Electro-osmotically actuated oscillatory flow of a physiological fluid on a porous microchannel subject to an external AC electric field having dissimilar frequencies

Science.gov (United States)

Misra, Jagadis C.; Chandra, Sukumar

2014-04-01

Electro-osmotic flow of a physiological fluid with prominent micropolar characteristics, flowing over a microchannel has been analyzed for a situation, where the system is subject to the action of an external AC electric field. In order to account for the rotation of the micro-particles suspended in the physiological fluid, the fluid has been treated as a micropolar fluid. The microchannel is considered to be bounded by two porous plates executing oscillatory motion. Such motion of the plates will normally induce oscillatory flow of the fluid. The governing equations of the fluid include a second-order partial differential equation depicting Gauss's law of electrical charge distributions and two other partial differential equations of second order that arise out of the laws of conservation of linear and angular momenta. These equations have been solved under the sole influence of electrokinetic forces, by using appropriate boundary conditions. This enabled us to determine explicit analytical expressions for the electro-osmotic velocity of the fluid and the microrotation of the suspended micro-particles. These expressions have been used to obtain numerical estimates of important physical variables associated with the oscillatory electro-osmotic flow of a blood sample inside a micro-bio-fluidic device. The numerical results presented in graphical form clearly indicate that the formation of an electrical double layer near the vicinity of the wall causes linear momentum to reduce. In contrast, the angular momentum increases with the enhancement of microrotation of the suspended microparticles. The study will find important applications in the validation of results of further experimental and numerical models pertaining to flow in micro-bio-fluidic devices. It will also be useful in the improvement of the design and construction of various micro-bio-fluidic devices.

Transport of magneto-nanoparticles during electro-osmotic flow in a micro-tube in the presence of magnetic field for drug delivery application

Science.gov (United States)

Mondal, A.; Shit, G. C.

2017-11-01

In this paper, we have examined the motion of magnetic-nanoparticles and the flow characteristics of biofluid in a micro-tube in the presence of externally applied magnetic field and electrokinetic effects. In the drug delivery system, the motion of the magnetic nanoparticles as carriers is important for therapeutic procedure in the treatment of tumor cells, infections and removing blood clots. The unidirectional electro-osmotic flow of biofluid is driven by the combined effects of pulsatile pressure gradient and electrokinetic force. The governing equation for unsteady electromagnetohydrodynamic flow subject to the no-slip boundary condition has been solved numerically by using Crank-Nicolson implicit finite difference scheme. We have analyzed the variation of axial velocity, velocity distribution of magnetic nanoparticles, volumetric flow rate and wall shear stress for various values of the non-dimensional parameters. The study reveals that blood flow velocity, carriers velocity and flow rate are strongly influenced by the electro-osmotic parameter as well as the Hartmann number. The particle mass parameter as well as the particle concentration parameter have efficient capturing effect on magnetic nanoparticles during blood flow through a micro-tube for drug delivery.

Suppression of ion conductance by electro-osmotic flow in nano-channels with weakly overlapping electrical double layers

Directory of Open Access Journals (Sweden)

Yang Liu

2016-08-01

Full Text Available This theoretical study investigates the nonlinear ionic current-voltage characteristics of nano-channels that have weakly overlapping electrical double layers. Numerical simulations as well as a 1-D mathematical model are developed to reveal that the electro-osmotic flow (EOF interplays with the concentration-polarization process and depletes the ion concentration inside the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. As a result of the EOF-driven ion depletion, a limiting-conductance behavior is identified, which is intrinsically different from the classical limiting-current behavior.

Polymer Coatings Reduce Electro-osmosis

Science.gov (United States)

Herren, Blair J.; Snyder, Robert; Shafer, Steven G.; Harris, J. Milton; Van Alstine, James M.

1989-01-01

Poly(ethylene glycol) film controls electrostatic potential. Electro-osmosis in quartz or glass chambers reduced or reversed by coating inside surface of chambers with monomacromolecular layers of poly(ethylene glycol). Stable over long times. Electrostatic potential across surface of untreated glass or plastic chamber used in electro-phoresis is negative and attracts cations in aqueous electrolyte. Cations solvated, entrains flow of electrolyte migrating toward cathode. Electro-osmotic flow interferes with desired electrophoresis of particles suspended in electrolyte. Polymer coats nontoxic, transparent, and neutral, advantageous for use in electrophoresis.

Analysis of metal ions migration to determine electro-osmotic flow for the in-situ cleanup of a tar-contaminated site

KAUST Repository

Lima, Ana T.

2012-03-01

An electro-osmosis experiment was set up on a former asphalt factory site, which is currently contaminated by tar, in Olst, the Netherlands. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from a contaminated clay layer by applying an electric gradient. But before calculating PAH removal, the direction and intensity of electro-osmosis have to be estimated. In field situations, tracers are used to get information about the water flow. In the present study, the inorganic elements concentration oscillations during electro-osmosis application are used as tracers. The experiment was set up in a clay layer, with the configuration 1m×1m×0.3m, at a depth of 4m below soil surface. Al, Ca, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Si, Ti and Zn concentrations were determined in 28 measurements and were performed during the experimental period of 159days. Then they were used in a first evaluation where auto and cross-correlations were analyzed to aid in the geochemical interpretation and select the most conservative elements. The second part of this study is devoted to estimate the migration of water based on the concentrations development of Cl - at the anode and Na + at the cathode. Electro-osmotic flow was estimated to be intense (2.9 -10 -9-2.18 -10 -8m -s -1) during the first 10 to 50days of experiment and to cease after this period. © 2012.

Analysis of metal ions migration to determine electro-osmotic flow for the in-situ cleanup of a tar-contaminated site

KAUST Repository

Lima, Ana T.; Rodrigues, Paulo C.; Loch, J.P. Gustav

2012-01-01

An electro-osmosis experiment was set up on a former asphalt factory site, which is currently contaminated by tar, in Olst, the Netherlands. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from a contaminated clay layer by applying an electric gradient. But before calculating PAH removal, the direction and intensity of electro-osmosis have to be estimated. In field situations, tracers are used to get information about the water flow. In the present study, the inorganic elements concentration oscillations during electro-osmosis application are used as tracers. The experiment was set up in a clay layer, with the configuration 1m×1m×0.3m, at a depth of 4m below soil surface. Al, Ca, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Si, Ti and Zn concentrations were determined in 28 measurements and were performed during the experimental period of 159days. Then they were used in a first evaluation where auto and cross-correlations were analyzed to aid in the geochemical interpretation and select the most conservative elements. The second part of this study is devoted to estimate the migration of water based on the concentrations development of Cl - at the anode and Na + at the cathode. Electro-osmotic flow was estimated to be intense (2.9 -10 -9-2.18 -10 -8m -s -1) during the first 10 to 50days of experiment and to cease after this period. © 2012.

Proton hopping mechanism in solid polymer electrolysis demonstrated by tritium enrichment and electro-osmotic drag measurement

International Nuclear Information System (INIS)

Saito, Masaaki; Imaizumi, Hiroshi; Kato, Norio; Ishii, Yoshiyuki; Saito, Keiichi

2010-01-01

Anomalies in tritium enrichment cannot be explained only by isotopic effects in water electrolysis. The temperature dependence of the enrichment factor had been reported as increasing with 1/T. However, the increase was difficult to explain on the basis of kinetics. In this study, electro-osmotic drag (EOD, number of water molecule accompanied by a proton) and tritium enrichment ratio were investigated using light water (H 2 O) and heavy water (D 2 O) by solid polymer electrolysis. The EOD decreased and tritium enrichment ratio increased at low temperature for H 2 O. Electrolysis showed no temperature dependence for D 2 O. It was revealed that proton hopping by a hydrogen bond network of water molecules (the Grotthuss mechanism) affects the temperature dependence of EOD and tritium enrichment in the case of H 2 O. (author)

Effects of Micromachining Processes on Electro-Osmotic Flow Mobility of Glass Surfaces

Directory of Open Access Journals (Sweden)

Norihisa Miki

2013-03-01

Full Text Available Silica glass is frequently used as a device material for micro/nano fluidic devices due to its excellent properties, such as transparency and chemical resistance. Wet etching by hydrofluoric acid and dry etching by neutral loop discharge (NLD plasma etching are currently used to micromachine glass to form micro/nano fluidic channels. Electro-osmotic flow (EOF is one of the most effective methods to drive liquids into the channels. EOF mobility is affected by a property of the micromachined glass surfaces, which includes surface roughness that is determined by the manufacturing processes. In this paper, we investigate the effect of micromaching processes on the glass surface topography and the EOF mobility. We prepared glass surfaces by either wet etching or by NLD plasma etching, investigated the surface topography using atomic force microscopy, and attempted to correlate it with EOF generated in the micro-channels of the machined glass. Experiments revealed that the EOF mobility strongly depends on the surface roughness, and therefore upon the fabrication process used. A particularly strong dependency was observed when the surface roughness was on the order of the electric double layer thickness or below. We believe that the correlation described in this paper can be of great help in the design of micro/nano fluidic devices.

Effect of hydrodynamic slippage on electro-osmotic flow in zeta potential patterned nanochannels

Energy Technology Data Exchange (ETDEWEB)

Datta, S; Choudhary, J N, E-mail: subhra-datta@iitd.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

2013-10-01

The effect of hydrodynamic slippage on the electro-osmotic flow in a nanochannel with thick electrical double layers whose wall surface potential has a periodic axial variation is studied. The equations of Stokes flow are solved exactly with the help of the Navier slip boundary condition and the Debye-Huckel linearization of the equation governing the potential of the electrical double layer. Each periodic cell of the flow field consists of four counter-rotating vortices. The cross-channel profile of the axial velocity at the center of the cell exhibits three extrema and a reversed velocity zone near the channel axis of symmetry. The size of the extrema and that of the reversed velocity zone increases with increase in the degree of slippage. In the limit when the wavelength of axial variation in surface potential is much larger than the channel width, the flow characteristics are interpreted in terms of the lubrication approximation. In the limit when the electrical double layer is much thinner than the channel height, the effect of slip is modeled by a Helmholtz-Smoluchowski apparent slip boundary condition that depends on the pattern wavelength. (paper)

Combining Electro-Osmotic Flow and FTA® Paper for DNA Analysis on Microfluidic Devices

Directory of Open Access Journals (Sweden)

Ryan Wimbles

2016-07-01

Full Text Available FTA® paper can be used to protect a variety of biological samples prior to analysis, facilitating ease-of-transport to laboratories or long-term archive storage. The use of FTA® paper as a solid phase eradicates the need to elute the nucleic acids from the matrix prior to DNA amplification, enabling both DNA purification and polymerase chain reaction (PCR-based DNA amplification to be performed in a single chamber on the microfluidic device. A disc of FTA® paper, containing a biological sample, was placed within the microfluidic device on top of wax-encapsulated DNA amplification reagents. The disc containing the biological sample was then cleaned up using Tris-EDTA (TE buffer, which was passed over the disc, via electro-osmotic flow, in order to remove any potential inhibitors of downstream processes. DNA amplification was successfully performed (from buccal cells, whole blood and semen using a Peltier thermal cycling system, whereupon the stored PCR reagents were released during the initial denaturing step due to the wax barrier melting between the FTA® disc and PCR reagents. Such a system offers advantages in terms of a simple sample introduction interface and the ability to process archived samples in an integrated microfluidic environment with minimal risk of contamination.

Drying brick masonry by electro-osmosis

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

2006-01-01

When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system...... movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

Electro-osmosis of non-Newtonian fluids in porous media using lattice Poisson-Boltzmann method.

Science.gov (United States)

Chen, Simeng; He, Xinting; Bertola, Volfango; Wang, Moran

2014-12-15

Electro-osmosis in porous media has many important applications in various areas such as oil and gas exploitation and biomedical detection. Very often, fluids relevant to these applications are non-Newtonian because of the shear-rate dependent viscosity. The purpose of this study was to investigate the behaviors and physical mechanism of electro-osmosis of non-Newtonian fluids in porous media. Model porous microstructures (granular, fibrous, and network) were created by a random generation-growth method. The nonlinear governing equations of electro-kinetic transport for a power-law fluid were solved by the lattice Poisson-Boltzmann method (LPBM). The model results indicate that: (i) the electro-osmosis of non-Newtonian fluids exhibits distinct nonlinear behaviors compared to that of Newtonian fluids; (ii) when the bulk ion concentration or zeta potential is high enough, shear-thinning fluids exhibit higher electro-osmotic permeability, while shear-thickening fluids lead to the higher electro-osmotic permeability for very low bulk ion concentration or zeta potential; (iii) the effect of the porous medium structure depends significantly on the constitutive parameters: for fluids with large constitutive coefficients strongly dependent on the power-law index, the network structure shows the highest electro-osmotic permeability while the granular structure exhibits the lowest permeability on the entire range of power law indices considered; when the dependence of the constitutive coefficient on the power law index is weaker, different behaviors can be observed especially in case of strong shear thinning. Copyright © 2014 Elsevier Inc. All rights reserved.

Hydrodynamic studies in a mixer of mixer settler system

International Nuclear Information System (INIS)

Shenoy, K.T.; Ghosh, S.K.; Keni, V.S.

1994-01-01

Pump-mix mixer settlers, with high throughput, are widely used in hydrometallurgical processing for recovery of uranium, copper etc. by solvent extraction. Detailed knowledge of hydrometallurgic behaviour in the mixer and settler is necessary for design. The paper presents the experimental study carried out on mixer hydrodynamics. The work was carried out on 40 litre, cubical, continuous flow mixer with bottom inlet and top discharge. The impeller was top shrouded turbine and working medium was water. Parameters such as impeller diameter, impeller clearance, inlet orifice size, impeller speed and flow rate were studied for effect on pumping head developed and power consumed by the mixer. Data are presented in the terms of dimensionless groups. Importance of the design variables is discussed. (author)

Hydrodynamic studies in a mixer of mixer settler system

Energy Technology Data Exchange (ETDEWEB)

Shenoy, K T; Ghosh, S K; Keni, V S [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Pump-mix mixer settlers, with high throughput, are widely used in hydrometallurgical processing for recovery of uranium, copper etc. by solvent extraction. Detailed knowledge of hydrometallurgic behaviour in the mixer and settler is necessary for design. The paper presents the experimental study carried out on mixer hydrodynamics. The work was carried out on 40 litre, cubical, continuous flow mixer with bottom inlet and top discharge. The impeller was top shrouded turbine and working medium was water. Parameters such as impeller diameter, impeller clearance, inlet orifice size, impeller speed and flow rate were studied for effect on pumping head developed and power consumed by the mixer. Data are presented in the terms of dimensionless groups. Importance of the design variables is discussed. (author). 2 refs., 7 figs., 2 tabs.

Terahertz radiation mixer

Science.gov (United States)

Wanke, Michael C [Albuquerque, NM; Allen, S James [Santa Barbara, CA; Lee, Mark [Albuquerque, NM

2008-05-20

A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

[Magnetic Fe₃O₄Microparticles Conditioning-Pressure Electro-osmotic Dewatering (MPEOD) of Sewage Sludge].

Science.gov (United States)

Qian, Xu; Wang, Yi-li; Zhao, Li

2016-05-15

For magnetic Fe₃O₄ microparticles conditioning--pressure electro-osmotic dewatering (MPEOD) process of activated sludge (AS), the effects of operating parameters (optimal dosage of Fe₃O₄, electric field duration, mechanical pressure and voltage) on the dewatering efficiency and energy consumption were investigated, and the optimal conditions were determined. Moreover, the properties of supernatant and sludge along MPEOD process were studied as well as the interaction force between the sludge biosolids. Taking the energy consumption into consideration, the results showed that the optimal dewatering effect for AS could be achieved with a magnetic Fe₃O₄ microparticles dosage of 0.15 g · g⁻¹, an electric field duration of 2 h, a mechanical pressure of 400-600 kPa and a voltage of 30-50 V. When MPEOD was conducted at 400 kPa and 50 V for 2 h, the sludge reduction rate reached 98.30%, the percentage of water removal was 99.34% and the moisture content of AS decreased from 99.18% to 44.46%. The corresponding consumption of energy was 0.013 3 kW · h · kg⁻¹. The coagulation mechanism played a slight role in the AS conditioning with magnetic Fe₃O₄ micro-particles. In fact, magnetic Fe₃O₄micro-particles could greatly decrease the acid-base interaction (WA) between AS biosolids, cause floc growth and enlarge pores in AS aggregates, which will be beneficial to AS dewatering. Compared to DLVO theory, the extended DLVO theory could accurately describe the aggregation and dispersion behavior of sludge particles.

Flashback resistant pre-mixer assembly

Science.gov (United States)

Laster, Walter R [Oviedo, FL; Gambacorta, Domenico [Oviedo, FL

2012-02-14

A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

Pressurised electro-osmotic dewatering of activated and anaerobically digested sludges: electrical variables analysis.

Science.gov (United States)

Citeau, M; Olivier, J; Mahmoud, A; Vaxelaire, J; Larue, O; Vorobiev, E

2012-09-15

Pressurised electro-osmotic dewatering (PEOD) of two sewage sludges (activated and anaerobically digested) was studied under constant electric current (C.C.) and constant voltage (C.V.) with a laboratory chamber simulating closely an industrial filter. The influence of sludge characteristics, process parameters, and electrode/filter cloth position was investigated. The next parameters were tested: 40 and 80 A/m², 20, 30, and 50 V-for digested sludge dewatering; and 20, 40 and 80 A/m², 20, 30, and 50 V-for activated sludge dewatering. Effects of filter cloth electric resistance and initial cake thickness were also investigated. The application of PEOD provides a gain of 12 points of dry solids content for the digested sludge (47.0% w/w) and for the activated sludge (31.7% w/w). In PEOD processed at C.C. or at C.V., the dewatering flow rate was similar for the same electric field intensity. In C.C. mode, both the electric resistance of cake and voltage increase, causing a temperature rise by ohmic effect. In C.V. mode, a current intensity peak was observed in the earlier dewatering period. Applying at first a constant current and later on a constant voltage, permitted to have better control of ohmic heating effect. The dewatering rate was not significantly affected by the presence of filter cloth on electrodes, but the use of a thin filter cloth reduced remarkably the energy consumption compared to a thicker one: 69% of reduction energy input at 45% w/w of dry solids content. The reduction of the initial cake thickness is advantageous to increase the final dry solids content. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of some factors on electro-osmotic dewatering of Laterite ...

African Journals Online (AJOL)

... effect on the EO process. The general effects were same for the two soil samples, but the rate of the effect varied, which implied that EO dewatering was site dependent. It was concluded that EO dewatering was a viable option for dewatering of tropical laterite. Keywords: Electro-osmosis, Soil Dewatering, Tropical Laterite, ...

Microwave mixer technology and applications

CERN Document Server

Henderson, Bert

2013-01-01

Although microwave mixers play a critical role in wireless communication and other microwave applications employing frequency conversion circuits, engineers find that most books on this subject emphasize theoretical aspects, rather than practical applications. That's about to change with the forthcoming release of Microwave Mixer Technology and Applications. Based on a review of over one thousand patents on mixers and frequency conversion, authors Bert Henderson and Edmar Camargo have written a comprehensive book for mixer designers who want solid ideas for solving their own design challenges.

Numerical analysis of finite Debye-length effects in induced-charge electro-osmosis

DEFF Research Database (Denmark)

Gregersen, Misha Marie; Andersen, Mathias Bækbo; Soni, G.

2009-01-01

For a microchamber filled with a binary electrolyte and containing a flat unbiased center electrode at one wall, we employ three numerical models to study the strength of the resulting induced-charge electro-osmotic (ICEO) flow rolls: (i) a full nonlinear continuum model resolving the double laye...

MM wave quasioptical SIS mixers

International Nuclear Information System (INIS)

Hu, Qing; Mears, C.A.; Richards, P.L.; Lloyd, F.L.

1988-08-01

We have tested the performance of planar SIS mixers with log-periodic antennas at near millimeter and submillimeter wave frequencies from 90 to 360 GHz. The large ωR/sub N/C product (/approximately/10 at 90 GHz) of our Nb/NbO/sub x//Pb-In-Au junctions requires an integrated inductive tuning element to resonate the junction capacitance at the operating frequencies. We have used two types of integrated tuning element, which were designed with the aid of measurements using a Fourier transform spectrometer. Preliminary results indicate that the tuning elements can give very good mixer performance up to at least 200 GHz. An inductive wire in parallel with a 5-junction array gives a minimum mixer noise temperature of 115K (DSB) at 90 GHz with a FWHM bandwidth of 8 GHz. An open-ended microstrip stub in parallel with a single junction, gives minimum mixer noise temperatures of 150 and 200K (DSB) near 90 and 180 GHz with FWHM bandwidths of 4 and 3 GHz, respectively. The relatively high mixer noise temperatures compared to those of waveguide SIS mixers in a similar frequency range are attributed mainly to the losses in our optical system, which is being improved. 13 refs., 6 figs., 1 tab

Scale-up of the mixer of a mixer-settler model used in a uranium solvent extraction process

International Nuclear Information System (INIS)

Santana, A.O. de; Dantas, C.C.

1995-01-01

Scale-up relations were obtained for the mixer of a box type mixer-settler used in an uranium extraction process from chloridric leaches. Three box type mixers of different sizes and with the same geometry were used for batch and continuous-flow experiments. The correlations between the extraction rate and he specific power input, D/T ratio(=turbine diameter/mixer width) and residence time were experimentally determined. The results showed that the extraction rate increases with the power input at a constant D/T ratio equal to 1/3, remaining however, independent from the mixer size for a specific value of the power input. This behaviour was observed for power input values ranging from 100 to 750 W/m 3 . (author) 8 refs.; 8 figs.; 4 tabs

Apparatus for controlled mixing in a high intensity mixer

International Nuclear Information System (INIS)

Crocker, Z.; Gupta, V.P.

1982-01-01

An apparatus and a process is disclosed for controlled mixing of a mixable material in a high intensity mixer. The system enables instantaneous, precise and continual monitoring of a batch in a high intensity mixer which heretofore could not be achieved. The process comprises the steps of feeding a batch of material into a high intensity mixer, agitating the batch in the mixer, monitoring batch temperature separately from mixer temperature and discharging the batch from the mixer when the batch temperature reaches a final predetermined level. The apparatus includes means for monitoring batch temperature in a high intensity mixer separately from mixer temperature, and means responsive to the batch temperature to discharge the batch when the batch temperature reaches a final predetermined level

Vibration mixer

Energy Technology Data Exchange (ETDEWEB)

Alekhin, S.A.; Chernov, V.S.; Denisenko, V.V.; Gorodnyanskiy, I.F.; Prokopov, L.I.; Tikhonov, Yu.P.

1983-01-01

The vibration mixer is proposed which contains a housing, vibration drive with rod installed in the upper part of the mixing mechanism made in the form of a hollow shaft with blades. In order to improve intensity of mixing and dispersion of the mud, the shaft with the blades is arranged on the rod of the vibrator and is equipped with a cam coupling whose drive disc is attached to the vibration rod. The rod is made helical, while the drive disc of the cam coupling is attached to the helical surface of the rod. In addition, the vibration mixer is equipped with perforated discs installed on the ends of the rods.

Topology optimization of microfluidic mixers

DEFF Research Database (Denmark)

Andreasen, Casper Schousboe; Gersborg, Allan Roulund; Sigmund, Ole

2009-01-01

This paper demonstrates the application of the topology optimization method as a general and systematic approach for microfluidic mixer design. The mixing process is modeled as convection dominated transport in low Reynolds number incompressible flow. The mixer performance is maximized by altering...

Pre-design mixer-settler based on phase inversion

International Nuclear Information System (INIS)

Widiatmo, Djarot S.W

1998-01-01

The mixer settler was designed to extract uranium from organic phase by n-Dodecane and to separate heavy metal from liquid waste. The mixer settler was designed to save solvent without reducing the extraction efficiency. Extraction efficiency depend on : two phase dispersion on mixing, the type of droplet formation and completeness phase separation. The mixer settler has three main part i.e. mixer chamber, droplet formation device and phase inversion column. Mixer chamber was operated in laminar mixing, the total flow rate 200 ml.second -1 . The mixer chamber dimensions was 5 cm diameter and 7 cm height. It was completed with paddle mixer 3 cm diameter, 1 cm height and the speed rotation was 300 rpm. The droplet formation device was perforated plate 5 cm diameter with 1 mm holes. Phase Inversion column dimensions was 5 cm diameter and 50 cm height. (author)

Mixer Assembly for a Gas Turbine Engine

Science.gov (United States)

Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Fotache, Catalin G. (Inventor); Smith, Lance L. (Inventor); Hautman, Donald J. (Inventor)

2018-01-01

A mixer assembly for a gas turbine engine is provided, including a main mixer with fuel injection holes located between at least one radial swirler and at least one axial swirler, wherein the fuel injected into the main mixer is atomized and dispersed by the air flowing through the radial swirler and the axial swirler.

Low Voltage Current Mode Switched-Current-Mirror Mixer

Directory of Open Access Journals (Sweden)

Chunhua Wang

2009-09-01

Full Text Available A new CMOS active mixer topology can operate at 1 V supply voltage by use of SCM (switched currentmirror. Such current-mode mixer requires less voltage headroom with good linearization. Mixing is achieved with four improved current mirrors, which are alternatively activated. For ideal switching, the operation is equivalent to a conventional active mixer. This paper analyzes the performance of the SCM mixer, in comparison with the conventional mixer, demonstrating competitive performance at a lower supply voltage. Moreover, the new mixer’s die, without any passive components, is very small, and the conversion gain is easy to adjust. An experimental prototype was designed and simulated in standard chartered 0.18μm RF CMOS Process with Spectre in Cadence Design Systems. Experimental results show satisfactory mixer performance at 2.4 GHz.

Realization of THz Band Mixer Using Graphene

Directory of Open Access Journals (Sweden)

E. Ghasemi Mizuji

2014-05-01

Full Text Available In this article a new method for creating mixer component in infrared and THz is suggested. Since the nonlinear property of admittance creates frequency components that do not exist in the input signal and the electrical conductivity is associated with admittance, in our work we have proven and simulated that the nonlinear property of graphene admittance can produce mixer component. The simulation results show that the mixer component is larger than other components, therefore the mixer works properly. Because of nano scale of graphene structure, this method paves the road to achieve super compact circuits.

Spare mitigation/retrieval mixer pumps

International Nuclear Information System (INIS)

Taylor, S.

1995-01-01

This document presents the functional design criteria for design, analysis, fabrication, testing, and installation of a waste tank mixer pump. The mixer pump will be operated to eliminate the periodic releases of large quantities of flammable gas (e.g., hydrogen) from Hanford Site waste tanks and also to accommodate retrieval of tank waste

Two-phase LMMHD mixer-development experiments

International Nuclear Information System (INIS)

Fabris, G.; Dunn, P.F.; Chow, J.C.F.

1978-01-01

The results of a series of experiments conducted to evaluate the fluid mechanical performance of various two-phase LMMHD mixer designs are presented. The results from both flow visualization studies of the local two-phase flows downstream from various mixer-element configurations and local measurements performed to characterize these flows are presented. A conceptual LMMHD mixer design is described that insures the generation of small bubbles, prevents the formation of gas slugs and separated regions, and favors the stabilization of a homogeneous foam flow

Geochemical effects of electro-osmosis in clays

KAUST Repository

Loch, J. P. Gustav

2010-02-13

Geochemical effects of electro-osmosis in bentonite clay are studied in the laboratory, where a 6 mm thick bentonite layer is subjected to direct current. Acidification and alkalization near anode and cathode are expected, possibly causing mineral deterioration, ion mobilization and precipitation of new solids. Afterwards the clay is analysed by XRF and anolyte and catholyte are analysed by ICP-MS. In addition, as a preliminary experiment treated bentonite is analysed by high resolution μ-XRF. Electro-osmotic flow is observed. Due to its carbonate content the bentonite is pH-buffering. Alkalization in the catholyte is substantial. Ca, Na and Sr are significantly removed from the clay and accumulate in the catholyte. Recovery in the catholyte accounts for a small fraction of the element-loss from the clay. The rest will have precipitated in undetected solid phases. μ-XRF indicates the loss of Ca-content throughout the bentonite layer. © The Author(s) 2010.

Fabrication and characterization of 8.87 THz schottky barrier mixer diodes for mixer

Science.gov (United States)

Wang, Wenjie; Li, Qian; An, Ning; Tong, Xiaodong; Zeng, Jianping

2018-04-01

In this paper we report on the fabrication and characterization of GaAs-based THz schottky barrier mixer diodes. Considering the analyzed results as well as fabrication cost and complexity, a group of trade-off parameters was determined. Electron-beam lithography and air-bridge technique have been used to obtain schottky diodes with a cut off frequency of 8.87 THz. Equivalent values of series resistance, ideal factor and junction capacitance of 10.2 (1) Ω, 1.14 (0.03) and 1.76(0.03) respectively have been measured for 0.7um diameter anode devices by DC and RF measurements. The schottky barrier diodes fabrication process is fully planar and very suitable for integration in THz frequency multiplier and mixer circuits. THz Schottky barrier diodes based on such technology with 2 μm diameter anodes have been tested at 1.6 THz in a sub-harmonic mixer.

Design and fabrication of an ac-electro-osmosis micropump with 3D high-aspect-ratio electrodes using only SU-8

International Nuclear Information System (INIS)

Rouabah, Hamza A; Morgan, Hywel; Green, Nicolas G; Park, Benjamin Y; Zaouk, Rabih B; Madou, Marc J

2011-01-01

Lab-on-a-chip devices require integrated pumping and fluid control in microchannels. A recently developed mechanism that can produce fluid flow is an integrated ac-electro-osmosis micropump. However, like most electrokinetic pumps, ac-electro-osmotic pumps are incapable of handling backpressure as the pumping force mechanism acts on the surface of the fluid rather than the bulk. This paper presents a novel 3D electrode structure designed to overcome this limitation. The electrodes are fabricated using carbon-MEMS technology based on the pyrolysis of the photo-patternable polymer SU-8. The novel ac-electro-osmosis micropump shows an increase in the flow velocity compared to planar electrodes.

A general numerical analysis of the superconducting quasiparticle mixer

Science.gov (United States)

Hicks, R. G.; Feldman, M. J.; Kerr, A. R.

1985-01-01

For very low noise millimeter-wave receivers, the superconductor-insulator-superconductor (SIS) quasiparticle mixer is now competitive with conventional Schottky mixers. Tucker (1979, 1980) has developed a quantum theory of mixing which has provided a basis for the rapid improvement in SIS mixer performance. The present paper is concerned with a general method of numerical analysis for SIS mixers which allows arbitrary terminating impedances for all the harmonic frequencies. This analysis provides an approach for an examination of the range of validity of the three-frequency results of the quantum mixer theory. The new method has been implemented with the aid of a Fortran computer program.

Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

Science.gov (United States)

Skalare, Anders; McGrath, William; Bumble, Bruce; LeDuc, Henry

2004-01-01

A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

Application of Electro-Technologies in Processing of Flax Fiber

Directory of Open Access Journals (Sweden)

G. S. Vijaya Raghavan

2013-08-01

Full Text Available Flax fibers used for various applications are obtained from flax stems. Retting followed by drying and mechanical separation leads to the production of fibers. This review article discusses the application of electro-technologies in the production of bast fibers from the flax stem. In these technologies, flax stems harvested from the field are subjected to microwave assisted retting, followed by electro–osmotic dewatering which reduces the water content of the stems. Dewatered stems are transferred to a microwave chamber for further drying, thus retted stems are obtained for further processing.

Simulations of induced-charge electro-osmosis in microfluidic devices

Science.gov (United States)

Ben, Yuxing

2005-03-01

Theories of nonlinear electrokinetic phenomena generally assume a uniform, neutral bulk electroylte in contact with a polarizable thin double layer near a metal or dielectric surface, which acts as a "capacitor skin". Induced-charge electro-osmosis (ICEO) is the general effect of nonlinear electro-osmotic slip, when an applied electric field acts on its own induced (diffuse) double-layer charge. In most theoretical and experimental work, ICEO has been studied in very simple geometries, such as colloidal spheres and planar, periodic micro-electrode arrays. Here we use finite-element simulations to predict how more complicated geometries of polarizable surfaces and/or electrodes yield flow profiles with subtle dependence on the amplitude and frequency of the applied voltage. We also consider how the simple model equations break down, due to surface conduction, bulk diffusion, and concentration polarization, for large applied voltages (as in most experiments).

The Robust Control Mixer Module Method for Control Reconfiguration

DEFF Research Database (Denmark)

Yang, Z.; Blanke, M.

1999-01-01

into a LTI dynamical system, and furthermore multiple dynamical control mixer modules can be employed in our consideration. The H_{\\infty} control theory is used for the analysis and design of the robust control mixer modules. Finally, one practical robot arm system as benchmark is used to test the proposed......The control mixer concept is efficient in improving an ordinary control system into a fault tolerant one, especially for these control systems of which the real-time and on-line redesign of the control laws is very difficult. In order to consider the stability, performance and robustness...... of the reconfigurated system simultaneously, and to deal with a more general controller reconfiguration than the static feedback mechanism by using the control mixer approach, the robust control mixer module method is proposed in this paper. The form of the control mixer module extends from a static gain matrix...

In situ electro-osmotic cleanup of tar contaminated soil—Removal of polycyclic aromatic hydrocarbons

KAUST Repository

Lima, Ana T.

2012-12-01

An in situ electro-osmosis experiment was set up in a tar contaminated clay soil in Olst, the Netherlands, at the site of a former asphalt factory. The main goal of this experiment was to remove polycyclic aromatic hydrocarbons (PAHs) from the contaminated clay layer by applying an electric gradient of 12 V m-1 across the soil over an electrode distance of 1 m. With the movement of water by electro-osmosis and the addition of a non-ionic surfactant (Tween 80), the non-polar PAHs were dragged along by convection and removed from the fine soil fraction. Soil samples were taken at the start and after 159 days at the end of the experiment. Water at the electrode wells was sampled regularly during the course of the experiment. The results reflect the heterogeneity of the soil characteristics and show the PAH concentrations within the experimental set up. After first having been released into the anolyte solution due to extraction by Tween 80 and subsequent diffusion, PAH concentrations increased significantly in the electrode reservoirs at the cathode side after 90 days of experiment. Although more detailed statistical analysis is necessary to quantify the efficiency of the remediation, it can be concluded that the use of electro-osmosis together with a non-ionic surfactant is a feasible technique to mobilize non-polar organic contaminants in clayey soils. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

Work plan, AP-102 mixer pump removal and pump replacement

International Nuclear Information System (INIS)

Jimenez, R.F.

1994-01-01

The objective of this work plan is to plan the steps and estimate the costs required to remove the failed AP-102 mixer pump, and to plan and estimate the cost of the necessary design and specification work required to order a new, but modified, mixer pump including the pump and pump pit energy absorbing design. The main hardware required for the removal of the mixer is as follows: a flexible receiver and blast shield; a metal container for the pulled mixer pump; and a trailer and strongback to haul and manipulate the container. Additionally: a gamma scanning device will be needed to detect the radioactivity emanating from the mixer as it is pulled from the tank; a water spray system will be required to remove tank waste from the surface of the mixer as it is pulled from the AP-102 tank; and a lifting yoke to lift the mixer from the pump pit (the SY-101 Mixer Lifting Yoke will be used). A ''green house'' will have to be erected over the AP-102 pump pit and an experienced Hoisting and Rigging crew must be assembled and trained in mixer pump removal methods before the actual removal is undertaken

In situ electro-osmotic cleanup of tar contaminated soil—Removal of polycyclic aromatic hydrocarbons

KAUST Repository

Lima, Ana T.; Kleingeld, Pieter J.; Heister, Katja; Loch, J.P. Gustav

2012-01-01

significantly in the electrode reservoirs at the cathode side after 90 days of experiment. Although more detailed statistical analysis is necessary to quantify the efficiency of the remediation, it can be concluded that the use of electro-osmosis together with a

Saltstone Osmotic Pressure

International Nuclear Information System (INIS)

Nichols, Ralph L.; Dixon, Kenneth L.

2013-01-01

Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency 3 , KNO 3 , Na 3 PO 4 x12H 2 O, and K 3 PO 4 when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that

Electro-chemo-hydro-mechanical coupling in clayey media; Couplage electro-chimio-hydro-mecaniques dans les milieux argileux

Energy Technology Data Exchange (ETDEWEB)

Lemaire, Th

2004-12-15

The aim of this study is to understand coupled phenomena that occur in swelling porous materials like clays. Electro-chemo-hydro-mechanical contributions are taken into account to analyze transfers in such minerals. In a first part, a general discussion is proposed to introduce mineralogical and physico- chemical considerations of clayey media. An important objective of this chapter is to show the crucial role of the microstructure. In a second part is presented an imbibition test in a MX80 bentonite powder. The hydraulic diffusivity versus water content curve's decrease is explained thanks to a double porosity model that shows the progressive collapse of meso-pores due to swelling effects at the micro-scale. Thus a multi-scale analysis is necessary to well describe clayey media behaviour. The third chapter exposes such a multi-scale modelling (periodic homogenization). It is based on the double-layer theory and introduces an innovative concept of virtual electrolyte solution. First numerical results are given in a simple geometry (parallel platelets). In the next part are proposed numerical simulations of two kinds: response of the system to a chemical gradient and simulation of electro-osmosis. The end of this chapter puts into relief the necessity to integrate pH effects in the model. In the last part, chemical surface exchanges are incorporated in the modelling to understand pH and ionic force roles in electro-osmotic process. (author)

21 CFR 888.4210 - Cement mixer for clinical use.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

Micro-mixer/combustor

KAUST Repository

Badra, Jihad Ahmad; Masri, Assaad Rachid

2014-01-01

A micro-mixer/combustor to mix fuel and oxidant streams into combustible mixtures where flames resulting from combustion of the mixture can be sustained inside its combustion chamber is provided. The present design is particularly suitable

Scale-up of mixer-settler for uranium extraction

International Nuclear Information System (INIS)

Santana, A.O. de.

1990-05-01

The aim of this work was to obtain scale-up relations for a box type mixer-settler used in uranium extraction process for chloridric leaches. Three box type units with different sizes and with the same geometry were used for scale-up of the mixer. The correlation between extraction rate and specific power input, D/T ratio (stirrer diameter/mixer length) and residence time were experimentally obtained. The results showed that the extraction increases with power input for a constant value of D/T equal to 1/3, remaining however independent from mixer sizes for a specific value of power input. This behavior was observed for power input values ranging from 100 to 750 w/m 9 . (author). 23 refs, 22 figs, 23 tabs

Saltstone Osmotic Pressure

Energy Technology Data Exchange (ETDEWEB)

Nichols, Ralph L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRN

2013-09-23

Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR- 2013-0004.

The Influence of the Osmotic Dehydration Process on Physicochemical Properties of Osmotic Solution.

Science.gov (United States)

Lech, Krzysztof; Michalska, Anna; Wojdyło, Aneta; Nowicka, Paulina; Figiel, Adam

2017-12-16

The osmotic dehydration (OD) process consists of the removal of water from a material during which the solids from the osmotic solution are transported to the material by osmosis. This process is commonly performed in sucrose and salt solutions. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, attempts have been made to search for alternatives that can be used for osmotic dehydration. One of these is an application of chokeberry juice with proven beneficial properties to human health. This study aimed to evaluate the physicochemical properties of the OD solution (chokeberry juice concentrate) before and after the osmotic dehydration of carrot and zucchini. The total polyphenolics content, antioxidant capacity (ABTS, FRAP), dynamic viscosity, density, and water activity were examined in relation to the juice concentration used for the osmotic solution before and after the OD process. During the osmotic dehydration process, the concentration of the chokeberry juice decreased. Compounds with lower molecular weight and lower antioxidant capacity present in concentrated chokeberry juice had a stronger influence on the exchange of compounds during the OD process in carrot and zucchini. The water activity of the osmotic solution increased after the osmotic dehydration process. It was concluded that the osmotic solution after the OD process might be successfully re-used as a product with high quality for i.e. juice production.

Research of UHPC properties prepared with industrial mixer

Science.gov (United States)

Šerelis, E.; Vaitkevičius, V.; Kerševičius, V.

2017-09-01

Ultra-high performance concrete (UHPC) mixture with advanced mechanical and durability properties was created using decent Zyklos ZZ50HE mixer. Zyklos ZZ50HE rotating pan mixer is similar to mixer which has common concrete plants. In experiment UHPC was prepared with Zyklos ZZ50HE mixer and thereafter best composition was selected and prepared with industrial HPGM 1125 mixer. Experiment results revealed that UHPC with W/C=0.29 and advanced mechanical and durability properties can be prepared. In experiment tremendous amount of micro steel fibres (up to 147 kg/m3) were incorporated in UHPC. Concrete with excellent salt scaling resistance and great mechanical properties was obtained. Compressive strength was increased about 30 % from 116 MPa to 150 MPa and flexural strength was increased about 5 times from 6.7 to 36.2 MPa. Salt-scaling resistance at 40 cycles in 3 % NaCl solution varied from 0.006 kg/m2 to 0.197 kg/m2. There were a few attempts to create UHPC and UHPFRC with decent technology, however, unsuccessfully till now. In the world practice this new material is currently used in the construction of bridges and viaducts.

7 CFR 58.228 - Dump hoppers, screens, mixers and conveyors.

Science.gov (United States)

2010-01-01

... Service 1 Equipment and Utensils § 58.228 Dump hoppers, screens, mixers and conveyors. The product contact surfaces of dump hoppers, screens, mixers and conveyors which are used in the process of transferring dry... 7 Agriculture 3 2010-01-01 2010-01-01 false Dump hoppers, screens, mixers and conveyors. 58.228...

Time-dependent chemo-electro-mechanical behavior of hydrogel-based structures

Science.gov (United States)

Leichsenring, Peter; Wallmersperger, Thomas

2018-03-01

Charged hydrogels are ionic polymer gels and belong to the class of smart materials. These gels are multiphasic materials which consist of a solid phase, a fluid phase and an ionic phase. Due to the presence of bound charges these materials are stimuli-responsive to electrical or chemical loads. The application of electrical or chemical stimuli as well as mechanical loads lead to a viscoelastic response. On the macroscopic scale, the response is governed by a local reversible release or absorption of water which, in turn, leads to a local decrease or increase of mass and a respective volume change. Furthermore, the chemo-electro-mechanical equilibrium of a hydrogel depends on the chemical composition of the gel and the surrounding solution bath. Due to the presence of bound charges in the hydrogel, this system can be understood as an osmotic cell where differences in the concentration of mobile ions in the gel and solution domain lead to an osmotic pressure difference. In the present work, a continuum-based numerical model is presented in order to describe the time-dependent swelling behavior of hydrogels. The numerical model is based on the Theory of Porous Media and captures the fluid-solid, fluid-ion and ion-ion interactions. As a direct consequence of the chemo-electro-mechanical equilibrium, the corresponding boundary conditions are defined following the equilibrium conditions. For the interaction of the hydrogel with surrounding mechanical structures, also respective jump condtions are formulated. Finaly, numerical results of the time-dependent behavior of a hydrogel-based chemo-sensor will be presented.

Problems of bentonite rebonding of synthetic system sands in turbine mixers

Directory of Open Access Journals (Sweden)

A. Fedoryszyn

2008-12-01

Full Text Available Turbine (rotor mixers are widely used in foundries for bentonite rebonding of synthetic system sands. They form basic equipment in modern sand processing plants. Their major advantage is the short time of the rebond mixing cycle.Until now, no complete theoretical description of the process of mixing in turbine mixers has been offered. Neither does it seem reasonable to try to adapt the theoretical backgrounds of the mixing process carried out in mixers of other types, for example, rooler mixers [1], to the description of operation of the turbine mixers. Truly one can risk the statement that the individual fundamental operations of mixing in rooler mixers, like kneading, grinding, mixing and thinning, are also performed in turbine mixers. Yet, even if so, in turbine mixers these processes are proceeding at a rate and intensity different than in the roller mixers. The fact should also be recalled that the theoretical backgrounds usually relate to the preparation of sand mixtures from new components, and this considerably restricts the field of application of these descriptions when referred to rebond mixing of the system sand. The fundamentals of the process of the synthetic sand rebonding with bentonite require determination and description of operations, like disaggregation, even distribution of binder and water within the entire volume of the rebonded sand batch, sand grains coating, binder activation and aeration.This study presents the scope of research on the sand rebonding process carried out in turbine mixers. The aim has been to determine the range and specific values of the designing and operating parameters to get optimum properties of the rebonded sand as well as energy input in the process.

Granular flow in static mixers by coupled DEM/CFD approach

Directory of Open Access Journals (Sweden)

Pezo Lato

2016-01-01

Full Text Available The mixing process greatly influence the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modelling of granular flow in multiple static mixer applications (1 - 3 Komax or Ross mixing elements were utilized, while the Computational Fluid Dynamic method was chosen for fluid flow modelling, using the Eulerian multiphase model. The main aim of this article is to predict the behaviour of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by RSD (relative standard deviation criterion, and the effects on the mixer type and the number of mixing elements on mixing process were studied. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA. Mathematical modelling is used for optimization of number of Ross and Komax segments in mixer in order to gain desirable mixing results. [Projekat Ministarstva nauke Republike Srbije, br. TR31055

Electro-osmotic flow of power-law fluid and heat transfer in a micro-channel with effects of Joule heating and thermal radiation

Science.gov (United States)

Shit, G. C.; Mondal, A.; Sinha, A.; Kundu, P. K.

2016-11-01

A mathematical model has been developed for studying the electro-osmotic flow and heat transfer of bio-fluids in a micro-channel in the presence of Joule heating effects. The flow of bio-fluid is governed by the non-Newtonian power-law fluid model. The effects of thermal radiation and velocity slip condition have been examined in the case of hydrophobic channel. The Poisson-Boltzmann equation governing the electrical double layer field and a body force generated by the applied electric potential field are taken into consideration. The results presented here pertain to the case where the height of the channel is much greater than the thickness of electrical double layer comprising the Stern and diffuse layers. The expressions for flow characteristics such as velocity, temperature, shear stress and Nusselt number have been derived analytically under the purview of the present model. The results estimated on the basis of the data available in the existing scientific literatures are presented graphically. The effects of thermal radiation have an important bearing on the therapeutic procedure of hyperthermia, particularly in understanding the heat transfer in micro-channel in the presence of electric potential. The dimensionless Joule heating parameter has a reducing impact on Nusselt number for both pseudo-plastic and dilatant fluids, nevertheless its impact on Nusselt number is more pronounced for dilatant fluid. Furthermore, the effect of viscous dissipation has a significant role in controlling heat transfer and should not be neglected.

Research on Mixer Parametric Modeling System Based on Redevelopment of ANSYS

Directory of Open Access Journals (Sweden)

Bin Zheng

2015-01-01

Full Text Available In this paper, the mixer parametric modeling system software was developed by using VB which was taken as the foreground development program, and the paper combined with ANSYS software to create the finite element model of mixer blade and cylinder for the following numerical simulation of the flow field and parameter optimization of mixer. The software user interface was developed by VB and the pre-process model was created by invoking APDL of ANSYS in background. Therefore, the operation of modeling, meshing, component-building of mixer blade and cylinder were completed by using APDL and the graphic and text were outputted and displayed on the mixer parametric modeling system user interface which was developed by VB. Practice proved that it is convenient to modify the mixer solid model created by the parametric design language of ANSYS due to the similar structure.

Mixer pump test plan for double shell tank AZ-101

International Nuclear Information System (INIS)

STAEHR, T.W.

1999-01-01

Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151

Mixer-settler performance evaluation in actinide extraction

International Nuclear Information System (INIS)

Camilo, R.L.; Goncalves, M.A.; Carvalho, E.I.; Nakazone, A.K.; Araujo, B.F. de; Araujo, J.A.

1988-07-01

This paper deals with four conceptions of mixer-settlers used for actinide purification and recovery. By means of the uranium concentration profiles in the organic and aqueous phases, the evaluation of each mixer-settler was made. The main purpose of this work is the data acquisition, for adapting the different contactor types to actinide recovery by liquid-liquid extraction, in the nuclear fuel cycle. (autor) [pt

Hot-electron bolometer terahertz mixers for the Herschel Space Observatory.

Science.gov (United States)

Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik

2008-03-01

We report on low noise terahertz mixers (1.4-1.9 THz) developed for the heterodyne spectrometer onboard the Herschel Space Observatory. The mixers employ double slot antenna integrated superconducting hot-electron bolometers (HEBs) made of thin NbN films. The mixer performance was characterized in terms of detection sensitivity across the entire rf band by using a Fourier transform spectrometer (from 0.5 to 2.5 THz, with 30 GHz resolution) and also by measuring the mixer noise temperature at a limited number of discrete frequencies. The lowest mixer noise temperature recorded was 750 K [double sideband (DSB)] at 1.6 THz and 950 K DSB at 1.9 THz local oscillator (LO) frequencies. Averaged across the intermediate frequency band of 2.4-4.8 GHz, the mixer noise temperature was 1100 K DSB at 1.6 THz and 1450 K DSB at 1.9 THz LO frequencies. The HEB heterodyne receiver stability has been analyzed and compared to the HEB stability in the direct detection mode. The optimal local oscillator power was determined and found to be in a 200-500 nW range.

The development of terahertz superconducting hot-electron bolometric mixers

International Nuclear Information System (INIS)

Semenov, Alexei; Richter, Heiko; Smirnov, Konstantin; Voronov, Boris; Gol'tsman, Gregory; Huebers, Heinz-Wilhelm

2004-01-01

We present recent advances in the development of NbN hot-electron bolometric (HEB) mixers for flying terahertz heterodyne receivers. Three important issues have been addressed: the quality of the source NbN films, the effect of the bolometer size on the spectral properties of different planar feed antennas, and the local oscillator (LO) power required for optimal operation of the mixer. Studies of the NbN films with an atomic force microscope indicated a surface structure that may affect the performance of the smallest mixers. Measured spectral gain and noise temperature suggest that at frequencies above 2.5 THz the spiral feed provides better overall performance than the double-slot feed. Direct measurements of the optimal LO power support earlier estimates made in the framework of the uniform mixer model

Methodology for calculating power consumption of planetary mixers

Science.gov (United States)

Antsiferov, S. I.; Voronov, V. P.; Evtushenko, E. I.; Yakovlev, E. A.

2018-03-01

The paper presents the methodology and equations for calculating the power consumption necessary to overcome the resistance of a dry mixture caused by the movement of cylindrical rods in the body of a planetary mixer, as well as the calculation of the power consumed by idling mixers of this type. The equations take into account the size and physico-mechanical properties of mixing material, the size and shape of the mixer's working elements and the kinematics of its movement. The dependence of the power consumption on the angle of rotation in the plane perpendicular to the axis of rotation of the working member is presented.

Alternate paddle configuration for improved wear resistance in the saltstone mixer

Energy Technology Data Exchange (ETDEWEB)

Reigel, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2013-09-23

The Saltstone Production Facility has a 10-inch Readco-Kurimoto continuous mixer that mixes the premix dry feeds and low-level waste salt solution to make fresh (uncured) saltstone. Inspection of the mixer in January 2013 showed significant wear on the third, fourth and fifth paddle pairs after the conveying augers. A 2-inch Readco-Kurimoto continuous mixer was used to test alternate paddle configurations for use in the 10-inch mixer to decrease the wear rate on the paddles. Two wear tests were conducted to investigate a method of reducing wear on the mixer paddles. The first test (wear test 2a) had a paddle configuration similar to the currently installed 10-inch mixer in the SPF. This test established baseline wear. The second test (wear test 2b) had a reconfigured paddle arrangement that replaced the flat paddles with helical paddles for paddle pairs 2 - 6 and aligned paddle pair 1 with the augers. The intent of the reconfiguration was to more effectively convey the partially wetted dry feeds through the transition region and into the liquid feed where paddle wear is reduced due to dry feeds and salt solution being mixed at the intended water to premix ratio. The design of the helical paddles provides conveyance through the transition region to the liquid feed inlet. The alignment with the auger is aimed to provide a smoother transition (minimizing the discontinuity between the auger and paddle pair 1) into the downstream paddles. A soft metal with low wear resistance (6000 series aluminum) was used for the wear testing paddles to determine wear patterns while minimizing run time and maximizing wear rate. For the two paddle configurations tested using the scaled 2-inch Readco-Kurimoto continuous mixer, with the first six paddles after the augers replaced by the wear paddles and the remaining paddles were stainless steel. Since the 10-inch SPF mixer is designed with the liquid inlet centered over paddle pairs 5 and 6, the scaled 2-inch mixer was configured the

Electro-chemo-hydro-mechanical coupling in clayey media

International Nuclear Information System (INIS)

Lemaire, Th.

2004-12-01

The aim of this study is to understand coupled phenomena that occur in swelling porous materials like clays. Electro-chemo-hydro-mechanical contributions are taken into account to analyze transfers in such minerals. In a first part, a general discussion is proposed to introduce mineralogical and physico- chemical considerations of clayey media. An important objective of this chapter is to show the crucial role of the microstructure. In a second part is presented an imbibition test in a MX80 bentonite powder. The hydraulic diffusivity versus water content curve's decrease is explained thanks to a double porosity model that shows the progressive collapse of meso-pores due to swelling effects at the micro-scale. Thus a multi-scale analysis is necessary to well describe clayey media behaviour. The third chapter exposes such a multi-scale modelling (periodic homogenization). It is based on the double-layer theory and introduces an innovative concept of virtual electrolyte solution. First numerical results are given in a simple geometry (parallel platelets). In the next part are proposed numerical simulations of two kinds: response of the system to a chemical gradient and simulation of electro-osmosis. The end of this chapter puts into relief the necessity to integrate pH effects in the model. In the last part, chemical surface exchanges are incorporated in the modelling to understand pH and ionic force roles in electro-osmotic process. (author)

Numerical simulation and PEPT measurements of a 3D conical helical-blade mixer: a high potential solids mixer for solid-state fermentation

NARCIS (Netherlands)

Schutyser, M.A.I.; Briels, W.J.; Rinzema, A.; Boom, R.M.

2003-01-01

Helical-blade solids mixers have a large potential as bioreactors for solid-state fermentation (SSF). Fundamental knowledge of the flow and mixing behavior is required for robust operation of these mixers. In this study predictions of a discrete particle model were compared to experiments with

Planar Submillimeter-Wave Mixer Technology with Integrated Antenna

Science.gov (United States)

Chattopadhyay, Gautam; Mehdi, Imran; Gill, John J.; Lee, Choonsup; lombart, Muria L.; Thomas, Betrand

2010-01-01

High-performance mixers at terahertz frequencies require good matching between the coupling circuits such as antennas and local oscillators and the diode embedding impedance. With the availability of amplifiers at submillimeter wavelengths and the need to have multi-pixel imagers and cameras, planar mixer architecture is required to have an integrated system. An integrated mixer with planar antenna provides a compact and optimized design at terahertz frequencies. Moreover, it leads to a planar architecture that enables efficient interconnect with submillimeter-wave amplifiers. In this architecture, a planar slot antenna is designed on a thin gallium arsenide (GaAs) membrane in such a way that the beam on either side of the membrane is symmetric and has good beam profile with high coupling efficiency. A coplanar waveguide (CPW) coupled Schottky diode mixer is designed and integrated with the antenna. In this architecture, the local oscillator (LO) is coupled through one side of the antenna and the RF from the other side, without requiring any beam sp litters or diplexers. The intermediate frequency (IF) comes out on a 50-ohm CPW line at the edge of the mixer chip, which can be wire-bonded to external circuits. This unique terahertz mixer has an integrated single planar antenna for coupling both the radio frequency (RF) input and LO injection without any diplexer or beamsplitters. The design utilizes novel planar slot antenna architecture on a 3- mthick GaAs membrane. This work is required to enable future multi-pixel terahertz receivers for astrophysics missions, and lightweight and compact receivers for planetary missions to the outer planets in our solar system. Also, this technology can be used in tera hertz radar imaging applications as well as for testing of quantum cascade lasers (QCLs).

Quantum limited quasiparticle mixers at 100 GHz

International Nuclear Information System (INIS)

Mears, C.A; Hu, Qing; Richards, P.L.; Worsham, A.H.; Prober, D.E.; Raeisaenen, A.V.

1990-09-01

We have made accurate measurements of the noise and gain of superconducting-insulating-superconducting (SIS) mixers employing small area (1μm 2 ) Ta/Ta 2 O 5 /Pb 0.9 Bi 0.1 tunnel junctions. We have measured an added mixer noise of 0.61 +/- 0.31 quanta at 95.0 GHz, which is within 25 percent of the quantum limit of 0.5 quanta. We have carried out a detailed comparison between theoretical predictions of the quantum theory of mixing and experimentally measured noise and gain. We used the shapes of I-V curves pumped at the upper and lower sideband frequencies to deduce values of the embedding admittances at these frequencies. Using these admittances, the mixer noise and gain predicted by quantum theory are in excellent agreement with experiment. 21 refs., 9 figs

Induced- and alternating-current electro-osmotic control of the diffusion layer growth in a microchannel-membrane interface device

Science.gov (United States)

Park, Sinwook; Yossifon, Gilad

2014-11-01

The passage of an electric current through an ionic permselective medium under an applied electric field is characterized by the formation of ionic concentration gradients, which result in regions of depleted and enriched ionic concentration at opposite ends of the medium. Induced-current electro-osmosis (ICEO) and alternating-current-electro-osmosis (ACEO) are shown to control the growth of the diffusion layer (DL) which, in turn, controls the diffusion limited ion transport through the microchannel-membrane system. We fabricated and tested devices made of a Nafion membrane connecting two opposite PDMS microchannels. An interdigitated electrode array was embedded within the microchannel with various distances from the microchannel-membrane interface. The induced ICEO (floating electrodes) / ACEO (active electrodes) vortices formed at the electrode array stir the fluid and thereby suppress the growth of the DL. The intensity of the ACEO vortices is controlled by either varying the voltage amplitude or the frequency, each having its own unique effect. Enhancement of the limiting current by on-demand control of the diffusion length is of importance in on-chip electro-dialysis, desalination and preconcentration of analytes.

Far-ir heterodyne radiometric measurements with quasioptical Schottky diode mixers

International Nuclear Information System (INIS)

Fetterman, H.R.; Tannenwald, P.E.; Clifton, B.J.; Parker, C.D.; Fitzgerald, W.D.; Erickson, N.R.

1978-01-01

We have made heterodyne radiometric measurements with GaAs Schottky diode mixers, mounted in a corner-reflector configuration, over the spectral range 170 μm to 1 mm. At 400 μm, system noise temperatures of 9700 K DSB (NEP=1.4 x 10 - 19 W/Hz) and mixer noise temperatures of 5900 K have been achieved. This same quasioptical mixer has also been used to generate 10 - 7 W of tunable radiation suitable for spectroscopic applications

Turbulent measurements in the lobe mixer of a turbofan engine. Turbofan engine lobe mixer nagare no ranryu keisoku

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Makoto; Ogawa, Yuji; Arakawa, Chuichi; Tagori, Tetsuo [Ishikawajima-Harima Heavy Industries, Co., Ltd., Tokyo, (Japan) Nippon Steel Corp., Tokyo, (Japan) The Univ. of Tokyo, Tokyo, (Japan). Faculty of Engineering The Univ. of Tsukuba, Tsukuba, (Japan)

1990-01-25

In order to examine the flow generated by the lobe mixer of a turbofan engine precisely, after measuring a three dimensional turbulent flow by a hot-wire anemometer, the mixing process of a bypass flow and a core flow with cross-sectional vortexes, and factors generating the vortex were clarified experimentally using the scale model of an exhaust duct with the lobe mixer. As a result, the mixing process was strongly affected by a lobe tip figure and a lobe figure near a center-body, and affected by the minimum gap between the lobe and center-body. The subsequent mixing process was scarcely affected by the ratio of a core flow velocity to a bypass flow one, although strongly affected by flow conditions on a lobe surface. Since the lobe mixer promoted the mixing around a center axis shifting a fast core flow outwards, it was unfavorable to mixing, however, it was expected to be useful for reducing engine jet noise. 3 refs., 7 figs.

Numerical simulation and PEPT measurements of a 3D conical helical-bla de mixer: A high potential solids mixer for solid-state fermentation

NARCIS (Netherlands)

Schutyser, M.A.I.; Schutyser, M.A.I.; Briels, Willem J.; Rinzema, A.; Boom, R.M.; Boom, R.M.

2003-01-01

Helical-blade solids mixers have a large potential as bioreactors for solid-state fermentation (SSF). Fundamental knowledge of the flow and mixing behavior is required for robust operation of these mixers. In this study predictions of a discrete particle model were compared to experiments with

Role of Osmotic Adjustment in Plant Productivity

Energy Technology Data Exchange (ETDEWEB)

Gebre, G.M.

2001-01-11

Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

Removal of PAHs from contaminated clayey soil by means of electro-osmosis

KAUST Repository

Lima, Ana T.

2011-06-01

The removal of polycyclic aromatic hydrocarbons (PAHs) from clayey soils is an intricate task. The low porosity of compacted clayey soil hinders bacterial activity and makes convective removal by hydraulic flow impossible. Electro-osmosis is a process that has been used for the mobilization and cleanup of contaminants in clayey soils with varying successes. The present study focuses on the remediation of a contaminated peaty clay soil, located in Olst - the Netherlands, by means of electro-osmosis. The soil was originally contaminated by an asphalt production plant, active from 1903 to 1983, and presents high levels of all 16 priority PAHs indicated by the US Environmental Protection Agency (EPA). Such a long contact times of PAH with the soil (≥100 years) presents a unique study material with well established solid/liquid contaminant partitioning equilibrium, preferable to artificially spiked soil. A batch of 6 electro-osmosis laboratory experiments was carried out to study the removal of 16 PAHs through electro-osmosis. In these experiments, water and a surfactant (Tween 80) were used to enhance the PAH desorption. The electro-osmotic conductivities ranged from 2.88 × 10-10 to a substantial 1.19 × 10-7 m2 V-1 s -1 when applying a current density of 0.005-0.127 A m-2. Electro-osmosis was expected to occur towards the cathode, because of natural soil characteristics (negative zeta potential), but presented scattered directions. The use of reference electrodes proved to be very effective to the prediction of the flow direction. Finally, the addition of Tween 80 as a surfactant enhanced PAH removal up to 30% of the total PAH content of the soil in 9 days. © 2011 Elsevier B.V.

Flow regimes in a T-mixer operating with a binary mixture

Science.gov (United States)

Camarri, Simone; Siconolfi, Lorenzo; Galletti, Chiara; Salvetti, Maria Vittoria

2015-11-01

Efficient mixing in small volumes is a key target in many processes. Among the most common micro-devices, passive T-shaped micro-mixers are widely used. For this reason, T-mixers have been studied in the literature and its working flow regimes have been identified. However, in most of the available theoretical studies it is assumed that only one working fluid is used, i.e. that the same fluid at the same thermodynamic conditions is entering the two inlet conduits of the mixer. Conversely, the practical use of micro-devices often involves the mixing of two different fluids or of the same fluid at different thermodynamic conditions. In this case flow regimes significantly different than those observed for a single working fluid may occur. The present work aims at investigating the flow regimes in a T-mixers when water at two different temperatures, i.e. having different viscosity and density, is entering the mixer. The effect of the temperature difference on the flow regimes in a 3D T-mixer is investigated by DNS and stability analysis and the results are compared to the case in which a single working fluid is employed.

Quasi-optical antenna-mixer-array design for terahertz frequencies

Science.gov (United States)

Guo, Yong; Potter, Kent A.; Rutledge, David B.

1992-01-01

A new quasi-optical antenna-mixer-array design for terahertz frequencies is presented. In the design, antenna and mixer are combined into an entity, based on the technology in which millimeter-wave horn antenna arrays have been fabricated in silicon wafers. It consists of a set of forward- and backward-looking horns made with a set of silicon wafers. The front side is used to receive incoming signal, and the back side is used to feed local oscillator signal. Intermediate frequency is led out from the side of the array. Signal received by the horn array is picked up by antenna probes suspended on thin silicon-oxynitride membranes inside the horns. Mixer diodes will be located on the membranes inside the horns. Modeling of such an antenna-mixer-array design is done on a scaled model at microwave frequencies. The impedance matching, RF and LO isolation, and patterns of the array have been tested and analyzed.

Transitory powder flow dynamics during emptying of a continuous mixer

OpenAIRE

Ammarcha , Chawki; Gatumel , Cendrine; Dirion , Jean-Louis; Cabassud , Michel; Mizonov , Vadim; Berthiaux , Henri

2013-01-01

International audience; This article investigates the emptying process of a continuous powder mixer, from both experimental and modelling points of view. The apparatus used in this work is a pilot scale commercial mixer Gericke GCM500, for which a specific experimental protocol has been developed to determine the hold up in the mixer and the real outflow. We demonstrate that the dynamics of the process is governed by the rotational speed of the stirrer, as it fixes characteristic values of th...

Development of air pulsed ejector mixer settlers of different capacities

Energy Technology Data Exchange (ETDEWEB)

Rajagopalan, C V; Periasamy, K; Koganti, S B [Reprocessing Programme, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

1994-06-01

Nuclear industry has made significant contributions in the development of liquid-liquid contactors, for the separation of one or more solutes from feed solutions wherein they provide a more economical alternative compared to other unit operations. The various equipment that are used can be broadly classified into three categories: (1) mixer settlers (2) liquid pulsed sieve plate columns (3) centrifugal contactors. Each one has its own merits and demerits. Mixer settlers score over the other contactors in their simple design and reliable operation over a wide range of process conditions. Air pulsed mixer settlers of different designs are in use in the fuel reprocessing industry. The present paper describes the development of a new type of mixer settler based on ejector as the mixing device. (author). 7 refs., 3 figs., 1 tab.

A Matlab-Based Graphical User Interface for Simulation and Control Design of a Hydrogen Mixer

Science.gov (United States)

Richter, Hanz; Figueroa, Fernando

2003-01-01

A Graphical User Interface (GUI) that facilitates prediction and control design tasks for a propellant mixer is described. The Hydrogen mixer is used in rocket test stand operations at the NASA John C. Stennis Space Center. The mixer injects gaseous hydrogen (GH2) into a stream of liquid hydrogen (LH2) to obtain a combined flow with desired thermodynamic properties. The flows of GH2 and LH2 into the mixer are regulated by two control valves, and a third control valve is installed at the exit of the mixer to regulate the combined flow. The three valves may be simultaneously operated in order to achieve any desired combination of total flow, exit temperature and mixer pressure within the range of operation. The mixer, thus, constitutes a three-input, three-output system. A mathematical model of the mixer has been obtained and validated with experimental data. The GUI presented here uses the model to predict mixer response under diverse conditions.

Development of a bi-functional silica monolith for electro-osmotic pumping and DNA clean-up/extraction using gel-supported reagents in a microfluidic device.

Science.gov (United States)

Oakley, Jennifer A; Shaw, Kirsty J; Docker, Peter T; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J

2009-06-07

A silica monolith used to support both electro-osmotic pumping (EOP) and the extraction/elution of DNA coupled with gel-supported reagents is described. The benefits of the combined EOP extraction/elution system were illustrated by combining DNA extraction and gene amplification using the polymerase chain reaction (PCR) process. All the reagents necessary for both processes were supported within pre-loaded gels that allow the reagents to be stored at 4 degrees C for up to four weeks in the microfluidic device. When carrying out an analysis the crude sample only needed to be hydrodynamically introduced into the device which was connected to an external computer controlled power supply via platinum wire electrodes. DNA was extracted with 65% efficiency after loading lysed cells onto a silica monolith. Ethanol contained within an agarose gel matrix was then used to wash unwanted debris away from the sample by EOP (100 V cm(-1) for 5 min). The retained DNA was subsequently eluted from the monolith by water contained in a second agarose gel, again by EOP using an electric field of 100 V cm(-1) for 5 min, and transferred into the PCR reagent containing gel. The eluted DNA in solution was successfully amplified by PCR, confirming that the concept of a complete self-contained microfluidic device could be realised for DNA sample clean up and amplification, using a simple pumping and on-chip reagent storage methodology.

A Multidisciplinary Approach to Mixer-Ejector Analysis and Design

Science.gov (United States)

Hendricks, Eric, S.; Seidel, Jonathan, A.

2012-01-01

The design of an engine for a civil supersonic aircraft presents a difficult multidisciplinary problem to propulsion system engineers. There are numerous competing requirements for the engine, such as to be efficient during cruise while yet quiet enough at takeoff to meet airport noise regulations. The use of mixer-ejector nozzles presents one possible solution to this challenge. However, designing a mixer-ejector which will successfully address both of these concerns is a difficult proposition. Presented in this paper is an integrated multidisciplinary approach to the analysis and design of these systems. A process that uses several low-fidelity tools to evaluate both the performance and acoustics of mixer-ejectors nozzles is described. This process is further expanded to include system-level modeling of engines and aircraft to determine the effects on mission performance and noise near airports. The overall process is developed in the OpenMDAO framework currently being developed by NASA. From the developed process, sample results are given for a notional mixer-ejector design, thereby demonstrating the capabilities of the method.

Hydrothermal Carbonization of Spent Osmotic Solution (SOS Generated from Osmotic Dehydration of Blueberries

Directory of Open Access Journals (Sweden)

Kaushlendra Singh

2014-09-01

Full Text Available Hydrothermal carbonization of spent osmotic solution (SOS, a waste generated from osmotic dehydration of fruits, has the potential of transformation into hydrochars, a value-added product, while reducing cost and overall greenhouse gas emissions associated with waste disposal. Osmotic solution (OS and spent osmotic solution (SOS generated from the osmotic dehydration of blueberries were compared for their thermo-chemical decomposition behavior and hydrothermal carbonization. OS and SOS samples were characterized for total solids, elemental composition, and thermo-gravimetric analysis (TGA. In addition, hydrothermal carbonization was performed at 250 °C and for 30 min to produce hydrochars. The hydrochars were characterized for elemental composition, Brunauer-Emmett-Teller (BET surface area, particle shape and surface morphology. TGA results show that the SOS sample loses more weight in the lower temperature range than the OS sample. Both samples produced, approximately, 40%–42% (wet-feed basis hydrochar during hydrothermal carbonization but with different properties. The OS sample produced hydrochar, which had spherical particles of 1.79 ± 1.30 μm diameter with a very smooth surface. In contrast, the SOS sample produced hydrochar with no definite particle shape but with a raspberry-like surface.

Study on velocity distribution in a pool by submersible mixers

International Nuclear Information System (INIS)

Tian, F; Shi, W D; Lu, X N; Chen, B; Jiang, H

2012-01-01

To study the distribution of submersible mixers and agitating effect in the sewage treatment pool, Pro/E software was utilized to build the three-dimensional model. Then, the large-scale computational fluid dynamics software FLUENT6.3 was used. ICEM software was used to build unstructured grid of sewage treatment pool. After that, the sewage treatment pool was numerically simulated by dynamic coordinate system technology and RNG k-ε turbulent model and PIOS algorithm. The macro fluid field and each section velocity flow field distribution were analyzed to observe the efficiency of each submersible mixer. The average velocity and mixing area in the sewage pool were studied simultaneously. Results show that: the preferred project B, two submersible mixers speed is 980 r/min, and setting angles are all 30°. Fluid mixing area in the pool has reached more than 95%. Under the action of two mixers, the fluid in the sewage pool form a continuous circulating water flow. The fluid is mixed adequately and average velocity of fluid in the pool is at around 0.241m/s, which agreed with the work requirements. Consequently it can provide a reference basis for practical engineering application of submersible mixers by using this method.

The development of mixer machine for organic animal feed production: Proposed study

Science.gov (United States)

Leman, A. M.; Wahab, R. Abdul; Zakaria, Supaat; Feriyanto, Dafit; Nor, M. I. F. Che Mohd; Muzarpar, Syafiq

2017-09-01

Mixer machine plays a major role in producing homogenous composition of animal feed. Long time production, inhomogeneous and minor agglomeration has been observed by existing mixer. Therefore, this paper proposed continuous mixer to enhance mixing efficiency with shorter time of mixing process in order to abbreviate the whole process in animal feed production. Through calculation of torque, torsion, bending, power and energy consumption will perform in mixer machine process. Proposed mixer machine is designed by two layer buckets with purpose for continuity of mixing process. Mixing process was performed by 4 blades which consists of various arm length such as 50, 100,150 and 225 mm in 60 rpm velocity clockwise rotation. Therefore by using this machine will produce the homogenous composition of animal feed through nutrition analysis and short operation time of mixing process approximately of 5 minutes. Therefore, the production of animal feed will suitable for various animals including poultry and aquatic fish. This mixer will available for various organic material in animal feed production. Therefore, this paper will highlights some areas such as continues animal feed supply chain and bio-based animal feed.

A flicker noise/IM3 cancellation technique for active mixer using negative impedance

NARCIS (Netherlands)

Cheng, W.; Annema, Anne J.; Wienk, Gerhardus J.M.; Nauta, Bram

2013-01-01

Abstract—This paper presents an approach to simultaneously cancel flicker noise and IM3 in Gilbert-type mixers, utilizing negative impedances. For proof of concept, two prototype double-balanced mixers in 0.16- m CMOS are fabricated. The first demonstration mixer chip was optimized for full IM3

Conversion Matrix Analysis of SiGe HBT Gilbert Cell Mixers

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

2004-01-01

The frequency response of SiGe HBT active mixers based on the Gilbert cell topology is analyzed theoretically. The time-varying operation of the Gilbert cell mixer is taken into account by applying conversion matrix analysis. The main bandwidth limiting mechanisms experienced in SiGe HBT Gilbert ...

MOSFET-Only Mixer/IIR Filter with Gain using Parametric Amplification

DEFF Research Database (Denmark)

Custódio, José R.; Oliveira, J.; Oliveira, L. B.

2010-01-01

This paper describes the design of a discrete-time passive Mixer/IIR filter. The use of an improved MOS Parametric Amplification leads to a moderate gain in the signal path and improved noise performance, instead of the conversion loss inherent to passive mixers. Simulation results demonstrate th...

Twin Screw Mixer/Fine Grind Facility

Data.gov (United States)

Federal Laboratory Consortium — The 40-mm Twin-Screw Mixer/Extruder (TSE) pilot plant is a continuous, remotely operated, flexible facility that can significantly enhance safety and environmental...

CONTINUOUS PRODUCTION OF HYDROXYPROPYL STARCH IN A STATIC MIXER REACTOR

NARCIS (Netherlands)

LAMMERS, G; STAMHUIS, EJ; BEENACKERS, AACM

A novel type of reactor for the chemical derivatization of starch pastes is presented. The design is based on the application of static mixers. The reactor shows excellent plug flow behaviour with a Peclet number of about 100. The viscosity behaviour of concentrated starch pastes in the static mixer

Numerical Investigation on Aerodynamic and Combustion Performance of Chevron Mixer Inside an Afterburner.

Science.gov (United States)

Yong, Shan; JingZhou, Zhang; Yameng, Wang

2014-11-01

To improve the performance of the afterburner for the turbofan engine, an innovative type of mixer, namely, the chevron mixer, was considered to enhance the mixture between the core flow and the bypass flow. Computational fluid dynamics (CFD) simulations investigated the aerodynamic performances and combustion characteristics of the chevron mixer inside a typical afterburner. Three types of mixer, namely, CC (chevrons tilted into core flow), CB (chevrons tilted into bypass flow), and CA (chevrons tilted into core flow and bypass flow alternately), respectively, were studied on the aerodynamic performances of mixing process. The chevrons arrangement has significant effect on the mixing characteristics and the CA mode seems to be advantageous for the generation of the stronger streamwise vortices with lower aerodynamic loss. Further investigations on combustion characteristics for CA mode were performed. Calculation results reveal that the local temperature distribution at the leading edge section of flame holder is improved under the action of streamwise vortices shedding from chevron mixers. Consequently, the combustion efficiency increased by 3.5% compared with confluent mixer under the same fuel supply scheme.

Design and Fabrication of a Foundry Sand Mixer Using Locally ...

African Journals Online (AJOL)

Most small foundry shops mix their sand manually which is not efficient since homogenous mix cannot be guaranteed and even when foundry mixer are available most of them are imported costing the nation huge foriegn exchange. A foundry sand mixer capable of mixing foundry sand has been designed and fabricated ...

Electric dewatering and drying of fine-grained products; Elektrisk afvanding og toerring af finkornede produkter

Energy Technology Data Exchange (ETDEWEB)

Hansen, H.K.; Villumsen, A.

2001-07-01

The aim of the project was to elucidate four aspects related to using electric direct current to find an energy saving alternative to existing methods within dewatering of fine-grained products. The four aspects were a) electrophoresis forced sedimentation of chalk slurry, b) electro osmotic dewatering of chalk slurry, c) electro osmotic dewatering of agricultural chalk and d) electro osmotic dewatering of liquid organic wastes. (EHS)

Electro-osmosis over inhomogeneously charged surfaces in presence of non-electrostatic ion-ion interactions

Science.gov (United States)

Ghosh, Uddipta; Chakraborty, Suman

2016-06-01

In this study, we attempt to bring out a generalized formulation for electro-osmotic flows over inhomogeneously charged surfaces in presence of non-electrostatic ion-ion interactions. To this end, we start with modified electro-chemical potential of the individual species and subsequently use it to derive modified Nernst-Planck equation accounting for the ionic fluxes generated because of the presence of non-electrostatic potential. We establish what we refer to as the Poisson-Helmholtz-Nernst-Planck equations, coupled with the Navier-Stokes equations, to describe the complete transport process. Our analysis shows that the presence of non-electrostatic interactions between the ions results in an excess body force on the fluid, and modifies the osmotic pressure as well, which has hitherto remained unexplored. We further apply our analysis to a simple geometry, in an effort to work out the Smoluchowski slip velocity for thin electrical double layer limits. To this end, we employ singular perturbation and develop a general framework for the asymptotic analysis. Our calculations reveal that the final expression for slip velocity remains the same as that without accounting for non-electrostatic interactions. However, the presence of non-electrostatic interactions along with ion specificity can significantly change the quantitative behavior of Smoluchowski slip velocity. We subsequently demonstrate that the presence of non-electrostatic interactions may significantly alter the effective interfacial potential, also termed as the "Zeta potential." Our analysis can potentially act as a guide towards the prediction and possibly quantitative determination of the implications associated with the existence of non-electrostatic potential, in an electrokinetic transport process.

Superconducting terahertz mixer using a transition-edge microbolometer

Science.gov (United States)

Prober, D. E.

1993-01-01

We present a new device concept for a mixer element for THz frequencies. This uses a superconducting transition-edge microbridge biased at the center of its superconducting transition near 4.2 K. It is fed from an antenna or waveguide structure. Power from a local oscillator and an RF signal produce a temperature and resulting resistance variation at the difference frequency. The new aspect is the use of a very short bridge in which rapid (less than 0.1 ns) outdiffusion of hot electrons occurs. This gives large intermediate frequency (IF) response. The mixer offers about 4 GHz IF bandwidth, about 80 ohm RF resistive impedance, good match to the IF amplifier, and requires only 1-20 nW of local oscillator power. The upper RF frequency is determined by antenna or waveguide properties. Predicted mixer conversion efficiency is 1/8, and predicted double-sideband receiver noise temperatures are 260 and 90 K for transition widths of 0.1 and 0.5 Tc, respectively.

Side-band-separating heterodyne mixer for band 9 of ALMA.

NARCIS (Netherlands)

Mena, F. P.; Baryshev, A. M.; Kooi, J.; Lodewijk, C. F. J.; Gerlofsma, G.; Hesper, R.; Wild, W.; Shen, XC; Lu, W; Zhang, J; Dou, WB

2006-01-01

Here we present the realization of a side-band-separating (2SB) heterodyne mixer for the frequency range from 602 to 720 GHz (corresponding to ALMA band 9). The mixer, in brief, consists of a quadrature hybrid, two LO injectors, two SIS junctions, and three dumping loads. All the parts were modeled

Numerical investigation of the effects of geometric parameters on transverse motion with slanted-groove micro-mixers

Energy Technology Data Exchange (ETDEWEB)

Baik, Seung Joo; Cho, Jae Yong; Choi, Se Bin; Lee, Joon Sang [School of Mechanical Engineering, Yonsei University, Seoul (Korea, Republic of)

2016-08-15

We investigated hydrodynamic phenomena inside several passive microfluidic mixers using a Lattice Boltzmann method (LBM) based on particle mesoscopic kinetic equations. Mixing processes were simulated in a Slanted grooved micro-mixer (SGM), a Staggered herringbone grooved micro-mixer (SHM), and a Bi-layered staggered herringbone grooved micro-mixer (BSHM). Then, the effects of six geometric mixer parameters (i.e., groove height to channel height ratio, groove width to groove pitch length ratio, groove pitch to groove height ratio, groove intersection angle, herringbone groove asymmetric ratio and bi-layered groove asymmetric ratio) on mixing were investigated using computed cross-flow velocity and helicity density distributions in the flow cross-section. We demonstrated that helicity density provides sufficient information to analyze micro helical motion within a micro-mixer, allowing for micro-mixer design optimization.

Sandwich-format 3D printed microfluidic mixers: a flexible platform for multi-probe analysis

International Nuclear Information System (INIS)

Kise, Drew P; Reddish, Michael J; Brian Dyer, R

2015-01-01

We report on a microfluidic mixer fabrication platform that increases the versatility and flexibility of mixers for biomolecular applications. A sandwich-format design allows the application of multiple spectroscopic probes to the same mixer. A polymer spacer is ‘sandwiched’ between two transparent windows, creating a closed microfluidic system. The channels of the mixer are defined by regions in the polymer spacer that lack material and therefore the polymer need not be transparent in the spectral region of interest. Suitable window materials such as CaF 2 make the device accessible to a wide range of optical probe wavelengths, from the deep UV to the mid-IR. In this study, we use a commercially available 3D printer to print the polymer spacers to apply three different channel designs into the passive, continuous-flow mixer, and integrated them with three different spectroscopic probes. All three spectroscopic probes are applicable to each mixer without further changes. The sandwich-format mixer coupled with cost-effective 3D printed fabrication techniques could increase the applicability and accessibility of microfluidic mixing to intricate kinetic schemes and monitoring chemical synthesis in cases where only one probe technique proves insufficient. (paper)

Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

Science.gov (United States)

Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

2012-10-23

An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

Development of a micro-mixer-settler for nuclear solvent extraction

International Nuclear Information System (INIS)

Shekhar Kumar; Bijendra Kumar; Sampath, M.; Sivakumar, D.; Kamachi Mudali, U.; Natarajan, R.

2012-01-01

Nuclear solvent extraction was traditionally performed with packed columns, pulse columns, mixer-settlers and centrifugal extractors. However for rapid separations at micro-flow level, micro mixer-settlers were desired and in the past, few of them were actually designed and operated in nuclear solvent extraction research. In the current era of micro-reactor and microchannel devices, there is a renewed interest for micro-mixer-settlers for costly solvents and specialty solutes where small flow-rate is not an issue. In this article, development of a simple but effective micro-mixer-settler for nuclear solvent extraction is reported. The developed unit was tested with 30% TBP/n-dodecane/nitric acid system and in both the regimes of mass transfer c → d (mass transfer from continuous phase to dispersed phase, also written as c → d) and d → c (mass transfer from dispersed phase to continuous phase, also written as d → c) nearly 100% efficiency was observed in extraction as well as stripping modes of operation. (author)

Calculation of lobe mixer flow with reynolds stress model. Oryoku hoteishiki model ni yoru lobe mixer ryu no suchi keisan

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Makoto; Arakawa, Chuichi; Tagori, Tetsuo [Ishikawajima-Harima Heavy Industries, Co., Ltd., Tokyo (Japan) Univ. of Tokyo, Tokyo (Japan). Faculty of Engineering Univ. of Tsukuba, Tsukuba (Japan)

1990-02-25

It is considered that exhaust gas energy of turbofan engine is partly collected to realize the improvement of propulsion efficiency together with the reduction of noise appeared by the change in velocity distribution of exhaust gas flow. Then Lobe mixer was studied and its effectiveness was widely recognized, however the development of more realistic prediction method of exhaust nozzle system including Lobe mixer, is not completed yet. The stress equation model with low Reynolds Number which is easily used by the expansion of Launder Reece Rodi model in three dimension coordinate system was newly constructed. Applicability of the stress equation in more complicated flow field was greatly improved. While the above model was applied to Lobe mixer system, then the qualitative reproduction of mixing process accompanied with flow around Lobe and longitudinal eddy of core or bi-pass flow, was realized. There is room for improvement of pressure strain correlation term and behavior of Reynolds stress very close by wall surface in this model. 16 refs., 9 figs., 1 tab.

Study of a new static mixer for two-phase and single-phase flows

International Nuclear Information System (INIS)

Foucrier, Michel

1996-01-01

The subject of this work is the study of OptimiX, a new static mixer, which is fully designed using an inverse method taking the final product features as input and based on the physical properties of the fluid to mix. The work began with the construction of an experimental loop which allowed us to qualify the mixer in two-phase and single-phase flow conditions. Next, a chemical method using a new test reaction and a micro-mixing model have been used to further characterise the mixer. This test reaction and the micro-mixing model have been developed by the 'Laboratoire des Sciences du Genie Chimique' of Nancy. The mixer OptimiX has proved to be an excellent device for both macro- and micro-mixing. The capability of this mixer to foster rapid reactions was also demonstrated. The well organised flow pattern of OptimiX, which results from its design, provides it with the unusual feature of being fully calculable. This work emphasizes the internal hydrodynamics of this mixer, justifies the universality of the design procedures, which validation is supported by the completed qualification work. (author) [fr

Matlab GUI for a Fluid Mixer

Science.gov (United States)

Barbieri, Enrique

2005-01-01

The Test and Engineering Directorate at NASA John C. Stennis Space Center developed an interest to study the modeling, evaluation, and control of a liquid hydrogen (LH2) and gas hydrogen (GH2) mixer subsystem of a ground test facility. This facility carries out comprehensive ground-based testing and certification of liquid rocket engines including the Space Shuttle Main engine. A software simulation environment developed in MATLAB/SIMULINK (M/S) will allow NASA engineers to test rocket engine systems at relatively no cost. In the progress report submitted in February 2004, we described the development of two foundation programs, a reverse look-up application using various interpolation algorithms, a variety of search and return methods, and self-checking methods to reduce the error in returned search results to increase the functionality of the program. The results showed that these efforts were successful. To transfer this technology to engineers who are not familiar with the M/S environment, a four-module GUI was implemented allowing the user to evaluate the mixer model under open-loop and closed-loop conditions. The progress report was based on an udergraduate Honors Thesis by Ms. Jamie Granger Austin in the Department of Electrical Engineering and Computer Science at Tulane University, during January-May 2003, and her continued efforts during August-December 2003. In collaboration with Dr. Hanz Richter and Dr. Fernando Figueroa we published these results in a NASA Tech Brief due to appear this year. Although the original proposal in 2003 did not address other components of the test facility, we decided in the last few months to extend our research and consider a related pressurization tank component as well. This report summarizes the results obtained towards a Graphical User Interface (GUI) for the evaluation and control of the hydrogen mixer subsystem model and for the pressurization tank each taken individually. Further research would combine the two

The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

KAUST Repository

Wang, Zhenyu

2011-05-01

Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

Antenna-coupled 30 THz hot electron bolometer mixers

OpenAIRE

Shcherbatenko, M.; Lobanov, Y.; Benderov, O.; Shurakov, A.; Ignatov, A.; Titova, N.; Finkel, M.; Maslennikov, S.; Kaurova, N.; Voronov, B.M.; Rodin, A.; Klapwijk, T.M.; Gol'tsman, G.N.

2015-01-01

We report on design and characterization of a superconducting Hot Electron Bolometer Mixer integrated with a logarithmic spiral antenna for mid-IR range observations. The antenna parameters have been adjusted to achieve the ultimate performance at 10 ?m (30 THz) range where O3, NH3, CO2, CH4, N2O, …. lines in the Earth’s atmosphere, in planetary atmospheres and in the interstellar space can be observed. The HEB mixer is made of a thin NbN film deposited onto a GaAs substrate. To couple the ra...

Acceptance test report: Field test of mixer pump for 241-AN-107 caustic addition project

International Nuclear Information System (INIS)

Leshikar, G.A.

1997-01-01

The field acceptance test of a 75 HP mixer pump (Hazleton serial number N-20801) installed in Tank 241-AN-107 was conducted from October 1995 thru February 1996. The objectives defined in the acceptance test were successfully met, with two exceptions recorded. The acceptance test encompassed field verification of mixer pump turntable rotation set-up and operation, verification that the pump instrumentation functions within established limits, facilitation of baseline data collection from the mixer pump mounted ultrasonic instrumentation, verification of mixer pump water flush system operation and validation of a procedure for its operation, and several brief test runs (bump) of the mixer pump

Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

International Nuclear Information System (INIS)

TEMPLETON, A.M.

2000-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications

Conversion Matrix Analysis of GaAs HEMT Active Gilbert Cell Mixers

DEFF Research Database (Denmark)

Jiang, Chenhui; Johansen, Tom Keinicke; Krozer, Viktor

2006-01-01

In this paper, the nonlinear model of the GaAs HEMT active Gilbert cell mixer is investigated. Based on the model, the conversion gain expression of active Gilbert cell mixers is derived theoretically by using conversion matrix analysis method. The expression is verified by harmonic balance simul...

Low noise Nb-SIS mixers at far above the gap frequency

NARCIS (Netherlands)

Gao, [No Value; vandeStadt, H; Jegers, JBM; Kovtonyuk, S; Hulshoff, W; Whyborn, ND; Klapwijk, TM; deGraauw, T; Liao, FJ; Liu, JY

1996-01-01

There are great interests in developing Nb SIS mixers because of the extremely low noise temperatures and because of the need of low local oscillator (LO) power. Several groups have demonstrated experimentally that Nb SIS mixers with integrated tuning elements can perform near the quantum noise

A simple image-reject mixer based on two parallel phase modulators

Science.gov (United States)

Hu, Dapeng; Zhao, Shanghong; Zhu, Zihang; Li, Xuan; Qu, Kun; Lin, Tao; Zhang, Kun

2018-02-01

A simple photonic microwave image-reject mixer (IRM) using two parallel phase modulators is proposed. First, a photonic microwave mixer with phase shift ability is achieved using two parallel phase modulators (PMs), an optical bandpass filter, three polarization controllers, three polarization beam splitters and two balanced photodetectors. At the output of the mixer, two frequency downconverted signals with tunable frequency difference can be obtained. By adjusting the phase difference as 90° and utilizing an electrical 90° hybrid, the useless components can be eliminated, and the image reject operation is realized. The key advantage of the proposed scheme is the usage of PM, which avoid the DC bias shifting problem and make the system simple and stable. A simulation is performed to verify the proposed scheme, a relative - 90° or 90° phase shift can be obtained between the two output ports of the photonic microwave mixer, at the output of the IRM, 60 dB image-reject ratio is obtained.

Water transport mechanisms across inorganic membranes in rad waste treatment by electro dialysis

International Nuclear Information System (INIS)

Andalaft, E.; Labayru, R.

1992-01-01

The work described in this paper deals with effects and mechanisms of water transport across an inorganic membrane, as related to some studied on the concentration of caesium, strontium, plutonium and other cations of interest to radioactive waste treatment. Several different water transport mechanisms are analysed and assessed as to their individual contribution towards the total transference of water during electro-dialysis using inorganic membranes. Water transfer assisted by proton jump mechanism, water of hydration transferred along with the ions, water related to thermo-osmotic effect, water transferred by concentration gradient and water transferred electrolytically under zeta potential surface charge drive are some of the different mechanism discussed. (author)

PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKAN MIXER SETTLER

Directory of Open Access Journals (Sweden)

Dwi Biyantoro

2017-01-01

Full Text Available ABSTRAK PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKANMIXER SETTLER. Telah dilakukan pemisahanZr – Hf secara sinambung menggunakan pengaduk pengenap (mixer settler 16 stage. Larutan umpan adalah zirkon nitrat dengan kadar Zr = 30786 ppm dan Hf = 499 ppm. Ekstraktan dipakai adalah solven 60 % TBP dalam kerosen dan larutan scrubbingyang dipakai adalah asam nitrat 1 M. Umpan masuk pada stageke 5 dikontakkan secara berlawanan arah dengan solven masuk pada stage ke 16 dan larutan scrubbing masuk pada stage ke 1. Tujuan penelitian ini adalah memisahkan unsur Zr dan Hf dari hasil olah pasir zirkon menggunakan solven TBP dengan alat mixer settler16 stage. Analisis umpan dan hasil proses pemisahan untuk zirkonium (Zr dilakukan dengan menggunakan alat pendar sinar-X, sedangkananalisis unsur hafnium (Hf menggunakan Analisis Pengaktifan Neutron (APN. Parameter penelitian dilakukan dengan variasi keasaman asam nitrat dalam umpan dan variasi waktu pada berbagai laju pengadukan. Hasil penelitian pemisahan unsur Zr dengan Hf diperolehkondisi optimum pada keasaman umpan 4 N HNO3, keseimbangan dicapai setelah 3jam dan laju pengadukan 3300 rpm. Hasil ekstrak  unsur zirkon (Zr diperoleh kadar sebesar 28577 ppm dengan efisiensi 92,76 % serta kadar pengotor hafnium (Hf sebesar 95 ppm. Kata Kunci: pemisahan Zr, Hf, ekstraksi, mixer settler, alat pendar sinar-X, APN. ABSTRACT SEPARATION of Zr - Hf CONTINUOUSLY USE THE MIXER SETTLER. Separation of Zr - Hf continuously using mixer settler 16 stage has been done. The feed solution is zircon nitrate concentration of Zr = 30786 ppm  and Hf = 499 ppm. As the solvent used extractant 60 % TBP in 40 % kerosene. Nitric acid solution used srubbing 1 M. The feed entered into stage to 5 is contacted with solvents direction on the stage to 16 and the scrubbing solution enter the stage to 1. The purpose of this study is to separate Zr and Hf of the results from the process of zircon sand using solvent TBP using 16 stage

Safety basis for the 241-AN-107 mixer pump installation and caustic addition

International Nuclear Information System (INIS)

Van Vleet, R.J.

1994-01-01

This safety Basis was prepared to determine whether or not the proposed activities of installing a 76 HP jet mixer pump and the addition of approximately 50,000 gallons of 19 M (50:50 wt %) aqueous caustic are within the safety envelope as described by Tank Farms (chapter six of WHC-SD-WM-ISB-001, Rev. 0). The safety basis covers the components, structures and systems for the caustic addition and mixer pump installation. These include: installation of the mixer pump and monitoring equipment; operation of the mixer pump, process monitoring equipment and caustic addition; the pump stand, caustic addition skid, the electrical skid, the video camera system and the two densitometers. Also covered is the removal and decontamination of the mixer pump and process monitoring system. Authority for this safety basis is WHC-IP-0842 (Waste Tank Administration). Section 15.9, Rev. 2 (Unreviewed Safety Questions) of WHC-IP-0842 requires that an evaluation be performed for all physical modifications

Compact terahertz passive spectrometer with wideband superconductor-insulator-superconductor mixer.

Science.gov (United States)

Kikuchi, K; Kohjiro, S; Yamada, T; Shimizu, N; Wakatsuki, A

2012-02-01

We developed a compact terahertz (THz) spectrometer with a superconductor-insulator-superconductor (SIS) mixer, aiming to realize a portable and highly sensitive spectrometer to detect dangerous gases at disaster sites. The receiver cryostat which incorporates the SIS mixer and a small cryocooler except for a helium compressor has a weight of 27 kg and dimensions of 200 mm × 270 mm × 690 mm. In spite of the small cooling capacity of the cryocooler, the SIS mixer is successfully cooled lower than 4 K, and the temperature variation is suppressed for the sensitive measurement. By adopting a frequency sweeping system using photonic local oscillator, we demonstrated a spectroscopic measurement of CH(3)CN gas in 0.2-0.5 THz range.

Development of novel micro swirl mixer for producing fine metal oxide nanoparticles by continuous supercritical hydrothermal method.

Science.gov (United States)

Kawasaki, Shin-ichiro; Sue, Kiwamu; Ookawara, Ryuto; Wakashima, Yuichiro; Suzuki, Akira

2010-01-01

Novel micro swirl mixers were developed to synthesize nanoparticles, and the effect of their mixing performance on the characteristics of the synthesized nanoparticles was determined. The results were compared with those obtained using simple T-shaped mixers under the same reaction conditions. The synthesis of NiO, whose characteristics depend on the mixing performance of the mixer, was chosen as a model reaction. Initial investigations highlighted that the average particle size decreased from 32 to 23 to 20 nm as the inner diameter of the swirl mixers was decreased from 3.2 mm (Swirl mixer, SM-3.2) to 0.8 mm (Micro swirl mixer, MSM-0.8) to 0.5 mm (Micro swirl mixer, MSM-0.5), respectively. On the other hand, a similar decrease in the average particle size from 34 to 20 nm was observed with a decrease in the inner diameter of the T-shaped mixers from 1.3 mm (Tee union, T-1.3) to 0.3 mm (Micro tee union, T-0.3), respectively. Further, narrow particle size distributions were observed with a decrease in the inner diameter of each mixer. Furthermore, a computational fluid dynamics (CFD) simulation indicated an excellent mixing mechanism, which contributed to the improvement in the heating rate and the formation of nanoparticles of smaller size with a narrow particle size distribution. The result presented here indicates that the micro swirl mixers produce high-quality metal oxide nanoparticles. The size of the obtained particles with improved size distributions was comparable to that of the particles obtained using the T-shaped mixers, although the inner diameter of the swirl mixers was larger. Therefore, preliminary evidence suggests that the swirl flow mixers have the ability to produce rapid and homogeneous fluid mixing, thus controlling the particle size.

A niobiumnitride mixer with niobium tuning circuit

International Nuclear Information System (INIS)

Plathner, B.; Schicke, M.; Lehnert, T.; Gundlach, K.H.; Rothermel, H.; Aoyagi, M.; Takada, S.

1996-01-01

This letter reports a low noise submillimeter-wave mixer using NbN tunnel junctions integrated in Nb matching circuits. The double side band receiver noise temperature was 245 K at 345 GHz. Plasma conditions for NbN film deposition on quartz substrates at room temperature are created by using a second Nb target as a selective nitrogen pump. Electrodes for tunnel junctions with critical temperatures above 15 K and normal state resistivities in the range from 130 to 160 μΩcm were obtained. This permits integrating NbN junctions into normal metal or non-NbN superconducting matching circuits, which is of great interest for THz mixers. copyright 1996 American Institute of Physics

The effects of arbitrary injection angle and flow conditions on venturi-jet mixer

Directory of Open Access Journals (Sweden)

Sundararaj S.

2012-01-01

Full Text Available This paper describes the effect of jet injection angle, cross flow Reynolds number and velocity ratio on entrainment and mixing of jet with incompressible cross flow in venturi-jet mixer. Five different jet injection angles 45o, 60o, 90o, 125o, 135o are tested to evaluate the entrainment of jet and mixing performances of the mixer. Tracer concentration along the downstream of the jet injection, cross flow velocity, jet velocity and pressure drop across the mixer are determined experimentally to characterize the mixing performance of the mixer. The experiments show that the performance of a venturi-jet-mixer substantially improves at high injection angle and can be augmented still by increasing velocity ratio. The jet deflects much and penetrates less in the cross flow as the cross flow Reynolds number is increased. The effect could contribute substantially to the better mixing index with moderate pressure drop. Normalized jet profile, concentration decay, jet velocity profile are computed from equations of conservation of mass, momentum and concentration written in natural co-ordinate systems. The comparison between the experimental and numerical results confirms the accuracy of the simulations. Correlations for jet trajectory and entrainment ratio of the mixer are obtained by multivariate-linear regression analysis using power law.

On-line separation of iodine species in reactor water using mixer-settlers

International Nuclear Information System (INIS)

Malmbeck, R.; Skarnemark, G.

1995-01-01

A method for separation of iodine species from water has been developed. It is based on liquid-liquid extraction and separation is achieved in four extraction steps. A system based on this method for continuous separation of iodine species using mixer-settlers has been developed. It consists of four mixer-settler batteries with 4,4,6 and 6 mixer-settler stages each. As organic phase an aliphatic kerosene is used and the separation is improved if the organic solvent has been pretreated with iodine carrier, stripped and washed. With an aqueous feed flowrate of 10 ml/min and mixer-settler battery phase flowratios of approximately 0.1 except for the elementary iodine strip battery with a phase flowratio of 1, the system separation performance is 92% for methyl iodide, 97% for iodate and elementary iodine and 99% for iodide. (orig.)

Continuous mixer, process and use in a pumping plant for a high viscosity fluid

Energy Technology Data Exchange (ETDEWEB)

Cholet, H.

1993-03-12

The invention concerns a novel continuous mixer comprising a rotary shaft carrying two or more vanes for mixing two or more fluids of different viscosities supplied at the inlet of the mixer body and for providing, at the mixer body outlet, a mixture of viscosity lower than that of the more or most viscous fluid. Preferentially, the vane profile is such that, without fluid circulation, rotation of the vanes produces a reaction force parallel to the rotational axis and in the same direction as the resulting flow or does not produce a reaction force of significant magnitude parallel to the rotational axis. The mixer shaft is connected to a pump shaft which is rotated by hydraulic motor driven by pressurized fluid injection. The mixer is used especially for facilitating viscous crude oil pumping from directional wells including horizontal or inclined portions.

Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

Energy Technology Data Exchange (ETDEWEB)

Finan, John D.; Leddy, Holly A. [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States); Guilak, Farshid, E-mail: guilak@duke.edu [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States)

2011-05-06

Highlights: {yields} The rate of nucleocytoplasmic transport increases under hyper-osmotic stress. {yields} The mechanism is a change in nuclear geometry, not a change in permeability of the nuclear envelope. {yields} Intracytoplasmic but not intranuclear diffusion is sensitive to osmotic stress. {yields} Pores in the chromatin of the nucleus enlarge under hyper-osmotic stress. -- Abstract: Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport.

Osmotic water transport in aquaporins

DEFF Research Database (Denmark)

Zeuthen, Thomas; Alsterfjord, Magnus; Beitz, Eric

2013-01-01

Abstract  We test a novel, stochastic model of osmotic water transport in aquaporins. A solute molecule present at the pore mouth can either be reflected or permeate the pore. We assume that only reflected solute molecules induce osmotic transport of water through the pore, while permeating solute...... molecules give rise to no water transport. Accordingly, the rate of water transport is proportional to the reflection coefficient σ, while the solute permeability, P(S), is proportional to 1 - σ. The model was tested in aquaporins heterologously expressed in Xenopus oocytes. A variety of aquaporin channel...... sizes and geometries were obtained with the two aquaporins AQP1 and AQP9 and mutant versions of these. Osmotic water transport was generated by adding 20 mM of a range of different-sized osmolytes to the outer solution. The osmotic water permeability and the reflection coefficient were measured...

Studies on osmotic concentration of radioactive effluents

International Nuclear Information System (INIS)

Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

1986-01-01

The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

The modeling of continuous mixers. Part I: The corotating twin-screw extruder

NARCIS (Netherlands)

Meijer, H.E.H.; Elemans, P.H.M.

1988-01-01

In many operations in polymer processing, such as polymer blending, devolatilization, or incorporation of fillers in a polymeric matrix, continuous mixers are used; e.g., corotating twin-screw extruders (ZSK), Buss Cokneaders and Farrel Continuous Mixers. Theoretical analysis of these machines tends

Osmotic stress on nitrification in an airlift bioreactor

International Nuclear Information System (INIS)

Jin Rencun; Zheng Ping; Mahmood, Qaisar; Hu Baolan

2007-01-01

The effect of osmotic pressure on nitrification was studied in a lab-scale internal-loop airlift-nitrifying reactor. The reactor slowly adapted to the escalating osmotic pressure during 270 days operation. The conditions were reversed to the initial stage upon full inhibition of the process. Keeping influent ammonium concentration constant at 420 mg N L -1 and hydraulic retention time at 20.7 h, with gradual increase in osmotic pressure from 4.3 to 18.8 x 10 5 Pa by adding sodium sulphate, the ammonium removal efficiencies of the nitrifying bioreactor were maintained at 93-100%. Further increase in osmotic pressure up to 19.2 x 10 5 Pa resulted in drop of the ammonium conversion to 69.2%. The osmotic pressure caused abrupt inhibition of nitrification without any alarm and the critical osmotic pressure value causing inhibition remained between 18.8 and 19.2 x 10 5 Pa. Nitrite oxidizers were found more sensitive to osmotic stress as compared with ammonia oxidizers, leading to nitrite accumulation up to 61.7% in the reactor. The performance of bioreactor recovered gradually upon lowering the osmotic pressure. Scanning and transmission electron microscopy indicated that osmotic stress resulted in simplification of the nitrifying bacterial populations in the activated sludge as the cellular size reduced; the inner membrane became thinner and some unknown inclusions appeared within the cells. The microbial morphology and cellular structure restored upon relieving the osmotic pressure. Addition of potassium relieved the effect of osmotic pressure upon nitrification. Results demonstrate that the nitrifying reactor possesses the potential to treat ammonium-rich brines after acclimatization

The Strength Analysis of Differential Planetary Gears of Gearbox for Concrete Mixer Truck

Science.gov (United States)

Bae, M. H.; Bae, T. Y.; Kim, D. J.

2018-03-01

The power train of mixer gearbox for concrete mixer truck includes differential planetary gears to get large reduction ratio for operating mixer a drum and simple structure. The planetary gears are very important part of a mixer gearbox where strength problems namely gear bending stress, gear compressive stress and scoring failure are the main concern. In the present study, calculating specifications of the differential planetary gears and analyzing the gear bending and compressive stresses as well as scoring factor of the differential planetary gears gearbox for an optimal design of the mixer gearbox in respect to cost and reliability are investigated. The analyses of actual gear bending and compressive stresses of the differential planetary gears using Lewes & Hertz equation and verifications of the calculated specifications of the differential planetary gears evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears. In addition, we also analyze actual gear scoring factor as well as evaluate the possibility of scoring failure of the differential planetary gear.

Design of mixer settler extraction cycles II for recovery uranium from phosphoric acid

International Nuclear Information System (INIS)

Abdul Jami; Hafni Lissa Nuri

2013-01-01

Mixer settler is technically designed for extraction and separation process of uranium from phosphoric acid solution. Design calculation results shows that: the mixer settler consists of two parts: part of extraction process in the mixer tank and part of separation process in settler tank. The mixer tank type of box with 4 baffles, the size of mixer tank, 0.8 m width, 0.8 m length, 1 m high of liquid, 1.05 m high of mixer tank, stirrer type of disk 6 blade, and power of mixing 4 hp and the settler tank type of rectangular with size of settler tank, 0.8 m width 5 m length, 1 m high of liquid, 1.05 m high of settler tank. For uranium recovery efficiency up to 91%, extraction process is done in 3 stage counter current flow using a solvent Organic (O) DEHPA-TOPO in Kerosene at a phase of ratio A/O of 2:1. The aqueous enter through stage 3 and the organic solvent enter through stage 1. The process of settling occurred with the value of settling velocity is 0.000694 m/s, dispersion factor Ψ = 0.3638 and the light fraction as the dispersed phase and value of Reynolds number (NRE) = 3,438. Because of the Reynolds number is lower than 5,000, it indicates that the quality of the separation is very good. (author)

Quantum noise in a terahertz hot electron bolometer mixer

OpenAIRE

Zhang, W.; Khosropanah, P.; Gao, J. R.; Kollberg, E. L.; Yngvesson, K. S.; Bansal, T.; Barends, R.; Klapwijk, T. M.

2010-01-01

We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model for HEB mixers, we confirm the effect of QN. The QN is found to be responsible for about half of the receiver noise at the highest frequency in our measurements. The ?-factor (the quantum efficiency ...

AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)

International Nuclear Information System (INIS)

THOMAS, W.K.

2000-01-01

Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field

Design and Characterization of 1.8-3.2 THz Schottky-based Harmonic Mixers

OpenAIRE

Bulcha, BT; Hesler, JL; Drakinskiy, V; Stake, J; Valavanis, A; Dean, P; Li, LH; Barker, NS

2016-01-01

A room-temperature Schottky diode-based WM-86 (WR-0.34) harmonic mixer was developed to build high-resolution spectrometers, and multi-pixel receivers in the THz region for applications such as radio astronomy, plasma diagnostics, and remote sensing. The mixer consists of a quartz-based Local Oscillator (LO), Intermediate-Frequency (IF) circuits, and a GaAs-based beam-lead THz circuit with an integrated diode. Measurements of the harmonic mixer were performed using a 2 THz solid-state source ...

Substrate Effects in Wideband SiGe HBT Mixer Circuits

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

2005-01-01

are also applied to predict short distance substrate coupling effects. Simulation results using extracted equivalent circuit models and substrate coupling networks are compared with experimental results obtained on a wideband mixer circuit implemented in a 0.35 μm, 60 GHz ft SiGe HBT BiCMOS process.......In this paper, the influence from substrate effects on the performance of wideband SiGe HBT mixer circuits is investigated. Equivalent circuit models including substrate networks are extracted from on-wafer test structures and compared with electromagnetic simulations. Electromagnetic simulations...

670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF

Science.gov (United States)

Chattopadhyay, Goutam; Schlecht, Erich T.; Lee, Choonsup; Lin, Robert H.; Gill, John J.; Mehdi, Imran; Sin, Seth; Deal, William; Loi, Kwok K.; Nam, Peta;

First Results of the Sideband-Separating Mixer for ALMA Band 9 Upgrade

NARCIS (Netherlands)

Khudchenko, Andrey; Hesper, Ronald; Baryshev, Andrey; Mena, F. Patricio; Gerlofma, Gerrit; Zijlstra, Tony; Klapwijk, Teun M.; Kooi, Jacob W.; Spaans, Marco

2011-01-01

Last year, the design and implementation details of a new modular sideband-separating mixer block, intended as an upgrade for the current single-ended ALMA Band 9 mixers, were presented at this conference. In high-frequency observation bands like ALMA Band 9 (600-720 GHz), which is strongly

VAPOR MIXER FOR GELATINIZATION OF STARCH IN LIQUEFYING STATION

Directory of Open Access Journals (Sweden)

V. V. Ananskikh

2015-01-01

Full Text Available Starch hydrolysis is main technological process in production of starch sweeteners. Acid hydrolysis of starch using hydrochloric acid is carried out very fast but it does not allow to carry out full hydrolysis and to produce products with given carbohydrate composition. Bioconversion of starch allows to eliminate these limitations. At production of starch sweeteners from starch using enzymes starch hydrolysis is carried out in two stages At first starch – starch liquefaction the rapid increase of viscosity takes place which requires intensive mixing. Liquefying station consists of jet-cooker, holder, pressure regulator and evaporator. Jet-cooker of starch is its main part, starch is quickly turns into soluble (gelatinized state and it is partially liquefied by injection of starch suspension by flow of water vapor under pressure not less than 0,8 MPa. Heat and hydraulic calculation were carried out in order to determine constructive sizes of mixer for cooking of starch. The main hydraulic definable parameters are pressure drop in mixer, vapor pressure at mixer inlet, daily capacity of station by glucose syrup M, product consumption (starch suspension, diameter of inlet section of vapor nozzle. The goal of calculation was to determine vapor consumption M1, diameter d2 of outlet section of confuser injector, length l2 of gelatinization section. For heat calculation there was used Shukhov’s formula along with heat balance equation for gelatinization process. The numerical solution obtained with adopted assumptions given in applied mathematical package MATHCAD, for M = 50 t/day gives required daily vapor consumption M1 = 14,446 т. At hydraulic calculation of pressure drop in mixer there was used Bernoulli’s theorem. Solving obtained equations using MATHCAD found diameter of outlet section of consufer d2 = 0,023 м, vapor pressure inside of mixer p2 = 3,966·105 Па, l2 = 0,128 м. Developed method of calculation is used to determine

RF Performance of a 600-720 GHz Sideband Separating Mixer with All-Copper Micromachined Waveguide Mixer Block

NARCIS (Netherlands)

Mena, F. P.; Kooi, J.; Baryshev, A. M.; Lodewijk, C. F. J.; Klapwijk, T. M.; Wild, W.; Desmaris, V.; Meledin, D.; Pavolotsky, A.; Belitsky, V.; Wild, Wolfgang

2008-01-01

Here we report on the RF performance of a 2SB mixer (600-720 GHz) fabricated in a new method that combines traditional micromachining with waveguide components fabricated by photolithography and electroplating. The latter allows reaching, in a reproducible way, the stringent accuracies necessary for

Turbofan forced mixer lobe flow modeling. 1: Experimental and analytical assessment

Science.gov (United States)

Barber, T.; Paterson, R. W.; Skebe, S. A.

1988-01-01

A joint analytical and experimental investigation of three-dimensional flowfield development within the lobe region of turbofan forced mixer nozzles is described. The objective was to develop a method for predicting the lobe exit flowfield. In the analytical approach, a linearized inviscid aerodynamical theory was used for representing the axial and secondary flows within the three-dimensional convoluted mixer lobes and three-dimensional boundary layer analysis was applied thereafter to account for viscous effects. The experimental phase of the program employed three planar mixer lobe models having different waveform shapes and lobe heights for which detailed measurements were made of the three-dimensional velocity field and total pressure field at the lobe exit plane. Velocity data was obtained using Laser Doppler Velocimetry (LDV) and total pressure probing and hot wire anemometry were employed to define exit plane total pressure and boundary layer development. Comparison of data and analysis was performed to assess analytical model prediction accuracy. As a result of this study a planar mixed geometry analysis was developed. A principal conclusion is that the global mixer lobe flowfield is inviscid and can be predicted from an inviscid analysis and Kutta condition.

A Formal Model of Identity Mixer

DEFF Research Database (Denmark)

Camenisch, Jan; Mödersheim, Sebastian Alexander; Sommer, Dieter

2010-01-01

Identity Mixer is an anonymous credential system developed at IBM that allows users for instance to prove that they are over 18 years old without revealing their name or birthdate. This privacy-friendly tech- nology is realized using zero-knowledge proofs. We describe a formal model of Identity...

Submersible canned motor mixer pump

International Nuclear Information System (INIS)

Guardiani, R.F.; Pollick, R.D.

1997-01-01

A mixer pump is described used in a waste tank for mobilizing high-level radioactive liquid waste having a column assembly containing power cables, a motor housing with electric motor means which includes a stator can of a stator assembly and a rotor can of a rotor assembly, and an impeller assembly with an impeller connected to a shaft of the rotor assembly. The column assembly locates the motor housing with the electric motor means adjacent to the impeller which creates an hydraulic head, and which forces the liquid waste into the motor housing to cool the electric motor means and to lubricate radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the impeller and electric motor means act to grind down large particles in the liquid waste flow. These larger particles are received in slots in the static bearing members of the radial bearing assemblies. Only solid waste particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the mixer pump. 10 figs

Deviations from mass transfer equilibrium and mathematical modeling of mixer-settler contactors

International Nuclear Information System (INIS)

Beyerlein, A.L.; Geldard, J.F.; Chung, H.F.; Bennett, J.E.

1980-01-01

This paper presents the mathematical basis for the computer model PUBG of mixer-settler contactors which accounts for deviations from mass transfer equilibrium. This is accomplished by formulating the mass balance equations for the mixers such that the mass transfer rate of nuclear materials between the aqueous and organic phases is accounted for. 19 refs

AlGaAs/GaAs quasi-bulk effect mixers: Analysis and experiments

Science.gov (United States)

Yngvesson, K. S.; Yang, J.-X.; Agahi, F.; Dai, D.; Musante, C.; Grammer, W.; Lau, K. M.

1992-01-01

The lowest noise temperature for any receiver in the 0.5 to 1 THz range has been achieved with the bulk InSb hot electron mixer, which unfortunately suffers from the problem of having a very narrow bandwidth (1-2 MHz). We have demonstrated a three order of magnitude improvement in the bandwidth of hot electron mixers, by using the two-dimensional electron gas (2DEG) medium at the hetero-interface between AlGaAs and GaAs. We have tested both inhouse MOCVD-grown material, and MBE materials, with similar results. The conversion loss (L(sub c)) at 94 GHz is presently 18 dB for a mixer operating at 20 K, and calculations indicate that L(sub c) can be decreased to about 10 dB in future devices. Calculated and measured curves of L(sub c), versus PLO and IDC, respectively, agree well. We argue that there are several different configurations of hot electron mixers, which will also show wide bandwidth, and that these devices are likely to become important as low-noise THz receivers in the future.

Osmocapsules for direct measurement of osmotic strength.

Science.gov (United States)

Kim, Shin-Hyun; Lee, Tae Yong; Lee, Sang Seok

2014-03-26

Monodisperse microcapsules with ultra-thin membranes are microfluidically designed to be highly sensitive to osmotic pressure, thereby providing a tool for the direct measurement of the osmotic strength. To make such osmocapsules, water-in-oil-in-water double-emulsion drops with ultra-thin shells are prepared as templates through emulsification of core-sheath biphasic flow in a capillary microfluidic device. When photocurable monomers are used as the oil phase, the osmocapsules are prepared by in-situ photopolymerization of the monomers, resulting in semipermeable membranes with a relatively large ratio of membrane thickness to capsule radius, approximately 0.02. These osmocapsules are buckled by the outward flux of water when they are subjected to a positive osmotic pressure difference above 125 kPa. By contrast, evaporation-induced consolidation of middle-phase containing polymers enables the production of osmocapsules with a small ratio of membrane thickness to capsule radius of approximately 0.002. Such an ultra-thin membrane with semi-permeability makes the osmocapsules highly sensitive to osmotic pressure; a positive pressure as small as 12.5 kPa induces buckling of the capsules. By employing a set of distinct osmocapsules confining aqueous solutions with different osmotic strengths, the osmotic strength of unknown solutions can be estimated through observation of the capsules that are selectively buckled. This approach provides the efficient measurement of the osmotic strength using only a very small volume of liquid, thereby providing a useful alternative to other measurement methods which use complex setups. In addition, in-vivo measurement of the osmotic strength can be potentially accomplished by implanting these biocompatible osmocapsules into tissue, which is difficult to achieve using conventional methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MICROFLUIDIC MIXERS FOR THE INVESTIGATION OF PROTEIN FOLDING USING SYNCHROTRON RADIATION CIRCULAR DICHROISM SPECTROSCOPY

International Nuclear Information System (INIS)

Kane, A; Hertzog, D; Baumgartel, P; Lengefeld, J; Horsley, D; Schuler, B; Bakajin, O

2006-01-01

The purpose of this study is to design, fabricate and optimize microfluidic mixers to investigate the kinetics of protein secondary structure formation with Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The mixers are designed to rapidly initiate protein folding reaction through the dilution of denaturant. The devices are fabricated out of fused silica, so that they are transparent in the UV. We present characterization of mixing in the fabricated devices, as well as the initial SRCD data on proteins inside the mixers

Recycling of osmotic solutions in microwave-osmotic dehydration: product quality and potential for creation of a novel product.

Science.gov (United States)

Wray, Derek; Ramaswamy, Hosahalli S

2016-08-01

Despite osmotic dehydration being a cost effective process for moisture removal, the cost implications of making, regenerating, and properly disposing of the spent osmotic solutions contributes greatly to the economic feasibility of the drying operation. The potential for recycling of osmotic solutions and their use for creation of a novel product was explored using microwave-osmotic dehydration under continuous flow spray (MWODS) conditions. Identical runs were repeated 10 times to determine the progressive physical and compositional effects of the thermal treatment and leaching from the cranberry samples. The microbiological stability and constant drying performance indicated that MWODS would be well suited for employing recycled solutions. While the anthocyanin content of the solution never approached that of cranberry juice concentrate, it is demonstrated that the spent syrup can infuse these health positive components into another product (apple). This study found that re-using osmotic solutions is a viable option to reduce cost in future MWODS applications, with no detriment to product quality and potential to use the spent solution for novel products. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

A compact D-band monolithic APDP-based sub-harmonic mixer

Science.gov (United States)

Zhang, Shengzhou; Sun, Lingling; Wang, Xiang; Wen, Jincai; Liu, Jun

2017-11-01

The paper presents a compact D-band monolithic sub-harmonic mixer (SHM) with 3 μm planar hyperabrupt schottky-varactor diodes offered by 70 nm GaAs mHEMT technology. According to empirical equivalent-circuit models, a wide-band large signal equivalent circuit model of the diode is proposed. Based on the extracted model, the mixer is implemented and optimized with a shunt-mounted anti-parallel diode pair (APDP) to fulfill the sub-harmonic mixing mechanism. Furthermore, a modified asymmetric three-transmission-line coupler is devised to achieve high-level coupling and minimize the chip size. The measured results show that the conversion gain varies between -13.9 dB and -17.5 dB from 110 GHz to 145 GHz, with a local oscillator (LO) power level of 14 dBm and an intermediate frequency (IF) of 1 GHz. The total chip size including probe GSG pads is 0.57 × 0.68mm2. In conclusion, the mixer exhibits outstanding figure-of-merits.

Extraction of indium from sulphate solutions with D2EHPA solutions using static mixers

International Nuclear Information System (INIS)

Nacevski, N.; Poposka, F.; Nikov, B.

1995-01-01

The possible use of static mixers as a reactor for the extraction of indium from sulphate solutions was investigated. The experimental work was focused on ''Kenics'' type static mixers, since these were found simplest and cheapest among a variety of models, and yet yielded acceptable preliminary results with low pressure drop along the reactor. A series of experiments was carried out in a stirred continuous flow reactor to compare the results. It was found that under certain (different) conditions both reactors perform satisfactorily. The energy consumption of a static mixer is of the same order of magnitude as that of a stirred vessel. The most significant achievement of the experimental work is establishing that the residence time in a static mixer is about two orders of magnitude less than that in a stirred reactor. (orig.)

Mixer pump test plan for double-shell tank AZ-101. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Symons, G.A.

1996-02-01

Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank waste. Mixer pumps were chosen as the planned method of retrieval for DSTs, based on engineering technology studies, past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site.

Mixer pump test plan for double-shell tank AZ-101. Revision 1

International Nuclear Information System (INIS)

Symons, G.A.

1996-02-01

Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank waste. Mixer pumps were chosen as the planned method of retrieval for DSTs, based on engineering technology studies, past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site

Self-assembly of silk fibroin under osmotic stress

Science.gov (United States)

Sohn, Sungkyun

The supramolecular self-assembly behavior of silk fibroin was investigated using osmotic stress technique. In Chapter 2, a ternary phase diagram of water-silk-LiBr was constructed based on X-ray results on the osmotically stressed regenerated silk fibroin of Bombyx mori silkworm. Microscopic data indicated that silk I is a hydrated structure and a rough estimate of the number of water molecules lost by the structure upon converting from silk I to silk II has been made, and found to be about 2.2 per [GAGAGS] hexapeptide. In Chapter 3, wet-spinning of osmotically stressed, regenerated silk fibroin was performed, based on the prediction that the enhanced control over structure and phase behavior using osmotic stress method helps improve the physical properties of wet-spun regenerated silk fibroin fibers. The osmotic stress was applied in order to pre-structure the regenerated silk fibroin molecule from its original random coil state to more oriented state, manipulating the phase of the silk solution in the phase diagram before the start of spinning. Monofilament fiber with a diameter of 20 microm was produced. In Chapter 4, we investigated if there is a noticeable synergistic osmotic pressure increase between co-existing polymeric osmolyte and salt when extremely highly concentrated salt molecules are present both at sample subphase and stressing subphase, as is the case of silk fibroin self-assembly. The equilibration method that measures osmotic pressure relative to a reference with known osmotic pressure was introduced. Osmotic pressure of aqueous LiBr solution up to 2.75M was measured and it was found that the synergistic effect was insignificant up to this salt concentration. Solution parameters of stressing solutions and Arrhenius kinetics based on time-temperature relationship for the equilibration process were derived as well. In Chapter 5, self-assembly behavior of natural silk fibroin within the gland of Bombyx mori silkworm was investigated using osmotic

A wideband current-commutating passive mixer for multi-standard receivers in a 0.18 μm CMOS

International Nuclear Information System (INIS)

Bao Kuan; Fan Xiangning; Li Wei; Wang Zhigong

2013-01-01

This paper reports a wideband passive mixer for direct conversion multi-standard receivers. A brief comparison between current-commutating passive mixers and active mixers is presented. The effect of source and load impedance on the linearity of a mixer is analyzed. Specially, the impact of the input impedance of the transimpedance amplifier (TIA), which acts as the load impedance of a mixer, is investigated in detail. The analysis is verified by a passive mixer implemented with 0.18 μm CMOS technology. The circuit is inductorless and can operate over a broad frequency range. On wafer measurements show that, with radio frequency (RF) ranges from 700 MHz to 2.3 GHz, the mixer achieves 21 dB of conversion voltage gain with a −1 dB intermediate frequency (IF) bandwidth of 10 MHz. The measured IIP3 is 9 dBm and the measured double-sideband noise figure (NF) is 10.6 dB at 10 MHz output. The chip occupies an area of 0.19 mm 2 and drains a current of 5.5 mA from a 1.8 V supply. (semiconductor integrated circuits)

Harnessing electro driven separation technique for the separation of selected agrochemicals

International Nuclear Information System (INIS)

Wan Aini Wan Ibrahim; Alam, S.M. Monjurul; Azli Sulaiman

2008-01-01

Electro driven separation techniques offer a different approach to the analysis of complex mixtures than do traditional pressure-driven chromatographic system; it may rely on electrophoresis, the transport of charged species through a medium by an applied field or may rely on electro driven mobile phase to provide a true chromatographic separation. In the current work the potential of an electro driven separation technique viz. Micellar electrokinetic chromatography (MEKC), is harnessed for the separation of selected agrochemicals (organophosphorus pesticides, OPPs) widely used in the agriculture sector in Malaysia. The current study compares the use of MEKC in normal mode (NM) and reverse mode (RM) for the separation of the selected OPPS. This study also highlights the difference in separations produced by performing separations in normal mode-MEKC (NM-MEKC) and reverse mode-MEKC (RM-MEKC) for the selected OPPs. In RM-MEKC, separation is conducted at acidic pH (pH 2.5 in the current work) where the electro osmotic flow (EOF) is weak whereas in NM-MEKC, the separation is carried out under basic pH (9.3 in this work) where the EOF is strong. A reverse migration order of the OPPs was observed under RM-MEKC. Separation under NM-MEKC was found to be superior to those of RM- MEKC. A comparison is also made between separations performed under sweeping-NM-MEKC and sweeping-RM-MEKC. In sweeping, the OPPs are prepared in the same background solution (BGS) minus the micelles and is adjusted to the same conductivity as the BGS. The study showed that NM-MEKC is more sensitive than RM-MEKC but sweeping-RM-MEKC is superior to sweeping-NM-MEKC. However, sweeping-RM-MEKC only separates two of the OPPs in a single run whereas sweeping-NM-MEKC separates four OPPs in a single run. The better choice of separation mode would be sweeping-NM- MEKC for more OPPs separation in a single run. (author)

Study on hydrodynamics and mass transfer of the critically safe multistage mixer-settler

International Nuclear Information System (INIS)

Zhang Weibo; Jiao Rongzhou; Liu Bingren

1992-08-01

The study on structure of critically safe multistage mixer-settler for the extraction process of high enriched uranium and plutonium has been completed. The mixer-settler has simple structure, good critical safety, flexibility in operation (O/A from 0.5 to 5) and high extraction efficiency (E x > 90%). These performances have been proved in the hydrodynamics and mass transfer experiments at a three stages cascade mixer-settler. Based on the others experience, a trapezoidal impeller combined with half-open turbine is developed which has stronger pumping and well mixing function at low rotating speed. The optimal rotating speed is 250 to 280 r/min obtained by experiments

Study on installation of the submersible mixer

International Nuclear Information System (INIS)

Tian, F; Shi, W D; He, X H; Xu, Y H; Jiang, H

2013-01-01

Study on installation of the submersible mixer for sewage treatment has been limited. In this article, large-scale computational fluid dynamics software FLUENT6.3 was adopted. ICEM software was used to build an unstructured grid of sewage treatment pool. After that, the sewage treatment pool was numerically simulated by dynamic coordinate system technology and RNG k-ε turbulent model and PIOS algorithm. Agitation pools on four different installation location cases were simulated respectively, and the external characteristic of the submersible mixer and the velocity cloud of the axial section were respectively comparatively analyzed. The best stirring effect can be reached by the installation location of case C, which is near the bottom of the pool 600 mm and blade distance the bottom at least for 200 mm wide and wide edge and narrow edge distance by 4:3. The conclusion can guide the engineering practice

Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

Science.gov (United States)

Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

1996-01-01

One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

Casein Micelle Dispersions under Osmotic Stress

Science.gov (United States)

Bouchoux, Antoine; Cayemitte, Pierre-Emerson; Jardin, Julien; Gésan-Guiziou, Geneviève; Cabane, Bernard

2009-01-01

Abstract Casein micelles dispersions have been concentrated and equilibrated at different osmotic pressures using equilibrium dialysis. This technique measured an equation of state of the dispersions over a wide range of pressures and concentrations and at different ionic strengths. Three regimes were found. i), A dilute regime in which the osmotic pressure is proportional to the casein concentration. In this regime, the casein micelles are well separated and rarely interact, whereas the osmotic pressure is dominated by the contribution from small residual peptides that are dissolved in the aqueous phase. ii), A transition range that starts when the casein micelles begin to interact through their κ-casein brushes and ends when the micelles are forced to get into contact with each other. At the end of this regime, the dispersions behave as coherent solids that do not fully redisperse when osmotic stress is released. iii), A concentrated regime in which compression removes water from within the micelles, and increases the fraction of micelles that are irreversibly linked to each other. In this regime the osmotic pressure profile is a power law of the residual free volume. It is well described by a simple model that considers the micelle to be made of dense regions separated by a continuous phase. The amount of water in the dense regions matches the usual hydration of proteins. PMID:19167314

A Passive X-Band Double Balanced Mixer Utilizing Diode Connected SiGe HBTs

DEFF Research Database (Denmark)

Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld

2013-01-01

In this paper, a passive double balanced mixer in SiGe HBT technology is presented. Due to lack of suitable passive mixing elements in the technology, the mixing elements are formed by diode connected HBTs. The mixer is optimized for use in doppler radars and is highly linear with 1 dB compressio...

Heat transfer and the continuous production of hydroxypropyl starch in a static mixer reactor

NARCIS (Netherlands)

Lammers, Gerard; Beenackers, Antonie A. C. M.

1994-01-01

A novel continuous reactor for the chemical derivation of aqueous starch solutions based on static mixers is proposed. Both the experimentally observed axial and radial temperature gradients in the static mixer could be accurately described by a pseudohomogeneous two-dimensional heat transfer (PTHT)

Electro photographic materials

International Nuclear Information System (INIS)

Buzdugan, A.; Andries, A.; Iovu, M.

2000-01-01

The invention relates to the creation of electro photographic materials . The invention allows to extend the material photosensitivity into the infrared range of the spectrum. An electro photographic materials contains an electro conducting base, including a dielectric base 1, for example glass, an electro conducting layer 2, for example of Al, Ni, Cr, an injecting layer 3, consisting of amorphous indium phosphide, a vitreous layer 4 of the arsenic sulphide - antimony sulphide system and a transporting layer 5 of the arsenic sulphide or arsenic selenide

A general numerical analysis program for the superconducting quasiparticle mixer

Science.gov (United States)

Hicks, R. G.; Feldman, M. J.; Kerr, A. R.

1986-01-01

A user-oriented computer program SISCAP (SIS Computer Analysis Program) for analyzing SIS mixers is described. The program allows arbitrary impedance terminations to be specified at all LO harmonics and sideband frequencies. It is therefore able to treat a much more general class of SIS mixers than the widely used three-frequency analysis, for which the harmonics are assumed to be short-circuited. An additional program, GETCHI, provides the necessary input data to program SISCAP. The SISCAP program performs a nonlinear analysis to determine the SIS junction voltage waveform produced by the local oscillator. The quantum theory of mixing is used in its most general form, treating the large signal properties of the mixer in the time domain. A small signal linear analysis is then used to find the conversion loss and port impedances. The noise analysis includes thermal noise from the termination resistances and shot noise from the periodic LO current. Quantum noise is not considered. Many aspects of the program have been adequately verified and found accurate.

Russian Pulsating Mixer Pump Deployment in the Gunite and Associated Tanks at ORNL

International Nuclear Information System (INIS)

Hatchell, Brian K.; Lewis, Ben; Johnson, Marshall A.; Randolph, J. G.

2001-01-01

In FY 1998, Pulsating Mixer Pump (PMP) technology, consisting of a jet mixer powered by a reciprocating air supply, was selected for deployment in one of the Gunite and Associated Tanks at Oak Ridge National Laboratory (ORNL) to mobilize settled solids. The pulsating mixer pump technology was identified during FY 1996 and FY 1997 technical exchanges between the U.S. Department of Energy (DOE) Tanks Focus Area Retrieval and Closure program, the DOE Environmental Management International Programs, and delegates from Russia as a promising technology that could be implemented in the DOE complex. During FY 1997, the pulsating mixer pump technology, provided by the Russian Integrated Mining Chemical Company, was tested at Pacific Northwest National Laboratory (PNNL) to observe its ability to suspend settled solids. Based on the results of this demonstration, ORNL and DOE staff determined that a modified pulsating mixer pump would meet project needs for remote sludge mobilization of Gunite tank sludge and reduce the cost of operation and maintenance of more expensive mixing systems. The functions and requirements of the system were developed by combining the results and recommendations from the pulsating mixer pump demonstration at PNNL with the requirements identified by staff at ORNL involved with the remediation of the Gunite and Associated Tanks. The PMP is comprised of a pump chamber, check valve, a working gas supply pipe, a discharge manifold, and four jet nozzles. The pump uses two distinct cycles, fill and discharge, to perform its mixing action. During the fill cycle, vacuum is applied to the pump chamber by an eductor, which draws liquid into the pump. When the liquid level inside the chamber reaches a certain level, the chamber is pressurized with compressed air to discharge the liquid through the jet nozzles and back into the tank to mobilize sludge and settled solids.

Osmotic dehydration of fruits and vegetables: a review.

Science.gov (United States)

Yadav, Ashok Kumar; Singh, Satya Vir

2014-09-01

The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effects of osmotic dehydration have been reviewed. Studied showed that combination of different osmotic agents were more effective than sucrose alone due to combination of properties of solutes. During the experiments it was found that optimum osmosis was found at approximately 40 °C, 40 °B of osmotic agent and in near about 132 min. Pretreatments also leads to increase the osmotic process in fruits and vegetables. Mass transfer kinetics study is an important parameter to study osmosis. Solids diffusivity were found in wide range (5.09-32.77 kl/mol) studied by Fick's laws of diffusion. These values vary depending upon types of fruits and vegetables and osmotic agents.

A Wideband Balun LNA I/Q-Mixer combination in 65nm CMOS

NARCIS (Netherlands)

Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

2008-01-01

An inductor-less LNA-mixer topology merges an I/Q current-commutating mixer with a noise-canceling balun/LNA. The topology achieves >18dB conversion gain, a flat NF<5.5dB, IIP2=+20dBm and IIP3=-3dBm from 500MHz to 7GHz. The core circuit consumes 16mW and occupies less than 0.01mm2 in 65nm CMOS.

The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

KAUST Repository

Wang, Zhenyu; Xiong, Liming; Li, Wenbo; Zhu, Jian-Kang; Zhu, Jianhua

2011-01-01

Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA

Flow optimisation of a biomass mixer; Stroemungstechnische Optimierung eines Biomasse-Ruehrwerks

Energy Technology Data Exchange (ETDEWEB)

Casartelli, E.; Waser, R. [Hochschule fuer Technik und Architektur Luzern (HTA), Horw (Switzerland); Fankhauser, H. [Fankhauser Maschinenfabrik, Malters (Switzerland)

2007-03-15

This illustrated final report for the Swiss Federal Office of Energy (SFOE) reports on the optimisation of a mixing system used in biomass reactors. Aim of this work was to improve the fluid dynamic qualities of the mixer in order to increase its efficiency while, at the same time, maintaining robustness and low price. Investigative work performed with CFD (Computational Fluid Dynamics) is reported on. CFD is quoted by the authors as being very effective in solving such optimisation problems as it is suited to flows that are not easily accessible for analysis. Experiments were performed on a fermenter / mixer model in order to confirm the computational findings. The results obtained with two and three-dimensional simulations are presented and discussed, as are those resulting from the tests with the 1:10 scale model of a digester. Initial tests with the newly developed mixer-propellers in a real-life biogas installation are reported on and further tests to be made are listed.

An ultra-broadband distributed passive gate-pumped mixer in 0.18 μm CMOS

International Nuclear Information System (INIS)

Yu Zhenxing; Feng Jun

2013-01-01

A broadband distributed passive gate-pumped mixer (DPGM) using standard 0.18 μm CMOS technology is presented. By employing distributed topology, the mixer can operate at a wide frequency range. In addition, a fourth-order low pass filter is applied to improve the port-to-port isolation. This paper also analyzes the impedance match and conversion loss of the mixer, which consumes zero dc power and exhibits a measured conversion loss of 9.4–17 dB from 3 to 40 GHz with a compact size of 0.78 mm 2 . The input referred 1 dB compression point is higher than 4 dBm at a fixed IF frequency of 500 MHz and RF frequency of 23 GHz, and the measured RF-to-LO, RF-to-IF and LO-to-IF isolations are better than 21, 38 and 45 dB, respectively. The mixer is suitable for WLAN, UWB, Wi-Max, automotive radar systems and other millimeter-wave radio applications. (semiconductor integrated circuits)

Sideband Separating Mixer for 600-720 GHz

NARCIS (Netherlands)

Khudchenko, Andrey; Hesper, Ronald; Barychev, Andrey; Gerlofma, Gerrit; Mena, Patricio; Zijlstra, Tony; Klapwijk, Teun; Spaans, Marco; Kooi, Jacob W.; Zhang, C; Zhang, XC; Siegel, PH; He, L; Shi, SC

2010-01-01

The ALMA Band 9 receiver cartridge (600-720 GHz) based on Dual Sideband (DSB) superconductor-insulator-superconductor (SIS) mixer is currently in full production. In the case of spectral line observations, the integration time to reach a certain signal-to-noise level can be reduced by about a factor

Criticality calculation method for mixer-settlers

International Nuclear Information System (INIS)

Gonda, Kozo; Aoyagi, Haruki; Nakano, Ko; Kamikawa, Hiroshi.

1980-01-01

A new criticality calculation code MACPEX has been developed to evaluate and manage the criticality of the process in the extractor of mixer-settler type. MACPEX can perform the combined calculation with the PUREX process calculation code MIXSET, to get the neutron flux and the effective multiplication constant in the mixer-settlers. MACPEX solves one-dimensional diffusion equation by the explicit difference method and the standard source-iteration technique. The characteristics of MACPEX are as follows. 1) Group constants of 4 energy groups for the 239 Pu-H 2 O solution, water, polyethylene and SUS 28 are provided. 2) The group constants of the 239 Pu-H 2 O solution are given by the functional formulae of the plutonium concentration, which is less than 50 g/l. 3) Two boundary conditions of the vacuum condition and the reflective condition are available in this code. 4) The geometrical bucklings can be calculated for a certain energy group and/or region by using the three dimentional neutron flux profiles obtained by CITATION. 5) The buckling correction search can be carried out in order to get a desired k sub(eff). (author)

An X-band Schottky diode mixer in SiGe technology with tunable Marchand balun

DEFF Research Database (Denmark)

Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld M.

2017-01-01

In this paper, we propose a double balanced mixer with a tunable Marchand balun. The circuit is designed in a SiGe BiCMOS process using Schottky diodes. The tunability of the Marchand balun is used to enhance critical parameters for double balanced mixers. The local oscillator-IF isolation can...

Application of electro-osmosis to radioactive waste processing

International Nuclear Information System (INIS)

Turner, A.D.

1989-01-01

Electro-osmotic dewatering (EOD) is a remotely controllable process for the final stage of slurry concentration after gravity settling or filtration prior to immobilization in cement. It operates by using an electric field instead of pressure as the driving force across a microporous non-conducting membrane - partitioning the solid and liquid components by charge separation. The high solids retention factor (> 99.99%) yields decontamination factors > 1000. Dewatering of a wide range of suspensions can be accomplished at a variety of membranes - including fabrics (eg cotton) for LLW, and ceramics or glass for MLW. Volume reduction factors of 10 can be achieved for low conductivity streams. Planar and tubular membrane designs have been considered for compact full-scale plants. Cost-benefit analyses indicate that, in common with other techniques, large savings on immobilization and disposal costs (> 87%) can be made by this further dewatering stage after gravity settling prior to cementing. Estimates for EOD of capital and running costs amount to 2% and 1.3% respectively of the savings made over 10 years, with electrical power contributing only 0.15%. (author)

Submillisecond mixing in a continuous-flow, microfluidic mixer utilizing mid-infrared hyperspectral imaging detection.

Science.gov (United States)

Kise, Drew P; Magana, Donny; Reddish, Michael J; Dyer, R Brian

2014-02-07

We report a continuous-flow, microfluidic mixer utilizing mid-infrared hyperspectral imaging detection, with an experimentally determined, submillisecond mixing time. The simple and robust mixer design has the microfluidic channels cut through a polymer spacer that is sandwiched between two IR transparent windows. The mixer hydrodynamically focuses the sample stream with two side flow channels, squeezing it into a thin jet and initiating mixing through diffusion and advection. The detection system generates a mid-infrared hyperspectral absorbance image of the microfluidic sample stream. Calibration of the hyperspectral image yields the mid-IR absorbance spectrum of the sample versus time. A mixing time of 269 μs was measured for a pD jump from 3.2 to above 4.5 in a D2O sample solution of adenosine monophosphate (AMP), which acts as an infrared pD indicator. The mixer was further characterized by comparing experimental results with a simulation of the mixing of an H2O sample stream with a D2O sheath flow, showing good agreement between the two. The IR microfluidic mixer eliminates the need for fluorescence labeling of proteins with bulky, interfering dyes, because it uses the intrinsic IR absorbance of the molecules of interest, and the structural specificity of IR spectroscopy to follow specific chemical changes such as the protonation state of AMP.

Numerical and Experimental Study on Mixing Performances of Simple and Vortex Micro T-Mixers

Directory of Open Access Journals (Sweden)

Mubashshir Ahmad Ansari

2018-04-01

Full Text Available Vortex flow increases the interface area of fluid streams by stretching along with providing continuous stirring action to the fluids in micromixers. In this study, experimental and numerical analyses on a design of micromixer that creates vortex flow were carried out, and the mixing performance was compared with a simple micro T-mixer. In the vortex micro T-mixer, the height of the inlet channels is half of the height of the main mixing channel. The inlet channel connects to the main mixing channel (micromixer at the one end at an offset position in a fashion that creates vortex flow. In the simple micro T-mixer, the height of the inlet channels is equal to the height of the channel after connection (main mixing channel. Mixing of fluids and flow field have been analyzed for Reynolds numbers in a range from 1–80. The study has been further extended to planar serpentine microchannels, which were combined with a simple and a vortex T-junction, to evaluate and verify their mixing performances. The mixing performance of the vortex T-mixer is higher than the simple T-mixer and significantly increases with the Reynolds number. The design is promising for efficiently increasing mixing simply at the T-junction and can be applied to all micromixers.

Influence of gas inlet angle on the mixing process in a Venturi mixer

Directory of Open Access Journals (Sweden)

Romańczyk Mathias

2017-01-01

Full Text Available In this paper numerical analysis were performed to investigate the influence of gas inlet angle on mixing process in a Venturi mixer. Performance of an industrial gas engine depends significantly on the quality of mixing air and fuel; therefore, on the homogeneity of the mixture. In addition, there must be a suitable, adapted to the current load of fuel, air ratio. Responsible for this fact, among others, is the mixer located before entering the combustion chamber of the engine. Incorrect mixture proportion can lead to unstable operation of the engine, as well as higher emissions going beyond current environmental standards in the European Union. To validate the simulation the Air-Fuel Ratio (AFR was mathematically calculated for the air-fuel mixture of lean combustion gas engine. In this study, an open source three-dimensional computational fluid dynamics (CFD modelling software OpenFOAM has been used, to investigate and analyse the influence of different gas inlet angles on mixer characteristics and their performances. Attention was focused on the air-fuel ratio changes, pressure loss, as well as improvement of the mixing quality in the Venturi mixer.

Packaging design criteria, transfer and disposal of 102-AP mixer pump

International Nuclear Information System (INIS)

Carlstrom, R.F.

1994-01-01

A mixer pump installed in storage tank 241-AP-102 (102-AP) has failed. This pump is referred to as the 102-AP mixer pump (APMP). The APMP will be removed from 102-AP 1 and a new pump will be installed. The main purpose of the Packaging Design Criteria (PDC) is to establish criteria necessary to design and fabricate a shipping container for the transfer and storage of the APMP from 102-AP. The PDC will be used as a guide to develop a Safety Evaluation for Packaging (SEP)

26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

Science.gov (United States)

2010-04-01

... stock refunds or credits on cement mixers. 48.4061-1 Section 48.4061-1 Internal Revenue INTERNAL REVENUE... § 48.4061-1 Temporary regulations with respect to floor stock refunds or credits on cement mixers. (a... of tax on motor vehicles) on the sale of a cement mixer after June 30, 1968, and before January 1...

Noise and conversion performance of a high-Tc superconducting Josephson junction mixer at 0.6 THz

Science.gov (United States)

Gao, Xiang; Du, Jia; Zhang, Ting; Guo, Yingjie Jay

2017-11-01

This letter presents both theoretical and experimental investigations on the noise and conversion performance of a high-Tc superconducting (HTS) step-edge Josephson-junction mixer at the frequency of 0.6 THz and operating temperatures of 20-40 K. Based on the Y-factor and U-factor methods, a double-sideband noise temperature of around 1000 K and a conversion gain of -3.5 dB were experimentally obtained at 20 K. At the temperature of 40 K, the measured mixer noise and conversion efficiency are around 2100 K and -10 dB, respectively. The experimental data are in good agreement with the numerical analysis results using the three-port model. A detailed performance comparison with other reported HTS terahertz mixers has confirmed the superior performance of our presented mixer device.

Flux intensification during microfiltration of distillery stillage using a kenics static mixer

Directory of Open Access Journals (Sweden)

Vasić Vesna M.

2017-01-01

Full Text Available The present work studies the effect of operating parameters (pH, feed flow rate, and transmembrane pressure on microfiltration of distillery stillage. Experiments were conducted in the presence of a Kenics static mixer as a turbulence promoter, and its influence on the flux improvement and specific energy consumption was examined. Response surface methodology was used to investigate the effect of selected factors on microfiltration performances. The results showed that response surface methodology is an appropriate model for mathematical presentation of the process. It was found that the use of a static mixer is justified at the feed flow rates higher than 100 L/h. In contrast, the use of a static mixer at low values of feed flow rate and transmembrane pressure has no justification from an economic point of view. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31002

Drug residues recovered in feed after various feedlot mixer truck cleanout procedures.

Science.gov (United States)

Van Donkersgoed, Joyce; Sit, Dan; Gibbons, Nicole; Ramogida, Caterina; Hendrick, Steve

2010-01-01

A study was conducted to determine the effectiveness of two methods of equipment cleanout, sequencing or flushing, for reducing drug carryover in feedlot mixer trucks. Feed samples were collected from total mixed rations before and after various feed mixer equipment cleanout procedures. Medicated rations contained either 11 ppm of tylosin or 166 or 331 ppm of chlortetracycline. There were no differences between sequencing and flushing or between flushing with dry barley and flushing with barley silage in the median proportion of drug recovered in the next ration. A larger drug reduction was achieved using flush material at a volume of 10 versus 5% of the mixer capacity and mixing the flush material for 3 versus 4 min. Regardless of the drug or prescription concentrations in the total mixed rations or the equipment cleanout procedure used, concentrations of chlortetracycline and tylosin recovered were very low.

21 CFR 864.6600 - Osmotic fragility test.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Osmotic fragility test. 864.6600 Section 864.6600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6600 Osmotic fragility...

Osmotic effects of polyethylene glycol.

Science.gov (United States)

Schiller, L R; Emmett, M; Santa Ana, C A; Fordtran, J S

1988-04-01

Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution.

High-k Scattering Receiver Mixer Performance for NSTX-U

Science.gov (United States)

Barchfeld, Robert; Riemenschneider, Paul; Domier, Calvin; Luhmann, Neville; Ren, Yang; Kaita, Robert

2016-10-01

The High-k Scattering system detects primarily electron-scale turbulence k θ spectra for studying electron thermal transport in NSTX-U. A 100 mW, 693 GHz probe beam passes through plasma, and scattered power is detected by a 4-pixel quasi optical, mixer array. Remotely controlled receiving optics allows the scattering volume to be located from core to edge with a k θ span of 7 to 40 cm-1. The receiver array features 4 RF diagonal input horns, where the electric field polarization is aligned along the diagonal of a square cross section horn, at 30 mm channel spacing. The local oscillator is provided by a 14.4 GHz source followed by a x48 multiplier chain, giving an intermediate frequency of 1 GHz. The receiver optics receive 4 discreet scattering angles simultaneously, and then focus the signals as 4 parallel signals to their respective horns. A combination of a steerable probe beam, and translating receiver, allows for upward or downward scattering which together can provide information about 2D turbulence wavenumber spectrum. IF signals are digitized and stored for later computer analysis. The performance of the receiver mixers is discussed, along with optical design features to enhance the tuning and performance of the mixers. Work supported in part by U.S. DOE Grant DE-FG02-99ER54518 and DE-AC02-09CH1146.

Osmotic homeostasis and NKLy lymphoma cells radiosensitivity

International Nuclear Information System (INIS)

Tishchenko, V.V.; Magda, I.N.

1992-01-01

In experiments with cells of ascites NKLy lymphoma differing in ploidy and position in the cell cycle, a study was made of the radiosensitivity, osmotic homeostasis peculiarities and thermoradiation changes in potassium content. It was shown that the resistance of osmotic homeostasis of NKLy cells to thermoradiation correlated with their radioresistance

Electro-Deposition Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

Fuel Continuous Mixer ? an Approach Solution to Use Straight Vegetable Oil for Marine Diesel Engines

Directory of Open Access Journals (Sweden)

Đặng Van Uy

2018-03-01

Full Text Available The vegetable oil is well known as green fuel for diesel engines due to its low sunphur content and renewable stock. However, there are some problems raising when vegetable oil is used as fuel for diesel engines such as highly effected by cold weather, lower general efficiency, separation in layer if mixed with diesel oil and so on. To overcome that disadvantiges, the authors propose a new idea that to use a continuous fuel mixer to blend vegetable oil with diesel oil to make so called a mixed fuel supplying to diesel engines inline. In order to ensure a quality of the mixed fuel created by continuous mixer, a homogeneous testing was introduced with believable results. Then, the continuous mixer has been installed into fuel supply system of diesel engine 6LU32 at a lab of Vietnam Maritime University in terms of checking a real operation of the fuel continuous mixer with diesel engine.

Salt Effect on Osmotic Pressure of Polyelectrolyte Solutions: Simulation Study

Directory of Open Access Journals (Sweden)

Jan-Michael Y. Carrillo

2014-07-01

Full Text Available Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations, we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs, we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution. This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have shown that the main contribution to the system osmotic pressure is due to salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive counterions first increases with decreases in the solution ionic strength then it saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.

A high conversion-gain Q-band InP DHBT subharmonic mixer using LO frequency doubler

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

2008-01-01

The paper presents analysis and design of a Q-band subharmonic mixer (SHM) with high conversion gain. The SHM consists of a local oscillator (LO) frequency doubler, RF pre-amplifier, and single-ended mixer. The SHM has been fabricated in a high-speed InP double heterojunction bipolar transistor (...

Hydrodynamic study of the rotating cylinder mixer of a laboratory centrifugal extractor

International Nuclear Information System (INIS)

Philipponeau, Yannick.

1979-08-01

As part of a research programme on solvent extraction kinetics the Fontenay-aux-Roses Nuclear Research Centre has undertaken to build a new centrifugal extractor prototype. The work was centred on a hydrodynamic study of the rotating cylinder mixer of the extractor, using a test apparatus specially designed for this purpose. This apparatus was used to determine the flow conditions of a liquid alone in the annular space of the mixer as a function of the working specifications. The existence of several types of flow was established. The stability region of which was determined as a function of different parameters for a number of liquid-liquid systems. The experiments showed in addition that two kinds of dispersion can be obtained, differing by the nature of the continuous phase. This was determined for various parameters of certain liquid-liquid systems. From this research the hydrodynamic behavior of the CEA centrifugal extractor prototype mixer is thus known [fr

Increased Resistance to osmotic lysis of sickled erythrocytes ...

African Journals Online (AJOL)

treated with CNw had significantly reduced osmotic lysis when compared with the untreated set (P<0.05, respectively) at various hypotonic NaCl concentrations. Various Hb genotypes exhibited a graded increase in osmotic pressure lysis in ...

High linearity current communicating passive mixer employing a simple resistor bias

International Nuclear Information System (INIS)

Liu Rongjiang; Guo Guiliang; Yan Yuepeng

2013-01-01

A high linearity current communicating passive mixer including the mixing cell and transimpedance amplifier (TIA) is introduced. It employs the resistor in the TIA to reduce the source voltage and the gate voltage of the mixing cell. The optimum linearity and the maximum symmetric switching operation are obtained at the same time. The mixer is implemented in a 0.25 μm CMOS process. The test shows that it achieves an input third-order intercept point of 13.32 dBm, conversion gain of 5.52 dB, and a single sideband noise figure of 20 dB. (semiconductor integrated circuits)

Structure and osmotic pressure of ionic microgel dispersions

Energy Technology Data Exchange (ETDEWEB)

Hedrick, Mary M. [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Chung, Jun Kyung; Denton, Alan R., E-mail: alan.denton@ndsu.edu [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States)

2015-01-21

We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions.

Structure and osmotic pressure of ionic microgel dispersions

International Nuclear Information System (INIS)

Hedrick, Mary M.; Chung, Jun Kyung; Denton, Alan R.

2015-01-01

We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions

Species transport mechanisms governing capacity loss in vanadium flow batteries: Comparing Nafion® and sulfonated Radel membranes

International Nuclear Information System (INIS)

Agar, Ertan; Knehr, K.W.; Chen, D.; Hickner, M.A.; Kumbur, E.C.

2013-01-01

Highlights: • Species transport mechanisms are investigated in Nafion ® and s-Radel for VRFBs. • Unlike diffusion in Nafion ® , crossover in s-Radel is dominated by convection. • In particular, electro-osmotic convection is the dominant mode in s-Radel. • Change in direction of convection causes a lower crossover in s-Radel. • Hydraulic and electrokinetic permeability are as important as vanadium permeability. -- Abstract: In this study, a 2-D, transient vanadium redox flow battery (VRFB) model was used to investigate and compare the ion transport mechanisms responsible for vanadium crossover in Nafion ® 117 and sulfonated Radel (s-Radel) membranes. Specifically, the model was used to distinguish the relative contribution of diffusion, migration, osmotic and electro-osmotic convection to the net vanadium crossover in Nafion ® and s-Radel. Model simulations indicate that diffusion is the dominant mode of vanadium transport in Nafion ® , whereas convection dominates the vanadium transport through s-Radel due to the lower vanadium permeability, and thus diffusivity of s-Radel. Among the convective transport modes, electro-osmotic convection (i.e., electro-osmotic drag) is found to govern the species crossover in s-Radel due to its higher fixed acid concentration and corresponding free ions in the membrane. Simulations also show that vanadium crossover in s-Radel changes direction during charge and discharge due to the change in the direction of electro-osmotic convection. This reversal in the direction of crossover during charge and discharge is found to result in significantly lower “net” crossover for s-Radel when compared to Nafion ® . Comparison of these two membranes also provides guidance for minimizing crossover in VRFB systems and underscores the importance of measuring the hydraulic and the electro-kinetic permeability of a membrane in addition to vanadium diffusion characteristics, when evaluating new membranes for VRFB applications

Complete Procedure for Fabrication of a Fused Silica Ultrarapid Microfluidic Mixer Used in Biophysical Measurements

Directory of Open Access Journals (Sweden)

Dena Izadi

2017-01-01

Full Text Available In this paper we present a method to fabricate a fused silica microfluidic device by employing low viscosity KMPR photoresists. The resulting device is a continuous-flow microfluidic mixer based on hydrodynamic focusing. The advantages of this new fabrication method compared to the traditional approach using a poly-silicon mask are simplification, and time and cost reduction, while still preserving the quality and the performance of the mixers. This process results in devices in which the focusing channel has an aspect ratio of 10:1. The newly-fabricated mixer is successfully used to observe the folding of the Pin1 WW domain at the microsecond time scale.

Mechanism of actuation in conducting polymers: Osmotic expansion

DEFF Research Database (Denmark)

Bay, Lasse; Jacobsen, Torben; West, Keld

2001-01-01

Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...

Drying and osmotic conditioning in Hancornia speciosa Gomes seeds

Directory of Open Access Journals (Sweden)

Tathiana Elisa Masetto

Full Text Available Hancornia speciosa is a native tree species of the Brazilian Cerrado whose seeds are desiccation sensitive. In this study, we aimed to evaluate drying and osmotic conditioning in H. speciosa seeds. We used fresh seeds with 48% moisture content, which were slowly dried until they attained contents of 20%, 15%, 10% and 5%. To evaluate osmotic conditioning, the seeds were imbibed in 12 mL osmotic solutions at 0.0; -0.2; -0.4 and -0.6 MPa for two days. After that, they were dehydrated until their original moisture content. The experiments were carried out in a completely randomized design with four repetitions with 50 seeds each. Reduction in moisture content from 20% to 5% decreased the physiological potential of seeds. H. speciosa seeds do not require osmotic priming with PEG solutions, because imbibition of seeds in osmotic solutions of up to -0.6 MPa results in reduction of germination rate and seedling length.

Design of the ME-I powder mixer. Report of the design and construction of the powder mixer, according to the safety requisites of the pellets fabrication process

International Nuclear Information System (INIS)

Mariano H, E.

1991-03-01

In order to fulfill the requirements of preparation of powder of UO 2 ; according to procedure P-M-PP-01, rev. 0, for the process of production of pellets, it was designed and manufactured a powders mixer to incorporate the lubricant one (zinc stearate) to the powder of UO 2 . This equipment allows to mix the powder of UO 2 evenly with the one zinc stearate, without forming considerable quantities of fine of UO 2 , besides a sure control for the operators of the process and an easy access to the mixer to inspect the mixture. (Author)

Work plan for vibration cable re-route and water flush system modifications for 107-AN mixer pump

International Nuclear Information System (INIS)

Leshikar, G.A.

1995-01-01

A mixer pump (75 horsepower Hazleton submersible) is to be installed in the central pump pit of Double-Shell Tank 241-AN-107 for the Caustic Addition Project. The mixer pump will be used as a platform to inject, mix, and entrain caustic with the waste, in order to bring the waste hydroxyl ion concentration into compliance with Tank Farm operating specifications. Testing of the mixer pump and caustic addition system revealed that the mixer pump's vibration cable picks up electromagnetic interference from the motor power cable during variable speed operation of the pump. Also, it was noted that the mixer pump's water flush system may not be as effective as desired. Ergo this work plan for improving the operation of these mixer pump subsystems. A new vibration cable shall be routed entirely outside the mixer pump support column pipe, up thru a new penetration in the pump mounting flange. The existing penetration in the side of the pipe is to be plugged. Increasing the distance between power and instrument cables may reduce or eliminate electromagnetic interference to the vibration monitor. The mixer pump water flush system shall be modified to allow pressure isolation of individual branches. A header is to be installed on the middle section of the support column. Each branch (there are three) shall contain a solenoid valve (normally open) to control flow into the branch. The solenoid cables shall be routed up thru three new penetrations in the pump mounting flange to a new electrical box mounted on the flange. The existing flush piping to the inlet screen will remain but the continuation of the flush piping to the pump discharge nozzles is to be removed and the tee plugged. New stainless steel tubing is to be run down to the pump discharge nozzles. Pressure isolation of individual branches will maximize the flush system's effectiveness at blasting potential sediment clogs out of the pump discharge nozzles

Enhanced monoclonal antibody production by gradual increase of osmotic pressure

OpenAIRE

Lin, Jianqiang; Takagi, Mutsumi; Qu, Yinbo; Gao, Peiji; Yoshida, Toshiomi

1999-01-01

The time length required for the adaptation of AFP-27 hybridoma cells to high osmotic pressure and the effect of a gradual increase of osmotic pressure on monoclonal antibody production were investigated. When the cells were subjected to an increase of osmotic pressure from 300 mOsmol kg-1 to 366 mOsmol kg- 1, the intracellular content of osmoprotective free amino acids reached a maximum level 6 h after the osmotic pressure was increased to 366 mOsmol kg-1. The same time period of 6 h incubat...

Proposal for electro-optic multiplier based on dual transverse electro-optic Kerr effect.

Science.gov (United States)

Li, Changsheng

2008-10-20

A novel electro-optic multiplier is proposed, which can perform voltage multiplication operation by use of the Kerr medium exhibiting dual transverse electro-optic Kerr effect. In this kind of Kerr medium, electro-optic phase retardation is proportional to the square of its applied electric field, and orientations of the field-induced birefringent axes are only related to the direction of the field. Based on this effect, we can design an electro-optic multiplier by selecting the crystals of 6/mmm, 432, and m3m classes and isotropic Kerr media such as glass. Simple calculation demonstrates that a kind of glass-ceramic material with a large Kerr constant can be used for the design of the proposed electro-optic multiplier.

Plant response to sunflower seeds to osmotic conditioning

Directory of Open Access Journals (Sweden)

Camila Santos Barros de Morais

2014-10-01

Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.

AZ-101 Mixer Pump Demonstration and Tests Data Management Analysis Plan

Energy Technology Data Exchange (ETDEWEB)

DOUGLAS, D.G.

2000-02-22

This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

AZ-101 Mixer Pump Demonstration and Tests: Data Management (Analysis) Plan

International Nuclear Information System (INIS)

DOUGLAS, D.G.

2000-01-01

This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

Robust Control Mixer Method for Reconfigurable Control Design Using Model Matching Strategy

DEFF Research Database (Denmark)

Yang, Zhenyu; Blanke, Mogens; Verhagen, Michel

2007-01-01

A novel control mixer method for recon¯gurable control designs is developed. The proposed method extends the matrix-form of the conventional control mixer concept into a LTI dynamic system-form. The H_inf control technique is employed for these dynamic module designs after an augmented control...... system is constructed through a model-matching strategy. The stability, performance and robustness of the reconfigured system can be guaranteed when some conditions are satisfied. To illustrate the effectiveness of the proposed method, a robot system subjected to failures is used to demonstrate...

Low-Noise Wide Bandwith, Hot Electron Bolometer Mixers for Submillimeter Wavelengths

Science.gov (United States)

McGrath, W. R.

1995-01-01

Recently a novel superconductive hot-electron micro-bolometer has been proposed which is both fast and sensitive (D. E. Prober, Appl. Phys. Lett. 62, 2119, 1993). This device has several important properties which make it useful as a heterodyne sensor for radioastronomy applications at frequencies above 1 THz. The thermal response time of the device is fast enough, several 10's of picoseconds, to allow for IF's of several GHz. This bolometer mixer should operate well up to at least 10 THz. There is no energy gap limitation as in an SIS mixer, since the mixing process relies on heating of the electron gas. In fact, rf power is absorbed more uniformly above the gap frequency. The mixer noise should be near quantum-limited, and the local oscillator (LO) power requirement is very low: / 10 nW for a Nb device. One of the unique features of this device is that it employs rapid electron diffusion into a normal metal, rather than phonon emission, as the thermal conductance that cools the heated electrons. In order for diffusion to dominate over phonon emission, the device must be short, less than 0.5.

Development of a multi-channel horn mixer array for microwave imaging plasma diagnostics

International Nuclear Information System (INIS)

Ito, Naoki; Kuwahara, Daisuke; Nagayama, Yoshio

2015-01-01

Microwave to millimeter-wave diagnostics techniques, such as interferometry, reflectometry, scattering, and radiometry, have been powerful tools for diagnosing magnetically confined plasmas. The resultant measurements have clarified several physics issues, including instability, wave phenomena, and fluctuation-induced transport. Electron cyclotron emission imaging has been an important tool in the investigation of temperature fluctuations, while reflectometry has been employed to measure plasma density profiles and their fluctuations. We have developed a horn-antenna mixer array (HMA), a 50 - 110 GHz 1D antenna array, which can be easily stacked as a 2D array. This article describes an upgrade to the horn mixer array that combines well-characterized mixers, waveguide-to-microstrip line transitions, intermediate frequency amplifiers, and internal local oscillator modules using a monolithic microwave integrated circuit technology to improve system performance. We also report on the use of a multi-channel HMA system. (author)

Improved Erythrocyte Osmotic Fragility and Packed Cell Volume ...

African Journals Online (AJOL)

Improved Erythrocyte Osmotic Fragility and Packed Cell Volume following administration of Aloe barbadensis Juice Extract in Rats. ... Abstract. Aloe barbadensis is a popular house plant that has a long history of a multipurpose folk remedy. ... Keywords: osmotic fragility, packed cell volume, haemoglobin, Aloe vera ...

The Robust Control Mixer Method for Reconfigurable Control Design By Using Model Matching Strategy

DEFF Research Database (Denmark)

Yang, Z.; Blanke, Mogens; Verhagen, M.

2001-01-01

This paper proposes a robust reconfigurable control synthesis method based on the combination of the control mixer method and robust H1 con- trol techniques through the model-matching strategy. The control mixer modules are extended from the conventional matrix-form into the LTI sys- tem form....... By regarding the nominal control system as the desired model, an augmented control system is constructed through the model-matching formulation, such that the current robust control techniques can be usedto synthesize these dynamical modules. One extension of this method with respect to the performance...... recovery besides the functionality recovery is also discussed under this framework. Comparing with the conventional control mixer method, the proposed method considers the recon gured system's stability, performance and robustness simultaneously. Finally, the proposed method is illustrated by a case study...

Feasibility Study on Using Two Mixer Pumps for Tank 241-AY-102 Waste Mixing

International Nuclear Information System (INIS)

Onishi, Yasuo; Wells, Beric E.

2004-01-01

The current waste retrieval plan at Hanford calls for using two mixer pumps to mix the waste stored in double-shell Tank 214-AY-102. The objective of this evaluation was to determine whether two rotating 300-hp mixer pumps placed 22 ft (6.7 m) off-center in the tank could adequately mix the AY-102 waste. The tank currently contains high-level waste that is 248 inches (6.3 m) deep, comprising 62 inches (1.58 m) of sludge and 186 inches (4.72 m) of supernatant liquid (Galbraith and others 2002). Based on the available data, AY-102 waste properties were determined, including the densities of liquid and agglomerated settled solids and crystals, the volume fraction of settled solids, the solid particle size distribution, the liquid and slurry viscosities, and the yield stress in shear (shear strength) of the settled solids layer. To evaluate the likely and bounding cases of AY-102 waste mixing, sludge erosion modeling was performed with a median value of 1,090 Pa (likely condition) and a conservative (more difficult to erode) 97.5 percentile value of 2,230 Pa for shear strength. According to model predictions, the two rotating mixer pumps would erode 89% of the sludge with shear strength of 1,090 Pa. They would erode sludge up to 41 ft (12.5 m) away from the mixer pumps but would not mobilize the bottom 2.5 inches (0.06-m) of sludge or sludge in the areas next to the tank wall, more than 26 ft (7.9 m) away. Once the sludge is mobilized, the solids were predicted to be uniformly suspended within the tank within a 1-vol% concentration variation except those in few inches at the bottom. With shear strength of 2,230 Pa, the two pumps would erode 85% of the sludge, slightly less than the 1,090-Pa shear strength case. In this case, the pump jets would mobilize the sludge up to 38 ft (11.6 m), except the bottom 2.5 inches of sludge. The mixer pumps would also leave the sludge at the tank wall, which is 20 ft or more from the pumps. Similar to the 1,090 Pa case, the solids were

The status of simulation codes for extraction process using mixer-settler

Energy Technology Data Exchange (ETDEWEB)

Byeon, Kee Hoh; Lee, Eil Hee; Kwon, Seong Gil; Kim, Kwang Wook; Yang, Han Beom; Chung, Dong Yong; Lim, Jae Kwan; Shin, Hyun Kyoo; Kim, Soo Ho

1999-10-01

We have studied and analyzed the mixer-settler simulation codes such as three kinds of SEPHIS series, PUBG, and EXTRA.M, which is the most recently developed code. All of these are sufficiently satisfactory codes in the fields of process/device modeling, but it is necessary to formulate the accurate distribution data and chemical reaction mechanism for the aspect of accuracy and reliability. In the aspect of application to be the group separation process, the mixer-settler model of these codes have no problems, but the accumulation and formulation of partitioning and reaction equilibrium data of chemical elements used in group separation process is very important. (author)

Design of an Efficient Turbulent Micro-Mixer for Protein Folding Experiments

Science.gov (United States)

Inguva, Venkatesh; Perot, Blair

2015-11-01

Protein folding studies require the development of micro-mixers that require less sample, mix at faster rates, and still provide a high signal to noise ratio. Chaotic to marginally turbulent micro-mixers are promising candidates for this application. In this study, various turbulence and unsteadiness generation concepts are explored that avoid cavitation. The mixing enhancements include flow turning regions, flow splitters, and vortex shedding. The relative effectiveness of these different approaches for rapid micro-mixing is discussed. Simulations found that flow turning regions provided the best mixing profile. Experimental validation of the optimal design is verified through laser confocal microscopy experiments. This work is support by the National Science Foundation.

Influence of melt mixer on injection molding of thermoset elastomers

Science.gov (United States)

Rochman, Arif; Zahra, Keith

2016-10-01

One of the drawbacks in injection molding is that the plasticizing screw is short such that polymers having high concentrations of additives, such as thermoset elastomers, might not mix homogeneously within the short period of time during the plasticizing stage. In this study, various melt mixers inside the nozzle chamber, together forming a mixing nozzle, were developed. Three different materials were investigated, namely nitrile butadiene rubber (NBR), ethylene propylene-diene monomer (EPDM) and fluorocarbon (FKM). The use of these melt mixers resulted in better homogeneity and properties of the molded parts despite a curing time reduction of 10 s. This was due to the increase in mixing and shearing introduced a higher rate of crosslinking formation in the molded parts.

New Osmosis Law and Theory: the New Formula that Replaces van't Hoff Osmotic Pressure Equation

OpenAIRE

Huang, Hung-Chung; Xie, Rongqing

2012-01-01

This article derived a new abstract concept from the osmotic process and concluded it via "osmotic force" with a new law -- "osmotic law". The "osmotic law" describes that, in an osmotic system, osmolyte moves osmotically from the side with higher "osmotic force" to the side with lower "osmotic force". In addition, it was proved mathematically that the osmotic process could be explained perfectly via "osmotic force" and "osmotic laws", which can prevent the difficulties in using current "osmo...

Wide-bandwidth electron bolometric mixers - A 2DEG prototype and potential for low-noise THz receivers

Science.gov (United States)

Yang, Jian-Xun; Agahi, Farid; Dai, Dong; Musante, Charles F.; Grammer, Wes; Lau, Kei M.; Yngvesson, K. S.

1993-01-01

This paper presents a new type of electron bolometric ('hot electron') mixer. We have demonstrated a 3 order-of-magnitude improvement in the bandwidth compared with previously known types of electron bolometric mixers, by using the two-dimensional electron gas (2DEG) medium at the heterointerface between AlGaAs and GaAs. We have tested both in-house MOCVD-grown material and MBE material, with similar results. The conversion loss (Lc) at 94 GHz is presently 18 dB for a mixer operating at 20 K, and calculations indicate that Lc can be decreased to about 10 dB in future devices. Calculated and measured curves of Lc versus P(LO), and I(DC), respectively, agree well. We argue that there are several different configurations of electron bolometric mixers, which will all show wide bandwidth, and that these devices are likely to become important as low-noise THz receivers in the future.

A Low Power 2.4 GHz CMOS Mixer Using Forward Body Bias Technique for Wireless Sensor Network

Science.gov (United States)

Yin, C. J.; Murad, S. A. Z.; Harun, A.; Ramli, M. M.; Zulkifli, T. Z. A.; Karim, J.

2018-03-01

Wireless sensor network (WSN) is a highly-demanded application since the evolution of wireless generation which is often used in recent communication technology. A radio frequency (RF) transceiver in WSN should have a low power consumption to support long operating times of mobile devices. A down-conversion mixer is responsible for frequency translation in a receiver. By operating a down-conversion mixer at a low supply voltage, the power consumed by WSN receiver can be greatly reduced. This paper presents a development of low power CMOS mixer using forward body bias technique for wireless sensor network. The proposed mixer is implemented using CMOS 0.13 μm Silterra technology. The forward body bias technique is adopted to obtain low power consumption. The simulation results indicate that a low power consumption of 0.91 mW is achieved at 1.6 V supply voltage. Moreover, the conversion gain (CG) of 21.83 dB, the noise figure (NF) of 16.51 dB and the input-referred third-order intercept point (IIP3) of 8.0 dB at 2.4 GHz are obtained. The proposed mixer is suitable for wireless sensor network.

Flicker noise comparison of direct conversion mixers using Schottky and HBT dioderings in SiGe:C BiCMOS technology

DEFF Research Database (Denmark)

Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld

2015-01-01

In this paper, we present flicker noise measurements of two X-band direct conversion mixers implemented in a SiGe:C BiCMOS technology. Both mixers use a ring structure with either Schottky diodes or diode-connected HBTs for double balanced operation. The mixers are packaged in a metal casing on a...... circuit demonstrates a 1/f noise corner frequency around 10 kHz....

Mass transfer kinetics during osmotic dehydration of pomegranate arils.

Science.gov (United States)

Mundada, Manoj; Hathan, Bahadur Singh; Maske, Swati

2011-01-01

The mass transfer kinetics during osmotic dehydration of pomegranate arils in osmotic solution of sucrose was studied to increase palatability and shelf life of arils. The freezing of the whole pomegranate at -18 °C was carried out prior to osmotic dehydration to increase the permeability of the outer cellular layer of the arils. The osmotic solution concentrations used were 40, 50, 60°Bx, osmotic solution temperatures were 35, 45, 55 °C. The fruit to solution ratio was kept 1:4 (w/w) during all the experiments and the process duration varied from 0 to 240 min. Azuara model and Peleg model were the best fitted as compared to other models for water loss and solute gain of pomegranate arils, respectively. Generalized Exponential Model had an excellent fit for water loss ratio and solute gain ratio of pomegranate arils. Effective moisture diffusivity of water as well as solute was estimated using the analytical solution of Fick's law of diffusion. For above conditions of osmotic dehydration, average effective diffusivity of water loss and solute gain varied from 2.718 × 10(-10) to 5.124 × 10(-10) m(2)/s and 1.471 × 10(-10) to 5.147 × 10(-10) m(2)/s, respectively. The final product was successfully utilized in some nutritional formulations such as ice cream and bakery products.

Scale-up of a mixer-settler extractor using a unit operations approach

International Nuclear Information System (INIS)

Lindholm, D.C.; Bautista, R.G.

1976-01-01

The results of scale-up studies on a continuous, multistage horizontal mixer-settler extractor are presented. The chemical and mechanical system involves the separation of lanthanum from a mixture of rare earth chlorides using di(2-ethylhexyl) phosphoric acid as the solvent and dilute HCl as a scrub solution in a bench scale extractor. Each stage has a hold-up of 2.6 l. A single stage unit is utilized for scale-up studies. Results are obtained on four sizes of geometrically similar units, the largest being six times the volume of the original bench size. A unit operations technique is chosen so that mixing and settling can be examined independently. Variables examined include type of continuous phase, flow rate of inlet streams, and power input to the mixer. Inlet flow-rate ratios are kept constant for all tests. Two potential methods of unbaffled pump-mixer scale-up are explored; the maintenance of constant impeller tip speed and constant power input. For the settler, the previously successful method of basing design on constant flow-rate per unit cross-sectional area is used

Analysis of a high-Tc hot-electron superconducting mixer for terahertz applications

International Nuclear Information System (INIS)

Karasik, B.S.; McGrath, W.R.; Gaidis, M.C.

1997-01-01

The prospects of a YBa 2 Cu 3 O 7-δ hot-electron bolometer mixer for a THz heterodyne receiver are discussed. The modeled device is a submicron bridge made from a 10-nm-thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of phonon diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated. The intrinsic conversion efficiency and the noise temperature have been calculated as functions of the device size, local oscillator (LO) power, and ambient temperature. Assuming thermal fluctuations and Johnson noise to be the main sources of noise, a minimum single sideband mixer noise temperature of congruent 2000 K is predicted. For our modeled device the intrinsic conversion loss at an intermediate frequency of 2.5 GHz is less than 10 dB and the required LO power is ∼1 endash 10 μW. copyright 1997 American Institute of Physics

Efficiency of Osmotic Dehydration of Apples in Polyols Solutions.

Science.gov (United States)

Cichowska, Joanna; Żubernik, Joanna; Czyżewski, Jakub; Kowalska, Hanna; Witrowa-Rajchert, Dorota

2018-02-17

The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

Numerical study of agglomerate abrasion in a tumbling mixer

NARCIS (Netherlands)

Thanh Nguyen, [No Value; Willemsz, Tofan; Frijlink, Henderik; Maarschalk, Kees van der Voort

2014-01-01

A numerical simulation using the Discrete Element Method (DEM) was performed to investigate the phenomena concerning the abrasion and breakage of agglomerates in a diffusion powder mixer. Agglomerates were created by defining a single structure of particles with bonds of different strengths using

Inverse osmotic process for radioactive laundry waste

Energy Technology Data Exchange (ETDEWEB)

Ebara, K; Takahashi, S; Sugimoto, Y; Yusa, H; Hyakutake, H

1977-01-07

Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount.

Osmotic stress tolerance in semi-terrestrial tardigrades

DEFF Research Database (Denmark)

Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

2016-01-01

Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high......-ionic osmolytes as compared to NaCl. Ramazzottius oberhaeuseri furthermore readily regained activity following gradual increases in non-ionic osmolytes and NaCl of up to 2434 ± 28 and 1905 ± 3 mOsm kg−1, respectively, showing that short-term acclimation promoted salt stress tolerance. Our results suggest...... that the limno-terrestrial R. oberhaeuseri enters a state of quiescence in the face of high external osmotic pressure and that it, in this state, is highly tolerant of ionic and osmotic stress....

An interfacially plasticized electro-responsive hydrogel for transdermal electro-activated and modulated (TEAM) drug delivery

NARCIS (Netherlands)

Indermun, S.; Choonara, Y.E.; Kumar, Pradeep; Toit, Du L.C.; Modi, G.; Luttge, R.; Pillay, V.

2014-01-01

This paper highlights the use of hydrogels in controlled drug delivery, and their application in stimuli responsive, especially electro-responsive, drug release. electro-conductive hydrogels (ECHs) displaying electro-responsive drug release were synthesized from semi-interpenetrating networks

Fecal osmotic gap and pH in experimental diarrhea of various causes.

Science.gov (United States)

Eherer, A J; Fordtran, J S

1992-08-01

Although the osmotic gap of fecal fluid is often used to distinguish osmotic diarrhea from secretory diarrhea, there has never been a scientific evaluation of the validity of this concept. Similarly, although a low fecal fluid pH value is used to indicate that diarrhea is mediated by carbohydrate malabsorption, the validity of this method is unproven. Therefore, in the present study, diarrhea was induced in normal subjects by different mechanisms and fecal fluid osmotic gap (using an assumed fecal fluid osmolality of 290 mOsm/kg) and pH were measured. In secretory diarrhea caused by phenolphthalein, the osmotic gap was always less than 50 mOsm/kg, whereas in osmotic diarrhea caused by polyethylene glycol, magnesium hydroxide, lactulose, and sorbitol, the osmotic gap always exceeded 50 mOsm/kg. In osmotic diarrhea caused by sodium sulfate, the fecal fluid osmotic gap was less than 50 mOsm/kg, but phenolphthalein-induced secretory diarrhea could be distinguished from sodium sulfate-induced osmotic diarrhea by the fecal chloride concentration. When diarrhea was caused by carbohydrate malabsorption (lactulose or sorbitol), the fecal fluid pH was always less than 5.6 and usually less than 5.3; by contrast, other causes of diarrhea rarely caused a fecal pH as low as 5.6 and never caused a pH less than 5.3. It is concluded that measurement of fecal fluid osmotic gap and pH can distinguish various mechanisms of experimental diarrhea in normal subjects. The concepts on which these tests are based are therefore verified experimentally.

Osmotic dehydration of fruit and berry raw materials in the food industry

Directory of Open Access Journals (Sweden)

N. A. Gribova

2017-01-01

Full Text Available Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% of water is contained. The process of osmotic dehydration with the help of various agents is less energy-intensive than the process of drying or freezing, since it can be processed at ambient temperature. Osmotic dehydration has potential advantages in preserving the quality of food and in maintaining healthy food for the food industry. Treatment includes dehydration of fruits and berries by an osmotic agent followed by dehydration in dry or frozen apparatus where the moisture content decreases and the product becomes more stable. This process is a partial dewatering process to provide improved product quality compared to conventional drying processes or freezing. The purpose of studying osmotic dehydration is to identify the advantages and disadvantages in the treatment of osmotic agents. Various aspects of osmotic dehydration technology are considered, namely the solutions used, the characteristics of solutions, the effect of variable processes and the qualitative characteristics of osmo-dehydrated products. Factors of osmotic dehydration that depend on the osmotic agent, concentration of solute, temperature, time, size, shape and compactness of the material, mixing and the ratio of the solution to the samples.

Investigation of LO-leakage cancellation and DC-offset influence on flicker-noise in X-band mixers

DEFF Research Database (Denmark)

Michaelsen, Rasmus; Johansen, Tom; Tamborg, Kjeld

2012-01-01

This paper describes an investigation on the influences in 1/f noise of LO-leakage and DC-offset cancellation for X-band mixers. Conditions for LO-leakage cancellation and zero DC-offset is derived. Measurements on a double balanced diode mixer shows an improvement in noise figure from 14.3dB to ...

Review of mixer design for low voltage - low power applications

Science.gov (United States)

Nurulain, D.; Musa, F. A. S.; Isa, M. Mohamad; Ahmad, N.; Kasjoo, S. R.

2017-09-01

A mixer is used in almost all radio frequency (RF) or microwave systems for frequency translation. Nowadays, the increase market demand encouraged the industry to deliver circuit designs to create proficient and convenient equipment with very low power (LP) consumption and low voltage (LV) supply in both digital and analogue circuits. This paper focused on different Complementary Metal Oxide Semiconductor (CMOS) design topologies for LV and LP mixer design. Floating Gate Metal Oxide Semiconductor (FGMOS) is an alternative technology to replace CMOS due to their high ability for LV and LP applications. FGMOS only required a few transistors per gate and can have a shift in threshold voltage (VTH) to increase the LP and LV performances as compared to CMOS, which makes an attractive option to replace CMOS.

The Media Mixer

DEFF Research Database (Denmark)

Vestergaard, Vitus; Mortensen, Christian Hviid

In recent years many museums have experimented with different approaches to involving users through digital media. We explore how remixing and content sharing can be used as a means for user participation. Remix culture is seen as a culture that allows and encourages the production of derivative...... works; works that are based on already existing works. This cultural practice thrives throughout the Internet, most notably on web2.0 sites like YouTube. The Media Museum has embraced the remix paradigm with the development of an interactive media experience centre called the Media Mixer. Here...... the museum users can produce, deconstruct, reconstruct and finally publish and share digital media content. The media content is created by the user in the museums physical environment, but it can be mixed with material from local or global archives. In that way the gap between the analogue and the digital...

The Media Mixer

DEFF Research Database (Denmark)

Vestergaard, Vitus; Mortensen, Christian Hviid

2011-01-01

content. The media content is created by the user in the museum's physical environment, but it can be mixed with material from web archives. It is the intention that the users learn about media through participatory and creative processes with media where the borders between producing, playing......We explore how remixing and content sharing can be used as a means for user participation in a digital museum age. Remix culture is seen as a culture that allows and encourages the production of derivative works; works that are based on already existing works. This cultural practice thrives...... throughout the Internet, most notably on web 2.0 sites like YouTube. The Media Museum has embraced the remix paradigm with the development of an interactive media experience centre called the Media Mixer. Here the museum users can produce, deconstruct, reconstruct and finally publish and share digital media...

A Simple Membrane Osmometer System & Experiments that Quantitatively Measure Osmotic Pressure

Science.gov (United States)

Marvel, Stephen C.; Kepler, Megan V.

2009-01-01

It is important for students to be exposed to the concept of osmotic pressure. Understanding this concept lays the foundation for deeper discussions that lead to more theoretical aspects of water movement associated with the concepts of free energy, water potential, osmotic potential, pressure potential, and osmotic adjustment. The concept of…

Efficiency of Osmotic Dehydration of Apples in Polyols Solutions

Directory of Open Access Journals (Sweden)

Joanna Cichowska

2018-02-01

Full Text Available The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

Mixing monoclonal antibody formulations using bottom-mounted mixers: impact of mechanism and design on drug product quality.

Science.gov (United States)

Gikanga, Benson; Chen, Yufei; Stauch, Oliver B; Maa, Yuh-Fun

2015-01-01

Using bottom-mounted mixers, particularly those that are magnetically driven, is becoming increasingly common during the mixing process in pharmaceutical and biotechnology manufacturing because of their associated low risk of contamination, ease of use, and ability to accommodate low minimum mixing volumes. Despite these benefits, the impact of bottom-mounted mixers on biologic drug product is not yet fully understood and is scarcely reported. This study evaluated four bottom-mounted mixers to assess their impact on monoclonal antibody formulations. Changes in product quality (size variants, particles, and turbidity) and impact on process performance (sterile filtration) were evaluated after mixing. The results suggested that mixers that are designed to function with no contact between the impeller and the drive unit are the most favorable and gentle to monoclonal antibody molecules. Designs with contact or a narrow clearance tended to shear and grind the protein and resulted in high particle count in the liquid, which would subsequently foul a filter membrane during sterile filtration using a 0.22 μm pore size filter. Despite particle formation, increases in turbidity of the protein solution and protein aggregation/fragmentation were not detected. Further particle analysis indicated particles in the range of 0.2-2 μm are responsible for filter fouling. A small-scale screening model was developed using two types of magnetic stir bars mimicking the presence or absence of contact between the impeller and drive unit in the bottom-mounted mixers. The model is capable of differentiating the sensitivity of monoclonal antibody formulations to bottom-mounted mixers with a small sample size. This study fills an important gap in understanding a critical bioprocess unit operation. Mixing is an important unit operation in drug product manufacturing for compounding (dilution, pooling, homogenization, etc.). The current trend in adopting disposable bottom-mounted mixers has

Inverse osmotic process for radioactive laundry waste

International Nuclear Information System (INIS)

Ebara, Katsuya; Takahashi, Sankichi; Sugimoto, Yoshikazu; Yusa, Hideo; Hyakutake, Hiroshi.

1977-01-01

Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount. (Furukawa, Y.)

A Sideband-Separating Mixer Upgrade for ALMA Band 9

NARCIS (Netherlands)

Hesper, R.; Gerlofsma, G.; Mena, P.; Spaans, M.; Baryshev, A.

2009-01-01

The ALMA band 9 (600-720 GHz) receiver cartridge, as currently being produced, features two single-ended (dual sideband) SIS mixers in orthogonal polarisations. In the case of spectral line observations in the presence of atmospheric backgound, the integration time to reach a certain desired signal

Transcriptome Profiling of Watermelon Root in Response to Short-Term Osmotic Stress.

Science.gov (United States)

Yang, Yongchao; Mo, Yanling; Yang, Xiaozheng; Zhang, Haifei; Wang, Yongqi; Li, Hao; Wei, Chunhua; Zhang, Xian

2016-01-01

Osmotic stress adversely affects the growth, fruit quality and yield of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). Increasing the tolerance of watermelon to osmotic stress caused by factors such as high salt and water deficit is an effective way to improve crop survival in osmotic stress environments. Roots are important organs in water absorption and are involved in the initial response to osmosis stress; however, few studies have examined the underlying mechanism of tolerance to osmotic stress in watermelon roots. For better understanding of this mechanism, the inbred watermelon accession M08, which exhibits relatively high tolerance to water deficits, was treated with 20% polyethylene glycol (PEG) 6000. The root samples were harvested at 6 h after PEG treatment and untreated samples were used as controls. Transcriptome analyses were carried out by Illumina RNA sequencing. A total of 5246 differentially expressed genes were identified. Gene ontology enrichment and biochemical pathway analyses of these 5246 genes showed that short-term osmotic stress affected osmotic adjustment, signal transduction, hormone responses, cell division, cell cycle and ribosome, and M08 may repress root growth to adapt osmotic stress. The results of this study describe the watermelon root transcriptome under osmotic stress and propose new insight into watermelon root responses to osmotic stress at the transcriptome level. Accordingly, these results allow us to better understand the molecular mechanisms of watermelon in response to drought stress and will facilitate watermelon breeding projects to improve drought tolerance.

A “twisted” microfluidic mixer suitable for a wide range of flow rate applications

KAUST Repository

Sivashankar, Shilpa

2016-06-27

This paper proposes a new “twisted” 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices.

Method of osmotic energy harvesting using responsive compounds and molecules

KAUST Repository

Hu, Xiao

2017-07-27

The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli responsive draw solutions that are competent in terms of energy production, geographic location flexibility, and the affordable, efficient and economical production and delivery of osmotic power. Specifically, the present invention is a novel osmotic power system that uses stimuli responsive draw solutions, economically feasible larger permeable membranes, and low grade heat sources to deliver osmotic power more efficiently and economically with less negative environmental impact, greater power output, and located in more geographically diverse areas of the world than previously thought possible for supporting such a power source.

Introduction and utilization of mixer-settler for uranium purification

International Nuclear Information System (INIS)

Tri-Murni

2002-01-01

A mixer settler made by Amersham was designed to separate U from the waste arising from 9 9 M o production using enriched U > 93 % 2 35 U as the raw material to be fissioned. The separation is based on liquid-liquid extraction, organic and aqueous phase, with counter current, the solution continuously flows while the two phases are mixed and settled. This equipment consists of two cycles, the first one for separation U from fission products while the second cycle for separating U from Pu. Each cycle consists of 10 extraction stages, 6 scrubbing stages, 12 stripping stages, 1 stages for solvent washing and another 1 stage for solvent conditioning. From the first cycle to the second one is equipped with solvent washing unit so that the solvent can be used continuously. It is also equipped with micro pumps to regulate the suction and emission of the waste and feed thanks of feed and solvent, as well as burette containing the reagent. Ever since the commissioning this mixer settler has been utilized. This equipment can be utilized for U purification from heavy metals using the product of U processing as the feed material by studying the appropriate solution and applicable solvent. The same also will do for U separation from impurities is the waste of fuel production and other wastes solvent. The same also will do for U separation from impurities in the waste of fuel production and other wastes containing U generated from research activities. The centers within BATAN that can utilize this mixer settler are P2BGGN, P2TBDU, P2PLR, P3TkN and P3TM

Quantified Effects of Late Pregnancy and Lactation on the Osmotic ...

African Journals Online (AJOL)

Quantified Effects of Late Pregnancy and Lactation on the Osmotic Stability of ... in the composition of erythrocyte membranes associated with the physiologic states. Keywords: Erythrocyteosmotic stability, osmotic fragility, late pregnancy, ...

Drying characteristics of osmotically pretreated cranberries : Energy and quality aspects

Energy Technology Data Exchange (ETDEWEB)

Grabowski, S.; Marcotte, M. [Agriculture and Agri-Food Canada, St. Hyacinthe, PQ (Canada). Food Research and Development Centre; Poirier, M.; Kudra, T. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

2002-06-01

This paper presents the results of a study in which osmotically pretreated cranberries were dried. The osmotic treatment included dehydration and sugar infusion. The process involved pretreating halved cranberries in a standard osmotic solution followed by freeze-drying, vacuum-drying and air-drying in various dryers, such as cabinet-air-through, fluid bed, pulsed fluid bed, and vibrated fluid bed dryers. The intent was to identify the best drying technology. The comparison criteria selected were energy consumption and product quality. Product quality for freeze-dried berries was quantified based on anthocyanins content, rehydration ratio, color, and taste. Unit heat consumption could be used for selecting the drying method, as all other drying methods yielded similar but slightly lower quality products. The highest energy efficiency was obtained with the vibrated fluid bed and the pulsed fluid bed. It was noted that drying rates were reduced during the second drying period when sugar was infused into the cranberries during osmotic pretreatment, but the total energy consumption was reduced by osmotic dehydration. 22 refs., 1 tab., 5 figs.

Detection of osmotic damages in GRP boat hulls

Science.gov (United States)

Krstulović-Opara, L.; Domazet, Ž.; Garafulić, E.

2013-09-01

Infrared thermography as a tool of non-destructive testing is method enabling visualization and estimation of structural anomalies and differences in structure's topography. In presented paper problem of osmotic damage in submerged glass reinforced polymer structures is addressed. The osmotic damage can be detected by a simple humidity gauging, but for proper evaluation and estimation testing methods are restricted and hardly applicable. In this paper it is demonstrated that infrared thermography, based on estimation of heat wave propagation, can be used. Three methods are addressed; Pulsed thermography, Fast Fourier Transform and Continuous Morlet Wavelet. An additional image processing based on gradient approach is applied on all addressed methods. It is shown that the Continuous Morlet Wavelet is the most appropriate method for detection of osmotic damage.

Modeling osmotic salinity effects on yield characteristics of substrate-grown greenhouse crops

NARCIS (Netherlands)

Sonneveld, C.; Bos, van den A.L.; Voogt, W.

2004-01-01

In a series of experiments with different osmotic potentials in the root environment, various vegetables, and ornamentals were grown in a substrate system. The osmotic potential was varied by addition of nutrients. Yield characteristics of the crop were related to the osmotic potential of the

PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

Science.gov (United States)

Tedeschi, Henry; James, Joseph M.; Anthony, William

1963-01-01

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

Use of osmotic dehydration to improve fruits and vegetables quality during processing.

Science.gov (United States)

Maftoonazad, Neda

2010-11-01

Osmotic treatment describes a preparation step to further processing of foods involving simultaneous transient moisture loss and solids gain when immersing in osmotic solutions, resulting in partial drying and improving the overall quality of food products. The different aspects of the osmotic dehydration (OD) technology namely the solutes employed, solutions characteristics used, process variables influence, as well as, the quality characteristics of the osmodehydrated products will be discussed in this review. As the process is carried out at mild temperatures and the moisture is removed by a liquid diffusion process, phase change that would be present in the other drying processes will be avoided, resulting in high quality products and may also lead to substantial energy savings. To optimize this process, modeling of the mass transfer phenomenon can improve high product quality. Several techniques such as microwave heating, vacuum, high pressure, pulsed electric field, etc. may be employed during or after osmotic treatment to enhance performance of the osmotic dehydration. Moreover new technologies used in osmotic dehydration will be discussed. Patents on osmotic dehydration of fruits and vegetables are also discussed in this article.

Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

OpenAIRE

Roselene Ferreira Oliveira; Lia Mara Moterlle; Edmar Clemente

2014-01-01

The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L.), red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET) and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS), tot...

Effect of mixing time and speed on experimental baking and dough testing with a 200g pin-mixer

Science.gov (United States)

Under mixing or over mixing the dough results in varied experimental loaf volumes. Bread preparation requires a trained baker to evaluate dough development and determine stop points of mixer. Instrumentation and electronic control of the dough mixer would allow for automatic mixing. This study us...

Enhanced methanol electro-oxidation reaction on Pt-CoOx/MWCNTs hybrid electro-catalyst

International Nuclear Information System (INIS)

Nouralishahi, Amideddin; Rashidi, Ali Morad; Mortazavi, Yadollah; Khodadadi, Abbas Ali; Choolaei, Mohammadmehdi

2015-01-01

Highlights: • Promoting effects of Cobalt oxide on methanol electro-oxidation over Pt/MWCNTs are investigated. • Higher activity, about 2.9 times, and enhanced stability are observed on Pt-CoO x /MWCNTs. • Electrochemical active surface area of Pt nanoparticles is significantly improved upon CoO x addition. • Bi-functional mechanism is facilitated in presence of CoO x . - Abstract: The electro-catalytic behavior of Pt-CoO x /MWCNTs in methanol electro-oxidation reaction (MOR) is investigated and compared to that of Pt/MWCNTs. The electro-catalysts were synthesized by an impregnation method using NaBH 4  as the reducing agent. The morphological and physical characteristics of samples are examined by XRD, TEM, ICP and EDS techniques. In the presence of CoO x , Pt nanoparticles were highly distributed on the support with an average particle size of 2 nm, an obvious decrease from 5.1 nm for Pt/MWCNTs. Cyclic voltammetry, CO-stripping, Chronoamperometry, and electrochemical impedance spectroscopy (EIS) measurements are used to study the electrochemical behavior of the electro-catalysts. The results revealed a considerable enhancement in the oxidation kinetics of CO ads on Pt active sites by the participation of CoO x . Compared to Pt/MWCNTs, Pt-CoO x /MWCNTs sample has a larger electrochemical active surface area (ECSA) and higher electro-catalytic activity and stability toward methanol electro-oxidation. According to the results of cyclic voltammetry, the forward anodic peak current density enhances more than 89% at the optimum atomic ratio of Pt:Co = 2:1. Furthermore, inclusion of cobalt oxide species causes the onset potential of methanol electro-oxidation reaction to shift 84 mV to negative values compared to that on Pt/MWCNTs. Based on EIS data, dehydrogenation of methanol is the rate-determining step of MOR on both Pt/MWCNTs and Pt-CoO x /MWCNTs, at small overpotentials. However, at higher overpotentials, the oxidation of adsorbed oxygen-containing groups

Optimum condition of producing crisp osmotic banana using superheated steam puffing.

Science.gov (United States)

Tabtiang, Surapit; Prachayawarakorn, Somkiat; Soponronnarit, Somchart

2017-03-01

Puffing can improve textural property of snacks. Nevertheless, high temperature puffing accelerates non-enzymatic browning reactions. The osmotic treatment using sucrose solution potentially retards the browning, but the high amount of sucrose gain causes hard texture. The objective of this work was therefore to study the effects of osmotic time, puffing time and puffing temperature on banana qualities such as colour, shrinkage and textural property. The experimental results showed that puffing temperature, puffing time and osmotic time significantly affected colour, shrinkage and textual properties. The optimisation using response surface methodology was used for a trade-off between colour and textural properties. To obtain a good quality product, the puffed osmotic banana should be operated at the osmotic time of 43 min and puffing temperature of 220 °C and puffing time of 2 min. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Osmotic stress upregulates the transcription of thiamine (vitamin B1 ...

African Journals Online (AJOL)

Osmotic stress upregulates the transcription of thiamine (vitamin B1) ... Oil palm's responses in terms of the expression profiles of these two thiamine biosynthesis genes to an osmotic stress inducer, polyethylene glycol ... from 32 Countries:.

Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

Science.gov (United States)

Kamachi, Yasuharu; Omasa, Takeshi

2018-04-01

Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Comparative evaluation of a two stroke compressed natural gas mixer design using simulation and experimental techniques

Energy Technology Data Exchange (ETDEWEB)

Ramasamy, D.; Bakar, R.A.; Rahim, M.F.; Noor, M.M. [Malaysia Pahang Univ., Pahang (Malaysia). Automotive Focus Group

2008-07-01

A study was conducted in which a two-stroke engine was converted for use with bi-fuel, notably compressed natural gas and gasoline. The excessive by-products generated by two-stroke engine combustion can be attributed to the inefficient combustion process. This prototype uniflow-type single-cylinder engine was equipped with a bi-fuel conversion system. A dedicated mixer was also developed to meter the gaseous fuel through the engine intake system. It was designed to meet air and fuel requirement similar to its gasoline counterpart. The mixer was modeled to obtain optimum orifice diameter using three different sizes of 14, 16 and 18 mm respectively. A standard computational fluid dynamics (CFD) software package was used to simulate the flow. A pressure reading was obtained during the prototype test. The drop in pressure across the venturi was shown to be an important parameter as it determined the actual fuel-air ratio in the actual engine. A good agreement of CFD outputs with that of the experimental outputs was recorded. The experimental technique validated the pressure distribution predicted by CFD means on the effects of the three insert rings in the CNG mixer. The simulation exercise can be used to predict the amount of CNG consumed by the engine. It was concluded that the 14 mm throat ring was best suited for the CNG mixer because it provided the best suction. Once the mixer is tested on a real engine, it will clear any doubts as to whether the throat can function at high engine speeds. 5 refs., 3 tabs., 8 figs.

Quantum noise in a terahertz hot electron bolometer mixer

NARCIS (Netherlands)

Zhang, W.; Khosropanah, P.; Gao, J. R.; Kollberg, E. L.; Yngvesson, K. S.; Bansal, T.; Barends, R.; Klapwijk, T. M.

2010-01-01

We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model

Handling support for mixer-settlers in hot cells with biological protection

International Nuclear Information System (INIS)

Lobao, Afonso dos Santos Tome; Forbicini, Sergio; Camilo, Ruth Luqueze

1996-01-01

The solvent extraction research facilities of IPEN/CNEN-SP carries out researching work in irradiated materials separation. This installation is provided with two cells with five operating windows, being that, each once of then has a pair of manipulators (master-slave type-MA-11 La Calhene). Solvent extraction research are carried out in acrylic mixer-settlers inside of the shielded cells. These equipment undergo an intense chemical attack which product failures in the acrylic material, so it is necessary to replace them periodically. The developed equipment is able to change the mixer-settlers without its rigidness,, level and the adjustment of the determined coordinates of the mechanical assemblage inside the cell. The definitive implantation of the equipment depends on the final tests on the cells where the fine adjustments will be made. (author)

An unsteady microfluidic T-form mixer perturbed by hydrodynamic pressure

International Nuclear Information System (INIS)

Ma Yanbao; Sun, Chien-Pin; Fields, Michael; Ho, Chih-Ming; Li Yang; Haake, David A; Churchill, Bernard M

2008-01-01

An unsteady microfluidic T-form mixer driven by pressure disturbances was designed and investigated. The performance of the mixer was examined both through numerical simulation and experimentation. Linear Stokes equations were used for these low Reynolds number flows. Unsteady mixing in a micro-channel of two aqueous solutions differing in concentrations of chemical species was described using a convection-dominated diffusion equation. The task was greatly simplified by employing linear superimposition of a velocity field for solving a scalar species concentration equation. Low-order-based numerical codes were found not to be suitable for simulation of a convection-dominated mixing process due to erroneous computational dissipation. The convection-dominated diffusion problem was addressed by designing a numerical algorithm with high numerical accuracy and computational-cost effectiveness. This numerical scheme was validated by examining a test case prior to being applied to the mixing simulation. Parametric analysis was performed using this newly developed numerical algorithm to determine the best mixing conditions. Numerical simulation identified the best mixing condition to have a Strouhal number (St) of 0.42. For a T-junction mixer (with channel width = 196 µm), about 75% mixing can be finished within a mixing distance of less than 3 mm (i.e. 15 channel width) at St = 0.42 for flow with a Reynolds number less than 0.24. Numerical results were validated experimentally by mixing two aqueous solutions containing yellow and blue dyes. Visualization of the flow field under the microscope revealed a high level of agreement between numerical simulation and experimental results

Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities.

Science.gov (United States)

Falghoush, Azeza; Beyenal, Haluk; Besser, Thomas E; Omsland, Anders; Call, Douglas R

2017-10-01

Biofilm-associated infections are a clinical challenge, in part because a hydrated matrix protects the bacterial community from antibiotics. Herein, we evaluated how different osmotic compounds (maltodextrin, sucrose, and polyethylene glycol [PEG]) enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities. Established (24-h) test tube biofilms (strain ATCC 17978) were treated with osmotic compounds in the presence or absence of 10× the MIC of different antibiotics (50 μg/ml tobramycin, 20 μg/ml ciprofloxacin, 300 μg/ml chloramphenicol, 30 μg/ml nalidixic acid, or 100 μg/ml erythromycin). Combining antibiotics with hypertonic concentrations of the osmotic compounds for 24 h reduced the number of biofilm bacteria by 5 to 7 log ( P baumannii strains were similarly treated with 400-Da PEG and tobramycin, resulting in a mean 2.7-log reduction in recoverable bacteria compared with tobramycin treatment alone. Multivariate regression models with data from different osmotic compounds and nine antibiotics demonstrated that the benefit from combining hypertonic treatments with antibiotics is a function of antibiotic mass and lipophilicity ( r 2 > 0.82; P baumannii and Escherichia coli K-12. Augmenting topical antibiotic therapies with a low-mass hypertonic treatment may enhance the efficacy of antibiotics against wound biofilms, particularly when using low-mass hydrophilic antibiotics. IMPORTANCE Biofilms form a barrier that protects bacteria from environmental insults, including exposure to antibiotics. We demonstrated that multiple osmotic compounds can enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities, but viscosity is a limiting factor, and the most effective compounds have lower molecular mass. The synergism between osmotic compounds and antibiotics is also dependent on the hydrophobicity and mass of the antibiotics. The statistical models presented herein provide a basis for predicting the optimal combination of

Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis

OpenAIRE

Tokuyama, T.; Ikeda, T.; Sato, K.

1998-01-01

BACKGROUND—In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated.
METHODS—Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before a...

On nonlinear thermo-electro-elasticity.

Science.gov (United States)

Mehnert, Markus; Hossain, Mokarram; Steinmann, Paul

2016-06-01

Electro-active polymers (EAPs) for large actuations are nowadays well-known and promising candidates for producing sensors, actuators and generators. In general, polymeric materials are sensitive to differential temperature histories. During experimental characterizations of EAPs under electro-mechanically coupled loads, it is difficult to maintain constant temperature not only because of an external differential temperature history but also because of the changes in internal temperature caused by the application of high electric loads. In this contribution, a thermo-electro-mechanically coupled constitutive framework is proposed based on the total energy approach. Departing from relevant laws of thermodynamics, thermodynamically consistent constitutive equations are formulated. To demonstrate the performance of the proposed thermo-electro-mechanically coupled framework, a frequently used non-homogeneous boundary-value problem, i.e. the extension and inflation of a cylindrical tube, is solved analytically. The results illustrate the influence of various thermo-electro-mechanical couplings.

Osmotic Power: A Fresh Look at an Old Experiment

Science.gov (United States)

Dugdale, Pam

2014-01-01

Electricity from osmotic pressure might seem a far-fetched idea but this article describes a prototype in Norway where the osmotic pressure generated between salt and fresh water drives a turbine. This idea was applied in a student investigation, where they were tasked with researching which alternative materials could be used for the…

Electro-weak theory

International Nuclear Information System (INIS)

Deshpande, N.G.

1980-01-01

By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given

A SiGe High Gain and Highly Linear F-Band Single-Balanced Subharmonic Mixer

OpenAIRE

Seyedhosseinzadeh, Neda; Nabavi, Abdolreza; Carpenter, Sona; He, Zhongxia Simon; Bao, Mingquan; Zirath, Herbert

2017-01-01

A compact, broadband, high gain, second-order active down-converter subharmonic mixer is demonstrated using a 130-nm SiGe BiCMOS technology. The mixer adopts a bottom-LO Gilbert topology, on-chip RF and LO baluns and two emitter-follower buffers to realize a high gain wideband operation in both RF and IF frequencies. The measured performance exhibits a flat conversion gain (CG) of about 11 dB from 90 to 130 GHz with an average LO power of +3 dBm and high 2LO-RF isolation better than 60 dB. Th...

Fabrication of microfluidic mixers with varying topography in glass using the powder-blasting process

International Nuclear Information System (INIS)

Sayah, Abdeljalil; Thivolle, Pierre-Antoine; Parashar, Virendra K; Gijs, Martin A M

2009-01-01

The powder-blasting method is used to fabricate structures with a three-dimensional topography in glass using elastomeric masks. The relation between the mask opening width and the erosion depth is exploited to fabricate microstructures with varying depth in a single micropatterning step. As an application, planar three-dimensional micro-mixers were fabricated, which consist of a repeating convergent microfluidic nozzle structure. Three different designs of the micro-mixers were considered. The mixing of co-flowing laminar streams results from the generation of multiple vortices at the exit of the different convergent nozzles

CERN Entrepreneur Mixer | 21 June | Pas perdus

CERN Multimedia

2016-01-01

  CERN Knowledge Transfer group is hosting an Entrepreneur Mixer, an event dedicated to building bridges between CERN innovative entrepreneurs. This will be a unique opportunity to discover business projects initiated by former CERN people, and to see how CERN technology is being exploited by start-up companies. The deadline for registration is Friday, 17 June. For more information, please visit the Indico page of the event: https://indico.cern.ch/event/537167/

Field measurement of mixing degree in coal mixer by later activable tracer method

International Nuclear Information System (INIS)

Yokooji, Makoto; Uemura, Katsumi; Adachi, Syoichi

1975-01-01

Mixing effectiveness in a rotary drum mixer for coke production was examined. Though the method to use the dispersion of characteristic values such as ash content or volatile components is common for measuring the mixing effectiveness, here the later activable tracer method with radioisotopes was employed, because the former method includes the dispersion of the characteristic values for raw materials themselves, and is poor in detectability. In a preliminary test, the expression for mixing degree was determined, and the tracer nuclide was selected. Coal mixture was irradiated in the TRIGA II reactor of St. Paul University for 4 hours at 100 kW. then further preliminary test was performed for La and Mn which were selected among the typical usable elements listed up by reviewing their γ-spectra. Finally, Mn was adopted by comparing both elements regarding their time required for activation analysis and economy. Manganese concentration originally contained in the coal mixture was 38 ppm. Mixing degree after passing through the coal mixer was 99.8%. The results of the regular test are shown in a table, and indicate that the mixer fully attained its aim. (Wakatsuki, Y.)

Numerical simulation of experimental data from planar SIS mixers with integrated tuning elements

International Nuclear Information System (INIS)

Mears, C.A.; Hu, Qing; Richards, P.L.

1988-08-01

We have used the full Tucker theory including the quantum susceptance to fit data from planar lithographed mm-wave mixers with bow tie antennas and integrated RF coupling elements. Essentially perfect fits to pumped IV curves have been obtained. The deduced imbedding admittances agree well with those independently calculated from the geometry of the antenna and matching structures. We find that the quantum susceptance is essential to the fit and thus to predictions of the mixer performance. For junctions with moderately sharp gap structures, the quantum susceptance is especially important in the production of steps with low and/or negative dynamic conductance. 15 refs., 4 figs

Comparison of the performance of full scale pulsed columns vs. mixer-settlers for uranium solvent extraction

International Nuclear Information System (INIS)

Movsowitz, R.L.; Kleinberger, R.; Buchalter, E.M.; Grinbaum, B.

2000-01-01

A rare opportunity arose to compare the performance of Bateman Pulsed Columns (BPC) vs. Mixer-Settlers at an industrial site, over a long period, when the Uranium Solvent Extraction Plant of WMC at Olympic Dam, South Australia was upgraded. The original plant was operated for years with two trains of 2-stage mixer-settler batteries for the extraction of uranium. When the company decided to increase the yield of the plant, the existing two trains of mixer-settlers for uranium extraction were arranged in series, giving one 4-stage battery. In parallel, two Bateman Pulsed Columns, of the disc-and-doughnut type, were installed to compare the performance of both types of equipment over an extended period.The plant has been operating in parallel for three years and the results show that the performance of the columns is excellent: the extraction yield is similar to the 4 mixer-settlers in series - about 98%, the entrainment of solvent is lower, there are less mechanical failures, less problems with crud, smaller solvent losses and the operation is simpler. The results convinced WMC to install an additional 10 BPC's for the expansion of their uranium plant. These columns were successfully commissioned early 1999. This paper includes quantitative comparison of both types of equipment. (author)

An I/Q mixer with an integrated differential quadrature all-pass filter for on-chip quadrature LO signal generation

International Nuclear Information System (INIS)

Amin, Najam Muhammad; Wang Zhigong; Li Zhiqun

2015-01-01

A down-conversion in-phase/quadrature (I/Q) mixer employing a folded-type topology, integrated with a passive differential quadrature all-pass filter (D-QAF), in order to realize the final down-conversion stage of a 60 GHz receiver architecture is presented in this work. Instead of employing conventional quadrature generation techniques such as a polyphase filter or a frequency divider for the local oscillator (LO) of the mixer, a passive D-QAF structure is employed. Fabricated in a 65 nm CMOS process, the mixer exhibits a voltage gain of 7–8 dB in an intermediate frequency (IF) band ranging from 10 MHz–1.75 GHz. A fixed LO frequency of 12 GHz is used to down-convert a radio frequency (RF) band of 10.25–13.75 GHz. The mixer displays a third order input referred intercept point (IIP 3 ) ranging from −8.75 to −7.37 dBm for a fixed IF frequency of 10 MHz and a minimum single-sideband noise figure (SSB-NF) of 11.3 dB. The mixer draws a current of 6 mA from a 1.2 V supply voltage dissipating a power of 7.2 mW. (paper)

Computational Fluid Dynamics and Experimental Studies of a New Mixing Element in a Static Mixer as a Heat Exchanger

Directory of Open Access Journals (Sweden)

Konopacki Maciej

2015-03-01

Full Text Available The main aim of this work is to study the thermal efficiency of a new type of a static mixer and to analyse the flow and temperature patterns and heat transfer efficiency. The measurements were carried out for the static mixer equipped with a new mixing insert. The heat transfer enhancement was determined by measuring the temperature profiles on each side of the heating pipe as well as the temperature field inside the static mixer. All experiments were carried out with varying operating parameters for four liquids: water, glycerol, transformer oil and an aqueous solution of molasses. Numerical CFD simulations were carried out using the two-equation turbulence k-ω model, provided by ANSYS Workbench 14.5 software. The proposed CFD model was validated by comparing the predicted numerical results against experimental thermal database obtained from the investigations. Local and global convective heat transfer coefficients and Nusselt numbers were detrmined. The relationship between heat transfer process and hydrodynamics in the static mixer was also presented. Moreover, a comparison of the thermal performance between the tested static mixer and a conventional empty tube was carried out. The relative enhancement of heat transfer was characterised by the rate of relative heat transfer intensification.

Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

Directory of Open Access Journals (Sweden)

Mourad Laqbaqbi

2017-03-01

Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

Micro-mixer/combustor

KAUST Repository

Badra, Jihad Ahmad

2014-09-18

A micro-mixer/combustor to mix fuel and oxidant streams into combustible mixtures where flames resulting from combustion of the mixture can be sustained inside its combustion chamber is provided. The present design is particularly suitable for diffusion flames. In various aspects the present design mixes the fuel and oxidant streams prior to entering a combustion chamber. The combustion chamber is designed to prevent excess pressure to build up within the combustion chamber, which build up can cause instabilities in the flame. A restriction in the inlet to the combustion chamber from the mixing chamber forces the incoming streams to converge while introducing minor pressure drop. In one or more aspects, heat from combustion products exhausted from the combustion chamber may be used to provide heat to at least one of fuel passing through the fuel inlet channel, oxidant passing through the oxidant inlet channel, the mixing chamber, or the combustion chamber. In one or more aspects, an ignition strip may be positioned in the combustion chamber to sustain a flame without preheating.

A Simple Student Laboratory on Osmotic Flow, Osmotic Pressure, and the Reflection Coefficient.

Science.gov (United States)

Feher, Joseph J.; Ford, George D.

1995-01-01

Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

Directory of Open Access Journals (Sweden)

Roselene Ferreira Oliveira

2014-09-01

Full Text Available The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L., red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS, total titratable acidity (TTA, reducing sugars (RS, total sugars (TS and parameters related to colour read (a*, chroma (c*, yellow (b*, luminosity (L* of the fresh and osmotically dehydrated guava slices. The dehydrated fruits lost about 34.45% of water, concentrating contents of soluble solids, total and reducing sugars, when compared to control samples. The pH value remained around 3.76 for the OD fruits and 3.87 for the fresh fruits. The colour of the dehydrated fruits was more intense than the control samples’. The guava slices osmotic dehydration had 21 days of shelf life, showed physicochemical characteristics significantly superior to the control samples’, having a stable and high quality product as a result.

The effects of exogenous proline and osmotic stress on morpho ...

African Journals Online (AJOL)

USER

2010-06-21

Jun 21, 2010 ... For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose. (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous L- proline ...

Swelling, mechanical and friction properties of PVA/PVP hydrogels after swelling in osmotic pressure solution.

Science.gov (United States)

Shi, Yan; Xiong, Dangsheng; Liu, Yuntong; Wang, Nan; Zhao, Xiaoduo

2016-08-01

The potential of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) hydrogels as articular cartilage replacements was in vitro evaluated by using a macromolecule-based solution to mimic the osmotic environment of cartilage tissue. The effects of osmotic pressure solution on the morphology, crystallinity, swelling, mechanical and friction properties of PVA/PVP hydrogels were investigated by swelling them in non-osmotic and osmotic pressure solutions. The results demonstrated that swelling ratio and equilibrium water content were greatly reduced by swelling in osmotic solution, and the swelling process was found to present pseudo-Fickian diffusion character. The crystallization degree of hydrogels after swelling in osmotic solution increased more significantly when it compared with that in non-osmotic solution. After swelling in osmotic solution for 28days, the compressive tangent modulus and storage modulus of hydrogels were significantly increased, and the low friction coefficient was reduced. However, after swelling in the non-osmotic solution, the compressive tangent modulus and friction coefficient of hydrogels were comparable with those of as-prepared hydrogels. The better material properties of hydrogels in vivo than in vitro evaluation demonstrated their potential application in cartilage replacement. Copyright © 2016 Elsevier B.V. All rights reserved.

FDC Mentor-Mentee Mixer Breaks the Ice Between Investigators and Trainees | Poster

Science.gov (United States)

The Frederick Diversity Committee’s mentor-mentee mixer gave research trainees, senior investigators, scientists, and administrative staff a chance to meet and mingle over refreshments and games following the Spring Research Festival.

Osmotic actuation for microfluidic components in point-of-care applications

KAUST Repository

Chen, Yu-Chih

2013-01-01

We present a novel design of micropumps and valves driven by osmotic force for point-of-care applications. Although there have been significant progresses in microfluidic components and control devices such as fluidic diodes, switches, resonators and digital-to-analog converters, the ultimate power source still depends on bulky off-chip components, which are expensive and cannot be easily miniaturized. For point-of-care applications, it is critical to integrate all the components in a compact size at low cost. In this work, we report two key active components actuated by osmotic mechanism for total integrated microfluidic system. For the proof of concept, we have demonstrated valve actuation, which can maintain stable ON/OFF switching operations under 125 kPa back pressure. We have also implemented an osmotic pump, which can pump a high flow rate over 30 μL/min for longer than 30 minutes. The experimental data demonstrates the possibility and potential of applying osmotic actuation in point-of-care disposable microfluidics. © 2013 IEEE.

Process design of a new injection method of liquid CO2 at the intermediate depths in the ocean using a static mixer

International Nuclear Information System (INIS)

Tajima, Hideo; Yamasaki, Akihiro; Kiyono, Fumio

2005-01-01

Process design for a new injection method of liquid CO 2 using a static mixer was conducted based on laboratory experimental results on the formation process of liquid CO 2 drops covered with hydrate film by a Kenics-type static mixer, and numerical simulation of the liquid CO 2 drops at 500 and 1500 m. The Sauter Mean Diameter (SMD) of the liquid CO 2 drops covered with hydrate film was dramatically decreased with the use of the static mixer; empirical equations were obtained for the SMD, and also the maximum and minimum diameters of the liquid CO 2 drops for a given flow velocity (Weber number, We). The ascending and dissolving behavior of a liquid CO 2 drop with hydrate released in the ocean at an intermediate depth was numerically simulated, and the maximum drop diameter to avoid evaporation of the drop before complete dissolution was estimated. Based on these results, scaling up of the static mixer was conducted by assuming a disposal process of CO 2 emitted from a 100-MW thermal power plant, and the mixer diameter was determined as a function of the given SMD. Moreover, the power consumption of the static mixer was evaluated and found to be almost negligible. (author)

Osmotic dehydration of fish: principal component analysis

Directory of Open Access Journals (Sweden)

Lončar Biljana Lj.

2014-01-01

Full Text Available Osmotic treatment of the fish Carassius gibelio was studied in two osmotic solutions: ternary aqueous solution - S1, and sugar beet molasses - S2, at three solution temperatures of 10, 20 and 30oC, at atmospheric pressure. The aim was to examine the influence of type and concentration of the used hypertonic agent, temperature and immersion time on the water loss, solid gain, dry mater content, aw and content of minerals (Na, K, Ca and Mg. S2 solution has proven to be the best option according to all output variables.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31055

Terahertz hot electron bolometer waveguide mixers for GREAT

OpenAIRE

Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J.

2012-01-01

Supplementing the publications based on the first-light observations with the German Receiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on the...

Electro-optic transceivers for terahertz-wave applications

International Nuclear Information System (INIS)

Chen, Q.; Tani, M.; Jiang, Zhiping; Zhang, X.-C.

2001-01-01

Because of the reciprocal behavior of the optical rectification and the electro-optic effect in a nonlinear optical crystal, an electro-optic transceiver can alternately transmit pulsed electromagnetic radiation (optical rectification) and detect the return signal (electro-optic effect) in the same crystal. However, the optimal condition of the electro-optic transceiver may be very different from that of the spatially separated emitter and receiver. We present a detailed description of the crystal-orientation dependence of the electro-optic terahertz devices (transmitter, receiver, and transceiver). It is found that for a (110) zinc-blende electro-optical crystal, the efficiency of the electro-optic transceiver will be optimized when the angle between the polarization of the optical pump beam and the crystallographic z axis [0,0,1] is 26 degree. Meanwhile, for a (111) crystal, the angle between the optical beam and the crystallographic direction [-1,-1,2] should be 23 degree. The experimental results from a (110) ZnTe transceiver verify theoretical calculations and demonstrate a direct way to optimize the working efficiency of an electro-optic terahertz transceiver. [copyright] 2001 Optical Society of America

The effects of exogenous proline and osmotic stress on morpho ...

African Journals Online (AJOL)

For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous Lproline (0, 2.5, 5 and 10 ...

Numerical analysis of finite Debye-length effects in induced-charge electro-osmosis.

Science.gov (United States)

Gregersen, Misha Marie; Andersen, Mathias Baekbo; Soni, Gaurav; Meinhart, Carl; Bruus, Henrik

2009-06-01

For a microchamber filled with a binary electrolyte and containing a flat unbiased center electrode at one wall, we employ three numerical models to study the strength of the resulting induced-charge electro-osmotic (ICEO) flow rolls: (i) a full nonlinear continuum model resolving the double layer, (ii) a linear slip-velocity model not resolving the double layer and without tangential charge transport inside this layer, and (iii) a nonlinear slip-velocity model extending the linear model by including the tangential charge transport inside the double layer. We show that, compared to the full model, the slip-velocity models significantly overestimate the ICEO flow. This provides a partial explanation of the quantitative discrepancy between observed and calculated ICEO velocities reported in the literature. The discrepancy increases significantly for increasing Debye length relative to the electrode size, i.e., for nanofluidic systems. However, even for electrode dimensions in the micrometer range, the discrepancies in velocity due to the finite Debye length can be more than 10% for an electrode of zero height and more than 100% for electrode heights comparable to the Debye length.

Electro-optic diffraction grating tuned laser

International Nuclear Information System (INIS)

Hughes, R.S.

1975-01-01

An electro-optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro-optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating is described. An optional angle multiplier may be used between the electro-optic diffraction grating and the reflective grating. (auth)

Fundamentals of electro-engineering I

International Nuclear Information System (INIS)

Rapsik, M.; Smola, M.; Bohac, M.; Mucha, M.

2004-01-01

This is the text-book of the fundamentals of electro-engineering. It contains the following chapters: (1) Selected terms in electro-engineering; (2) Fundamental electric values; (3) Energy and their transformations; (4) Water, hydro-energy and hydro-energetic potential of the Slovak Republic; (5) Nuclear power engineering; (6) Conventional thermal power plants; (7) Heating and cogeneration of electric power and heat production; (8) Equipment of electricity supply system; (9) Measurements in electro-engineering ; (10) Regulation of frequency and voltage, electric power quality

Osmotic consolidation of suspensions and gels

International Nuclear Information System (INIS)

Miller, K.T.; Zukoski, C.F.

1994-01-01

An osmotic method for the consolidation of suspensions of ceramic particles is demonstrated. Concentrated solutions of poly(ethylene oxide) are separated from a suspension of ceramic particles by a semipermeable membrane, creating a gradient in solvent chemical potential. Solvent passes from the suspension into the polymer solution, lowering its free energy and consolidating the suspension. Dispersions of stable 8-nm hydrous zirconia particles were consolidated to over 47% by volume. Suspensions of α-alumina in three states of aggregation (dispersed, weakly flocculated, and strongly flocculated) were consolidated to densities greater than or equal to those produced in conventional pressure filtration. Moreover, the as-consolidated alumina bodies were partially drained of fluid during the osmotic consolidation process, producing cohesive partially dried bodies with improved handling characteristics

Electro-optic polymers for high speed modulators

NARCIS (Netherlands)

Balakrishnan, M.; Diemeer, Mart; Driessen, A.; Faccini, M.; Verboom, Willem; Reinhoudt, David; Leinse, Arne; Megret, P.; Wuilpart, M.; Bette, S.; Staquet, N.

2005-01-01

Different electro-optic polymer systems are analyzed with respect to their electro-optic activity, glass transition temperature $(T_g)$ and photodefinable properties. The polymers tested are polysulfone (PS) and polycarbonate (PC). The electro-optic chromophore,

Photonics-Based Microwave Image-Reject Mixer

Directory of Open Access Journals (Sweden)

Dan Zhu

2018-03-01

Full Text Available Recent developments in photonics-based microwave image-reject mixers (IRMs are reviewed with an emphasis on the pre-filtering method, which applies an optical or electrical filter to remove the undesired image, and the phase cancellation method, which is realized by introducing an additional phase to the converted image and cancelling it through coherent combination without phase shift. Applications of photonics-based microwave IRM in electronic warfare, radar systems and satellite payloads are described. The inherent challenges of implementing photonics-based microwave IRM to meet specific requirements of the radio frequency (RF system are discussed. Developmental trends of the photonics-based microwave IRM are also discussed.

Recent experimental data may point to a greater role for osmotic pressures in the subsurface

Science.gov (United States)

Neuzil, C.E.; Provost, A.M.

2009-01-01

Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by Neuzil (2000) suggesting that Pierre Shale could generate large osmotic pressures when highly compacted. In the last few years, additional laboratory and in situ experiments have greatly increased the number of data on osmotic properties of argillaceous formations, but they have not been systematically examined. In this paper we compile these data and explore their implications for osmotic pressure generation in subsurface systems. Rather than base our analysis on osmotic efficiencies, which depend strongly on concentration, we calculated values of a quantity we term osmotic specific surface area (Aso) that, in principle, is a property of the porous medium only. The Aso values are consistent with a surprisingly broad spectrum of osmotic behavior in argillaceous formations, and all the formations tested exhibited at least a modest ability to generate osmotic pressure. It appears possible that under appropriate conditions some formations can be highly effective osmotic membranes able to generate osmotic pressures exceeding 30 MPa (3 km of head) at porosities as high as ∼0.1 and pressures exceeding 10 MPa at porosities as high as ∼0.2. These findings are difficult to reconcile with the lack of compelling field evidence for osmotic pressures, and we propose three explanations for the disparity: (1) Our analysis is flawed and argillaceous formations are less effective osmotic membranes than it suggests; (2) the necessary subsurface conditions, significant salinity differences within intact argillaceous formations, are rare; or (3) osmotic pressures are unlikely to be detected and are not recognized when encountered. The last possibility

Structural analysis: Flexible receiver yoke brace for the 241SY101 mixer pump

International Nuclear Information System (INIS)

Jones, K.M.

1994-01-01

This report documents the structural analysis of the flexible-receiver yoke brace that will be used to maintain the mixer pump lifting yoke in a vertical position during the removal of the mixer pump from waste tank 241SY101. During the removal process, the crane is connected to a lifting yoke which is attached to the lifting on the mounting flange of the mixer pump. The pump then can be lifted from the tank. At one point in the removal procedure, the crane will be disconnected from the lifting yoke. At this time, it is possible for the lifting yoke to rotate around the pinned connection between it and the pump if it is subjected to a horizontal load. To prevent the rotation of the lifting yoke, the yoke brace was designed to maintain the yoke in a vertical position while it is disconnected from the crane. This analysis addressed the adequacy of the yoke brace to provide support for the lifting yoke during high winds and a seismic event. The results of this analysis show that, when subjected to a combined design wind and seismic load, the yoke brace design is acceptable to maintain the lifting yoke in a vertical position when the yoke is disconnected from the crane

Gene expression analysis in response to osmotic stimuli in the intervertebral disc with DNA microarray.

Science.gov (United States)

Zhang, Wenzhi; Li, Xu; Shang, Xifu; Zhao, Qichun; Hu, Yefeng; Xu, Xiang; He, Rui; Duan, Liqun; Zhang, Feng

2013-12-27

Intervertebral disc (IVD) cells experience a broad range of physicochemical stimuli under physiologic conditions, including alterations in their osmotic environment. At present, the molecular mechanisms underlying osmotic regulation in IVD cells are poorly understood. This study aims to screen genes affected by changes in osmotic pressure in cells of subjects aged 29 to 63 years old, with top-scoring pair (TSP) method. Gene expression data set GSE1648 was downloaded from Gene Expression Omnibus database, including four hyper-osmotic stimuli samples, four iso-osmotic stimuli samples, and three hypo-osmotic stimuli samples. A novel, simple method, referred to as the TSP, was used in this study. Through this method, there was no need to perform data normalization and transformation before data analysis. A total of five pairs of genes ((CYP2A6, FNTB), (PRPF8, TARDBP), (RPS5, OAZ1), (SLC25A3, NPM1) and (CBX3, SRSF9)) were selected based on the TSP method. We inferred that all these genes might play important roles in response to osmotic stimuli and age in IVD cells. Additionally, hyper-osmotic and iso-osmotic stimuli conditions were adverse factors for IVD cells. We anticipate that our results will provide new thoughts and methods for the study of IVD disease.

Design of Ka-band antipodal finline mixer and detector

International Nuclear Information System (INIS)

Yao Changfei; Xu Jinping; Chen Mo

2009-01-01

This paper mainly discusses the analysis and design of a finline single-ended mixer and detector. In the circuit, for the purpose of eliminating high-order resonant modes and improving transition loss, metallic via holes are implemented along the mounting edge of the substrate embedded in the split-block of the WG-finline-microstrip transition. Meanwhile, a Ka band slow-wave and bandstop filter, which represents a reactive termination, is designed for the utilization of idle frequencies and operation frequencies energy. Full-wave analysis is carried out to optimize the input matching network of the mixer and the detector circuit using lumped elements to model the nonlinear diode. The exported S-matrix of the optimized circuit is used for conversion loss and voltage sensitivity analysis. The lowest measured conversion loss is 3.52 dB at 32.2 GHz; the conversion loss is flat and less than 5.68 dB in the frequency band of 29-34 GHz. The highest measured zero-bias voltage sensitivity is 1450 mV/mW at 38.6 GHz, and the sensitivity is better than 1000 mV/mW in the frequency band of 38-40 GHz.

Quantification of osmotic water transport in vivo using fluorescent albumin.

Science.gov (United States)

Morelle, Johann; Sow, Amadou; Vertommen, Didier; Jamar, François; Rippe, Bengt; Devuyst, Olivier

2014-10-15

Osmotic water transport across the peritoneal membrane is applied during peritoneal dialysis to remove the excess water accumulated in patients with end-stage renal disease. The discovery of aquaporin water channels and the generation of transgenic animals have stressed the need for novel and accurate methods to unravel molecular mechanisms of water permeability in vivo. Here, we describe the use of fluorescently labeled albumin as a reliable indicator of osmotic water transport across the peritoneal membrane in a well-established mouse model of peritoneal dialysis. After detailed evaluation of intraperitoneal tracer mass kinetics, the technique was validated against direct volumetry, considered as the gold standard. The pH-insensitive dye Alexa Fluor 555-albumin was applied to quantify osmotic water transport across the mouse peritoneal membrane resulting from modulating dialysate osmolality and genetic silencing of the water channel aquaporin-1 (AQP1). Quantification of osmotic water transport using Alexa Fluor 555-albumin closely correlated with direct volumetry and with estimations based on radioiodinated ((125)I) serum albumin (RISA). The low intraperitoneal pressure probably accounts for the negligible disappearance of the tracer from the peritoneal cavity in this model. Taken together, these data demonstrate the appropriateness of pH-insensitive Alexa Fluor 555-albumin as a practical and reliable intraperitoneal volume tracer to quantify osmotic water transport in vivo. Copyright © 2014 the American Physiological Society.

Design of a ×4 subharmonic sub-millimeter wave diode mixer, based on an analytic expression for small-signal conversion admittance parameters

DEFF Research Database (Denmark)

Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Krozer, Viktor

2013-01-01

Instead of using frequency multipliers before a fundamental mixer, subharmonic mixers can be used. In order to develop novel subharmonic mixer architectures it is necessary to know the exact signal phase at the nonlinear element. The purpose of this paper is to generalize the description of the s....... With an RF frequency of 640 GHz, this design achieves a conversion gain of −13.5 dB with a LO-power of only −2.5 dBm....

Enhanced methanol electro-oxidation reaction on Pt-CoO{sub x}/MWCNTs hybrid electro-catalyst

Energy Technology Data Exchange (ETDEWEB)

Nouralishahi, Amideddin, E-mail: Nouralishahi@ut.ac.ir [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Caspian Faculty of Engineering, University of Tehran, P.O. Box 43841-119, Rezvanshahr (Iran, Islamic Republic of); Catalysis and Nanotechnology Research Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-1998, Tehran (Iran, Islamic Republic of); Rashidi, Ali Morad, E-mail: Rashidiam@ripi.ir [Catalysis and Nanotechnology Research Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-1998, Tehran (Iran, Islamic Republic of); Mortazavi, Yadollah, E-mail: Mortazav@ut.ac.ir [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Khodadadi, Abbas Ali, E-mail: Khodadad@ut.ac.ir [Catalysis and Nanostructured Materials Research Laboratory, School of Chemical Engineering, University of Tehran, P.O. Box 11155/4563, Tehran (Iran, Islamic Republic of); Choolaei, Mohammadmehdi, E-mail: Choolaeimm@ripi.ir [Catalysis and Nanotechnology Research Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-1998, Tehran (Iran, Islamic Republic of)

2015-04-30

Highlights: • Promoting effects of Cobalt oxide on methanol electro-oxidation over Pt/MWCNTs are investigated. • Higher activity, about 2.9 times, and enhanced stability are observed on Pt-CoO{sub x}/MWCNTs. • Electrochemical active surface area of Pt nanoparticles is significantly improved upon CoO{sub x} addition. • Bi-functional mechanism is facilitated in presence of CoO{sub x}. - Abstract: The electro-catalytic behavior of Pt-CoO{sub x}/MWCNTs in methanol electro-oxidation reaction (MOR) is investigated and compared to that of Pt/MWCNTs. The electro-catalysts were synthesized by an impregnation method using NaBH{sub 4} as the reducing agent. The morphological and physical characteristics of samples are examined by XRD, TEM, ICP and EDS techniques. In the presence of CoO{sub x}, Pt nanoparticles were highly distributed on the support with an average particle size of 2 nm, an obvious decrease from 5.1 nm for Pt/MWCNTs. Cyclic voltammetry, CO-stripping, Chronoamperometry, and electrochemical impedance spectroscopy (EIS) measurements are used to study the electrochemical behavior of the electro-catalysts. The results revealed a considerable enhancement in the oxidation kinetics of CO{sub ads} on Pt active sites by the participation of CoO{sub x}. Compared to Pt/MWCNTs, Pt-CoO{sub x}/MWCNTs sample has a larger electrochemical active surface area (ECSA) and higher electro-catalytic activity and stability toward methanol electro-oxidation. According to the results of cyclic voltammetry, the forward anodic peak current density enhances more than 89% at the optimum atomic ratio of Pt:Co = 2:1. Furthermore, inclusion of cobalt oxide species causes the onset potential of methanol electro-oxidation reaction to shift 84 mV to negative values compared to that on Pt/MWCNTs. Based on EIS data, dehydrogenation of methanol is the rate-determining step of MOR on both Pt/MWCNTs and Pt-CoO{sub x}/MWCNTs, at small overpotentials. However, at higher overpotentials, the

Osmotic and Heat Stress Effects on Segmentation.

Directory of Open Access Journals (Sweden)

Julian Weiss

Full Text Available During vertebrate embryonic development, early skin, muscle, and bone progenitor populations organize into segments known as somites. Defects in this conserved process of segmentation lead to skeletal and muscular deformities, such as congenital scoliosis, a curvature of the spine caused by vertebral defects. Environmental stresses such as hypoxia or heat shock produce segmentation defects, and significantly increase the penetrance and severity of vertebral defects in genetically susceptible individuals. Here we show that a brief exposure to a high osmolarity solution causes reproducible segmentation defects in developing zebrafish (Danio rerio embryos. Both osmotic shock and heat shock produce border defects in a dose-dependent manner, with an increase in both frequency and severity of defects. We also show that osmotic treatment has a delayed effect on somite development, similar to that observed in heat shocked embryos. Our results establish osmotic shock as an alternate experimental model for stress, affecting segmentation in a manner comparable to other known environmental stressors. The similar effects of these two distinct environmental stressors support a model in which a variety of cellular stresses act through a related response pathway that leads to disturbances in the segmentation process.

Effect of sulphuric acid concentration on electroosmotic flow through polymer electrolyte membranes in PEM fuel cells. Paper no. IGEC-1-061

International Nuclear Information System (INIS)

Karimi, G.; Li, X.

2005-01-01

Polymer electrolyte membrane (PEM) fuel cells are highly efficient and environmentally clean, and hence one of the most promising power sources for both stationary and mobile applications. The operations of PEM fuel cells are complicated by the electroosmotic flow of water from anode to cathode through the polymer electrolyte membrane leading to the membrane dehydration and fuel cell performance degradations. In this study, electro osmotic flow in polymer electrolyte membranes is modeled by incorporating the electro kinetic effects in the presence of euphoric acid. The governing Poisson-Boatman and the Nervier-Stokes equations were solved numerically for a single membrane pore to determine the electro osmotic flow distributions through the membrane over a wide range of acid concentrations. The presence of euphoric acid modifies the protons distribution in the membrane and hence alters the driving force for electroosmotic drag. Numerical results indicate that the electro osmotic flow increases steadily with acid concentration. The water transport due to electro osmosis is almost doubled at 2 M acid concentration compared with that of non-doped membrane. The value of electroosmotic drag coefficient however falls steadily with acid concentration due to the presence of a larger number of protons in the electrolyte. (author)

Modeling and Optimization of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applicaitons

Science.gov (United States)

Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.; Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.

1996-01-01

The development of a YBa(sub 2)Cu(sub 3)O(sub 7-(kronecker delta))(YBCO) hot-electron bolometer (HEB) quasioptical mixer for a 2.5 heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of heat diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated....a single sideband temperature of less than 2000k is predicted.

Dependence of osmotic pressure on solution properties

International Nuclear Information System (INIS)

Fritz, S.J.

1978-01-01

Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

The Role of Superoxide Dismutase in Inducing of Wheat Seedlings Tolerance to Osmotic Shock

Directory of Open Access Journals (Sweden)

Oboznyi A.I.

2013-08-01

Full Text Available Influence of short-term hardening osmotic exposure (immersion in 1 M sucrose solution with subsequent transferring to distilled water for 20 min on the hydrogen peroxide generation and superoxide dismutase activity in wheat (Triticum aestivum L., cv. Elegiya seedlings and their tolerance to osmotic shock were investigated. During the initial 30 min after osmotic exposure, the increasing of hydrogen peroxide amount in roots and shoots (to a lesser extent was observed, but the resistance of the seedlings and superoxide dismutase (SOD activity decreased. Sometime later the decrease in hydrogen peroxide amount and the increase of seedlings tolerance to osmotic shock took place. SOD activity increased in 10 min after hardening osmotic exposure. Transient accumulation of hydrogen peroxide induced in this way was suppressed by the treatment of seedlings with sodium diethyldithiocarbamate (DDC, SOD inhibitor. DDC and hydrogen peroxide scavenger dimethylthiourea decreased positive hardening effect of osmotic exposure on the development of seedlings tolerance. It was concluded that SOD providing the generation of signal hydrogen peroxide pool took part in the induction of seedlings tolerance to osmotic shock development caused by preliminary hardening effect.

Osmotic generation of 'anomalous' fluid pressures in geological environments

Science.gov (United States)

Neuzii, C.E.

2000-01-01

Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures - large departures from hydrostatic pressure that are not explicable in terms of topographic or fluid-density effects are widely found in geological settings, and are commonly considered to result from processes that alter the pore or fluid volume, which in turn implies crustal changes happening at a rate too slow to observe directly. Yet if osmosis can explain some anomalies, there is no need to invoke such dynamic geological processes in those cases. Here I report results of a nine- year in situ measurement of fluid pressures and solute concentrations in shale that are consistent with the generation of large (up to 20 MPa) osmotic-pressure anomalies which could persist for tens of millions of years. Osmotic pressures of this magnitude and duration can explain many of the pressure anomalies observed in geological settings. The require, however, small shale porosity and large contrasts in the amount of dissolved solids in the pore waters - criteria that may help to distinguish between osmotic and crystal-dynamic origins of anomalous pressures.

Open source laboratory sample rotator mixer and shaker

Directory of Open Access Journals (Sweden)

Karankumar C. Dhankani

2017-04-01

Full Text Available An open-source 3-D printable laboratory sample rotator mixer is developed here in two variants that allow users to opt for the level of functionality, cost saving and associated complexity needed in their laboratories. First, a laboratory sample rotator is designed and demonstrated that can be used for tumbling as well as gentle mixing of samples in a variety of tube sizes by mixing them horizontally, vertically, or any position in between. Changing the mixing angle is fast and convenient and requires no tools. This device is battery powered and can be easily transported to operate in various locations in a lab including desktops, benches, clean hoods, chemical hoods, cold rooms, glove boxes, incubators or biological hoods. Second, an on-board Arduino-based microcontroller is incorporated that adds the functionality of a laboratory sample shaker. These devices can be customized both mechanically and functionally as the user can simply select the operation mode on the switch or alter the code to perform custom experiments. The open source laboratory sample rotator mixer can be built by non-specialists for under US$30 and adding shaking functionality can be done for under $20 more. Thus, these open source devices are technically superior to the proprietary commercial equipment available on the market while saving over 90% of the costs.

A planar microfluidic mixer based on logarithmic spirals

International Nuclear Information System (INIS)

Scherr, Thomas; Nandakumar, Krishnaswamy; Quitadamo, Christian; Tesvich, Preston; Park, Daniel Sang-Won; Hayes, Daniel; Monroe, W Todd; Tiersch, Terrence; Choi, Jin-Woo

2012-01-01

A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as the Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional (3D) simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing. (paper)

OSMOTIC DEHYDRATION KINETICS OF GUAVAS IN MALTOSE SOLUTIONS WITH CALCIUM SALT*

Directory of Open Access Journals (Sweden)

S. DI S. MASTRANTONIO

2009-03-01

Full Text Available

The osmotic dehydration kinetics of guavas in maltose solutions at 40 and 60ºBrix, with addition of 0, 0.6 and 1.2% of calcium lactate was studied in this paper and the final product quality was evaluated. The experiments were carried out up to 60 hours and samples were taken for analysis at different times to evaluate guavas weight reduction, water loss and sugar gain and to characterize the product according to its texture and color. After 24 hours of process the mass transfer of water and sugar between the osmotic solution and the fruit was negligible, showing that process equilibrium was reached. The increase of sugar concentration in the osmotic solution showed strong influence on the dehydration process, increasing the water loss and reducing sugar gain. The presence of calcium ions in the osmotic solution also influenced the kinetics of mass transfer and showed a strong influence on fruit texture. Higher values of stress and strain at failure were obtained when calcium lactate was employed. The effect of the different osmotic treatments on the color parameters was also investigated and significant changes were observed in the values of chroma C* and hue H* due to sugar concentration and calcium addition.

The BLIXER, a Wideband Balun-LNA-I/Q-Mixer Topology

NARCIS (Netherlands)

Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, Domine M.W.; Nauta, Bram

2008-01-01

Abstract—This paper proposes to merge an I/Q current-commutating mixer with a noise-canceling balun-LNA. To realize a high bandwidth, the real part of the impedance of all RF nodes is kept low, and the voltage gain is not created at RF but in baseband where capacitive loading is no problem. Thus a

Osmotic dehydration of Braeburn variety apples in the production of sustainable food products

Science.gov (United States)

Ciurzyńska, Agnieszka; Cichowska, Joanna; Kowalska, Hanna; Czajkowska, Kinga; Lenart, Andrzej

2018-01-01

The aim of this work was to investigate the effects of osmotic dehydration conditions on the properties of osmotically pre-treated dried apples. The scope of research included analysing the most important mass exchange coefficients, i.e. water loss, solid gain, reduced water content and water activity, as well as colour changes of the obtained dried product. In the study, apples were osmotically dehydrated in one of two 60% solutions: sucrose or sucrose with an addition of chokeberry juice concentrate, for 30 and 120 min, in temperatures of 40 and 60°C. Ultrasound was also used during the first 30 min of the dehydration process. After osmotic pre-treatment, apples were subjected to innovative convective drying with the puffing effect, and to freeze-drying. Temperature and dehydration time increased the effectiveness of mass exchange during osmotic dehydration. The addition of chokeberry juice concentrate to standard sucrose solution and the use of ultrasound did not change the value of solid gain and reduced water content. Water activity of the dried apple tissue was not significantly changed after osmotic dehydration, while changes in colour were significant.

Neutral lipid production in Dunaliella salina during osmotic stress and adaptation

DEFF Research Database (Denmark)

Yao, Shuo; Lu, Jingquan; Sárossy, Zsuzsa

2016-01-01

The salt-tolerant green microalga Dunaliella salina can survive both hyper- and hypo-osmotic shock. Upon osmotic shock, the cells transiently and rapidly decreased or increased in size within minutes and slowly over hours acquired their original cell size and volume. Cell size distribution differs...... significantly in the cultures grown in the salinity range from 1.5 to 15 % NaCl. By using Nile Red fluorescence to detect neutral lipids, it became clear that only hyper-osmotic shock on cells induced transient neutral lipid appearance in D. salina, while those transferred from 9 to 15 % NaCl stimulated...

Phase-locking of a terahertz solid-state source using a superconducting hot-electron bolometer mixer

International Nuclear Information System (INIS)

Miao, W; Zhang, W; Zhou, K M; Li, S L; Zhang, K; Duan, W Y; Yao, Q J; Shi, S C

2013-01-01

We report on a scheme whereby the local-oscillator (LO) of a THz heterodyne receiver can be phase-locked by the mixer of the heterodyne receiver. This scheme is demonstrated for the phase-locking of an 847.6 GHz Gunn oscillator and multiplier chain combined source with a superconducting hot-electron bolometer (HEB) mixer. We show that with this technique the phase-locked beat signal can reach a signal-to-noise ratio higher than 70 dB in a resolution bandwidth (RBW) of 1 Hz. This phase-locking scheme should find good use in THz heterodyne spectrometers. (paper)

A review on controlled porosity osmotic pump tablets and its evaluation

Directory of Open Access Journals (Sweden)

Chinmaya Keshari Sahoo

2015-12-01

Full Text Available Conventional drug delivery system provides an immediate release of drug which does not control the release of the drug and does not maintain effective concentration at target site for a longer period of time. Hence to avoid the shortcomings there is development of various controlled drug delivery systems. Among these osmotic drug delivery system (ODDS utilizes the principle of osmotic pressure and delivers drug dose in an optimized manner to maintain drug concentration within the therapeutic window and minimizes toxic effects. ODDS releases drug at a controlled rate that is independent of the pH and thermodynamics of dissolution medium. The release of drug from ODDS follows zero order kinetics. The release of drug from osmotic system depends upon various formulation factors such as solubility, osmotic pressure of the core components, size of the delivery orifice and nature of the rate controlling membrane. Controlled porosity osmotic pump (CPOP contains drug, osmogens, excipients in core and a coating of semipermeable membrane with water soluble additives. In CPOP water soluble additives dissolve after coming in contact with water, resulting in an in situ formation of a microporous membrane. The present study gives an idea about osmosis, CPOP, components of CPOP and its evaluation.

Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

Science.gov (United States)

Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

2014-01-01

The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

Osmotic Effects in Sludge Dewatering

DEFF Research Database (Denmark)

Keiding, Kristian; Rasmussen, Michael R.

2003-01-01

A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...

Recent development in osmotic dehydration of fruit and vegetables: a review.

Science.gov (United States)

Chandra, Suresh; Kumari, Durvesh

2015-01-01

Osmotic dehydration of fruits and vegetables is achieved by placing the solid/semi solid, whole or in pieces, in a hypertonic solution (sugar and/or salt) with a simultaneous counter diffusion of solutes from the osmotic solution into the tissues. Osmotic dehydration is recommended as a processing method to obtain better quality of food products. Partial dehydration allows structural, nutritional, sensory, and other functional properties of the raw material to be modified. However, the food industry uptake of osmotic dehydration of foods has not been extensive as expected due to the poor understanding of the counter current flow phenomena associated with it. However, these flows are in a dynamic equilibrium with each other and significantly influence the final product in terms of preservation, nutrition, and organoleptic properties. The demand of healthy, natural, nutritious, and tasty processed food products continuously increases, not only for finished products, but also for ingredient to be included in complex foods such as ice cream, cereals, dairy, confectionaries, and bakery products.

A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

KAUST Repository

Zhu, Jianhua

2010-04-16

Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

Modeling emulsification processes in rotary-disk mixers

Science.gov (United States)

Laponov, S. V.; Shulaev, N. S.; Ivanov, S. P.; Bondar', K. E.; Suleimanov, D. F.

2017-10-01

This article presents the experimental studies results of emulsification processes in liquid-liquid systems in rotary-disk mixers, allowing regulating the distribution of dispersed particles by changing the process conditions and the ratio of the dispersed phase. It is shown that with the increase of mixer’s revolutions per minute (RPM), both the size of dispersed particles and the deviation of dispersed particles sizes from the average decrease. The increase of the dispersed particles part results in the increase of particles average sizes at the current energy consumption. Discovered relationships can be used in the design of industrial equipment and laboratory research.

The rate of hypo-osmotic challenge influences regulatory volume decrease (RVD) and mechanical properties of articular chondrocytes.

Science.gov (United States)

Wang, Z; Irianto, J; Kazun, S; Wang, W; Knight, M M

2015-02-01

Osteoarthritis (OA) is associated with a gradual reduction in the interstitial osmotic pressure within articular cartilage. The aim of this study was to compare the effects of sudden and gradual hypo-osmotic challenge on chondrocyte morphology and biomechanics. Bovine articular chondrocytes were exposed to a reduction in extracellular osmolality from 327 to 153 mOsmol/kg applied either suddenly (osmotic stress, 66% of chondrocytes exhibited an increase in diameter followed by RVD, whilst 25% showed no RVD. By contrast, cells exposed to gradual hypo-osmotic stress exhibited reduced cell swelling without subsequent RVD. There was an increase in the equilibrium modulus for cells exposed to sudden hypo-osmotic stress. However, gradual hypo-osmotic challenge had no effect on cell mechanical properties. This cell stiffening response to sudden hypo-osmotic challenge was abolished when actin organization was disrupted with cytochalasin D or RVD inhibited with REV5901. Both sudden and gradual hypo-osmotic challenge reduced cortical F-actin distribution and caused chromatin decondensation. Sudden hypo-osmotic challenge increases chondrocyte mechanics by activation of RVD and interaction with the actin cytoskeleton. Moreover, the rate of hypo-osmotic challenge is shown to have a profound effect on chondrocyte morphology and biomechanics. This important phenomenon needs to be considered when studying the response of chondrocytes to pathological hypo-osmotic stress. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Plasma osmotic changes during major abdominal surgery.

Science.gov (United States)

Malone, R A; McLeavey, C A; Arens, J F

1977-12-01

Fluid balance across the capillary membrane is maintained normally by a balance of hydrostatic and colloid osmotic pressures (COP). In 12 patients having major intra-abdominal procedures, the COP was followed during the operative and immediate postoperative periods. The patients' intraoperative fluid management consisted of replacing shed blood with blood and following Shires' concept of crystalloid replacement. Significant decreases in COP to approximately two thirds of the initial value occurred in patients having intra-abdominal procedures versus only a 10 percent decrease in those having peripheral procedures (greater than .001). As a result of this decrease in COP, the balance between hydrostatic and colloid osmotic pressures is lost and risk of pulmonary intersitial edema is increased.

Numerical study of fluid motion in bioreactor with two mixers

Energy Technology Data Exchange (ETDEWEB)

Zheleva, I., E-mail: izheleva@uni-ruse.bg [Department of Heat Technology, Hydraulics and Ecology, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria); Lecheva, A., E-mail: alecheva@uni-ruse.bg [Department of Mathematics, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria)

2015-10-28

Numerical study of hydrodynamic laminar behavior of a viscous fluid in bioreactor with multiple mixers is provided in the present paper. The reactor is equipped with two disk impellers. The fluid motion is studied in stream function-vorticity formulation. The calculations are made by a computer program, written in MATLAB. The fluid structure is described and numerical results are graphically presented and commented.

Controlled porosity solubility modulated osmotic pump tablets of gliclazide.

Science.gov (United States)

Banerjee, Arti; Verma, P R P; Gore, Subhash

2015-06-01

A system that can deliver drug at a controlled rate is very important for the treatment of various chronic diseases such as diabetes, asthma, and heart disease. Poorly water-soluble drug with pH-dependent solubility such as gliclazide (GLZ) offers challenges in the controlled-release formulation because of low dissolution rate and poor bioavailability. Solid dispersion (SD) of GLZ consisted of hydroxypropyl cellulose (HPC-SSL) as a polymeric solubilizer was manufactured by hot melt extrusion (HME) technology. Then, controlled porosity osmotic pump (CPOP) tablet of gliclazide was designed to deliver drug in a controlled manner up to 16 h. The developed formulation was optimized for type and level of pore former and coating weight gain. The optimized formulation was found to exhibit zero order kinetics independent of pH and agitation speed but depends on osmotic pressure of dissolution media indicated that mechanism of drug release was osmotic pressure. The in vivo performance prediction of developed formulation using convolution approach revealed that the developed formulation was superior to the existing marketed extended-release formulation in terms of attaining steady state plasma levels and indicated adequate exposure in translating hypoglycemic response. The prototype solubilization method combined with controlled porosity osmotic pump based technique could provide a unique way to increase dissolution rate and bioavailability of many poorly water-soluble, narrow therapeutic index drugs used in diabetes, cardiovascular diseases, etc.

Unified Frequency-Domain Analysis of Switched-Series-RC Passive Mixers and Samplers

NARCIS (Netherlands)

Soer, M.C.M.; Klumperink, Eric A.M.; de Boer, Pieter-Tjerk; van Vliet, Frank Edward; Nauta, Bram

2010-01-01

Abstract—A wide variety of voltage mixers and samplers are implemented with similar circuits employing switches, resistors, and capacitors. Restrictions on duty cycle, bandwidth, or output frequency are commonly used to obtain an analytical expression for the response of these circuits. This paper

The osmotic stress response of split influenza vaccine particles in an acidic environment.

Science.gov (United States)

Choi, Hyo-Jick; Kim, Min-Chul; Kang, Sang-Moo; Montemagno, Carlo D

2014-12-01

Oral influenza vaccine provides an efficient means of preventing seasonal and pandemic disease. In this work, the stability of envelope-type split influenza vaccine particles in acidic environments has been investigated. Owing to the fact that hyper-osmotic stress can significantly affect lipid assembly of vaccine, osmotic stress-induced morphological change of split vaccine particles, in conjunction with structural change of antigenic proteins, was investigated by the use of stopped-flow light scattering (SFLS), intrinsic fluorescence, transmission electron microscopy (TEM), and hemagglutination assay. Split vaccine particles were found to exhibit a step-wise morphological change in response to osmotic stress due to double-layered wall structure. The presence of hyper-osmotic stress in acidic medium (0.3 osmolarity, pH 2.0) induced a significant level of membrane perturbation as measured by SFLS and TEM, imposing more damage to antigenic proteins on vaccine envelope than can be caused by pH-induced conformational change at acidic iso-osmotic condition. Further supports were provided by the intrinsic fluorescence and hemagglutinin activity measurements. Thus, hyper-osmotic stress becomes an important factor for determining stability of split vaccine particles in acidic medium. These results are useful in better understanding the destabilizing mechanism of split influenza vaccine particles in gastric environment and in designing oral influenza vaccine formulations.

The effects of osmotic stress on the structure and function of the cell nucleus.

Science.gov (United States)

Finan, John D; Guilak, Farshid

2010-02-15

Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically- or volume-activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper-osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo-osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically-induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis. (c) 2009 Wiley-Liss, Inc.

A simple three-dimensional-focusing, continuous-flow mixer for the study of fast protein dynamics.

Science.gov (United States)

Burke, Kelly S; Parul, Dzmitry; Reddish, Michael J; Dyer, R Brian

2013-08-07

We present a simple, yet flexible microfluidic mixer with a demonstrated mixing time as short as 80 μs that is widely accessible because it is made of commercially available parts. To simplify the study of fast protein dynamics, we have developed an inexpensive continuous-flow microfluidic mixer, requiring no specialized equipment or techniques. The mixer uses three-dimensional, hydrodynamic focusing of a protein sample stream by a surrounding sheath solution to achieve rapid diffusional mixing between the sample and sheath. Mixing initiates the reaction of interest. Reactions can be spatially observed by fluorescence or absorbance spectroscopy. We characterized the pixel-to-time calibration and diffusional mixing experimentally. We achieved a mixing time as short as 80 μs. We studied the kinetics of horse apomyoglobin (apoMb) unfolding from the intermediate (I) state to its completely unfolded (U) state, induced by a pH jump from the initial pH of 4.5 in the sample stream to a final pH of 2.0 in the sheath solution. The reaction time was probed using the fluorescence of 1-anilinonaphthalene-8-sulfonate (1,8-ANS) bound to the folded protein. We observed unfolding of apoMb within 760 μs, without populating additional intermediate states under these conditions. We also studied the reaction kinetics of the conversion of pyruvate to lactate catalyzed by lactate dehydrogenase using the intrinsic tryptophan emission of the enzyme. We observe sub-millisecond kinetics that we attribute to Michaelis complex formation and loop domain closure. These results demonstrate the utility of the three-dimensional focusing mixer for biophysical studies of protein dynamics.

The osmotic second virial coefficient and the Gibbs-McMillan-Mayer framework

DEFF Research Database (Denmark)

Mollerup, J.M.; Breil, Martin Peter

2009-01-01

The osmotic second virial coefficient is a key parameter in light scattering, protein crystallisation. self-interaction chromatography, and osmometry. The interpretation of the osmotic second virial coefficient depends on the set of independent variables. This commonly includes the independent...... variables associated with the Kirkwood-Buff, the McMillan-Mayer, and the Lewis-Randall solution theories. In this paper we analyse the osmotic second virial coefficient using a Gibbs-McMillan-Mayer framework which is similar to the McMillan-Mayer framework with the exception that pressure rather than volume...... is an independent variable. A Taylor expansion is applied to the osmotic pressure of a solution where one of the solutes is a small molecule, a salt for instance, that equilibrates between the two phases. Other solutes are retained. Solvents are small molecules that equilibrate between the two phases...

On equations for the total suction and its matric and osmotic components

International Nuclear Information System (INIS)

Dao, Vinh N.T.; Morris, Peter H.; Dux, Peter F.

2008-01-01

A clear fundamental understanding of suctions is crucial for the study of the behaviour of plastic cement mortar and concrete, including plastic shrinkage cracking. In this paper, the expression relating the change in free energy of the pore water with an isothermal change in pressure is first derived. Based upon definitions of suctions, it is then shown that total, matric, and osmotic suctions can all be expressed in the same thermodynamic form. The widely accepted, but not yet satisfactorily validated, assumption that the total suction comprises matric and osmotic components is then confirmed theoretically. The well-known Kelvin equation for matric suction, and Morse and van't Hoff equations for osmotic suction are subsequently derived from the corresponding thermodynamic equations. The applicability of latter two equations in evaluating the osmotic suctions of cement mortar and concrete is highlighted

Expression profiling on soybean leaves reveals integration of ER- and osmotic-stress pathways

Directory of Open Access Journals (Sweden)

Dewey Ralph E

2007-11-01

Full Text Available Abstract Background Despite the potential of the endoplasmic reticulum (ER stress response to accommodate adaptive pathways, its integration with other environmental-induced responses is poorly understood in plants. We have previously demonstrated that the ER-stress sensor binding protein (BiP from soybean exhibits an unusual response to drought. The members of the soybean BiP gene family are differentially regulated by osmotic stress and soybean BiP confers tolerance to drought. While these results may reflect crosstalk between the osmotic and ER-stress signaling pathways, the lack of mutants, transcriptional response profiles to stresses and genome sequence information of this relevant crop has limited our attempts to identify integrated networks between osmotic and ER stress-induced adaptive responses. As a fundamental step towards this goal, we performed global expression profiling on soybean leaves exposed to polyethylene glycol treatment (osmotic stress or to ER stress inducers. Results The up-regulated stress-specific changes unmasked the major branches of the ER-stress response, which include enhancing protein folding and degradation in the ER, as well as specific osmotically regulated changes linked to cellular responses induced by dehydration. However, a small proportion (5.5% of total up-regulated genes represented a shared response that seemed to integrate the two signaling pathways. These co-regulated genes were considered downstream targets based on similar induction kinetics and a synergistic response to the combination of osmotic- and ER-stress-inducing treatments. Genes in this integrated pathway with the strongest synergistic induction encoded proteins with diverse roles, such as plant-specific development and cell death (DCD domain-containing proteins, an ubiquitin-associated (UBA protein homolog and NAC domain-containing proteins. This integrated pathway diverged further from characterized specific branches of ER-stress as

30 GHz monolithic balanced mixers using an ion-implanted FET-compatible 3-inch GaAs wafer process technology

Science.gov (United States)

Bauhahn, P.; Contolatis, A.; Sokolov, V.; Chao, C.

1986-01-01

An all ion-implanted Schottky barrier mixer diode which has a cutoff frequency greater than 1000 GHz has been developed. This new device is planar and FET-compatible and employs a projection lithography 3-inch wafer process. A Ka-band monolithic balanced mixer based on this device has been designed, fabricated and tested. A conversion loss of 8 dB has been measured with a LO drive of 10 dBm at 30 GHz.

A novel microfluidic mixer based on dual-hydrodynamic focusing for interrogating the kinetics of DNA-protein interaction.

Science.gov (United States)

Li, Ying; Xu, Fei; Liu, Chao; Xu, Youzhi; Feng, Xiaojun; Liu, Bi-Feng

2013-08-21

Kinetic measurement of biomacromolecular interaction plays a significant role in revealing the underlying mechanisms of cellular activities. Due to the small diffusion coefficient of biomacromolecules, it is difficult to resolve the rapid kinetic process with traditional analytical methods such as stopped-flow or laminar mixers. Here, we demonstrated a unique continuous-flow laminar mixer based on microfluidic dual-hydrodynamic focusing to characterize the kinetics of DNA-protein interactions. The time window of this mixer for kinetics observation could cover from sub-milliseconds to seconds, which made it possible to capture the folding process with a wide dynamic range. Moreover, the sample consumption was remarkably reduced to <0.55 μL min⁻¹, over 1000-fold saving in comparison to those reported previously. We further interrogated the interaction kinetics of G-quadruplex and the single-stranded DNA binding protein, indicating that this novel micromixer would be a useful approach for analyzing the interaction kinetics of biomacromolecules.

Scale-up of mixer-settler for uranium extraction; Determinacao das relacoes de `scale-up` em misturador-decantador tipo caixa utilizado na extracao de uranio

Energy Technology Data Exchange (ETDEWEB)

Santana, A.O. de

1990-05-01

The aim of this work was to obtain scale-up relations for a box type mixer-settler used in uranium extraction process for chloridric leaches. Three box type units with different sizes and with the same geometry were used for scale-up of the mixer. The correlation between extraction rate and specific power input, D/T ratio (stirrer diameter/mixer length) and residence time were experimentally obtained. The results showed that the extraction increases with power input for a constant value of D/T equal to 1/3, remaining however independent from mixer sizes for a specific value of power input. This behavior was observed for power input values ranging from 100 to 750 w/m{sup 9}. (author). 23 refs, 22 figs, 23 tabs.

Water transport mechanisms across inorganic membranes in rad waste treatment by electro dialysis. Mecanismos de transporte de agua atraves de membranas inorganicas en tratamiento de desechos radiactivos por electrodialisis

Energy Technology Data Exchange (ETDEWEB)

Andalaft, E; Labayru, R [Comision Chilena de Energia Nuclear, Santiago (Chile)

1992-12-01

The work described in this paper deals with effects and mechanisms of water transport across an inorganic membrane, as related to some studied on the concentration of caesium, strontium, plutonium and other cations of interest to radioactive waste treatment. Several different water transport mechanisms are analysed and assessed as to their individual contribution towards the total transference of water during electro-dialysis using inorganic membranes. Water transfer assisted by proton jump mechanism, water of hydration transferred along with the ions, water related to thermo-osmotic effect, water transferred by concentration gradient and water transferred electrolytically under zeta potential surface charge drive are some of the different mechanism discussed. (author).

Fabrication of High-T(sub c) Hot-Electron Bolometric Mixers for Terahertz Applications

Science.gov (United States)

Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.; Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

1996-01-01

Superocnducting hot-electron bolometers (HEB) represent a promising candidate for heterodyne mixing at frequencies exceeding 1 THz. Nb HEB mixers offer performance competitive with tunnel junctions without the frequency limit imposed by the superconducting energy gap.

Studies of Protein Solution Properties Using Osmotic Pressure Measurements

Science.gov (United States)

Agena, S.; Bogle, David; Pusey, Marc; Agena, S.

1998-01-01

Examination of the protein crystallization process involves investigation of the liquid and solid state and a protein's properties in these states. Liquid state studies such as protein self association in solution by light scattering methods or other methods have been used to examine a protein Is properties and therefore its crystallization process and conditions. Likewise can osmotic pressure data be used to examine protein properties and various published osmotic pressure studies were examined by us to correlate osmotic pressure to protein solution properties. The solution behavior of serum albumin, alpha - chymotrypsin, beta - lactoglobulin and ovalbumin was examined over a range of temperatures, pH values and different salt types and concentrations. Using virial expansion and a local composition model the non ideal solution behavior in form of the activity coefficients (thermodynamic) was described for the systems. This protein activity coefficient data was related to a protein's solubility behavior and this process and the results will be presented.

Folding propensity of intrinsically disordered proteins by osmotic stress

International Nuclear Information System (INIS)

Mansouri, Amanda L.; Grese, Laura N.; Rowe, Erica L.

2016-01-01

Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR). Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain a-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. In conclusion, by focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.

Experiments on Josephson mixers for heterodyne reception at 0.3 mm wavelength

International Nuclear Information System (INIS)

Blaney, T.G.; Knight, D.J.E.

1974-01-01

A point contact Josephson junction was investigated as a heterodyne mixer at 337 μm. The conversion efficiency reached about -32 dB using a laser local oscillator and about -42 dB using 9th or 12th harmonic mixing with a klystron

Analysis of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applications

Science.gov (United States)

Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

1996-01-01

The prospects of a YBa2Cu3O7(delta)(YBCO) hot-electron bolometer (HEB) mixer for a THz heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate.

Experimental Support for a Predictive Osmotic Model of Clay Membranes

International Nuclear Information System (INIS)

Fritz, S.J.

2001-01-01

Osmosis has been cited as a mechanism for explaining anomalously high fluid pressures in the subsurface. Clays and shales act as membranes, and osmotic flux across these units may result in pressures sufficiently high to explain these anomalies. The theoretical osmotic pressures as calculated solely from solution properties can be quite large; however, it is not yet resolved whether these geologic membranes are sufficiently ideal to generate such pressures

Double Modulation Scheme for Switching Mixers Controlled by Sigma-Delta Modulators

DEFF Research Database (Denmark)

Nielsen, Per Asbeck; Fallesen, Carsten

1998-01-01

. This modification can be carried out on a large variety of mixers including the above mentioned. Although the principle was meant to be used to down convert analog signals, the principle is general and can be used in digital circuits too. This paper verifies the new mixing scheme and compares it to the traditional...

SAXS investigations on lipid membranes under osmotic stress

Energy Technology Data Exchange (ETDEWEB)

Rubim, R.L.; Vieira, V.; Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

2012-07-01

Full text: In this work we, experimentally, investigate the interactions between lipid bilayers. A structural characterization is performed by small angle x-ray scattering (SAXS) on multilamellar systems under known osmotic pressure. Changes in the composition of membranes can modify their mechanical properties and structural parameters, like the flexibility of these membranes, which plays a key role on the determination of the tridimensional organization of bilayers. The membranes are composed of soya lecithin, where the major component is DPPC (Dipalmitoylphosphatidylcholine), and fatty acids are incorporated to the membrane in different concentrations, in order to turn the membrane more fluid. The membranes are inserted in a solution of PVP [poly(vinyl-pyrrolidone) - 40000] and the polymer will apply an osmotic pressure on them. The osmotic pressure is controlled by preparing PVP solutions of desired composition and, as we know the concentration of polymer in solution, we can obtain the intensity of the osmotic pressure. SAXS experiments were done in order to determine the distance between the bilayer. From the position of the Bragg peaks, the lamellar periodicity (the thickness of the membranes plus their distance of separation) was determined. Using theoretical model for the form and structure factors we fitted those experimental data and determined the thickness of the membranes. The distance between the membranes was controlled by the osmotic pressure (P) applied to the membranes and, for a given pressure, we determine the distance between the bilayers (a) on equilibrium. The experimental curve P(a) is theoretically described by the different contributions from van der Waals, hydration and fluctuation forces. From the fitting of experimental curves, relevant parameters characterizing the strength of the different interactions are obtained, such as Hamaker and rigidity constant [2, 3]. We observe that the separation between the bilayers on equilibrium is

Self Oscillating Mixer with Dielectric Resonator for Low Noise Block Application

Directory of Open Access Journals (Sweden)

Endon Bharata

2011-08-01

Full Text Available In this paper, the development of a self oscillating mixer (SOM as part of a low noise block (LNB for a satellite television receiver is investigated numerically and experimentally. In contrast to other mixers, the developed SOM requires no separate local oscillator as it generates own local oscillator signal. The SOM is developed using a monolithic microwave integrated circuit (MMIC comprised of two bipolar transistors coupled as a Darlington pair and a dielectric resonator to establish a local oscillator signal. The SOM is designed to oscillate at 3.62GHz driven from 50W signal generator. The prototype of SOM is fabricated on a dielectric substrate of glass-reinforced hydrocarbon/ceramic lamination (RO4350B board which has a thickness of 0.762mm and relative permittivity of 3.66. The prototype is then characterized experimentally and exhibits a conversion gain of 8dB with the input and output voltage standing wave ratio (VSWR less than 2 across the 2520MHz to 2670MHz operating frequency band.

Asymmetric flows over symmetric surfaces: capacitive coupling in induced-charge electro-osmosis

Energy Technology Data Exchange (ETDEWEB)

Mansuripur, T S [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Pascall, A J; Squires, T M [Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 (United States)], E-mail: squires@engineering.ucsb.edu

2009-07-15

We report curious asymmetric induced-charge electro-osmotic (ICEO) flows over a symmetric, planar gate electrode under applied ac electric fields, whereas symmetric, counter-rotating rolls are expected. Furthermore, the asymmetric component of the flow is consistently directed towards the grounded electrode. We propose that capacitive coupling of the gate electrode to the microscope stage-a comparatively large equipotential surface that acts effectively as a ground-is responsible for this symmetry breaking. This stray capacitance drives the formation of a double layer whose zeta potential is proportional to the potential drop from the electrolyte directly above the gate electrode to the external stage. Therefore, the charge in this 'stray' double layer varies in phase with the driving field, resulting in a rectified, steady flow as with standard ICEO. We experimentally vary the stray capacitance, the electric potential of the stage and the location of the gate electrode, and find that the effect on the stray flow is qualitatively consistent with the predictions of the proposed mechanism. In the process, we demonstrate that capacitive coupling offers an additional means of manipulating fluid flow over a polarizable surface.

Asymmetric flows over symmetric surfaces: capacitive coupling in induced-charge electro-osmosis

International Nuclear Information System (INIS)

Mansuripur, T S; Pascall, A J; Squires, T M

2009-01-01

We report curious asymmetric induced-charge electro-osmotic (ICEO) flows over a symmetric, planar gate electrode under applied ac electric fields, whereas symmetric, counter-rotating rolls are expected. Furthermore, the asymmetric component of the flow is consistently directed towards the grounded electrode. We propose that capacitive coupling of the gate electrode to the microscope stage-a comparatively large equipotential surface that acts effectively as a ground-is responsible for this symmetry breaking. This stray capacitance drives the formation of a double layer whose zeta potential is proportional to the potential drop from the electrolyte directly above the gate electrode to the external stage. Therefore, the charge in this 'stray' double layer varies in phase with the driving field, resulting in a rectified, steady flow as with standard ICEO. We experimentally vary the stray capacitance, the electric potential of the stage and the location of the gate electrode, and find that the effect on the stray flow is qualitatively consistent with the predictions of the proposed mechanism. In the process, we demonstrate that capacitive coupling offers an additional means of manipulating fluid flow over a polarizable surface.

A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

DEFF Research Database (Denmark)

Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

1990-01-01

Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...

Medically relevant ElectroNeedle technology development.

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Carrie Frances; Thomas, Michael Loren; McClain, Jaime L.; Harper, Jason C.; Achyuthan, Komandoor E.; Ten Eyck, Gregory A.

2008-11-01

ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology.

Recommendation to use iso-osmotic contrast medium in interventional treatment

International Nuclear Information System (INIS)

Zhou Bing; Cheng Yongde

2012-01-01

With the rapid development of imaging diagnostic and interventional therapeutic techniques, the contrast medium (CM) has been used more and more common in clinical practice, and meanwhile more and more attention has been paid to the CM-related adverse events. Contrast induced nephropathy (CN) is the most common CM-related adverse event, and CM-related neurotoxicity has already attracted the physicians' attention. The osmotic pressure of the iso-osmotic contrast medium (IOCM) is quite the same as that of the plasma, and therefore its safety is higher than that of low-osmotic contrast medium (LOCM), the patient's tolerance to IOCM is better than that to LOCM. For this reason, the use of IOCM should be strongly recommended in interventional procedures, which is of great significance to the reduction of the occurrence of CM-related adverse events. (authors)

The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

KAUST Repository

Wang, Zhen-Yu; Gehring, Christoph A; Zhu, Jianhua; Li, Feng-Min; Zhu, Jian-Kang; Xiong, Liming

2014-01-01

Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

KAUST Repository

Wang, Zhen-Yu

2014-11-21

Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

The safety of osmotically acting cathartics in colonic cleansing

DEFF Research Database (Denmark)

Nyberg, Caroline; Hendel, J.; Nielsen, O.H.

2010-01-01

Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate...... hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal...

A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

KAUST Repository

Zhu, Jianhua; Lee, Byeongha; Dellinger, Michael T.; Cui, Xinping; Zhang, Changqing; Wu, Shang; Nothnagel, Eugene A.; Zhu, Jian-Kang

2010-01-01

Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have

Understanding Fast and Robust Thermo-osmotic Flows through Carbon Nanotube Membranes: Thermodynamics Meets Hydrodynamics.

Science.gov (United States)

Fu, Li; Merabia, Samy; Joly, Laurent

2018-04-19

Following our recent theoretical prediction of the giant thermo-osmotic response of the water-graphene interface, we explore the practical implementation of waste heat harvesting with carbon-based membranes, focusing on model membranes of carbon nanotubes (CNT). To that aim, we combine molecular dynamics simulations and an analytical model considering the details of hydrodynamics in the membrane and at the tube entrances. The analytical model and the simulation results match quantitatively, highlighting the need to take into account both thermodynamics and hydrodynamics to predict thermo-osmotic flows through membranes. We show that, despite viscous entrance effects and a thermal short-circuit mechanism, CNT membranes can generate very fast thermo-osmotic flows, which can overcome the osmotic pressure of seawater. We then show that in small tubes confinement has a complex effect on the flow and can even reverse the flow direction. Beyond CNT membranes, our analytical model can guide the search for other membranes to generate fast and robust thermo-osmotic flows.

241-SY-101 mixer pump lifetime expectancy. Final report

International Nuclear Information System (INIS)

Shaw, C.P.

1995-01-01

The purpose of WHC-SD-WM-TI-726, Rev. 0 241-SY-101 Mixer Pump Lifetime Expectancy is to determine a best estimate of the mean lifetime of non-repairable (located in the waste) essential features of the hydrogen mitigation mixer pump presently installed in 101-SY. The estimated mean lifetime is 9.1 years. This report does not demonstrate operation of the entire pump assembly within the Tank Farm ''safety envelope''. It was recognized by the Defense Nuclear Facilities Safety Board (DNFSB) this test pump was not specifically designed for long term service in tank 101-SY. In June 95 the DNFSB visited Hanford and ask the question, ''how long will this test pump last and how will the essential features fail?'' During the 2 day meeting with the DNFSB it was discussed and defined within the meeting just exactly what essential features of the pump must operate. These essential features would allow the pump to operate for the purpose of extending the window for replacement. Operating with only essential features would definitely be outside the operating safety envelope and would require a waiver. There are three essential features: 1. The pump itself (i.e. the impeller and motor) must operate 2. Nozzles and discharges leg must remain unplugged 3. The pump can be re-aimed, new waste targeted, even if manually

Direct measurement of osmotic pressure of glycosaminoglycan solutions by membrane osmometry at room temperature.

Science.gov (United States)

Chahine, Nadeen O; Chen, Faye H; Hung, Clark T; Ateshian, Gerard A

2005-09-01

Articular cartilage is a hydrated soft tissue composed of negatively charged proteoglycans fixed within a collagen matrix. This charge gradient causes the tissue to imbibe water and swell, creating a net osmotic pressure that enhances the tissue's ability to bear load. In this study we designed and utilized an apparatus for directly measuring the osmotic pressure of chondroitin sulfate, the primary glycosaminoglycan found in articular cartilage, in solution with varying bathing ionic strength (0.015 M, 0.15 M, 0.5 M, 1 M, and 2 M NaCl) at room temperature. The osmotic pressure (pi) was found to increase nonlinearly with increasing chondroitin sulfate concentration and decreasing NaCl ionic bath environment. Above 1 M NaCl, pi changes negligibly with further increases in salt concentration, suggesting that Donnan osmotic pressure is negligible above this threshold, and the resulting pressure is attributed to configurational entropy. Results of the current study were also used to estimate the contribution of osmotic pressure to the stiffness of cartilage based on theoretical and experimental considerations. Our findings indicate that the osmotic pressure resulting from configurational entropy is much smaller in cartilage (based on an earlier study on bovine articular cartilage) than in free solution. The rate of change of osmotic pressure with compressive strain is found to contribute approximately one-third of the compressive modulus (H(A)(eff)) of cartilage (Pi approximately H(A)(eff)/3), with the balance contributed by the intrinsic structural modulus of the solid matrix (i.e., H(A) approximately 2H(A)(eff)/3). A strong dependence of this intrinsic modulus on salt concentration was found; therefore, it appears that proteoglycans contribute structurally to the magnitude of H(A), in a manner independent of osmotic pressure.

Robust Position Control of Electro-mechanical Systems

OpenAIRE

Rong Mei; Mou Chen

2013-01-01

In this work, the robust position control scheme is proposed for the electro-mechanical system using the disturbance observer and backstepping control method. To the external unknown load of the electro-mechanical system, the nonlinear disturbance observer is given to estimate the external unknown load. Combining the output of the developed nonlinear disturbance observer with backstepping technology, the robust position control scheme is proposed for the electro-mechanical system. The stabili...

Effect of osmotic stress on in vitro propagation of Musa sp. (Malbhog ...

African Journals Online (AJOL)

This study demonstrates up to 36% reduced microbial contamination in aseptic culture establishment and subsequent micropropagation due to osmotic stress induction in the banana suckers. Osmotic stress was induced by keeping the freshly collected suckers in shade and measuring fresh weight at 0, 7, 14, 21, and 28 ...

3D-printed conductive static mixers enable all-vanadium redox flow battery using slurry electrodes

Science.gov (United States)

Percin, Korcan; Rommerskirchen, Alexandra; Sengpiel, Robert; Gendel, Youri; Wessling, Matthias

2018-03-01

State-of-the-art all-vanadium redox flow batteries employ porous carbonaceous materials as electrodes. The battery cells possess non-scalable fixed electrodes inserted into a cell stack. In contrast, a conductive particle network dispersed in the electrolyte, known as slurry electrode, may be beneficial for a scalable redox flow battery. In this work, slurry electrodes are successfully introduced to an all-vanadium redox flow battery. Activated carbon and graphite powder particles are dispersed up to 20 wt% in the vanadium electrolyte and charge-discharge behavior is inspected via polarization studies. Graphite powder slurry is superior over activated carbon with a polarization behavior closer to the standard graphite felt electrodes. 3D-printed conductive static mixers introduced to the slurry channel improve the charge transfer via intensified slurry mixing and increased surface area. Consequently, a significant increase in the coulombic efficiency up to 95% and energy efficiency up to 65% is obtained. Our results show that slurry electrodes supported by conductive static mixers can be competitive to state-of-the-art electrodes yielding an additional degree of freedom in battery design. Research into carbon properties (particle size, internal surface area, pore size distribution) tailored to the electrolyte system and optimization of the mixer geometry may yield even better battery properties.

Study on enhanced lymphatic tracing of isosulfan blue injection by influence of osmotic pressure on lymphatic exposure.

Science.gov (United States)

Ye, Tiantian; He, Rui; Wu, Yue; Shang, Lei; Wang, Shujun

2018-04-01

Isosulfan blue (IB) is being used as a lymphatic tracer has been approved by the FDA in 1981. This study aimed at improving lymphatic exposure of IB injection by osmotic pressure regulation to achieve step-by step lymphatic tracing. First, IB injection with appropriate osmotic pressure, stability, and suitable pH was prepared. Next, the lymphatic tracing ability of different osmotic pressure was studied to determine the blue-stained state of IB in three-level lymph nodes after subcutaneous administration. Furthermore, pharmacokinetics of lymphatic drainage, lymph node uptake, and plasma concentration was investigate to explore the improving law of the lymphatic tracing by osmotic pressure, and combined with tissue irritation to determine the optimal osmotic pressure. At last, the tissue distribution in mice of IB injection which had the property of optimal osmotic pressure was investigated. The results showed that increasing osmotic pressure could significantly reduce injection site retention and increase IB concentration of lymph node. The lymph nodes could be obviously blue-stained by IB injection which had 938 mmol/kg osmotic pressure and would not cause inflammatory reaction and blood exposure. The tissue distribution study suggested that IB injection which had 938 mmol/kg osmotic pressure was mainly distributed into gallbladder and duodenum that verified the reports that 90% IB was excreted through the feces through biliary excretion. In conclusion, this study provides the basic study to improve lymphatic exposure of IB injection by regulate the osmotic pressure and have the potential to be the helpful guidance for the elective lymph node dissection.

Osmotic and stimulant laxatives for the management of childhood constipation

OpenAIRE

Gordon, Morris; Macdonald, John; Parker, Claire; Akobeng, Anthony; Thomas, Adrian

2016-01-01

Background\\ud \\ud Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice.\\ud \\ud \\ud Objectives\\ud \\ud We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation.\\ud \\ud \\ud Search methods\\ud \\ud We searched ...

Solute Transfer in Osmotic Dehydration of Vegetable Foods: A Review.

Science.gov (United States)

Muñiz-Becerá, Sahylin; Méndez-Lagunas, Lilia L; Rodríguez-Ramírez, Juan

2017-10-01

While various mechanisms have been proposed for the water transfer during osmotic dehydration (OD), little progress has been made to understand the mechanisms of solute transfer during osmotic dehydration. The transfer of solutes has been often described only by the diffusion mechanism; however, numerous evidences suggest the participation of a variety of mechanisms. This review deals with the main issues of solute transfer in the OD of vegetables. In this context, several studies suggest that during OD of fruits and vegetables, the migration of solutes is not influenced by diffusion. Thus, new theories that may explain the solute transport are analyzed, considering the influence of the plant microstructure and its interaction with the physicochemical properties of osmotic liquid media. In particular, the surface adhesion phenomenon is analyzed and discussed, as a possible mechanism present during the transfer of solutes in OD. © 2017 Institute of Food Technologists®.

Osmotic stress response in the wine yeast Dekkera bruxellensis.

Science.gov (United States)

Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Piškur, Jure; Compagno, Concetta

2013-12-01

Dekkera bruxellensis is mainly associated with lambic beer fermentation and wine production and may contribute in a positive or negative manner to the flavor development. This yeast is able to produce phenolic compounds, such as 4-ethylguaiacol and 4-ethylphenol which could spoil the wine, depending on their concentration. In this work we have investigated how this yeast responds when exposed to conditions causing osmotic stress, as high sorbitol or salt concentrations. We observed that osmotic stress determined the production and accumulation of intracellular glycerol, and the expression of NADH-dependent glycerol-3-phosphate dehydrogenase (GPD) activity was elevated. The involvement of the HOG MAPK pathway in response to this stress condition was also investigated. We show that in D. bruxellensis Hog1 protein is activated by phosphorylation under hyperosmotic conditions, highlighting the conserved role of HOG MAP kinase signaling pathway in the osmotic stress response. Gene Accession numbers in GenBank: DbHOG1: JX65361, DbSTL1: JX965362. Copyright © 2013 Elsevier Ltd. All rights reserved.

An InP HBT sub-harmonic mixer for E-band wireless communication

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Krozer, Viktor

2010-01-01

This paper reports on a novel balanced HBT subharmonic mixer (SHM) for E-band wireless communication. An LO spiral type Marchand balun is integrated with the SHM. The SHM has been fabricated in a InP double heterojunction bipolar transistor (DHBT) circuit-oriented technology with fT /fmax = 180GHz...

Design and characterization of downconversion mixers and the on-chip calibration techniques for monolithic direct conversion radio receivers

OpenAIRE

Kivekäs, Kalle

2002-01-01

This thesis consists of eight publications and an overview of the research topic, which is also a summary of the work. The research described in this thesis is focused on the design of downconversion mixers and direct conversion radio receivers for UTRA/FDD WCDMA and GSM standards. The main interest of the work is in the 1-3 GHz frequency range and in the Silicon and Silicon-Germanium BiCMOS technologies. The RF front-end, and especially the mixer, limits the performance of direct conversion ...

Electro-active sensor, method for constructing the same; apparatus and circuitry for detection of electro-active species

Science.gov (United States)

Buehler, Martin (Inventor)

2009-01-01

An electro-active sensor includes a nonconductive platform with a first electrode set attached with a first side of a nonconductive platform. The first electrode set serves as an electrochemical cell that may be utilized to detect electro-active species in solution. A plurality of electrode sets and a variety of additional electrochemical cells and sensors may be attached with the nonconductive platform. The present invention also includes a method for constructing the aforementioned electro-active sensor. Additionally, an apparatus for detection and observation is disclosed, where the apparatus includes a sealable chamber for insertion of a portion of an electro-active sensor. The apparatus allows for monitoring and detection activities. Allowing for control of attached cells and sensors, a dual-mode circuitry is also disclosed. The dual-mode circuitry includes a switch, allowing the circuitry to be switched from a potentiostat to a galvanostat mode.

Osmotically driven membrane process for the management of urban runoff in coastal regions

KAUST Repository

Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary L.

2014-01-01

An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier

The dependence of molecular transmembrane electrotransfer efficiency on medium conductivity and osmotic pressure

OpenAIRE

Jakutavičiūtė, Milda; Ruzgys, Paulius; Šatkauskas, Saulius

2014-01-01

The electrotransfer efficiency was evaluated for different external medium conductivities, osmotic pressures and electric pulse voltages. It was found that increase in conductivity or decrease in electric pulse strength decreases electrotransfer efficiency. Decrease in osmotic pressure tends to decrease electrotransfer efficiency.

Cross-Stream PIV Measurements of Jets With Internal Lobed Mixers

Science.gov (United States)

Bridges, James; Wernet, Mark P.

2004-01-01

With emphasis being placed on enhanced mixing of jet plumes for noise reduction and on predictions of jet noise based upon turbulent kinetic energy, unsteady measurements of jet plumes are a very important part of jet noise studies. Given that hot flows are of most practical interest, optical techniques such as Particle Image Velocimetry (PIV) are applicable. When the flow has strong azimuthal features, such as those generated by chevrons or lobed mixers, traditional PIV, which aligns the measurement plane parallel to the dominant flow direction is very inefficient, requiring many planes of data to be acquired and stacked up to produce the desired flow cross-sections. This paper presents PIV data acquired in a plane normal to the jet axis, directly measuring the cross-stream gradients and features of an internally mixed nozzle operating at aircraft engine flow conditions. These nozzle systems included variations in lobed mixer penetration, lobe count, lobe scalloping, and nozzle length. Several cases validating the accuracy of the PIV data are examined along with examples of its use in answering questions about the jet noise generation processes in these nozzles. Of most interest is the relationship of low frequency aft-directed noise with turbulence kinetic energy and mean velocity.

Terahertz Heterodyne Receiver with an Electron-Heating Mixer and a Heterodyne Based on the Quantum-Cascade Laser

Science.gov (United States)

Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P.

2017-12-01

We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed.

Mixer pump long term operations plan for Tank 241-SY-101 mitigation

International Nuclear Information System (INIS)

Irwin, J.J.

1994-01-01

This document provides the general Operations Plan for performance of the mixer pump long term operations for Tank 241-SY-101 mitigation of gas retention and periodic release in Tank 101-SY. This operations plan will utilize a 112 kW (150 hp) mixing pump to agitate/suspend the particulates in the tank

design and fabrication of a fou fabrication of a foundry sand mixer

African Journals Online (AJOL)

eobe

favourably with the the imported existing one which urably with the the imported existing one which foundry shops will eliminate the use manual effort save the the country of huge save the the country of huge foreign exchange used i foreign exchange used i. Keywords: Keywords:foundry,sand mixer,fabrication,design,bla.

Enhanced methanol electro-oxidation activity of Pt/MWCNTs electro-catalyst using manganese oxide deposited on MWCNTs

International Nuclear Information System (INIS)

Nouralishahi, Amideddin; Khodadadi, Abbas Ali; Mortazavi, Yadollah; Rashidi, Alimorad; Choolaei, Mohammadmehdi

2014-01-01

Highlights: • Promoting effects of manganese oxide (MnO x ) on methanol electro-oxidation over Pt/MWCNTs are studied. • 3.3 times higher activity and improved stability are observed on Pt/MnO x -MWCNTs in MOR. • Both hydrogen spill over and bi-functional mechanism are facilitated in presence of MnO x . • MnO x significantly enhances electrochemical active surface area and dispersion of Pt nanoparticles. • Proton conductivity of electrocatalyst layer is improved upon MnO x incorporation. - Abstract: Electro-oxidation of methanol on platinum nanoparticles supported on a nanocomposite of manganese oxide (MnO x ) and multi-wall carbon nanotubes (MWCNTs) is investigated. The morphology, structure, and chemical composition of the electro-catalysts are characterized by TEM, XRD, EDS, TGA, and H 2 -TPR. The electro-catalytic properties of electrodes are examined by cyclic voltammetry, CO-stripping, electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Compared to Pt/MWCNTs, the Pt/MnO x -MWCNTs electro-catalyst exhibits about 3.3 times higher forward peak current density, during cyclic voltammetry, and 4.6 times higher exchange current density in methanol electro-oxidation reaction. In addition, deposition of manganese oxide onto MWCNTs dramatically increases the electrochemical active surface area from 29.7 for Pt/MWCNTs to 89.4 m 2 g −1 Pt for Pt/MnO x -MWCNTs. The results of long-term cyclic voltammetry show superior stability of Pt nanoparticles upon addition of manganese oxide to the support. Furthermore, the kinetics of formation of the chemisorbed OH groups improves upon manganese oxide incorporation. This leads to a lower onset potential of CO ads oxidation on Pt/MnO x -MWCNTs than on Pt/MWCNTs

Granular flow in static mixers by coupled DEM/CFD approach

OpenAIRE

Pezo Lato; Pezo Milada; Jovanović Aca; Kosanić Nenad; Petrović Aleksandar; Lević Ljubinko

2016-01-01

The mixing process greatly influence the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modell...

A discussion on the safety classification of the tank 241-SY-101 mixer pump

International Nuclear Information System (INIS)

Van Vleet, R.J.

1997-01-01

An analysis, consistent with the methodology used in the draft TWRS FSAR (HNF-SD-WM-SAR-067), is presented to show that the classification of the mixer pump in tank 241-SY-101 should be safety significant

Suppressive effect of cellulose on osmotic diarrhea caused by maltitol in healthy female subjects.

Science.gov (United States)

Oku, Tsuneyuki; Hongo, Ryoko; Nakamura, Sadako

2008-08-01

Using a single-group time-series design, we determined that osmotic diarrhea caused by maltitol ingestion was suppressed by the addition of not only soluble but also insoluble dietary fiber in healthy humans. We then clarified that cellulose delayed gastric emptying in rats. Twenty-seven healthy volunteers ingested maltitol step-wise at doses of 15, 20, 25, 30, 35, 40 and 45 g from small to large amounts. Within that range of ingested amounts, 22 out of 27 subjects experienced osmotic diarrhea from maltitol ingestion, and the minimal dose level of maltitol that induced osmotic diarrhea (MMD) was established for each subject. When 5 g of cellulose was added to the MMD, osmotic diarrhea was suppressed in 13 out of 19 subjects (68.4%), while partially hydrolyzed alginate-Na (PHA-Na), a soluble dietary fiber, suppressed osmotic diarrhea in 10 out of 20 subjects (50.0%). When a mixed solution of cellulose and maltitol was administered to rats, the gastric emptying of maltitol was significantly delayed at 30 and 60 min after administration (p=0.019, p=0.013), respectively. PHA-Na also significantly delayed gastric emptying at 30 min (p=0.013). In conclusion, cellulose can suppress the osmotic diarrhea caused by maltitol ingestion in humans and delay the gastric emptying of maltitol in rats. A new physiological property of cellulose was clarified in this study.

Lower critical solution temperature (LCST) phase separation of glycol ethers for forward osmotic control.

Science.gov (United States)

Nakayama, Daichi; Mok, Yeongbong; Noh, Minwoo; Park, Jeongseon; Kang, Sunyoung; Lee, Yan

2014-03-21

Lower critical solution temperature (LCST) phase transition of glycol ether (GE)-water mixtures induces an abrupt change in osmotic pressure driven by a mild temperature change. The temperature-controlled osmotic change was applied for the forward osmosis (FO) desalination. Among three GEs evaluated, di(ethylene glycol) n-hexyl ether (DEH) was selected as a potential FO draw solute. A DEH-water mixture with a high osmotic pressure could draw fresh water from a high-salt feed solution such as seawater through a semipermeable membrane at around 10 °C. The water-drawn DEH-water mixture was phase-separated into a water-rich phase and a DEH-rich phase at around 30 °C. The water-rich phase with a much reduced osmotic pressure released water into a low-salt solution, and the DEH-rich phase was recovered into the initial DEH-water mixture. The phase separation behaviour, the residual GE concentration in the water-rich phase, the osmotic pressure of the DEH-water mixture, and the osmotic flux between the DEH-water mixture and salt solutions were carefully analysed for FO desalination. The liquid-liquid phase separation of the GE-water mixture driven by the mild temperature change between 10 °C and 30 °C is very attractive for the development of an ideal draw solute for future practical FO desalination.

Wide-band operation of quasi-optical distributed superconductor/insulator/superconductor mixers with epitaxial NbN/AlN/NbN junctions

International Nuclear Information System (INIS)

Kohjiro, S; Shitov, S V; Wang, Z; Uzawa, Y; Miki, S; Kawakami, A; Shoji, A

2004-01-01

For the optimum design of integrated receivers operating above the gap frequency of Nb, we have designed, fabricated and tested NbN-based quasi-optical superconductor/insulator/superconductor (SIS) mixers. The mixer chip incorporates a resonant half-wavelength epitaxial NbN/AlN/NbN junction, a twin-slot antenna and their coupling circuits. We adopted two kinds of coupling circuit between the antenna and the SIS junction: one is an in-phase feed with a length of 95 μm and the other is an anti-phase feed of 30 μm length. It was found that the anti-phase mixer reveals a 3 dB bandwidth of 43% of the centre frequency; the uncorrected double-sideband receiver noise temperature T RX = 691 K at 0.91 THz and T RX = 844 K at 0.80 THz, while 17% and T RX = 1250 K at 0.79 THz for the in-phase version. Possible reasons for this difference are discussed, which could be transmission loss and its robustness with respect to the variation of junction parameters. These experimental results suggest the NbN-based distributed mixer with the anti-phase feed is a better candidate for wide-band integrated receivers operating above 0.7 THz

Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents.

Science.gov (United States)

Tsironi, T N; Taoukis, P S

2012-02-01

The objectives of the study were to evaluate the effect of selected antimicrobial agents on the shelf life of osmotically pretreated gilthead seabream and to establish reliable kinetic equations for shelf-life determination validated in dynamic conditions. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (HDM, DE 47) plus 5% NaCl and 0·5% carvacrol, 0·5% glucono-δ-lactone or 1% Citrox (commercial antimicrobial mix). Untreated and treated slices were aerobically packed and stored isothermally (0-15°C). Microbial growth and quality-related chemical indices were modelled as functions of temperature. Models were validated at dynamic storage conditions. Osmotic pretreatment with the use of antimicrobials led to significant shelf-life extension of fillets, in terms of microbial growth and organoleptic deterioration. The shelf life was 7 days for control samples at 5°C. The osmotic pretreatment with carvacrol, glucono-δ-lactone and Citrox allowed for shelf-life extension by 8, 10 and 5 days at 5°C, respectively. The results of the study show the potential of adding carvacrol, glucono-δ-lactone or Citrox in the osmotic solution to extend the shelf life and improve commercial value of chilled osmotically pretreated fish products. The developed models can be a reliable tool for predicting the shelf life of fresh or minimally processed gilthead seabream fillets in the real chill chain. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Optimization of a continuous hybrid impeller mixer via computational fluid dynamics.

Science.gov (United States)

Othman, N; Kamarudin, S K; Takriff, M S; Rosli, M I; Engku Chik, E M F; Meor Adnan, M A K

2014-01-01

This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD) using computational fluid dynamics (CFD). In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT). Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD) was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using a k-ε turbulence model was performed using CFD techniques. The multiple reference frame (MRF) was implemented and a steady state was initially achieved followed by a transient condition for RTD determination.

Multi frequency excited MEMS cantilever beam resonator for Mixer-Filter applications

KAUST Repository

Chandran, Akhil A.

2016-09-15

Wireless communication uses Radio Frequency waves to transfer information from one point to another. The modern RF front end devices are implementing MEMS in their designs so as to exploit the inherent properties of MEMS devices, such as its low mass, low power consumption, and small size. Among the components in the RF transceivers, band pass filters and mixers play a vital role in achieving the optimum RF performance. And this paper aims at utilizing an electrostatically actuated micro cantilever beam resonator\\'s nonlinear frequency mixing property to realize a Mixer-Filter configuration through multi-frequency excitation. The paper studies about the statics and dynamics of the device. Simulations are carried out to study the added benefits of multi frequency excitation. The modelling of the cantilever beam has been done using a Reduced Order Model of the Euler-Bernoulli\\'s beam equation by implementing the Galerkin discretization. The device is shown to be able to down-convert signals from 960 MHz of frequency to an intermediate frequency around 50 MHz and 70 MHz in Phase 1 and 2, respectively. The simulation showed promising results to take the project to the next level. © 2016 IEEE.

Multi frequency excited MEMS cantilever beam resonator for Mixer-Filter applications

KAUST Repository

Chandran, Akhil A.; Younis, Mohammad I.

2016-01-01

Wireless communication uses Radio Frequency waves to transfer information from one point to another. The modern RF front end devices are implementing MEMS in their designs so as to exploit the inherent properties of MEMS devices, such as its low mass, low power consumption, and small size. Among the components in the RF transceivers, band pass filters and mixers play a vital role in achieving the optimum RF performance. And this paper aims at utilizing an electrostatically actuated micro cantilever beam resonator's nonlinear frequency mixing property to realize a Mixer-Filter configuration through multi-frequency excitation. The paper studies about the statics and dynamics of the device. Simulations are carried out to study the added benefits of multi frequency excitation. The modelling of the cantilever beam has been done using a Reduced Order Model of the Euler-Bernoulli's beam equation by implementing the Galerkin discretization. The device is shown to be able to down-convert signals from 960 MHz of frequency to an intermediate frequency around 50 MHz and 70 MHz in Phase 1 and 2, respectively. The simulation showed promising results to take the project to the next level. © 2016 IEEE.

Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

OpenAIRE

Simon Swapna; Korukkanvilakath Samban Shylaraj

2017-01-01

Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000), and followed by the pot...

Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion.

Science.gov (United States)

Yan, Jing; Nadell, Carey D; Stone, Howard A; Wingreen, Ned S; Bassler, Bonnie L

2017-08-23

Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmotic pressure difference between the biofilm and the external environment. This pressure difference promotes biofilm expansion on nutritious surfaces by physically swelling the colony, which enhances nutrient uptake, and enables matrix-producing cells to outcompete non-matrix-producing cheaters via physical exclusion. Osmotic pressure together with crosslinking of the matrix also controls the growth of submerged biofilms and their susceptibility to invasion by planktonic cells. As the basic physicochemical principles of matrix crosslinking and osmotic swelling are universal, our findings may have implications for other biofilm-forming bacterial species.Most bacteria live in biofilms, surface-attached communities encased in an extracellular matrix. Here, Yan et al. show that matrix production in Vibrio cholerae increases the osmotic pressure within the biofilm, promoting biofilm expansion and physical exclusion of non-matrix producing cheaters.

Evaluation of Flygt Mixers for Application in Savannah River Site Tank 19. Test Results from Phase B: Mid-Scale Testing at PNNL

International Nuclear Information System (INIS)

Powell, M.R.; Combs, W.H.; Farmer, J.R.; Gladki, H.; Hatchell, B.K.; Johnson, M.A.; Poirier, M.R.; Rodwell, P.O.

1999-01-01

Pacific Northwest National Laboratory (PNNL) performed mixer tests using 3-kW (4-hp) Flygt mixers in 1.8- and 5.7-m-diameter tanks at the 336 building facility in Richland, Washington to evaluate candidate scaling relationships for Flygt mixers used for sludge mobilization and particle suspension. These tests constituted the second phase of a three-phase test program involving representatives from ITT Flygt Corporation, the Savannah River Site (SRS), the Oak Ridge National Laboratory (ORNL), and PNNL. The results of the first phase of tests, which were conducted at ITT Flygt's facility in a 0.45-m-diameter tank, are documented in Powell et al. (1999). Although some of the Phase B tests were geometrically similar to selected Phase A tests (0.45-m tank), none of the Phase B tests were geometrically, cinematically, and/or dynamically similar to the planned Tank 19 mixing system. Therefore, the mixing observed during the Phase B tests is not directly indicative of the mixing expected in Tank 19 and some extrapolation of the data is required to make predictions for Tank 19 mixing. Of particular concern is the size of the mixer propellers used for the 5.7-m tank tests. These propellers were more than three times larger than required by geometric scaling of the Tank 19 mixers. The implications of the lack of geometric similarity, as well as other factors that complicate interpretation of the test results, are discussed in Section 5.4

Relation between lowered colloid osmotic pressure, respiratory failure, and death.

Science.gov (United States)

Tonnesen, A S; Gabel, J C; McLeavey, C A

1977-01-01

Plasma colloid osmotic pressure was measured each day in 84 intensive care unit patients. Probit analysis demonstrated a direct relationship between colloid osmotic pressure (COP) and survival. The COP associated with a 50% survival rate was 15.0 torr. COP was higher in survivors than in nonsurvivors without respiratory failure and in patients who recovered from respiratory failure. We conclude that lowered COP is associated with an elevated mortality rate. However, the relationship to death is not explained by the relationship to respiratory failure.

Study of Crud Formation Using One Stage Mixer Settler for U-Th Extraction

International Nuclear Information System (INIS)

Busron-Masduki; Mashudi; Didiek-Herhady, R; Endang-Susiantini

2000-01-01

It was carried out solvent extraction of used fuel simulation solution ofU-Th using one stage of mixer settler. The ratio of U/Th was 1/9. Thesolution of U- Th and extractant of 30% TBP diluted in the diluent ofn-dodecane filled in the mixer chamber with the ratio of 1/1 then stirred.The first experiment determined equilibrium time and optimum rpm and thensearched the influenced parameter of crud formation of thorium, zirconium(fission product), phosphate acid, butanol, bentonite powder (represent offines solid), ferrum, silicium according to the TBP degradation of DBP.Zirconium and thorium are significant parameter of crud formation. Theequilibrium time was 1.5 hour, optimum rpm was 1800. The weightest crud wasobtained related to the cumulative parameter which result of 250 gram crud.According to this result and for radiation dose of 1 watt, the extractantmust be regenerated before exceed 48 days to hold the crud formation whichdisturbance the extraction process. (author)

Osmotic stress adaptation of Paracoccidioides lutzii, Pb01, monitored by proteomics.

Science.gov (United States)

Rodrigues, Leandro Nascimento da Silva; Brito, Wesley de Almeida; Parente, Ana Flávia Alves; Weber, Simone Schneider; Bailão, Alexandre Melo; Casaletti, Luciana; Borges, Clayton Luiz; Soares, Célia Maria de Almeida

2016-10-01

The ability to respond to stressful conditions is essential for most living organisms. In pathogenic organisms, this response is required for effective transition from a saprophytic lifestyle to the establishment of pathogenic interactions within a susceptible host. Hyperosmotic stress has been used as a model to study signal transduction and seems to cause many cellular adaptations, including the alteration of protein expression and cellular volume as well as size regulation. In this work, we evaluated the proteomic profile of Paracoccidioides lutzii Pb01 yeast cells during osmotic stress induced by potassium chloride. We performed a high accuracy proteomic technique (NanoUPLC-MS(E)) to identify differentially expressed proteins during osmotic shock. The data describe an osmoadaptative response of this fungus when subjected to this treatment. Proteins involved in the synthesis of cell wall components were modulated, which suggested cell wall remodeling. In addition, alterations in the energy metabolism were observed. Furthermore, proteins involved in amino acid metabolism and hydrogen peroxide detoxification were modulated during osmotic stress. Our study suggests that P. lutzii Pb01. presents a vast osmoadaptative response that is composed of different proteins that act together to minimize the effects caused by osmotic stress. Copyright © 2016 Elsevier Inc. All rights reserved.

Tertiary treatment of landfill leachate by an integrated Electro-Oxidation/Electro-Coagulation/Electro-Reduction process: Performance and mechanism.

Science.gov (United States)

Ding, Jing; Wei, Liangliang; Huang, Huibin; Zhao, Qingliang; Hou, Weizhu; Kabutey, Felix Tetteh; Yuan, Yixing; Dionysiou, Dionysios D

2018-06-05

This study presents an integrated Electro-Oxidation/Electro-Coagulation/Electro-Reduction (EO/EC/ER) process for tertiary landfill leachate treatment. The influence of variables including leachate characteristics and operation conditions on the performance of EO/EC/ER process was evaluated. The removal mechanisms were explored by comparing results of anode, cathode, and bipolar electrode substitution experiments. The performance of the process in a scaled-up reactor was investigated to assure the feasibility of the process. Results showed that simultaneous removal of carbonaceous and nitrogenous pollutants was achieved under optimal conditions. Ammonia removal was due to the free chlorine generation of EO while organic matter degradation was achieved by both EO and EC processes. Nitrate removal was attributed to both ER and EC processes, with the higher removal achieved by ER process. In a scaled-up reactor, the EO/EC/ER process was able to remove 50-60% organic matter and 100% ammonia at charge of 1.5 Ah/L with energy consumption of 15 kW h/m 3 . Considering energy cost, the process is more efficient to meet the requirement of organic removal efficiency less than 70%. These results show the feasibility and potential of the EO/EC/ER process as an alternative tertiary treatment to achieve the simultaneous removal of organic matter, ammonia, nitrate, and color of leachate. Copyright © 2018 Elsevier B.V. All rights reserved.

Arabidopsis decuple mutant reveals the importance of SnRK2 kinases in osmotic stress responses in vivo

KAUST Repository

Fujii, Hiroaki

2011-01-10

Osmotic stress associated with drought or salinity is a major factor that limits plant productivity. Protein kinases in the SNF1-related protein kinase 2 (SnRK2) family are activated by osmotic stress, suggesting that the kinases are involved in osmotic stress signaling. However, due to functional redundancy, their contribution to osmotic stress responses remained unclear. In this report, we constructed an Arabidopsis line carrying mutations in all 10 members of the SnRK2 family. The decuple mutant snrk2.1/2/3/4/5/6/7/8/9/10 grew poorly under hyperosmotic stress conditions but was similar to the wild type in culture media in the absence of osmotic stress. The mutant was also defective in gene regulation and the accumulation of abscisic acid (ABA), proline, and inositol 1,4,5-trisphosphate under osmotic stress. In addition, analysis of mutants defective in the ABA-activated SnRK2s (snrk2.2/3/6) and mutants defective in the rest of the SnRK2s (snrk2.1/4/5/7/8/9/10) revealed that SnRK2s are a merging point of ABA-dependent and -independent pathways for osmotic stress responses. These results demonstrate critical functions of the SnRK2s in mediating osmotic stress signaling and tolerance.

Temperature and pressure dependent osmotic pressure in liquid sodium-cesium alloys

International Nuclear Information System (INIS)

Rashid, R.I.M.A.

1987-01-01

The evaluation of the osmotic pressure in terms of the concentration fluctuations of mixtures and the equations of state of the pure liquids is considered. The temperature and pressure dependent experimentally measured concentration-concentration correlations in the long wavelength limit of liquid sodium-cesium alloys are used to demonstrate the appreciable dependence of the temperature and pressure on the osmotic pressure as a function of concentration. Introducing interchange energies as functions of temperature and pressure, our analysis is consistent with the Flory model. Thus, a formalism for evaluating the state dependent osmotic pressure is developed and our numerical work is considered to be an extension of the calculations of Rashid and March in the sense that a temperature and pressure dependent interchange energy parameter that more closely parameterizes the state dependent concentration fluctuations in the liquid alloys, is used. (author)

In vitro screening of potato genotypes for osmotic stress tolerance

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Gelmesa Dandena

2017-02-01

Full Text Available Potato (Solanum tuberosum L. is a cool season crop which is susceptible to both drought and heat stresses. Lack of suitable varieties of the crop adapted to drought-prone areas of the lowland tropics deprives farmers living in such areas the opportunity to produce and use the crop as a source of food and income. As a step towards developing such varieties, the present research was conducted to evaluate different potato genotypes for osmotic stress tolerance under in vitro conditions and identify drought tolerant genotypes for future field evaluation. The experiment was carried out at the Leibniz University of Hannover, Germany, by inducing osmotic stress using sorbitol at two concentrations (0.1 and 0.2 M in the culture medium. A total of 43 genotypes collected from different sources (27 advanced clones from CIP, nine improved varieties, and seven farmers’ cultivars were used in a completely randomized design with four replications in two rounds. Data were collected on root and shoot growth. The results revealed that the main effects of genotype, sorbitol treatment, and their interactions significantly (P < 0.01 influenced root and shoot growthrelated traits. Under osmotic stress, all the measured root and shoot growth traits were significantly correlated. The dendrogram obtained from the unweighted pair group method with arithmetic mean allowed grouping of the genotypes into tolerant, moderately tolerant, and susceptible ones to a sorbitol concentration of 0.2 M in the culture medium. Five advanced clones (CIP304350.100, CIP304405.47, CIP392745.7, CIP388676.1, and CIP388615.22 produced shoots and rooted earlier than all other genotypes, with higher root numbers, root length, shoot and root mass under osmotic stress conditions induced by sorbitol. Some of these genotypes had been previously identified as drought-tolerant under field conditions, suggesting the capacity of the in vitro evaluation method to predict drought stress tolerant

Alterations in the colonic microbiota in response to osmotic diarrhea.

Science.gov (United States)

Gorkiewicz, Gregor; Thallinger, Gerhard G; Trajanoski, Slave; Lackner, Stefan; Stocker, Gernot; Hinterleitner, Thomas; Gülly, Christian; Högenauer, Christoph

2013-01-01

Diseases of the human gastrointestinal (GI) tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG). Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status) or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy) are used.

Alterations in the colonic microbiota in response to osmotic diarrhea.

Directory of Open Access Journals (Sweden)

Gregor Gorkiewicz

Full Text Available BACKGROUND & AIMS: Diseases of the human gastrointestinal (GI tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. METHODS: We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG. Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. RESULTS: Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. CONCLUSIONS: Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy are used.

A view on thermodynamics of concentrated electrolytes: Modification necessity for electrostatic contribution of osmotic coefficient

Science.gov (United States)

Sahu, Jyoti; Juvekar, Vinay A.

2018-05-01

Prediction of the osmotic coefficient of concentrated electrolytes is needed in a wide variety of industrial applications. There is a need to correctly segregate the electrostatic contribution to osmotic coefficient from nonelectrostatic contribution. This is achieved in a rational way in this work. Using the Robinson-Stokes-Glueckauf hydrated ion model to predict non-electrostatic contribution to the osmotic coefficient, it is shown that hydration number should be independent of concentration so that the observed linear dependence of osmotic coefficient on electrolyte concentration in high concentration range could be predicted. The hydration number of several electrolytes (LiCl, NaCl, KCl, MgCl2, and MgSO4) has been estimated by this method. The hydration number predicted by this model shows correct dependence on temperature. It is also shown that the electrostatic contribution to osmotic coefficient is underpredicted by the Debye-Hückel theory at concentration beyond 0.1 m. The Debye-Hückel theory is modified by introducing a concentration dependent hydrated ionic size. Using the present analysis, it is possible to correctly estimate the electrostatic contribution to the osmotic coefficient, beyond the range of validation of the D-H theory. This would allow development of a more fundamental model for electrostatic interaction at high electrolyte concentrations.

Controlled release of glaucocalyxin - a self-nanoemulsifying system from osmotic pump tablets with enhanced bioavailability.

Science.gov (United States)

Yanfei, Miao; Guoguang, Chen; Lili, Ren; Pingkai, Ouyang

2017-03-01

The purpose of this study was to develop a new formulation to enhance the bioavailability simultaneously with controlled release of glaucocalyxin A (GLA). In this study, controlled release of GLA was achieved by the osmotic release strategy taking advantage of the bioavailability enhancing capacity of self-nanoemulsifying drug delivery systems (SNEDDS). The formulation of GLA-SNEDDS was selected by the solubility and pseudoternary-phase diagrams studies. The prepared GLA-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized GLA-SNEDDS were used to prepare GLA-SNEDDS osmotic pump tablet via direct powder compression method. The effect of formulation variables on the release characteristic was investigated. GLA-SNEDDS osmotic pump tablets were administered to beagle dogs and their pharmacokinetics were compared to GLA and GLA-SNEDDS as a control. In vitro drug release studies indicated that the GLA-SNEDDS osmotic pump tablet showed sustained release profiles with 90% released within 12 h. Pharmacokinetic study showed steady blood GLA with prolonged T max and mean residence time (MRT), and enhanced bioavailability for GLA-SNEDDS osmotic pump tablet. It was concluded that simultaneous controlling on GLA release and enhanced bioavailability had been achieved by a combination of osmotic pump tablet and SNEDDS.

Photoinduced electro-optics measurements of biosilica transformation to cristobalite

Energy Technology Data Exchange (ETDEWEB)

Fuchs, Ido [Department of Chemistry and the Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 52900 (Israel); Aluma, Yaniv; Ilan, Micha [Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Kityk, Iwan [Institute of Electronic Systems, Faculty of Electrical Engineering, Czestochowa University, Czestochowa 42-201 (Poland); Mastai, Yitzhak, E-mail: Yitzhak.Mastai@biu.ac.il [Department of Chemistry and the Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 52900 (Israel)

2015-03-15

In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica. - Graphical abstract: The phase transformation of biosilica from marine sponges to Cristobalite under thermal treatment was investigated using photoinduced electro optics measurements. The figure shows the changes of the electro-optic coefficient of cristobalite and biosilica. - Highlights: • We examine phase transformation of biosilica. • We report transition from amorphous biosilica to crystalline Cristobalite. • Biosilica transformation to Cristobalite at temperature of 850 °C. • Biosilica transformation is studied with photoinduced measurements. • We examine changes in the photoinduced linear electro optics properties.

Photoinduced electro-optics measurements of biosilica transformation to cristobalite

International Nuclear Information System (INIS)

Fuchs, Ido; Aluma, Yaniv; Ilan, Micha; Kityk, Iwan; Mastai, Yitzhak

2015-01-01

In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica. - Graphical abstract: The phase transformation of biosilica from marine sponges to Cristobalite under thermal treatment was investigated using photoinduced electro optics measurements. The figure shows the changes of the electro-optic coefficient of cristobalite and biosilica. - Highlights: • We examine phase transformation of biosilica. • We report transition from amorphous biosilica to crystalline Cristobalite. • Biosilica transformation to Cristobalite at temperature of 850 °C. • Biosilica transformation is studied with photoinduced measurements. • We examine changes in the photoinduced linear electro optics properties

Design of a side-band-separating heterodyne mixer for band 9 of ALMA

NARCIS (Netherlands)

Baryshev, AM; Kooi, J; Mena, FR; Lodewijk, CRJ; Wild, W

2005-01-01

A side-band-separating (SBS) heterodyne mixer has been designed for the Atacama Large Millimeter Array (ALMA) 602-720 GHz band, as it will present a great improvement over the current double-side-band configuration under development at the moment. Here we present design details and the results of

Osmotic heat engine using thermally responsive ionic liquids

KAUST Repository

Zhong, Yujiang

2017-07-11

The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

Direct electro-optic effect in langasites and α-quartz

Science.gov (United States)

Ivanov, Vadim

2018-05-01

Strain-constant (clamped) electro-optic coefficients r11S of langasite La3Ga5SiO14 (LGS), langatate La3Ga5.5Ta0.5O14 (LGT), catangasite Ca3TaGa3Si2O14 (CTGS) and α-quartz are measured at 1540 nm in the frequency range of 3-25 MHz. Experimental ratio of clamped and unclamped electro-optic coefficients r11S/r11T is 0.97 for LGS, 0.91 for LGT, 0.31 for CTGS, and 0.49 for quartz. Most of direct electro-optic effect in LGS and LGT is associated with lanthanum ions: clamped electro-optic coefficient r11S in lanthanum-free CTGS is 14 times less than in LGS. Low piezoelectric contribution to unclamped electro-optic coefficient r11T makes LGS and LGT promising materials for electro-optic devices, whose performance can be deteriorated by piezoelectric effect, especially, for high-voltage optical voltage sensors.

Quantitative characterization of magnetic separators: Comparison of systems with and without integrated microfluidic mixers

DEFF Research Database (Denmark)

Lund-Olesen, Torsten; Bruus, Henrik; Hansen, Mikkel Fougt

2006-01-01

micrographs, and simulations and analytical models of bead trajectories, capture efficiencies, and capture distributions. We show that the efficiencies of both systems compare favorably to those in the literature. For the studied geometries, the mixer is demonstrated to increase the bead capture...

Release and Decay Kinetics of Copeptin vs AVP in Response to Osmotic Alterations in Healthy Volunteers.

Science.gov (United States)

Fenske, Wiebke K; Schnyder, Ingeborg; Koch, Gilbert; Walti, Carla; Pfister, Marc; Kopp, Peter; Fassnacht, Martin; Strauss, Konrad; Christ-Crain, Mirjam

2018-02-01

Copeptin is the C-terminal fragment of the arginine vasopressin (AVP) prohormone whose measurement is more robust than that of AVP. Similar release and clearance characteristics have been suggested promoting copeptin as a surrogate marker. To characterize the physiology of osmotically regulated copeptin release and its half-life in direct comparison with plasma AVP. Ninety-one healthy volunteers underwent a standardized three-phase test protocol including (1) osmotic stimulation into the hypertonic range by hypertonic-saline infusion followed by osmotic suppression via (2) oral water load and (3) subsequent glucose infusion. Plasma copeptin, AVP, serum sodium, and osmolality levels were measured in regular intervals. In phase 1, an increase in median osmotic pressure [289 (286; 291) to 311 (309; 314) mOsm/kg H2O] caused similar release kinetics of plasma copeptin [4 (3.1; 6) to 29.3 (18.6; 48.2) pmol/L] and AVP [1 (0.7; 1.6) to 10.3 (6.8; 18.8) pg/mL]. Subsequent osmotic suppression to 298 (295; 301) mOsm/kg at the end of phase 3 revealed markedly different decay kinetics between both peptides-an estimated initial half-life of copeptin being approximately 2 times longer than that of AVP (26 vs 12 minutes). Copeptin is released in equimolar amounts with AVP in response to osmotic stimulation, suggesting its high potential as an AVP surrogate for differentiation of osmotic disorders. Furthermore, we here describe the decay kinetics of copeptin in response to osmotic depression enabling to identify a half-life for copeptin in direct comparison with AVP. Copyright © 2017 Endocrine Society

Interaction of prechilling, temperature, osmotic stress, and light in Picea abies seed germination

International Nuclear Information System (INIS)

Leinonen, K.; Rita, H.

1995-01-01

A multi-factor experimental approach and proportional odds model was used to study interactions between five environmental factors significant to Norway spruce seed germination: prechilling (at +4.5 °C), suboptimal temperatures (+12 and +16 °C), osmotically induced water stress (–0.3 Mpa and 0 Mpa), prolonged white light, and short-period far-red light. Temperature and osmotic stress interacted with one another in the germination of seeds: the effect of osmotic stress being stronger at +16 °C than at +12 °C. In natural conditions, this interaction may prevent germination early in the summer when soil dries and temperature increases. Prolonged white light prevented germination at low temperature and low osmotic potential. Inhibitory effect was less at higher temperatures and higher osmotic potential, as well as after prechilling. Short-period far-red light did not prevent germination of unchilled seeds in darkness. Prechilling tended to make seeds sensitive to short pulses of far-red light, an effect which depended on temperature: at +12 °C the effect on germination was promotive, but at +16 °C, inhibitory and partly reversible by white light. It seems that Norway spruce seeds may have adapted to germinate in canopy shade light rich in far-red. The seeds may also have evolved mechanisms to inhibit germination in prolonged light

Sorbitol treatment extends lifespan and induces the osmotic stress response in Caenorhabditis elegans

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Devon eChandler-Brown

2015-10-01

Full Text Available The response to osmotic stress is a highly conserved process for adapting to changing environmental conditions. Prior studies have shown that hyperosmolarity by addition of sorbitol to the growth medium is sufficient to increase both chronological and replicative lifespan in the budding yeast, Saccharomyces cerevisiae. Here we report a similar phenomenon in the nematode Caenorhabditis elegans. Addition of sorbitol to the nematode growth medium induces an adaptive osmotic response and increases C. elegans lifespan by about 35%. Lifespan extension from 5% sorbitol behaves similarly to dietary restriction in a variety of genetic backgrounds, increasing lifespan additively with mutation of daf-2(e1370 and independently of daf-16(mu86, sir-2.1(ok434, aak-2(ok524, and hif-1(ia04. Dietary restriction by bacterial deprivation or mutation of eat-2(ad1113 fails to further extend lifespan in the presence of 5% sorbitol. Two mutants with constitutive activation of the osmotic response, osm-5(p813 and osm-7(n1515, were found to be long-lived, and lifespan extension from sorbitol required the glycerol biosynthetic enzymes GPDH-1 and GPDH-2. Taken together, these observations demonstrate that exposure to sorbitol at levels sufficient to induce an adaptive osmotic response extends lifespan in worms and define the osmotic stress response pathway as a longevity pathway conserved between yeast and nematodes.

Salinity- and population-dependent genome regulatory response during osmotic acclimation in the killifish (Fundulus heteroclitus) gill.

Science.gov (United States)

Whitehead, Andrew; Roach, Jennifer L; Zhang, Shujun; Galvez, Fernando

2012-04-15

The killifish Fundulus heteroclitus is abundant in osmotically dynamic estuaries and it can quickly adjust to extremes in environmental salinity. We performed a comparative osmotic challenge experiment to track the transcriptomic and physiological responses to two salinities throughout a time course of acclimation, and to explore the genome regulatory mechanisms that enable extreme osmotic acclimation. One southern and one northern coastal population, known to differ in their tolerance to hypo-osmotic exposure, were used as our comparative model. Both populations could maintain osmotic homeostasis when transferred from 32 to 0.4 p.p.t., but diverged in their compensatory abilities when challenged down to 0.1 p.p.t., in parallel with divergent transformation of gill morphology. Genes involved in cell volume regulation, nucleosome maintenance, ion transport, energetics, mitochondrion function, transcriptional regulation and apoptosis showed population- and salinity-dependent patterns of expression during acclimation. Network analysis confirmed the role of cytokine and kinase signaling pathways in coordinating the genome regulatory response to osmotic challenge, and also posited the importance of signaling coordinated through the transcription factor HNF-4α. These genome responses support hypotheses of which regulatory mechanisms are particularly relevant for enabling extreme physiological flexibility.

Osmotic phenomena in application for hyperbaric oxygen treatment.

Science.gov (United States)

Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

2011-03-01

Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

Multi-dimensional electro-omosis consolidation of clays

NARCIS (Netherlands)

Yuan, J.; Hicks, M.A.; Dijkstra, J.

2012-01-01

Electro-osmosis consolidation is an innovative and effective ground improvement method for soft clays. But electro-osmosis is also a very complicated process, as the mechanical behaviour, and hydraulic and electrical properties of the soil are changing rapidly during the treatment process; this

Novel regulation of aquaporins during osmotic stress.

Science.gov (United States)

Vera-Estrella, Rosario; Barkla, Bronwyn J; Bohnert, Hans J; Pantoja, Omar

2004-08-01

Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions.

Osmotic Gradients Induce Bio-reminiscent Morphological Transformations in Giant Unilamellar Vesicles

Directory of Open Access Journals (Sweden)

Kamila eOglecka

2012-05-01

Full Text Available We report observations of large-scale, in-plane and out-of-plane membrane deformations in giant uni- and multilamellar vesicles composed of binary and ternary lipid mixtures in the presence of net transvesicular osmotic gradients. The lipid mixtures we examined consisted of binary mixtures of DOPC and DPPC lipids and ternary mixtures comprising POPC, sphingomyelin, and cholesterol over a range of compositions – both of which produce co-existing phases for selected ranges of compositions at room temperature under thermodynamic equilibrium. In the presence of net osmotic gradient, we find that the in-plane phase separation potential of these mixtures is non-trivially altered and a variety of out-of-plane morphological remodeling occurs. The repertoire of membrane deformations we observe display striking resemblance to their biological counterparts in live cells encompassing vesiculation, membrane fission and fusion, tubulation and pearling, as well as expulsion of entrapped vesicles from multicompartmental GUV architectures through large, self-healing transient pores. These observations suggest that the forces introduced by simple osmotic gradients across membrane boundaries could act as a trigger for shape-dependent membrane and vesicle trafficking activities. We speculate that such coupling of osmotic gradients with membrane properties might have provided lipid-mediated mechanisms during the early evolution of membrane compartmentalization in the absence of osmoregulatory protein machinery.

Electro-optical Detection of Charged Particles

International Nuclear Information System (INIS)

Lazarus, D.M.

2001-01-01

The electric field of charged particles can induce transient changes in the polarization of light that produce sub-picosecond modulation of a laser beam. This is a consequence of the electro-optical effect in which the presence of the electric field in an electro-optical medium produces a change in the index of refraction of the medium resulting in a phase retardation between polarization components parallel and perpendicular to the electric field. We have observed the electro-optical effect due to 10 picosecond electron beam bunches with rise times that were limited by the bandwidth of our data acquisition system. This technology is being applied to particle beam diagnostics and has the potential to produce charged particle detectors combining excellent spatial resolution with unprecedented temporal precision.

Osmotic therapies added to antibiotics for acute bacterial meningitis

Science.gov (United States)

Wall, Emma Cb; Ajdukiewicz, Katherine Mb; Bergman, Hanna; Heyderman, Robert S; Garner, Paul

2018-01-01

Background Every day children and adults die from acute community-acquired bacterial meningitis, particularly in low-income countries, and survivors risk deafness, epilepsy and neurological disabilities. Osmotic therapies may attract extra-vascular fluid and reduce cerebral oedema, and thus reduce death and improve neurological outcomes. This is an update of a Cochrane Review first published in 2013. Objectives To evaluate the effects of osmotic therapies added to antibiotics for acute bacterial meningitis in children and adults on mortality, deafness and neurological disability. Search methods We searched CENTRAL (2017, Issue 1), MEDLINE (1950 to 17 February 2017), Embase (1974 to 17 February 2017), CINAHL (1981 to 17 February 2017), LILACS (1982 to 17 February 2017) and registers of ongoing clinical trials (ClinicalTrials.com, WHO ICTRP) (21 February 2017). We also searched conference abstracts and contacted researchers in the field (up to 12 December 2015). Selection criteria Randomised controlled trials testing any osmotic therapy in adults or children with acute bacterial meningitis. Data collection and analysis Two review authors independently screened the search results and selected trials for inclusion. Results are presented using risk ratios (RR) and 95% confidence intervals (CI) and grouped according to whether the participants received steroids or not. We used the GRADE approach to assess the certainty of the evidence. Main results We included five trials with 1451 participants. Four trials evaluated glycerol against placebo, and one evaluated glycerol against 50% dextrose; in addition three trials evaluated dexamethasone and one trial evaluated acetaminophen (paracetamol) in a factorial design. Stratified analysis shows no effect modification with steroids; we present aggregate effect estimates. Compared to placebo, glycerol probably has little or no effect on death in people with bacterial meningitis (RR 1.08, 95% CI 0.90 to 1.30; 5 studies, 1272

A “twisted” microfluidic mixer suitable for a wide range of flow rate applications

KAUST Repository

Sivashankar, Shilpa; Agambayev, Sumeyra; Mashraei, Yousof; Li, Erqiang; Thoroddsen, Sigurdur T; Salama, Khaled N.

2016-01-01

in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted

Optimization of Vacuum Frying Parameters in Combination with Osmotic Dehydration of Kiwi Slices to Produce Healthy Product

Directory of Open Access Journals (Sweden)

Fatemeh Aghabozorg Afjeh Aghabozorg Afjeh

2014-05-01

Full Text Available Osmotic dehydration under discontinuous reduced pressure is one of the new methods of preparation fruits and vegetable processing with in view of good health. Processing of foods at high temperatures used to cook them can cause the formation of carcinogenic substances like acrylamide, and this risk remains even if the trans-fat is removed. The low temperatures employed in this method resulted in the products with the desired texture, nutritional, and colour. The purpose of this research was evaluation of the variable effects of osmotic dehydration process (ambient pressure, contact time of product and solution, concentration and temperature of osmotic solution on the quality factors of product (colour changes, texture, moisture, oil uptake, and water loss to solid gain ratio and achieving the optimum process conditions. Studying the quality parameters of the product, the temperature range of osmotic solution, pressure, concentration of the osmotic solution and contact time of product and solution were assumed as 30 to 50°C, 500 to 700 mbar, 30 to 50% and 60 to 180 min, respectively. The test plans involving 31 tests were obtained by using response surface statistical models and central composite design. They were fried at the condition of 108ºC, 8 min and 320 mbar by using statistical correlations, 48.71ºC for the osmotic solution temperature, 592.07 mbar for the pressure, 62.92 min for the time and 34.87% for the osmotic solution. Concentrations were obtained as optimum conditions of osmotic dehydration of kiwi slices under reduced pressure. In summary combination of osmotic dehydration and vacuum frying improved the quality of the final fried kiwi, so this method is recommended for production of healthy products.

Osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50oC

International Nuclear Information System (INIS)

Lemire, R.J.; Sagert, N.H.; Lau, D.W.P.

1983-01-01

Vapor pressure osmometry was used to measure osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50 o C and at molalities up to 0.2 mol·kg -1 . The data were fitted to three- and four-parameter equations containing limiting-law terms for a 4:1 electrolyte. The variation of the osmotic coefficients as a function of temperature was found to be small. The results are compared to published values for the osmotic coefficients. (author)

Optimization of a Continuous Hybrid Impeller Mixer via Computational Fluid Dynamics

Directory of Open Access Journals (Sweden)

N. Othman

2014-01-01

Full Text Available This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD using computational fluid dynamics (CFD. In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT. Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using a k-ε turbulence model was performed using CFD techniques. The multiple reference frame (MRF was implemented and a steady state was initially achieved followed by a transient condition for RTD determination.

A numerical method for osmotic water flow and solute diffusion with deformable membrane boundaries in two spatial dimension

Science.gov (United States)

Yao, Lingxing; Mori, Yoichiro

2017-12-01

Osmotic forces and solute diffusion are increasingly seen as playing a fundamental role in cell movement. Here, we present a numerical method that allows for studying the interplay between diffusive, osmotic and mechanical effects. An osmotically active solute obeys a advection-diffusion equation in a region demarcated by a deformable membrane. The interfacial membrane allows transmembrane water flow which is determined by osmotic and mechanical pressure differences across the membrane. The numerical method is based on an immersed boundary method for fluid-structure interaction and a Cartesian grid embedded boundary method for the solute. We demonstrate our numerical algorithm with the test case of an osmotic engine, a recently proposed mechanism for cell propulsion.

The osmotic pressure of 3He-4He mixtures along the phase separation curve

NARCIS (Netherlands)

van de Klundert, L.J.M.; Bos, M.R.E.; van der Meij, J.A.M.; Steffens, H.A.

1977-01-01

The osmotic pressure of 3He-4He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated.

The osmotic pressure of 3He-4He mixtures along the phase separation curve

International Nuclear Information System (INIS)

Klundert, L.J.M. van de; Bos, M.R.E.; Meij, J.A.M. van der; Steffens, H.A.

1977-01-01

The osmotic pressure of 3 He- 4 He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4 He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated. (Auth.)

Crosslinked polyimide electro-optic materials

Energy Technology Data Exchange (ETDEWEB)

Kowalczyk, T.C.; Kosc, T.Z.; Singer, K.D. [Case Western Reserve University, Department of Physics, Cleveland, Ohio 44106-7079 (United States); Beuhler, A.J.; Wargowski, D.A. [Amoco Research Center, Amoco Chemical Co., Naperville, Illinois 60566 (United States); Cahill, P.A.; Seager, C.H.; Meinhardt, M.B. [Sandia National Laboratories, Division 1811, Albuquerque, New Mexico 87185-1407 (United States); Ermer, S. [Lockheed Research and Development Division, Palo Alto, California 94304 (United States)

1995-11-15

We report studies of the optical and electro-optic properties of guest--host polymeric nonlinear optical materials based on aromatic, fluorinated, fully imidized, organic soluble, thermally, and photochemically crosslinkable, guest--host polyimides. We have introduced temperature stable nonlinear optical chromophores into these polyimides and studied optical losses, electric field poling, electro-optic properties, and orientational stability. We measured electro-optic coefficients of 5.5 and 12.0 pm/V for ((2,6-Bis(2-(3-(9-(ethyl)carbazolyl))ethenyl)4H-pyran-4-ylidene)propanedinitrile) (4-(Dicyanomethylene)-2-methyl-6-(p -dimethylaminostyryl)-4H-pyran) DCM-doped guest--host systems at 800 nm using a poling field of 1.3 MV/cm. Poling induced nonlinearities in single-layer films were in agreement with the oriented gas model, but were lower in three-layer films due to voltage division across the layers. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Does Osmotic Stress Affect Natural Product Expression in Fungi?

Science.gov (United States)

Overy, David; Correa, Hebelin; Roullier, Catherine; Chi, Wei-Chiung; Pang, Ka-Lai; Rateb, Mostafa; Ebel, Rainer; Shang, Zhuo; Capon, Rob; Bills, Gerald; Kerr, Russell

2017-08-13

The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of Aspergillus aculeatus was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of A. aculeatus was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains.

Osmotically-driven membrane processes for water reuse and energy recovery

Science.gov (United States)

Achilli, Andrea

Osmotically-driven membrane processes are an emerging class of membrane separation processes that utilize concentrated brines to separate liquid streams. Their versatility of application make them an attractive alternative for water reuse and energy production/recovery. This work focused on innovative applications of osmotically-driven membrane processes. The novel osmotic membrane bioreactor (OMBR) system for water reuse was presented. Experimental results demonstrated high sustainable flux and relatively low reverse diffusion of solutes from the draw solution into the mixed liquor. Membrane fouling was minimal and controlled with osmotic backwashing. The OMBR system was found to remove greater than 99% of organic carbon and ammonium-nitrogen. Forward osmosis (FO) can employ different draw solution in its process. More than 500 inorganic compounds were screened as draw solution candidates, the desktop screening process resulted in 14 draw solutions suitable for FO applications. The 14 draw solutions were then tested in the laboratory to evaluate water flux and reverse salt diffusion through the membrane. Results indicated a wide range of water flux and reverse salt diffusion depending on the draw solution utilized. Internal concentration polarization was found to lower both water flux and reverse salt diffusion by reducing the draw solution concentration at the interface between the support and dense layer of the membrane. A small group of draw solutions was found to be most suitable for FO processes with currently available FO membranes. Another application of osmotically-driven membrane processes is pressure retarded osmosis (PRO). PRO was investigated as a viable source of renewable energy. A PRO model was developed to predict water flux and power density under specific experimental conditions. The predictive model was tested using experimental results from a bench-scale PRO system. Previous investigations of PRO were unable to verify model predictions due to

Electro-optic methods for longitudinal bunch diagnostics at FLASH

International Nuclear Information System (INIS)

Steffen, B.R.

2007-07-01

Precise measurements of the temporal profile of sub-picosecond electron bunches are of high interest for the optimization and operation of VUV and X-ray free electron lasers. In this thesis, the shortest electro-optic signals measured so far for electron bunch diagnostics are presented, reaching a time resolution of better than 50 fs (rms). The e ects that introduce signal distortions and limit the time resolution are studied in numerical simulations for different electro-optic detection materials and techniques. The time resolution is mainly limited by lattice resonances of the electro-optic crystal. Electro-optic signals as short as 54 fs (rms) are obtained with gallium phosphide (GaP) crystals in a crossed polarizer detection scheme using temporally resolved electro-optic detection. Measuring near crossed polarization, where the electro-optic signal is proportional to the velocity field of the relativistic electron bunch, the shortest obtained signal width is 70 fs (rms). The electro-optic signals are compared to electron bunch shapes that are measured simultaneously with a transverse deflecting structure with 20 fs resolution. Numerical simulations using the bunch shapes as determined with the transverse deflecting cavity as input data are in excellent agreement with electro-optical signals obtained with GaP, both for temporally and spectrally resolved measurements. In the case of zinc telluride (ZnTe) the observed signals are slightly broader and significantly smaller than expected from simulations. These discrepancies are probably due to the poor optical quality of the available ZnTe crystals. (orig.)

Electro-optic methods for longitudinal bunch diagnostics at FLASH

Energy Technology Data Exchange (ETDEWEB)

Steffen, B.R.

2007-07-15

Precise measurements of the temporal profile of sub-picosecond electron bunches are of high interest for the optimization and operation of VUV and X-ray free electron lasers. In this thesis, the shortest electro-optic signals measured so far for electron bunch diagnostics are presented, reaching a time resolution of better than 50 fs (rms). The e ects that introduce signal distortions and limit the time resolution are studied in numerical simulations for different electro-optic detection materials and techniques. The time resolution is mainly limited by lattice resonances of the electro-optic crystal. Electro-optic signals as short as 54 fs (rms) are obtained with gallium phosphide (GaP) crystals in a crossed polarizer detection scheme using temporally resolved electro-optic detection. Measuring near crossed polarization, where the electro-optic signal is proportional to the velocity field of the relativistic electron bunch, the shortest obtained signal width is 70 fs (rms). The electro-optic signals are compared to electron bunch shapes that are measured simultaneously with a transverse deflecting structure with 20 fs resolution. Numerical simulations using the bunch shapes as determined with the transverse deflecting cavity as input data are in excellent agreement with electro-optical signals obtained with GaP, both for temporally and spectrally resolved measurements. In the case of zinc telluride (ZnTe) the observed signals are slightly broader and significantly smaller than expected from simulations. These discrepancies are probably due to the poor optical quality of the available ZnTe crystals. (orig.)

Sugar beet molasses: Properties and applications in osmotic dehydration of fruits and vegetables

Directory of Open Access Journals (Sweden)

Šarić Ljubiša Ć.

2016-01-01

Full Text Available Molasses is an important by-product of sugar beet or sugar cane refining industry and it was one of the first sweeteners used in human nutrition. Sugar cane molasses has unique characteristics that can make it suitable for application in food industry, especially in confectionery and bakery products. On the other hand, sugar beet molasses has not had greater application in the human diet, primarily because of its strong smell and taste of the beet, which makes it unattractive for consumption. Since recent investigations showed that sugar beet molasses can be used as a hypertonic solution in osmotic dehydration of different materials of plant and animal origin, the objective of this work was to review recently studied sugar beet molasses in terms of its applications in osmotic dehydrations of fruits and vegetables. Previous studies showed that sugar beet molasses is an excellent medium for osmotic dehydration of fruits and vegetables (apple, carrot, plum, etc. primarily due to a high content of dry matter (80%, w/w and specific nutrient content. An important advantage of using sugar beet molasses as a hypertonic solution is an enrichment of the dehydrated material in minerals and vitamins, which penetrate from molasses into the plant tissue. Concentration of sugar beet molasses solution and immersion time had the biggest influence on the process of osmotic dehydration of fruit and vegetables, while the temperature of the solution was the least influential parameter. The effect of immersion time on the kinetics of osmotic dehydration in sugar beet molasses increases with an increase in concentration of hypertonic solution. Fruit and vegetables dehydrated in sugar beet molasses had a higher dry matter content compared to samples treated in sucrose solutions. Besides, application of sugar beet molasses in osmotic dehydration of fruits and vegetables had some other advantages such as lower cost of molasses compared to sugar and its liquid aggregate

High-Tc superconducting Josephson mixers for terahertz heterodyne detection

International Nuclear Information System (INIS)

Malnou, M.; Feuillet-Palma, C.; Olanier, L.; Lesueur, J.; Bergeal, N.; Ulysse, C.; Faini, G.; Febvre, P.; Sirena, M.

2014-01-01

We report on an experimental and theoretical study of the high-frequency mixing properties of ion-irradiated YBa 2 Cu 3 O 7 Josephson junctions embedded in THz antennas. We investigated the influence of the local oscillator power and frequency on the device performances. The experimental data are compared with theoretical predictions of the general three-port model for mixers in which the junction is described by the resistively shunted junction model. A good agreement is obtained for the conversion efficiency in different frequency ranges, spanning above and below the characteristic frequencies f c of the junctions

A Theoretical-Experimental Comparison of an Improved Ammonia-Water Bubble Absorber by Means of a Helical Static Mixer

Directory of Open Access Journals (Sweden)

Jesús Cerezo

2017-12-01

Full Text Available The heat transfer in double pipe heat exchangers is very poor. This complicates its application in absorption cooling systems, however, the implementation of simple passive techniques should help to increase the heat and mass transfer mainly in the absorber. This paper carried out a simulation and its experimental comparison of a NH3-H2O bubble absorption process using a double tube heat exchanger with a helical screw static mixer in both central and annular sides. The experimental results showed that the absorption heat load per area is 31.61% higher with the helical screw mixer than the smooth tube. The theoretical and experimental comparison showed that the absorption heat load difference values were 28.0 and 21.9% for smooth tube and the helical mixer, respectively. These difference values were caused by the calculation of the log mean temperature difference in equilibrium conditions to avoid the overlap of solution temperatures. Therefore, the theoretical and experimental results should be improved when the absorption heat is included in the heat transfer equation or avoiding the operation condition when output is lower than input solution temperature.

Quercitol and osmotic adaptation of field-grown Eucalyptus under seasonal drought stress.

Science.gov (United States)

Arndt, Stefan K; Livesley, Stephen J; Merchant, Andrew; Bleby, Timothy M; Grierson, Pauline F

2008-07-01

This study investigated the role of quercitol in osmotic adjustment in field-grown Eucalyptus astringens Maiden subject to seasonal drought stress over the course of 1 year. The trees grew in a native woodland and a farm plantation in the semi-arid wheatbelt region of south Western Australia. Plantation trees allocated relatively more biomass to leaves than woodland trees, but they suffered greater drought stress over summer, as indicated by lower water potentials, CO(2)assimilation rates and stomatal conductances. In contrast, woodland trees had relatively fewer leaves and suffered less drought stress. Plantation trees under drought stress engaged in osmotic adjustment, but woodland trees did not. Quercitol made a significant contribution to osmotic adjustment in drought-stressed trees (25% of total solutes), and substantially more quercitol was measured in the leaves of plantation trees (5% dry matter) than in the leaves of woodland trees (2% dry matter). We found no evidence that quercitol was used as a carbon storage compound while starch reserves were depleted under drought stress. Differences in stomatal conductance, biomass allocation and quercitol production clearly indicate that E. astringens is both morphologically and physiologically 'plastic' in response to growth environment, and that osmotic adjustment is only one part of a complex strategy employed by this species to tolerate drought.

Effect of process variables on the osmotic dehydration of star-fruit slices

Directory of Open Access Journals (Sweden)

Camila Dalben Madeira Campos

2012-06-01

Full Text Available The objective of this work was to study the effect of blanching and the influence of temperature, solution concentration, and the initial fruit:solution ratio on the osmotic dehydration of star-fruit slices. For blanching, different concentrations of citric and ascorbic acids were studied. The samples immersed in 0.75% citric acid presented little variation in color in relation to the fresh star-fruit. Osmotic dehydration was carried out in an incubator with orbital shaking, controlled temperature, and constant shaking at 120 rpm. The influence of process variables was studied in trials defined by a complete 23 central composite design. In general, water loss and solids gain were positively influenced by temperature and by solution concentration. Nevertheless, lower temperatures reduced water loss throughout the osmotic dehydration process. An increase in the amount of dehydrating solution (initial fruit:solution ratio slightly influenced the evaluated responses. The process carried out at 50 ºC with a solution concentration of 50% resulted in a product with lower solids gain and greater water loss. Under these conditions, blanching minimized the effect of the osmotic treatment on star-fruit browning, and therefore the blanched fruits showed little variation in color in relation to the fresh fruit.

Microfluidic active mixers employing ultra-high aspect-ratio rare-earth magnetic nano-composite polymer artificial cilia

International Nuclear Information System (INIS)

Rahbar, Mona; Gray, Bonnie L; Shannon, Lesley

2014-01-01

We present a new micromixer based on highly magnetic, flexible, high aspect-ratio, artificial cilia that are fabricated as individual micromixer elements or in arrays for improved mixing performance. These new cilia enable high efficiency, fast mixing in a microchamber, and are controlled by small electromagnetic fields. The artificial cilia are fabricated using a new micromolding process for nano-composite polymers. Cilia fibers with aspect-ratios as high as 8:0.13 demonstrate the fabrication technique's capability in creating ultra-high aspect-ratio microstructures. Cilia, which are realized in polydimethylsiloxane doped with rare-earth magnetic powder, are magnetized to produce permanent magnetic structures with bidirectional deflection capabilities, making them highly suitable as mixers controlled by electromagnetic fields. Due to the high magnetization level of the polarized nano-composite polymer, we are able to use miniature electromagnets providing relatively small magnetic fields of 1.1 to 7 mT to actuate the cilia microstructures over a very wide motion range. Mixing performances of a single cilium, as well as different arrays of multiple cilia ranging from 2 to 8 per reaction chamber, are characterized and compared with passive diffusion mixing performance. The mixer cilia are actuated at different amplitudes and frequencies to optimize mixing performance. We demonstrate that more than 85% of the total volume of the reaction chamber is fully mixed after 3.5 min using a single cilium mixer at 7 mT compared with only 20% of the total volume mixed with passive diffusion. The time to achieve over 85% mixing is further reduced to 70 s using an array of eight cilia microstructures. The novel microfabrication technique and use of rare-earth permanently-magnetizable nano-composite polymers in mixer applications has not been reported elsewhere by other researchers. We further demonstrate improved mixing over other cilia micromixers as enabled by the high

Flow cytometric determination of osmotic behaviour of animal erythrocytes toward their engineering for drug delivery

Directory of Open Access Journals (Sweden)

Kostić Ivana T.

2015-01-01

Full Text Available Despite the fact that the methods based on the osmotic properties of the cells are the most widely used for loading of drugs in human and animal erythrocytes, data related to the osmotic properties of erythrocytes derived from animal blood are scarce. This work was performed with an aim to investigate the possibility of use the flow cytometry as a tool for determination the osmotic behaviour of porcine and bovine erythrocytes, and thus facilitate the engineering of erythrocytes from animal blood to be drug carriers. The method of flow cytometry successfully provided the information about bovine and porcine erythrocyte osmotic fragility, and made the initial steps in assessment of erythrocyte shape in a large number of erythrocytes. Although this method is not able to confirm the swelling of pig erythrocytes, it indicated to the differences in pig erythrocytes that had basic hematological parameters inside and outside the reference values. In order to apply/use the porcine and bovine erythrocytes as drug carriers, the method of flow cytometry, confirming the presence of osmotically different fractions of red blood cells, indicated that various amounts of the encapsulated drug in porcine and bovine erythrocytes can be expected.

Net Fluorescein Flux Across Corneal Endothelium Strongly Suggests Fluid Transport is due to Electro-osmosis.

Science.gov (United States)

Sanchez, J M; Cacace, V; Kusnier, C F; Nelson, R; Rubashkin, A A; Iserovich, P; Fischbarg, J

2016-08-01

We have presented prior evidence suggesting that fluid transport results from electro-osmosis at the intercellular junctions of the corneal endothelium. Such phenomenon ought to drag other extracellular solutes. We have investigated this using fluorescein-Na2 as an extracellular marker. We measured unidirectional fluxes across layers of cultured human corneal endothelial (HCE) cells. SV-40-transformed HCE layers were grown to confluence on permeable membrane inserts. The medium was DMEM with high glucose and no phenol red. Fluorescein-labeled medium was placed either on the basolateral or the apical side of the inserts; the other side carried unlabeled medium. The inserts were held in a CO2 incubator for 1 h (at 37 °C), after which the entire volume of the unlabeled side was collected. After that, label was placed on the opposite side, and the corresponding paired sample was collected after another hour. Fluorescein counts were determined with a (Photon Technology) DeltaScan fluorometer (excitation 380 nm; emission 550 nm; 2 nm bwth). Samples were read for 60 s. The cells utilized are known to transport fluid from the basolateral to the apical side, just as they do in vivo in several species. We used 4 inserts for influx and efflux (total: 20 1-h periods). We found a net flux of fluorescein from the basolateral to the apical side. The flux ratio was 1.104 ± 0.056. That difference was statistically significant (p = 0.00006, t test, paired samples). The endothelium has a definite restriction at the junctions. Hence, an asymmetry in unidirectional fluxes cannot arise from osmosis, and can only point instead to paracellular solvent drag. We suggest, once more, that such drag is due to electro-osmotic coupling at the paracellular junctions.

Drying of carrots in slices with osmotic dehydration

African Journals Online (AJOL)

SAM

2014-07-23

Jul 23, 2014 ... extend the shelf-life by a few weeks, one year or more. The methods .... drated carrots, this work studied the drying of carrot with pre-osmotic ... e) Weight Loss - obtained directly using balance semi-analytical model BEL ...

Complex modeling of technological processes in pneumatic mixers for production of dry construction mixtures

Science.gov (United States)

Orekhova, T. N.; Nosov, O. A.; Prokopenko, V. S.; Kachaev, A. E.

2018-03-01

The improvement of the design of the pneumatic mixers aimed at the possibility of obtaining homogeneous disperse systems, while the resource and energy saving issues play an important role in the conditions of enterprises that use this type of equipment in their technological chain, is described in the article.

Comparative Erythrocytes Osmotic Fragility Test and some ...

African Journals Online (AJOL)

Erythrocytes osmotic fragility and haematological parameters of subjects with HbAS (sickle cell trait) and HbSS (sickle cell anaemia) were determined and compared with subjects with HbAA (normal adult haemoglobin), which acted as control. They were divided into three groups of 40 subjects for HbAA, 35 subjects for ...

A novel zinc-finger-like gene from Tamarix hispida is involved in salt and osmotic tolerance.

Science.gov (United States)

An, Yan; Wang, Yucheng; Lou, Lingling; Zheng, Tangchun; Qu, Guan-Zheng

2011-11-01

In the present study, a zinc-finger-like cDNA (ThZFL) was cloned from the Tamarix hispida. Northern blot analysis showed that the expression of ThZFL can be induced by salt, osmotic stress and ABA treatment. Overexpression of the ThZFL confers salt and osmotic stress tolerance in both yeast Saccharomyces cerevisiae and tobacco. Furthermore, MDA levels in ThZFL transformed tobacco were significantly decreased compared with control plants under salt and osmotic stress, suggesting ThZFL may confer stress tolerance by decreasing membrane lipid peroxidation. Subcellular localization analysis showed the ThZFL protein is localized in the cell wall. Our results indicated the ThZFL gene is an excellent candidate for genetic engineering to improve salt and osmotic tolerance in agricultural plants.

Effects of Crust Ingestion on Mixer Pump Performance in Tank 241-SY-101: Workshop Results

International Nuclear Information System (INIS)

Brennen, C.E.; Stewart, C.W.; Meyer, P.A.

1999-01-01

In August 1999, a workshop was held at Pacific Northwest National Laboratory to discuss the effects of crust ingestion on mixer pump performance in Hanford Waste Tank 241-SY-101. The main purpose of the workshop was to evaluate the potential for crust ingestion to degrade mixing and/or damage the mixer pump. The need for a previously determined 12-inch separation between the top of the mixer pump inlet and the crust base was evaluated. Participants included a representative from the pump manufacturer, an internationally known expert in centrifugal pump theory, Hanford scientists and engineers, and operational specialists representing relevant fields of expertise. The workshop focused on developing an understanding of the pump design, addressing the physics of entrainment of solids and gases into the pump, and assessing the effects of solids and gases on pump performance. The major conclusions are summarized as follows: (1) Entrainment of a moderate amount of solids or gas from the crust should not damage the pump or reduce its lifetime, though mixing effectiveness will be somewhat reduced. (2) Air binding should not damage the pump. Vibrations due to ingestion of gas, solids, and objects potentially could cause radial loads that might reduce the lifetime of bearings and seals. However, significant damage would require extreme conditions not associated with the small bubbles, fine solids, and chunks of relatively weak material typical of the crust. (3) The inlet duct extension opening, 235 inches from the tank bottom, should be considered the pump inlet, not the small gap at 262 inches. (4) A suction vortex exists at the inlet of all pumps. The characteristics of the inlet suction vortex in the mixer pump are very hard to predict, but its effects likely extend upward several feet. Because of this, the current 12-inch limit should be replaced with criteria based on actual monitored pump performance. The most obvious criterion (in addition to current operational

The osmotic fragility of human erythrocytes is inhibited by laser irradiation

International Nuclear Information System (INIS)

Habodaszova, D.; Sikurova, L.; Waczulikova, I.

2004-01-01

In this study we investigated the influence of green laser irradiation (532 nm, 30 mW, 31,7 J/cm 2 ) on the membrane integrity of human erythrocytes and compared the results with the effect of infrared laser irradiation (810 nm, 50 mW, 31,3 J/cm 2 ). To evaluate the membrane integrity of erythrocytes, one clinical parameter, the osmotic fragility, was investigated. We observed a decrease in osmotic fragility of the erythrocytes after irradiation by the green laser light as well as by the infrared laser compared to non-irradiated controls (Authors)

Safety Evaluation for Packaging 101-SY Hydrogen Mitigation Mixer Pump package

International Nuclear Information System (INIS)

Carlstrom, R.F.

1994-01-01

This Safety Evaluation for Packaging (SEP) provides analysis and considered necessary to approve a one-time transfer of the 101-SY Hydrogen Mitigation Mixer Pump (HMMP). This SEP will demonstrate that the transfer of the HMMP in a new shipping container will provide an equivalent degree of safety as would be provided by packages meeting US Department of Transportation (DOT)/US Nuclear Regulatory Commission (NRC) requirements. This fulfills onsite, transportation requirements implemented by WHC-CM-2-14

Safety Evaluation for Packaging 101-SY Hydrogen Mitigation Mixer Pump package

Energy Technology Data Exchange (ETDEWEB)

Carlstrom, R.F.

1994-10-05

This Safety Evaluation for Packaging (SEP) provides analysis and considered necessary to approve a one-time transfer of the 101-SY Hydrogen Mitigation Mixer Pump (HMMP). This SEP will demonstrate that the transfer of the HMMP in a new shipping container will provide an equivalent degree of safety as would be provided by packages meeting US Department of Transportation (DOT)/US Nuclear Regulatory Commission (NRC) requirements. This fulfills onsite, transportation requirements implemented by WHC-CM-2-14.

Effect of Osmotic Stress on Seed Germination Indices of Nigella sativa and Silybum marianum

Directory of Open Access Journals (Sweden)

H Balouchi

2012-04-01

Full Text Available Evaluation of medicinal plants to drought and salt stress tolerance, in an attempt to plant them under drought and saline regions, is of utmost importance. Environmental stresses, especially drought and salt, reduce the global crop yields more than other factors. Selection of drought tolerant crops at germination stage, usually is, the fast and low cost method. In order to study the effect of osmotic stress on germination indices of black cumin and milk thistle, an experiment carried out in a completely randomized design with four replications at the Seed Technology Laboratoary of Yasouj University in 2008. Treatments were 0 (as control, -2.4, -4.8, -7.2 and -9.4 bar osmotic potentials created by using PEG 6000. Results showed that, decreasing of osmotic potential reduced speed of germination and its percentage, root and shoot lengths and dry matter in these two plants. Black cumin showed higher tolerance, to -4.8 bar osmotic potential, as compared to milk thistle. However, milk thistle showed higher tolerance to drought stress, up to this osmotic potential (-4.8 bar, compared to black cumin. Milk thistle had lower germination speed and percentage at higher drought stress as compared to black cumin. Generally, milk thistle showed better growth and survival than black cumin due to its higher root and shoot length and dry matter.

Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

International Nuclear Information System (INIS)

González, Emilio J.; Calvar, Noelia; Macedo, Eugénia A.

2014-01-01

Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

Design and Fabrication of an Industrial Poultry Feed Tumble Mixer

Directory of Open Access Journals (Sweden)

Osokam Shadrach ONYEGU

2012-08-01

Full Text Available This paper presents the design and fabrication of a poultry feed industrial tumble mixer. The design computations to handle a 50Kg mass of feed was done in the MS Excel environment for proper machine design approach. The machine was designed using AUTOCAD 2D/3D design software and proper material selection was done before the assembling and fabrication of parts. The efficiency of the machine, its associated cost of production and the product obtained after few minutes of mixing were outstanding, thereby, making the design acceptable and cost effective.

Electro-active bio-films: formation, characterization and mechanisms

International Nuclear Information System (INIS)

Parot, Sandrine

2007-01-01

Some bacteria, which are able to exchange electrons with a conductive material without mediator form on conductive surfaces electro-active bio-films. This bacterial property has been recently discovered (2001). Objectives of this work are to develop electro-active bio-films in various natural environments from indigenous flora, then through complementary electrochemical techniques (chrono-amperometry and cyclic voltammetry), to evaluate electro-activity of isolates coming from so-formed bio-films and to characterize mechanisms of electron transfer between bacteria and materials. First, electro-active bio-films have been developed under chrono-amperometry in garden compost and in water coming from Guyana mangrove. These bio-films were respectively able to use an electrode as electron acceptor (oxidation) or as electron donor (reduction). In compost, results obtained in chrono-amperometry and cyclic voltammetry suggest a two-step electron transfer: slow substrate consumption, then rapid electron transfer between bacteria and the electrode. Thereafter, the ability to reduce oxygen was demonstrated with cyclic voltammetry for facultative aerobic isolates from compost bio-films (Enterobacter spp. and Pseudomonas spp.) and for aerobic isolates obtained from marine electro-active bio-films (Roseobacter spp. in majority). Finally, bio-films inducing current increase in chrono-amperometry were developed in bioreactor with synthetic medium from a pure culture of isolates. Hence, for the first time, electro-activity of several anaerobic strains of Geobacter bremensis isolated from compost bio-films was highlighted. (author) [fr

Osmotic concentration in three races of honey bee, Apis mellifera L. under environmental conditions of arid zone.

Science.gov (United States)

Ali, Hussain; Alqarni, Abdulaziz S; Owayss, Ayman A; Hassan, Awad M; Smith, Brian H

2017-07-01

Hemolymph osmolarity has great effect on honey bee health, especially in arid and semi-arid zones. It regulates water and nutrients in stressed tissues. Osmotic concentration in three races ( Apis mellifera ligustica , A. m. carnica and A. m. jemenitica ) of Apis mellifera was tested in central Saudi Arabia during spring and summer seasons in 2015. Newly emerged bee workers were first marked and later their hemolymph was extracted after intervals of 1, 5, 10, 15, 20 and 25 days. A significant positive correlation between age and osmolarity was found in all three races during spring and summer seasons. The lowest combined osmotic concentration for all three races was found after 1 day interval, while the highest osmotic concentration was recorded after 25 days. Among all races, A. m. ligustica showed significantly high osmotic concentration after 25 days in spring and summer seasons as compared to the other two races. Only A. m. jemenitica showed similar osmotic concentration after 10 and 15 days in both spring and summer seasons compared to other two races. Mean osmotic concentration of all three races was significantly different after 20 and 25 days in spring and summer seasons. Overall mean recorded during summer was significantly higher than the mean of spring season. Combined osmotic concentration in young drones of all races was significantly lower than that of old drones during spring and summer seasons.

Electro-osmotic pumping of sodium chloride solutions

CSIR Research Space (South Africa)

Schoeman, JJ

1997-08-20

Full Text Available : J = IAt/2cbF (35) 2.2.1. Current efficiency The amount of salt transferred per Faraday of current passed through a symmetric unit cell is given from Eq. (35) by \\[1\\]: 2JCb _ A~ (36) Cp -- I/F The overall... the volume of the solution that enters the bag per unit area (7.55cm 2) in t seconds (V/t=2J), I the applied current density (mA/cm z) and F the Faraday constant. The maximum brine concentration, c~ ax, was deter- mined...

Osmotic dehydration of fruit and berry raw materials in the food industry

OpenAIRE

N. A. Gribova; L. G. Eliseeva

2017-01-01

Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% o...

Analytical Expressions for Thermo-Osmotic Permeability of Clays

Science.gov (United States)

Gonçalvès, J.; Ji Yu, C.; Matray, J.-M.; Tremosa, J.

2018-01-01

In this study, a new formulation for the thermo-osmotic permeability of natural pore solutions containing monovalent and divalent cations is proposed. The mathematical formulation proposed here is based on the theoretical framework supporting thermo-osmosis which relies on water structure alteration in the pore space of surface-charged materials caused by solid-fluid electrochemical interactions. The ionic content balancing the surface charge of clay minerals causes a disruption in the hydrogen bond network when more structured water is present at the clay surface. Analytical expressions based on our heuristic model are proposed and compared to the available data for NaCl solutions. It is shown that the introduction of divalent cations reduces the thermo-osmotic permeability by one third compared to the monovalent case. The analytical expressions provided here can be used to advantage for safety calculations in deep underground nuclear waste repositories.

A new insight into membrane fouling mechanism in submerged membrane bioreactor: osmotic pressure during cake layer filtration.

Science.gov (United States)

Zhang, Meijia; Peng, Wei; Chen, Jianrong; He, Yiming; Ding, Linxian; Wang, Aijun; Lin, Hongjun; Hong, Huachang; Zhang, Ye; Yu, Haiying

2013-05-15

Big gap between experimental filtration resistance of cake layer formed on membrane surface and the hydraulic resistance calculated through the Carman-Kozeny equation, suggested the existence of a new membrane fouling mechanism: osmotic pressure during cake layer filtration in SMBR system. An osmotic pressure model based on chemical potential difference was then proposed. Simulation of the model showed that osmotic pressure accounted for the major fraction of total operation pressure, and pH, applied pressure and ionic strength were the key determining factors for osmosis effect. It was found that, variations of osmotic pressure with pH, applied pressure and added ionic strength were well coincident with perditions of model's simulation, providing the first direct evidences of the real occurrence of osmosis mechanism and the feasibility of the proposed model. These findings illustrate the essential role of osmotic pressure in filtration resistance, and improve fundamental understanding on membrane fouling in SMBR systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phase separation in an experimental mixer-settler

International Nuclear Information System (INIS)

Eckert, N.L.; Gormely, L.S.

1989-01-01

An experimental investigation was undertaken to study the factors affecting phase separation in a laboratory scale mixer-settler using a laboratory-prepared commercial oxime-copper system, and a system obtained from the Key Lake uranium extraction circuit. Besides being dependent on specific settler flow, the dispersion band thickness was found to be a function of the phase ratio and dispersion introduction level (uranium system only), and temperature. Drop size was found to be independent of dispersion throughout, a weak function of impeller speed, and a relatively strong function of the phase ratio. Microscopic examination of the uranium dispersion revealed the existence of drops within drops. With the exception of the organic continuous copper system, it was possible to distinguish two horizontal sublayers within the dispersion band. This structure conforms to the model provided by Barnea and Mizrahi. (author)

Tirilazad mesylate protects stored erythrocytes against osmotic fragility.

Science.gov (United States)

Epps, D E; Knechtel, T J; Bacznskyj, O; Decker, D; Guido, D M; Buxser, S E; Mathews, W R; Buffenbarger, S L; Lutzke, B S; McCall, J M

1994-12-01

The hypoosmotic lysis curve of freshly collected human erythrocytes is consistent with a single Gaussian error function with a mean of 46.5 +/- 0.25 mM NaCl and a standard deviation of 5.0 +/- 0.4 mM NaCl. After extended storage of RBCs under standard blood bank conditions the lysis curve conforms to the sum of two error functions instead of a possible shift in the mean and a broadening of a single error function. Thus, two distinct sub-populations with different fragilities are present instead of a single, broadly distributed population. One population is identical to the freshly collected erythrocytes, whereas the other population consists of osmotically fragile cells. The rate of generation of the new, osmotically fragile, population of cells was used to probe the hypothesis that lipid peroxidation is responsible for the induction of membrane fragility. If it is so, then the antioxidant, tirilazad mesylate (U-74,006f), should protect against this degradation of stored erythrocytes. We found that tirilazad mesylate, at 17 microM (1.5 mol% with respect to membrane lecithin), retards significantly the formation of the osmotically fragile RBCs. Concomitantly, the concentration of free hemoglobin which accumulates during storage is markedly reduced by the drug. Since the presence of the drug also decreases the amount of F2-isoprostanes formed during the storage period, an antioxidant mechanism must be operative. These results demonstrate that tirilazad mesylate significantly decreases the number of fragile erythrocytes formed during storage in the blood bank.

A physiological evaluation of the enhanced osmotic stress tolerance ...

African Journals Online (AJOL)

ELO

2012-01-05

Jan 5, 2012 ... SR3 and Jinan 177 were hydroponically subjected to osmotic stress, the accumulation of proline .... hydroponically in half strength Hoagland's solution for three weeks ..... ascrobate specific peroxidase in spinach chloroplasts.

A submillimetre-wave SIS mixer using NbN/MgO/NbN trilayers grown epitaxially on an MgO substrate

CERN Document Server

Uzawa, Y; Saito, A; Takeda, M; Wang, Z

2002-01-01

We have designed, fabricated and tested a quasi-optical superconductor-insulator-superconductor (SIS) mixer employing distributed NbN/MgO/NbN tunnel junctions and NbN/MgO/NbN microstriplines at submillimetre-wave frequencies. These trilayers were fabricated by dc- and rf-magnetron sputtering on an MgO substrate at ambient temperature so that the NbN and MgO films were grown epitaxially. Our SIS mixer consists of an MgO hyperhemispherical lens with an antireflection cap and a self-complementary log-periodic antenna made of a single-crystal NbN film, on which the distributed SIS junctions and the two-section impedance transformers were mirror-symmetrically placed at the feed point of the antenna. As designed, the junctions are 0.6 mu m wide and 15.5 mu m long, which is sufficient to absorb the incoming signal along this lossy transmission line, assuming a current density of 10 kA cm sup - sup 2. The mixer showed good I-V characteristics, with subgap-to-normal resistance ratios of about 13, although weak-link br...

Electro-chemical grinding

Science.gov (United States)

Feagans, P. L.

1972-01-01

Electro-chemical grinding technique has rotation speed control, constant feed rates, and contour control. Hypersonic engine parts of nickel alloys can be almost 100% machined, keeping tool pressure at virtual zero. Technique eliminates galling and permits constant surface finish and burr-free interrupted cutting.

Methods to increase the rate of mass transfer during osmotic dehydration of foods.

Science.gov (United States)

Chwastek, Anna

2014-01-01

Traditional methods of food preservation such as freezing, freeze drying (lyophilization), vacuum drying, convection drying are often supplemented by new technologies that enable obtaining of high quality products. Osmotic dehydration is more and more often used during processing of fruits and vegetables. This method allows maintaining good organoleptic and functional properties in the finished product. Obtaining the desired degree of dehydration or saturation of the material with an osmoactive substance often requires  elongation of time or use of high temperatures. In recent years much attention was devoted to techniques aimed at increasing the mass transfer between the dehydrated material and the hypertonic solution. The work reviews the literature focused on methods of streamlining the process of osmotic dehydration which include the use of: ultrasound, high hydrostatic pressure, vacuum osmotic dehydration and pulsed electric field.

Molecular sieving action of the cell membrane during gradual osmotic hemolysis

Energy Technology Data Exchange (ETDEWEB)

MacGregor, R.D. II

1977-05-01

Rat erythrocytes were hemolyzed by controlled gradual osmotic hemolysis to study cell morphology and hemoglobin loss from individual cells. Results suggest that each increase in the rate of loss of a protein from the cells during the initial phases of controlled gradual osmotic hemolysis is caused by the passage of a previously impermeable species across the stressed membrane. Similarly, during the final stages of controlled gradual osmotic hemolysis, each sharp decrease in the rate of loss of a protein corresponds to the termination of a molecular flow. A theoretical model is described that predicts the molecular sieving of soluble globular proteins across the stressed red cell membrane. Hydrophobic interactions occur between the soluble proteins and the lipid bilayer portion of the cell membrane. A spectrin network subdivides the bilayer into domains that restrict the insertion of large molecules into the membrane. Other membrane proteins affect soluble protein access to the membrane. Changes in the loss curves caused by incubation of red cells are discussed in terms of the model.

Controlling Release of Integral Lipid Nanoparticles Based on Osmotic Pump Technology.

Science.gov (United States)

Tian, Zhiqiang; Yu, Qin; Xie, Yunchang; Li, Fengqian; Lu, Yi; Dong, Xiaochun; Zhao, Weili; Qi, Jianping; Wu, Wei

2016-08-01

To achieve controlled release of integral nanoparticles by the osmotic pump strategy using nanostructured lipid carriers (NLCs) as model nanoparticles. NLCs was prepared by a hot-homogenization method, transformed into powder by lyophilization, and formulated into osmotic pump tablets (OPTs). Release of integral NLCs was visualized by live imaging after labeling with a water-quenching fluorescent probe. Effects of formulation variables on in vitro release characteristics were evaluated by measuring the model drug fenofibrate. Pharmacokinetics were studied in beagle dogs using the core tablet and a micronized fenofibrate formulation as references. NLCs are released through the release orifices of the OPTs as integral nanoparticles. Near zero-order kinetics can be achieved by optimizing the influencing variables. After oral administration, decreased C max and steady drug levels for as long as over 24 h are observed. NLC-OPTs show an oral bioavailability of the model drug fenofibrate similar to that of the core tablets, which is about 1.75 folds that of a fast-release formulation. Controlled release of integral NLCs is achieved by the osmotic pump strategy.

Self-consistent unstirred layers in osmotically driven flows

DEFF Research Database (Denmark)

Jensen, Kåre Hartvig; Bohr, Tomas; Bruus, Henrik

2010-01-01

It has long been recognized that the osmotic transport characteristics of membranes may be strongly influenced by the presence of unstirred concentration boundary layers adjacent to the membrane. Previous experimental as well as theoretical works have mainly focused on the case where the solutions...

Osmotic stress, endogenous abscisic acid and the control of leaf morphology in Hippuris vulgaris L

Science.gov (United States)

Goliber, T. E.; Feldman, L. J.

1989-01-01

Previous reports indicate that heterophyllous aquatic plants can be induced to form aerial-type leaves on submerged shoots when they are grown in exogenous abscisic acid (ABA). This study reports on the relationship between osmotic stress (e.g. the situation encountered by a shoot tip when it grows above the water surface), endogenous ABA (as measured by gas chromatography-electron capture detector) and leaf morphology in the heterophyllous aquatic plant, Hippuris vulgaris. Free ABA could not be detected in submerged shoots of H. vulgaris but in aerial shoots ABA occurred at ca. 40 ng (g fr wt)-1. When submerged shoots were osmotically stressed ABA appeared at levels of 26 to 40 ng (g fr wt)-1. These and other data support two main conclusions: (1) Osmotically stressing a submerged shoot causes the appearance of detectable levels of ABA. (2) The rise of ABA in osmotically stressed submerged shoots in turn induces a change in leaf morphology from the submerged to the aerial form. This corroborates the hypothesis that, in the natural environment, ABA levels rise in response to the osmotic stress encountered when a submerged shoot grows up through the water/air interface and that the increased ABA leads to the production of aerial-type leaves.

Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

KAUST Repository

Han, Gang; Zuo, Jian; Wan, Chunfeng; Chung, Neal Tai-Shung

2015-01-01

unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic

Simulation Modeling of Non-Homogeneous Mixture in the Horizontal Drum Mixer

Directory of Open Access Journals (Sweden)

Andrey Vladimirovich Ostroukh

2015-05-01

Full Text Available The paper proposes a simulation model of the diffusion mixing of solids, based on the theory of probability and stochastic diffusion model of imperfect processes of solid particles. It is assumed that the particles have different sizes and density. Model of the program implemented in the AnyLogic SoftWare. Developed a simulation model to evaluate the differences between the intense mixing processes in time and assess their impact on the course of other processes in a horizontal drum mixer.

Resolving Overlimiting Current Mechanisms in Microchannel-Nanochannel Interface Devices

Science.gov (United States)

Yossifon, Gilad; Leibowitz, Neta; Liel, Uri; Schiffbauer, Jarrod; Park, Sinwook

2015-11-01

We present results demonstrating the space charge-mediated transition between classical, diffusion-limited current and surface-conduction dominant over-limiting currents in a shallow micro-nanochannel device. The extended space charge layer develops at the depleted micro-nanochannel entrance at high current and is correlated with a distinctive maximum in the dc resistance. Experimental results for a shallow surface-conduction dominated system are compared with theoretical models, allowing estimates of the effective surface charge at high voltage to be obtained. Further, we extend the study to microchannels of moderate to large depths where the role of various electro-convection mechanisms becomes dominant. In particular, electro-osmotic of the second kind and electro-osmotic instability (EOI) which competes each other at geometrically heterogeneous (e.g. undulated nanoslot interface, array of nanoslots) nanoslot devices. Also, these effects are also shown to be strongly modulated by the non-ideal permselectivity of the nanochannel.

Ebselen exhibits glycation-inhibiting properties and protects against osmotic fragility of human erythrocytes in vitro.

Science.gov (United States)

Soares, Julio C M; Folmer, Vanderlei; Da Rocha, João B T; Nogueira, Cristina W

2014-05-01

Diabetic status is associated with an increase on oxidative stress markers in humans and animal models. We have investigated the in vitro effects of high concentrations of glucose on the profile of oxidative stress and osmotic fragility of blood from control and diabetic patients; we considered whether its antioxidant properties could afford some protection against glucose-induced osmotic fragility, and whether ebselen could act as an inhibitor of hemoglobin glycation. Raising blood glucose to 5-100 mmol/L resulted in a concentration-dependent increase of glycated hemoglobin (HbA1c; P Ebselen significantly reduced the glucose-induced increase in osmotic fragility and inhibited HbA1c formation (P < 0.0001). These results indicate that blood from patients with uncontrolled diabetes are more sensitive to osmotic shock than from patients with controlled diabetes and control subjects in relation to increased production of free radicals in vivo. © 2014 International Federation for Cell Biology.

Effect of Osmotic Pressure on the Stability of Whole Inactivated Influenza Vaccine for Coating on Microneedles.

Directory of Open Access Journals (Sweden)

Hyo-Jick Choi

Full Text Available Enveloped virus vaccines can be damaged by high osmotic strength solutions, such as those used to protect the vaccine antigen during drying, which contain high concentrations of sugars. We therefore studied shrinkage and activity loss of whole inactivated influenza virus in hyperosmotic solutions and used those findings to improve vaccine coating of microneedle patches for influenza vaccination. Using stopped-flow light scattering analysis, we found that the virus underwent an initial shrinkage on the order of 10% by volume within 5 s upon exposure to a hyperosmotic stress difference of 217 milliosmolarity. During this shrinkage, the virus envelope had very low osmotic water permeability (1 - 6×10-4 cm s-1 and high Arrhenius activation energy (Ea = 15.0 kcal mol-1, indicating that the water molecules diffused through the viral lipid membranes. After a quasi-stable state of approximately 20 s to 2 min, depending on the species and hypertonic osmotic strength difference of disaccharides, there was a second phase of viral shrinkage. At the highest osmotic strengths, this led to an undulating light scattering profile that appeared to be related to perturbation of the viral envelope resulting in loss of virus activity, as determined by in vitro hemagglutination measurements and in vivo immunogenicity studies in mice. Addition of carboxymethyl cellulose effectively prevented vaccine activity loss in vitro and in vivo, believed to be due to increasing the viscosity of concentrated sugar solution and thereby reducing osmotic stress during coating of microneedles. These results suggest that hyperosmotic solutions can cause biphasic shrinkage of whole inactivated influenza virus which can damage vaccine activity at high osmotic strength and that addition of a viscosity enhancer to the vaccine coating solution can prevent osmotically driven damage and thereby enable preparation of stable microneedle coating formulations for vaccination.

Theory-inspired development of organic electro-optic materials

Energy Technology Data Exchange (ETDEWEB)

Dalton, Larry R., E-mail: dalton@chem.washington.ed [Department of Chemistry, Bagley Hall 202D, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Department of Electrical Engineering, Bagley Hall 202D, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

2009-11-30

Real-time, time-dependent density functional theory (RTTDDFT) and pseudo-atomistic Monte Carlo-molecular dynamics (PAMCMD) calculations have been used in a correlated manner to achieve quantitative definition of structure/function relationships necessary for the optimization of electro-optic activity in organic materials. Utilizing theoretical guidance, electro-optic coefficients (at telecommunication wavelengths) have been increased to 500 pm/V while keeping optical loss to less than 2 dB/cm. RTTDDFT affords the advantage of permitting explicit treatment of time-dependent electric fields, both applied fields and internal fields. This modification has permitted the quantitative simulation of the variation of linear and nonlinear optical properties of chromophores and the electro-optic activity of materials with optical frequency and dielectric permittivity. PAMCMD statistical mechanical calculations have proven an effective means of treating the full range of spatially-anisotropic intermolecular electrostatic interactions that play critical roles in defining the degree of noncentrosymmetric order that is achieved by electric field poling of organic electro-optic materials near their glass transition temperatures. New techniques have been developed for the experimental characterization of poling-induced acentric order including a modification of variable angle polarization absorption spectroscopy (VAPAS) permitting a meaningful correlation of theoretical and experimental data related to poling-induced order for a variety of complex organic electro-optic materials.

Theory-inspired development of organic electro-optic materials

International Nuclear Information System (INIS)

Dalton, Larry R.

2009-01-01

Real-time, time-dependent density functional theory (RTTDDFT) and pseudo-atomistic Monte Carlo-molecular dynamics (PAMCMD) calculations have been used in a correlated manner to achieve quantitative definition of structure/function relationships necessary for the optimization of electro-optic activity in organic materials. Utilizing theoretical guidance, electro-optic coefficients (at telecommunication wavelengths) have been increased to 500 pm/V while keeping optical loss to less than 2 dB/cm. RTTDDFT affords the advantage of permitting explicit treatment of time-dependent electric fields, both applied fields and internal fields. This modification has permitted the quantitative simulation of the variation of linear and nonlinear optical properties of chromophores and the electro-optic activity of materials with optical frequency and dielectric permittivity. PAMCMD statistical mechanical calculations have proven an effective means of treating the full range of spatially-anisotropic intermolecular electrostatic interactions that play critical roles in defining the degree of noncentrosymmetric order that is achieved by electric field poling of organic electro-optic materials near their glass transition temperatures. New techniques have been developed for the experimental characterization of poling-induced acentric order including a modification of variable angle polarization absorption spectroscopy (VAPAS) permitting a meaningful correlation of theoretical and experimental data related to poling-induced order for a variety of complex organic electro-optic materials.

Novel Regulation of Aquaporins during Osmotic Stress1

Science.gov (United States)

Vera-Estrella, Rosario; Barkla, Bronwyn J.; Bohnert, Hans J.; Pantoja, Omar

2004-01-01

Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions. PMID:15299122

Glucose Monitoring System Based on Osmotic Pressure Measurements

Directory of Open Access Journals (Sweden)

Alexandra LEAL

2011-02-01

Full Text Available This paper presents the design and development of a prototype sensor unit for implementation in a long-term glucose monitoring system suitable for estimating glucose levels in people suffering from diabetes mellitus. The system utilizes osmotic pressure as the sensing mechanism and consists of a sensor prototype that is integrated together with a pre-amplifier and data acquisition unit for both data recording and processing. The sensor prototype is based on an embedded silicon absolute pressure transducer and a semipermeable nanoporous membrane that is enclosed in the sensor housing. The glucose monitoring system facilitates the integration of a low power microcontroller that is combined with a wireless inductive powered communication link. Experimental verification have proven that the system is capable of tracking osmotic pressure changes using albumin as a model compound, and thereby show a proof of concept for novel long term tracking of blood glucose from remote sensor nodes.

Electro/powder separation process

International Nuclear Information System (INIS)

Dunn, J.P.

1977-01-01

A report is presented to introduce the ELECTRO/POWDER process to the P/M Industry. The process effectively uses electrostatic forces to convey, sort, meter, and blend fine powders. The major advantages of this separating process consist of the processing of primary particles, low particle energy due to particle velocity control and the pattern of particle movement over the sieve (vertical oscillation of particles above the sieve aperture). The report briefly describes the forces involved in both mechanical and sieving devices, with major emphasis on the operating principles of this process. Sieve separation of particulates is basically the result of two physical separating processes which occur simultaneously or independently; separation (dispersion) of particulates from each other and the size separation by passage through fixed apertures. In order to accomplish this goal, mechanical sieving devices utilize various motions to induce shear forces between the sieve surface and the particulates, and between the particulates themselves. It is noted that the ELECTRO/POWDER process is making steady progress in becoming an industrial tool for sieving and feeding of fine particles. Its potential extends into both the blending and admixing of powders, either by incorporating two opposing feeders, one being charged with the opposite polarity or by modifying the ELECTRO/SIEVE to incorporate more than one input and a solid electrode to replace the sieve electrode

Foaming/antifoaming in WTP Tanks Equipped with Pulse Jet Mixer and Air Spargers

International Nuclear Information System (INIS)

HASSAN, NEGUIB

2004-01-01

The River Protection Project-Waste Treatment Plant (RPP-WTP) requested Savannah River National Laboratory (SRNL) to conduct small-scale foaming and antifoam testing using actual Hanford waste and simulants subjected to air sparging. The foaminess of Hanford tank waste solutions was previously demonstrated in SRNL during WTP evaporator foaming and ultrafiltration studies and commercial antifoam DOW Q2-3183A was recommended to mitigate the foam in the evaporators. Currently, WTP is planning to use air spargers in the HLW Lag Storage Vessels, HLW Concentrate Receipt Vessel, and the Ultrafiltration Vessels to assist the performance of the Jet Pulse Mixers (JPM). Sparging of air into WTP tanks will induce a foam layer within the process vessels. The air dispersion in the waste slurries and generated foams could present problems during plant operation. Foam in the tanks could also adversely impact hydrogen removal and mitigation. Antifoam (DOW Q2-3183A) will be used to control foaming in Hanford sparged waste processing tanks. These tanks will be mixed by a combination of pulse-jet mixers and air spargers. The percent allowable foaminess or freeboard in WTP tanks are shown in tables

Modelling electro-active polymers with a dispersion-type anisotropy

Science.gov (United States)

Hossain, Mokarram; Steinmann, Paul

2018-02-01

We propose a novel constitutive framework for electro-active polymers (EAPs) that can take into account anisotropy with a chain dispersion. To enhance actuation behaviour, particle-filled EAPs become promising candidates nowadays. Recent studies suggest that particle-filled EAPs, which can be cured under an electric field during the manufacturing time, do not necessarily form perfect anisotropic composites, rather they create composites with dispersed chains. Hence in this contribution, an electro-mechanically coupled constitutive model is devised that considers the chain dispersion with a probability distribution function in an integral form. To obtain relevant quantities in discrete form, numerical integration over the unit sphere is utilized. Necessary constitutive equations are derived exploiting the basic laws of thermodynamics that result in a thermodynamically consistent formulation. To demonstrate the performance of the proposed electro-mechanically coupled framework, we analytically solve a non-homogeneous boundary value problem, the extension and inflation of an axisymmetric cylindrical tube under electro-mechanically coupled load. The results capture various electro-mechanical couplings with the formulation proposed for EAP composites.

Advanced Design Mixer Pump Tank 18 Design Modifications Summary Report

International Nuclear Information System (INIS)

Adkins, B.J.

2002-01-01

The Westinghouse Savannah River Company (WSRC) is preparing to retrieve high level waste (HLW) from Tank 18 in early FY03 to provide feed for the Defense Waste Processing Facility (DWPF) and to support tank closure in FY04. As part of the Tank 18 project, WSRC will install a single Advanced Design Mixer Pump (ADMP) in the center riser of Tank 18 to mobilize, suspend, and mix radioactive sludge in preparation for transfer to Tank 7. The use of a single ADMP is a change to the current baseline of four (4) standard slurry pumps used during previous waste retrieval campaigns. The ADMP was originally conceived by Hanford and supported by SRS to provide a more reliable and maintainable mixer pump for use throughout the DOE complex. The ADMP underwent an extensive test program at SRS between 1998 and 2002 to assess reliability and hydraulic performance. The ADMP ran for approximately 4,200 hours over the four-year period. A detailed tear down and inspection of the pump following the 4,2 00-hour run revealed that the gas mechanical seals and anti-friction bearings would need to be refurbished/replaced prior to deployment in Tank 18. Design modifications were also needed to meet current Authorization Basis safety requirements. This report documents the modifications made to the ADMP in support of Tank 18 deployment. This report meets the requirements of Tanks Focus Area (TFA) Milestone 3591.4-1, ''Issue Report on Modifications Made to the ADMP,'' contained in Technical Task Plan (TTP) SR16WT51, ''WSRC Retrieval and Closure.''

Correlation and prediction of osmotic coefficient and water activity of aqueous electrolyte solutions by a two-ionic parameter model

International Nuclear Information System (INIS)

Pazuki, G.R.

2005-01-01

In this study, osmotic coefficients and water activities in aqueous solutions have been modeled using a new approach based on the Pitzer model. This model contains two physically significant ionic parameters regarding ionic solvation and the closest distance of approach between ions in a solution. The proposed model was evaluated by estimating the osmotic coefficients of nine electrolytes in aqueous solutions. The obtained results showed that the model is suitable for predicting the osmotic coefficients in aqueous electrolyte solutions. Using adjustable parameters, which have been calculated from regression between the experimental osmotic coefficient and the results of this model, the water activity coefficients of aqueous solutions were calculated. The average absolute relative deviations of the osmotic coefficients between the experimental data and the calculated results were in agreement

Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion

OpenAIRE

Yan, Jing; Nadell, Carey D.; Stone, Howard A.; Wingreen, Ned S.; Bassler, Bonnie L.

2017-01-01

Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmot...

Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

Energy Technology Data Exchange (ETDEWEB)

Cochrane, T. T., E-mail: agteca@hotmail.com [AGTECA S.A., 230 Oceanbeach Road, Mount Maunganui, Tauranga 3116 (New Zealand); Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz [Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

2016-01-15

Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f

Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

International Nuclear Information System (INIS)

Cochrane, T. T.; Cochrane, T. A.

2016-01-01

Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N f ,” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N f was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N f , the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N f using recorded

Compliant electro-thermal microactuators

DEFF Research Database (Denmark)

Jonsmann, Jacques; Sigmund, Ole; Bouwstra, Siebe

1999-01-01

This paper describes design, microfabrication and characterisation of topology optimised compliant electro-thermal microactuators. The actuators are fabricated by a fast prototyping process using laser micromachining and electroplating. Actuators are characterised with respect to displacement...

The presence and growth of Legionella species in thermostatic shower mixer taps: an exploratory field study

NARCIS (Netherlands)

Joost van Hoof; P.W.J.J. van der Wielen; E. van der Blom; O.W.W. Nuijten; L. Hornstra

2014-01-01

Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of

The roles of different salts and a novel osmotic pressure control strategy for improvement of DHA production by Schizochytrium sp.

Science.gov (United States)

Hu, Xue-Chao; Ren, Lu-Jing; Chen, Sheng-Lan; Zhang, Li; Ji, Xiao-Jun; Huang, He

2015-11-01

The effects of different osmotic pressure, changed by six salts (NaCl, Na2SO4, (NH4)2SO4, KH2PO4 and MSG), on cell growth and DHA synthesis by Schizochytrium sp. were investigated. Six optimal mediums were obtained to study different osmotic pressure combinations at cell growth stage and DHA synthesis stage. Results showed that cultivated cell in higher osmotic pressure condition and fermented in lower osmotic pressure condition was benefit to enhance DHA synthesis. Combination 17-6 could get the maximum cell dry weight of 56.95 g/L and the highest DHA percentage in total fatty acids of 55.21%, while combination 17-B could get the highest lipid yield of 33.47 g/L with 42.10% DHA in total fatty acids. This was the first report about the enhancement of DHA production by osmotic regulation and this work provided two novel osmotic control processes for high lipid yield and high DHA percentage in total fatty acids.

Calcium and Calmodulin Are Involved in Nitric Oxide-Induced Adventitious Rooting of Cucumber under Simulated Osmotic Stress.

Science.gov (United States)

Niu, Lijuan; Yu, Jian; Liao, Weibiao; Yu, Jihua; Zhang, Meiling; Dawuda, Mohammed M

2017-01-01

Osmotic stress is a major form of abiotic stress that adversely affects growth and development of plants and subsequently reduces yield and quality of crops. In this study, the effect of nitric oxide (NO) and calcium (Ca 2+ ) on the process of adventitious rooting in cucumber ( Cucumis sativus L.) under simulated osmotic stress was investigated. The results revealed that the effect of exogenous NO and Ca 2+ in promoting the development of adventitious roots in cucumber seedlings under simulated osmotic stress was dose-dependent, with a maximal biological response at 10 μM NO donor nitroprusside (SNP) or 200 μM Ca 2+ . The application of Ca 2+ chelators or channel inhibitors and calmodulin (CaM) antagonists significantly reversed NO-induced adventitious rooting, implying that endogenous Ca 2+ /CaM might be involved in NO-induced adventitious rooting under osmotic stress. Moreover, intracellular Ca amount was also increased by NO in cucumber hypocotyls during the development of adventitious roots under osmotic stress. This increase of endogenous Ca 2+ was inhibited by NO specific scavenger 2-(4-carboxyphenyl) -4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), nitrate reductase inhibitors tungstate (Na 2 WO 4 ) and sodium azide (NaN 3 ) . This gives an indication that Ca 2+ might be a downstream signaling molecule in the adventitious root development by NO under osmotic condition. The results also show that NO or Ca 2+ play a positive role in improving plant water status and photosynthetic system by increasing chlorophyll content and photochemical activity in leaves. Furthermore, NO and Ca 2+ treatment might alleviate the negative effects of osmotic stress by decreasing membrane damage and reactive oxygen species (ROS) production by enhancing the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Therefore, Ca 2+ /CaM may act as a downstream signaling molecule in NO-induced development of adventitious root

Rational design of organic electro-optic materials

CERN Document Server

Dalton, L R

2003-01-01

Quantum mechanical calculations are used to optimize the molecular first hyperpolarizability of organic chromophores and statistical mechanical calculations are used to optimize the translation of molecular hyperpolarizability to macroscopic electro-optic activity (to values of greater than 100 pm V sup - sup 1 at telecommunications wavelengths). Macroscopic material architectures are implemented exploiting new concepts in nanoscale architectural engineering. Multi-chromophore-containing dendrimers and dendronized polymers not only permit optimization of electro-optic activity but also of auxiliary properties including optical loss (both absorption and scattering), thermal and photochemical stability and processability. New reactive ion etching and photolithographic techniques permit the fabrication of three-dimensional optical circuitry and the integration of that circuitry with semiconductor very-large-scale integration electronics and silica fibre optics. Electro-optic devices have been fabricated exploiti...

Stress responses of the industrial workhorse Bacillus licheniformis to osmotic challenges.

Directory of Open Access Journals (Sweden)

Rebecca Schroeter

Full Text Available The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl, and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes, the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

Stress responses of the industrial workhorse Bacillus licheniformis to osmotic challenges.

Science.gov (United States)

Schroeter, Rebecca; Hoffmann, Tamara; Voigt, Birgit; Meyer, Hanna; Bleisteiner, Monika; Muntel, Jan; Jürgen, Britta; Albrecht, Dirk; Becher, Dörte; Lalk, Michael; Evers, Stefan; Bongaerts, Johannes; Maurer, Karl-Heinz; Putzer, Harald; Hecker, Michael; Schweder, Thomas; Bremer, Erhard

2013-01-01

The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl), and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes), the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

An analysis of the effects of osmotic backwashing on the seawater reverse osmosis process.

Science.gov (United States)

Park, JunYoung; Jeong, WooWon; Nam, JongWoo; Kim, JaeHun; Kim, JiHoon; Chon, Kangmin; Lee, Euijong; Kim, HyungSoo; Jang, Am

2014-01-01

Fouling control is an important consideration in the design and operation of membrane-based water treatment processes. It has been generally known that chemical cleaning is still the most common method to remove foultants and maintain the performance of reverse osmosis (RO) desalination. Regardless of the chemical membrane cleaning methods applied effectively, however, frequent chemical cleaning can shorten the membrane life. In addition, it also increases operating and maintenance costs due to the waste chemical disposal. As an alternative, osmotic backwashing can be applied to RO membranes by diluting the concentration polarization (CP) layer. In this study, the effects of osmotic backwashing were analysed under different total dissolved salts (TDSs) and backwashing conditions, and the parameters of the osmotic backwashing were evaluated. The results of the analysis based on the properties of the organic matters found in raw water showed that the cleaning efficiency in respect to the fouling by hydrophilic organic matters was the greatest. Osmotic backwashing was carried out by changing the TDS of the permeate. As a result, the backwashing volume decreased with time due to the CP of the permeate and the backwashing volume. The difference in the osmotic pressure between the raw water and the permeate (Delta pi) also decreased as time passed. It was confirmed that when the temperature of the effluent was high, both the cleaning efficiency and the backwashing volume, which inpours at the same time, increased. When the circulation flow of the effluent was high, both the cleaning efficiency and the backwashing volume increased.

Estimating contribution of anthocyanin pigments to osmotic adjustment during winter leaf reddening.

Science.gov (United States)

Hughes, Nicole M; Carpenter, Kaylyn L; Cannon, Jonathan G

2013-01-15

The association between plant water stress and synthesis of red, anthocyanin pigments in leaves has led some plant biologists to propose an osmotic function of leaf reddening. According to this hypothesis, anthocyanins function as a solute in osmotic adjustment (OA), contributing to depression of osmotic potential (Ψ(π)) and maintenance of turgor pressure during drought-stressed conditions. Here we calculate the percent contribution of anthocyanin to leaf Ψ(π) during OA in two angiosperm evergreen species, Galax urceolata and Gaultheria procumbens. Both species exhibit dramatic leaf reddening under high light during winter, concomitant with declines in leaf water potential and accumulation of solutes. Data previously published by the authors on osmotic potential at full turgor (Ψ(π,100)) of G. urceolata and G. procumbens leaves before and after leaf reddening were used to estimate OA. In vivo molar concentrations of anthocyanin, glucose, fructose, and sucrose measured from the same individuals were converted to pressure equivalents using the Ideal Gas Law, and percent contribution to OA was estimated. Estimated mean OA during winter was -0.7MPa for G. urceolata and -0.8MPa for G. procumbens. In vivo concentrations of anthocyanin (3-10mM) were estimated to account for ∼2% of OA during winter, and comprised <0.7% of Ψ(π,100) in both species. Glucose, fructose, and sucrose combined accounted for roughly 50 and 80% of OA for G. urceolata and G. procumbens, respectively, and comprised ∼20% of Ψ(π,100). We observed that a co-occurring, acyanic species (Vinca minor) achieved similar OA without synthesizing anthocyanin. We conclude that anthocyanins represent a measurable, albeit meager, component of OA in red-leafed evergreen species during winter. However, due to their low concentrations, metabolic costliness relative to other osmolytes, and striking red color (unnecessary for an osmotic function), it is unlikely that they are synthesized solely for an

Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

International Nuclear Information System (INIS)

González, Emilio J.; Calvar, Noelia; Domínguez, Ángeles; Macedo, Eugénia A.

2013-01-01

Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

Magneto-optic and electro-optic modulators

International Nuclear Information System (INIS)

Hutchinson, D.P.; Ma, C.H.; Price, T.R.; Staats, P.A.; Sluis, K.L.V.

1982-01-01

An important aspect of the Faraday rotation diagnostic for tokamak plasma measurement has been the development of suitable polarization modulators for submillimeter wavelength. The problems are to obtain high optical transmission and fast modulation frequencies. In ORNL, the authors have developed both a magneto-optic and an electro-optic submillimeter-wave modulators. These devices have been operated at modulation frequency of approximately 100 kHz, and both have high transmission. The original magneto-optic modulator consists of a 3 mm thick by 1.4 cm diameter 2-111 ferrite disk mounted at the center of an air core coil. Recently, a new ferrite modulator has been tested, which allows a much higher modulation frequency than the original device. A laboratory set-up designed to simulate a plasma heterodyne interferometer/polarimeter experiment has been used to determine the modulator characteristics. A mechanical polarization rotor was used to simulate the rotation by plasma. The transmission of the ferrite disk was 80 % at a wavelength of 0.447 mm. The authors have also performed preliminary measurement on an electro-optic modulator first demonstrated by Fetterman at Lincoln Laboratory, U.S. This device is a classical electro-optic modulator using a cryogenically cooled (4.2 K) LiTaO 3 crystal. Experiments are underway to determine the electro-optic properties of the crystal over the temperature range from 4.2 K to 77 K and over the range of wavelength from 0.118 mm to 0.447 mm. (Wakatsuki, Y.)

Concrete decontamination scoping tests

International Nuclear Information System (INIS)

Archibald, K.E.

1995-01-01

This report details the research efforts and scoping tests performed at the Idaho Chemical Process Plant using scabbling, chemical, and electro-osmotic decontamination techniques on radiologically contaminated concrete

Improving the Efficiency of 3-D Hydrogeological Mixers: Dilution Enhancement Via Coupled Engineering-Induced Transient Flows and Spatial Heterogeneity

Science.gov (United States)

Di Dato, Mariaines; de Barros, Felipe P. J.; Fiori, Aldo; Bellin, Alberto

2018-03-01

Natural attenuation and in situ oxidation are commonly considered as low-cost alternatives to ex situ remediation. The efficiency of such remediation techniques is hindered by difficulties in obtaining good dilution and mixing of the contaminant, in particular if the plume deformation is physically constrained by an array of wells, which serves as a containment system. In that case, dilution may be enhanced by inducing an engineered sequence of injections and extractions from such pumping system, which also works as a hydraulic barrier. This way, the aquifer acts as a natural mixer, in a manner similar to the industrialized engineered mixers. Improving the efficiency of hydrogeological mixers is a challenging task, owing to the need to use a 3-D setup while relieving the computational burden. Analytical solutions, though approximated, are a suitable and efficient tool to seek the optimum solution among all possible flow configurations. Here we develop a novel physically based model to demonstrate how the combined spatiotemporal fluctuations of the water fluxes control solute trajectories and residence time distributions and therefore, the effectiveness of contaminant plume dilution and mixing. Our results show how external forcing configurations are capable of inducing distinct time-varying groundwater flow patterns which will yield different solute dilution rates.

Efficiency of osmotic pipe flows

DEFF Research Database (Denmark)

Haaning, Louise Sejling; Jensen, Kaare Hartvig; Helix Nielsen, Claus

2013-01-01

efficiency of these flows is limited by the presence of “unstirred” concentration boundary layers near the tube walls, and our primary aim is to understand and quantify these layers and their effect on the flow. We measure the outlet flow rate Qout while varying the inlet flow rate Q*, concentration c......We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping...

Influence of osmotic processes on the excess-hydraulic head measured in the Toarcian/Domerian argillaceous formation of Tournemire

International Nuclear Information System (INIS)

Tremosa, J.

2010-01-01

In the framework of the studies dealing on ability to store radioactive wastes in argillaceous formations, signification of interstitial pressures is an important point to understand water and solutes transport. In very low permeability argillaceous formations, like those studied in the Callovo-Oxfordian of the Paris basin by ANDRA, pore pressure is frequently higher than the theoretical hydrostatic pressure or than the pressure in the surrounding aquifers. Such an overpressure is also measured in the Toarcian/Domerian argillaceous formation (k = 10 -21 m 2 ), studied by the IRSN in the underground research laboratory of Tournemire (Aveyron, France). The hydraulic head profile has been specified in this manuscript and found to present a 30 ±10 m excess head. This excess-head can be due to compaction disequilibrium of the argillaceous formation, diagenetic evolution of the rock, tectonic compression, changes in hydrodynamic boundary conditions or osmotic processes. Amongst these potential causes, chemical osmosis and thermo-osmosis, a fluid flow under a chemical concentration and a temperature gradient, respectively, are expected to develop owing to the small pore size and the electrostatic interactions related to the charged surface of clay minerals. The goal of the work presented here was to study and quantify the contribution of each cause to the measured excess-head. Chemo-osmotic and thermo-osmotic permeabilities were obtained by experiments and using theoretical models. Theoretical models are based on the reproduction of the interactions occurring between the charged surface of clay minerals and pore solution and their up-scaling at the representative elementary volume macroscopic scale. Chemical osmosis phenomenon is related to anionic exclusion and the determination of the chemo-osmotic efficiency requires the resolution of an electrical interactions model. A triple-layer-model which considers diffuse layers overlapping was improved during this thesis to be

Hydrogel Walkers with Electro-Driven Motility for Cargo Transport.

Science.gov (United States)

Yang, Chao; Wang, Wei; Yao, Chen; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

2015-08-28

In this study, soft hydrogel walkers with electro-driven motility for cargo transport have been developed via a facile mould-assisted strategy. The hydrogel walkers consisting of polyanionic poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylamide) exhibit an arc looper-like shape with two "legs" for walking. The hydrogel walkers can reversibly bend and stretch via repeated "on/off" electro-triggers in electrolyte solution. Based on such bending/stretching behaviors, the hydrogel walkers can move their two "legs" to achieve one-directional walking motion on a rough surface via repeated "on/off" electro-triggering cycles. Moreover, the hydrogel walkers loaded with very heavy cargo also exhibit excellent walking motion for cargo transport. Such hydrogel systems create new opportunities for developing electro-controlled soft systems with simple design/fabrication strategies in the soft robotic field for remote manipulation and transportation.

Electro Spray Method for Flexible Display

Science.gov (United States)

2016-05-12

AFRL-AFOSR-JP-TR-2016-0095 Electro Spray Method for Flexible Display Yukiharu Uraoka NARA INSTITUTE OF SCIENCE AND TECHNOLOGY Final Report 11/26/2016...DATES COVERED (From - To)  20 Mar 2013 to 19 May 2016 4. TITLE AND SUBTITLE Electro Spray Method for Flexible Display 5a.  CONTRACT NUMBER 5b.  GRANT...NUMBER FA2386-13-1-4024 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Yukiharu Uraoka 5d.  PROJECT NUMBER 5e.  TASK NUMBER 5f.   WORK UNIT NUMBER 7