Fluid casting of particle-based articles

DOEpatents

Menchhofer, Paul

1995-01-01

A method for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets or hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product.

Fluid casting of particle-based articles

DOEpatents

Menchhofer, P.

1995-03-28

A method is disclosed for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product. 1 figure.

Interactive FORTRAN IV computer programs for the thermodynamic and transport properties of selected cryogens (fluids pack)

NASA Technical Reports Server (NTRS)

Mccarty, R. D.

1980-01-01

The thermodynamic and transport properties of selected cryogens had programmed into a series of computer routines. Input variables are any two of P, rho or T in the single phase regions and either P or T for the saturated liquid or vapor state. The output is pressure, density, temperature, entropy, enthalpy for all of the fluids and in most cases specific heat capacity and speed of sound. Viscosity and thermal conductivity are also given for most of the fluids. The programs are designed for access by remote terminal; however, they have been written in a modular form to allow the user to select either specific fluids or specific properties for particular needs. The program includes properties for hydrogen, helium, neon, nitrogen, oxygen, argon, and methane. The programs include properties for gaseous and liquid states usually from the triple point to some upper limit of pressure and temperature which varies from fluid to fluid.

Knowledge-based zonal grid generation for computational fluid dynamics

NASA Technical Reports Server (NTRS)

Andrews, Alison E.

1988-01-01

Automation of flow field zoning in two dimensions is an important step towards reducing the difficulty of three-dimensional grid generation in computational fluid dynamics. Using a knowledge-based approach makes sense, but problems arise which are caused by aspects of zoning involving perception, lack of expert consensus, and design processes. These obstacles are overcome by means of a simple shape and configuration language, a tunable zoning archetype, and a method of assembling plans from selected, predefined subplans. A demonstration system for knowledge-based two-dimensional flow field zoning has been successfully implemented and tested on representative aerodynamic configurations. The results show that this approach can produce flow field zonings that are acceptable to experts with differing evaluation criteria.

Magnetorheological fluid based automotive steer-by-wire systems

NASA Astrophysics Data System (ADS)

Ahmadkhanlou, Farzad; Washington, Gregory N.; Bechtel, Stephen E.; Wang, Yingru

2006-03-01

The idea of this paper is to design a Magnetorheological (MR) fluid based damper for steer-by-wire systems to provide sensory feedback to the driver. The advantages of using MR fluids in haptic devices stem from the increase in transparency gained from the lightweight semiactive system and controller implementation. The performance of MR fluid based steer-by wire system depends on MR fluid model and specifications, MR damper geometry, and the control algorithm. All of these factors are addressed in this study. The experimental results show the improvements in steer-by-wire by adding force feedback to the system.

[Preparation and characterization of a polyvinylpyrrolidone water-based magnetic fluid].

PubMed

Xie, Jian-feng; Zhang, Yang-de; Zeng, Zhao-wu; Wang, Xiao-li; Liu, Xing-yan; Zhou, Wei-hua

2008-03-01

To prepare a stable water-based magnetic fluid. A water-based magnetic fluid was prepared by addition of polyvinylpyrrolidone (PVP) as the coating agent for the magnetic particles. After preparation of Fe3O4 by co-precipitation method, PVP was added for its coating, followed by ultrasonic agitation and purification. The magnetic nanoparticles of homogeneously small size and water-based magnetic fluid were obtained, which had good dispersion in water with strong magnetism. PVP can be used as a surfactant to stabilize the magnetic fluid.

Properties of forced convection experimental with silicon carbide based nano-fluids

NASA Astrophysics Data System (ADS)

Soanker, Abhinay

With the advent of nanotechnology, many fields of Engineering and Science took a leap to the next level of advancements. The broad scope of nanotechnology initiated many studies of heat transfer and thermal engineering. Nano-fluids are one such technology and can be thought of as engineered colloidal fluids with nano-sized colloidal particles. There are different types of nano-fluids based on the colloidal particle and base fluids. Nano-fluids can primarily be categorized into metallic, ceramics, oxide, magnetic and carbon based. The present work is a part of investigation of the thermal and rheological properties of ceramic based nano-fluids. alpha-Silicon Carbide based nano-fluid with Ethylene Glycol and water mixture 50-50% volume concentration was used as the base fluid here. This work is divided into three parts; Theoretical modelling of effective thermal conductivity (ETC) of colloidal fluids, study of Thermal and Rheological properties of alpha-SiC nano-fluids, and determining the Heat Transfer properties of alpha-SiC nano-fluids. In the first part of this work, a theoretical model for effective thermal conductivity (ETC) of static based colloidal fluids was formulated based on the particle size, shape (spherical), thermal conductivity of base fluid and that of the colloidal particle, along with the particle distribution pattern in the fluid. A MATLAB program is generated to calculate the details of this model. The model is specifically derived for least and maximum ETC enhancement possible and thereby the lower and upper bounds was determined. In addition, ETC is also calculated for uniform colloidal distribution pattern. Effect of volume concentration on ETC was studied. No effect of particle size was observed for particle sizes below a certain value. Results of this model were compared with Wiener bounds and Hashin- Shtrikman bounds. The second part of this work is a study of thermal and rheological properties of alpha-Silicon Carbide based nano-fluids

Microscope-Based Fluid Physics Experiments in the Fluids and Combustion Facility on ISS

NASA Technical Reports Server (NTRS)

Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Malarik, Diane C.

2000-01-01

At the NASA Glenn Research Center, the Microgravity Science Program is planning to conduct a large number of experiments on the International Space Station in both the Fluid Physics and Combustion Science disciplines, and is developing flight experiment hardware for use within the International Space Station's Fluids and Combustion Facility. Four fluids physics experiments that require an optical microscope will be sequentially conducted within a subrack payload to the Fluids Integrated Rack of the Fluids and Combustion Facility called the Light Microscopy Module, which will provide the containment, changeout, and diagnostic capabilities to perform the experiments. The Light Microscopy Module is planned as a fully remotely controllable on-orbit microscope facility, allowing flexible scheduling and control of experiments within International Space Station resources. This paper will focus on the four microscope-based experiments, specifically, their objectives and the sample cell and instrument hardware to accommodate their requirements.

A collaborative exercise on DNA methylation based body fluid typing.

PubMed

Jung, Sang-Eun; Cho, Sohee; Antunes, Joana; Gomes, Iva; Uchimoto, Mari L; Oh, Yu Na; Di Giacomo, Lisa; Schneider, Peter M; Park, Min Sun; van der Meer, Dieudonne; Williams, Graham; McCord, Bruce; Ahn, Hee-Jung; Choi, Dong Ho; Lee, Yang Han; Lee, Soong Deok; Lee, Hwan Young

2016-10-01

A collaborative exercise on DNA methylation based body fluid identification was conducted by seven laboratories. For this project, a multiplex methylation SNaPshot reaction composed of seven CpG markers was used for the identification of four body fluids, including blood, saliva, semen, and vaginal fluid. A total of 30 specimens were prepared and distributed to participating laboratories after thorough testing. The required experiments included four increasingly complex tasks: (1) CE of a purified single-base extension reaction product, (2) multiplex PCR and multiplex single-base extension reaction of bisulfite-modified DNA, (3) bisulfite conversion of genomic DNA, and (4) extraction of genomic DNA from body fluid samples. In tasks 2, 3 and 4, one or more mixtures were analyzed, and specimens containing both known and unknown body fluid sources were used. Six of the laboratories generated consistent body fluid typing results for specimens of bisulfite-converted DNA and genomic DNA. One laboratory failed to set up appropriate conditions for capillary analysis of reference single-base extension products. In general, variation in the values obtained for DNA methylation analysis between laboratories increased with the complexity of the required experiments. However, all laboratories concurred on the interpretation of the DNA methylation profiles produced. Although the establishment of interpretational guidelines on DNA methylation based body fluid identification has yet to be performed, this study supports the addition of DNA methylation profiling to forensic body fluid typing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sphere based fluid systems

NASA Technical Reports Server (NTRS)

Elleman, Daniel D. (Inventor); Wang, Taylor G. (Inventor)

1989-01-01

Systems are described for using multiple closely-packed spheres. In one system for passing fluid, a multiplicity of spheres lie within a container, with all of the spheres having the same outside diameter and with the spheres being closely nested in one another to create multiple interstitial passages of a known size and configuration and smooth walls. The container has an inlet and outlet for passing fluid through the interstitial passages formed between the nested spheres. The small interstitial passages can be used to filter out material, especially biological material such as cells in a fluid, where the cells can be easily destroyed if passed across sharp edges. The outer surface of the spheres can contain a material that absorbs a constitutent in the flowing fluid, such as a particular contamination gas, or can contain a catalyst to chemically react the fluid passing therethrough, the use of multiple small spheres assuring a large area of contact of these surfaces of the spheres with the fluid. In a system for storing and releasing a fluid such as hydrogen as a fuel, the spheres can include a hollow shell containing the fluid to be stored, and located within a compressable container that can be compressed to break the shells and release the stored fluid.

Enantioselective simultaneous analysis of selected pharmaceuticals in environmental samples by ultrahigh performance supercritical fluid based chromatography tandem mass spectrometry.

PubMed

Camacho-Muñoz, Dolores; Kasprzyk-Hordern, Barbara; Thomas, Kevin V

2016-08-31

In order to assess the true impact of each single enantiomer of pharmacologically active compounds (PACs) in the environment, highly efficient, fast and sensitive analytical methods are needed. For the first time this paper focuses on the use of ultrahigh performance supercritical fluid based chromatography coupled to a triple quadrupole mass spectrometer to develop multi-residue enantioselective methods for chiral PACs in environmental matrices. This technique exploits the advantages of supercritical fluid chromatography, ultrahigh performance liquid chromatography and mass spectrometry. Two coated modified 2.5 μm-polysaccharide-based chiral stationary phases were investigated: an amylose tris-3,5-dimethylphenylcarbamate column and a cellulose tris-3-chloro-4-methylphenylcarbamate column. The effect of different chromatographic variables on chiral recognition is highlighted. This novel approach resulted in the baseline resolution of 13 enantiomers PACs (aminorex, carprofen, chloramphenicol, 3-N-dechloroethylifosfamide, flurbiprofen, 2-hydroxyibuprofen, ifosfamide, imazalil, naproxen, ofloxacin, omeprazole, praziquantel and tetramisole) and partial resolution of 2 enantiomers PACs (ibuprofen and indoprofen) under fast-gradient conditions (<10 min analysis time). The overall performance of the methods was satisfactory. The applicability of the methods was tested on influent and effluent wastewater samples. To the best of our knowledge, this is the first feasibility study on the simultaneous separation of chemically diverse chiral PACs in environmental matrices using ultrahigh performance supercritical fluid based chromatography coupled with tandem mass spectrometry. Copyright © 2016 Elsevier B.V. All rights reserved.

Model identification methodology for fluid-based inerters

NASA Astrophysics Data System (ADS)

Liu, Xiaofu; Jiang, Jason Zheng; Titurus, Branislav; Harrison, Andrew

2018-06-01

Inerter is the mechanical dual of the capacitor via the force-current analogy. It has the property that the force across the terminals is proportional to their relative acceleration. Compared with flywheel-based inerters, fluid-based forms have advantages of improved durability, inherent damping and simplicity of design. In order to improve the understanding of the physical behaviour of this fluid-based device, especially caused by the hydraulic resistance and inertial effects in the external tube, this work proposes a comprehensive model identification methodology. Firstly, a modelling procedure is established, which allows the topological arrangement of the mechanical networks to be obtained by mapping the damping, inertance and stiffness effects directly to their respective hydraulic counterparts. Secondly, an experimental sequence is followed, which separates the identification of friction, stiffness and various damping effects. Furthermore, an experimental set-up is introduced, where two pressure gauges are used to accurately measure the pressure drop across the external tube. The theoretical models with improved confidence are obtained using the proposed methodology for a helical-tube fluid inerter prototype. The sources of remaining discrepancies are further analysed.

Selective enrichment in bioactive compound from Kniphofia uvaria by super/subcritical fluid extraction and centrifugal partition chromatography.

PubMed

Duval, Johanna; Destandau, Emilie; Pecher, Virginie; Poujol, Marion; Tranchant, Jean-François; Lesellier, Eric

2016-05-20

Nowadays, a large portion of synthetic products (active cosmetic and therapeutic ingredients) have their origin in natural products. Kniphofia uvaria is a plant from Africa which has proved in the past by in-vivo tests an antioxidant activity due to compounds present in roots. Recently, we have observed anthraquinones in K. uvaria seeds extracts. These derivatives are natural colorants which could have interesting bioactive potential. The aim of this study was to obtain an extract enriched in anthraquinones from K. uvaria seeds which mainly contains glycerides. First, the separation of the seed compounds was studied by using supercritical fluid chromatography (SFC) in the goal to provide a rapid quantification method of these bioactive compounds. A screening of numerous polar stationary phases was achieved for selecting the most suited phase to the separation of the four anthraquinones founded in the seeds. A gradient elution was optimized for improving the separation of the bioactive compounds from the numerous other families of major compounds of the extracts (fatty acids, di- and triglycerides). Besides, a non-selective and green Supercritical Fluid Extraction (SFE) with pure CO2 was applied to seeds followed by a Centrifugal Partition Chromatography (CPC). The CPC system was optimized by using the Arizona phase system, to enrich the extract in anthraquinones. Two systems were selected to isolate the bioactive compounds from the oily extract with varied purity target. The effect of the injection mode for these very viscous samples was also studied. Finally, in order to directly apply a selective process of extraction to the seeds, the super/subcritical fluid extraction was optimized to increase the anthraquinone yield in the final extract, by studying varied modifier compositions and nature, as well as different temperatures and backpressures. Conditions suited to favour an enrichment factor bases on the ratio of anthraquinone and trilycerides extracted are

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, Terry D.

1997-01-01

A fluid transfer apparatus includes: a) a plurality of orifices for connection with fluid sources; b) a plurality of orifices for connection with fluid targets; c) a set of fluid source conduits and fluid target conduits associated with the orifices; d) a pump fluidically interposed between the source and target conduits to transfer fluid therebetween; e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; g) pump control means for controlling operation of the pump; h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits.

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, T.D.

1997-08-26

A fluid transfer apparatus includes: (a) a plurality of orifices for connection with fluid sources; (b) a plurality of orifices for connection with fluid targets; (c) a set of fluid source conduits and fluid target conduits associated with the orifices; (d) a pump fluidically interposed between the source and target conduits to transfer fluid there between; (e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; (f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; (g) pump control means for controlling operation of the pump; (h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; (i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and (j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits. 6 figs.

Variable flexure-based fluid filter

DOEpatents

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.

Physically-Based Rendering of Particle-Based Fluids with Light Transport Effects

NASA Astrophysics Data System (ADS)

Beddiaf, Ali; Babahenini, Mohamed Chaouki

2018-03-01

Recent interactive rendering approaches aim to efficiently produce images. However, time constraints deeply affect their output accuracy and realism (many light phenomena are poorly or not supported at all). To remedy this issue, in this paper, we propose a physically-based fluid rendering approach. First, while state-of-the-art methods focus on isosurface rendering with only two refractions, our proposal (1) considers the fluid as a heterogeneous participating medium with refractive boundaries, and (2) supports both multiple refractions and scattering. Second, the proposed solution is fully particle-based in the sense that no particles transformation into a grid is required. This interesting feature makes it able to handle many particle types (water, bubble, foam, and sand). On top of that, a medium with different fluids (color, phase function, etc.) can also be rendered.

Low-gravity fluid physics: A program overview

NASA Technical Reports Server (NTRS)

1990-01-01

An overview is presented of the microgravity fluid physics program at Lewis Research Center. One of the main reasons for conducting low gravity research in fluid physics is to study phenomena such as surface tension, interfacial contact angles, and diffusion independent of such gravitationally induced effects as buoyant convection. Fluid physics is at the heart of many space-based technologies including power systems, thermal control systems, and life support systems. Fundamental understanding of fluid physics is a key ingredient to successful space systems design. In addition to describing ground-based and space-based low-gravity facilities, selected experiments are presented which highlight Lewis work in fluid physics. These experiments can be categorized into five theme areas which summarize the work being conducted at Lewis for OSSA: (1) isothermal/iso-solutal capillary phenomena; (2) capillary phenomena with thermal/solutal gradients; (3) thermal-solutal convection; (4) first- and second-order phase transitions in a static fluid; and (5) multiphase flow.

Fluid technology (selected components, devices, and systems): A compilation

NASA Technical Reports Server (NTRS)

1974-01-01

Developments in fluid technology and hydraulic equipment are presented. The subjects considered are: (1) the use of fluids in the operation of switches, amplifiers, and servo devices, (2) devices and data for laboratory use in the study of fluid dynamics, and (3) the use of fluids as controls and certain methods of controlling fluids.

Balanced Fluid Versus Saline-Based Fluid in Post-operative Severe Traumatic Brain Injury Patients: Acid-Base and Electrolytes Assessment

PubMed Central

Hassan, Mohamad Hasyizan; Hassan, Wan Mohd Nazaruddin Wan; Zaini, Rhendra Hardy Mohd; Shukeri, Wan Fadzlina Wan Muhd; Abidin, Huda Zainal; Eu, Chong Soon

2017-01-01

Background Normal saline (NS) is a common fluid of choice in neurosurgery and neuro-intensive care unit (ICU), but it does not contain other electrolytes and has the potential to cause hyperchloremic metabolic acidosis with prolonged infusion. These problems may be reduced with the availability of balanced fluid (BF), which becomes a more physiological isotonic solution with the presence of complete electrolyte content. This study aimed to compare the changes in electrolytes and acid–base between NS and BF (Sterofundin® ISO) therapy for post-operative severe traumatic brain injury (TBI) patients in neuro-ICU. Methods Sixty-six severe TBI patients who required emergency craniotomy or craniectomy and were planned for post-operative ventilation were randomised into NS (n = 33) and BF therapy groups (n = 33). The calculation of maintenance fluid given was based on the Holliday-Segar method. The electrolytes and acid–base parameters were assessed at an 8 h interval for 24 h. The data were analysed using repeated measures ANOVA. Results The NS group showed a significant lower base excess (−3.20 versus −1.35, P = 0.049), lower bicarbonate level (22.03 versus 23.48 mmol/L, P = 0.031), and more hyperchloremia (115.12 versus 111.74 mmol/L, P < 0.001) and hypokalemia (3.36 versus 3.70 mmol/L, P < 0.001) than the BF group at 24 h of therapy. The BF group showed a significantly higher level of calcium (1.97 versus 1.79 mmol/L, P = 0.003) and magnesium (0.94 versus 0.80 mmol/L, P < 0.001) than the NS group at 24 h of fluid therapy. No significant differences were found in pH, pCO2, lactate, and sodium level. Conclusion BF therapy showed better effects in maintaining higher electrolyte parameters and reducing the trend toward hyperchloremic metabolic acidosis than the NS therapy during prolonged fluid therapy for postoperative TBI patients. PMID:29386975

Balanced Fluid Versus Saline-Based Fluid in Post-operative Severe Traumatic Brain Injury Patients: Acid-Base and Electrolytes Assessment.

PubMed

Hassan, Mohamad Hasyizan; Hassan, Wan Mohd Nazaruddin Wan; Zaini, Rhendra Hardy Mohd; Shukeri, Wan Fadzlina Wan Muhd; Abidin, Huda Zainal; Eu, Chong Soon

2017-10-01

Normal saline (NS) is a common fluid of choice in neurosurgery and neuro-intensive care unit (ICU), but it does not contain other electrolytes and has the potential to cause hyperchloremic metabolic acidosis with prolonged infusion. These problems may be reduced with the availability of balanced fluid (BF), which becomes a more physiological isotonic solution with the presence of complete electrolyte content. This study aimed to compare the changes in electrolytes and acid-base between NS and BF (Sterofundin® ISO) therapy for post-operative severe traumatic brain injury (TBI) patients in neuro-ICU. Sixty-six severe TBI patients who required emergency craniotomy or craniectomy and were planned for post-operative ventilation were randomised into NS ( n = 33) and BF therapy groups ( n = 33). The calculation of maintenance fluid given was based on the Holliday-Segar method. The electrolytes and acid-base parameters were assessed at an 8 h interval for 24 h. The data were analysed using repeated measures ANOVA. The NS group showed a significant lower base excess (-3.20 versus -1.35, P = 0.049), lower bicarbonate level (22.03 versus 23.48 mmol/L, P = 0.031), and more hyperchloremia (115.12 versus 111.74 mmol/L, P < 0.001) and hypokalemia (3.36 versus 3.70 mmol/L, P < 0.001) than the BF group at 24 h of therapy. The BF group showed a significantly higher level of calcium (1.97 versus 1.79 mmol/L, P = 0.003) and magnesium (0.94 versus 0.80 mmol/L, P < 0.001) than the NS group at 24 h of fluid therapy. No significant differences were found in pH, pCO 2 , lactate, and sodium level. BF therapy showed better effects in maintaining higher electrolyte parameters and reducing the trend toward hyperchloremic metabolic acidosis than the NS therapy during prolonged fluid therapy for postoperative TBI patients.

Selection and properties of alternative forming fluids for TRISO fuel kernel production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, M. P.; King, J. C.; Gorman, B. P.

2013-01-01

Current Very High Temperature Reactor (VHTR) designs incorporate TRi-structural ISOtropic (TRISO) fuel, which consists of a spherical fissile fuel kernel surrounded by layers of pyrolytic carbon and silicon carbide. An internal sol-gel process forms the fuel kernel using wet chemistry to produce uranium oxyhydroxide gel spheres by dropping a cold precursor solution into a hot column of trichloroethylene (TCE). Over time, gelation byproducts inhibit complete gelation, and the TCE must be purified or discarded. The resulting TCE waste stream contains both radioactive and hazardous materials and is thus considered a mixed hazardous waste. Changing the forming fluid to a non-hazardousmore » alternative could greatly improve the economics of TRISO fuel kernel production. Selection criteria for a replacement forming fluid narrowed a list of ~10,800 chemicals to yield ten potential replacement forming fluids: 1-bromododecane, 1- bromotetradecane, 1-bromoundecane, 1-chlorooctadecane, 1-chlorotetradecane, 1-iododecane, 1-iodododecane, 1-iodohexadecane, 1-iodooctadecane, and squalane. The density, viscosity, and surface tension for each potential replacement forming fluid were measured as a function of temperature between 25 °C and 80 °C. Calculated settling velocities and heat transfer rates give an overall column height approximation. 1-bromotetradecane, 1-chlorooctadecane, and 1-iodododecane show the greatest promise as replacements, and future tests will verify their ability to form satisfactory fuel kernels.« less

Selection and properties of alternative forming fluids for TRISO fuel kernel production

NASA Astrophysics Data System (ADS)

Baker, M. P.; King, J. C.; Gorman, B. P.; Marshall, D. W.

2013-01-01

Current Very High Temperature Reactor (VHTR) designs incorporate TRi-structural ISOtropic (TRISO) fuel, which consists of a spherical fissile fuel kernel surrounded by layers of pyrolytic carbon and silicon carbide. An internal sol-gel process forms the fuel kernel using wet chemistry to produce uranium oxyhydroxide gel spheres by dropping a cold precursor solution into a hot column of trichloroethylene (TCE). Over time, gelation byproducts inhibit complete gelation, and the TCE must be purified or discarded. The resulting TCE waste stream contains both radioactive and hazardous materials and is thus considered a mixed hazardous waste. Changing the forming fluid to a non-hazardous alternative could greatly improve the economics of TRISO fuel kernel production. Selection criteria for a replacement forming fluid narrowed a list of ˜10,800 chemicals to yield ten potential replacement forming fluids: 1-bromododecane, 1-bromotetradecane, 1-bromoundecane, 1-chlorooctadecane, 1-chlorotetradecane, 1-iododecane, 1-iodododecane, 1-iodohexadecane, 1-iodooctadecane, and squalane. The density, viscosity, and surface tension for each potential replacement forming fluid were measured as a function of temperature between 25 °C and 80 °C. Calculated settling velocities and heat transfer rates give an overall column height approximation. 1-bromotetradecane, 1-chlorooctadecane, and 1-iodododecane show the greatest promise as replacements, and future tests will verify their ability to form satisfactory fuel kernels.

Working fluid selection for the Organic Rankine Cycle (ORC) exhaust heat recovery of an internal combustion engine power plant

NASA Astrophysics Data System (ADS)

Douvartzides, S.; Karmalis, I.

2016-11-01

Organic Rankine cycle technology is capable to efficiently convert low-grade heat into useful mechanical power. In the present investigation such a cycle is used for the recovery of heat from the exhaust gases of a four stroke V18 MAN 51/60DF internal combustion engine power plant operating with natural gas. Design is focused on the selection of the appropriate working fluid of the Rankine cycle in terms of thermodynamic, environmental and safety criteria. 37 candidate fluids have been considered and all Rankine cycles examined were subcritical. The thermodynamic analysis of all fluids has been comparatively undertaken and the effect of key operation conditions such as the evaporation pressure and the superheating temperature was taken into account. By appropriately selecting the working fluid and the Rankine cycle operation conditions the overall plant efficiency was improved by 5.52% and fuel consumption was reduced by 12.69%.

Physically-Based Modelling and Real-Time Simulation of Fluids.

NASA Astrophysics Data System (ADS)

Chen, Jim Xiong

1995-01-01

Simulating physically realistic complex fluid behaviors presents an extremely challenging problem for computer graphics researchers. Such behaviors include the effects of driving boats through water, blending differently colored fluids, rain falling and flowing on a terrain, fluids interacting in a Distributed Interactive Simulation (DIS), etc. Such capabilities are useful in computer art, advertising, education, entertainment, and training. We present a new method for physically-based modeling and real-time simulation of fluids in computer graphics and dynamic virtual environments. By solving the 2D Navier -Stokes equations using a CFD method, we map the surface into 3D using the corresponding pressures in the fluid flow field. This achieves realistic real-time fluid surface behaviors by employing the physical governing laws of fluids but avoiding extensive 3D fluid dynamics computations. To complement the surface behaviors, we calculate fluid volume and external boundary changes separately to achieve full 3D general fluid flow. To simulate physical activities in a DIS, we introduce a mechanism which uses a uniform time scale proportional to the clock-time and variable time-slicing to synchronize physical models such as fluids in the networked environment. Our approach can simulate many different fluid behaviors by changing the internal or external boundary conditions. It can model different kinds of fluids by varying the Reynolds number. It can simulate objects moving or floating in fluids. It can also produce synchronized general fluid flows in a DIS. Our model can serve as a testbed to simulate many other fluid phenomena which have never been successfully modeled previously.

2013 AAHA/AAFP fluid therapy guidelines for dogs and cats.

PubMed

Davis, Harold; Jensen, Tracey; Johnson, Anthony; Knowles, Pamela; Meyer, Robert; Rucinsky, Renee; Shafford, Heidi

2013-01-01

Fluid therapy is important for many medical conditions in veterinary patients. The assessment of patient history, chief complaint, physical exam findings, and indicated additional testing will determine the need for fluid therapy. Fluid selection is dictated by the patient's needs, including volume, rate, fluid composition required, and location the fluid is needed (e.g., interstitial versus intravascular). Therapy must be individualized, tailored to each patient, and constantly re-evaluated and reformulated according to changes in status. Needs may vary according to the existence of either acute or chronic conditions, patient pathology (e.g., acid-base, oncotic, electrolyte abnormalities), and comorbid conditions. All patients should be assessed for three types of fluid disturbances: changes in volume, changes in content, and/or changes in distribution. The goals of these guidelines are to assist the clinician in prioritizing goals, selecting appropriate fluids and rates of administration, and assessing patient response to therapy. These guidelines provide recommendations for fluid administration for anesthetized patients and patients with fluid disturbances.

Intravenous fluid prescription practices among pediatric residents in Korea.

PubMed

Lee, Jiwon M; Jung, Younghwa; Lee, Se Eun; Lee, Jun Ho; Kim, Kee Hyuck; Koo, Ja Wook; Park, Young Seo; Cheong, Hae Il; Ha, Il-Soo; Choi, Yong; Kang, Hee Gyung

2013-07-01

Recent studies have established the association between hypotonic fluids administration and hospital-acquired hyponatremia in children. The present paper investigated the pattern of current practice in intravenous fluid prescription among Korean pediatric residents, to underscore the need for updated education. A survey-based analysis was carried out. Pediatric residents at six university hospitals in Korea completed a survey consisting of four questions. Each question proposed a unique scenario in which the respondents had to prescribe either a hypotonic or an isotonic fluid for the patient. Ninety-one responses were collected and analyzed. In three of the four scenarios, a significant majority prescribed the hypotonic fluids (98.9%, 85.7%, and 69.2%, respectively). Notably, 69.2% of the respondents selected the hypotonic fluids for postoperative management. Almost all (96.7%) selected the isotonic fluids for hydration therapy. In the given scenarios, the majority of Korean pediatric residents would prescribe a hypotonic fluid, except for initial hydration. The current state of pediatric fluid management, notably, heightens the risk of hospital-acquired hyponatremia. Updated clinical practice education on intravenous fluid prescription, therefore, is urgently required.

Organosiloxane working fluids for the liquid droplet radiator

NASA Technical Reports Server (NTRS)

Buch, R. R.; Huntress, A. R.

1985-01-01

Siloxane-based working fluids for advanced space radiators requiring direct fluid exposure to the space environment are evaluated. Isolation of five candidate fluids by vacuum distillation from existing siloxane polymers is discussed. The five fluids recovered include a polydimethylsiloxane, three phenyl-containing siloxanes, and a methylhexylsiloxane. Vapor pressures and viscosities for the five fluids are reported over the temperature range of 250 to 400 K. Use of thermal-gravimetric analysis to reliably estimate vapor pressures of 10 to the -8 power Pascals is described. Polydimethylsiloxane (PDMS) and polymethylphenylsiloxane (PMPS) are selected from the five candidate fluids based on favorable vapor pressure and viscosity, as well as perceived stability in low-Earth orbit environments. Characterization of these fluids by infrared spectroscopy, Si-29 NMR, gel-permeation chromatography, and liquid chromatography is presented. Both fluids consist of narrow molecular weight distributions, with average molecular weights of about 2500 for PDMS and 1300 for PMPS.

Bipolar membranes with fluid distribution passages

NASA Technical Reports Server (NTRS)

Hitchens, G. Duncan (Inventor); Archer, Shivaun (Inventor); Tennakoon, Charles L. (Inventor); Gonzalez-Martin, Anuncia (Inventor); Cisar, Alan J. (Inventor)

1999-01-01

The present invention provides a bipolar membrane and methods for making and using the membrane. The bipolar membrane comprises a cation-selective region, an anion-selective region, an interfacial region between the anion-selective region and the cation-selective region, and means for delivering fluid directly into the interfacial region. The means for delivering fluid includes passages that may comprise a fluid-permeable material, a wicking material, an open passage disposed within the membrane or some combination thereof. The passages may be provided in many shapes, sizes and configurations, but preferably deliver fluid directly to the interfacial region so that the rate of electrodialysis is no longer limited by the diffusion of fluid through the cation- or anion-selective regions to the interfacial region.

Development of mRNA-based body fluid identification using reverse transcription loop-mediated isothermal amplification.

PubMed

Satoh, Tetsuya; Kouroki, Seiya; Ogawa, Keita; Tanaka, Yorika; Matsumura, Kazutoshi; Iwase, Susumu

2018-04-25

Identifying body fluids from forensic samples can provide valuable evidence for criminal investigations. Messenger RNA (mRNA)-based body fluid identification was recently developed, and highly sensitive parallel identification using reverse transcription polymerase chain reaction (RT-PCR) has been described. In this study, we developed reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a simple, rapid assay for identifying three common forensic body fluids, namely blood, semen, and saliva, and evaluated its specificity and sensitivity. Hemoglobin beta (HBB), transglutaminase 4 (TGM4), and statherin (STATH) were selected as marker genes for blood, semen, and saliva, respectively. RT-LAMP could be performed in a single step including both reverse transcription and DNA amplification under an isothermal condition within 60 min, and detection could be conveniently performed via visual fluorescence. Marker-specific amplification was performed in each assay, and no cross-reaction was observed among five representative forensically relevant body fluids. The detection limits of the assays were 0.3 nL, 30 nL, and 0.3 μL for blood, semen, and saliva, respectively, and their sensitivities were comparable with those of RT-PCR. Furthermore, RT-LAMP assays were applicable to forensic casework samples. It is considered that RT-LAMP is useful for body fluid identification.

The Sonographic Appearance of Spinal Fluid at Clinically Selected Interspaces in Sitting Versus Lateral Positions.

PubMed

Vitberg, Yaffa M; Tseng, Peggy; Kessler, David O

2018-05-01

Our objective was to describe the sonographic appearance of fluid at clinically selected interspinous spaces and see if additional interspaces could be identified as suitable and safe targets for needle insertion. We also measured the reproducibility of fluid measurements and assessed for positional differences. A prospective convenience sample of infants younger than 3 months was enrolled in the pediatric emergency department. Excluded were clinically unstable infants or those with spinal dysraphism. Infants were first held in standard lateral lumbar puncture position. Pediatric emergency medicine (PEM) physicians marked infants' backs at the level they would insert a needle using the landmark palpation technique. A PEM sonologist imaged and measured the spinal fluid in 2 orthogonal planes at this marked level in lateral then sitting positions. Fluid measurements were repeated by a second blinded PEM sonologist. Forty-six infants were enrolled. Ultrasound verified the presence of fluid at the marked level as determined by the landmark palpation technique in 98% of cases. Ultrasound identified additional suitable spaces 1 space higher (82%) and 2 spaces higher (41%). Intraclass correlation coefficient of all measurements was excellent (>0.85), with differences noted for sitting versus lateral position in mean area of fluid 0.34 mm versus 0.31 mm (difference, 0.03; 95% confidence interval [CI], 0.005-0.068), dorsal fluid pocket 0.23 mm versus 0.15 mm (difference, 0.08; 95% CI, 0.031-0.123), and nerve root-to-canal ratio 0.44 versus 0.51 (difference, 0.07; 95% CI, 0.004-0.117). Ultrasound can verify the presence of fluid at interspaces determined by the landmark palpation technique and identify additional suitable spaces at higher levels. There were statistically greater fluid measurements in sitting versus lateral positions. These novel fluid measurements were shown to be reliable.

Drivers of choice for fluid milk versus plant-based alternatives: What are consumer perceptions of fluid milk?

PubMed

McCarthy, K S; Parker, M; Ameerally, A; Drake, S L; Drake, M A

2017-08-01

Fluid milk consumption has declined for decades while consumption of nondairy alternatives has increased. A better understanding of why consumers purchase fluid milk or nondairy alternatives is needed to assist increased sales of milk or maintain sales without further decline. The objective of this study was to determine the extrinsic attributes that drive purchase within each product category. The second objective was to determine the personal values behind the purchase of each beverage type to give further understanding why particular attributes are important. An online conjoint survey was launched with 702 dairy consumers, 172 nondairy consumers, and 125 consumers of both beverages. Individual means-end chain interviews were conducted with fluid milk consumers (n = 75), plant-based alternative consumers (n = 68), and consumers of both beverages (n = 78). Fat content was the most important attribute for dairy milk followed by package size and label claims. Consumers of fluid milk preferred 1 or 2% fat content, gallon, or half-gallon packaging, conventionally pasteurized store-brand milk. Sugar level was the most important attribute for plant-based beverages, followed by plant source and package size. Almond milk was the most desirable plant source, and half-gallon packaging was the most preferred packaging. Means-end chain interviews results suggested that maintaining a balanced diet and healthy lifestyle was important to all consumer groups. Lactose free was an important attribute for plant-based alternative consumers and consumers of both dairy and nondairy. A distinguishing characteristic of those who only drank nondairy plant-based alternatives was that plant-based beverages contributed to a goal to consume less animal products, beliefs about animal mistreatment, and perceived lesser effect on the environment than fluid milk. Unique to fluid milk consumers was that fluid milk was perceived as a staple food item. These results suggest that the dairy industry

Method and Apparatus for Measuring Fluid Flow

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Nguyen, Thanh X. (Inventor); Carl, James R. (Inventor)

1997-01-01

Method and apparatus for making measurements on fluids related to their complex permeability are disclosed. A microwave probe is provided for exposure to the fluids. The probe can be non-intrusive or can also be positioned at the location where measurements are to be made. The impedance of the probe is determined. in part. by the complex dielectric constant of the fluids at the probe. A radio frequency signal is transmitted to the probe and the reflected signal is phase and amplitude detected at a rapid rate for the purpose of identifying the fluids. Multiple probes may be selectively positioned to monitor the behavior of the fluids including their flow rate. Fluids may be identified as between two or more different fluids as well as multiple phases of the same fluid based on differences between their complex permittivities.

Soy Protein Isolate As Fluid Loss Additive in Bentonite-Water-Based Drilling Fluids.

PubMed

Li, Mei-Chun; Wu, Qinglin; Song, Kunlin; Lee, Sunyoung; Jin, Chunde; Ren, Suxia; Lei, Tingzhou

2015-11-11

Wellbore instability and formation collapse caused by lost circulation are vital issues during well excavation in the oil industry. This study reports the novel utilization of soy protein isolate (SPI) as fluid loss additive in bentonite-water based drilling fluids (BT-WDFs) and describes how its particle size and concentration influence on the filtration property of SPI/BT-WDFs. It was found that high pressure homogenization (HPH)-treated SPI had superior filtration property over that of native SPI due to the improved ability for the plugging pore throat. HPH treatment also caused a significant change in the surface characteristic of SPI, leading to a considerable surface interaction with BT in aqueous solution. The concentration of SPI had a significant impact on the dispersion state of SPI/BT mixtures in aquesous solution. At low SPI concentrations, strong aggregations were created, resulting in the formation of thick, loose, high-porosity and high-permeability filter cakes and high fluid loss. At high SPI concentrations, intercatlated/exfoliated structures were generated, resulting in the formation of thin, compact, low-porosity and low-permeability filter cakes and low fluid loss. The SPI/BT-WDFs exhibited superior filtration property than pure BT-WDFs at the same solid concentraion, demonstrating the potential utilization of SPI as an effective, renewable, and biodegradable fluid loss reducer in well excavation applications.

Multiscale turbulence models based on convected fluid microstructure

NASA Astrophysics Data System (ADS)

Holm, Darryl D.; Tronci, Cesare

2012-11-01

The Euler-Poincaré approach to complex fluids is used to derive multiscale equations for computationally modeling Euler flows as a basis for modeling turbulence. The model is based on a kinematic sweeping ansatz (KSA) which assumes that the mean fluid flow serves as a Lagrangian frame of motion for the fluctuation dynamics. Thus, we regard the motion of a fluid parcel on the computationally resolvable length scales as a moving Lagrange coordinate for the fluctuating (zero-mean) motion of fluid parcels at the unresolved scales. Even in the simplest two-scale version on which we concentrate here, the contributions of the fluctuating motion under the KSA to the mean motion yields a system of equations that extends known results and appears to be suitable for modeling nonlinear backscatter (energy transfer from smaller to larger scales) in turbulence using multiscale methods.

Constant-Differential-Pressure Two-Fluid Accumulator

NASA Technical Reports Server (NTRS)

Piecuch, Benjamin; Dalton, Luke T.

2010-01-01

A two-fluid accumulator has been designed, built, and demonstrated to provide an acceptably close approximation to constant differential static pressure between two fluids over the full ranges of (1) accumulator stroke, (2) rates of flow of the fluids, and (3) common static pressure applied to the fluids. Prior differential- pressure two-fluid accumulators are generally not capable of maintaining acceptably close approximations to constant differential pressures. The inadequacies of a typical prior differential-pressure two-fluid accumulator can be summarized as follows: The static differential pressure is governed by the intrinsic spring rate (essentially, the stiffness) of an accumulator tank. The spring rate can be tailored through selection of the tank-wall thickness, selection of the number and/or shape of accumulator convolutions, and/or selection of accumulator material(s). Reliance on the intrinsic spring rate of the tank results in three severe limitations: (1) The spring rate and the expulsion efficiency tend to be inversely proportional to each other: that is to say, as the stiffness (and thus the differential pressure) is increased, the range of motion of the accumulator is reduced. (2) As the applied common static pressure increases, the differential pressure tends to decrease. An additional disadvantage, which may or may not be considered limiting, depending on the specific application, is that an increase in stiffness entails an increase in weight. (3) The additional weight required by a low expulsion efficiency accumulator eliminates the advantage given to such gas storage systems. The high expulsion efficiency provided by this two-fluid accumulator allows for a lightweight, tightly packaged system, which can be used in conjunction with a fuel cell-based system.

Non-invasive, transdermal, path-selective and specific glucose monitoring via a graphene-based platform

NASA Astrophysics Data System (ADS)

Lipani, Luca; Dupont, Bertrand G. R.; Doungmene, Floriant; Marken, Frank; Tyrrell, Rex M.; Guy, Richard H.; Ilie, Adelina

2018-06-01

Currently, there is no available needle-free approach for diabetics to monitor glucose levels in the interstitial fluid. Here, we report a path-selective, non-invasive, transdermal glucose monitoring system based on a miniaturized pixel array platform (realized either by graphene-based thin-film technology, or screen-printing). The system samples glucose from the interstitial fluid via electroosmotic extraction through individual, privileged, follicular pathways in the skin, accessible via the pixels of the array. A proof of principle using mammalian skin ex vivo is demonstrated for specific and `quantized' glucose extraction/detection via follicular pathways, and across the hypo- to hyper-glycaemic range in humans. Furthermore, the quantification of follicular and non-follicular glucose extraction fluxes is clearly shown. In vivo continuous monitoring of interstitial fluid-borne glucose with the pixel array was able to track blood sugar in healthy human subjects. This approach paves the way to clinically relevant glucose detection in diabetics without the need for invasive, finger-stick blood sampling.

Respiratory Adaptations in Acid-base Disturbances: Role of Cerebral Fluids,

DTIC Science & Technology

1979-06-19

The respiratory and metabolic components of acid-base homeostasis are defined. A quantitative empirical description of the (incomplete) mutual...literature. Respiratory adaptations in steady acid-base disturbances of metabolic origin (hyperventilation with hypocapnia in primary metabolic acidosis, and...hypoventilation with hypercapnia in metabolic alkalosis ) are analyzed as a function of the acidity of the cerebral fluids (cerebrospinal and cerebral interstitial fluid). (Author)

Cellulose-Based Smart Fluids under Applied Electric Fields

PubMed Central

Choi, Kisuk; Gao, Chun Yan; Nam, Jae Do

2017-01-01

Cellulose particles, their derivatives and composites have special environmentally benign features and are abundant in nature with their various applications. This review paper introduces the essential properties of several types of cellulose and their derivatives obtained from various source materials, and their use in electro-responsive electrorheological (ER) suspensions, which are smart fluid systems that are actively responsive under applied electric fields, while, at zero electric field, ER fluids retain a liquid-like state. Given the actively controllable characteristics of cellulose-based smart ER fluids under an applied electric field regarding their rheological and dielectric properties, they can potentially be applied for various industrial devices including dampers and haptic devices. PMID:28891966

Generating a Simulated Fluid Flow over a Surface Using Anisotropic Diffusion

NASA Technical Reports Server (NTRS)

Rodriguez, David L. (Inventor); Sturdza, Peter (Inventor)

2016-01-01

A fluid-flow simulation over a computer-generated surface is generated using a diffusion technique. The surface is comprised of a surface mesh of polygons. A boundary-layer fluid property is obtained for a subset of the polygons of the surface mesh. A gradient vector is determined for a selected polygon, the selected polygon belonging to the surface mesh but not one of the subset of polygons. A maximum and minimum diffusion rate is determined along directions determined using the gradient vector corresponding to the selected polygon. A diffusion-path vector is defined between a point in the selected polygon and a neighboring point in a neighboring polygon. An updated fluid property is determined for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and the gradient vector.

Impact of a carbohydrate-electrolyte drink on ingestive behaviour, affect and self-selected intensity during recreational exercise after 24-h fluid restriction.

PubMed

Peacock, Oliver J; Thompson, Dylan; Stokes, Keith A

2013-01-01

This study examined the effects of a carbohydrate-electrolyte drink on voluntary fluid intake, affect and self-selected intensity during recreational exercise after fluid restriction. In a randomised counterbalanced design, ten physically active adults were dehydrated via a 24-h period of fluid restriction before completing two 20-min bouts of cardiovascular exercise, 20-min of resistance exercise and 20 min on a cycle ergometer at a self-selected intensity with ad libitum access to water (W) or a carbohydrate-electrolyte solution (CES). Fluid restriction induced hypohydration of ∼1.2% initial body mass. Fluid intake during exercise was greater with CES (2105 ± 363 vs. 1470 ± 429 mL; P<0.01) and resulted in more adequate hydration (-0.03 ± 0.65 vs. -1.26 ± 0.80%; P<0.01). Plasma glucose concentrations (4.48 ± 0.40 vs. 4.28 ± 0.32 mmol L(-1); P<0.01) and pleasure ratings (2.63 ± 1.17 vs. 1.81 ± 1.37; P<0.01) were greater with CES than W. Mean power output during exercise performed at a self-selected intensity was 5.6% greater with CES (171 ± 63 vs. 162 ± 60 W; P<0.05). In physically active adults performing a 'real-life' recreational exercise simulation, CES resulted in more adequate hydration and an enhanced affective experience that corresponded with an increase in self-selected exercise intensity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation and electrical properties of oil-based magnetic fluids

NASA Astrophysics Data System (ADS)

Sartoratto, P. P. C.; Neto, A. V. S.; Lima, E. C. D.; Rodrigues de Sá, A. L. C.; Morais, P. C.

2005-05-01

This paper describes an improvement in the preparation of magnetic fluids for electrical transformers. The samples are based on surface-coated maghemite nanoparticles dispersed in transformer insulating oil. Colloidal stability at 90°C was higher for oleate-grafted maghemite-based magnetic fluid, whereas decanoate and dodecanoate-grafted samples were very unstable. Electrical properties were evaluated for samples containing 0.80%-0.0040% maghemite volume fractions. Relative permittivity varied from 8.8 to 2.1 and the minimum value of the loss factor was 12% for the most diluted sample. The resistivity falls in the range of 0.7-2.5×1010Ωm, whereas the ac dielectric strength varied from 70to79kV. These physical characteristics reveal remarkable step forward in the properties of the magnetic fluid samples and may result in better operation of electrical transformers.

A magneto-rheological fluid-based torque sensor for smart torque wrench application

NASA Astrophysics Data System (ADS)

Ahmadkhanlou, Farzad; Washington, Gregory N.

2013-04-01

In this paper, the authors have developed a new application where MR fluid is being used as a sensor. An MR-fluid based torque wrench has been developed with a rotary MR fluid-based damper. The desired set torque ranges from 1 to 6 N.m. Having continuously controllable yield strength, the MR fluid-based torque wrench presents a great advantage over the regular available torque wrenches in the market. This design is capable of providing continuous set toque from the lower limit to the upper limit while regular torque wrenches provide discrete set torques only at some limited points. This feature will be especially important in high fidelity systems where tightening torque is very critical and the tolerances are low.

Fines classification based on sensitivity to pore-fluid chemistry

USGS Publications Warehouse

Jang, Junbong; Santamarina, J. Carlos

2016-01-01

The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing characteristic of fine grains, pore-fluid chemistry is not addressed in current classification systems. Liquid limits obtained with electrically contrasting pore fluids (deionized water, 2-M NaCl brine, and kerosene) are combined to define the soil “electrical sensitivity.” Liquid limit and electrical sensitivity can be effectively used to classify fine grains according to their fluid-soil response into no-, low-, intermediate-, or high-plasticity fine grains of low, intermediate, or high electrical sensitivity. The proposed methodology benefits from the accumulated experience with liquid limit in the field and addresses the needs of a broader range of geotechnical engineering problems.

Selective-placement burial of drilling fluids: 2. Effects on buffalograss and fourwing saltbrush. [Atriplex canescens; Buchloe dactyloides

DOE Office of Scientific and Technical Information (OSTI.GOV)

McFarland, M.L.; Hartmann, S.; Ueckert, D.N.

Surface disposal of spent drilling fluids used in petroleum and natural gas exploration causes surface soil contamination that severely inhibits secondary plant succession and artificial revegetation efforts. Selective-placement burial was evaluated at two locations in western Texas for on-site disposal of drilling fluids in arid and semiarid regions. Establishment, yield, and chemical composition of fourwing saltbrush (Atriplex canescens (Pursh Nutt.)) and buffalograss (Buchloe dactyloides (Nutt.) Engelm.) transplants on undisturbed soils and on plots with spent drilling fluids and cuttings buried 30, 90 (with and without a 30-cm coarse limestone capillary barrier) and 150 cm were compared. Survival of both speciesmore » was 97 to 100% 17 months after planting on plots with buried drilling wastes. Canopy cover and aboveground biomass of fourwing saltbrush were greater over buried drilling wastes than on untreated plots, whereas canopy cover and aboveground biomass of buffalograss were not affected by the treatments. Significant increases in Na, M, and Mg concentrations in buffalograss after 17 months on plots with drilling fluids buried 30 cm deep at one location indicated plant uptake of some drilling fluid constituents. Elevated Zn concentrations in fourwing saltbush indicated that a portion of the Zn in the drilling fluids was available for plant uptake, while no evidence of plant accumulation of Ba, Cr, Cu, or Ni from drilling fluids was detected.« less

Supercritical fluid crystallization of griseofulvin: crystal habit modification with a selective growth inhibitor.

PubMed

Jarmer, Daniel J; Lengsfeld, Corinne S; Anseth, Kristi S; Randolph, Theodore W

2005-12-01

Poly (sebacic anhydride) (PSA) was used as a growth inhibitor to selectively modify habit of griseofulvin crystals formed via the Precipitation with a compressed-fluid antisolvent (PCA) process. PSA and griseofulvin were coprecipitated within a PCA injector, which provided efficient mixing between the solution and compressed antisolvent process streams. Griseofulvin crystal habit was modified from acicular to bipyramidal when the mass ratio of PSA/griseofulvin in the solution feed stream was selective growth inhibition mechanism. SEM micrographs showed regions on griseofulvin crystals where PSA microparticles had preferentially adsorbed. X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) analysis of the griseofulvin crystals indicated no changes in the crystalline form after the habit modification. Powder compressibility decreased from 49 +/- 3% to 28 +/- 7% with the modification in crystal habit. No change in the physical stability of the processed powder was observed after being stored at 25 degrees C/60% RH and 40 degrees C/70% RH for 23 days. Despite the change in crystal habit, griseofulvin crystals achieved 100% dissolution within 60 min in a simulated gastric fluid. (c) 2005 Wiley-Liss, Inc.

Understanding, Classifying, and Selecting Environmentally Acceptable Hydraulic Fluids

DTIC Science & Technology

2016-08-01

installed in land facilities or off- road vehicles such as excavators, bulldozers, backhoes, etc.), while others are installed on floating plants...and oily bilge tanks for the collection and proper disposal of oil- contaminated bilge water • Performing routine maintenance , including regular...regulations. Maintenance of machinery systems containing EA hydraulic fluids must strictly follow the hydraulic fluid manufacturer’s recommendations

Designing a Robust Micromixer Based on Fluid Stretching

NASA Astrophysics Data System (ADS)

Mott, David; Gautam, Dipesh; Voth, Greg; Oran, Elaine

2010-11-01

A metric for measuring fluid stretching based on finite-time Lyapunov exponents is described, and the use of this metric for optimizing mixing in microfluidic components is explored. The metric is implemented within an automated design approach called the Computational Toolbox (CTB). The CTB designs components by adding geometric features, such a grooves of various shapes, to a microchannel. The transport produced by each of these features in isolation was pre-computed and stored as an "advection map" for that feature, and the flow through a composite geometry that combines these features is calculated rapidly by applying the corresponding maps in sequence. A genetic algorithm search then chooses the feature combination that optimizes a user-specified metric. Metrics based on the variance of concentration generally require the user to specify the fluid distributions at inflow, which leads to different mixer designs for different inflow arrangements. The stretching metric is independent of the fluid arrangement at inflow. Mixers designed using the stretching metric are compared to those designed using a variance of concentration metric and show excellent performance across a variety of inflow distributions and diffusivities.

Agent-Based Chemical Plume Tracing Using Fluid Dynamics

NASA Technical Reports Server (NTRS)

Zarzhitsky, Dimitri; Spears, Diana; Thayer, David; Spears, William

2004-01-01

This paper presents a rigorous evaluation of a novel, distributed chemical plume tracing algorithm. The algorithm is a combination of the best aspects of the two most popular predecessors for this task. Furthermore, it is based on solid, formal principles from the field of fluid mechanics. The algorithm is applied by a network of mobile sensing agents (e.g., robots or micro-air vehicles) that sense the ambient fluid velocity and chemical concentration, and calculate derivatives. The algorithm drives the robotic network to the source of the toxic plume, where measures can be taken to disable the source emitter. This work is part of a much larger effort in research and development of a physics-based approach to developing networks of mobile sensing agents for monitoring, tracking, reporting and responding to hazardous conditions.

The Research of New Environment-Friendly Oil-based Drilling Fluid Base Oil

NASA Astrophysics Data System (ADS)

Sui, Dianjie; Sun, Yuxue; Zhao, Jingyuan; Zhao, Fulei; Zhu, Xiuyu; Xu, Jianjun

2018-01-01

In this paper, the heavy hydrocarbon of Daqing is used, and the desulfurization and de-aromatization experiments and refining process are carried out, A base oil suitable for oil-based drilling fluid was developed, and the performance of base oil was evaluated, we can know the aromatics content of oil base is low, less toxic, less pollution and it can meet the requirement of environmental protection.

Errors in fluid therapy in medical wards.

PubMed

Mousavi, Maryam; Khalili, Hossein; Dashti-Khavidaki, Simin

2012-04-01

Intravenous fluid therapy remains an essential part of patients' care during hospitalization. There are only few studies that focused on fluid therapy in the hospitalized patients, and there is not any consensus statement about fluid therapy in patients who are hospitalized in medical wards. The aim of the present study was to assess intravenous fluid therapy status and related errors in the patients during the course of hospitalization in the infectious diseases wards of a referral teaching hospital. This study was conducted in the infectious diseases wards of Imam Khomeini Complex Hospital, Tehran, Iran. During a retrospective study, data related to intravenous fluid therapy were collected by two clinical pharmacists of infectious diseases from 2008 to 2010. Intravenous fluid therapy information including indication, type, volume and rate of fluid administration was recorded for each patient. An internal protocol for intravenous fluid therapy was designed based on literature review and available recommendations. The data related to patients' fluid therapy were compared with this protocol. The fluid therapy was considered appropriate if it was compatible with the protocol regarding indication of intravenous fluid therapy, type, electrolyte content and rate of fluid administration. Any mistake in the selection of fluid type, content, volume and rate of administration was considered as intravenous fluid therapy errors. Five hundred and ninety-six of medication errors were detected during the study period in the patients. Overall rate of fluid therapy errors was 1.3 numbers per patient during hospitalization. Errors in the rate of fluid administration (29.8%), incorrect fluid volume calculation (26.5%) and incorrect type of fluid selection (24.6%) were the most common types of errors. The patients' male sex, old age, baseline renal diseases, diabetes co-morbidity, and hospitalization due to endocarditis, HIV infection and sepsis are predisposing factors for the

Magnetic timing valves for fluid control in paper-based microfluidics.

PubMed

Li, Xiao; Zwanenburg, Philip; Liu, Xinyu

2013-07-07

Multi-step analytical tests, such as an enzyme-linked immunosorbent assay (ELISA), require delivery of multiple fluids into a reaction zone and counting the incubation time at different steps. This paper presents a new type of paper-based magnetic valves that can count the time and turn on or off a fluidic flow accordingly, enabling timed fluid control in paper-based microfluidics. The timing capability of these valves is realized using a paper timing channel with an ionic resistor, which can detect the event of a solution flowing through the resistor and trigger an electromagnet (through a simple circuit) to open or close a paper cantilever valve. Based on this principle, we developed normally-open and normally-closed valves with a timing period up to 30.3 ± 2.1 min (sufficient for an ELISA on paper-based platforms). Using the normally-open valve, we performed an enzyme-based colorimetric reaction commonly used for signal readout of ELISAs, which requires a timed delivery of an enzyme substrate to a reaction zone. This design adds a new fluid-control component to the tool set for developing paper-based microfluidic devices, and has the potential to improve the user-friendliness of these devices.

[Analysis on accuracy and influencing factors of oral fluid-based rapid HIV self-testing among men who have sex with men].

PubMed

Li, Youfang; Wang, Yumiao; Zhang, Renzhong; Wang, Jue; Li, Zhiqing; Wang, Ling; Pan, Songfeng; Yang, Yanling; Ma, Yanling; Jia, Manhong

2016-01-01

To understood the accuracy of oral fluid-based rapid HIV self-testing among men who have sex with men (MSM) and related factors. Survey was conducted among MSM selected through non-probability sampling to evaluate the quality of their rapid HIV self-testing, and related information was analyzed. The most MSM were aged 21-30 years (57.0%). Among them, 45.7% had educational level of college or above, 78.5% were unmarried, 59.3% were casual laborers. The overall accuracy rate of oral fluid based self-testing was 95.0%, the handling of"inserting test paper into tube as indicated by arrow on it"had the highest accuracy rate (98.0%), and the handling of"gently upsetting tube for 3 times"had lowest accuracy rate (65.0%); Chi-square analysis showed that educational level, no touch with middle part of test paper, whether reading the instruction carefully, whether understanding the instruction and inserting test paper into tube as indicated by the arrow on it were associated with the accuracy of oral fluid-based rapid HIV self-testing, (P<0.05). Multivariate logistic regression analysis indicated that educational level, no touch with middle part of test paper and understanding instructions were associated with the accuracy of oral fluid-based rapid HIV self-testing. The accuracy of oral fluid-based rapid HIV self-testing was high among MSM, the accuracy varied with the educational level of the MSM. Touch with the middle part of test paper or not and understanding the instructions or not might influence the accuracy of the self-testing.

The Chemical Behavior of Fluids Released during Deep Subduction Based on Fluid Inclusions

NASA Astrophysics Data System (ADS)

Frezzotti, M. L.; Ferrando, S.

2014-12-01

We present a review of current research on fluid inclusions in (HP-) UHP metamorphic rocks that, combined with existing experimental research and thermodynamic models, allow us to investigate the chemical and physical properties of fluids released during deep subduction, their solvent and element transport capacity, and the subsequent implications for the element recycling in the mantle wedge. An impressive number of fluid inclusion studies indicate three main populations of fluid inclusions in HP and UHP metamorphic rocks: i) aqueous and/or non-polar gaseous fluid inclusions (FI), ii) multiphase solid inclusions (MSI), and iii) melt inclusions (MI). Chemical data from preserved fluid inclusions in rocks match with and implement "model" fluids by experiments and thermodynamics, revealing a continuity behind the extreme variations of physico-chemical properties of subduction-zone fluids. From fore-arc to sub-arc depths, fluids released by progressive devolatilization reactions from slab lithologies change from relatively diluted chloride-bearing aqueous solutions (± N2), mainly influenced by halide ligands, to (alkali) aluminosilicate-rich aqueous fluids, in which polymerization probably governs the solubility and transport of major (e.g., Si and Al) and trace elements (including C). Fluid inclusion data implement the petrological models explaining deep volatile liberation in subduction zones, and their flux into the mantle wedge.

A refractometry-based glucose analysis of body fluids.

PubMed

Zirk, Kai; Poetzschke, Harald

2007-05-01

In principle, refractometry appears to be a suitable method for the measurement of glucose concentrations in body fluids (such as blood and the intercellular fluid), even though the refractive index of the measured samples, as an additive property, is not specific. But, if certain conditions are fulfilled, the glucose content can be calculated using the refractive index in combination with values from a further measurement. This study describes the determination of the glucose content using refractometry in human blood serum derivates, which were selected - due to their ready availability - to be used as a model for interstitial fluid. Refractometry of body fluids requires the elimination of disturbing components from the measurement sample. First of all, a homogenous fluid (i.e. consisting of one phase) is required, so that all cells and components in suspension need to be separated out. Furthermore, certain dissolved macromolecular components which are known to disturb the measurement process must also be removed. In human serum samples which had been ultrafiltrated with a range of ultrafilters of different pore sizes, a comparative evaluation showed that only ultrafiltration through a filter with a separation limit of between 3 and 30kDa resulted in maximal reduction of the refractive index (compared to native serum), whereas ultrafilters with greater separation limits did not. The total content of osmotically active solutes (the tonicity) also exerts a clear influence. However, exemplary measurements in blood plasma fluid from one volunteer showed that the electrical conductivity is (without an additive component) directly proportional to the osmolality: physiological changes in the state of body hydration (hyperhydration and dehydration) do not lead to any considerable changes in the relation between ionised and uncharged solute particles, but instead result in a sufficiently clear dilution or concentration of the blood fluid's low molecular components. This

Selective placement disposal of drilling fluids in west Texas

DOE Office of Scientific and Technical Information (OSTI.GOV)

McFarland, M.L.

1988-01-01

Burial of spent drilling fluids used in petroleum and natural gas exploration was evaluated as an alternative disposal technique for reducing surface soil contamination in western Texas. Simulated reserve pits were constructed to provide burial depths of 30, 90, and 150 cm below the surface, with orderly replacement of stockpiled subsoil and topsoil. Movement of soluble salts and heavy metals from drilling fluids into the overlying soil was monitored over a 20-month period. The effects of depth of drilling fluid burial on establishment, yields, and chemical composition of transplanted fourwing saltbush (Atriplex canescens (Pursh) Nutt.) and buffalograss (Buchloe dactyloides (Nutt.)more » Engelm.) were determined for two growing seasons. Sodium, Ca{sup +2}, and Cl{sup {minus}} were the dominant mobile ions, while migration of Mg{sup +2}, K{sup +}, and SO{sub 4}{sup {minus}2} was observed to a lesser degree. Exchangeable sodium percentages in the 15-cm zone immediately above drilling fluid ranged from 1.9 to 19.0 after 20 months. Total concentrations of Ba, Cr, Cu, Ni, and Zn were greater in drilling fluids than in native soil, but there was no evidence of migration of these metals into overlying soil.« less

Transesterification reaction for synthesis of palm-based ethylhexyl ester and formulation as base oil for synthetic drilling fluid.

PubMed

Abdul Habib, Nor Saiful Hafiz; Yunus, Robiah; Rashid, Umer; Taufiq-Yap, Yun H; Abidin, Zurina Zainal; Syam, Azhari Muhammad; Irawan, Sonny

2014-01-01

The use of vegetable oil-based ester as a base fluid in synthetic drilling fluid has become a trend in drilling operations due to its environmental advantages. The transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (2EH) produced 98% of palm oil-based ethylhexyl ester in less than 30 minutes. Since the transesterification reaction of POME with 2EH is a reversible reaction, its kinetics was studied in the presence of excess EH and under vacuum. The POME-to-EH molar ratio and vacuum pressure were held constant at 1:2 and 1.5 mbar respectively and the effects of temperature (70 to 110°C) were investigated. Using excess of EH and continual withdrawal of methanol via vacuum promoted the reaction to complete in less than 10 minutes. The rate constant of the reaction (k) obtained from the kinetics study was in the range of 0.44 to 0.66 s⁻¹ and the activation energy was 15.6 kJ.mol⁻¹. The preliminary investigations on the lubrication properties of drilling mud formulated with palm oil-based 2EH ester indicated that the base oil has a great potential to substitute the synthetic ester-based oil for drilling fluid. Its high kinematic viscosity provides better lubrication to the drilling fluid compared to other ester-based oils. The pour point (-15°C) and flash point (204°C) values are superior for the drilling fluid formulation. The plastic viscosity, HPHT filtrate loss and emulsion stability of the drilling fluid had given acceptable values, while gel strength and yield point could be improved by blending it with proper additives.

Generating a Simulated Fluid Flow Over an Aircraft Surface Using Anisotropic Diffusion

NASA Technical Reports Server (NTRS)

Rodriguez, David L. (Inventor); Sturdza, Peter (Inventor)

2013-01-01

A fluid-flow simulation over a computer-generated aircraft surface is generated using a diffusion technique. The surface is comprised of a surface mesh of polygons. A boundary-layer fluid property is obtained for a subset of the polygons of the surface mesh. A pressure-gradient vector is determined for a selected polygon, the selected polygon belonging to the surface mesh but not one of the subset of polygons. A maximum and minimum diffusion rate is determined along directions determined using a pressure gradient vector corresponding to the selected polygon. A diffusion-path vector is defined between a point in the selected polygon and a neighboring point in a neighboring polygon. An updated fluid property is determined for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and angular difference between the diffusion-path vector and the pressure-gradient vector.

Accurate fluid force measurement based on control surface integration

NASA Astrophysics Data System (ADS)

Lentink, David

2018-01-01

Nonintrusive 3D fluid force measurements are still challenging to conduct accurately for freely moving animals, vehicles, and deforming objects. Two techniques, 3D particle image velocimetry (PIV) and a new technique, the aerodynamic force platform (AFP), address this. Both rely on the control volume integral for momentum; whereas PIV requires numerical integration of flow fields, the AFP performs the integration mechanically based on rigid walls that form the control surface. The accuracy of both PIV and AFP measurements based on the control surface integration is thought to hinge on determining the unsteady body force associated with the acceleration of the volume of displaced fluid. Here, I introduce a set of non-dimensional error ratios to show which fluid and body parameters make the error negligible. The unsteady body force is insignificant in all conditions where the average density of the body is much greater than the density of the fluid, e.g., in gas. Whenever a strongly deforming body experiences significant buoyancy and acceleration, the error is significant. Remarkably, this error can be entirely corrected for with an exact factor provided that the body has a sufficiently homogenous density or acceleration distribution, which is common in liquids. The correction factor for omitting the unsteady body force, {{{ {ρ f}} {1 - {ρ f} ( {{ρ b}+{ρ f}} )}.{( {{{{ρ }}b}+{ρ f}} )}}} , depends only on the fluid, {ρ f}, and body, {{ρ }}b, density. Whereas these straightforward solutions work even at the liquid-gas interface in a significant number of cases, they do not work for generalized bodies undergoing buoyancy in combination with appreciable body density inhomogeneity, volume change (PIV), or volume rate-of-change (PIV and AFP). In these less common cases, the 3D body shape needs to be measured and resolved in time and space to estimate the unsteady body force. The analysis shows that accounting for the unsteady body force is straightforward to non

A review of solid-fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid-liquid and multiphase solid-liquid flows

NASA Astrophysics Data System (ADS)

Wright, Stuart F.; Zadrazil, Ivan; Markides, Christos N.

2017-09-01

Experimental techniques based on optical measurement principles have experienced significant growth in recent decades. They are able to provide detailed information with high-spatiotemporal resolution on important scalar (e.g., temperature, concentration, and phase) and vector (e.g., velocity) fields in single-phase or multiphase flows, as well as interfacial characteristics in the latter, which has been instrumental to step-changes in our fundamental understanding of these flows, and the development and validation of advanced models with ever-improving predictive accuracy and reliability. Relevant techniques rely upon well-established optical methods such as direct photography, laser-induced fluorescence, laser Doppler velocimetry/phase Doppler anemometry, particle image/tracking velocimetry, and variants thereof. The accuracy of the resulting data depends on numerous factors including, importantly, the refractive indices of the solids and liquids used. The best results are obtained when the observational materials have closely matched refractive indices, including test-section walls, liquid phases, and any suspended particles. This paper reviews solid-liquid and solid-liquid-liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid-liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330-1.620 and 1.251-1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials in single-phase liquid or multiphase liquid-liquid flow systems. In addition, the refractive indices of fluids can be further tuned with the use of additives, which also allows for the matching of important flow similarity parameters such as density and viscosity.

Speckle tracking and speckle content based composite strain imaging for solid and fluid filled lesions.

PubMed

Rabbi, Md Shifat-E; Hasan, Md Kamrul

2017-02-01

Strain imaging though for solid lesions provides an effective way for determining their pathologic condition by displaying the tissue stiffness contrast, for fluid filled lesions such an imaging is yet an open problem. In this paper, we propose a novel speckle content based strain imaging technique for visualization and classification of fluid filled lesions in elastography after automatic identification of the presence of fluid filled lesions. Speckle content based strain, defined as a function of speckle density based on the relationship between strain and speckle density, gives an indirect strain value for fluid filled lesions. To measure the speckle density of the fluid filled lesions, two new criteria based on oscillation count of the windowed radio frequency signal and local variance of the normalized B-mode image are used. An improved speckle tracking technique is also proposed for strain imaging of the solid lesions and background. A wavelet-based integration technique is then proposed for combining the strain images from these two techniques for visualizing both the solid and fluid filled lesions from a common framework. The final output of our algorithm is a high quality composite strain image which can effectively visualize both solid and fluid filled breast lesions in addition to the speckle content of the fluid filled lesions for their discrimination. The performance of our algorithm is evaluated using the in vivo patient data and compared with recently reported techniques. The results show that both the solid and fluid filled lesions can be better visualized using our technique and the fluid filled lesions can be classified with good accuracy. Copyright © 2016 Elsevier B.V. All rights reserved.

Physics-Based Computational Algorithm for the Multi-Fluid Plasma Model

DTIC Science & Technology

2014-06-30

applying it to study laser - 20 Physics-Based Multi-Fluid Plasma Algorithm Shumlak Figure 6: Blended finite element method applied to the species...separation problem in capsule implosions. Number densities and electric field are shown after the laser drive has compressed the multi-fluid plasma and...6 after the laser drive has started the compression. A separation clearly develops. The solution is found using an explicit advance (CFL=1) for the

Comparison of sample preparation techniques and data analysis for the LC-MS/MS-based identification of proteins in human follicular fluid.

PubMed

Lehmann, Roland; Schmidt, André; Pastuschek, Jana; Müller, Mario M; Fritzsche, Andreas; Dieterle, Stefan; Greb, Robert R; Markert, Udo R; Slevogt, Hortense

2018-06-25

The proteomic analysis of complex body fluids by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis requires the selection of suitable sample preparation techniques and optimal parameter settings in data analysis software packages to obtain reliable results. Proteomic analysis of follicular fluid, as a representative of a complex body fluid similar to serum or plasma, is difficult as it contains a vast amount of high abundant proteins and a variety of proteins with different concentrations. However, the accessibility of this complex body fluid for LC-MS/MS analysis is an opportunity to gain insights into the status, the composition of fertility-relevant proteins including immunological factors or for the discovery of new diagnostic and prognostic markers for, for example, the treatment of infertility. In this study, we compared different sample preparation methods (FASP, eFASP and in-solution digestion) and three different data analysis software packages (Proteome Discoverer with SEQUEST, Mascot and MaxQuant with Andromeda) combined with semi- and full-tryptic databank search options to obtain a maximum coverage of the follicular fluid proteome. We found that the most comprehensive proteome coverage is achieved by the eFASP sample preparation method using SDS in the initial denaturing step and the SEQUEST-based semi-tryptic data analysis. In conclusion, we have developed a fractionation-free methodical workflow for in depth LC-MS/MS-based analysis for the standardized investigation of human follicle fluid as an important representative of a complex body fluid. Taken together, we were able to identify a total of 1392 proteins in follicular fluid. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Seismic low-frequency-based calculation of reservoir fluid mobility and its applications

NASA Astrophysics Data System (ADS)

Chen, Xue-Hua; He, Zhen-Hua; Zhu, Si-Xin; Liu, Wei; Zhong, Wen-Li

2012-06-01

Low frequency content of seismic signals contains information related to the reservoir fluid mobility. Based on the asymptotic analysis theory of frequency-dependent reflectivity from a fluid-saturated poroelastic medium, we derive the computational implementation of reservoir fluid mobility and present the determination of optimal frequency in the implementation. We then calculate the reservoir fluid mobility using the optimal frequency instantaneous spectra at the low-frequency end of the seismic spectrum. The methodology is applied to synthetic seismic data from a permeable gas-bearing reservoir model and real land and marine seismic data. The results demonstrate that the fluid mobility shows excellent quality in imaging the gas reservoirs. It is feasible to detect the location and spatial distribution of gas reservoirs and reduce the non-uniqueness and uncertainty in fluid identification.

Zirconia coated carbonyl iron particle-based magnetorheological fluid for polishing

NASA Astrophysics Data System (ADS)

Shafrir, Shai N.; Romanofsky, Henry J.; Skarlinski, Michael; Wang, Mimi; Miao, Chunlin; Salzman, Sivan; Chartier, Taylor; Mici, Joni; Lambropoulos, John C.; Shen, Rui; Yang, Hong; Jacobs, Stephen D.

2009-08-01

Aqueous magnetorheological (MR) polishing fluids used in magnetorheological finishing (MRF) have a high solids concentration consisting of magnetic carbonyl iron particles and nonmagnetic polishing abrasives. The properties of MR polishing fluids are affected over time by corrosion of CI particles. Here we report on MRF spotting experiments performed on optical glasses using a zirconia coated carbonyl iron (CI) particle-based MR fluid. The zirconia coated magnetic CI particles were prepared via sol-gel synthesis in kg quantities. The coating layer was ~50-100 nm thick, faceted in surface structure, and well adhered. Coated particles showed long term stability against aqueous corrosion. "Free" nano-crystalline zirconia polishing abrasives were co-generated in the coating process, resulting in an abrasivecharged powder for MRF. A viable MR fluid was prepared simply by adding water. Spot polishing tests were performed on a variety of optical glasses over a period of 3 weeks with no signs of MR fluid degradation or corrosion. Stable material removal rates and smooth surfaces inside spots were obtained.

Cellulose nanoparticles as modifiers for rheology and fluid loss in bentonite water-based fluids.

PubMed

Li, Mei-Chun; Wu, Qinglin; Song, Kunlin; Qing, Yan; Wu, Yiqiang

2015-03-04

Rheological and filtration characteristics of drilling fluids are considered as two critical aspects to ensure the success of a drilling operation. This research demonstrates the effectiveness of cellulose nanoparticles (CNPs), including microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) in enhancing the rheological and filtration performances of bentonite (BT) water-based drilling fluids (WDFs). CNCs were isolated from MFC through sulfuric acid hydrolysis. In comparison with MFC, the resultant CNCs had much smaller dimensions, more negative surface charge, higher stability in aqueous solutions, lower viscosity, and less evident shear thinning behavior. These differences resulted in the distinctive microstructures between MFC/BT- and CNC/BT-WDFs. A typical "core-shell" structure was created in CNC/BT-WDFs due to the strong surface interactions among BT layers, CNCs, and immobilized water molecules. However, a similar structure was not formed in MFC/BT-WDFs. As a result, CNC/BT-WDFs had superior rheological properties, higher temperature stability, less fluid loss volume, and thinner filter cakes than BT and MFC/BT-WDFs. Moreover, the presence of polyanionic cellulose (PAC) further improved the rheological and filtration performances of CNC/BT-WDFs, suggesting a synergistic effect between PAC and CNCs.

The DC and AC insulating properties of magnetic fluids based on transformer oil

NASA Astrophysics Data System (ADS)

Tomo, L.; Marton, K.; Herchl, F.; Kopanský, P.; Potoová, I.; Koneracká, M.; Timko, M.

2006-01-01

The AC-dielectric breakdown was investigated in magnetic fluids based on transformer oil TECHNOL US 4000 for two orientations of external magnetic field (B E and B E) and in B = 0. The found results were compared with those obtained formerly for the DC-dielectric breakdown. The observations of the time development of the AC-dielectric breakdown showed the presence of partial discharges long before the complete breakdown occurrence, while for DC-dielectric breakdown a complete breakdown of the gap next to the onset of a measurable ionization was characteristic. The comparison of the AC-dielectric breakdown strengths of pure transformer oil and transformer-oil-based magnetic fluid showed better dielectric properties of magnetic fluid in external magnetic field and comparable, but not worse, in B = 0. Regarding to the better heat transfer, provided by magnetic fluids, they could be used in power transformers as insulating fluids.

A MEMS SOI-based piezoresistive fluid flow sensor

NASA Astrophysics Data System (ADS)

Tian, B.; Li, H. F.; Yang, H.; Song, D. L.; Bai, X. W.; Zhao, Y. L.

2018-02-01

In this paper, a SOI (silicon-on-insulator)-based piezoresistive fluid flow sensor is presented; the presented flow sensor mainly consists of a nylon sensing head, stainless steel cantilever beam, SOI sensor chip, printed circuit board, half-cylinder gasket, and stainless steel shell. The working principle of the sensor and some detailed contrastive analysis about the sensor structure were introduced since the nylon sensing head and stainless steel cantilever beam have distinct influence on the sensor performance; the structure of nylon sensing head and stainless steel cantilever beam is also discussed. The SOI sensor chip was fabricated using micro-electromechanical systems technologies, such as reactive ion etching and low pressure chemical vapor deposition. The designed fluid sensor was packaged and tested; a calibration installation system was purposely designed for the sensor experiment. The testing results indicated that the output voltage of the sensor is proportional to the square of the fluid flow velocity, which is coincident with the theoretical derivation. The tested sensitivity of the sensor is 3.91 × 10-4 V ms2/kg.

Magnetorheology of dimorphic magnetorheological fluids based on nanofibers

NASA Astrophysics Data System (ADS)

Bombard, Antonio J. F.; Gonçalves, Flavia R.; Morillas, Jose R.; de Vicente, Juan

2014-12-01

We report a systematic experimental investigation on the use of nanofibers to enhance the magnetorheological (MR) effect in conventional (microsphere-based) MR fluids formulated in polyalphaolefin oil/1-octanol. Two kinds of nanofibers are employed that have very similar morphology but very different magnetic properties. On the one hand we use non-magnetic goethite nanofibers. On the other hand we employ magnetic chromium dioxide nanofibers. For appropriate concentrations the on-state relative yield stress increases up to 80% when incorporating the nanofibers in the formulation. A similar yield stress enhancement is found for both nanofibers investigated (magnetic and non-magnetic) suggesting that the main factor behind this MR enhancement is the particle shape anisotropy. The relative yield stresses obtained by partial substitution of carbonyl iron particles with nanofibers are significantly larger than those measured in previous works on MR fluids formulated by partial substitution with non-magnetic micronsized spherical particles. We also demonstrate that these dimorphic MR fluids also exhibit remarkably larger long-term sedimentation stability while keeping the same penetration and redispersibility characteristics.

ASSESSING THE IMPACT OF SYNTHETIC-BASED DRILLING FLUIDS ON BENTHIC ORGANISMS IN TEMPERATE WATERS

EPA Science Inventory

Efforts to enhance the efficiency of oil/gas drilling operations and to minimize hazards to marine ecosystems have resulted in the increased use of synthetic-based fluids (SBF). SBFs have performance characteristics closely related to oil-based fluids (OBF) however their lower PA...

Light-Induced Gelling in a Micellar Fluid Based on a Zwitterionic Surfactant.

NASA Astrophysics Data System (ADS)

Kumar, Rakesh; Raghavan, Srinivasa

2007-03-01

Fluids with photoresponsive rheological properties (i.e. photorheological or PR fluids) can be useful in a range of applications, such as in dampers, sensors, and valves for microfluidic or MEMS devices. Previously, we have demonstrated a cationic surfactant-based PR fluid whose viscosity can be rapidly decreased by UV irradiation. This viscosity decrease was not reversible. Here, we describe a different formulation based on a zwitterionic surfactant that shows a rapid increase in viscosity (gelling) upon exposure to UV radiation. The formulation consists of the zwitterionic surfactant and a photosensitive cinnamic acid derivative. Initially, the viscosity of the fluid is low indicating the presence of small micelles. Upon UV irradiation, the cinnamic acid derivative is photoisomerized from trans to cis. In turn, the small micelles transform into long wormlike micelles, thus increasing the solution viscosity by more than five orders of magnitude. Small angle neutron scattering (SANS) data confirms the dramatic increase in micelle length. Possible reasons for such changes in micelle dimensions will be discussed.

Study on the effect of polymeric rheology modifier on the rheological properties of oil-based drilling fluids

NASA Astrophysics Data System (ADS)

Ma, C.; Li, L.; Yang, Y. P.; Hao, W. W.; Zhang, Q.; Lv, J.

2018-01-01

A new type of polymeric rheology modifier was synthesized by suspension polymerization, and the effect of rheology modifier on the rheological properties of oil-based drilling fluids was investigated. The results indicated that the obtained polymer had good capacity of improvement of shearing force of oil-based drilling fluids under high temperature and high pressure conditions. Moreover, the obtained polymer can improve the stability of oil-based drilling fluids greatly. As a result, the obtained polymer is a good rheology modifier for oil-based drilling fluids, and it can optimize oil-based drilling fluid system with good rheological properties, good static suspension ability for cuttings and environmental protection function. It can play an essential role in safe drilling jobs and improvement of drilling efficiency.

Long Duration Life Test of Propylene Glycol Water Based Thermal Fluid Within Thermal Control Loop

NASA Technical Reports Server (NTRS)

Le, Hung; Hill, Charles; Stephan, Ryan A.

2010-01-01

Evaluations of thermal properties and resistance to microbial growth concluded that 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture was desirable for use as a fluid within a vehicle s thermal control loop. However, previous testing with a commercial mixture of PG and water containing phosphate corrosion inhibitors resulted in corrosion of aluminum within the test system and instability of the test fluid. This paper describes a follow-on long duration testing and analysis of 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture with inorganic corrosion inhibitors used in place of phosphates. The test evaluates the long-term fluid stability and resistance to microbial and chemical changes

[Present status and trend of heart fluid mechanics research based on medical image analysis].

PubMed

Gan, Jianhong; Yin, Lixue; Xie, Shenghua; Li, Wenhua; Lu, Jing; Luo, Anguo

2014-06-01

With introduction of current main methods for heart fluid mechanics researches, we studied the characteristics and weakness for three primary analysis methods based on magnetic resonance imaging, color Doppler ultrasound and grayscale ultrasound image, respectively. It is pointed out that particle image velocity (PIV), speckle tracking and block match have the same nature, and three algorithms all adopt block correlation. The further analysis shows that, with the development of information technology and sensor, the research for cardiac function and fluid mechanics will focus on energy transfer process of heart fluid, characteristics of Chamber wall related to blood fluid and Fluid-structure interaction in the future heart fluid mechanics fields.

A diffusion tensor imaging tractography algorithm based on Navier-Stokes fluid mechanics.

PubMed

Hageman, Nathan S; Toga, Arthur W; Narr, Katherine L; Shattuck, David W

2009-03-01

We introduce a fluid mechanics based tractography method for estimating the most likely connection paths between points in diffusion tensor imaging (DTI) volumes. We customize the Navier-Stokes equations to include information from the diffusion tensor and simulate an artificial fluid flow through the DTI image volume. We then estimate the most likely connection paths between points in the DTI volume using a metric derived from the fluid velocity vector field. We validate our algorithm using digital DTI phantoms based on a helical shape. Our method segmented the structure of the phantom with less distortion than was produced using implementations of heat-based partial differential equation (PDE) and streamline based methods. In addition, our method was able to successfully segment divergent and crossing fiber geometries, closely following the ideal path through a digital helical phantom in the presence of multiple crossing tracts. To assess the performance of our algorithm on anatomical data, we applied our method to DTI volumes from normal human subjects. Our method produced paths that were consistent with both known anatomy and directionally encoded color images of the DTI dataset.

Electrostatically frequency tunable micro-beam-based piezoelectric fluid flow energy harvester

NASA Astrophysics Data System (ADS)

Rezaee, Mousa; Sharafkhani, Naser

2017-07-01

This research investigates the dynamic behavior of a sandwich micro-beam based piezoelectric energy harvester with electrostatically adjustable resonance frequency. The system consists of a cantilever micro-beam immersed in a fluid domain and is subjected to the simultaneous action of cross fluid flow and nonlinear electrostatic force. Two parallel piezoelectric laminates are extended along the length of the micro-beam and connected to an external electric circuit which generates an output power as a result of the micro-beam oscillations. The fluid-coupled structure is modeled using Euler-Bernoulli beam theory and the equivalent force terms for the fluid flow. Fluid induced forces comprise the added inertia force which is evaluated using equivalent added mass and the drag and lift forces which are evaluated using relative velocity and Van der Pol equation. In addition to flow velocity and fluid density, the influence of several design parameters such as external electrical resistance, piezo layer position, and dc voltage on the generated power are investigated by using Galerkin and step by step linearization method. It is shown that for given flowing fluid parameters, i.e., density and velocity, one can adjust the applied dc voltage to tune resonance frequency so that the lock-in phenomenon with steady large amplitude oscillations happens, also by adjusting the harvester parameters including the mechanical and electrical ones, the maximal output power of the harvester becomes possible.

The DC dielectric breakdown strength of magnetic fluids based on transformer oil

NASA Astrophysics Data System (ADS)

Kopčanský, Peter; Tomčo, Ladislav; Marton, Karol; Koneracká, Martina; Timko, Milan; Potočová, Ivana

2005-03-01

The DC dielectric breakdown strength of magnetic fluids based on transformer oil TECHNOL US 4000, with different saturation magnetizations, was investigated in various orientations of external magnetic field. It was shown that the dielectric breakdown strength in H∣∣ E is strongly influenced by the aggregation effects. As a boundary volume concentration of magnetic particles, below which the magnetic fluids have better dielectric properties than pure transformer oil, the volume concentration Φ=0.01 was found. Thus magnetic fluids with Φ<0.01 are suitable for the use as a high-voltage insulation.

Alternate working fluids for solar air conditioning applications

NASA Technical Reports Server (NTRS)

Evans, R. D.; Beck, J. K.

1978-01-01

An experimental investigation of sixteen different refrigerant-absorbent fluid pairs has been carried out in order to determine their suitability as the working fluid in a solar-powered absorption cycle air conditioner. The criteria used in the initial selection of a refrigerant-absorbent pair included: high affinity (large negative deviation from Raoult's Law), high solubility, low specific heat, low viscosity, stability, corrosive properties, safety, and cost. For practical solar considerations of a fluid pair, refrigerants were selected with low boiling points whereas absorbent fluids were selected with a boiling point considerably above that of the refrigerant. Additional restrictions are determined by the operating temperatures of the absorber and the generator; these temperatures were specified as 100 F (39 C) and 170 F (77 C). Data are presented for a few selected pressures at the specified absorber and generator temperatures.

Fluid-structural dynamics of ground-based and microgravity caloric tests

NASA Technical Reports Server (NTRS)

Kassemi, M.; Oas, J. G.; Deserranno, Dimitri

2005-01-01

Microgravity caloric tests aboard the 1983 SpaceLab1 mission produced nystagmus results with an intensity comparable to those elicited during post- and pre- flight tests, thus contradicting the basic premise of Barany's convection hypothesis for caloric stimulation. In this work, we present a dynamic fluid structural analysis of the caloric stimulation of the lateral semicircular canal based on two simultaneous driving forces for the endolymphatic flow: natural convection driven by the temperature-dependent density variation in the bulk fluid and expansive convection caused by direct volumetric displacement of the endolymph during the thermal irrigation. Direct numerical simulations indicate that on earth, the natural convection mechanism is dominant. But in the microgravity environment of orbiting spacecraft, where buoyancy effects are mitigated, expansive convection becomes the sole mechanism for producing cupular displacement. A series of transient 1 g and microgravity case studies are presented to delineate the differences between the dynamics of the 1 g and microgravity endolymphatic flows. The impact of these different flow dynamics on the endolymph-cupula fluid-structural interactions is also analyzed based on the time evolutions of cupular displacement and velocity and the transcupular pressure differences.

Fluid-structural dynamics of ground-based and microgravity caloric tests.

PubMed

Kassemi, M; Oas, J G; Deserranno, Dimitri

2005-01-01

Microgravity caloric tests aboard the 1983 SpaceLab1 mission produced nystagmus results with an intensity comparable to those elicited during post- and pre- flight tests, thus contradicting the basic premise of Barany's convection hypothesis for caloric stimulation. In this work, we present a dynamic fluid structural analysis of the caloric stimulation of the lateral semicircular canal based on two simultaneous driving forces for the endolymphatic flow: natural convection driven by the temperature-dependent density variation in the bulk fluid and expansive convection caused by direct volumetric displacement of the endolymph during the thermal irrigation. Direct numerical simulations indicate that on earth, the natural convection mechanism is dominant. But in the microgravity environment of orbiting spacecraft, where buoyancy effects are mitigated, expansive convection becomes the sole mechanism for producing cupular displacement. A series of transient 1 g and microgravity case studies are presented to delineate the differences between the dynamics of the 1 g and microgravity endolymphatic flows. The impact of these different flow dynamics on the endolymph-cupula fluid-structural interactions is also analyzed based on the time evolutions of cupular displacement and velocity and the transcupular pressure differences.

Numerical simulation of nanofluids based on power-law fluids with flow and heat transfer

NASA Astrophysics Data System (ADS)

Li, Lin; Jiang, Yongyue; Chen, Aixin

2017-04-01

In this paper, we investigate the heat transfer of nanofluids based on power-law fluids and movement of nanoparticles with the effect of thermophoresis in a rotating circular groove. The velocity of circular groove rotating is a constant and the temperature on the wall is kept to be zero all the time which is different from the temperature of nanofluids in the initial time. The effects of thermophoresis and Brownian diffusion are considered in temperature and concentration equations, and it is assumed that the thermal conductivity of nanofluids is a function of concentration of nanoparticles. Based on numerical results, it can be found that nanofluids improve the process of heat transfer than base fluids in a rotating circular groove. The enhancement of heat transfer increases as the power law index of base fluids decreases.

Method and Apparatus for Measuring Fluid Flow

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Nguyen, Than X. (Inventor); Carl, James R. (Inventor)

1995-01-01

The invention is a method and apparatus for monitoring the presence, concentration, and the movement of fluids. It is based on utilizing electromagnetic measurements of the complex permittivity of the fluids for detecting and monitoring the fluid. More particularly the apparatus uses one or more microwave probes which are placed at the locations where the measurements are to be made. A radio frequency signal is transmitted to the probe and the reflected signal is phase and amplitude detected at a rapid rate for the purpose of identifying the fluids, based on their dielectric constant at the probe. The apparatus can be used for multiple purposes including measures of flow rates, turbulence, dispersion, fluid identification, and changes in flow conditions of multiple fluids or multiple states of a single fluid in a flowline or a holding container. The apparatus includes a probe consisting of two electrical conductors separated by an insulator. A radio frequency signal is communicated to the probe and is reflected back from the portion of the probe exposed to the fluid. The radio frequency signal also provides a reference signal. An oscillator generates a second signal which combined with each of the reference signal and the reflected signal to produce signals of lower frequencies to facilitate filtering and amplifying those signals. The two signals are then mixed in a detector to produce an output signal that is representative of the phase and amplitude change caused by the reflection of the signal at the probe exposed to the fluid. The detector may be a dual phase detector that provides two such output signals that are in phase quadrature. A phase shifter may be provided for selectively changing the phase of the reference signal to improve the sensitivity of at least one of the output signals for more accurate readings and/or for calibration purposes. The two outputs that are in quadrature with respect to each other may be simultaneously monitored to account for

Liquid metal batteries - materials selection and fluid dynamics

NASA Astrophysics Data System (ADS)

Weier, T.; Bund, A.; El-Mofid, W.; Horstmann, G. M.; Lalau, C.-C.; Landgraf, S.; Nimtz, M.; Starace, M.; Stefani, F.; Weber, N.

2017-07-01

Liquid metal batteries are possible candidates for massive and economically feasible large-scale stationary storage and as such could be key components of future energy systems based mainly or exclusively on intermittent renewable electricity sources. The completely liquid interior of liquid metal batteries and the high current densities give rise to a multitude of fluid flow phenomena that will primarily influence the operation of future large cells, but might be important for today’s smaller cells as well. The paper at hand starts with a discussion of the relative merits of using molten salts or ionic liquids as electrolytes for liquid metal cells and touches the choice of electrode materials. This excursus into electrochemistry is followed by an overview of investigations on magnetohydrodynamic instabilities in liquid metal batteries, namely the Tayler instability and electromagnetically excited gravity waves. A section on electro-vortex flows complements the discussion of flow phenomena. Focus of the flow related investigations lies on the integrity of the electrolyte layer and related critical parameters.

Immunisations and antibiotics in patients with anterior skull base cerebrospinal fluid leaks.

PubMed

Rimmer, J; Belk, C; Lund, V J; Swift, A; White, P

2014-07-01

There are no UK guidelines for the use of antibiotics and/or immunisations in patients with an active anterior skull base cerebrospinal fluid leak. This study aimed to define current UK practice in this area and inform appropriate guidelines for ENT surgeons. A web-based survey of all members of the British Rhinological Society was carried out and the literature in this area was reviewed. Of those who responded to the survey, 14 per cent routinely give prophylactic antibiotics to patients with cerebrospinal fluid leaks, and 34.9 per cent recommend immunisation against at least one organism, most commonly Streptococcus pneumoniae (86.7 per cent). There is no evidence to support the use of antibiotic prophylaxis in patients with a cerebrospinal fluid leak. We propose that all such patients are advised to seek immunisation against pneumococcus, meningococcus and haemophilus.

A universal constraint-based formulation for freely moving immersed bodies in fluids

NASA Astrophysics Data System (ADS)

Patankar, Neelesh A.

2012-11-01

Numerical simulation of moving immersed bodies in fluids is now practiced routinely. A variety of variants of these approaches have been published, most of which rely on using a background mesh for the fluid equations and tracking the body using Lagrangian points. In this talk, generalized constraint-based governing equations will be presented that provide a unified framework for various immersed body techniques. The key idea that is common to these methods is to assume that the entire fluid-body domain is a ``fluid'' and then to constrain the body domain to move in accordance with its governing equations. The immersed body can be rigid or deforming. The governing equations are developed so that they are independent of the nature of temporal or spatial discretization schemes. Specific choices of time stepping and spatial discretization then lead to techniques developed in prior literature ranging from freely moving rigid to elastic self-propelling bodies. To simulate Brownian systems, thermal fluctuations can be included in the fluid equations via additional random stress terms. Solving the fluctuating hydrodynamic equations coupled with the immersed body results in the Brownian motion of that body. The constraint-based formulation leads to fractional time stepping algorithms a la Chorin-type schemes that are suitable for fast computations of rigid or self-propelling bodies whose deformation kinematics are known. Support from NSF is gratefully acknowledged.

Self-reconfigurable ship fluid-network modeling for simulation-based design

NASA Astrophysics Data System (ADS)

Moon, Kyungjin

Our world is filled with large-scale engineering systems, which provide various services and conveniences in our daily life. A distinctive trend in the development of today's large-scale engineering systems is the extensive and aggressive adoption of automation and autonomy that enable the significant improvement of systems' robustness, efficiency, and performance, with considerably reduced manning and maintenance costs, and the U.S. Navy's DD(X), the next-generation destroyer program, is considered as an extreme example of such a trend. This thesis pursues a modeling solution for performing simulation-based analysis in the conceptual or preliminary design stage of an intelligent, self-reconfigurable ship fluid system, which is one of the concepts of DD(X) engineering plant development. Through the investigations on the Navy's approach for designing a more survivable ship system, it is found that the current naval simulation-based analysis environment is limited by the capability gaps in damage modeling, dynamic model reconfiguration, and simulation speed of the domain specific models, especially fluid network models. As enablers of filling these gaps, two essential elements were identified in the formulation of the modeling method. The first one is the graph-based topological modeling method, which will be employed for rapid model reconstruction and damage modeling, and the second one is the recurrent neural network-based, component-level surrogate modeling method, which will be used to improve the affordability and efficiency of the modeling and simulation (M&S) computations. The integration of the two methods can deliver computationally efficient, flexible, and automation-friendly M&S which will create an environment for more rigorous damage analysis and exploration of design alternatives. As a demonstration for evaluating the developed method, a simulation model of a notional ship fluid system was created, and a damage analysis was performed. Next, the models

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

PubMed

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

A Diffusion Tensor Imaging Tractography Algorithm Based on Navier-Stokes Fluid Mechanics

PubMed Central

Hageman, Nathan S.; Toga, Arthur W.; Narr, Katherine; Shattuck, David W.

2009-01-01

We introduce a fluid mechanics based tractography method for estimating the most likely connection paths between points in diffusion tensor imaging (DTI) volumes. We customize the Navier-Stokes equations to include information from the diffusion tensor and simulate an artificial fluid flow through the DTI image volume. We then estimate the most likely connection paths between points in the DTI volume using a metric derived from the fluid velocity vector field. We validate our algorithm using digital DTI phantoms based on a helical shape. Our method segmented the structure of the phantom with less distortion than was produced using implementations of heat-based partial differential equation (PDE) and streamline based methods. In addition, our method was able to successfully segment divergent and crossing fiber geometries, closely following the ideal path through a digital helical phantom in the presence of multiple crossing tracts. To assess the performance of our algorithm on anatomical data, we applied our method to DTI volumes from normal human subjects. Our method produced paths that were consistent with both known anatomy and directionally encoded color (DEC) images of the DTI dataset. PMID:19244007

Fluid identification based on P-wave anisotropy dispersion gradient inversion for fractured reservoirs

NASA Astrophysics Data System (ADS)

Zhang, J. W.; Huang, H. D.; Zhu, B. H.; Liao, W.

2017-10-01

Fluid identification in fractured reservoirs is a challenging issue and has drawn increasing attentions. As aligned fractures in subsurface formations can induce anisotropy, we must choose parameters independent with azimuths to characterize fractures and fluid effects such as anisotropy parameters for fractured reservoirs. Anisotropy is often frequency dependent due to wave-induced fluid flow between pores and fractures. This property is conducive for identifying fluid type using azimuthal seismic data in fractured reservoirs. Through the numerical simulation based on Chapman model, we choose the P-wave anisotropy parameter dispersion gradient (PADG) as the new fluid factor. PADG is dependent both on average fracture radius and fluid type but independent on azimuths. When the aligned fractures in the reservoir are meter-scaled, gas-bearing layer could be accurately identified using PADG attribute. The reflection coefficient formula for horizontal transverse isotropy media by Rüger is reformulated and simplified according to frequency and the target function for inverting PADG based on frequency-dependent amplitude versus azimuth is derived. A spectral decomposition method combining Orthogonal Matching Pursuit and Wigner-Ville distribution is used to prepare the frequency-division data. Through application to synthetic data and real seismic data, the results suggest that the method is useful for gas identification in reservoirs with meter-scaled fractures using high-qualified seismic data.

Heat transfer fluids containing nanoparticles

DOEpatents

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.

Analysis of organophosphate hydraulic fluids in U.S. Air force base soils

PubMed

David; Seiber

1999-04-01

Tri-aryl and tri-alkyl organophosphates (TAPs) have been used extensively as flame-retardant hydraulic fluids and fluid additives in commercial and military aircraft. Up to 80% of the consumption of these fluids has been estimated to be lost to unrecovered leakage. Tri-aryl phosphate components of these fluids are resistant to volatilization and solubilization in water, thus, their primary environmental fate pathway is sorption to soils. Environmental audits of military air bases generally do not include quantification of these compounds in soils. We have determined the presence and extent of TAP contamination in soil samples from several U.S. Air Force bases. Soils were collected, extracted, and analyzed using GC/FPD and GC/MS. Tricresyl phosphate was the most frequently found TAP in soil, ranging from 0.02 to 130 ppm. Other TAPs in soils included triphenyl phosphate and isopropylated triphenyl phosphate. Observations are made regarding the distribution, typical concentrations, persistence, and need for further testing of TAPs in soils at military installations. Additionally, GC and mass spectral data for these TAPs are presented, along with methods for their extraction, sample clean-up, and quantification.

Knowledge Of Maintenance Intravenous Fluid Therapy In Acutely Ill Hospitalized Children Among Residents.

PubMed

Haque, Anwarul; Mirza, Sadiq; Jafri, Sidra Kaleem; Naseem, Faizia; Khan, Khalid Mahmood; Afzal, Muhammad Faheem; Hamid, Muhammad Haroon

2016-01-01

Isotonic saline is recommended as maintenance intravenous fluid therapy (MIVFT) for most of the acutely ill hospitalized children. The aim of this study is to assess the current knowledge of paediatric residents regarding the selection of MIVFT in hospitalized children. We conducted a paper-based questionnaire survey to paediatric residents from ten centres asking selection of MIVFT in four common clinical scenarios in 6-month and 10-year old patients as well as monitoring of fluid balance and electrolyte. 445 responses were collected (>90% response rate). Majority [78.3% (n=348)] of them were FCPS-trainees. The 0.9%, 0.45% and 0.2% solution were selected by 45.8%, 43.98% and 10.92% respectively. The isotonic and hypotonic solution was prescribed in 6- mo (35.22% vs. 64.76% [p<0.001]) and 10-year (54.49% vs. 44.98%) in four different clinical scenarios respectively. 0.45% solution was most commonly prescribed MIVFT in pneumonia (50.22%) and meningitis (45.39%) and 0.9% solution was most commonly selected in acute gastroenteritis (55.05%) and post-operative patients (51.23%). Fluid balance and electrolyte monitoring were selected by 96.9% and 55.7% respondents respectively. Our survey reports that more than fifty percent of paediatric residents have inadequate knowledge about maintenance intravenous fluid therapy in acutely ill hospitalized children.

Magnetic field sensor based on cascaded microfiber coupler with magnetic fluid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, Lianmin; Su, Delong; Wang, Zhaofang

A kind of magnetic field sensor based on cascaded microfiber coupler with magnetic fluid is proposed and experimentally demonstrated. The magnetic fluid is utilized as the cladding of the fused regions of the cascaded microfiber coupler. As the interference valley wavelength of the sensing structure is sensitive to the ambient variation, considering the magnetic-field-dependent refractive index of magnetic fluid, the proposed structure is employed for magnetic field sensing. The effective coupling length for each coupling region of the as-fabricated cascaded microfiber coupler is 6031 μm. The achieved sensitivity is 125 pm/Oe, which is about three times larger than that of the previouslymore » similar structure based on the single microfiber coupler. Experimental results indicate that the sensing sensitivity can be easily improved by increasing the effective coupling length or cascading more microfiber couplers. The proposed magnetic field sensor is attractive due to its low cost, immunity to electromagnetic interference, as well as high sensitivity, which also has the potentials in other tunable all-fiber photonic devices, such as filter.« less

Electrodeposition of metals from supercritical fluids

PubMed Central

Ke, Jie; Su, Wenta; Howdle, Steven M.; George, Michael W.; Cook, David; Perdjon-Abel, Magda; Bartlett, Philip N.; Zhang, Wenjian; Cheng, Fei; Levason, William; Reid, Gillian; Hyde, Jason; Wilson, James; Smith, David C.; Mallik, Kanad; Sazio, Pier

2009-01-01

Electrodeposition is a widely used materials-deposition technology with a number of unique features, in particular, the efficient use of starting materials, conformal, and directed coating. The properties of the solvent medium for electrodeposition are critical to the technique's applicability. Supercritical fluids are unique solvents which give a wide range of advantages for chemistry in general, and materials processing in particular. However, a widely applicable approach to electrodeposition from supercritical fluids has not yet been developed. We present here a method that allows electrodeposition of a range of metals from supercritical carbon dioxide, using acetonitrile as a co-solvent and supercritical difluoromethane. This method is based on a careful selection of reagent and supporting electrolyte. There are no obvious barriers preventing this method being applied to deposit a range of materials from many different supercritical fluids. We present the deposition of 3-nm diameter nanowires in mesoporous silica templates using this methodology. PMID:19706479

Supercritical fluid extraction of selected pharmaceuticals from water and serum.

PubMed

Simmons, B R; Stewart, J T

1997-01-24

Selected drugs from benzodiazepine, anabolic agent and non-steroidal anti-inflammatory drug (NSAID) therapeutic classes were extracted from water and serum using a supercritical CO2 mobile phase. The samples were extracted at a pump pressure of 329 MPa, an extraction chamber temperature of 45 degrees C, and a restrictor temperature of 60 degrees C. The static extraction time for all samples was 2.5 min and the dynamic extraction time ranged from 5 to 20 min. The analytes were collected in appropriate solvent traps and assayed by modified literature HPLC procedures. Analyte recoveries were calculated based on peak height measurements of extracted vs. unextracted analyte. The recovery of the benzodiazepines ranged from 80 to 98% in water and from 75 to 94% in serum. Anabolic drug recoveries from water and serum ranged from 67 to 100% and 70 to 100%, respectively. The NSAIDs were recovered from water in the 76 to 97% range and in the 76 to 100% range from serum. Accuracy, precision and endogenous peak interference, if any, were determined for blank and spiked serum extractions and compared with classical sample preparation techniques of liquid-liquid and solid-phase extraction reported in the literature. For the benzodiazepines, accuracy and precision for supercritical fluid extraction (SFE) ranged from 1.95 to 3.31 and 0.57 to 1.25%, respectively (n = 3). The SFE accuracy and precision data for the anabolic agents ranged from 4.03 to 7.84 and 0.66 to 2.78%, respectively (n = 3). The accuracy and precision data reported for the SFE of the NSAIDs ranged from 2.79 to 3.79 and 0.33 to 1.27%, respectively (n = 3). The precision of the SFE method from serum was shown to be comparable to the precision obtained with other classical preparation techniques.

The wettability and swelling of selected mucoadhesive polymers in simulated saliva and vaginal fluids.

PubMed

Rojewska, M; Olejniczak-Rabinek, M; Bartkowiak, A; Snela, A; Prochaska, K; Lulek, J

2017-08-01

The surface properties play a particularly important role in the mucoadhesive drug delivery systems. In these formulations, the adsorption of polymer matrix to mucous membrane is limited by the wetting and swelling process of the polymer structure. Hence, the performance of mucoadhesive drug delivery systems made of polymeric materials depends on multiple factors, such as contact angle, surface free energy and water absorption rate. The aim of our study was to analyze the effect of model saliva and vaginal fluids on the wetting properties of selected mucoadhesive (Carbopol 974P NF, Noveon AA-1, HEC) and film-forming (Kollidon VA 64) polymers as well as their blends at the weight ratio 1:1 and 1:1:1, prepared in the form of discs. Surface properties of the discs were determined by measurements of advancing contact angle on the surface of polymers and their blends using the sessile drop method. The surface energy was determined by the OWRK method. Additionally, the mass swelling factor and hydration percentage of examined polymers and their blends in simulated biological fluids were evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Selective detection of underivatized 2,4-dichlorophenoxyacetic acid in soil by supercritical fluid chromatography with ion mobility detection.

PubMed

Morrissey, M A; Hill, H H

1989-09-01

A simplified procedure was developed for the determination of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils. Soil samples were separated by supercritical fluid chromatography after extraction without derivatization and without the use of column chromatography for cleanup. Interferences in the chromatographic separation were eliminated by using a tunably selective ion mobility detector. An atmospheric pressure ion formed by the free acid was selectively monitored so the detector could monitor 2,4-D in the presence of other electron-capturing compounds. For a randomly chosen soil sample, the level of 2,4-D detected was estimated at 500 ppb.

Electrowetting (EW)-based valve combined with hydrophilic teflon microfluidic guidance in controlling continuous fluid flow.

PubMed

Cheng, Ji-Yen; Hsiung, Lo-Chang

2004-12-01

Electrowetting (EW)-based techniques have been widely used in manipulating discrete liquid. However, few articles discussed the controlling of continuous fluid flow by using EW-based techniques. In this paper, an EW-based valve combined with plasma-modified Teflon surface, which serves as a microfluidic guidance, in controlling continuous fluid flow has been demonstrated. The plasma-modified Teflon surface is firstly demonstrated for confining continuous fluid flow. The EW-based microfluidic device possesses the functions of a valve and a microchannel without complex moving parts and grooved microchannels. The quantitative characteristics of the EW-based valve are also studied. Propylene carbonate (PC) is firstly demonstrated as the working liquid in the EW-based device because of its applications in parallel oligonucleotide synthesis. It is found that lower valve actuation voltage reduces the deterioration of the valve and improves the valve stability.

Intravenous Fluid Mixing in Normal Gravity, Partial Gravity, and Microgravity: Down-Selection of Mixing Methods

NASA Technical Reports Server (NTRS)

Niederhaus, Charles E.; Miller, Fletcher J.

2008-01-01

The missions envisioned under the Vision for Space Exploration will require development of new methods to handle crew medical care. Medications and intravenous (IV) fluids have been identified as one area needing development. Storing certain medications and solutions as powders or concentrates can both increase the shelf life and reduce the overall mass and volume of medical supplies. The powders or concentrates would then be mixed in an IV bag with Sterile Water for Injection produced in situ from the potable water supply. Fluid handling in microgravity is different than terrestrial settings, and requires special consideration in the design of equipment. This document describes the analyses and down-select activities used to identify the IV mixing method to be developed that is suitable for ISS and exploration missions. The chosen method is compatible with both normal gravity and microgravity, maintains sterility of the solution, and has low mass and power requirements. The method will undergo further development, including reduced gravity aircraft experiments and computations, in order to fully develop the mixing method and associated operational parameters.

Systems, compositions, and methods for fluid purification

DOEpatents

Ho, W.S. Winston; Verweij, Hendrik; Shqau, Krenar; Ramasubranian, Kartik

2015-12-22

Disclosed herein are membranes comprising a substrate, a support layer, and a selective layer. In some embodiments the membrane may further comprise a permeable layer. Methods of forming membranes are also disclosed comprising forming a support layer on a substrate, removing adsorbed species from the support layer, preparing a solution containing inorganic materials of a selective layer, contacting the support layer with the solution, drying the membrane, and exposing the membrane to rapid thermal processing. Also disclosed are methods of fluid purification comprising providing a membrane having a feed side and a permeable side, passing a fluid mixture across the feed side of the membrane, providing a driving force for transmembrane permeation, removing from the permeate side a permeate stream enriched in a purified fluid, and withdrawing from the feed side a fluid that is depleted in a purified fluid.

Serum and peritoneal fluid concentrations of soluble human leukocyte antigen, tumor necrosis factor alpha and interleukin 10 in patients with selected ovarian pathologies.

PubMed

Sipak-Szmigiel, Olimpia; Włodarski, Piotr; Ronin-Walknowska, Elżbieta; Niedzielski, Andrzej; Karakiewicz, Beata; Słuczanowska-Głąbowska, Sylwia; Laszczyńska, Maria; Malinowski, Witold

2017-04-04

Although immune system plays a key role in the pathogenesis of both endometriosis and ovarian cancer, its function is different. Therefore, we hypothesized, that selected immune parameters can serve as diagnostic markers of these two conditions. The aim of this study was to compare serum and peritoneal fluid concentrations of sHLA-G, IL-10 and TNF-alpha in women with selected ovarian pathologies: benign serous cysts, endometrioma and malignant tumors. Clinical significance of using them for diagnostic purposes in women with serous ovarian cysts, endometriosis, and ovarian cancer, which in the future may improve the early diagnosis of ovarian diseases. The study included women treated surgically for benign serous ovarian cysts, ovarian endometrioma and serous ovarian adenocarcinomas. Peripheral blood and peritoneal fluid samples were obtained intraoperatively. Patients with benign serous cysts, endometrioma and ovarian malignancies did not differ significantly in terms of their serum and peritoneal fluid concentrations of sHLA-G. Ovarian cancer patients presented with significantly higher median serum concentrations of IL-10 and TNF-alpha than other study subjects. Median concentrations of IL-10 and TNF-alpha in peritoneal fluid turned out to be the highest in ovarian cancer patients, followed by women with endometrioma and subjects with benign serous cysts. All these intergroup differences were statistically significant. Irrespective of the group, median concentrations of sHLA-G, IL-10 and TNF-alpha in peritoneal fluid were higher than serum levels of these markers. Elevated serum and peritoneal fluid concentrations of IL-10 and TNF-alpha distinguish ovarian malignancies and endometriomas from benign serous ovarian cysts. In contrast to endometriosis, ovarian malignancies are characterized by elevated peritoneal fluid concentrations of IL-10 and TNF-alpha, elevated serum concentrations of IL-10 and low serum levels of TNF-alpha. Serum and peritoneal fluid

Fluid mechanics in fluids at rest.

PubMed

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.

Experimental analysis to improving thermosyphon (TPCT) thermal efficiency using nanoparticles/based fluids (water)

NASA Astrophysics Data System (ADS)

Hoseinzadeh, S.; Sahebi, S. A. R.; Ghasemiasl, R.; Majidian, A. R.

2017-05-01

In the present study an experimental set-up is used to investigate the effect of a nanofluid as a working fluid to increase thermosyphon efficiency. Nanofluids are a new form of heat transfer media prepared by suspending metallic and nonmetallic nanoparticles in a base fluid. The nanoparticles added to the fluid enhance the thermal characteristics of the base fluid. The nanofluid used in this experiment was a mixture of water and nanoparticles prepared with 0.5%, 1%, 1.5%, or 2% (v) concentration of silicon carbide (SiC) nanoparticles and 1%, 2% and 3% (v) concentration of aluminum oxide (Al2O3) in an ultrasonic homogenizer. The results indicate that the SiC/water and Al2O3/water nanofluids increase the thermosyphon performance. The efficiency of the thermosyphon using the 2% (v) (SiC) nanoparticles nanofluid was 1.11 times that of pure water and the highest efficiency occurs for the 3% (Al2O3) nanoparticle concentration with input power of 300 W. The decrease in the temperature difference between the condenser and evaporator confirms these enhancements.

Breakdown of single spin-fluid model in the heavily hole-doped superconductor CsFe2As2

NASA Astrophysics Data System (ADS)

Zhao, D.; Li, S. J.; Wang, N. Z.; Li, J.; Song, D. W.; Zheng, L. X.; Nie, L. P.; Luo, X. G.; Wu, T.; Chen, X. H.

2018-01-01

Although Fe-based superconductors are correlated electronic systems with multiorbital, previous nuclear magnetic resonance (NMR) measurement suggests that a single spin-fluid model is sufficient to describe its spin behavior. Here, we first observed the breakdown of single spin-fluid model in a heavily hole-doped Fe-based superconductor CsFe2As2 by site-selective NMR measurement. At high-temperature regime, both Knight shift and nuclear spin-lattice relaxation at 133Cs and 75As nuclei exhibit distinct temperature-dependent behavior, suggesting the breakdown of the single spin-fluid model in CsFe2As2 . This is ascribed to the coexistence of both localized and itinerant spin degree of freedom at 3 d orbitals, which is consistent with the orbital-selective Mott phase. With decreasing temperature, the single spin-fluid behavior is recovered below T*˜75 K due to a coherent state among 3 d orbitals. The Kondo liquid scenario is proposed to understand the low-temperature coherent state.

An EQT-based cDFT approach for thermodynamic properties of confined fluid mixtures

NASA Astrophysics Data System (ADS)

Motevaselian, M. H.; Aluru, N. R.

2017-04-01

We present an empirical potential-based quasi-continuum theory (EQT) to predict the structure and thermodynamic properties of confined fluid mixtures. The central idea in the EQT is to construct potential energies that integrate important atomistic details into a continuum-based model such as the Nernst-Planck equation. The EQT potentials can be also used to construct the excess free energy functional, which is required for the grand potential in the classical density functional theory (cDFT). In this work, we use the EQT-based grand potential to predict various thermodynamic properties of a confined binary mixture of hydrogen and methane molecules inside graphene slit channels of different widths. We show that the EQT-cDFT predictions for the structure, surface tension, solvation force, and local pressure tensor profiles are in good agreement with the molecular dynamics simulations. Moreover, we study the effect of different bulk compositions and channel widths on the thermodynamic properties. Our results reveal that the composition of methane in the mixture can significantly affect the ordering of molecules and thermodynamic properties under confinement. In addition, we find that graphene is selective to methane molecules.

Synthesis and Performance Evaluation of a New Deoiling Agent for Treatment of Waste Oil-Based Drilling Fluids

PubMed Central

Liu, Pingting; Huang, Zhiyu; Deng, Hao; Wang, Rongsha; Xie, Shuixiang

2014-01-01

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent (SDA), as a novel surfactant for treatment of waste oil-based drilling fluid, was synthesized by amine, formic acid, and formaldehyde solution. With this agent, the waste oil-based drilling fluid can be treated without complex process and expensive equipment. Furthermore, the agent used in the treatment can be recycled, which reduces waste of resource and energy. The switch performance, deoiling performance, structural characterization, and mechanisms of action are studied. The experimental results show that the oil content of the recycled oil is higher than 96% and more than 93% oil in waste oil-based drilling fluid can be recycled. The oil content of the solid residues of deoiling is less than 3%. PMID:25045749

Synthesis and performance evaluation of a new deoiling agent for treatment of waste oil-based drilling fluids.

PubMed

Liu, Pingting; Huang, Zhiyu; Deng, Hao; Wang, Rongsha; Xie, Shuixiang

2014-01-01

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent (SDA), as a novel surfactant for treatment of waste oil-based drilling fluid, was synthesized by amine, formic acid, and formaldehyde solution. With this agent, the waste oil-based drilling fluid can be treated without complex process and expensive equipment. Furthermore, the agent used in the treatment can be recycled, which reduces waste of resource and energy. The switch performance, deoiling performance, structural characterization, and mechanisms of action are studied. The experimental results show that the oil content of the recycled oil is higher than 96% and more than 93% oil in waste oil-based drilling fluid can be recycled. The oil content of the solid residues of deoiling is less than 3%.

Pressure-Responsive, Surfactant-Free CO2-Based Nanostructured Fluids

PubMed Central

2017-01-01

Microemulsions are extensively used in advanced material and chemical processing. However, considerable amounts of surfactant are needed for their formulation, which is a drawback due to both economic and ecological reasons. Here, we describe the nanostructuration of recently discovered surfactant-free, carbon dioxide (CO2)-based microemulsion-like systems in a water/organic-solvent/CO2 pressurized ternary mixture. “Water-rich” nanodomains embedded into a “water-depleted” matrix have been observed and characterized by the combination of Raman spectroscopy, molecular dynamics simulations, and small-angle neutron scattering. These single-phase fluids show a reversible, pressure-responsive nanostructuration; the “water-rich” nanodomains at a given pressure can be instantaneously degraded/expanded by increasing/decreasing the pressure, resulting in a reversible, rapid, and homogeneous mixing/demixing of their content. This pressure-triggered responsiveness, together with other inherent features of these fluids, such as the absence of any contaminant in the ternary mixture (e.g., surfactant), their spontaneous formation, and their solvation capability (enabling the dissolution of both hydrophobic and hydrophilic molecules), make them appealing complex fluid systems to be used in molecular material processing and in chemical engineering. PMID:28846386

Electrorheological Fluids with High Shear Stress Based on Wrinkly Tin Titanyl Oxalate.

PubMed

Wu, Jinghua; Zhang, Lei; Xin, Xing; Zhang, Yang; Wang, Hui; Sun, Aihua; Cheng, Yuchuan; Chen, Xinde; Xu, Gaojie

2018-02-21

Electrorheological (ER) fluids are considered as a type of smart fluids because their rheological characteristics can be altered through an electric field. The discovery of giant ER effect revived the researchers' interest in the ER technological area. However, the poor stability including the insufficient dynamic shear stress, the large leakage current density, and the sedimentation tendency still hinders their practical applications. Herein, we report a facile and scalable coprecipitation method for synthesizing surfactant-free tin titanyl oxalate (TTO) particles with tremella-like wrinkly microstructure (W-TTO). The W-TTO-based ER fluids exhibit enhanced ER activity compared to that of the pristine TTO because of the improved wettability between W-TTO and the silicone oil. In addition, the static yield stress and leakage current of W-TTO ER fluids also show a fine time stability during the 30 day tests. More importantly, the dynamic shear stress of W-TTO ER fluids can remain stable throughout the shear rate range, which is valuable for their use in engineering applications. The results in this work provided a promising strategy to solving the long-standing problem of ER fluid stability. Moreover, this convenient route of synthesis may be considered a green approach for the mass production of giant ER materials.

FluidCam 1&2 - UAV-based Fluid Lensing Instruments for High-Resolution 3D Subaqueous Imaging and Automated Remote Biosphere Assessment of Reef Ecosystems

NASA Astrophysics Data System (ADS)

Chirayath, V.; Instrella, R.

2016-02-01

We present NASA ESTO FluidCam 1 & 2, Visible and NIR Fluid-Lensing-enabled imaging payloads for Unmanned Aerial Vehicles (UAVs). Developed as part of a focused 2014 earth science technology grant, FluidCam 1&2 are Fluid-Lensing-based computational optical imagers designed for automated 3D mapping and remote sensing of underwater coastal targets from airborne platforms. Fluid Lensing has been used to map underwater reefs in 3D in American Samoa and Hamelin Pool, Australia from UAV platforms at sub-cm scale, which has proven a valuable tool in modern marine research for marine biosphere assessment and conservation. We share FluidCam 1&2 instrument validation and testing results as well as preliminary processed data from field campaigns. Petabyte-scale aerial survey efforts using Fluid Lensing to image at-risk reefs demonstrate broad applicability to large-scale automated species identification, morphology studies and reef ecosystem characterization for shallow marine environments and terrestrial biospheres, of crucial importance to improving bathymetry data for physical oceanographic models and understanding climate change's impact on coastal zones, global oxygen production, carbon sequestration.

FluidCam 1&2 - UAV-Based Fluid Lensing Instruments for High-Resolution 3D Subaqueous Imaging and Automated Remote Biosphere Assessment of Reef Ecosystems

NASA Astrophysics Data System (ADS)

Chirayath, V.

2015-12-01

We present NASA ESTO FluidCam 1 & 2, Visible and NIR Fluid-Lensing-enabled imaging payloads for Unmanned Aerial Vehicles (UAVs). Developed as part of a focused 2014 earth science technology grant, FluidCam 1&2 are Fluid-Lensing-based computational optical imagers designed for automated 3D mapping and remote sensing of underwater coastal targets from airborne platforms. Fluid Lensing has been used to map underwater reefs in 3D in American Samoa and Hamelin Pool, Australia from UAV platforms at sub-cm scale, which has proven a valuable tool in modern marine research for marine biosphere assessment and conservation. We share FluidCam 1&2 instrument validation and testing results as well as preliminary processed data from field campaigns. Petabyte-scale aerial survey efforts using Fluid Lensing to image at-risk reefs demonstrate broad applicability to large-scale automated species identification, morphology studies and reef ecosystem characterization for shallow marine environments and terrestrial biospheres, of crucial importance to improving bathymetry data for physical oceanographic models and understanding climate change's impact on coastal zones, global oxygen production, carbon sequestration.

Selective Recovery of Critical Materials from Geothermal Fluid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayes, Richard T.; Halstenberg, Phillip W.; Moyer, Bruce A.

This project, funded by the DOE Small Business Voucher program, assisted the partner with the development of ion-imprinted adsorbents for the selective extraction of rare earth elements (REE) from geothermal brines. This effort seeks to utilize a currently untapped resource thus diversifying the U. S. REE market. The initial stage of the program focused on the adsorbent developed by partner and optimization of the adsorbent. The adsorbent was based upon an ion imprinted ligand that was copolymerized with a crosslinker to generate the REE selectivity. During this task, the adsorbents were irradiated via electron beam at the NEO Beam Electronmore » Beam Crosslinking Facility (Mercury Plastics, Middlefield, OH) to induce further crosslinking. The irradiation crosslinked adsorbents exhibited no difference in the Fourier transform infrared spectroscopic (FTIR) analysis suggesting inefficiency in the crosslinking. In the later stage of the effort, a new method was proposed and studied at ORNL involving a new partnership between the partner and a commercial polymer vender. This resulted in a new material being developed which allows the partner to utilize a commercial support and integrate the synthesis into a production-ready product stream. This will enhance the route to commercialization for the partner resulting in a quicker market penetration for the product. The new adsorbent exhibits selectivity for REE over transition metals commonly found within geothermal brines. Further optimization is required for enhanced selectivity, capacity, and intra-lanthanide separations.« less

[Research on K-means clustering segmentation method for MRI brain image based on selecting multi-peaks in gray histogram].

PubMed

Chen, Zhaoxue; Yu, Haizhong; Chen, Hao

2013-12-01

To solve the problem of traditional K-means clustering in which initial clustering centers are selected randomly, we proposed a new K-means segmentation algorithm based on robustly selecting 'peaks' standing for White Matter, Gray Matter and Cerebrospinal Fluid in multi-peaks gray histogram of MRI brain image. The new algorithm takes gray value of selected histogram 'peaks' as the initial K-means clustering center and can segment the MRI brain image into three parts of tissue more effectively, accurately, steadily and successfully. Massive experiments have proved that the proposed algorithm can overcome many shortcomings caused by traditional K-means clustering method such as low efficiency, veracity, robustness and time consuming. The histogram 'peak' selecting idea of the proposed segmentootion method is of more universal availability.

Experimental and analytical study on fluid whirl and fluid whip modes

NASA Technical Reports Server (NTRS)

Muszynska, Agnes

1994-01-01

Fluid whirl and fluid whip are rotor self-excited, lateral vibrations which occur due to rotor interactions with the surrounding fluid. There exist various modes of fluid whirl and fluid whip. These modes are close to rotor modes corresponding to free vibrations (based on the linear model). Small differences are due to nonlinearities in the system. This paper presents experimental and analytical results on the lowest modes of fluid whirls and fluid whip. Examples of rotors supported in fluid lubricated bearings show the variations of rotor deflection amplitudes and phases in the whirl and whip modes with changes of rotative speeds and/or changes in lumped mass locations along the shaft.

The Stability and Oxidation Resistance of Iron- and Cobalt-Based Magnetic Nanoparticle Fluids Fabricated by Inert-Gas Condensation

DTIC Science & Technology

2005-01-01

imaging, drug delivery, and hyperthermia treatment for cancer . Ideal magnetic nanoparticle fluids have well-separated, biocompatible nanoparticles with a...Based Magnetic Nanoparticle Fluids Fabricated by Inert-Gas Condensation DISTRIBUTION: Approved for public release, distribution unlimited This paper...Oxidation Resistance of Iron- and Cobalt-Based Magnetic Nanoparticle Fluids Fabricated by Inert-Gas Condensation Nguyen H. Hail, Raymond Lemoine’, Shaina

Sampling guidelines for oral fluid-based surveys of group-housed animals.

PubMed

Rotolo, Marisa L; Sun, Yaxuan; Wang, Chong; Giménez-Lirola, Luis; Baum, David H; Gauger, Phillip C; Harmon, Karen M; Hoogland, Marlin; Main, Rodger; Zimmerman, Jeffrey J

2017-09-01

Formulas and software for calculating sample size for surveys based on individual animal samples are readily available. However, sample size formulas are not available for oral fluids and other aggregate samples that are increasingly used in production settings. Therefore, the objective of this study was to develop sampling guidelines for oral fluid-based porcine reproductive and respiratory syndrome virus (PRRSV) surveys in commercial swine farms. Oral fluid samples were collected in 9 weekly samplings from all pens in 3 barns on one production site beginning shortly after placement of weaned pigs. Samples (n=972) were tested by real-time reverse-transcription PCR (RT-rtPCR) and the binary results analyzed using a piecewise exponential survival model for interval-censored, time-to-event data with misclassification. Thereafter, simulation studies were used to study the barn-level probability of PRRSV detection as a function of sample size, sample allocation (simple random sampling vs fixed spatial sampling), assay diagnostic sensitivity and specificity, and pen-level prevalence. These studies provided estimates of the probability of detection by sample size and within-barn prevalence. Detection using fixed spatial sampling was as good as, or better than, simple random sampling. Sampling multiple barns on a site increased the probability of detection with the number of barns sampled. These results are relevant to PRRSV control or elimination projects at the herd, regional, or national levels, but the results are also broadly applicable to contagious pathogens of swine for which oral fluid tests of equivalent performance are available. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Methods for simulation-based analysis of fluid-structure interaction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barone, Matthew Franklin; Payne, Jeffrey L.

2005-10-01

Methods for analysis of fluid-structure interaction using high fidelity simulations are critically reviewed. First, a literature review of modern numerical techniques for simulation of aeroelastic phenomena is presented. The review focuses on methods contained within the arbitrary Lagrangian-Eulerian (ALE) framework for coupling computational fluid dynamics codes to computational structural mechanics codes. The review treats mesh movement algorithms, the role of the geometric conservation law, time advancement schemes, wetted surface interface strategies, and some representative applications. The complexity and computational expense of coupled Navier-Stokes/structural dynamics simulations points to the need for reduced order modeling to facilitate parametric analysis. The proper orthogonalmore » decomposition (POD)/Galerkin projection approach for building a reduced order model (ROM) is presented, along with ideas for extension of the methodology to allow construction of ROMs based on data generated from ALE simulations.« less

Spontaneous mirror-symmetry breaking induces inverse energy cascade in 3D active fluids

PubMed Central

Słomka, Jonasz; Dunkel, Jörn

2017-01-01

Classical turbulence theory assumes that energy transport in a 3D turbulent flow proceeds through a Richardson cascade whereby larger vortices successively decay into smaller ones. By contrast, an additional inverse cascade characterized by vortex growth exists in 2D fluids and gases, with profound implications for meteorological flows and fluid mixing. The possibility of a helicity-driven inverse cascade in 3D fluids had been rejected in the 1970s based on equilibrium-thermodynamic arguments. Recently, however, it was proposed that certain symmetry-breaking processes could potentially trigger a 3D inverse cascade, but no physical system exhibiting this phenomenon has been identified to date. Here, we present analytical and numerical evidence for the existence of an inverse energy cascade in an experimentally validated 3D active fluid model, describing microbial suspension flows that spontaneously break mirror symmetry. We show analytically that self-organized scale selection, a generic feature of many biological and engineered nonequilibrium fluids, can generate parity-violating Beltrami flows. Our simulations further demonstrate how active scale selection controls mirror-symmetry breaking and the emergence of a 3D inverse cascade. PMID:28193853

Fundamental Vocabulary Selection Based on Word Familiarity

NASA Astrophysics Data System (ADS)

Sato, Hiroshi; Kasahara, Kaname; Kanasugi, Tomoko; Amano, Shigeaki

This paper proposes a new method for selecting fundamental vocabulary. We are presently constructing the Fundamental Vocabulary Knowledge-base of Japanese that contains integrated information on syntax, semantics and pragmatics, for the purposes of advanced natural language processing. This database mainly consists of a lexicon and a treebank: Lexeed (a Japanese Semantic Lexicon) and the Hinoki Treebank. Fundamental vocabulary selection is the first step in the construction of Lexeed. The vocabulary should include sufficient words to describe general concepts for self-expandability, and should not be prohibitively large to construct and maintain. There are two conventional methods for selecting fundamental vocabulary. The first is intuition-based selection by experts. This is the traditional method for making dictionaries. A weak point of this method is that the selection strongly depends on personal intuition. The second is corpus-based selection. This method is superior in objectivity to intuition-based selection, however, it is difficult to compile a sufficiently balanced corpora. We propose a psychologically-motivated selection method that adopts word familiarity as the selection criterion. Word familiarity is a rating that represents the familiarity of a word as a real number ranging from 1 (least familiar) to 7 (most familiar). We determined the word familiarity ratings statistically based on psychological experiments over 32 subjects. We selected about 30,000 words as the fundamental vocabulary, based on a minimum word familiarity threshold of 5. We also evaluated the vocabulary by comparing its word coverage with conventional intuition-based and corpus-based selection over dictionary definition sentences and novels, and demonstrated the superior coverage of our lexicon. Based on this, we conclude that the proposed method is superior to conventional methods for fundamental vocabulary selection.

Effect of additives on eremomycin sorbent selectivity in separation of salbutamol enantiomers using supercritical fluid chromatography

NASA Astrophysics Data System (ADS)

Pokrovskiy, O. I.; Kayda, A. S.; Usovich, O. I.; Parenago, O. O.; Lunin, V. V.

2017-11-01

A regime is found in which chiral stationary phase based on macrocyclic glycopeptide eremomycin allows separation of salbutamol sulfate enantiomers in supercritical fluid chromatography. Enantioseparation occurs only when two dynamic modifiers are used simultaneously: isopropylamin + trifluoroacetic acid or isopropylamin + ammonium acetate. Amine molar concentration in mobile phase has to be higher than acid molar concentration, otherwise enantiomers coelute. We suppose that with amine excess a mechanism of enantiorecognition is realized which involves ionic sorbent-sorbate interactions. Such mechanism is well-known for glycopeptide chiral selectors in liquid chromatography, but for supercritical fluid chromatography it is reported for the first time.

Oil Based Drilling Fluid Waste: An Overview on Environmentally Persistent Pollutants

NASA Astrophysics Data System (ADS)

Siddique, Shohel; Kwoffie, Lorraine; Addae-Afoakwa, Kofi; Yates, Kyari; Njuguna, James

2017-05-01

Operational discharges of spent drilling fluid, produced water, and accumulated drill cuttings from oil and gas industry are a continuous point source of environmental pollution. To meet the strict environmental standard for waste disposal, oil and gas industry is facing a numerous challenges in technological development to ensure a clean and safe environment. Oil and gas industry generates a large amount of spent drilling fluid, produced water, and drill cuttings, which are very different in every drilling operation in terms of composition and characterisation. This review article highlights the knowledge gap in identifying the different sources of waste streams in combined drilling waste. This paper also emphasises how different chemicals turn into environmentally significant pollutants after serving great performance in oil and gas drilling operations. For instance, oil based drilling fluid performs excellent in deeper drilling and drilling in the harsh geological conditions, but ended with (produces) a significant amount of persistent toxic pollutants in the environment. This review paper provides an overview on the basic concepts of drilling fluids and their functions, sources and characterisation of drilling wastes, and highlights some environmentally significant elements including different minerals present in drilling waste stream.

Magnetic power piston fluid compressor

NASA Technical Reports Server (NTRS)

Gasser, Max G. (Inventor)

1994-01-01

A compressor with no moving parts in the traditional sense having a housing having an inlet end allowing a low pressure fluid to enter and an outlet end allowing a high pressure fluid to exit is described. Within the compressor housing is at least one compression stage to increase the pressure of the fluid within the housing. The compression stage has a quantity of magnetic powder within the housing, is supported by a screen that allows passage of the fluid, and a coil for selectively providing a magnetic field across the magnetic powder such that when the magnetic field is not present the individual particles of the powder are separated allowing the fluid to flow through the powder and when the magnetic field is present the individual particles of the powder pack together causing the powder mass to expand preventing the fluid from flowing through the powder and causing a pressure pulse to compress the fluid.

Methods of use for sensor based fluid detection devices

NASA Technical Reports Server (NTRS)

Lewis, Nathan S. (Inventor)

2001-01-01

Methods of use and devices for detecting analyte in fluid. A system for detecting an analyte in a fluid is described comprising a substrate having a sensor comprising a first organic material and a second organic material where the sensor has a response to permeation by an analyte. A detector is operatively associated with the sensor. Further, a fluid delivery appliance is operatively associated with the sensor. The sensor device has information storage and processing equipment, which is operably connected with the device. This device compares a response from the detector with a stored ideal response to detect the presence of analyte. An integrated system for detecting an analyte in a fluid is also described where the sensing device, detector, information storage and processing device, and fluid delivery device are incorporated in a substrate. Methods for use for the above system are also described where the first organic material and a second organic material are sensed and the analyte is detected with a detector operatively associated with the sensor. The method provides for a device, which delivers fluid to the sensor and measures the response of the sensor with the detector. Further, the response is compared to a stored ideal response for the analyte to determine the presence of the analyte. In different embodiments, the fluid measured may be a gaseous fluid, a liquid, or a fluid extracted from a solid. Methods of fluid delivery for each embodiment are accordingly provided.

Magnetic Fluid Friction and Wear Behavior

NASA Technical Reports Server (NTRS)

Keith, Theo G., Jr.

1998-01-01

The friction and wear properties of two groups of magnetic fluids, one developed at NASA Lewis Research Center and a commercial fluid, were evaluated for boundary lubrication. Friction and wear measurements were made using a pin-on-disk apparatus. Three different ball materials were evaluated, (1) 440C, (2) Al2O3, and (3) Si3N4 against 440C disks. The first class of magnetic fluids have a low vapor pressure hydrocarbon base oil and are suitable for space application. Four variations of this fluid were evaluated: (1) the base oil, (2) base oil with anti-wear additives, (3) a 100 Gauss strength magnetic fluid, and (4) a 400 gauss magnetic fluid. The commercial fluid base oil and four different magnetic particle concentration levels have been evaluated. A space qualified fluorinated lubricant was tested for base line comparison. Hardness, optical microscopy, surface profilometry, and surface analysis were used to characterize the test specimens. Friction was unaffected by the concentration of magnetic particles. Wear rates for magnetic fluids were slightly higher than the base oil. The low vapor pressure magnetic fluid has better wear characteristics than the space qualified fluorinated lubricant.

Method for separating metal chelates from other materials based on solubilities in supercritical fluids

DOEpatents

Wai, Chien M.; Smart, Neil G.; Phelps, Cindy

2001-01-01

A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents. In especially preferred embodiments, at least one of the chelating agents is fluorinated.

Metalworking and machining fluids

DOEpatents

Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

2010-10-12

Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

Positive and negative effects of dielectric breakdown in transformer oil based magnetic fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jong-Chul, E-mail: jclee01@gwnu.ac.kr; Lee, Won-Ho; Lee, Se-Hee

The transformer oil based magnetic fluids can be considered as the next-generation insulation fluids because they offer exciting new possibilities to enhance dielectric breakdown voltage as well as heat transfer performance compared to pure transformer oils. In this study, we have investigated the dielectric breakdown strength of the fluids with the various volume concentrations of nanoparticles in accordance with IEC 156 standard and have tried to find the reason for changing the dielectric breakdown voltage of the fluids from the magnetic field analysis. It was found that the dielectric breakdown voltage of pure transformer oil is around 12 kV withmore » the gap distance of 1.5 mm. In the case of our transformer oil-based magnetic fluids with 0.08% < Φ < 0.6% (Φ means the volume concentration of magnetic nanoparticles), the dielectric breakdown voltage shows above 40 kV, which is 3.3 times higher positively than that of pure transformer oil. Negatively in the case when the volume concentration of magnetic nanoparticles is above 0.65%, the dielectric breakdown voltage decreases reversely. From the magnetic field analysis, the reason might be considered as two situations: the positive is for the conductive nanoparticles dispersed well near the electrodes, which play an important role in converting fast electrons to slow negatively charged particles, and the negative is for the agglomeration of the particles near the electrodes, which leads to the breakdown initiation.« less

Apparatus for Pumping a Fluid

NASA Technical Reports Server (NTRS)

van Boeyen, Roger W. (Inventor); Reeh, Jonathan A. (Inventor); Kesmez, Mehmet (Inventor); Heselmeyer, Eric A. (Inventor); Parkey, Jeffrey S. (Inventor)

2016-01-01

An electrochemically actuated pump and an electrochemical actuator for use with a pump. The pump includes one of various stroke volume multiplier configurations with the pressure of a pumping fluid assisting actuation of a driving fluid bellows. The electrochemical actuator has at least one electrode fluidically coupled to the driving fluid chamber of the first pump housing and at least one electrode fluidically coupled to the driving fluid chamber of the second pump housing. Accordingly, the electrochemical actuator selectively pressurizes hydrogen gas within a driving fluid chamber. The actuator may include a membrane electrode assembly including an ion exchange membrane with first and second catalyzed electrodes in contact with opposing sides of the membrane, and first and second hydrogen gas chambers in fluid communication with the first and second electrodes, respectively. A controller may reverse the polarity of a voltage source electrically coupled to the current collectors.

Choice of optimal working fluid for binary power plants at extremely low temperature brine

NASA Astrophysics Data System (ADS)

Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

2016-12-01

The geothermal energy development problems based on using binary power plants utilizing lowpotential geothermal resources are considered. It is shown that one of the possible ways of increasing the efficiency of heat utilization of geothermal brine in a wide temperature range is the use of multistage power systems with series-connected binary power plants based on incremental primary energy conversion. Some practically significant results of design-analytical investigations of physicochemical properties of various organic substances and their influence on the main parameters of the flowsheet and the technical and operational characteristics of heat-mechanical and heat-exchange equipment for binary power plant operating on extremely-low temperature geothermal brine (70°C) are presented. The calculation results of geothermal brine specific flow rate, capacity (net), and other operation characteristics of binary power plants with the capacity of 2.5 MW at using various organic substances are a practical interest. It is shown that the working fluid selection significantly influences on the parameters of the flowsheet and the operational characteristics of the binary power plant, and the problem of selection of working fluid is in the search for compromise based on the priorities in the field of efficiency, safety, and ecology criteria of a binary power plant. It is proposed in the investigations on the working fluid selection of the binary plant to use the plotting method of multiaxis complex diagrams of relative parameters and characteristic of binary power plants. Some examples of plotting and analyzing these diagrams intended to choose the working fluid provided that the efficiency of geothermal brine is taken as main priority.

Environmentally Friendly Procedure Based on Supercritical Fluid Chromatography and Tandem Mass Spectrometry Molecular Networking for the Discovery of Potent Antiviral Compounds from Euphorbia semiperfoliata.

PubMed

Nothias, Louis-Félix; Boutet-Mercey, Stéphanie; Cachet, Xavier; De La Torre, Erick; Laboureur, Laurent; Gallard, Jean-François; Retailleau, Pascal; Brunelle, Alain; Dorrestein, Pieter C; Costa, Jean; Bedoya, Luis M; Roussi, Fanny; Leyssen, Pieter; Alcami, José; Paolini, Julien; Litaudon, Marc; Touboul, David

2017-10-27

A supercritical fluid chromatography-based targeted purification procedure using tandem mass spectrometry and molecular networking was developed to analyze, annotate, and isolate secondary metabolites from complex plant extract mixture. This approach was applied for the targeted isolation of new antiviral diterpene esters from Euphorbia semiperfoliata whole plant extract. The analysis of bioactive fractions revealed that unknown diterpene esters, including jatrophane esters and phorbol esters, were present in the samples. The purification procedure using semipreparative supercritical fluid chromatography led to the isolation and identification of two new jatrophane esters (13 and 14) and one known (15) and three new 4-deoxyphorbol esters (16-18). The structure and absolute configuration of compound 16 were confirmed by X-ray crystallography. This compound was found to display antiviral activity against Chikungunya virus (EC 50 = 0.45 μM), while compound 15 proved to be a potent and selective inhibitor of HIV-1 replication in a recombinant virus assay (EC 50 = 13 nM). This study showed that a supercritical fluid chromatography-based protocol and molecular networking can facilitate and accelerate the discovery of bioactive small molecules by targeting molecules of interest, while minimizing the use of toxic solvents.

Dielectric properties of transformer paper impregnated by mineral oil based magnetic fluid

NASA Astrophysics Data System (ADS)

Timko, M.; Kopčanský, P.; Marton, K.; Tomčo, L.; Koneracká, M.

2010-01-01

The influence of combined magnetic and electric field on permittivity of transformer paper used in power transformers was observed. Transformer paper was impregnated by pure transformer oil ITO 100 and magnetic fluids based on transformer oil ITO 100 with different concentrations of magnetite nanoparticles. The measurements were carried out with help of high precision capacitance bridge. The electric intensity between circular planar electrodes was in the region of weak electric field (E > 106 V/m). The increase of electric permittivity of transformer paper impregnated by magnetic fluid opposite pure transformer paper was observed. The experiments showed that permittivity of insulator system consisting of pure transformer paper and impregnated transformer paper naturally depends on number of paper layers. The magnetodielectric effect was found to be dependent on magnetite nanoparticles concentration in magnetic fluids.

Measurement of the Density of Base Fluids at Pressures 0.422 to 2.20 Gpa

NASA Technical Reports Server (NTRS)

Hamrock, B. J.; Jacobson, B. O.; Bergstroem, S. I.

1985-01-01

The influence of pressure on the density of six base fluids is experimentally studied for a range of pressures from 0.422 to 2.20 GPa. An important parameter used to describe the results is the change in relative volume with change in pressure dv sub r/dp. For pressures less than the solidification pressure (p ps) a small change in pressure results in a large change in dv sub r/ps. For pressures greater than the solidification pressure (p ps) there is no change in dv sub r/dp with changing pressure. The solidification pressures of the base fluids varies considerably, as do the slopes that the experimental data assumes for p ps. A new formula is developed that describes the effect of pressure on density in terms of four constants. These constants vary for the different base fluids tested.

Sys-BodyFluid: a systematical database for human body fluid proteome research

PubMed Central

Li, Su-Jun; Peng, Mao; Li, Hong; Liu, Bo-Shu; Wang, Chuan; Wu, Jia-Rui; Li, Yi-Xue; Zeng, Rong

2009-01-01

Recently, body fluids have widely become an important target for proteomic research and proteomic study has produced more and more body fluid related protein data. A database is needed to collect and analyze these proteome data. Thus, we developed this web-based body fluid proteome database Sys-BodyFluid. It contains eleven kinds of body fluid proteomes, including plasma/serum, urine, cerebrospinal fluid, saliva, bronchoalveolar lavage fluid, synovial fluid, nipple aspirate fluid, tear fluid, seminal fluid, human milk and amniotic fluid. Over 10 000 proteins are presented in the Sys-BodyFluid. Sys-BodyFluid provides the detailed protein annotations, including protein description, Gene Ontology, domain information, protein sequence and involved pathways. These proteome data can be retrieved by using protein name, protein accession number and sequence similarity. In addition, users can query between these different body fluids to get the different proteins identification information. Sys-BodyFluid database can facilitate the body fluid proteomics and disease proteomics research as a reference database. It is available at http://www.biosino.org/bodyfluid/. PMID:18978022

Sys-BodyFluid: a systematical database for human body fluid proteome research.

PubMed

Li, Su-Jun; Peng, Mao; Li, Hong; Liu, Bo-Shu; Wang, Chuan; Wu, Jia-Rui; Li, Yi-Xue; Zeng, Rong

2009-01-01

Recently, body fluids have widely become an important target for proteomic research and proteomic study has produced more and more body fluid related protein data. A database is needed to collect and analyze these proteome data. Thus, we developed this web-based body fluid proteome database Sys-BodyFluid. It contains eleven kinds of body fluid proteomes, including plasma/serum, urine, cerebrospinal fluid, saliva, bronchoalveolar lavage fluid, synovial fluid, nipple aspirate fluid, tear fluid, seminal fluid, human milk and amniotic fluid. Over 10,000 proteins are presented in the Sys-BodyFluid. Sys-BodyFluid provides the detailed protein annotations, including protein description, Gene Ontology, domain information, protein sequence and involved pathways. These proteome data can be retrieved by using protein name, protein accession number and sequence similarity. In addition, users can query between these different body fluids to get the different proteins identification information. Sys-BodyFluid database can facilitate the body fluid proteomics and disease proteomics research as a reference database. It is available at http://www.biosino.org/bodyfluid/.

Electrorheological Fluid Based Force Feedback Device

NASA Technical Reports Server (NTRS)

Pfeiffer, Charles; Bar-Cohen, Yoseph; Mavroidis, Constantinos; Dolgin, Benjamin

1999-01-01

Parallel to the efforts to develop fully autonomous robots, it is increasingly being realized that there are applications where it is essential to have a fully controlled robot and "feel" its operating conditions, i.e. telepresence. This trend is a result of the increasing efforts to address tasks where humans can perform significantly better but, due to associated hazards, distance, physical limitations and other causes, only robots can be employed to perform these tasks. Such robots need to be assisted by a human that remotely controls the operation. To address the goal of operating robots as human surrogates, the authors launched a study of mechanisms that provide mechanical feedback. For this purpose, electrorheological fluids (ERF) are being investigated for the potential application as miniature haptic devices. This family of electroactive fluids has the property of changing the viscosity during electrical stimulation. Consequently, ERF can be used to produce force feedback haptic devices for tele-operated control of medical and space robotic systems. Forces applied at the robot end-effector due to a compliant environment are reflected to the user using an ERF device where a change in the system viscosity will occur proportionally to the transmitted force. Analytical model and control algorithms are being developed taking into account the non-linearities of these type of devices. This paper will describe the concept and the developed mechanism of ERF based force feedback. The test process and the physical properties of this device will be described and the results of preliminary tests will be presented.

Influenza A Virus Surveillance Based on Pre-Weaning Piglet Oral Fluid Samples.

PubMed

Panyasing, Y; Goodell, C; Kittawornrat, A; Wang, C; Levis, I; Desfresne, L; Rauh, R; Gauger, P C; Zhang, J; Lin, X; Azeem, S; Ghorbani-Nezami, S; Yoon, K-J; Zimmerman, J

2016-10-01

Influenza A virus (IAV) surveillance using pre-weaning oral fluid samples from litters of piglets was evaluated in four ˜12 500 sow and IAV-vaccinated, breeding herds. Oral fluid samples were collected from 600 litters and serum samples from their dams at weaning. Litter oral fluid samples were tested for IAV by virus isolation, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), RT-PCR subtyping and sequencing. Commercial nucleoprotein (NP) enzyme-linked immunosorbent assay (ELISA) kits and NP isotype-specific assays (IgM, IgA and IgG) were used to characterize NP antibody in litter oral fluid and sow serum. All litter oral fluid specimens (n = 600) were negative by virus isolation. Twenty-five oral fluid samples (25/600 = 4.2%) were qRT-PCR positive based on screening (Laboratory 1) and confirmatory testing (Laboratory 2). No hemagglutinin (HA) and neuraminidase (NA) gene sequences were obtained, but matrix (M) gene sequences were obtained for all qRT-PCR-positive samples submitted for sequencing (n = 18). Genetic analysis revealed that all M genes sequences were identical (GenBank accession no. KF487544) and belonged to the triple reassortant influenza A virus M gene (TRIG M) previously identified in swine. The proportion of IgM- and IgA-positive samples was significantly higher in sow serum and litter oral fluid samples, respectively (P < 0.01). Consistent with the extensive use of IAV vaccine, no difference was detected in the proportion of IgG- and blocking ELISA-positive sow serum and litter oral fluids. This study supported the use of oral fluid sampling as a means of conducting IAV surveillance in pig populations and demonstrated the inapparent circulation of IAV in piglets. Future work on IAV oral fluid diagnostics should focus on improved procedures for virus isolation, subtyping and sequencing of HA and NA genes. The role of antibody in IAV surveillance remains to be elucidated, but longitudinal assessment of specific

Acid-Base and Plasma Biochemical Changes Using Crystalloid Fluids in Stranded Juvenile Loggerhead Sea Turtles (Caretta caretta).

PubMed

Camacho, María; Quintana, María Del Pino; Calabuig, Pascual; Luzardo, Octavio P; Boada, Luis D; Zumbado, Manuel; Orós, Jorge

2015-01-01

The aim of this study was to compare the efficacy and effects on acid-base and electrolyte status of several crystalloid fluids in 57 stranded juvenile loggerhead turtles. Within a rehabilitation program four different crystalloid fluids were administered (0.9% Na Cl solution; 5% dextrose + 0.9% Na Cl solutions 1:1; 0.9% Na Cl + lactated Ringer's solutions 1:1; lactated Ringer's solution). Crystalloid fluids were intracoelomically administered during three days (20 ml/kg/day). Animals were sampled at three different moments: Upon admission for evaluating the type of acid-base or biochemical disorder, post-fluid therapy treatment for controlling the evolution of the disorder, and post-recovery period for obtaining the baseline values for rehabilitated loggerhead turtles. Each sample was analyzed with a portable electronic blood analyzer for pH, pO2, pCO2, lactate, sodium, potassium, chloride, glucose, and BUN concentration. Admission and post-fluid therapy treatment values were compared with those obtained for each turtle immediately before release. The highest percentage of acid-base recovery and electrolyte balance was observed in turtles treated with mixed saline-lactated Ringer's solution (63.6%), followed by turtles treated with physiological saline solution (55%), lactated Ringer's solution (33.3%), and dextrose-saline solutions (10%). Most turtles treated with lactated Ringer's solution had lower lactate concentrations compared with their initial values; however, 66.6% of turtles treated with lactated Ringer's solution had metabolic alkalosis after therapy. Significant higher concentrations of glucose were detected after saline-dextrose administration compared with all the remaining fluids. This is the first study evaluating the effects of several crystalloid fluids on the acid-base status and plasma biochemical values in stranded loggerhead sea turtles. Reference convalescent venous blood gas, acid-base, and plasma biochemical values, useful for veterinary

DNA methylation-based age prediction from various tissues and body fluids

PubMed Central

Jung, Sang-Eun; Shin, Kyoung-Jin; Lee, Hwan Young

2017-01-01

Aging is a natural and gradual process in human life. It is influenced by heredity, environment, lifestyle, and disease. DNA methylation varies with age, and the ability to predict the age of donor using DNA from evidence materials at a crime scene is of considerable value in forensic investigations. Recently, many studies have reported age prediction models based on DNA methylation from various tissues and body fluids. Those models seem to be very promising because of their high prediction accuracies. In this review, the changes of age-associated DNA methylation and the age prediction models for various tissues and body fluids were examined, and then the applicability of the DNA methylation-based age prediction method to the forensic investigations was discussed. This will improve the understandings about DNA methylation markers and their potential to be used as biomarkers in the forensic field, as well as the clinical field. PMID:28946940

Evaluation of an amide-based stationary phase for supercritical fluid chromatography

PubMed Central

Borges-Muñoz, Amaris C.; Colón, Luis A.

2017-01-01

A relatively new stationary phase containing a polar group embedded in a hydrophobic backbone (i.e., ACE® C18-amide) was evaluated for use in supercritical fluid chromatography. The amide-based column was compared with columns packed with bare silica, C18 silica, and a terminal-amide silica phase. The system was held at supercritical pressure and temperature with a mobile phase composition of CO2 and methanol as cosolvent. The linear solvation energy relationship model was used to evaluate the behavior of these stationary phases, relating the retention factor of selected probes to specific chromatographic interactions. A five-component test mixture, consisting of a group of drug-like molecules was separated isocratically. The results show that the C18-amide stationary phase provided a combination of interactions contributing to the retention of the probe compounds. The hydrophobic interactions are favorable; however, the electron donating ability of the embedded amide group shows a large positive interaction. Under the chromatographic conditions used, the C18-amide column was able to provide baseline resolution of all the drug-like probe compounds in a text mixture, while the other columns tested did not. PMID:27396487

4D ERT-based calibration and prediction of biostimulant induced changes in fluid conductivity

NASA Astrophysics Data System (ADS)

Johnson, T. C.; Versteeg, R. J.; Day-Lewis, F. D.; Major, W. R.; Wright, K. E.

2008-12-01

In-situ bioremediation is an emerging and cost-effective method of removing organic contaminants from groundwater. The performance of bioremedial systems depends on the adequate delivery and distribution of biostimulants to contaminated zones. Monitoring the distribution of biostimulants using monitoring wells is expensive, time consuming, and provides inadequate information between sampling wells. We discuss a Hydrogeophysical Performance Monitoring System (HPMS) deployed to monitor bioremediation efforts at a TCE-contaminated Superfund site in Brandywine MD. The HPMS enables autonomous electrical geophysical data acquisition, processing, quality-assurance/quality-control, and inversion. Our objective is to demonstrate the feasibility and cost effectiveness of the HPMS to provide near real-time information on the spatiotemporal behavior of injected biostimulants. As a first step, we use time-lapse electrical resistivity tomography (ERT) to estimate changes in bulk conductivity caused by the injectate. We demonstrate how ERT-based bulk conductivity estimates can be calibrated with a small number of fluid conductivity measurements to produce ERT-based estimates of fluid conductivity. The calibration procedure addresses the spatially variable resolution of the ERT tomograms. To test the validity of these estimates, we used the ERT results to predict the fluid conductivity at tens of points prior to field sampling of fluid conductivity at the same points. The comparison of ERT-predicted vs. observed fluid conductivity displays a high degree of correlation (correlation coefficient over 0.8), and demonstrates the ability of the HPMS to estimate the four-dimensional (4D) distribution of fluid conductivity caused by the biostimulant injection.

Prediction of Body Fluids where Proteins are Secreted into Based on Protein Interaction Network

PubMed Central

Hu, Le-Le; Huang, Tao; Cai, Yu-Dong; Chou, Kuo-Chen

2011-01-01

Determining the body fluids where secreted proteins can be secreted into is important for protein function annotation and disease biomarker discovery. In this study, we developed a network-based method to predict which kind of body fluids human proteins can be secreted into. For a newly constructed benchmark dataset that consists of 529 human-secreted proteins, the prediction accuracy for the most possible body fluid location predicted by our method via the jackknife test was 79.02%, significantly higher than the success rate by a random guess (29.36%). The likelihood that the predicted body fluids of the first four orders contain all the true body fluids where the proteins can be secreted into is 62.94%. Our method was further demonstrated with two independent datasets: one contains 57 proteins that can be secreted into blood; while the other contains 61 proteins that can be secreted into plasma/serum and were possible biomarkers associated with various cancers. For the 57 proteins in first dataset, 55 were correctly predicted as blood-secrete proteins. For the 61 proteins in the second dataset, 58 were predicted to be most possible in plasma/serum. These encouraging results indicate that the network-based prediction method is quite promising. It is anticipated that the method will benefit the relevant areas for both basic research and drug development. PMID:21829572

Spotlight on the use of new natural surfactants in colloidal gas aphron (CGA) fluids: A mechanistic study

NASA Astrophysics Data System (ADS)

Ali Ahmadi, Mohammad; Galedarzadeh, Morteza; Reza Shadizadeh, Seyed

2017-12-01

Colloidal gas aphron-based (CGA) drilling fluids are defined as gas bubbles with diameters in ranges of 10 to 100 microns which are created by intensive stirring of an aphronizer surfactant solution at high speed. Furthermore, CGA-based drilling fluid properties like stability and aphron size distribution extremely depend on the inherent characteristics of the aphronizer surfactant. The selection of an appropriate surface active agent plays a vital role in the generation of micro-bubbles with the favorable characteristics. The primary motivation behind this paper is to evaluate the potential of new natural surfactants as aphronizer in CGA-based drilling fluids. Here, two new natural based surfactants derived from roots of Glycyrrhiza glabra and leaves of Matricaria recutita plant are implemented for the preparation of aphron-based fluids. The physico-chemical properties of the aphronized fluids prepared from these surfactants are studied by different fundamental tests comprising rheological characterizations, bubble size measurements, and stability tests. The effect of polymer and surfactant concentration was also evaluated. According to the experimental outcomes of this research, the two introduced natural surfactants are appropriate for generating CGA-based drilling fluids while they have no environmental impacts and have very low cost in comparison to commercial and industrial surfactants.

Base fluid in improving heat transfer for EV car battery

NASA Astrophysics Data System (ADS)

Bin-Abdun, Nazih A.; Razlan, Zuradzman M.; Shahriman, A. B.; Wan, Khairunizam; Hazry, D.; Ahmed, S. Faiz; Adnan, Nazrul H.; Heng, R.; Kamarudin, H.; Zunaidi, I.

2015-05-01

This study examined the effects of base fluid (as coolants) channeling inside the heat exchanger in the process of the increase in thermal conductivity between EV car battery and the heat exchanger. The analysis showed that secondary cooling system by means of water has advantages in improving the heat transfer process and reducing the electric power loss on the form of thermal energy from batteries. This leads to the increase in the efficiency of the EV car battery, hence also positively reflecting the performance of the EV car. The present work, analysis is performed to assess the design and use of heat exchanger in increasing the performance efficiency of the EV car battery. This provides a preface to the use this design for nano-fluids which increase and improve from heat transfer.

Dielectrophoresis-magnetophoresis force driven magnetic nanoparticle movement in transformer oil based magnetic fluids.

PubMed

Lee, Jong-Chul; Lee, Sangyoup

2013-09-01

Magnetic fluid is a stable colloidal mixture contained magnetic nanoparticles coated with a surfactant. Recently, it was found that the fluid has properties to increase heat transfer and dielectric characteristics due to the added magnetic nanoparticles in transformer oils. The magnetic nanoparticles in the fluid experience an electrical force directed toward the place of maximum electric field strength when the electric field is applied. And when the external magnetic field is applied, the magnetic nanoparticles form long chains oriented along the direction of the field. The behaviors of magnetic nanoparticles in both the fields must play an important role in changing the heat transfer and dielectric characteristics of the fluids. In this study, we visualized the movement of magnetic nanoparticles influenced by both the fields applied in-situ. It was found that the magnetic nanoparticles travel in the region near the electrode by the electric field and form long chains along the field direction by the magnetic field. It can be inferred that the movement of magnetic nanoparticles appears by both the fields, and the breakdown voltage of transformer oil based magnetic fluids might be influenced according to the dispersion of magnetic nanoparticles.

Development of a Mechatronic Syringe Pump to Control Fluid Flow in a Microfluidic Device Based on Polyimide Film

NASA Astrophysics Data System (ADS)

Sek Tee, Kian; Sharil Saripan, Muhammad; Yap, Hiung Yin; Fhong Soon, Chin

2017-08-01

With the advancement in microfluidic technology, fluid flow control for syringe pump is always essential. In this paper, a mechatronic syringe pump will be developed and customized to control the fluid flow in a poly-dimethylsiloxane (PDMS) microfluidic device based on a polyimide laminating film. The syringe pump is designed to drive fluid with flow rates of 100 and 1000 μl/min which intended to drive continuous fluid in a polyimide based microfluidic device. The electronic system consists of an Arduino microcontroller board and a uni-polar stepper motor. In the system, the uni-polar stepper motor was coupled to a linear slider attached to the plunger of a syringe pump. As the motor rotates, the plunger pumps the liquid out of the syringe. The accuracy of the fluid flow rate was determined by adjusting the number of micro-step/revolution to drive the stepper motor to infuse fluid into the microfluidic device. With the precise control of the electronic system, the syringe pump could accurately inject fluid volume at 100 and 1000 μl/min into a microfluidic device.

Paper-based surfaced enhanced Raman spectroscopy for drug level testing with tear fluid

NASA Astrophysics Data System (ADS)

Yamada, Kenji; Yokoyama, Moe; Jeong, Hieyong; Kido, Michiko; Ohno, Yuko

2015-07-01

The purpose of this study was to show the effectiveness of therapeutic drug level testing by Paper-based Surfaced Enhanced Raman Spectroscopy (PSERS) for artificial lacrimal fluid. We have been used substrates which consist of a common filter paper and gold nano-rods. The targets were Phenobarbital (PB) which dissolved in artificial lacrimal fluid. We measured them using PSERS which the wavelength was 785nm, the power was 30mW. It was found that there were the strong peaks of PB at 997cm-1 and 1026cm-1 which corresponded with solid PB spectral peak for 1mM artificial lacrimal fluid. The results demonstrated the usefulness of this method. It is concluded that our method for therapeutic drug level testing is very efficient.

Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics.

PubMed

Cebral, J R; Mut, F; Chung, B J; Spelle, L; Moret, J; van Nijnatten, F; Ruijters, D

2017-06-01

Hemodynamics is thought to be an important factor for aneurysm progression and rupture. Our aim was to evaluate whether flow fields reconstructed from dynamic angiography data can be used to realistically represent the main flow structures in intracranial aneurysms. DSA-based flow reconstructions, obtained during interventional treatment, were compared qualitatively with flow fields obtained from patient-specific computational fluid dynamics models and quantitatively with projections of the computational fluid dynamics fields (by computing a directional similarity of the vector fields) in 15 cerebral aneurysms. The average similarity between the DSA and the projected computational fluid dynamics flow fields was 78% in the parent artery, while it was only 30% in the aneurysm region. Qualitatively, both the DSA and projected computational fluid dynamics flow fields captured the location of the inflow jet, the main vortex structure, the intrasaccular flow split, and the main rotation direction in approximately 60% of the cases. Several factors affect the reconstruction of 2D flow fields from dynamic angiography sequences. The most important factors are the 3-dimensionality of the intrasaccular flow patterns and inflow jets, the alignment of the main vortex structure with the line of sight, the overlapping of surrounding vessels, and possibly frame rate undersampling. Flow visualization with DSA from >1 projection is required for understanding of the 3D intrasaccular flow patterns. Although these DSA-based flow quantification techniques do not capture swirling or secondary flows in the parent artery, they still provide a good representation of the mean axial flow and the corresponding flow rate. © 2017 by American Journal of Neuroradiology.

Controllable magneto-rheological fluid-based dampers for drilling

DOEpatents

Raymond, David W [Edgewood, NM; Elsayed, Mostafa Ahmed [Youngsville, LA

2006-05-02

A damping apparatus and method for a drillstring comprising a bit comprising providing to the drillstring a damping mechanism comprising magnetorheological fluid and generating an electromagnetic field affecting the magnetorheological fluid in response to changing ambient conditions encountered by the bit.

National survey of fluid therapy in acute pancreatitis: current practice lacks a sound evidence base.

PubMed

Haydock, Matthew D; Mittal, Anubhav; van den Heever, Marc; Rossaak, Jeremy I; Connor, Saxon; Rodgers, Michael; Petrov, Maxim S; Windsor, John A

2013-10-01

Fluid therapy (FT) is a critical intervention in managing acute pancreatitis (AP). There is a paucity of evidence to guide FT and virtually no data on current prescribing practice. This survey aims to characterize current practice and opinion with regard to FT in AP throughout New Zealand. Information was collected on fluid selection, administration, and goal-directed FT. The survey was distributed online and in print to all doctors employed in General Surgery Departments in New Zealand on 1 May 2012. Monthly email reminders were sent for 6 months. The overall response rate was 47 % (n = 190/408). Crystalloids were the preferred initial fluid for all categories of severity; however, colloid use increased with severity (p < 0.001). Fluid volume also increased with severity (p = 0.001), with 74 % of respondents prescribing >4 L for AP with organ failure (OF). Clinicians treating 26-50 patients per year with AP were less likely to prescribe colloid for AP with OF (8 vs 43 %) (p = 0.001). Rate of fluid administration in AP with OF varied according to physicians' seniority (p = 0.004); consultants prescribed >4 L more than other groups (83 vs 68 %). Only 17 % of respondents reported the use of guidelines. This survey reveals significant variation in prescription of FT for AP, and aggressive FT is commonly prescribed for AP with OF. There is little adherence to published guidelines or best available evidence.

Microfluidic-based Broadband Measurements of Fluid Permittivity and Permeability to 100 GHz

NASA Astrophysics Data System (ADS)

Little, Charles A. E.

This dissertation concerns the development of unique microfluidic microwave devices and associated microwave calibrations to quantitatively extract the broadband permittivity and permeability of fluids between 100 kHz and 110 GHz. The devices presented here consist of SU-8- and PDMS-based microfluidic channels integrated lithographically with coplanar waveguides (CPWs), measured via an external vector network analyzer (VNA). By applying our hybrid set of microwave calibrations to the raw data we extract distributed circuit parameters, representative of the electromagnetic response of the microfluidic channel. We then correlate these parameters to the permittivity and permeability of the fluid within the channels. We are primarily focused on developing devices, calibrations, and analyses to characterize various chemical and biological systems. The small fluid volumes and overall scale of our devices lends the technique to point-of-care blood and cell analysis, as well as to the analysis of high-value chemicals. Broadband microwave microfluidics is sensitive to three primary categories of phenomena: Ionic, dipolar, and magnetic resonances. All three can occur in complex fluids such as blood, proteins and particle suspensions. In order to make quantitative measurements, we need to be able to model and separate all three types of responses. Here we first measure saline solutions (NaCl and water) as an ideal system to better understanding both the ionic and dipolar response. Specifically, we are targeting the electrical double-layer (EDL) response, an ionic effect, which dominates over the intrinsic fluid response at lower frequencies. We have found that the EDL response for saline obeys a strict Debye-type relaxation model, the frequency response of which is dependent solely on the conductivity of the solution. To develop a better understanding of the magnetic response, we first measure magnetic nanoparticles; showing it is possible to detect the magnetic resonances of

Calculation of nanodrop profile from fluid density distribution.

PubMed

Berim, Gersh O; Ruckenstein, Eli

2016-05-01

Two approaches are examined, which can be used to determine the drop profile from the fluid density distributions (FDDs) obtained on the basis of microscopic theories. For simplicity, only two-dimensional (cylindrical, or axisymmetrical) distributions are examined and it is assumed that the fluid is either in contact with a smooth solid or separated from the smooth solid by a lubricating liquid film. The first approach is based on the sharp-kink interface approximation in which the density of the liquid inside and the density of the vapor outside the drop are constant with the exception of the surface layer of the drop where the density is different from the above ones. In this case, the drop profile was calculated by minimizing the total potential energy of the system. The second approach is based on a nonuniform FDD obtained either by the density functional theory or molecular dynamics simulations. To determine the drop profile from such an FDD, which does not contain sharp interfaces, three procedures can be used. In the first two procedures, P1 and P2, the one-dimensional FDDs along straight lines which are parallel to the surface of the solid are extracted from the two-dimensional FDD. Each of those one-dimensional FDDs has a vapor-liquid interface at which the fluid density changes from vapor-like to liquid-like values. Procedure P1 uses the locations of the equimolar dividing surfaces for the one-dimensional FDDs as points of the drop profile. Procedure P2 is based on the assumption that the fluid density is constant on the surface of the drop, that density being selected either arbitrarily or as a fluid density at the location of the equimolar dividing surface for one of the one-dimensional FDDs employed in procedure P1. In the third procedure, P3, which is suggested for the first time in this paper, the one-dimensional FDDs are taken along the straight lines passing through a selected point inside the drop (radial line). Then, the drop profile is

Utilization of sulphurized palm oil as cutting fluid base oil for broaching process

NASA Astrophysics Data System (ADS)

Sukirno; Ningsih, Y. R.

2017-03-01

Broaching is one of the most severe metal cutting operation that requires the use of cutting fluids formulated with extreme pressure (EP) additives to minimize metal-to-metal contact and improve tool life. Enhancement of EP performances of the cutting fluids can be achieved by addition of sulphur containing compounds that will allow the formation of metal sulfide film that has low shear strength and good antiweld properties and acts as protection layer from wear and seizure. Most of the cutting fluids are mineral oil based. However, as regards to health and environmental issues, reseach on vegetable oil based cutting fluid have been increased recently. This paper reports a study on the sulphurization of palm oil derivatives and its usage as broaching oil. Sulphurization of the palm oil derivative was conducted via non-catalytic sulphurization using elemental sulphur at various composition and under heating of 150-160°C for 3 hr. Broaching oil was made by blending the sulphurized palm oil and additive packages. The performance parameters of the broaching oil that has been observed including load carrying capacity, wear scar diameter, corrosion protection, oxidative stability, and surface finish of workpiece. From this research, it was found that sulphurized FAME based broaching oil has excellent EP properties. The optimum formulation was obtained on composition of sulphurized FAME-mineral oil with 6% wt of sulphur. The result from the test showed that kinematic viscosity of sulphurized palm oil was about 25.3 cSt (at 40 °C), load carrying capacity was 400 kgf, and wear scar diameter was 0.407 mm. In addition, it can be concluded that the class of corrosion protection of modified palm oil was 1.b (slight tarnish category), oxidative stability at 160 °C was obtained for 0.11 hr, and the surface roughness of workpiece was about 0.0418-0.0579 μm. These performances are comparable to commercial broaching oil. By this result, it indicates that sulphurized palm oil is

Clinical outcomes of percutaneous drainage of breast fluid collections following mastectomy with expander-based breast reconstruction

PubMed Central

2015-01-01

PURPOSE To determine clinical outcomes of patients who underwent imaging-guided percutaneous drainage of breast fluid collections following mastectomy and breast reconstruction. MATERIAL AND METHODS Retrospective review included all consecutive patients who underwent percutaneous drainage of fluid collections following mastectomy with tissue expander-based reconstruction between January 2007 and September 2012. A total of 879 mastectomies (563 patients) with expander-based breast reconstruction were performed during this period. 28 patients (5%) developed fluid collections, which led to 30 imaging-guided percutaneous drainage procedures. The median follow up time was 533 days. Patient characteristics, surgical technique, microbiology analysis, and clinical outcomes were reviewed. RESULTS The mean age was 51.5 years (range 30.9 to 69.4 years) and the median time between breast reconstruction and drainage was 35 days (range 4 to 235 days). Erythema and swelling were the most common presenting symptoms. The median volume of fluid evacuated at the time of drain placement was 70 mL. Drains were left in place for a median 14 days (range 6 to 34 days). Microorganisms were detected in the fluid in 12 of 30 drainage procedures, with Staphylococcus aureus being the most common microorganism. No further intervention was needed in 21 of 30 drainage procedures (70%). However, surgical intervention (removal of expanders) was needed following 6 (20%) drainages, and additional percutaneous drainage procedures were performed following 3 (10%) drainages. CONCLUSION Percutaneous drainage is an effective means of treating post operative fluid collections after expander-based breast reconstruction and can obviate the need for repeat surgery in most cases. PMID:23810309

Second Microgravity Fluid Physics Conference

NASA Technical Reports Server (NTRS)

1994-01-01

The conference's purpose was to inform the fluid physics community of research opportunities in reduced-gravity fluid physics, present the status of the existing and planned reduced gravity fluid physics research programs, and inform participants of the upcoming NASA Research Announcement in this area. The plenary sessions provided an overview of the Microgravity Fluid Physics Program information on NASA's ground-based and space-based flight research facilities. An international forum offered participants an opportunity to hear from French, German, and Russian speakers about the microgravity research programs in their respective countries. Two keynote speakers provided broad technical overviews on multiphase flow and complex fluids research. Presenters briefed their peers on the scientific results of their ground-based and flight research. Fifty-eight of the sixty-two technical papers are included here.

Drilling fluid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, J.A.; Patel, B.B.

1987-11-03

A drilling fluid additive mixture is described consisting essentially of a sulfoalkylated tannin in admixture with a non-sulfoalkylated alkali-solubilized lignite wherein the weight ratio of the sulfoalkylated tannin to the non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1. The sulfoalkylated tannin has been sulfoalkylated with at least one -(C(R-)/sub 2/-SO/sub 3/M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.

Microbial Metabolism in Serpentinite Fluids

NASA Astrophysics Data System (ADS)

Crespo-Medina, M.; Brazelton, W. J.; Twing, K. I.; Kubo, M.; Hoehler, T. M.; Schrenk, M. O.

2013-12-01

Serpentinization is the process in which ultramafic rocks, characteristic of the upper mantle, react with water liberating mantle carbon and reducing power to potenially support chemosynthetic microbial communities. These communities may be important mediators of carbon and energy exchange between the deep Earth and the surface biosphere. Our work focuses on the Coast Range Ophiolite Microbial Observatory (CROMO) in Northern California where subsurface fluids are accessible through a series of wells. Preliminary analyses indicate that the highly basic fluids (pH 9-12) have low microbial diversity, but there is limited knowledge about the metabolic capabilities of these communties. Metagenomic data from similar serpentine environments [1] have identified Betaproteobacteria belonging to the order Burkholderiales and Gram-positive bacteria from the order Clostridiales as key components of the serpentine microbiome. In an effort to better characterize the microbial community, metabolism, and geochemistry at CROMO, fluids from two representative wells (N08B and CSWold) were sampled during recent field campaigns. Geochemical characterization of the fluids includes measurements of dissolved gases (H2, CO, CH4), dissolved inorganic and organic carbon, volatile fatty acids, and nutrients. The wells selected can be differentiated in that N08B had higher pH (10-11), lower dissolved oxygen, and cell counts ranging from 105-106 cells mL-1 of fluid, with an abundance of the betaproteobacterium Hydrogenophaga. In contrast, fluids from CSWold have slightly lower pH (9-9.5), DO, and conductivity, as well as higher TDN and TDP. CSWold fluid is also characterized for having lower cell counts (~103 cells mL-1) and an abundance of Dethiobacter, a taxon within the phylum Clostridiales. Microcosm experiments were conducted with the purpose of monitoring carbon fixation, methanotrophy and metabolism of small organic compounds, such as acetate and formate, while tracing changes in fluid

A selective optical sensor based on [9]mercuracarborand-3, a new type of ionophore with a chloride complexing cavity

NASA Technical Reports Server (NTRS)

Badr, I. H.; Johnson, R. D.; Diaz, M.; Hawthorne, M. F.; Bachas, L. G.; Daunert, S. (Principal Investigator)

2000-01-01

A highly selective optical sensor for chloride, based on the multidentate Lewis acid ionophore [9]mercuracarborand-3, is described herein. This sensor is constructed by embedding the mercuracarborand ionophore, a suitable pH-sensitive lipophilic dye, and lipophilic cationic sites in a plasticized polymeric membrane. The multiple complementary interactions offered by the preorganized complexing cavity of [9]mercuracarborand-3 is shown to control the anion selectivity pattern of the optical film. The film exhibits a significantly enhanced selectivity for chloride over a variety of lipophilic anions such as perchlorate, nitrate, salicylate, and thiocyanate. Furthermore, the optical selectivity coefficients obtained for chloride over other biologically relevant anions are shown to meet the selectivity requirements for the determination of chloride in physiological fluids, unlike previously reported chloride optical sensors. In addition, the optical film responds to chloride reversibly over a wide dynamic range (16 microM-136 mM) with fast response and recovery times.

Modeling and test of a kinaesthetic actuator based on MR fluid for haptic applications.

PubMed

Yang, Tae-Heon; Koo, Jeong-Hoi; Kim, Sang-Youn; Kwon, Dong-Soo

2017-03-01

Haptic display units have been widely used for conveying button sensations to users, primarily employing vibrotactile actuators. However, the human feeling for pressing buttons mainly relies on kinaesthetic sensations (rather than vibrotactile sensations), and little studies exist on small-scale kinaesthetic haptic units. Thus, the primary goals of this paper are to design a miniature kinaesthetic actuator based on Magneto-Rheological (MR) fluid that can convey various button-clicking sensations and to experimentally evaluate its haptic performance. The design focuses of the proposed actuator were to produce sufficiently large actuation forces (resistive forces) for human users in a given size constraint and to offer a wide range of actuation forces for conveying vivid haptic sensations to users. To this end, this study first performed a series of parametric studies using mathematical force models for multiple operating modes of MR fluid in conjunction with finite element electromagnetism analysis. After selecting design parameters based on parametric studies, a prototype actuator was constructed, and its performance was evaluated using a dynamic mechanical analyzer. It measured the actuator's resistive force with a varying stroke (pressed depth) up to 1 mm and a varying input current from 0 A to 200 mA. The results show that the proposed actuator creates a wide range of resistive forces from around 2 N (off-state) to over 9.5 N at 200 mA. In order to assess the prototype's performance in the terms of the haptic application prospective, a maximum force rate was calculated to determine just noticeable difference in force changes for the 1 mm stoke of the actuator. The results show that the force rate is sufficient to mimic various levels of button sensations, indicating that the proposed kinaesthetic actuator can offer a wide range of resistive force changes that can be conveyed to human operators.

Peritoneal fluid culture

MedlinePlus

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 ...

[Discrimination of varieties of brake fluid using visual-near infrared spectra].

PubMed

Jiang, Lu-lu; Tan, Li-hong; Qiu, Zheng-jun; Lu, Jiang-feng; He, Yong

2008-06-01

A new method was developed to fast discriminate brands of brake fluid by means of visual-near infrared spectroscopy. Five different brands of brake fluid were analyzed using a handheld near infrared spectrograph, manufactured by ASD Company, and 60 samples were gotten from each brand of brake fluid. The samples data were pretreated using average smoothing and standard normal variable method, and then analyzed using principal component analysis (PCA). A 2-dimensional plot was drawn based on the first and the second principal components, and the plot indicated that the clustering characteristic of different brake fluid is distinct. The foregoing 6 principal components were taken as input variable, and the band of brake fluid as output variable to build the discriminate model by stepwise discriminant analysis method. Two hundred twenty five samples selected randomly were used to create the model, and the rest 75 samples to verify the model. The result showed that the distinguishing rate was 94.67%, indicating that the method proposed in this paper has good performance in classification and discrimination. It provides a new way to fast discriminate different brands of brake fluid.

Evaluation on the Presence of Nano Silver Particle in Improving a Conventional Water-based Drilling Fluid

NASA Astrophysics Data System (ADS)

Husin, H.; Ahmad, N.; Jamil, N.; Chyuan, O. H.; Roslan, A.

2018-05-01

Worldwide demand in oil and gas energy consumption has been driving many of oil and gas companies to explore new oil and gas resource field in an ultra-deep water environment. As deeper well is drilled, more problems and challenges are expected. The successful of drilling operation is highly dependent on properties of drilling fluids. As a way to operate drilling in challenging and extreme surroundings, nanotechnology with their unique properties is employed. Due to unique physicochemical, electrical, thermal, hydrodynamic properties and exceptional interaction potential of nanomaterials, nanoparticles are considered to be the most promising material of choice for smart fluid design for oil and gas field application. Throughout this paper, the effect of nano silver particle in improving a conventional water based drilling fluid was evaluated. Results showed that nano silver gave a significant improvement to the conventional water based drilling fluid in terms of its rheological properties and filtration test performance.

Non-Toxic, Low-Freezing, Drop-In Replacement Heat Transfer Fluids

NASA Technical Reports Server (NTRS)

Cutbirth, J. Michael

2012-01-01

A non-toxic, non-flammable, low-freezing heat transfer fluid is being developed for drop-in replacement within current and future heat transfer loops currently using water or alcohol-based coolants. Numerous water-soluble compounds were down-selected and screened for toxicological, physical, chemical, compatibility, thermodynamic, and heat transfer properties. Two fluids were developed, one with a freezing point near 0 C, and one with a suppressed freezing point. Both fluids contain an additive package to improve material compatibility and microbial resistance. The optimized sub-zero solution had a freezing point of 30 C, and a freezing volume expansion of 10-percent of water. The toxicity of the solutions was experimentally determined as LD(50) greater than 5g/kg. The solutions were found to produce minimal corrosion with materials identified by NASA as potentially existing in secondary cooling loops. Thermal/hydrodynamic performance exceeded that of glycol-based fluids with comparable freezing points for temperatures Tf greater than 20 C. The additive package was demonstrated as a buffering agent to compensate for CO2 absorption, and to prevent microbial growth. The optimized solutions were determined to have physically/chemically stable shelf lives for freeze/thaw cycles and longterm test loop tests.

Rough-Fuzzy Clustering and Unsupervised Feature Selection for Wavelet Based MR Image Segmentation

PubMed Central

Maji, Pradipta; Roy, Shaswati

2015-01-01

Image segmentation is an indispensable process in the visualization of human tissues, particularly during clinical analysis of brain magnetic resonance (MR) images. For many human experts, manual segmentation is a difficult and time consuming task, which makes an automated brain MR image segmentation method desirable. In this regard, this paper presents a new segmentation method for brain MR images, integrating judiciously the merits of rough-fuzzy computing and multiresolution image analysis technique. The proposed method assumes that the major brain tissues, namely, gray matter, white matter, and cerebrospinal fluid from the MR images are considered to have different textural properties. The dyadic wavelet analysis is used to extract the scale-space feature vector for each pixel, while the rough-fuzzy clustering is used to address the uncertainty problem of brain MR image segmentation. An unsupervised feature selection method is introduced, based on maximum relevance-maximum significance criterion, to select relevant and significant textural features for segmentation problem, while the mathematical morphology based skull stripping preprocessing step is proposed to remove the non-cerebral tissues like skull. The performance of the proposed method, along with a comparison with related approaches, is demonstrated on a set of synthetic and real brain MR images using standard validity indices. PMID:25848961

A Fluid-driven Earthquake Cycle, Omori's Law, and Fluid-driven Aftershocks

NASA Astrophysics Data System (ADS)

Miller, S. A.

2015-12-01

Few models exist that predict the Omori's Law of aftershock rate decay, with rate-state friction the only physically-based model. ETAS is a probabilistic model of cascading failures, and is sometimes used to infer rate-state frictional properties. However, the (perhaps dominant) role of fluids in the earthquake process is being increasingly realised, so a fluid-based physical model for Omori's Law should be available. In this talk, I present an hypothesis for a fluid-driven earthquake cycle where dehydration and decarbonization at depth provides continuous sources of buoyant high pressure fluids that must eventually make their way back to the surface. The natural pathway for fluid escape is along plate boundaries, where in the ductile regime high pressure fluids likely play an integral role in episodic tremor and slow slip earthquakes. At shallower levels, high pressure fluids pool at the base of seismogenic zones, with the reservoir expanding in scale through the earthquake cycle. Late in the cycle, these fluids can invade and degrade the strength of the brittle crust and contribute to earthquake nucleation. The mainshock opens permeable networks that provide escape pathways for high pressure fluids and generate aftershocks along these flow paths, while creating new pathways by the aftershocks themselves. Thermally activated precipitation then seals up these pathways, returning the system to a low-permeability environment and effective seal during the subsequent tectonic stress buildup. I find that the multiplicative effect of an exponential dependence of permeability on the effective normal stress coupled with an Arrhenius-type, thermally activated exponential reduction in permeability results in Omori's Law. I simulate this scenario using a very simple model that combines non-linear diffusion and a step-wise increase in permeability when a Mohr Coulomb failure condition is met, and allow permeability to decrease as an exponential function in time. I show very

[Individualized fluid-solid coupled model of intracranial aneurysms based on computed tomography angiography data].

PubMed

Wang, Fuyu; Xu, Bainan; Sun, Zhenghui; Liu, Lei; Wu, Chen; Zhang, Xiaojun

2012-10-01

To establish an individualized fluid-solid coupled model of intracranial aneurysms based on computed tomography angiography (CTA) image data. The original Dicom format image data from a patient with an intracranial aneurysm were imported into Mimics software to construct the 3D model. The fluid-solid coupled model was simulated with ANSYS and CFX software, and the sensitivity of the model was analyzed. The difference between the rigid model and fluid-solid coupled model was also compared. The fluid-solid coupled model of intracranial aneurysm was established successfully, which allowed direct simulation of the blood flow of the intracranial aneurysm and the deformation of the solid wall. The pressure field, stress field, and distribution of Von Mises stress and deformation of the aneurysm could be exported from the model. A small Young's modulus led to an obvious deformation of the vascular wall, and the walls with greater thicknesses had smaller deformations. The rigid model and the fluid-solid coupled model showed more differences in the wall shear stress and blood flow velocity than in pressure. The fluid-solid coupled model more accurately represents the actual condition of the intracranial aneurysm than the rigid model. The results of numerical simulation with the model are reliable to study the origin, growth and rupture of the aneurysms.

FIXED DOSE COMBINATIONS WITH SELECTIVE BETA-BLOCKERS: QUANTITATIVE DETERMINATION IN BIOLOGICAL FLUIDS.

PubMed

Mahu, Ştefania Corina; Hăncianu, Monica; Agoroaei, Luminiţa; Grigoriu, Ioana Cezara; Strugaru, Anca Monica; Butnaru, Elena

2015-01-01

Hypertension is one of the most common causes of death, a complex and incompletely controlled disease for millions of patients. Metoprolol, bisoprolol, nebivolol and atenolol are selective beta-blockers frequently used in the management of arterial hypertension, alone or in fixed combination with other substances. This study presents the most used analytical methods for simultaneous determination in biological fluids of fixed combinations containing selective beta-blockers. Articles in Pub-Med, Science Direct and Wiley Journals databases published between years 2004-2014 were reviewed. Methods such as liquid chromatography--mass spectrometry--mass spectrometry (LC-MS/MS), high performance liquid chromatography (HPLC) or high performance liquid chromatography--mass spectrometry (HPLC-MS) were used for determination of fixed combination with beta-blockers in human plasma, rat plasma and human breast milk. LC-MS/MS method was used for simultaneous determination of fixed combinations of metoprolol with simvastatin, hydrochlorothiazide or ramipril, combinations of nebivolol and valsartan, or atenolol and amlodipine. Biological samples were processed by protein precipitation techniques or by liquid-liquid extraction. For the determination of fixed dose combinations of felodipine and metoprolol in rat plasma liquid chromatography--electrospray ionization--mass spectrometry (LC-ESI-MS/MS) was applied, using phenacetin as internal standard. HPLC-MS method was applied for the determination of bisoprolol and hydrochlorothiazide in human plasma. For the determination of atenolol and chlorthalidone from human breast milk and human plasma the HPLC method was used. The analytical methods were validated according to the specialized guidelines, and were applied to biological samples, thing that confirms the permanent concern of researchers in this field.

Optical fiber F-P magnetic field sensor based on magnetostrictive effect of magnetic fluid

NASA Astrophysics Data System (ADS)

Shi, Fuquan; Luo, Yan; Che, Jiajia; Ren, Zhijun; peng, Baojin

2018-07-01

magnetic field sensor of air-gap Fabry-Perot fiber interferometersis proposed based on magnetostrictive effect. The sensor is consisted of single-model fiber (SMF), air-gap, no-core fiber (NCF) and magnetic fluid. Those are sealed in the capillary, SMF and NCF are connect with air chamber and magnetic fluid column. With the presence of an external magnetic field, air chamber cavity length changes because of the magneto-volume variation of magnetic fluids. This situation causes a change in the optical path difference. Detection of the drift of interference spectrum leads to the detection of the change in magnetic field. When the magnetic field is parallel to the direction in which the capillary is placed, the sensitivity is 0.2347 nm/mT; when the magnetic fluid is perpendicular to the direction in which the capillary is placed, the sensitivity is 0.325 nm/http://mT.%20In.

Online selective kernel-based temporal difference learning.

PubMed

Chen, Xingguo; Gao, Yang; Wang, Ruili

2013-12-01

In this paper, an online selective kernel-based temporal difference (OSKTD) learning algorithm is proposed to deal with large scale and/or continuous reinforcement learning problems. OSKTD includes two online procedures: online sparsification and parameter updating for the selective kernel-based value function. A new sparsification method (i.e., a kernel distance-based online sparsification method) is proposed based on selective ensemble learning, which is computationally less complex compared with other sparsification methods. With the proposed sparsification method, the sparsified dictionary of samples is constructed online by checking if a sample needs to be added to the sparsified dictionary. In addition, based on local validity, a selective kernel-based value function is proposed to select the best samples from the sample dictionary for the selective kernel-based value function approximator. The parameters of the selective kernel-based value function are iteratively updated by using the temporal difference (TD) learning algorithm combined with the gradient descent technique. The complexity of the online sparsification procedure in the OSKTD algorithm is O(n). In addition, two typical experiments (Maze and Mountain Car) are used to compare with both traditional and up-to-date O(n) algorithms (GTD, GTD2, and TDC using the kernel-based value function), and the results demonstrate the effectiveness of our proposed algorithm. In the Maze problem, OSKTD converges to an optimal policy and converges faster than both traditional and up-to-date algorithms. In the Mountain Car problem, OSKTD converges, requires less computation time compared with other sparsification methods, gets a better local optima than the traditional algorithms, and converges much faster than the up-to-date algorithms. In addition, OSKTD can reach a competitive ultimate optima compared with the up-to-date algorithms.

Lamellar Biogels: Fluid-Membrane-Based Hydrogels Containing Polymer Lipids

NASA Astrophysics Data System (ADS)

Warriner, Heidi E.; Idziak, Stefan H. J.; Slack, Nelle L.; Davidson, Patrick; Safinya, Cyrus R.

1996-02-01

A class of lamellar biological hydrogels comprised of fluid membranes of lipids and surfactants with small amounts of low molecular weight poly(ethylene glycol)-derived polymer lipids (PEG-lipids) were studied by x-ray diffraction, polarized light microscopy, and rheometry. In contrast to isotropic hydrogels of polymer networks, these membrane-based birefringent liquid crystalline biogels, labeled Lα,g, form the gel phase when water is added to the liquid-like lamellar L_α phase, which reenters a liquid-like mixed phase upon further dilution. Furthermore, gels with larger water content require less PEG-lipid to remain stable. Although concentrated (~50 weight percent) mixtures of free PEG (molecular weight, 5000) and water do not gel, gelation does occur in mixtures containing as little as 0.5 weight percent PEG-lipid. A defining signature of the Lα,g regime as it sets in from the fluid lamellar L_α phase is the proliferation of layer-dislocation-type defects, which are stabilized by the segregation of PEG-lipids to the defect regions of high membrane curvature that connect the membranes.

Concept of planetary gear system to control fluid mixture ratio

NASA Technical Reports Server (NTRS)

Mcgroarty, J. D.

1966-01-01

Mechanical device senses and corrects for fluid flow departures from the selected flow ratio of two fluids. This system has been considered for control of rocket engine propellant mixture control but could find use wherever control of the flow ratio of any two fluids is desired.

Mass spectrometry-based cDNA profiling as a potential tool for human body fluid identification.

PubMed

Donfack, Joseph; Wiley, Anissa

2015-05-01

Several mRNA markers have been exhaustively evaluated for the identification of human venous blood, saliva, and semen in forensic genetics. As new candidate human body fluid specific markers are discovered, evaluated, and reported in the scientific literature, there is an increasing trend toward determining the ideal markers for cDNA profiling of body fluids of forensic interest. However, it has not been determined which molecular genetics-based technique(s) should be utilized to assess the performance of these markers. In recent years, only a few confirmatory, mRNA/cDNA-based methods have been evaluated for applications in body fluid identification. The most frequently described methods tested to date include quantitative polymerase chain reaction (qPCR) and capillary electrophoresis (CE). However these methods, in particular qPCR, often favor narrow multiplex PCR due to the availability of a limited number of fluorescent dyes/tags. In an attempt to address this technological constraint, this study explored matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) for human body fluid identification via cDNA profiling of venous blood, saliva, and semen. Using cDNA samples at 20pg input phosphoglycerate kinase 1 (PGK1) amounts, body fluid specific markers for the candidate genes were amplified in their corresponding body fluid (i.e., venous blood, saliva, or semen) and absent in the remaining two (100% specificity). The results of this study provide an initial indication that MALDI-TOF MS is a potential fluorescent dye-free alternative method for body fluid identification in forensic casework. However, the inherent issues of low amounts of mRNA, and the damage caused to mRNA by environmental exposures, extraction processes, and storage conditions are important factors that significantly hinder the implementation of cDNA profiling into forensic casework. Published by Elsevier Ireland Ltd.

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid

PubMed Central

Koczula, Anna; Jarek, Michael; Visscher, Christian; Valentin-Weigand, Peter; Goethe, Ralph; Willenborg, Jörg

2017-01-01

Streptococcus suis is a zoonotic pathogen that can cause severe pathologies such as septicemia and meningitis in its natural porcine host as well as in humans. Establishment of disease requires not only virulence of the infecting strain but also an appropriate metabolic activity of the pathogen in its host environment. However, it is yet largely unknown how the streptococcal metabolism adapts to the different host niches encountered during infection. Our previous isotopologue profiling studies on S. suis grown in porcine blood and cerebrospinal fluid (CSF) revealed conserved activities of central carbon metabolism in both body fluids. On the other hand, they suggested differences in the de novo amino acid biosynthesis. This prompted us to further dissect S. suis adaptation to porcine blood and CSF by RNA deep sequencing (RNA-seq). In blood, the majority of differentially expressed genes were associated with transport of alternative carbohydrate sources and the carbohydrate metabolism (pentose phosphate pathway, glycogen metabolism). In CSF, predominantly genes involved in the biosynthesis of branched-chain and aromatic amino acids were differentially expressed. Especially, isoleucine biosynthesis seems to be of major importance for S. suis in CSF because several related biosynthetic genes were more highly expressed. In conclusion, our data revealed niche-specific metabolic gene activity which emphasizes a selective adaptation of S. suis to host environments. PMID:28212285

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid.

PubMed

Koczula, Anna; Jarek, Michael; Visscher, Christian; Valentin-Weigand, Peter; Goethe, Ralph; Willenborg, Jörg

2017-02-15

Streptococcus suis is a zoonotic pathogen that can cause severe pathologies such as septicemia and meningitis in its natural porcine host as well as in humans. Establishment of disease requires not only virulence of the infecting strain but also an appropriate metabolic activity of the pathogen in its host environment. However, it is yet largely unknown how the streptococcal metabolism adapts to the different host niches encountered during infection. Our previous isotopologue profiling studies on S. suis grown in porcine blood and cerebrospinal fluid (CSF) revealed conserved activities of central carbon metabolism in both body fluids. On the other hand, they suggested differences in the de novo amino acid biosynthesis. This prompted us to further dissect S. suis adaptation to porcine blood and CSF by RNA deep sequencing (RNA-seq). In blood, the majority of differentially expressed genes were associated with transport of alternative carbohydrate sources and the carbohydrate metabolism (pentose phosphate pathway, glycogen metabolism). In CSF, predominantly genes involved in the biosynthesis of branched-chain and aromatic amino acids were differentially expressed. Especially, isoleucine biosynthesis seems to be of major importance for S. suis in CSF because several related biosynthetic genes were more highly expressed. In conclusion, our data revealed niche-specific metabolic gene activity which emphasizes a selective adaptation of S. suis to host environments.

SPH modeling of fluid-solid interaction for dynamic failure analysis of fluid-filled thin shells

NASA Astrophysics Data System (ADS)

Caleyron, F.; Combescure, A.; Faucher, V.; Potapov, S.

2013-05-01

This work concerns the prediction of failure of a fluid-filled tank under impact loading, including the resulting fluid leakage. A water-filled steel cylinder associated with a piston is impacted by a mass falling at a prescribed velocity. The cylinder is closed at its base by an aluminum plate whose characteristics are allowed to vary. The impact on the piston creates a pressure wave in the fluid which is responsible for the deformation of the plate and, possibly, the propagation of cracks. The structural part of the problem is modeled using Mindlin-Reissner finite elements (FE) and Smoothed Particle Hydrodynamics (SPH) shells. The modeling of the fluid is also based on an SPH formulation. The problem involves significant fluid-structure interactions (FSI) which are handled through a master-slave-based method and the pinballs method. Numerical results are compared to experimental data.

Ultraselective Carbon Molecular Sieve Membranes with Tailored Synergistic Sorption Selective Properties.

PubMed

Zhang, Chen; Koros, William J

2017-09-01

Membrane-based separations can reduce the energy consumption and the CO 2 footprint of large-scale fluid separations, which are traditionally practiced by energy-intensive thermally driven processes. Here, a new type of membrane structure based on nanoporous carbon is reported, which, according to this study, is best referred to as carbon/carbon mixed-matrix (CCMM) membranes. The CCMM membranes are formed by high-temperature (up to 900 °C) pyrolysis of polyimide precursor hollow-fiber membranes. Unprecedentedly high permselectivities are seen in CCMM membranes for CO 2 /CH 4 , N 2 /CH 4 , He/CH 4 , and H 2 /CH 4 separations. Analysis of permeation data suggests that the ultrahigh selectivities result from substantially increased sorption selectivities, which is hypothetically owing to the formation of ultraselective micropores that selectively exclude the bulkier CH 4 molecules. With tunable sorption selectivities, the CCMM membranes outperform flexible polymer membranes and traditional rigid molecular-sieve membranes. The capability to increase sorption selectivities is a powerful tool to leverage diffusion selectivities, and has opened the door to many challenging and economically important fluid separations that require ultrafine differentiation of closely sized molecules. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Current Applications of Chromatographic Methods in the Study of Human Body Fluids for Diagnosing Disorders.

PubMed

Jóźwik, Jagoda; Kałużna-Czaplińska, Joanna

2016-01-01

Currently, analysis of various human body fluids is one of the most essential and promising approaches to enable the discovery of biomarkers or pathophysiological mechanisms for disorders and diseases. Analysis of these fluids is challenging due to their complex composition and unique characteristics. Development of new analytical methods in this field has made it possible to analyze body fluids with higher selectivity, sensitivity, and precision. The composition and concentration of analytes in body fluids are most often determined by chromatography-based techniques. There is no doubt that proper use of knowledge that comes from a better understanding of the role of body fluids requires the cooperation of scientists of diverse specializations, including analytical chemists, biologists, and physicians. This article summarizes current knowledge about the application of different chromatographic methods in analyses of a wide range of compounds in human body fluids in order to diagnose certain diseases and disorders.

Static characteristics design of hydrostatic guide-ways based on fluid-structure interactions

NASA Astrophysics Data System (ADS)

Lin, Shuo; Yin, YueHong

2016-10-01

With the raising requirements in micro optical systems, the available machines become hard to achieve the process dynamic and accuracy in all aspects. This makes compact design based on fluid/structure interactions (FSI) important. However, there is a difficulty in studying FSI with oil film as fluid domain. This paper aims at static characteristic design of a hydrostatic guide-way with capillary restrictors based on FSI. The pressure distribution of the oil film land is calculated by solving the Reynolds-equation with Galerkin technique. The deformation of structure is calculated by commercial FEM software, MSC. Nastran. A matlab program is designed to realize the coupling progress by modifying the load boundary in the submitting file and reading the deformation result. It's obvious that the stiffness of the hydrostatic bearing decreases with the weakening of the bearing structure. This program is proposed to make more precise prediction of bearing stiffness.

Fluorescent Gold Nanoclusters for Selective Detection of Dopamine in Cerebrospinal fluid

PubMed Central

Govindaraju, Saravanan; Ankireddy, Seshadri Reddy; Viswanath, Buddolla; Kim, Jongsung; Yun, Kyusik

2017-01-01

Since the last two decades, protein conjugated fluorescent gold nanoclusters (NCs) owe much attention in the field of medical and nanobiotechnology due to their excellent photo stability characteristics. In this paper, we reported stable, nontoxic and red fluorescent emission BSA-Au NCs for selective detection of L-dopamine (DA) in cerebrospinal fluid (CSF). The evolution was probed by various instrumental techniques such as UV-vis spectroscopy, High resolution transmission electron microscopy (HTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL). The synthesised BSA-Au NCs were showing 4–6 nm with high fluorescent ~8% Quantum yield (QY). The fluorescence intensity of BSA-Au NCs was quenched upon the addition of various concentrations of DA via an electron transfer mechanism. The decrease in BSA-Au NCs fluorescence intensity made it possible to determine DA in PBS buffer and the spiked DA in CSF in the linear range from 0 to 10 nM with the limit of detection (LOD) 0.622 and 0.830 nM respectively. Best of our knowledge, as-prepared BSA-Au NCs will gain possible strategy and good platform for biosensor, drug discovery, and rapid disease diagnosis such as Parkinson’s and Alzheimer diseases. PMID:28067307

A comparison of field-dependent rheological properties between spherical and plate-like carbonyl iron particles-based magneto-rheological fluids

NASA Astrophysics Data System (ADS)

Tan Shilan, Salihah; Amri Mazlan, Saiful; Ido, Yasushi; Hajalilou, Abdollah; Jeyadevan, Balachandran; Choi, Seung-Bok; Azhani Yunus, Nurul

2016-09-01

This work proposes different sizes of the plate-like particles from conventional spherical carbonyl iron (CI) particles by adjusting milling time in the ball mill process. The ball mill process to make the plate-like particles is called a solid-state powder processing technique which involves repeated welding, fracturing and re-welding of powder particles in a high-energy ball mill. The effect of ball milling process on the magnetic behavior of CI particles is firstly investigated by vibrating sample magnetometer. It is found form this investigation that the plate-like particles have higher saturation magnetization (about 8%) than that of the spherical particles. Subsequently, for the investigation on the sedimentation behavior the cylindrical measurement technique is used. It is observed from this measurement that the plate-like particles show slower sedimentation rate compared to the spherical particles indicating higher stability of the MR fluid. The field-dependent rheological properties of MR fluids based on the plate-like particles are then investigated with respect to the milling time which is directly connected to the size of the plate-like particles. In addition, the field-dependent rheological properties such as the yield stress are evaluated and compared between the plate-like particles based MR fluids and the spherical particles based MR fluid. It is found that the yield shear stress of the plate-like particles based MR fluid is increased up to 270% compared to the spherical particles based MR fluid.

Seismoelectric Effects based on Spectral-Element Method for Subsurface Fluid Characterization

NASA Astrophysics Data System (ADS)

Morency, C.

2017-12-01

Present approaches for subsurface imaging rely predominantly on seismic techniques, which alone do not capture fluid properties and related mechanisms. On the other hand, electromagnetic (EM) measurements add constraints on the fluid phase through electrical conductivity and permeability, but EM signals alone do not offer information of the solid structural properties. In the recent years, there have been many efforts to combine both seismic and EM data for exploration geophysics. The most popular approach is based on joint inversion of seismic and EM data, as decoupled phenomena, missing out the coupled nature of seismic and EM phenomena such as seismoeletric effects. Seismoelectric effects are related to pore fluid movements with respect to the solid grains. By analyzing coupled poroelastic seismic and EM signals, one can capture a pore scale behavior and access both structural and fluid properties.Here, we model the seismoelectric response by solving the governing equations derived by Pride and Garambois (1994), which correspond to Biot's poroelastic wave equations and Maxwell's electromagnetic wave equations coupled electrokinetically. We will show that these coupled wave equations can be numerically implemented by taking advantage of viscoelastic-electromagnetic mathematical equivalences. These equations will be solved using a spectral-element method (SEM). The SEM, in contrast to finite-element methods (FEM) uses high degree Lagrange polynomials. Not only does this allow the technique to handle complex geometries similarly to FEM, but it also retains exponential convergence and accuracy due to the use of high degree polynomials. Finally, we will discuss how this is a first step toward full coupled seismic-EM inversion to improve subsurface fluid characterization. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

a New ER Fluid Based Haptic Actuator System for Virtual Reality

NASA Astrophysics Data System (ADS)

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.

EEG feature selection method based on decision tree.

PubMed

Duan, Lijuan; Ge, Hui; Ma, Wei; Miao, Jun

2015-01-01

This paper aims to solve automated feature selection problem in brain computer interface (BCI). In order to automate feature selection process, we proposed a novel EEG feature selection method based on decision tree (DT). During the electroencephalogram (EEG) signal processing, a feature extraction method based on principle component analysis (PCA) was used, and the selection process based on decision tree was performed by searching the feature space and automatically selecting optimal features. Considering that EEG signals are a series of non-linear signals, a generalized linear classifier named support vector machine (SVM) was chosen. In order to test the validity of the proposed method, we applied the EEG feature selection method based on decision tree to BCI Competition II datasets Ia, and the experiment showed encouraging results.

Characterization of fluids and fluid-fluid interaction by fiber optic refractive index sensor measurements

NASA Astrophysics Data System (ADS)

Schmidt-Hattenberger, C.; Weiner, M.; Liebscher, A.; Spangenberg, E.

2009-04-01

A fiber optic refractive index sensor is tested for continuous monitoring of fluid-fluid and fluid-gas interactions within the frame of laboratory investigations of CO2 storage, monitoring and safety technology research (COSMOS project, "Geotechnologien" program). The sensor bases on a Fabry-Perot white light interferometer technique, where the refractive index (RI) of the solution under investigation is measured by variation of the liquid-filled Fabry-Perot optical cavity length. Such sensor system is typically used for measuring and controlling oil composition and also fluid quality. The aim of this study is to test the application of the fiber optic refractive index sensor for monitoring the CO2 dissolution in formation fluids (brine, oil, gas) of CO2 storage sites. Monitoring and knowledge of quantity and especially rate of CO2 dissolution in the formation fluid is important for any assessment of long-term risks of CO2 storage sites. It is also a prerequisite for any precise reservoir modelling. As a first step we performed laboratory experiments in standard autoclaves on a variety of different fluids and fluid mixtures (technical alcohols, pure water, CO2, synthetic brines, natural formation brine from the Ketzin test site). The RI measurements are partly combined with default electrical conductivity and sonic velocity measurements. The fiber optic refractive index sensor system allows for RI measurements within the range 1.0000 to 1.7000 RI with a resolution of approximately 0.0001 RI. For simple binary fluid mixtures first results indicate linear relationships between refractive indices and fluid composition. Within the pressure range investigated (up to 60 bar) the data suggest only minor changes of RI with pressure. Further, planned experiments will focus on the determination of i) the temperature dependency of RI, ii) the combined effects of pressure and temperature on RI, and finally iii) the kinetics of CO2 dissolution in realistic formation fluids.

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

NASA Astrophysics Data System (ADS)

Hou, Xu; Hu, Yuhang; Grinthal, Alison; Khan, Mughees; Aizenberg, Joanna

2015-03-01

Living organisms make extensive use of micro- and nanometre-sized pores as gatekeepers for controlling the movement of fluids, vapours and solids between complex environments. The ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and lab-on-chip systems. But although specific gating and transport behaviours have been realized by precisely tailoring pore surface chemistries and pore geometries, a single system capable of controlling complex, selective multiphase transport has remained a distant prospect, and fouling is nearly inevitable. Here we introduce a gating mechanism that uses a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state. Theoretical modelling and experiments demonstrate that for each transport substance, the gating threshold--the pressure needed to open the pores--can be rationally tuned over a wide pressure range. This enables us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas from escaping. These capabilities allow us to dynamically modulate gas-liquid sorting in a microfluidic flow and to separate a three-phase air-water-oil mixture, with the liquid lining ensuring sustained antifouling behaviour. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures and membrane materials, and to micro- as well as macroscale fluid systems, we expect it to prove useful in a wide range of applications.

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour.

PubMed

Hou, Xu; Hu, Yuhang; Grinthal, Alison; Khan, Mughees; Aizenberg, Joanna

2015-03-05

Living organisms make extensive use of micro- and nanometre-sized pores as gatekeepers for controlling the movement of fluids, vapours and solids between complex environments. The ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and lab-on-chip systems. But although specific gating and transport behaviours have been realized by precisely tailoring pore surface chemistries and pore geometries, a single system capable of controlling complex, selective multiphase transport has remained a distant prospect, and fouling is nearly inevitable. Here we introduce a gating mechanism that uses a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state. Theoretical modelling and experiments demonstrate that for each transport substance, the gating threshold-the pressure needed to open the pores-can be rationally tuned over a wide pressure range. This enables us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas from escaping. These capabilities allow us to dynamically modulate gas-liquid sorting in a microfluidic flow and to separate a three-phase air-water-oil mixture, with the liquid lining ensuring sustained antifouling behaviour. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures and membrane materials, and to micro- as well as macroscale fluid systems, we expect it to prove useful in a wide range of applications.

Simulation of solid-liquid flows in a stirred bead mill based on computational fluid dynamics (CFD)

NASA Astrophysics Data System (ADS)

Winardi, S.; Widiyastuti, W.; Septiani, E. L.; Nurtono, T.

2018-05-01

The selection of simulation model is an important step in computational fluid dynamics (CFD) to obtain an agreement with experimental work. In addition, computational time and processor speed also influence the performance of the simulation results. Here, we report the simulation of solid-liquid flow in a bead mill using Eulerian model. Multiple Reference Frame (MRF) was also used to model the interaction between moving (shaft and disk) and stationary (chamber exclude shaft and disk) zones. Bead mill dimension was based on the experimental work of Yamada and Sakai (2013). The effect of shaft rotation speed of 1200 and 1800 rpm on the particle distribution and the flow field was discussed. For rotation speed of 1200 rpm, the particles spread evenly throughout the bead mill chamber. On the other hand, for the rotation speed of 1800 rpm, the particles tend to be thrown to the near wall region resulting in the dead zone and found no particle in the center region. The selected model agreed well to the experimental data with average discrepancies less than 10%. Furthermore, the simulation was run without excessive computational cost.

Direct numerical simulation of viscoelastic-fluid-based nanofluid turbulent channel flow with heat transfer

NASA Astrophysics Data System (ADS)

Yang, Juan-Cheng; Li, Feng-Chen; Cai, Wei-Hua; Zhang, Hong-Na; Yu, Bo

2015-08-01

Our previous experimental studies have confirmed that viscoelastic-fluid-based nanofluid (VFBN) prepared by suspending nanoparticles in a viscoelastic base fluid (VBF, behaves drag reduction at turbulent flow state) can reduce turbulent flow resistance as compared with water and enhance heat transfer as compared with VBF. Direct numerical simulation (DNS) is performed in this study to explore the mechanisms of heat transfer enhancement (HTE) and flow drag reduction (DR) for the VFBN turbulent flow. The Giesekus model is used as the constitutive equation for VFBN. Our previously proposed thermal dispersion model is adopted to take into account the thermal dispersion effects of nanoparticles in the VFBN turbulent flow. The DNS results show similar behaviors for flow resistance and heat transfer to those obtained in our previous experiments. Detailed analyses are conducted for the turbulent velocity, temperature, and conformation fields obtained by DNSs for different fluid cases, and for the friction factor with viscous, turbulent, and elastic contributions and heat transfer rate with conductive, turbulent and thermal dispersion contributions of nanoparticles, respectively. The mechanisms of HTE and DR of VFBN turbulent flows are then discussed. Based on analogy theory, the ratios of Chilton-Colburn factor to friction factor for different fluid flow cases are investigated, which from another aspect show the significant enhancement in heat transfer performance for some cases of water-based nanofluid and VFBN turbulent flows. Project supported by the National Natural Science Foundation of China (Grant No. 51276046), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20112302110020), the China Postdoctoral Science Foundation (Grant No. 2014M561037), and the President Fund of University of Chinese Academy of Sciences, China (Grant No. Y3510213N00).

Rapid and inexpensive body fluid identification by RNA profiling-based multiplex High Resolution Melt (HRM) analysis

PubMed Central

Hanson, Erin K.; Ballantyne, Jack

2014-01-01

Positive identification of the nature of biological material present on evidentiary items can be crucial for understanding the circumstances surrounding a crime. However, traditional protein-based methods do not permit the identification of all body fluids and tissues, and thus molecular based strategies for the conclusive identification of all forensically relevant biological fluids and tissues need to be developed. Messenger RNA (mRNA) profiling is an example of such a molecular-based approach. Current mRNA body fluid identification assays involve capillary electrophoresis (CE) or quantitative RT-PCR (qRT-PCR) platforms, each with its own limitations. Both platforms require the use of expensive fluorescently labeled primers or probes. CE-based assays require separate amplification and detection steps thus increasing the analysis time. For qRT-PCR assays, only 3-4 markers can be included in a single reaction since each requires a different fluorescent dye. To simplify mRNA profiling assays, and reduce the time and cost of analysis, we have developed single- and multiplex body fluid High Resolution Melt (HRM) assays for the identification of common forensically relevant biological fluids and tissues. The incorporated biomarkers include IL19 (vaginal secretions), IL1F7 (skin), ALAS2 (blood), MMP10 (menstrual blood), HTN3 (saliva) and TGM4 (semen).  The HRM assays require only unlabeled PCR primers and a single saturating intercalating fluorescent dye (Eva Green). Each body-fluid-specific marker can easily be identified by the presence of a distinct melt peak. Usually, HRM assays are used to detect variants or isoforms for a single gene target. However, we have uniquely developed duplex and triplex HRM assays to permit the simultaneous detection of multiple targets per reaction. Here we describe the development and initial performance evaluation of the developed HRM assays. The results demonstrate the potential use of HRM assays for rapid, and relatively inexpensive

Rapid and inexpensive body fluid identification by RNA profiling-based multiplex High Resolution Melt (HRM) analysis.

PubMed

Hanson, Erin K; Ballantyne, Jack

2013-01-01

Positive identification of the nature of biological material present on evidentiary items can be crucial for understanding the circumstances surrounding a crime. However, traditional protein-based methods do not permit the identification of all body fluids and tissues, and thus molecular based strategies for the conclusive identification of all forensically relevant biological fluids and tissues need to be developed. Messenger RNA (mRNA) profiling is an example of such a molecular-based approach. Current mRNA body fluid identification assays involve capillary electrophoresis (CE) or quantitative RT-PCR (qRT-PCR) platforms, each with its own limitations. Both platforms require the use of expensive fluorescently labeled primers or probes. CE-based assays require separate amplification and detection steps thus increasing the analysis time. For qRT-PCR assays, only 3-4 markers can be included in a single reaction since each requires a different fluorescent dye. To simplify mRNA profiling assays, and reduce the time and cost of analysis, we have developed single- and multiplex body fluid High Resolution Melt (HRM) assays for the identification of common forensically relevant biological fluids and tissues. The incorporated biomarkers include IL19 (vaginal secretions), IL1F7 (skin), ALAS2 (blood), MMP10 (menstrual blood), HTN3 (saliva) and TGM4 (semen).  The HRM assays require only unlabeled PCR primers and a single saturating intercalating fluorescent dye (Eva Green). Each body-fluid-specific marker can easily be identified by the presence of a distinct melt peak. Usually, HRM assays are used to detect variants or isoforms for a single gene target. However, we have uniquely developed duplex and triplex HRM assays to permit the simultaneous detection of multiple targets per reaction. Here we describe the development and initial performance evaluation of the developed HRM assays. The results demonstrate the potential use of HRM assays for rapid, and relatively inexpensive

Fluid Shifts

NASA Technical Reports Server (NTRS)

Stenger, Michael; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.;

Multicomponent Pt-Based Zigzag Nanowires as Selectivity Controllers for Selective Hydrogenation Reactions.

PubMed

Bai, Shuxing; Bu, Lingzheng; Shao, Qi; Zhu, Xing; Huang, Xiaoqing

2018-06-22

The selective hydrogenation of α, β-unsaturated aldehyde is an extremely important transformation, while developing efficient catalysts with desirable selectivity to highly value-added products is challenging, mainly due to the coexistence of two conjugated unsaturated functional groups. Herein, we report that a series of Pt-based zigzag nanowires (ZNWs) can be adopted as selectivity controllers for α, β-unsaturated aldehyde hydrogenation, where the excellent unsaturated alcohol (UOL) selectivity (>95%) and high saturated aldehyde (SA) selectivity (>94%) are achieved on PtFe ZNWs and PtFeNi ZNWs+AlCl 3 , respectively. The excellent UOL selectivity of PtFe ZNWs is attributed to the lower electron density of the surface Pt atoms, while the high SA selectivity of PtFeNi ZNWs+AlCl 3 is due to synergy between PtFeNi ZNWs and AlCl 3 , highlighting the importance of Pt-based NWs with precisely controlled surface and composition for catalysis and beyond.

Micromachined Fluid Inertial Sensors

PubMed Central

Liu, Shiqiang; Zhu, Rong

2017-01-01

Micromachined fluid inertial sensors are an important class of inertial sensors, which mainly includes thermal accelerometers and fluid gyroscopes, which have now been developed since the end of the last century for about 20 years. Compared with conventional silicon or quartz inertial sensors, the fluid inertial sensors use a fluid instead of a solid proof mass as the moving and sensitive element, and thus offer advantages of simple structures, low cost, high shock resistance, and large measurement ranges while the sensitivity and bandwidth are not competitive. Many studies and various designs have been reported in the past two decades. This review firstly introduces the working principles of fluid inertial sensors, followed by the relevant research developments. The micromachined thermal accelerometers based on thermal convection have developed maturely and become commercialized. However, the micromachined fluid gyroscopes, which are based on jet flow or thermal flow, are less mature. The key issues and technologies of the thermal accelerometers, mainly including bandwidth, temperature compensation, monolithic integration of tri-axis accelerometers and strategies for high production yields are also summarized and discussed. For the micromachined fluid gyroscopes, improving integration and sensitivity, reducing thermal errors and cross coupling errors are the issues of most concern. PMID:28216569

[Fluid therapy in acute pancreatitis].

PubMed

de-Madaria, Enrique

2013-12-01

Severe acute pancreatitis (AP) is associated with an increased need for fluids due to fluid sequestration and, in the most severe cases, with decreased peripheral vascular tone. For several decades, clinical practice guidelines have recommended aggressive fluid therapy to improve the prognosis of AP. This recommendation is based on theoretical models, animal studies, and retrospective studies in humans. Recent studies suggest that aggressive fluid administration in all patients with AP could have a neutral or harmful effect. Fluid therapy based on Ringer's lactate could improve the course of the disease, although further studies are needed to confirm this possibility. Most patients with AP do not require invasive monitoring of hemodynamic parameters to guide fluid therapy administration. Moreover, the ability of these parameters to improve prognosis has not been demonstrated. Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.

Damping of a fluid-conveying pipe surrounded by a viscous annulus fluid

NASA Astrophysics Data System (ADS)

Kjolsing, Eric J.; Todd, Michael D.

2017-04-01

To further the development of a downhole vibration based energy harvester, this study explores how fluid velocity affects damping in a fluid-conveying pipe stemming from a viscous annulus fluid. A linearized equation of motion is formed which employs a hydrodynamic forcing function to model the annulus fluid. The system is solved in the frequency domain through the use of the spectral element method. The three independent variables investigated are the conveyed fluid velocity, the rotational stiffness of the boundary (using elastic springs), and the annulus fluid viscosity. It was found that, due to the hydrodynamic functions frequency-dependence, increasing the conveyed fluid velocity increases the systems damping ratio. It was also noted that stiffer systems saw the damping ratio increase at a slower rate when compared to flexible systems as the conveyed fluid velocity was increased. The results indicate that overestimating the stiffness of a system can lead to underestimated damping ratios and that this error is made worse if the produced fluid velocity or annulus fluid viscosity is underestimated. A numeric example was provided to graphically illustrate these errors. Approved for publication, LA-UR-15-28006.

Novel cavitation fluid jet polishing process based on negative pressure effects.

PubMed

Chen, Fengjun; Wang, Hui; Tang, Yu; Yin, Shaohui; Huang, Shuai; Zhang, Guanghua

2018-04-01

Traditional abrasive fluid jet polishing (FJP) is limited by its high-pressure equipment, unstable material removal rate, and applicability to ultra-smooth surfaces because of the evident air turbulence, fluid expansion, and a large polishing spot in high-pressure FJP. This paper presents a novel cavitation fluid jet polishing (CFJP) method and process based on FJP technology. It can implement high-efficiency polishing on small-scale surfaces in a low-pressure environment. CFJP uses the purposely designed polishing equipment with a sealed chamber, which can generate a cavitation effect in negative pressure environment. Moreover, the collapse of cavitation bubbles can spray out a high-energy microjet and shock wave to enhance the material removal. Its feasibility is verified through researching the flow behavior and the cavitation results of the negative pressure cavitation machining of pure water in reversing suction flow. The mechanism is analyzed through a computational fluid dynamics simulation. Thus, its cavitation and surface removal mechanisms in the vertical CFJP and inclined CFJP are studied. A series of polishing experiments on different materials and polishing parameters are conducted to validate its polishing performance compared with FJP. The maximum removal depth increases, and surface roughness gradually decreases with increasing negative outlet pressures. The surface becomes smooth with the increase of polishing time. The experimental results confirm that the CFJP process can realize a high material removal rate and smooth surface with low energy consumption in the low-pressure environment, together with compatible surface roughness to FJP. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental determination of nanofluid specific heat with SiO2 nanoparticles in different base fluids

NASA Astrophysics Data System (ADS)

Akilu, S.; Baheta, A. T.; Sharma, K. V.; Said, M. A.

2017-09-01

Nanostructured ceramic materials have recently attracted attention as promising heat transfer fluid additives owing to their outstanding heat storage capacities. In this paper, experimental measurements of the specific heats of SiO2-Glycerol, SiO2-Ethylene Glycol, and SiO2-Glycerol/Ethylene Glycol mixture 60:40 ratio (by mass) nanofluids with different volume concentrations of 1.0-4.0% have been carried out using differential scanning calorimeter at temperatures of 25 °C and 50 °C. Experimental results indicate lower specific heat capacities are found with SiO2 nanofluids compared to their respective base fluids. The specific heat was decreasing with the increase of concentration, and this decrement depends on upon the type of the base fluid. It is observed that temperature has a positive impact on the specific heat capacity. Furthermore, the experimental values were compared with the theoretical model predictions, and a satisfactory agreement was established.

Fullerol ionic fluids.

PubMed

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).

Fullerol ionic fluids

NASA Astrophysics Data System (ADS)

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).

Cryogenic fluid management experiment

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.; Fester, D. A.

1981-01-01

The cryogenic fluid management experiment (CFME), designed to characterize subcritical liquid hydrogen storage and expulsion in the low-q space environment, is discussed. The experiment utilizes a fine mesh screen fluid management device to accomplish gas-free liquid expulsion and a thermodynamic vent system to intercept heat leak and control tank pressure. The experiment design evolved from a single flight prototype to provision for a multimission (up to 7) capability. A detailed design of the CFME, a dynamic test article, and dedicated ground support equipment were generated. All materials and parts were identified, and components were selected and specifications prepared. Long lead titanium pressurant spheres and the flight tape recorder and ground reproduce unit were procured. Experiment integration with the shuttle orbiter, Spacelab, and KSC ground operations was coordinated with the appropriate NASA centers, and experiment interfaces were defined. Phase 1 ground and flight safety reviews were conducted. Costs were estimated for fabrication and assembly of the CFME, which will become the storage and supply tank for a cryogenic fluid management facility to investigate fluid management in space.

Investigation of mud density and weighting materials effect on drilling fluid filter cake properties and formation damage

NASA Astrophysics Data System (ADS)

Fattah, K. A.; Lashin, A.

2016-05-01

Drilling fluid density/type is an important factor in drilling and production operations. Most of encountered problems during rotary drilling are related to drilling mud types and weights. This paper aims to investigate the effect of mud weight on filter cake properties and formation damage through two experimental approaches. In the first approach, seven water-based drilling fluid samples with same composition are prepared with different densities (9.0-12.0 lb/gal) and examined to select the optimum mud weight that has less damage. The second approach deals with investigating the possible effect of the different weighting materials (BaSO4 and CaCO3) on filter cake properties. High pressure/high temperature loss tests and Scanning Electron Microscopy (SEM) analyses were carried out on the filter cake (two selected samples). Data analysis has revealed that mud weigh of 9.5 lb/gal has the less reduction in permeability of ceramic disk, among the seven used mud densities. Above 10.5 ppg the effect of the mud weight density on formation damage is stabilized at constant value. Fluids of CaCO3-based weighting material, has less reduction in the porosity (9.14%) and permeability (25%) of the filter disk properties than the BaSO4-based fluid. The produced filter cake porosity increases (from 0.735 to 0.859) with decreasing of fluid density in case of drilling samples of different densities. The filtration loss tests indicated that CaCO3 filter cake porosity (0.52) is less than that of the BaSO4 weighted material (0.814). The thickness of the filter cake of the BaSO4-based fluid is large and can cause some problems. The SEM analysis shows that some major elements do occur on the tested samples (Ca, Al, Si, and Ba), with dominance of Ca on the expense of Ba for the CaCO3 fluid sample and vice versa. The less effect of 9.5 lb/gal mud sample is reflected in the well-produced inter-particle pore structure and relatively crystal size. A general recommendation is given to

Development of Environmentally Benign and Reduced Corrosion Runway Deicing Fluid

DTIC Science & Technology

2009-08-01

PCNA Peter Cremer North America PG Propylene glycol P&G Proctor and Gamble Inc. PNNL Pacific Northwest National Laboratory RDF Runway Deicing...Navy/NAVAIR Defining Navy needs Mack Findley Peter Cremer North America (PCNA) Bio-based raw materials selection Pat Viani SMI AMS 1435 testing...SMI), and other laboratories under the leadership of SAE G-12 Fluids Subcommittee, and is expected to provide a better indication of compatibility with

Microfluidic viscometers for shear rheology of complex fluids and biofluids

PubMed Central

Wang, William S.; Vanapalli, Siva A.

2016-01-01

The rich diversity of man-made complex fluids and naturally occurring biofluids is opening up new opportunities for investigating their flow behavior and characterizing their rheological properties. Steady shear viscosity is undoubtedly the most widely characterized material property of these fluids. Although widely adopted, macroscale rheometers are limited by sample volumes, access to high shear rates, hydrodynamic instabilities, and interfacial artifacts. Currently, microfluidic devices are capable of handling low sample volumes, providing precision control of flow and channel geometry, enabling a high degree of multiplexing and automation, and integrating flow visualization and optical techniques. These intrinsic advantages of microfluidics have made it especially suitable for the steady shear rheology of complex fluids. In this paper, we review the use of microfluidics for conducting shear viscometry of complex fluids and biofluids with a focus on viscosity curves as a function of shear rate. We discuss the physical principles underlying different microfluidic viscometers, their unique features and limits of operation. This compilation of technological options will potentially serve in promoting the benefits of microfluidic viscometry along with evincing further interest and research in this area. We intend that this review will aid researchers handling and studying complex fluids in selecting and adopting microfluidic viscometers based on their needs. We conclude with challenges and future directions in microfluidic rheometry of complex fluids and biofluids. PMID:27478521

Fluid Mechanics and Homeland Security

NASA Astrophysics Data System (ADS)

Settles, Gary S.

2006-01-01

Homeland security involves many applications of fluid mechanics and offers many opportunities for research and development. This review explores a wide selection of fluids topics in counterterrorism and suggests future directions. Broad topics range from preparedness and deterrence of impending terrorist attacks to detection, response, and recovery. Specific topics include aircraft hardening, blast mitigation, sensors and sampling, explosive detection, microfluidics and labs-on-a-chip, chemical plume dispersal in urban settings, and building ventilation. Also discussed are vapor plumes and standoff detection, nonlethal weapons, airborne disease spread, personal protective equipment, and decontamination. Involvement in these applications requires fluid dynamicists to think across the traditional boundaries of the field and to work with related disciplines, especially chemistry, biology, aerosol science, and atmospheric science.

Zirconia-coated carbonyl-iron-particle-based magnetorheological fluid for polishing optical glasses and ceramics.

PubMed

Shafrir, Shai N; Romanofsky, Henry J; Skarlinski, Michael; Wang, Mimi; Miao, Chunlin; Salzman, Sivan; Chartier, Taylor; Mici, Joni; Lambropoulos, John C; Shen, Rui; Yang, Hong; Jacobs, Stephen D

2009-12-10

We report on magnetorheological finishing (MRF) spotting experiments performed on glasses and ceramics using a zirconia-coated carbonyl-iron (CI)-particle-based magnetorheological (MR) fluid. The zirconia-coated magnetic CI particles were prepared via sol-gel synthesis in kilogram quantities. The coating layer was approximately 50-100 nm thick, faceted in surface structure, and well adhered. Coated particles showed long-term stability against aqueous corrosion. "Free" nanocrystalline zirconia polishing abrasives were cogenerated in the coating process, resulting in an abrasive-charged powder for MRF. A viable MR fluid was prepared simply by adding water. Spot polishing tests were performed on a variety of optical glasses and ceramics over a period of nearly three weeks with no signs of MR fluid degradation or corrosion. Stable material removal rates and smooth surfaces inside spots were obtained.

More Analytical Tools for Fluids Management in Space

NASA Astrophysics Data System (ADS)

Weislogel, Mark

Continued advances during the 2000-2010 decade in the analysis of a class of capillary-driven flows relevant to materials processing and fluids management aboard spacecraft have been made. The class of flows addressed concern combined forced and spontaneous capillary flows in complex containers with interior edges. Such flows are commonplace in space-based fluid systems and arise from the particular container geometry and wetting properties of the system. Important applications for this work include low-g liquid fill and/or purge operations and passive fluid phase separation operations, where the container (i.e. fuel tank, water processer, etc.) geometry possesses interior edges, and where quantitative information of fluid location, transients, flow rates, and stability is critical. Examples include the storage and handling of liquid propellants and cryogens, water conditioning for life support, fluid phase-change thermal systems, materials processing in the liquid state, on-orbit biofluids processing, among others. For a growing number of important problems, closed-form expressions to transient three-dimensional flows are possible that, as design tools, replace difficult, time-consuming, and rarely performed numerical calculations. An overview of a selection of solutions in-hand is presented with example problems solved. NASA drop tower, low-g aircraft, and ISS flight ex-periment results are employed where practical to buttress the theoretical findings. The current review builds on a similar review presented at COSPAR, 2002, for the approximate decade 1990-2000.

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, X; Hu, YH; Grinthal, A

Living organisms make extensive use of micro- and nanometre-sized pores as gatekeepers for controlling the movement of fluids, vapours and solids between complex environments. The ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and lab-on-chip systems(1-10). But although specific gating and transport behaviours have been realized by precisely tailoring pore surface chemistries and pore geometries(6,11-17), a single system capable of controlling complex, selective multiphase transport has remained a distant prospect, and fouling ismore » nearly inevitable(11,12). Here we introduce a gating mechanism that uses a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state. Theoretical modelling and experiments demonstrate that for each transport substance, the gating threshold-the pressure needed to open the pores-can be rationally tuned over a wide pressure range. This enables us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas from escaping. These capabilities allow us to dynamically modulate gas-liquid sorting in a microfluidic flow and to separate a three-phase air-water-oil mixture, with the liquid lining ensuring sustained antifouling behaviour. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures and membrane materials, and to micro- as well as macroscale fluid systems, we expect it to prove useful in a wide range of applications.« less

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Xu; Hu, Yuhang; Grinthal, Alison

Living organisms make extensive use of micro- and nanometre-sized pores as gatekeepers for controlling the movement of fluids, vapours and solids between complex environments. In addition, the ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and lab-on-chip systems 1-10.But although specific gating and transport behaviours have been realized by precisely tailoring pore surface chemistries and pore geometries 6,11–17, a single system capable of controlling complex, selective multiphase transport has remained a distant prospect,more » and fouling is nearly inevitable.Here we introduce a gating mechanism that uses a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state.Theoretical modelling and experiments demonstrate that for each transport substance, the gating threshold—the pressure needed to open the pores—can be rationally tuned over a wide pressure range. This enables us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas from escaping.These capabilities allow us to dynamically modulate gas–liquid sorting in a microfluidic flow and to separate a three-phase air water–oil mixture, with the liquid lining ensuring sustained antifouling behaviour. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures and membrane materials, and to micro- as well as macroscale fluid systems, we expect it to prove useful in a wide range of applications.« less

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

DOE PAGES

Hou, Xu; Hu, Yuhang; Grinthal, Alison; ...

2015-03-04

Living organisms make extensive use of micro- and nanometre-sized pores as gatekeepers for controlling the movement of fluids, vapours and solids between complex environments. In addition, the ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and lab-on-chip systems 1-10.But although specific gating and transport behaviours have been realized by precisely tailoring pore surface chemistries and pore geometries 6,11–17, a single system capable of controlling complex, selective multiphase transport has remained a distant prospect,more » and fouling is nearly inevitable.Here we introduce a gating mechanism that uses a capillary-stabilized liquid as a reversible, reconfigurable gate that fills and seals pores in the closed state, and creates a non-fouling, liquid-lined pore in the open state.Theoretical modelling and experiments demonstrate that for each transport substance, the gating threshold—the pressure needed to open the pores—can be rationally tuned over a wide pressure range. This enables us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas from escaping.These capabilities allow us to dynamically modulate gas–liquid sorting in a microfluidic flow and to separate a three-phase air water–oil mixture, with the liquid lining ensuring sustained antifouling behaviour. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures and membrane materials, and to micro- as well as macroscale fluid systems, we expect it to prove useful in a wide range of applications.« less

Weight-based determination of fluid overload status and mortality in pediatric intensive care unit patients requiring continuous renal replacement therapy

PubMed Central

Selewski, David T.; Cornell, Timothy T.; Lombel, Rebecca M.; Blatt, Neal B.; Han, Yong Y.; Mottes, Theresa; Kommareddi, Mallika; Kershaw, David B.; Shanley, Thomas P.; Heung, Michael

2012-01-01

Purpose In pediatric intensive care unit (PICU) patients, fluid overload (FO) at initiation of continuous renal replacement therapy (CRRT) has been reported to be an independent risk factor for mortality. Previous studies have calculated FO based on daily fluid balance during ICU admission, which is labor intensive and error prone. We hypothesized that a weight-based definition of FO at CRRT initiation would correlate with the fluid balance method and prove predictive of outcome. Methods This is a retrospective single-center review of PICU patients requiring CRRT from July 2006 through February 2010 (n = 113). We compared the degree of FO at CRRT initiation using the standard fluid balance method versus methods based on patient weight changes assessed by both univariate and multivariate analyses. Results The degree of fluid overload at CRRT initiation was significantly greater in nonsurvivors, irrespective of which method was used. The univariate odds ratio for PICU mortality per 1% increase in FO was 1.056 [95% confidence interval (CI) 1.025, 1.087] by the fluid balance method, 1.044 (95% CI 1.019, 1.069) by the weight-based method using PICU admission weight, and 1.045 (95% CI 1.022, 1.07) by the weight-based method using hospital admission weight. On multivariate analyses, all three methods approached significance in predicting PICU survival. Conclusions Our findings suggest that weight-based definitions of FO are useful in defining FO at CRRT initiation and are associated with increased mortality in a broad PICU patient population. This study provides evidence for a more practical weight-based definition of FO that can be used at the bedside. PMID:21533569

Studying effect of carrier fluid viscosity in magnetite based ferrofluids using optical tweezers

NASA Astrophysics Data System (ADS)

Savitha, S.; Iyengar, Shruthi S.; Ananthamurthy, Sharath; Bhattacharya, Sarbari

2018-02-01

Ferrofluids with varying viscosities of carrier fluids have been prepared with magnetite (Fe3O4) nanoparticles. The nanoparticles were synthesized by chemical co-precipitation and characterized using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). They were found to be nearly spherical in shape with an almost uniform size of 13nm. The superparamagnetic nature of the water based ferrofluids at room temperature was established by SQUID magnetometry. Dynamic light scattering (DLS) was carried out to establish the size of the nanoparticle clusters in the ferrofluids synthesized. The results indicate an increase in cluster size with increase in carrier fluid viscosity. This is supported by results from Raman Spectroscopy. A further attempt to characterise these ferrofluids was made by studying the behaviour of well characterised non-magnetic micron sized probes that are optically trapped while suspended in the ferrofluid. An increase in carrier fluid viscosity results in a decrease in corner frequency when only the carrier fluid is used as the suspending medium. When the magnetic component is also present the corner frequency is higher than with just the carrier fluid. This relative increase happens at all laser powers at the trapping plane. This trend is also found to be independent of the size and material of the probe particle. Comparisons of various parameters that influence optical trapping lead us to believe that the enhancement could be due to a directed motion of the magnetic clusters in the presence of an optical trap.

Size-selective pulmonary dose indices for metal-working fluid aerosols in machining and grinding operations in the automobile manufacturing industry.

PubMed

Woskie, S R; Smith, T J; Hallock, M F; Hammond, S K; Rosenthal, F; Eisen, E A; Kriebel, D; Greaves, I A

1994-01-01

The current metal-working fluid exposures at three locations that manufacture automotive parts were assessed in conjunction with epidemiological studies of the mortality and respiratory morbidity experiences of workers at these plants. A rationale is presented for selecting and characterizing epidemiologic exposure groups in this environment. More than 475 full-shift personal aerosol samples were taken using a two-stage personal cascade impactor with median size cut-offs of 9.8 microns and 3.5 microns, plus a backup filter. For a sample of 403 workers exposed to aerosols of machining or grinding fluids, the mean total exposure was 706 micrograms/m3 (standard error (SE) = 21 micrograms/m3). Among 72 assemblers unexposed to machining fluids, the mean total exposure was 187 +/- 10 (SE) micrograms/m3. An analysis of variance model identified factors significantly associated with exposure level and permitted estimates of exposure for workers in the unsampled machine type/metal-working fluid groups. Comparison of the results obtained from personal impactor samples with predictions from an aerosol-deposition model for the human respiratory tract showed high correlation. However, the amount collected on the impactor stage underestimates extrathoracic deposition and overestimates tracheobronchial and alveolar deposition, as calculated by the deposition model. When both the impactor concentration and the deposition-model concentration were used to estimate cumulative thoracic concentrations for the worklives of a subset of auto workers, there was no significant difference in the rank order of the subjects' cumulative concentration. However, the cumulative impactor concentration values were significantly higher than the cumulative deposition-model concentration values for the subjects.

Distribution of crystalloid fluid changes with the rate of infusion: a population-based study.

PubMed

Hahn, R G; Drobin, D; Zdolsek, J

2016-05-01

Crystalloid fluid requires 30 min for complete distribution throughout the extracellular fluid space and tends to cause long-standing peripheral edema. A kinetic analysis of the distribution of Ringer's acetate with increasing infusion rates was performed to obtain a better understanding of these characteristics of crystalloids. Data were retrieved from six studies in which 76 volunteers and preoperative patients had received between 300 ml and 2375 ml of Ringer's acetate solution at a rate of 20-80 ml/min (0.33-0.83 ml/min/kg). Serial measurements of the blood hemoglobin concentration were used as inputs in a kinetic analysis based on a two-volume model with micro-constants, using software for nonlinear mixed effects. The micro-constants describing distribution (k12) and elimination (k10) were unchanged when the rate of infusion increased, with half-times of 16 and 26 min, respectively. In contrast, the micro-constant describing how rapidly the already distributed fluid left the peripheral space (k21) decreased by 90% when the fluid was infused more rapidly, corresponding to an increase in the half-time from 3 to 30 min. The central volume of distribution (V(c)) doubled. The return of Ringer's acetate from the peripheral fluid compartment to the plasma was slower with high than with low infusion rates. Edema is a normal consequence of plasma volume expansion with this fluid, even in healthy volunteers. The results are consistent with the view that the viscoelastic properties of the interstitial matrix are responsible for the distribution and redistribution characteristics of crystalloid fluid. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Drilling fluid thinner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, B.

1989-06-27

A drilling fluid additive is described comprising a mixture of: (a) a sulfoalkylated tannin and (b) chromium acetate selected from the group consisting of chromium (III) acetate and chromium (II) acetate, wherein the chromium acetate is present in a weight ratio of the chromium acetate to the sulfoalkylated tannin in the range of from about 1:20 to about 1:1.

Structure, thermodynamics, and solubility in tetromino fluids.

PubMed

Barnes, Brian C; Siderius, Daniel W; Gelb, Lev D

2009-06-16

To better understand the self-assembly of small molecules and nanoparticles adsorbed at interfaces, we have performed extensive Monte Carlo simulations of a simple lattice model based on the seven hard "tetrominoes", connected shapes that occupy four lattice sites. The equations of state of the pure fluids and all of the binary mixtures are determined over a wide range of density, and a large selection of multicomponent mixtures are also studied at selected conditions. Calculations are performed in the grand canonical ensemble and are analogous to real systems in which molecules or nanoparticles reversibly adsorb to a surface or interface from a bulk reservoir. The model studied is athermal; objects in these simulations avoid overlap but otherwise do not interact. As a result, all of the behavior observed is entropically driven. The one-component fluids all exhibit marked self-ordering tendencies at higher densities, with quite complex structures formed in some cases. Significant clustering of objects with the same rotational state (orientation) is also observed in some of the pure fluids. In all of the binary mixtures, the two species are fully miscible at large scales, but exhibit strong species-specific clustering (segregation) at small scales. This behavior persists in multicomponent mixtures; even in seven-component mixtures of all the shapes there is significant association between objects of the same shape. To better understand these phenomena, we calculate the second virial coefficients of the tetrominoes and related quantities, extract thermodynamic volume of mixing data from the simulations of binary mixtures, and determine Henry's law solubilities for each shape in a variety of solvents. The overall picture obtained is one in which complementarity of both the shapes of individual objects and the characteristic structures of different fluids are important in determining the overall behavior of a fluid of a given composition, with sometimes

Third Microgravity Fluid Physics Conference

NASA Technical Reports Server (NTRS)

1996-01-01

The conference's purpose was to inform the fluid physics community of research opportunities in reduced-gravity fluid physics, present the status of the existing and planned reduced gravity fluid physics research programs, and inform participants of the upcoming NASA Research Announcement in this area. The plenary sessions provided an overview of the Microgravity Fluid Physics Program, present and future areas of emphasis, information on NASA's ground-based and space-based flight research facilities-especially use of the International Space Station, and the process by which future investigators enter the program. An international forum offered participants an opportunity to hear from Russian speakers about their microgravity research programs. Three keynote speakers provided broad technical overviews on the history and future development of the moon and on multiphase flow and complex fluids research. One keynote paper and an extended abstract are included in the proceedings. One hundred and thirty-two technical papers were presented in 28 sessions. Presenters briefed their peers on the scientific results of their ground-based and flight research. One hundred and twenty-two papers are included here.

Fluid loss control additives for oil well cementing compositions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crema, S.C.; Kucera, C.H.

1992-03-03

This patent describes a cementing composition useful in cementing oil, gas and water wells. It comprises hydraulic cement; and a fluid loss additive in an amount effective to reduce fluid loss, the fluid loss additive comprised of a copolymer of acrylamide monomer and vinyl formamide monomer and derivatives thereof in a weight percent ratio of from about 95:5 to 5:95, the copolymer having a molecular weight range of from about 10,000 to 3,000,000, the acrylamide monomer being selected from the group consisting of acrylamide, methacrylamide, N,N-dimethyl(meth)acrylamide, dialkylaminoalkyl(meth) acrylamide and mixtures thereof, the vinyl formamide monomer being selected from the groupmore » consisting of vinyl formamide, its hydrolysis products and derivatives thereof.« less

Development of an operation strategy for hydrogen production using solar PV energy based on fluid dynamic aspects

NASA Astrophysics Data System (ADS)

Amores, Ernesto; Rodríguez, Jesús; Oviedo, José; de Lucas-Consuegra, Antonio

2017-06-01

Alkaline water electrolysis powered by renewable energy sources is one of the most promising strategies for environmentally friendly hydrogen production. However, wind and solar energy sources are highly dependent on weather conditions. As a result, power fluctuations affect the electrolyzer and cause several negative effects. Considering these limiting effects which reduce the water electrolysis efficiency, a novel operation strategy is proposed in this study. It is based on pumping the electrolyte according to the current density supplied by a solar PV module, in order to achieve the suitable fluid dynamics conditions in an electrolysis cell. To this aim, a mathematical model including the influence of electrode-membrane distance, temperature and electrolyte flow rate has been developed and used as optimization tool. The obtained results confirm the convenience of the selected strategy, especially when the electrolyzer is powered by renewable energies.

7 CFR 2902.20 - Fluid-filled transformers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Fluid-filled transformers. 2902.20 Section 2902.20... Items § 2902.20 Fluid-filled transformers. (a) Definition. (1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

7 CFR 3201.20 - Fluid-filled transformers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false Fluid-filled transformers. 3201.20 Section 3201.20... Designated Items § 3201.20 Fluid-filled transformers. (a) Definition. (1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

7 CFR 3201.20 - Fluid-filled transformers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Fluid-filled transformers. 3201.20 Section 3201.20... Designated Items § 3201.20 Fluid-filled transformers. (a) Definition—(1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

7 CFR 2902.20 - Fluid-filled transformers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Fluid-filled transformers. 2902.20 Section 2902.20... Items § 2902.20 Fluid-filled transformers. (a) Definition. (1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

7 CFR 3201.20 - Fluid-filled transformers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Fluid-filled transformers. 3201.20 Section 3201.20... Designated Items § 3201.20 Fluid-filled transformers. (a) Definition—(1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

Fluid Analysis and Improved Structure of an ATEG Heat Exchanger Based on Computational Fluid Dynamics

NASA Astrophysics Data System (ADS)

Tang, Z. B.; Deng, Y. D.; Su, C. Q.; Yuan, X. H.

2015-06-01

In this study, a numerical model has been employed to analyze the internal flow field distribution in a heat exchanger applied for an automotive thermoelectric generator based on computational fluid dynamics. The model simulates the influence of factors relevant to the heat exchanger, including the automotive waste heat mass flow velocity, temperature, internal fins, and back pressure. The result is in good agreement with experimental test data. Sensitivity analysis of the inlet parameters shows that increase of the exhaust velocity, compared with the inlet temperature, makes little contribution (0.1 versus 0.19) to the heat transfer but results in a detrimental back pressure increase (0.69 versus 0.21). A configuration equipped with internal fins is proved to offer better thermal performance compared with that without fins. Finally, based on an attempt to improve the internal flow field, a more rational structure is obtained, offering a more homogeneous temperature distribution, higher average heat transfer coefficient, and lower back pressure.

Group contribution methodology based on the statistical associating fluid theory for heteronuclear molecules formed from Mie segments.

PubMed

Papaioannou, Vasileios; Lafitte, Thomas; Avendaño, Carlos; Adjiman, Claire S; Jackson, George; Müller, Erich A; Galindo, Amparo

2014-02-07

A generalization of the recent version of the statistical associating fluid theory for variable range Mie potentials [Lafitte et al., J. Chem. Phys. 139, 154504 (2013)] is formulated within the framework of a group contribution approach (SAFT-γ Mie). Molecules are represented as comprising distinct functional (chemical) groups based on a fused heteronuclear molecular model, where the interactions between segments are described with the Mie (generalized Lennard-Jonesium) potential of variable attractive and repulsive range. A key feature of the new theory is the accurate description of the monomeric group-group interactions by application of a high-temperature perturbation expansion up to third order. The capabilities of the SAFT-γ Mie approach are exemplified by studying the thermodynamic properties of two chemical families, the n-alkanes and the n-alkyl esters, by developing parameters for the methyl, methylene, and carboxylate functional groups (CH3, CH2, and COO). The approach is shown to describe accurately the fluid-phase behavior of the compounds considered with absolute average deviations of 1.20% and 0.42% for the vapor pressure and saturated liquid density, respectively, which represents a clear improvement over other existing SAFT-based group contribution approaches. The use of Mie potentials to describe the group-group interaction is shown to allow accurate simultaneous descriptions of the fluid-phase behavior and second-order thermodynamic derivative properties of the pure fluids based on a single set of group parameters. Furthermore, the application of the perturbation expansion to third order for the description of the reference monomeric fluid improves the predictions of the theory for the fluid-phase behavior of pure components in the near-critical region. The predictive capabilities of the approach stem from its formulation within a group-contribution formalism: predictions of the fluid-phase behavior and thermodynamic derivative properties of

Zirconia-coated carbonyl-iron-particle-based magnetorheological fluid for polishing optical glasses and ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafrir, Shai N.; Romanofsky, Henry J.; Skarlinski, Michael

2009-12-10

We report on magnetorheological finishing (MRF) spotting experiments performed on glasses and ceramics using a zirconia-coated carbonyl-iron (CI)-particle-based magnetorheological (MR) fluid. The zirconia-coated magnetic CI particles were prepared via sol-gel synthesis in kilogram quantities. The coating layer was {approx}50-100 nm thick, faceted in surface structure, and well adhered. Coated particles showed long-term stability against aqueous corrosion. ''Free'' nanocrystalline zirconia polishing abrasives were cogenerated in the coating process, resulting in an abrasive-charged powder for MRF. A viable MR fluid was prepared simply by adding water. Spot polishing tests were performed on a variety of optical glasses and ceramics over a periodmore » of nearly three weeks with no signs of MR fluid degradation or corrosion. Stable material removal rates and smooth surfaces inside spots were obtained.« less

Design of a broadband ultra-large area acoustic cloak based on a fluid medium

NASA Astrophysics Data System (ADS)

Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Jiang, Ping

2014-10-01

A broadband ultra-large area acoustic cloak based on fluid medium was designed and numerically implemented with homogeneous metamaterials according to the transformation acoustics. In the present work, fluid medium as the body of the inclusion could be tuned by changing the fluid to satisfy the variant acoustic parameters instead of redesign the whole cloak. The effective density and bulk modulus of the composite materials were designed to agree with the parameters calculated from the coordinate transformation methodology by using the effective medium theory. Numerical simulation results showed that the sound propagation and scattering signature could be controlled in the broadband ultra-large area acoustic invisibility cloak, and good cloaking performance has been achieved and physically realized with homogeneous materials. The broadband ultra-large area acoustic cloaking properties have demonstrated great potentials in the promotion of the practical applications of acoustic cloak.

Gripping characteristics of an electromagnetically activated magnetorheological fluid-based gripper

NASA Astrophysics Data System (ADS)

Choi, Young T.; Hartzell, Christine M.; Leps, Thomas; Wereley, Norman M.

2018-05-01

The design and test of a magnetorheological fluid (MRF)-based universal gripper (MR gripper) are presented in this study. The MR gripper was developed to have a simple design, but with the ability to produce reliable gripping and handling of a wide range of simple objects. The MR gripper design consists of a bladder mounted atop an electromagnet, where the bladder is filled with an MRF, which was formulated to have long-term stable sedimentation stability, that was synthesized using a high viscosity linear polysiloxane (HVLP) carrier fluid with a carbonyl iron particle (CIP) volume fraction of 35%. Two bladders were fabricated: a magnetizable bladder using a magnetorheological elastomer (MRE), and a passive (non-magnetizable) silicone rubber bladder. The holding force and applied (initial compression) force of the MR gripper for a bladder fill volume of 75% were experimentally measured, for both magnetizable and passive bladders, using a servohydraulic material testing machine for a range of objects. The gripping performance of the MR gripper using an MRE bladder was compared to that of the MR gripper using a passive bladder.

Mass transfer in supercritical fluids instancing selected fluids in supercritical carbon dioxide

NASA Astrophysics Data System (ADS)

Hu, Miao; Benning, Rainer; Delgado, Antonio; Ertunc, Oezguer

The research interests lie in a deeper understanding of the mechanisms of diffusion and nucle-ation of organic solutes in near-and supercritical state of a solvent, which count as important means of mass transfer in the process engineering industry. The use of supercritical fluids in industrial processes, such as extraction and particle handling, has become a more and more popular method. Take a closer look at the two processes one would find that there are obviously two sub-processes involved in each of the process, namely the diffusion/nucleation as well as a phase transition procedure. Because of the operational limitations in the practice, this phase transition can-not be neglected. So it is also included in the theoretical approach. Classically to deduce conclusions from experiment results, mathematical/physical models outlining property changes and summarizing characteristics of the two processes are expected. In order to become an insight of these phenomena from the origin, and also to serve as a fundamental attribute for the numerical simulation later, the theories of statistical thermodynamics are adopted here as a proper means to describe the behaviors of the two processes. As the diffusion coefficients of the samples in our case are only of an order of approx. 10-8m2s-1, it can be assumed that the processes are in equilibrium (local changes are neglectably small), a model can be built on a general macroscopic approach for equilibrium systems, namely the Boltzmann-Gibbs distri-bution. And some rather general methods e.g. linear response theory can be applied. But as the transfer phenomena are genuinely not equilibrium systems, from this aspect a model can also be built based on the microscopic description -the kinetic theory of the behaviors of the particles of this non-equilibrium system. The characteristics under compensated gravity are also to be considered in the models. The differences and constraints between the models are to be compared and

Prospects of Supercritical Fluids in Realizing Graphene-Based Functional Materials.

PubMed

Padmajan Sasikala, Suchithra; Poulin, Philippe; Aymonier, Cyril

2016-04-13

Supercritical-fluids science and technology predate all the approaches that are currently established for graphene production by several decades in advanced materials design. However, it has only recently been proposed as a plausible approach for graphene processing. Since then, supercritical fluids have emerged into contention as an alternative to existing technologies because of their scalability and versatility in processing graphene materials, which include composites, aerogels, and foams. Here, an overview is presented of such materials prepared through supercritical fluids from an advanced materials science standpoint, with a discussion on their fundamental properties and technological applications. The benefits of supercritical-fluid processing over conventional liquid-phase processing are presented. The benefits include not only better performances for advanced applications but also environmental issues associated with the synthesis process. Nevertheless, the limitations of supercritical-fluid processing are also stressed, along with challenges that are still faced toward the achievement of the great expectations from graphene materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolution of fluid therapy.

PubMed

Kampmeier, Tim; Rehberg, Sebastian; Ertmer, Christian

2014-09-01

The human organism consists of evolutionary conserved mechanisms to prevent death from hypovolaemia. Intravenous fluid therapy to support these mechanisms had first been published about 180 years ago. The present review depicts the evolution of fluid therapy from early, not well-defined solutions up to modern balanced fluids. Notably, evidence accumulates that the most commonly used fluid (i.e. 0.9% saline) has no advantage over balanced solutions, increases the risk of acute kidney injury and should therefore be abandoned. Notably, in published trials, the prognostically important 'golden hours' of shock, where fluid therapy may be essential, have not been adequately addressed. It is therefore unclear whether negative data on colloids in some trials reflect real harm or rather inadequate use. Future studies should focus on optimal protocols for initiation, dosing and discontinuation of fluid therapy in specific disease entities. Moreover, the practice of de-resuscitation after fluid-based haemodynamic stabilization should be further investigated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Formulation and evaluation of C-Ether fluids as lubricants useful to 260 C. [air breathing engines

NASA Technical Reports Server (NTRS)

Clark, F. S.; Miller, D. R.

1980-01-01

Three base stocks were evaluated in bench and bearing tests to determine their suitability for use at bulk oil temperatures (BOT) from -40 C to +260 C. A polyol ester gave good bearing tests at a bulk temperature of 218 C, but only a partially successful run at 274 C. These results bracket the fluid's maximum operating temperature between these values. An extensive screening program selected lubrication additives for a C-ether (modified polyphenyl ether) base stock. One formulation lubricated a bearing for 111 hours at 274 C (BOT), but this fluid gave many deposit related problems. Other C-ether blends produced cage wear or fatigue failures. Studies of a third fluid, a C-ether/disiloxane blend, consisted of bench oxidation and lubrication tests. These showed that some additives react differently in the blend than in pure C-ethers.

Phase-resolved fluid dynamic forces of a flapping foil energy harvester based on PIV measurements

NASA Astrophysics Data System (ADS)

Liburdy, James

2017-11-01

Two-dimensional particle image velocimetry measurements are performed in a wind tunnel to evaluate the spatial and temporal fluid dynamic forces acting on a flapping foil operating in the energy harvesting regime. Experiments are conducted at reduced frequencies (k = fc/U) of 0.05 - 0.2, pitching angle of, and heaving amplitude of A / c = 0.6. The phase-averaged pressure field is obtained by integrating the pressure Poisson equation. Fluid dynamic forces are then obtained through the integral momentum equation. Results are compared with a simple force model based on the concept of flow impulse. These results help to show the detailed force distributions, their transient nature and aide in understanding the impact of the fluid flow structures that contribute to the power production.

Fluid delivery control system

DOEpatents

Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad

2006-06-06

A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.

Magnetic Fluids--Part 2.

ERIC Educational Resources Information Center

Hoon, S. B.; Tanner, B. K.

1985-01-01

Continues a discussion of magnetic fluids by providing background information on and procedures for conducting several demonstrations. Indicates that, with a little patience and ingenuity, only modest magnetic fields and about 20 ml of low-viscosity, commercial magnetite-water-based magnetic fluid are required. (JN)

Distinguishing infected from noninfected abdominal fluid collections after surgery: an imaging, clinical, and laboratory-based scoring system.

PubMed

Gnannt, Ralph; Fischer, Michael A; Baechler, Thomas; Clavien, Pierre-Alain; Karlo, Christoph; Seifert, Burkhardt; Lesurtel, Mickael; Alkadhi, Hatem

2015-01-01

Mortality from abdominal abscesses ranges from 30% in treated cases up to 80% to 100% in patients with undrained or nonoperated abscesses. Various computed tomographic (CT) imaging features have been suggested to indicate infection of postoperative abdominal fluid collections; however, features are nonspecific and substantial overlap between infected and noninfected collections exists. The purpose of this study was to develop and validate a scoring system on the basis of CT imaging findings as well as laboratory and clinical parameters for distinguishing infected from noninfected abdominal fluid collections after surgery. The score developmental cohort included 100 consecutive patients (69 men, 31 women; mean age, 58 ± 17 years) who underwent portal-venous phase CT within 24 hours before CT-guided intervention of postoperative abdominal fluid collections. Imaging features included attenuation (Hounsfield unit [HU]), volume, wall enhancement and thickness, fat stranding, as well as entrapped gas of fluid collections. Laboratory and clinical parameters included diabetes, intake of immunosuppressive drugs, body temperature, C-reactive protein, and leukocyte blood cell count. The score was validated in a separate cohort of 30 consecutive patients (17 men, 13 women; mean age, 51 ± 15 years) with postoperative abdominal fluid collections. Microbiologic analysis from fluid samples served as the standard of reference. Diabetes, body temperature, C-reactive protein, attenuation of the fluid collection (in HUs), wall enhancement and thickness of the wall, adjacent fat stranding, as well as entrapped gas within the fluid collection were significantly different between infected and noninfected collections (P < 0.001). Multiple logistic regression analysis revealed diabetes, C-reactive protein, attenuation of the fluid collection (in HUs), as well as entrapped gas as significant independent predictors of infection (P < 0.001) and thus was selected for constructing a scoring

Forensic interlaboratory evaluation of the ForFLUID kit for vaginal fluids identification.

PubMed

Giampaoli, Saverio; Alessandrini, Federica; Berti, Andrea; Ripani, Luigi; Choi, Ajin; Crab, Roselien; De Vittori, Elisabetta; Egyed, Balazs; Haas, Cordula; Lee, Hwan Young; Korabecná, Marie; Noel, Fabrice; Podini, Daniele; Tagliabracci, Adriano; Valentini, Alessio; Romano Spica, Vincenzo

2014-01-01

Identification of vaginal fluids is an important step in the process of sexual assaults confirmation. Advances in both microbiology and molecular biology defined technical approaches allowing the discrimination of body fluids. These protocols are based on the identification of specific bacterial communities by microfloraDNA (mfDNA) amplification. A multiplex real time-PCR assay (ForFLUID kit) has been developed for identifying biological fluids and for discrimination among vaginal, oral and fecal samples. In order to test its efficacy and reliability of the assay in the identification of vaginal fluids, an interlaboratory evaluation has been performed on homogeneous vaginal swabs. All the involved laboratories were able to correctly recognize all the vaginal swabs, and no false positives were identified when the assay was applied on non-vaginal samples. The assay represents an useful molecular tool that can be easily adopted by forensic geneticists involved in vaginal fluid identification. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.; Symons, E. P.; Kroeger, E. W.

1984-01-01

The Cryogenic Fluid Management Facility (CFMF) is a reusable test bed which is designed to be carried into space in the Shuttle cargo bay to investigate systems and technologies required to efficiently and effectively manage cryogens in space. The facility hardware is configured to provide low-g verification of fluid and thermal models of cryogenic storage, transfer concepts and processes. Significant design data and criteria for future subcritical cryogenic storage and transfer systems will be obtained. Future applications include space-based and ground-based orbit transfer vehicles (OTV), space station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, space-based weapon systems and space-based orbit maneuvering vehicles (OMV). This paper describes the facility and discusses the cryogenic fluid management technology to be investigated. A brief discussion of the integration issues involved in loading and transporting liquid hydrogen within the Shuttle cargo bay is also included.

Cryogenic fluid management (base R/T): Cryogenic fluid systems, Cryogenic Orbital Nitrogen Experiment (CONE), Cryogenic Orbital Hydrogen Experiment (COHE). (Transportation focused technology)

NASA Technical Reports Server (NTRS)

Symons, Pat

1991-01-01

The topics presented are covered in viewgraph form. The concluded remarks are: (1) advanced cryogenic fluid systems technology is enhancing or enabling to all known transportation scenarios for space exploration; (2) an integrated/coordinated program involving LeRC/MSFC has been formulated to address all known CFM needs - new needs should they develop, can be accommodated within available skills/facilities; (3) all required/experienced personnel and facilities are finally in place - data from initial ground-based experiments is being collected and analyzed - small scale STS experiments are nearing flight - program is beginning to yield significant results; (4) future proposed funding to primarily come from two sources; and (5) cryogenic fluid experimentation is essential to provide required technology and assure implementation in future NASA missions.

Synthesis and optimization of lectin functionalized nanoprobes for the selective recovery of glycoproteins from human body fluids.

PubMed

Ferreira, José A; Daniel-da-Silva, Ana Luísa; Alves, Renato M P; Duarte, Daniel; Vieira, Igor; Santos, Lúcio Lara; Vitorino, Rui; Amado, Francisco

2011-09-15

Biomedical sciences, and in particular biomarker research, demand efficient glycoprotein enrichment platforms. Herein magnetic nanoprobes (MNP), after being coated with three broad-spectrum lectins-concanavalin A (ConA), wheat germ agglutinin (WGA), and Maackia amurensis lectin (MA)-were utilized to selectively capture glycoproteins from human body fluids. Additionally, a new methodology, based on protection of the lectins with their target sugars prior to coupling with MNPs, was proposed to overcome the nonspecific nature of conjugation. This approach contributed to preserve lectin conformation, increasing by 40% and 90% the affinity of ConA and MA for glycoproteins in relation to synthesis with nonprotected lectins. Optimal operating conditions (temperature, time) and maximum binding capacities were further determined for each lectin by use of fetuin as a reference. The enhanced performance of lectin-based nanoplatforms was demonstrated by comparing MNP@ConA with conventional Sepharose@ConA. These experiments have shown that ConA immobilized on MNP exhibited 5 times higher affinity for fetuin and ovalbumin when compared with Sepharose@ConA with the same amount of immobilized lectin. MNP@Lectins were then applied to human serum, saliva, and urine and the recovered proteins were digested with trypsin and analyzed by nano-HPLC MALDI-TOF/TOF. This allowed the identification of 180 proteins, 90% of which were found to be glycosylated by use of bioinformatics tools, therefore revealing low levels of unspecific binding. Thus, MNP@lectins have proved to be a valuable tool for glycoproteomic studies, particularly when dealing with minute amounts of material.

Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.

1985-01-01

The Cryogenic Fluid Management Facility is a reusable test bed which is designed to be carried within the Shuttle cargo bay to investigate the systems and technologies associated with the efficient management of cryogens in space. Cryogenic fluid management consists of the systems and technologies for: (1) liquid storage and supply, including capillary acquisition/expulsion systems which provide single-phase liquid to the user system, (2) both passive and active thermal control systems, and (3) fluid transfer/resupply systems, including transfer lines and receiver tanks. The facility contains a storage and supply tank, a transfer line and a receiver tank, configured to provide low-g verification of fluid and thermal models of cryogenic storage and transfer processes. The facility will provide design data and criteria for future subcritical cryogenic storage and transfer system applications, such as Space Station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, and ground-based and space-based orbit transfer vehicles (OTV).

Enthalpy-based equation of state for highly porous materials employing modified soft sphere fluid model

NASA Astrophysics Data System (ADS)

Nayak, Bishnupriya; Menon, S. V. G.

2018-01-01

Enthalpy-based equation of state based on a modified soft sphere model for the fluid phase, which includes vaporization and ionization effects, is formulated for highly porous materials. Earlier developments and applications of enthalpy-based approach had not accounted for the fact that shocked states of materials with high porosity (e.g., porosity more than two for Cu) are in the expanded fluid region. We supplement the well known soft sphere model with a generalized Lennard-Jones formula for the zero temperature isotherm, with parameters determined from cohesive energy, specific volume and bulk modulus of the solid at normal condition. Specific heats at constant pressure, ionic and electronic enthalpy parameters and thermal excitation effects are calculated using the modified approach and used in the enthalpy-based equation of state. We also incorporate energy loss from the shock due to expansion of shocked material in calculating porous Hugoniot. Results obtained for Cu, even up to initial porosities ten, show good agreement with experimental data.

In situ Raman-based detections of the hydrothermal vent and cold seep fluids

NASA Astrophysics Data System (ADS)

Zhang, Xin; Du, Zengfeng; Zheng, Ronger; Luan, Zhendong; Qi, Fujun; Cheng, Kai; Wang, Bing; Ye, Wangquan; Liu, Xiaorui; Chen, Changan; Guo, Jinjia; Li, Ying; Yan, Jun

2016-04-01

Hydrothermal vents and cold seeps, and their associated biological communities play an important role in global carbon and sulphur biogeochemical cycles. Most of the studies of fluid composition geochemistry are based on recovered samples, both with gas-tight samplers and as open specimens, but the in situ conditions are difficult to maintain in recovered samples. Determination in situ of the chemical signals of the emerging fluids are challenging due to the high pressure, often strongly acidic and temperature in which few sensors can survive. Most of those sensors used so far are based on electrochemistry, and can typically detect only a few chemical species. Here we show that direct measurement of critical chemical species of hydrothermal vents and cold seeps can be made rapidly and in situ by means of a new hybrid version of earlier deep-sea pore water Raman probe carried on the ROV (Remote Operated Vehicle) Faxian. The fluid was drawn through the probe by actuating a hydraulic pump on the ROV, and measured at the probe optical cell through a sapphire window. We have observed the concentrations of H2S, HS-, SO42-, HSO4-, CO2, and H2 in hydrothermal vent fluids from the Pacmanus and Desmos vent systems in the Manus back-arc basin, Papua New Guinea. Two black smokers (279° C and 186° C) at the Pacmanus site showed the characteristic loss of SO42-, and the increase of CO2 and well resolved H2S and HS- peaks. At the white smoker of Onsen site the strong HSO4-peak observed at high temperature quickly dropped with strong accompanying increase of SO42-and H2 peaks when the sample contained in the Raman sensing cell was removed from the hot fluid due to rapid thermal deprotonation. We report here also the finding of a new lower temperature (88° C) white smoker "Kexue" field at the Desmos site with strong H2S, HS- and CO2 signals. We also have detected the concentrations of CH4,H2S, HS-, SO42-, and S8 in cold seep fluids and the surrounding sediment pore water from

Methodologies for Reservoir Characterization Using Fluid Inclusion Gas Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dilley, Lorie M.

2015-04-13

The purpose of this project was to: 1) evaluate the relationship between geothermal fluid processes and the compositions of the fluid inclusion gases trapped in the reservoir rocks; and 2) develop methodologies for interpreting fluid inclusion gas data in terms of the chemical, thermal and hydrological properties of geothermal reservoirs. Phase 1 of this project was designed to conduct the following: 1) model the effects of boiling, condensation, conductive cooling and mixing on selected gaseous species; using fluid compositions obtained from geothermal wells, 2) evaluate, using quantitative analyses provided by New Mexico Tech (NMT), how these processes are recorded bymore » fluid inclusions trapped in individual crystals; and 3) determine if the results obtained on individual crystals can be applied to the bulk fluid inclusion analyses determined by Fluid Inclusion Technology (FIT). Our initial studies however, suggested that numerical modeling of the data would be premature. We observed that the gas compositions, determined on bulk and individual samples were not the same as those discharged by the geothermal wells. Gases discharged from geothermal wells are CO 2-rich and contain low concentrations of light gases (i.e. H 2, He, N, Ar, CH4). In contrast many of our samples displayed enrichments in these light gases. Efforts were initiated to evaluate the reasons for the observed gas distributions. As a first step, we examined the potential importance of different reservoir processes using a variety of commonly employed gas ratios (e.g. Giggenbach plots). The second technical target was the development of interpretational methodologies. We have develop methodologies for the interpretation of fluid inclusion gas data, based on the results of Phase 1, geologic interpretation of fluid inclusion data, and integration of the data. These methodologies can be used in conjunction with the relevant geological and hydrological information on the system to create fluid

Wellbottom fluid implosion treatment system

DOEpatents

Brieger, Emmet F.

2001-01-01

A system for inducing implosion shock forces on perforation traversing earth formations with fluid pressure where an implosion tool is selected relative to a shut in well pressure and a tubing pressure to have a large and small area piston relationship in a well tool so that at a predetermined tubing pressure the pistons move a sufficient distance to open an implosion valve which permits a sudden release of well fluid pressure into the tubing string and produces an implosion force on the perforations. A pressure gauge on the well tool records tubing pressure and well pressure as a function of time.

Flocking from a quantum analogy: spin-orbit coupling in an active fluid

NASA Astrophysics Data System (ADS)

Loewe, Benjamin; Souslov, Anton; Goldbart, Paul M.

2018-01-01

Systems composed of strongly interacting self-propelled particles can form a spontaneously flowing polar active fluid. The study of the connection between the microscopic dynamics of a single such particle and the macroscopic dynamics of the fluid can yield insights into experimentally realizable active flows, but this connection is well understood in only a few select cases. We introduce a model of self-propelled particles based on an analogy with the motion of electrons that have strong spin-orbit coupling. We find that, within our model, self-propelled particles are subject to an analog of the Heisenberg uncertainty principle that relates translational and rotational noise. Furthermore, by coarse-graining this microscopic model, we establish expressions for the coefficients of the Toner-Tu equations—the hydrodynamic equations that describe an active fluid composed of these ‘active spins.’ The connection between stochastic self-propelled particles and quantum particles with spin may help realize exotic phases of matter using active fluids via analogies with systems composed of strongly correlated electrons.

Outcome prediction in monochorionic diamniotic twin pregnancies with moderately discordant amniotic fluid.

PubMed

Van Mieghem, T; Eixarch, E; Gucciardo, L; Done, E; Gonzales, I; Van Schoubroeck, D; Lewi, L; Gratacos, E; Deprest, J

2011-01-01

The aim of this study was to identify predictors of twin-to-twin transfusion syndrome (TTTS) and selective intrauterine growth restriction (sIUGR) in monochorionic diamniotic (MCDA) twin pregnancies with moderate amniotic fluid discordance (mAFD). Monochorionic twins with mAFD (n = 45; gestational age, 15-29 weeks) were assessed for extent of fluid discordance, fetal growth discordance and fetal cardiac dysfunction, and were followed longitudinally. A prediction algorithm was constructed for TTTS and sIUGR and validated in an unrelated cohort (n = 52). Cardiac dysfunction could not predict TTTS or sIUGR. Twins below 20 weeks of gestation with a fluid discordance of ≥ 3.1 cm had a risk of TTTS of 85.7%. Sensitivity for TTTS was nevertheless only 55%. An intertwin weight discordance of ≥ 25% had 63% sensitivity and 76% specificity for sIUGR without TTTS. The outcome of MCDA twins with mAFD remains unpredictable, yet high-risk and low-risk subgroups for TTTS can be identified based on severity of fluid discordance and gestational age.

A novel passive micromixer based on unbalanced splits and collisions of fluid streams

NASA Astrophysics Data System (ADS)

Ansari, Mubashshir Ahmad; Kim, Kwang-Yong; Anwar, Khalid; Kim, Sun Min

2010-05-01

A new passive micromixer based on the concept of unbalanced splits and cross-collisions of fluid streams is designed and fabricated. Experimental and numerical studies have been carried out on the micromixer at Reynolds numbers ranging from 10 to 80. The three-dimensional Navier-Stokes equations have been used to analyze the mixing and flow behavior of the micromixer, which is composed of two sub-channels of unequal widths which repeatedly undergo splitting and recombination. The difference between the mass flow rates in the two sub-channels creates an unbalanced collision of the two fluid streams. Mixing is mainly due to the combined effect of unbalanced collisions of the fluid streams and Dean vortices. The micromixer shows interesting mixing behavior for different ratios of the widths of the two split sub-channels. The sub-channels wherein the major sub-channel is twice as wide as the minor sub-channel exhibit the highest mixing performance at Reynolds numbers larger than 40. The results show the lowest mixing performance for the case of uniform width, where balanced collisions occur.

Site-specific distribution of claudin-based paracellular channels with roles in biological fluid flow and metabolism.

PubMed

Tanaka, Hiroo; Tamura, Atsushi; Suzuki, Koya; Tsukita, Sachiko

2017-10-01

The claudins are a family of membrane proteins with at least 27 members in humans and mice. The extracellular regions of claudin proteins play essential roles in cell-cell adhesion and the paracellular barrier functions of tight junctions (TJs) in epithelial cell sheets. Furthermore, the extracellular regions of some claudins function as paracellular channels in the paracellular barrier that allow the selective passage of water, ions, and/or small organic solutes across the TJ in the extracellular space. Structural analyses have revealed a common framework of transmembrane, cytoplasmic, and extracellular regions among the claudin-based paracellular barriers and paracellular channels; however, differences in the claudins' extracellular regions, such as their charges and conformations, determine their properties. Among the biological systems that involve fluid flow and metabolism, it is noted that hepatic bile flow, renal Na + reabsorption, and intestinal nutrient absorption are dynamically regulated via site-specific distributions of paracellular channel-forming claudins in tissue. Here, we focus on how site-specific distributions of claudin-2- and claudin-15-based paracellular channels drive their organ-specific functions in the liver, kidney, and intestine. © 2017 New York Academy of Sciences.

Microgravity Fluids for Biology, Workshop

NASA Technical Reports Server (NTRS)

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.

Inter-operator Reliability of Magnetic Resonance Image-Based Computational Fluid Dynamics Prediction of Cerebrospinal Fluid Motion in the Cervical Spine.

PubMed

Martin, Bryn A; Yiallourou, Theresia I; Pahlavian, Soroush Heidari; Thyagaraj, Suraj; Bunck, Alexander C; Loth, Francis; Sheffer, Daniel B; Kröger, Jan Robert; Stergiopulos, Nikolaos

2016-05-01

For the first time, inter-operator dependence of MRI based computational fluid dynamics (CFD) modeling of cerebrospinal fluid (CSF) in the cervical spinal subarachnoid space (SSS) is evaluated. In vivo MRI flow measurements and anatomy MRI images were obtained at the cervico-medullary junction of a healthy subject and a Chiari I malformation patient. 3D anatomies of the SSS were reconstructed by manual segmentation by four independent operators for both cases. CFD results were compared at nine axial locations along the SSS in terms of hydrodynamic and geometric parameters. Intraclass correlation (ICC) assessed the inter-operator agreement for each parameter over the axial locations and coefficient of variance (CV) compared the percentage of variance for each parameter between the operators. Greater operator dependence was found for the patient (0.19 < ICC < 0.99) near the craniovertebral junction compared to the healthy subject (ICC > 0.78). For the healthy subject, hydraulic diameter and Womersley number had the least variance (CV = ~2%). For the patient, peak diastolic velocity and Reynolds number had the smallest variance (CV = ~3%). These results show a high degree of inter-operator reliability for MRI-based CFD simulations of CSF flow in the cervical spine for healthy subjects and a lower degree of reliability for patients with Type I Chiari malformation.

Technical Competencies Applied in Experimental Fluid Dynamics

NASA Astrophysics Data System (ADS)

Tagg, Randall

2017-11-01

The practical design, construction, and operation of fluid dynamics experiments require a broad range of competencies. Three types are instrumental, procedural, and design. Respective examples would be operation of a spectrum analyzer, soft-soldering or brazing flow plumbing, and design of a small wind tunnel. Some competencies, such as the selection and installation of pumping systems, are unique to fluid dynamics and fluids engineering. Others, such as the design and construction of electronic amplifiers or optical imaging systems, overlap with other fields. Thus the identification and development of learning materials and methods for instruction are part of a larger effort to identify competencies needed in active research and technical innovation.

Two-body perturbation theory versus first order perturbation theory: A comparison based on the square-well fluid.

PubMed

Mercier Franco, Luís Fernando; Castier, Marcelo; Economou, Ioannis G

2017-12-07

We show that the Zwanzig first-order perturbation theory can be obtained directly from a truncated Taylor series expansion of a two-body perturbation theory and that such truncation provides a more accurate prediction of thermodynamic properties than the full two-body perturbation theory. This unexpected result is explained by the quality of the resulting approximation for the fluid radial distribution function. We prove that the first-order and the two-body perturbation theories are based on different approximations for the fluid radial distribution function. To illustrate the calculations, the square-well fluid is adopted. We develop an analytical expression for the two-body perturbed Helmholtz free energy for the square-well fluid. The equation of state obtained using such an expression is compared to the equation of state obtained from the first-order approximation. The vapor-liquid coexistence curve and the supercritical compressibility factor of a square-well fluid are calculated using both equations of state and compared to Monte Carlo simulation data. Finally, we show that the approximation for the fluid radial distribution function given by the first-order perturbation theory provides closer values to the ones calculated via Monte Carlo simulations. This explains why such theory gives a better description of the fluid thermodynamic behavior.

Design and Evaluation of Perceptual-based Object Group Selection Techniques

NASA Astrophysics Data System (ADS)

Dehmeshki, Hoda

Selecting groups of objects is a frequent task in graphical user interfaces. It is required prior to many standard operations such as deletion, movement, or modification. Conventional selection techniques are lasso, rectangle selection, and the selection and de-selection of items through the use of modifier keys. These techniques may become time-consuming and error-prone when target objects are densely distributed or when the distances between target objects are large. Perceptual-based selection techniques can considerably improve selection tasks when targets have a perceptual structure, for example when arranged along a line. Current methods to detect such groups use ad hoc grouping algorithms that are not based on results from perception science. Moreover, these techniques do not allow selecting groups with arbitrary arrangements or permit modifying a selection. This dissertation presents two domain-independent perceptual-based systems that address these issues. Based on established group detection models from perception research, the proposed systems detect perceptual groups formed by the Gestalt principles of good continuation and proximity. The new systems provide gesture-based or click-based interaction techniques for selecting groups with curvilinear or arbitrary structures as well as clusters. Moreover, the gesture-based system is adapted for the graph domain to facilitate path selection. This dissertation includes several user studies that show the proposed systems outperform conventional selection techniques when targets form salient perceptual groups and are still competitive when targets are semi-structured.

An earthquake instability model based on faults containing high fluid-pressure compartments

USGS Publications Warehouse

Lockner, D.A.; Byerlee, J.D.

1995-01-01

It has been proposed that large strike-slip faults such as the San Andreas contain water in seal-bounded compartments. Arguments based on heat flow and stress orientation suggest that in most of the compartments, the water pressure is so high that the average shear strength of the fault is less than 20 MPa. We propose a variation of this basic model in which most of the shear stress on the fault is supported by a small number of compartments where the pore pressure is relatively low. As a result, the fault gouge in these compartments is compacted and lithified and has a high undisturbed strength. When one of these locked regions fails, the system made up of the neighboring high and low pressure compartments can become unstable. Material in the high fluid pressure compartments is initially underconsolidated since the low effective confining pressure has retarded compaction. As these compartments are deformed, fluid pressure remains nearly unchanged so that they offer little resistance to shear. The low pore pressure compartments, however, are overconsolidated and dilate as they are sheared. Decompression of the pore fluid in these compartments lowers fluid pressure, increasing effective normal stress and shear strength. While this effect tends to stabilize the fault, it can be shown that this dilatancy hardening can be more than offset by displacement weakening of the fault (i.e., the drop from peak to residual strength). If the surrounding rock mass is sufficiently compliant to produce an instability, slip will propagate along the fault until the shear fracture runs into a low-stress region. Frictional heating and the accompanying increase in fluid pressure that are suggested to occur during shearing of the fault zone will act as additional destabilizers. However, significant heating occurs only after a finite amount of slip and therefore is more likely to contribute to the energetics of rupture propagation than to the initiation of the instability. We present

Using Behavior Change Techniques to Guide Selections of Mobile Applications to Promote Fluid Consumption.

PubMed

Conroy, David E; Dubansky, Alexandra; Remillard, Joshua; Murray, Robert; Pellegrini, Christine A; Phillips, Siobhan M; Streeper, Necole M

2017-01-01

To determine the extent to which validated techniques for behavior change have been infused in commercially available fluid consumption applications (apps). Coders evaluated behavior change techniques represented in online descriptions for 50 fluid consumption apps and the latest version of each app. Apps incorporated a limited range of behavior change techniques (<20% of taxonomy). The number of techniques varied by operating system but not as a function of whether apps were free or paid. Limitations include the lack of experimental evidence establishing the efficacy of these apps. Patients with urolithiasis can choose from many apps to support the recommended increase in fluid intake. Apps for iOS devices incorporate more behavior change techniques compared to apps for the Android operating system. Free apps are likely to expose patients to a similar number of techniques as paid apps. Physicians and patients should screen app descriptions for features to promote self-monitoring and provide feedback on discrepancies between behavior and a fluid consumption goal. Copyright © 2016 Elsevier Inc. All rights reserved.

Probability of detecting Porcine reproductive and respiratory syndrome virus infection using pen-based swine oral fluid specimens as a function of within-pen prevalence.

PubMed

Olsen, Chris; Wang, Chong; Christopher-Hennings, Jane; Doolittle, Kent; Harmon, Karen M; Abate, Sarah; Kittawornrat, Apisit; Lizano, Sergio; Main, Rodger; Nelson, Eric A; Otterson, Tracy; Panyasing, Yaowalak; Rademacher, Chris; Rauh, Rolf; Shah, Rohan; Zimmerman, Jeffrey

2013-05-01

Pen-based oral fluid sampling has proven to be an efficient method for surveillance of infectious diseases in swine populations. To better interpret diagnostic results, the performance of oral fluid assays (antibody- and nucleic acid-based) must be established for pen-based oral fluid samples. Therefore, the objective of the current study was to determine the probability of detecting Porcine reproductive and respiratory syndrome virus (PRRSV) infection in pen-based oral fluid samples from pens of known PRRSV prevalence. In 1 commercial swine barn, 25 pens were assigned to 1 of 5 levels of PRRSV prevalence (0%, 4%, 12%, 20%, or 36%) by placing a fixed number (0, 1, 3, 5, or 9) of PRRSV-positive pigs (14 days post PRRSV modified live virus vaccination) in each pen. Prior to placement of the vaccinated pigs, 1 oral fluid sample was collected from each pen. Thereafter, 5 oral fluid samples were collected from each pen, for a total of 150 samples. To confirm individual pig PRRSV status, serum samples from the PRRSV-negative pigs (n = 535) and the PRRSV vaccinated pigs (n = 90) were tested for PRRSV antibodies and PRRSV RNA. The 150 pen-based oral fluid samples were assayed for PRRSV antibody and PRRSV RNA at 6 laboratories. Among the 100 samples from pens containing ≥1 positive pig (≥4% prevalence) and tested at the 6 laboratories, the mean positivity was 62% for PRRSV RNA and 61% for PRRSV antibody. These results support the use of pen-based oral fluid sampling for PRRSV surveillance in commercial pig populations.

Supercritical Fluid Chromatography--Theoretical Background and Applications on Natural Products.

PubMed

Hartmann, Anja; Ganzera, Markus

2015-11-01

The use of supercritical fluid chromatography for natural product analysis as well as underlying theoretical mechanisms and instrumental requirements are summarized in this review. A short introduction focusing on the historical development of this interesting separation technique is followed by remarks on the current instrumental design, also describing possible detection modes and useable stationary phases. The overview on relevant applications is grouped based on their basic intention, may it be (semi)preparative or purely analytical. They indicate that supercritical fluid chromatography is still primarily considered for the analysis of nonpolar analytes like carotenoids, fatty acids, or terpenes. The low polarity of supercritical carbon dioxide, which is used with modifiers almost exclusively as a mobile phase today, combined with high efficiency and fast separations might explain the popularity of supercritical fluid chromatography for the analysis of these compounds. Yet, it has been shown that more polar natural products (e.g., xanthones, flavonoids, alkaloids) are separable too, with the same (if not superior) selectivity and reproducibility than established approaches like HPLC or GC. Georg Thieme Verlag KG Stuttgart · New York.

Multiobjective immune algorithm with nondominated neighbor-based selection.

PubMed

Gong, Maoguo; Jiao, Licheng; Du, Haifeng; Bo, Liefeng

2008-01-01

Abstract Nondominated Neighbor Immune Algorithm (NNIA) is proposed for multiobjective optimization by using a novel nondominated neighbor-based selection technique, an immune inspired operator, two heuristic search operators, and elitism. The unique selection technique of NNIA only selects minority isolated nondominated individuals in the population. The selected individuals are then cloned proportionally to their crowding-distance values before heuristic search. By using the nondominated neighbor-based selection and proportional cloning, NNIA pays more attention to the less-crowded regions of the current trade-off front. We compare NNIA with NSGA-II, SPEA2, PESA-II, and MISA in solving five DTLZ problems, five ZDT problems, and three low-dimensional problems. The statistical analysis based on three performance metrics including the coverage of two sets, the convergence metric, and the spacing, show that the unique selection method is effective, and NNIA is an effective algorithm for solving multiobjective optimization problems. The empirical study on NNIA's scalability with respect to the number of objectives shows that the new algorithm scales well along the number of objectives.

Artificial Intelligence In Computational Fluid Dynamics

NASA Technical Reports Server (NTRS)

Vogel, Alison Andrews

1991-01-01

Paper compares four first-generation artificial-intelligence (Al) software systems for computational fluid dynamics. Includes: Expert Cooling Fan Design System (EXFAN), PAN AIR Knowledge System (PAKS), grid-adaptation program MITOSIS, and Expert Zonal Grid Generation (EZGrid). Focuses on knowledge-based ("expert") software systems. Analyzes intended tasks, kinds of knowledge possessed, magnitude of effort required to codify knowledge, how quickly constructed, performances, and return on investment. On basis of comparison, concludes Al most successful when applied to well-formulated problems solved by classifying or selecting preenumerated solutions. In contrast, application of Al to poorly understood or poorly formulated problems generally results in long development time and large investment of effort, with no guarantee of success.

Effect of fluid compressibility on journal bearing performance

NASA Technical Reports Server (NTRS)

Dimofte, Florin

1993-01-01

An analysis was undertaken to determine the effect of fluid film compressibility on the performance of fluid film bearings. A new version of the Reynolds equation was developed, using a polytropic expansion, for both steady-state and dynamic conditions. Polytropic exponents from 1 (isothermal) to 1000 (approaching an incompressible liquid) were evaluated for two bearing numbers, selected from a range of practical interest for cryogenic application, and without cavitation. Bearing loads were insensitive to fluid compressibility for low bearing numbers, as was expected. The effect of compressibility on attitude angle was significant, even when the bearing number was low. A small amount of fluid compressibility was enough to obtain stable running conditions. Incompressible liquid lacked stability at all conditions. Fluid compressibility can be used to control the bearing dynamic coefficients, thereby influencing the dynamic behavior of the rotor-bearing system.

Endothelin ETA Receptor Blockade, by Activating ETB Receptors, Increases Vascular Permeability and Induces Exaggerated Fluid Retention.

PubMed

Vercauteren, Magali; Trensz, Frederic; Pasquali, Anne; Cattaneo, Christophe; Strasser, Daniel S; Hess, Patrick; Iglarz, Marc; Clozel, Martine

2017-05-01

Endothelin (ET) receptor antagonists have been associated with fluid retention. It has been suggested that, of the two endothelin receptor subtypes, ET B receptors should not be blocked, because of their involvement in natriuresis and diuresis. Surprisingly, clinical data suggest that ET A -selective antagonists pose a greater risk of fluid overload than dual antagonists. The purpose of this study was to evaluate the contribution of each endothelin receptor to fluid retention and vascular permeability in rats. Sitaxentan and ambrisentan as ET A -selective antagonists and bosentan and macitentan as dual antagonists were used as representatives of each class, respectively. ET A -selective antagonism caused a dose-dependent hematocrit/hemoglobin decrease that was prevented by ET B -selective receptor antagonism. ET A -selective antagonism led to a significant blood pressure reduction, plasma volume expansion, and a greater increase in vascular permeability than dual antagonism. Isolated vessel experiments showed that ET A -selective antagonism increased vascular permeability via ET B receptor overstimulation. Acutely, ET A -selective but not dual antagonism activated sympathetic activity and increased plasma arginine vasopressin and aldosterone concentrations. The hematocrit/hemoglobin decrease induced by ET A -selective antagonism was reduced in Brattleboro rats and in Wistar rats treated with an arginine vasopressin receptor antagonist. Finally, the decrease in hematocrit/hemoglobin was larger in the venous than in the arterial side, suggesting fluid redistribution. In conclusion, by activating ET B receptors, endothelin receptor antagonists (particularly ET A -selective antagonists) favor edema formation by causing: 1) fluid retention resulting from arginine vasopressin and aldosterone activation secondary to vasodilation, and 2) increased vascular permeability. Plasma volume redistribution may explain the clinical observation of a hematocrit/hemoglobin decrease

Model structure identification for wastewater treatment simulation based on computational fluid dynamics.

PubMed

Alex, J; Kolisch, G; Krause, K

2002-01-01

The objective of this presented project is to use the results of an CFD simulation to automatically, systematically and reliably generate an appropriate model structure for simulation of the biological processes using CSTR activated sludge compartments. Models and dynamic simulation have become important tools for research but also increasingly for the design and optimisation of wastewater treatment plants. Besides the biological models several cases are reported about the application of computational fluid dynamics ICFD) to wastewater treatment plants. One aim of the presented method to derive model structures from CFD results is to exclude the influence of empirical structure selection to the result of dynamic simulations studies of WWTPs. The second application of the approach developed is the analysis of badly performing treatment plants where the suspicion arises that bad flow behaviour such as short cut flows is part of the problem. The method suggested requires as the first step the calculation of fluid dynamics of the biological treatment step at different loading situations by use of 3-dimensional CFD simulation. The result of this information is used to generate a suitable model structure for conventional dynamic simulation of the treatment plant by use of a number of CSTR modules with a pattern of exchange flows between the tanks automatically. The method is explained in detail and the application to the WWTP Wuppertal Buchenhofen is presented.

Selective adsorption and phase equilibria of confined fluids: Density-functional theory and Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Sowers, Susanne Lynn

1997-11-01

Microporous sorbents such as carbons, silicas and aluminas are used commercially in a variety of separation, purification and selective reaction applications. A detailed study of the effects of the porous material characteristics on the adsorption equilibrium properties such as selectivity and phase equilibria of fluid mixtures can enhance our understanding of adsorption on a molecular level. Such knowledge will improve our utilization of such adsorbents and provide a tool for directing the future of tailoring sorbents for particular separation processes. The effect of pore size, shape and pressure on the selective adsorption of trace pollutants from an inert gas was studied using prototype mixtures of Lennard-Tones (LJ) N2/CCl4, CF4, and SO2. Both nonlocal density functional theory (DFT) and grand canonical Monte Carlo (GCMC) molecular simulations were used in order to investigate the validity of the theory, which is much quicker and easier to use. Our results indicate that there is an optimal pore size and shape for which the pollutant selectivity is greatly enhanced. In many industrial adsorption processes relative humidity can greatly affect the life of an adsorbent bed, as seen in breakthrough curves. Therefore, the influence of water vapor on the selective adsorption of CCl4 from a mixture of N2/CCl4/H20 in activated carbon was studied using GCMC simulations. The equilibrium adsorption properties are found to be dependent upon both the density of active sites on the pore walls and the relative humidity. Liquid-liquid transitions in porous materials are of interest in connection with oil recovery, lubrication, coating technology and pollution control. The results of a study on the effect of confinement on the liquid-liquid equilibrium of binary LJ mixtures using DFT are compared with those of molecular simulation and experiments. Our findings show that the phase coexistence for the confined mixture is in general decreased and shifted toward the component which

Morph-X-Select: Morphology-based tissue aptamer selection for ovarian cancer biomarker discovery

PubMed Central

Wang, Hongyu; Li, Xin; Volk, David E.; Lokesh, Ganesh L.-R.; Elizondo-Riojas, Miguel-Angel; Li, Li; Nick, Alpa M.; Sood, Anil K.; Rosenblatt, Kevin P.; Gorenstein, David G.

2016-01-01

High affinity aptamer-based biomarker discovery has the advantage of simultaneously discovering an aptamer affinity reagent and its target biomarker protein. Here, we demonstrate a morphology-based tissue aptamer selection method that enables us to use tissue sections from individual patients and identify high-affinity aptamers and their associated target proteins in a systematic and accurate way. We created a combinatorial DNA aptamer library that has been modified with thiophosphate substitutions of the phosphate ester backbone at selected 5′dA positions for enhanced nuclease resistance and targeting. Based on morphological assessment, we used image-directed laser microdissection (LMD) to dissect regions of interest bound with the thioaptamer (TA) library and further identified target proteins for the selected TAs. We have successfully identified and characterized the lead candidate TA, V5, as a vimentin-specific sequence that has shown specific binding to tumor vasculature of human ovarian tissue and human microvascular endothelial cells. This new Morph-X-Select method allows us to select high-affinity aptamers and their associated target proteins in a specific and accurate way, and could be used for personalized biomarker discovery to improve medical decision-making and to facilitate the development of targeted therapies to achieve more favorable outcomes. PMID:27839510

Silicon-Based Chemical Motors: An Efficient Pump for Triggering and Guiding Fluid Motion Using Visible Light.

PubMed

Esplandiu, Maria J; Farniya, Ali Afshar; Bachtold, Adrian

2015-11-24

We report a simple yet highly efficient chemical motor that can be controlled with visible light. The motor made from a noble metal and doped silicon acts as a pump, which is driven through a light-activated catalytic reaction process. We show that the actuation is based on electro-osmosis with the electric field generated by chemical reactions at the metal and silicon surfaces, whereas the contribution of diffusio-osmosis to the actuation is negligible. Surprisingly, the pump can be operated using water as fuel. This is possible because of the large ζ-potential of silicon, which makes the electro-osmotic fluid motion sizable even though the electric field generated by the reaction is weak. The electro-hydrodynamic process is greatly amplified with the addition of reactive species, such as hydrogen peroxide, which generates higher electric fields. Another remarkable finding is the tunability of silicon-based pumps. That is, it is possible to control the speed of the fluid with light. We take advantage of this property to manipulate the spatial distribution of colloidal microparticles in the liquid and to pattern colloidal microparticle structures at specific locations on a wafer surface. Silicon-based pumps hold great promise for controlled mass transport in fluids.

Goal-Directed Fluid Resuscitation Protocol Based on Arterial Waveform Analysis of Major Burn Patients in a Mass Burn Casualty.

PubMed

Chiao, Hao-Yu; Chou, Chang-Yi; Tzeng, Yuan-Sheng; Wang, Chih-Hsin; Chen, Shyi-Gen; Dai, Niann-Tzyy

2018-02-01

Adequate fluid titration during the initial resuscitation period of major burn patients is crucial. This study aimed to evaluate the feasibility and efficacy of a goal-directed fluid resuscitation protocol that used hourly urine output plus the arterial waveform analysis FloTrac (Edwards LifeSciences, Irvine, Calif) system for major burns to avoid fluid overload. We conducted a retrospective cohort study of 43 major burn patients at the Tri-Service General Hospital after the Formosa Fun Coast Dust Explosion on June 27, 2015. Because of the limited capacity of intensive care units (ICUs), 23 intubated patients were transferred from the burn wards or emergency department to the ICU within 24 hours. Fluid administration was adjusted to achieve a urine output of 30 to 50 mL/h, cardiac index greater than 2.5 L/min/m, and stroke volume variation (SVV) less than 12%. The hourly crystalloid fluid infusion rate was titrated based on SVV and hourly urine output. Of the 23 critically burned patients admitted to the ICU, 13 patients who followed the goal-directed fluid resuscitation protocol within 12 hours postburn were included in the analysis. The mean age (years) was 21.8, and the mean total body surface area (TBSA) burned (%) was 68.0. The mean Revised Baux score was 106.8. All patients sustained inhalation injury. The fluid volumes administered to patients in the first 24 hours and the second 24 hours (mL/kg/% total body surface area) were 3.62 ± 1.23 and 2.89 ± 0.79, respectively. The urine outputs in the first 24 hours and the second 24 hours (mL/kg/h) were 1.13 ± 0.66 and 1.53 ± 0.87, respectively. All patients achieved the established goals within 32 hours postburn. In-hospital mortality rate was 0%. The SVV-based goal-directed fluid resuscitation protocol leads to less unnecessary fluid administration during the early resuscitation phase. Clinicians can efficaciously manage the dynamic body fluid changes in major burn patients under the guidance of the protocol.

Identification of body fluid-specific DNA methylation markers for use in forensic science.

PubMed

Park, Jong-Lyul; Kwon, Oh-Hyung; Kim, Jong Hwan; Yoo, Hyang-Sook; Lee, Han-Chul; Woo, Kwang-Man; Kim, Seon-Young; Lee, Seung-Hwan; Kim, Yong Sung

2014-11-01

DNA methylation, which occurs at the 5'-position of the cytosine in CpG dinucleotides, has great potential for forensic identification of body fluids, because tissue-specific patterns of DNA methylation have been demonstrated, and DNA is less prone to degradation than proteins or RNA. Previous studies have reported several body fluid-specific DNA methylation markers, but DNA methylation differences are sometimes low in saliva and vaginal secretions. Moreover, specific DNA methylation markers in four types of body fluids (blood, saliva, semen, and vaginal secretions) have not been investigated with genome-wide profiling. Here, we investigated novel DNA methylation markers for identification of body fluids for use in forensic science using the Illumina HumanMethylation 450K bead array, which contains over 450,000 CpG sites. Using methylome data from 16 samples of blood, saliva, semen, and vaginal secretions, we first selected 2986 hypermethylated or hypomethylated regions that were specific for each type of body fluid. We then selected eight CpG sites as novel, forensically relevant DNA methylation markers: cg06379435 and cg08792630 for blood, cg26107890 and cg20691722 for saliva, cg23521140 and cg17610929 for semen, and cg01774894 and cg14991487 for vaginal secretions. These eight selected markers were evaluated in 80 body fluid samples using pyrosequencing, and all showed high sensitivity and specificity for identification of the target body fluid. We suggest that these eight DNA methylation markers may be good candidates for developing an effective molecular assay for identification of body fluids in forensic science. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

NetProt: Complex-based Feature Selection.

PubMed

Goh, Wilson Wen Bin; Wong, Limsoon

2017-08-04

Protein complex-based feature selection (PCBFS) provides unparalleled reproducibility with high phenotypic relevance on proteomics data. Currently, there are five PCBFS paradigms, but not all representative methods have been implemented or made readily available. To allow general users to take advantage of these methods, we developed the R-package NetProt, which provides implementations of representative feature-selection methods. NetProt also provides methods for generating simulated differential data and generating pseudocomplexes for complex-based performance benchmarking. The NetProt open source R package is available for download from https://github.com/gohwils/NetProt/releases/ , and online documentation is available at http://rpubs.com/gohwils/204259 .

Inter-Operator Dependence of Magnetic Resonance Image-Based Computational Fluid Dynamics Prediction of Cerebrospinal Fluid Motion in the Cervical Spine

PubMed Central

Martin, Bryn A.; Yiallourou, Theresia I.; Pahlavian, Soroush Heidari; Thyagaraj, Suraj; Bunck, Alexander C.; Loth, Francis; Sheffer, Daniel B.; Kröger, Jan Robert; Stergiopulos, Nikolaos

2015-01-01

For the first time, inter-operator dependence of MRI based computational fluid dynamics (CFD) modeling of cerebrospinal fluid (CSF) in the cervical spinal subarachnoid space (SSS) is evaluated. In vivo MRI flow measurements and anatomy MRI images were obtained at the cervico-medullary junction of a healthy subject and a Chiari I malformation patient. 3D anatomies of the SSS were reconstructed by manual segmentation by four independent operators for both cases. CFD results were compared at nine axial locations along the SSS in terms of hydrodynamic and geometric parameters. Intraclass correlation (ICC) assessed the inter-operator agreement for each parameter over the axial locations and coefficient of variance (CV) compared the percentage of variance for each parameter between the operators. Greater operator dependence was found for the patient (0.19 0.78). For the healthy subject, hydraulic diameter and Womersley number had the least variance (CV= ~2%). For the patient, peak diastolic velocity and Reynolds number had the smallest variance (CV= ~3%). These results show a high degree of inter-operator reliability for MRI-based CFD simulations of CSF flow in the cervical spine for healthy subjects and a lower degree of reliability for patients with Type I Chiari malformation. PMID:26446009

Hamiltonian closures in fluid models for plasmas

NASA Astrophysics Data System (ADS)

Tassi, Emanuele

2017-11-01

This article reviews recent activity on the Hamiltonian formulation of fluid models for plasmas in the non-dissipative limit, with emphasis on the relations between the fluid closures adopted for the different models and the Hamiltonian structures. The review focuses on results obtained during the last decade, but a few classical results are also described, in order to illustrate connections with the most recent developments. With the hope of making the review accessible not only to specialists in the field, an introduction to the mathematical tools applied in the Hamiltonian formalism for continuum models is provided. Subsequently, we review the Hamiltonian formulation of models based on the magnetohydrodynamics description, including those based on the adiabatic and double adiabatic closure. It is shown how Dirac's theory of constrained Hamiltonian systems can be applied to impose the incompressibility closure on a magnetohydrodynamic model and how an extended version of barotropic magnetohydrodynamics, accounting for two-fluid effects, is amenable to a Hamiltonian formulation. Hamiltonian reduced fluid models, valid in the presence of a strong magnetic field, are also reviewed. In particular, reduced magnetohydrodynamics and models assuming cold ions and different closures for the electron fluid are discussed. Hamiltonian models relaxing the cold-ion assumption are then introduced. These include models where finite Larmor radius effects are added by means of the gyromap technique, and gyrofluid models. Numerical simulations of Hamiltonian reduced fluid models investigating the phenomenon of magnetic reconnection are illustrated. The last part of the review concerns recent results based on the derivation of closures preserving a Hamiltonian structure, based on the Hamiltonian structure of parent kinetic models. Identification of such closures for fluid models derived from kinetic systems based on the Vlasov and drift-kinetic equations are presented, and

Image-based computational fluid dynamics in the lung: virtual reality or new clinical practice?

PubMed

Burrowes, Kelly S; De Backer, Jan; Kumar, Haribalan

2017-11-01

The development and implementation of personalized medicine is paramount to improving the efficiency and efficacy of patient care. In the respiratory system, function is largely dictated by the choreographed movement of air and blood to the gas exchange surface. The passage of air begins in the upper airways, either via the mouth or nose, and terminates at the alveolar interface, while blood flows from the heart to the alveoli and back again. Computational fluid dynamics (CFD) is a well-established tool for predicting fluid flows and pressure distributions within complex systems. Traditionally CFD has been used to aid in the effective or improved design of a system or device; however, it has become increasingly exploited in biological and medical-based applications further broadening the scope of this computational technique. In this review, we discuss the advancement in application of CFD to the respiratory system and the contributions CFD is currently making toward improving precision medicine. The key areas CFD has been applied to in the pulmonary system are in predicting fluid transport and aerosol distribution within the airways. Here we focus our discussion on fluid flows and in particular on image-based clinically focused CFD in the ventilatory system. We discuss studies spanning from the paranasal sinuses through the conducting airways down to the level of the alveolar airways. The combination of imaging and CFD is enabling improved device design in aerosol transport, improved biomarkers of lung function in clinical trials, and improved predictions and assessment of surgical interventions in the nasal sinuses. WIREs Syst Biol Med 2017, 9:e1392. doi: 10.1002/wsbm.1392 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

Fluid resuscitation in acute pancreatitis

PubMed Central

Aggarwal, Aakash; Manrai, Manish; Kochhar, Rakesh

2014-01-01

Acute pancreatitis remains a clinical challenge, despite an exponential increase in our knowledge of its complex pathophysiological changes. Early fluid therapy is the cornerstone of treatment and is universally recommended; however, there is a lack of consensus regarding the type, rate, amount and end points of fluid replacement. Further confusion is added with the newer studies reporting better results with controlled fluid therapy. This review focuses on the pathophysiology of fluid depletion in acute pancreatitis, as well as the rationale for fluid replacement, the type, optimal amount, rate of infusion and monitoring of such patients. The basic goal of fluid epletion should be to prevent or minimize the systemic response to inflammatory markers. For this review, various studies and reviews were critically evaluated, along with authors’ recommendations, for predicted severe or severe pancreatitis based on the available evidence. PMID:25561779

Fluid Power, Rate Training Manual.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

Fundamentals of hydraulics and pneumatics are presented in this manual, prepared for regular navy and naval reserve personnel who are seeking advancement to Petty Officer Third Class. The history of applications of compressed fluids is described in connection with physical principles. Selection of types of liquids and gases is discussed with a…

The role of fluid pressure on frictional behavior at the base of the seismogenic zone

USGS Publications Warehouse

Hirth, Greg; Beeler, Nicholas M.

2015-01-01

To characterize stress and deformation style at the base of the seismogenic zone, we investigate how the mechanical properties of fluid-rock systems respond to variations in temperature and strain rate. The role of fluids on the processes responsible for the brittle-ductile transition in quartz-rich rocks has not been explored at experimental conditions where the kinetic competition between microcracking and viscous flow is similar to that expected in the Earth. Our initial analysis of this competition suggests that the effective stress law for sliding friction should not work as efficiently near the brittle-ductile transition as it does at shallow conditions

GWAS-based pathway analysis differentiates between fluid and crystallized intelligence.

PubMed

Christoforou, A; Espeseth, T; Davies, G; Fernandes, C P D; Giddaluru, S; Mattheisen, M; Tenesa, A; Harris, S E; Liewald, D C; Payton, A; Ollier, W; Horan, M; Pendleton, N; Haggarty, P; Djurovic, S; Herms, S; Hoffman, P; Cichon, S; Starr, J M; Lundervold, A; Reinvang, I; Steen, V M; Deary, I J; Le Hellard, S

2014-09-01

Cognitive abilities vary among people. About 40-50% of this variability is due to general intelligence (g), which reflects the positive correlation among individuals' scores on diverse cognitive ability tests. g is positively correlated with many life outcomes, such as education, occupational status and health, motivating the investigation of its underlying biology. In psychometric research, a distinction is made between general fluid intelligence (gF) - the ability to reason in novel situations - and general crystallized intelligence (gC) - the ability to apply acquired knowledge. This distinction is supported by developmental and cognitive neuroscience studies. Classical epidemiological studies and recent genome-wide association studies (GWASs) have established that these cognitive traits have a large genetic component. However, no robust genetic associations have been published thus far due largely to the known polygenic nature of these traits and insufficient sample sizes. Here, using two GWAS datasets, in which the polygenicity of gF and gC traits was previously confirmed, a gene- and pathway-based approach was undertaken with the aim of characterizing and differentiating their genetic architecture. Pathway analysis, using genes selected on the basis of relaxed criteria, revealed notable differences between these two traits. gF appeared to be characterized by genes affecting the quantity and quality of neurons and therefore neuronal efficiency, whereas long-term depression (LTD) seemed to underlie gC. Thus, this study supports the gF-gC distinction at the genetic level and identifies functional annotations and pathways worthy of further investigation. © 2014 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.

Magnetically Actuated Propellant Orientation Experiment, Controlling Fluid Motion With Magnetic Fields in a Low-Gravity Environment

NASA Technical Reports Server (NTRS)

Martin, J. J.; Holt, J. B.

2000-01-01

This report details the results of a series of fluid motion experiments to investigate the use of magnets to orient fluids in a low-gravity environment. The fluid of interest for this project was liquid oxygen (LO2) since it exhibits a paramagnetic behavior (is attracted to magnetic fields). However, due to safety and handling concerns, a water-based ferromagnetic mixture (produced by Ferrofluidics Corporation) was selected to simplify procedures. Three ferromagnetic fluid mixture strengths and a nonmagnetic water baseline were tested using three different initial fluid positions with respect to the magnet. Experiment accelerometer data were used with a modified computational fluid dynamics code termed CFX-4 (by AEA Technologies) to predict fluid motion. These predictions compared favorably with experiment video data, verifying the code's ability to predict fluid motion with and without magnetic influences. Additional predictions were generated for LO2 with the same test conditions and geometries used in the testing. Test hardware consisted of a cylindrical Plexiglas tank (6-in. bore with 10-in. length), a 6,000-G rare Earth magnet (10-in. ring), three-axis accelerometer package, and a video recorder system. All tests were conducted aboard the NASA Reduced-Gravity Workshop, a KC-135A aircraft.

Magnetic field sensing based on tilted fiber Bragg grating coated with nanoparticle magnetic fluid

NASA Astrophysics Data System (ADS)

Yang, Dexing; Du, Lei; Xu, Zengqi; Jiang, Yajun; Xu, Jian; Wang, Meirong; Bai, Yang; Wang, Haiyan

2014-02-01

A magnetic field sensor based on a tilted fiber Bragg grating (TFBG) coated with magnetic fluid is proposed and demonstrated experimentally. The sensing element is made by injecting the magnetic fluid into a capillary tube which contains a TFBG. The resonant wavelengths of the cladding modes of TFBG shift by varying the magnetic field which is perpendicular to the axis of TFBG. The results indicate that the resonant wavelength shifts of the cladding modes show a nonlinear dependence on the magnetic field. As the magnetic field increases to 32 mT, the largest resonant wavelength shift reaches to 106 pm. Moreover, this sensor shows good repeatability when it is used for magnetic field sensing.

Magnetorheological fluid based on thixotropic PTFE-oil organogel

NASA Astrophysics Data System (ADS)

Zhang, Hansong; Yan, Hua; Hu, Zhide; Yang, Jianjian; Niu, Fanghao

2018-04-01

Polytetrafluoroethylene (PTFE) micropowders were employed in this work to fabricate PTFE-oil organogel, then carbonyl iron particles were dispersed in this thixotropic organogel to prepare magnetorheological fluids without any other additives. By performing a comparative investigation of MRFs' performances, enhanced magnetorheological response, suspension stability and tribological performance were obtained contrast to pure silicon oil based MRFs. The experimental results revealed a changeable viscosity of organogel, considerable increases in thixotropy also can be observed with the increase of PTFE content. Sedimentation tests demonstrated a much better suspension stability of MRFs based on organogel, suggesting that the internal network microstructures formed by hydrogen bonds between PTFE microparticles and oil molecular chains are likely to impose the gaps among magnetic particles thus hinder the particle aggregation and sedimentation. Moreover, a critical PTFE volume fraction about 4.7 vol% was recognized in this study, lower content organogels tended to display enhanced yield stresses contrast to pure silicon oil based MRFs while high content organogels showed slightly lower ones. It may suggest a compromise between nonmagnetic particle adsorption and the reinforcement effect of network microstructures. The adsorption is likely to decrease the saturation magnetization of carbonyl iron particles and to hinder the formation of field-induced chains, however, the reinforcement effect tends to strengthen these magnetic chains. Besides, the tribological tests confirmed the lubricant effects of PTFE-oil organogel by acquiring rather sharp decreases in friction coefficients of organogel based MRFs especially in the presence of magnetic field.

Drilling fluid filter

DOEpatents

Hall, David R.; Fox, Joe; Garner, Kory

2007-01-23

A drilling fluid filter for placement within a bore wall of a tubular drill string component comprises a perforated receptacle with an open end and a closed end. A hanger for engagement with the bore wall is mounted at the open end of the perforated receptacle. A mandrel is adjacent and attached to the open end of the perforated receptacle. A linkage connects the mandrel to the hanger. The linkage may be selected from the group consisting of struts, articulated struts and cams. The mandrel operates on the hanger through the linkage to engage and disengage the drilling fluid filter from the tubular drill string component. The mandrel may have a stationary portion comprising a first attachment to the open end of the perforated receptacle and a telescoping adjustable portion comprising a second attachment to the linkage. The mandrel may also comprise a top-hole interface for top-hole equipment.

Settling of a sphere through a fluid-fluid interface: influence of the Reynolds number

NASA Astrophysics Data System (ADS)

Pierson, Jean-Lou; Magnaudet, Jacques

2015-11-01

When a particle sediments through a horizontal fluid-fluid interface (a situation frequently encountered in oceanography as well as in coating processes), it often tows a tail of the upper fluid into the lower one. This feature is observed in both inertia- and viscosity-dominated regimes. Nevertheless the tail evolution and the particle motion are found to highly depend on the ratio of the two effects, i.e. on the Reynolds number. In this work we study numerically the settling of a sphere through a horizontal fluid-fluid interface using an Immersed Boundary Method combined with a Volume of Fluid approach. To get some more insight into the underlying physical mechanisms, we combine this computational approach with a semi-analytical description based on the concept of Darwin ''drift'' which allows us to predict the interface evolution, hence the thickness of the film encapsulating the sphere, in the two limits of Stokes flow and potential flow. This work was funded by DGA whose financial support is greatly appreciated.

Systems and methods for selective hydrogen transport and measurement

DOEpatents

Glatzmaier, Gregory C

2013-10-29

Systems and methods for selectively removing hydrogen gas from a hydrogen-containing fluid volume are disclosed. An exemplary system includes a proton exchange membrane (PEM) selectively permeable to hydrogen by exclusively conducting hydrogen ions. The system also includes metal deposited as layers onto opposite sides or faces of the PEM to form a membrane-electrode assembly (MEA), each layer functioning as an electrode so that the MEA functions as an electrochemical cell in which the ionic conductors are hydrogen ions, and the MEA functioning as a hydrogen selective membrane (HSM) when located at the boundary between a hydrogen-containing fluid volume and a second fluid.

Fluid regimens for colostomy irrigation: a systematic review.

PubMed

Lizarondo, Lucylynn; Aye Gyi, Aye; Schultz, Tim

2008-09-01

Background  Various techniques for managing faecal evacuation have been proposed; however, colostomy irrigation is favoured as it leads to better patient outcomes. Alternative fluid regimens for colostomy irrigation have been suggested to achieve effective evacuation. Aim  The objective of this review was to summarise the best available evidence on the most effective fluid regimen for colostomy irrigation. Search strategy  Trials were identified by electronic searches of CINAHL, PubMed, MEDLINE, Current Contents, the Cochrane Library and EMBASE. Unpublished articles and references lists from included studies were also searched. Selection criteria  Randomised controlled trials and before-and-after studies investigating any fluid regimen for colostomy irrigation were eligible for inclusion. Outcomes measured included fluid inflow time, total wash-out time, haemodynamic changes during irrigation, cramps, leakage episodes, quality of life and level of satisfaction. Data collection and analysis  Trial selection, quality appraisal and data extraction were carried out independently by two reviewers. Differences in opinion were resolved by discussion. Main results  The systematic literature search strategy identified two cross-over trials that compared water with another fluid regimen. Owing to the differences in irrigating solutions used, the results were not pooled for analysis. Both the polyethylene glycol electrolyte solution and glyceryl trinitrate performed significantly better than water. Conclusion  There is some evidence to support the effectiveness of fluid regimens other than water, such as polyethylene glycol electrolyte and glyceryl trinitrate, for colostomy irrigation. Further well-designed clinical trials are required to establish solid evidence on the effectiveness of other irrigating solutions that might enhance colonic irrigation. © 2008 The Authors. Journal Compilation © Blackwell Publishing Asia Pty Ltd.

The potentiation of the antimicrobial activities of cutting fluid preservatives by EDTA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izzat, I.N.; Bennett, E.O.

1978-01-01

The potentiation of the antimicrobial activities of cutting fluid preservatives by EDTA was confirmed in experiments in which 500 ppm of the disodium salt of EDTA was used in combination with 12 different metalworking fluids containing 500 ppm of o-phenylphenol, tris(hydroxymethyl) nitromethane, hexahydro- 1,3,5-tris(2-hydroxyethyl)-s-triazine alone or complexed with iodine, hexahydro- 1,3,5-triethyl-s-triazine, 1-(3-chloroallyl)- 3,5,7-triaza- 1-azoniaadamantane hydrochloride, 1,2-benzisothiazolin-3-one, 4-(2-nitrobutyl) morpholine and 4,4-(2-ethyl-2-nitrotrimethylene) dimorpholine, or the sodium salt of 2-pyridinethiol- 1-oxide as a preservative. Based on a previous observation that the proper selection of the hydraulic fluid employed in the cutting machine is a major factor in controlling rancidity, the possibility of spoilagemore » control by treating the fluid with EDTA alone was also demonstrated; the EDTA had a greater beneficial effect with a synthetic coolant than with an oil emulsion. Published data on the effects of EDTA indicate that it poses no significant water pollution problems upon disposal, exhibits a low order of animal toxicity, and rarely causes human allergies. Tables and 65 references.« less

32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.37 Voluntary breath and bodily fluid testing based on implied consent... the person was driving under the influence of alcohol or drugs. (3) A request was made to the person...

32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.37 Voluntary breath and bodily fluid testing based on implied consent... the person was driving under the influence of alcohol or drugs. (3) A request was made to the person...

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

NASA Astrophysics Data System (ADS)

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.

MOBILE ON-SITE RECYCLING OF METALWORKING FLUIDS

EPA Science Inventory

Product quality, waste reduction, and economic issues were evaluated for a technology designed to recycle metalworking fluids. mulsion-type fluids were tested at two sites and a synthetic fluid was tested at a third site. he specific recycling unit evaluated is based on the techn...

An evaluation of Computational Fluid dynamics model for flood risk analysis

NASA Astrophysics Data System (ADS)

Di Francesco, Silvia; Biscarini, Chiara; Montesarchio, Valeria

2014-05-01

This work presents an analysis of the hydrological-hydraulic engineering requisites for Risk evaluation and efficient flood damage reduction plans. Most of the research efforts have been dedicated to the scientific and technical aspects of risk assessment, providing estimates of possible alternatives and of the risk associated. In the decision making process for mitigation plan, the contribute of scientist is crucial, due to the fact that Risk-Damage analysis is based on evaluation of flow field ,of Hydraulic Risk and on economical and societal considerations. The present paper will focus on the first part of process, the mathematical modelling of flood events which is the base for all further considerations. The evaluation of potential catastrophic damage consequent to a flood event and in particular to dam failure requires modelling of the flood with sufficient detail so to capture the spatial and temporal evolutions of the event, as well of the velocity field. Thus, the selection of an appropriate mathematical model to correctly simulate flood routing is an essential step. In this work we present the application of two 3D Computational fluid dynamics models to a synthetic and real case study in order to evaluate the correct evolution of flow field and the associated flood Risk . The first model is based on a opensource CFD platform called openFoam. Water flow is schematized with a classical continuum approach based on Navier-Stokes equation coupled with Volume of fluid (VOF) method to take in account the multiphase character of river bottom-water- air systems. The second model instead is based on the Lattice Boltzmann method, an innovative numerical fluid dynamics scheme based on Boltzmann's kinetic equation that represents the flow dynamics at the macroscopic level by incorporating a microscopic kinetic approach. Fluid is seen as composed by particles that can move and collide among them. Simulation results from both models are promising and congruent to

A multiscale quasi-continuum theory to determine thermodynamic properties of fluid mixtures in nanochannels

NASA Astrophysics Data System (ADS)

Motevaselian, Mohammad Hossein; Mashayak, Sikandar Y.; Aluru, Narayana R.

2015-11-01

We present an empirical potential-based quasi-continuum theory (EQT) that seamlessly integrates the interatomic potentials into a continuum framework such as the Nernst-Planck equation. EQT is a simple and fast approach, which provides accurate predictions of potential of mean force (PMF) and density distribution of confined fluids at multiple length-scales, ranging from few Angstroms to macro meters. The EQT potentials can be used to construct the excess free energy functional in the classical density functional theory (cDFT). The combination of EQT and cDFT (EQT-cDFT), allows one to predict the thermodynamic properties of confined fluids. Recently, the EQT-cDFT framework was developed for single component LJ fluids confined in slit-like graphene channels. In this work, we extend the framework to confined LJ fluid mixtures and demonstrate it by simulating a mixture of methane and hydrogen molecules inside slit-like graphene channels. We show that the EQT-cDFT predictions for the structure of the confined fluid mixture compare well with the MD simulations. In addition, our results show that graphene nanochannels exhibit a selective adsorption of methane over hydrogen.

Selective Distance-Based K+ Quantification on Paper-Based Microfluidics.

PubMed

Gerold, Chase T; Bakker, Eric; Henry, Charles S

2018-04-03

In this study, paper-based microfluidic devices (μPADs) capable of K + quantification in aqueous samples, as well as in human serum, using both colorimetric and distance-based methods are described. A lipophilic phase containing potassium ionophore I (valinomycin) was utilized to achieve highly selective quantification of K + in the presence of Na + , Li + , and Mg 2+ ions. Successful addition of a suspended lipophilic phase to a wax printed paper-based device is described and offers a solution to current approaches that rely on organic solvents, which damage wax barriers. The approach provides an avenue for future alkali/alkaline quantification utilizing μPADs. Colorimetric spot tests allowed for K + quantification from 0.1-5.0 mM using only 3.00 μL of sample solution. Selective distance-based quantification required small sample volumes (6.00 μL) and gave responses sensitive enough to distinguish between 1.0 and 2.5 mM of sample K + . μPADs using distance-based methods were also capable of differentiating between 4.3 and 6.9 mM K + in human serum samples. Distance-based methods required no digital analysis, electronic hardware, or pumps; any steps required for quantification could be carried out using the naked eye.

Chemical Characterization and Thermal Stressing Studies of Perfluorohexane Fluids for Space-Based Applications

NASA Technical Reports Server (NTRS)

Arnold, William A.; Hartman, Thomas G.; McQuillen, John

2006-01-01

exposure of perfluorohexane fluids to high temperatures is the production of perfluoroisobutene (PFiB), which is extremely toxic. An ultra-high sensitivity PFiB-specific analysis based on GC-MS with negative ion chemical ionization (NICI) detection was used to evaluate the samples following thermal stressing. The perfluorohexanes examined here under conditions reflective of the ISS TCCS environment showed no signs of PFiB production with an analytical detection limit of 10 part per billion (ppb v/v).

Large scale cryogenic fluid systems testing

NASA Technical Reports Server (NTRS)

1992-01-01

NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

Recent advances in quantitative analysis of fluid interfaces in multiphase fluid flow measured by synchrotron-based x-ray microtomography

NASA Astrophysics Data System (ADS)

Schlueter, S.; Sheppard, A.; Wildenschild, D.

2013-12-01

Imaging of fluid interfaces in three-dimensional porous media via x-ray microtomography is an efficient means to test thermodynamically derived predictions on the relationship between capillary pressure, fluid saturation and specific interfacial area (Pc-Sw-Anw) in partially saturated porous media. Various experimental studies exist to date that validate the uniqueness of the Pc-Sw-Anw relationship under static conditions and with current technological progress direct imaging of moving interfaces under dynamic conditions is also becoming available. Image acquisition and subsequent image processing currently involves many steps each prone to operator bias, like merging different scans of the same sample obtained at different beam energies into a single image or the generation of isosurfaces from the segmented multiphase image on which the interface properties are usually calculated. We demonstrate that with recent advancements in (i) image enhancement methods, (ii) multiphase segmentation methods and (iii) methods of structural analysis we can considerably decrease the time and cost of image acquisition and the uncertainty associated with the measurement of interfacial properties. In particular, we highlight three notorious problems in multiphase image processing and provide efficient solutions for each: (i) Due to noise, partial volume effects, and imbalanced volume fractions, automated histogram-based threshold detection methods frequently fail. However, these impairments can be mitigated with modern denoising methods, special treatment of gray value edges and adaptive histogram equilization, such that most of the standard methods for threshold detection (Otsu, fuzzy c-means, minimum error, maximum entropy) coincide at the same set of values. (ii) Partial volume effects due to blur may produce apparent water films around solid surfaces that alter the specific fluid-fluid interfacial area (Anw) considerably. In a synthetic test image some local segmentation methods

The effect of initial resident fluid saturation on the interaction between resident and infiltrating fluids in porous media

NASA Astrophysics Data System (ADS)

Hsu, S. Y.; Chen, H.; Huang, Q. Z.; Lee, T. Y.; Chiu, Y.; Chang, L. C.; Lamorski, K.; Sławiński, C.; Tsao, C. W.

2017-12-01

The interplay between resident ("old") fluid already in the vadose zone and infiltrating ("new") fluid was examined with micromodel experiments. The geometric patterns of the micromodels are based on a pore doublet and a 2D pore geometry of a sand-packing soil scanned by Micro X-Ray CT. We studied the old and new fluid interaction during imbibition process subject to different evaporation times (different the initial old fluid saturations). The results found that, in the pore-doublet micromodel experiment, the old fluid was mixed and displaced by the new fluid, and an increase in the initial old fluid saturation led to a decrease in the amount of old fluid displaced by the new fluid. On the other hand, the most of the old fluid in the micromodel of 2D sand-packing pore geometry was displaced by and mixed with the new fluid. However, a small amount of the initial old fluid that occupied pore throats remained untouched by the new fluid due to the air blockage. The amount of untouched old fluid increased as the initial old fluid saturation decreased. Our finding reveals the effect of pore geometry and inital old fluid distribution on the interaction between resident and infiltrating fluids.

Effect of pre-donation fluid intake on fluid shift from interstitial to intravascular compartment in blood donors.

PubMed

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 < 0.05). The difference was not significant between donors with water intake (GII: 106 ± 52 ml) and oral rehydrating fluid intake (GIII: 87 ± 41 ml). The shifted fluid volume increased with increasing BMI and decreased with increasing age in females. The fluid shift increased in females than in males. The age, gender, BMI and VVR did not significantly contribute to the volume of fluid shift following 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.

Immiscible fluid: Heat of fusion heat storage system

NASA Technical Reports Server (NTRS)

Edie, D. D.; Melsheimer, S. S.; Mullins, J. C.

1980-01-01

Both heat and mass transfer in direct contact aqueous crystallizing systems were studied as part of a program desig- ned to evaluate the feasibility of direct contact heat transfer in phase change storage using aqueous salt system. Major research areas, discussed include (1) crystal growth velocity study on selected salts; (2) selection of salt solutions; (3) selection of immiscible fluids; (4) studies of heat transfer and system geometry; and (5) system demonstration.

Zernike ultrasonic tomography for fluid velocity imaging based on pipeline intrusive time-of-flight measurements.

PubMed

Besic, Nikola; Vasile, Gabriel; Anghel, Andrei; Petrut, Teodor-Ion; Ioana, Cornel; Stankovic, Srdjan; Girard, Alexandre; d'Urso, Guy

2014-11-01

In this paper, we propose a novel ultrasonic tomography method for pipeline flow field imaging, based on the Zernike polynomial series. Having intrusive multipath time-offlight ultrasonic measurements (difference in flight time and speed of ultrasound) at the input, we provide at the output tomograms of the fluid velocity components (axial, radial, and orthoradial velocity). Principally, by representing these velocities as Zernike polynomial series, we reduce the tomography problem to an ill-posed problem of finding the coefficients of the series, relying on the acquired ultrasonic measurements. Thereupon, this problem is treated by applying and comparing Tikhonov regularization and quadratically constrained ℓ1 minimization. To enhance the comparative analysis, we additionally introduce sparsity, by employing SVD-based filtering in selecting Zernike polynomials which are to be included in the series. The first approach-Tikhonov regularization without filtering, is used because it is the most suitable method. The performances are quantitatively tested by considering a residual norm and by estimating the flow using the axial velocity tomogram. Finally, the obtained results show the relative residual norm and the error in flow estimation, respectively, ~0.3% and ~1.6% for the less turbulent flow and ~0.5% and ~1.8% for the turbulent flow. Additionally, a qualitative validation is performed by proximate matching of the derived tomograms with a flow physical model.

FLUID: A numerical interpolation procedure for obtaining thermodynamic and transport properties of fluids

NASA Technical Reports Server (NTRS)

Fessler, T. E.

1977-01-01

A computer program subroutine, FLUID, was developed to calculate thermodynamic and transport properties of pure fluid substances. It provides for determining the thermodynamic state from assigned values for temperature-density, pressure-density, temperature-pressure, pressure-entropy, or pressure-enthalpy. Liquid or two-phase (liquid-gas) conditions are considered as well as the gas phase. A van der Waals model is used to obtain approximate state values; these values are then corrected for real gas effects by model-correction factors obtained from tables based on experimental data. Saturation conditions, specific heat, entropy, and enthalpy data are included in the tables for each gas. Since these tables are external to the FLUID subroutine itself, FLUID can implement any gas for which a set of tables has been generated. (A setup phase is used to establish pointers dynamically to the tables for a specific gas.) Data-table preparation is described. FLUID is available in both SFTRAN and FORTRAN

On the Relationship between Fluid Intelligence, Gesture Production, and Brain Structure

ERIC Educational Resources Information Center

Wartenburger, Isabell; Kuhn, Esther; Sassenberg, Uta; Foth, Manja; Franz, Elizabeth A.; van der Meer, Elke

2010-01-01

Individuals scoring high in fluid intelligence tasks generally perform very efficiently in problem solving tasks and analogical reasoning tasks presumably because they are able to select the task-relevant information very quickly and focus on a limited set of task-relevant cognitive operations. Moreover, individuals with high fluid intelligence…

Fluid imbalance

MedlinePlus

... up in the body. This is called fluid overload (volume overload). This can lead to edema (excess fluid in ... Water imbalance; Fluid imbalance - dehydration; Fluid buildup; Fluid overload; Volume overload; Loss of fluids; Edema - fluid imbalance; ...

Uranium(VI) Binding Forms in Selected Human Body Fluids: Thermodynamic Calculations versus Spectroscopic Measurements.

PubMed

Osman, Alfatih A A; Geipel, Gerhard; Barkleit, Astrid; Bernhard, Gert

2015-02-16

Human exposure to uranium increasingly becomes a subject of interest in many scientific disciplines such as environmental medicine, toxicology, and radiation protection. Knowledge about uranium chemical binding forms(speciation) in human body fluids can be of great importance to understand not only its biokinetics but also its relevance in risk assessment and in designing decorporation therapy in the case of accidental overexposure. In this study, thermodynamic calculations of uranium speciation in relevant simulated and original body fluids were compared with spectroscopic data after ex-situ uranium addition. For the first time, experimental data on U(VI) speciation in body fluids (saliva, sweat, urine) was obtained by means of cryogenic time-resolved laser-induced fluorescence spectroscopy (cryo-TRLFS) at 153 K. By using the time dependency of fluorescence decay and the band positions of the emission spectra, various uranyl complexes were demonstrated in the studied samples. The variations of the body fluids in terms of chemical composition, pH, and ionic strength resulted in different binding forms of U(VI). The speciation of U(VI) in saliva and in urine was affected by the presence of bioorganic ligands, whereas in sweat, the distribution depends mainly on inorganic ligands. We also elucidated the role of biological buffers, i.e., phosphate (H(2)PO(4−)/HPO(4)(2−)) on U(VI) distribution, and the system Ca(2+)/UO(2)(2+)/PO(4)(3−) was discussed in detail in both saliva and urine. The theoretical speciation calculations of the main U(VI) species in the investigated body fluids were significantly consistent with the spectroscopic data. Laser fluorescence spectroscopy showed success and reliability for direct determination of U(VI) in such biological matrices with the possibility for further improvement.

Gas chromatography-mass spectrometry-based metabolic profiling of cerebrospinal fluid from epileptic dogs.

PubMed

Hasegawa, Tetsuya; Sumita, Maho; Horitani, Yusuke; Tamai, Reo; Tanaka, Katsuhiro; Komori, Masayuki; Takenaka, Shigeo

2014-04-01

Epilepsy is a common neurological disorder with seizures, but diagnostic approaches in veterinary clinics remain limited. Cerebrospinal fluid (CSF) is a body fluid used for diagnosis in veterinary medicine. In this study, we explored canine epilepsy diagnostic biomarkers using gas chromatography-mass spectrometry (GC-MS)-based metabolic profiling of CSF and multivariate data analysis. Profiles for subjects with idiopathic epilepsy differed significantly from those of healthy controls and subjects with symptomatic epilepsy. Among 60 identified metabolites, the levels of 20 differed significantly among the three groups. Glutamic acid was significantly increased in idiopathic epilepsy, and some metabolites including ascorbic acid were changed in both forms of epilepsy. These findings show that metabolic profiles of CSF differ between idiopathic and symptomatic epilepsy and that metabolites including glutamic acid and ascorbic acid in CSF may be useful for diagnosis of canine epilepsy.

Highly selective electrode for potentiometric analysis of methadone in biological fluids and pharmaceutical formulations.

PubMed

Ardeshiri, Moslem; Jalali, Fahimeh

2016-06-01

In order to develop a fast and simple procedure for methadone analysis in biological fluids, a graphite paste electrode (GPE) was modified with the ion-pair of methadone-phosphotungstic acid, and multiwalled carbon nanotubes (MWCNTs). Optimized composition of the electrode with respect to graphite powder:paraffin oil:MWCNTs:ion pair, was 58:30:8:4 (w/w%). The electrode showed a near-Nernstian slope of 58.9 ± 0.3 mV/decade for methadone in a wide linear range of 1.0 × 10(-8)-4.6 × 10(-3)M, with a detection limit of 1.0 × 10(-8)M. The electrode response was independent of pH in the range of 5-11, with a fast response time (~4s) at 25 °C. The sensor showed high selectivity and was successfully applied to the determination of sub-micromolar concentrations of methadone in human blood serum and urine samples, with recoveries in the range of 95-99.8%. The average recovery of methadone from tablets (5 mg/tablet) by using the proposed method was 98%. The life time of the modified electrode was more than 5 months, due to the characteristic of GPE which can be cut off and fresh electrode surface be available. A titration procedure was performed for methadone analysis by using phosphotungstic acid, as titrating agent, which showed an accurate end point and 1:1 stoichiometry for the ion-pair formed (methadone:phosphotungstic acid). The simple and rapid procedure as well as excellent detection limit and selectivity are some of the advantages of the proposed sensor for methadone. Copyright © 2016 Elsevier B.V. All rights reserved.

A summary of existing and planned experiment hardware for low-gravity fluids research

NASA Technical Reports Server (NTRS)

Hill, Myron E.; O'Malley, Terence F.

1991-01-01

NASA's ground-based and space-based low-gravity facilities are summarized, and an overview of selected experiments that have been developed for use in these facilities is presented. A variety of ground-based facilities (drop towers and aircraft) used to conduct low-gravity experiments for in-space experimentation are described. Capabilities that are available to the researcher and future on-orbit fluids facilities are addressed. The payload bay facilities range from the completely self-contained, relatively small get-away-special canisters to the Materials Science Laboratory and to the larger Spacelab facilities that require crew interaction.

Performance Analysis of Water Based Copper Oxide Nano Fluids in Heat Exchanger with Twisted Insert

NASA Astrophysics Data System (ADS)

Ashok Reddy, K.; Hanmanthu, Bhukya

2018-03-01

A new experimental setup has been designed for conducting experiments in a copper round pipe heat exchanger with inner diameter di=14.5mm and outer diameter do=16mm and length L = 1720 mm . By using two copper oxide nano concentrations of 0.1% and 0.3% with water as based fluid, the heat transfer rates have been obtained with helical twisted insert H/D=5 in turbulent flow condition. Reynolds number and friction factor with pressure gradient have been evaluated. The heat transfer rates of 0.1% conc. Nano-fluid with insert was found to be 13.77% more when compared to water.

Evidence of improved fluid management in patients receiving haemodialysis following a self-affirmation theory-based intervention: A randomised controlled trial.

PubMed

Wileman, Vari; Chilcot, Joseph; Armitage, Christopher J; Farrington, Ken; Wellsted, David M; Norton, Sam; Davenport, Andrew; Franklin, Gail; Da Silva Gane, Maria; Horne, Robert; Almond, Mike

2016-01-01

Haemodialysis patients are at risk of serious health complications; yet, treatment non-adherence remains high. Warnings about health risks associated with non-adherence may trigger defensive reactions. We studied whether an intervention based on self-affirmation theory reduced resistance to health-risk information and improved fluid treatment adherence. In a cluster randomised controlled trial, 91 patients either self-affirmed or completed a matched control task before reading about the health-risks associated with inadequate fluid control. Patients' perceptions of the health-risk information, intention and self-efficacy to control fluid were assessed immediately after presentation of health-risk information. Interdialytic weight gain (IDWG), excess fluid removed during haemodialysis, is a clinical measure of fluid treatment adherence. IDWG data were collected up to 12 months post-intervention. Self-affirmed patients had significantly reduced IDWG levels over 12 months. However, contrary to predictions derived from self-affirmation theory, self-affirmed participants and controls did not differ in their evaluation of the health-risk information, intention to control fluid or self-efficacy. A low-cost, high-reach health intervention based on self-affirmation theory was shown to reduce IDWG over a 12-month period, but the mechanism by which this apparent behaviour change occurred is uncertain. Further work is still required to identify mediators of the observed effects.

Performance of journal bearings with semi-compressible fluids

NASA Technical Reports Server (NTRS)

Carpino, M.; Peng, J.-P.

1991-01-01

Cryogenic fluids in isothermal rigid surface and foil type journal bearings can sometimes be treated as semicompressible fluids. In these applications, the fluid density is a function of the pressure. At low pressures, the fluids can change from a liquid to a saturated liquid-vapor phase. The performance of a rigid surface journal bearing with an idealized semicompressible fluid is discussed. Pressure solutions are based upon a Reynolds equation which includes the effects of a compressibility via the bulk modulus of the fluid. Results are contrasted with the performance of isothermal constant property incompressible fluids.

Leak locating microphone, method and system for locating fluid leaks in pipes

DOEpatents

Kupperman, David S.; Spevak, Lev

1994-01-01

A leak detecting microphone inserted directly into fluid within a pipe includes a housing having a first end being inserted within the pipe and a second opposed end extending outside the pipe. A diaphragm is mounted within the first housing end and an acoustic transducer is coupled to the diaphragm for converting acoustical signals to electrical signals. A plurality of apertures are provided in the housing first end, the apertures located both above and below the diaphragm, whereby to equalize fluid pressure on either side of the diaphragm. A leak locating system and method are provided for locating fluid leaks within a pipe. A first microphone is installed within fluid in the pipe at a first selected location and sound is detected at the first location. A second microphone is installed within fluid in the pipe at a second selected location and sound is detected at the second location. A cross-correlation is identified between the detected sound at the first and second locations for identifying a leak location.

Next Generation Programmable Bio-Nano-Chip System for On-Site Detection in Oral Fluids.

PubMed

Christodoulides, Nicolaos; De La Garza, Richard; Simmons, Glennon W; McRae, Michael P; Wong, Jorge; Newton, Thomas F; Kosten, Thomas R; Haque, Ahmed; McDevitt, John T

2015-11-23

Current on-site drug of abuse detection methods involve invasive sampling of blood and urine specimens, or collection of oral fluid, followed by qualitative screening tests using immunochromatographic cartridges. Test confirmation and quantitative assessment of a presumptive positive are then provided by remote laboratories, an inefficient and costly process decoupled from the initial sampling. Recently, a new noninvasive oral fluid sampling approach that is integrated with the chip-based Programmable Bio-Nano-Chip (p-BNC) platform has been developed for the rapid (~ 10 minutes), sensitive detection (~ ng/ml) and quantitation of 12 drugs of abuse. Furthermore, the system can provide the time-course of select drug and metabolite profiles in oral fluids. For cocaine, we observed three slope components were correlated with cocaine-induced impairment using this chip-based p-BNC detection modality. Thus, this p-BNC has significant potential for roadside drug testing by law enforcement officers. Initial work reported on chip-based drug detection was completed using 'macro' or "chip in the lab" prototypes, that included metal encased "flow cells", external peristaltic pumps and a bench-top analyzer system instrumentation. We now describe the next generation miniaturized analyzer instrumentation along with customized disposables and sampling devices. These tools will offer real-time oral fluid drug monitoring capabilities, to be used for roadside drug testing as well as testing in clinical settings as a non-invasive, quantitative, accurate and sensitive tool to verify patient adherence to treatment.

Timing, predictors, and progress of third space fluid accumulation during preliminary phase fluid resuscitation in adult patients with dengue.

PubMed

Premaratna, R; Ragupathy, A; Miththinda, J K N D; de Silva, H J

2013-07-01

Fluid leakage remains the hallmark of dengue hemorrhagic fever (DHF). The applicability of currently recommended predictors of DHF for adults with dengue is questionable as these are based on studies conducted in children. One hundred and two adults with dengue were prospectively followed up to investigate whether home-based or hospital-based early phase fluid resuscitation has an impact on clinical and hematological parameters used for the diagnosis of early or critical phase fluid leakage. In the majority of subjects, third space fluid accumulation (TSFA) was detected on the fifth and sixth days of infection. The quantity and quality of fluids administered played no role in TSFA. A reduction in systolic blood pressure appeared to be more helpful than a reduction in pulse pressure in predicting fluid leakage. TSFA occurred with lower percentage rises in packed cell volume (PCV) than stated in the current recommendations. A rapid reduction in platelets, progressive reduction in white blood cells, percentage rises in Haemoglobin (Hb), and PCV, and rises in aspartate aminotransferase and alanine aminotransferase were observed in patients with TSFA and therefore with the development of severe illness. Clinicians should be aware of the limitations of currently recommended predictors of DHF in adult patients who are receiving fluid resuscitation. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Discriminative Projection Selection Based Face Image Hashing

NASA Astrophysics Data System (ADS)

Karabat, Cagatay; Erdogan, Hakan

Face image hashing is an emerging method used in biometric verification systems. In this paper, we propose a novel face image hashing method based on a new technique called discriminative projection selection. We apply the Fisher criterion for selecting the rows of a random projection matrix in a user-dependent fashion. Moreover, another contribution of this paper is to employ a bimodal Gaussian mixture model at the quantization step. Our simulation results on three different databases demonstrate that the proposed method has superior performance in comparison to previously proposed random projection based methods.

Interpretation of Oral Fluid Tests for Drugs of Abuse

PubMed Central

CONE, EDWARD J.; HUESTIS, MARILYN A.

2009-01-01

Oral fluid testing for drugs of abuse offers significant advantages over urine as a test matrix. Collection can be performed under direct observation with reduced risk of adulteration and substitution. Drugs generally appear in oral fluid by passive diffusion from blood, but also may be deposited in the oral cavity during oral, smoked, and intranasal administration. Drug metabolites also can be detected in oral fluid. Unlike urine testing, there may be a close correspondence between drug and metabolite concentrations in oral fluid and in blood. Interpretation of oral fluid results for drugs of abuse should be an iterative process whereby one considers the test results in the context of program requirements and a broad scientific knowledge of the many factors involved in determining test outcome. This review delineates many of the chemical and metabolic processes involved in the disposition of drugs and metabolites in oral fluid that are important to the appropriate interpretation of oral fluid tests. Chemical, metabolic, kinetic, and analytic parameters are summarized for selected drugs of abuse, and general guidelines are offered for understanding the significance of oral fluid tests. PMID:17332074

Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT.

PubMed

Wallace, Adam N; Vyhmeister, Ross; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; Ramirez-Giraldo, Juan Carlos; McKinstry, Robert C

2015-06-01

Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality.

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

PubMed

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.

Cold enzymatic bleaching of fluid whey.

PubMed

Campbell, R E; Drake, M A

2013-01-01

Chemical bleaching of fluid whey and retentate with hydrogen peroxide (HP) alone requires high concentrations (100-500 mg of HP/kg) and recent studies have demonstrated that off-flavors are generated during chemical bleaching that carry through to spray-dried whey proteins. Bleaching of fluid whey and retentate with enzymes such as naturally present lactoperoxidase or an exogenous commercial peroxidase (EP) at cold temperatures (4°C) may be a viable alternative to traditional chemical bleaching of whey. The objective of this study was to determine the optimum level of HP for enzymatic bleaching (both lactoperoxidase and EP) at 4°C and to compare bleaching efficacy and sensory characteristics to HP chemical bleaching at 4°C. Selected treatments were subsequently applied for whey protein concentrate with 80% protein (WPC80) manufacture. Fluid Cheddar whey and retentate (80% protein) were manufactured in triplicate from pasteurized whole milk. The optimum concentration of HP (0 to 250 mg/kg) to activate enzymatic bleaching at 4°C was determined by quantifying the loss of norbixin. In subsequent experiments, bleaching efficacy, descriptive sensory analysis, and volatile compounds were monitored at selected time points. A control with no bleaching was also evaluated. Enzymatic bleaching of fluid whey and retentate at 4°C resulted in faster bleaching and higher bleaching efficacy (color loss) than bleaching with HP alone at 250 mg/kg. Due to concentrated levels of naturally present lactoperoxidase, retentate bleached to completion (>80% norbixin destruction in 30 min) faster than fluid whey at 4°C (>80% norbixin destruction in 12h). In fluid whey, the addition of EP decreased bleaching time. Spray-dried WPC80 from bleached wheys, regardless of bleaching treatment, were characterized by a lack of sweet aromatic and buttery flavors, and the presence of cardboard flavor concurrent with higher relative abundance of 1-octen-3-ol and 1-octen-3-one. Among enzymatically

Extension of Generalized Fluid System Simulation Program's Fluid Property Database

NASA Technical Reports Server (NTRS)

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.

Insights on the criteria of selection of vegetable and mineral dielectric fluids used in power transformers on the basis of their biodegradability and toxicity assessments.

PubMed

Módenes, Aparecido Nivaldo; Sanderson, Karina; Trigueros, Daniela Estelita Goes; Schuelter, Adilson Ricken; Espinoza-Quiñones, Fernando Rodolfo; Neves, Camila Vargas; Zanão Junior, Luiz Antônio; Kroumov, Alexander Dimitrov

2018-05-01

Leakage of transformer dielectric fluids is a concern because it may pose a risk of environmental contamination. In this study, the deleterious effects of vegetable and mineral dielectric fluids in water bodies were investigated using biodegradability and acute toxicity tests with Danio rerio and Artemia salina. Regarding biodegradability, all four tested vegetable oils (soy, canola, sunflower and crambe) were considered as easily biodegradable, presenting degradation rates significantly higher than the Lubrax-type mineral fluid. Acute toxicity tests were performed in two separate experiments without solution renewal. In the first experiment, the organisms were exposed in direct contact to different concentrations of vegetable (soy) and mineral (Lubrax) oils. Total soy-type vegetable oil has a higher toxic effect than Lubrax-type mineral oil. In the second experiment, the organisms were exposed to increasing percentages of the water-soluble fraction (WSF) of both types of tested oils. The LC 50 values for the water-soluble fraction of the Lubrax-type mineral oil were about 5 and 8% for the Danio rerio and Artemia salina bioindicators, respectively, whereas the vegetable oil did not present toxic effect, regardless of its WSF. These results have shown that a strict selection of dielectric fluids and monitoring the leakage from power transformers is a serious duty of environmental protection agencies. Copyright © 2018 Elsevier Ltd. All rights reserved.

In-line monitoring of (MR) fluid properties

NASA Astrophysics Data System (ADS)

Kordonski, William; Gorodkin, Sergei; Behlok, Ray

2015-05-01

Proper functionality of devices and processes based on (MR) fluids greatly depends, along with other factors, on stability of fluid characteristics such as concentration of magnetic particles and magnetic properties of the particles. The concentration of magnetic particles may change due to evaporation or leakage of carrier fluid, as well as particle sedimentation. Magnetic properties may change due to temperature, corrosion of particles or irreversible aggregation. In-line noninvasive monitoring of particle concentration and magnetic properties allows, in one way or another, compensation for the impact of destabilizing factors and provides system stable output. Two novel methods of in-line measurement of MR fluid magnetic permeability or magnetic particle concentration are considered in this presentation. The first one is based on the principle of mutual inductance and is intended for monitoring MR fluid flowing in pipes or channels. In the second one, permeability is measured by a flash-mount sensor which reacts on changes in the reluctance of the MR fluid layer adjacent to the wall. The use of the methods for stabilization of the material removal rate in high precision finishing process employing aqueous MR fluid is discussed.

Alzheimer’s disease cerebrospinal fluid biomarker in cognitively normal subjects

PubMed Central

Toledo, Jon B.; Zetterberg, Henrik; van Harten, Argonde C.; Glodzik, Lidia; Martinez-Lage, Pablo; Bocchio-Chiavetto, Luisella; Rami, Lorena; Hansson, Oskar; Sperling, Reisa; Engelborghs, Sebastiaan; Osorio, Ricardo S.; Vanderstichele, Hugo; Vandijck, Manu; Hampel, Harald; Teipl, Stefan; Moghekar, Abhay; Albert, Marilyn; Hu, William T.; Monge Argilés, Jose A.; Gorostidi, Ana; Teunissen, Charlotte E.; De Deyn, Peter P.; Hyman, Bradley T.; Molinuevo, Jose L.; Frisoni, Giovanni B.; Linazasoro, Gurutz; de Leon, Mony J.; van der Flier, Wiesje M.; Scheltens, Philip; Blennow, Kaj; Shaw, Leslie M.

2015-01-01

In a large multicentre sample of cognitively normal subjects, as a function of age, gender and APOE genotype, we studied the frequency of abnormal cerebrospinal fluid levels of Alzheimer’s disease biomarkers including: total tau, phosphorylated tau and amyloid-β1-42. Fifteen cohorts from 12 different centres with either enzyme-linked immunosorbent assays or Luminex® measurements were selected for this study. Each centre sent nine new cerebrospinal fluid aliquots that were used to measure total tau, phosphorylated tau and amyloid-β1-42 in the Gothenburg laboratory. Seven centres showed a high correlation with the new Gothenburg measurements; therefore, 10 cohorts from these centres are included in the analyses here (1233 healthy control subjects, 40–84 years old). Amyloid-β amyloid status (negative or positive) and neurodegeneration status (negative or positive) was established based on the pathological cerebrospinal fluid Alzheimer’s disease cut-off values for cerebrospinal fluid amyloid-β1-42 and total tau, respectively. While gender did not affect these biomarker values, APOE genotype modified the age-associated changes in cerebrospinal fluid biomarkers such that APOE ε4 carriers showed stronger age-related changes in cerebrospinal fluid phosphorylated tau, total tau and amyloid-β1-42 values and APOE ε2 carriers showed the opposite effect. At 40 years of age, 76% of the subjects were classified as amyloid negative, neurodegeneration negative and their frequency decreased to 32% at 85 years. The amyloid-positive neurodegeneration-negative group remained stable. The amyloid-negative neurodegeneration-positive group frequency increased slowly from 1% at 44 years to 16% at 85 years, but its frequency was not affected by APOE genotype. The amyloid-positive neurodegeneration-positive frequency increased from 1% at 53 years to 28% at 85 years. Abnormally low cerebrospinal fluid amyloid-β1-42 levels were already frequent in midlife and APOE genotype

A lattice Boltzmann investigation of steady-state fluid distribution, capillary pressure and relative permeability of a porous medium: Effects of fluid and geometrical properties

NASA Astrophysics Data System (ADS)

Li, Zi; Galindo-Torres, Sergio; Yan, Guanxi; Scheuermann, Alexander; Li, Ling

2018-06-01

Simulations of simultaneous steady-state two-phase flow in the capillary force-dominated regime were conducted using the state-of-the-art Shan-Chen multi-component lattice Boltzmann model (SCMC-LBM) based on two-dimensional porous media. We focused on analyzing the fluid distribution (i.e., WP fluid-solid, NP fluid-solid and fluid-fluid interfacial areas) as well as the capillary pressure versus saturation curve which was affected by fluid and geometrical properties (i.e., wettability, adhesive strength, pore size distribution and specific surface area). How these properties influenced the relative permeability versus saturation relation through apparent effective permeability and threshold pressure gradient was also explored. The SCMC-LBM simulations showed that, a thin WP fluid film formed around the solid surface due to the adhesive fluid-solid interaction, resulting in discrete WP fluid distributions and reduction of the WP fluid mobility. Also, the adhesive interaction provided another source of capillary pressure in addition to capillary force, which, however, did not affect the mobility of the NP fluid. The film fluid effect could be enhanced by large adhesive strength and fine pores in heterogeneous porous media. In the steady-state infiltration, not only the NP fluid but also the WP fluid were subjected to the capillary resistance. The capillary pressure effect could be alleviated by decreased wettability, large average pore radius and improved fluid connectivity in heterogeneous porous media. The present work based on the SCMC-LBM investigations elucidated the role of film fluid as well as capillary pressure in the two-phase flow system. The findings have implications for ways to improve the macroscopic flow equation based on balance of force for the steady-state infiltration.

Drilling fluids: Where should research dollars be spent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauber

This article discusses the question of where to apply research dollars in the field of drilling fluids which is gravely impacted by environmental concerns. In fact, environmental regulations are the driving force in determining the thrust of drilling fluids research. For example, use of oil-base fluids offshore have, for all practical purposes, been precluded by high disposal costs since offshore disposal has been prohibited. Consequently it must be determined if a water-base mud can be developed that has all or most of the advantages of an oil-base mud.

Physically based model for extracting dual permeability parameters using non-Newtonian fluids

NASA Astrophysics Data System (ADS)

Abou Najm, M. R.; Basset, C.; Stewart, R. D.; Hauswirth, S.

2017-12-01

Dual permeability models are effective for the assessment of flow and transport in structured soils with two dominant structures. The major challenge to those models remains in the ability to determine appropriate and unique parameters through affordable, simple, and non-destructive methods. This study investigates the use of water and a non-Newtonian fluid in saturated flow experiments to derive physically-based parameters required for improved flow predictions using dual permeability models. We assess the ability of these two fluids to accurately estimate the representative pore sizes in dual-domain soils, by determining the effective pore sizes of macropores and micropores. We developed two sub-models that solve for the effective macropore size assuming either cylindrical (e.g., biological pores) or planar (e.g., shrinkage cracks and fissures) pore geometries, with the micropores assumed to be represented by a single effective radius. Furthermore, the model solves for the percent contribution to flow (wi) corresponding to the representative macro and micro pores. A user-friendly solver was developed to numerically solve the system of equations, given that relevant non-Newtonian viscosity models lack forms conducive to analytical integration. The proposed dual-permeability model is a unique attempt to derive physically based parameters capable of measuring dual hydraulic conductivities, and therefore may be useful in reducing parameter uncertainty and improving hydrologic model predictions.

Selecting supplier combination based on fuzzy multicriteria analysis

NASA Astrophysics Data System (ADS)

Han, Zhi-Qiu; Luo, Xin-Xing; Chen, Xiao-Hong; Yang, Wu-E.

2015-07-01

Existing multicriteria analysis (MCA) methods are probably ineffective in selecting a supplier combination. Thus, an MCA-based fuzzy 0-1 programming method is introduced. The programming relates to a simple MCA matrix that is used to select a single supplier. By solving the programming, the most feasible combination of suppliers is selected. Importantly, this result differs from selecting suppliers one by one according to a single-selection order, which is used to rank sole suppliers in existing MCA methods. An example highlights such difference and illustrates the proposed method.

Fluid density and concentration measurement using noninvasive in situ ultrasonic resonance interferometry

DOEpatents

Pope, Noah G.; Veirs, Douglas K.; Claytor, Thomas N.

1994-01-01

The specific gravity or solute concentration of a process fluid solution located in a selected structure is determined by obtaining a resonance response spectrum of the fluid/structure over a range of frequencies that are outside the response of the structure itself. A fast fourier transform (FFT) of the resonance response spectrum is performed to form a set of FFT values. A peak value for the FFT values is determined, e.g., by curve fitting, to output a process parameter that is functionally related to the specific gravity and solute concentration of the process fluid solution. Calibration curves are required to correlate the peak FFT value over the range of expected specific gravities and solute concentrations in the selected structure.

Fluid density and concentration measurement using noninvasive in situ ultrasonic resonance interferometry

DOEpatents

Pope, N.G.; Veirs, D.K.; Claytor, T.N.

1994-10-25

The specific gravity or solute concentration of a process fluid solution located in a selected structure is determined by obtaining a resonance response spectrum of the fluid/structure over a range of frequencies that are outside the response of the structure itself. A fast Fourier transform (FFT) of the resonance response spectrum is performed to form a set of FFT values. A peak value for the FFT values is determined, e.g., by curve fitting, to output a process parameter that is functionally related to the specific gravity and solute concentration of the process fluid solution. Calibration curves are required to correlate the peak FFT value over the range of expected specific gravities and solute concentrations in the selected structure. 7 figs.

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

NASA Astrophysics Data System (ADS)

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.

Cryogenic fluid management in space

NASA Technical Reports Server (NTRS)

Antar, Basil N.

1988-01-01

Many future space based vehicles and satellites will require on orbit refuelling procedures. Cryogenic fluid management technology is being developed to assess the requirements of such procedures as well as to aid in the design and development of these vehicles. Cryogenic fluid management technology for this application could be divided into two areas of study, one is concerned with fluid transfer process and the other with cryogenic liquid storage. This division is based upon the needed technology for the development of each area. In the first, the interaction of fluid dynamics with thermodynamics is essential, while in the second only thermodynamic analyses are sufficient to define the problem. The following specific process related to the liquid transfer area are discussed: tank chilldown and fill; tank pressurization; liquid positioning; and slosh dynamics and control. These specific issues are discussed in relation with the required technology for their development in the low gravity application area. In each process the relevant physics controlling the technology is identified and methods for resolving some of the basic questions are discussed.

Validation of an All-Pressure Fluid Drop Model: Heptane Fluid Drops in Nitrogen

NASA Technical Reports Server (NTRS)

Harstad, K.; Bellan, J.; Bulzan, Daniel L. (Technical Monitor)

2000-01-01

, however none of these studies identified the crucial differences between the subcritical and supercritical behavior. In fact, in two of these studies, it was found that the subcritical and supercritical behavior is similar as the drop diameter decreased according to the classical d(exp 2)-law over a wide range of pressures and drop diameters. The present study is devoted to the exploration of differences in fluid-behavior characteristics under subcritical and supercritical conditions in the particular case of heptane fluid drops in nitrogen; these substances were selected because of the availability of experimental observations for model validation.

40 CFR Appendix 3 to Subpart A of... - Procedure for Mixing Base Fluids With Sediments

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Procedure for Mixing Base Fluids With Sediments 3 Appendix 3 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS OIL AND GAS EXTRACTION POINT SOURCE CATEGORY Offshore...

40 CFR Appendix 3 to Subpart A of... - Procedure for Mixing Base Fluids With Sediments

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Procedure for Mixing Base Fluids With Sediments 3 Appendix 3 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS OIL AND GAS EXTRACTION POINT SOURCE CATEGORY Offshore...

Fluid delivery manifolds and microfluidic systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Renzi, Ronald F.; Sommer, Gregory J.; Singh, Anup K.

2017-02-28

Embodiments of fluid distribution manifolds, cartridges, and microfluidic systems are described herein. Fluid distribution manifolds may include an insert member and a manifold base and may define a substantially closed channel within the manifold when the insert member is press-fit into the base. Cartridges described herein may allow for simultaneous electrical and fluidic interconnection with an electrical multiplex board and may be held in place using magnetic attraction.

Controlling Capillary-Driven Fluid Transport in Paper-Based Microfluidic Devices Using a Movable Valve.

PubMed

Li, Bowei; Yu, Lijuan; Qi, Ji; Fu, Longwen; Zhang, Peiqing; Chen, Lingxin

2017-06-06

This paper describes a novel strategy for fabricating the movable valve on paper-based microfluidic devices to manipulate capillary-driven fluids. The movable valve fabrication is first realized using hollow rivets as the holding center to control the paper channel in different layer movement that results in the channel's connection or disconnection. The relatively simple valve fabrication procedure is robust, versatile, and compatible with microfluidic paper-based analytical devices (μPADs) with differing levels of complexity. It is remarkable that the movable valve can be convenient and free to control fluid without the timing setting, advantages that make it user-friendly for untrained users to carry out the complex multistep operations. For the performance of the movable valve to be verified, several different designs of μPADs were tested and obtained with satisfactory results. In addition, in the proof-of-concept enzyme-linked immunosorbent assay experiments, we demonstrate the use of these valves in μPADs for the successful analysis of samples of carcino-embryonic antigen, showing good sensitivity and reproducibility. We hope this technique will open new avenues for the fabrication of paper-based valves in an easily adoptable and widely available way on μPADs and provide potential point-of-care applications in the future.

Terahertz artificial material based on integrated metal-rod-array for phase sensitive fluid detection.

PubMed

You, Borwen; Chen, Ching-Yu; Yu, Chin-Ping; Liu, Tze-An; Hattori, Toshiaki; Lu, Ja-Yu

2017-04-17

A terahertz artificial material composed of metal rod array is experimentally investigated on its transmission spectral property and successfully incorporated into microfluidics as a miniaturized terahertz waveguide with an extended optical-path-length for label-free fluidic sensing. Theoretical and experimental characterizations of terahertz transmission spectra show that the wave guidance along the metal rod array originates from the resonance of transverse-electric-polarized waves within the metal rod slits. The extended optical path length along three layers of metal-rod-array enables terahertz waves sufficiently overlapping the fluid molecules embedded among the rods, leading to strongly enhanced phase change by approximately one order of magnitude compared with the blank metal-parallel-plate waveguide. Based on the enhanced phase sensitivity, three kinds of colorless liquid analytes, namely, acetone, methanol, and ethanol, with different dipole moments are identified in situ using the metal-rod-array-based microfluidic sensor. The detection limit in molecular amounts of a liquid analyte is experimentally demonstrated to be less than 0.1 mmol, corresponding to 2.7 μmol/mm². The phase sensitive terahertz metal-rod-array-based sensor potentially has good adaptability in lab-chip technology for various practical applications, such as industrial toxic fluid detection and medical breath inspection.

Scaffolding for solving problem in static fluid: A case study

NASA Astrophysics Data System (ADS)

Koes-H, Supriyono; Muhardjito, Wijaya, Charisma P.

2018-01-01

Problem solving is one of the basic abilities that should be developed from learning physics. However, students still face difficulties in the process of non-routine problem-solving. Efforts are necessary to be taken in order to identify such difficulties and the solutions to solve them. An effort in the form of a diagnosis of students' performance in problem solving can be taken to identify their difficulties, and various instructional scaffolding supports can be utilized to eliminate the difficulties. This case study aimed to describe the students' difficulties in solving static fluid problems and the effort to overcome such difficulties through different scaffolding supports. The research subjects consisted of four 10-grade students of (Public Senior High School) SMAN 4 Malang selected by purposive sampling technique. The data of students' difficulties were collected via think-aloud protocol implemented on students' performance in solving non-routine static fluid problems. Subsequently, combined scaffolding supports were given to the students based on their particular difficulties. The research findings pointed out that there were several conceptual difficulties discovered from the students when solving static fluid problems, i.e. the use of buoyancy force formula, determination of all forces acting on a plane in a fluid, the resultant force on a plane in a fluid, and determination of a plane depth in a fluid. An effort that can be taken to overcome such conceptual difficulties is providing a combination of some appropriate scaffolding supports, namely question prompts with specific domains, simulation, and parallel modeling. The combination can solve students' lack of knowledge and improve their conceptual understanding, as well as help them to find solutions by linking the problems with their prior knowledge. According to the findings, teachers are suggested to diagnose the students' difficulties so that they can provide an appropriate combination of

Bartter syndrome prenatal diagnosis based on amniotic fluid biochemical analysis.

PubMed

Garnier, Arnaud; Dreux, Sophie; Vargas-Poussou, Rosa; Oury, Jean-François; Benachi, Alexandra; Deschênes, Georges; Muller, Françoise

2010-03-01

Bartter syndrome is an autosomic recessive disease characterized by severe polyuria and sodium renal loss. The responsible genes encode proteins involved in electrolyte tubular reabsorption. Prenatal manifestations, mainly recurrent polyhydramnios because of fetal polyuria, lead to premature delivery. After birth, polyuria leads to life-threatening dehydration. Prenatal genetic diagnosis needs an index case. The aim of this study was to analyze amniotic fluid biochemistry for the prediction of Bartter syndrome. We retrospectively studied 16 amniotic fluids of Bartter syndrome-affected fetuses diagnosed after birth, only six of them being genetically proven. We assayed total proteins, alpha-fetoprotein, and electrolytes and defined a Bartter index corresponding to the multiplication of total protein and of alpha-fetoprotein. Results were compared with two control groups matched for gestational age-non-Bartter polyhydramnios (n = 30) and nonpolyhydramnios (n = 60). In Bartter syndrome, we observed significant differences (p < 0.0001) for protein amniotic fluid levels when compared with the two control groups (1.55 g/L, 3.9 g/L, and 5.2 g/L, respectively) and low Bartter index (0.16, 0.82, and 1.0, respectively). No statistical difference was observed for electrolytes. In conclusion, Bartter syndrome can be prenatally suspected on amniotic fluid biochemistry (sensitivity 93% and specificity 100%), allowing appropriate management before and after birth.

Microbial community changes in hydraulic fracturing fluids and produced water from shale gas extraction.

PubMed

Murali Mohan, Arvind; Hartsock, Angela; Bibby, Kyle J; Hammack, Richard W; Vidic, Radisav D; Gregory, Kelvin B

2013-11-19

Microbial communities associated with produced water from hydraulic fracturing are not well understood, and their deleterious activity can lead to significant increases in production costs and adverse environmental impacts. In this study, we compared the microbial ecology in prefracturing fluids (fracturing source water and fracturing fluid) and produced water at multiple time points from a natural gas well in southwestern Pennsylvania using 16S rRNA gene-based clone libraries, pyrosequencing, and quantitative PCR. The majority of the bacterial community in prefracturing fluids constituted aerobic species affiliated with the class Alphaproteobacteria. However, their relative abundance decreased in produced water with an increase in halotolerant, anaerobic/facultative anaerobic species affiliated with the classes Clostridia, Bacilli, Gammaproteobacteria, Epsilonproteobacteria, Bacteroidia, and Fusobacteria. Produced water collected at the last time point (day 187) consisted almost entirely of sequences similar to Clostridia and showed a decrease in bacterial abundance by 3 orders of magnitude compared to the prefracturing fluids and produced water samplesfrom earlier time points. Geochemical analysis showed that produced water contained higher concentrations of salts and total radioactivity compared to prefracturing fluids. This study provides evidence of long-term subsurface selection of the microbial community introduced through hydraulic fracturing, which may include significant implications for disinfection as well as reuse of produced water in future fracturing operations.

Probing Reliability of Transport Phenomena Based Heat Transfer and Fluid Flow Analysis in Autogeneous Fusion Welding Process

NASA Astrophysics Data System (ADS)

Bag, S.; de, A.

2010-09-01

The transport phenomena based heat transfer and fluid flow calculations in weld pool require a number of input parameters. Arc efficiency, effective thermal conductivity, and viscosity in weld pool are some of these parameters, values of which are rarely known and difficult to assign a priori based on the scientific principles alone. The present work reports a bi-directional three-dimensional (3-D) heat transfer and fluid flow model, which is integrated with a real number based genetic algorithm. The bi-directional feature of the integrated model allows the identification of the values of a required set of uncertain model input parameters and, next, the design of process parameters to achieve a target weld pool dimension. The computed values are validated with measured results in linear gas-tungsten-arc (GTA) weld samples. Furthermore, a novel methodology to estimate the overall reliability of the computed solutions is also presented.

Physics based simulation of seismicity induced in the vicinity of a high-pressure fluid injection

NASA Astrophysics Data System (ADS)

McCloskey, J.; NicBhloscaidh, M.; Murphy, S.; O'Brien, G. S.; Bean, C. J.

2013-12-01

High-pressure fluid injection into subsurface is known, in some cases, to induce earthquakes in the surrounding volume. The increasing importance of ';fracking' as a potential source of hydrocarbons has made the seismic hazard from this effect an important issue the adjudication of planning applications and it is likely that poor understanding of the process will be used as justification of refusal of planning in Ireland and the UK. Here we attempt to understand some of the physical controls on the size and frequency of induced earthquakes using a physics-based simulation of the process and examine resulting earthquake catalogues The driver for seismicity in our simulations is identical to that used in the paper by Murphy et al. in this session. Fluid injection is simulated using pore fluid movement throughout a permeable layer from a high-pressure point source using a lattice Boltzmann scheme. Diffusivities and frictional parameters can be defined independently at individual nodes/cells allowing us to reproduce 3-D geological structures. Active faults in the model follow a fractal size distribution and exhibit characteristic event size, resulting in a power-law frequency-size distribution. The fluid injection is not hydraulically connected to the fault (i.e. fluid does not come into physical contact with the fault); however stress perturbations from the injection drive the seismicity model. The duration and pressure-time function of the fluid injection can be adjusted to model any given injection scenario and the rate of induced seismicity is controlled by the local structures and ambient stress field as well as by the stress perturbations resulting from the fluid injection. Results from the rate and state fault models of Murphy et al. are incorporated to include the effect of fault strengthening in seismically quite areas. Initial results show similarities with observed induced seismic catalogues. Seismicity is only induced where the active faults have not been

Fluid management in the optimization of space construction

NASA Technical Reports Server (NTRS)

Snyder, Howard

1990-01-01

Fluid management impacts strongly on the optimization of space construction. Large quantities of liquids are needed for propellants and life support. The mass of propellant liquids is comparable to that required for the structures. There may be a strong dynamic interaction between the stored liquids and the space structure unless the design minimizes the interaction. The constraints of cost and time required optimization of the supply/resupply strategy. The proper selection and design of the fluid management methods for: slosh control; stratification control; acquisition; transfer; gauging; venting; dumping; contamination control; selection of tank configuration and size; the storage state and the control system can improve the entire system performance substantially. Our effort consists of building mathematical/computer models of the various fluid management methods and testing them against the available experimental data. The results of the models are used as inputs to the system operations studies. During the past year, the emphasis has been on modeling: the transfer of cryogens; sloshing and the storage configuration. The work has been intermeshed with ongoing NASA design and development studies to leverage the funds provided by the Center.

Guiding principles of fluid and volume therapy.

PubMed

Aditianingsih, Dita; George, Yohanes W H

2014-09-01

Fluid therapy is a core concept in the management of perioperative and critically ill patients for maintenance of intravascular volume and organ perfusion. Recent evidence regarding the vascular barrier and its role in terms of vascular leakage has led to a new concept for fluid administration. The choice of fluid used should be based on the fluid composition and the underlying pathophysiology of the patient. Avoidance of both hypo- and hypervolaemia is essential when treating circulatory failure. In daily practice, the assessment of individual thresholds in order to optimize cardiac preload and avoid hypovolaemia or deleterious fluid overload remains a challenge. Liberal versus restrictive fluid management has been challenged by recent evidence, and the ideal approach appears to be goal-directed fluid therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Theorethical principles of fluid managment according to physicochemical Stewart approach.

PubMed

Smuszkiewicz, Piotr; Szrama, Jakub

2013-01-01

Interpreting acid base disturbances according to the physicochemical Stewart approach allows the cause of such abnormalities to be discovered. This method is based on three independent variables: SID (strong ion difference), mainly sodium and chloride; weak acids concentration - Atot, mainly albumins and phosphate; and carbon dioxide tension - pCO₂. These three independent variables are responsible for the change of water dissociation and for the change in H+ concentration and, consequently, the change in serum pH value. The SID value of the fluids administered to a patient is responsible for the change of serum SID value and therefore causes a change in the patient's acid base status. During the infusion of a given fluid, the SID value of the serum becomes closer to the SID value of that fluid; on the other hand, the infusion causes a decrease in Atot concentration. In order to avoid acid base disturbances connected with fluid administration, the SID value of fluids being administered should be greater than 0 and lower then the serum SID. It has been suggested that fluids should be given of which the SID value is as close as possible to the actual serum HCO₃ concentration. Knowing the SID value of the fluid administered, and the serum HCO₃ concentration, one can expect a change of serum pH after a fluid infusion. Administering a fluid with a SID greater than the HCO₃ concentration causes a pH increase towards alkalosis. Likewise, administering a a fluid with a SID lower than the HCO₃ concentration causes a pH decrease towards acidosis. It seems that knowledge of the electrolyte concentration and the SID value of an administered fluid is an important factor regarding acid base disturbances.

Chemical Signatures of and Precursors to Fractures Using Fluid Inclusion Stratigraphy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorie M. Dilley

Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Open or recently closed fractures would be more susceptible to enhancing the permeability of the system. Identifying dense fracture areas as well as large open fractures from small fracture systems will assist in fracture stimulation site selection. Geothermal systems are constantly generating fractures (Moore, Morrow et al. 1987), and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. These fluid inclusions are faithful records of pore fluid chemistry. Fluid inclusions trappedmore » in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. This report presents the results of the project to determine fracture locations by the chemical signatures from gas analysis of fluid inclusions. With this project we hope to test our assumptions that gas chemistry can distinguish if the fractures are open and bearing production fluids or represent prior active fractures and whether there are chemical signs of open fracture systems in the wall rock above the fracture. Fluid Inclusion Stratigraphy (FIS) is a method developed for the geothermal industry which applies the mass quantification of fluid inclusion gas data from drill cuttings and applying known gas ratios and compositions to determine depth profiles of fluid barriers in a modern geothermal system (Dilley, 2009; Dilley et al., 2005; Norman et al., 2005). Identifying key gas signatures associated with fractures for isolating geothermal fluid production is the latest advancement in the application of FIS to geothermal systems (Dilley and Norman, 2005; Dilley and Norman, 2007). Our hypothesis is that peaks in FIS data are related to location of fractures. Previous work (DOE Grant DE-FG36-06GO16057) has indicated differences

An adjoint-based framework for maximizing mixing in binary fluids

NASA Astrophysics Data System (ADS)

Eggl, Maximilian; Schmid, Peter

2017-11-01

Mixing in the inertial, but laminar parameter regime is a common application in a wide range of industries. Enhancing the efficiency of mixing processes thus has a fundamental effect on product quality, material homogeneity and, last but not least, production costs. In this project, we address mixing efficiency in the above mentioned regime (Reynolds number Re = 1000 , Peclet number Pe = 1000) by developing and demonstrating an algorithm based on nonlinear adjoint looping that minimizes the variance of a passive scalar field which models our binary Newtonian fluids. The numerical method is based on the FLUSI code (Engels et al. 2016), a Fourier pseudo-spectral code, which we modified and augmented by scalar transport and adjoint equations. Mixing is accomplished by moving stirrers which are numerically modeled using a penalization approach. In our two-dimensional simulations we consider rotating circular and elliptic stirrers and extract optimal mixing strategies from the iterative scheme. The case of optimizing shape and rotational speed of the stirrers will be demonstrated.

Supercritical-fluid extraction and chromatography-mass spectrometry for analysis of mycotoxins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, R.D.; Udseth, H.R.

1982-07-01

The use of direct supercritical-fluid injection-mass spectrometry for the rapid analysis of mycotoxins of the tricothecene group is demonstrated. A solution containing diacetoxyscirpenol or T-2 toxin is injected into a fluid consisting primarily of pentane or carbon dioxide and is rapidly brought to supercritical conditions. Direct injection of the fluid stream into a chemical ionization source allows thermally labile compounds to be analyzed. Under these conditions trichothecene mass spectra showing significant (M + 1)/sup +/ ions and distinctive fragmentation patterns are obtained. Detection limits are in the subnanogram range. Direct analysis from complex substrates using selective supercritical-fluid extraction is proposed.more » 4 figures.« less

Computational fluid dynamics uses in fluid dynamics/aerodynamics education

NASA Technical Reports Server (NTRS)

Holst, Terry L.

1994-01-01

The field of computational fluid dynamics (CFD) has advanced to the point where it can now be used for the purpose of fluid dynamics physics education. Because of the tremendous wealth of information available from numerical simulation, certain fundamental concepts can be efficiently communicated using an interactive graphical interrogation of the appropriate numerical simulation data base. In other situations, a large amount of aerodynamic information can be communicated to the student by interactive use of simple CFD tools on a workstation or even in a personal computer environment. The emphasis in this presentation is to discuss ideas for how this process might be implemented. Specific examples, taken from previous publications, will be used to highlight the presentation.

The rationale for microcirculatory guided fluid therapy.

PubMed

Ince, Can

2014-06-01

The ultimate purpose of fluid administration in states of hypovolemia is to correct cardiac output to improve microcirculatory perfusion and tissue oxygenation. Observation of the microcirculation using handheld microscopes gives insight into the nature of convective and diffusive defect in hypovolemia. The purpose of this article is to introduce a new platform for hemodynamic-targeted fluid therapy based on the correction of tissue and microcirculatory perfusion assumed to be at risk during hypovolemia. Targeting systemic hemodynamic targets and/or clinical surrogates of hypovolemia gives inadequate guarantee for the correction of tissue perfusion by fluid therapy especially in conditions of distributive shock as occur in inflammation and sepsis. Findings are presented, which support the idea that only clinical signs of hypovolemia associated with low microcirculatory flow can be expected to benefit from fluid therapy and that fluid overload causes a defect in the diffusion of oxygen transport. We hypothesized that the optimal amount of fluid needed for correction of hypovolemia is defined by a physiologically based functional microcirculatory hemodynamic platform where convection and diffusion need to be optimized. Future clinical trials using handheld microscopes able to automatically evaluate the microcirculation at the bedside will show whether such a platform will indeed optimize fluid therapy.

An agent-based method for simulating porous fluid-saturated structures with indistinguishable components

NASA Astrophysics Data System (ADS)

Kashani, Jamal; Pettet, Graeme John; Gu, YuanTong; Zhang, Lihai; Oloyede, Adekunle

2017-10-01

Single-phase porous materials contain multiple components that intermingle up to the ultramicroscopic level. Although the structures of the porous materials have been simulated with agent-based methods, the results of the available methods continue to provide patterns of distinguishable solid and fluid agents which do not represent materials with indistinguishable phases. This paper introduces a new agent (hybrid agent) and category of rules (intra-agent rule) that can be used to create emergent structures that would more accurately represent single-phase structures and materials. The novel hybrid agent carries the characteristics of system's elements and it is capable of changing within itself, while also responding to its neighbours as they also change. As an example, the hybrid agent under one-dimensional cellular automata formalism in a two-dimensional domain is used to generate patterns that demonstrate the striking morphological and characteristic similarities with the porous saturated single-phase structures where each agent of the ;structure; carries semi-permeability property and consists of both fluid and solid in space and at all times. We conclude that the ability of the hybrid agent to change locally provides an enhanced protocol to simulate complex porous structures such as biological tissues which could facilitate models for agent-based techniques and numerical methods.

Tactile display device using an electrorheological fluid

NASA Technical Reports Server (NTRS)

Garner, H. Douglas (Inventor)

1994-01-01

A tactile display device utilizes an electrorheological fluid to activate a plurality of tactile dots. A voltage is selectively produced uniformly across an electrorheological fluid flowing between a common ground electrode and a plurality of conductive dot electrodes, thereby producing an increase in the fluid's viscosity to the extent that fluid flow between the two electrodes is restricted. The flow restriction produces a build-up of electrorheological fluid in a corresponding dot actuator chamber. The resulting pressure increase in the chamber displaces an elastic diaphragm fixed to a display surface to form a lump which can be perceived by the reader as one dot in a Braille character cell. A flow regulation system provides a continually pressurized flow system and provides for free flow of the electrorheological fluid through the plurality of dot actuator chambers when they are not activated. The device is adaptable to printed circuit techniques and can simultaneously display tactile dots representative of a full page of Braille characters stored on a medium such as a tape cassette or to display tactile dots representative of non-Braille data appearing on a computer monitor or contained on another data storage medium. In an alternate embodiment, the elastic diaphragm drives a plurality of spring-loaded pins provided with positive stops to maintain consistent displacements of the pins in both their actuated and nonactuated positions.

Information Gain Based Dimensionality Selection for Classifying Text Documents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumidu Wijayasekara; Milos Manic; Miles McQueen

2013-06-01

Selecting the optimal dimensions for various knowledge extraction applications is an essential component of data mining. Dimensionality selection techniques are utilized in classification applications to increase the classification accuracy and reduce the computational complexity. In text classification, where the dimensionality of the dataset is extremely high, dimensionality selection is even more important. This paper presents a novel, genetic algorithm based methodology, for dimensionality selection in text mining applications that utilizes information gain. The presented methodology uses information gain of each dimension to change the mutation probability of chromosomes dynamically. Since the information gain is calculated a priori, the computational complexitymore » is not affected. The presented method was tested on a specific text classification problem and compared with conventional genetic algorithm based dimensionality selection. The results show an improvement of 3% in the true positives and 1.6% in the true negatives over conventional dimensionality selection methods.« less

INVESTIGATIONS ON THE OCCURRENCE OF Rh SUBSTANCES IN AMNIOTIC FLUID

PubMed Central

Witebsky, Ernest; Mohn, James F.

1945-01-01

1. Rh substances are found in amniotic fluid. Not all anti-Rh sera seem to be suitable for the detection of Rh substances in amniotic fluid. Careful selection of Rh antisera, as well as quantitative considerations, determine success or failure of their demonstration. 2. The baby's Rh type and not the mother's determines the occurrence of Rh substances in amniotic fluid. 3. There are Rh secretors and Rh non-secretors. At least four out of five individuals are secretors. 4. The secretion of Rh substance into the amniotic fluid would seem to be entirely independent of the secretion of the blood group specific substances. 5. The majority of Rh-positive amniotic fluids seem to contain both Rh1 and Rh2 substances. However, in certain instances fluids belonging to the pure Rh1 type or pure Rh2 type were found. 6. Three cases of erythroblastosis were described. All three came from Rh-negative mothers with Rh-positive babies. The amniotic fluids of all three failed to reveal the presence of Rh substances. PMID:19871489

Fuzzy System-Based Target Selection for a NIR Camera-Based Gaze Tracker

PubMed Central

Naqvi, Rizwan Ali; Arsalan, Muhammad; Park, Kang Ryoung

2017-01-01

Gaze-based interaction (GBI) techniques have been a popular subject of research in the last few decades. Among other applications, GBI can be used by persons with disabilities to perform everyday tasks, as a game interface, and can play a pivotal role in the human computer interface (HCI) field. While gaze tracking systems have shown high accuracy in GBI, detecting a user’s gaze for target selection is a challenging problem that needs to be considered while using a gaze detection system. Past research has used the blinking of the eyes for this purpose as well as dwell time-based methods, but these techniques are either inconvenient for the user or requires a long time for target selection. Therefore, in this paper, we propose a method for fuzzy system-based target selection for near-infrared (NIR) camera-based gaze trackers. The results of experiments performed in addition to tests of the usability and on-screen keyboard use of the proposed method show that it is better than previous methods. PMID:28420114

Flavour chemicals in electronic cigarette fluids.

PubMed

Tierney, Peyton A; Karpinski, Clarissa D; Brown, Jessica E; Luo, Wentai; Pankow, James F

2016-04-01

Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids. Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local 'vape' shops and online retailers. In many liquids, total flavour chemicals were found to be in the ∼1-4% range (10-40 mg/mL); labelled levels of nicotine were in the range of 0.6-2.4% (6 to 24 mg/mL). A significant number of the flavour chemicals were aldehydes, a compound class recognised as 'primary irritants' of mucosal tissue of the respiratory tract. Many of the products contained the same flavour chemicals: vanillin and/or ethyl vanillin was found in 17 of the liquids as one of the top three flavour chemicals, and/or at ≥0.5 mg/mL. The concentrations of some flavour chemicals in e-cigarette fluids are sufficiently high for inhalation exposure by vaping to be of toxicological concern. Regulatory limits should be contemplated for levels of some of the more worrisome chemicals as well as for total flavour chemical levels. Ingredient labeling should also be required. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Thermophysical Properties of Nanoparticle-Enhanced Ionic Liquids (NEILs) Heat-Transfer Fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.

2013-06-20

An experimental investigation was completed on nanoparticle enhanced ionic liquid heat transfer fluids as an alternative to conventional organic based heat transfer fluids (HTFs). These nanoparticle-based HTFs have the potential to deliver higher thermal conductivity than the base fluid without a significant increase in viscosity at elevated temperatures. The effect of nanoparticle morphology and chemistry on thermophysical properties was examined. Whisker shaped nanomaterials were found to have the largest thermal conductivity temperature dependence and were also less likely to agglomerate in the base fluid than spherical shaped nanomaterials.

Determining temperature limits of drilling fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thuren, J.B.; Chenevert, M.E.; Huang, W.T.W.

A capillary three tube viscometer has been designed which allows the measurement of rheological properties of time dependent non-Newtonian fluids in laminar flow at high temperture and pressure. The objective of this investigation is to determine the temperature stability of clay-water suspensions containing various drilling fluid additives. The additives studied consisted of viscosifiers, filtrate reducers, and chemical thinners. The temperature range studied is from room temperature to 550{sup 0}F. The system pressure is consistently maintained above the vapor pressure. The Bentonite and water standardized base mud used is equivalent to a 25 ppB fluid. Stabilization of the base mud ismore » necessary to obtain steady state laminar flow conditions and to obtain reliable temperature thinning effects with each temperature interval under investigation. Generally the temperature levels are maintained for one hour until 550{sup 0}F is attained. The last interval is then maintained until system fluid degradation occurs. Rheological measurements are obtained from differential pressure transducers located in a three diameter tube test section and externally at ambient conditions from a Baroid Rotational Viscometer. The power law model for non-Newtonian fluids is used to correlate the data.« less

Manipulation of fluids in three-dimensional porous photonic structures with patterned surface properties

DOEpatents

Aizenberg, Joanna; Burgess, Ian B.; Mishchenko, Lidiya; Hatton, Benjamin; Loncar, Marko

2016-03-08

A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.

Manipulation of fluids in three-dimensional porous photonic structures with patterned surface properties

DOEpatents

Aizenberg, Joanna; Burgess, Ian; Mishchenko, Lidiya; Hatton, Benjamin; Loncar, Marko

2017-12-26

A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.

Cross-omics comparison of stress responses in mesothelial cells exposed to heat- versus filter-sterilized peritoneal dialysis fluids.

PubMed

Kratochwill, Klaus; Bender, Thorsten O; Lichtenauer, Anton M; Herzog, Rebecca; Tarantino, Silvia; Bialas, Katarzyna; Jörres, Achim; Aufricht, Christoph

2015-01-01

Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses.

A new hysteresis model based on force-displacement characteristics of magnetorheological fluid actuators subjected to squeeze mode operation

NASA Astrophysics Data System (ADS)

Chen, Peng; Bai, Xian-Xu; Qian, Li-Jun; Choi, Seung-Bok

2017-06-01

This paper presents a new hysteresis model based on the force-displacement characteristics of magnetorheological (MR) fluid actuators (or devices) subjected to squeeze mode operation. The idea of the proposed model is originated from experimental observation of the field-dependent hysteretic behavior of MR fluids, which shows that from a view of rate-independence of hysteresis, a gap width-dependent hysteresis is occurred in the force-displacement relationship instead of the typical relationship of the force-velocity. To effectively and accurately portray the hysteresis behavior, the gap width-dependent hysteresis elements, the nonlinear viscous effect and the inertial effect are considered for the formulation of the hysteresis model. Then, a model-based feedforward force tracking control scheme is established through an observer which can estimate the virtual displacement. The effectiveness of the proposed hysteresis model is validated through the identification and prediction of the damping force of MR fluids in the squeeze mode. In addition, it is shown that superior force tracking performance of the feedforward control associated with the proposed hysteresis mode is evaluated by adopting several tracking trajectories.

Contourlet domain multiband deblurring based on color correlation for fluid lens cameras.

PubMed

Tzeng, Jack; Liu, Chun-Chen; Nguyen, Truong Q

2010-10-01

Due to the novel fluid optics, unique image processing challenges are presented by the fluidic lens camera system. Developed for surgical applications, unique properties, such as no moving parts while zooming and better miniaturization than traditional glass optics, are advantages of the fluid lens. Despite these abilities, sharp color planes and blurred color planes are created by the nonuniform reaction of the liquid lens to different color wavelengths. Severe axial color aberrations are caused by this reaction. In order to deblur color images without estimating a point spread function, a contourlet filter bank system is proposed. Information from sharp color planes is used by this multiband deblurring method to improve blurred color planes. Compared to traditional Lucy-Richardson and Wiener deconvolution algorithms, significantly improved sharpness and reduced ghosting artifacts are produced by a previous wavelet-based method. Directional filtering is used by the proposed contourlet-based system to adjust to the contours of the image. An image is produced by the proposed method which has a similar level of sharpness to the previous wavelet-based method and has fewer ghosting artifacts. Conditions for when this algorithm will reduce the mean squared error are analyzed. While improving the blue color plane by using information from the green color plane is the primary focus of this paper, these methods could be adjusted to improve the red color plane. Many multiband systems such as global mapping, infrared imaging, and computer assisted surgery are natural extensions of this work. This information sharing algorithm is beneficial to any image set with high edge correlation. Improved results in the areas of deblurring, noise reduction, and resolution enhancement can be produced by the proposed algorithm.

Impact of Menu Sequencing on Internet-Based Educational Module Selection

ERIC Educational Resources Information Center

Bensley, Robert; Brusk, John J.; Rivas, Jason; Anderson, Judith V.

2006-01-01

Patterns of Internet-based menu item selection can occur for a number of reasons, many of which may not be based on interest in topic. It then becomes important to ensure menu order is devised in a way that ensures the greatest accuracy in matching user need with selection. This study examined the impact of menu rotation on the selection of…

Assessment of the Flammability of Aircraft Hydraulic Fluids

DTIC Science & Technology

1979-07-01

and C. Y. Ito, Editors, " Thermophysical Properties of Selected Aerospace Materials," Part 1, Thermal Radiation Properties , Purdue University., 1976...34 Thermophysical Properties of Selected Aerospace Materials," Part 1, Thermal Radiation Properties , Purdue University, 1976. 9. J. M. Kuchta, "Summary of...propagation properties , and heats of combustion of a number of aircraft fluids. These included currently used (cont’d) FtORM DD I JAN 7 1473 EDITION

Efficacy of intravenous fluid warming during goal-directed fluid therapy in patients undergoing laparoscopic colorectal surgery: a randomized controlled trial.

PubMed

Choi, Ji-Won; Kim, Duk-Kyung; Lee, Seung-Won; Park, Jung-Bo; Lee, Gyu-Hong

2016-06-01

To evaluate the clinical efficacy of intravenous (IV) fluid warming in patients undergoing laparoscopic colorectal surgery. Adult patients undergoing laparoscopic colorectal surgery were randomly assigned to receive either IV fluids at room temperature (control group) or warmed IV fluids (warm fluids group). Each patient received a standardized goal-directed fluid regimen based on stroke volume variances. Oesophageal temperature was measured at 15 min intervals for 2 h after induction of anaesthesia. A total of 52 patients were enrolled in the study. The drop in core temperature in the warm fluids group was significantly less than in the control group 2 h after the induction of anaesthesia. This significant difference was seen from 30 min after induction. IV fluid warming was associated with a smaller drop in core temperature than room temperature IV fluids in laparoscopic colorectal surgery incorporating goal-directed fluid therapy. © The Author(s) 2016.

Lennard-Jones fluids in two-dimensional nano-pores. Multi-phase coexistence and fluid structure

NASA Astrophysics Data System (ADS)

Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

2014-03-01

We present a number of fundamental findings on the wetting behaviour of nano-pores. A popular model for fluid confinement is a one-dimensional (1D) slit pore formed by two parallel planar walls and it exhibits capillary condensation (CC): a first-order phase transition from vapour to capillary-liquid (Kelvin shift). Capping such a pore at one end by a third orthogonal wall forms a prototypical two-dimensional (2D) pore. We show that 2D pores possess a wetting temperature such that below this temperature CC remains of first order, above it becomes a continuous phase transition manifested by a slab of capillary-liquid filling the pore from the capping wall. Continuous CC exhibits hysteresis and can be preceded by a first-order capillary prewetting transition. Additionally, liquid drops can form in the corners of the 2D pore (remnant of 2D wedge prewetting). The three fluid phases, vapour, capillary-liquid slab and corner drops, can coexist at the pore triple point. Our model is based on the statistical mechanics of fluids in the density functional formulation. The fluid-fluid and fluid-substrate interactions are dispersive. We analyze in detail the microscopic fluid structure, isotherms and full phase diagrams. Our findings also suggest novel ways to control wetting of nano-pores. We are grateful to the European Research Council via Advanced Grant No. 247031 for support.

A monolithic Lagrangian approach for fluid-structure interaction problems

NASA Astrophysics Data System (ADS)

Ryzhakov, P. B.; Rossi, R.; Idelsohn, S. R.; Oñate, E.

2010-11-01

Current work presents a monolithic method for the solution of fluid-structure interaction problems involving flexible structures and free-surface flows. The technique presented is based upon the utilization of a Lagrangian description for both the fluid and the structure. A linear displacement-pressure interpolation pair is used for the fluid whereas the structure utilizes a standard displacement-based formulation. A slight fluid compressibility is assumed that allows to relate the mechanical pressure to the local volume variation. The method described features a global pressure condensation which in turn enables the definition of a purely displacement-based linear system of equations. A matrix-free technique is used for the solution of such linear system, leading to an efficient implementation. The result is a robust method which allows dealing with FSI problems involving arbitrary variations in the shape of the fluid domain. The method is completely free of spurious added-mass effects.

Body Fluids Monitor

NASA Technical Reports Server (NTRS)

Siconolfi, Steven F. (Inventor)

2000-01-01

Method and apparatus are described for determining volumes of body fluids in a subject using bioelectrical response spectroscopy. The human body is represented using an electrical circuit. Intra-cellular water is represented by a resistor in series with a capacitor; extra-cellular water is represented by a resistor in series with two parallel inductors. The parallel inductors represent the resistance due to vascular fluids. An alternating, low amperage, multifrequency signal is applied to determine a subject's impedance and resistance. From these data, statistical regression is used to determine a 1% impedance where the subject's impedance changes by no more than 1% over a 25 kHz interval. Circuit component, of the human body circuit are determined based on the 1% impedance. Equations for calculating total body water, extra-cellular water, total blood volume, and plasma volume are developed based on the circuit components.

New mathematics for old physics: The case of lattice fluids

NASA Astrophysics Data System (ADS)

Barberousse, Anouk; Imbert, Cyrille

2013-08-01

We analyze the effects of the introduction of new mathematical tools on an old branch of physics by focusing on lattice fluids, which are cellular automata (CA)-based hydrodynamical models. We examine the nature of these discrete models, the type of novelty they bring about within scientific practice and the role they play in the field of fluid dynamics. We critically analyze Rohrlich's, Fox Keller's and Hughes' claims about CA-based models. We distinguish between different senses of the predicates "phenomenological" and "theoretical" for scientific models and argue that it is erroneous to conclude, as they do, that CA-based models are necessarily phenomenological in any sense of the term. We conversely claim that CA-based models of fluids, though at first sight blatantly misrepresenting fluids, are in fact conservative as far as the basic laws of statistical physics are concerned and not less theoretical than more traditional models in the field. Based on our case-study, we propose a general discussion of the prospect of CA for modeling in physics. We finally emphasize that lattice fluids are not just exotic oddities but do bring about new advantages in the investigation of fluids' behavior.

Risk-based audit selection of dairy farms.

PubMed

van Asseldonk, M A P M; Velthuis, A G J

2014-02-01

Dairy farms are audited in the Netherlands on numerous process standards. Each farm is audited once every 2 years. Increasing demands for cost-effectiveness in farm audits can be met by introducing risk-based principles. This implies targeting subpopulations with a higher risk of poor process standards. To select farms for an audit that present higher risks, a statistical analysis was conducted to test the relationship between the outcome of farm audits and bulk milk laboratory results before the audit. The analysis comprised 28,358 farm audits and all conducted laboratory tests of bulk milk samples 12 mo before the audit. The overall outcome of each farm audit was classified as approved or rejected. Laboratory results included somatic cell count (SCC), total bacterial count (TBC), antimicrobial drug residues (ADR), level of butyric acid spores (BAB), freezing point depression (FPD), level of free fatty acids (FFA), and cleanliness of the milk (CLN). The bulk milk laboratory results were significantly related to audit outcomes. Rejected audits are likely to occur on dairy farms with higher mean levels of SCC, TBC, ADR, and BAB. Moreover, in a multivariable model, maxima for TBC, SCC, and FPD as well as standard deviations for TBC and FPD are risk factors for negative audit outcomes. The efficiency curve of a risk-based selection approach, on the basis of the derived regression results, dominated the current random selection approach. To capture 25, 50, or 75% of the population with poor process standards (i.e., audit outcome of rejected), respectively, only 8, 20, or 47% of the population had to be sampled based on a risk-based selection approach. Milk quality information can thus be used to preselect high-risk farms to be audited more frequently. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Advanced statistical analysis of Raman spectroscopic data for the identification of body fluid traces: semen and blood mixtures.

PubMed

Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

2012-10-10

Conventional confirmatory biochemical tests used in the forensic analysis of body fluid traces found at a crime scene are destructive and not universal. Recently, we reported on the application of near-infrared (NIR) Raman microspectroscopy for non-destructive confirmatory identification of pure blood, saliva, semen, vaginal fluid and sweat. Here we expand the method to include dry mixtures of semen and blood. A classification algorithm was developed for differentiating pure body fluids and their mixtures. The classification methodology is based on an effective combination of Support Vector Machine (SVM) regression (data selection) and SVM Discriminant Analysis of preprocessed experimental Raman spectra collected using an automatic mapping of the sample. This extensive cross-validation of the obtained results demonstrated that the detection limit of the minor contributor is as low as a few percent. The developed methodology can be further expanded to any binary mixture of complex solutions, including but not limited to mixtures of other body fluids. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic Fracturing in Shale Gas Systems and Electromagnetic Geophysical Monitoring of Fluid Migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jihoon; Um, Evan; Moridis, George

2014-12-01

We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostlymore » filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled

Development of an achiral supercritical fluid chromatography method with ultraviolet absorbance and mass spectrometric detection for impurity profiling of drug candidates. Part II. Selection of an orthogonal set of stationary phases.

PubMed

Lemasson, Elise; Bertin, Sophie; Hennig, Philippe; Boiteux, Hélène; Lesellier, Eric; West, Caroline

2015-08-21

Impurity profiling of organic products that are synthesized as possible drug candidates requires complementary analytical methods to ensure that all impurities are identified. Supercritical fluid chromatography (SFC) is a very useful tool to achieve this objective, as an adequate selection of stationary phases can provide orthogonal separations so as to maximize the chances to see all impurities. In this series of papers, we have developed a method for achiral SFC-MS profiling of drug candidates, based on a selection of 160 analytes issued from Servier Research Laboratories. In the first part of this study, focusing on mobile phase selection, a gradient elution with carbon dioxide and methanol comprising 2% water and 20mM ammonium acetate proved to be the best in terms of chromatographic performance, while also providing good MS response [1]. The objective of this second part was the selection of an orthogonal set of ultra-high performance stationary phases, that was carried out in two steps. Firstly, a reduced set of analytes (20) was used to screen 23 columns. The columns selected were all 1.7-2.5μm fully porous or 2.6-2.7μm superficially porous particles, with a variety of stationary phase chemistries. Derringer desirability functions were used to rank the columns according to retention window, column efficiency evaluated with peak width of selected analytes, and the proportion of analytes successfully eluted with good peak shapes. The columns providing the worst performances were thus eliminated and a shorter selection of columns (11) was obtained. Secondly, based on 160 tested analytes, the 11 columns were ranked again. The retention data obtained on these columns were then compared to define a reduced set of the best columns providing the greatest orthogonality, to maximize the chances to see all impurities within a limited number of runs. Two high-performance columns were thus selected: ACQUITY UPC(2) HSS C18 SB and Nucleoshell HILIC. Copyright © 2015

Optical analysis of suspended particles in the cerebrospinal fluid obtained by puncture from patients diagnosed with the disorders of cerebrospinal fluid (CSF) circulation

NASA Astrophysics Data System (ADS)

Staroń, Waldemar; Herbowski, Leszek; Gurgul, Henryk

2007-04-01

The goal of the work was to determine the values of cumulative parameters of the cerebrospinal fluid. Values of the parameters characterise statistical cerebrospinal fluid obtained by puncture from the patients diagnosed due to suspicion of normotensive hydrocephalus. The cerebrospinal fluid taken by puncture for the routine examinations carried out at the patients suspected of normotensive hydrocephalus was analysed. In the paper there are presented results of examinations of several dozens of puncture samples of the cerebrospinal fluid coming from various patients. Each sample was examined under the microscope and photographed in 20 randomly chosen places. On the basis of analysis of the pictures showing the area of 100 x 100μm, the selected cumulative parameters such as count, numerical density, field area and field perimeter were determined for each sample. Then the average value of the parameters was determined as well.

Liquid chromatography tandem mass spectrometry determination of selected synthetic cathinones and two piperazines in oral fluid. Cross reactivity study with an on-site immunoassay device.

PubMed

de Castro, Ana; Lendoiro, Elena; Fernández-Vega, Hadriana; Steinmeyer, Stefan; López-Rivadulla, Manuel; Cruz, Angelines

2014-12-29

Since the past few years, several synthetic cathinones and piperazines have been introduced into the drug market to substitute illegal stimulant drugs such as amphetamine and derivatives or cocaine due to their unregulated situation. These emerging drugs are not usually included in routine toxicological analysis. We developed and validated a LC-MS/MS method for the determination of methedrone, methylone, mephedrone, 3,4-methylenedioxypyrovalerone (MDPV), fluoromethcathinone, fluoromethamphetamine, 1-(3-chlorophenyl)piperazine (mCPP) and 3-trifluoromethylphenylpiperazine (TFMPP) in oral fluid. Sample extraction was performed using Strata X cartridges. Chromatographic separation was achieved in 10min using an Atlantis(®) T3 column (100mm×2.1mm, 3μm), and formic acid 0.1% and acetonitrile as mobile phase. The method was satisfactorily validated, including selectivity, linearity (0.2-0.5 to 200ng/mL), limits of detection (0.025-0.1ng/mL) and quantification (0.2-0.5ng/mL), imprecision and accuracy in neat oral fluid (%CV=0.0-12.7% and 84.8-103.6% of target concentration, respectively) and in oral fluid mixed with Quantisal™ buffer (%CV=7.2-10.3% and 80.2-106.5% of target concentration, respectively), matrix effect in neat oral fluid (-11.6 to 399.7%) and in oral fluid with Quantisal™ buffer (-69.9 to 131.2%), extraction recovery (87.9-134.3%) and recovery from the Quantisal™ (79.6-107.7%), dilution integrity (75-99% of target concentration) and stability at different conditions (-14.8 to 30.8% loss). In addition, cross reactivity produced by the studied synthetic cathinones in oral fluid using the Dräger DrugTest 5000 was assessed. All the analytes produced a methamphetamine positive result at high concentrations (100 or 10μg/mL), and fluoromethamphetamine also at low concentration (0.075μg/mL). Copyright © 2014 Elsevier B.V. All rights reserved.

Scrutinization of thermal radiation, viscous dissipation and Joule heating effects on Marangoni convective two-phase flow of Casson fluid with fluid-particle suspension

NASA Astrophysics Data System (ADS)

Mahanthesh, B.; Gireesha, B. J.

2018-03-01

The impact of Marangoni convection on dusty Casson fluid boundary layer flow with Joule heating and viscous dissipation aspects is addressed. The surface tension is assumed to vary linearly with temperature. Physical aspects of magnetohydrodynamics and thermal radiation are also accounted. The governing problem is modelled under boundary layer approximations for fluid phase and dust particle phase and then Runge-Kutta-Fehlberg method based numeric solutions are established. The momentum and heat transport mechanisms are focused on the result of distinct governing parameters. The Nusselt number is also calculated. It is established that the rate of heat transfer can be enhanced by suspending dust particles in the base fluid. The temperature field of fluid phase and temperature of dust phase are quite reverse for thermal dust parameter. The radiative heat, viscous dissipation and Joule heating aspects are constructive for thermal fields of fluid and dust phases. The velocity of dusty Casson fluid dominates the velocity of dusty fluid while this trend is opposite in the case of temperature. Moreover qualitative behaviour of fluid phase and dust phase temperature/velocity are similar.

Selected Styles in Web-Based Educational Research

ERIC Educational Resources Information Center

Mann, Bruce, Ed.

2006-01-01

"Selected Styles in Web-Based Educational Research" is concerned with the most common research styles in Web-based teaching or learning. It is intended for practitioners, educators and students, who wish to learn how to conduct research in online teaching and learning, and helps define style in educational research methodology. To…

Numerical investigation of fluid mud motion using a three-dimensional hydrodynamic and two-dimensional fluid mud coupling model

NASA Astrophysics Data System (ADS)

Yang, Xiaochen; Zhang, Qinghe; Hao, Linnan

2015-03-01

A water-fluid mud coupling model is developed based on the unstructured grid finite volume coastal ocean model (FVCOM) to investigate the fluid mud motion. The hydrodynamics and sediment transport of the overlying water column are solved using the original three-dimensional ocean model. A horizontal two-dimensional fluid mud model is integrated into the FVCOM model to simulate the underlying fluid mud flow. The fluid mud interacts with the water column through the sediment flux, current, and shear stress. The friction factor between the fluid mud and the bed, which is traditionally determined empirically, is derived with the assumption that the vertical distribution of shear stress below the yield surface of fluid mud is identical to that of uniform laminar flow of Newtonian fluid in the open channel. The model is validated by experimental data and reasonable agreement is found. Compared with numerical cases with fixed friction factors, the results simulated with the derived friction factor exhibit the best agreement with the experiment, which demonstrates the necessity of the derivation of the friction factor.

Fluid overload in the ICU: evaluation and management.

PubMed

Claure-Del Granado, Rolando; Mehta, Ravindra L

2016-08-02

Fluid overload is frequently found in acute kidney injury patients in critical care units. Recent studies have shown the relationship of fluid overload with adverse outcomes; hence, manage and optimization of fluid balance becomes a central component of the management of critically ill patients. In critically ill patients, in order to restore cardiac output, systemic blood pressure and renal perfusion an adequate fluid resuscitation is essential. Achieving an appropriate level of volume management requires knowledge of the underlying pathophysiology, evaluation of volume status, and selection of appropriate solution for volume repletion, and maintenance and modulation of the tissue perfusion. Numerous recent studies have established a correlation between fluid overload and mortality in critically ill patients. Fluid overload recognition and assessment requires an accurate documentation of intakes and outputs; yet, there is a wide difference in how it is evaluated, reviewed and utilized. Accurate volume status evaluation is essential for appropriate therapy since errors of volume evaluation can result in either in lack of essential treatment or unnecessary fluid administration, and both scenarios are associated with increased mortality. There are several methods to evaluate fluid status; however, most of the tests currently used are fairly inaccurate. Diuretics, especially loop diuretics, remain a valid therapeutic alternative. Fluid overload refractory to medical therapy requires the application of extracorporeal therapies. In critically ill patients, fluid overload is related to increased mortality and also lead to several complications like pulmonary edema, cardiac failure, delayed wound healing, tissue breakdown, and impaired bowel function. Therefore, the evaluation of volume status is crucial in the early management of critically ill patients. Diuretics are frequently used as an initial therapy; however, due to their limited effectiveness the use of continuous

Survey of less-inflammable hydraulic fluids for aircraft

NASA Technical Reports Server (NTRS)

Drake, Wray V; Drell, I L

1950-01-01

A survey of current information on civil and military development of less-inflammable hydraulic fluids for aircraft is presented. Types of less-inflammable fluid reported include: glycol derivative, water base, silicone, ester, and halogenated compound. Specification requirements, physical and chemical properties, hydraulic-system test results, and advantages and disadvantages of various hydraulic fluids are discussed. For completely satisfactory service, some modification of currently available fluids or of present hydraulic-system parts still appears necessary.

Computer program for computing the properties of seventeen fluids. [cryogenic liquids

NASA Technical Reports Server (NTRS)

Brennan, J. A.; Friend, D. G.; Arp, V. D.; Mccarty, R. D.

1992-01-01

The present study describes modifications and additions to the MIPROPS computer program for calculating the thermophysical properties of 17 fluids. These changes include adding new fluids, new properties, and a new interface to the program. The new program allows the user to select the input and output parameters and the units to be displayed for each parameter. Fluids added to the MIPROPS program are carbon dioxide, carbon monoxide, deuterium, helium, normal hydrogen, and xenon. The most recent modifications to the MIPROPS program are the addition of viscosity and thermal conductivity correlations for parahydrogen and the addition of the fluids normal hydrogen and xenon. The recently added interface considerably increases the program's utility.

Comparing topography-based verbal behavior with stimulus selection-based verbal behavior

PubMed Central

Sundberg, Carl T.; Sundberg, Mark L.

1990-01-01

Michael (1985) distinguished between two types of verbal behavior: topography-based and stimulus selection-based verbal behavior. The current research was designed to empirically examine these two types of verbal behavior while addressing the frequently debated question, Which augmentative communication system should be used with the nonverbal developmentally disabled person? Four mentally retarded adults served as subjects. Each subject was taught to tact an object by either pointing to its corresponding symbol (selection-based verbal behavior), or making the corresponding sign (topography-based verbal behavior). They were then taught an intraverbal relation, and were tested for the emergence of stimulus equivalence relations. The results showed that signed responses were acquired more readily than pointing responses as measured by the acquisition of tacts and intraverbals, and the formation of equivalence classes. These results support Michael's (1985) analysis, and have important implications for the design of language intervention programs for the developmentally disabled. ImagesFig. 1Fig. 2 PMID:22477602

Combustion, Complex Fluids, and Fluid Physics Experiments on the ISS

NASA Technical Reports Server (NTRS)

Motil, Brian; Urban, David

2012-01-01

From the very early days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefront of this research looking at both fundamental studies in microgravity as well as experiments targeted at reducing the risks to long duration human missions to the moon, Mars, and beyond. In the current International Space Station (ISS) era, we now have an orbiting laboratory that provides the highly desired condition of long-duration microgravity. This allows continuous and interactive research similar to Earth-based laboratories. Because of these capabilities, the ISS is an indispensible laboratory for low gravity research. NASA GRC has been actively involved in developing and operating facilities and experiments on the ISS since the beginning of a permanent human presence on November 2, 2000. As the lead Center for combustion, complex fluids, and fluid physics; GRC has led the successful implementation of the Combustion Integrated Rack (CIR) and the Fluids Integrated Rack (FIR) as well as the continued use of other facilities on the ISS. These facilities have supported combustion experiments in fundamental droplet combustion; fire detection; fire extinguishment; soot phenomena; flame liftoff and stability; and material flammability. The fluids experiments have studied capillary flow; magneto-rheological fluids; colloidal systems; extensional rheology; pool and nucleate boiling phenomena. In this paper, we provide an overview of the experiments conducted on the ISS over the past 12 years.

Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial.

PubMed

Corbella, Davide; Toppin, Patrick Jason; Ghanekar, Anand; Ayach, Nour; Schiff, Jeffery; Van Rensburg, Adrian; McCluskey, Stuart A

2018-04-10

Intravenous fluid management for deceased donor kidney transplantation is an important, modifiable risk factor for delayed graft function (DGF). The primary objective of this study was to determine if goal-directed fluid therapy using esophageal Doppler monitoring (EDM) to optimize stroke volume (SV) would alter the amount of fluid given. This randomized, proof-of-concept trial enrolled 50 deceased donor renal transplant recipients. Data collected included patient characteristics, fluid administration, hemodynamics, and complications. The EDM was used to optimize SV in the EDM group. In the control group, fluid management followed the current standard of practice. The groups were compared for the primary outcome of total intraoperative fluid administered. There was no difference in the mean (standard deviation) volume of intraoperative fluid administered to the 24 control and 26 EDM patients [2,307 (750) mL vs 2,675 (842) mL, respectively; mean difference, 368 mL; 95% confidence interval (CI), - 87 to + 823; P = 0.11]. The incidence of complications in the control and EDM groups was similar (15/24 vs 17/26, respectively; P = 0.99), as was the incidence of delayed graft failure (8/24 vs 11/26, respectively; P = 0.36). Goal-directed fluid therapy did not alter the volume of fluid administered or the incidence of complications. This proof-of-concept trial provides needed data for conducting a larger trial to determine the influence of fluid therapy on the incidence in DGF in deceased donor kidney transplantation. www.clinicaltrials.gov (NCT02512731). Registered 31 July 2015.

Fluid-cooled heat sink for use in cooling various devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth

The disclosure provides a fluid-cooled heat sink having a heat transfer base, a shroud, and a plurality of heat transfer fins in thermal communication with the heat transfer base and the shroud, where the heat transfer base, heat transfer fins, and the shroud form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop ofmore » the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.« less

Development of a passive micromixer based on repeated fluid twisting and flattening, and its application to DNA purification.