión y deformación; Elasticidad en fluidos: presión; Temperatura y dilatación térmica; Estática de fluidos; Fenómenos de superficie: tensión superficial, capilaridad; Dinámica de fluidos ideales; Fluidos reales: viscosidad.

Characterisation of electrorheological liquids based on suspensions; Charakterisierung von elektrorheologischen Fluessigkeiten auf Basis von Suspensionen

Energy Technology Data Exchange (ETDEWEB)

Johnston, Lucien [FLUDICON GmbH, Darmstadt (Germany); Schneider, Steffen; Schneider, Ines [Wehrwissenschaftliches Institut fuer Werk-, Explosiv- und Betriebsstoffe (WIWEB), Erding (Germany)

2008-08-15

Electrorheological fluids (ERF) belong to the group of 'Smart Materials'. These suspensions have the favourable property of changing their viscosity in an electrical field. This change is spontaneous (response time under 1 ms), continuously variable (from a thin fluid to a semi-solid state), reversible and can be repeated as often as desired. ER-fluids also have certain sensory properties. The sum of these properties allows for the design of mechanical valves which have no moving components. Instead of adjusting the cross-sectional area of a valve orifice, variations in pressure drop over the valve are realised by altering the viscosity of the fluid itself. The simplicity and effectiveness of the ER-effect has lead to a diverse range of applications which make use of this property - from continuously variable hydraulic shock absorbers to highly dynamic actuators. Since the discovery of the ER-effect in the 1904s, many ER-fluids have been developed and tested. This article will discuss the properties and composition of an industrially successful ER-suspension as well as highlighting its implementation in a diverse range of engineering applications. (orig.)

Results of test of acid fluids neutralization in the well H-43, Los Humeros geothermal field, Puebla; Resultados de la prueba de neutralizacion de fluidos acidos en el pozo H-43, campo geotermico de Los Humeros, Puebla

Energy Technology Data Exchange (ETDEWEB)

Flores Armenta, Magaly del Carmen; Ramirez Montes, Miguel; Sandoval Medina, Fernando; Rosales Lopez, Cesar [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

2011-07-15

The well H-43 was drilled in Los Humeros Geothermal Field, Pue., in 2007 and 2008. When well production was measured, it was found the well produced acid fluids with high corrosion potential. Then it was decided to try to neutralize the acidity of the H-43 fluids by adding a solution of sodium hydroxide. This is a basic substance used to neutralize mainly the acid groups H+, and the goal was to raise the pH of the fluids to minimize its corrosive features. First sodium hydroxide was injected into the well to protect the casing of 244.4 mm (9 5/8 in) against corrosion and then all the surface installations. It was possible to increase the pH of the well fluid from 5.2 up to 6.8 without altering the steam production, thus demonstrating the neutralization procedure is feasible. The approximate costs of the neutralization tests performed, including equipment for the proposed neutralization system, the neutralizer (NaOH), and drilling the well are about 71.4 million pesos (around 5.5 million USD). We estimate a benefit/cost ratio of 1.5 and a return on investment in five years, considering the income from energy sales at present value. [Spanish] El pozo H-43 fue perforado en el campo de Los Humeros, Pue., en 2007-2008, y al evaluar su produccion se encontro que producia fluidos acidos de alto potencial corrosivo. Se decidio por tanto realizar una prueba para neutralizar la acidez de los fluidos de este pozo, que consistio en agregarle una solucion de hidroxido de sodio. Esta es una sustancia basica que neutraliza principalmente los grupos acidos H+, con lo que se buscaba aumentar el pH del fluido lo necesario para reducir al maximo su caracter corrosivo. La inyeccion del hidroxido de sodio se realizo dentro del pozo a fin de proteger de la corrosion a la tuberia de revestimiento de 244.4 mm (9 5/8 pulgadas), y posteriormente a todos los equipos superficiales. Como resultado de la prueba, se logro aumentar el pH del fluido producido por el pozo de 5.2 a un maximo de 6

Volume-constrained optimization of magnetorheological and electrorheological valves and dampers

Science.gov (United States)

Rosenfeld, Nicholas C.; Wereley, Norman M.

2004-12-01

This paper presents a case study of magnetorheological (MR) and electrorheological (ER) valve design within a constrained cylindrical volume. The primary purpose of this study is to establish general design guidelines for volume-constrained MR valves. Additionally, this study compares the performance of volume-constrained MR valves against similarly constrained ER valves. Starting from basic design guidelines for an MR valve, a method for constructing candidate volume-constrained valve geometries is presented. A magnetic FEM program is then used to evaluate the magnetic properties of the candidate valves. An optimized MR valve is chosen by evaluating non-dimensional parameters describing the candidate valves' damping performance. A derivation of the non-dimensional damping coefficient for valves with both active and passive volumes is presented to allow comparison of valves with differing proportions of active and passive volumes. The performance of the optimized MR valve is then compared to that of a geometrically similar ER valve using both analytical and numerical techniques. An analytical equation relating the damping performances of geometrically similar MR and ER valves in as a function of fluid yield stresses and relative active fluid volume, and numerical calculations are provided to calculate each valve's damping performance and to validate the analytical calculations.

Electrorheological properties of suspensions of hollow globular titanium oxide/polypyrrole particles

Czech Academy of Sciences Publication Activity Database

Sedlačík, M.; Mrlík, M.; Pavlínek, V.; Sáha, P.; Quadrat, Otakar

2012-01-01

Roč. 290, č. 1 (2012), s. 41-48 ISSN 0303-402X R&D Projects: GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : electrorheology * titanium oxide * hollow globular clusters Subject RIV: JI - Composite Materials Impact factor: 2.161, year: 2012

Presence of Leishmania amastigotes in peritoneal fluid of a dog with leishmaniasis from Alagoas, Northeast Brazil Presença de formas amastigotas de Leishmania em fluido peritoneal de cão com leishmaniose proveniente de Alagoas, nordeste do Brasil

Directory of Open Access Journals (Sweden)

Filipe Dantas-Torres

2006-08-01

Full Text Available The goal of this short communication is to report the uncommon presence of intracellular amastigotes of Leishmania in peritoneal fluid of a dog with leishmaniasis from Alagoas State, Brazil. Physical examination of an adult male rottweiler suspected to be suffering of leishmaniasis revealed severe loss of weight, ascitis, splenomegaly, moderately enlarged lymph nodes, onychogryphosis, generalized alopecia, skin ulcers on the posterior limbs, and conjunctivitis. Samples of bone marrow, popliteal lymph node, skin ulcer, and peritoneal fluid were collected and smears of each sample were prepared and stained with hematoxylin and eosin. Numerous amastigotes were detected in bone marrow, popliteal lymph node, and skin ulcer smears. Smears of peritoneal fluid revealed the unusual presence of several free and intracellular amastigotes of Leishmania. Future studies are needed to determine whether the cytology of ascitic fluid represents a useful tool for diagnosis Leishmania infection in ascitic dogs, particularly in those living in areas where canine leishmaniasis is enzootic.O objetivo desta comunicação é descrever a presença incomum de formas amastigotas de Leishmania em fluido peritoneal de um cão com leishmaniose proveniente do Estado de Alagoas, nordeste do Brasil. O exame físico de um cão macho adulto da raça rottweiler, apresentando suspeita de leishmaniose, revelou perda de peso severa, esplenomegalia, linfonodos moderadamente aumentados, ascite, onicogrifose, alopecia generalizada, conjuntivite e presença de lesões cutâneas ulceradas localizadas nos membros posteriores. Foram coletadas amostras de medula óssea, linfonodo poplíteo, fluido peritoneal e úlcera cutânea. A partir das amostras, foram elaborados esfregaços, os quais foram corados pela hematoxilina e eosina. Inúmeras formas amastigotas foram detectadas na medula óssea, linfonodo poplíteo e úlcera cutânea. Esfregaços de fluido peritoneal revelaram a presença, n

Determinação de cumarina em extrato fluido e tintura de guaco por espectrofotometria derivada de primeira ordem Determination of coumarin in fluid extract and tinture of "guaco" by first derivative spectrophotometry

Directory of Open Access Journals (Sweden)

Adriana de Carvalho Osório

2004-12-01

Full Text Available O objetivo do trabalho foi desenvolver um método de doseamento de cumarina (1,2-benzopirano em extrato fluido e tintura de guaco (Mikania glomerata Sprengel. O método desenvolvido foi por espectrofotometria derivada de primeira ordem, que se mostrou preciso, exato, reprodutível e de fácil execução.The objective of this work was to develop a method for coumarin(1,2-benzopyran dosage in fluid extract and tinture of "guaco" (Mikania glomerata Sprengel. First derivative spectrophotometry was developed and proved to be accurate, exact, reprodutive and of easy execution.

Reduced abrasion drilling fluid = Reduced abrasion drilling fluid

NARCIS (Netherlands)

2010-01-01

Se propoersiona un fluido de perforación de abarsividad reducida y un método de perforación de un hoyo en formaciones subterráneas haciendo circular un fluido de perforación de abrasividad reducida a través de este. El fluido de abarsividad reducida comprende un fluido de perforación, un primer

Analysis of the yielding behavior of electrorheological suspensions by controlled shear stress experiments

Czech Academy of Sciences Publication Activity Database

Pavlínek, V.; Sáha, P.; Perez-Gonzales, K.; de Vargas, L.; Stejskal, Jaroslav; Quadrat, Otakar

2006-01-01

Roč. 16, 1-2 (2006), s. 14-18 ISSN 1430-6395 R&D Projects: GA ČR GA202/06/0419 Institutional research plan: CEZ:AV0Z40500505 Keywords : electrorheology * yield stress * suspensions * polyaniline Subject RIV: CD - Macromolecular Chemistry

Dynamic analysis of electro- and magneto-rheological fluid dampers using duct flow models

International Nuclear Information System (INIS)

Esteki, Kambiz; Bagchi, Ashutosh; Sedaghati, Ramin

2014-01-01

Magneto-rheological (MR) and electro-rheological (ER) fluid dampers provide a semi-active control mechanism for suppressing vibration responses of a structure. MR and ER fluids change their viscosity under the influence of magnetic and electrical fields, respectively, which facilitates automatic control when these fluids are used in damping devices. The existing models, namely the phenomenological models for simulating the behavior of MR and ER dampers, rely on various parameters determined experimentally by the manufacturers for each damper configuration. It is of interest to develop mechanistic models of these dampers which can be applied to various configurations so that their fundamental characteristics can be studied to develop flexible design solutions for smart structures. This paper presents a formulation for dynamic analysis of electro-rheological (ER) and magneto-rheological (MR) fluid dampers in flow and mix mode configurations under harmonic and random excitations. The procedure employs the vorticity transport equation and the regularization function to deal with the unsteady flow and nonlinear behavior of ER/MR fluid in general motion. The finite difference method has been used to solve the governing differential equations. Using the developed approach, the damping force of ER/MR dampers can be calculated under any type of excitation. (paper)

Apuntes de Mecánica de Fluidos

OpenAIRE

Martín Domingo, Agustín

2011-01-01

Esta publicacion contiene unos apuntes para la parte de Mecánica de Fluidos de las asignaturas de la ETSAM, junto con cierta cantidad de material adicional que excede el ámbito del curso. Aunque está lejos de ser completa y de estar libre de errores, el autor espera sea útil.

Basic research of electro-rheological gel drum for novel linear actuator

Energy Technology Data Exchange (ETDEWEB)

Koyanagi, K; Yamaguchi, T; Oshima, T [Toyama Prefectural University, Toyama (Japan); Kakinuma, Y [Keio University, Kanagawa (Japan); Anzai, H; Sakurai, K [Fujikura Kasei, Tochigi (Japan)], E-mail: koyanagi@pu-toyama.ac.jp

2009-02-01

In recent years, robots that coexist with human are under active researches. Such robots need high safety, backdriveability, large generative force, high speed response, good controllability, and so on. We have put emphasis on the backdriveability and created a novel prototype linear actuator with an ER (Electro-Rheological) gel, a new functional material. It is an all-purpose actuator satisfying characteristics for human-coexistence welfare robot.

Elección de fluidos en el periodo perioperatorio del trasplante renal

OpenAIRE

Alejandro Gonzalez-Castro; María Ortiz-Lasa; Yhivian Peñasco; Camilo González; Carmen Blanco; Juan Carlos Rodriguez-Borregan

2017-01-01

El suero salino normal (SSN) ha sido clásicamente el fluido de resucitación elegido en el periodo perioperatorio del trasplante renal frente a aquellas soluciones balanceadas con potasio. Sin embargo, los problemas derivados de la hipercloremia desencadenada por la infusión de SSN han llevado a la realización de estudios que comparaban esta solución con los fluidos equilibrados. Mediante la presente revisión narrativa se deduce que el uso de cristaloides balanceados con contenido de potasio e...

Soldagem em operação: parte 1 - efeito do arrefecimento causado pelo fluido em tubulação de espessura 11 mm In-service welding: part 1: effect of freezing caused by fluid in 11 mm thick pipe

Directory of Open Access Journals (Sweden)

Paulo Faria

2012-12-01

Full Text Available Este trabalho avalia, na soldagem em operação, a influência do arrefecimento causado por um líquido fluindo em contato com a parede interna de uma tubulação sendo soldada por TIG (GTAW e eletrodo revestido (SMAW. A soldagem foi realizada na ligação de conexões de aço ASTM A105 a um tubo API 5L Gr X60 com espessura de 11 mm e de 6 mm. A circulação do fluido foi feita com água potável em duas faixas de temperatura, de 6 a 10ºC e 26 a 36ºC. Foram simuladas quatro juntas soldadas, avaliadas por meio de ensaios não destrutivos (inspeção visual, líquido penetrante, partículas magnéticas e ultrasom. Esta parte do trabalho apresenta os resultados dos ensaios destrutivos (tração, dobramento, impacto, fratura e dureza e análise macrográfica e micrográfica para o tubo de 11 mm de espessura. As juntas soldadas não apresentaram os problemas típicos da soldagem em operação, como trincas a frio e risco de perfuração. Os procedimentos de soldagem puderam ser qualificados, atendendo os critérios de aceitação das normas pertinentes. Foi possível concluir que o resfriamento acelerado causado pelo fluido em circulação, elevou consideravelmente a taxa de resfriamento na superfície interna do tubo. O efeito do arrefecimento causado pelo fluido no interior do tubo foi mais significativo que a temperatura deste fluido, tendo provocado o aumento na dureza da zona fundida e zona termicamente afetada e reduzido o alongamento no ensaio de tração, porém ainda em valores adequados para o tubo de 11 mm de espessura.This work evaluates for in-service welding, the influence of cooling caused by a liquid flowing in contact with the inner wall of a pipe being welded by TIG (GTAW and stick electrode (SMAW. The welding was done to join connections of an ASTM A105 to an 11mm and 6 mm thick API 5L Gr X60 steel pipe. The fluid circulation was made with potable water within two temperature ranges, of 6 to 10ºC and 26 to 36ºC. Four welded

LA DINÁMICA DE FLUIDOS COMPUTACIONAL, SU APLICACIÓN AL ESTUDIO DE LAS CARACTERÍSTICAS DE UN INTERCAMBIADOR DE TUBOS TÉRMICOS

Directory of Open Access Journals (Sweden)

David Fernández Rivas

2005-09-01

Full Text Available Para el estudio y el diseño de un intercambiador de calor del tipo Termosifón se emplea por primera vez enCuba una novedosa técnica de modelación numérica, la Dinámica de Fluidos Computacional, uso quepudiera ahorrar al país numerosos recursos. Este trabajo continua, con nuevos aportes, una largainvestigación que ha tenido como objetivo central, la instalación de tubos térmicos termosifón (ITTT. Lasimulación computacional, es una poderosa herramienta que se emplea para conocer parámetros de interésen la operación de dicha instalación. Se trabaja con programas de Dinámica de Fluidos Computacional(DFC para acortar el tiempo de experimentación y ahorrar recursos materiales y humanos durante elestudio de diferentes variantes de arreglos geométricos de los tubos térmicos. Se logran conocer lasparticularidades que los diferentes arreglos de tubos introducen al proceso de intercambio de calor. Esteresultado brinda una importante contribución para la futura construcción de un termosifón a escalaindustrial. Esta investigación ha suscitado mucho interés por lo que pudiera significar para la eficiencia de lacaldera las nuevas condiciones impuestas por la quema de combustible cubano.Palabras Claves: Dinámica de Fluidos Computacional, Tubos térmicos, termosifón.__________________________________________________________________________AbstractThe Computational Fluids Dynamic it is used for studying a thermosyphon heat exchanger like a noveltechnique of numeric modeling, for the first time in Cuba. This technique could save a lot of resources. Thiswork is the continuation of a long research in the heat pipes technology. Working with Computational FluidsDynamic (DFC programs, consumes less time in the experimentation and allows saving material andhuman resources for these studies. It is possible to know many particularities of different geometries of tubesarrangements. This investigation will guarantee a future thermosyphon

Mechanical and electro-rheological properties of electrospun poly(vinyl alcohol) nanofibre mats filled with carbon black nanoparticles

International Nuclear Information System (INIS)

Chuangchote, Surawut; Sirivat, Anuvat; Supaphol, Pitt

2007-01-01

The present contribution reports, for the first time, the mechanical and electro-rheological properties of electrospun poly(vinyl alcohol) (PVA) nanofibre mats with or without the incorporation of carbon black (CB) nanoparticles. The effects of sonication and the addition of CB on morphological appearance, average diameter of the as-spun fibre mats, and that of the individual fibres, were thoroughly investigated. Incorporation of CB (1-10% based on the weight of PVA) in 10% w/v PVA solution did not affect the morphology and average diameter of the obtained fibres (∼160 nm), but it affected both the mechanical and the electro-rheological properties of the as-spun PVA/CB fibre mats, in which the mats became more rigid with the addition and increasing amount of CB

The effect of compatibility of suspension particles with the oil medium on electrorheological efficiency

Czech Academy of Sciences Publication Activity Database

Stěnička, M.; Pavlínek, V.; Sáha, P.; Blinova, Natalia V.; Stejskal, Jaroslav; Quadrat, Otakar

2012-01-01

Roč. 23, č. 9 (2012), s. 1055-1059 ISSN 1045-389X R&D Projects: GA ČR GA202/09/1626; GA AV ČR IAA400500905 Institutional research plan: CEZ:AV0Z40500505 Keywords : electrorheological * suspension * polyaniline Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.523, year: 2012

Instabilities in a Relativistic Viscous Fluid

Science.gov (United States)

Corona-Galindo, M. G.; Klapp, J.; Vazquez, A.

1990-11-01

RESUMEN. Las ecuaciones hidrodinamicas de un fluido imperfecto relativista son resueltas, y los modos hidrodinamicos son analizados con el prop6sito de estabiecer correlaciones con las estructuras cosmol6gicas. ABSTRACT The hydrodynamical equations of a relativistic imperfect fluid are solved, and the hydrodynamical modes are analysed with the aim to establish correlations with cosmological structures. Ke, words: COSMOLOGY - HYDRODYNAMICS - RELATIVITY

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid.

Science.gov (United States)

Yoon, Chang-Min; Jang, Yoonsun; Noh, Jungchul; Kim, Jungwon; Jang, Jyongsik

2017-10-24

Electrophotorheological (EPR) fluids, whose rheological activity is dually responsive to light and electric fields (E fields), is formulated by mixing photosensitive spiropyran-decorated silica (SP-sSiO 2 ) nanoparticles with zwitterionic lecithin and mineral oil. A reversible photorheological (PR) activity of the EPR fluid is developed via the binding and releasing mechanism of lecithin and merocyanine (MC, a photoisomerized form of SP) under ultraviolet (UV) and visible (VIS) light applications. Moreover, the EPR fluid exhibits an 8-fold higher electrorheological (ER) performance compared to the SP-sSiO 2 nanoparticle-based ER fluid (without lecithin) under an E field, which is attributed to the enhanced dielectric properties facilitated by the binding of the lecithin and SP molecules. Upon dual application of UV light and an E field, the EPR fluid exhibits high EPR performance (ca. 115.3 Pa) that far exceeds its separate PR (ca. 0.8 Pa) and ER (ca. 57.5 Pa) activities, because of the synergistic contributions of the PR and ER effects through rigid and fully connected fibril-like structures. Consequently, this study offers a strategy on formulation of dual-stimuli responsive smart fluid systems.

Electrorheology of silicone oil suspensions of urea-modified poly[(glycidyl methacrylate)-co-(ethylene dimethacrylate)] particles

Czech Academy of Sciences Publication Activity Database

Belza, T.; Pavlínek, V.; Sáha, P.; Beneš, Milan J.; Horák, Daniel; Quadrat, Otakar

2007-01-01

Roč. 385, č. 1 (2007), s. 1-8 ISSN 0378-4371 R&D Projects: GA MŠk 2B06053 Institutional research plan: CEZ:AV0Z40500505 Keywords : Electrorheology * Suspension * Poly(glycidyl methacrylate-co-(ethylene dimethacrylate) Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.430, year: 2007

Fluid heating system (SAF®: effects on clinical and biochemistry parameters in dogs submitted to inhalatory anesthesia Sistema de aquecimento de fluidos (SAF®: efeitos sobre parâmetros clínicos e bioquímica sérica em cadelas sob anestesia inalatória

Directory of Open Access Journals (Sweden)

Ingrid Bueno Atayde

2009-04-01

Full Text Available PURPOSE: To evaluate and describe immediate effects of the infusion of saline solution heated by SAF® in bitches submitted to halothane anesthesia. METHODS: Thirteen bitches were employed and submitted to elective ovariohysterectomy in acclimatized operating room at 22ºC, allocated in two groups: GI, which received non-heated fluid and GII, which received fluid heated at 37ºC by SAF®. The following parameters were evaluated in 30-minutes intervals (M0, M30, M60 and M90: rectal and cutaneous temperatures (TR and TC, cardiac and respiratory frequencies (HR and ƒ, mean arterial blood pressure (MAP, serum concentration of urea, creatinin, serum activities of alanin aminotranspherasis (ALT, alkaline phosphatasis (ALP and also hypnosis parameters. RESULTS: There were no significant alterations on clinical and biochemical, but there was group effect on mean arterial blood pressure, urea, ALT, ALP and hypnosis parameters. CONCLUSION: The isolated use of Fluid Heating System (SAF® was not enough to avoid hypothermia or lead to significant clinical and biochemical alterations in bitches submitted to halothane anesthesia.OBJETIVO: Avaliar e descrever os efeitos imediatos da infusão de solução salina 0,9% aquecida pelo SAF® sobre cadelas sob anestesia inalatória. MÉTODOS: Foram utilizadas 13 cadelas submetidas a ovariohisterectomia eletiva em centro cirúrgico climatizado a 22ºC, divididas em dois grupos: GI, que recebeu fluido em temperatura ambiente e GII, que recebeu fluido aquecido a 37ºC pelo SAF®. Os parâmetros clínicos avaliados em intervalos de 30 minutos (M0, M30, M60 e M90 foram: temperatura retal (TR e cutânea (TC, freqüências cardíaca (FR e respiratória (ƒ, pressão arterial média (PAM, tempo de hipnose, concentrações séricas de uréia e creatinina e atividades das enzimas séricas alanina aminotransferase (ALT e fosfatase alcalina (ALP. RESULTADOS: Não foram evidenciadas alterações clínicas e bioqu

New electrorheological fluids - characteristics and implementation in industrial and mobile applications

International Nuclear Information System (INIS)

Gurka, M; Adams, D; Johnston, L; Petricevic, R

2009-01-01

Various applications for controllable dampers in the industrial and automotive sector are demanding an improved ER-Fluid, concerning performance and long time behavior. The new ER-Fluid RheOil (registered) 3.0 developed by us and presented here overcomes the main disadvantages like sedimentation and re-dispersing behavior. Besides this, better ER-performance (control ratio, current-density, step response time) could also be achieved. During tests of the response to changing temperature and long time behavior no significant degradation of the fluid or abrasive wear in the components was found over a wide temperature range.

Electrorheological Properties of Suspensions Prepared from Poly(Li-tert-butyl methacrylate) Ionomer

OpenAIRE

YAVUZ, Mustafa

2014-01-01

The synthesis, characterisation and partial hydrolysis of poly(tert-butylmethacrylate), (PTBMA), and the electrorheological (ER) properties of its suspensions were investigated. The polymer was synthesised by radical polymerisation and partially hydrolysed by para-toluenesulphonic acid monohydrate (PTSA.H2O), and then converted to a lithium salt (PTBMA-Li) by washing with a LiOH(aq) solution. From particle size measurements, the average particle size of PTBMA-Li was determined to be ...

Uma nova metodologia para a simulação de escoamentos de fluidos viscoelásticos A new approach for simulation of viscoelastic fluid flows

Directory of Open Access Journals (Sweden)

André R. Muniz

2005-03-01

Full Text Available É proposta neste trabalho uma nova metodologia para resolução das equações governantes de fluidos viscoelásticos, baseada no método dos volumes finitos, usando o arranjo co-localizado para as variáveis e malhas estruturadas. São utilizadas aproximações de alta ordem para os fluxos lineares e não-lineares médios nas interfaces dos volumes, e para os termos não-lineares que surgem da discretização das equações constitutivas. Nesta metodologia, os valores médios das variáveis nos volumes são usados durante todo o procedimento de resolução, e os valores pontuais são obtidos ao final, através da deconvolução dos valores médios. O sistema de equações discretizadas é resolvido de forma simultânea, pelo método de Newton. A metodologia é exemplificada para um problema clássico em mecânica de fluidos computacional, o escoamento stick-slip, usando como equação constitutiva o modelo de Oldroyd-B. As soluções obtidas apresentaram boa precisão, sendo livres de oscilações mesmo em regiões de grandes gradientes das variáveis.In this work, a new methodology to solve the governing equations of viscoelastic fluid flows is proposed. This methodology is based on the finite-volume method with co-located arrangement of the variables, using high-order approximations for the linear and nonlinear average fluxes in the interfaces and for the nonlinear terms resulting from the discretization of the constitutive equations. In this methodology, the average values of the variable in the volumes are used during the resolution, and the point values are recovered in the post-processing step by deconvolution of the average values. The nonlinear equations, resulting from the discretization technique, are solved simultaneously, using the Newton's method. The solutions obtained are oscillation-free and accurate, as can be seen in the solution of the stick-slip flow, used as an illustrative example.

A vivência dos trabalhadores de Enfermagem que sofreram acidente com fluido biológico: um olhar fenomenológico

OpenAIRE

Carolina Luiza Bernardes

2014-01-01

RESUMO A exposição ocupacional aos fluidos biológicos é inerente ao trabalho desempenhado pela equipe de enfermagem durante a realização da assistência, tornando o trabalhador susceptível a ocorrência de acidentes e exposto aos fluidos corporais que podem conter diferentes patógenos causadores de doenças como HIV, Hepatite B e C. Trata-se de um estudo de natureza qualitativa que objetivou compreender a experiência do acidente com fluido biológico e da assistência prestada aos trabalhadores de...

Análise da transferência de calor de fluidos térmicos aditivado com etilenoglicol e polímeros

OpenAIRE

Santana, Rony Oliveira de

2016-01-01

Um sistema de arrefecimento é usado para manter a temperatura ideal de funcionamento e evitar sobreaquecimento, através de um fluido térmico também chamado fluido de arrefecimento e um trocador de calor. Os fluidos de arrefecimento são normalmente compostos por uma solução de água e um aditivo, além de aditivos inibidores de corrosão e corantes. O etilenoglicol é um tipo de álcool amplamente utilizado como aditivo por ser totalmente solúvel, com baixa ou nenhuma atividade corrosiva e quimicam...

Características físicas e químicas do extrato fluido de Cordia ecalyoulata Vell - Boragináceae

OpenAIRE

Saito, Maria Lúcia; Oliveira, Fernando de

1986-01-01

São apresentadas características físicas e químicas e a determinação do teor de alantoina nos extratos fluidos de Cordía ecalyculata Vell, planta medicinal popularmente conheaida como "chá de bugre" e "porangaba". A alantoina foi encontrada em teores variando de 0,36 a 0,73% nos extratos fluidos, preparados com drogas de procedências diferentes. Verificou-se também a presença de ácido alantóico, produto de decomposição da alantoina, nos extratos fluidos, que ao mesmo tempo tiveram o valor do ...

Adaptabilidad de mallados por aproximación a la mecánica de un fluido

OpenAIRE

Mantilla Núñez, Irla Doraliza; Mantilla Núñez, Irla Doraliza

1999-01-01

En este trabajo se plantea un método de adaptabilidad de mallados a un cierto estimador de error, conservando el número de grados de libertad y las conectividades de la malla original. El principio del método consiste en considerar los nodos del mallado original como las partículas de un fluido rotacional y compresible, cuya compresibilidad local es proporcional a la desviación del error sobre su media (con lo que se consigue que, globalmente, el fluido sea incompresible). Este método da ...

Modeling and control of an off-road truck using electrorheological dampers

International Nuclear Information System (INIS)

Holzmann, K; Kemmetmueller, W; Kugi, A; Stork, M; Rosenfeldt, H; Schneider, S

2009-01-01

This work deals with the mathematical modeling and control of the semi-active suspension of an MAN off-road truck with a payload of 5 tons which comprises electrorheological dampers. Thereby, a cascaded control structure with four controllers for the control of a quarter-car in the inner control loop and a superimposed control strategy for the overall vehicle is used. The main goal of the control strategy is to reduce the motion of the chassis (especially roll, pitch and vertical movement) while increasing driving stability. The capability of the overall control strategy is demonstrated by means of simulation studies and measurement results.

Fluidos, bombas e instalaciones hidráulicas

OpenAIRE

Heras Jiménez, Salvador Augusto de las

2011-01-01

A la portada: Universitat Politècnica de Catalunya. Barcelonatech Descripció del recurs: 2 de maig de 2012 Esta obra describe los principios fundamentales que rigen el funcionamiento de las bombas y las instalaciones hidráulicas más usuales, sus características operativas y los criterios de diseño y selección. El contenido del libro se estructura en tres grupos básicos. Los dos primeros temas tratan de la mecánica de los fluidos y sus propiedades: los principios y las leyes de conser...

Investigation of the touch sensitivity of ER fluid based tactile display

Science.gov (United States)

Liu, Yanju; Davidson, Rob; Taylor, Paul

2005-05-01

A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5x5 touch sensitive tactile display array including electrorheological (ER) fluid has been developed and investigated. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. In the meantime, it is possible to sense the touching force normal to the display"s surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

Comportamiento de la corrosión de diferentes aleaciones de titanio y tantalio en contacto con fluidos fisiológicos

OpenAIRE

Dueñas Santacruz, Ernesto Diego

2013-01-01

Programa de doctorado: Tecnología industrial El objetivo de la tesis es el estudio del comportamiento de diferentes aleaciones de titanio y tantalio en contacto con fluidos fisiológicos. En concreto, se trata de tres aleaciones con un contenido de un cinco, un quince y un veinticinco por ciento de tantalio. En cuanto al fluido fisiológico, se trata de una disolución Ringer.

Eficacia del extracto fluido de Vimang® en el tratamiento de pacientes con alveolitis

Directory of Open Access Journals (Sweden)

Yolanda Del Toro Gámez

2014-09-01

Full Text Available Se realizó un ensayo clínico de fase III en 118 pacientes con alveolitis, atendidos en la consulta estomatológica del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, para evaluar la eficacia del extracto fluido de Vimang® en el tratamiento de ellos. La muestra se dividió en 2 grupos (experimental y control, distribuidos aleatoriamente; los integrantes del primero, tratados con el mencionado extracto; y los del segundo, con Alvogyl. Los resultados del estudio fueron validados mediante el estadígrafo de Ji al cuadrado. Se concluye que el extracto fluido de Vimang® fue eficaz para eliminar la alveolitis en menor tiempo y sin reacciones adversas, por lo cual se recomendó generalizar su uso

Tamper indicating and sensing optical-based smart structures

International Nuclear Information System (INIS)

Sliva, P.; Anheier, N.C.; Gordon, N.R.; Simmons, K.L.; Stahl, K.A.; Undem, H.A.

1995-05-01

This paper has presented an overview of the type of optical-based structures that can be designed and constructed. These smart structures are capable of responding to their environment. The examples given represent a modest sampling of the complexity that can be achieved in both design and practice. Tamper-indicating containers and smart, sensing windows demonstrate just a few of the applications. We have shown that optical-based smart structures can be made multifunctional with the sensing built in. The next generation smart structure will combine the sensing functionality of these optical-based smart structures with other sensors such as piezoelectrics and electro-rheological fluids to not only be able to respond to the environment, but to adapt to it as well. An example of functionality in this regime would be a piezosensor that senses pressure changes (e.g., shock waves), which then causes an electro-rheological fluid to change viscosity. A fiber sensor located in or near the electro-rheological fluid senses the stiffness change and sends a signal through a feedback loop back to the piezosensor for additional adjustments to the electro-rheological fluid

Towards the design of new and improved drilling fluid additives using molecular dynamics simulations

Directory of Open Access Journals (Sweden)

Richard L. Anderson

2010-03-01

Full Text Available During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nanoscopic dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide-diamine, poly(ethylene glycol and poly(ethylene oxide-diacrylate inhibitor molecules with montmorillonite clay are studied.Durante a exploração de óleo e gás um fluido de perfuração é usado para lubrificar 'bit' da perfuradora, manter a pressão hidrostática, transmitir sensores de leitura, remover resíduos da rocha e inibir o inchamento da argila instável baseada nas formações dos folhelhos. O aumento das preocupações ambientais bem como a legislação resultante levou à procura de novos fluidos de perfuração com componentes biodegradáveis. No caso dos aditivos para inibir o inchamento das argilas o entendimento das interações entre os aditivos e as argilas tem que ser adquirido para permitir o

Contact with hospital syringes containing body fluids: implications for medical waste management regulation Jeringas en contacto con sangre y fluidos corporales utilizadas en el hospital: implicaciones para el manejo de desechos hospitalarios

Directory of Open Access Journals (Sweden)

Patricia Volkow

2003-04-01

Full Text Available OBJECTIVE: To determine amount of syringes used in the hospital and extent of contact with blood and body fluids of these syringes. MATERIAL AND METHODS: Syringe use was surveyed at a tertiary care center for one week; syringes were classified into the following four categories according to use: a contained blood; b contained other body fluids (urine, gastric secretion, cerebrospinal fluid, wound drainage; c used exclusively for drug dilution and application in plastic intravenous (IV tubes, and d for intramuscular (IM, subcutaneous (SC, or intradermic (ID injections. RESULTS: A total of 7 157 plastic disposable syringes was used; 1 227 (17% contained blood during use, 346 (4.8%, other body fluids, 5 257 (73% were used exclusively for drug dilution and application in plastic IV lines, and 327 (4.5% were utilized for IM, SC, or ID injections. An estimated 369 140 syringes used annually, or eight syringes per patient per in-hospital day. All syringes were disposed of as regulated medical waste, in observance of the law. CONCLUSIONS: There is an urgent need to review recommendations for medical waste management by both international agencies and local governments, based on scientific data and a cost-benefit analysis, to prevent resource waste and further environmental damage.OBJETIVO: Cuantificar el número de jeringas que se utilizan en el hospital y calcular cuántas de éstas entran en contacto con sangre o fluidos corporales. MATERIAL Y MÉTODOS: Se hizo una encuesta del uso de jeringas en un hospital de tercer nivel de atención durante toda una semana. Se clasificaron, de acuerdo con el uso que se les dio, en cuatro categorías: a aspiración de sangre, b otros fluidos corporales (orina, secreción gástrica, líquido cefalorraquídeo, drenaje de herida, etcétera, c uso exclusivo para diluir medicamentos y administrarlos a través de tubos de terapia intravenosa, d para aplicación de inyecciones intramusculares (IM, subcutáneas (SC o

Electrorheology leads to healthier and tastier chocolate.

Science.gov (United States)

Tao, Rongjia; Tang, Hong; Tawhid-Al-Islam, Kazi; Du, Enpeng; Kim, Jeongyoo

2016-07-05

Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. Although this issue was called into attention decades ago, no actual solution was found. To bypass this critical outstanding problem, two manufacturers introduced some low-calorie fats to substitute for cocoa butter. Somehow, their products are not allowed in most countries. Here we show that this issue is deeply related to the basic science of soft matter, especially to the viscosity of liquid suspension and maximally random jammed (MRJ) density. When the concentration of cocoa solid is high, close to the MRJ density, removing a small amount of fat will jam the chocolate flow. Applying unconventional electrorheology to liquid chocolate with applied field in the flow direction, we aggregate the cocoa particles into prolate spheroids in micrometers. This microstructure change breaks the rotational symmetry, reduces liquid chocolate's viscosity along the flow direction, and increases its MRJ density significantly. Hence the fat level in chocolate can be effectively reduced. We are expecting a new class of healthier and tastier chocolate soon.

Electrorheology leads to healthier and tastier chocolate

Science.gov (United States)

Tao, Rongjia; Tang, Hong; Tawhid-Al-Islam, Kazi; Du, Enpeng; Kim, Jeongyoo

2016-01-01

Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. Although this issue was called into attention decades ago, no actual solution was found. To bypass this critical outstanding problem, two manufacturers introduced some low-calorie fats to substitute for cocoa butter. Somehow, their products are not allowed in most countries. Here we show that this issue is deeply related to the basic science of soft matter, especially to the viscosity of liquid suspension and maximally random jammed (MRJ) density. When the concentration of cocoa solid is high, close to the MRJ density, removing a small amount of fat will jam the chocolate flow. Applying unconventional electrorheology to liquid chocolate with applied field in the flow direction, we aggregate the cocoa particles into prolate spheroids in micrometers. This microstructure change breaks the rotational symmetry, reduces liquid chocolate’s viscosity along the flow direction, and increases its MRJ density significantly. Hence the fat level in chocolate can be effectively reduced. We are expecting a new class of healthier and tastier chocolate soon. PMID:27325758

Temperature and shear rate characteristics of electrorheological gel applied to a clutch

International Nuclear Information System (INIS)

Koyanagi, K; Takata, Y; Motoyoshi, T; Oshima, T; Kakinuma, Y; Anzai, H; Sakurai, K

2013-01-01

This investigation reports the physical characteristics of electrorheological (ER) gels, which are a type of functional material having controlled surface friction. We previously developed slip clutches using ER gels sandwiched between electrodes, and verified their responses and controllability. We newly report the temperature and shear rate characteristics of ER gel in this study because the input and output electrodes of the clutch continuously slip past each other. While the temperature of ER gels increased when energized, the shear stress hardly changed. Instead, wearing and adaptation to the electrode affect the property. The shear rate hardly affected the shear stress in the high-shear-rate region. Conversely, the shear stress depended on the shear rate in the lower region.

Dispositivo para la medición automática del volumen de un fluido que corre por un conducto y el procedimiento para su medición y su posterior vaciado autónomo en función de la cantidad de fluido acumulado

OpenAIRE

Apalkov, Andrey; Fernández Saavedra, Roemi E.; Armada, Manuel; Otero-Rodríguez, Manuel Ángel

2012-01-01

Dispositivo para la medición del volumen de un fluido que corre por un conducto y su posterior vaciado autónomo compuesto por un receptor de líquido (1) y un sensor capacitivo (7) y que se caracteriza porque el receptor de líquido (1) tiene en su interior un elemento central móvil (12) con un obturador (13) para controlar el vaciado del líquido. El procedimiento para la medición y vaciado se caracteriza porque se mide el volumen de fluido Vi en el receptor ...

Cutting fluids and clean technologies; Los fluidos de corte y las tecnologias limpias (III)

Energy Technology Data Exchange (ETDEWEB)

Terradillos, J.; Arnaiz, A.

2003-07-01

Metalworking fluids are an essential constituent of manufacturing and represent an important part of machining cost and disposal charges. Practically all cutting fluids currently in use fall into four categories: straight oils, soluble oils, semi-synthetic fluids and synthetic oils. The composition of these fluids depends on the machining requirements and primary functions include improving tool life, reducing thermal deformation of parts and improving surface finish and flushing away chips from the cutting zone. To maintain cutting fluid quality in the long term and, at the same time, reduce its environmental impact, three strategies could be followed: Prevention, Minimization and Evaluation, Related to prevention, different approaches exist for reducing the impact of cutting fluids. They include dry cutting, machining using a minimum quantity of lubricant (MQL) and developing environmental friendly acceptable formulations or refrigerant gases. (Author)

Fluidos intravenosos isotónicos en el paciente pediátrico: evolución de la natremia y efectos adversos

OpenAIRE

Toledo Parreño, Juan Diego

2016-01-01

Los fluidos hipotónicos se siguen usando de forma mayoritaria en niños hospitalizados pese al riesgo de hiponatremia iatrogénica, edema cerebral y muerte reportado en la literatura científica y en las advertencias de seguridad de organismos sanitarios internacionales. Se sabe que estímulos frecuentes en los niños hospitalizados inducen secreción no osmótica de ADH . Si a estas circunstancias sumamos el empleo de fluidos hipotónicos como los que resultan del trabajo clásico de Holliday-Se...

Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

OpenAIRE

Carlos Vallejos; Job Balladares

2014-01-01

La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes d...

Comparação entre os métodos de aplicação de fluido de corte convencional e otimizado na retificação plana de cerâmicas Grinding of alumina ceramics with different cooling and lubrification techniques: conventional and minimum quantity of lubrification (MQL

Directory of Open Access Journals (Sweden)

D. M. Iceri

2012-03-01

Full Text Available Com o grande crescimento tecnológico e a necessidade de melhoria, um dos materiais que ganhou uma grande gama na área da engenharia mecânica é a cerâmica, pois possui vantagens físico-químicas e propriedades mecânicas significativas sobre o aço. Entretanto, sua usinagem é um processo difícil e delicado, que requer ainda uma grande atenção em relação ao seu estudo. Assim, o processo de retificação é um dos métodos que tem apresentado bons resultados, porém um grande problema acerca de tal processo é o uso excessivo de fluidos de corte, o que se tornou uma preocupação mundial, já que os fluidos apresentam graves problemas socioambientais, além disso, o fluido de corte é responsável por uma grande parte do custo final do processo, provocando, desse modo, um grande interesse em pesquisas referentes a métodos alternativos de forma a reduzir o consumo e melhorar as características do fluido de corte utilizado. Este trabalho visa comparar duas técnicas de lubri-refrigeração, o método convencional e a Lubrificação Otimizada. O uso do método otimizado é uma alternativa à diminuição do volume de fluido utilizado, já que este tem como princípio a aplicação de uma menor quantidade de fluido de corte com uma alta velocidade, localmente aplicada, ou seja, com essa redução benefícios ambientais e socioeconômicas são obtidos. A análise do trabalho será feita a partir da avaliação das variáveis de saída do processo de retificação plana tais como o comportamento rugosidade e desgaste do rebolo, já que por elas é possível avaliar o processo em relação a qualidade da peça versus custo. Com essas analises, pretende-se avaliar se a técnica otimizada é viável a substituição da refrigeração convencional na retificação plana de cerâmicas.The great technological growth and the improvement needs, a material that has gained a wide range in mechanical engineering is the ceramics because of its

Estudio de Mercado de la Microencapsulación de Fluidos

OpenAIRE

de Batlle Mercadé, Juan Batlle

2016-01-01

El TFG desarrollado a continuación trata sobre un estudio de mercado de la microencapsulación de fluidos llevado a cabo por petición de una empresa especializada en este producto. Los objetivos de este proyecto son: en primer lugar, dimensionar el mercado de las micropartículas para las zonas geográficas de Europa (EU) y Estados Unidos (EEUU) en cuatro sectores (Pharma, Functional Food, Personal Care y Home Care); en segundo lugar, identificar la demanda no cubierta mediante las necesidades d...

Modelamiento numérico de yacimientos naturalmente fracturados con flujo de fluidos composicional acoplado a deformación geomecánica

OpenAIRE

Arango Acevedo, María Adelaida

2009-01-01

Se desarrolla un modelo matemático que permite evaluar el comportamiento geomecánico en macizos rocosos que contienen fracturas y valorar el cambio de la permeabilidad debido a la variación en el estado de esfuerzos, causado por la diferencia en la presión de los fluidos presentes en el yacimiento, que por su complejidad deben ser analizados como fluidos composicionales. El modelo matemático se plantea en tres dimensiones y en coordenadas cartesianas partiendo de las ecuaciones de flujo de fl...

Peroxidação lipídica e vitamina E no soro e no fluido folicular de mulheres inférteis com endometriose submetidas à estimulação ovariana controlada Lipid peroxidation and vitamin E in serum and follicular fluid of infertile women with endometriosis submitted to controlled ovarian hyperstimulation

Directory of Open Access Journals (Sweden)

Carla Campos Petean

2007-06-01

Full Text Available OBJETIVO: avaliar o nível de peroxidação lipídica e vitamina E no fluido folicular e soro de pacientes inférteis, com ou sem endometriose, submetidas à indução da ovulação para procedimentos de reprodução assistida. MÉTODOS: estudo prospectivo envolvendo, consecutivamente, 36 pacientes inférteis com idade entre 20 e 38 anos, divididas em dois grupos: Endometriose (n=17 e Controle (n=19, laqueadura tubária prévia ou fator masculino. Amostras sanguíneas foram coletadas em: D1 (imediatamente antes do início do uso de gonadotrofinas, D2 (dia da aplicação da gonadotrofina coriônica humana e D3 (dia da aspiração folicular. Em D3, amostras de fluido folicular livres de contaminação sanguínea foram coletadas e armazenadas. O nível de eroxidação lipídica foi mensurado pela quantificação de malondialdeído (MDA por espectrofotometria, e o status antioxidante por meio da medida da vitamina E por cromatografia líquida de alta pressão. RESULTADOS: em D1, nenhuma diferença significante foi observada entre os Grupos Endometriose (2,4 nmol/mL e Controle (1,9 nmol/mL no nível de MDA. Contudo, os níveis de vitamina E foram significativamente mais elevados no Grupo Controle (24 mimol/L. Em D2, os níveis de MDA foram significantemente maiores no Grupo Endometriose (2,3 nmol/mL quando comparados com o Controle (1,4 nmol/mL, enquanto os níveis de vitamina E permaneceram significativamente mais elevados no Controle (23,4 mimol/L. Em D3 não houve diferença significante nos níveis de MDA e de vitamina E do soro e fluido folicular entre os grupos. Contudo, em D3, os níveis de vitamina E foram significativamente mais elevados no soro do que no fluido folicular em ambos os grupos, e os níveis de MDA foram significativamente menores no fluido folicular do que no soro apenas no Grupo Controle. CONCLUSÃO: antes do início da indução da ovulação, uma diminuição significativa nos níveis séricos de vitamina E foi observada em

Dinámica de fluidos computacional aplicada al estudio de regeneradores térmicos

Directory of Open Access Journals (Sweden)

Cesar Nieto Lodoño

2004-01-01

Full Text Available En el presente artículo, muestra los resultados logrados durante la simulación de un regenerador térmico de lecho poroso empacado, sometido a convección forzada transitoria y su respectiva verificación experimental. Para visualizar la aplicación de la Dinámica de Fluidos Computacional (en inglés Computational Fluid Dynamics, CFD en regeneradores de calor, se realiza un estudio detallado de los elementos que conforman la malla; analizando su distribución, tamaño y respectivo efecto sobre la precisión de los resultados. Se establecen las simplificaciones y alcances de los modelos empleados. Se comprueba la veracidad de los resultados obtenidos, mediante la validación experimental de estos en un modelo físico idéntico al empleado durante la simulación. Estas etapas permitieron observar que el comportamiento exponencial de la temperatura en los elementos empacados durante el periodo de calentamiento, fue idéntico al observado por Mejía [8]. Los resultados obtenidos aquí, verifican la capacidad de la CFD para el estudio de los regeneradores térmicos.

Gas inflow in oil base fluids; Influxo de gas em fluidos a base de oleo

Energy Technology Data Exchange (ETDEWEB)

Lazaro, Welmar [PETROBRAS, Rio de Janeiro (Brazil). Dept. de Perfuracao. Div. de Fluidos de Perfuracao; Boas, Mario Barbosa V [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1990-12-31

One of the major problems related to the use of oil base fluids is the dissolution of the natural gas in the fluid. This paper attempts initially at making a bibliographical review of all that was written on the subject of drilling fluids up to now. It also mentions some theoretical aspects regarding the process of gas dissolution in diesel oils, in order to produce an understanding of how the dissolution mechanism is processed. For a same increase in measured volume on the surface, the amount of gas incorporated into the fluid is significantly larger if the gas is dissolved in the oil phase than if it is emulsified in the fluid, as occurs when the fluid is water base. A rig team used to working with water-base fluids may be surprised with the fact that an increase of 20 bbl of fluid on the surface of a 5000 m well can mean the incorporation of about 1800 m{sup 3} of gas, if the fluid is oil-base and all the gas is in solution instead of the incorporation of 900 m{sup 3} if the fluid is water base. This paper has the goal of warning drilling engineers and technicians about this problem, as well as presenting charts and equations that allow for a more realistic evaluation of the amount of gas incorporated into oil fluids. (author) 16 refs., 7 figs., 2 tabs.

Organofilização de argilas bentoníticas com tensoativos não- iônicos visando seu uso em fluidos de perfuração base óleo Nonionic surfactants organophilization bentonite clays aiming their use in oil base drilling fluids

Directory of Open Access Journals (Sweden)

I. A. Silva

2012-09-01

Full Text Available O uso de tensoativos não iônicos vem substituindo os tradicionais tensoativos iônicos dentre outros motivos pelo seu elevado potencial de resistência a degradação térmica. Assim, este trabalho tem por objetivo o desenvolvimento de argilas organofílicas através da incorporação de tensoativos não iônicos visando seu uso em fluidos de perfuração de poços de petróleo base óleo. Argilas bentoníticas natural, industrializadas e organofilizadas foram caracterizadas por análise química, difração de raios X e análises térmicas. Após a organofilização foi realizado o inchamento de Foster, visando a escolha dos tensoativos mais adequados aos meios líquidos orgânicos dispersantes: éster, diesel e parafina. Com as dispersões obtidas foram determinadas as propriedades reológicas através de viscosidades aparente e plástica. Os resultados evidenciaram que as argilas organofilicas apresentaram um aumento do espaçamento interlamelar e que as dispersões apresentaram propriedades reológicas dentro das especificações da Petrobrás, para uso como argilas organofílicas em fluidos de perfuração em base óleo.The nonionic surfactants use is replacing the traditional ionic surfactants among other reasons because of its high resistance to thermal degradation potential. This work aims the organoclays development through the nonionic surfactants incorporation in order to oil base drilling fluids use. The natural bentonite clay, and industrialized organophilizated were characterized by chemical analysis, X-ray diffraction and thermal analysis. After, the clay organophilization was performed by Foster swelling, seeking the most appropriate choice of surfactants to the liquid media organic dispersants, ester, paraffin and diesel. With the obtained dispersions were determined by plastic and apparent viscosities the rheological properties. The results showed that organoclays increase in the interlayer spacing and that the dispersions

Student designed experiments to learn fluids

Science.gov (United States)

Stern, Catalina

2013-11-01

Lasers and high speed cameras are a wonderful tool to visualize the very complex behavior of fluids, and to help students grasp concepts like turbulence, surface tension and vorticity. In this work we present experiments done by physics students in their senior year at the School of Science of the National University of Mexico as a final project in the continuum mechanics course. Every semester, the students make an oral presentation of their work and videos and images are kept in the web page ``Pasión por los Fluidos''. I acknowledge support from the Physics Department of Facultad de Ciencias, Universidad Nacional Autónoma de México.

Synthesis of flower-like BaTiO3/Fe3O4 hierarchically structured particles and their electrorheological and magnetic properties.

Science.gov (United States)

Wang, Baoxiang; Yin, Yichao; Liu, Chenjie; Yu, Shoushan; Chen, Kezheng

2013-07-21

Flower-like BaTiO3/Fe3O4 hierarchically structured particles composed of nano-scale structures on micro-scale materials were synthesized by a simple solvothermal approach and characterized by the means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), magnetic testing and rotary viscometer. The influences on the morphology and structure of solvothermal times, type and amount of surfactant, EG : H2O ratio, etc. were studied. Magnetic testing results show that the samples have strong magnetism and they exhibit superparamagnetic behavior, as evidenced by no coercivity and the remanence at room temperature, due to their very small sizes, observed on the M-H loop. The saturation magnetization (M(s)) value can achieve 18.3 emu g(-1). The electrorheological (ER) effect was investigated using a suspension of the flower-like BaTiO3/Fe3O4 hierarchically structured particles dispersed in silicone oil. We can observe a slight shear-thinning behavior of shear viscosity at a low shear rate region even at zero applied electric field and a Newtonian fluid behavior at high shear rate regions.

Fluidos supercríticos em química analítica. I. Cromatografia com fluido supercrítico: conceitos termodinâmicos Supercritical fluid in analytical chemistry. I. Supercritical fluid chromatography: thermodynamic definitions

OpenAIRE

Emanuel Carrilho; Maria Cecília H. Tavares; Fernando M. Lanças

2001-01-01

Under the chromatographic point of view, the physico-chemical properties of a supercritical fluid are intermediate to those of the gases and liquids. Many times they approach the best features of each one, as for example, the solubilization power of liquids and low viscosity of gases. The thermodynamic definitions and main physico-chemical features of a supercritical fluid will be presented in this article. The use of supercritical fluids in analytical chemistry has been extremely modest in B...

Nonlinear electrorheological instability of two Rivlin-Ericksen elastico-viscous fluids

CERN Document Server

El-Dib, Y O

2003-01-01

The behaviour of surface waves propagating between two Rivlin-Ericksen elastico-viscous fluids is examined. The investigation is made in the presence of a vertical electric field and a relative horizontal constant velocity. The influence of both surface tension and gravity force is taken into account. Due to the inclusion of streaming flow a mathematical simplification is considered. The viscoelastic contribution is demonstrated in the boundary conditions. From this point of view the approximation equations of motion are solved in the absence of viscoelastic effects. The solutions of the linearized equations of motion under nonlinear boundary conditions lead to derivation of a nonlinear equation governing the interfacial displacement and having damping terms with complex coefficients. This equation is accomplished by utilizing the cubic nonlinearity. The use of the Gardner-Morikawa transformation yields a simplified linear dispersion relation so that the periodic solution for the linear form is utilized. The ...

Application of SPCALC for chemical and thermodynamic speciation of fluids -example for wells LV-4A, LV-11 and LV-13, Las Tres Virgenes geothermal field, BCS; Aplicacion del SPCALC en la especiacion quimica y termodinamica de fluidos: ejemplo del caso de los pozos LV-4A, LV-11 y LV-13, del campo geotermico de Las Tres Virgenes, BCS

Energy Technology Data Exchange (ETDEWEB)

Viggiano Guerra, J.C.; Sandoval Medina, F.; Flores Armenta, M.C. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx, E-mail: magaly.flores@cfe.gob.mx; Perez, R.J. [Universidad de Calgary (Canada); Gonzalez Partida, E. [Universidad Nacional Autonoma de Mexico, Centro de Geociencias, Mexico, D.F. (Mexico)

2009-01-15

SPCALC is an excellent software application providing chemical and multi-phase speciation for geothermal fluids. Recently it was acquired by the Comision Federal de Electricidad (CFE) through a contract with the National Autonomous University of Mexico (UNAM) and the University of Calgary, Canada. Software methodology consists of calculating thermodynamic variables, such as activity (a) and fugacity (f) of chemical species, as well as the saturation indices (log Q/K) of mineral phases of the reservoir. In other words, it models the thermodynamic conditions of the reservoir (pH among other) and simulates the fluid-corrosion rate. This allows the software to foresee scaling and corrosion. In this paper, pervasive fluids in Cretaceous granitic rocks penetrated by wells LV-4A, LV-11 and LV-13 in Las Tres Virgenes geothermal field, BCS, are modeled, starting with chemical analyses. The more important ratios among activities [those which influence the fluid-rock interaction (i.e. {sup a}K{sup +}/{sup a}H{sup +}, {sup a}Ca{sup ++}/{sup a}H{sup +}, {sup a}Na{sup +}/{sup a}H{sup +}, {sup a}Mg{sup ++}/{sup a}H{sup +}) and whose results are the minerals visible under a microscope] are graphed in balance diagrams compatible with the pressure (P) and temperature (T) conditions in the reservoir. Epidote (zoisite) is the mineral found in congruent equilibrium with the system. The main mineral association at those conditions (200-250 degrees Celsius and {approx}18 bar), as observed in the well cuttings, is calcite+illite-quartz{+-}epidote, which is explained by the hydrolithic reactions that form replacement calcite in the presence of CO{sub 2}, thus restricting the formation of epidote and eventually eliminating it. The process enhances the CO{sub 2} molarity in the residual fluid, even up to {sup m}CO{sub 2} 1, which means the CO{sub 2} can be diluted back into fluid and intervene again in the process of calcite formation (2HCO{sub 3}{sup -} + Ca{sup ++} = calcite + H{sub 2}O

Physics of field-responsive fluids

Science.gov (United States)

Wan, Tsz Kai Jones

Electrorheological (ER) fluid is a new class of material, which possesses a variety of potential applications, such as shock absorbers and clutches. It is formed by microparticles that are dispersed in a host fluid. The particles will form chains rapidly when we apply an electric field to the ER fluid. However, due to the inadequacy of knowledge, the proposed applications have not been commercialized yet. The prediction of the strength of the ER effect is the main concern in the theoretical investigation of ER fluids. The ER effect is originated from the induced interaction between the polarized particles in an ER fluid. Existing theories assume that the particles are at rest. In a realistic situation, the fluid flow exerts force and torque on the particles, setting the particles in both translational and rotational motions under these actions. Recent experiments showed that the induced forces between the rotating particles are markedly different from the values predicted by existing theories. To overcome the discrepancy between theory and experiment, we formulate a model to take the particle motion into account, and derive the dependence of forces on the angular velocity of the rotating particles. We develop first-principles methods to investigate the dynamic ER effects in which the suspended particles can have translational or rotational motions. A model based on the relaxation of polarization charge on the particle surfaces is proposed and solved for various experimental conditions. The method can be extended to study the ER effects of coated particles, crystalline particles, and to the magnetorheological effects of paramagnetic particles. Moreover, the nonlinear ER effects under a strong applied field will be studied by the same approach. The results may help in the preparation of materials for the design of ER fluids.

Desenvolvimento de forma farmacêutica líquida de uso oral, isenta de substâncias glicogênicas, com extrato fluido de Mikania glomerata Sprengel - Asteraceae (guaco

Directory of Open Access Journals (Sweden)

N.C. Lubi

Full Text Available Mikania glomerata Sprengel, Asteraceae (guaco é tradicionalmente empregado como expectorante na forma de infusão, extrato fluido, tintura e xarope. Este trabalho teve como objetivo o desenvolvimento de uma forma farmacêutica líquida, isenta de substâncias glicogênicas, veiculando o extrato fluido desta, como substituto do xarope de guaco para pessoas, que por alguma restrição não possam ingerir sacarose ou açúcar invertido, componente dos xaropes em geral. Desenvolveu-se uma formulação líquida, definindo-se as concentrações de conservantes, agentes umectantes, edulcorantes e flavorizantes, testaram-se polímeros, espessantes usuais em processos tecnológicos, para reproduzir a viscosidade fornecida pelos xaropes. Analisou-se o comportamento reológico e uma avaliação preliminar das características físicas do produto. Dos polímeros testados, o alginato de sódio (1% foi o que apresentou melhores resultados frente aos parâmetros analisados, com comportamento reológico semelhante ao dos fluidos Newtonianos, e pH adequado ao uso oral, além da compatibilidade frente ao extrato fluido de guaco.

Fisiologia do transporte de fluidos e solutos atraves da membrana peritoneal

OpenAIRE

Aguirre,Anna Rita; Abensur,Hugo

2014-01-01

Nesta revisão, são explicados os fenômenos envolvidos nas trocas de fluidos e solutos através da membrana peritoneal, tanto na situação fisiológica quanto no contexto da diálise peritoneal. Para tanto, são utilizados os modelos matemáticos desenvolvidos para estudo do transporte pela membrana, tais como o "Modelo de Poros" e o "Modelo Distributivo". Os ganhos científicos com as pesquisas nesse campo são contemplados e as áreas q...

Control of repulsive force in a virtual environment using an electrorheological haptic master for a surgical robot application

Science.gov (United States)

Oh, Jong-Seok; Choi, Seung-Hyun; Choi, Seung-Bok

2014-01-01

This paper presents control performances of a new type of four-degrees-of-freedom (4-DOF) haptic master that can be used for robot-assisted minimally invasive surgery (RMIS). By adopting a controllable electrorheological (ER) fluid, the function of the proposed master is realized as a haptic feedback as well as remote manipulation. In order to verify the efficacy of the proposed master and method, an experiment is conducted with deformable objects featuring human organs. Since the use of real human organs is difficult for control due to high cost and moral hazard, an excellent alternative method, the virtual reality environment, is used for control in this work. In order to embody a human organ in the virtual space, the experiment adopts a volumetric deformable object represented by a shape-retaining chain linked (S-chain) model which has salient properties such as fast and realistic deformation of elastic objects. In haptic architecture for RMIS, the desired torque/force and desired position originating from the object of the virtual slave and operator of the haptic master are transferred to each other. In order to achieve the desired torque/force trajectories, a sliding mode controller (SMC) which is known to be robust to uncertainties is designed and empirically implemented. Tracking control performances for various torque/force trajectories from the virtual slave are evaluated and presented in the time domain.

Control of repulsive force in a virtual environment using an electrorheological haptic master for a surgical robot application

International Nuclear Information System (INIS)

Oh, Jong-Seok; Choi, Seung-Hyun; Choi, Seung-Bok

2014-01-01

This paper presents control performances of a new type of four-degrees-of-freedom (4-DOF) haptic master that can be used for robot-assisted minimally invasive surgery (RMIS). By adopting a controllable electrorheological (ER) fluid, the function of the proposed master is realized as a haptic feedback as well as remote manipulation. In order to verify the efficacy of the proposed master and method, an experiment is conducted with deformable objects featuring human organs. Since the use of real human organs is difficult for control due to high cost and moral hazard, an excellent alternative method, the virtual reality environment, is used for control in this work. In order to embody a human organ in the virtual space, the experiment adopts a volumetric deformable object represented by a shape-retaining chain linked (S-chain) model which has salient properties such as fast and realistic deformation of elastic objects. In haptic architecture for RMIS, the desired torque/force and desired position originating from the object of the virtual slave and operator of the haptic master are transferred to each other. In order to achieve the desired torque/force trajectories, a sliding mode controller (SMC) which is known to be robust to uncertainties is designed and empirically implemented. Tracking control performances for various torque/force trajectories from the virtual slave are evaluated and presented in the time domain. (paper)

Isotopic Evolution of Wells in the Geothermal Field of Los Azufres, Michoacan, Mexico; Evolucion isotopica de fluidos de pozos del campo geotermico de Los Azufres, Michoacan, Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Portugal Marin, Enrique; Arellano Gomez, Victor Manel; Aragon Aguilar, Alfonso [Instituto de Investigaciones Electricas (Mexico); Sandoval Medina, Fernando [Comision Federal de Electricidad (Mexico)

2002-12-01

Isotopic ({delta}{sup 1}8 O and {delta}D) data from production and reinjection web fluids from the Los Azufres geothermal field were interpreted in order to define reservoir evolution and the occurrence of physical processes as a result of exploitation. The study included data of 30 wells, which were sampled in September, 2000. General results indicate that different phenomena seem to occur in both zones of the field. In the southern zone there are two different trends of behavior: a mixture of fluids evidenced by the {delta}D versus {delta}{sup 1}8 O trend with a positive slope, was interpreted as the result of reservoir vapor separation at a temperature above 220 Celsius degrees, since for temperatures above 220 Celsius degrees deuterium behaves as a volatile component. No well-defined {delta}{sup D} vs {delta}{sup 1}8 O trend was found for the northern zone, but some points seem to fit the same negative slope trend found in the souther zone. The study of reservoir temperatures estimated by different approaches for particular wells through time, as well as temperature results obtained with a heat and flow well simulator, suggest that reservoir boiling occurs in localized areas in both zone of the field. This process is probably due to exploitation. [Spanish] Se interpretaron datos isotopicos ({delta}{sup 1}8 O y {delta}D) de fluidos de pozos productores y de reinyeccion del campo geotermico de Los Azufres, Michoacan, Mexico, para definir la evolucion del yacimiento y la ocurrencia de procesos fisicos como resultado de la explotacion. En el estudio se consideran datos de treinta pozos segun el muestreo realizado en septiembre de 2000. El estudio de la evolucion en el tiempo de las estimaciones de temperatura de yacimiento mediante diferentes tecnicas, asi como la temperatura obtenida de simulacion de pozos, sugiere que ocurre ebullicion en areas localizadas en ambas zonas del campo debido a la explotacion. Los resultados generales indican la existencia de

Aplicación de la tecnología de los fluidos supercríticos a la purificación de carbohidratos prebióticos

OpenAIRE

Montañés Salcedo, Fernando Óscar

2010-01-01

En la presente memoria se exponen los resultados más relevantes obtenidos durante la realización del trabajo de investigación titulado “Aplicación de la tecnología de fluidos supercríticos a la purificación de carbohidratos prebióticos”, en el que se ha estudiado la posibilidad de fraccionar mezclas complejas de carbohidratos procedentes de isomerizados mediante una tecnología limpia de extracción, como es la extracción con fluidos supercríticos (SFE). Este enfoque resulta completamente noved...

Invasion of geothermal fluids into hydrocarbon reservoirs; La invasion de fluidos geotermicos en yacimientos de hidrocarburos

Energy Technology Data Exchange (ETDEWEB)

Suarez Arriaga, Mario Cesar [Universidad Michoacana, Facultad de Ciencias, Morelia, Michoacan (Mexico)]. E-mail: msuarez@umich.mx

2009-01-15

Oil reservoirs beneath the coast of the Gulf of Mexico contain geothermal brine at 150 degrees Celsius and produce a mixture of hot brine and oil. Water from an aquifer 6000 m deep flows vertically through conductive faults. These nonisothermal conditions affect the effective saturations and the relative permeability of the immiscible phases. Dynamic viscosities of oil and water diminish, affecting the displacement of both fluids. Studied wells produce from the oil-saturated zone above the aquifer, yet the total volume of produced water can equal or exceed the volume of oil. The presence of water is a severe problem. We produced an original numerical model able to predict the critical production when the wells start to be invaded by geothermal brine. The model has a single equation in partial derivatives, of a parabolic and nonlineal type, which is a function of water saturation, three-dimension space and time. A gas phase can be included in the model. This equation is a generalization of the classic isothermal result of Buckley-Leverett, in a single dimension. The model is solved numerically by using the Finite Element method on a nonstructured network. The historic effect of water invasion observed in some critical cases is reproduced. After production with both phases stable, a sudden brine invasion can occur with a sharp reduction of the oil volume produced. The immediate objective is to optimize the production so the well will be able to produce a stable water-oil mix where oil always prevails. [Spanish] Se reportan reservorios de aceite situados en la costa del Golfo de Mexico que son invadidos por salmuera geotermica con una temperatura de 150 grados centigrados, produciendo una mezcla variable de agua caliente y aceite. El agua de un acuifero, a 6000 metros de profundidad, fluye verticalmente por fallas conductivas. Estas condiciones no isotermicas afectan las saturaciones efectivas y las permeabilidades relativas de las fases inmiscibles. Las viscosidades

Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

Directory of Open Access Journals (Sweden)

Carlos Vallejos

2014-12-01

Full Text Available La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes de desechos tecnológicos. Como resultado de la investigación se concluyó que tales imanes son aptos para este propósito, con un rango de optimización en la combustión del gas de entre el 13 y el 20%. Esto pudo demostrarse mediante la aplicación de principios generales de la mecánica de fluidos, del campo magnético y de la termodinámica. Los resultados contribuyen a la búsqueda de estrategias para disminuir el uso de combustibles fosiles en los hogares y otros espacios donde se utiliza gas licuado para la cocción de los alimentos, así cómo para contribuir al bienestar de la microeconomía.

Desenvolvimento embrionário de oócitos bovinos mantidos em fluido folicular bovino de folículos de diferentes diâmetros

Directory of Open Access Journals (Sweden)

Lucio Pereira Rauber

2003-01-01

Full Text Available Oócitos bovinos têm sido mantidos em fluido folicular como meio para transporte e para aumento de sua competência, antes da maturação. Oitocentos e oitenta e um (881 oócitos foram aspirados de folículos de 2 a 8mm, de ovários de abatedouro, para avaliar o efeito da manutenção de oócitos bovinos em fluido folicular bovino de folículos de diferentes tamanhos sobre o desenvolvimento embrionário. Os oócitos foram distribuídos aleatoriamente em quatro tratamentos, com sete repetições cada. No grupo controle (n=217, os oócitos foram maturados por 24h em TCM-199 com Soro de Égua em Estro (SEE, piruvato e rFSH-h, em estufa a 39°C, com 5,00% de CO2 e umidade saturada. No tratamento FFpequeno (n=216, os oócitos foram mantidos por 6h em fluido folicular de folículos de 3 a 5mm a 30°C e posteriormente maturados por 18h nas mesmas condições do grupo controle. Os oócitos dos tratamentos FFmédio (n=226 e FFgrande (n=222 foram mantidos em fluido folicular de folículos com 5,1 a 8mm e folículos maiores de 8,1mm, respectivamente e, após, maturados por 18h. Após a fecundação por 18h, os zigotos foram cultivados por 8 dias em SOFaaci com 5,00% de SEE, em estufa a 39°C, em bolsas gaseificadas com 5,00%CO2, 5,00%O2 e 90,00%N2. Oócitos do grupo FFpequeno resultaram em menor (P;0,05 entre os grupos. O fluido folicular de folículos médios e grandes pode ser utilizado para o manutenção de oócitos bovinos por 6h a 30°C, antes da maturação por 18h.

Utilização de código aberto de dinâmica de fluidos computacional para estudo de placas de orifício

OpenAIRE

Thiago Teixeira Kunz

2014-01-01

Este trabalho apresenta simulações numéricas de escoamento de fluidos através de placas de orifício, elementos primários de medição de vazão, em comparação aos resultados esperados por normas internacionais. O coeficiente de descarga usado para a determinação da vazão de um escoamento em uma tubulação foi obtido numericamente através da aplicação do modelo de turbulência de baixo Reynolds proposto por Launder-Sharma, resolvido através de um código aberto de Dinâmica de Fluidos Computacional. ...

SIMULACIÓN NUMÉRICA DE FLUJO MONOFÁSICO DE FLUIDOS ACOPLADO A DEFORMACIÓN GEOMECÁNICA

Directory of Open Access Journals (Sweden)

MARIA ADELAIDA ARANGO ACEVEDO

2010-01-01

Full Text Available La simulación de flujo de fluidos en medios porosos es usada en la industria petrolera como herramienta para caracterizar yacimientos. Sin embargo, el análisis se ha llevado a cabo de manera convencional con suposiciones que deben ser levantadas para los yacimientos con complejidades no consideradas anteriormente. En la actualidad se encuentra que los yacimientos no son ideales como se pensaba y que las propiedades petrofísicas varían¿ esta es la base de la simulación acoplada a geomecánica. La ecuación de flujo de fluidos se plantea para un yacimiento naturalmente fracturado con flujo monofásico y se acopla con las ecuaciones de deformación por medio de las relaciones de esfuerzo ¿ deformación ¿ presión. Estas son resueltas usando la técnica de diferencias finitas y un método iterativo tipo Picard. El resultado es un simulador numérico para la interpretación de pruebas de presión que considera los cambios de la permeabilidad con la variación del esfuerzo utilizando el módulo de permeabilidad.

Efeito do Arrefecimento Causado pelo Fluido Durante a Soldagem em Operação em Tubulações com Espessura de Parede de 6 e 11 mm

Directory of Open Access Journals (Sweden)

Jefferson Pinto Soares

Full Text Available Resumo Este trabalho compara a influência do arrefecimento causado por um fluído em circulação e em contato com a parede interna de uma tubulação, que caracteriza a soldagem em operação. Foram avaliadas duas espessuras de parede do tubo e duas temperaturas do fluido interno. A soldagem foi realizada na ligação de conexões de aço ASTM A105 a um tubo API 5L Gr X60 com espessura de 11 mm e de 6 mm, utilizando os processos TIG (GTAW e eletrodo revestido (SMAW. A circulação do fluido foi feita com água potável em duas faixas de temperatura, de 6 a 10 °C e 18 a 36 °C. Durante a soldagem, a temperatura interna do tubo e a taxa de resfriamento foram monitoradas. Foram preparadas quatro juntas soldadas, avaliadas por ensaios não destrutivos (inspeção visual, líquido penetrante, partículas magnéticas e ultrassom, ensaios destrutivos (tração, dobramento, impacto, fratura e dureza e análise macrográfica e micrográfica. Os resultados mostram que, com os procedimentos adotados, não é necessária a adoção de cuidados especiais quanto à possibilidade de perfuração e vazamento de fluido durante a soldagem em operação. Houve evidencias que o efeito do arrefecimento do fluido no interior do tubo foi mais significativo que a espessura da parede do tubo no aumento da taxa de resfriamento. Ainda, a temperatura do fluido em circulação no tubo exerceu papel secundário no aumento da taxa de resfriamento e na redução da temperatura máxima na parede interna do tubo. O arrefecimento causado pelo fluido provocou aumento na dureza da ZF e ZTA, reduziu o alongamento no ensaio de tração, porém ainda em valores adequados. Estes comportamentos foram mais observados no tubo de menor espessura, de 6 mm. Foi possível, pelos resultados dos ensaios não destrutivos e ensaios mecânicos obtidos, qualificar os procedimentos de soldagem, com base nas normas especializadas neste processo.

a New ER Fluid Based Haptic Actuator System for Virtual Reality

Science.gov (United States)

Böse, H.; Baumann, M.; Monkman, G. J.; Egersdörfer, S.; Tunayar, A.; Freimuth, H.; Ermert, H.; Khaled, W.

The concept and some steps in the development of a new actuator system which enables the haptic perception of mechanically inhomogeneous virtual objects are introduced. The system consists of a two-dimensional planar array of actuator elements containing an electrorheological (ER) fluid. When a user presses his fingers onto the surface of the actuator array, he perceives locally variable resistance forces generated by vertical pistons which slide in the ER fluid through the gaps between electrode pairs. The voltage in each actuator element can be individually controlled by a novel sophisticated switching technology based on optoelectric gallium arsenide elements. The haptic information which is represented at the actuator array can be transferred from a corresponding sensor system based on ultrasonic elastography. The combined sensor-actuator system may serve as a technology platform for various applications in virtual reality, like telemedicine where the information on the consistency of tissue of a real patient is detected by the sensor part and recorded by the actuator part at a remote location.

Ambientes Virtuales Para la enseñanza de la Mecánica de Fluidos: Algunos ejemplos simplificados aplicando ANSYS

Directory of Open Access Journals (Sweden)

Watson L. Vargas

2005-01-01

Full Text Available Para que un ambiente de enseñanza virtual pueda soportar un aprendizaje real, dichos ambientes deben proveer interacciones enseñanza-aprendizaje de alto nivel. En este artículo, se muestra como una herramienta computacional como ANSYS puede proveer un ambiente virtual para el aprendizaje de la mecánica de fluidos no sólo a nivel de pregrado si no también a niveles superiores. Las simulaciones computacionales, --aplicando ANSYS/FLOTRAN-CFD o cualquiera otro software de capacidades similares--, en el contexto de la enseñanza de la mecánica de fluidos son de interés fundamental dado que soportan un ambiente de simulación poderoso que puede aplicarse no sólo a la comprensión de ideas y conceptos fundamentales sino tambien al diseño y optimización de procesos de aplicación práctica

Avaliação da sensibilidade dolorosa e fatores envolvidos na qualidade da amostra citológica do fluxo papilar: resultados preliminares da utilização de sistema automatizado de coleta Assessment of pain sensitivity and factors involved in the quality of the sample fluid cytologic papillary: preliminary results from the use of automated collection

Directory of Open Access Journals (Sweden)

José Roberto Filassi

2010-10-01

Full Text Available OBJETIVO: avaliar a sensibilidade dolorosa e os fatores envolvidos na produção de fluido papilar adequado para análise de citologia oncótica, por meio de sistema automatizado de coleta. MÉTODOS: foram selecionadas 50 mulheres assintomáticas, sem antecedente pessoal ou familiar de câncer de mama, fora do ciclo gravídico-puerperal para coleta de fluido papilar por meio de sistema automatizado. Foram registradas e relacionadas com a produção de fluido papilar a idade da paciente, tabagismo, antecedente de cirurgia mamária, paridade, amamentação, estado menopausal e idade da menarca. Todo o material coletado foi fixado em meio apropriado, e encaminhado separadamente para análise de citologia oncótica. A sensibilidade dolorosa do procedimento de coleta foi avaliada por meio da Escala Category-Ratio Scale (CR10 de Borg. RESULTADOS: a idade variou de 22 a 59 anos, média de 41,6±8,6 anos. Das 50 pacientes, 20 (40% não apresentaram fluido papilar adequado para análise em nenhuma das mamas. Naquelas pacientes que se obteve fluido papilar adequado para análise de citologia oncótica, a paridade esteve inversamente relacionada com a capacidade de obter amostra celular adequada, nível de significância estatística (p=0,035, OR=0,0032 (IC 95%=0,0001-0,1388. Em relação à sensibilidade dolorosa, o exame foi bem tolerado. CONCLUSÕES: o método automatizado de coleta de fluido papilar para análise de citologia oncótica foi bem tolerado pelas mulheres tendo produzido material analisável em 60% dos casos, esteve inversamente relacionado com a paridade.PURPOSE: to evaluate painful sensitivity and factors involved in producing papillary fluid suitable for cytological analysis by means of automated collection. METHODS: we selected 50 asymptomatic women without a personal or family history of breast cancer, outside the pregnancy and childbirth cycle in order to collect papillary fluid by the automated system. We recorded and related to the

Oil base fluids without tensoactive additives; Fluidos a base de oleo sem tensoativos

Energy Technology Data Exchange (ETDEWEB)

Machado, Jose Carlos V; Aragao, Atila Fernando L [PETROBRAS, XX (Brazil). Centro de Desenvolvimento de Recursos Humanos Norte e Nordeste

1990-12-31

The goal of this paper is to define an ideal oil base fluid composition without tensoactive additives, since these may cause damage to producing formation during drilling or well completion. We investigated the rheological, filtrating and phase separation properties of the systems composed of diesel oil, organophilic clay and a polar agent (water or ethyl alcohol). In order to to that, we used the 286 Baroid digital rotating viscometer, filtrating cells standardized according to the American Petroleum Institute (AP) for temperatures of 25 deg C to 149 deg C and pressures of 6,89 x 10{sup 5} Pa (100 psig) to 3,44 x 10{sup 6} (500 psig), and the setting method, according to the determinations of respectively rheological, filtrating and phase separation parameters. Results proved that the composition: diesel oil-94% v/v, Na Cl saturated solution - 6% v/v and bentone - 17,1 to 22,8 kg/m{sup 3} (6 to 8 lb/bbl), is ideal to meet the properties required for drilling and well completion operations for low densities, that is 0,84% to 1,02 (6,9 to 8,5 ib/gal). In order to obtain densities in the interval of 1,02 to 1,14 (8,5 to 9,5 ib/gal) the system should be condensed with calcite (Ca CO{sub 3}) and the base fluid composition should be : diesel oil-94 to 98% v/v, Na Cl saturated solution - 2 to 6% v/v and bentone 17,1 to 22,8 kg/m{sup 3} (6 to 8 ib/bbl). The average cost per barrel for the systems studied here is of the same order of conventional oil base fluids (with tensoactive additives). (author) 13 refs., 7 figs., 3 tabs.

Oil base fluids without tensoactive additives; Fluidos a base de oleo sem tensoativos

Energy Technology Data Exchange (ETDEWEB)

Machado, Jose Carlos V.; Aragao, Atila Fernando L. [PETROBRAS, XX (Brazil). Centro de Desenvolvimento de Recursos Humanos Norte e Nordeste

1989-12-31

The goal of this paper is to define an ideal oil base fluid composition without tensoactive additives, since these may cause damage to producing formation during drilling or well completion. We investigated the rheological, filtrating and phase separation properties of the systems composed of diesel oil, organophilic clay and a polar agent (water or ethyl alcohol). In order to to that, we used the 286 Baroid digital rotating viscometer, filtrating cells standardized according to the American Petroleum Institute (AP) for temperatures of 25 deg C to 149 deg C and pressures of 6,89 x 10{sup 5} Pa (100 psig) to 3,44 x 10{sup 6} (500 psig), and the setting method, according to the determinations of respectively rheological, filtrating and phase separation parameters. Results proved that the composition: diesel oil-94% v/v, Na Cl saturated solution - 6% v/v and bentone - 17,1 to 22,8 kg/m{sup 3} (6 to 8 lb/bbl), is ideal to meet the properties required for drilling and well completion operations for low densities, that is 0,84% to 1,02 (6,9 to 8,5 ib/gal). In order to obtain densities in the interval of 1,02 to 1,14 (8,5 to 9,5 ib/gal) the system should be condensed with calcite (Ca CO{sub 3}) and the base fluid composition should be : diesel oil-94 to 98% v/v, Na Cl saturated solution - 2 to 6% v/v and bentone 17,1 to 22,8 kg/m{sup 3} (6 to 8 ib/bbl). The average cost per barrel for the systems studied here is of the same order of conventional oil base fluids (with tensoactive additives). (author) 13 refs., 7 figs., 3 tabs.

Estudo dos métodos de extração de carotenóides em cenoura por fluido supercrítico (efs e convencional A study of the methods of carotenoid extraction in carrots using supercritical fluid extraction (sfe and conventional methods

Directory of Open Access Journals (Sweden)

Ellem Waleska Nascimento da Fonseca Contado

2010-12-01

Full Text Available A cenoura (Daucus carota L. , planta da família das umbelíferas, produz uma raiz aromática e comestível, sendo uma das hortaliças mais cultivadas no Brasil. Representa a principal fonte de origem vegetal em carotenóides pró-vitamínicos A, especialmente o á e o β-caroteno, sendo, também, uma grande fonte de fibra dietética, antioxidantes e minerais. Conduziu-se este trabalho, com o objetivo de avaliar dois processos de extração de β-caroteno, fluído super crítico (EFS e o convencional e analisar a composição centesimal da cenoura in natura. O teor de β-caroteno obtido pela extração por EFS e por convencional foi de 2.457 e 2.455 µg/100g, respectivamente. Os valores médios encontrados para a matéria-seca da cenoura foram de: matéria-seca = 8,9%; extrato etéreo = 0,29%; cinzas = 8,11%; fibra bruta = 14,57%, proteína bruta = 6,4%, extrato não nitrogenado = 6,3% e valor calórico = 27,7kcal. Conclui-se que a extração de carotenóides em cenoura pelo fluido supercritico é uma técnica de separação viável, pois este fluido é inerte, não deixa resíduo final e não gera resíduo ambiental. Pelos teores encontrados conclui-se também que as cenouras são boas fontes de fibras, apresentam alto teor de umidade e baixo teor de gorduras, cinzas e valor calórico.The carrot (Daucus carota L. is a plant of the Umbelliferae family. It produces an aromatic and edible root, and is one of the most widely cultivated vegetable in Brazil. It represents the main source of plant-origin, pro-vitamin A carotenoids, especially α and β-carotene, and is also a great source of dietary fiber, antioxidants and minerals. This study aimed to evaluate two methods of extraction of β-carotene, supercritical fluid (SFE and conventional, and to examine the proximate composition of the carrot in nature. The contents of β-carotene obtained by SFE and by conventional extraction were 2,457 and 2,455 µg/100g, respectively. The average values found

Water and clay based drilling fluids for oil wells; Fluidos hidroargilosos para perfuracao de pocos de petroleo

Energy Technology Data Exchange (ETDEWEB)

Medeiros, R.C.A. de; Amorim, L.V.; Santana, L.N. de L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil)], e-mail: nalealves@hotmail.com

2008-07-01

In the onshore drilling of wells are commonly used aqueous fluids containing bentonite clays. However, to perform their functions generally there is the necessity of additives to drilling fluids, like viscositying, filtered reducer and lubricant. Thus, this work aims to develop water and clay base drilling fluids with low solid text, and with polymeric and lubricants additives. Were studied a sample of industrialized sodium bentonite clays, three polymeric compounds in the ternary form and a sample of lubricant, in different concentrations. Were determined the flow curves, the apparent and plastic viscosities, the yield limit and gel force in Fann 35A viscometer, the filtered volume in API filter-press and the lubricity coefficient in Ofite lubricimeter. The results showed that the fluid had pseudoplastic behavior, the polymeric additives adjusts their rheological properties and filtration and the addition of 1% of lubricant is sufficient to improve the lubricity of fluids. (author)

Funcionamiento de un termosifón cilíndrico con distintos fluidos de trabajo

OpenAIRE

Arcís Tellería, José

2010-01-01

Actualmente, las investigaciones llevadas a cabo en el campo de la transmisión de calor mediante termosifón, tratan de conocer el comportamiento de las distintas sustancias, con el fin de optimizar dicha tecnología para la transferencia de calor. En este sentido, en el Área de Máquinas y Motores Térmicos, perteneciente al Departamento de Ingeniería Mecánica, Energética y de Materiales de la Universidad Pública de Navarra, se está llevando a cabo un proyecto de investigación con fluidos de tra...

Effect of Temperature and Electric Field on the Damping and Stiffness Characteristics of ER Fluid Short Squeeze Film Dampers

Directory of Open Access Journals (Sweden)

H. P. Jagadish

2013-01-01

Full Text Available Squeeze film dampers are novel rotor dynamic devices used to alleviate small amplitude, large force vibrations and are used in conjunction with antifriction bearings in aircraft jet engine bearings to provide external damping as these possess very little inherent damping. Electrorheological (ER fluids are controllable fluids in which the rheological properties of the fluid, particularly viscosity, can be controlled in accordance with the requirements of the rotor dynamic system by controlling the intensity of the applied electric field and this property can be utilized in squeeze film dampers, to provide variable stiffness and damping at a particular excitation frequency. The paper investigates the effect of temperature and electric field on the apparent viscosity and dynamic (stiffness and damping characteristics of ER fluid (suspension of diatomite in transformer oil using the available literature. These characteristics increase with the field as the viscosity increases with the field. However, these characteristics decrease with increase in temperature and shear strain rate as the viscosity of the fluid decreases with temperature and shear strain rate. The temperature is an important parameter as the aircraft jet engine rotors are located in a zone of high temperature gradients and the damper fluid is susceptible to large variations in temperature.

Response to exploitation (1982-2002) of the Los Azufres, Michoacan (Mexico) geothermal field. Part II: South Zone; Respuesta a la explotacion (1982-2003) del yacimiento geotermico de Los Azufres, Michoacan (Mexico). Parte II: Zona Sur

Energy Technology Data Exchange (ETDEWEB)

Arellano G, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico); Torres R, Marco Antonio [Comision Federal de Electricidad, Morelia, Michoacan (Mexico); Barragan R, Rosa Maria [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico); Sandoval M, Fernando [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

2005-06-01

The paper describes the thermodynamic evolution of fluids in the Los Azufres geothermal field's southern zone reservoir, as a response to exploitation from 1982 to 2002. Thermodynamic conditions for the reservoir fluids were estimated with production data using the WELFLO heat-and-flow well simulator. In the southern zone, initial fluid thermodynamic conditions indicated that compressed liquid, two-phase fluids and vapor occurred in the reservoir, depending on the well depths. The fist response to exploitation consisted in a pressure drop an enthalpy increase. For the long term, the following patterns have been identified: pressure and mass flow-rate drop, boiling, cooling, vapor production and in some wells affected by injection an increase in both pressure and mass flow rate. The isotopic results of well fluids in the southern zone showed the occurrence of two processes. The first, with a positive slope, indicates a mixing of reservoir and injection fluids and mainly affects wells Az-2, Az-16, Az-33, Az-36 and Az-46. The second, with a negative slope, results from the original processes of reservoir steam separation and partial condensation. [Spanish] En este trabajo se presenta un estudio sobre la evolucion termodinamica de los fluidos de la zona sur del yacimiento de Los Azufres, como respuesta a la extraccion e inyeccion de fluidos, desde el inicio de su explotacion en 1982 hasta el ano 2002. Las condiciones termodinamicas de los fluidos del yacimiento se estimaron mediante el simulador de flujo de fluidos y calor en pozos WELFLO, a partir de datos de produccion. Las condiciones termodinamicas iniciales de los fluidos de la zona sur, indicaron la existencia de liquido comprimido, dos fases con liquido dominante y dos fases con vapor dominante, dependiendo de la profundidad de los pozos. La respuesta inicial de la zona sur a la explotacion consistio en una disminucion de la presion y un aumento en la entalpia mientras que a mas largo plazo se han observado

Optimization of surfactant application for synthetic drilling fluid; Otimizacao da aplicacao de emulsificante em fluidos de perfuracao sinteticos

Energy Technology Data Exchange (ETDEWEB)

Arruda, Jefferson Teixeira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Santos, Telma Pitanga; Medeiros, Ana Catarina da Rocha; Garcia, Rosangela Balaban [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Lab. de Pesquisa em Petroleo

2008-07-01

The most common synthetic drilling fluids are made of polymerized olefins, paraffin and esters, which have absence of aromatics hydrocarbons and biodegradability as advantages. These fluids have good performance during the drilling operations (high thermal stability) and have low toxicity. Nevertheless, their big disadvantage is the high cost, which limits their use. One of the biggest challenges in working with synthetic fluids is the control of water/oil emulsion stability, being the surfactant the main agent responsible for keeping this stability between both phases of the fluid. The water/oil and oil/water emulsion is defined by the chemical nature of the surfactant. The emulsions can be changed from oil/water to water/oil and vice versa by many mechanisms, such as temperature variation, addition of another surfactant and alteration of the disperse phase volumetric percentage. The aim of this work was the optimization of synthetic drilling fluids formulations by using commercial surfactants. The optimized formulations showed similar rheological properties. After aging at high temperature (300 deg F), some tendency to migration of oil phase in both fluids was observed. This result was associated to the fluid's viscosity. However, the formulations showed high electrical stability, indicating formation of stable emulsions. The HTHP filtration volumes were small. (author)

Análise teórica da recuperação de calor para geração de energia em indústrias de cimento e cal utilizando o ciclo de Rankine orgânico

Directory of Open Access Journals (Sweden)

Ricardo Carrasco Carpio

2015-06-01

Full Text Available O presente trabalho consiste em uma apresentação do estado da arte do Ciclo Rankine Orgânico, um ciclo termodinâmico que usa um fluido orgânico como fluido de trabalho e que pode ser usado para recuperação de calor rejeitado em processos industriais, gerando assim energia elétrica para abastecer a própria indústria, o que consequentemente causa uma redução no custo de produção da empresa. São apresentados alguns fluidos orgânicos e alguns de seus parâmetros termodinâmicos.Palavras-chave: Cogeração. Ciclo Rankine Orgânico. Fluidos de Trabalho.ABSTRACTTheoretical analysis of heat recovery for power generation in cement and lime industries using the organic Rankine cycleThis work aims to present the state of the art of the Organic Rankine Cycle, a thermodynamic cycle that uses an organic fluid as a working fluid that can be used to recover the rejected heat in industrial processes, thus generating electricity to supply industry itself, which causes a reduction in the production cost of the company. It also presents some organic fluids and some of their thermodynamic parameters.Keywords: Cogeneration. Organic Rankine Cycle. Working Fluids.

Fisiologia do transporte de fluidos e solutos atraves da membrana peritoneal

Directory of Open Access Journals (Sweden)

Anna Rita Aguirre

2014-03-01

Full Text Available Nesta revisão, são explicados os fenômenos envolvidos nas trocas de fluidos e solutos através da membrana peritoneal, tanto na situação fisiológica quanto no contexto da diálise peritoneal. Para tanto, são utilizados os modelos matemáticos desenvolvidos para estudo do transporte pela membrana, tais como o "Modelo de Poros" e o "Modelo Distributivo". Os ganhos científicos com as pesquisas nesse campo são contemplados e as áreas que merecem pesquisas adicionais também são citadas. Assim, o estado atual do conhecimento fisiológico a respeito dessa modalidade de terapia renal substitutiva, no que se refere aos eventos relacionados à membrana peritoneal, encontra-se sintetizado nesse manuscrito.

Experiencias en el uso de la ORIMATITA® como densificante de fluidos de perforación en el Norte de Monagas, Venezuela

NARCIS (Netherlands)

Rengifo, R.; Quercia Bianchi, G.; Quiroga, F.; Chacón, O.; Ojeda, F.; Rollinson, J.; Rivers, R.; Tovar, J.G.

2004-01-01

La barita ha sido predominantemente el material densificante usado en los fluidos de perforación. Las minas de barita se encuentran ubicadas lejos de los centros de consumo, lo cual, debido al transporte, incrementa el costo final del mineral. En Venezuela, dentro de la industria petrolera nacional,

Multiple sclerosis test or the 4 humors: cerebrospinal fluid serum, tears and saliva; Esclerosis multiple test de los 4 humores: liquido cefalorraquideo, suero, lagrimas y saliva

Energy Technology Data Exchange (ETDEWEB)

Oehninger Gatti, C; Buzo Del Puerto, R; Chouza Antelo, C; Scotti Bianchi, C; Cibils, D; Alcantara Pelaez, J; Gomez, A; Heuguerot Oliveira, C

1994-12-15

4 were studied biological fluids easily accessible to the immune exploration (cerebrospinal fluid, serum, tears and saliva) in 25 patients with Multiple Sclerosis (MS) during a push clinical disease. The level of interleukin-2 receptor soluble (RsIL-2) was significantly increased by at least 3 of these 4 fluids, compared with normal controls. The sensitivity and specificity of its determination for the diagnosis of the condition was higher than other immunochemical parameters, oligoclonal distribution (OD) of immunoglobulin (Ig) light chain imbalance-and-evoked electrophysiological studies. This method is used to establish a more accurate diagnosis of Multiple Sclerosis as well as to monitor its biological activity with nuclear magnetic resonance (NMR) (Author) [Spanish] Se estudiaron 4 fluidos biologicos de facil acceso a la exploracion inmune (liquido cefalorraquideo, suero, lagrimas y saliva) en 25 pacientes con Esclerosis Multiple (EM) obtenidos durante un empuje clinico de la enfermedad. El nivel del receptor de Interleukina-2 soluble (RsIL-2) se encontro significativamente aumentado en por lo menos 3 de estos 4 fluidos, en comparacion con el de los controles normales. La sensibilidad y especificidad de su determinacion para el diagnostico de la afeccion, fue mayor que la de otros parametros inmunoquimicos - distribucion oligoclonal (DO) de inmunoglobulinas (Ig), disbalance de cadenas livianas - y estudios electrofisiologicos -potenciales evocados-. Este metodo es utilizado para establecer un diagnostico mas certero de la Esclerosis Multiple asi como tambien para monitorizar su actividad biologica junto con la resonancia magnetica nuclear (RMN)(Author)

Uso de aceites esenciales extraídos por medio de fluidos supercríticos para la elaboración de alimentos funcionales

Directory of Open Access Journals (Sweden)

Angélica Esquivel F.

2007-11-01

Full Text Available El consumo de alimentos funcionales y la tendencia a productos cada vez más naturales se ha incrementado en los últimos años, dando pie a nuevas investigaciones en el campo de la obtención de aditivos que pueden generar alimentos funcionales. En esta revisión, se discutió sobre la técnica de obtención de extractos naturales conocida como extracción por medio de fluidos supercríticos, se evaluó el método de extracción, las ventajas y desventajas de este, así como las condiciones ideales de extracción de algunos compuestos naturales que se pueden utilizar como ingredientes funcionales debido a su poder antioxidante; adicionalmente, se revisó el uso que se les está dando a los compuestos extraídos por medio de fluidos supercríticos en la ciencia de alimentos.

Caracterización del tipo de cavitación mediante dinámica computacional de fluidos para posteriores aplicaciones al estudio experimental del daño por cavitación

OpenAIRE

Moll, Flavio; Manuele, Diego; Coussirat Núñez, Miguel Gustavo; Guardo Zabaleta, Alfredo de Jesús; Fontanals García, Alfred

2011-01-01

La cavitación se corresponde a una estructura bifásica (líquido-vapor) cuando la presión del líquido disminuye hasta su presión de vapor, pv. Esta disminución de pv puede deberse a diversos factores relacionados con la hidrodinámica del flujo y las propiedades físicas del fluido, pudiendo presentar diferentes características. En la cavitación hidrodinámica, pueden distinguirse efectos que pueden producir un acoplamiento fluido-estructura (lock-in) que puede favorecen la falla del material, só...

Eficiência agronômica de fertilizantes fosfatados fluidos e sólidos

Directory of Open Access Journals (Sweden)

W.B. Scivittaro

1997-09-01

Full Text Available Um experimento para avaliar a eficiência agronômica de fertilizantes fosfatados fluidos e sólidos foi desenvolvido em casa de vegetação no Centro de Energia Nuclear na Agricultura - CENA/USP, em Piracicaba (SP, de junho a outubro de 1992. Plantas de milho foram cultivadas durante 30 dias, por três cultivos sucessivos, em vasos contendo 1 kg de dois latossolos vermelho-amarelos com diferentes capacidades de retenção de fósforo. Os fosfatos na forma fluida - ácido fosfórico e suspensão coloidal 10-30-00 e sólida - fosfato monoamônico e superfosfato triplo foram aplicados no primeiro cultivo nas doses 0, 70, 140 e 210 mg kg-1 de P2O5 (0, 30,6, 61,2 e 91,8 mg kg-1 de P. Avaliaram-se os tratamentos pelo rendimento de matéria seca, pela absorção de fósforo e pelos índices: de eficiência agronômica (IEA e equivalente em superfosfato triplo (EqST. Os resultados indicaram não haver diferenças entre as fontes fosfatadas fluidas e sólidas quanto ao seu efeito sobre a produção de matéria seca e absorção de fósforo pelas plantas de milho. Entretanto, a aplicação de doses crescentes dos fosfatos aos solos promoveu aumentos significativos no rendimento de matéria seca e absorção de fósforo. Em ambos os solos, a eficiência agronômica dos fertilizantes fosfatados fluidos e sólidos foi semelhante.

Extração por fluido supercrítico

Directory of Open Access Journals (Sweden)

Aldo Adolar Maul

Full Text Available Acima de uma certa temperatura e pressão representados pelo ponto crítico, os gases não mais podem ser liquefeitos e em função do aumento da densidade passam para o que alguns consideram um estado intermediário entre o líquido e o gasoso: tornam-se "supercríticos" e podem então agir em parte como solventes. 0 dióxido de carbono em estado supercrítico pode dissolver ou incorporar a maioria das moléculas orgânicas. Já utilizado na indústria agroalimentar, está agora entrando na indústria farmacêutica. O presente trabalho tem como objetivo apresentar o atual estágio de utilização, as vantagens e desvantagens, princípios e perspectivas de aplicação da tecnologia de extração por fluidos supercríticos, principalmente dióxido de carbono , de uma maneira ampla, na obtenção de insumos farmacêuticos e fitoterápicos.

pH, sódio, potássio, cálcio, magnésio e alumínio em solos contaminados com fluido de perfuração de poços de petróleo após ensaios de lixiviação

Directory of Open Access Journals (Sweden)

Fábio Cardoso de Freitas

2015-08-01

Full Text Available Na exploração do petróleo, o uso de fluidos de perfuração é essencial para o equilíbrio da pressão entre as formações e o interior do poço, além de impedir o refluxo do reservatório de petróleo ao poço. Os fluidos também são responsáveis pela elevação dos cascalhos de perfuração à superfície. Entretanto, estes podem ser potenciais contaminantes do ambiente, uma vez que chegam à superfície impregnados de fluidos. O trabalho objetivou avaliar o pH e os teores de Na+, K+, Ca2+, Mg2+e Al3+em um Latossolo e um Planossolo submetidos a doses de fluido de perfuração, após sofrerem dois ensaios de lixiviação. Os resultados mostraram que a adição dos fluidos ao Planossolo e Latossolo nas concentrações de 4%, 8% e 16% (m/m reduziu o alumínio tóxico a zero e promoveu aumento do pH do solo, Na+, K+e Ca2+em comparação ao controle

Avaliação do fluido peritoneal de asininos Evaluation of peritoneal fluid from asinines

Directory of Open Access Journals (Sweden)

M.F.C. Louro

2006-10-01

Full Text Available The peritoneal fluid from six female health donkeys was evaluated. In each animal, it was carried out eight abdominocentesis with 40x12 needles, at 72-hour intervals. All animals presented clinical changes, and there was higher frequency of yellow-tinged fluid with turbidity aspect. Means, and respective standard deviations, for cytology and protein concentration were: erythrocytes, 24.7±11.7x10³/mm³; leukocytes, 15.8±6.79x10³/mm³; mesothelial cells, 3.85±1.30x10³/mm³; neutrophils, 10.9±4.51x10³/mm³; lymphocytes, 1.41±0.51x10³/mm³; macrophages, 0.98±0.55x10³/mm³; eosinophils, 2.48±1.36x10³/mm³, and total proteins, 1.97±0.31 g/dl.

Planeamiento estratégico de Ingeniería de Sistemas de Fluidos S.A.C.

OpenAIRE

Arana, Fernando; Iparraguirre, Miguel; Vásquez, Mariela

2015-01-01

La finalidad del presente trabajo de investigación es la elaboración de un plan estratégico para la empresa Ingeniería de Sistemas de Fluidos SAC para los siguientes tres años. Este plan se inicia analizando el entorno externo en el que se desempeña ISF SAC, tanto el entorno general como el entorno de la industria, de esta manera conocer las oportunidades y amenazas a las que se debe enfrentar la empresa. Una vez analizado el entorno externo, se realiza el análisis interno en el cual se evalú...

Fluidos supercríticos em química analítica. II. Cromatografia com fluido supercrítico: instrumentação Supercritical fluid in analytical chemistry. II. Supercritical fluid chromatography: instrumentation

Directory of Open Access Journals (Sweden)

Emanuel Carrilho

2003-10-01

Full Text Available The first paper in this series discussed the basic theory involved in supercritical fluid chromatography (SFC and how the technique progressed from gas and liquid chromatography. The first SFC instruments were simple adaptations of the commercially available liquid chromatographs with packed columns followed by modifications in gas chromatographs using open tubular capillary columns. In this paper, the most important aspects regarding instrumentation are covered, including practical, simple, and the most important, inexpensive solutions to build a home-made SFC system.

Experimental petrology for the thermobarometric determination of mineral paragenesis: the fluid inclusions; Petrologia experimental para la determinacion termobarometrica de paragenesis minerales: las inclusiones fluidas

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Partida, Eduardo; Torres Rodriguez, Vicente; Birkle, Peter [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1994-05-01

There is a great number of phenomena in nature in which some fluid participates as the main component. Such is the case of oil deposits formation, of metallic minerals, geothermal systems, metamorphic and diagenetic deposits. The common denominator of all of them is that in some part of their stages important physico-chemical processes occurred in the related fluids, leaving evidence of such phenomena in the fluid inclusions. The Geothermal Department has petrologic vanguard tools for reservoir problems resolution, since it has laboratories for the study on fluid inclusions by means of the technique called cryoscopic-microthermometry that permits the definition of physico-chemical conditions of the brine that participated or participates in the hydrothermal systems formation. The method simultaneously permits to know the characteristics of the initial brine that participated in the interaction water-rock phenomenon, observe the boiling phenomena, and determine conditions of initial pressure in the reservoirs. [Espanol] Existe un gran numero de fenomenos en la naturaleza en los que participa algun fluido como componente principal. Tal es el caso de la formacion de yacimientos de petroleo, de minerales metalicos, de sistemas geotermicos, yacimientos metamorficos y diageneticos. El comun denominador de todos ellos es que en alguna de sus etapas ocurrieron procesos fisicoquimicos importantes en los fluidos relacionados, quedando evidencia de tales fenomenos en las inclusiones fluidas. El Departamento de Geotermia cuenta con herramientas petrologicas de vanguardia para la resolucion de problemas en yacimientos, ya que tiene laboratorios para el estudio de las inclusiones fluidas por medio de la tecnica denominada microtermometria-crioscopica que permite definir condiciones fisicoquimicas de la salmuera que participo o participa en la formacion de sistemas hidrotermales. El metodo permite simultaneamente conocer las caracteristicas de la salmuera inicial que participo en

Geochemical evidences of the boiling phenomena in Los Humeros geothermal field; Evidencias geoquimicas del fenomeno de ebullicion en el campo de Los Humeros

Energy Technology Data Exchange (ETDEWEB)

Munguia Bracamontes, Fernando; Lopez Mendiola, Juan Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

The geochemical behavior of the fluids in the geothermal field Los Humeros suggests the existence of a reservoir of relatively low permeability, with hydrostatic pressure gradients and thermodynamic conditions of pressure-temperature close to the boiling point in stationary conditions, that is, non-disturbed. Nevertheless, the fluid geochemistry also indicates the presence of steam under stationary conditions, mainly in the fault, fracture, fissure, etc. zones. The steam diminishes progressively as the extraction time increases, being replaced by boiling fluid. [Espanol] El comportamiento geoquimico de los fluidos en el campo geotermico de Los Humeros sugiere la existencia de un yacimiento de relativa baja permeabilidad, con gradientes de presion hidrostatica y condiciones termodinamicas de presion-temperatura cercanas al punto de ebullicion a condiciones estables; es decir, no perturbadas. Sin embargo, la geoquimica de los fluidos tambien indica la existencia de vapor bajo condiciones estables, principalmente en las zonas de fallas, fracturas, fisuras, etc. El vapor disminuye progresivamente conforme aumenta el tiempo de extraccion, siendo reemplazado por fluido en ebullicion.

Geochemical evidences of the boiling phenomena in Los Humeros geothermal field; Evidencias geoquimicas del fenomeno de ebullicion en el campo de Los Humeros

Energy Technology Data Exchange (ETDEWEB)

Munguia Bracamontes, Fernando; Lopez Mendiola, Juan Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1989-12-31

The geochemical behavior of the fluids in the geothermal field Los Humeros suggests the existence of a reservoir of relatively low permeability, with hydrostatic pressure gradients and thermodynamic conditions of pressure-temperature close to the boiling point in stationary conditions, that is, non-disturbed. Nevertheless, the fluid geochemistry also indicates the presence of steam under stationary conditions, mainly in the fault, fracture, fissure, etc. zones. The steam diminishes progressively as the extraction time increases, being replaced by boiling fluid. [Espanol] El comportamiento geoquimico de los fluidos en el campo geotermico de Los Humeros sugiere la existencia de un yacimiento de relativa baja permeabilidad, con gradientes de presion hidrostatica y condiciones termodinamicas de presion-temperatura cercanas al punto de ebullicion a condiciones estables; es decir, no perturbadas. Sin embargo, la geoquimica de los fluidos tambien indica la existencia de vapor bajo condiciones estables, principalmente en las zonas de fallas, fracturas, fisuras, etc. El vapor disminuye progresivamente conforme aumenta el tiempo de extraccion, siendo reemplazado por fluido en ebullicion.

Directed line liquids

International Nuclear Information System (INIS)

Kamien, R.D.

1992-01-01

This thesis is devoted to the study of ensembles of dense directed lines. These lines are principally to be thought of as polymers, though they also have the morphology of flux lines in high temperature superconductors, strings of colloidal spheres in electrorheological fluids and the world lines of quantum mechanical bosons. The authors discuss how directed polymer melts, string-like formations in electrorheological and ferro-fluids, flux lines in high temperature superconductors and the world lines of quantum mechanical bosons all share similar descriptions. They study a continuous transition in all of these systems, and then study the critical mixing properties of binary mixtures of directed polymers through the renormalization group. They predict the exponents for a directed polymer blend consolute point and a novel two-phase superfluid liquid-gas critical point

Fortificação do leite fluido na prevenção e tratamento da anemia carencial ferropriva em crianças menores de 4 anos Fortification of fluid milk for the prevention and treatment of iron defficiency anemia in children under 4 years of age

Directory of Open Access Journals (Sweden)

Marco A. A. Torres

1996-08-01

Full Text Available Observou-se a eficácia da fortificação do leite fluido com 3 mg de ferro aminoácido quelato no combate à carência de ferro em crianças menores de quatro anos. Foram acompanhadas 269 crianças que receberam, durante 12 meses, um litro de leite fortificado por dia, e que foram avaliadas a cada 6 meses de acompanhamento. Antes de se iniciar a intervenção, a anemia estava presente em 62,3% das crianças. Após 6 meses, este percentual reduziu-se a 41,8% e, ao final de um ano, a 26,4%. As maiores reduções foram detectadas nas faixas etárias de 12 a 23 meses e em menores de um ano. Das crianças que apresentavam hemoglobinas iniciais inferiores a 9,5 g/dl, 59,3% recuperaram-se da anemia ao final de um ano de acompanhamento. Naquelas com hemoglobinas iniciais entre 9,5 e 10,9 g/dl, o percentual de recuperação da anemia foi de 66,7%. Encontrou-se, ainda, melhores evoluções hematológicas em crianças que ingeriam quantidades superiores a 750 ml/dia de leite fortificado, pertencentes a famílias que não dividiam o suplemento recebido com outros membros e naquelas com apenas uma criança com menos de 5 anos no núcleo familiar. Concluiu-se pela viabilidade e eficácia da fortificação do leite fluido como medida de intervenção no combate à carência de ferro em pré-escolares.The effectiveness of the use of chelate aminoacid iron fortified fluid milk in the treatment of iron deficiency in children under four years of age was studied. The 269 children included in this trial received 1 liter/day of fluid milk fortified with 3 mg of chelate aminoacid iron and were evaluated at six monthly intervals. At the beginning of the study 62.3% of the children presented anemia. After 6 months, this percentage had decreased to 41.8% and at the end of one year to 26.4%. The greatest decreases occurred in the groups comprising the subjects who were of 12 to 23 months of age and those under one year of age. Among the children who presented initial

Reconfigurable Full-Page Braille Displays

Science.gov (United States)

Garner, H. Douglas

1994-01-01

Electrically actuated braille display cells of proposed type arrayed together to form full-page braille displays. Like other braille display cells, these provide changeable patterns of bumps driven by digitally recorded text stored on magnetic tapes or in solid-state electronic memories. Proposed cells contain electrorheological fluid. Viscosity of such fluid increases in strong electrostatic field.

Selecting working fluids in an organic Rankine cycle for power generation from low temperature heat sources

Directory of Open Access Journals (Sweden)

Fredy Vélez

2014-01-01

Full Text Available Este trabajo presenta un estudio termodinámico realizado sobre el uso de fuentes de calor de baja temperatura para la generaci ón de energía a través de un ciclo Rankin e subcrítico con fluidos de trabajo orgánicos. Un análisis d el estado del arte de esta tecn ología muestra como línea de investigación abierta, la selección del fluido de trabajo, pues hasta ahora, no existe un fluido que satisfaga t odos los aspectos medioambientales y técnicos a tener en cuenta en estos ciclos. Por ello, se ha desarrollado una serie de simulaciones que permiten estudiar el comportamiento del ciclo Rankine con difer entes configuraciones y fluidos (húmedo, seco e isoentrópico, permitiendo con ello observar de qué manera influyen cambios ta nto en esos tipos de fluidos utilizados (refrigerantes, hidroca rburos y agua, como de condiciones de temperatura, presión, flujo, etc. , sobre la eficiencia total del ciclo. Con el trabajo realizado se demuestra la viabilidad de este tipo de proceso en la recuperación de calore s en la industria y/o aprovechamiento de fuentes renovables de baja y media temperatura para la producción de energía eléctrica.

Shocking chocolate into shape

Science.gov (United States)

Ornes, Stephen

2016-11-01

Wouldn't you love chocolate to have less fat but all the taste? Stephen Ornes discovers how the study of electrorheological fluids has led one physicist to a develop a new way to trim the fat from chocolate

Water and clay based drilling fluids: rheologic, filtration and lubricity behavior; Fluidos hidroargilosos: comportamento reologico, de filtracao e lubricidade

Energy Technology Data Exchange (ETDEWEB)

Amorim, Luciana V.; Pereira, Melquesedek S.; Ferreira, Heber C. [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

2008-07-01

The aim of this work is to provide continuity for UFCG studies presenting results of rheological, filtration and the lubricity behaviors obtained with fluids prepared with bentonite clays from Paraiba, in binary compositions, after treatment with lubricants agents. It was selected two samples of bentonite clays and four lubricants (Lub 1, Lub 2, Lub 3 and Lub 4). The results showed that: depending on the composition, the drilling fluids presented bingham and pseudo plastic rheological behaviors, and with the additives bingham behavior; among the rheological and filtration properties evaluated, the apparent viscosity, yield limiting and the water loss are the have changes with the addition of lubricants; the values of the lubricity coefficient (LC) of fluids without additives were next of 0.50, independent of the composition of the bentonite clay mixture; after addition of the lubricants, the LC of fluids reduced for values next to 0,11, independent of its concentration and lubricants the best-performing are the Lub 2 and Lub 4. (author)

Volume management in critically ill patients: new insights Avaliação da volemia em pacientes críticos: nova proposta

Directory of Open Access Journals (Sweden)

Marcel Rezende Lopes

2006-08-01

Full Text Available In order to turn a fluid challenge into a significant increase in stroke volume and cardiac output, 2 conditions must be met: 1 fluid infusion has to significantly increase cardiac preload and 2 the increase in cardiac preload has to induce a significant increase in stroke volume. In other words, a patient can be nonresponder to a fluid challenge because preload does not increase during fluid infusion or/and because the heart (more precisely, at least 1 of the ventricles is operating on the flat portion of the Frank-Starling curve. Volumetric markers of cardiac preload are therefore useful for checking whether cardiac preload effectively increases during fluid infusion. If this is not the case, giving more fluid, using a venoconstricting agent (to avoid venous pooling, or reducing the intrathoracic pressure (to facilitate the increase in intrathoracic blood volume may be useful for achieving increased cardiac preload. Arterial pulse pressure variation is useful for determining whether stroke volume can/will increase when preload does increase. If this is not the case, only an inotropic drug can improve cardiac output. Therefore, the best option for determining the usefulness of, and monitoring fluid therapy in critically ill patients is the combination of information provided by the static indicators of cardiac preload and arterial pulse pressure variation.Para ser efetivo em aumentar significativamente o volume sistólico um volume de fluido precisa preencher duas condições : 1- A infusão deste fluido tem que aumentar a pré-carga 2- O aumento da pré-carga tem que promover uma elevação proporcional do volume sistólico Em outras palavras o paciente pode ser não responsivo à infusão de volume em termos de volume sistólico, devido a quantidade de fluidos ainda não ser a necessária ou o coração já estar operando na faixa superior da curva de Frank-Starling. Os indicadores volumétricos da pré-carga cardíaca são úteis para

Compatibilidad y estabilidad organoléptica de bases semisólidas que contienen quitina y extracto fluido de Guacamaya francesa para elaborar una crema con ambos principios activos

Directory of Open Access Journals (Sweden)

Yinet Barrese Pérez

2004-04-01

Full Text Available Se realizó el estudio de las posibles interacciones (compatibilidad que pudieran existir entre los principios activos quitina y Guacamaya francesa (extracto fluido, mediante pruebas de contacto con una serie de sustancias auxiliares que constituían candidatos potenciales a ser utilizados en la formulación semisólida. Una vez realizadas dichas pruebas se escogieron las materias primas para elaborar bases que fueron puestas en contacto con los principios activos, seleccionándose la base de laurilsulfato de sodio-alcohol estearílico-petrolato blanco como la idónea para desarrollar una crema.The study of the possible interactions (compatibility that may exist between the active principles quitine and French Macaw (fluid extract was conducted by contact tests with a series of auxiliary substances which are potential candidates to be used in the semisolid formulation. Once these tests were made, the raw materials were selected to prepare bases that would be in contact with the active principles. The basis of sodium-laurylsulfate-stearyl alochol-white petrolatum was selected as the idoneous to develop an ointment.

Geochemical model of a geothermal system: an approach on the analytical uncertainty; Modelo geoquimico de sistema geotermico: un enfoque sobre la incertidumbre analitica

Energy Technology Data Exchange (ETDEWEB)

Pal Verma, Mahendra [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2008-07-01

A procedure was developed to consider the analytical uncertainty in each parameter of geochemical analysis of geothermal fluid. The estimation of the uncertainty is based on the results of the geochemical analyses of geothermal fluids (numbered from the 0 to the 14), obtained within the framework of the comparisons program among the geochemical laboratories in the last 30 years. Also the propagation of the analytical uncertainty was realized in the calculation of the parameters of the geothermal fluid in the reservoir, through the methods of interval of uncertainty and GUM (Guide to the expression of Uncertainty of Measurement). The application of the methods is illustrated in the pH calculation of the geothermal fluid in the reservoir, considering samples 10 and 11 as separated waters at atmospheric conditions. [Spanish] Se desarrollo un procedimiento para estimar la incertidumbre analitica en cada parametro de analisis geoquimico de fluido geotermico. La estimacion de la incertidumbre esta basada en los resultados de los analisis geoquimicos de fluidos geotermicos (numerados del 0 al 14), obtenidos en el marco del programa de comparaciones entre los laboratorios geoquimicos en los ultimos 30 anos. Tambien se realizo la propagacion de la incertidumbre analitica en el calculo de los parametros del fluido geotermico en el yacimiento, a traves de los metodos de intervalo de incertidumbre y GUM (Guide to the expression of Uncertainty of Measurement). La aplicacion de los metodos se ilustra en el calculo de pH del fluido geotermico en el yacimiento, considerando las muestras 10 y 11 como aguas separadas a las condiciones atmosfericas.

Restart of circulation of gelled drilling fluids; Estudo do inicio da recirculacao de fluidos de perfuracao gelificados

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Gabriel M. de [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Rocha, Leandro L.V. da; Franco, Admilson T.; Negrao, Cezar O.R. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Programa de Pos Graduacao em Engenharia Mecanica e de Materiais; Martins, Andre L. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

This paper describes a mathematical model that simulates the start-up flow of gelled drilling fluids in annular spaces with the purpose to predict pressure peaks at the beginning of the flow. The model comprises the one-dimensional conservation equations of mass and momentum, which are discretized by Finite Volume Method. Fully implicit and up-wind discretization schemes are used and the resultant algebraic equations are solved iteratively by developing a FORTRAN algorithm. The model has the potentiality to be easily adapted to a flow inside a tube. Cases studies are conducted to evaluate the temporal variation of velocity and pressure fields inside both the annular space and a tube. One observed that increasing fluid compressibility or viscosity leads to a reduction of the pressure peaks. (author)

Response to exploitation (1982-2002) of the Los Azufres, Michoacan (Mexico) geothermal field. Part I: North Zone; Respuesta a la explotacion (1982-2003) del yacimiento geotermico de Los Azufres, Michoacan (Mexico). Parte I: Zona Norte

Energy Technology Data Exchange (ETDEWEB)

Arellano G, Victor Manuel; Barragan R, Rosa Maria [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Torres R, Marco Antonio; Sandoval M, Fernando [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

2004-12-01

This work studies the thermodynamic evolution of the Los Azufres northern zone reservoir fluids as a response of exploitation since 1982 to 2002 is presented. Thermodynamic conditions for reservoir fluids were estimated using the WELFLO heat-and flow-well simulator, using production data as the input. The initial thermodynamic conditions of the north zone wells indicated the presence of compressed liquid; also it was noticed that the first response to exploitation was a pressure drop and an enthalpy increase, while the long term response indicated a very small pressure change but a high enthalpy increment. The analysis of production, chemical and isotopic (d18O, dD) data in this zone showed interference effects of fluids reinjected in well Az-52 on well Az-5; and in well Az-15 on wells Az-13, Az-28 and Az-43. At the present time due to the low injection flow rates, this effect is minimal. [Spanish] En este trabajo se presenta un estudio sobre la evolucion termodinamica de los fluidos de la zona norte del yacimiento de Los Azufres desde el inicio de su explotacion en 1982 hasta el ano 2002, considerando las condiciones de fondo de pozos del campo, como respuesta a la extraccion e inyeccion de fluidos. Las condiciones termodinamicas de los fluidos del yacimiento se estimaron mediante el simulador del flujo de fluidos y calor en pozos {sup W}ELFLO{sup ,} a partir de datos de produccion. Las condiciones termodinamicas iniciales de los fluidos de la zona norte de campo se encontraron en la region de liquido comprimido; la primera respuesta a la explotacion consistio en una disminucion de presion y un incremento en la entalpia. A largo plazo, se observaron cambios muy pequenos en la presion y grandes incrementos en la entalpia. El analisis de datos quimicos, isotopicos (d18O, dD) y de produccion de pozos en la zona norte evidencio la ocurrencia de interferencia de fluidos de reinyeccion del pozo Az-52 con el pozo Az-5 y del pozo Az-15 con los pozos Az-13, Az-28 y Az 43

Choice of fluids in the perioperative period of kidney transplantation

Directory of Open Access Journals (Sweden)

Alejandro Gonzalez-Castro

2017-11-01

Full Text Available Normal saline has traditionally been the resuscitation fluid of choice in the perioperative period of kidney transplantation over balanced potassium solutions. However, the problems arising from hyperchloraemia triggered by the infusion of normal saline have led to studies being conducted that compare this solution with balanced solutions. From this narrative review it can be concluded that the use of balanced crystalloids containing potassium in the perioperative period of kidney transplantation can be considered safe. These solutions do not affect serum potassium levels any more than normal saline, whilst maintaining a better acid–base balance in these patients. Resumen: El suero salino normal (SSN ha sido clásicamente el fluido de resucitación elegido en el periodo perioperatorio del trasplante renal frente a aquellas soluciones balanceadas con potasio. Sin embargo, los problemas derivados de la hipercloremia desencadenada por la infusión de SSN han llevado a la realización de estudios que comparaban esta solución con los fluidos equilibrados. Mediante la presente revisión narrativa se deduce que el uso de cristaloides balanceados con contenido de potasio en su formulación, en el perioperatorio de trasplante renal, puede considerarse seguro. Estas soluciones no provocan una alteración del potasio sérico mayor que la provocada por el SSN y mantienen mejor el equilibrio ácido-base en estos enfermos. Keywords: Kidney transplantation, Normal saline, Balanced solutions, Hyperchloraemia, Hyperkalaemia, Palabras clave: Trasplante renal, Suero salino normal, Soluciones balanceadas, Hipercloremia, Hiperpotasemia

Manipulation of microfluidic droplets by electrorheological fluid

KAUST Repository

Zhang, Menying; Gong, Xiuqing; Wen, Weijia

2009-01-01

Microfluidics, especially droplet microfluidics, attracts more and more researchers from diverse fields, because it requires fewer materials and less time, produces less waste and has the potential of highly integrated and computer

Electrorheological (ER) Fluids: A Research Needs Assessment

Science.gov (United States)

1993-05-01

is given as line (g). Experimental results a correspond to polyaniline in silicone oil, e.c•,=36 (Gow 1990); * hollow silica spheres in corn oil ye...Malishauskas, 1981) (Fig. 18b). In Minsk, we have designed a new model of a screw valve (Shulman, 1978b). Its electrodes are fabricated in the form of...Takimoto, both of whom were very gracious. Dr. Takimoto is primarily involved in ER research. I was not shown any facilities while there, primarily

Modelamiento de Fluidos Magnetoreológicos (FMR Producidos con Magnetita Mineral

Directory of Open Access Journals (Sweden)

Claudia Molina

2015-07-01

Full Text Available Esta investigación establece la correlación entre los resultados del cambio de densidad de un FMR, expuesto a un campo magnético de intensidad variable, con los resultados de la simulación del sistema por elementos finitos, en ANSYS. A nivel de laboratorio se prepararon doce muestras de FMR, con: magnetita mineral como material magnético molida a 325, 400 y 500 mallas; aceites 20W30 y 20W50 como fluidos de transporte y, aditivos antigravitacionales y antiaglomerantes. Con el FMR de mayor estabilidad fisicoquímica (baja reactividad y sedimentación, se realizaron pruebas de variación de la densidad, en función de la intensidad de un campo magnético. La correlación de los resultados de las pruebas de laboratorio con los resultados de la simulación, fue de 0.92, lo cual indica que la predicción del comportamiento de la densidad del FMR, en presencia de un campo magnético de intensidad variable, es un procedimiento confiable.

Water base drilling fluids for high-angle wells; Fluidos a base de agua para perfuracao de pocos com elevada inclinacao

Energy Technology Data Exchange (ETDEWEB)

Passarelli, Rui [PETROBRAS, Rio de Janeiro (Brazil). Dept. de Perfuracao. Div. de Fluidos de Perfuracao; Lomba, Rosana Fatima T [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1990-12-31

Horizontal drilling has experimented a large increase in last years. In Brazil, two horizontal wells were drilled in Fazenda Belem and Carmopolis Fields. The first one reached a final measured depth of 1128 m and the horizontal length was 533 m. The drilling fluid program was elaborated after a large number of laboratory tests, in order to get a composition that best fitted the drilling requirements, mainly the desirable lubricity. The idea of using a water-base fluid instead of an oil-based, known as more suitable in this case, arose because the Company is interested in drilling this kind of well offshore, in deep water, where the use of oil-base muds is forbidden. Different compositions of water base muds were developed and tested in laboratory and the results led to low-solids salt fluids having a lubricant in its composition. The lubricity coefficients of these fluids are similar to those obtained with oil-base muds. 9-FZB-446D-CE well was drilled with the chosen fluid and high values of torque and drag were not registered, being the operation a total success. (author) 10 tabs.

Water base drilling fluids for high-angle wells; Fluidos a base de agua para perfuracao de pocos com elevada inclinacao

Energy Technology Data Exchange (ETDEWEB)

Passarelli, Rui [PETROBRAS, Rio de Janeiro (Brazil). Dept. de Perfuracao. Div. de Fluidos de Perfuracao; Lomba, Rosana Fatima T. [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1989-12-31

Horizontal drilling has experimented a large increase in last years. In Brazil, two horizontal wells were drilled in Fazenda Belem and Carmopolis Fields. The first one reached a final measured depth of 1128 m and the horizontal length was 533 m. The drilling fluid program was elaborated after a large number of laboratory tests, in order to get a composition that best fitted the drilling requirements, mainly the desirable lubricity. The idea of using a water-base fluid instead of an oil-based, known as more suitable in this case, arose because the Company is interested in drilling this kind of well offshore, in deep water, where the use of oil-base muds is forbidden. Different compositions of water base muds were developed and tested in laboratory and the results led to low-solids salt fluids having a lubricant in its composition. The lubricity coefficients of these fluids are similar to those obtained with oil-base muds. 9-FZB-446D-CE well was drilled with the chosen fluid and high values of torque and drag were not registered, being the operation a total success. (author) 10 tabs.

Monitoring artificially stimulated fluid movement in the Cretaceous Dakota aquifer, western Kansas

Science.gov (United States)

Macfarlane, Allen; Förster, Andrea; Merriam, Daniel; Schrötter, Jörg; Healey, John

2002-10-01

Aquifer properties can be evaluated by monitoring artificially stimulated fluid movements between wells, if the fluid is heated. Changes in the temperature profile recorded in observation wells indicate the flow path of the heated fluid, which in effect acts as a tracer. A fluid-flow experiment in the Cretaceous Dakota Formation at the Hodgeman County site, west-central Kansas, demonstrated the advantage of using the distributed optical-fiber temperature sensing method for monitoring transient temperature conditions in this hydrological application. The fluid flow in the aquifer was increased by producing water from a pumping well and injecting heated water in an injection well 13 m (43 ft) distant from the pumping well. The time-temperature series data obtained and compared with results from previous pumping tests point to interwell heterogeneity of the aquifer and to a zone in the sandstone aquifer of high hydraulic conductivity. However, the experiment would have allowed further clarification of aquifer heterogeneity and thermal properties if at least one observation well had been present between the injection and production wells. Résumé. Les caractéristiques d'un aquifère peuvent être évaluées en effectuant un suivi des mouvements du fluide stimulés artificiellement entre des puits, si le fluide est chauffé. Les variations de profils de température enregistrés dans les puits d'observation donnent des informations sur les directions d'écoulement du fluide chauffé, qui en fait se comporte comme un traceur. Réalisée dans la formation crétacée de Dakota, sur le site du Comté de Hodgeman (centre-ouest du Kansas), une expérience a démontré l'intérêt d'utiliser la méthode de détection distribuée de température par fibres optiques pour suivre les variations de température dans cette application hydrologique. L'écoulement du fluide dans l'aquifère a été favorisé en extrayant de l'eau par pompage et en injectant de l'eau chaude dans un

Productive fluid intervals in wells H-35 and H-39, Los Humeros geothermal field, Puebla (Mexico); Intervalos productores de fluidos en los pozos H-35 y H-39 del campo geotermico Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Medina Martinez, Moises [Comision Federal de Electridad, Perote, Veracruz (Mexico)

2000-12-01

This paper presents the results of log interpretations using the percentage method to define the productive fluid intervals in wells H-35 and H-39. These were identified with pressure, temperature and flow rate (PTS) electronic logs, used for the first time in this field. The test were carried out with the well integrated to the electrical generation units. Well H-35 fed steam to Units 1, 4, 5 and 7 through a plate with a restriction orifice diameter of 50.8 mm (2 inches), a well head pressure of 45 bars and a mass flow rate of 40 t/h. Well H-39 fed steam to Unit 3 through plate with a restriction orifice diameter of 50.8 mm (2 inches), a well head pressure of 27 bars and a mass flow rate of 30 t/h. [Spanish] Se presenta la intervencion realizada por el metodo de porcentajes para definir los intervalos productores de fluidos en los pozos H-35 y H-39. El estudio se hizo a partir de datos obtenidos con una sonda electronica de presion, temperatura y velocidad de flujo (PTS), utilizada por primera vez en este campo. En ambos casos se realizaron las pruebas con el pozo integrado a las unidades de generacion electrica, el primero suministra vapor para las Unidades 1, 4, 5 y 7 a traves de una placa de orificio de restriccion de 50.8 mm (2 pulgadas) de diametro, con presion de cabezal de 45 bar manometricos y un gasto de mezcla de 40 t/h. El segundo alimenta a la Unidad 3, fluye por orificio de 50.8 mm (2 pulgadas) de diametro y produce 30 t/h de mezcla con una presion en la cabeza de 27 bar.

Fluidos iónicos en lubricación de contactos aluminio-acero : interacciones superficiales y triboquímicas

OpenAIRE

Jiménez Ballesta, Ana Eva

2009-01-01

Los líquidos iónicos (LI) son fluidos de altas prestaciones con un amplio rango de estabilidad térmica. Actualmente están siendo objeto de estudio en una gran variedad de contactos, siendo una de sus aplicaciones tribológicas más interesante la lubricación del contacto aluminio-acero. En este trabajo se estudia la influencia de la longitud de la cadena lateral del catión y de la naturaleza del anión sobre la capacidad lubricante de 6 LI derivados del catión imidazolio, un derivado de piridini...

Research on antibodies anti toxoplasma gondii in intraocular fluids (Aqueous and vitreous humor) from patients with ocular toxoplasmosis, in the City of Belém, Pará State

OpenAIRE

Carmo, Ediclei Lima do; Almeida, Edmundo Frota; Bichara, Cléa Nazaré; Póvoa, Marinete Marins

2005-01-01

Foi realizada pesquisa de anticorpos IgG, IgM e IgA anti-Toxoplasma gondii no soro e fluidos intra-oculares (humor aquoso e vítreo) de pacientes com toxoplasmose ocular. A partir dos resultados obtidos verificou-se que anticorpos IgG e IgA intraocular anti-Toxoplasma gondii podem vir a ser importantes marcadores no diagnóstico de toxoplasmose ocular.Tests were performed for antibodies IgG, IgM and IgA anti-Toxoplasma gondii antibodies in serum and intraocular fluids (Aqueous and vitreous humo...

Gaseous equilibrium in sector CP IV of the Cerro Prieto, B.C. Mexico geothermal field; Equilibrio gaseoso en el sector CP IV del campo geotermico Cerro Prieto, B.C., Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel; Portugal Marin, Enrique [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); De Leon Vivar, Jesus [Comision Federal de Electricidad, Campo Geotermico Cerro Prieto, Cerro Prieto, B. C. (Mexico)

2007-07-01

Sector CP IV is located in the NE portion of the Cerrro Prieto geothermal field. The wells of this zone produce two-phase fluids, with different characteristics as far as their steam fraction content; in the central part and towards the NW the fluids are of dominant liquid type whereas towards the E and the S, the fluid contains a relatively higher steam fraction. The results of gaseous equilibrium FT- HSH3 showed that the fluids in the deposit are at temperatures between 275 Celsius degrees and 310 Celsius degrees and contain steam fractions between 0.01 and 0.5. The data found for the natural state are aligned in a tendency defined in the diagram FT- HSH3, that suggest the wells receive different proportions from preexisting steam in the deposit, which are mixed with the liquid phase to produce the observed discharges. The present data, besides showing the presence of deposit steam, also indicates the entrance of lower temperature fluid in the central part of sector CP IV. [Spanish] El sector CP IV se localiza en la porcion NE del campo geotermico Cerro Prieto. Los pozos de esta zona producen fluidos bifasicos, con diferentes caracteristicas en cuanto a su contenido de fraccion de vapor: en la parte central y hacia el NW los fluidos son de tipo liquido dominante mientras que hacia el E y hacia el S, el fluido contiene una fraccion relativamente alta de vapor. Los resultados de equilibrio gaseoso FT-HSH3 mostraron que los fluidos en el yacimiento se encuentran a temperaturas de entre 275 grados Celsius y 310 grados Celsius y contienen fracciones de vapor de entre -.01 y .5. Los datos hallados para el estado natural se alinean en una tendencia definida en el diagrama FT-HSH3, que sugiere que los pozos reciben diferentes proporciones de vapor pre-existente en el yacimiento, que se mezclan con fase liquida para producir las descargas que se observan. Los datos actuales, ademas de mostrar la presencia de vapor de yacimiento, tambien indican la entrada de fluidos de

Viscous properties of aluminum oxide nanotubes and aluminium oxide nanoparticles - silicone oil suspensions

Science.gov (United States)

Thapa, Ram; French, Steven; Delgado, Adrian; Ramos, Carlos; Gutierrez, Jose; Chipara, Mircea; Lozano, Karen

2010-03-01

Electrorheological (ER) fluids consisting of γ-aluminum oxide nanotubes and γ-aluminum oxide nanoparticles dispersed within silicone oil were prepared. The relationship between shear stress and shear rate was measured and theoretically simulated by using an extended Bingham model for both the rheological and electrorheological features of these systems. Shear stress and viscosity showed a sharp increase for the aluminum oxide nanotubes suspensions subjected to applied electric fields whereas aluminum oxide nanoparticles suspensions showed a moderate change. It was found that the transition from liquid to solid state (mediated by the applied electric field) can be described by a power law and that for low applied voltages the relationship is almost linear.

DETERMINACIÓN DEL TIEMPO DE MEZCLA EN UN TANQUE DE ALMACENAMIENTO PARA AGUA POTABLE MEDIANTE DINÁMICA DE FLUIDOS COMPUTACIONAL -CFD- Determining the Blend Time in a Drinking Water Storage Tank through Computational Fluid Dynamic (CFD

Directory of Open Access Journals (Sweden)

Santiago Laín

2011-12-01

Full Text Available Para estimar el comportamiento hidráulico de un tanque de almacenamiento de agua potable se usó un programa para la simulación de dinámica computacional de fluidos, evaluando numéricamente los perfiles de velocidad y el tiempo de mezcla. Los perfiles de velocidad mostraron un valor máximo a la salida de 0,76 m.s-1 y velocidades de 0,2 m.s-1 cerca de las paredes, propiciando zonas de recirculación cerca del chorro de entrada. La inyección del trazador y el coeficiente de variación para 17 puntos de monitoreo en el tanque resultaron en un tiempo de mezcla de 19,06 horas y se verificó que cerca de las paredes la mezcla es menos eficiente que en la trayectoria del chorro de entrada. El volumen necesario que debe entrar al tanque para que haya buena mezcla resultó inversamente proporcional a la masa de agua almacenada.In order to estimate the hydraulic behavior of a drinking water storage tank, Computational Fluid Dynamic (CFD simulation program was used to numerically evaluate blend speed and time profiles. Speed profiles showed a maximum value when leaving at 0.76 m.s-1 and 0.2 m.s-1 speeds near walls, creating recirculation areas near the inlet stream. Injection of tracer and the variation coefficient for 17 monitoring points in the tank resulted in a blend time of 19.06 hours and it was found that the blend near walls is less efficient than in the inlet stream trajectory. Necessary volume to enter the tank in order to achieve a good blend was inversely proportional to the water mass stored.

Significado tectónico y migración de fluidos hidrotermales en una red de fallas y vetas de un Dúplex de rumbo: un ejemplo del Sistema de Falla de Atacama Tectonic significance and hydrothermal fluid migration within a strike-slip duplex fault-vein network: an example from the Atacama Fault System

Directory of Open Access Journals (Sweden)

Viviana Olivares

2010-07-01

Full Text Available El Dúplex Caleta Coloso es una estructura de rumbo desarrollada durante la deformación frágil del Sistema de Falla de Atacama (SFA en el Cretácico Temprano. En su interior hay un sistema de vetas hidrotermales que documentan la naturaleza de la relación entre el transporte de fluidos y el desarrollo del dúplex. El sistema de vetas de orientación dominante NW se localiza en la roca de caja, adyacentes a las zonas de falla. Según su mineralogía dominante hay vetas de clorita, epidota-cuarzo y calcita-limonita, y según las relaciones de corte o su estructura interna, se definieron vetas tempranas (clorita, intermedias (epidota-cuarzo y tardías (calcita-limonitas. Algunas vetas muestran cristales perpendiculares u oblicuos a sus paredes (vetas de extensión y de extensión oblicua o fibras minerales orientadas paralelas a las estrías de las fallas (vetas-fallas. Estas últimas tienen indicadores cinemáticos compatibles con las fallas, evidenciando que fueron sincinemáticas con el desarrollo del dúplex. Según su microestructura, ellas se habrían formado en fracturas abiertas llenas de fluidos, bajo condiciones de presión inferior a la hidrostática, lo cual indicaría que la precipitación mineral ocurrió por caídas abruptas de la presión en una corteza somera (The Caleta Coloso Duplex is a brittle strike-slip structure developed along the Atacama Fault System during the Early Cretaceous. A hydrothermal vein system existing within the duplex documents the nature of the link between fluid transport and progressive structural development. The dominantly NW-striking vein system occurs near or at the damage zone of the duplex fault zones. Veins can be classified according to their composition and crosscutting relationships into early chlorite veins, intermediate epidotic-quartz veins and late calcite-limonite veins. Some of them exhibit minerals with their long axes oriented orthogonally or obliquely with respect to the vein walls

La flora como recurso terapéutico : el caso de los extractos fluidos de los Laboratorios Codex en México

OpenAIRE

Hersch Martínez, Paul

2008-01-01

Entre las fuentes para una historia social de la terapéutica en México, es pertinente analizar la producción de sus laboratorios farmacéuticos, aún cuando reflejen de manera limitada e indirecta la práctica terapéutica misma. Una primera aproximación a los extractos fluidos de los Laboratorios Codex producidos en el segundo cuarto del siglo XX, permite destacar la diversidad florística de la materia prima empleada en ellos y sus propiedades terapéuticas, avaladas entonces por las autoridades ...

GRINDING OF HARDENED STEELS USING OPTIMIZED COOLING RECTIFICADO DE ACEROS ENDURECIDOS USANDO REFRIGERACIÓN OPTIMIZADA

Directory of Open Access Journals (Sweden)

Manoel Cléber de Sampaio Alves

2008-06-01

Full Text Available Grinding – the final machining process of a workpiece – requires large amounts of cutting fluids for the lubrication, cooling and removal of chips. These fluids are highly aggressive to the environment. With the technological advances of recent years, the worldwide trend is to produce increasingly sophisticated components with very strict geometric and dimensional tolerances, good surface finish, at low costs, and particularly without damaging the environment. The latter requirement can be achieved by recycling cutting fluids, which is a costly solution, or by drastically reducing the amount of cutting fluids employed in the grinding process. This alternative was investigated here by varying the plunge velocity in the plunge cylindrical grinding of ABNT D6 steel, rationalizing the application of two cutting fluids and using a superabrasive CBN (cubic boron nitride grinding wheel with vitrified binder to evaluate the output parameters of tangential cutting force, acoustic emission, roughness, roundness, tool wear, residual stress and surface integrity, using scanning electron microscopy (SEM to examine the test specimens. The performance of the cutting fluid, grinding wheel and plunge velocity were analyzed to identify the best machining conditions which allowed for a reduction of the cutting fluid volume, reducing the machining time without impairing the geometric and dimensional parameters, and the surface finish and integrity of the machined components.La rectificación, proceso final de fabricación de una pieza, hace uso intenso de fluidos de corte con la finalidad de lubricación, refrigeración y remoción de astillas (imperfecciones. Sin embargo, estos fluidos son extremamente agresivos al medio. Con el avance tecnológico la tendencia mundial es producir piezas cada vez mas sofisticadas, con elevado grado de tolerancia geométrica, dimensional, con buen acabamiento superficial, con bajo costo y, principalmente, sin causar daños al

Evaluation of the aging of polymeric drilling fluids to oil wells; Avaliacao do envelhecimento de fluidos de perfuracao polimericos para pocos de petroleo

Energy Technology Data Exchange (ETDEWEB)

Farias, K.V.; Amorim, L.V. [Universidade Federal de Campina Grande, PB (Brazil). Unidade Academica de Engenharia Mecanica, UAEM/CCT - UFCG], e-mail: kassie@dem.ufcg.edu.br; Leite, R.S. [Universidade Federal de Campina Grande, PB (Brazil). Graduacao Engenharia de Materiais; Lira, H.L. [Universidade Federal de Campina Grande, PB (Brazil). Unidade Academica de Engenharia de Materiais, UAEMa/ CCT - UFCG

2010-07-01

The aim of this work is to evaluate the aging of polymeric drilling fluids to oil wells, from the rheological, filtration and lubricity properties in the temperatures 100 degree F ({approx} 38 degree C) and 150 degree F ({approx} 66 degree C). The results had been compared with a standard fluid used for the oil industry and had evidenced that the polymeric fluids had presented good thermal stability, presenting a small reduction in the rheological properties and better values of lubricity coefficient that a reference fluid. (author)

INFLUÊNCIA DA TEMPERATURA NA REOLOGIA DE FLUIDOS DE PERFURAÇÃO PREPARADOS COM CARBOXIMETILCELULOSE, GOMA XANTANA E BENTONITA

Directory of Open Access Journals (Sweden)

Klismeryane Costa de Melo

2013-10-01

Full Text Available O comportamento reológico dos fluidos de perfuração pode sofrer alterações ao longo da perfuração em função do gradiente de temperatura do poço. A degradação térmica sofrida por alguns aditivos utilizados como viscosificantes restringe a utilização da classe dependendo da temperatura a qual será exposto. Este trabalho apresenta um estudo sobre o comportamento reológico da Goma Xantana (GX, da Carboximetilcelulose (CMC e da Bentonita (BNT em função da temperatura. Os Modelos matemáticos de Ostwald de Waale e o de Herschel-Bulkley foram aplicados para determinar os parâmetros reológicos. O efeito da hidratação dos polímeros e da argila na reologia de soluções aquosas foram previamente estudados. A caracterização reológica foi realizada através de ensaios de reologia, utilizando sistema de cilindros coaxiais, para obtenção das curvas de fluxo. A reologia foi avaliada em função da temperatura para cada um dos aditivos utilizados. Os resultados mostraram que a CMC se solubiliza rapidamente em água, porém apresenta maior degradação quando exposta a temperatura mais elevada. A GX se mostrou apta para ser utilizada em formulações de fluidos que serão usados em poços com gradiente de temperatura mais elevados. A bentonita não apresentou alterações no comportamento reológico em função do gradiente de temperatura estudado.

Fluido-Dynamic and Electromagnetic Characterization of 3D Carbon Dielectrophoresis with Finite Element Analysis

Directory of Open Access Journals (Sweden)

Rodrigo Martinez-Duarte

2008-12-01

Full Text Available The following work presents the fluido-dynamic and electromagnetic characterization of an array of 3D electrodes to be used in high throughput and high efficiency Carbon Dielectrophoresis (CarbonDEP applications such as filters, continuous particle enrichment and positioning of particle populations for analysis. CarbonDEP refers to the induction of Dielectrophoresis (DEP by carbon surfaces. The final goal is, through an initial stage of modeling and analysis, to reduce idea-to-prototype time and cost of CarbonDEP devices to be applied in the health care field. Finite Element Analysis (FEA is successfully conducted to model flow velocity and electric fields established by polarized high aspect ratio carbon cylinders, and its planar carbon connecting leads, immersed in a water-based medium. Results demonstrate correlation between a decreasing flow velocity gradient and an increasing electric field gradient toward electrodes’ surfaces which is optimal for selected CarbonDEP applications. Simulation results are experimentally validated in the proposed applications.

Sign changing solutions of the p(x)-Laplacian equation

Indian Academy of Sciences (India)

ples, such as nonlinear elasticity theory, electrorheological fluids, etc. (see [21, 22]). It also has wide applications in different research fields, such as image processing model. (see e.g. [5 ... Here, we introduce some definitions and results which will be used in the next section. Firstly ..... image restoration, SIAM J. Appl. Math.

Evaluation of low toxicity mineral oil base drilling fluids; Avaliacao de fluidos de perfuracao a base de oleo mineral de baixa toxidez

Energy Technology Data Exchange (ETDEWEB)

Ponte, Ielton Frederico da [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1989-12-31

In order to introduce low toxicity mineral oil base drilling fluids in Brazil, we carried out a series with a low aromatic content basic oil for lubricants, produced by PETROBRAS: the Lubrax Industrial OB-9 (Lubind OB-9). This oil, as well as its mixture with aviation kerosene to reduce viscosity, was found adequate for use in drilling fluids together with other national products developed by companies that supply additives for drilling fluids in Brazil. We present the results of laboratory tests with systems of four different manufacturers, one of which was chosen for initial field tests. These tests, which were carried out at the Miranga and Bu River Fields, in the Drilling District of Bahia, produced satisfactory results. We anticipate the use of these fluids in other areas where the company operates. (author) 2 refs., 3 tabs.

Evaluation of low toxicity mineral oil base drilling fluids; Avaliacao de fluidos de perfuracao a base de oleo mineral de baixa toxidez

Energy Technology Data Exchange (ETDEWEB)

Ponte, Ielton Frederico da [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1990-12-31

In order to introduce low toxicity mineral oil base drilling fluids in Brazil, we carried out a series with a low aromatic content basic oil for lubricants, produced by PETROBRAS: the Lubrax Industrial OB-9 (Lubind OB-9). This oil, as well as its mixture with aviation kerosene to reduce viscosity, was found adequate for use in drilling fluids together with other national products developed by companies that supply additives for drilling fluids in Brazil. We present the results of laboratory tests with systems of four different manufacturers, one of which was chosen for initial field tests. These tests, which were carried out at the Miranga and Bu River Fields, in the Drilling District of Bahia, produced satisfactory results. We anticipate the use of these fluids in other areas where the company operates. (author) 2 refs., 3 tabs.

Receptores de estrógeno e progesterona em células do sedimento de fluido peritoneal na endometriose pélvica: estudo imunocitoquímico

Directory of Open Access Journals (Sweden)

Eleutério Junior José

2001-01-01

Full Text Available Objetivo: avaliar a expressão de receptores de estrógeno (RE e progesterona (RP em esfregaços de sedimento de fluido peritoneal em pacientes com endometriose, comparando-a com a de mulheres sem endometriose. Métodos: foi realizado imunocitoquímica para RE e RP em esfregaços de sedimento de fluido peritoneal em 19 casos de endometriose e 7 sem endometriose (controle. Os dados foram submetidos ao teste t de Student para análise estatística. Resultados: em 84,6% dos casos de pacientes com endometriose, células tipo endometrial expressaram RE, numa média de 4,1%, ao passo que nos casos sem endometriose foi positivo em 42,9%, com uma expressão média de 4,5% (p = 0,1706. RP foi expresso apenas em um caso, com endometriose, com história de rotura de endometrioma. Conclusões: não houve diferença da expressão de RE entre os casos de endometriose e os casos-controle, observando-se um comportamento distinto em tecidos. Um mais aprofundado estudo deve ser feito para melhor avaliar o enigmático mecanismo envolvido na manifestação de receptores hormonais em células esfoliadas.

Obtenção de argilas organofílicas purificadas através de tensoativos iônicos e não iônicos visando uso em fluidos de perfuração base óleo Getting purified organoclays by ionic and non-ionic surfactant aiming use in oil based drilling fluids

Directory of Open Access Journals (Sweden)

J. M. R. Costa

2012-12-01

Full Text Available Em perfurações de petróleo sensíveis ao contato com água, torna-se necessária a utilização de fluidos de perfuração base óleo. Nestes casos, utilizam-se argilas organofílicas, que são obtidas a partir de argilas bentoníticas purificadas e tratadas com a adição de tensoativos. A utilização do hidrociclone pode representar uma ferramenta eficiente e de custo acessível para purificar argilas naturais em escala industrial. Este trabalho tem por objetivo estudar a purificação de argilas bentoníticas utilizando-se um hidrociclone, visando o desenvolvimento de argilas organofílicas para uso em fluidos de perfuração base óleo. As caracterizações das amostras das argilas estudadas - Brasgel PA e Chocolate - foram efetuadas por meio das técnicas: análise granulométrica por difração de laser, difração de raios X (DRX e análise química por fluorescência de raios X. A caracterização das argilas organofílicas obtidas foi efetuada por meio dos seguintes métodos: DRX e por uma modificação do inchamento de Foster. Os resultados mostram que o processo de purificação foi eficiente na redução de impurezas presentes na bentonita e que a argila organofílica purificada tratada com Praepagen WB e Imidazolina Oléica Vegetal apresenta valores de inchamento de Foster em éster, óleo diesel e parafina superiores aos obtidos com argilas organofílicas sem purificação (natural, e evidenciando maior afinidade com o tensoativo Praepagen WB.Oil drilling in sensitive contact with water, becomes required the use of oil base drilling fluids. In these cases, organoclays are used, which are made from clay bentonite purified and treated with surfactants addition. The use of the hydrocyclone can be a effective tool and affordable for purifying clays in industrial scale. This work aims to study the purification of clays bentonite using a hydrocyclone, aiming to develop organoclays for use in oil base drilling fluids. The

Water-based inhibitive drilling fluids for oil wells: preliminary study; Fluidos aquosos inibidos para perfuracao de pocos de petroleo: estudo preliminar

Energy Technology Data Exchange (ETDEWEB)

Farias, Kassie V.; Amorim, Luciana V.; Silva, Aline R.V.; Ferreira, Heber C. [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

2008-07-01

The aim of this work is to do formulations of water-based inhibitive drilling fluids and to evaluate their rheologic, filtration and lubrication properties and the degree of swell of clays. It was studied eight formulations containing the following additives: viscosity, filtered reducer, controlling of pH, hydratable clays inhibitors, anti-foamy, bactericide, lubricant and sealant. The fluids were prepared according to the field practice that consists of adding to water the additives under constant agitation. After 24 h resting, it was carried out a study of the rheologic behavior, in a Fann 35 A viscosimeter, and of the filtration properties in a Fann press-filter and of lubricity in a Ofite Lubricity tester through the determination of the flow curves, apparent and plastic viscosities, yield limit, gel force, filtered volume, filter-cake thickness and lubricity coefficient. It was also been essays to evaluate the capacity of inhibition of clay with the chemical inhibitors isolated and in set. The results had proven that the presence of inhibitor of clay in drilling fluids has great importance and promotes the inhibition of the swell of clay in all concentrations studied and amongst the formulations developed, six had presented performance next to the fluid Standard. (author)

Technical Evaluation Report on the Fluid Dynamics Panel Symposium on Vortex Flow Aerodynamics Held in Scheveningen, The Netherlands, 1-4 October 1990 (L’Aerodynamiques des Ecoulements Tourbillonnaires)

Science.gov (United States)

1992-04-01

Canadai Professor J. Jimenez Escuela Tcniea Superior dc Prot. A. Bonnet Inenieros Aeronauticos Department Airodynarmque Dept. de Mecanica de Fluidos... Mecanica de Fluido provided with pre-prints or summaries of papers to be Plaza Cardenal Cisneros 3 presented in advance of the meeting. 28040 Madrid

Evaluation of differential risk of arrest of drilling and polymeric fluids; Avaliacao do risco de prisao diferencial de fluidos de perfuracao hidroargilosos e polimericos

Energy Technology Data Exchange (ETDEWEB)

Sarmento, L.R.B.; Lira, D.S.; Nascimento, R.C.A.M.; Amorim, L.V. [Universidadde Federal de Campina Grande (UFCG), PB (Brazil)], Email: ligia_rafa@hotmail.com

2010-07-01

This work evaluates the risk of differential sticking (DS) of clay and water based drilling fluids, before and after adding polymer and lubricant additives, and polymeric fluids. From the results, it was concluded that the addition of lubricant to the clay and water based fluids reduces the torque necessary to free the pipes that are stuck by differential pressure, as for the polymeric fluids presented the lowest filtration losses, cake thickness, differential sticking coefficient and DS risk. (author)

Simulations of magnetorheological suspensions in Poiseuille flow

Energy Technology Data Exchange (ETDEWEB)

Pappas, Yannis; Klingenberg, Daniel J. [University of Wisconsin-Madison, Department of Chemical and Biological Engineering, Madison, WI (United States)

2006-06-15

Particle-level simulations are conducted to study magnetorheological fluids in plane Poiseuille flow. The importance of the boundary conditions for the particles at the channel walls is examined by considering two extreme cases: no friction and infinite coefficient of friction. The inclusion of friction produces Bingham fluid behavior, as commonly observed experimentally for MR suspensions. Lamellar structures, similar to those reported for electrorheological fluids in shear flow, are observed in the post-yield region for both particle boundary conditions. The formation of these lamellae is accompanied by an increase in the bulk fluid velocity. The slip boundary condition produces higher fluid velocities and thicker lamellar structures. (orig.)

Fluidos supercríticos em química analítica. I. Cromatografia com fluido supercrítico: conceitos termodinâmicos

Directory of Open Access Journals (Sweden)

Carrilho Emanuel

2001-01-01

Full Text Available Under the chromatographic point of view, the physico-chemical properties of a supercritical fluid are intermediate to those of the gases and liquids. Many times they approach the best features of each one, as for example, the solubilization power of liquids and low viscosity of gases. The thermodynamic definitions and main physico-chemical features of a supercritical fluid will be presented in this article. The use of supercritical fluids in analytical chemistry has been extremely modest in Brazil, even considering the enormous potential of their applications, and their use in several techniques, such as chromatography (SFC and supercritical fluid extration (SFE. This article series is intended to discuss the historical evolution, instrumentation features and potential and limitations of the supercritical fluid use in analytical chemistry. A special focus will be centered on chromatography and extration techniques using supercritical fluids.

Coleção fluídica na interface do LASIK causada por glaucoma secundário à ceratouveíte herpética: relato de caso LASIK interface fluid accumulation caused by glaucoma associated with herpetic keratouveitis: case report

Directory of Open Access Journals (Sweden)

Eliane Mayumi Nakano

2007-02-01

Full Text Available A infecção por Herpes simplex vírus (HSV é causa freqüente de inflamação intra-ocular ou uveíte anterior. A hipertensão ocular é característica comumente observada nas ceratouveítes herpéticas. Neste relato descrevemos o acúmulo de fluido e descolamento do "flap" corneano da ceratomileusis, no pós-operatório tardio de LASIK (28 meses, associado a quadro hipertensivo ocular secundário a ceratouveíte herpética. Este achado corrobora a suposição que a cicatrização corneana após LASIK seja apenas parcial e o espaço virtual produzido pela ceratomileuisis permaneça indefinidamente. Condições de aumento excessivo da pressão intra-ocular podem causar edema corneano com acúmulo de fluido da interface.Herpes simplex virus infection is a frequent cause of intraocular inflammation or anterior uveitis. Ocular hypertension is a common feature in herpetic keratouveitis. We describe a fluid accumulation and flap displacement in late postoperative period (28 months of LASIK associated with ocular hypertension caused by herpetic keratouveitis. This finding supports the theory that flap attachment after LASIK is only partial and the virtual space remains indefinitely. The presence of ocular hypertension may lead to corneal edema and fluid accumulation in the interface.

Design of calamitic self-assembling reactive mesogenic units: mesomorphic behaviour and rheological characterization

Czech Academy of Sciences Publication Activity Database

Bubnov, Alexej M.; Cigl, Martin; Machado, A.; Pociecha, D.; Hamplová, Věra; Cidade, M.T.

2017-01-01

Roč. 44, Aug (2017), s. 1-13 ISSN 0267-8292 R&D Projects: GA ČR GA16-12150S Institutional support: RVO:68378271 Keywords : functional reactive mesogens * liquid crystals * self-assembling behaviour * nematic * smectic * electrorheological fluids Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 2.661, year: 2016

Pesquisa de anticorpos anti Toxoplasma gondii em fluidos intra-oculares (humor vítreo e humor aquoso) de pacientes com toxoplasmose ocular, na cidade de Belém, PA

OpenAIRE

Carmo,Ediclei Lima do; Almeida,Edmundo Frota; Bichara,Cléa Nazaré; Póvoa,Marinete Marins

2005-01-01

Foi realizada pesquisa de anticorpos IgG, IgM e IgA anti-Toxoplasma gondii no soro e fluidos intra-oculares (humor aquoso e vítreo) de pacientes com toxoplasmose ocular. A partir dos resultados obtidos verificou-se que anticorpos IgG e IgA intraocular anti-Toxoplasma gondii podem vir a ser importantes marcadores no diagnóstico de toxoplasmose ocular.

NAVIER-STOKES EM GPU

OpenAIRE

ALEX LAIER BORDIGNON

2006-01-01

Nesse trabalho, mostramos como simular um fluido em duas dimensões em um domínio com fronteiras arbitrárias. Nosso trabalho é baseado no esquema stable fluids desenvolvido por Joe Stam. A implementação é feita na GPU (Graphics Processing Unit), permitindo velocidade de interação com o fluido. Fazemos uso da linguagem Cg (C for Graphics), desenvolvida pela companhia NVidia. Nossas principais contribuições são o tratamento das múltiplas fronteiras, o...

Control and particles distribution in drilling fluids while drilling; Controle e distribuicao de particulas em fluidos de perfuracao enquanto perfurando

Energy Technology Data Exchange (ETDEWEB)

Santos, Luiz Augusto dos [PETROBRAS, XX (Brazil). Dept. de Perfuracao. Div. de Fluidos de Perfuracao

1988-12-31

Factors contributing both directly and indirectly to formation damage are discussed, including plugging by solids disseminated in drilling fluids, filtrations, spurt loss, and cake deposition. (author) 6 refs., 12 figs., 4 tabs.

Proceedings of the International Conference on Electrorheological Fluids (4th) Held in Feldkirch (Austria) on 20-23 July 1993

Science.gov (United States)

1994-01-01

important to use a high-resolution rheometer for detailed examination of the response of ER fluids. We exam ~ned the difference between data obtained...ERZ researc fC1 ro m its itmcv1ikth1l -14 Exam pl.’ olt these devicesý inchltde autoomtmive shock tthSorberie’" and cnigtte n~ionts𔃿 1-1,tNever...Differential Tranrsfuriner [LVUTI Torsjui Elemien~t Mouningi~ Ltam ;p Lonner i un Figur-e 7: Cross-sectional view ot Lhe insulated IIAAKE. CV 20 iiiewaeniucnet

Synergy and lubricant effect of biosurfactant/biodiesel addition in polymeric fluids; Acao lubrificante e sinergia da adicao de biosurfactante/biodiesel em fluidos polimericos

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Suzan I.G.; Costa, Marta; Macedo, Sinara P.N. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

The lubricity coefficient (CL) and filtrate volume of the polymeric drilling fluids contained glycerin, paraffin, biodiesel and biosurfactant were investigated to evidence the influence and efficiency when used individually or through associated. All the tested fluids were aged in rotative oven for 16 hours, at 200 deg F. In this study, the association of biodiesel with biosurfactant proved to be promising because it reduced the CL in 87% and the volume of filtered by 22%. Those results become promising when the applicability is approached in perforation of wells, because it means a smaller wear and tear of the drills when we told the lubricity data, and a smaller damage the formation when we provided a smaller invasion of the perforation fluid the formations. To evaluate the effect of the degradation of the products, the fluids were stocked to room temperature by thirty (30) days, being soon afterwards. That time of stockpiling went ideal to the hydration of the molecules, because its viscosity was alters sensibly and influencing positively in the filtrate and in rheologic mediated. (author)

Controllable synthesis of hierarchical strontium molybdate by sonochemical method

Energy Technology Data Exchange (ETDEWEB)

Jiang, Wanquan; Zhu, Wei [Department of Chemistry, University of Science and Technology of China (USTC), Hefei 230026 (China); Peng, Chao; Yang, Fan; Xuan, Shouhu; Gong, Xinglong [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, USTC, Hefei 230027 (China)

2012-09-15

Large-scale chrysanthemum-like strontium molybdate (SrMoO{sub 4}) with hierarchical structure has been successfully synthesized via a facile and fast ultrasound irradiation approach at room temperature. By varying the experimental conditions, SrMoO{sub 4} with different morphologies, such as spindles, peanuts, spheres, and rods, can be obtained. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). The influent parameters including concentration, pH value, and surfactants have been investigated. A possible growth mechanism is proposed and the shape evolution of the products is characterized. The as-prepared chrysanthemum-like SrMoO{sub 4} particles are used as the precursor for electrorheological fluid and their electrorheological property is investigated. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Emulsifiers performance on the stability of the drilling fluid base biodiesel; Desempenho de emulsificantes sobre a estabilidade de fluido de perfuracao a base de biodiesel

Energy Technology Data Exchange (ETDEWEB)

Moreira, Giselle P.; Costa, Marta [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

This work was prepared six (6) formulations of biodiesel based drilling fluids. Three formulations in the proportion oil-water 70/30 and other three in 60/40, just varying the employed surfactants: new product derived the citric acid (developed at our laboratory) and two other commercial surfactants. After production the fluids, It was analyzed them performance of the products through rheological properties to 135 deg F , filtrate volume in HPHT to 500 psi and to 200 deg F, electric stability to 135 deg F and phase separation during seven days of rest. The rheological analyses allowed to determine the behavior every fluids, though flow curves. Those fluids presented same behavior of the fluids used in oil field (Binghamianos). The laboratory tests demonstrated that new surfactant reduced the filtrated volume and provided mechanics and thermic stability. (author)

Análise do proteoma do fluido intercelular de raízes de cana-de-açúcar colonizadas por Glomus clarum.

OpenAIRE

Simão Lindoso de Souza

2002-01-01

Os mecanismos que regulam o desenvolvimento de micorrizas arbusculares (MAs) em condições de baixo e alto nível de P ainda são desconhecidos. Tem sido proposto que proteínas secretadas no apoplasto das raízes podem ter papel importante na regulação de MAs. A análise comparativa do proteoma do fluido intercelular (FI) de raízes colonizadas por fungos micorrízicos arbusculares (FMAs) com o de raízes não-colonizadas, em condições de baixo e alto nível de P, poderia contribuir para a elucidação d...

Water drilling fluids: evaluation of lubricity and clay swelling control; Fluidos de perfuracao a base de agua: avaliacao de lubricidade e controle de inchamento de argilas

Energy Technology Data Exchange (ETDEWEB)

Felix, Thiago de Freitas; Arruda, Jefferson Teixeira; Medeiros, Ana Catarina; Garcia, Rosangela Balaban [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

During the oil well drilling, drilling fluids are used in order to transport the cuttings until the surface. This fluid is also responsible for the mechanical sustentation of the well walls, the control of undesirable production of fluids in the formation, the lubricity and the cooling of the bit. The drilling fluids based on water are extensively applied due to their lower cost, thermal stability, biodegradability, easiness of pumping and treatment, resulting in smaller environmental impacts. However, some situations, such as hydrophilic shale drilling, request the use of additives to avoid the hydration of them and, consequently, the tool imprisonment or migration (filtration) of the drilling fluids into the rock. The goal of this work was to develop and test formulations of water-base drilling fluids with high capacity of inhibition of clay swelling and lubricity, obtaining drillings with larger penetration rate and calipers without enlargements. The results showed that the appropriate combination of commonly used commercial products can promote the obtaining of fluids with equal or better performance than those used by world companies. (author)

Green line fracturing systems fluids in Campos Basin, Brazil; Sistemas de fluidos de fraturamento na Bacia de Campos: evolucao em beneficio do meio ambiente

Energy Technology Data Exchange (ETDEWEB)

Melo, Alexandre B. de; Araujo, Cosme J.C. de; Martinho, Flavio M.; Gaspar, Fernando [BJ Services do Brasil, Rio de Janeiro, RJ (Brazil)

2008-07-01

The constant demand for Services Companies in Oil and Gas Industry to reduce the environmental impacts has led to a race in search of new cleaner technologies. Fluids with low toxicity are the target of research and development by the companies which are committed to ensure the aspects of quality, health, safety and environment from manufacturing up to the use in the final destination of these products. The replacement of these fluids is happening at a larger speed than in the past on the based in two factors: greater awareness on the part of these companies in relation to the environmental and by new environmental laws. The fluids systems used in fracturing operations are not an exception to this rule. Service companies today are in the process of replacing their formulations with systems less aggressive to the environment so-called 'green' systems. In this context the new technological developments of fracturing fluids are of fundamental importance to assist the new environmental requirements of both operators and government regulatory bodies and also to ensure better effectiveness of these products. This paper reports the research, development and application of new environmentally acceptable fracturing fluids technology, reviews the pioneering case histories in offshore operations and the benefits experienced in the Campos Basin - Brazil. (author)

Electro-elastoviscous response of polyaniline functionalized nano-porous zeolite based colloidal dispersions.

Science.gov (United States)

Chattopadhyay, Ankur; Rani, Poonam; Srivastava, Rajendra; Dhar, Purbarun

2018-06-01

The present article discusses the typical influence of grafted conducting polymers in the mesoscale pores of dielectric particles on the static and dynamic electrorheology and electro-viscoelastic behavior of corresponding colloids. Nanocrystalline meso-nanoporous zeolite has been prepared by chemical synthesis and subsequently polyaniline (PANI) coating has been implemented. Electrorheological (ER) suspensions have been formed by dispersing the nanoparticles in silicone oil and their viscoelastic behaviors are examined to understand the nature of such complex colloidal systems under electric fields. PANI-Zeolite ER fluids demonstrate higher static electroviscous effects and yield stress potential than untreated Zeolite, typically studied in literature. Transient electro-viscous characterizations show a stable and negligible hysteresis behavior when both the fluids are exposed to constant as well as time varying electric field intensities. Further oscillatory shear experiments of frequency and strain sweeps exhibit predominant elastic behavior in case of Zeolite based ER suspensions as compared to PANI systems. Detailed investigations reveal Zeolite based ER suspensions display enhanced relative yielding as well as electro-viscoelastic stability than the PANI-Zeolite. The steady state viscous behaviors are scaled against the non-dimensional Mason number to model the system behavior for both fluids. Experimental data of flow behaviors of both the ER fluids are compared with semi-classical models and it is found that the CCJ model possesses a closer proximity than traditional Bingham model, thereby revealing the fluids to be generic pseudo-linear fluids. The present article reveals that while the PANI based fluids are typically hailed superior in literature, it is only restricted to steady shear utilities. In case of dynamic and oscillatory systems, the traditional Zeolite based fluids exhibit superior ER caliber. Copyright © 2018 Elsevier Inc. All rights reserved.

Electrorheological (ER) fluids: A research needs assessment. Final report

Energy Technology Data Exchange (ETDEWEB)

Krieger, I.M.; Collins, E.A. [Consultec Scientific, Inc., Knoxville, TN (United States)

1993-05-01

This report consists of seven sections: (1) Executive Summary, (2) Introduction, (3) Overview, (4) Recommendations, (5) Panelist Reports, (6) Overseas Research and Development, and (7) Extended Bibliography. The Appendix contains the reports of site visits and contacts and other supplementary documents.

Drilling fluids formulation with cationic hydro-soluble polymers as inhibitors reactive shales; Formulacao de fluidos de perfuracao contendo polimeros cationicos hidrossoluveis como inibidores de formacoes reativas

Energy Technology Data Exchange (ETDEWEB)

Souza, Carlos Eduardo C. de; Nascimento, Regina Sandra V. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Sa, Carlos Henrique [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

Poly(diallyldimethylammonium chloride), having different molecular weight, and a copolymer with acrylamide were evaluated as shale inhibitor additive for water based drilling fluid, as well as the compatibility of these polycations with others additives present in the drilling fluid and the testing results for these fluids were compared with those for formulations with commercial cationic polymers from drilling fluids additives suppliers. The ability of the polymers and KCl systems in inhibiting the clay's dispersion were evaluated with hot rolling tests. The others additives, like viscosifier and fluid loss control agent, had their added amount systematically optimized by rheological and filtration tests. All cationic polymers and the electrolyte were able to inhibit the swelling and dispersion of clay and the results showed a synergistic increase in clay inhibition for the combination of polymer and KCl over either additive alone. The results suggested that greater polymer adsorption, implies in lower content of water in clays and better inhibition of swelling and dispersion of the clay. The polycations were compatible with the other additives in drilling fluids and the fluids formulated with these polymers were able to inhibit efficiently the dispersion and disintegration of clay and to keep the cuttings and barite in suspension. (author)

Características sólido-fluido en el crisol del horno alto según el modelo de desgaste nodal (MDN

Directory of Open Access Journals (Sweden)

Martín, R.

2009-08-01

Full Text Available The coke porosity is one of the most important variables that can affect the pig iron production and the lining corrosion. Up to now, the existing bibliography about lining corrosion always connects a deeper wear to an increase in the fluid flow (pig iron at the blast furnace hearth. However, there is no evidence of any deterministic model that could link, from the theoretical point of view, the following variables: lining corrosion, porosity of dead coke and flow of pig iron at the hearth. Besides justifying the lining corrosion profiles, the Nodal Wear Model (NWM can be an effective instrument to interpret the coke porosity and the pig iron speed rates that are generated inside the hearth.

La porosidad del coque aparece como unas de las variables que más pueden afectar a la producción de arrabio y a la correspondiente corrosión de los revestimientos. Hasta el momento, en la bibliografía existente sobre la corrosión de los revestimientos, siempre se asocia un mayor desgaste con el correspondiente incremento del flujo del fluido (arrabio en el crisol. No obstante, no se tiene referencia de ningún modelo determinístico que pudiera relacionar, desde el punto de vista teórico, las siguientes variables: corrosión de los revestimientos, porosidad del coque inactivo y flujo del arrabio en el crisol. El Modelo de Desgaste Nodal (MDN, además de justificar los perfiles de corrosión de los revestimientos a lo largo de la campaña, puede ser un instrumento eficaz para interpretar la porosidad del coque y los gradientes de velocidad del arrabio que se generan dentro del crisol.

Análisis del comportamiento de flujo de fluidos en un horno de reverbero agitado con diferentes impulsores, mediante la modelación física y numérica

Directory of Open Access Journals (Sweden)

Juárez, R.

2009-10-01

Full Text Available A fluid flow analysis and particle trajectory in a 5 t molten capacity scaled 1:2 model of a reverberatory furnace was performed using both physical and numerical simulation. The design of the system allowed studying the behavior of the liquid in a system agitated by impellers. The parameters studied were, rotating speed, shape and height of the impeller. The physical and numerical simulations were used to determine circulation and mixing times, fluid flow patterns and velocity profiles in the agitation and melting chambers. Using experimental data, it was possible to establish the interaction between turbulent flow and circulating solid particles. The original design of the reverberatory furnace was modified based on the physical and numerical simulation analysis. The new design showed an increased magnesium removal rate by means of a more efficient and faster mixing.

Utilizando la simulación física y numérica, en este trabajo se presenta un análisis del flujo de fluidos y la trayectoria de partículas, en un modelo escala 1:2 de un horno de reverbero de 5 t. La caracterización del sistema sirvió para determinar el comportamiento del líquido en un sistema agitado mediante impulsores de diferentes formas rotando a diferentes velocidades y alturas, lo cual ha permitido determinar tiempos de circulación, de mezclado, patrones de flujo y patrones de velocidad en las cubas de agitación y fusión. Además, se aportan datos experimentales de la interacción entre flujos turbulentos y partículas sólidas. Los resultados obtenidos sugirieron cambios en la geometría del diseño de un horno convencional, propiciando mezclado más rápido y eficiente e incrementando la eficiencia en la remoción de magnesio.

DINÁMICA DE FLUIDOS COMPUTACIONALES (CFD) Y SU USO PARA ANALIZAR LA DISTRIBUCION DE GASES AL INTERIOR DE INSTALACIONES PECUARIAS: UNA REVISIÓN DE LITERATURA

OpenAIRE

Alves Damasceno, Flávio; da Costa Baêta, Fernando; Arêdes Martins, Marcio; Osorio Saraz, Jairo Alexander; Ferreira Tinoco, Ilda de Fátima

2011-01-01

Actualmente, uno de los casos de mayor discusión en la producción animal, es la emisión de gases y de distribución de temperatura asociados al cambio climático y al comportamiento animal, principalmente con gases como metano (CH4) y el amoniaco (NH3). La aplicación de la dinámica de los fluidos computacionales (CFD) para predecir el comportamiento de esos gases, especialmente en el sector de producción animal, esta comenzando a ganar gran importancia. A lo largo de los años, la versatilidad, ...

Alternative techniques to monitoring the corrosive potential for fluids in submarine pipelines; Tecnicas alternativas para monitorar o potencial corrosivo de fluidos transportados em oleodutos submarinos

Energy Technology Data Exchange (ETDEWEB)

Andrade, Cynthia de Azevedo; Brito, Rosane Fernandes de; Paiva, Eva M. de O. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Tecnologia de Materiais, Equipamentos e Corrosao; Freitas, Nair Domingues de; Salvador, Angelica Dias [PETROBRAS, Macae, RJ (Brazil). Unidade de Negocios da Bacia de Campos

2003-07-01

PETROBRAS in search of being a benchmark in safety, environment and health, established in July 2001 a work group to elaborate a standard for Pipeline Integrity Management. This standard set the requirements for Pipeline Integrity Management and establishes, among others criteria, the actions required to detect, monitor and control internal corrosion of pipelines. The first step to evaluate, monitor and control the internal corrosion is to define the corrosive potential of transported fluids. Some oil pipelines located in central and southern areas of the Campos Basin transport high water cut produced fluids (> 30%) and with demulsifiers, which allow oil and water separation and increase internal corrosion risks. Despite of these, it is not possible to check the internal corrosion rates using conventional techniques because the fluids are produced through sub-sea 'manifolds'. In order to investigate the possibility of corrosion inhibition by crude oils, laboratory tests were performed simulating real field conditions in terms of fluid compositions, water cut and temperature. Experiments were conducted to determine the corrosion rate of specimens, the emulsion stability and the initial temperature of wax precipitation. This paper presents the results of the study realized to define the fluids' corrosive potential of four Campos Basin platforms that are transported through sub-sea 'manifolds. (author)

Evaluation of the rheological behavior of drilling fluids in annular flow conditions; Avaliacao do comportamento reologico de fluidos de perfuracao no escoamento anular

Energy Technology Data Exchange (ETDEWEB)

Silva, Maria das Gracas Pena; Martins, Andre Leibsohn; Oliveira, Antonio Augusto Junqueira de [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1988-12-31

The rheological behavior of drilling fluids during annular flow in a physical simulator well (Surface Hydraulic System - SHS)was investigated. Measurement of volumetric flow and pressure drop the 10-meter simulator well was used to assess applicability of the Bingham, power Law, Casson, and Herschell-Bulkley models to the annular flow of water and oil-based fluids under different temperatures. Additionally, under different pre-set deformation ranges, SHS-observed behavior was compared with behavior observed using the traditional Fann VG 35 A viscometer. (author) 8 refs., 21 figs., 15 tabs.

A dinâmica dos fluidos complementada e a sustentação da asa

Directory of Open Access Journals (Sweden)

Weltner Klaus

2001-01-01

Full Text Available A explicação convencional da sustentação da asa, usando a lei de Bernoulli, apresenta equívocos graves que são aqui analisados. Usamos as leis de Newton para demonstrar coerentemente a sustentação que se origina na aceleração do ar para baixo pela asa. A velocidade do fluxo de ar acima da asa é maior do que abaixo dela. Mostramos que isto é decorrência e não causa da baixa pressão. Se uma linha de corrente for curva existe um gradiente de pressão perpendicular à velocidade, fato que não pode ser negligenciado na representação da dinâmica dos fluidos. A análise da curvatura das linhas de corrente em volta de um obstáculo esclarece a geração e a distribuição das pressões. Outras aplicações equivocadas da lei de Bernoulli são detalhadamente analisadas segundo o nosso enfoque. Apresentamos experimentos convincentes e facilmente realizáveis em sala de aula, compreensíveis mesmo para o ensino médio.

Dielectric materials for electrical engineering

CERN Document Server

Martinez-Vega, Juan

2013-01-01

Part 1 is particularly concerned with physical properties, electrical ageing and modeling with topics such as the physics of charged dielectric materials, conduction mechanisms, dielectric relaxation, space charge, electric ageing and life end models and dielectric experimental characterization. Part 2 concerns some applications specific to dielectric materials: insulating oils for transformers, electrorheological fluids, electrolytic capacitors, ionic membranes, photovoltaic conversion, dielectric thermal control coatings for geostationary satellites, plastics recycling and piezoelectric poly

Analysis of production data and fluid thermodynamic conditions in wells of Los Humeros, Pue; Analisis de datos de produccion y condiciones termodinamicas del fluido de alimentacion de pozos de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Arellano Gomez, Victor Manuel; Aragon Aguilar, Alfonso; Barragan Reyes, Rosa Maria [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Flores Armenta, Magaly; Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Tovar Aguado, Rigoberto [Comision Federal de Electricidad (Mexico)]. E-mail: vag@iie.org.mx

2008-07-15

Production data from 22 wells of the Los Humeros geothermal field in Puebla, Mexico, were analyzed to estimate the thermodynamic conditions (pressure and enthalpy) of the bottom-hole fluids entering the wells and the changes to the fluids after exploitation. The bottom-well conditions were obtained by simulating the production histories of the wells, using the WELLSIM numerical simulator. The reservoir temperature was estimated by the FT-HSH2 gas-equilibrium method, which provided values matching very well the measured-well temperatures under static conditions. To estimate the rates of change of the well-bottom thermodynamic variables-pressure and enthalpy-the linear and the harmonic methods were used. According to these models, overall results indicated pressure-decline rates of between 0.92 (linear method) and 1.03 bar/year (harmonic method), average enthalpy increases of between 9.4 (linear) and 10.3 (harmonic) kJ/kg/year, and a temperature increase of about 1.2 degrees Celsius/year (linear method). These rates of parameter change were considered moderate, likely due to recharge from the deeper reservoir. The wells showing higher-pressure declines were H-35, H-1, and H-1D; and the wells showing higher-enthalpy increases were H-1D, H-3D, and H-19D. Most wells showed temperature increases, although a temperature decrease was noticed in wells H-16R and H-36, probably due to mechanical damage in the wells or weak communication with the deeper reservoir. [Spanish] Se realizo un analisis de los datos de produccion de 22 pozos del campo geotermico de Los Humeros, Pue., Mexico, con objeto de estimar las condiciones termodinamicas (presion y entalpia) de sus fluidos de alimentacion y su evolucion en el tiempo como respuesta a la explotacion. Las condiciones a fondo de pozo se obtuvieron al simular las historias de produccion de los pozos mediante el simulador numerico WELLSIM. La temperatura de fondo se estimo mediante el metodo de equilibrio gaseoso FT-HSH2 ya que fue

The rational use of energy in industrial refrigeration equipment through the appropriate selection of the refrigerant fluid as the working substance; Uso racional de la energia en equipos de refrigeracion industrial mediante la eleccion apropiada del refrigerante como sustancia de trabajo

Energy Technology Data Exchange (ETDEWEB)

Reyes Z, Jesus [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1994-12-31

This paper presents an analysis for diminishing the energy consumption in the industrial refrigeration equipment through the appropriate selection of the refrigerant fluid. The analysis shows the safety levels and the refrigerant toxicity, the construction advantages of the equipment, as well as the ecological impact derived from its utilization. By means of the liquid injection and the compression of the gas in two stages, a capacity increase is achieved and an energy demand reduction for the installation. Finally, an economical analysis is presented, comprising the equipment cost, operation, maintenance, consumption cost of the utilized fluids, etc. Demonstrating the selection of the working fluid employed. This analysis was made considering the PETROLEOS MEXICANOS installations. Nevertheless, this application can be adopted in any industrial installation for the rational energy use. Additionally the main advantages for the use of the proposed systems are shown, saving fuel expenses and increasing the thermal efficiency and diminishing the air pollution. [Espanol] Este trabajo presenta un analisis para disminuir el consumo de energia en los equipos de refrigeracion industrial mediante la seleccion apropiada del refrigerante. El analisis muestra los niveles de seguridad y toxicidad del refrigerante, las ventajas constructivas del equipo, asi como el impacto ecologico derivado de su empleo. Por la inyeccion de liquido y la compresion del gas en dos etapas, se logra un aumento de capacidad de enfriamiento y disminucion de la energia demandada por la instalacion. Finalmente un analisis economico se presenta, involucrando los gastos del equipo, operacion, mantenimiento, costos de consumos de fluidos utilizados, etc. Que demuestran la seleccion del fluido de trabajo utilizado. Este analisis fue hecho tomando en cuenta las instalaciones de Petroleos Mexicanos. No obstante, esta aplicacion puede ser adaptada en cualquier instalacion industrial para un uso racional de los

MODELAGEM TERMODINÂMICA DO FRACIONAMENTO DO ÓLEO DE MANTEIGA COM FLUIDOS SUPERCRÍTICOS

Directory of Open Access Journals (Sweden)

Guilherme B. M. NEVES

1997-12-01

Full Text Available O fracionamento do óleo de manteiga em frações de propriedades físicas e químicas diferentes mostra-se uma possível solução para o problema do excedente de óleo de manteiga no mercado internacional, despertando interesse em seu estudo. Com o objetivo de se modelar o equilíbrio de fases neste processo, foi feito um agrupamento dos 1331 triglicerídeos presentes no óleo de manteiga em 14 famílias. Assim, os componentes de uma mesma família possuem um comportamento semelhante quando expostos ao CO2 Supercrítico (CO2 SC. A seguir, utilizando a Equação de Peng-Robinson, realizou-se o cálculo do equilíbrio de fases no sistema óleo de manteiga/CO2, sendo o óleo de manteiga representado por uma mistura de 14 componentes hipotéticos, as famílias. Foram desenvolvidas correlações para a temperatura e pressão críticas e parâmetros de interação binária das famílias. O modelo foi capaz de correlacionar dados obtidos da literatura. As predições do equilíbrio de fases estão em excelente concordância com os dados obtidos pelos autores deste trabalho para os sistemas de óleo de manteiga/CO2. O procedimento mostrado aqui aplica-se não só ao dióxido de carbono supercrítico mas também a outros fluidos ou misturas de fluidos supercríticos, e também não somente ao óleo de manteiga, mas a todos os óleos/gorduras cuja constituição principal sejam triglicerídeos.Fractionation of butter oil into fractions with different physical and chemical properties is a possible solution for the problem of the excess of butter oil in the international market. With the objective of modeling the phase equilibria, the 1331 triglycerides were grouped into 14 families according to the number of carbons. Components belonging to the same family are considered to exhibit similar behavior when exposed to supercritical carbon dioxide (SC CO2. Using the Peng-Robinson equation of state, phase equilibrium calculations were performed for the butter

Optimization of organo clay production for applications in based oil drilling fluid; Otimizacao do processo de organofilizacao para aplicacoes em fluidos de perfuracao base oleo

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Heber S; Martins, Alice B; Costa, Danubia L. da; Ferreira, Heber C; Neves, Gelmires de A; Melo, Tomas J.A. de [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Teixeira Neto, Erico [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2008-07-01

The organophilic clays are widely used as an agent dispersed in the composition of oil based drilling fluids. The organophilic clays are gotten from bentonite clays treated, in watery way, with ionic surfactants, that are adsorbed in the surface of interlayer of the clays, re-covered them with a organic layer. A fundamental stage of production of the organophilic clays is the dispersion of bentonite clays, in way that variables like: speed of agitation, temperature and time of cure, influences directly in plastic and apparent viscosities of these dispersions, together with other variables of organophilization process, like, temperature and time of cure of organophilization, has direct influence in efficiency of the organophilization process. This work considers a study of these variable, using bentonite clays: Brasgel PA{sup R} and Cloisite Na{sup +R}, treated with the ionic surfactant Praepagem WB{sup R}. The organophilic clays gotten had been characterized by rays X diffraction, Foster's swelling, and the results were compared with the commercial organophilic clay VG-69{sup R}, industrially treated with ionic surfactant. Viscosities plastic and apparent of the dispersions had been measured in the midst of organic dispersant diesel oil used to obtain the oil based drilling fluids. Preliminary results of Foster's swelling and preparation of fluids show that the clays have affinity with the means liquid organic dispersants, and the fluids meet specifications of PETROBRAS (N-22581-1997 and N-2259 to 1997) for use in the of diesel oil based drilling fluids. (author)

A new controllable damper with neuro controller

International Nuclear Information System (INIS)

Kobayashi, N.; Kobayashi, H.; Saito, O.; Yokoi, R.; Morishita, S.

1993-01-01

A new controllable damper is proposed for suppressing the vibration of the piping system for wide frequency range. Electro-Rheological fluid (ER fluid) is enclosed in the damper casing in place of oil, and the apparent viscosity of ER fluid can be varied by applying electric field strength (E.F.S.), which is controlled by an adaptive neural network controller. The shaking test is conducted about a simplified L-shaped piping model with a prototype controllable damper. The test results show the effectiveness of the presented controllable damper for suppressing very small amplitude vibration of the piping system. Furthermore an application of neural network is discussed to control E.F.S. of the electrode. (author)

Investigation of electrokinetic and electrorheological properties of polyindole prepared in the presence of a surfactant

Energy Technology Data Exchange (ETDEWEB)

Unal, H. Ibrahim, E-mail: hiunal@gazi.edu.tr [Gazi University, Chemistry Department, Smart Materials Research Lab., Ankara (Turkey); Sahan, Bekir; Erol, Ozlem [Gazi University, Chemistry Department, Smart Materials Research Lab., Ankara (Turkey)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Aggregated morphology was determined for PIN, spherical and porous hollows and everniae form morphologies were recorded for SPIN. Black-Right-Pointing-Pointer The PIN/SO and SPIN/SO systems showed almost similar electrokinetic attitudes and a typical shear thinning non-Newtonian viscoelastic behavior, vibration damping capability at elevated frequencies, and enhanced storage moduli with increasing temperature. Black-Right-Pointing-Pointer Non-linear recoverable viscoelastic manner was revealed from the creep-recovery experiments under external electric field. - Abstract: In this study, synthesis of polyindole (PIN) was carried out without and with the presence of a sodium dodecyl sulfate (SDS) surfactant (SPIN), using FeCl{sub 3} as an oxidizing agent. The synthesized materials were subjected to various characterizations techniques namely: particle size, magnetic susceptibility, elemental analysis, density, conductivity, dielectric constant, FTIR, {sup 1}H NMR, TGA, XRD, and SEM. Characterization results revealed the successful preparation of the homopolymers of PIN and SPIN. Zeta ({zeta})-potentials of the samples were measured in aqueous and non-aqueous (silicone oil, SO) media. Electrokinetic properties of PIN and SPIN in aqueous media were determined by {zeta}-potential measurements in the presence of various electrolytes (NaCl, BaCl{sub 2}, AlCl{sub 3}, Na{sub 2}SO{sub 4}) and surfactants (cetyltrimethyl ammonium bromide, SDS, and Triton X-100). Besides, the effect of pH onto {zeta}-potentials of the materials was also examined. The suspensions prepared in SO were subjected to external electric field strength and their electrorheological (ER) properties were investigated. Then the effects of shear rate, frequency, and temperature onto ER activities of the suspensions were examined. Further, creep and creep-recovery tests were applied to the PIN/SO and SPIN/SO suspension systems and reversible non-linear viscoelastic

Evaluation of drilling fluids flow regime in annular sections; Avaliacao do regime de escoamento de fluidos de perfuracao em secoes anulares

Energy Technology Data Exchange (ETDEWEB)

Silva, Maria das Gracas Pena [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Setor de Tecnologia de Perfuracao

1990-12-31

The determination of the transition zone between the laminar and turbulent flow regimes of particular importance in optimizing the hydraulics of drilling operations. The principal advantage which laminar flow in the annular space has in drilling operations in the avoidance of wall enlargement (wash-outs), maintaining formation integrity as much as possible. On the other hand, a lower-energy regime such as laminar flow does not provide the same cuttings-carrying capacity as that obtained when the drilling fluid is in turbulent flow. However, to be able to optimize the hydraulics it is necessary to have determined, among other parameters, the transition zone, in order to maximize the drilling rate while obtaining the hole clear of cuttings and maintaining the hole diameter constant over the whole of the section drilled. This paper presents, based on experimental results obtained on the SHS physical simulator, the transition zone expressed through the critical Reynolds numbers and those for low stable turbulence of various drilling fluids tested over the temperature range of 25-80 deg C. (author) 20 refs., 7 figs., 4 tabs.

Optimization of organo clay production for applications in based oil drilling fluid; Otimizacao do processo de organofilizacao para aplicacoes em fluidos de perfuracao base oleo

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Heber S.; Martins, Alice B.; Costa, Danubia L. da; Ferreira, Heber C.; Neves, Gelmires de A.; Melo, Tomas J.A. de [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Teixeira Neto, Erico [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2008-07-01

The organophilic clays are widely used as an agent dispersed in the composition of oil based drilling fluids. The organophilic clays are gotten from bentonite clays treated, in watery way, with ionic surfactants, that are adsorbed in the surface of interlayer of the clays, re-covered them with a organic layer. A fundamental stage of production of the organophilic clays is the dispersion of bentonite clays, in way that variables like: speed of agitation, temperature and time of cure, influences directly in plastic and apparent viscosities of these dispersions, together with other variables of organophilization process, like, temperature and time of cure of organophilization, has direct influence in efficiency of the organophilization process. This work considers a study of these variable, using bentonite clays: Brasgel PA{sup R} and Cloisite Na{sup +R}, treated with the ionic surfactant Praepagem WB{sup R}. The organophilic clays gotten had been characterized by rays X diffraction, Foster's swelling, and the results were compared with the commercial organophilic clay VG-69{sup R}, industrially treated with ionic surfactant. Viscosities plastic and apparent of the dispersions had been measured in the midst of organic dispersant diesel oil used to obtain the oil based drilling fluids. Preliminary results of Foster's swelling and preparation of fluids show that the clays have affinity with the means liquid organic dispersants, and the fluids meet specifications of PETROBRAS (N-22581-1997 and N-2259 to 1997) for use in the of diesel oil based drilling fluids. (author)

A preliminary interpretation of gas composition in the CP IV sector wells, Cerro Prieto geothermal field, Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor M; Portugal Marin, Enrique [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Perez Hernandez, Alfredo; Rodriguez Rodriguez, Marco Helio; Leon Vivar, Jesus de [Comision Federal de Electricidad, Residencia General Cerro Prieto, B.C. (Mexico)

2007-07-15

-temperature fluids descending through the H fault to the reservoir was inferred, since results for the wells affected by this process (located at the center of the CP IV area) showed small or negative excess steam values and slightly lower temperatures (265-270 degrees Celsius). [Spanish] A fin de aumentar la capacidad de generacion de 620 a 720 MW, se desarrollo el sector Cerro Prieto IV (CP IV) en la porcion NE del campo geotermico de Cerro Prieto, donde se perforaron catorce pozos nuevos a partir del ano 2000. Los pozos de la zona de CP IV producen fluidos bifasicos con caracteristicas heterogeneas en cuanto a la fraccion de vapor: en la porcion central y hacia el NW los pozos producen liquido dominante mientras que hacia el E y S producen una fraccion de vapor relativamente alta. En este trabajo se estudia la composicion gaseosa de los fluidos producidos para obtener parametros del yacimiento tales como la temperatura y la fraccion de vapor e identificar diferentes aportes de fluidos a los pozos. Se utilizo un metodo basado en la reaccion de Fischer Tropsch y el equilibrio del H{sub 2}S con pirita-pirrotita como amortiguador (FT-HSH3). Los resultados para el estado inicial indican que existen fluidos con temperaturas de yacimiento entre 275 y 310 grados Celsius asi valores de exceso de vapor entre -1 y 50%. Los resultados se alinean en un patron de mezcla FT-HSH3 que sugiere que los pozos descargan una mezcla de los dos miembros finales en diferentes proporciones. Uno de ellos parece ser un liquido con una temperatura superior a los 300 grados Celsius con exceso de vapor negativo o insignificante. El otro parece ser un fluido bifasico con temperatura de unos 275 grados Celsius y un exceso de fraccion de vapor de aproximadamente 0.5. De acuerdo con datos de cada pozo y dependiendo de las condiciones de produccion de cada uno, pueden ocurrir mezclas de fluidos con diferentes proporciones de liquido y vapor en el yacimiento. Datos de 2005 de pozos perforados despues del ano 2000

An integrated fluid-chemical model towards modeling the formation of intra-luminal thrombus in abdominal aortic aneurysms

Directory of Open Access Journals (Sweden)

Jacopo eBiasetti

2012-07-01

Full Text Available Abdominal Aortic Aneurysms (AAAs are frequently characterized by the presenceof an Intra-Luminal Thrombus (ILT known to influence biochemically and biomechanicallytheir evolution. ILT progression mechanism is still unclear and little is known regardingthe impact on this mechanism of the chemical species transported by blood flow.Chemical agonists and antagonists of platelets activation, aggregation, and adhesion andthe proteins involved in the coagulation cascade (CC may play an important role in ILTdevelopment. Starting from this assumption, the evolution of chemical species involvedin the CC, their relation to coherent vortical structures (VSs and their possible effect onILT evolution have been studied. To this end a fluido-chemical model that simulates theCC through a series of convection-diffusion-reaction (CDR equations has been developed.The model involves plasma-phase and surface bound enzymes and zymogens, and includesboth plasma-phase and membrane-phase reactions. Blood is modeled as a non-Newtonianincompressible fluid. VSs convect thrombin in the domain and lead to the high concentration observed in the distal portion of the AAA. This finding is in line with the clinicalobservations showing that the thickest ILT is usually seen in the distal AAA region. Theproposed model, due to its ability to couple the fluid and chemical domains, provides anintegrated mechanochemical picture that potentially could help unveil mechanisms of ILTformation and development.

Exame do fluido peritoneal e hemograma de eqüinos submetidos à laparotomia e infusão intraperitoneal de carboximetilcelulose Peritoneal fluid exam and hemogram of horses submited to laparotomy and carboxymethylcellulose intraperitoneal infusion

Directory of Open Access Journals (Sweden)

Marco Aurélio Ferreira Lopes

1999-03-01

Full Text Available A aplicação intraperitoneal de carboximetilcelulose (CMC tem sido utilizada na prevenção de aderências peritoneais em animais e em humanos. Os objetivos deste trabalho foram avaliar a resposta do peritônio ao trauma cirúrgico e à aplicação de CMC e estudar como se processa a metabolização da CMC. Dezenove eqüinos mestiços foram submetidos à laparotomia, quando se produziram lesões no jejuno distal por abrasão da serosa e isquemia. Nos 9 eqüinos do grupo tratamento, antes da síntese da parede abdominal, foi instilada, na cavidade peritoneal, uma solução estéril de CMC, a 1% na dose de 7ml/kg. Nos eqüinos do grupo controle, nenhum medicamento foi aplicado na cavidade peritoneal. Após a cirurgia, colheram-se sangue e fluido peritoneal em 9 momentos: 4 horas após o fim da cirurgia, nos 3 primeiros dias pós-operatórios, pela manhã e a cada 48 horas nos dias subseqüentes (no 5º, 7º, 9º, 11º e 13º dias pós-operatórios. Os exames laboratoriais demonstraram que todos os animais desenvolveram inflamação peritoneal. Entretanto, nos animais do grupo tratamento, esta inflamação foi mais intensa e com um curso mais longo. Observou-se também que a excreção da CMC ocorreu por fagocitose.Intraperitoneal application of carboxymethylcellulose (CMC has been used for peritoneal adhesions prevention in animals and humans. The objectives of this research was to study the peritoneal response to surgical trauma and application of CMC and also to study how CMC excretion occurs. Nineteen healthy mixed breed horses were submited to laparotomy to produce lesions in distal jejunum by serosal abrasion and ischemia. In the nine horses of the treatment group, 7ml/kg of a 1% CMC sterile solution were instilated in peritoneal cavity before abdominal wall syntesis. No medication was instiled in peritoneal cavitiy of the control group horses. After surgery, blood and peritoneal fluid were colected in 9 postoperative moments: 4 hours after

Electrorheology for energy production and conservation

Science.gov (United States)

Huang, Ke

Recently, based on the physics of viscosity, we developed a new technology, which utilizes electric or magnetic fields to change the rheology of complex fluids to reduce the viscosity, while keeping the temperature unchanged. The method is universal and applicable to all complex fluids with suspended particles of nano-meter, submicrometer, or micrometer size. Completely different from the traditional viscosity reduction method, raising the temperature, this technology is energy-efficient, as it only requires small amount of energy to aggregate the suspended particles. In this thesis, we will first discuss this new technology in detail, both in theory and practice. Then, we will report applications of our technology to energy science research. Presently, 80% of all energy sources are liquid fuels. The viscosity of liquid fuels plays an important role in energy production and energy conservation. With an electric field, we can reduce the viscosity of asphalt-based crude oil. This is important and useful for heavy crude oil and off-shore crude oil production and transportation. Especially, since there is no practical way to raise the temperature of crude oil inside the deepwater pipelines, our technology may play a key role in future off-shore crude oil production. Electrorehology can also be used to reduce the viscosity of refinery fuels, such as diesel fuel and gasoline. When we apply this technology to fuel injection, the fuel droplets in the fuel atomization become smaller, leading to faster combustion in the engine chambers. As the fuel efficiency of internal combustion engines depends on the combustion speed and timing, the fast combustion produces much higher fuel efficiency. Therefore, adding our technology on existing engines improves the engine efficiency significantly. A theoretical model for the engine combustion, which explains how fast combustion improves the engine efficiency, is also presented in the thesis. As energy is the key to our national

Evaluation of glycerol derivative as emulsifier for oil based drilling fluids; Avaliacao de derivados de glicerina como emulsificante para fluidos de perfuracao de base oleo

Energy Technology Data Exchange (ETDEWEB)

Andrade, Susan A. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica; Cavalcanti, Milena Y.; Rodrigues Junior, Jorge; Lachter, Elizabeth R.; Nascimento, Regina Sandra V. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Quimica

2008-07-01

In view of the growing search for new applications for the surplus glycerine of biodiesel production, the use of a glycerine derivative as emulsifier in oil based muds is proposed in this work. Glycerine monooleate was synthesized through esterification reaction, and characterized by NMR{sup 13}C. Its applicability as emulsifier was verified through electric stability tests performed on inverted phase drilling fluids. The obtained results were compared with two formulations containing different emulsifiers (sorbitol monooleate and trimethylolpropane monooleate). It was also evaluated the rheological properties of the formulated fluids through standard tests. It was verified that the fluid that contained the glycerine derivative showed considerably better electric stability results than the other systems. It also presented rheological properties similar to the ones shown by the system that contained the commercial emulsifier (sorbitol monooleate). Thus, it was found that glycerine monooleate is a potential substitute to the currently emulsifiers (author)

Electro fluido dynamic techniques to design instructive biomaterials for tissue engineering and drug delivery

Energy Technology Data Exchange (ETDEWEB)

Guarino, Vincenzo, E-mail: vguarino@unina.it; Altobelli, Rosaria; Cirillo, Valentina; Ambrosio, Luigi [Institute for Polymers, Composites and Biomaterials, Department of Chemical Sciences & Materials Technology, National Research Council of Italy, V.le Kennedy 54, Naples (Italy)

2015-12-17

A large variety of processes and tools is continuously investigated to discover new solutions to design instructive materials with controlled chemical, physical and biological properties for tissue engineering and drug delivery. Among them, electro fluido dynamic techniques (EFDTs) are emerging as an interesting strategy, based on highly flexible and low-cost processes, to revisit old biomaterial’s manufacturing approach by utilizing electrostatic forces as the driving force for the fabrication of 3D architectures with controlled physical and chemical functionalities to guide in vitro and in vivo cell activities. By a rational selection of polymer solution properties and process conditions, EFDTs allow to produce fibres and/or particles at micro and/or nanometric size scale which may be variously assembled by tailored experimental setups, thus giving the chance to generate a plethora of different 3D devices able to incorporate biopolymers (i.e., proteins, polysaccharides) or active molecules (e.g., drugs) for different applications. Here, we focus on the optimization of basic EFDTs - namely electrospinning, electrospraying and electrodynamic atomization - to develop active platforms (i.e., monocomponent, protein and drug loaded scaffolds and µ-scaffolds) made of synthetic (PCL, PLGA) or natural (chitosan, alginate) polymers. In particular, we investigate how to set materials and process parameters to impart specific morphological, biochemical or physical cues to trigger all the fundamental cell–biomaterial and cell– cell cross-talking elicited during regenerative processes, in order to reproduce the complex microenvironment of native or pathological tissues.

Electro fluido dynamic techniques to design instructive biomaterials for tissue engineering and drug delivery

International Nuclear Information System (INIS)

Guarino, Vincenzo; Altobelli, Rosaria; Cirillo, Valentina; Ambrosio, Luigi

2015-01-01

A large variety of processes and tools is continuously investigated to discover new solutions to design instructive materials with controlled chemical, physical and biological properties for tissue engineering and drug delivery. Among them, electro fluido dynamic techniques (EFDTs) are emerging as an interesting strategy, based on highly flexible and low-cost processes, to revisit old biomaterial’s manufacturing approach by utilizing electrostatic forces as the driving force for the fabrication of 3D architectures with controlled physical and chemical functionalities to guide in vitro and in vivo cell activities. By a rational selection of polymer solution properties and process conditions, EFDTs allow to produce fibres and/or particles at micro and/or nanometric size scale which may be variously assembled by tailored experimental setups, thus giving the chance to generate a plethora of different 3D devices able to incorporate biopolymers (i.e., proteins, polysaccharides) or active molecules (e.g., drugs) for different applications. Here, we focus on the optimization of basic EFDTs - namely electrospinning, electrospraying and electrodynamic atomization - to develop active platforms (i.e., monocomponent, protein and drug loaded scaffolds and µ-scaffolds) made of synthetic (PCL, PLGA) or natural (chitosan, alginate) polymers. In particular, we investigate how to set materials and process parameters to impart specific morphological, biochemical or physical cues to trigger all the fundamental cell–biomaterial and cell– cell cross-talking elicited during regenerative processes, in order to reproduce the complex microenvironment of native or pathological tissues

Electro fluido dynamic techniques to design instructive biomaterials for tissue engineering and drug delivery

Science.gov (United States)

Guarino, Vincenzo; Altobelli, Rosaria; Cirillo, Valentina; Ambrosio, Luigi

2015-12-01

A large variety of processes and tools is continuously investigated to discover new solutions to design instructive materials with controlled chemical, physical and biological properties for tissue engineering and drug delivery. Among them, electro fluido dynamic techniques (EFDTs) are emerging as an interesting strategy, based on highly flexible and low-cost processes, to revisit old biomaterial's manufacturing approach by utilizing electrostatic forces as the driving force for the fabrication of 3D architectures with controlled physical and chemical functionalities to guide in vitro and in vivo cell activities. By a rational selection of polymer solution properties and process conditions, EFDTs allow to produce fibres and/or particles at micro and/or nanometric size scale which may be variously assembled by tailored experimental setups, thus giving the chance to generate a plethora of different 3D devices able to incorporate biopolymers (i.e., proteins, polysaccharides) or active molecules (e.g., drugs) for different applications. Here, we focus on the optimization of basic EFDTs - namely electrospinning, electrospraying and electrodynamic atomization - to develop active platforms (i.e., monocomponent, protein and drug loaded scaffolds and µ-scaffolds) made of synthetic (PCL, PLGA) or natural (chitosan, alginate) polymers. In particular, we investigate how to set materials and process parameters to impart specific morphological, biochemical or physical cues to trigger all the fundamental cell-biomaterial and cell- cell cross-talking elicited during regenerative processes, in order to reproduce the complex microenvironment of native or pathological tissues.

ACCURACY COMPARISON OF A MECHANISTIC METHOD AND COMPUTATIONAL FLUID DYNAMICS (CFD FOR GREENHOUSE INNER TEMPERATURE PREDICTIONS

Directory of Open Access Journals (Sweden)

E. Rico-García

2007-01-01

Full Text Available El movimiento de aire causado por la ventilación en los invernaderos es un factor importante que afecta la uniformidad de sus condiciones climáticas y consecuentemente la uniformidad y calidad del crecimiento de las plantas. La predicción de las condiciones climáticas de los invernaderos es realmente importante para tomar las acciones apropiadas para controlar el clima interno. En este trabajo se compararon un modelo mecanicista y otro basado en la dinámica de fluidos computarizada para determinar su precisión para predecir las temperaturas internas de los invernaderos en las condiciones climáticas mexicanas. Los resultados muestran que el modelo mecanicista tiene un mejor ajuste a las temperaturas internas (R2 = 0.97 que el basado en la dinámica de fluidos computarizada (R2 = 0.94. Sin embargo, ambos modelos pueden ser usados como herramientas ingenieriles para el diseño de invernaderos.

Subvolcanic contact metasomatism at El Laco Volcanic Complex, Central Andes Metasomatismo de contacto subvolcánico en el Complejo Volcánico El Laco, Andes centrales

Directory of Open Access Journals (Sweden)

José A Naranjo

2010-01-01

Full Text Available Studies of drill cores from the Pasos Blancos area at El Laco in the central Andes, northern Chile, give evidence of an intense and extensive subvolcanic contact-metasomatic process. This process resulted from shallow-level emplacement of very volatile-rich iron-oxide magma, with discharge of volatiles that resulted in extensive fracturing of overlying volcanic rocks. The brecciated rocks were altered (mainly extensive scapolitization and formation of pyroxene by hot magmatic fluids emitted from the cooling intrusion , and accompanied by magnetite deposition. With time and decreasing temperature, the metasomatic fluids evolved to fluids of hydrothermal character, and a final recent geothermal event took place that deposited superficial gypsum over a large part of the El Laco Volcanic Complex.Estudios realizados en testigos de sondajes en el area de Pasos Blancos en El Laco, en los Andes Centrales del norte de Chile, dan evidencias de un intenso y extenso proceso subvolcánico de metasomatismo de contacto. Este proceso es el resultado de un emplazamiento a poca profundidad de un magma de óxido de fierro muy rico en volátiles y cuya descarga de gases produjo un intenso fracturamiento de las rocas sobrepuestas. Las rocas brechizadas fueron alteradas (principalmente una extensa escapolitización y formación de piroxeno, junto con la depositación de magnetita, por los fluidos magmáticos calientes emitidos por la intrusión durante su enfriamiento. Los fluidos metasomáticos evolucionaron en el tiempo y con la disminución de temperatura, a fluidos de carácter hidrotermal y finalmente tuvo lugar un evento geotérmico reciente, el cual depositó yeso superficial en gran parte del Complejo Volcánico El Laco.

Behavior patterns of chemical and isotopic species (2006-2007) in the Los Azufres, Mich., geothermal field, as a response to reinjection; Patrones de comportamiento de especies quimicas e isotopicas (2006-2007) en el campo geotermico de Los Azufres, Mich., en respuesta a la reinyeccion

Energy Technology Data Exchange (ETDEWEB)

Barragan R, Rosa Maria; Arellano G, Victor Manuel; Martinez E, Ignacio; Aragon A, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Reyes D, Lisette; Gonzalez, Rubi [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres, Morelia, Michoacan (Mexico)

2009-07-15

Chemical and isotopic ({delta}18 O y {delta}D) data from the Los Azufres geothermal field fluids for 2006 and 2007 were analyzed to investigate changes in their behavior patterns and their relation to reinjection. Total discharge chlorides, reservoir temperatures, excess steam in well feeding fluids, CO{sub 2} concentrations at reservoir and total discharge conditions, and liquid saturations were calculated. Contour lines of certain parameters were obtained for 2006 and 2007 to relate them to the contours obtained for 2005 and to the reinjection histories. Fluid isotopic compositions, including injection fluids, were correlated to estimate fluid mixing effects between the reservoir and reinjection fluids. Results suggest chemical parameters respond to the mass flow rate injected and to the isotopic composition of injection fluids. {delta}D vs {delta}18 O relationships show a number of wells produce different proportions of reinjection returns. In the northern zone, wells AZ-65D, AZ-13, AZ-32, AZ-9A, AZ-9AD, AZ-28A, AZ-69D and AZ-44 produce relatively high proportions, while wells AZ-5, AZ-28 and AZ-19, among others, produce lower proportions. Wells AZ-2A, AZ-16AD, AZ-46 and AZ-33 from the southern field zone produce higher proportions of reinjection returns while wells AZ-34, AZ-36 and AZ-37 produce lower proportions. The liquid saturation distribution in 2007 shows the maximum saturation zones have decreased compared with 2005 and 2006 data. In 2007, maximum liquid saturations were found around wells AZ-22 and AZ-23 (southern zone) and AZ-28, AZ-32, AZ-45 and AZ-48 (northern zone). Minimum saturations were found around wells AZ-6 and AZ-16 (southern zone) and AZ-56 (northern zone). The CO{sub 2} levels for the reservoir liquid were used to trace paths of reinjection fluids, considering these fluids are depleted in this gas. Thus the minimum CO{sub 2} contour lines indicate the movement of the reinjection fluids in the reservoir. [Spanish] Se analizaron datos

Evaluation of eco toxicity, biocide effectiveness and corrosiveness of fluid for pipelines hydro testing; Avaliacao da ecotoxicidade, eficiencia biocida e da corrosividade de fluidos para teste hidroestatico de dutos

Energy Technology Data Exchange (ETDEWEB)

Andrade, Cynthia A.; Veiga, Leticia F.; Penna, Monica O.; Souza, Leonardo S. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Nascimento, Juliana R.; Oliveira, Fabio F.; Amigo, Alexandre A.; Chaves, Claudia [Fundacao Gorceix, Ouro Preto, MG (Brazil)

2005-07-01

Before the installation of subsea pipelines for draining the oil and gas production, the line need to be submitted to hydrostatic tests. In these, the lines are flooded with sea water and chemicals and pressurized to check the leakage occurrence. By the end of the test, the fluid needs to be discharged in-situ. Based on the environmental restrictions, this study began, and the three most important aspects in relation to the environmental risks had been evaluated: the toxicity, the biocide efficiency and the fluids' corrosiveness. By the partial results, it was observed that the fluids which had presented the best results in all studied aspects were the ones that contained the biocide THPS, combined with U.V. and a quaternary salt. In relation to the corrosion, it could be established that the studied fluids do not present impacts in internal corrosion, since during the test, the pipes are totally flooded with the fluid, remaining stamped and all the internal air having been removed. An important aspect is: even with concentrations below of the recommended ones for biocides, in order to guarantee lower environmental risks, by making use of alternative techniques (U.V.) and efficient biocide products, it is also possible to reach success in terms of biocide's efficiency. A regular monitoring procedure of the fulfilling fluid's quality is essential. (author)

Fluidos supercríticos em química analítica. III.: aplicações Supercritical fluids in analytical chemistry. III.: applications

Directory of Open Access Journals (Sweden)

Emanuel Carrilho

2006-07-01

Full Text Available The first two papers in this series described the basic theory involved in supercritical fluid chromatography (SFC, how the technique evolved from gas and liquid chromatography and how the instrumentation was developed. Over the last two years, a commercial, dedicated packed-column SFC/MS instrument appeared on the market. The SFC continues to grow in use, with fundamental developments, coupled with a steady rise in the number of industrial users and applications.

"Estudo comparativo da resistência à infiltração que diferentes materiais resinosos utilizados na cimentação de retentores intra-radiculares oferecem à passagem de fluidos que atravessam a dentina"

OpenAIRE

Marcio Katsuyoshi Mukai

2005-01-01

O Objetivo deste estudo é avaliar in vitro, a resistência que diferentes materiais resinosos têm a passagem de fluidos que atravessam a dentina na ausência de cemento radicular. Foram utilizados 60 dentes humanos cedidos pelo banco de dentes da FOUSP. Os dentes foram submetidos a tratamento endodôntico segundo a técnica de Paiva e Antoniazzi e armazenados a uma temperatura de 37°C em umidade 100% por 24 horas para o preparo do retentor intra -radicular respeitando o limite apical de 4 mm. Os ...

Estudio comparativo de flujo de fluido a través de una placa de orificio usando las ecuaciones de Stokes y de Navier-Stokes

Directory of Open Access Journals (Sweden)

Miryam Lucía Guerra-Mazo

2016-05-01

Full Text Available Presenta los resultados de la comparación entre las ecuaciones de Stokes y de Navier-Stokes para la simulación del flujo de agua líquida, a condiciones atmosféricas, a través de una placa orificio concéntrica. A partir de los datos experimentales que fueron tomados en el banco de fluidos, se evaluaron las simulaciones de ambas ecuaciones, usando el software libre Freefem++cs, que se basa en el método de los elementos finitos; las variables evaluadas son velocidad y presión en un intervalo de tiempo. Al analizar los resultados obtenidos con las simulaciones y comparar con los datos experimentales se encontró que las ecuaciones de Navier-Stokes representan mejor el sistema que la ecuación de Stokes.

Analysis of productive evolution of well M-19A, Cerro Prieto geothermal field, BC; Analisis de la evolucion productiva del pozo M-19A del campo geotermico de Cerro Prieto, BC

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-Rodriguez, Marco H; Romero-Rios, Francisco [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

2007-07-15

Well M-19A has been the most productive in the Cerro Prieto field, producing around 40 million tons of fluid. The well went on line in February 1975 and was in continuous operation until June 2006. Monthly measurements for over 30 years of operating conditions and chemical and isotopic analyses of the fluids allow identification of the most significant processes occurring in the zone where the well is located. Three dominant recharge types have been identified, each lasting about 10 years. They are a) a recharge of fluids of lower temperature than the production fluids, even though the chemical and isotopic compositions are similar; b) a recharge of lower-temperature fluids with diluted chemical and isotopic compositions; and c) a progressive recharge of reinjected water with a higher chloride concentration and heavy isotopic composition. The production and reinjection rates for over 30 years of production history in the M-19A well zone allow for speculation of a reservoir pressure recovery, which is confirmed with a calculation using production data from well M-19A. The evolution of the reservoir pressure in the zone contrasts with the rest of the reservoir, where a constant pressure drop is observed, particularly toward the central and eastern parts of the field. [Spanish] El pozo M-19A ha sido el mas productivo del campo geotermico de Cerro Prieto, BC, alcanzando una extraccion de mas de 40 millones de toneladas de fluido. Fue integrado a produccion en febrero de 1975 y hasta junio de 2006 ha permanecido en produccion en forma continua. Las mediciones mensuales de sus condiciones operativas y los analisis quimicos e isotopicos del agua producida permiten identificar los procesos mas significativos que han ocurrido a lo largo de esos mas de 30 anos en la zona donde se localiza el pozo. Se han identificado tres tipos de recarga dominantes que se presentan durante un periodo cercano a 10 anos cada uno, los cuales son: a) una recarga de fluidos de menor temperatura

Electrorheology of polyaniline, carbonized polyaniline, and their core-shell composites

Czech Academy of Sciences Publication Activity Database

Sedlacik, M.; Pavlinek, V.; Mrlik, M.; Morávková, Zuzana; Hajná, Milena; Trchová, Miroslava; Stejskal, Jaroslav

2013-01-01

Roč. 101, 15 June (2013), s. 90-92 ISSN 0167-577X R&D Projects: GA ČR GA202/09/1626 Institutional support: RVO:61389013 Keywords : polyaniline * carbonization * carbonized polyaniline Subject RIV: BK - Fluid Dynamics Impact factor: 2.269, year: 2013

Preparação e caracterização de fluidos magnéticos de maghemita funcionalizada com o aminoácido L-Lisina e dextrana para carreamento de plasmídeos

OpenAIRE

Silva, Breiner Gabriel Canedo

2016-01-01

Neste trabalho, foram sintetizadas nanopartículas magnéticas constituídas de maghemita funcionalizada com L-Lisina ou DL-Histidina (cristalitos com diâmetro médio de 4,5 a 8,1 nm), pelo método da coprecipitação dos íons Fe (II) e (III). Os sólidos obtidos foram dispersos em água para obtenção de suspensões aquosas denominadas fluidos magnéticos. As amostras obtidas foram caracterizadas pelas técnicas de difração de raios X, espectroscopia de infravermelho, termogravimetria, espectrofotometria...

Treatment of cutting fluid: comparative study of different processes of recycling; Tratamiento de fluidos de corte estudio comparativo de los diferentes procesos de reciclaje

Energy Technology Data Exchange (ETDEWEB)

Labarta Carreno, C.E.; Ipinar, E.

1997-12-31

The environmental concerning about cutting fluid (commonly known in Spain as taladrines) is deeply analyzed in this paper by the authors. They describe the history of these hazardous effluents what kind there, are their characteristics, and finally they study comparatively the different industrial processes for their treatment. (Author) 7 refs.

Implementação paralela de um código de elementos finitos em 2D para as Equações de Navier-Stokes para fluidos incompressíveis com transporte de escalares.

OpenAIRE

Pedro Juan Torres López

2010-01-01

O estudo do fluxo de água e do transporte escalar em reservatórios hidrelétricos é importante para a determinação da qualidade da água durante as fases iniciais do enchimento e durante a vida útil do reservatório. Neste contexto, um código de elementos finitos paralelo 2D foi implementado para resolver as equações de Navier-Stokes para fluido incompressível acopladas a transporte escalar, utilizando o modelo de programação de troca de mensagens, a fim de realizar simulações em um ambiente de ...

Actividad analgésica y antipirética de un extracto fluido de Pimenta dioica L. y evaluación de su toxicidad aguda oral

Directory of Open Access Journals (Sweden)

Ania Benítez López

1998-12-01

Full Text Available Se estudió la actividad analgésica y antipirética del extracto fluido de Pimenta dioica L. en animales de experimentación, así como su toxicidad aguda oral. Se evaluó el efecto analgésico a las dosis 825, 1 320 y 1 650 mg/kg mediante la técnica de contorsiones inducidas por agentes químicos (Witkin y col, 1961, y la antipiresia fue testada en conejos a las dosis 206 y 406 mg/kg, frente a una endotoxina de E. coli. Se compararon los resultados obtenidos en ambos estudios con ibuprofeno 200 mg/kg, y se demostró que el extracto administrado por vía oral, a las dosis de 1 650 mg/kg -analgesia- y 406 mg/kg -antipiresia- posee una efectividad similar al ibuprofeno. Se realizó el estudio toxicológico en ratones, y se obtuvo una DL50 de 2,56 g/kg, lo que permite clasificar al extracto como no tóxico.The analgesic and antipyretic activity of the Pimenta dioica L. fluid extract was studied in experimental animals, as well as its acute oral toxicity. The analgesic effect was evaluated at doses of 825, 1 320 and 1 650 mg/kg by the technique of contorsions induced by chemical agents (Witkin et. al., 1961, whereas antipyresis was tested in rabbits at doses of 206 and 406 mg/kg against an endotoxin of E. coli. The results obtained in both studies were compared with ibuprofen 200 mg/kg, and it was proved that the oral administration of the extract at doses of 1 650 mg/kg -analgesia- and 406 mg/kg -antipyresis- has an efectivity similar to that of ibuprofen. The toxicological study was conducted in mice and it was obtained a DL50 of 2.56 g/kg, which allows to classify the extract as non toxic.

Methodology to predict friction pressure drop in drilling fluid flows; Metodologia para previsao de perdas de carga em escoamentos de fluidos de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Scheid, Claudia Miriam; Calcada, Luis Americo [Universidade Federal Rural do Rio de Janeiro (UFRRJ). Departamento de Engenharia Quimica (Brazil)], e-mails: scheid@ufrrj.br, calcada@ufrrj.br; Rocha, Daniele Cristine [Centro de Pesquisas da Petrobras (CENPES). Engenharia Basica de Abastecimento - Gas e Energia (Brazil)], e-mail: drocha@petrobras.com.br; Aranha, Pedro Esteves [Centro de Pesquisas da Petrobras (CENPES). Gerencia de Perfuracao e Completacao de Pocos (Brazil)], e-mail: pearanha@petrobras.com.br; Aragao, Atila Fernando Lima [E and P Construcao de Pocos Maritimos. Gerencia de Tecnologia de Fluidos (Brazil)], e-mail: atila_aragao@petrobras.com.br

2009-12-15

An extensive experimental study is detailed to evaluate the friction pressure drop resulting from the flow through pipe and annular sections, accessories such as tool joints, bit jets and stabilizers of four different drilling fluids used in deep water operations. After a data analysis process, it was possible to compile a set of equations to predict relevant hydraulic friction pressure loss calculations, such as: hydraulic diameter for annular flows, friction factors for pipe and annular turbulent flows and discharge coefficients for accessories. (author)

OpenDx programs for visualization of computational fluid dynamics (CFD) simulations; Programas para visualizacao de simulacoes computacionais de dinamica de fluidos (CFD) usando o OpenDx

Energy Technology Data Exchange (ETDEWEB)

Silva, Marcelo Mariano da

2008-01-15

The search for high performance and low cost hardware and software solutions always guides the developments performed at the IEN parallel computing laboratory. In this context, this dissertation about the building of programs for visualization of computational fluid dynamics (CFD) simulations using the open source software OpenDx was written. The programs developed are useful to produce videos and images in two or three dimensions. They are interactive, easily to use and were designed to serve fluid dynamics researchers. A detailed description about how this programs were developed and the complete instructions of how to use them was done. The use of OpenDx as development tool is also introduced. There are examples that help the reader to understand how programs can be useful for many applications. (author)

Ocorrência de acidente de trabalho por materiais perfurocortantes e fluidos biológicos em estudantes e trabalhadores da saúde de um hospital escola de Brasília Frecuencia de accidentes del trabajo causados por instrumentos puntiagudo-cortantes y fluidos biológicos entre estudiantes y personal de un hospital escuela de la ciudad de Brasilia Occurrence of work accidents caused by sharp-edged hollow-pointed equipment and biological fluids among medical students and health personnel in a Brasília university hospital

Directory of Open Access Journals (Sweden)

Helena Eri Shimizu

2002-12-01

Full Text Available estudo teve por objetivo verificar e analisar a ocorrência de acidentes de trabalho causados por materiais perfurocortantes e fluidos biológicos em estudantes e trabalhadores da área da saúde. Foi realizado em um hospital-escola de Brasilia. A coleta de dados foi feita a partir dos registros de acidentes de trabalho mantidos pela Comissão de Controle de Infecção Hospitalar e referentes ao período de agosto de 1998 a junho de 2000. Verificou-se que 117 pessoas sofreram acidentes de trabalho, em sua grande maioria causados por agulhas. Concluiu-se que existe a necessidade de melhoria nos sistemas de prevenção de acidentes na instituição.El objetivo del estudio fue el de verificar y analizar la frecuencia de accidentes del trabajo causados por instrumentos puntiagudo-cortantes entre estudiantes y personal de un hospital escuela de la ciudad de Brasilia. Los datos, recogidos de los registros de accidentes del trabajo de la Comisión de Control de Infección Hospitalaria, corresponden al periodo entre agosto de 1998 y junio de 2000. Se verifico que 117 personas sufrieron accidentes del trabajo, en su gran mayoría causados por agujas. Se llegó a la conclusión de que es necesario mejorar el sistema de prevención de accidentes en dicha institución.The objective of the study was to check and analyze the occurrence of work accidents caused by sharp-edged hollow-pointed equipment and biological fluids among medical students and health personnel. It was carried out in a Brasilia university hospital. The data were collected from records of work accidents kept by the Hospital Infection Control Committee, from August 1998 to June 2000. It has turned out that 117 persons were victims of work accidents, the vast majority of them caused by needles. The study has reached the conclusion that the accident prevention system must be improved at the above mentioned hospital.

Las alteraciones silíceas de las lavas de Montaña Señalo, erupción de Timanfaya (1730-1736 (Lanzarote, Islas Canarias

Directory of Open Access Journals (Sweden)

García, A.

2009-06-01

Full Text Available The presence of hydrothermal alterations within the lavas of Timanfaya eruption (1730-1736, with high proportions of quartz and opal, suggests the effective circulation of hot fluids. The source of these fluids would be located under the island, where silica would be dissolved from sandstones and radiolarites, moving this way towards the surface as Si(OH4 colloids. Study of opal indicates the presence of A-initial CT and C phases in the collected samples, which, considering the time needed for producing this phase transformations in the diagenetic evolution of opal (10,000-50,000 years, suggests an accelerating process, probably related with either the presence of fluid circulation or weathering processes. Such circumstances are necessary for explaining the presence of such components affecting 300 years old lavas.La presencia de alteraciones de origen hidrotermal entre las lavas de la erupción de Timanfaya (1730-36, con altas proporciones del cuarzo y ópalo, indica la circulación efectiva de fluidos calientes. El origen de estos fluidos estaría en zonas profundas por debajo de la isla, donde se produciría la disolución de la sílice a partir de areniscas y radiolaritas, movilizándose de esta manera este componente hacia la superficie en forma de coloides de Si(OH4. El estudio en profundidad del ópalo indica la presencia de fases tipo A-inicio de CT y C. Si se tiene en cuenta el tiempo en el que se producen estas transformaciones en la evolución diagenética de esta fase amorfa (10.000-50.000 años, indicaría la presencia de un proceso acelerador que podría estar relacionado con una importante circulación de fluidos o con procesos de alteración meteórica, capaces de producir estas transformaciones en unas lavas de menos de 300 años.

Caracterização físico-química e dielétrica de óleos biodegradáveis para transformadores elétricos Physico-chemical and dielectric characterization of biodegradable oils for electric transformers

Directory of Open Access Journals (Sweden)

Claudia R Silva

2012-02-01

Full Text Available O óleo mineral, originário do petróleo, é o fluido isolante tradicionalmente utilizado em transformadores elétricos. Diante do apelo por fontes de energia limpa e renovável o setor elétrico também é pressionado a apresentar alternativas ao fluido de origem fóssil. Neste estudo, óleos de algodão, babaçu, girassol, milho e soja, foram avaliados quanto ao seu potencial para utilização como fluido dielétrico. As propriedades avaliadas foram densidade, viscosidade, acidez, tensão de ruptura, fator de perda, teor de água e corrosividade. Os resultados obtidos foram comparados aos limites estabelecidos na NBR 15422. Os óleos vegetais apresentaram densidade e viscosidade dentro dos limites recomendados; além disso, não se mostraram corrosivos mas devem ser submetidos a tratamentos específicos que os conduzam a atender outras especificações; o tratamento dos óleos com solução de hidróxido de sódio diminuiu a acidez, melhorou a tensão de ruptura e diminuiu o fator de perda.The mineral oil, originated from petroleum, is the insulating fluid traditionally used in electrical transformers. Responding to appeals for clean and renewable energy sources, the electrical sector is also under pressure to present alternatives to the fluid of fossil origin. In this study, cotton, `babassu', sunflower, corn and soybean oils were evaluated for their potential of utilization as a dielectric fluid. The properties investigated were density, viscosity, acidity, breakdown voltage, loss factor, water content and corrosivity. The results were compared with the values of the limits established in NBR 15422. Vegetable oils showed density and viscosity within the limits set by standard, however, higher than those presented by the studied mineral oil. It was found that vegetable oils have to pass through improvements to meet other specifications required. The treatment of oils with sodium hydroxide solution reduced the acidity, improved the breakdown

Evolução da fracturação e da interacção sólido-fluido de rochas ígneas em ambiente de circulação hidrotermal

OpenAIRE

Lopes, Sofia Alexandra Correia

2009-01-01

Tese de mestrado, Ciências Geofísicas (Geofísica Interna), Universidade de Lisboa, Faculdade de Ciências, 2009 Este trabalho centrou-se no estudo da evolução da fracturação numa rocha, desde o desenvolvimento de microfracturas até à ruptura macroscópica. A caracterização deste processo foi feito com base nas medições da variação de diversas propriedades físicas e mecânicas em duas rochas ígneas, granito e basalto, sujeitos à acção térmica e/ou mecânica, com e sem circulação de fluido. Este...

Development of high performance drilling fluids from national products: part I; Desenvolvimento de fluidos de perfuracao de alto desempenho a partir de produtos nacionais: parte I

Energy Technology Data Exchange (ETDEWEB)

Farias, Kassie V.; Amorim, Luciana V. [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Agencia Nacional do Petroleo (ANP), Brasilia, DF (Brazil). Programa de Recursos Humanos; Lira, Helio L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

2008-07-01

This work has a main objective to develop formulations of high performance water-based drilling fluids composed of national additives and evaluate their rheologic, filtration and lubrication behavior. It was developed ten formulations containing the following additives: viscosity, filtered reducer, controlling of pH, hydra table clays inhibitors, anti foamy, bactericide, lubricant and sealant. The fluids were prepared according to the field practice that consists of adding to water the additives under constant agitation. After 24 h resting, it was carried out a study of the rheologic behavior, in a Fann 35 A viscosimeter, and of the filtration properties in a Fann press-filter and of lubricity in a Ofite lubricimeter through the determination of the flow curves, apparent and plastic viscosities, yield limit, gel force, filtered volume, filter-cake thickness and lubricity coefficient. The results obtained were very promising, with properties close to the standard. (author)

Contact with hospital syringes containing body fluids: implications for medical waste management regulation Jeringas en contacto con sangre y fluidos corporales utilizadas en el hospital: implicaciones para el manejo de desechos hospitalarios

OpenAIRE

Patricia Volkow; Bénédicte Jacquemin; Diana Vilar-Compte; José Ramón Castillo

2003-01-01

OBJECTIVE: To determine amount of syringes used in the hospital and extent of contact with blood and body fluids of these syringes. MATERIAL AND METHODS: Syringe use was surveyed at a tertiary care center for one week; syringes were classified into the following four categories according to use: a) contained blood; b) contained other body fluids (urine, gastric secretion, cerebrospinal fluid, wound drainage); c) used exclusively for drug dilution and application in plastic intravenous (IV) tu...

Analysis of nitrogen injection as alternative fluid to steam in heavy oil reservoir; Analise da injecao de nitrogenio como fluido alternativo ao vapor em reservatorio de oleo pesado

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Marcos Allyson Felipe; Galvao, Edney Rafael Viana Pinheiro; Barillas, Jennys Lourdes; Mata, Wilson da; Dutra Junior, Tarcilio Viana [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

2012-07-01

Many of hydrocarbon reserves existing in the world are formed by heavy oils (deg API between 10 and 20). Moreover, several heavy oil fields are mature and, thus, offer great challenges for oil industry. Among the thermal methods used to recover these resources, steam flooding has been the main economically viable alternative. Latent heat carried by steam heats the reservoir, reducing oil viscosity and facilitating the production. This method has many variations and has been studied both theoretically and experimentally (in pilot projects and in full field applications). In order to increase oil recovery and reduce steam injection costs, the injection of alternative fluid has been used on three main ways: alternately, co-injected with steam and after steam injection interruption. The main objective of these injection systems is to reduce the amount of heat supplied to the reservoir, using cheaper fluids and maintaining the same oil production levels. In this paper, the use of N{sub 2} as an alternative fluid to the steam was investigated. The analyzed parameters were oil recoveries and net cumulative oil productions. The reservoir simulation model corresponds to an oil reservoir of 100 m x 100 m x 28 m size, on a Cartesian coordinates system (x, y and z directions). It is a semi synthetic model with some reservoir data similar to those found in Potiguar Basin, Brazil. All studied cases were done using the simulator STARS from CMG (Computer Modelling Group, version 2009.10). It was found that N{sub 2} injection after steam injection interruption achieved the highest net cumulative oil compared to others injection system. Moreover, it was observed that N2 as alternative fluid to steam did not present increase on oil recovery. (author)

Solución analítica del problema directo de la tomografía de capacitancia eléctrica para un fluido bifásico con una inclusión circular

Directory of Open Access Journals (Sweden)

Silvia Reyes

2012-01-01

Full Text Available En este artículo se expone un modelo matemático al problema de la Tomografía de Capacitancia Eléctrica (TCE, para el caso de un fluido bifásico dieléctrico con una inclusión circular. Se resuelve el problema directo, que consiste en obtener una expresión analítica para las capacitancias mutuas. La solución del problema directo servirá para validar cualquier método de solución al problema inverso, para calibrar los equipos de medición actualmente existentes y además para construir un método de discretización adaptiva para resolver el problema inverso de la TCE.

Nursing knowledge and practices regarding subcutaneous fluid administration.

Science.gov (United States)

Gomes, Nathália Silva; Silva, Andrea Mara Bernardes da; Zago, Luana Barbosa; Silva, Érica Carneiro de Lima E; Barichello, Elizabeth

2017-01-01

To describe the evidence in the literature regarding the knowledge and practices of the nursing team about subcutaneous administration of drugs and fluids in adults. Integrative review of the literature using the descriptors "nursing", "hypodermoclysis", "drug administration routes", "adult health," and "knowledge," in English, Spanish, and Portuguese, with no publication deadline. Of the 569 articles found, eight made up the sample. A predominance of international journals (75%) with more than five years of publication (62.5%). The analysis of the methodological characteristics showed a predominance of literature reviews (25%), quantitative studies (62.5%), cross-sectional studies (50%), and non-experimental studies (50%). Although it is an old technique with proven efficacy, hypodermoclysis is still little used, a puzzling fact due to its advantages and indications for any age. descrever as evidências, na literatura, sobre os conhecimentos e as práticas da equipe de enfermagem na administração de medicamentos e de fluidos por via subcutânea no adulto. revisão integrativa da literatura utilizando os descritores enfermagem, hipodermóclise, vias de administração de medicamentos, saúde do adulto e conhecimento; nos idiomas inglês, espanhol e português, sem data limite de publicação. Dos 569 artigos encontrados, oito compuseram a amostra. predomínio de revistas internacionais (75%) e com mais de cinco anos de publicação (62,5%). Ao analisarem-se as características metodológicas, predominaram: revisões de literatura (25%), estudos quantitativos (62,5%), estudos transversais (50%) e não-experimentais (50%). apesar de se tratar de uma técnica antiga com eficácia comprovada, a hipodermóclise ainda é pouco utilizada, fato incoerente pelas suas vantagens e suas indicações para qualquer idade.

Cutting and drill fluids destruction by electro-coagulation: a new technological option. Eliminacion de fluidos de corte y taladrinas por electrocoagulacion: una nueva alternativa tecnologia

Energy Technology Data Exchange (ETDEWEB)

Alava, J.I.; Ipinaza, E.; Ortiz de Urbina, G.; Mugica, J.C.; Yurramendi, L.; Labarta, C.; Solazabal, R. (Centro Tecnologico de Materiales, San Sebastian (Spain))

1994-01-01

With the aim of comparison between incoming technologies, that use electro coagulation as a method for cutting fluids elimination, some restricted conditions have been selected that, equalized the feature of different electro technologies. It has been also specifically selected, those treatments, that are starting-up in the industrial environment. The comparison shows the efficiency of the destruction of organic compounds (until 98%) and equalized his environmental advantages and disadvantages. (Author) 10 refs. (Author)

Operational durability of a giant ER valve for Braille display

Science.gov (United States)

Luning, Xu; Han, Li; Yufei, Li; Shen, Rong; Kunquan, Lu

2017-05-01

The compact configuration of giant ER (electrorheological) valves provides the possibility of realizing a full-page Braille display. The operational durability of ER valves is a key issue in fulfilling a Braille display. A giant ER valve was used to investigate the variations in pressure drops and critical pressure drops of the valves over a long period under some typical operational parameters. The results indicate that neither the pressure drops nor critical pressure drops of giant ER valves show apparent deterioration over a long period. Without ER fluid exchange, a blockage appears in the channel of the valve because the ER structures induced by an external electric field cannot be broken by the Brownian motion of hydraulic oil molecules when the external electric field is removed. Forcing ER fluid flow is an effective and necessary method to keep the channel of the valve unblocked. Thus the operational durability of the valve using giant ER fluids is able to meet the demands of Braille display.

Correlação da atividade de lactato desidrogenase e concentração de lactato com a classificação de efusões em cães Correlation of lactate dehydrogenase and lactate concentration with dog's effusion classification

Directory of Open Access Journals (Sweden)

Paula Nunes Rosato

2011-09-01

Full Text Available As efusões são problemas clínicos frequentes e que ocorrem em consequência de uma enfermidade que culmine com diminuição da pressão coloidosmótica intravascular, elevação da pressão hidrostática local, aumento da permeabilidade vascular e/ou comprometimento da drenagem realizada pelos vasos linfáticos. Dessa maneira, a avaliação laboratorial desse fluido torna-se relevante para que, em conjunto com os sinais clínicos apresentados pelo paciente, possa ser firmado um possível diagnóstico e instituída ação terapêutica adequada. Assim sendo, a classificação de uma efusão em transudato ou exsudato torna-se um dos pontos críticos para a elucidação do diagnóstico e condução do caso clínico. Em Medicina Veterinária, o método tradicional de classificação de uma efusão é baseado na contagem celular e na concentração de proteínas do fluido. Contudo, diversos estudos evidenciam que tais parâmetros não são suficientes para a correta classificação de todas as efusões. Assim, o presente estudo foi conduzido com o objetivo de verificar a correlação de outros parâmetros bioquímicos com a diferenciação das efusões transudativas e exsudativas e, para tal, foram avaliadas as atividades de lacatato desidrogenase (LDH das efusões, a relação de sua atividade fluido/soro, concentração de lactato das efusões, o gradiente de concentração de lactato do soro para o fluido e a concentração de proteínas das efusões. Os resultados obtidos permitiram observar que a atividade de LDH, a relação LDH efusão/soro, a concentração de lactato e o gradiente de concentração de lactato soro/efusão apresentam diferença estatisticamente significativa (PThe effusions are frequent clinical problems and can occur in consequence to an illness that culminates with decrease of the intravascular coloidosmotic pressure, increase of local hydrostatic pressure, increase of vascular permeability and/or compromising of the

Semi-industrial production of organo clays to use in base oil drilling fluid; Producao em escala piloto de argilas organofilicas visando uso em fluidos de perfuracao base oleo

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Heber S.; Martins, Alice B.; Costa, Danubia L. da; Ferreira, Heber C.; Neves, Gelmires de A.; Melo, Tomas J.A. de [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Teixeira Neto, Erico [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2008-07-01

The drilling fluids are essential to the operations of exploration of oil. The organoclays are widely used in the composition of the oil based drilling fluids and raw materials are of high value added. These clays can be obtained, traditionally, from bentonitic clay treated, in water, with ionic surfactants, however, non-ionic surfactants can be adsorbed on the surface of interlamelar bentonitic clay, naturally hydrophilic, making them organophilic. A pilot plant for production of organoclays was mounted in the Recycling Laboratory / UFCG. The bentonitic clay imported Cloisite Na{sup +R} was treated with a non-ionic surfactant in levels of 40, 50 and 60% in scale and bench-scale pilot. The commercial organoclay VG-69{sup R} was used as a standard for comparison of results. The clay obtained were characterized by X-ray diffraction, and Foster's swelling. The oil based fluids were prepared in accordance with the standards of PETROBRAS (N-22581 1997 and N-2259, 1997). Tests show that the characterization of organoclays have obtained intercalation of non-ionic surfactant with great expansion of layers of clay, with interlayer distances more significant than the clay trade, both on clay obtained in the laboratory scale as in clays obtained by pilot scale, with results very similar for both methods. It appears that it is possible the pilot-scale production of organoclays with equivalent quality produced in the laboratory scale and quality compatible with the clay used commercially. (author)

Influência dos cátions lítio (Li + , sódio (Na + e potássio (K + na reologia de bentonitas brasileiras para uso em fluidos de perfuração base aquosa

Directory of Open Access Journals (Sweden)

I. A. da Silva

Full Text Available Resumo Os cátions lítio (Li+, sódio (Na+ e potássio (K+ encontram-se em primeiro lugar no plano de seletividade para a obtenção de bentonitas monocatiônicas a partir das policatiônicas, influenciando de forma específica o comportamento reológico dos fluidos de perfuração base água. O objetivo deste trabalho foi estudar a influência do Li+, Na+ e K+ na reologia de bentonitas do estado da Paraíba, Brasil, para uso em fluidos de perfuração à base de água. Os novos depósitos de bentonitas brasileiras foram comparados com base nas suas características químicas, físicas, mineralógicas, propriedades reológicas e de filtração. As amostras de bentonitas foram caracterizadas por meio da composição química através do método clássico, capacidade de troca de cátions, análise granulométrica por difração a laser, difração de raios X e análises térmicas. A reologia das dispersões foi estudada e determinadas as viscosidades aparente, viscosidade plástica e limite de escoamento com base nas normas da API e Petrobras, além dos estudos de inchamento em água e filtrado. Os resultados mostraram uma melhora significativa nas propriedades reológicas e de filtração das dispersões após a aditivação com os carbonatos de lítio e de sódio, nessa ordem, havendo presença de tixotropia nas curvas de fluxo das dispersões de argilas estudadas.

Bráquetes convencionais e autoligados: detecção de micro-organismos na saliva e in situ, avaliação de parâmetros periodontais e quantificação de citocinas no fluido crevicular

OpenAIRE

Ana Zilda Nazar Bergamo

2014-01-01

O aparelho ortodôntico promove alterações microbiológicas na cavidade bucal, em função da variedade de materiais sólidos e elásticos que possuem, os quais funcionam como áreas de retenção, levando a um acúmulo de biofilme e predispondo o hospedeiro à cárie dental e à doença periodontal. Os objetivos do presente estudo, in vivo, foram: 1) Avaliar, as alterações no índice de placa (PI), índice gengival (GI), índice de sangramento gengival (GBI) e no volume do fluido crevicular, em pacientes com...

Active structuring of colloidal armour on liquid drops

OpenAIRE

Dommersnes, Paul; Rozynek, Zbigniew; Mikkelsen, Alexander; Castberg, Rene; Kjerstad, Knut; Hersvik, Kjetil; Fossum, Jon Otto

2013-01-01

Adsorption and assembly of colloidal particles at the surface of liquid droplets are at the base of particle-stabilized emulsions and templating. Here we report that electrohydrodynamic and electro-rheological effects in leaky-dielectric liquid drops can be used to structure and dynamically control colloidal particle assemblies at drop surfaces, including electric-fieldassisted convective assembly of jammed colloidal ‘ribbons’, electro-rheological colloidal chains confined to a...

Multiphysical modelling of fluid transport through osteo-articular media

Directory of Open Access Journals (Sweden)

Thibault Lemaire

2010-03-01

Full Text Available In this study, a multiphysical description of fluid transport through osteo-articular porous media is presented. Adapted from the model of Moyne and Murad, which is intended to describe clayey materials behaviour, this multiscale modelling allows for the derivation of the macroscopic response of the tissue from microscopical information. First the model is described. At the pore scale, electrohydrodynamics equations governing the electrolyte movement are coupled with local electrostatics (Gauss-Poisson equation, and ionic transport equations. Using a change of variables and an asymptotic expansion method, the macroscopic description is carried out. Results of this model are used to show the importance of couplings effects on the mechanotransduction of compact bone remodelling.Neste estudo uma descrição multifísica do transporte de fluidos em meios porosos osteo articulares é apresentada. Adaptado a partir do modelo de Moyne e Murad proposto para descrever o comportamento de materiais argilosos a modelagem multiescala permite a derivação da resposta macroscópica do tecido a partir da informação microscópica. Na primeira parte o modelo é apresentado. Na escala do poro as equações da eletro-hidrodinâmica governantes do movimento dos eletrolitos são acopladas com a eletrostática local (equação de Gauss-Poisson e as equações de transporte iônico. Usando uma mudança de variáveis e o método de expansão assintótica a derivação macroscópica é conduzida. Resultados do modelo proposto são usados para salientar a importância dos efeitos de acoplamento sobre a transdução mecânica da remodelagem de ossos compactados.

Thermostabilisation of human serum butyrylcholinesterase for detection of its inhibitors in water and biological fluids

Directory of Open Access Journals (Sweden)

Lakshmanan Jaganathan

1999-01-01

Full Text Available The ability of gelatine-trehalose to convert the normally fragile, dry human serum BChE into a thermostable enzyme and its use in the detection of cholinesterase inhibitors in water and biological fluids is described. Gelatine or trehalose alone is unable to protect the dry enzyme against exposure to high temperature, while a combination of gelatine and trehalose were able to protect the enzyme activity against prolonged exposure to temperature as high as +50°C. A method for rapid, simple and inexpensive means of screening for cholinesterase inhibitors such as carbamates and organophosphates in water, vegetables and human blood has been developed.A capacidade da gelatina-trehalose em converter a frágil BChE do soro humano em uma enzima termoestável e seu uso na descoberta de inibidores de colinesterase em água e fluidos biológicos é apresentado. A Gelatina ou trehalose são incapazes de proteger a enzima seca BchE do soro humano contra exposição a elevadas temperaturas, enquanto que uma combinação de gelatina e trehalose são capazes de proteger a atividade de enzima contra exposição prolongada a temperaturas elevadas e da ordem de 50° C. Um método barato, simples e rápido de screening para inibidores de colinesterase tal como carbamatos e organofosfatos em água, verduras e sangue humano foi desenvolvido.

Study of rock-drilling fluid interactions that contribute for the borehole instability; Estudo das interacoes rocha-fluido de perfuracao que contribuem para a instabilidade dos pocos de petroleo

Energy Technology Data Exchange (ETDEWEB)

Correa, Cleysson C.; Nascimento, Regina S.V. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Sa, Carlos H. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

In this work it was developed a new three points flexural mechanical test submersed for the simultaneous evaluation of the mechanical and chemical nature processes involved in the rock/drilling fluid interactions, which contribute for the borehole instability. The utilized fluids were air, mineral oil, distilled water and water solutions of non hydrolized polyacrylamide, poly(diallyldimethylammonium chloride) with different molecular weights, and the copolymer with acrylamide. Cuttings rolling tests were utilized to help in the understanding of the mechanisms involved in the shale's inhibition process. The results suggest that shale/polymer interactions are responsible for the shale's mechanical resistance, since the quantity of water and total carbon content of the shales were the same, after the test, independently of the inhibitor used. The results also suggest that the shale instability depends on the amount of adsorbed water, since independently of the inhibitor utilized, the quantity of adsorbed water was the same as that obtained with the shale/water system. (author)

Maximizing light olefins production in fluid catalytic cracking (FCC) units; Maximizacao de olefinas leves em unidades de craqueamento catalitico fluido

Energy Technology Data Exchange (ETDEWEB)

Pimenta, Ricardo D.M.; Pinho, Andrea de Rezende [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

The Fluid Catalytic Cracking (FCC) process is widely spread over the ten PETROBRAS refineries in its thirteen industrial units. The importance of the FCC process resides on its high gasoline output, being the main supplier of this important product to the system. Additionally, FCC process is the main source of light hydrocarbons in the LPG range, including light olefins. The increasing demand for ethylene, propylene and butylenes was encouraging to concentrate the research efforts on studies about alternatives for the traditional FCC process. In the present work, the proposals from main licensors (UOP, KBR, Stone and Webster) for a light-olefins-driven FCC process (Petrochemical FCC) will be compared. Furthermore, the catalytic route for light olefins production in FCC units is also described. An additive based on ZSM- 5 zeolite, which is produced following a PETROBRAS proprietary technology, is being largely applied into the catalyst inventories of all FCC units. An analysis of different scenarios was performed to estimate the maximum potential of light olefins production from the highest possible ZSM-5 additive usage. More specifically for the case of ethylene, which production is also boosted by the same type of additive, studies are being conducted with the objective of recovering it from a C2 stream using specific units to do the splitting (UPGR). The search for increasing light olefins production in the refining processes is in line with PETROBRAS strategic plan which targeted for the company a more intense activity in the Brazilian petrochemical market (author)

Fluid mechanics in fluids at rest.

Science.gov (United States)

Brenner, Howard

2012-07-01

Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

SEM observation of grain boundary structures in quartz-iron oxide rocks deformed at intermediate metamorphic conditions

Directory of Open Access Journals (Sweden)

Leonardo Lagoeiro

2011-09-01

Full Text Available Several studies have demonstrated the effect of a second phase on the distribution of fluid phase and dissolution of quartz grains. However, as most observations came from aggregates deformed under hydrostatic stress conditions and mica-bearing quartz rocks, 3-D distribution of pores on quartz-quartz (QQB and quartz-hematite boundaries (QHB has been studied. Several fracture surfaces oriented according to finite strain ellipsoid were analyzed. The pore distribution characterizes the porosity and grain shape as highly anisotropic, which results from the nature and orientation of boundaries. QHB have physical/chemical properties very different from QQB, once the hematite plates have strong effect on wetting behavior of fluid, likewise micas in quartzites. They are pore-free flat surfaces, normal to compression direction, suggesting that they were once wetted with a continuous fluid film acting as faster diffusion pathway. At QQB, the pores are faceted, isolated, close to its edges reflecting the crystallographic control and an interconnected network of fluid along grain junctions. The QQB facing the extension direction are sites of fluid concentration. As consequence, the anisotropic dissolution and grain growth were responsible for the formation of hematite plates and tabular quartz grains significantly contributing for the generation of the foliation observed in the studied rocks.Muitos estudos têm demonstrado o efeito de uma segunda fase sobre a distribuição de fase fluida e dissolução de grãos de quartzo. Entretanto, como a maioria das observações vêm de agregados deformados sob condições de tensão hidrostática e em rochas quartzosas ricas em mica, a distribuição 3D de poros e bordas quartzo-quartzo (BQQ e quartzo-hematita (BQH tem sido estudada. Várias superfícies de fraturas orientadas segundo o elipsóide de deformação finita foram analisadas. A distribuição dos poros caracteriza a porosidade e a forma dos grãos como

Evolution evidence of a basic fluid to an acid based in the analysis of hydrothermal alteration of the geothermic field of the Azufres, Michoacan; Evidencias de evolucion de un fluido basico a acido a partir del analisis de la alteracion hidrotermal del campo geotermico de los Azufres, Michoacan

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Partida, Eduardo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2000-07-01

Hydrothermal alteration at the Los Azufres geothermal field is mostly composed of calc-silicate minerals that define a propylitic alteration zone, which shows progressive dehydration with depth and temperature increase. A generalized zoning of the calc-silicate zone can be observed, with zeolites in the upper part and epidote-clinozoisite at the deepest levels. An argillic alteration zone overlies the calc-silicate zone and is the dominant surface manifestation of the hydrothermal alteration. In some parts, there is a mineral assemblage composed of kaolinite-alunite-native sulfur-quartz (advanced argillic zone) formed by the interaction of vapor and shallow groundwater. The proto-fluid at the Los Azufres geothermal system is related to a neutral sodium chlorine brine, which favors deep propyllitic alteration (productive zone). This zone is characterized by secondary permeability due to fracturing. At depth the geothermal field is dominated by a pressurized liquid, yielding to vapor at more shallow zone. The gradual change from a liquid to a vapor phase occurs through boiling at depths between 1,200 and 1,500 m, and is accompanied by changes in the hydrothermal alteration mineralogy. The type of alteration passes from proylitic to argillic by means of an oxidation-acidification process, which includes the participation of a gas, particularly CO{sub 2}. Considering the physicochemical characteristic of the brine and the evolution of the paragenetic sequence, the Los Azufres geothermal field could de considered a model for hydrothermal behavior at ore deposits which develop by boiling and oxidation of low sulfidation fossil hydrothermal fluids. [Spanish] En el campo geotermico de Los Azufres la zona de alteracion hidrotermal esta formada en su mayor parte por calcosilicatos (que definen una zona paragenetica del tipo propilitico), los cuales muestran una deshidratacion progresiva conforme se va profundizando e incrementandose la temperatura. Se puede generalizar un

Synthesis of polyisoprene and its evaluation as reducer of flow loss temperature of paraffinic drilling fluid; Sintese de poliisopreno e sua avaliacao como redutor da temperatura de perda de fluidez de fluido de perfuracao parafinico

Energy Technology Data Exchange (ETDEWEB)

Palermo, Luiz Carlos; Pires, Renata V.; Sant' Anna, Monica; Cardoso, Jaciene J.F.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro/ Instituto de Macromoleculas/ Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)], e-mail: luizpalermo@ima.ufrj.br

2011-07-01

N-paraffin fluids are widely used in drilling oil wells. However, under low temperature, such as those found in deep water, they lose their ability to flow due to solidification of paraffins. In order to keep the fluid flowing, isoparaffins are added to fluids. Nevertheless, the safety of the process is affected, due to its low flash point, especially during the storage in platforms offshore. This paper aims to obtain polymeric additives that can reduce the flow loss temperature of the n-paraffin fluid, replacing the isoparaffin, without affecting its rheological properties. So, oligomers/polymers based on isoprene were synthesized and the rheological behavior of the products and their mixtures with n-paraffin, as a function of decreasing temperature, was evaluated. Products from chemical degradation of natural rubber (NR) were also evaluated. The results showed that samples presenting relatively low molar mass, about 5,000 g/mol, exhibited good performance. When obtaining product by polymerization, a chain transfer agent must be used. (author)

Cuantificación de la eficiencia de la fachada cerámica ventilada mediante técnicas de la mecánica de fluidos computacional

Directory of Open Access Journals (Sweden)

Bengochea Escribano, M. A.

2011-04-01

Full Text Available In some countries, summer over-heating is a big problem in a building’s energy balance. Ventilated façades are a useful tool when applied to building design, especially in bioclimatic building design. A ventilated facade is a complex, multi-layer structural solution that enables dry installation of the covering elements. The objective of this paper is to quantify the efficiency improvement in the building thermal when this sort of facade is installed. These improvements are due to convection produced in the air gap of the façade. This convection depends on the air movement inside the gap and the heat transmission in this motion. These quantities are mathematically modelled by Computational Fluid Dynamics (CFD techniques using a commercial code: STAR CCM+. The proposed method allows an assessment of the energy potential of the ventilated façade and its capacity for cooling.

En muchos países, el calentamiento en los edificios que se da en verano se convierte en una fuente de consumo energético importante. La fachada ventilada se convierte en una herramienta de diseño sostenible, especialmente en diseños preocupados por el bioclimatismo. La fachada ventilada es un sistema de envolvente del edificio basada en la combinación de los paneles cerámicos con la cámara de aire con objeto de favorecer un ahorro energético en condiciones adecuadas, especialmente frente a las necesidades de refrigeración. El objetivo de la presente contribución es cuantificar la contribución a la eficiencia energética en el comportamiento térmico de los edificios cuando se instala este tipo de fachada. Estas mejoras se deben a la convección producida por el movimiento del aire en la capa de la fachada. El movimiento convectivo del aire está ligado al intercambio de calor con los paneles de la fachada. Esta cuantificación se realiza por medio de la Fluido Dinámica Computacional utilizando un código comercial: STAR CCM+. La metodolog

Evaluation of polymers of different degrees viscosities as additives for drilling fluids for oil well; Avaliacao de polimeros de diferentes graus de viscosidades como aditivos para fluidos de perfuracao de pocos de petroleo

Energy Technology Data Exchange (ETDEWEB)

Farias, K.V.; Amorim, L.V.; Silva, A.V. [Universidade Federal de Campina Grande (DEMa/UFCG), PB (Brazil); Lira, H.L. [Universidade Federal de Campina Grande (CCT/UFCG), PB (Brazil). Centro de Ciencias e Tecnologia. Unidade Academica de Engenharia de Materiais], e-mail: kassiefarias@gmail.com

2008-07-01

The objective of this work is to study the polymers influence of different degrees of viscosity, used as viscositying and filtered reducer additives, in the rheological, filtration and lubricity properties of drilling fluids for oil wells. Were determined the rheological behavior, the apparent and plastic viscosities, the yield limit and gel force, the filtered volume and the lubricity coefficient in accordance with API standard. The fluids showed pseudoplastic behavior with properties close to the standard fluid; the increase of viscositying and filtered reducer concentrations lead to the increase of rheological properties and the filtered reducer values, from the concentration of 3,5g/350mL of water it acted as viscositying, increasing the values of apparent and plastic viscosities, yield limit and gel force, being 3,0g/350mL of water the adequate concentration of this additive, promoting better results of rheological and filtration properties. (author)

Limpeza da superfície de corte de rebolos por um sistema de ar comprimido na retificação cilíndrica externa de mergulho de materiais cerâmicos refrigerados com a técnica da mínima quantidade de lubrificante (MQL Grinding wheel surface cleaning using a compressed air system, in external plunge grinding of ceramics using the minimum quantity lubricant (MQL technique

Directory of Open Access Journals (Sweden)

E. C. Bianchi

2012-06-01

Full Text Available Nos processos de retificação, a utilização de fluidos de corte é uma maneira de implementar a qualidade final do processo, pois os fluidos têm como finalidade a lubrificação na área de contato entre a peça e ferramenta e a refrigeração das superfícies, assim evitando danificações na superfície da peça. Com isso, a utilização de fluidos de corte tem sido constantemente estudada, visando diminuir a utilização deste, pois a utilização de fluidos de corte tem seus problemas. O custo do produto final aumenta consideravelmente com o uso de fluidos de corte no processo de retificação, além de que os fluidos de corte são substâncias tóxicas e nocivas tanto às pessoas quanto ao meio ambiente. Portanto, indústrias, universidades e centros de pesquisas são levados a pesquisar métodos alternativos menos prejudiciais ao meio ambiente. Dentre as alternativas surge a técnica da mínima quantidade de lubrificante (MQL, que também tem suas desvantagens, como por exemplo, a formação de um borra de óleo na superfície de corte do rebolo, o que gera uma rugosidade maior na peça. Porém, visando minimizar o problema da formação da borra de óleo podem ser usados jatos de ar comprimido incidindo na superfície de corte do rebolo, com o objetivo de limpar a mesma. Este estudo será feito através da análise da avaliação das variáveis de saída do processo de retificação externa, como o comportamento da rugosidade superficial e dos desvios de circularidade. Através dos resultados obtidos pretende-se estudar a técnica do MQL, visando melhorá-la através da limpeza da superfície de corte do rebolo com jatos de ar comprimido.In grinding, the use of cutting fluids aims to improve the final quality of the process, because their purpose is to lubricate the contact area between workpiece and tool and the surface cooling, thus avoiding damages on the machined part. Therefore, this subject has been constantly studied, in order

Influence of Parameters of Core Bingham Material on Critical Behaviour of Three-Layered Annular Plate

Directory of Open Access Journals (Sweden)

Pawlus Dorota

2017-12-01

Full Text Available The paper presents the dynamic response of annular three-layered plate subjected to loads variable in time. The plate is loaded in the plane of outer layers. The plate core has the electrorheological properties expressed by the Bingham body model. The dynamic stability loss of plate with elastic core is determined by the critical state parameters, particularly by the critical stresses. Numerous numerical observations show the influence of the values of viscosity constant and critical shear stresses, being the Bingham body parameters, on the supercritical viscous fluid plate behaviour. The problem has been solved analytically and numerically using the orthogonalization method and finite difference method. The solution includes both axisymmetric and asymmetric plate dynamic modes.

Fluids in crustal deformation: Fluid flow, fluid-rock interactions, rheology, melting and resources

Science.gov (United States)

Lacombe, Olivier; Rolland, Yann

2016-11-01

Fluids exert a first-order control on the structural, petrological and rheological evolution of the continental crust. Fluids interact with rocks from the earliest stages of sedimentation and diagenesis in basins until these rocks are deformed and/or buried and metamorphosed in orogens, then possibly exhumed. Fluid-rock interactions lead to the evolution of rock physical properties and rock strength. Fractures and faults are preferred pathways for fluids, and in turn physical and chemical interactions between fluid flow and tectonic structures, such as fault zones, strongly influence the mechanical behaviour of the crust at different space and time scales. Fluid (over)pressure is associated with a variety of geological phenomena, such as seismic cycle in various P-T conditions, hydrofracturing (including formation of sub-horizontal, bedding-parallel veins), fault (re)activation or gravitational sliding of rocks, among others. Fluid (over)pressure is a governing factor for the evolution of permeability and porosity of rocks and controls the generation, maturation and migration of economic fluids like hydrocarbons or ore forming hydrothermal fluids, and is therefore a key parameter in reservoir studies and basin modeling. Fluids may also help the crust partially melt, and in turn the resulting melt may dramatically change the rheology of the crust.

Electrohydrodynamic fibrillation governed enhanced thermal transport in dielectric colloids under a field stimulus.

Science.gov (United States)

Dhar, Purbarun; Maganti, Lakshmi Sirisha; Harikrishnan, A R

2018-05-30

Electrorheological (ER) fluids are known to exhibit enhanced viscous effects under an electric field stimulus. The present article reports the hitherto unreported phenomenon of greatly enhanced thermal conductivity in such electro-active colloidal dispersions in the presence of an externally applied electric field. Typical ER fluids are synthesized employing dielectric fluids and nanoparticles and experiments are performed employing an in-house designed setup. Greatly augmented thermal conductivity under a field's influence was observed. Enhanced thermal conduction along the fibril structures under the field effect is theorized as the crux of the mechanism. The formation of fibril structures has also been experimentally verified employing microscopy. Based on classical models for ER fluids, a mathematical formalism has been developed to predict the propensity of chain formation and statistically feasible chain dynamics at given Mason numbers. Further, a thermal resistance network model is employed to computationally predict the enhanced thermal conduction across the fibrillary colloid microstructure. Good agreement between the mathematical model and the experimental observations is achieved. The domineering role of thermal conductivity over relative permittivity has been shown by proposing a modified Hashin-Shtrikman (HS) formalism. The findings have implications towards better physical understanding and design of ER fluids from both 'smart' viscoelastic as well as thermally active materials points of view.

Study of methane solubility in oil base used in oil base drilling fluid; Estudo da solubilidade de metano em base oleo utilizada em fluido de perfuracao base oleo

Energy Technology Data Exchange (ETDEWEB)

Silva, Carolina Teixeira da; Mariolani, Jose Ricardo Lenzi [Universidade Estadual de Campinas, SP (Brazil); Ribeiro, Paulo Roberto; Lomba, Rosana Fatima Teixeira; Bonet, Euclides Jose

2004-07-01

During drilling a well, it is necessary to prevent and control high pressurized zones because while drilling on those zones, could occur a kick if the formation pressure were higher then downhole pressure, allowing the entering of undesirables fluids from the formation to the wellbore. If the well is not controlled this kick could became a blowout, generating damages to the environment, to the equipment and the human life. When drilling using oil-based mud, the concern related to the well control would be higher due the gas solubility in the mud, which could make it hard to detect the kick, especially in deep and ultra deep waters. In this work we have studied the interaction between methane and organic liquids used in drilling fluids, and the measurement and analysis of the thermodynamic properties of those gas liquid mixtures. There have been measured parameters like the oil formation volume factor (FVF{sub o}), bubble pressure, solubility (Rs) and the density of the saturated liquid in function of methane mole fraction and temperature. The results have shown that the gas solubility, at downhole conditions and during kick circulation, is a factor very important to the safety during well drilling in deep and ultra deep waters. (author)

Modelización del proceso de episienitización (decuarcificación-albitización: formulación cinética y transporte advectivo en medio continuo

Directory of Open Access Journals (Sweden)

Caballero, J. M.

1999-04-01

Full Text Available The development of episyenites from Sierra de Guadarrama has been modelized. The process mainly consists in a coupled process of dequartztification-albitization. The model is based on pure advective mass transport in a continuum medium, where the reactive process is formulated from a kinetic point of view. It is demonstrated the possibility of its formation through the action of low-salinity fluids (2,32 wt % NaCl equiv., partially equilibrated with a biotite monzogranite, linked to isobaric reaction paths across negative geothermal gradients, intersecting the quartz retrograde solubility field, and associated to a quick fluid-resident mobilisation due to the environment tectonic opening. The model explains the albitic nature of the alteration against former models. These predict microcline formation from the gradient relations ∂logKmic/∂T > ∂logKab/∂T (0.05739 and 0.05735 and ∂logKKCl/∂T NaCl/∂T (-0.038 and -0.036. Albite formation arises from the anortite component presence, because ∂logKan/∂T =0,1293 ≻ ∂logKmic/∂T. Non-equilibrium relations are very small, which implies that alteration intensity arises from the circulation of huge fluid volumes. This process feature together the kinetic rate constants result in a small change, spatial and temporal, of the fluid composition, being practically null for its main components (Na, K and, subordinately to these, the pH. The model also shows the necessity of handling geochemical systems as complex as possible. In this way, the proposed aqueous speciation proves that pH evolution along decreasing temperature is not necessarily acid, but inlet fluid pH dependent due to the calculated concentrations show that its behaviour mainly depends as much from Hel as from the NaOH base dissociation.Se modeliza teóricamente la formación de las episienitas de la Sierra de Guadarrama, consistente básicamente en un proceso acoplado de decuarcificaci

Evaluation of testosterone serum levels in testicular interstitial fluid under thyroxine influence; Avaliacao da testosterona no fluido intersticial testicular sob influencia da tiroxina

Energy Technology Data Exchange (ETDEWEB)

Silva, Isvania Maria S. da; Pereira, Simey de L.S.; Souza, Grace Mary L.; Carvalho, Elaine F.M.B.; Catanho, Maria Teresa J. de A. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Silveira, Maria de Fatima G. da [Pernambuco Univ., Recife, PE (Brazil). Dept. de Anatomia; Lima Filho, Guilherme L. [Universidade de Pernambuco (UPE), Nazare da Mata, PE (Brazil). Faculdade de Formacao de Professores

2000-07-01

The thyroid hormones possibly exert a reciprocal action between testicular steroids and Sertoli's cells during the premature period. This work aims to evaluate thyroxine effect on testosterone serum levels and in the testicular interstitial fluid (TIF) in rats. Wistar males rats, 22 days old, 80g of body weight, were induced to hyperthyroidism with thyroxine (20{mu}g/kg) in periods of 5, 10, 15 and 20 consecutive days. After the treatment the animals were weighed and sacrificed for blood and testis collection. From the blood serum and from the TIF drained from the testis were performed testes in order to obtain testosterone attached to {sup 125} I with a specific activity of 36,86 MBq/ig. The results have shown a testosterone significant lineal increase in both - serum and TIF - in the group treated with thyroxine as a time function. In the control group, testosterone levels remained low in both serum and TIF dosages. As a result, we were able to verify that the testosterone levels could be modified by thyroxine in serum and TIF. And so, it could affect luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in hypophysis. (author)

Solution of the Rayleigh-Plesset Equation Through the Finite Element Method Solución de la ecuación de Rayleigh-Plesset por medio del método del elemento finito

Directory of Open Access Journals (Sweden)

G.A Ramírez R.

2013-03-01

Full Text Available In this work we present numerical solutions of the Rayleigh-Plesset equation which describes the evolution of cavitating bubbles. In order to do that, we consider FEMG (Finite Element Method Galerkin; this simulation is performed for an inviscid and incompressible fluid in an uniform temperature field with constant surface tension, and the cavitation model into the which the pressure inside bubbles is equal to the fluid vapor pressure. Thus, in this problem is considered the Dirichlet boundary problem, and we obtained criteria for the boundary conditions at the cavitation phenomenon through to the which give rise to the bubble growing.En este trabajo se plantean soluciones numéricas a la ecuación de Rayleigh-Plesset que describe la evolución de las burbujas en la cavitación. Para ello, se considera el MEFG (Método del Elemento Finito de Galerkin; tal simulación se realiza en un fluido invíscido e incompresible en un campo de temperatura uniforme, una tensión superficial esencialmente constante, y el modelo de cavitación en el flujo siendo la presión interna de las burbujas igual a la presión de vapor del fluido. De esta manera, para el problema se considera el problema de Dirichlet y se obtienen los criterios de frontera que auspician el fenómeno de cavitación a través del crecimiento de las burbujas o cavidades.

Connection Between Thermodynamics and Dynamics of Simple Fluids in Pores: Impact of Fluid-Fluid Interaction Range and Fluid-Solid Interaction Strength.

Science.gov (United States)

Krekelberg, William P; Siderius, Daniel W; Shen, Vincent K; Truskett, Thomas M; Errington, Jeffrey R

2017-08-03

Using molecular simulations, we investigate how the range of fluid-fluid (adsorbate-adsorbate) interactions and the strength of fluid-solid (adsorbate-adsorbent) interactions impact the strong connection between distinct adsorptive regimes and distinct self-diffusivity regimes reported in [Krekelberg, W. P.; Siderius, D. W.; Shen, V. K.; Truskett, T. M.; Errington, J. R. Langmuir 2013 , 29 , 14527-14535]. Although increasing the fluid-fluid interaction range changes both the thermodynamics and the dynamic properties of adsorbed fluids, the previously reported connection between adsorptive filling regimes and self-diffusivity regimes remains. Increasing the fluid-fluid interaction range leads to enhanced layering and decreased self-diffusivity in the multilayer-formation regime but has little effect on the properties within film-formation and pore-filling regimes. We also find that weakly attractive adsorbents, which do not display distinct multilayer formation, are hard-sphere-like at super- and subcritical temperatures. In this case, the self-diffusivity of the confined and bulk fluid has a nearly identical scaling-relationship with effective density.

Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1999-12-31

In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1998-12-31

In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

Two-phase cooling fluids; Les fluides frigoporteurs diphasiques

Energy Technology Data Exchange (ETDEWEB)

Lallemand, A. [Institut National des Sciences Appliquees (INSA), 69 - Lyon (France)

1997-12-31

In the framework of the diminution of heat transfer fluid consumption, the concept of indirect refrigerating circuits, using cooling intermediate fluids, is reviewed and the fluids that are currently used in these systems are described. Two-phase cooling fluids advantages over single-phase fluids are presented with their thermophysical characteristics: solid fraction, two-phase mixture enthalpy, thermal and rheological properties, determination of heat and mass transfer characteristics, and cold storage through ice slurry

Reacting fluids analysis and polluting emissions; Analisis de fluidos reactivos y emisiones contaminantes

Energy Technology Data Exchange (ETDEWEB)

Munoz Ledo, Ramon; Ley Koo, Marcos [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Varela Ham, Ruben [Universidad Autonoma Metropolitana, Mexico, D. F. (Mexico)

1993-12-31

A problem is set up of a reacting flow which occurs in a gas exhausting duct, which is boiled down to a problem of initial conditions (temperature, pressure and concentration of species) freeing the selection of reaction mechanisms. Through some pre-established algorithms calculation routines can be programmed in specific problems of chemistry kinetics. With the calculation routines set forth in base of the selected mechanism, the temperature, pressure, etc., conditions, a general program is obtained containing the differential equations for the mechanisms, and with its solution, with a certain degree of uncertainty, the gases at a duct outlet can be predicted. The exhaust gases will carry unburned particles and products that can be polluting or not. If we vary the working conditions, we can find the optimum values to work with equipment that produces exhaust gases, anticipating with it the more efficient utilization of the equipment and the energy with the least possible pollution. [Espanol] Se plantea un problema de un flujo reactivo que se lleva a cabo en un ducto de salida de gases de escape, para lo cual se reduce a un problema de condiciones iniciales (temperatura, presion y concentracion de especies), y dejando en libertad la seleccion de mecanismos de reaccion. Mediante algunos algoritmos preestablecidos se pueden programar las rutinas de calculo en problemas especificos de cinetica quimica. Con las rutinas de calculo planteadas en base al mecanismo seleccionado, las condiciones de temperatura, presion, etc. se obtiene un programa general que contiene las ecuaciones diferenciales para el mecanismo y con su solucion se puede predecir con cierto grado de incertidumbre los gases a la salida de un ducto, los gases de salida llevaran particulas inquemadas y productos que pueden ser contaminantes o no, si hacemos variacion en las condiciones de trabajo podemos encontrar los valores optimos para trabajar con equipos que producen gases de escape, previendo con ello el uso mas eficiente de los equipos y la energia con la menor contaminacion posible.

Reacting fluids analysis and polluting emissions; Analisis de fluidos reactivos y emisiones contaminantes

Energy Technology Data Exchange (ETDEWEB)

Munoz Ledo, Ramon; Ley Koo, Marcos [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Varela Ham, Ruben [Universidad Autonoma Metropolitana, Mexico, D. F. (Mexico)

1992-12-31

A problem is set up of a reacting flow which occurs in a gas exhausting duct, which is boiled down to a problem of initial conditions (temperature, pressure and concentration of species) freeing the selection of reaction mechanisms. Through some pre-established algorithms calculation routines can be programmed in specific problems of chemistry kinetics. With the calculation routines set forth in base of the selected mechanism, the temperature, pressure, etc., conditions, a general program is obtained containing the differential equations for the mechanisms, and with its solution, with a certain degree of uncertainty, the gases at a duct outlet can be predicted. The exhaust gases will carry unburned particles and products that can be polluting or not. If we vary the working conditions, we can find the optimum values to work with equipment that produces exhaust gases, anticipating with it the more efficient utilization of the equipment and the energy with the least possible pollution. [Espanol] Se plantea un problema de un flujo reactivo que se lleva a cabo en un ducto de salida de gases de escape, para lo cual se reduce a un problema de condiciones iniciales (temperatura, presion y concentracion de especies), y dejando en libertad la seleccion de mecanismos de reaccion. Mediante algunos algoritmos preestablecidos se pueden programar las rutinas de calculo en problemas especificos de cinetica quimica. Con las rutinas de calculo planteadas en base al mecanismo seleccionado, las condiciones de temperatura, presion, etc. se obtiene un programa general que contiene las ecuaciones diferenciales para el mecanismo y con su solucion se puede predecir con cierto grado de incertidumbre los gases a la salida de un ducto, los gases de salida llevaran particulas inquemadas y productos que pueden ser contaminantes o no, si hacemos variacion en las condiciones de trabajo podemos encontrar los valores optimos para trabajar con equipos que producen gases de escape, previendo con ello el uso mas eficiente de los equipos y la energia con la menor contaminacion posible.

Corrosion behavior of Cu Al Ni shape memory alloy in an oil land field produced fluid; Corrosao da liga com memoria de forma CuAlNi em fluido produzido de campo terrestre de petroleo

Energy Technology Data Exchange (ETDEWEB)

Souza, Ricardo Estefany Aquino [PETROBRAS S.A., Aracaju/Maceio, SE/AL (Brazil). Unidade de Negocios SE-AL; Cruz, Maria Clara Pinto; Figueiredo, Renan T.; Souza, Luciete da Paixao; Araujo, Paulo M.M. [Universidade Tiradentes (UNIT), Aracaju, SE (Brazil)

2008-07-01

The corrosion behavior of the CuAlNi shape memory alloy in oil landfield produced groundwater was investigated with polarization curve and mass loss measurements, the latter carried out by immersion in laboratory and field tests. The physico-chemical analysis of five types of oil landfield produced groundwater showed the presence of H{sub 2}S and CO{sub 2}, high salinity, chloride, sulfide and iron ions and relatively neutral pH. The results from electrochemical tests in aerated produced groundwater, in the range of salinity encountered, suggested that the corrosion rate increases at higher saline concentrations. The results from field tests with corrosion test specimens showed a moderate to severe corrosion rate and suggested, in the other hand, that corrosion rates were influenced not only by salinity and oxidizing ions present in the flowing fluid, but also by solid materials in suspension, the fluid's temperature, and the flow velocity. This research is part of a major project which aims to develop couplings for landfield produced fluid transportation pipe connections without welded nor threaded joints. (author)

Viscous Flow with Large Fluid-Fluid Interface Displacement

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Hassager, Ole; Saasen, Arild

1998-01-01

The arbitrary Lagrange-Euler (ALE) kinematic description has been implemented in a 3D transient finite element program to simulate multiple fluid flows with fluid-fluid interface or surface displacements. The description of fluid interfaces includes variable interfacial tension, and the formulation...... is useful in the simulation of low and intermediate Reynolds number viscous flow. The displacement of two immiscible Newtonian fluids in a vertical (concentric and eccentric) annulus and a (vertical and inclined)tube is simulated....

Fluid transport due to nonlinear fluid-structure interaction

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard

1997-01-01

This work considers nonlinear fluid-structure interaction for a vibrating pipe containing fluid. Transverse pipe vibrations will force the fluid to move relative to the pipe creating unidirectional fluid flow towards the pipe end. The fluid flow induced affects the damping and the stiffness...... of the pipe. The behavior of the system in response to lateral resonant base excitation is analysed numerically and by the use of a perturbation method (multiple scales). Exciting the pipe in the fundamental mode of vibration seems to be most effective for transferring energy from the shaker to the fluid......, whereas higher modes of vibration can be used to transport fluid with pipe vibrations of smaller amplitude. The effect of the nonlinear geometrical terms is analysed and these terms are shown to affect the response for higher modes of vibration. Experimental investigations show good agreement...

Fluid-fluid level on MR image: significance in Musculoskeletal diseases

Energy Technology Data Exchange (ETDEWEB)

Chung, Hye Won; Lee, Kyung Won [Seoul Naitonal University, Seoul (Korea, Republic of). Coll. of Medicine; Song, Chi Sung [Seoul City Boramae Hospital, Seoul (Korea, Republic of); Han, Sang Wook; Kang, Heung Sik [Seoul Naitonal University, Seoul (Korea, Republic of). Coll. of Medicine

1998-01-01

To evaluate the frequency, number and signal intensity of fluid-fluid levels of musculoskeletal diseases on MR images, and to determine the usefulness of this information for the differentiation of musculoskeletal diseases. MR images revealed fluid-fluid levels in the following diseases : giant cell tumor(6), telangiectatic osteosarcoma(4), aneurysmal bone cyst(3), synovial sarcoma(3), chondroblastoma(2), soft tissue tuberculous abscess(2), hematoma(2), hemangioma (1), neurilemmoma(1), metastasis(1), malignant fibrous histiocytoma(1), bursitis(1), pyogenic abscess(1), and epidermoid inclusion cyst(1). Fourteen benign tumors and ten malignant, three abscesses, and the epidermoid inclusion cyst showed only one fluid-fluid level in a unilocular cyst. On T1-weighted images, the signal intensities of fluid varied, but on T2-weighted images, superior layers were in most cases more hyperintense than inferior layers. Because fluid-fluid layers are a nonspecific finding, it is difficult to specifically diagnose each disease according to the number of fluid-fluid levels or signal intensity of fluid. In spite of the nonspecificity of fluid-fluid levels, they were frequently seen in cases of giant cell tumor, telangiectatic osteosarcoma, aneurysmal bone cycle, and synovial sarcoma. Nontumorous diseases such abscesses and hematomas also demonstrated this finding. (author). 11 refs., 1 tab., 4 figs.

Fluid-fluid level on MR image: significance in Musculoskeletal diseases

International Nuclear Information System (INIS)

Chung, Hye Won; Lee, Kyung Won; Han, Sang Wook; Kang, Heung Sik

1998-01-01

To evaluate the frequency, number and signal intensity of fluid-fluid levels of musculoskeletal diseases on MR images, and to determine the usefulness of this information for the differentiation of musculoskeletal diseases. MR images revealed fluid-fluid levels in the following diseases : giant cell tumor(6), telangiectatic osteosarcoma(4), aneurysmal bone cyst(3), synovial sarcoma(3), chondroblastoma(2), soft tissue tuberculous abscess(2), hematoma(2), hemangioma (1), neurilemmoma(1), metastasis(1), malignant fibrous histiocytoma(1), bursitis(1), pyogenic abscess(1), and epidermoid inclusion cyst(1). Fourteen benign tumors and ten malignant, three abscesses, and the epidermoid inclusion cyst showed only one fluid-fluid level in a unilocular cyst. On T1-weighted images, the signal intensities of fluid varied, but on T2-weighted images, superior layers were in most cases more hyperintense than inferior layers. Because fluid-fluid layers are a nonspecific finding, it is difficult to specifically diagnose each disease according to the number of fluid-fluid levels or signal intensity of fluid. In spite of the nonspecificity of fluid-fluid levels, they were frequently seen in cases of giant cell tumor, telangiectatic osteosarcoma, aneurysmal bone cycle, and synovial sarcoma. Nontumorous diseases such abscesses and hematomas also demonstrated this finding. (author). 11 refs., 1 tab., 4 figs

Development of new additive for drilling fluid from the partial hydrophobization N,N,N-trimethyl chitosan (TMC); Desenvolvimento de novos aditivos para fluidos de perfuracao a partir da hidrofobizacao parcial da N,N,N trimetilquitosana (TMQ)

Energy Technology Data Exchange (ETDEWEB)

Carmo, Thacyla C. do; Lopes, Grazielle; Silva, Joaquim F.M. da; Nascimento, Regina S.V., E-mail: cycyla@hotmail.co [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Polo de Xistoquimica

2009-07-01

N,N,N-trimethyl chitosan (TMC) hydrophobically modified can act as an excellent additive for drilling fluids water based, working as inhibitor of reactive shales and rheological modifiers. The cationic chitosan was obtained by reaction of chitosan with CH{sub 3}I in N-methyl-2-pyrrolidone to obtain the TMC and chitosan was also hydrophobically modified with palmitoil chloride to get Quit P. Through another route, Quit P was modified to obtain the cationic TMCP. The derivatives were characterized by FT-IR and {sup 1}HNMR spectrophotometry allowing the calculation of the degree of quaternization of the TMC. The rheology tests showed that the system with TMCP presented pseudo plastic behavior, while the system with TMC behaved as a Newtonian fluid. The results indicated that TMCP can act as rheology modifier for water-based drilling fluids. (author)

Coste del kWh eólico generado en Cuba, a partir de datos de viento de una región de buenos potenciales eólicos // Cost of the kW h generated with wind energy in Cuba, analyzing the data of wind of a region of good potentials.

Directory of Open Access Journals (Sweden)

Deivis Avila - Prats

2010-09-01

Full Text Available La detección de defectos en tubos sometidos a presión interna es un aspecto poco estudiado. Unode los problemas a resolver es el modelado de los defectos, en particular los del tipo grieta cerrada.La dinámica de un tubo con un fluido interno a presión implica dificultades adicionales al problema.Se presentan los principios y las ecuaciones necesarias para poder modelar por el método de loselementos finitos la presencia de una grieta transversal parcial en un tubo de paredes delgadas envarios escenarios: vacío, con un fluido interno y con un fluido a presión. El análisis modal esempleado para determinar los cambios en los parámetros del modelo y valorar la influencia de lagrieta en los mismos. Se parte del experimento de S.M. Murigendrappa y S.K. Maiti, el efecto de lagrieta está representado por una reducción de la rigidez a la flexión del tubo en la zona de extensiónd, cuya extensión es determinada a partir del concepto de energía potencial de la deformación,planteado por A P. Bovsunovsky y V. V. Matveev.Palabras claves: grieta cerrada, análisis modal, tubos, elementos finitos._____________________________________________________________________________AbstractFail detection in pipes under internal pressure is a not enough studied matter. A main problem is faultmodeling, particularly the closed crack type. The dynamic of a pipe filled with a fluid under pressureimplies additional challenges. The equations and principles needed to obtain a finite elements modelof a partial transverse crack in a thin walled pipe are shown in different sceneries: empty, filled withfluid and filled with fluid under certain pressure. A modal analysis is performed to obtain the changesin modal parameters and crack influence. The result shows a good agreement with those obtained byS.M. Murigendrappa and S.K. Maiti. The crack is modeled trough a reduction of bending stiffness in areduced zone. Its extension is calculated using the principle of equal

Auxillary Fluid Flowmeter

DEFF Research Database (Denmark)

RezaNejad Gatabi, Javad; Forouzbakhsh, Farshid; Ebrahimi Darkhaneh, Hadi

2010-01-01

The Auxiliary Fluid Flow meter is proposed to measure the fluid flow of any kind in both pipes and open channels. In this kind of flow measurement, the flow of an auxiliary fluid is measured Instead of direct measurement of the main fluid flow. The auxiliary fluid is injected into the main fluid ...

Study with liquid and steam tracers at the Tejamaniles area, Los Azufres, Mich., geothermal field; Estudio con trazadores de liquido y vapor en el area Tejamaniles del campo geotermico de Los Azufres, Mich.

Energy Technology Data Exchange (ETDEWEB)

Iglesias, Eduardo R. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx; Flores Armenta, Magaly [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Torres, Rodolfo J. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Reyes Picasso, Neftali [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Reyes Delgado, Lisette [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

2011-01-15

monitored producing wells, and (ii) there is vertical permeability in the reservoir area between the distances mentioned. The vertical flow implies the injected fluid, relatively cold (about 40 degrees Celsius), is heated sufficiently to flow upward by convection, thus preventing, or at least slowing down, thermal interference. Results suggest the recovery of steam generated by injection into Az-08 generally tends to decrease exponentially with the horizontal distance of the studied wells to the injector, and with the vertical distance between the injection area and the corresponding production areas. [Spanish] La Comision Federal de Electricidad (CFE) inyecta salmueras producidas por pozos de la zona en el pozo Az-08, localizado en el area Tejamaniles, al suroeste del campo geotermico de Los Azufres, Mich. Los objetivos principales de este estudio son: determinar si el fluido inyectado recarga nueve pozos productores del area y, si esto ocurre, estimar que fraccion del fluido inyectado recarga a cada pozo productor. Cinco de los pozos seleccionados producen mezcla; el resto produce solo vapor. Por esta razon se diseno este estudio con inyeccion simultanea de trazadores de liquido y de vapor. Los nueve pozos productores seleccionados detectaron el trazador de vapor, y los cinco pozos que producen mezcla detectaron el trazador de fase liquida. Las curvas de residencia de ambos trazadores presentan series de picos que reflejan la conocida naturaleza fracturada de este yacimiento. Los resultados demuestran que las areas de alimentacion de los nueve pozos seleccionados son recargadas por el fluido inyectado en el pozo Az-08. Conviene aclarar que al momento de preparar este trabajo se habia completado el arribo del trazador de vapor en todos los pozos, pero los pozos que producen mezcla continuaban registrando arribo del trazador de liquido. Hasta 407 dias despues de la inyeccion de los trazadores, el porcentaje total de recuperacion del trazador de fase liquida en los cinco

Fluids engineering

International Nuclear Information System (INIS)

Anon.

1991-01-01

Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

Personalised fluid resuscitation in the ICU: still a fluid concept?

Science.gov (United States)

van Haren, Frank

2017-12-28

The administration of intravenous fluid to critically ill patients is one of the most common, but also one of the most fiercely debated, interventions in intensive care medicine. Even though many thousands of patients have been enrolled in large trials of alternative fluid strategies, consensus remains elusive and practice is widely variable. Critically ill patients are significantly heterogeneous, making a one size fits all approach unlikely to be successful.New data from basic, animal, and clinical research suggest that fluid resuscitation could be associated with significant harm. There are several important limitations and concerns regarding fluid bolus therapy as it is currently being used in clinical practice. These include, but are not limited to: the lack of an agreed definition; limited and short-lived physiological effects; no evidence of an effect on relevant patient outcomes; and the potential to contribute to fluid overload, specifically when fluid responsiveness is not assessed and when targets and safety limits are not used.Fluid administration in critically ill patients requires clinicians to integrate abnormal physiological parameters into a clinical decision-making model that also incorporates the likely diagnosis and the likely risk or benefit in the specific patient's context. Personalised fluid resuscitation requires careful attention to the mnemonic CIT TAIT: context, indication, targets, timing, amount of fluid, infusion strategy, and type of fluid.The research agenda should focus on experimental and clinical studies to: improve our understanding of the physiological effects of fluid infusion, e.g. on the glycocalyx; evaluate new types of fluids; evaluate novel fluid minimisation protocols; study the effects of a no-fluid strategy for selected patients and scenarios; and compare fluid therapy with other interventions. The adaptive platform trial design may provide us with the tools to evaluate these types of interventions in the intrinsically

Modern fluid dynamics

CERN Document Server

Kleinstreuer, Clement

2018-01-01

Modern Fluid Dynamics, Second Edition provides up-to-date coverage of intermediate and advanced fluids topics. The text emphasizes fundamentals and applications, supported by worked examples and case studies. Scale analysis, non-Newtonian fluid flow, surface coating, convection heat transfer, lubrication, fluid-particle dynamics, microfluidics, entropy generation, and fluid-structure interactions are among the topics covered. Part A presents fluids principles, and prepares readers for the applications of fluid dynamics covered in Part B, which includes computer simulations and project writing. A review of the engineering math needed for fluid dynamics is included in an appendix.

Avaliação de modelos matemáticos para o estudo da cinética de passagem de partículas e de fluidos por bovinos em pastagem recebendo suplementos contendo diferentes níveis de proteína não-degradável no rúmen Evaluation of mathematical models for estimating the kinetics of ruminal Passage of particles and liquid of grazing steers Supplemented with different rumen-undegradable protein levels

Directory of Open Access Journals (Sweden)

José Carlos Pereira

2005-12-01

Full Text Available Estudaram-se os comportamentos dos parâmetros da cinética de passagem de partículas e de fluidos em bovinos mantidos em pastagem de Brachiaria brizantha, em duas épocas (época 1 = meses de maio, junho e julho/2000; e época 2 = meses de março, abril e maio/2001, recebendo suplementos contendo diferentes níveis de proteína não-degradável no rúmen (PNDR. Na época 1 os animais foram alimentados com suplementos contendo 20, 40 e 60% de PNDR, feno de Brachiaria brizantha e mistura mineral ad libitum, enquanto na época 2, foram distribuídos nos tratamentos: T0 = pastagem de capim-braquiária + mistura mineral ad libitum; T40 = pastagem + suplemento com 40% de PNDR; e T60 = pastagem + suplemento com 60% de PNDR. Na estimativa da taxa de passagem de partículas pelo rúmen, utilizou-se como indicador o Cr-mordente, enquanto a cinética de passagem de fluidos foi estimada com Co-EDTA, durante três períodos, de agosto a setembro/2001, utilizando-se os mesmos animais e tratamentos da época 2. As estimativas dos parâmetros da cinética de passagem de partículas foram determinadas a partir do ajuste dos dados aos modelos bicompartimentais (G1G1, G2G1, G3G1, G4G1, G5G1 e G6G1, enquanto, para a cinética de passagem de fluidos, foi utilizado o modelo G1G1. Os critérios de escolha do melhor modelo foram a freqüência observada dos valores mínimos para o quadrado médio residual, obtido com os ajustes dos diferentes modelos e o número de corridas de sinal dos resíduos padronizados. Os modelos G2G1 e G3G1 mostraram-se mais eficientes na determinação das estimativas dos parâmetros de cinética de passagem de partículas, nas épocas 1 e 2, respectivamente. As estimativas do tempo médio de retenção ruminal de partículas e de fluidos não foram influenciadas pelos diferentes níveis de PNDR do suplemento.The effects of supplements containing different rumen-undegradable protein (RUP levels on the ruminal passage rate of particles and

I.C.E.F.M. 94. Proceedings of the International Conference on Experimental Fluid Mechanics (2nd) Held in Torino, Italy on July 4-8, 1994,

Science.gov (United States)

1994-07-08

Dipartimento di Ingegneiia Aeronautica e Spaziale - Politecnico di Torino Centro Studi Dinamica Fluidi del CNR SPONSORED BY Politecnico di Torino Consiglio...M.C.G. and VIEGAS, D.X. • Grupo de Mecfnica dos Fluidos Universidade de Coimbra (Portugal) ABSTRACT The external flow around an intercity bus was...Corso Duca degli Abruzzi, 24 - 10129 Torino (Italy) G. Guglieri C.N.R. Centro di Studio per la Dinamica dei Fluidi Corso Duca degli Abruzzi, 24

Extração do óleo de manjericão usando fluido supercrítico: analise experimental e matemática

Directory of Open Access Journals (Sweden)

Nídia Alves de Barros

2014-01-01

Full Text Available O óleo essencial de manjericão (Ocimum basilicum L. é valorizado no mercado internacional e amplamente usado nas indústrias de condimentos, cosméticos e medicinais. Entre todos os processos que podem ser aplicados na obtenção do óleo, a extração usando fluido supercrítico (EFS pode ser um método seletivo e eficiente, dependendo das condições operacionais, como temperatura e pressão, que precisam ser otimizadas. O objetivo deste estudo foi comparar a eficiência da extração supercrítica, utilizando planejamento experimental, na extração do óleo de manjericão com os métodos convencionais (hidrodestilação e soxhlet. Para a realização da parte experimental, foi utilizado dióxido de carbono como solvente para a EFS e hexano, para aplicação no soxhlet. Foi realizado um delineamento central composto rotacional (DCCR, aplicando três pressões (100, 200 e 300 bar e três temperaturas (30, 40 e 50ºC. Através da hidrodestilação, obteve-se o menor rendimento (0,26%, usando o Soxhlet, o rendimento foi de 2,39% sendo superior, comparado á EFS, que foi de 0,43%. O DCCR mostrou que, para otimizar o processo, é necessário aumentar a pressão e a temperatura para o alcance de maiores rendimentos. Foi possível constatar que o modelo matemático representou bem o processo de extração, propiciando o "scale-up" deste.

Fluid Mechanics.

Science.gov (United States)

Drazin, Philip

1987-01-01

Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

Electric fluid pump

Science.gov (United States)

Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

2015-09-29

An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

Principles of fluid mechanics

International Nuclear Information System (INIS)

Kreider, J.F.

1985-01-01

This book is an introduction on fluid mechanics incorporating computer applications. Topics covered are as follows: brief history; what is a fluid; two classes of fluids: liquids and gases; the continuum model of a fluid; methods of analyzing fluid flows; important characteristics of fluids; fundamentals and equations of motion; fluid statics; dimensional analysis and the similarity principle; laminar internal flows; ideal flow; external laminar and channel flows; turbulent flow; compressible flow; fluid flow measurements

Numerical Modeling of Fluid-Structure Interaction with Rheologically Complex Fluids

OpenAIRE

Chen, Xingyuan

2014-01-01

In the present work the interaction between rheologically complex fluids and elastic solids is studied by means of numerical modeling. The investigated complex fluids are non-Newtonian viscoelastic fluids. The fluid-structure interaction (FSI) of this kind is frequently encountered in injection molding, food processing, pharmaceutical engineering and biomedicine. The investigation via experiments is costly, difficult or in some cases, even impossible. Therefore, research is increasingly aided...

Maintenance fluid therapy and fluid creep impose more significant fluid, sodium, and chloride burdens than resuscitation fluids in critically ill patients: a retrospective study in a tertiary mixed ICU population.

Science.gov (United States)

Van Regenmortel, Niels; Verbrugghe, Walter; Roelant, Ella; Van den Wyngaert, Tim; Jorens, Philippe G

2018-04-01

Research on intravenous fluid therapy and its side effects, volume, sodium, and chloride overload, has focused almost exclusively on the resuscitation setting. We aimed to quantify all fluid sources in the ICU and assess fluid creep, the hidden and unintentional volume administered as a vehicle for medication or electrolytes. We precisely recorded the volume, sodium, and chloride burdens imposed by every fluid source administered to 14,654 patients during the cumulative 103,098 days they resided in our 45-bed tertiary ICU and simulated the impact of important strategic fluid choices on patients' chloride burdens. In septic patients, we assessed the impact of the different fluid sources on cumulative fluid balance, an established marker of morbidity. Maintenance and replacement fluids accounted for 24.7% of the mean daily total fluid volume, thereby far exceeding resuscitation fluids (6.5%) and were the most important sources of sodium and chloride. Fluid creep represented a striking 32.6% of the mean daily total fluid volume [median 645 mL (IQR 308-1039 mL)]. Chloride levels can be more effectively reduced by adopting a hypotonic maintenance strategy [a daily difference in chloride burden of 30.8 mmol (95% CI 30.5-31.1)] than a balanced resuscitation strategy [daily difference 3.0 mmol (95% CI 2.9-3.1)]. In septic patients, non-resuscitation fluids had a larger absolute impact on cumulative fluid balance than did resuscitation fluids. Inadvertent daily volume, sodium, and chloride loading should be avoided when prescribing maintenance fluids in view of the vast amounts of fluid creep. This is especially important when adopting an isotonic maintenance strategy.

Study of the stability of sugar Ester and its application potential with additives in the drilling fluids; Estudo da estabilidade do ester de acucar e sua potencial aplicacao como aditivo em fluido de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Suzan I.G.; Costa, Marta; Macedo, Sinara P.N. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

This work describe the enzymatic synthesis of the glucose ester starting from fatty acid, using protease Bacillus subtilis as biologic catalyst. The efficiency of ester has determined through the surface tension analyses in different pH (2-12), temperature (25-100 deg C) and salinity (50-115 g/L of NaCl). For a better understanding as for the applicability of the ester of sugar in drilling fluids, it was done necessary to know the values of interfacial tension of the oil/water; in that analysis, the mineral oil was investigated as oily phase and, as aqueous phase, biosurfactant solution. The results of interfacial tension of the water/oil and biosurfactant /oil they allowed to quantify us the influence of the benefactor's front to an organic phase, because the same made a significant reduction the interfacial tension of 26,0725 mN/m (water/oil) or 1,7527 mN/m (biosurfactant aqueous solution/oil). D-glucose ester was shown stable in different concentrations of NaCl, pH and temperature, and efficient in the reduction of the superficial tension of the water (of 72 mN/m for 28 mN/m). Preliminary test reveal that the ricinoleoil of D-glucose presents functionality as lubricant for drilling fluids to the base water. In the studied formulations, the obtained composition reduces the coefficient of lubricity of 0,20 for 0,04 and it stabilizes the fluid, reducing the volume of the filtrate of 5,0 mL for 3,4 mL. (author)

Fenómenos de transporte : un curso introductorio

OpenAIRE

Betancourt Grajales, Ramiro

1991-01-01

Fenómenos de transporte, es el nombre colectivo que se da al estudio sistemático e integrado de tres áreas clásicas de la ciencia de la Ingeniería : 1) Transporte de Energía o Calor, 2) Transporte de Masa o Difusión, y 3) Transporte de Cantidad de Movimiento o Impulso (Momentum en Inglés), o Dinámica de Fluidos. Debido a que con frecuencia el transporte de masa y de calor ocurren en un fluido, algunos planes de estudio incluyen estos procesos en su tratamiento de la mecánica de fluidos....

Self lubricating fluid bearings

International Nuclear Information System (INIS)

Kapich, D.D.

1980-01-01

The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid [fr

Use of organoclays obtained with nonionic surfactants for drilling fluids base organic; O uso de argilas organofilicas obtidas com tensoativo nao-ionico para fluidos de perfuracao base organica

Energy Technology Data Exchange (ETDEWEB)

Sousa, F.K.A. [Universidade Federal de Campina Grande (UATEC/UFCG), PB (Brazil). Unidade Academica de Tecnologia do Desenvolvimento], e-mail: kegealves@ufcg.edu.br; Neves, G.A.; Ferreira, H.C.; Silva, A.L. [Universidade Federal de Campina Grande (UFCG/UAEMa), PB (Brazil). Unidade Academica de Engenharia de Materiais; Campos, L.F.A. [Departamento de Engenharia de Materiais, DEMat/CCT/UFPB, PB (Brazil)

2010-07-01

This paper aims to use the compositions of organo clays obtained with nonionic surfactant for drilling fluids organic base containing additives, emulsifiers, brine, activator, reducer filtered, adensante and evaluate their rheological, filtration and electrical stability. Were studied through the mixture delineament, ten compositions of organo clays, and its performance is evaluated by means of the rheological behavior (flow curves, GI, GF, VA, VP and LE) and the tests recommended by API (PE, EE and VF). The results were compared with the standard PETROBRAS and showed that among the developed compositions, two compositions showed promising that met most of the properties and use the clay of inferior quality (Bofe and Verde-lodo) in greater quantity and minimum clay Chocolate UBM, considered the best clay in the region mines Boa Vista, PB. (author)

Standardization of Thermo-Fluid Modeling in Modelica.Fluid

Energy Technology Data Exchange (ETDEWEB)

Franke, Rudiger; Casella, Francesco; Sielemann, Michael; Proelss, Katrin; Otter, Martin; Wetter, Michael

2009-09-01

This article discusses the Modelica.Fluid library that has been included in the Modelica Standard Library 3.1. Modelica.Fluid provides interfaces and basic components for the device-oriented modeling of onedimensional thermo-fluid flow in networks containing vessels, pipes, fluid machines, valves and fittings. A unique feature of Modelica.Fluid is that the component equations and the media models as well as pressure loss and heat transfer correlations are decoupled from each other. All components are implemented such that they can be used for media from the Modelica.Media library. This means that an incompressible or compressible medium, a single or a multiple substance medium with one or more phases might be used with one and the same model as long as the modeling assumptions made hold. Furthermore, trace substances are supported. Modeling assumptions can be configured globally in an outer System object. This covers in particular the initialization, uni- or bi-directional flow, and dynamic or steady-state formulation of mass, energy, and momentum balance. All assumptions can be locally refined for every component. While Modelica.Fluid contains a reasonable set of component models, the goal of the library is not to provide a comprehensive set of models, but rather to provide interfaces and best practices for the treatment of issues such as connector design and implementation of energy, mass and momentum balances. Applications from various domains are presented.

Thermophysical properties of supercritical fluids and fluid mixtures

International Nuclear Information System (INIS)

Sengers, J.V.

1991-07-01

This research is concerned with the development of a quantitative scientific description of the thermodynamic and transport properties of supercritical and subcritical fluids and fluid mixtures. It is known that the thermophysical properties of fluids and fluid mixtures asymptotically close to the critical point satisfy scaling laws with universal critical exponents and universal scaling functions. However, the range of validity of these asymptotic scaling laws is quite small. As a consequence, the impact of the modern theory of critical phenomena on chemical engineering has been limited. On the other hand, an a priori estimate of the range of temperatures and densities, where critical fluctuations become significant, can be made on the basis of the so-called Ginzburg criterion. A recent analysis of this criterion suggests that this range is actually quite large and for a fluid like carbon dioxide can easily extend to 100 degrees or so above the critical temperature. Hence, the use of traditional engineering equations like cubic equations is not scientifically justified in a very wide range of temperatures and densities around the critical point. We have therefore embarked on a scientific approach to deal with the global effects of critical fluctuations on the thermophysical properties of fluids and fluid mixtures. For this purpose it is not sufficient to consider the asymptotic critical fluctuations but we need to deal also with the nonasymptotic critical fluctuations. The goal is to develop scientifically based questions that account for the crossover of the thermophysical properties from their asymptotic singular behavior in the near vicinity of the critical point to their regular behavior very far away from the critical point

Simulation of the flow phenomena in geothermal wells: developments and applications; Simulacion de los fenomenos de flujo en pozos geotermicos: desarrollos y aplicaciones

Energy Technology Data Exchange (ETDEWEB)

Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1994-07-01

In this paper the numerical simulators and the specialized computer programs that have been developed in the Departamento de Geotermia of the Instituto de Investigaciones Electricas (IIE) for the study of mass transport phenomena, momentum and heat in geothermal wells, are delineated. The developments can be assembled in 5 types: a) Fluid circulation during geothermal well construction; b) Production; c) Construction; d) Return to the thermal equilibrium; e) Thermodynamic and fluid transport properties, cements, and rocks. The applications realized include, besides the normal flow phenomena that occur in geothermal wells, the study of special problems that have been found in several wells of the geothermal fields in the country. These developments constitute a tool of great utility for the reservoir engineer`s daily work and for the understanding of the specific phenomena of infrequent occurrence. [Espanol] En este trabajo se describen los simuladores numericos y programas de computo especializados que se han desarrollado en el Departamento de Geotermia del Instituto de Investigaciones Electricas (IIE), para estudiar los fenomenos de transporte de masa, momentum y calor en pozos geotermicos. Los desarrollos pueden agruparse en 5 tipos: a) circulacion de fluidos durante la construccion de pozos, b) produccion, c) inyeccion, d) retorno a equilibrio termico, e) propiedades termodinamicas y de transporte de los fluidos, cementos y rocas. Las aplicaciones realizadas incluyen, ademas de los fenomenos normales de flujo que ocurren en pozos geotermicos, el estudio de problemas especiales que se han encontrado en diversos pozos de los campos geotermicos del pais. Estos desarrollos constituyen una herramienta de gran utilidad para el trabajo diario del ingeniero de yacimientos y para el entendimiento de fenomenos especificos de ocurrencia poco frecuente.

Theoretical study of fluidized solar collector performance

Energy Technology Data Exchange (ETDEWEB)

Adulla, S. H; Kassem, M A; El-Refaie, M. F. [Cairo University, Giza (Egypt)

2000-07-01

This work presents a proposed novel design aiming to increasing the absorber-to-fluid heat transfer coefficient. This is accomplished by introducing small solid particles inside the collector tubes. When the collector liquid flows, it causes the particles to be fluidized and spread in the tubes. The particles material, size and total number should be turned together with the fluid mass flow rate to keep the bed, or particle dispersion, length within the physical length of collector tubes. Thus, the particles would be confined in the collector only; and not carried over to other parts of the circulation loop. While moving, the particles erode the thermal boundary layer formed on the tube inner surface, hence increasing the heat transfer coefficient. [Spanish] Este articulo presenta un diseno novedoso destinado a aumentar el coeficiente de trasferencia de calor de absorbedor a fluido. Esto se lleva a cabo mediante la introduccion de particulas solidas dentro de los tubos del colector. Cuando fluye el liquido del colector origina que las particulas se fluidicen y se diseminen en los tubos. El material de las particulas, tamano y numero total debera de ser puesto en movimiento junto con el regimen de flujo de masa de fluido para mantener el lecho o la dispersion de particulas por largo tiempo dentro de la longitud fisica de los tubos de colector. De esta manera las particulas seran confinadas solamente en el colector y no seran arrastradas a otras partes del anillo de circulacion. Al moverse, las particulas erosionan la capa de frontera termica formada en la superficie interior del tubo, aumentando por tanto el coeficiente de transmision de calor.

CT findings of a unicameral calcaneal bone cyst containing a fluid-fluid level.

Science.gov (United States)

Gallagher, Thomas A; Lim-Dunham, Jennifer E; Vade, Aruna

2007-03-01

Calcaneal unicameral bone cysts often contain fluid, but rarely contain fluid-fluid levels. We present a case focusing on the CT findings of a large calcaneal bone cyst with a fluid-fluid level and a review of the literature.

Atomistic Modeling of the Fluid-Solid Interface in Simple Fluids

Science.gov (United States)

Hadjiconstantinou, Nicolas; Wang, Gerald

2017-11-01

Fluids can exhibit pronounced structuring effects near a solid boundary, typically manifested in a layered structure that has been extensively shown to directly affect transport across the interface. We present and discuss several results from molecular-mechanical modeling and molecular-dynamics (MD) simulations aimed at characterizing the structure of the first fluid layer directly adjacent to the solid. We identify a new dimensionless group - termed the Wall number - which characterizes the degree of fluid layering, by comparing the competing effects of wall-fluid interaction and thermal energy. We find that in the layering regime, several key features of the first layer layer - including its distance from the solid, its width, and its areal density - can be described using mean-field-energy arguments, as well as asymptotic analysis of the Nernst-Planck equation. For dense fluids, the areal density and the width of the first layer can be related to the bulk fluid density using a simple scaling relation. MD simulations show that these results are broadly applicable and robust to the presence of a second confining solid boundary, different choices of wall structure and thermalization, strengths of fluid-solid interaction, and wall geometries.

Synovial fluid analysis

Science.gov (United States)

Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

Editorial Special Issue on Fluid Mechanics and Fluid Power (FMFP ...

Indian Academy of Sciences (India)

This special issue of Sadhana contains selected papers from two conferences related to fluid mechanics held in India recently, Fluid Mechanics and Fluid Power conference at NIT, Hamirpur, and an International Union of Theoretical ... A simple, well thought out, flow visualization experiment or a computation can sometimes ...

FOREWORD Fluid Mechanics and Fluid Power (FMFP)

Indian Academy of Sciences (India)

This section of the Special Issue carries selected articles from the Fluid Mechanics and Fluid. Power Conference held during 12–14 December 2013 at the National Institute of Technology,. Hamirpur (HP). The section includes three review articles and nine original research articles. These were selected on the basis of their ...

Quantification of ventilated facade efficiency by using computational fluid mechanics techniques; Cuantificacion de la eficiencia de la fachada ceramica ventilada mediante tecnicas de la mecanica de fluidos computacional

Energy Technology Data Exchange (ETDEWEB)

Mora Perez, M.; Lopez Patino, G.; Bengochea Escribano, M. A.; Lopez Jimenez, P. A.

2011-07-01

In some countries, summer over-heating is a big problem in a buildings energy balance. Ventilated facades are a useful tool when applied to building design, especially in bio climatic building design. A ventilated facade is a complex, multi-layer structural solution that enables dry installation of the covering elements. The objective of this paper is to quantify the efficiency improvement in the building thermal when this sort of facade is installed. These improvements are due to convection produced in the air gap of the facade. This convection depends on the air movement inside the gap and the heat transmission in this motion. These quantities are mathematically modelled by Computational Fluid Dynamics (CFD) techniques using a commercial code: STAR CCM+. The proposed method allows an assessment of the energy potential of the ventilated facade and its capacity for cooling. (Author) 23 refs.

statistical fluid theory for associating fluids containing alternating ...

Indian Academy of Sciences (India)

Statistical associating fluid theory of homonuclear dimerized chain fluids and homonuclear ... The proposed models account for the appropriate .... where gHNM(1,1) is the expression for the contact value of the correlation func- tion of two ...

Fluid inclusion geothermometry

Science.gov (United States)

Cunningham, C.G.

1977-01-01

Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.

Energy variational analysis of ions in water and channels: Field theory for primitive models of complex ionic fluids.

Science.gov (United States)

Eisenberg, Bob; Hyon, Yunkyong; Liu, Chun

2010-09-14

component is added to the energy or dissipation, the Euler-Lagrange equations change form and interaction terms appear without additional adjustable parameters. EnVarA has previously been used to compute properties of liquid crystals, polymer fluids, and electrorheological fluids containing solid balls and charged oil droplets that fission and fuse. Here we apply EnVarA to the primitive model of electrolytes in which ions are spheres in a frictional dielectric. The resulting Euler-Lagrange equations include electrostatics and diffusion and friction. They are a time dependent generalization of the Poisson-Nernst-Planck equations of semiconductors, electrochemistry, and molecular biophysics. They include the finite diameter of ions. The EnVarA treatment is applied to ions next to a charged wall, where layering is observed. Applied to an ion channel, EnVarA calculates a quick transient pile-up of electric charge, transient and steady flow through the channel, stationary "binding" in the channel, and the eventual accumulation of salts in "unstirred layers" near channels. EnVarA treats electrolytes in a unified way as complex rather than simple fluids. Ad hoc descriptions of interactions and flow have been used in many areas of science to deal with the nonideal properties of electrolytes. It seems likely that the variational treatment can simplify, unify, and perhaps derive and improve those descriptions.

Energy variational analysis of ions in water and channels: Field theory for primitive models of complex ionic fluids

Science.gov (United States)

Eisenberg, Bob; Hyon, YunKyong; Liu, Chun

2010-09-01

component is added to the energy or dissipation, the Euler-Lagrange equations change form and interaction terms appear without additional adjustable parameters. EnVarA has previously been used to compute properties of liquid crystals, polymer fluids, and electrorheological fluids containing solid balls and charged oil droplets that fission and fuse. Here we apply EnVarA to the primitive model of electrolytes in which ions are spheres in a frictional dielectric. The resulting Euler-Lagrange equations include electrostatics and diffusion and friction. They are a time dependent generalization of the Poisson-Nernst-Planck equations of semiconductors, electrochemistry, and molecular biophysics. They include the finite diameter of ions. The EnVarA treatment is applied to ions next to a charged wall, where layering is observed. Applied to an ion channel, EnVarA calculates a quick transient pile-up of electric charge, transient and steady flow through the channel, stationary "binding" in the channel, and the eventual accumulation of salts in "unstirred layers" near channels. EnVarA treats electrolytes in a unified way as complex rather than simple fluids. Ad hoc descriptions of interactions and flow have been used in many areas of science to deal with the nonideal properties of electrolytes. It seems likely that the variational treatment can simplify, unify, and perhaps derive and improve those descriptions.

Buffer fluid

Energy Technology Data Exchange (ETDEWEB)

Mirzadzhanzade, A Kh; Dedusanko, G Ya; Dinaburg, L S; Markov, Yu M; Rasizade, Ya N; Rozov, V N; Sherstnev, N M

1979-08-30

A drilling fluid is suggested for separating the drilling and plugging fluids which contains as the base increased solution of polyacrylamide and additive. In order to increase the viscoelastic properties of the liquid with simultaneous decrease in the periods of its fabrication, the solution contains as an additive dry bentonite clay. In cases of the use of a buffer fluid under conditions of negative temperatures, it is necessary to add to it table salt or ethylene glycol.

Fluid geochemistry associated associated to rocks: preliminary tests om minerals of granite rocks potentially hostess of radioactive waste repository; Geoquimica de fluidos associados a rochas: testes preliminares em minerais de rochas granitoides potencialmente hospedeiras de repositorios de rejeitos radioativos

Energy Technology Data Exchange (ETDEWEB)

Amorim, Lucas E.D.; Rios, Francisco J.; Oliveira, Lucilia A.R. de; Alves, James V.; Fuzikawa, Kazuo; Garcia, Luiz; Ribeiro, Yuri, E-mail: LDAmorim@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Matos, Evandro C. de [Industrias Nucleares do Brasil S.A. (INB), Caetite, BA (Brazil)

2009-07-01

Fluid inclusions (FI) are micro cavities present on crystals and imprison the mineralizer fluids, and are formed during or posterior to the mineral formation. Those kind of studies are very important for orientation of the engineer barrier projects for this purpose, in order to avoid that the solutions present in the mineral FI can affect the repository walls. This work proposes the development of FI micro compositional studies in the the hostess minerals viewing the contribution for a better understanding of the solution composition present in the metamorphosis granitoid rocks. So, micro thermometric, microchemical and characterization of the material confined in the FI, and the hostess minerals. Great part of the found FI are present in the quartz and plagioclase crystals. The obtained data on the mineral compositions and their inclusions will allow to formulate hypothesis on the process which could occurs at the repository walls, decurrens from of the corrosive character (or not) of the fluids present in the FI, and propose measurements to avoid them

Design Program in Graphic User Interface Environment for Automobile ER Devices

Science.gov (United States)

Lim, S. C.; Park, J. S.; Sohn, J. W.; Choi, S. B.

This work presents a design and analysis program for vehicle devices utilizing an electrorheological (ER) fluid. The program is operated in graphic user interface (GUI) environment and the initial window is consisted of four subprogram modules which are related to ER shock absorber, ER seat damper, ER engine mount, and ER anti-lock brake system (ABS), respectively. In order to execute each module, both material properties and design parameters are to be chosen by the user. Then, the output display window shows the field-dependent performance characteristics to be considered as design criteria. In addition, control performances of the vehicle system equipped with ER devices are displayed in time and frequency domain. In order to demonstrate the effectiveness of the proposed program, ER shock absorber and ER ABS are designed and manufactured and their performance characteristics are evaluated.

Fluid Shifts

Science.gov (United States)

Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.;

PERCEPÇÕES E CONSUMO DE JOVENS UNIVERSITÁRIAS BRASILEIRAS EM RELAÇÃO AO LEITE FLUIDO INDUSTRIALIZADO: UM ESTUDO DE CASO Perceptions and consumption among Brazilian young female university students in relation to industrialized fluid milk: the case study.

Directory of Open Access Journals (Sweden)

K. L. SAMPAIO

2008-08-01

Full Text Available

O presente estudo teve como objetivo avaliar, entre jovens universitárias, as crenças, atitudes e hábitos de consumo de leites fluidos (pasteurizados tipo A, B e C e leite longa vida comercializados no Brasil. Para o estudo de crenças e atitudes, utilizou-se escala Likert de atitude. Avaliou-se também, através da aplicação do inquérito recordatório 24 horas, o consumo de cálcio, fósforo, protéico e calórico. Participaram da pesquisa 291 universitárias da Universidade Estadual de Campinas. O leite consumido pela maioria das jovens (79% foi o longa vida, percebido por elas como microbiologicamente seguro, de bom sabor e qualidade. O leite pasteurizado tipo C foi percebido como sendo de baixa qualidade tanto em termos sensoriais como microbiológicos e nutricionais; sendo consumido por 2% das entrevistadas. O consumo de leite revelou-se baixo frente às recomendações, sendo que somente 20% das entrevistadas informaram consumir a desejável quantidade de um copo de leite (230ml de duas a três vezes ao dia. O consumo médio de cálcio encontrado foi de 737,2 mg/dia, o de fósforo 954,5 mg/dia, o protéico 83,4 g/dia e o calórico 1752,2 Kcal/dia. O estudo revelou a necessidade de um trabalho de educação nutricional para a aquisição de conhecimentos e mudança de hábitos cotidianos.

Computational Fluid Dynamics

International Nuclear Information System (INIS)

Myeong, Hyeon Guk

1999-06-01

This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.

Active structuring of colloidal armour on liquid drops

Science.gov (United States)

Dommersnes, Paul; Rozynek, Zbigniew; Mikkelsen, Alexander; Castberg, Rene; Kjerstad, Knut; Hersvik, Kjetil; Otto Fossum, Jon

2013-06-01

Adsorption and assembly of colloidal particles at the surface of liquid droplets are at the base of particle-stabilized emulsions and templating. Here we report that electrohydrodynamic and electro-rheological effects in leaky-dielectric liquid drops can be used to structure and dynamically control colloidal particle assemblies at drop surfaces, including electric-field-assisted convective assembly of jammed colloidal ‘ribbons’, electro-rheological colloidal chains confined to a two-dimensional surface and spinning colloidal domains on that surface. In addition, we demonstrate the size control of ‘pupil’-like openings in colloidal shells. We anticipate that electric field manipulation of colloids in leaky dielectrics can lead to new routes of colloidosome assembly and design for ‘smart armoured’ droplets.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-01-01

®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding

Evaluation of the problematic of corrosion in bottoms of tanks of crude oil storage; Evaluacion de la problematica de corrosion en fondos de tanques de almacenamiento de petroleo crudo

Energy Technology Data Exchange (ETDEWEB)

Malo T, Jose M; Uruchurtu C, Jorge; Meza, Beatriz [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Lopez C, Luis F [Region Marina Suroeste, Pemex (Mexico)

2003-07-01

In this article the results related to the corrosive aggressiveness of the water fluids of crude oil of the Marine Terminal of Dos Bocas (TMDB), on the effectiveness of the anticorrosive control methods and on the control measures that could be adopted are presented. Also, this article comprises a work made by personnel of the Instituto de Investigaciones Electricas (IIE) during year 2002. The corrosion in tanks is of electrochemical nature and has its origin in the watery phase that accompanies the crude oil on being extracted from underground. In the case of the storage tanks, the watery phase separates at the bottom, causing the wetness of the bottom steel plates and its degradation. Due to the limited access to the interior of the tank during its operation, a testing device was designed that was connected to a drain valve of a tank of the terminal. The experimental work looked for the evaluation of the aggressiveness of the fluids, the type of corrosion products formed and the effectiveness of the cathodic protection and of the coatings. Additionally, fluid samples were collected, for analyzing the natural aggressiveness level that presents the water contained in the three types of crude: Mayan, Olmeca and Istmo handled in the terminal, studying steel samples and of plant fluids under controlled laboratory conditions. The aggressiveness was obtained from measurements of corrosion rates and analysis of microbial activity. The feasibility of applying the method of cathodic protection was analyzed, observing its effectiveness, as well as particular corrosion forms as the ones that occur in the pontoons. The results of the study lead to propose a monitoring scheme to pursuit the integrity of the coatings, the operation of the cathodic protection and the corrosion in tanks, with which a better control of the operation of the anticorrosive methods and of the degradation that occurs with the corrosion, could be obtained. [Spanish] En este trabajo se presentan

Respuesta de geófonos a campos electromagnéticos

Directory of Open Access Journals (Sweden)

Patricia M Gauzellino

2010-12-01

numéricos muestran la respuesta de los geófonos a partir de fuentes electromagnética y la posible identificación de contactos entre fluidos de reservorio.Electro-osmosis in saturated porous media is the physical phenomenon in which an electrical potential variation gives rise to fluid flow. The reciprocal phenomenon, called electro-filtration effect, is an electrical charge flux originated by pressure gradients in the pore fluid. The quotient between electrical potential and pressure gradient represents the electrokinetic coupling coefficient. In 1999 a proof field was performed, where seismic waves were generated by electromagnetic source. In this work it is explained why happen these phenomena. The equations that govern the coupled seismic and electromagnetic wavefields are presented and the transport coefficients (electrical conductivity, dynamic permeability and electrokinetic coupling coefficient are analyzed. Some assumptions on the model allow solve a simplified set of equations where Maxwell's equations are decoupled from Biot's equations. For the Maxwell's equations it is possible to separate the electromagnetic fields in primary and secondary parts. The former can be found analytically, while to find the latter a numerical procedure is employed. Dissipative effects in porous media can be included by using complex viscoelastic moduli in space-frequency domain. Also, it is important notice that pressure gradients in the pore fluid are correctly represented if the grid points are calculated using diffusive skin depth of 55 the Biot slow wave. Numerical examples illustrate the capabilities of the modeling for detecting reservoir fluid contacts.

Molecular mechanics and structure of the fluid-solid interface in simple fluids

Science.gov (United States)

Wang, Gerald J.; Hadjiconstantinou, Nicolas G.

2017-09-01

Near a fluid-solid interface, the fluid spatial density profile is highly nonuniform at the molecular scale. This nonuniformity can have profound effects on the dynamical behavior of the fluid and has been shown to play an especially important role when modeling a wide variety of nanoscale heat and momentum transfer phenomena. We use molecular-mechanics arguments and molecular-dynamics (MD) simulations to develop a better understanding of the structure of the first fluid layer directly adjacent to the solid in the layering regime, as delineated by a nondimensional number that compares the effects of wall-fluid interaction to thermal energy. Using asymptotic analysis of the Nernst-Planck equation, we show that features of the fluid density profile close to the wall, such as the areal density of the first layer ΣFL (defined as the number of atoms in this layer per unit of fluid-solid interfacial area), can be expressed as polynomial functions of the fluid average density ρave. This is found to be in agreement with MD simulations, which also show that the width of the first layer hFL is a linear function of the average density and only a weak function of the temperature T . These results can be combined to show that, for system average densities corresponding to a dense fluid (ρave≥0.7 ), the ratio C ≡ΣFLρavehFL, representing a density enhancement with respect to the bulk fluid, depends only weakly on temperature and is essentially independent of density. Further MD simulations suggest that the above results, nominally valid for large systems (solid in contact with semi-infinite fluid), also describe fluid-solid interfaces under considerable nanoconfinement, provided ρave is appropriately defined.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil

2010-01-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like). © 2010 The Royal Society of Chemistry.

Fullerol ionic fluids

Science.gov (United States)

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-09-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like).

The Impact of Solid Surface Features on Fluid-Fluid Interface Configuration

Science.gov (United States)

Araujo, J. B.; Brusseau, M. L. L.

2017-12-01

Pore-scale fluid processes in geological media are critical for a broad range of applications such as radioactive waste disposal, carbon sequestration, soil moisture distribution, subsurface pollution, land stability, and oil and gas recovery. The continued improvement of high-resolution image acquisition and processing have provided a means to test the usefulness of theoretical models developed to simulate pore-scale fluid processes, through the direct quantification of interfaces. High-resolution synchrotron X-ray microtomography is used in combination with advanced visualization tools to characterize fluid distributions in natural geologic media. The studies revealed the presence of fluid-fluid interface associated with macroscopic features on the surfaces of the solids such as pits and crevices. These features and respective fluid interfaces, which are not included in current theoretical or computational models, may have a significant impact on accurate simulation and understanding of multi-phase flow, energy, heat and mass transfer processes.

Prevalence, extension and characteristics of fluid-fluid levels in bone and soft tissue tumors

Energy Technology Data Exchange (ETDEWEB)

Dyck, P. van; Venstermans, C.; Gielen, J.; Parizel, P.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Vanhoenacker, F.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); AZ St-Maarten, Department of Radiology, Duffel/Mechelen (Belgium); Vogel, J. [Leiden University Medical Centre, Department of Orthopedics, Leiden (Netherlands); Kroon, H.M.; Bloem, J.L. [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Schepper, A.M.A. de [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands)

2006-12-15

The purpose of this study was to determine the prevalence, extension and signal characteristics of fluid-fluid levels in a large series of 700 bone and 700 soft tissue tumors. Out of a multi-institutional database, MRI of 700 consecutive patients with a bone tumor and MRI of 700 consecutive patients with a soft tissue neoplasm were retrospectively reviewed for the presence of fluid-fluid levels. Extension (single, multiple and proportion of the lesion occupied by fluid-fluid levels) and signal characteristics on magnetic resonance imaging of fluid-fluid levels were determined. In all patients, pathologic correlation was available. Of 700 patients with a bone tumor, 19 (10 male and 9 female; mean age, 29 years) presented with a fluid-fluid level (prevalence 2.7%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included aneurysmal bone cyst (ten cases), fibrous dysplasia (two cases), osteoblastoma (one case), simple bone cyst (one case), telangiectatic osteosarcoma (one case), ''brown tumor'' (one case), chondroblastoma (one case) and giant cell tumor (two cases). Of 700 patients with a soft tissue tumor, 20 (9 males and 11 females; mean age, 34 years) presented with a fluid-fluid level (prevalence 2.9%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included cavernous hemangioma (12 cases), synovial sarcoma (3 cases), angiosarcoma (1 case), aneurysmal bone cyst of soft tissue (1 case), myxofibrosarcoma (1 case) and high-grade sarcoma ''not otherwise specified'' (2 cases). In our series, the largest reported in the literature to the best of our knowledge, the presence of fluid-fluid levels is a rare finding with a prevalence of 2.7 and 2.9% in bone and soft tissue tumors, respectively. Fluid-fluid levels remain a non-specific finding and can

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2010-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2012-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Numerical study on the effect of non-condensable gases on the bi-phasic flow in geothermal wells; Estudio numerico del efecto de gases incondensables sobre el flujo bifasico en pozos geotermicos

Energy Technology Data Exchange (ETDEWEB)

Santoyo Gutierrez, Edgar; Garcia Gutierrez, Alfonso; Santoyo Gutierrez, Socrates; Morales Rosas, Jose Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1993-09-01

The objective of this paper is to describe a numerical study to determine the flow characteristics that predominate in geothermal wells and that produces a significant amount of non-condensable gases. It is known that these gases affect the thermodynamic conditions that dominate the fluid transport in the well or inclusively within the proper producing reservoir, therefore, it is extremely important to evaluate this effect. For this purpose the numerical model Geopozo V2.0 was developed. This model considers the carbon dioxide (CO{sub 2}) as the representative gas of the non-condensable gases present in the geothermal fluid. Due to this consideration, Geopozo V2.0 includes a methodology or the estimation of the thermodynamic and transport properties of geothermal fluids, considering these as a mix of two components: H{sub 2}O (vapor and liquid) and CO{sub 2}, under conditions of monophasic and biphasic flow. The application of Geopozo V2.0 for a typical case of flow in geothermal wells with high CO{sub 2} content revealed that the presence of this gas affects significantly the location of the flashing point inside the well and consequently, the amount of steam produced. This is of importance or the design and selection of the surface and generation equipment, aspect that to this date has been ignored (Suwana, 1991). [Espanol] El objetivo de este trabajo es describir un estudio numerico para determinar las caracteristicas del flujo que predominan en pozos geotermicos y que producen una cantidad significante de gases incondensables. Se tiene conocimiento de que estos gases afectan las condiciones termodinamicas que dominan el transporte de fluidos en el pozo o incluso dentro del mismo yacimiento geotermico productor, por lo que es de suma importancia evaluar dicho efecto. Para ello fue desarrollado el modelo numerico Geopozo V2.0. Este modelo considera al dioxido de carbono (CO{sub 2}) como el gas representativo de los incondensables presentes en el fluido geotermico

Fluid dynamics transactions

CERN Document Server

Fiszdon, W

1965-01-01

Fluid Dynamics Transactions, Volume 2 compiles 46 papers on fluid dynamics, a subdiscipline of fluid mechanics that deals with fluid flow. The topics discussed in this book include developments in interference theory for aeronautical applications; diffusion from sources in a turbulent boundary layer; unsteady motion of a finite wing span in a compressible medium; and wall pressure covariance and comparison with experiment. The certain classes of non-stationary axially symmetric flows in magneto-gas-dynamics; description of the phenomenon of secondary flows in curved channels by means of co

Theoretical Fluid Dynamics

CERN Document Server

Shivamoggi, Bhimsen K

1998-01-01

"Although there are many texts and monographs on fluid dynamics, I do not know of any which is as comprehensive as the present book. It surveys nearly the entire field of classical fluid dynamics in an advanced, compact, and clear manner, and discusses the various conceptual and analytical models of fluid flow." - Foundations of Physics on the first edition. Theoretical Fluid Dynamics functions equally well as a graduate-level text and a professional reference. Steering a middle course between the empiricism of engineering and the abstractions of pure mathematics, the author focuses

Fluid sampling tool

Science.gov (United States)

Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

1999-05-25

A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

Profile of Brazilian workers victims of occupational accidents with biological fluids.

Science.gov (United States)

Miranda, Fernanda Moura D'Almeida; Cruz, Elaine Drehmer de Almeida; Félix, Jorge Cestari Vinícius; Kalinke, Luciana Puchalski; Mantovani, Maria de Fátima; Sarquis, Leila Maria Mansano

2017-01-01

To characterize the Brazilian workers victims of occupational accidents with biological fluids. Epidemiological and descriptive research, in which 284,877 notifications of the Notifiable Diseases Information System were analyzed between 2007 and 2014. We used Stata 13 for data analysis. The highest incidence density occurred in females with 0.8 cases per 1,000 workers/year (n = 222,042, 77.9%); in the age group of 20 to 24 years old, with 0.6 cases per 1,000 workers/year (n = 64,221, 23.3%); with some high school and some college, with 0.6 cases per 1,000 workers/year (n = 141,275, 49.6%). We found that these accidents occurred among 23 occupational subgroups. For the most part, the workers had an employment relationship and had issued the Occupational Accident Notification. It is necessary to rethink the measures of orientation to workers regarding the risks and relative prophylaxis for these accidents, with the aim of reducing them. Caracterizar os trabalhadores brasileiros vítimas de acidente de trabalho com fluidos biológicos. Pesquisa epidemiológica, descritiva, na qual foram analisadas 284.877 notificações do Sistema Nacional de Notificação de Agravos, entre 2007 e 2014. Utilizou-se Stata 13 para a análise dos dados. A maior densidade de incidência ocorreu no sexo feminino com 0,8 caso a cada 1.000 trabalhadores/ano (n = 222.042; 77,9%); na faixa etária de 20 a 24 anos com 0,6 caso a cada 1.000 trabalhadores/ano (n = 64.221; 23,3%); com Ensino Médio e Superior incompleto com 0,6 caso a cada 1.000 trabalhadores/ano (n = 141.275; 49,6%). Verificou-se que esses acidentes ocorreram entre 23 subgrupos ocupacionais. Em sua maioria, os trabalhadores possuíam vínculo empregatício e tiveram emitida a Comunicação de Acidente de Trabalho. Faz-se necessário repensar as medidas de orientação aos trabalhadores quanto aos riscos e profilaxia relativa para estes acidentes, visando reduzi-los ou diminui-los.

Variable flexure-based fluid filter

Science.gov (United States)

Brown, Steve B.; Colston, Jr., Billy W.; Marshall, Graham; Wolcott, Duane

2007-03-13

An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

Process fluid cooling system

International Nuclear Information System (INIS)

Farquhar, N.G.; Schwab, J.A.

1977-01-01

A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

ESTUDO TERMODINÂMICO DA APLICAÇÃO DE HIDROCARBONETOS EM SISTEMA DE REFRIGERAÇÃO

Directory of Open Access Journals (Sweden)

Jucélio Gomes da Silva

2010-11-01

Full Text Available Os esforços de pesquisa e desenvolvimento na área de Refrigeração e Ar-Condicionado aplicados ao uso de fluidos refrigerantes naturais não esta associada somente à necessidade de preservação do meio-ambiente em si, mas também apresenta grande importância na necessidade latente do aumento da eficiência energética dos equipamentos. Neste sentido, o presente trabalho trata da avaliação termodinâmica da aplicação de fluidos refrigerantes hidrocarbonetos em um sistema de refrigeração residencial que utiliza o HFC134a como fluido de trabalho. Uma análise teórico-computacional foi desenvolvida para o R134a, propano (R290 e as misturas selecionadas (R290/R600a 60%/40%, R290/R600a/R134a 40%/30%/30% e R600a/R290-GLP 70%/30% no ciclo de refrigeração padrão ASHRAE, utilizando as propriedades termodinâmicas e termofísicas fornecidas pelo software REFPROP 6.0. Os resultados das simulações computacionais foram comparados entre os fluidos para indicação da melhor alternativa ao HFC134a. Neste sentido, pôde-se observar que os hidrocarbonetos reduzem os níveis de pressão no condensador e evaporador, além de menores trabalhos de compressão serem necessários no sistema devido às propriedades termofísicas privilegiadas destes fluidos. A utilização destes fluidos também proporciona uma menor temperatura de descarga do compressor, incrementando a vida útil deste componente de alto valor do sistema.

PERMEABILIDAD DENTINARIA

OpenAIRE

Gálvez, Luis H.

2014-01-01

Se entiende por permeabilidad dentinaria a la capacidad de difusión y/o transporte de fluidos y solutos a través del sistema canalicular comunicante. Se entiende por permeabilidad dentinaria a la capacidad de difusión y/o transporte de fluidos y solutos a través del sistema canalicular comunicante.

Space Station fluid management logistics

Science.gov (United States)

Dominick, Sam M.

1990-01-01

Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

Fluid dynamics

CERN Document Server

Bernard, Peter S

2015-01-01

This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.

Thermophysical properties of supercritical fluids and fluid mixtures

International Nuclear Information System (INIS)

Sengers, J.V.

1989-08-01

The purpose of the research is to extend the theory of critical phenomena in fluids and fluid mixtures to obtain scientifically based equations that include the crossover from the asymptotic singular behavior of the thermophysical properties close to the critical point to the regular behavior of these properties far away from the critical point

Fluid Creep and Over-resuscitation.

Science.gov (United States)

Saffle, Jeffrey R

2016-10-01

Fluid creep is the term applied to a burn resuscitation, which requires more fluid than predicted by standard formulas. Fluid creep is common today and is linked to several serious edema-related complications. Increased fluid requirements may accompany the appropriate resuscitation of massive injuries but dangerous fluid creep is also caused by overly permissive fluid infusion and the lack of colloid supplementation. Several strategies for recognizing and treating fluid creep are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluid sampling tool

Science.gov (United States)

Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

1999-05-25

A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

Working fluid selection for organic Rankine cycles - Impact of uncertainty of fluid properties

DEFF Research Database (Denmark)

Frutiger, Jerome; Andreasen, Jesper Graa; Liu, Wei

2016-01-01

of processmodels and constraints 2) selection of property models, i.e. Penge Robinson equation of state 3)screening of 1965 possible working fluid candidates including identification of optimal process parametersbased on Monte Carlo sampling 4) propagating uncertainty of fluid parameters to the ORC netpower output......This study presents a generic methodology to select working fluids for ORC (Organic Rankine Cycles)taking into account property uncertainties of the working fluids. A Monte Carlo procedure is described as a tool to propagate the influence of the input uncertainty of the fluid parameters on the ORC....... The net power outputs of all the feasible working fluids were ranked including their uncertainties. The method could propagate and quantify the input property uncertainty of the fluidproperty parameters to the ORC model, giving an additional dimension to the fluid selection process. In the given analysis...

Supercritical fluid reverse micelle separation

Science.gov (United States)

Fulton, J.L.; Smith, R.D.

1993-11-30

A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

Fluid and particle mechanics

CERN Document Server

Michell, S J

2013-01-01

Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

Fiber optic fluid detector

Science.gov (United States)

Angel, S.M.

1987-02-27

Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

A constitutive theory of reacting electrolyte mixtures

Science.gov (United States)

Costa Reis, Martina; Wang, Yongqi; Bono Maurizio Sacchi Bassi, Adalberto

2013-11-01

A constitutive theory of reacting electrolyte mixtures is formulated. The intermolecular interactions among the constituents of the mixture are accounted for through additional freedom degrees to each constituent of the mixture. Balance equations for polar reacting continuum mixtures are accordingly formulated and a proper set of constitutive equations is derived with basis in the Müller-Liu formulation of the second law of thermodynamics. Moreover, the non-equilibrium and equilibrium responses of the reacting mixture are investigated in detail by emphasizing the inner and reactive structures of the medium. From the balance laws and constitutive relations, the effects of molecular structure of constituents upon the fluid flow are studied. It is also demonstrated that the local thermodynamic equilibrium state can be reached without imposing that the set of independent constitutive variables is time independent, neither spatially homogeneous nor null. The resulting constitutive relations presented throughout this work are of relevance to many practical applications, such as swelling of clays, developing of bio and polymeric membranes, and use of electrorheological fluids in industrial processes. The first author acknowledges financial support from National Counsel of Technological and Scientific Development (CNPq) and German Academic Exchange Service (DAAD).

Design and Implementation of a High-Voltage Generator with Output Voltage Control for Vehicle ER Shock-Absorber Applications

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2013-01-01

Full Text Available A self-oscillating high-voltage generator is proposed to supply voltage for a suspension system in order to control the damping force of an electrorheological (ER fluid shock absorber. By controlling the output voltage level of the generator, the damping force in the ER fluid shock absorber can be adjusted immediately. The shock absorber is part of the suspension system. The high-voltage generator drives a power transistor based on self-excited oscillation, which converts dc to ac. A high-frequency transformer with high turns ratio is used to increase the voltage. In addition, the system uses the car battery as dc power supply. By regulating the duty cycle of the main switch in the buck converter, the output voltage of the buck converter can be linearly adjusted so as to obtain a specific high voltage for ER. The driving system is self-excited; that is, no additional external driving circuit is required. Thus, it reduces cost and simplifies system structure. A prototype version of the actual product is studied to measure and evaluate the key waveforms. The feasibility of the proposed system is verified based on experimental results.

Control of an ER haptic master in a virtual slave environment for minimally invasive surgery applications

International Nuclear Information System (INIS)

Han, Young-Min; Choi, Seung-Bok

2008-01-01

This paper presents the control performance of an electrorheological (ER) fluid-based haptic master device connected to a virtual slave environment that can be used for minimally invasive surgery (MIS). An already developed haptic joint featuring controllable ER fluid and a spherical joint mechanism is adopted for the master system. Medical forceps and an angular position measuring device are devised and integrated with the joint to establish the MIS master system. In order to embody a human organ in virtual space, a volumetric deformable object is used. The virtual object is then mathematically formulated by a shape-retaining chain-linked (S-chain) model. After evaluating the reflection force, computation time and compatibility with real-time control, the haptic architecture for MIS is established by incorporating the virtual slave with the master device so that the reflection force for the object of the virtual slave and the desired position for the master operator are transferred to each other. In order to achieve the desired force trajectories, a sliding mode controller is formulated and then experimentally realized. Tracking control performances for various force trajectories are evaluated and presented in the time domain

Hyperacid volcano-hydrothermal fluids from Copahue volcano, Argentina: Analogs for "subduction zone fluids"?

Science.gov (United States)

Varekamp, J. C.

2007-12-01

Hyperacid concentrated Chlorine-Sulfate brines occur in many young arc volcanoes, with pH values Copahue volcanic system (Argentina) suggest reservoir temperatures of 175-300 oC, whereas the surface fluids do not exceed local boiling temperatures. These fluids are generated at much lower P-T conditions than fluids associated with a dehydrating subducted sediment complex below arc volcanoes, but their fundamental chemical compositions may have similarities. Incompatible trace element, major element concentrations and Pb isotope compositions of the fluids were used to determine the most likely rock protoliths for these fluids. Mean rock- normalized trace element diagrams then indicate which elements are quantitatively extracted from the rocks and which are left behind or precipitated in secondary phases. Most LILE show flat rock-normalized patterns, indicating close to congruent dissolution, whereas Ta-Nb-Ti show strong depletions in the rock-normalized diagrams. These HFSE are either left behind in the altered rock protolith or were precipitated along the way up. The behavior of U and Th is almost identical, suggesting that in these low pH fluids with abundant ligands Th is just as easily transported as U, which is not the case in more dilute, neutral fluids. Most analyzed fluids have steeper LREE patterns than the rocks and have negative Eu anomalies similar to the rocks. Fluids that interacted with newly intruded magma e.g., during the 2000 eruption, have much less pronounced Eu anomalies, which was most likely caused by the preferential dissolution of plagioclase when newly intruded magma interacted with the acid fluids. The fluids show a strong positive correlation between Y and Cd (similar to MORB basalts, Yi et al., JGR, 2000), suggesting that Cd is mainly a rock-derived element that may not show chalcophilic behavior. The fluids are strongly enriched (relative to rock) in As, Zn and Pb, suggesting that these elements were carried with the volcanic gas phase

Differentiating benign from malignant bone tumors using fluid-fluid level features on magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yu, Hong; Cui, Jian Ling; Cui, Sheng Jie; Sun, Ying Cal; Cui, Feng Zhen [Dept. of Radiology, The Third Hospital of Hebei Medical University, Hebei Province Biomechanical Key Laborary of Orthopedics, Shijiazhuang, Hebei (China)

2014-12-15

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI). This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the chi2 test. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.

Differentiating benign from malignant bone tumors using fluid-fluid level features on magnetic resonance imaging

International Nuclear Information System (INIS)

Yu, Hong; Cui, Jian Ling; Cui, Sheng Jie; Sun, Ying Cal; Cui, Feng Zhen

2014-01-01

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI). This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the chi2 test. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.

Phoresis in fluids.

Science.gov (United States)

Brenner, Howard

2011-12-01

This paper presents a unified theory of phoretic phenomena in single-component fluids. Simple formulas are given for the phoretic velocities of small inert force-free non-Brownian particles migrating through otherwise quiescent single-component gases and liquids and animated by a gradient in the fluid's temperature (thermophoresis), pressure (barophoresis), density (pycnophoresis), or any combination thereof. The ansatz builds upon a recent paper [Phys. Rev. E 84, 046309 (2011)] concerned with slip of the fluid's mass velocity at solid surfaces--that is, with phenomena arising from violations of the classical no-slip fluid-mechanical boundary condition. Experimental and other data are cited in support of the phoretic model developed herein.

Plasmas and fluids

International Nuclear Information System (INIS)

Anon.

1986-01-01

Plasma and fluid physics includes the fields of fusion research and space investigation. This book discusses the most important advances in these areas over the past decade and recommends a stronger commitment to basic research in plasma and fluid physics. The book recommends that plasma and fluid physics be included in physics curriculums because of their increasing importance in energy and defense. The book also lists recent accomplishments in the fields of general plasma physics, fusion plasma confinement and heating, space and astrophysical plasmas, and fluid physics and lists research opportunities in these areas. A funding summary explains how research monies are allocated and suggests ways to improve their effectiveness

Schroedinger fluid

International Nuclear Information System (INIS)

Kan, K.K.

1983-01-01

The relationship of nuclear internal flow and collective inertia, the difference of this flow from that of a classical fluid, and the approach of this flow to rigid flow in independent-particle model rotation are elucidated by reviewing the theory of Schroedinger fluid and its implications for collective vibration and rotation. (author)

Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia.

Science.gov (United States)

Saraghi, Mana

2015-01-01

Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.

Repository for high level radioactive wastes in Brazil: the importance of geochemical (Micro thermometric) studies and fluid migration in potential host rocks; Repositorios para rejeitos radioativos de alto nivel (RANR) no Brasil: a importancia de estudos geoquimicos (microtermometricos) e de migracao de fluidos em rochas potenciamente hospedeiras

Energy Technology Data Exchange (ETDEWEB)

Rios, Francisco Javier; Fuzikawa, Kazuo; Alves, James Vieira; Neves, Jose Marques Correia [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Inclusoes Fluidas e Metalogenese]. E-mail: javier@cdtn.br

2003-04-15

A detailed fluid inclusion study of host rocks, is of fundamental importance in the selection of geologically suitable areas for high level nuclear waste repository constructions (HLRW). The LIFM-CDTN is enabled to develop studies that confirm: the presence or not, of corrosive fluid in minerals from host rocks of the repository and the possible presence of micro fractures (and fluid leakage) when these rocks are submitted to high temperatures. These fluid geochemistry studies, with permeability determinations by means of pressurized air injection must be carried out in rocks hosting nuclear waste. Micro fracture determination is of vital importance since many naturally corrosive solutions, present in the mineral rocks, could flow out through these plans affecting the walls of the repository. (author)

Fiber optic fluid detector

Science.gov (United States)

Angel, S. Michael

1989-01-01

Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

Hybrid solar-electric oven construction prototype; Construccion de prototipo de horno hibrido solar-electrico

Energy Technology Data Exchange (ETDEWEB)

Hernandez Roman, M. A; Pineda Pinon, J; Arcos Pichardo, A [CICATA, Santiago de Queretaro, Queretaro (Mexico)

2013-03-15

The oven construction consists of a solar collector system of cylindrical parabolic type, a heating through electrical resistance and a curing chamber. The warm fluid is air, which is injected into the chamber through forced draft. The temperature required in the system is within a range of 150 to 300 degrees Celsius. [Spanish] La construccion del horno consta de un sistema de captacion solar del tipo cilindrico parabolico, un sistema de calentamiento a traves de resistencias electricas y una camara de curado. El fluido a calentar es aire, el cual es inyectado dentro de la camara a traves de tiro forzado. La temperatura solicitada en el sistema es dentro de un rango de 150 a 300 grados centigrados.

SIMULACIÓN DE UN ESCURRIMIENTO REACTIVO AL INTERIOR DE UNA CÁMARA DE COMBUSTIÓN REACTIVE FLUID FLOW SIMULATION INSIDE COMBUSTION CHAMBER

Directory of Open Access Journals (Sweden)

Carlos H Salinas Lira

2007-04-01

Full Text Available El presente trabajo dice relación con la simulación de gases calientes al interior de una cámara de tubular combustión. Siendo así, se generan mallas en dominios tubulares curvilíneos. La inyección de combustible es realizada a través de un cuerpo esférico posicionado en el eje de simetría de la cámara afectado por un flujo primario axial y un flujo secundario radial. El fluido es considerado Newtoniano incompresible y con propiedades termo físicas constantes, en cuanto el flujo es considerado laminar, modelado a través de la ecuaciones de Navier-Stokes. La formulación de Shvab-Zel'dovich es utilizada para modelar el transporte de energía y especies a través de una variable denominada Potencial de Acoplamiento. El modelo matemático es resuelto numéricamente a través del Método de los Volúmenes Finitos descrito en coordenadas curvilíneas con arreglo co-localizado de variables. Los términos difusivos son representados por diferencias centradas y se usa el esquema WUDS para los términos convectivos. La integración temporal es del tipo implícito. Resultados de campos de velocidades, temperaturas y concentraciones son mostrados y comparados con datos encontrados en la literatura especializada. Se concluye en cuanto a la calidad cualitativa y cuantitativa de los resultados generados y en particular en lo que dice relación con la forma de la llama.The present work is related to the simulation of hot gases inside a tubular combustion chamber. This way, meshes are generated in tubular curvilinear domains. The fuel injection is carried out through a spherical body positioned in the chamber symmetry axis, affected by an axial primary flow and a radial secondary flow. The fluid is considered Newtonian incompressible, with constant thermo physics properties. In regard to the fluid flow, this is considered laminar, modeled through Navier-Stokes Equations. The Shvab-Zel'dovich formulation is used to model energy and species transport

Fully Soft 3D-Printed Electroactive Fluidic Valve for Soft Hydraulic Robots.

Science.gov (United States)

Zatopa, Alex; Walker, Steph; Menguc, Yigit

2018-06-01

Soft robots are designed to utilize their compliance and contortionistic abilities to both interact safely with their environment and move through it in ways a rigid robot cannot. To more completely achieve this, the robot should be made of as many soft components as possible. Here we present a completely soft hydraulic control valve consisting of a 3D-printed photopolymer body with electrorheological (ER) fluid as a working fluid and gallium-indium-tin liquid metal alloy as electrodes. This soft 3D-printed ER valve weighs less than 10 g and allows for onboard actuation control, furthering the goal of an entirely soft controllable robot. The soft ER valve pressure-holding capabilities were tested under unstrained conditions, cyclic valve activation, and the strained conditions of bending, twisting, stretching, and indentation. It was found that the max holding pressure of the valve when 5 kV was applied across the electrodes was 264 kPa, and that the holding pressure deviated less than 15% from the unstrained max holding pressure under all strain conditions except for indentation, which had a 60% max pressure increase. In addition, a soft octopus-like robot was designed, 3D printed, and assembled, and a soft ER valve was used to stop the fluid flow, build pressure in the robot, and actuate six tentacle-like soft bending actuators.

Bayesian spatial modeling applied to environmental monitoring due to the use of different drilling fluids in the maritime exploration activity; Modelagem espacial Bayesiana aplicada ao monitoramento ambiental decorrente do uso de diferentes fluidos de perfuracao na atividade exploratoria maritima

Energy Technology Data Exchange (ETDEWEB)

Pulgati, Fernando H. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Zouain, Ricardo N.A. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Geociencias. Centro de Estudos de Geologia Costeira e Oceanica; Fachel, Jandyra M.G. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Matematica; Landau, Luiz [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Metodos Computacionais em Engenharia (LAMCE)

2004-07-01

Controlling and monitoring environmental researches have accompanied the development of offshore exploration drill activities aimed at finding oil and gas reserves, as there has been an increase in the environmental demands and restrictions. Three stages of the drilling process were isolated and the effects of different fluids were measured using Bayesian spatial models. The probable impact of the use of non-aqueous fluid (NAF) was measured through changes observed in sea sediments in three different occasions: previous to the activity, one (1) month after the end of the activity, and one (1) year after the end of the activity. BACI (Before-After Control Impact) design, which allows the control of temporal and spatial variation components, was chosen. (author)

Working fluid selection for organic Rankine cycles - Impact of uncertainty of fluid properties

DEFF Research Database (Denmark)

Frutiger, Jerome; Andreasen, Jesper Graa; Liu, Wei

2016-01-01

This study presents a generic methodology to select working fluids for ORC (Organic Rankine Cycles)taking into account property uncertainties of the working fluids. A Monte Carlo procedure is described as a tool to propagate the influence of the input uncertainty of the fluid parameters on the ORC...... modeloutput, and provides the 95%-confidence interval of the net power output with respect to the fluid property uncertainties. The methodology has been applied to a molecular design problem for an ORCusing a low-temperature heat source and consisted of the following four parts: 1) formulation...... of processmodels and constraints 2) selection of property models, i.e. Penge Robinson equation of state 3)screening of 1965 possible working fluid candidates including identification of optimal process parametersbased on Monte Carlo sampling 4) propagating uncertainty of fluid parameters to the ORC netpower output...

Análisis de sistema de conversores fluido-dinámicos de energía renovable para la Patagonia Austral de Argentina

Directory of Open Access Journals (Sweden)

Carlos Victor Manuel Labriola

2014-06-01

Full Text Available El potencial de energía en mares y océanos se puede clasificar de distintas formas, por ejemplo: * La energía de las mareas ó Mareomotriz * La energía de las corrientes marinas * La energía de las olas ó Undimotriz * La energía térmica oceánica (OTEC. De estas formas de energía oceánica, tres son posibles en la zona Atlántica de nuestra Patagonia Austral, la Mareomotriz, la Undimotriz y la de corrientes marinas. La Energía Mareomotriz se da desde Viedma hasta Tierra del Fuego con amplitudes de mareas de 4m hasta 20m, la Energía de las Olas se da en la costa de Chubut y Santa Cruz con potenciales de 10 a 30kW/m lineal de frente de ola y el aprovechamiento de las corrientes marinas se puede dar en lugares puntuales como ser la desembocadura del río Deseado o la de Río Gallegos. Para estas Fuentes de Energía se está realizando un banco de pruebas de modelos conversores de las mismas a Energía Eléctrica, en la Unidad Académica Caleta Olivia (UACO de la Universidad Nacional de la Patagonia Austral (UNPA. Este banco dispondrá de dos canales de ensayos hidrodinámicos uno para energía de las corrientes marinas y otro para las olas. El primero dispondrá de una bomba de circulación con velocidad de fluido variable entre 0 y 4m/s. El banco para olas tendrá un sistema de batido del agua para producir ondas de amplitud y período variable. Además se están dimensionando dos modelos de conversores de energía oceánica. Uno es una turbina, tipo eólica sumergida y el otro modelo es de tubo electromecánico oscilante como conversor energético de las olas.

Explosive Evaporating Phenomena of Cryogenic Fluids by Direct Contacting Normal Temperature Fluids

Directory of Open Access Journals (Sweden)

T Watanabe

2016-09-01

Full Text Available Cryogenic fluids have characteristics such as thermal stratification and flashing by pressure release in storage vessel. The mixture of the extreme low temperature fluid and the normal temperature fluid becomes the cause which causes pressure vessel and piping system crush due to explosive boiling and rapid freezing. In recent years in Japan, the demand of cryogenic fluids like a LH2, LNG is increasing because of the advance of fuel cell device technology, hydrogen of engine, and stream of consciousness for environmental agreement. These fuel liquids are cryogenic fluids. On the other hand, as for fisheries as well, the use of a source of energy that environment load is small has been being a pressing need. And, the need of the ice is high, as before, for keeping freshness of marine products in fisheries. Therefore, we carried out the experiments related to promotion of evaporating cryogenic fluids and generation of ice, in the contact directly of the water and liquid nitrogen. From the results of visualization, phenomena of explosive evaporating and ice forming were observed by using video camera.

Thermodynamics of Fluid Polyamorphism

Directory of Open Access Journals (Sweden)

Mikhail A. Anisimov

2018-01-01

Full Text Available Fluid polyamorphism is the existence of different condensed amorphous states in a single-component fluid. It is either found or predicted, usually at extreme conditions, for a broad group of very different substances, including helium, carbon, silicon, phosphorous, sulfur, tellurium, cerium, hydrogen, and tin tetraiodide. This phenomenon is also hypothesized for metastable and deeply supercooled water, presumably located a few degrees below the experimental limit of homogeneous ice formation. We present a generic phenomenological approach to describe polyamorphism in a single-component fluid, which is completely independent of the molecular origin of the phenomenon. We show that fluid polyamorphism may occur either in the presence or in the absence of fluid phase separation depending on the symmetry of the order parameter. In the latter case, it is associated with a second-order transition, such as in liquid helium or liquid sulfur. To specify the phenomenology, we consider a fluid with thermodynamic equilibrium between two distinct interconvertible states or molecular structures. A fundamental signature of this concept is the identification of the equilibrium fraction of molecules involved in each of these alternative states. However, the existence of the alternative structures may result in polyamorphic fluid phase separation only if mixing of these structures is not ideal. The two-state thermodynamics unifies all the debated scenarios of fluid polyamorphism in different areas of condensed-matter physics, with or without phase separation, and even goes beyond the phenomenon of polyamorphism by generically describing the anomalous properties of fluids exhibiting interconversion of alternative molecular states.

Cerebrospinal fluid culture

Science.gov (United States)

... Alternative Names Culture - CSF; Spinal fluid culture; CSF culture Images Pneumococci organism References Karcher DS, McPherson RA. Cerebrospinal, synovial, serous body fluids, and alternative specimens. In: McPherson RA, Pincus ...

Fluid, solid and fluid-structure interaction simulations on patient-based abdominal aortic aneurysm models.

Science.gov (United States)

Kelly, Sinead; O'Rourke, Malachy

2012-04-01

This article describes the use of fluid, solid and fluid-structure interaction simulations on three patient-based abdominal aortic aneurysm geometries. All simulations were carried out using OpenFOAM, which uses the finite volume method to solve both fluid and solid equations. Initially a fluid-only simulation was carried out on a single patient-based geometry and results from this simulation were compared with experimental results. There was good qualitative and quantitative agreement between the experimental and numerical results, suggesting that OpenFOAM is capable of predicting the main features of unsteady flow through a complex patient-based abdominal aortic aneurysm geometry. The intraluminal thrombus and arterial wall were then included, and solid stress and fluid-structure interaction simulations were performed on this, and two other patient-based abdominal aortic aneurysm geometries. It was found that the solid stress simulations resulted in an under-estimation of the maximum stress by up to 5.9% when compared with the fluid-structure interaction simulations. In the fluid-structure interaction simulations, flow induced pressure within the aneurysm was found to be up to 4.8% higher than the value of peak systolic pressure imposed in the solid stress simulations, which is likely to be the cause of the variation in the stress results. In comparing the results from the initial fluid-only simulation with results from the fluid-structure interaction simulation on the same patient, it was found that wall shear stress values varied by up to 35% between the two simulation methods. It was concluded that solid stress simulations are adequate to predict the maximum stress in an aneurysm wall, while fluid-structure interaction simulations should be performed if accurate prediction of the fluid wall shear stress is necessary. Therefore, the decision to perform fluid-structure interaction simulations should be based on the particular variables of interest in a given

Effect of pre-donation fluid intake on fluid shift from interstitial to intravascular compartment in blood donors.

Science.gov (United States)

Deepika, Chenna; Murugesan, Mohandoss; Shastry, Shamee

2018-02-01

Fluid shifts from interstitial to intravascular space during blood donation helps in compensating the lost blood volume. We aimed to determine the volume of fluid shift following donation in donors with and without pre-donation fluid intake. We studied the fluid shift in 325 blood donors prospectively. Donors were divided in groups- with no fluid intake (GI) and either water (GII) or oral rehydrating fluids (GIII) before donation. Fluid shift following donation was calculated based on the difference between the pre and post donation blood volume. The influence of oral fluid intake, age, gender and body mass index (BMI) on volume of fluid shift was analyzed. The fluid shift was significant between donors without fluids (GI: 127 ± 81 ml) and donors with fluid intake (GII & III: 96 ± 45 ml) (p donation. As per our observation, the oral fluids before donation might not contribute to increase in fluid shift in blood donors after donation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Energy variational analysis of ions in water and channels: Field theory for primitive models of complex ionic fluids

International Nuclear Information System (INIS)

Eisenberg, Bob; Hyon, YunKyong; Liu, Chun

2010-01-01

. If a new component is added to the energy or dissipation, the Euler–Lagrange equations change form and interaction terms appear without additional adjustable parameters. EnVarA has previously been used to compute properties of liquid crystals, polymer fluids, and electrorheological fluids containing solid balls and charged oil droplets that fission and fuse. Here we apply EnVarA to the primitive model of electrolytes in which ions are spheres in a frictional dielectric. The resulting Euler–Lagrange equations include electrostatics and diffusion and friction. They are a time dependent generalization of the Poisson–Nernst–Planck equations of semiconductors, electrochemistry, and molecular biophysics. They include the finite diameter of ions. The EnVarA treatment is applied to ions next to a charged wall, where layering is observed. Applied to an ion channel, EnVarA calculates a quick transient pile-up of electric charge, transient and steady flow through the channel, stationary “binding” in the channel, and the eventual accumulation of salts in “unstirred layers” near channels. EnVarA treats electrolytes in a unified way as complex rather than simple fluids. Ad hoc descriptions of interactions and flow have been used in many areas of science to deal with the nonideal properties of electrolytes. It seems likely that the variational treatment can simplify, unify, and perhaps derive and improve those descriptions.

Heating production fluids in a wellbore

Science.gov (United States)

Orrego, Yamila; Jankowski, Todd A.

2016-07-12

A method for heating a production fluid in a wellbore. The method can include heating, using a packer fluid, a working fluid flowing through a first medium disposed in a first section of the wellbore, where the first medium transfers heat from the packer fluid to the working fluid. The method can also include circulating the working fluid into a second section of the wellbore through a second medium, where the second medium transfers heat from the working fluid to the production fluid. The method can further include returning the working fluid to the first section of the wellbore through the first medium.

ESTUDIO COMPARATIVO DE MODELOS NUMÉRICOS PARA EL SEGUIMIENTO DE INTERFACES MÓVILES: ESTUDIO DEL DERRAME DE UNA COLUMNA DE LÍQUIDO COMPARATIVE STUDY OF NUMERICAL MODELS FOR MOVING INTERFACE PROBLEMS: ANALYSIS OF THE COLLAPSE OF A LIQUID COLUMN

Directory of Open Access Journals (Sweden)

Juan Pablo Barraza

2007-04-01

Full Text Available En este trabajo se presenta la simulación numérica del problema del derrame de una columna de líquido. El análisis numérico se realiza utilizando el método de volúmenes finitos y la técnica conocida como VOF para el seguimiento de la superficie interfaz. Se asume que el problema puede ser descrito por las ecuaciones de cantidad de movimiento y continuidad para un fluido incompresible. Dichas ecuaciones se resuelven tanto para el fluido como para el aire en todo el dominio de análisis en conjunto con la ecuación que describe el movimiento de la interfaz. Se estudia el comportamiento de dos fluidos de diferente viscosidad. Se evalúa la respuesta frente a cambios en la discretización espacial y la incidencia en los resultados cuando se utiliza un modelo turbulento para la descripción del flujo. Los resultados obtenidos para la posición de la superficie libre se comparan con las predicciones calculadas con una formulación de elementos finitos de malla fija y, además, con mediciones experimentales reportadas en la literatura.The simulation of the collapse of a liquid column problem is presented in this work. The numerical analysis is done using a finite volume technique, where the well-known VOF technique is applied to describe the free surface motion. The adopted mathematical model is given by the Navier-Stokes equations for incompressible flows. These equations are solved in the whole domain occupied by both fluids (liquid and air together with the interface motion equation. The study focuses on the analysis of two liquids with different viscosities. The response is assessed by considering various spatial discretizations when a turbulent model is applied. The computed numerical results are compared with those obtained using a fixed-mesh finite element technique and with experimental measurements reported in the literature.

Microgravity Fluids for Biology, Workshop

Science.gov (United States)

Griffin, DeVon; Kohl, Fred; Massa, Gioia D.; Motil, Brian; Parsons-Wingerter, Patricia; Quincy, Charles; Sato, Kevin; Singh, Bhim; Smith, Jeffrey D.; Wheeler, Raymond M.

2013-01-01

Microgravity Fluids for Biology represents an intersection of biology and fluid physics that present exciting research challenges to the Space Life and Physical Sciences Division. Solving and managing the transport processes and fluid mechanics in physiological and biological systems and processes are essential for future space exploration and colonization of space by humans. Adequate understanding of the underlying fluid physics and transport mechanisms will provide new, necessary insights and technologies for analyzing and designing biological systems critical to NASAs mission. To enable this mission, the fluid physics discipline needs to work to enhance the understanding of the influence of gravity on the scales and types of fluids (i.e., non-Newtonian) important to biology and life sciences. In turn, biomimetic, bio-inspired and synthetic biology applications based on physiology and biology can enrich the fluid mechanics and transport phenomena capabilities of the microgravity fluid physics community.

Fluid Statics and Archimedes

Indian Academy of Sciences (India)

librium of a vertical slice fluid (Figure Id) of height H and again using the fact .... same fluid having the same shape and same volume as the body. This fluid volume .... example, can be caused by the heating of air near the ground by the sun ...

Agarwood Waste as A New Fluid Loss Control Agent in Water-based Drilling Fluid

Directory of Open Access Journals (Sweden)

Azlinda Azizi

2013-10-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Agarwood has been used widely in various ways, including traditional medicine and art. The usage of agarwood has grown broader in modern times include in therapeutic medicines and perfumery. In this paper the agarwood waste has been explored to be used as a fluid loss control agent to control fluid loss without affecting the drilling fluid rheological properties which are density, pH, viscosity, yield point and gel strength. Agarwood waste was used as an additive in the drilling fluid system due to its unique characteristic. Rheological and filtration measurements were performed on the formulated water-based drilling fluid. Formulations of a base solution of fresh water, sodium hydroxide, bentonite, barite, and xanthan gum were presented. The performance of the agarwood waste as the fluid loss control agent was compared with based fluid formulation and water-based drilling fluid with treating with conventional fluid loss control agent (starch. The filtrate volume of drilling fluid with agarwood waste was about 13 ml while for drilling fluid with conventional fluid loss control agent, starch gave 12 ml of filtrate volume after undergoing filtration test by using LPLT filter press. The performance of drilling fluid with agarwood was efficient as drilling fluid with starch. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso

Extension of Generalized Fluid System Simulation Program's Fluid Property Database

Science.gov (United States)

Patel, Kishan

2011-01-01

This internship focused on the development of additional capabilities for the General Fluid Systems Simulation Program (GFSSP). GFSSP is a thermo-fluid code used to evaluate system performance by a finite volume-based network analysis method. The program was developed primarily to analyze the complex internal flow of propulsion systems and is capable of solving many problems related to thermodynamics and fluid mechanics. GFSSP is integrated with thermodynamic programs that provide fluid properties for sub-cooled, superheated, and saturation states. For fluids that are not included in the thermodynamic property program, look-up property tables can be provided. The look-up property tables of the current release version can only handle sub-cooled and superheated states. The primary purpose of the internship was to extend the look-up tables to handle saturated states. This involves a) generation of a property table using REFPROP, a thermodynamic property program that is widely used, and b) modifications of the Fortran source code to read in an additional property table containing saturation data for both saturated liquid and saturated vapor states. Also, a method was implemented to calculate the thermodynamic properties of user-fluids within the saturation region, given values of pressure and enthalpy. These additions required new code to be written, and older code had to be adjusted to accommodate the new capabilities. Ultimately, the changes will lead to the incorporation of this new capability in future versions of GFSSP. This paper describes the development and validation of the new capability.

Synovial Fluid Analysis

Science.gov (United States)

... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... is being tested? Synovial fluid is a thick liquid that acts as a lubricant for the body's ...

Swellable packers in fracturing and stimulation

Directory of Open Access Journals (Sweden)

Jorge Ordóñez

2017-12-01

Full Text Available En el presente trabajo se presenta la idea del uso de swellable packers como herramienta adicional, enfocado principalmente en el uso alternativo de cemento. Los swellable packers contienen elastómeros que absorben cierto tipo de fluido, existiendo dos grandes grupos que son: elastómeros con tendencia a fluido con base agua y elastómeros con tendencia a fluido con base aceite. Estos packers fueron creados con el objetivo de usarse como aisladores de zonas, ya que son packers que gracias a sus elastómeros se hinchan al contacto con el fluido al que son a fin, logrando un sello completo en diferentes zonas. Con el pasar de los años se los enfocó en usos diferentes para el que netamente fueron creados, usos como: estimulación de pozos, incluyendo fracturamientos (resistencia a altas presiones, completacion de pozos, trabajos de cementación, etc.  Luego del análisis de varios casos y de presentar las ventajas del uso de esta herramienta se propone el empleo de los swellable packers en reemplazo del cemento, esto ayudará a reducir costos de operaciones, tiempo de rig y NPTs.

Fluid structure interaction due to fluid communications between fluid volumes. Application to seismic behaviour of F.B.R. vessels

International Nuclear Information System (INIS)

Durandet, E.; Gibert, R.J.; Gantenbein, F.

1988-01-01

The internal structures of a pool-type breeder reactor are mainly axisymmetric shells separated by fluid volumes which are connected one to another by small communications. Unfortunately, the communications destroy the axisymmetry of the problem and a correct modelisation by finite element method generally need a lot of small elements compared to the size of the standard mesh of the fluid volumes. To overcome these difficulties, an equivalent axisymmetric element based on a local tridimensional solution in the vicinity of the fluid communication is defined and will be described in the paper. This special fluid element is characterized by an equivalent length and annular cross-section. The second part of the paper is devoted to the application to an horizontal seismic calculation of breeder reactor

Gastric fluid versus amniotic fluid analysis for the identification of intra-amniotic infection due to Ureaplasma species.

Science.gov (United States)

Kim, Sun Min; Romero, Roberto; Lee, JoonHo; Chaemsaithong, Piya; Docheva, Nikolina; Yoon, Bo Hyun

2016-01-01

Early neonatal sepsis is often due to intra-amniotic infection. The stomach of the neonate contains fluid swallowed before and during delivery. The presence of bacteria as well as neutrophils detected by culture or Gram stain of the gastric fluid during the first day of life is suggestive of exposure to bacteria or inflammation. We undertook this study to determine the relationship between gastric fluid analysis and amniotic fluid obtained by transabdominal amniocentesis in the detection of Ureaplasma species, the most frequent microorganisms responsible for intra-amniotic infection. The study population consisted of 100 singleton pregnant women who delivered preterm neonates (Ureaplasma species was performed. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL). (1) Ureaplasma species were detected by culture or PCR in 18% (18/100) of amniotic fluid samples and in 5% (5/100) of gastric fluid samples; (2) among the amniotic fluid cases positive for Ureaplasma species, these microorganisms were identified in 27.8% (5/18) of gastric fluid samples; (3) none of the cases negative for Ureaplasma species in the amniotic fluid were found to be positive for these microorganisms in the gastric fluid; (4) patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms had a significantly higher rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death than those with both amniotic fluid and gastric fluid negative for Ureaplasma species; and (5) no significant differences were observed in the rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death between patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms and those with both amniotic fluid and gastric fluid positive for Ureaplasma species. Gastric fluid analysis has 100

Improved Fluid Perturbation Theory: Equation of state for Fluid Xenon

OpenAIRE

Li, Qiong; Liu, Hai-Feng; Zhang, Gong-Mu; Zhao, Yan-Hong; Tian, Ming-Feng; Song, Hai-Feng

2016-01-01

The traditional fluid perturbation theory is improved by taking electronic excitations and ionizations into account, in the framework of average ion spheres. It is applied to calculate the equation of state for fluid Xenon, which turns out in good agreement with the available shock data.

Métodos de extração e/ou concentração de compostos encontrados em fluidos biológicos para posterior determinação cromatográfica Methods of extraction and/or concentration of compounds found in biological fluids for subsequent chromatographic determination

Directory of Open Access Journals (Sweden)

Sonia C. N. Queiroz

2001-02-01

Full Text Available When organic compounds present in biological fluids are analysed by chromatographic methods, it is generally necessary to carry out a prior sample preparation due the high complexity of this type of sample, especially when the compounds to be determinated are found in very low concentrations. This article describes some of the principal methods for sample preparation in analyses of substances present in biological fluids. The methods include liquid-liquid extraction, solid phase extraction, supercritical fluid extraction and extraction using solid and liquid membranes. The advantages and disadvantages of these methods are discussed.

Numerical study of shear thickening fluid with discrete particles embedded in a base fluid

Directory of Open Access Journals (Sweden)

W Zhu

2016-09-01

Full Text Available The Shear Thickening Fluid (STF is a dilatant material, which displays non-Newtonian characteristics in its unique ability to transit from a low viscosity fluid to a high viscosity fluid. The research performed investigates the STF behavior by modeling and simulation of the interaction between the base flow and embedded rigid particles when subjected to shear stress. The model considered the Lagrangian description of the rigid particles and the Eulerian description of fluid flow. The numerical analysis investigated key parameters such as applied flow acceleration, particle distribution and arrangement, volume concentration of particles, particle size, shape and their behavior in a Newtonian and non-Newtonian fluid base. The fluid-particle interaction model showed that the arrangement, size, shape and volume concentration of the particles had a significant effect on the behavior of the STF. Although non-conclusive, the addition of particles in non-Newtonian fluids showed a promising trend of improved shear thickening effects at high shear strain rates.

Simplified Aeroelastic Model for Fluid Structure Interaction between Microcantilever Sensors and Fluid Surroundings.

Directory of Open Access Journals (Sweden)

Fei Wang

Full Text Available Fluid-structural coupling occurs when microcantilever sensors vibrate in a fluid. Due to the complexity of the mechanical characteristics of microcantilevers and lack of high-precision microscopic mechanical testing instruments, effective methods for studying the fluid-structural coupling of microcantilevers are lacking, especially for non-rectangular microcantilevers. Here, we report fluid-structure interactions (FSI of the cable-membrane structure via a macroscopic study. The simplified aeroelastic model was introduced into the microscopic field to establish a fluid-structure coupling vibration model for microcantilever sensors. We used the finite element method to solve the coupled FSI system. Based on the simplified aeroelastic model, simulation analysis of the effects of the air environment on the vibration of the commonly used rectangular microcantilever was also performed. The obtained results are consistent with the literature. The proposed model can also be applied to the auxiliary design of rectangular and non-rectangular sensors used in fluid environments.

Rigid Body Sampling and Individual Time Stepping for Rigid-Fluid Coupling of Fluid Simulation

Directory of Open Access Journals (Sweden)

Xiaokun Wang

2017-01-01

Full Text Available In this paper, we propose an efficient and simple rigid-fluid coupling scheme with scientific programming algorithms for particle-based fluid simulation and three-dimensional visualization. Our approach samples the surface of rigid bodies with boundary particles that interact with fluids. It contains two procedures, that is, surface sampling and sampling relaxation, which insures uniform distribution of particles with less iterations. Furthermore, we present a rigid-fluid coupling scheme integrating individual time stepping to rigid-fluid coupling, which gains an obvious speedup compared to previous method. The experimental results demonstrate the effectiveness of our approach.

Thermal Fluid Engineering

International Nuclear Information System (INIS)

Jang, Byeong Ju

1984-01-01

This book is made up of 5 chapters. They are fluid mechanics, fluid machines, Industrial thermodynamics, steam boiler and steam turbine. It introduces hydrostatics, basic theory of fluid movement and law of momentum. It also deals with centrifugal pump, axial flow pump, general hydraulic turbine, and all phenomena happening in the pump. It covers the law of thermodynamics, perfect gas, properties of steam, and flow of gas and steam and water tube boiler. Lastly it explains basic format, theory, loss and performance as well as principle part of steam turbine.

Fluid jet electric discharge source

Science.gov (United States)

Bender, Howard A [Ripon, CA

2006-04-25

A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

Ecotoxicological testing of performance fluids

International Nuclear Information System (INIS)

Kallqvist, T.

1990-05-01

The report deals with a project comprising the testing of drilling fluids concerning ecotoxicology, biological degradation, and toxicity. Two types of drilling fluids were tested for toxic effects on marine algae and biological degradability. A fluid based on mineral oil was readily degradable (98% DOC removal in 28 days) while an ether based oil degraded more slowly (56% DOC removal in 28 days). The toxicity of both fluids was tested after emulsification of the oils in water and separating the oil and water phase after equilibration. The EC 50 values obtained with this approach were 8.15 g/l for the oil based fluid and 116 g/l for the ether fluid. 9 figs., 8 tabs

Peritoneal fluid culture

Science.gov (United States)

Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... The peritoneal fluid culture may be negative, even if you have ... diagnosis of peritonitis is based on other factors, in addition ...

Time Independent Fluids

Science.gov (United States)

Collyer, A. A.

1973-01-01

Discusses theories underlying Newtonian and non-Newtonian fluids by explaining flow curves exhibited by plastic, shear-thining, and shear-thickening fluids and Bingham plastic materials. Indicates that the exact mechanism governing shear-thickening behaviors is a problem of further study. (CC)

Editorial Special Issue on Fluid Mechanics and Fluid Power (FMFP ...

Indian Academy of Sciences (India)

a shark is more efficient than a propeller; the notoriously complicated and nonlinear Navier–. Stokes equations governing fluid motion provide fertile ground for research to both applied and pure mathematicians. There is the phenomenon of turbulence in fluid flows. A statement in 1932, attributed to Horace Lamb, author of ...

Acoustic Velocity and Attenuation in Magnetorhelogical fluids based on an effective density fluid model

Directory of Open Access Journals (Sweden)

Shen Min

2016-01-01

Full Text Available Magnetrohelogical fluids (MRFs represent a class of smart materials whose rheological properties change in response to the magnetic field, which resulting in the drastic change of the acoustic impedance. This paper presents an acoustic propagation model that approximates a fluid-saturated porous medium as a fluid with a bulk modulus and effective density (EDFM to study the acoustic propagation in the MRF materials under magnetic field. The effective density fluid model derived from the Biot’s theory. Some minor changes to the theory had to be applied, modeling both fluid-like and solid-like state of the MRF material. The attenuation and velocity variation of the MRF are numerical calculated. The calculated results show that for the MRF material the attenuation and velocity predicted with this effective density fluid model are close agreement with the previous predictions by Biot’s theory. We demonstrate that for the MRF material acoustic prediction the effective density fluid model is an accurate alternative to full Biot’s theory and is much simpler to implement.

Fluid Behavior and Fluid-Solid Interactions in Nanoporous Media

Science.gov (United States)

Xu, H.

2015-12-01

Although shale oil/gas production in the US has increased exponentially, the low energy recovery is a daunting problem needed to be solved for its sustainability and continued growth, especially in light of the recent oil/gas price decline. This is apparently related to the small porosity (a few to a few hundred nm) and low permeability (10-16-10-20 m2) of tight shale formations. The fundamental question lies in the anomalous behavior of fluids in nanopores due to confinement effects, which, however, remains poorly understood. In this study, we combined experimental characterization and observations, particularly using small-angle neutron scattering (SANS), with pore-scale modeling using lattice Boltzmann method (LBM), to examine the fluid behavior and fluid-solid interactions in nanopores at reservoir conditions. Experimentally, we characterized the compositions and microstructures of a shale sample from Wolfcamp, Texas, using a variety of analytical techniques. Our analyses reveal that the shale sample is made of organic-matter (OM)-lean and OM-rich layers that exhibit different chemical and mineral compositions, and microstructural characteristics. Using the hydrostatic pressure system and gas-mixing setup we developed, in-situ SANS measurements were conducted at pressures up to 20 kpsi on shale samples imbibed with water or water-methane solutions. The obtained results indicate that capillary effect plays a significant role in fluid-nanopore interactions and the associated changes in nanopore structures vary with pore size and pressure. Computationally, we performed LBM modeling to simulate the flow behavior of methane in kerogen nanoporous structure. The correction factor, which is the ratio of apparent permeability to intrinsic permeability, was calculated. Our results show that the correction factor is always greater than one (non-continuum/non-Darcy effects) and increases with decreasing nanopore size, intrinsic permeability and pressure. Hence, the

Heat transfer fluids containing nanoparticles

Science.gov (United States)

Singh, Dileep; Routbort, Jules; Routbort, A.J.; Yu, Wenhua; Timofeeva, Elena; Smith, David S.; France, David M.

2016-05-17

A nanofluid of a base heat transfer fluid and a plurality of ceramic nanoparticles suspended throughout the base heat transfer fluid applicable to commercial and industrial heat transfer applications. The nanofluid is stable, non-reactive and exhibits enhanced heat transfer properties relative to the base heat transfer fluid, with only minimal increases in pumping power required relative to the base heat transfer fluid. In a particular embodiment, the plurality of ceramic nanoparticles comprise silicon carbide and the base heat transfer fluid comprises water and water and ethylene glycol mixtures.

Assessment of magnetic fluid stability in non-homogeneous magnetic field of a single-tooth magnetic fluid sealer

Energy Technology Data Exchange (ETDEWEB)

Arefyev, I.M.; Demidenko, O.V.; Saikin, M.S.

2017-06-01

A special experimental stand has been developed and made to test magnetic fluid. It represents a single-tooth magnetic fluid sealer. The type of dependence of the pressure differential on magnetic fluid sealer operation time is used as a criterion to determine magnetic fluid stability and magnetic fluid sealer service life under such conditions. The siloxane-based magnetic fluid was used as the test sample. The colloidal stability as well as stability of the synthesized magnetic fluid in magnetic fields in static mode were determined. It has been found that the obtained magnetic fluid is stable in static mode and, consequently, can be used to conduct necessary tests on stand. Short-term and life tests on stand have shown that MF remains stable and efficient for at least 360 days of continuous utilization. - Highlights: • An experimental single-tooth magnetic fluid sealer has been developed and made. • The magnetic fluid based on siloxane liquid was used as the test sample. • Short-term and life tests of the magnetic fluid were conducted. • The magnetic fluid stability was determined by necessary tests on stand.

BRONCHOALVEOLAR LAVAGE FLUID BACTERIAL ISOLATION AND SENSIBILITY IN HEALTH AND SICK DOGS La identificación bacteriana y sensibilidad antimicrobiana de líquido de lavado tracheobronchial de sanos y enfermos perros IDENTIFICAÇÃO BACTERIANA E SENSIBILIDADE ANTIMICROBIANA DO FLUIDO DE LAVAGEM TRAQUEOBRÔNQUICA DE CÃES SADIOS E DOENTES

Directory of Open Access Journals (Sweden)

Paula Cristina Basso

2009-09-01

Full Text Available Research of antimicrobials use and resistance in food animals have been developed in various countries, although few studies include the bacteria prevalence in respiratory tract of companion animal. The aim of this paper was to verify antimicrobial resistance profile from bronchoalveolar lavage fluid of health and sick dogs. Twenty animals were evaluated, 10 in the health group (group 1 and 10 in respiratory distress group (group 2. The bronchoalveolar lavage was performed through an endotracheal tube or guided by a rigid endoscope. Culture, identification and bacterial sensibility of the fluid were performed through agar diffusion method. The bacterial isolated were: Haemophilus aphrophilus, Staphylococcus aureus, S. epidermidis, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosas e Proteus mirabilis. Of all samples, 63% showed resistance to at least one class of antibiotics. Therefore antibiotic resistance is present in sick as well in health animals and ceftriaxone and amoxicilin associated with clavulanic acid are effective against respiratory tract bacteria.

KEY WORDS: Antibiotic resistance, bacteria, respiratory distress.

Nacional de Encuestas sobre el uso de antibióticos y la resistencia a los antibióticos en la producción animal se llevan a cabo en varios países, sin embargo pocos estudios que incluyen agentes bacterianos asociados con las vías respiratorias de los animales domésticos. El objetivo de este estudio fue verificar el perfil de resistencia a los antimicrobianos en el líquido de lavado tracheobronchial sanos y enfermos perros. Hemos utilizado 20 animales, 10 clínicamente sanos (grupo 1 y 10 con trastorno respiratorio (grupo 2. La colecci��n de la tracheobronchial lavado se realizó con el tubo endotraqueal o guiado con la ayuda de un endoscopio rígido. Se han realizado el cultivo y la identificaci