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Sample records for current potential drop

  1. Verification of the Viability of Equipotential Switching Direct Current Potential Drop Method for Piping Wall Loss Monitoring with Signal Sensitivity Analysis

    International Nuclear Information System (INIS)

    Ryu, Kyung Ha; Hwang, Il Soon; Kim, Ji Hyun

    2008-01-01

    Flow accelerated corrosion (FAC) phenomenon of low alloy carbon steels in nuclear power plant has been known as one of major degradation mechanisms. It has a potential to cause nuclear pipe rupture accident which may directly impact on the plant reliability and safety. Recently, the equipotential switching direct current potential drop (ES-DCPD) method has been developed, by the present authors, as a method to monitor wall loss in a piping. This method can rapidly monitor the thinning of piping, utilizing either the wide range monitoring (WiRM) or the narrow range monitoring (NaRM) technique. WiRM is a method to monitor wide range of straight piping, whereas NaRM focuses significantly on a narrow range such as an elbow. WiRM and NaRM can improve the reliability of the current FAC screening method that is based on computer modeling on fluid flow conditions. In this paper, the measurements by ES-DCPD are performed with signal sensitivity analyses in the laboratory environment for extended period and showed the viability of ES-DCPD for real plant applications.

  2. Vlasov simulations of parallel potential drops

    Directory of Open Access Journals (Sweden)

    H. Gunell

    2013-07-01

    Full Text Available An auroral flux tube is modelled from the magnetospheric equator to the ionosphere using Vlasov simulations. Starting from an initial state, the evolution of the plasma on the flux tube is followed in time. It is found that when applying a voltage between the ends of the flux tube, about two thirds of the potential drop is concentrated in a thin double layer at approximately one Earth radius altitude. The remaining part is situated in an extended region 1–2 Earth radii above the double layer. Waves on the ion timescale develop above the double layer, and they move toward higher altitude at approximately the ion acoustic speed. These waves are seen both in the electric field and as perturbations of the ion and electron distributions, indicative of an instability. Electrons of magnetospheric origin become trapped between the magnetic mirror and the double layer during its formation. At low altitude, waves on electron timescales appear and are seen to be non-uniformly distributed in space. The temporal evolution of the potential profile and the total voltage affect the double layer altitude, which decreases with an increasing field aligned potential drop. A current–voltage relationship is found by running several simulations with different voltages over the system, and it agrees with the Knight relation reasonably well.

  3. Four-point potential drop measurements for materials characterization

    Science.gov (United States)

    Bowler, Nicola

    2011-01-01

    The technique of measuring the voltage difference (potential drop) between two of the four electrodes of a four-point probe, in order to determine conductivity or surface resistivity of a test piece, is well established in the direct-current (dc) or quasi-dc regime. The technique finds wide usage in the semiconductor industry for the purpose of measuring surface resistivity of semiconductors, and also in the measurement of conductivity of metals, particularly of ferromagnetic metals for which conductivity cannot be easily measured using eddy-current nondestructive evaluation (NDE). In these applications, the conductivity of the test piece is deduced from an analytic formula that depends on the geometry of the probe and test piece. Such a formula requires, as an input, the measured value of the potential drop. Several analytical expressions exist for a variety of test-piece geometries and probe arrangements. Recently, it has been shown that broadband measurements of the potential drop, known as 'alternating current potential drop' (ac PD) measurements, can be used not only to obtain the conductivity of a test piece, but also its linear permeability μ. The beauty of this measurement is that the two parameters are completely decoupled in the quasi-static regime. In fact, μ does not appear in the quasi-static expression for σ. Hence, σ may be obtained from low-frequency ac PD measurements and then μ may be deduced as the frequency increases beyond the quasi-static regime, once σ is known. In this review, both dc and ac solutions that are useful in determining the conductivity of metals and semiconductors, and the permeability of ferromagnetic conductors, are summarized. In particular, flat test pieces with arbitrary thickness are considered. At the next level of complexity, a solution for a half-space coated with a surface layer is given, along with a discussion of the use of the four-point potential drop method for determining thickness of a surface layer, such

  4. Stress Drops for Potentially Induced Earthquake Sequences

    Science.gov (United States)

    Huang, Y.; Beroza, G. C.; Ellsworth, W. L.

    2015-12-01

    Stress drop, the difference between shear stress acting across a fault before and after an earthquake, is a fundamental parameter of the earthquake source process and the generation of strong ground motions. Higher stress drops usually lead to more high-frequency ground motions. Hough [2014 and 2015] observed low intensities in "Did You Feel It?" data for injection-induced earthquakes, and interpreted them to be a result of low stress drops. It is also possible that the low recorded intensities could be a result of propagation effects. Atkinson et al. [2015] show that the shallow depth of injection-induced earthquakes can lead to a lack of high-frequency ground motion as well. We apply the spectral ratio method of Imanishi and Ellsworth [2006] to analyze stress drops of injection-induced earthquakes, using smaller earthquakes with similar waveforms as empirical Green's functions (eGfs). Both the effects of path and linear site response should be cancelled out through the spectral ratio analysis. We apply this technique to the Guy-Greenbrier earthquake sequence in central Arkansas. The earthquakes migrated along the Guy-Greenbrier Fault while nearby injection wells were operating in 2010-2011. Huang and Beroza [GRL, 2015] improved the magnitude of completeness to about -1 using template matching and found that the earthquakes deviated from Gutenberg-Richter statistics during the operation of nearby injection wells. We identify 49 clusters of highly similar events in the Huang and Beroza [2015] catalog and calculate stress drops using the source model described in Imanishi and Ellsworth [2006]. Our results suggest that stress drops of the Guy-Greenbrier sequence are similar to tectonic earthquakes at Parkfield, California (the attached figure). We will also present stress drop analysis of other suspected induced earthquake sequences using the same method.

  5. Experimental observations of anomalous potential drops over ion density cavities

    International Nuclear Information System (INIS)

    Bohm, M.

    1991-08-01

    Experiments are reported showing the plasma potential response when a step voltage is applied over the plasma column between the two plasma sources in a triple plasma machine. The time resolution is sufficient to resolve potential variations caused essentially by the electron motion, and two independent probe methods are used to obtain this time resolution. Depending on the initial conditions two different responses were observed on the time scale of the electron motion. When the initial ion density varies along the plasma column and has a local minimum (that is, forms an ion density cavity), the applied potential drop becomes distributed over the cavity after a few electron transit times. Later the profile steepens to a double layer on the time scale of the ion motion. The width of the cavity is comparable to the length of the plasma column. When the initial density is axially uniform, most of the potential drop instead concentrates to a narrow region at the low potential end of the plasma column after a few electron transit times. On the time scale of the ion motion this potential drop begins to propagate into the plasma as a double layer. The results obtained are consistent with those from numerical simulations with similar boundary conditions. Further experiments are necessary to get conclusive insight into the voltage supporting capability of an ion density cavity. (au) (34 refs.)

  6. DC potential drop method for evaluating material degradation

    International Nuclear Information System (INIS)

    Seok, Chang Sung; Bae, Bong Kook; Koo, Jae Mean

    2004-01-01

    The remaining life estimation for the aged components in power plants as well as chemical plants are very important because mechanical properties of the components are degraded with in-service exposure time in high temperatures. Since it is difficult to take specimens from the operating components to evaluate mechanical properties of components, nondestructive techniques are needed to evaluate the degradation. In this study, test materials with several different degradation levels were prepared by isothermal aging heat treatment at 630 .deg. C. The DC potential drop method and destructive methods such as tensile and fracture toughness were used in order to evaluate the degradation of 1Cr-1Mo-0.25V steels. In this result, we can see that tensile strength and fracture toughness can be calculated from resistivity and it is possible to evaluate material degradation using DC potential drop method, non-destructive method

  7. Evaluation of the nugget diameter in spot welded joints between two steel sheets by means of a potential drop technique

    Science.gov (United States)

    Tohmyoh, Hironori; Ikarashi, Hidetomo; Matsui, Yoichi; Hasegawa, Yuta; Obara, Satoshi

    2015-08-01

    A potential drop technique which utilizes the electrical circuit used in resistance spot welding is reported. Spot welded samples comprising two steel sheets were inserted between the two Cu electrodes and a constant direct current was supplied between the electrodes. The potential drop between two points, one on each electrode, was determined by analysis for various values of nugget diameter and various values of the contact resistance between the Cu electrodes and the steel sheet sample. The nugget diameter of the spot welded joint could be quantitatively evaluated from the measured potential drop and the equation obtained from the analysis.

  8. Potential hydroelectric power Mora Canal Drop. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willer, D.C.

    1978-12-01

    The feasibility of installing a hydroelectric power plant on the Mora Canal Drop site in Idaho was studied. It was recommended that a 1900 kW unit be installed to generate 8,113,000 kWh per year. The project should cost approximately $1.8 million. The generating cost would be between 20.3 and 22.2 mills/kWh. A local utility has offered to buy all power produced at 26 mills/kWh. No adverse environment, safety, or socio-economic effects are foreseen. (LCL)

  9. Stable Amplification and High Current Drop Bistable Switching in Supercritical GaAs Tills

    DEFF Research Database (Denmark)

    Izadpanah, S.H; Jeppsson, B; Jeppesen, Palle

    1974-01-01

    Bistable switching with current drops of 40% and switching times of 100 ps are obtained in pulsed operation of 10¿m supercritically doped n+ nn+ GaAs Transferred Electron Devices (TEDs). When CW-operated the same devices exhibit a 5-17 GHz bandwidth for the stable negative resistance.......Bistable switching with current drops of 40% and switching times of 100 ps are obtained in pulsed operation of 10¿m supercritically doped n+ nn+ GaAs Transferred Electron Devices (TEDs). When CW-operated the same devices exhibit a 5-17 GHz bandwidth for the stable negative resistance....

  10. HIV Patients Drop Out in Indonesia: Associated Factors and Potential Productivity Loss.

    Science.gov (United States)

    Siregar, Adiatma Ym; Pitriyan, Pipit; Wisaksana, Rudi

    2016-07-01

    this study reported various factors associated with a higher probability of HIV patients drop out, and potential productivity loss due to HIV patients drop out. we analyzed data of 658 HIV patients from a database in a main referral hospital in Bandung city, West Java, Indonesia from 2007 to 2013. First, we utilized probit regression analysis and included, among others, the following variables: patients' status (active or drop out), CD4 cell count, TB and opportunistic infection (OI), work status, sex, history of injecting drugs, and support from family and peers. Second, we used the drop out data from our database and CD 4 cell count decline rate from another study to estimate the productivity loss due to HIV patients drop out. lower CD4 cell count was associated with a higher probability of drop out. Support from family/peers, living with family, and diagnosed with TB were associated with lower probability of drop out. The productivity loss at national level due to treatment drop out (consequently, due to CD4 cell count decline) can reach US$365 million (using average wage). first, as lower CD 4 cell count was associated with higher probability of drop out, we recommend (to optimize) early ARV initiation at a higher CD 4 cell count, involving scaling up HIV service at the community level. Second, family/peer support should be further emphasized to further ensure treatment success. Third, dropping out from ART will result in a relatively large productivity loss.

  11. Stress drop estimates of potentially induced earthquakes in the Guy-Greenbrier sequence

    Science.gov (United States)

    Huang, Yihe; Beroza, Gregory C.; Ellsworth, William L.

    2016-09-01

    We calculate corner frequencies and stress drops for 25 potentially induced earthquakes (Mw 2.17 - 2.57) in the Guy-Greenbrier sequence in the central Arkansas. We use the spectral ratio method, employing highly similar earthquakes as empirical Green's functions (eGfs). We show that multiple eGfs give consistent corner frequency estimates for the same earthquake and find a range of stress drops of 1.02 MPa to 42.50 MPa with a median of 10.57 MPa by using the Brune spectral model and the source parameters given by Sato and Hirasawa. We also analyze stress drop dependence on the assumed spectral models and source parameters and use a bootstrapping analysis to calculate the uncertainty in corner frequency and stress drop estimates. The Boatwright spectral model leads to lower stress drop estimates than the Brune spectral model due to the limited bandwidth and fixed fall-off rates. We find that the uncertainty in the stress drop of each earthquake is generally much smaller than the range of stress drop estimates. The value and range of these stress drops of the potentially induced earthquakes are similar to tectonic earthquakes in California reported by other spectral ratio studies. Our results highlight the value of spectral ratio analyses of earthquakes in the central United States.

  12. Direct comparison of unloading compliance and potential drop techniques in J-integral testing

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, J.J.; Nanstad, R.K.

    1984-01-01

    Single-specimen J-integral testing is performed commonly with the unloading compliance technique. Use of modern instrumentation techniques and powerful desktop computers have made this technique a standard. However, this testing technique is slow and tedious, with the loading rate fixed at a slow quasi-static rate. For these reasons the dc potential drop technique was investigated for crack length measurement during a J-integral test. For direct comparison, both unloading compliance and potential drop were used simultaneously during a J-integral test. The results showed good agreement between the techniques. However, the potential drop technique showed an offset in crack length due to plastic blunting processes. Taking this offset into account, J/sub Ic/ values calculated by both techniques compared well.

  13. Calculation of Water Drop Trajectories to and About Arbitrary Three-Dimensional Bodies in Potential Airflow

    Science.gov (United States)

    Norment, H. G.

    1980-01-01

    Calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Any subsonic, external, non-lifting flow can be accommodated; flow into, but not through, inlets also can be simulated. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Code descriptions include operating instructions, card inputs and printouts for example problems, and listing of the FORTRAN codes. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

  14. Potential Multi-Canister Overpack (MCO) Cask Drop in the K West Basin South Loadout Pit

    International Nuclear Information System (INIS)

    POWERS, T.B.

    1999-01-01

    This calculation note documents the probabilistic calculation of a potential drop of a multi-canister overpack (MCO) cask or MCO cask and immersion pail at the K West Basin south loadout pit. The calculations are in support of the cask loading system (CLS) subproject alignment of CLS equipment in the K West Basin south loadout pit

  15. Deformed potential energy of $^{263}Db$ in a generalized liquid drop model

    CERN Document Server

    Chen Bao Qiu; Zhao Yao Lin; 10.1088/0256-307X/20/11/009

    2003-01-01

    The macroscopic deformed potential energy for super-heavy nuclei /sup 263/Db, which governs the entrance and alpha decay channels, is determined within a generalized liquid drop model (GLDM). A quasi- molecular shape is assumed in the GLDM, which includes volume-, surface-, and Coulomb-energies, proximity effects, mass asymmetry, and an accurate nuclear radius. The microscopic single particle energies derived from a shell model in an axially deformed Woods- Saxon potential with a quasi-molecular shape. The shell correction is calculated by the Strutinsky method. The total deformed potential energy of a nucleus can be calculated by the macro-microscopic method as the summation of the liquid-drop energy and the Strutinsky shell correction. The theory is applied to predict the deformed potential energy of the experiment /sup 22/Ne+/sup 241/Am to /sup 263/Db* to /sup 259/Db+4 n, which was performed on the Heavy Ion Accelerator in Lanzhou. It is found that the neck in the quasi-molecular shape is responsible for t...

  16. Energy from streaming current and potential

    NARCIS (Netherlands)

    Olthuis, Wouter; Schippers, Bob; Eijkel, Jan C.T.; van den Berg, Albert

    2005-01-01

    It is investigated how much energy can be delivered by a streaming current source. A streaming current and subsequent streaming potential originate when double layer charge is transported by hydrodynamic flow. Theory and a network model of such a source is presented and initial experimental results

  17. Potential risk factors associated with risk for drop-out and relapse during and following withdrawal of opioid prescription medication.

    Science.gov (United States)

    Heiwe, Susanne; Lönnquist, Ingeborg; Källmén, Håkan

    2011-10-01

    Withdrawal of opioid medication in patients with chronic pain has a drop-out and relapse problem. To evaluate if depressive symptoms, anxiety and pain intensity are potential risk factors for drop-out or relapse during the withdrawal process. Further, to assess internal consistency of scales for assessment of these potential risk factors. Twenty-nine patients were included. After 2 years 28 of these were followed-up. Those with depressive symptoms at baseline had a significant risk for drop-out from the withdrawal program (odds ratio 1.37) and relapse into use of opioids at follow-up (odds ratio 1.44). Drop-outs rated depressive symptoms significantly higher before detoxification. Those who relapsed rated significantly higher for pain intensity, depressive symptoms and abstinence prior to withdrawal. All scales had high reliability. To avoid drop-out and relapse clinical practice need to screen for depressive symptoms, pain intensity, and abstinence. This article presents significant reliability of scales useful within dependency centers. They can be used to identify these risk factors for drop-out and relapse, respectively, when initiating the withdrawal process. Taking these risk factors into consideration could improve the outcome of the withdrawal process by preventing drop-out and relapse. Copyright © 2011 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

  18. Analysis of a potential meteorite-dropping event over the south of Spain in 2007

    Science.gov (United States)

    Madiedo, J. M.; Trigo-Rodríguez, J. M.

    2008-09-01

    Introduction Four potential meteorite-dropping events happened over Spain during 2007. All them are being carefully studied in the framework of the SPanish Meteor Network (SPMN). Due to the large range of visibility of these events, they usually appear far away from the recording stations, or in broad daylight. The later was the case of the most remarkable of these events: the diurnal bolide witnessed by thousands of people in the afternoon of May 10, at 17h57m01±5s UTC. That magnificent daylight event produced the Puerto Lápice meteorite, an eucrite with a total known weight of about 500 grams [1, 2]. Other wonderful event happened during the afternoon of March 2, 2007 at 18h51m06±1s UTC: a magnificent bolide (Fig. 1) was seen over the Pyrenees by several eyewitnesses located in Catalonia and Aragon, but also from the South of France. Unfortunately it was not recorded by SPMN stations and a very limited number of visual reports were received. Figure 1. The appearance of the March 2, 2007 bolide as drawn made by the second author and fortunate eyewitness from Sant Celoni (Barcelona). Another potential meteorite-dropping diurnal bolide was witnessed from several locations over the south of Spain on the afternoon of June 29. A sonic boom was reported by witnesses located near from the estimated impact area, in the province of Huelva (Andalusia). In some cases these also reported that the bolide generated electrophonic sounds and that the sonic boom was accompanied by vibration of objects inside their houses. However, despite several expeditions to the impact area have been made, the meteorite produced by this bolide has not been found yet. This is mainly due to the high uncertainty in the calculation of the impact point, as the region is quite unpopulated and just about a dozen of eyewitnesses could be interviewed. On the other hand, the characteristics of the vegetation that grows in the area also poses important difficulties to the search tasks. Besides, as in

  19. Electron cooling and finite potential drop in a magnetized plasma expansion

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Sanchez, M. [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Navarro-Cavallé, J. [Escuela Técnica Superior de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ahedo, E. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganés 28911, Madrid (Spain)

    2015-05-15

    The steady, collisionless, slender flow of a magnetized plasma into a surrounding vacuum is considered. The ion component is modeled as mono-energetic, while electrons are assumed Maxwellian upstream. The magnetic field has a convergent-divergent geometry, and attention is restricted to its paraxial region, so that 2D and drift effects are ignored. By using the conservation of energy and magnetic moment of particles and the quasi-neutrality condition, the ambipolar electric field and the distribution functions of both species are calculated self-consistently, paying attention to the existence of effective potential barriers associated to magnetic mirroring. The solution is used to find the total potential drop for a set of upstream conditions, plus the axial evolution of various moments of interest (density, temperatures, and heat fluxes). The results illuminate the behavior of magnetic nozzles, plasma jets, and other configurations of interest, showing, in particular, in the divergent plasma the collisionless cooling of electrons, and the generation of collisionless electron heat fluxes.

  20. Calculation of the force acting on a drop in a nonuniform flow of a current-supporting fluid

    International Nuclear Information System (INIS)

    Korovin, V.M.

    1993-01-01

    In the context of wide use of intense electric currents in various technological process, it is of practical interest to investigate the characteristics of the force action of electromagnetic fields on a variety of inclusions - solid particles, drops, gas bubbles - suspended in current-supporting fluids. In the available studies one treats the simplest case, in which the vortical component of the electromagnetic forces, generated by the interaction of the current with the internal magnetic field, is nonvanishing only in small vicinities near these inclusions, and therefore these electromagnetic forces do not generate global motion of the homogeneous current-supporting fluid. In practice, in most cases the vortical component of electromagnetic forces plays a substantial role in the whole operating region of the technological device, and the motion of the current-supporting fluid is created specifically by electromagnetic forces. In the case of a varying electromagnetic field the forces acting on particles are located in the conducting fluid, moving under the field action, were calculated by Korovim (Korovim, V. M., open-quotes The calculation of forces acting on suspended particles during the flow of a conducting fluid in a varying electromagnetic field,close quotes Magn. Gidrodin, No. 1 95-102 (1991)). In the present study the authors generalize the method suggested by Korovin for calculating forces applied to both drops and particles and gas bubbles suspended in the gradient flow of a fluid moving under the action of a constant electromagnetic field. 6 refs

  1. Current wound healing procedures and potential care

    Science.gov (United States)

    Dreifke, Michael B.; Jayasuriya, Amil A.; Jayasuriya, Ambalangodage C.

    2015-01-01

    In this review, we describe current and future potential wound healing treatments for acute and chronic wounds. The current wound healing approaches are based on autografts, allografts, and cultured epithelial autografts, and wound dressings based on biocompatible and biodegradable polymers. The Food and Drug Administration approved wound healing dressings based on several polymers including collagen, silicon, chitosan, and hyaluronic acid. The new potential therapeutic intervention for wound healing includes sustained delivery of growth factors, and siRNA delivery, targeting micro RNA, and stem cell therapy. In addition, environment sensors can also potentially utilize to monitor and manage micro environment at wound site. Sensors use optical, odor, pH, and hydration sensors to detect such characteristics as uric acid level, pH, protease level, and infection – all in the hopes of early detection of complications. PMID:25579968

  2. Calculation of water drop trajectories to and about arbitrary three-dimensional lifting and nonlifting bodies in potential airflow

    Science.gov (United States)

    Norment, H. G.

    1985-01-01

    Subsonic, external flow about nonlifting bodies, lifting bodies or combinations of lifting and nonlifting bodies is calculated by a modified version of the Hess lifting code. Trajectory calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Inlet flow can be accommodated, and high Mach number compressibility effects are corrected for approximately. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

  3. Electrostatic potential wells for on-demand drop manipulation in microchannels.

    Science.gov (United States)

    de Ruiter, Riëlle; Pit, Arjen M; de Oliveira, Vitor Martins; Duits, Michèl H G; van den Ende, Dirk; Mugele, Frieder

    2014-03-07

    Precise control and manipulation of individual drops are crucial in many lab-on-a-chip applications. We present a novel hybrid concept for channel-based discrete microfluidics with integrated electrowetting functionality by incorporating co-planar electrodes (separated by a narrow gap) in one of the microchannel walls. By combining the high throughput of channel-based microfluidics with the individual drop control achieved using electrical actuation, we acquire the strengths of both worlds. The tunable strength of the electrostatic forces enables a wide range of drop manipulations, such as on-demand trapping and release, guiding, and sorting of drops in the microchannel. In each of these scenarios, the retaining electrostatic force competes with the hydrodynamic drag force. The conditions for trapping can be predicted using a simple model that balances these forces.

  4. Spume Drops: Their Potential Role in Air-Sea Gas Exchange

    Science.gov (United States)

    Monahan, Edward C.; Staniec, Allison; Vlahos, Penny

    2017-12-01

    After summarizing the time scales defining the change of the physical properties of spume and other droplets cast up from the sea surface, the time scales governing drop-atmosphere gas exchange are compared. Following a broad review of the spume drop production functions described in the literature, a subset of these functions is selected via objective criteria, to represent typical, upper bound, and lower bound production functions. Three complementary mechanisms driving spume-atmosphere gas exchange are described, and one is then used to estimate the relative importance, over a broad range of wind speeds, of this spume drop mechanism compared to the conventional, diffusional, sea surface mechanism in air-sea gas exchange. While remaining uncertainties in the wind dependence of the spume drop production flux, and in the immediate sea surface gas flux, preclude a definitive conclusion, the findings of this study strongly suggest that, at high wind speeds (>20 m s-1 for dimethyl sulfide and >30 m s-1 for gases such a carbon dioxide), spume drops do make a significant contribution to air-sea gas exchange.Plain Language SummaryThis paper evaluates the existing spume drop generation functions available to date and selects a reasonable upper, lower and mid range function that are reasonable for use in air sea exchange models. Based on these the contribution of spume drops to overall air sea gas exchange at different wind speeds is then evaluated to determine the % contribution of spume. Generally below 20ms-1 spume drops contribute <1% of gas exchange but may account for a significant amount of gas exchange at higher wind speeds.

  5. Impedance and electrically evoked compound action potential (ECAP drop within 24 hours after cochlear implantation.

    Directory of Open Access Journals (Sweden)

    Joshua Kuang-Chao Chen

    Full Text Available Previous animal study revealed that post-implantation electrical detection levels significantly declined within days. The impact of cochlear implant (CI insertion on human auditory pathway in terms of impedance and electrically evoked compound action potential (ECAP variation within hours after surgery remains unclear, since at this time frequency mapping can only commence weeks after implantation due to factors associated with wound conditions. The study presented our experiences with regards to initial switch-on within 24 hours, and thus the findings about the milieus inside cochlea within the first few hours after cochlear implantation in terms of impedance/ECAP fluctuations. The charts of fifty-four subjects with profound hearing impairment were studied. A minimal invasive approach was used for cochlear implantation, characterized by a small skin incision (≈ 2.5 cm and soft techniques for cochleostomy. Impedance/ECAP was measured intro-operatively and within 24 hours post-operatively. Initial mapping within 24 hours post-operatively was performed in all patients without major complications. Impedance/ECAP became significantly lower measured within 24 hours post-operatively as compared with intra-operatively (p<0.001. There were no differences between pre-operative and post-operative threshold for air-conduction hearing. A significant drop of impedance/ECAP in one day after cochlear implantation was revealed for the first time in human beings. Mechanisms could be related to the restoration of neuronal sensitivity to the electrical stimulation, and/or the interaction between the matrix enveloping the electrodes and the electrical stimulation of the initial switch-on. Less wound pain/swelling and soft techniques both contributed to the success of immediate initial mapping, which implied a stable micro-environment inside the cochlea despite electrodes insertion. Our research invites further studies to correlate initial impedance/ECAP changes

  6. Manipulating the voltage drop in graphene nanojunctions using a gate potential

    DEFF Research Database (Denmark)

    Papior, Nick Rübner; Gunst, Tue; Stradi, Daniele

    2016-01-01

    the impact of electrostatic gating in nanojunctions between graphene electrodes operating at finite bias. Using first principles quantum transport simulations, we show that the voltage drop across \\emph{symmetric} junctions changes dramatically and controllably in gated systems compared to non...... of graphene in the proximity of the Dirac point. Due to the electrostatic gating, each electrode exposes different density of states in the bias window between the two different electrode Fermi energies, thereby leading to a non-symmetry in the voltage drop across the device. This selective pinning is found...

  7. Electrostatic potential wells for on-demand drop manipulation in microchannels

    NARCIS (Netherlands)

    de Ruiter, Riëlle; Pit, Arjen; Martins de Oliveira, V.; Duits, Michael H.G.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2014-01-01

    Precise control and manipulation of individual drops are crucial in many lab-on-a-chip applications. We present a novel hybrid concept for channel-based discrete microfluidics with integrated electrowetting functionality by incorporating co-planar electrodes (separated by a narrow gap) in one of the

  8. Acceptability and Potential Effectiveness of a Foot Drop Stimulator in Children and Adolescents with Cerebral Palsy

    Science.gov (United States)

    Prosser, Laura A.; Curatalo, Lindsey A.; Alter, Katharine E.; Damiano, Diane L.

    2012-01-01

    Aim: Ankle-foot orthoses are the standard of care for foot drop in cerebral palsy (CP), but may overly constrain ankle movement and limit function in those with mild CP. Functional electrical stimulation (FES) may be a less restrictive and more effective alternative, but has rarely been used in CP. The primary objective of this study was to…

  9. Obesity: Current and Potential Pharmacotherapeutics and Targets

    Science.gov (United States)

    Narayanaswami, Vidya; Dwoskin, Linda P.

    2016-01-01

    Obesity is a global epidemic that contributes to a number of health complications including cardiovascular disease, type 2 diabetes, cancer and neuropsychiatric disorders. Pharmacotherapeutic strategies to treat obesity are urgently needed. Research over the past two decades has increased substantially our knowledge of central and peripheral mechanisms underlying homeostatic energy balance. Homeostatic mechanisms involve multiple components including neuronal circuits, some originating in hypothalamus and brain stem, as well as peripherally-derived satiety, hunger and adiposity signals that modulate neural activity and regulate eating behavior. Dysregulation of one or more of these homeostatic components results in obesity. Coincident with obesity, reward mechanisms that regulate hedonic aspects of food intake override the homeostatic regulation of eating. In addition to functional interactions between homeostatic and reward systems in the regulation of food intake, homeostatic signals have the ability to alter vulnerability to drug abuse. Regarding the treatment of obesity, pharmacological monotherapies primarily focus on a single protein target. FDA-approved monotherapy options include phentermine (Adipex-P®), orlistat (Xenical®), lorcaserin (Belviq®) and liraglutide (Saxenda®). However, monotherapies have limited efficacy, in part due to the recruitment of alternate and counter-regulatory pathways. Consequently, a multi-target approach may provide greater benefit. Recently, two combination products have been approved by the FDA to treat obesity, including phentermine/topiramate (Qsymia®) and naltrexone/bupropion (Contrave®). The current review provides an overview of homeostatic and reward mechanisms that regulate energy balance, potential therapeutic targets for obesity and current treatment options, including some candidate therapeutics in clinical development. Finally, challenges in anti-obesity drug development are discussed. PMID:27773782

  10. Current-potential characteristics of electrochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Battaglia, Vincent S. [Univ. of California, Berkeley, CA (United States)

    1993-07-01

    This dissertation contains investigations in three distinct areas. Chapters 1 and 2 provide an analysis of the effects of electromagnetic phenomena during the initial stages of cell discharge. Chapter 1 includes the solution to Maxwell`s equations for the penetration of the axial component of an electric field into an infinitely long cylindrical conductor. Chapter 2 contains the analysis of the conductor included in a radial circuit. Chapter 3 provides a complete description of the equations that describe the growth of an oxide film. A finite difference program was written to solve the equations. The system investigated is the iron/iron oxide in a basic, aqueous solution. Chapters 4 and 5 include the experimental attempts for replacing formaldehyde with an innocuous reducing agent for electroless deposition. In chapter 4, current-versus-voltage curves are provided for a sodium thiosulfate bath in the presence of a copper disk electrode. Also provided are the cathodic polarization curves of a copper/EDTA bath in the presence of a copper electrode. Chapter 5 contains the experimental results of work done with sodium hypophosphite as a reducing agent. Mixed-potential-versus-time curves for solutions containing various combinations of copper sulfate, nickel chloride, and hypophosphite in the presence of a palladium disk electrode provide an indication of the reducing power of the solutions.

  11. Mutagenic Potential of Direct Current Electric Fields

    National Research Council Canada - National Science Library

    Obringer, John

    1997-01-01

    .... EMF can be subdivided into either electric fields (E-field) or magnetic fields (B-field). Our research used a reverse mutagenesis bacteriophage T4D model to quantitatively study the effects of direct current E-fields...

  12. Study of Hot Salt Stress Corrosion Crack Initiation of Alloy IMI 834 by using DC Potential Drop Method

    Energy Technology Data Exchange (ETDEWEB)

    Pustode, Mangesh D. [Bharat Forge Ltd., Pune (India); Dewangan, Bhupendra [Tata Steel, Jamshedpur (India); Raja, V. S. [Indian Institute of Technology Bombay, Mumbai (India); Paulose, Neeta; Babu, Narendra [Gas Turbine Research Establishment (GTRE), Bangalore (India)

    2016-10-15

    DC potential drop technique was employed during the slow strain rate tests to study the hot salt stress corrosion crack (HSSCC) initiation at 300 and 400 ℃. Threshold stresses for HSSCC initiation were found to about 88 % of the yield strength at both temperatures, but the time from crack initiation to final failure (Δtscc) decreased significantly with temperature, which reflects larger tendency for brittle fracture and secondary cracking. The brittle fracture features consisted of transgranular cracking through the primary α grain and discontinuous faceted cracking through the transformed β grains.

  13. Electric Mars: A Large Trans-Terminator Electric Potential Drop on Closed Magnetic Field Lines Above Utopia Planitia

    Science.gov (United States)

    Collinson, Glyn; Mitchell, David; Xu, Shaosui; Glocer, Alex; Grebowsky, Joseph; Hara, Takuya; Lillis, Robert; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-Andre

    2017-01-01

    Abstract Parallel electric fields and their associated electric potential structures play a crucial role inionospheric-magnetospheric interactions at any planet. Although there is abundant evidence that parallel electric fields play key roles in Martian ionospheric outflow and auroral electron acceleration, the fields themselves are challenging to directly measure due to their relatively weak nature. Using measurements by the Solar Wind Electron Analyzer instrument aboard the NASA Mars Atmosphere and Volatile EvolutioN(MAVEN) Mars Scout, we present the discovery and measurement of a substantial (Phi) Mars 7.7 +/-0.6 V) parallel electric potential drop on closed magnetic field lines spanning the terminator from day to night above the great impact basin of Utopia Planitia, a region largely free of crustal magnetic fields. A survey of the previous 26 orbits passing over a range of longitudes revealed similar signatures on seven orbits, with a mean potential drop (Phi) Mars of 10.9 +/- 0.8 V, suggestive that although trans-terminator electric fields of comparable strength are not ubiquitous, they may be common, at least at these northerly latitudes.

  14. Electric Mars: A large trans-terminator electric potential drop on closed magnetic field lines above Utopia Planitia

    Science.gov (United States)

    Collinson, Glyn; Mitchell, David; Xu, Shaosui; Glocer, Alex; Grebowsky, Joseph; Hara, Takuya; Lillis, Robert; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-André; Fedorov, Andrey; Liemohn, Mike; Andersson, Laila; Jakosky, Bruce

    2017-02-01

    Parallel electric fields and their associated electric potential structures play a crucial role in ionospheric-magnetospheric interactions at any planet. Although there is abundant evidence that parallel electric fields play key roles in Martian ionospheric outflow and auroral electron acceleration, the fields themselves are challenging to directly measure due to their relatively weak nature. Using measurements by the Solar Wind Electron Analyzer instrument aboard the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) Mars Scout, we present the discovery and measurement of a substantial (ΦMars=7.7 ± 0.6 V) parallel electric potential drop on closed magnetic field lines spanning the terminator from day to night above the great impact basin of Utopia Planitia, a region largely free of crustal magnetic fields. A survey of the previous 26 orbits passing over a range of longitudes revealed similar signatures on seven orbits, with a mean potential drop (ΦMars) of 10.9 ± 0.8 V, suggestive that although trans-terminator electric fields of comparable strength are not ubiquitous, they may be common, at least at these northerly latitudes.

  15. Benzodiazepine dependence potential: current studies and trends.

    Science.gov (United States)

    Smith, D E

    1984-01-01

    The appearance of newer, short-acting benzodiazepines has produced misconceptions regarding the potential addictive quality of these drugs. Following a review of the Smith and Wesson (1983) barbiturate withdrawal technique, application of this procedure to the withdrawal of individuals addicted to short-acting benzodiazepines is reviewed. Attention is also given to the emergence of "look-alike" drugs, and the resultant implications for substance abuse treatment personnel.

  16. Potential suitable areas of giant ground sloths dropped before its extinction in South America

    DEFF Research Database (Denmark)

    Lima-Ribeiro, Matheus Souza; Varela, Sara; Nogues, David Bravo

    2012-01-01

    of the climate preferences through time for the two species and modeled their potential distributions at last glacial maximum (LGM, 21 ky BP) and mid-Holocene (6 ky BP) using Bioclimatic Envelope Modeling (BEM), fossil records and paleoclimatic simulations. The model predictions showed a drastic reduction...

  17. [HOMOCYSTEINE-INDUCED MEMBRANE CURRENTS, CALCIUM RESPONSES AND CHANGES OF MITOCHONDRIAL POTENTIAL IN RAT CORTICAL NEURONS].

    Science.gov (United States)

    Abushik, P A; Karelina, T V; Sibarov, D A; Stepanenko, J D; Giniatullin, R; Antonov, S M

    2015-01-01

    Homocysteine, a sulfur-containing amino acid, exhibits neurotoxic effects and is involved in the pathogenesis of several major neurodegenerative disorders. In contrast to well studied excitoxicity of glutamate, the mechanism of homocysteine neurotoxicity is not clearly understood. By using whole-cell patch-clamp, calcium imaging (fluo-3) and measurements of mitochondrial membrane potential (rhodamine 123) we studied transmembrane currents, calcium signals and changes in mitochondrial membrane potential induced by homocysteine versus responses induced by NMDA and glutamate in cultured rat cortical neurons. L-homocysteine (50 µM) induced inward currents that could be completely blocked by the selective antagonist of NMDA receptors - AP-5. In contrast to NMDA-induced currents, homocysteine-induced currents had a smaller steady-state amplitude. Comparison of calcium responses to homocysteine, NMDA or glutamate demonstrated that in all cortical neurons homocysteine elicited short, oscillatory-type calcium responses, whereas NMDA or glutamate induced sustained increase of intracellular calcium. Analysis of mitochondrial changes demonstrated that in contrast to NMDA homocysteine did not cause a drop of mitochondrial membrane potential at the early stages of action. However, after its long-term action, as in the case of NMDA and glutamate, the changes in mitochondrial membrane potential were comparable with the full drop of respiratory chain induced by protonophore FCCP. Our data suggest that in cultured rat cortical neuron homocysteine at the first stages of action induces neurotoxic effects through activation of NMDA-type ionotropic glutamate receptors with strong calcium influx through the channels of these receptors. The long-term action of homocysteine may lead to mitochondrial disfuction and appears as a drop of mitochondrial membrane potential.

  18. Medicinal plants with teratogenic potential: current considerations

    Directory of Open Access Journals (Sweden)

    Kassiane Cristine da Silva Costa

    2012-09-01

    Full Text Available The aim of this study was to present the implications of the use of herbs during pregnancy, pointing out those that should be avoided during this condition because of their abortifacient and/or teratogenic potential. We carried out searches in the databases ScienceDirect, Scielo and Google Scholar, adopting as criteria for inclusion: book chapters and/or complete articles (with abstract, available in English, Portuguese or Spanish, published from 1996 to in 2011. After a pre-selection of 83 articles, 49 bibliographies were used in the manufacturing end of the article, where 25 were from the Scielo database, 18 from ScienceDirect and 6 from Google Scholar. From the articles studied, we identified the four most commonly used plants as emmenagogue/abortifacient agents by patients of the Department of Prenatal SUS: senne, arruda, boldo and buchinha-do-norte or cabacinha. Thus, we conclude that people often adhere to the maxim "if it's natural, it does no harm" in their rational use of natural products, without the right guidance, believing that these products are safe to use. This usage is even more worrisome among the elderly, pregnant women and children. Regarding the safety of these products, some information and reliable data are scarce or contradictory.Este trabalho busca as implicações atuais sobre o uso de plantas medicinais durante a gravidez, alertando sobre aquelas que devem ser evitadas nesse período por serem potencialmente abortivas e/ou teratogênicas. Para tanto, foram realizadas buscas nas bases de dados Sciencedirect, Scielo e Google scholar, adotando-se como critérios de inclusão capítulos de livros e/ou artigos completos (com abstract e disponíveis, em português, inglês ou espanhol, publicados de 1996 a 2011. Após uma pré-seleção de 83 artigos, 49 bibliografias foram utilizadas na confecção final do artigo, sendo 25 provenientes da base de dados Scielo, 18 do Sciencedirect e 06 do Google scholar. A partir dos

  19. The UV filtering potential of drop-casted layers of frustules of three diatom species

    DEFF Research Database (Denmark)

    Su, Yanyan; Lenau, Torben Anker; Gundersen, Emil

    2018-01-01

    Diatoms are in focus as biological materials for a range of photonic applications. Many of theseapplications would require embedding a multitude of diatoms in a matrix (e.g. paint, crème or lacquer); however, most studies on the photonic and spectral properties of diatoms frustules (silica walls)...... performance of layers of diatom frustules is of central relevance for their potential use as innovative bio-based UV filters.......) havebeen carried out on single cells. In this study, for the first time, we test the spectral properties of layersof frustules of three diatom species (Coscinodiscus granii, Thalassiosira punctifera and Thalassiosira pseudonana), with special focus on transmission and reflectance in the UV range....... The transmittance efficiency in the UV A and B range was: T. pseudonana (56–59%) >C. granii (53–54%) >T. punctifera (18–21%) for the rinsed frustules. To investigate the underlying cause of these differences, we performed X-ray scattering analysis, measurement of layer thickness and microscopic determination...

  20. Application of the potential-drop method to measurements of hydrogen-induced sub-critical crack growth in zirconium-2.5 wt% niobium

    International Nuclear Information System (INIS)

    Simpson, L.A.; Clarke, C.F.

    1977-10-01

    Adaptation of the potential-drop method of crack-following to the problem of hydrogen-induced sub-critical crack growth in Zr-2.5% Nb is described. Reasons for non-linearity in the calibration of crack extension against potential drop in compact tension specimens are discussed. It is shown that despite non-linearities, careful comparison of fractographic features with the potential-drop record can lead to a continuous plot of crack velocity against time or stress intensity factor. Procedures for correcting data through temperature and load changes are also described. The application of the technique to studies of the mechanism of hydrogen crack growth is illustrated with several examples. (author)

  1. Current Drive in a Ponderomotive Potential with Sign Reversal

    International Nuclear Information System (INIS)

    Fisch, N.J.; Rax, J.M.; Dodin, I.Y.

    2003-01-01

    Noninductive current drive can be accomplished through ponderomotive forces with high efficiency when the potential changes sign over the interaction region. The effect can practiced upon both ions and electrons. The current drive efficiencies, in principle, might be higher than those possible with conventional radio-frequency current-drive techniques, since different considerations come into play

  2. Poststroke Muscle Architectural Parameters of the Tibialis Anterior and the Potential Implications for Rehabilitation of Foot Drop

    Directory of Open Access Journals (Sweden)

    John W. Ramsay

    2014-01-01

    Full Text Available Poststroke dorsiflexor weakness and paretic limb foot drop increase the risk of stumbling and falling and decrease overall functional mobility. It is of interest whether dorsiflexor muscle weakness is primarily neurological in origin or whether morphological differences also contribute to the impairment. Ten poststroke hemiparetic individuals were imaged bilaterally using noninvasive medical imaging techniques. Magnetic resonance imaging was used to identify changes in tibialis anterior muscle volume and muscle belly length. Ultrasonography was used to measure fascicle length and pennation angle in a neutral position. We found no clinically meaningful bilateral differences in any architectural parameter across all subjects, which indicates that these subjects have the muscular capacity to dorsiflex their foot. Therefore, poststroke dorsiflexor weakness is primarily neural in origin and likely due to muscle activation failure or increased spasticity of the plantar flexors. The current finding suggests that electrical stimulation methods or additional neuromuscular retraining may be more beneficial than targeting muscle strength (i.e., increasing muscle mass.

  3. Effects of a potential drop of a shipping cask, a waste container, and a bare fuel assembly during waste-handling operations

    International Nuclear Information System (INIS)

    Wu, C.L.; Lee, J.; Lu, D.L.; Jardine, L.J.

    1991-12-01

    This study investigates the effects of potential drops of a typical shipping cask, waste container, and bare fuel assembly during waste-handling operations at the prospective Yucca Mountain Repository. The waste-handling process (one stage, no consolidation configuration) is examined to estimate the maximum loads imposed on typical casks and containers as they are handled by various pieces of equipment during waste-handling operations. Maximum potential drop heights for casks and containers are also evaluated for different operations. A nonlinear finite-element model is employed to represent a hybrid spent fuel container subject to drop heights of up to 30 ft onto a reinforced concrete floor. The impact stress, strain, and deformation are calculated, and compared to the failure criteria to estimate the limiting (maximum permissible) drop height for the waste container. A typical Westinghouse 17 x 17 PWR fuel assembly is analyzed by a simplified model to estimate the energy absorption by various parts of the fuel assembly during a 30 ft drop, and to determine the amount of kinetic energy in a fuel pin at impact. A nonlinear finite-element analysis of an individual fuel pin is also performed to estimate the amount of fuel pellet fracture due to impact. This work was completed on May 1990

  4. Effects of a potential drop of a shipping cask, a waste container, and a bare fuel assembly during waste-handling operations; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.L.; Lee, J.; Lu, D.L.; Jardine, L.J. [Bechtel National, Inc., San Francisco, CA (United States)

    1991-12-01

    This study investigates the effects of potential drops of a typical shipping cask, waste container, and bare fuel assembly during waste-handling operations at the prospective Yucca Mountain Repository. The waste-handling process (one stage, no consolidation configuration) is examined to estimate the maximum loads imposed on typical casks and containers as they are handled by various pieces of equipment during waste-handling operations. Maximum potential drop heights for casks and containers are also evaluated for different operations. A nonlinear finite-element model is employed to represent a hybrid spent fuel container subject to drop heights of up to 30 ft onto a reinforced concrete floor. The impact stress, strain, and deformation are calculated, and compared to the failure criteria to estimate the limiting (maximum permissible) drop height for the waste container. A typical Westinghouse 17 {times} 17 PWR fuel assembly is analyzed by a simplified model to estimate the energy absorption by various parts of the fuel assembly during a 30 ft drop, and to determine the amount of kinetic energy in a fuel pin at impact. A nonlinear finite-element analysis of an individual fuel pin is also performed to estimate the amount of fuel pellet fracture due to impact. This work was completed on May 1990.

  5. Pressure Drop

    Science.gov (United States)

    Lawson, Mike

    2010-01-01

    Mike Lawson briefly discussed pressure drop for aerospace applications and presented short stories about adventures experienced while working at NASA and General Dynamics, including exposure to technologies like the Crew and Equipment Translation Aid (CETA) cart and the SWME.

  6. Foot Drop

    Science.gov (United States)

    ... is being done? The National Institute of Neurological Disorders and Stroke (NINDS) conducts research related to the neurological conditions that cause foot drop in its laboratories at the National ...

  7. Energy Generation Potential of West African Ocean Current ...

    African Journals Online (AJOL)

    A review of the West African ocean current energy generating potential is carried out. The peculiarity of the West African ocean characteristic is discussed and the challenges noted. Based on this review, it is found that ocean current represents an alternative source of renewable energy in West Africa in a streamed regular ...

  8. Action potential propagation: ion current or intramembrane electric field?

    Science.gov (United States)

    Martí, Albert; Pérez, Juan J; Madrenas, Jordi

    2018-01-01

    The established action potential propagation mechanisms do not satisfactorily explain propagation on myelinated axons given the current knowledge of biological channels and membranes. The flow across ion channels presents two possible effects: the electric potential variations across the lipid bilayers (action potential) and the propagation of an electric field through the membrane inner part. The proposed mechanism is based on intra-membrane electric field propagation, this propagation can explain the action potential saltatory propagation and its constant delay independent of distance between Ranvier nodes in myelinated axons.

  9. Drop Tower Physics

    Science.gov (United States)

    Dittrich, William A. Toby

    2014-10-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in The Physics Teacher1 in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at the drop tower in Bremen, Germany. Using these drop towers, one can briefly investigate various physical systems operating in this near zero-g environment. The resulting "Drop Tower Physics" is a new and exciting way to challenge students with a physical example that requires solid knowledge of many basic physics principles, and it forces them to practice the scientific method. The question is, "How would a simple toy, like a pendulum, behave when it is suddenly exposed to a zero-g environment?" The student must then postulate a particular behavior, test the hypothesis against physical principles, and if the hypothesis conforms to these chosen physical laws, the student can formulate a final conclusion. At that point having access to a drop tower is very convenient, in that the student can then experimentally test his or her conclusion. The purpose of this discussion is to explain the response of these physical systems ("toys") when the transition is made to a zero-g environment and to provide video demonstrations of this behavior to support in-class discussions of Drop Tower Physics.

  10. Currents along the Tsitsikamma coast, South Africa, and potential ...

    African Journals Online (AJOL)

    Potential net monthly displacements calculated for three depths (5m, 23m and 31m) indicate that passive, neutrally buoyant biological material (e.g. squid ... Wind-driven coastal upwelling, prevalent during the summer, causes the surface layer of the coastal counter-current to flow offshore for several days, resulting in ...

  11. A potential method for the estimation of drop size distribution from a dual-wavelength airborne radar

    Science.gov (United States)

    Meneghini, R.; Kozu, T.

    1991-01-01

    In order to investigate the role of the drop size distribution (DSD) from a dual-wavelength airborne radar and to recover profiled rain rates, a procedure is described for the purpose of estimating the DSD. The method differs from previous approaches in that it provides 2n + 1 parameters of the profiled DSD (where n is the number of range gates) and it uses a recursive procedure beginning at the range gate near the surface progressing backwards toward the storm top. The method is argued to be useful both as a diagnostic tool and as a means by which more detailed information on the vertical structure of the precipitation can be obtained.

  12. N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: Glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population

    Directory of Open Access Journals (Sweden)

    Mark A Babizhayev

    2008-10-01

    months of treatment with N-acetylcarnosine lubricant eye drops as those with the worth pretreatment vision.Patients or other participants: The authors made a reference to electronic records of the product sales to patients who have been made the repurchase of the Can-C™ eye drops since December 2001.Intervention: Based on this analysis of recorded adjustments to inventory, various parameters were analyzed during the continued repurchase behavior program, including testimonials from buyers. With these figures, researchers judged on the patients’ compliance rate to self-administer NAC eye-drops.Main outcome measure and results: The ophthalmic drug showed potential for the nonsurgical treatment of age-related cataracts for participants after controlling for age, gender and daily activities and on a combined basis of repurchases behavior reports in more than 50,000 various cohort survivors, has been demonstrated to have a high efficacy and good tolerability for prevention and treatment of visual impairment determined for the older population with relative stable pattern of causes for blindness and visual impairment. The mechanisms of prevention and reversal of cataracts with NAC ophthalmic drug are considered which include prevention by the intraocular released carnosine of free-radical-induced inactivation of proprietary lens antioxidant enzymes (superoxide dismutase; prevention of carbohydrate and metal-catalyzed autooxidation of ascorbic acid-induced cross-linking glycation reactions to the lens proteins; transglycation properties of carnosine, allowing it to compete for the glycating agent, protecting proteins (lens crystallins against modification; universal antioxidant and scavenging activity towards lipid hydroperoxides, aldehydes and oxygen radicals; activation with L-carnosine ingredient of proteasome activity in the lens; chaperone-like disaggregating to lens crystallins activity of NAC and of its bioactivated principal carnosine. Blindness incidence increased

  13. Performance Prediction of Centrifugal Compressor for Drop-In Testing Using Low Global Warming Potential Alternative Refrigerants and Performance Test Codes

    Directory of Open Access Journals (Sweden)

    Joo Hoon Park

    2017-12-01

    Full Text Available As environmental regulations to stall global warming are strengthened around the world, studies using newly developed low global warming potential (GWP alternative refrigerants are increasing. In this study, substitute refrigerants, R-1234ze (E and R-1233zd (E, were used in the centrifugal compressor of an R-134a 2-stage centrifugal chiller with a fixed rotational speed. Performance predictions and thermodynamic analyses of the centrifugal compressor for drop-in testing were performed. A performance prediction method based on the existing ASME PTC-10 performance test code was proposed. The proposed method yielded the expected operating area and operating point of the centrifugal compressor with alternative refrigerants. The thermodynamic performance of the first and second stages of the centrifugal compressor was calculated as the polytropic state. To verify the suitability of the proposed method, the drop-in test results of the two alternative refrigerants were compared. The predicted operating range based on the permissible deviation of ASME PTC-10 confirmed that the temperature difference was very small at the same efficiency. Because the drop-in test of R-1234ze (E was performed within the expected operating range, the centrifugal compressor using R-1234ze (E is considered well predicted. However, the predictions of the operating point and operating range of R-1233zd (E were lower than those of the drop-in test. The proposed performance prediction method will assist in understanding thermodynamic performance at the expected operating point and operating area of a centrifugal compressor using alternative gases based on limited design and structure information.

  14. An electrochemical and optical study of the rupture and restoration of the passivating HgO multilayer on a dropping mercury electrode in aqueous 1 M NaOH solution at anodic potentials

    NARCIS (Netherlands)

    Pieterse, M.M.J.; Sluyters-Rehbach, M.; Sluyters, J.H.

    1979-01-01

    It is shown that the passivating layer on the surface of a dropping mercury electrode in 1 M NaOH at anodic potentials due to drop growth continuously is being mechanically ruptured and electrochemically repaired. This phenomenon is studied by means of microscopy, reflectometry and polarography. The

  15. Conversion disorder: current problems and potential solutions for DSM-5.

    Science.gov (United States)

    Stone, Jon; LaFrance, W Curt; Brown, Richard; Spiegel, David; Levenson, James L; Sharpe, Michael

    2011-12-01

    Conversion disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) describes neurological symptoms, including weakness, numbness and events resembling epilepsy or syncope, which can be positively identified as not being due to recognised neurological disease. This review combines perspectives from psychiatry, psychology and neurology to identify and discuss key problems with the current diagnostic DSM-IV criteria for conversion disorder and to make the following proposals for DSM-5: (a) abandoning the label "conversion disorder" and replacing it with an alternative term that is both theoretically neutral and potentially more acceptable to patients and practitioners; (b) relegating the requirements for "association of psychological factors" and the "exclusion of feigning" to the accompanying text; (c) adding a criterion requiring clinical findings of internal inconsistency or incongruity with recognised neurological or medical disease and altering the current 'disease exclusion' criteria to one in which the symptom must not be 'better explained' by a disease if present, (d) adding a 'cognitive symptoms' subtype. We also discuss whether conversion symptoms are better classified with other somatic symptom disorders or with dissociative disorders and how we might address the potential heterogeneity of conversion symptoms in classification. 2011 Elsevier Inc. All rights reserved.

  16. Current status of Indian medicinal plants with aphrodisiac potential

    Directory of Open Access Journals (Sweden)

    Ramandeep Singh

    2013-01-01

    Full Text Available In India, indigenous remedies have been used in treatment of sexual dysfunction since the time of Charaka and Sushruta. Plants have been always an exemplary source of drugs and many of the currently available drugs have been derived directly or indirectly from them. An aphrodisiac is defined as an agent that arouses sexual desire. Erectile dysfunction or sexual dysfunction (ED or SD or male impotence is defined as the inability of a man to achieve and maintain an erection sufficient for mutually satisfactory intercourse with his partner. Sexual health and function are important determinants of quality of life. To overcome the problem of male sexual (or erectile dysfunction, various Indian natural aphrodisiac plants potentials were preferred. The ethnobotanical information reports that about 200 plants possess aphrodisiac potential. Out of several Indian medicinal plants, 33 plants were reviewed. In this review, studies on Indian medicinal plants were reviewed and their possible therapeutic applications were discussed. This review discusses about aphrodisiac potential of Indian medicinal plants, its botanical name, common name, family, extract, models used, part used and references, which are helpful for researchers to develop new herbal aphrodisiac formulations. In the recent years, interest in drugs of plant origin has been progressively increased.

  17. Current and potential applications of bismuth-based drugs.

    Science.gov (United States)

    Keogan, Donal M; Griffith, Darren M

    2014-09-23

    : Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.

  18. LIFELONG LEARNING THROUGH SECOND LIFE: CURRENT TRENDS, POTENTIALS AND LIMITATIONS

    Directory of Open Access Journals (Sweden)

    Nil GOKSEL-CANBEK

    2011-08-01

    Full Text Available Lifelong Learning (LLL has been a remarkable response to people-centered educational demand of 21st century. In order to provide effective formal, non-formal, and informal learning, immersive educational activities undertaken throughout life should be aimed to create a learning society in which people can experience individual and collective learning with no constrains of time or location. The concept of lifelong learning within the context of distance immersive education encompasses diverse 3D activities. The three dimensional, Web-based structured activities supported by distance learning technologies can be viewed as interactive tools which foster LLL. In this perspective, Second Life (SL can be regarded as one of the learning simulation milieus that allow learners to participate in various educational LLL activities in individual or group forms. The following paper examines how SL, taking advantage of its simulative nature and the possibility for creative interaction among participants, which are also common in games, allows the learners to participate in immersive constructivist learning activities. The article will also touch on the current uses of SL as a tool for LLL, as well as its potentials for further development according to the current trends in adult education. Further, the authors will discuss its limitations and will make suggestions towards a more complete pedagogical use.

  19. Current evidence on the anticancer potential of Chios mastic gum.

    Science.gov (United States)

    Giaginis, Constantinos; Theocharis, Stamatios

    2011-11-01

    Chios mastic gum derived from the plant Pistacia lentiscus L. variation chia has been shown to exert beneficial effects on a wide range of human disorders. The most comprehensive data so far have indicated that mastic gum provides protection against gastrointestinal malfunctions and bacterial infections. Substantial evidence has also suggested that mastic gum exhibits hepatoprotective and cardioprotective, antiinflammatory/antioxidant, and antiatherogenic properties. In the last decade, an increasing number of studies further evaluated the potential antiproliferative properties of mastic gum against several types of human neoplasia. The present review aims to summarize the current data concerning the anticancer activities of mastic gum and their major constituents, highlighting also the molecular mechanisms through which they exert anticancer function. Mastic gum constituents that belong to the chemical class of triterpenoids appear to be mainly responsible for its anticancer potential. Thus, a brief discussion is dedicated to the anticancer activity of synthetic and naturally occurring triterpenoid analogues with similar chemical structure to mastic gum constituents. Taking into consideration the available data so far, Chios mastic gum could be considered as a conglomeration of effective anticancer drugs.

  20. The Geothermal Potential, Current and Opportunity in Taiwan

    Science.gov (United States)

    Song, Sheng-Rong

    2016-04-01

    Located in the west Pacific Rim of Fire, Taiwan possesses rich geothermal resources due to volcanic activities and rapid uplifting of plate collision. Based on available data prior to 1980, Taiwan may have about 1 GWe of potential shallow geothermal energy, which is less than 3% of the national gross power generation. A 3-Mw pilot power plant, therefore, was constructed in 1981 and terminated in 1993 in the Chingshui geothermal field of Ilan, northeastern Taiwan. Recently, one of the National Science & Technology Program (NSTP) projects has been conducting research and reevaluating the island-wide deep geothermal energy. Four hot potential sites have been recognized. They are: (1) Tatun Volcano Group of northern Taiwan; (2) I-Lan Plain of NE Taiwan; (3) Lu-Shan area of Central Taiwan; and (4) Hua-Tung area of eastern Taiwan. We found that the geothermal resource in Taiwan may be as high as 160 GWe, with 33.6 GWe of exploitable geothermal energy. There are no any commercial geothermal power plants until now in Taiwan, although the potential is great. However, geothermal energy has been listed as one of major tasks of National Energy Program, Phase II (NEP-II) in Taiwan. We will conduct more detailed geothermal energy surveys on some proposed hot sites and to construct an EGS pilot geothermal plant with 1 MWe capability in a few years. Currently, there are three nuclear power plants, named No. 1, 2 & 3, in operations, which produce 16.5% gross generation of electricity and one (No. 4) is under construction, but is stopped and sealed now in Taiwan. Furthermore, the life-span of 40-year operation for those three power plants will be close-at hand and retire in 2018-2019, 2021-2023 and 2024-2025, respectively. Therefore, to find alternative energy sources, especially on the clean, renewable and sustainable ones for generating electricity are emergent and important for Taiwan's government in next few years. Among various energy sources, geothermal energy can be as base

  1. Current use and potential of additive manufacturing for optical applications

    Science.gov (United States)

    Brunelle, Matthew; Ferralli, Ian; Whitsitt, Rebecca; Medicus, Kate

    2017-10-01

    Additive manufacturing, or 3D printing, has become widely used in recent years for the creation of both prototype and end-use parts. Because the parts are created in a layer-by-layer manner, the flexibility of additive manufacturing is unparalleled and has opened the design space to enable features like undercuts and internal channels which cannot exist on traditional, subtractively manufactured parts. This flexibility can also be leveraged for optical applications. This paper outlines some of the current uses of 3D printing in the optical manufacturing process at Optimax. Several materials and additive technologies are utilized, including polymer printing through fused deposition modeling, which creates parts by depositing a softened thermoplastic filament in a layerwise fashion. Stereolithography, which uses light to cure layers of a photopolymer resin, will also be discussed. These technologies are used to manufacture functional prototypes, fixtures, sealed housings, and other components. Additionally, metal printing through selective laser melting, which uses a laser to melt metal powder layers into a dense solid, will be discussed due to the potential to manufacture thermally stable opticalmechanical assembly frameworks and functional optics. Examples of several additively manufactured optical components will be shown.

  2. The current-voltage characteristic and potential oscillations of a double layer in a triple plasma device

    International Nuclear Information System (INIS)

    Carpenter, R.T.; Torven, S.

    1986-07-01

    The properties of a strong double layer in a current circuit with a capacitance and an inductance are investigated in a triple plasma device. The double layer gives rise to a region of negative differential resistance in the current-voltage characteristic of the device, and this gives non-linear oscillations in the current and the potential drop over the double layer (PhiDL). For a sufficiently large circuit inductance PhiDL reaches an amplitude given by the induced voltage (-LdI/dt) which is much larger than the circuit EMF due to the rapid current decrease when PhiDL increases. A variable potential minimum exists in the plasma on the low potential side of the double layer, and the depth of the minimum increases when PhiDL increases. An increasing fraction of the electrons incident at the double layer are then reflected, and this is found to be the main process giving rise to the negative differential resistance. A qualitative model for the variation of the minimum potential with PhiDL is also proposed. It is based on the condition that the minimum potential must adjust itself self-consistentely so that quasi-neutrality is maintained in the plasma region where the minimum is assumed. (authors)

  3. Determination of J-integral R-curves for the pressure vessel material A 533 B1 using the potential drop technique and the multi-specimen method

    International Nuclear Information System (INIS)

    Krompholz, K.; Ullrich, G.

    1985-01-01

    J-integral experiments at room temperature were performed on three point bend type specimens of the nuclear pressure vessel material A 533 B1 with a/w-ratios of 0.3 and 0.5. Following the ASTM-proposal for the multi-specimen technique a value is obtained close to the value obtained in the HSST round robin test. On the other hand, from the measurement of the Jsub(IC)-value by means of the potential drop technique there is an indication that a lower value of Jsub(IC) is correct. This is in agreement with the multi-specimen technique using linear regression lines without excluding 'invalid' points. That is reasonable if fractographic investigations gives clear indications that stable crack growth has occurred as is the case in this work. (Auth.)

  4. Current and potential U.S. Corn Stover Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Robin Lambert [ORNL; Nelson, R [Kansas State University; Perlack, Robert D [ORNL; Sheehan, J. [National Renewable Energy Laboratory (NREL); Wright, Lynn L [subcontractor

    2007-01-01

    Agricultural residues such as corn (Zea mays L.) stover are a potential feedstock for bioenergy and bio-based products that could reduceU.S. dependence on foreign oil. Collection of such residues must take into account concerns that residue removal could increase erosion, reduce crop productivity, and deplete soil carbon and nutrients. This article estimates where and how much corn stover can be collected sustainably in the USA using existing commercial equipment and estimates costs of that collection. Erosion constraints to collection were considered explicitly, and crop productivity and soil nutrient constraints were considered implicitly, by recognizing the value of residues for maintaining soil moisture and including the cost of fertilizer to replace nutrients removed. Possible soil carbon loss was not considered in the analysis. With an annual production of 196 million Mg of corn grain (about9.2 billion bushels), the USA produces 196 million Mg of stover. Under current rotation and tillage practices, about 30% of this stover could be collected for less than $33 per Mg, taking into consideration erosion and soil moisture concerns and nutrient replacement costs. Wind erosion is a major constraint to stover collection. Analysis suggests three regions of the country (central Illinois, northern Iowa/southern Minnesota, and along the Platte River in Nebraska) produce sufficient stover to support large biorefineries with one million Mg per year feedstock demands and that if farmers converted to universal no-till production of corn, then over 100 million Mg of stover could be collected annually without causing erosion to exceed the tolerable soil loss.

  5. Dilating Eye Drops

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Dilating Eye Drops En Español Read in Chinese What are dilating eye drops? Dilating eye drops contain medication to enlarge ( ...

  6. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  7. Market potential of superconductor current limiters; Marktpotential von supraleitenden Strombegrenzern

    Energy Technology Data Exchange (ETDEWEB)

    Lakner, M.; Braun, D. [ABB Schweiz AG, Corporate Research, Baden-Daettwil (Switzerland); Schnyder, G.; Mauchle, P. [Schnyder Ingenieure AG, Huenenberg (Switzerland)

    2003-07-01

    This final report for the Swiss Federal Office of Energy describes the two concepts - 'resistive' and 'inductive' - used for Superconducting Fault Current Limiters (SCFCL) that utilise the transition from zero to finite resistance to limit short-circuit currents. The main advantages of SCFCL are compared to other current-limiting technologies: They can limit any type of prospective fault current, operate fail-safe, be self-triggered and self-restoring. Their main disadvantage - the cooling effort necessary - is also discussed. The application possibilities of SCFCL were investigated by simulating the impact on utility and industrial grids. Applications of SCFCL such as the coupling of medium-voltage grids and their use in series with a circuit-breaker on the secondary side of a substation transformer are discussed. It is also shown that, by using fault current limiters, considerable cost savings can be made, especially in connection with new installations or the extension of existing plants.

  8. Business History in Poland: Current State and Future Potential

    OpenAIRE

    Anna Pikos; Tomasz Olejniczak

    2017-01-01

    Purpose: This article explores the gap in the business history literature devoted to Central and Eastern Europe and discusses the potential of conducting business history research in Poland. Methodology: This is an explorative and tentative study based on a recently developed database of 387 Polish companies which are more than 100 years old. Findings: The article explores the reasons behind the lack of business history debate in the Polish academia and discusses its future potential. We argu...

  9. Massive Open Online Courses (MOOCs): Current Applications and Future Potential

    Science.gov (United States)

    Milheim, William D.

    2013-01-01

    Massive Open Online Courses (or MOOCs) are the subject of numerous recent articles in "The Chronicle of Higher Education," "The New York Times," and other publications related to their increasing use by a variety of universities to reach large numbers of online students. This article describes the current state of these online…

  10. Potential energy savings by using direct current for residential applications

    DEFF Research Database (Denmark)

    Diaz, Enrique Rodriguez; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2017-01-01

    This paper presents a study of the potential energy savings by implementing dc distribution systems for residential applications. In general, it is commonly accepted that the use of dc voltage improves the efficiency of the distribution, due to a decrease in the conduction losses and an efficiency...... improvement in the power converter units. However, for residential applications, the efficiency is not always improved. A grid connected residential microgrid, with renewable energy sources (RES), energy storage systems (ESS) and local loads, is presented in this work. The microgrid has been modelled...... loads. However, for isolated microgrids, the use of dc voltage has the potential to bring a significant efficiency improvement. Nevertheless the potential for cost reduction in all scenarios is very promising....

  11. Perivascular cells and tissue engineering: Current applications and untapped potential.

    Science.gov (United States)

    Avolio, Elisa; Alvino, Valeria V; Ghorbel, Mohamed T; Campagnolo, Paola

    2017-03-01

    The recent development of tissue engineering provides exciting new perspectives for the replacement of failing organs and the repair of damaged tissues. Perivascular cells, including vascular smooth muscle cells, pericytes and other tissue specific populations residing around blood vessels, have been isolated from many organs and are known to participate to the in situ repair process and angiogenesis. Their potential has been harnessed for cell therapy of numerous pathologies; however, in this Review we will discuss the potential of perivascular cells in the development of tissue engineering solutions for healthcare. We will examine their application in the engineering of vascular grafts, cardiac patches and bone substitutes as well as other tissue engineering applications and we will focus on their extensive use in the vascularization of engineered constructs. Additionally, we will discuss the emerging potential of human pericytes for the development of efficient, vascularized and non-immunogenic engineered constructs. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Transmutation potential of current and innovative nuclear power systems

    International Nuclear Information System (INIS)

    Slessarev, I.; Salvatores, M.; Uematsu, M.

    1993-01-01

    In the present paper we have investigated the transmutation potential of different nuclear systems from a physical point of view. Transuranium (TRU) elements have been considered, but also long lived fission products (LLFP). The potential for transmutation has to take into account not only the consumption of a specific nucleus (or of a specific 'family' of nuclei), but also the reproduction of other nuclei of higher masses. The present study allows an intercomparison taking into account both aspects. Technological, safety and design constraints were not considered at this stage. However strategic indications for future studies have been obtained. 3 refs., 3 tabs

  13. Coalescence of a Drop inside another Drop

    Science.gov (United States)

    Mugundhan, Vivek; Jian, Zhen; Yang, Fan; Li, Erqiang; Thoroddsen, Sigurdur

    2016-11-01

    Coalescence dynamics of a pendent drop sitting inside another drop, has been studied experimentally and in numerical simulations. Using an in-house fabricated composite micro-nozzle, a smaller salt-water drop is introduced inside a larger oil drop which is pendent in a tank containing the same liquid as the inner drop. On touching the surface of outer drop, the inner drop coalesces with the surrounding liquid forming a vortex ring, which grows in time to form a mushroom-like structure. The initial dynamics at the first bridge opening up is quantified using Particle Image Velocimetry (PIV), while matching the refractive index of the two liquids. The phenomenon is also numerically simulated using the open-source code Gerris. The problem is fully governed by two non-dimensional parameters: the Ohnesorge number and the diameter ratios of the two drops. The validated numerical model is used to better understand the dynamics of the phenomenon. In some cases a coalescence cascade is observed with liquid draining intermittently and the inner drop reducing in size.

  14. Electrostatic potential profile and nonlinear current in an interacting ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. We consider an interacting one-dimensional molecular wire attached to two metal electrodes on either side of it. The electrostatic potential profile across the wire-electrode interface has been deduced solving the Schrodinger and Poisson equations self-consistently. Since the Poisson distribution crucially depends ...

  15. Potential diagnostic applications of biosensors: current and future directions

    OpenAIRE

    Song, Shiping; Xu, Hui; Fan, Chunhai

    2006-01-01

    This review describes recent advances in biosensors of potential clinical applications. Biosensors are becoming increasingly important and practical tools in pathogen detection, molecular diagnostics, environmental monitoring, food safety control as well as in homeland defense. Electrochemical biosensors are particularly promising toward these goals arising due to several combined advantages including low-cost, operation convenience, and miniaturized devices. We review the clinical applicatio...

  16. Current status of Indian medicinal plants with aphrodisiac potential

    OpenAIRE

    Ramandeep Singh; Ashraf Ali; G. Jeyabalan; Alok Semwal

    2013-01-01

    In India, indigenous remedies have been used in treatment of sexual dysfunction since the time of Charaka and Sushruta. Plants have been always an exemplary source of drugs and many of the currently available drugs have been derived directly or indirectly from them. An aphrodisiac is defined as an agent that arouses sexual desire. Erectile dysfunction or sexual dysfunction (ED or SD) or male impotence is defined as the inability of a man to achieve and maintain an erection sufficient for mutu...

  17. Current assessment and future potential of the international nuclear market

    International Nuclear Information System (INIS)

    Cassidy, P.R.

    1983-01-01

    This is a study of the current and future situation of the international nuclear market. This paper highlights the projections as seen not only by Bechtel Power Corporation, but also by the international nuclear community. It covers in particular the electric power growth projection; the percentage of probable nuclear power generation; operating services for existing nuclear power plants; and the nuclear fuel cycle. (NEA) [fr

  18. Therapeutic potential of snake venom in cancer therapy: current perspectives

    Science.gov (United States)

    Vyas, Vivek Kumar; Brahmbhatt, Keyur; Bhatt, Hardik; Parmar, Utsav

    2013-01-01

    Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer. Snake venom toxins contributed significantly to the treatment of many medical conditions. There are many published studies describing and elucidating the anti-cancer potential of snake venom. Cancer therapy is one of the main areas for the use of protein peptides and enzymes originating from animals of different species. Some of these proteins or peptides and enzymes from snake venom when isolated and evaluated may bind specifically to cancer cell membranes, affecting the migration and proliferation of these cells. Some of substances found in the snake venom present a great potential as anti-tumor agent. In this review, we presented the main results of recent years of research involving the active compounds of snake venom that have anticancer activity. PMID:23593597

  19. Intradermal delivery of vaccines: potential benefits and current challenges

    Science.gov (United States)

    Hickling, JK; Jones, KR; Friede, M; Chen, D; Kristensen, D

    2011-01-01

    Abstract Delivery of vaccine antigens to the dermis and/or epidermis of human skin (i.e. intradermal delivery) might be more efficient than injection into the muscle or subcutaneous tissue, thereby reducing the volumes of antigen. This is known as dose-sparing and has been demonstrated in clinical trials with some, but not all, vaccines. Dose-sparing could be beneficial to immunization programmes by potentially reducing the costs of purchase, distribution and storage of vaccines; increasing vaccine availability and effectiveness. The data obtained with intradermal delivery of some vaccines are encouraging and warrant further study and development; however significant gaps in knowledge and operational challenges such as reformulation, optimizing vaccine presentation and development of novel devices to aid intradermal vaccine delivery need to be addressed. Modelling of the costs and potential savings resulting from intradermal delivery should be done to provide realistic expectations of the potential benefits and to support cases for investment. Implementation and uptake of intradermal vaccine delivery requires further research and development, which depends upon collaboration between multiple stakeholders in the field of vaccination. PMID:21379418

  20. Business History in Poland: Current State and Future Potential

    Directory of Open Access Journals (Sweden)

    Anna Pikos

    2017-11-01

    Full Text Available Purpose: This article explores the gap in the business history literature devoted to Central and Eastern Europe and discusses the potential of conducting business history research in Poland. Methodology: This is an explorative and tentative study based on a recently developed database of 387 Polish companies which are more than 100 years old. Findings: The article explores the reasons behind the lack of business history debate in the Polish academia and discusses its future potential. We argue that given the size of population and a unique historical context, the Polish sample is worth studying as it can provide valuable contributions to well established debates in the field of business history debates covering issues such as continuity, longevity, and survival strategies. Research limitations and implications: This is an explorative and tentative study and therefore has several limitations, including a limited scope of companies included in the database, sources of data, and poor quality of corporate archives. Originality and value: This is the first article explicitly discussing the potential of conducting business history studies in the context of empirical data concerning Polish long-lived companies.

  1. Intradermal delivery of vaccines: potential benefits and current challenges.

    Science.gov (United States)

    Hickling, J K; Jones, K R; Friede, M; Zehrung, D; Chen, D; Kristensen, D

    2011-03-01

    Delivery of vaccine antigens to the dermis and/or epidermis of human skin (i.e. intradermal delivery) might be more efficient than injection into the muscle or subcutaneous tissue, thereby reducing the volumes of antigen. This is known as dose-sparing and has been demonstrated in clinical trials with some, but not all, vaccines. Dose-sparing could be beneficial to immunization programmes by potentially reducing the costs of purchase, distribution and storage of vaccines; increasing vaccine availability and effectiveness. The data obtained with intradermal delivery of some vaccines are encouraging and warrant further study and development; however significant gaps in knowledge and operational challenges such as reformulation, optimizing vaccine presentation and development of novel devices to aid intradermal vaccine delivery need to be addressed. Modelling of the costs and potential savings resulting from intradermal delivery should be done to provide realistic expectations of the potential benefits and to support cases for investment. Implementation and uptake of intradermal vaccine delivery requires further research and development, which depends upon collaboration between multiple stakeholders in the field of vaccination.

  2. Triclosan: Current Status, Occurrence, Environmental Risks and Bioaccumulation Potential

    Science.gov (United States)

    Dhillon, Gurpreet Singh; Kaur, Surinder; Pulicharla, Rama; Brar, Satinder Kaur; Cledón, Maximiliano; Verma, Mausam; Surampalli, Rao Y.

    2015-01-01

    Triclosan (TCS) is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated. PMID:26006133

  3. Current Capabilities and Development Potential in Surgical Robotics

    Directory of Open Access Journals (Sweden)

    Mathias Hoeckelmann

    2015-05-01

    Full Text Available Commercial surgical robots have been in clinical use since the mid-1990s, supporting surgeons in various tasks. In the past decades, many systems emerged as research platforms, and a few entered the global market. This paper summarizes the currently available surgical systems and research directions in the broader field of surgical robotics. The widely deployed teleoperated manipulators aim to enhance human cognitive and physical skills and provide smart tools for surgeons, while image-guided robotics focus on surpassing human limitations by introducing automated targeting and treatment delivery methods. Both concepts are discussed based on prototypes and commercial systems. Through concrete examples the possible future development paths of surgical robots are illustrated. While research efforts are taking different approaches to improve the capacity of such systems, the aim of this survey is to assess their maturity from the commercialization point of view.

  4. How to know and choose online games: differences between current and potential players.

    Science.gov (United States)

    Teng, Ching-I; Lo, Shao-Kang; Wang, Pe-Cheng

    2007-12-01

    This study investigated how different adolescent players acquire game information and the criteria they use in choosing online games and found that (1) current players generally use comprehensive information sources more than potential players do; (2) current players rely on free trials and smooth display of motion graphics as choice criteria more than potential players do; (3) potential players rely on the look of advertisements more than current players do; (4) both current and potential players most likely use word-of-mouth and gaming programs on TV as information sources; and (5) endorser attractiveness is ranked the least important among six choice criteria by both current and potential players.

  5. Cardiac gene therapy: therapeutic potential and current progress.

    Science.gov (United States)

    Kizana, E; Alexander, I E

    2003-10-01

    Cardiovascular disease remains a major cause of morbidity and mortality in modern societies. While contemporary treatment modalities are making steady inroads to reduce this disease burden there remains a pressing need to vigorously explore novel therapeutic strategies. Rapid advances in our understanding of molecular pathology and the evolution of increasingly efficient gene transfer technology offer the imminent prospect of gene-based approaches to, at least, a subset of cardiovascular pathophysiologies. Initially envisaged as a treatment strategy for inherited monogenic disorders, it is now apparent that gene therapy has broader potential that encompasses acquired polygenic diseases, including many that affect the cardiovascular system. Extensive in vitro and animal studies are providing an increasingly sound scientific basis for cautious human evaluation. This review focuses on gene therapy of diseases primarily afflicting the heart, and provides an overview of gene and vector delivery systems with particular emphasis on systems suited to individual cardiac conditions. The pathophysiology underlying these conditions and molecular targets for therapeutic intervention are also reviewed.

  6. Respiratory gated radiotherapy: current techniques and potential benefits

    International Nuclear Information System (INIS)

    Giraud, P.; Campana, F.; Rosenwald, J.C.; Cosset, J.M.; Reboul, F.; Garcia, R.; Clippe, S.; Carrie, C.; Dubray, B.

    2003-01-01

    Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. These techniques presently investigated in several medical centers worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. Physical, technical and physiological questions still remain to be answered. This paper describes the most frequently used gated techniques and the main published clinical reports on the use of respiration-gated radiotherapy in order to evaluate the impact of these techniques. (author)

  7. Alluvial aquifers in the Mzingwane catchment: Their distribution, properties, current usage and potential expansion

    Science.gov (United States)

    Moyce, William; Mangeya, Pride; Owen, Richard; Love, David

    The Mzingwane River is a sand filled channel, with extensive alluvial aquifers distributed along its banks and bed in the lower catchment. LandSat TM imagery was used to identify alluvial deposits for potential groundwater resources for irrigation development. On the false colour composite band 3, band 4 and band 5 (FCC 345) the alluvial deposits stand out as white and dense actively growing vegetation stands out as green making it possible to mark out the lateral extent of the saturated alluvial plain deposits using the riverine fringe and vegetation . The alluvial aquifers form ribbon shaped aquifers extending along the channel and reaching over 20 km in length in some localities and are enhanced at lithological boundaries. These alluvial aquifers extend laterally outside the active channel, and individual alluvial aquifers have been measured with area ranging from 45 ha to 723 ha in the channels and 75 ha to 2196 ha on the plains. The alluvial aquifers are more pronounced in the Lower Mzingwane, where the slopes are gentler and allow for more sediment accumulation. Estimated water resources potential ranges between 175,000 m 3 and 5,430,000 m 3 in the channels and between 80,000 m 3 and 6,920,000 m 3 in the plains. Such a water resource potential can support irrigation ranging from 18 ha to 543 ha for channels alluvial aquifers and 8 ha to 692 ha for plain alluvial aquifers. Currently, some of these aquifers are being used to provide water for domestic use, livestock watering and dip tanks, commercial irrigation and market gardening. The water quality of the aquifers in general is fairly good due to regular recharge and flushing out of the aquifers by annual river flows and floodwater. Water salinity was found to increase significantly in the end of the dry season, and this effect was more pronounced in water abstracted from wells on the alluvial plains. During drought years, recharge is expected to be less and if the drought is extended water levels in the

  8. Current and potential ant impacts in the Pacific region

    Science.gov (United States)

    Loope, Lloyd L.; Krushelnycky, Paul D.

    2007-01-01

    Worldwide, ants are a powerful ecological force, and they appear to be dominant components of animal communities of many tropical and temperate ecosystems in terms of biomass and numbers of individuals (Bluthgen et al. 2000). For example, ants comprise up to 94% of arthropod individuals in fogging samples taken from diverse lowland tropical rainforest canopies, and 86% of the biomass (Davidson et al. 2003). The majority of these ant species and individuals obtain carbohydrates either from extrafloral nectaries or from sap-feeding Hemiptera that pass carbohydrate-rich “honeydew” to attending ants while concentrating nitrogen (N) from N-poor plant sap (Davidson et al. 2003). Honeydew and nectar represent key resources for arboreal ant species, although most ant species are at least partly carnivorous or scavengers (Bluthgen et al. 2004). In contrast to most of the terrestrial world, the biotas of many Pacific islands evolved without ants. Whereas endemic ant species are found in New Zealand (ca. 10 spp.), Tonga (ca. 10 spp.), and Samoa (ca. 12 spp.), other islands of Polynesia and parts of Micronesia likely lack native ants (Wilson and Taylor 1967, Wetterer 2002, Wetterer and Vargo 2003). About 20 Indo-Australian and western Pacific ant species range to the east and north of Samoa, but it is unclear how many of these were transported there by humans at some time (Wilson and Taylor 1967). Most of the remainder of the ant species currently found on Pacific islands are widespread species that fall in the category of “tramp species,” dispersed by recent human commerce and generally closely tied to human activity and urban areas (Wilson and Taylor 1967, McGlynn 1999). In Pacific island situations, some of these tramp ant species are able to thrive beyond areas of human activity. Relatively few ant species have been successful invaders of native communities on continents, and these include most of the species that pose the greatest problems for Pacific islands

  9. Assessing current and future techno-economic potential of concentrated solar power and photovoltaic electricity generation

    International Nuclear Information System (INIS)

    Köberle, Alexandre C.; Gernaat, David E.H.J.; Vuuren, Detlef P. van

    2015-01-01

    CSP and PV technologies represent energy sources with large potentials. We present cost-supply curves for both technologies using a consistent methodology for 26 regions, based on geoexplicit information on solar radiation, land cover type and slope, exploring individual potential and interdependencies. For present day, both CSP and PV supply curves start at $0.18/kWh, in North Africa, South America, and Australia. Applying accepted learning rates to official capacity targets, we project prices to drop to $0.11/kWh for both technologies by 2050. In an alternative “fast-learning” scenario, generation costs drop to $0.06–0.07/kWh for CSP, and $0.09/kWh for PV. Competition between them for best areas is explored along with sensitivities of their techno-economic potentials to land use restrictions and land cover type. CSP was found to be more competitive in desert sites with highest direct solar radiation. PV was a clear winner in humid tropical regions, and temperate northern hemisphere. Elsewhere, no clear winner emerged, highlighting the importance of competition in assessments of potentials. Our results show there is ample potential globally for both technologies even accounting for land use restrictions, but stronger support for RD&D and higher investments are needed to make CSP and PV cost-competitive with established power technologies by 2050. - Highlights: • A consistent assessment of global potential for CSP and PV, with cost-supply curves for 26 regions. • Combined global CSP and PV potential below US$0.35/kWh estimated at 135,128 TWh per year. • Competition for same land-based solar resource implies that potentials cannot be added. • Attractive areas are MENA, Northern Chile, Australia, China and Southwestern USA. • Costs are projected to go down over time, reaching US$0.06–0.11/KWh for attractive sites in 2050

  10. Scanning drop sensor

    Science.gov (United States)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Shinde, Aniketa A.; Guevarra, Dan W.; Jones, Ryan J.; Marcin, Martin R.; Mitrovic, Slobodan

    2017-05-09

    Electrochemical or electrochemical and photochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  11. Are the Stress Drops of Small Earthquakes Good Predictors of the Stress Drops of Larger Earthquakes?

    Science.gov (United States)

    Hardebeck, J.

    2017-12-01

    stress drops can predict the categories of the 15 events. I find that they cannot, rather the large event stress drops are uncorrelated with the local mean stress drop from the Shearer catalog. These results imply that the regionalization of stress drops of small events does not extend to the larger events, at least with current standard techniques of stress drop estimation.

  12. Bubble and drop interfaces

    CERN Document Server

    Miller

    2011-01-01

    The book aims at describing the most important experimental methods for characterizing liquid interfaces, such as drop profile analysis, bubble pressure and drop volume tensiometry, capillary pressure technique, and oscillating drops and bubbles. Besides the details of experimental set ups, also the underlying theoretical basis is presented in detail. In addition, a number of applications based on drops and bubbles is discussed, such as rising bubbles and the very complex process of flotation. Also wetting, characterized by the dynamics of advancing contact angles is discussed critically. Spec

  13. A magnetic vector potential corresponding to a centrally conservative current element force

    International Nuclear Information System (INIS)

    Minteer, Timothy M

    2015-01-01

    The magnetic vector potential (Coulomb gauge) is commonly introduced in magnetostatic chapters of electromagnetism textbooks. However, what is not typically presented are the infinite subsets of the Coulomb gauge associated with differential current elements. This work provides a comparison of various differential magnetic vector potentials, differential magnetostatic potential energies, as well as differential current element forces as a collective work not available elsewhere. The differential magnetic vector potential highlighted in this work is the Coulomb–Ampère gauge corresponding to the centrally conservative Ampère current element force. The centrally conservative force is modeled as a mean valued continual exchange of energy carrier mediators accounting for both the differential magnetostatic potential energy and Ampère current element force of two differential current elements. (paper)

  14. Initial Electrospreading of Aqueous Electrolyte Drops

    Science.gov (United States)

    Chen, Longquan; Li, Chunli; van der Vegt, Nico F. A.; Auernhammer, Günter K.; Bonaccurso, Elmar

    2013-01-01

    The early spreading of a liquid drop on a solid surface driven by inertial, capillary, and electrostatic forces is of fundamental interest, since most commonly used surfaces are (naturally) charged. We studied the effect of applying an electric potential between a drop and a surface on the early spreading of aqueous electrolyte drops. We found that spreading dynamics not only depended on the potential, but also on the electrolyte concentration. Based on molecular dynamics simulations of the ion distribution in spreading nanodrops under an applied potential, we propose a simple model to explain the relation between applied potential, electrolyte concentration, and early spreading dynamics.

  15. Turbulence, bubbles and drops

    NARCIS (Netherlands)

    van der Veen, Roeland

    2016-01-01

    In this thesis, several questions related to drop impact and Taylor-Couette turbulence are answered. The deformation of a drop just before impact can cause a bubble to be entrapped. For many applications, such as inkjet printing, it is crucial to control the size of this entrapped bubble. To study

  16. Current Reversal Due to Coupling Between Asymmetrical Driving Force and Ratchet Potential

    International Nuclear Information System (INIS)

    Ai Baoquan; Xie Huizhang; Liu Lianggang

    2006-01-01

    Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potential are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal. The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.

  17. Novel description of ionic currents recorded with the action potential clamp technique: application to excitatory currents in suprachiasmatic nucleus neurons.

    Science.gov (United States)

    Clay, John R

    2015-07-01

    The traditional method of recording ionic currents in neurons has been with voltage-clamp steps. Other waveforms such as action potentials (APs) can be used. The AP clamp method reveals contributions of ionic currents that underlie excitability during an AP (Bean BP. Nat Rev Neurosci 8: 451-465, 2007). A novel usage of the method is described in this report. An experimental recording of an AP from the literature is digitized and applied computationally to models of ionic currents. These results are compared with experimental AP-clamp recordings for model verification or, if need be, alterations to the model. The method is applied to the tetrodotoxin-sensitive sodium ion current, INa, and the calcium ion current, ICa, from suprachiasmatic nucleus (SCN) neurons (Jackson AC, Yao GL, Bean BP. J Neurosci 24: 7985-7998, 2004). The latter group reported voltage-step and AP-clamp results for both components. A model of INa is constructed from their voltage-step results. The AP clamp computational methodology applied to that model compares favorably with experiment, other than a modest discrepancy close to the peak of the AP that has not yet been resolved. A model of ICa was constructed from both voltage-step and AP-clamp results of this component. The model employs the Goldman-Hodgkin-Katz equation for the current-voltage relation rather than the traditional linear dependence of this aspect of the model on the Ca(2+) driving force. The long-term goal of this work is a mathematical model of the SCN AP. The method is general. It can be applied to any excitable cell.

  18. Modulation of membrane potential by an acetylcholine-activated potassium current in trout atrial myocytes

    DEFF Research Database (Denmark)

    Molina, C.E.; Gesser, Hans; Llach, A.

    2007-01-01

    Application of the current-clamp technique in rainbow trout atrial myocytes has yielded resting membrane potentials that are incompatible with normal atrial function. To investigate this paradox, we recorded the whole membrane current (Im) and compared membrane potentials recorded in isolated...... cardiac myocytes and multicellular preparations. Atrial tissue and ventricular myocytes had stable resting potentials of -87 ± 2 mV and -83.9 ± 0.4 mV, respectively. In contrast, 50 out of 59 atrial myocytes had unstable depolarized membrane potentials that were sensitive to the holding current. We...... hypothesized that this is at least partly due to a small slope conductance of Im around the resting membrane potential in atrial myocytes. In accordance with this hypothesis, the slope conductance of Im was about sevenfold smaller in atrial than in ventricular myocytes. Interestingly, ACh increased Im at -120...

  19. Chemical potential of quasi-equilibrium magnon gas driven by pure spin current.

    Science.gov (United States)

    Demidov, V E; Urazhdin, S; Divinskiy, B; Bessonov, V D; Rinkevich, A B; Ustinov, V V; Demokritov, S O

    2017-11-17

    Pure spin currents provide the possibility to control the magnetization state of conducting and insulating magnetic materials. They allow one to increase or reduce the density of magnons, and achieve coherent dynamic states of magnetization reminiscent of the Bose-Einstein condensation. However, until now there was no direct evidence that the state of the magnon gas subjected to spin current can be treated thermodynamically. Here, we show experimentally that the spin current generated by the spin-Hall effect drives the magnon gas into a quasi-equilibrium state that can be described by the Bose-Einstein statistics. The magnon population function is characterized either by an increased effective chemical potential or by a reduced effective temperature, depending on the spin current polarization. In the former case, the chemical potential can closely approach, at large driving currents, the lowest-energy magnon state, indicating the possibility of spin current-driven Bose-Einstein condensation.

  20. Effect of Over Zone Feeding on Rail Potential and Stray Current in DC Mass Transit System

    Directory of Open Access Journals (Sweden)

    Guifu Du

    2016-01-01

    Full Text Available DC traction power system with running rails as reflux conductor has been adopted in Guangzhou Metro Line 8. During the operation of the Guangzhou Metro Line, a high rail potential has been observed, and the leakage of stray current increases significantly. Because of the electrical connectivity of the catenary, over zone feeding of traction current may exist when multiple trains run in multiple traction substations. Guangzhou Metro Line 8 suspects that over zone feeding of traction current is the major cause of the high rail potential. In this paper, a unified chain model of DC traction power system is proposed to simulate the distribution of rail potential and stray current. Field tests and simulations have been carried out to study whether over zone feeding has an impact on rail potential and stray current. Results show that over zone feeding widely exists in DC traction power system and that the rail potential and stray current can be reduced effectively by preventing the over zone feeding of traction current.

  1. "Who am I supposed to let down?": The caring work and emotional practices of vocational educational training teachers working with potential drop-out students

    DEFF Research Database (Denmark)

    Lippke, Lena

    2012-01-01

    Purpose – Because of high drop-out rates among the students entering vocational education in Denmark retention of students has become pivotal to Danish educational policy. Thus vocational educational training (VET) colleges have been asked to work on implementing different kinds of retention...... initiatives and as a result, most colleges have established extended basic courses aimed at students with personal, social and/or academic difficulties. This paper aims to explore the emotional aspects of vocational educational teachers’ work and present a preliminary analysis of the notion of care...... as socially situated within the vocational educational system. Design/methodology/approach – This paper derives from a study based on fieldwork at a VET college offering extended basic courses. During the fieldwork nine weeks of participating observations and 13 interviews with teachers were conducted...

  2. Four-point probe measurements using current probes with voltage feedback to measure electric potentials

    Science.gov (United States)

    Lüpke, Felix; Cuma, David; Korte, Stefan; Cherepanov, Vasily; Voigtländer, Bert

    2018-02-01

    We present a four-point probe resistance measurement technique which uses four equivalent current measuring units, resulting in minimal hardware requirements and corresponding sources of noise. Local sample potentials are measured by a software feedback loop which adjusts the corresponding tip voltage such that no current flows to the sample. The resulting tip voltage is then equivalent to the sample potential at the tip position. We implement this measurement method into a multi-tip scanning tunneling microscope setup such that potentials can also be measured in tunneling contact, allowing in principle truly non-invasive four-probe measurements. The resulting measurement capabilities are demonstrated for \

  3. Increasing Extracted Beam Current Density in Ion Thrusters through Plasma Potential Modification

    Science.gov (United States)

    Arthur, Neil; Foster, John

    2015-09-01

    A gridded ion thruster's maximum extractable beam current is determined by the space charge limit. The classical formulation does not take into account finite ion drift into the acceleration gap. It can be shown that extractable beam current can be increased beyond the conventional Child-Langmuir law if the ions enter the gap at a finite drift speed. In this work, ion drift in a 10 cm thruster is varied by adjusting the plasma potential relative to the potential at the extraction plane. Internal plasma potential variations are achieved using a novel approach involving biasing the magnetic cusps. Ion flow variations are assessed using simulated beam extraction in conjunction with a retarding potential analyzer. Ion beam current density changes at a given total beam voltage in full beam extraction tests are characterized as a function of induced ion drift velocity as well.

  4. Effects of tacrolimus on action potential configuration and transmembrane ion currents in canine ventricular cells.

    Science.gov (United States)

    Szabó, László; Szentandrássy, Norbert; Kistamás, Kornél; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Horváth, Balázs; Magyar, János; Bányász, Tamás; Pál, Balázs; Nánási, Péter P

    2013-03-01

    Tacrolimus is a commonly used immunosuppressive agent which causes cardiovascular complications, e.g., hypertension and hypertrophic cardiomyopathy. In spite of it, there is little information on the cellular cardiac effects of the immunosuppressive agent tacrolimus in larger mammals. In the present study, therefore, the concentration-dependent effects of tacrolimus on action potential morphology and the underlying ion currents were studied in canine ventricular cardiomyocytes. Standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques were applied in myocytes enzymatically dispersed from canine ventricular myocardium. Tacrolimus (3-30 μM) caused a concentration-dependent reduction of maximum velocity of depolarization and repolarization, action potential amplitude, phase-1 repolarization, action potential duration, and plateau potential, while no significant change in the resting membrane potential was observed. Conventional voltage clamp experiments revealed that tacrolimus concentrations ≥3 μM blocked a variety of ion currents, including I(Ca), I(to), I(K1), I(Kr), and I(Ks). Similar results were obtained under action potential voltage clamp conditions. These effects of tacrolimus developed rapidly and were fully reversible upon washout. The blockade of inward currents with the concomitant shortening of action potential duration in canine myocytes is the opposite of those observed previously with tacrolimus in small rodents. It is concluded that although tacrolimus blocks several ion channels at higher concentrations, there is no risk of direct interaction with cardiac ion channels when applying tacrolimus in therapeutic concentrations.

  5. Effects of pioglitazone on cardiac ion currents and action potential morphology in canine ventricular myocytes.

    Science.gov (United States)

    Kistamás, Kornél; Szentandrássy, Norbert; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Bárándi, László; Horváth, Balázs; Szebeni, Andrea; Magyar, János; Bányász, Tamás; Kecskeméti, Valéria; Nánási, Péter P

    2013-06-15

    Despite its widespread therapeutical use there is little information on the cellular cardiac effects of the antidiabetic drug pioglitazone in larger mammals. In the present study, therefore, the concentration-dependent effects of pioglitazone on ion currents and action potential configuration were studied in isolated canine ventricular myocytes using standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques. Pioglitazone decreased the maximum velocity of depolarization and the amplitude of phase-1 repolarization at concentrations ≥3 μM. Action potentials were shortened by pioglitazone at concentrations ≥10 μM, which effect was accompanied with significant reduction of beat-to-beat variability of action potential duration. Several transmembrane ion currents, including the transient outward K(+) current (Ito), the L-type Ca(2+) current (ICa), the rapid and slow components of the delayed rectifier K(+) current (IKr and IKs, respectively), and the inward rectifier K(+) current (IK1) were inhibited by pioglitazone under conventional voltage clamp conditions. Ito was blocked significantly at concentrations ≥3 μM, ICa, IKr, IKs at concentrations ≥10 μM, while IK1 at concentrations ≥30 μM. Suppression of Ito, ICa, IKr, and IK1 has been confirmed also under action potential voltage clamp conditions. ATP-sensitive K(+) current, when activated by lemakalim, was effectively blocked by pioglitazone. Accordingly, action potentials were prolonged by 10 μM pioglitazone when the drug was applied in the presence of lemakalim. All these effects developed rapidly and were readily reversible upon washout. In conclusion, pioglitazone seems to be a harmless agent at usual therapeutic concentrations. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Polarization Potential Has No Effect on Maximum Current Density Produced by Halotolerant Bioanodes

    Directory of Open Access Journals (Sweden)

    Muriel González-Muñoz

    2018-03-01

    Full Text Available Halotolerant bioanodes are considered an attractive alternative in microbial electrochemical systems, as they can operate under higher conductive electrolytes, in comparison with traditional wastewater and freshwater bioanodes. The dependency between energetic performance and polarization potential has been addressed in several works; however the vast majority discusses its effect when wastewater or freshwater inocula are employed, and fewer reports focus on inocula from highly-saline environments. Moreover, the effect of the polarization potential on current production is not fully understood. To determine if the polarization potential has a significant effect on current production, eight bioanodes were grown by chronoamperometry at positive and negative potentials relative to the reference electrode (+0.34 V/SHE and −0.16 V/SHE, in a three-electrode set-up employing sediments from a hyperhaline coastal lagoon. The maximum current density obtained was the same, despite the differences in the applied potential. Our findings indicate that even if differences in organic matter removal and coulombic efficiency are obtained, the polarization potential had no statistically significant effect on overall current density production.

  7. [Optimize dropping process of Ginkgo biloba dropping pills by using design space approach].

    Science.gov (United States)

    Shen, Ji-Chen; Wang, Qing-Qing; Chen, An; Pan, Fang-Lai; Gong, Xing-Chu; Qu, Hai-Bin

    2017-07-01

    In this paper, a design space approach was applied to optimize the dropping process of Ginkgo biloba dropping pills. Firstly, potential critical process parameters and potential process critical quality attributes were determined through literature research and pre-experiments. Secondly, experiments were carried out according to Box-Behnken design. Then the critical process parameters and critical quality attributes were determined based on the experimental results. Thirdly, second-order polynomial models were used to describe the quantitative relationships between critical process parameters and critical quality attributes. Finally, a probability-based design space was calculated and verified. The verification results showed that efficient production of Ginkgo biloba dropping pills can be guaranteed by operating within the design space parameters. The recommended operation ranges for the critical dropping process parameters of Ginkgo biloba dropping pills were as follows: dropping distance of 5.5-6.7 cm, and dropping speed of 59-60 drops per minute, providing a reference for industrial production of Ginkgo biloba dropping pills. Copyright© by the Chinese Pharmaceutical Association.

  8. Current Reversals of an Underdamped Brownian Particle in an Asymmetric Deformable Potential

    Science.gov (United States)

    Cai, Chun-Chun; Liu, Jian-Li; Chen, Hao; Li, Feng-Guo

    2018-03-01

    Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force, respectively. From numerical simulations, we obtain the current average velocity. The current reversals and the absolute negative mobility are presented. The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear. When the static force is small, the increase of the potential deformation suppresses the absolute negative mobility. When the force is large, the absolute negative mobility disappears. In particular, when the potential deformation is equal to 0.015, the two current reversals present with the increasing of the force. Remarkably, when the potential deformation is small, there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior. Supported in part by the National Natural Science Foundation of China under Grant Nos. 11575064 and 11175067, and the Natural Science Foundation of Guangdong Province under Grant No. 2016A030313433

  9. Impact of granular drops

    KAUST Repository

    Marston, J. O.

    2013-07-15

    We investigate the spreading and splashing of granular drops during impact with a solid target. The granular drops are formed from roughly spherical balls of sand mixed with water, which is used as a binder to hold the ball together during free-fall. We measure the instantaneous spread diameter for different impact speeds and find that the normalized spread diameter d/D grows as (tV/D)1/2. The speeds of the grains ejected during the “splash” are measured and they rarely exceed twice that of the impact speed.

  10. Observation of negative potential depression on double layer during a phase of current disruption

    International Nuclear Information System (INIS)

    Fujita, H.; Matsuo, K.; Yagura, S.

    1984-01-01

    The negative potential depression with a depth of approximately electron temperature is observed on the low potential tail of the double layer just at the moment when the electron current passing through the layer is disrupted. The depression is confirmed to serve as an electron thermal barrier and form an ion hole from phase-space measurements of electrons and ions, respectively. The depth of the depression becomes maximum when the density around the depression becomes most inhomogeneous. (author)

  11. Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Kevin A. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2013-10-03

    Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States.

  12. Large drops cause complete coalescence

    Indian Academy of Sciences (India)

    The thin film below the drop drains out slowly with time, finally creating a hole in the drop when it comes in contact with the interface at t=0.37 Tc, a small matrix drop, also called satellite drop, is seen to be trapped during the film rupture. Such an entrapment was observed by Thoroddsen et al (2008) and Chen et al (2006).

  13. Two secondary drops

    Indian Academy of Sciences (India)

    Figure shows formation of two secondary drops of unequal size and their merger. The process is same as the earlier process until t= 0.039 Tc with necking occurring at two places, one at the bottom of the column and the other at the middle. The necking at the middle of the liquid column is due to Raleigh instability.

  14. Two secondary drops

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Notes: Figure shows formation of two secondary drops of unequal size and their merger. The process is same as the earlier process until t= 0.039 Tc with necking occurring at two places, one at the bottom of the column and the other at the middle. The necking at the ...

  15. Lambda-dropping

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1997-01-01

    the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each......Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

  16. The current and potential contribution of home-grown vegetables to ...

    African Journals Online (AJOL)

    In this paper the current and potential utilisation of crops (bought and home produce) in diets in South Africa is reviewed. Available data shows that at all levels, national, household and individual, the amounts of fruits and vegetables available and consumed are about half the WHO (2003) recommendations of at least 400g ...

  17. Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brockway, Anna M. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Ulrich, Elaine [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-04-01

    This report provides a high-level overview of the current U.S. shared solar landscape and the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  18. Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brockway, Anna M. [U.S. Department of Energy, Washington, DC (United States); Ulrich, Elaine [U.S. Department of Energy, Washington, DC (United States); Margolis, Robert [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-04-07

    This report provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  19. A Comparative Study of Current and Potential Users of Mobile Payment Services

    Directory of Open Access Journals (Sweden)

    Chanchai Phonthanukitithaworn

    2016-11-01

    Full Text Available Previous studies of mobile payment (m-payment services have primarily focused on a single group of adopters. This study identifies the factors that influence an individual’s intention to use m-payment services and compares groups of current users (adopters with potential users (non-adopters. A research model that reflects the behavioral intention to use m-payment services is developed and empirically tested using structural equation modeling on a data set consisting of 529 potential users and 256 current users of m-payment services in Thailand. The results show that the factors that influence current users’ intentions to use m-payment services are compatibility, subjective norms, perceived trust, and perceived cost. Subjective norms, compatibility, ease of use, and perceived risk influenced potential users’ intentions to use m-payment. Subjective norms and perceived risk had a stronger influence on potential users, while perceived cost had a stronger influence on current users, in terms of their intentions to use m-payment services. Discussions, limitations, and recommendations for future research are addressed.

  20. THE MATHEMATIC MODEL OF POTENTIAL RELAXATION IN COULOSTATIC CONDITIONS FOR LIMITING DIFFUSION CURRENT CASE

    Directory of Open Access Journals (Sweden)

    O. H. Kapitonov

    2010-05-01

    Full Text Available A mathematical model of coulostatic relaxation of the potential for solid metallic electrode was presented. The solution in the case of limiting diffusion current was obtained. On the basis of this model the technique of concentration measurements for heavy metal ions in diluted solutions was suggested. The model adequacy was proved by experimental data.

  1. Cultural landscapes as heritage in Malaysia: Potentials, threats, and current practices

    NARCIS (Netherlands)

    Ahmad, R.

    2013-01-01

    The rural cultural landscape in Malaysia is relatively under-researched. The current heritage practices focus on built heritage as national heritage, which implies the everyday landscapes of the rural areas have been neglected as potential heritage and have received little attention from politicians

  2. Current Animal Models of Postoperative Spine Infection and Potential Future Advances

    Directory of Open Access Journals (Sweden)

    Alexandra eStavrakis

    2015-05-01

    Full Text Available Implant related infection following spine surgery is a devastating complication for patients and can potentially lead to significant neurological compromise, disability, morbidity, and even mortality. This paper provides an overview of the existing animal models of postoperative spine infection and highlights the strengths and weaknesses of each model. In addition there is discussion regarding potential modifications to these animal models to better evaluate preventative and treatment strategies for this challenging complication. Current models are effective in simulating surgical procedures but fail to evaluate infection longitudinally using multiple techniques. Potential future modifications to these models include using advanced imaging technologies to evaluate infection, use of bioluminescent bacterial species, and testing of novel treatment strategies against multiple bacterial strains. There is potential to establish a postoperative spine infection model using smaller animals, such as mice, as these would be a more cost-effective screening tool for potential therapeutic interventions.

  3. Current and potential sustainable corn stover feedstock for biofuel production in the United States

    Science.gov (United States)

    Tan, Zhengxi; Liu, Shu-Guang; Tieszen, Larry L.; Bliss, Norman

    2012-01-01

    Increased demand for corn (Zea mays L.) stover as a feedstock for cellulosic ethanol raises concerns about agricultural sustainability. Excessive corn stover harvesting could have long-term impacts on soil quality. We estimated current and future stover production and evaluated the potential harvestable stover amount (HSA) that could be used for biofuel feedstock in the United States by defining the minimum stover requirement (MSR) associated with the current soil organic carbon (SOC) content, tillage practices, and crop rotation systems. Here we show that the magnitude of the current HSA is limited (31 Tg y−1, dry matter) due to the high MSR for maintaining the current SOC content levels of soils that have a high carbon content. An alternative definition of MSR for soils with a moderate level of SOC content could significantly elevate the annual HSA to 68.7 Tg, or even to 132.2 Tg if the amount of currently applied manure is counted to partially offset the MSR. In the future, a greater potential for stover feedstock could come from an increase in stover yield, areal harvest index, and/or the total planted area. These results suggest that further field experiments on MSR should be designed to identify differences in MSR magnitude between maintaining SOC content and preventing soil erosion, and to understand the role of current SOC content level in determining MSR from soils with a wide range of carbon contents and climatic conditions.

  4. Dynamic Control of the Vortex Pinning Potential in a Superconductor Using Current Injection through Nanoscale Patterns.

    Science.gov (United States)

    Kalcheim, Yoav; Katzir, Eran; Zeides, Felix; Katz, Nadav; Paltiel, Yossi; Millo, Oded

    2017-05-10

    Control over the vortex potential at the nanoscale in a superconductor is a subject of great interest for both fundamental and technological reasons. Many methods for achieving artificial pinning centers have been demonstrated, for example, with magnetic nanostructures or engineered imperfections, yielding many intriguing effects. However, these pinning mechanisms do not offer dynamic control over the strength of the patterned vortex potential because they involve static nanostructures created in or near the superconductor. Dynamic control has been achieved with scanning probe methods on the single vortex level but these are difficult so scale up. Here, we show that by applying controllable nanopatterned current injection, the superconductor can be locally driven out of equilibrium, creating an artificial vortex potential that can be tuned by the magnitude of the injected current, yielding a unique vortex channeling effect.

  5. Effect of palytoxin on membrane and potential and current of frog myelinated fibers.

    Science.gov (United States)

    Dubois, J M; Cohen, J B

    1977-04-01

    Palytoxin is a highly toxic compound isolated form several zoanthid Palythoa species. The effects of palytoxin on the nodal membrane of frog myelinated fiber have been studied under current clamp and under voltage clamp conditions. Under current clamp conditions, palytoxin (0.1 microng/ml, 3 x 10(-8)M) induces a depolarization which is not reversed by washing. The resting potential reaches a value of -35 mV after 10 minutes. During the same period, the evoked action potential shows a gradual decline and finally disapears after about 30 minutes. The membrane depolarization is suppressed by removal of Na ions from the external medium, but only slightly diminished when tetrodotoxin (10(-6)M) is subsequently added to the external medium. When the potential of the nodal membrane is maintained at -70 mV, palytoxin (0.1 microng/ml) causes the appearance of an inward current that increases in magnitude during 30 minutes before attaining a steady-state value. The kinetics of development of that current is modified in the presence of tetrodotoxin or saxitoxin. Voltage clamp analysis shows that palytoxin causes an increase of the resting sodium permeability that is accompanied by a shift of the voltage dependence of the transient sodium permeability in the direction of membrane hyperpolarization. The shift in the voltage dependence of the transient permeability is accompanied by a decrease of the peak transient permeability. A similar shift in the potential dependence of the sodium inactivation is observed. During and after the application of palytoxin, the internal sodium concentration increases. The steady-state (potassium) conductance is also decreased at the same time as the leak current is increasing.

  6. Potential effects of climate change on a marine invasion: The importance of current context

    Directory of Open Access Journals (Sweden)

    Isabelle M. CÔTÉ, Stephanie J. GREEN

    2012-02-01

    Full Text Available Species invasions threaten marine biodiversity globally. There is a concern that climate change is exacerbating this problem. Here, we examined some of the potential effects of warming water temperatures on the invasion of Western Atlantic habitats by a marine predator, the Indo-Pacific lionfish (Pterois volitans and P. miles. We focussed on two temperature-dependent aspects of lionfish life-history and behaviour: pelagic larval duration, because of its link to dispersal potential, and prey consumption rate, because it is an important determinant of the impacts of lionfish on native prey. Using models derived from fundamental metabolic theory, we predict that the length of time spent by lionfish in the plankton in early life should decrease with warming temperatures, with a concomitant reduction in potential dispersal distance. Although the uncertainty around change in dispersal distances is large, predicted reductions are, on average, more than an order of magnitude smaller than the current rate of range expansion of lionfish in the Caribbean. Nevertheless, because shorter pelagic larval duration has the potential to increase local retention of larvae, local lionfish management will become increasingly important under projected climate change. Increasing temperature is also expected to worsen the current imbalance between rates of prey consumption by lionfish and biomass production by their prey, leading to a heightened decline in native reef fish biomass. However, the magnitude of climate-induced decline is predicted to be minor compared to the effect of current rates of lionfish population increases (and hence overall prey consumption rates on invaded reefs. Placing the predicted effects of climate change in the current context thus reveals that, at least for the lionfish invasion, the threat is clear and present, rather than future [Current Zoology 58 (1: 1–8, 2012].

  7. Euler potentials for two line currents aligned with an ambient uniform magnetic field

    Czech Academy of Sciences Publication Activity Database

    Romashets, E.; Vandas, Marek

    2011-01-01

    Roč. 116, A9 (2011), A09277/1-A09277/8 ISSN 0148-0227 R&D Projects: GA MŠk(CZ) ME09032; GA ČR GA205/09/0170 Institutional research plan: CEZ:AV0Z10030501 Keywords : magnetic field * Birkeland currents * Euler potentials Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.021, year: 2011

  8. Potential scour for marine current turbines based on experience of offshore wind turbine

    Science.gov (United States)

    Chen, L.; Lam, W. H.; Shamsuddin, A. H.

    2013-06-01

    The oceans have tremendous untapped natural resources. These sources are capable to make significant contribution to our future energy demands. Marine current energy offers sustainable and renewable alternative to conventional sources. Survival problems of Marine Current Turbines (MCTs) need to be addressed due to the harsh marine environment. The analogous researches in wind turbine have been conducted. Some of the results and knowledge are transferable to marine current energy industry. There still exist some gaps in the state of knowledge. Scour around marine structures have been well recognised as an engineering issue as scour is likely to cause structural instability. This paper aims to review different types of foundation of MCTs and potential scour and scour protection around these foundations based on the experience of offshore wind turbine farm.

  9. Evaluation of Cask Drop Criticality Issues at K Basin

    Energy Technology Data Exchange (ETDEWEB)

    GOLDMANN, L.H.

    2000-01-24

    An analysis of ability of Multi-canister Overpack (MCO) to withstand drops at K Basin without exceeding the criticality design requirements. Report concludes the MCO will function acceptably. The spent fuel currently residing in the 105 KE and 105 KW storage basins will be placed in fuel storage baskets which will be loaded into the MCO cask assembly. During the basket loading operations the MCO cask assembly will be positioned near the bottom of the south load out pit (SLOP). The loaded MCO cask will be lifted from the SLOP transferred to the transport trailer and delivered to the Cold Vacuum Drying Facility (CVDF). In the wet condition there is a potential for criticality problems if significant changes in the designed fuel configurations occur. The purpose of this report is to address structural issues associated with criticality design features for MCO cask drop accidents in the 105 KE and 105 KW facilities.

  10. Theoretical Analysis of Potential and Current Distributions in Planar Electrodes of Lithium-ion Batteries

    International Nuclear Information System (INIS)

    Taheri, Peyman; Mansouri, Abraham; Yazdanpour, Maryam; Bahrami, Majid

    2014-01-01

    An analytical model is proposed to describe the two-dimensional distribution of potential and current in planar electrodes of pouch-type lithium-ion batteries. A concentration-independent polarization expression, obtained experimentally, is used to mimic the electrochemical performance of the battery. By numerically solving the charge balance equation on each electrode in conjugation with the polarization expression, the battery behavior during constant-current discharge processes is simulated. Our numerical simulations show that reaction current between the electrodes remains approximately uniform during most of the discharge process, in particular, when depth-of-discharge varies from 5% to 85%. This observation suggests to simplify the electrochemical behavior of the battery such that the charge balance equation on each electrode can be solved analytically to obtain closed-form solutions for potential and current density distributions. The analytical model shows fair agreement with numerical data at modest computational cost. The model is applicable for both charge and discharge processes, and its application is demonstrated for a prismatic 20 Ah nickel-manganese-cobalt lithium-ion battery during discharge processes

  11. RF Rectification on LAPD and NSTX: the relationship between rectified currents and potentials

    Science.gov (United States)

    Perkins, R. J.; Carter, T.; Caughman, J. B.; van Compernolle, B.; Gekelman, W.; Hosea, J. C.; Jaworski, M. A.; Kramer, G. J.; Lau, C.; Martin, E. H.; Pribyl, P.; Tripathi, S. K. P.; Vincena, S.

    2017-10-01

    RF rectification is a sheath phenomenon important in the fusion community for impurity injection, hot spot formation on plasma-facing components, modifications of the scrape-off layer, and as a far-field sink of wave power. The latter is of particular concern for the National Spherical Torus eXperiment (NSTX), where a substantial fraction of the fast-wave power is lost to the divertor along scrape-off layer field lines. To assess the relationship between rectified currents and rectified voltages, detailed experiments have been performed on the Large Plasma Device (LAPD). An electron current is measured flowing out of the antenna and into the limiters, consistent with RF rectification with a higher RF potential at the antenna. The scaling of this current with RF power will be presented. The limiters are also floated to inhibit this DC current; the impact of this change on plasma-potential and wave-field measurements will be shown. Comparison to data from divertor probes in NSTX will be made. These experiments on a flexible mid-sized experiment will provide insight and guidance into the effects of ICRF on the edge plasma in larger fusion experiments. Funded by the DOE OFES (DE-FC02-07ER54918 and DE-AC02-09CH11466), NSF (NSF- PHY 1036140), and the Univ. of California (12-LR- 237124).

  12. Current and Future Potential Risk of Establishment of Grapholita molesta (Lepidoptera: Tortricidae) in Washington State.

    Science.gov (United States)

    Neven, Lisa G; Kumar, Sunil; Yee, Wee L; Wakie, Tewodros

    2018-02-17

    The oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is a primary pest of stone fruits that cause significant economic damage. Larvae, which enter the host plant through shoot tips, damage shoots, and ripe fruits. Native to Asia, this pest now occurs in many fruit-growing countries, including the United States and Canada. Though the pest was previously reported from many states within the United States, its current distribution and the environmental variables that influence its distribution are not properly identified. The objectives of this study were to 1) identify the environmental factors associated with G. molesta current distribution, 2) predict the current distribution of G. molesta in Washington State (WA) using Maxent and Climex models, 3) identify those areas within WA best suited for establishment of pest free zones, areas of low pest prevalence, and pest free production areas, and 4) identify regions most at risk for further expansion of G. molesta populations as a function of climate change. The current models predicted a small portion of central WA is suitable to support G. molesta, which is consistent with observed distributions. However, climate change models predict that more areas will become suitable for the pest. These results indicate that action should be taken to monitor and reduce current populations of G. molesta to stem its potential expansion into the major commercial tree fruit production areas in the state.

  13. Tunneling currents between carbon nanotubes inside the 3-dimensional potential of a dielectric matrix

    Science.gov (United States)

    Tsagarakis, M. S.; Xanthakis, J. P.

    2017-07-01

    We have examined the tunneling currents between CNTs dispersed in a dielectric matrix as is normally the case in a tensile stress or toxic gas sensors. Due to the randomness of the immersion process the CNTs are at random angles and configurations between them, thus producing a 3-dimensional potential (3-D). We have produced a method that solves the Laplace equation for this type of problem and uses the WKB formulation to calculate the transmission coefficient between CNTs. We have then shown that the tunneling currents between a pair of CNTs depend critically on their relative angle and configuration. In particular we have shown that the tunneling currents do not occur only along a CNT tip to CNT tip configuration but other more efficient paths exist which give a current higher by two orders of magnitude from what a simple 1D theory would give. On the other hand the tunneling current between non-coplanar CNTs is negligible. We conclude that such phenomena cannot be analyzed by a simple 1-dimensional WKB theory and the percolation threshold necessary for conduction may be lower than the one such a theory would predict.

  14. Mechanisms of generation of membrane potential resonance in a neuron with multiple resonant ionic currents.

    Directory of Open Access Journals (Sweden)

    David M Fox

    2017-06-01

    Full Text Available Neuronal membrane potential resonance (MPR is associated with subthreshold and network oscillations. A number of voltage-gated ionic currents can contribute to the generation or amplification of MPR, but how the interaction of these currents with linear currents contributes to MPR is not well understood. We explored this in the pacemaker PD neurons of the crab pyloric network. The PD neuron MPR is sensitive to blockers of H- (IH and calcium-currents (ICa. We used the impedance profile of the biological PD neuron, measured in voltage clamp, to constrain parameter values of a conductance-based model using a genetic algorithm and obtained many optimal parameter combinations. Unlike most cases of MPR, in these optimal models, the values of resonant- (fres and phasonant- (fϕ = 0 frequencies were almost identical. Taking advantage of this fact, we linked the peak phase of ionic currents to their amplitude, in order to provide a mechanistic explanation the dependence of MPR on the ICa gating variable time constants. Additionally, we found that distinct pairwise correlations between ICa parameters contributed to the maintenance of fres and resonance power (QZ. Measurements of the PD neuron MPR at more hyperpolarized voltages resulted in a reduction of fres but no change in QZ. Constraining the optimal models using these data unmasked a positive correlation between the maximal conductances of IH and ICa. Thus, although IH is not necessary for MPR in this neuron type, it contributes indirectly by constraining the parameters of ICa.

  15. Preliminary results of a pilot study investigating the potential of salivary cortisol measurements to detect occult adrenal suppression secondary to steroid nose drops.

    Science.gov (United States)

    Patel, R S; Wallace, A M; Hinnie, J; McGarry, G W

    2001-06-01

    Adrenocortical suppression is a well-known risk of systemic steroids, but is thought less likely to occur with topical intranasal corticosteroids. However, the UK Committee on the Safety of Medicines (UKCSM) has expressed concern about the possibility of this complication. We assessed the prevalence of adrenal suppression in patients with rhinitis using intranasal beclomethasone and betamethasone; and the potential value of salivary cortisol as a tool for detecting this complication. Sixty-six patients (38 men: 28 women; mean age 49.6[SD 16.0] years) were prospectively screened for adrenal insufficiency using clinical assessment and salivary cortisol measurements. Abnormalities at this initial screening were confirmed with a Short Synacthen Test (SST). No patient was clinically Cushingoid. All 22 beclomethasone users had normal salivary cortisols. Eleven (25%) of 44 patients using betamethasone had subnormal salivary cortisol levels (mean morning cortisol 2.8[SD 0.9]nmol/l) suggesting adrenal suppression, which was confirmed by an impaired SST in each case. The positive predictive value of salivary cortisol measurements was 100%. Only patients with abnormal salivary cortisols had a SST, so no comment can be made about sensitivity/specificity. Topical betamethasone may produce occult adrenal insufficiency and assessment of adrenal function is recommended in these patients. Measurement of salivary cortisol is a useful, non-invasive and economical test for monitoring patients using intranasal corticosteroids.

  16. Electrochemical Potential Influences Phenazine Production, Electron Transfer and Consequently Electric Current Generation by Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Erick M. Bosire

    2017-05-01

    Full Text Available Pseudomonas aeruginosa has gained interest as a redox mediator (phenazines producer in bioelectrochemical systems. Several biotic and abiotic factors influence the production of phenazines in synergy with the central virulence factors production regulation. It is, however, not clear how the electrochemical environment may influence the production and usage of phenazines by P. aeruginosa. We here determined the influence of the electrochemical potential on phenazine production and phenazine electron transfer capacity at selected applied potentials from -0.4 to +0.4 V (vs. Ag/AgClsat using P. aeruginosa strain PA14. Our study reveals a profound influence of the electrochemical potential on the amount of phenazine-1-carboxylate production, whereby applied potentials that were more positive than the formal potential of this dominating phenazine (E° ′PCA = -0.24 V vs. Ag/AgClsat stimulated more PCA production (94, 84, 128, and 140 μg mL-1 for -0.1, 0.1, 0.2, and 0.3 V, respectively compared to more reduced potentials (38, 75, and 7 μg mL-1 for -0.4, -0.3, and -0.24 V, respectively. Interestingly, P. aeruginosa seems to produce an additional redox mediator (with E° ′ ∼ 0.052 V at applied potentials below 0 V, which is most likely adsorbed to the electrode or present on the cells forming the biofilm around electrodes. At fairly negative applied electrode potentials, both PCA and the unknown redox compound mediate cathodic current generation. This study provides important insights applicable in optimizing the BES conditions and cultures for effective production and utilization of P. aeruginosa phenazines. It further stimulates investigations into the physiological impacts of the electrochemical environment, which might be decisive in the application of phenazines for electron transfer with P. aeruginosa pure- or microbial mixed cultures.

  17. Blood drop patterns: Formation and applications.

    Science.gov (United States)

    Chen, Ruoyang; Zhang, Liyuan; Zang, Duyang; Shen, Wei

    2016-05-01

    The drying of a drop of blood or plasma on a solid substrate leads to the formation of interesting and complex patterns. Inter- and intra-cellular and macromolecular interactions in the drying plasma or blood drop are responsible for the final morphologies of the dried patterns. Changes in these cellular and macromolecular components in blood caused by diseases have been suspected to cause changes in the dried drop patterns of plasma and whole blood, which could be used as simple diagnostic tools to identify the health of humans and livestock. However, complex physicochemical driving forces involved in the pattern formation are not fully understood. This review focuses on the scientific development in microscopic observations and pattern interpretation of dried plasma and whole blood samples, as well as the diagnostic applications of pattern analysis. Dried drop patterns of plasma consist of intricate visible cracks in the outer region and fine structures in the central region, which are mainly influenced by the presence and concentration of inorganic salts and proteins during drying. The shrinkage of macromolecular gel and its adhesion to the substrate surface have been thought to be responsible for the formation of the cracks. Dried drop patterns of whole blood have three characteristic zones; their formation as functions of drying time has been reported in the literature. Some research works have applied engineering treatment to the evaporation process of whole blood samples. The sensitivities of the resultant patterns to the relative humidity of the environment, the wettability of the substrates, and the size of the drop have been reported. These research works shed light on the mechanisms of spreading, evaporation, gelation, and crack formation of the blood drops on solid substrates, as well as on the potential applications of dried drop patterns of plasma and whole blood in diagnosis. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  18. Predicting the potential distribution in China of Euwallacea fornicates (Eichhoff) under current and future climate conditions.

    Science.gov (United States)

    Ge, Xuezhen; Jiang, Chao; Chen, Linghong; Qiu, Shuang; Zhao, Yuxiang; Wang, Tao; Zong, Shixiang

    2017-04-19

    Euwallacea fornicatus (Eichhoff) is an important forest pest that has caused serious damage in America and Vietnam. In 2014, it attacked forests of Acer trialatum in the Yunnan province of China, creating concern in China's Forestry Bureau. We used the CLIMEX model to predict and compare the potential distribution for E. fornicates in China under current (1981-2010) and projected climate conditions (2011-2040) using one scenario (RCP8.5) and one global climate model (GCM), CSIRO-Mk3-6-0. Under both current and future climate conditions, the model predicted E. fornicates to be mainly distributed in the south of China. Comparing distributions under both climate conditions showed that the area of potential distribution was projected to increase (mainly because of an increase in favourable habitat) and shift to the north. Our results help clarify the potential effect of climate change on the range of this forest pest and provide a reference and guide to facilitate its control in China.

  19. Point-of-care testing for respiratory viruses in adults: The current landscape and future potential.

    Science.gov (United States)

    Brendish, Nathan J; Schiff, Hannah F; Clark, Tristan W

    2015-11-01

    Respiratory viruses are responsible for a large proportion of acute respiratory illness in adults as well as children, and are associated with a huge socio-economic burden worldwide. Development of accurate point-of-care tests (POCT) for respiratory viruses has been listed as a priority by the World Health Organisation and replacing the current paradigm of empirical antimicrobial use with directed use is a listed goal of the movement for reduction in antimicrobial resistance. POCTs for respiratory viruses have previously been limited by the poor sensitivity of antigen detection based tests and by a limited range of detectable viruses. Highly accurate molecular platforms are now able to test for a comprehensive range of viruses, can be operated by non-laboratory staff and can generate a result in approximately 1 h, making them potentially deployable as POCTs. The potential clinical benefits of POC testing for respiratory viruses in adults include a reduction in unnecessary antibiotic use, improved antiviral prescribing for influenza and rationalisation of isolation facilities. We review here the burden of disease, the currently available molecular platforms with potential for POCT use and the existing evidence for clinical and economic benefits of testing for respiratory viruses in adults. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  20. Current State-of-the-Art MRI for Comprehensive Evaluation of Potential Living Liver Donors.

    Science.gov (United States)

    Jhaveri, Kartik S; Guo, Lijun; Guimarães, Luís

    2017-07-01

    This review focuses on the role of state-of-the-art MRI-based techniques for comprehensive evaluation of living donors providing single-visit assessment of the liver vasculature via MR angiography, of the biliary tract via conventional T2-weighted MR cholangiography and T1-weighted gadoxetate disodium-enhanced MR cholangiography, and of hepatic steatosis via T2*-corrected multiecho chemical shift-based water-fat separation MRI and high-speed T2-corrected multiecho MR spectroscopy. By using current state-of-the-art techniques, MRI can provide a one-stop-shop method for evaluation of the potential living liver donors.

  1. Predicting the potential distribution in China of Euwallacea fornicates (Eichhoff) under current and future climate conditions

    OpenAIRE

    Ge, Xuezhen; Jiang, Chao; Chen, Linghong; Qiu, Shuang; Zhao, Yuxiang; Wang, Tao; Zong, Shixiang

    2017-01-01

    Euwallacea fornicatus (Eichhoff) is an important forest pest that has caused serious damage in America and Vietnam. In 2014, it attacked forests of Acer trialatum in the Yunnan province of China, creating concern in China?s Forestry Bureau. We used the CLIMEX model to predict and compare the potential distribution for E. fornicates in China under current (1981?2010) and projected climate conditions (2011?2040) using one scenario (RCP8.5) and one global climate model (GCM), CSIRO-Mk3-6-0. Unde...

  2. µ-Conotoxins Modulating Sodium Currents in Pain Perception and Transmission: A Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Elisabetta Tosti

    2017-09-01

    Full Text Available The Conus genus includes around 500 species of marine mollusks with a peculiar production of venomous peptides known as conotoxins (CTX. Each species is able to produce up to 200 different biological active peptides. Common structure of CTX is the low number of amino acids stabilized by disulfide bridges and post-translational modifications that give rise to different isoforms. µ and µO-CTX are two isoforms that specifically target voltage-gated sodium channels. These, by inducing the entrance of sodium ions in the cell, modulate the neuronal excitability by depolarizing plasma membrane and propagating the action potential. Hyperexcitability and mutations of sodium channels are responsible for perception and transmission of inflammatory and neuropathic pain states. In this review, we describe the current knowledge of µ-CTX interacting with the different sodium channels subtypes, the mechanism of action and their potential therapeutic use as analgesic compounds in the clinical management of pain conditions.

  3. Bone Marrow Stem Cell Derived Paracrine Factors for Regenerative Medicine: Current Perspectives and Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Tom J. Burdon

    2011-01-01

    Full Text Available During the past several years, there has been intense research in the field of bone marrow-derived stem cell (BMSC therapy to facilitate its translation into clinical setting. Although a lot has been accomplished, plenty of challenges lie ahead. Furthermore, there is a growing body of evidence showing that administration of BMSC-derived conditioned media (BMSC-CM can recapitulate the beneficial effects observed after stem cell therapy. BMSCs produce a wide range of cytokines and chemokines that have, until now, shown extensive therapeutic potential. These paracrine mechanisms could be as diverse as stimulating receptor-mediated survival pathways, inducing stem cell homing and differentiation or regulating the anti-inflammatory effects in wounded areas. The current review reflects the rapid shift of interest from BMSC to BMSC-CM to alleviate many logistical and technical issues regarding cell therapy and evaluates its future potential as an effective regenerative therapy.

  4. [Ion currents through batrachotoxin-modified sodium channels of node of Ranvier membranes at high positive and negative potentials].

    Science.gov (United States)

    Mozhaeva, G N; Naumova, A P; Khodorov, B I

    1983-01-01

    Ionic currents through batrachotoxin-modified sodium channels in frog nerve fibres were measured over a wide range of membrane potentials. At potentials above +80 mV currents decay in time and their steady-state level decreased as potentials increased. "Instantaneous" current measurements have shown that this phenomenon was due to the decrease in net channel conductance. Scorpion toxin affected current kinetics only slightly at these potentials, which suggested that these decays were not caused by usual inactivation process. Externally applied procaine induced slow (tens of ms) potential-dependent block of batrachotoxin-modified channels at large positive potentials. At large negative potentials (above -100 mV) "instantaneus" currents decreased due to fast voltage-dependent block of the channels by calcium ions.

  5. Modelization of the Current and Future Habitat Suitability of Rhododendron ferrugineum Using Potential Snow Accumulation.

    Directory of Open Access Journals (Sweden)

    Benjamin Komac

    Full Text Available Mountain areas are particularly sensitive to climate change. Species distribution models predict important extinctions in these areas whose magnitude will depend on a number of different factors. Here we examine the possible impact of climate change on the Rhododendron ferrugineum (alpenrose niche in Andorra (Pyrenees. This species currently occupies 14.6 km2 of this country and relies on the protection afforded by snow cover in winter. We used high-resolution climatic data, potential snow accumulation and a combined forecasting method to obtain the realized niche model of this species. Subsequently, we used data from the high-resolution Scampei project climate change projection for the A2, A1B and B1 scenarios to model its future realized niche model. The modelization performed well when predicting the species's distribution, which improved when we considered the potential snow accumulation, the most important variable influencing its distribution. We thus obtained a potential extent of about 70.7 km(2 or 15.1% of the country. We observed an elevation lag distribution between the current and potential distribution of the species, probably due to its slow colonization rate and the small-scale survey of seedlings. Under the three climatic scenarios, the realized niche model of the species will be reduced by 37.9-70.1 km(2 by the end of the century and it will become confined to what are today screes and rocky hillside habitats. The particular effects of climate change on seedling establishment, as well as on the species' plasticity and sensitivity in the event of a reduction of the snow cover, could worsen these predictions.

  6. Modelization of the Current and Future Habitat Suitability of Rhododendron ferrugineum Using Potential Snow Accumulation.

    Science.gov (United States)

    Komac, Benjamin; Esteban, Pere; Trapero, Laura; Caritg, Roger

    2016-01-01

    Mountain areas are particularly sensitive to climate change. Species distribution models predict important extinctions in these areas whose magnitude will depend on a number of different factors. Here we examine the possible impact of climate change on the Rhododendron ferrugineum (alpenrose) niche in Andorra (Pyrenees). This species currently occupies 14.6 km2 of this country and relies on the protection afforded by snow cover in winter. We used high-resolution climatic data, potential snow accumulation and a combined forecasting method to obtain the realized niche model of this species. Subsequently, we used data from the high-resolution Scampei project climate change projection for the A2, A1B and B1 scenarios to model its future realized niche model. The modelization performed well when predicting the species's distribution, which improved when we considered the potential snow accumulation, the most important variable influencing its distribution. We thus obtained a potential extent of about 70.7 km(2) or 15.1% of the country. We observed an elevation lag distribution between the current and potential distribution of the species, probably due to its slow colonization rate and the small-scale survey of seedlings. Under the three climatic scenarios, the realized niche model of the species will be reduced by 37.9-70.1 km(2) by the end of the century and it will become confined to what are today screes and rocky hillside habitats. The particular effects of climate change on seedling establishment, as well as on the species' plasticity and sensitivity in the event of a reduction of the snow cover, could worsen these predictions.

  7. Current and potential trade in horticultural products irradiated for phytosanitary purposes

    International Nuclear Information System (INIS)

    Bustos-Griffin, Emilia; Hallman, Guy J.; Griffin, Robert L.

    2012-01-01

    The current status of trade in horticultural products irradiated for phytosanitary purposes is examined, including trends, strengths and weaknesses. A strategy is proposed to take advantage of the best future opportunities for increasing trade in irradiated horticultural products by identifying best possibilities for expanding both the number and volume of commodities for irradiation and then applying appropriate business criteria in a general analysis of the commodities, commercial scenarios, and geographic regions where the greatest potential exists for expansion. The results show that fresh fruits such as mango, papaya, citrus, grapes, and vegetables such as tomatoes, onions, asparagus, garlic, and peppers from Asia and the Americas show the greatest potential. Substantial opportunities for additional growth exist, especially as regulatory conditions become more favorable. - Highlights: ► This research examined the trade in horticultural products irradiated for Phytosanitary purposes. ► Paper describes strategies for enhancing trade in irradiated horticultural products. ► Results identify commodities and regions with the greatest potential. ► Additional growth potential exists, especially as regulatory conditions become more favorable.

  8. Fly ashes from coal and petroleum coke combustion: current and innovative potential applications.

    Science.gov (United States)

    González, Aixa; Navia, Rodrigo; Moreno, Natalia

    2009-12-01

    Coal fly ashes (CFA) are generated in large amounts worldwide. Current combustion technologies allow the burning of fuels with high sulfur content such as petroleum coke, generating non-CFA, such as petroleum coke fly ash (PCFA), mainly from fluidized bed combustion processes. The disposal of CFA and PCFA fly ashes can have severe impacts in the environment such as a potential groundwater contamination by the leaching of heavy metals and/or particulate matter emissions; making it necessary to treat or reuse them. At present CFA are utilized in several applications fields such as cement and concrete production, agriculture and soil stabilization. However, their reuse is restricted by the quality parameters of the end-product or requirements defined by the production process. Therefore, secondary material markets can use a limited amount of CFA, which implies the necessity of new markets for the unused CFA. Some potential future utilization options reviewed herein are zeolite synthesis and valuable metals extraction. In comparison to CFA, PCFA are characterized by a high Ca content, suggesting a possible use as neutralizers of acid wastewaters from mining operations, opening a new potential application area for PCFA that could solve contamination problems in emergent and mining countries such as Chile. However, this potential application may be limited by PCFA heavy metals leaching, mainly V and Ni, which are present in PCFA in high concentrations.

  9. Migration study of 1,3-butadiene in eye-drop solutions.

    Science.gov (United States)

    Pistos, Constantinos; Karampela, Sevasti; Vardakou, Ioanna; Papoutsis, Ioannis; Spiliopoulou, Chara; Athanaselis, Sotiris

    2012-07-01

    The potential deleterious effects of extractables/leachables in pharmaceutical products led the USP, EP, and JP to require extractable and toxicity testing of container/closure systems. To that, a headspace gas chromatography flame ionization detection method was developed and validated for the determination of 1,3-butadiene (1,3-BD) as a potential extractable residue from a pharmaceutical container/closure system into eye-drop solutions. A migration study was further applied in eight eye-drop solutions (currently marketed products) after short- and long-term exposure of these products at various temperatures. This method allows the establishment of safety-qualification thresholds for 1,3-BD being capable of monitoring eye-drop solution products for this residue.

  10. Nonequivalence of the magnetostatic potential energy corresponding to the Ampère and Grassmann current element force formulas

    International Nuclear Information System (INIS)

    Minteer, Timothy M

    2013-01-01

    The equivalence of the Ampère and Grassmann (Biot–Savart/Lorentz) current element force formulas is well established. However, when the magnetostatic potential energy corresponding to these force formulas is evaluated, the formulas are found to be nonequivalent. The historical current element force formulas are first presented. The magnetostatic potential energy corresponding to these historical current element force formulas are then analysed. The end result establishes the Grassmann and Neumann current element force formulas as the only commonly referenced formulas giving the correct magnetostatic potential energy for circuital currents. (paper)

  11. Biphasic response of action potential duration to metabolic inhibition in rabbit and human ventricular myocytes: role of transient outward current and ATP-regulated potassium current

    NARCIS (Netherlands)

    Verkerk, A. O.; Veldkamp, M. W.; van Ginneken, A. C.; Bouman, L. N.

    1996-01-01

    Inhibition of cell metabolism is associated with significant changes in action potential duration. The aim of this study was to investigate the time course of the changes in action potential duration during metabolic inhibition and to determine what changes in membrane currents are responsible. The

  12. Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

    International Nuclear Information System (INIS)

    Frank, A; Heller, R; Goldacker, W; Kling, A; Schmidt, C

    2008-01-01

    Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability

  13. Acoustic noise alters selective attention processes as indicated by direct current (DC) brain potential changes.

    Science.gov (United States)

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-09-26

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts-which are discussed to represent different states of cortical activation-of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest-besides some limitations-that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested "attention shift". Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed.

  14. Acoustic Noise Alters Selective Attention Processes as Indicated by Direct Current (DC Brain Potential Changes

    Directory of Open Access Journals (Sweden)

    Karin Trimmel

    2014-09-01

    Full Text Available Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes. This study investigated brain direct current (DC potential shifts—which are discussed to represent different states of cortical activation—of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest—besides some limitations—that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested “attention shift”. Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed.

  15. Current source density analysis of the potential evoked in hippocampus by perirhinal cortex stimulation.

    Science.gov (United States)

    Liu, P; Bilkey, D K

    1997-01-01

    Previous anatomical research has demonstrated that the perirhinal cortex (PRC) projects to the dorsal hippocampal CA1 field. We have recently presented data (Liu and Bilkey, Hippocampus 1996; 6:125-135) which suggests that this pathway courses via the lateral perforant path (LPP). In the present study, laminar profiles of the average evoked potentials and current source density (CSD) analysis were used to study the input from the perirhinal cortex to the dorsal hippocampus in the urethane-anaesthetized rat. Stimulation of the lateral perforant path activated a current sink in the stratum lacunosum-moleculare of CA1 and the outer molecular layer of the dentate gyrus with an onset latency of 3.5 ms. Stimulation of the perirhinal cortex produced a very similar sink-source pattern with an onset latency of 4.0 ms. Higher-intensity stimulation of lateral entorhinal cortex also produced a similar pattern with an onset latency of 4.5 ms. Electrolytic lesions of PRC conducted 4-5 days prior to testing resulted in a major decrease (58%) in the amplitude of the LPP-elicited potentials and a corresponding reduction across the whole source-sink pattern. A similar result was observed following ibotenic acid lesions of PRC. In contrast, similar-sized electrolytic lesions of lateral entorhinal cortex produced a much smaller (16%) decrease in potential amplitude and little change in the source-sink pattern. These data provide further support for the hypothesis that perirhinal cortex projects to both the dentate gyrus and CA1 regions of the hippocampus via the lateral perforant path.

  16. Inflammatory mediators potentiate high affinity GABA(A) currents in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Lee, Kwan Yeop; Gold, Michael S

    2012-06-19

    Following acute tissue injury action potentials may be initiated in afferent processes terminating in the dorsal horn of the spinal cord that are propagated back out to the periphery, a process referred to as a dorsal root reflex (DRR). The DRR is dependent on the activation of GABA(A) receptors. The prevailing hypothesis is that DRR is due to a depolarizing shift in the chloride equilibrium potential (E(Cl)) following an injury-induced activation of the Na(+)-K(+)-Cl(-)-cotransporter. Because inflammatory mediators (IM), such as prostaglandin E(2) are also released in the spinal cord following tissue injury, as well as evidence that E(Cl) is already depolarized in primary afferents, an alternative hypothesis is that an IM-induced increase in GABA(A) receptor mediated current (I(GABA)) could underlie the injury-induced increase in DRR. To test this hypothesis, we explored the impact of IM (prostaglandin E(2) (1 μM), bradykinin (10 μM), and histamine (1 μM)) on I(GABA) in dissociated rat dorsal root ganglion (DRG) neurons with standard whole cell patch clamp techniques. IM potentiated I(GABA) in a subpopulation of medium to large diameter capsaicin insensitive DRG neurons. This effect was dependent on the concentration of GABA, manifest only at low concentrations (emergence of injury-induced DRR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Current and potential carbon stocks in Moso bamboo forests in China.

    Science.gov (United States)

    Li, Pingheng; Zhou, Guomo; Du, Huaqiang; Lu, Dengsheng; Mo, Lufeng; Xu, Xiaojun; Shi, Yongjun; Zhou, Yufeng

    2015-06-01

    Bamboo forests provide important ecosystem services and play an important role in terrestrial carbon cycling. Of the approximately 500 bamboo species in China, Moso bamboo (Phyllostachys pubescens) is the most important one in terms of distribution, timber value, and other economic values. In this study, we estimated current and potential carbon stocks in China's Moso bamboo forests and in their products. The results showed that Moso bamboo forests in China stored about 611.15 ± 142.31 Tg C, 75% of which was in the top 60 cm soil, 22% in the biomass of Moso bamboos, and 3% in the ground layer (i.e., bamboo litter, shrub, and herb layers). Moso bamboo products store 10.19 ± 2.54 Tg C per year. The potential carbon stocks reach 1331.4 ± 325.1 Tg C, while the potential C stored in products is 29.22 ± 7.31 Tg C a(-1). Our results indicate that Moso bamboo forests and products play a critical role in C sequestration. The information gained in this study will facilitate policy decisions concerning carbon sequestration and management of Moso bamboo forests in China. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Soil organic carbon of an intensively reclaimed region in China: Current status and carbon sequestration potential.

    Science.gov (United States)

    Deng, Xunfei; Zhan, Yu; Wang, Fei; Ma, Wanzhu; Ren, Zhouqiao; Chen, Xiaojia; Qin, Fangjin; Long, Wenli; Zhu, Zhenling; Lv, Xiaonan

    2016-09-15

    Land reclamation has been highly intensive in China, resulting in a large amount of soil organic carbon (SOC) loss to the atmosphere. Evaluating the factors which drive SOC dynamics and carbon sequestration potential in reclaimed land is critical for improving soil fertility and mitigating global warming. This study aims to determine the current status and factors important to the SOC density in a typical reclaimed land located in Eastern China, where land reclamation has been undergoing for centuries. A total of 4746 topsoil samples were collected from 2007 to 2010. The SOC density of the reclaimed land (3.18±0.05kgCm(-2); mean±standard error) is significantly lower than that of the adjacent non-reclaimed land (5.71±0.04kgCm(-2)) (pcarbon sequestration potential of the reclaimed lands may achieve a maximum of 5.80±1.81kgCO2m(-2) (mean±SD) when dryland is converted to flooded land with vegetable-rice cropping system and soil pH of ~5.9. Note that in some scenarios the methane emission substantially offsets the carbon sequestration potential, especially for continuous rice cropping system. With the optimal setting for carbon sequestration, it is estimated that the dryland reclaimed in the last 50years in China is able to sequester 0.12milliontons CO2 equivalent per year. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Kevin

    2013-09-15

    Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States. This project created a national database of ocean current energy resources to help advance awareness and market penetration in ocean current energy resource assessment. The database, consisting of joint velocity magnitude and direction probability histograms, was created from data created by seven years of numerical model simulations. The accuracy of the database was evaluated by ORNL?s independent validation effort documented in a separate report. Estimates of the total theoretical power resource contained in the ocean currents were calculated utilizing two separate approaches. Firstly, the theoretical energy balance in the Gulf Stream system was examined using the two-dimensional ocean circulation equations based on the assumptions of the Stommel model for subtropical gyres with the quasi-geostrophic balance between pressure gradient, Coriolis force, wind stress and friction driving the circulation. Parameters including water depth, natural dissipation rate and wind stress are calibrated in the model so that the model can reproduce reasonable flow properties including volume flux and energy flux. To represent flow dissipation due to turbines additional turbine drag coefficient is formulated and included in the model. Secondly, to determine the reasonableness of the total power

  20. First drop dissimilarity in drop-on-demand inkjet devices

    International Nuclear Information System (INIS)

    Famili, Amin; Palkar, Saurabh A.; Baldy, William J. Jr.

    2011-01-01

    As inkjet printing technology is increasingly applied in a broader array of applications, careful characterization of its method of use is critical due to its inherent sensitivity. A common operational mode in inkjet technology known as drop-on-demand ejection is used as a way to deliver a controlled quantity of material to a precise location on a target. This method of operation allows ejection of individual or a sequence (burst) of drops based on a timed trigger event. This work presents an examination of sequences of drops as they are ejected, indicating a number of phenomena that must be considered when designing a drop-on-demand inkjet system. These phenomena appear to be driven by differences between the first ejected drop in a burst and those that follow it and result in a break-down of the linear relationship expected between driving amplitude and drop mass. This first drop, as quantified by high-speed videography and subsequent image analysis, can be different in morphology, trajectory, velocity, and volume from subsequent drops within a burst. These findings were confirmed orthogonally by both volume and mass measurement techniques which allowed quantitation down to single drops.

  1. Lifetime of oil drops pressed by buoyancy against a planar interface: Large drops

    Science.gov (United States)

    Rojas, Clara; García-Sucre, Máximo; Urbina-Villalba, Germán

    2010-11-01

    In a previous report [C. Rojas, G. Urbina-Villalba, and M. García-Sucre, Phys. Rev. E 81, 016302 (2010)10.1103/PhysRevE.81.016302] it was shown that emulsion stability simulations are able to reproduce the lifetime of micrometer-size drops of hexadecane pressed by buoyancy against a planar water-hexadecane interface. It was confirmed that small drops (ri<10μm) stabilized with β -casein behave as nondeformable particles, moving with a combination of Stokes and Taylor tensors as they approach the interface. Here, a similar methodology is used to parametrize the potential of interaction of drops of soybean oil stabilized with bovine serum albumin. The potential obtained is then employed to study the lifetime of deformable drops in the range 10≤ri≤1000μm . It is established that the average lifetime of these drops can be adequately replicated using the model of truncated spheres. However, the results depend sensibly on the expressions of the initial distance of deformation and the maximum film radius used in the calculations. The set of equations adequate for large drops is not satisfactory for medium-size drops (10≤ri≤100μm) , and vice versa. In the case of large particles, the increase in the interfacial area as a consequence of the deformation of the drops generates a very large repulsive barrier which opposes coalescence. Nevertheless, the buoyancy force prevails. As a consequence, it is the hydrodynamic tensor of the drops which determine the characteristic behavior of the lifetime as a function of the particle size. While the average values of the coalescence time of the drops can be justified by the mechanism of film thinning, the scattering of the experimental data of large drops cannot be rationalized using the methodology previously described. A possible explanation of this phenomenon required elaborate simulations which combine deformable drops, capillary waves, repulsive interaction forces, and a time-dependent surfactant adsorption.

  2. Spread of pathogens through rain drop impact

    Science.gov (United States)

    Kim, Seungho; Gruszewski, Hope; Gidley, Todd; Schmale, David G., III; Jung, Sunghwan

    2017-11-01

    Rain drop impact can disperse micron-sized pathogenic particles over long distances. In this study, we aim to elucidate mechanisms for disease dispersal when a rain drop impacts a particle-laden solid surface. Three different dispersal types were observed depending on whether the dispersed glass particles were dry or wet. For a dry particle dispersal, the movement of contact line made the particles initially jump off the surface with relatively high velocity. Then, air vortex was formed due to the air current entrained along with the falling drop, and advected the particles with relatively low velocity. For a wet particle dispersal, the contact line of a spreading liquid became unstable due to the presence of the particles on the substrate. This caused splashing at the contact line and ejected liquid droplets carrying the particles. Finally, we released a drop onto wheat plants infected with the rust fungus, Puccinia triticina, and found that nearly all of the satellite droplets from a single drop contained at least one rust spore. Also, we visualized such novel dispersal dynamics with a high-speed camera and characterized their features by scaling models. This research was partially supported by National Science Foundation Grant CBET-1604424.

  3. Current EU-27 technical potential of organic waste streams for biogas and energy production.

    Science.gov (United States)

    Lorenz, Helge; Fischer, Peter; Schumacher, Britt; Adler, Philipp

    2013-11-01

    Anaerobic digestion of organic waste generated by households, businesses, agriculture, and industry is an important approach as method of waste treatment - especially with regard to its potential as an alternative energy source and its cost-effectiveness. Separate collection of biowaste from households or vegetal waste from public green spaces is already established in some EU-27 countries. The material recovery in composting plants is common for biowaste and vegetal waste. Brewery waste fractions generated by beer production are often used for animal feeding after a suitable preparation. Waste streams from paper industry generated by pulp and paper production such as black liquor or paper sludge are often highly contaminated with toxic substances. Recovery of chemicals and the use in thermal processes like incineration, pyrolysis, and gasification are typical utilization paths. The current utilization of organic waste from households and institutions (without agricultural waste) was investigated for EU-27 countries with Germany as an in-depth example. Besides of biowaste little is known about the suitability of waste streams from brewery and paper industry for anaerobic digestion. Therefore, an evaluation of the most important biogas process parameters for different substrates was carried out, in order to calculate the biogas utilization potential of these waste quantities. Furthermore, a calculation of biogas energy potentials was carried out for defined waste fractions which are most suitable for anaerobic digestion. Up to 1% of the primary energy demand can be covered by the calculated total biogas energy potential. By using a "best-practice-scenario" for separately collected biowaste, the coverage of primary energy demand may be increased above 2% for several countries. By using sector-specific waste streams, for example the German paper industry could cover up to 4.7% and the German brewery industry up to 71.2% of its total energy demand. Copyright © 2013

  4. Modeling the yield potential of dryland canola under current and future climates in California

    Science.gov (United States)

    George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.

    2012-12-01

    -adapted canola varieties can be justified, and the potential value of a California canola industry both now and in the future. Winter annual crops like canola use rainfall in a Mediterranean climate like California more efficiently than spring or summer crops. Our results suggest that under current production costs and seed prices, dry farmed canola will have good potential in certain areas of the California. Canola yields decline with annual winter precipitation, however economically viable yields are still achieved at relatively precipitation levels (200 mm). Results from simulation, combined with related economic modeling (reported elsewhere) suggest that canola will be viable in a variety of production systems in the northern Sacramento Valley and some coastal locations, even under drier future climate scenarios. The in-field evaluation of Australian canola varieties should contribute to maintain or improving resource use efficiency and farm profitability.

  5. The potential of large critical currents in the high Tc oxides

    International Nuclear Information System (INIS)

    Deutcher, G.

    1993-01-01

    The potential for high critical current densities is examined. on a thermodynamical basis, the energy scale for vortex pinning can be derived for instance from a measurement of the width of the critical region. This energy scale is of the order of 0.2 eV in YBCO, which is sufficient for practical applications. Another important parameter is the short coherence length. The inner plane length, of the order of a few lattice spacing, is favorable for pinning by point defects. But the very short outer plane length gives rise to anomalous magnetic behavior, unfavorable for high-field applications at high temperature; this is true in particular in most anisotropic oxides, such as the Bi compounds (author)

  6. Current status and future potential of energy derived from Chinese agricultural land: a review.

    Science.gov (United States)

    Zhai, Ningning; Mao, Chunlan; Feng, Yongzhong; Zhang, Tong; Xing, Zhenjie; Wang, Yanhong; Zou, Shuzhen; Yin, Dongxue; Han, Xinhui; Ren, Guangxin; Yang, Gaihe

    2015-01-01

    Energy crisis is receiving attention with regard to the global economy and environmental sustainable development. Developing new energy resources to optimize the energy supply structure has become an important measure to prevent energy shortage as well as achieving energy conservation and emission reduction in China. This study proposed the concept of energy agriculture and constructed an energy agricultural technical support system based on the analysis of energy supply and demand and China's foreign dependence on energy resources, combined with the function of agriculture in the energy field. Manufacturing technology equipment and agricultural and forestry energy, including crop or forestry plants and animal feces, were used in the system. The current status and future potential of China's marginal land resources, energy crop germplasm resources, and agricultural and forestry waste energy-oriented resources were analyzed. Developing the function of traditional agriculture in food production may promote China's social, economic, and environmental sustainable development and achieve energy saving and emission reduction.

  7. Guided current-induced skyrmion motion in 1D potential well.

    Science.gov (United States)

    Purnama, I; Gan, W L; Wong, D W; Lew, W S

    2015-05-29

    Magnetic skyrmions are particle-like magnetization configurations which can be found in materials with broken inversion symmetry. Their topological nature allows them to circumvent around random pinning sites or impurities as they move within the magnetic layer, which makes them interesting as information carriers in memory devices. However, when the skyrmion is driven by a current, a Magnus force is generated which leads to the skyrmion moving away from the direction of the conduction electron flow. The deflection poses a serious problem to the realization of skyrmion-based devices, as it leads to skyrmion annihilation at the film edges. Here, we show that it is possible to guide the movement of the skyrmion and prevent it from annihilating by surrounding and compressing the skyrmion with strong local potential barriers. The compressed skyrmion receives higher contribution from the spin transfer torque, which results in the significant increase of the skyrmion speed.

  8. Cranberry as promising natural source of potential anticancer agents: current evidence and future perspectives.

    Science.gov (United States)

    Katsargyris, Athanasios; Tampaki, Ekaterini-Christina; Giaginis, Constantinos; Theocharis, Stamatios

    2012-07-01

    Accumulating evidence suggest that dietary modification can lower the risk for several cancer types' development. Cranberry in particular, has been shown to have anti-oxidative, -inflammatory and -proliferative properties in vitro. To present the latest knowledge regarding the role of cranberry extracts against human cancer several types. A review of the literature documenting both in vitro and in vivo anti-cancer effects of whole cranberry and/or its extracts is conducted. Current data provide evidence for several anti-cancer properties of either whole cranberry and/or its extracts. The discovery of the specific cranberry components and the appropriate concentrations that exert such beneficial effects along with verification of the preliminary in vitro results in in vivo settings could potentially lead to the invention of novel safer and efficient anti-cancer therapeutic agents.

  9. Current knowledge and potential applications of cavitation technologies for the petroleum industry.

    Science.gov (United States)

    Avvaru, Balasubrahmanyam; Venkateswaran, Natarajan; Uppara, Parasuveera; Iyengar, Suresh B; Katti, Sanjeev S

    2018-04-01

    Technologies based on cavitation, produced by either ultrasound or hydrodynamic means, are part of growing literature for individual refinery unit processes. In this review, we have explained the mechanism through which these cavitation technologies intensify individual unit processes such as enhanced oil recovery, demulsification of water in oil emulsions during desalting stage, crude oil viscosity reduction, oxidative desulphurisation/demetallization, and crude oil upgrading. Apart from these refinery processes, applications of this technology are also mentioned for other potential crude oil sources such as oil shale and oil sand extraction. The relative advantages and current situation of each application/process at commercial scale is explained. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Marine Benthic Habitats and Seabed Suitability Mapping for Potential Ocean Current Energy Siting Offshore Southeast Florida

    Directory of Open Access Journals (Sweden)

    Amanda Mulcan

    2015-05-01

    Full Text Available This study examines the legal framework for ocean current energy policy and regulation to develop a metric for assessing the biological and geological characteristics of a seabed area with respect to the siting of OCE devices, a framework of criteria by which to assess seabed suitability (seabed suitability framework that can facilitate the siting, and implementation of ocean current energy (OCE projects. Seafloor geology and benthic biological data were analyzed in conjunction with seafloor core sample geostatistical interpolation to locate suitable substrates for OCE anchoring. Existing submarine cable pathways were considered to determine pathways for power transmission cables that circumvent biologically sensitive areas. Suitability analysis indicates that areas east of the Miami Terrace and north of recently identified deep-sea coral mounds are the most appropriate for OCE siting due to abundance of sand/sediment substrate, existing underwater cable route access, and minimal biological presence (i.e., little to no benthic communities. Further reconnaissance requires higher resolution maps of geological substrate and benthic community locations to identify specific OCE development locations, classify benthic conditions, and minimize potentially negative OCE environmental impacts.

  11. The Barrett-Lennard Relationship Inventory (BLRI): current and potential uses with family systems.

    Science.gov (United States)

    Ganley, R M

    1989-03-01

    The search for and measurement of important relationship qualities have always been of interest to family therapists. Within a Rogerian perspective, empathy, regard, and congruence are believed to be among the most important indicators of the quality of human relationships. These variables, or conceptually similar ones, are also important in several current models of family functioning. Barrett-Lennard (1,2) developed an instrument, the Barrett-Lennard Relationship Inventory (BLRI), to measure empathy, regard, and congruence. Although the major use of the BLRI has been in psychotherapy outcome research (13), several studies have shown that it is a sensitive indicator of marital satisfaction and of changes occurring in marital-improvement programs. The present study is a factor analysis of the BLRI based on data from 345 women who rated levels of empathy, regard, and congruence in their relationship with their husbands. The results robustly confirm the three-factor structure of the BLRI in what is believed to be the first factor analysis in the context of a family member rating a relationship within the family. The replication of the BLRI's structure in a new relationship context suggests that the dimensions tapped by the BLRI may have some generality and warrant further exploration in a family-systems context. Several advantages of the BLRI over other currently available instruments are discussed, as are potential uses of the BLRI in systems research beyond the marital unit.

  12. Improvement Strategies, Cost Effective Production, and Potential Applications of Fungal Glucose Oxidase (GOD): Current Updates.

    Science.gov (United States)

    Dubey, Manish K; Zehra, Andleeb; Aamir, Mohd; Meena, Mukesh; Ahirwal, Laxmi; Singh, Siddhartha; Shukla, Shruti; Upadhyay, Ram S; Bueno-Mari, Ruben; Bajpai, Vivek K

    2017-01-01

    Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.

  13. Endomorphins potentiate acid-sensing ion channel currents and enhance the lactic acid-mediated increase in arterial blood pressure: effects amplified in hindlimb ischaemia.

    Science.gov (United States)

    Farrag, Mohamed; Drobish, Julie K; Puhl, Henry L; Kim, Joyce S; Herold, Paul B; Kaufman, Marc P; Ruiz-Velasco, Victor

    2017-12-01

    Chronic limb ischaemia, characterized by inflammatory mediator release and a low extracellular pH, leads to acid-sensing ion channel (ASIC) activation and reflexively increases mean arterial pressure; endomorphin release is also increased under inflammatory conditions. We examined the modulation of ASIC currents by endomorphins in sensory neurons from rats with freely perfused and ligated femoral arteries: peripheral artery disease (PAD) model. Endomorphins potentiated sustained ASIC currents in both groups of dorsal root ganglion neurons, independent of mu opioid receptor stimulation or G protein activation. Intra-arterial administration of lactic acid (to simulate exercising muscle and evoke a pressor reflex), endomorphin-2 and naloxone resulted in a significantly greater pressor response than lactic acid alone, while administration of APETx2 inhibited endomorphin's enhancing effect in both groups. These results suggest a novel role for endomorphins in modulating ASIC function to effect lactic acid-mediated reflex increase in arterial pressure in patients with PAD. Chronic muscle ischaemia leads to accumulation of lactic acid and other inflammatory mediators with a subsequent drop in interstitial pH. Acid-sensing ion channels (ASICs), expressed in thin muscle afferents, sense the decrease in pH and evoke a pressor reflex known to increase mean arterial pressure. The naturally occurring endomorphins are also released by primary afferents under ischaemic conditions. We examined whether high affinity mu opioid receptor (MOR) agonists, endomorphin-1 (E-1) and -2 (E-2), modulate ASIC currents and the lactic acid-mediated pressor reflex. In rat dorsal root ganglion (DRG) neurons, exposure to E-2 in acidic solutions significantly potentiated ASIC currents when compared to acidic solutions alone. The potentiation was significantly greater in DRG neurons isolated from rats whose femoral arteries were ligated for 72 h. Sustained ASIC current potentiation was also observed

  14. Student Drop-Out from German Higher Education Institutions

    Science.gov (United States)

    Heublein, Ulrich

    2014-01-01

    28% of students of any one year currently give up their studies in bachelor degree programmes at German higher education institutions. Drop-out is to be understood as the definite termination in the higher education system without obtaining an academic degree. The drop-out rate is thereby calculated with the help of statistical estimation…

  15. Mesenchymal Stem Cells and Metabolic Syndrome: Current Understanding and Potential Clinical Implications

    Directory of Open Access Journals (Sweden)

    Kenichi Matsushita

    2016-01-01

    Full Text Available Metabolic syndrome is an obesity-based, complicated clinical condition that has become a global epidemic problem with a high associated risk for cardiovascular disease and mortality. Dyslipidemia, hypertension, and diabetes or glucose dysmetabolism are the major factors constituting metabolic syndrome, and these factors are interrelated and share underlying pathophysiological mechanisms. Severe obesity predisposes individuals to metabolic syndrome, and recent data suggest that mesenchymal stem cells (MSCs contribute significantly to adipocyte generation by increasing the number of adipocytes. Accordingly, an increasing number of studies have examined the potential roles of MSCs in managing obesity and metabolic syndrome. However, despite the growing bank of experimental and clinical data, the efficacy and the safety of MSCs in the clinical setting are still to be optimized. It is thus hoped that ongoing and future studies can elucidate the roles of MSCs in metabolic syndrome and lead to MSC-based therapeutic options for affected patients. This review discusses current understanding of the relationship between MSCs and metabolic syndrome and its potential implications for patient management.

  16. Disease resistance breeding in rose: current status and potential of biotechnological tools.

    Science.gov (United States)

    Debener, Thomas; Byrne, David H

    2014-11-01

    The cultivated rose is a multispecies complex for which a high level of disease protection is needed due to the low tolerance of blemishes in ornamental plants. The most important fungal diseases are black spot, powdery mildew, botrytis and downy mildew. Rose rosette, a lethal viral pathogen, is emerging as a devastating disease in North America. Currently rose breeders use a recurrent phenotypic selection approach and perform selection for disease resistance for most pathogen issues in a 2-3 year field trial. Marker assisted selection could accelerate this breeding process. Thus far markers have been identified for resistance to black spot (Rdrs) and powdery mildew and with the ability of genotyping by sequencing to generate 1000s of markers our ability to identify markers useful in plant improvement should increase exponentially. Transgenic rose lines with various fungal resistance genes inserted have shown limited success and RNAi technology has potential to provide virus resistance. Roses, as do other plants, have sequences homologous to characterized R-genes in their genomes, some which have been related to specific disease resistance. With improving next generation sequencing technology, our ability to do genomic and transcriptomic studies of the resistance related genes in both the rose and the pathogens to reveal novel gene targets to develop resistant roses will accelerate. Finally, the development of designer nucleases opens up a potentially non-GMO approach to directly modify a rose's DNA to create a disease resistant rose. Although there is much potential, at present rose breeders are not using marker assisted breeding primarily because a good suite of marker/trait associations (MTA) that would ensure a path to stable disease resistance is not available. As our genomic analytical tools improve, so will our ability to identify useful genes and linked markers. Once these MTAs are available, it will be the cost savings, both in time and money, that will

  17. Activation of Transient Receptor Potential Vanilloid 4 Increases NMDA-Activated Current in Hippocampal Pyramidal Neurons.

    Science.gov (United States)

    Li, Lin; Qu, Weijun; Zhou, Libin; Lu, Zihong; Jie, Pinghui; Chen, Lei; Chen, Ling

    2013-01-01

    The glutamate excitotoxicity, mediated through N-methyl-d-aspartate receptors (NMDARs), plays an important role in cerebral ischemia injury. Transient receptor potential vanilloid 4 (TRPV4) can be activated by multiple stimuli that may happen during stroke. The present study evaluated the effect of TRPV4 activation on NMDA-activated current (INMDA) and that of blocking TRPV4 on brain injury after focal cerebral ischemia in mice. We herein report that activation of TRPV4 by 4α-PDD and hypotonic stimulation increased INMDA in hippocampal CA1 pyramidal neurons, which was sensitive to TRPV4 antagonist 10 μ M/2 μ 1/mouse [DOSAGE ERROR CORRECTED] and NMDAR antagonist AP-5, indicating that TRPV4 activation potentiates NMDAR response. In addition, the increase in INMDA by hypotonicity was sensitive to the antagonist of NMDAR NR2B subunit, but not of NR2A subunit. Furthermore, antagonists of calcium/calmodulin-dependent protein kinase II (CaMKII) significantly attenuated hypotonicity-induced increase in INMDA, while antagonists of protein kinase C or casein kinase II had no such effect, indicating that phosphorylation of NR2B subunit by CaMKII is responsible for TRPV4-potentiated NMDAR response. Finally, we found that intracerebroventricular injection of 10 μ m/2 μ 1/mouse [DOSAGE ERROR CORRECTED] after 60 min middle cerebral artery occlusion reduced the cerebral infarction with at least a 12 h efficacious time-window. These findings indicate that activation of TRPV4 increases NMDAR function, which may facilitate glutamate excitotoxicity. Closing TRPV4 may exert potent neuroprotection against cerebral ischemia injury through many mechanisms at least including the prevention of NMDAR-mediated glutamate excitotoxicity.

  18. Gas Pressure-Drop Experiment

    Science.gov (United States)

    Luyben, William L.; Tuzla, Kemal

    2010-01-01

    Most chemical engineering undergraduate laboratories have fluid mechanics experiments in which pressure drops through pipes are measured over a range of Reynolds numbers. The standard fluid is liquid water, which is essentially incompressible. Since density is constant, pressure drop does not depend on the pressure in the pipe. In addition, flow…

  19. Hanging drop crystal growth apparatus

    Science.gov (United States)

    Naumann, Robert J. (Inventor); Witherow, William K. (Inventor); Carter, Daniel C. (Inventor); Bugg, Charles E. (Inventor); Suddath, Fred L. (Inventor)

    1990-01-01

    This invention relates generally to control systems for controlling crystal growth, and more particularly to such a system which uses a beam of light refracted by the fluid in which crystals are growing to detect concentration of solutes in the liquid. In a hanging drop apparatus, a laser beam is directed onto drop which refracts the laser light into primary and secondary bows, respectively, which in turn fall upon linear diode detector arrays. As concentration of solutes in drop increases due to solvent removal, these bows move farther apart on the arrays, with the relative separation being detected by arrays and used by a computer to adjust solvent vapor transport from the drop. A forward scattering detector is used to detect crystal nucleation in drop, and a humidity detector is used, in one embodiment, to detect relative humidity in the enclosure wherein drop is suspended. The novelty of this invention lies in utilizing angular variance of light refracted from drop to infer, by a computer algorithm, concentration of solutes therein. Additional novelty is believed to lie in using a forward scattering detector to detect nucleating crystallites in drop.

  20. Improvement Strategies, Cost Effective Production, and Potential Applications of Fungal Glucose Oxidase (GOD: Current Updates

    Directory of Open Access Journals (Sweden)

    Manish K. Dubey

    2017-06-01

    Full Text Available Fungal glucose oxidase (GOD is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.

  1. Current state, habitat and potential invasiveness of Montia linearis (Douglas ex Hook. Greene in Poland

    Directory of Open Access Journals (Sweden)

    Iwona Dembicz

    2015-10-01

    Full Text Available Montia linearis is a vascular plant originating from western North America. The expansion of this species has been observed for several decades. For the first time M. linearis was found in Europe in 1989. Further six populations were documented by 2004 within the continent: three in Poland, two in Denmark and one in Hungary. Apart from discovering a new population of M. linearis, we confirmed two out of the three previously known localities of the species in Poland. All the currently known populations of M. linearis occupied predominantly meadow habitats, especially intensively managed sites. Some individuals were also found in disturbed sites with bare soil. The studied species inhabited soils of various types with broad range of fertility as well as humidity. Montia linearis populations reached densities up to 87 individuals per 0.04 m2. The number of seeds produced by an individual was between 10 and 55 in 90% of the studied specimens, however much more fertile specimens were also observed. As the previously presented hypothesis of M. linearis dispersal with rail transport seemed not to be well supported, the connection between the M. linearis presence and cattle husbandry is considered. It is possible that the species can be transferred with living animals or manure. The species was able to survive for at least 26 years within once inhabited site. Further spread of M. linearis within Europe is highly probable. The aim of the study is to: (i describe the current state of populations of M. linearis in Poland, (ii provide information on habitat preferences and biology of the species, (iii assess the invasiveness potential of M. linearis in Poland.

  2. THE POTENTIAL FOR NEUTRINO PHYSICS AT MUON COLLIDERS AND DEDICATED HIGH CURRENT MUON STORAGE RINGS

    Energy Technology Data Exchange (ETDEWEB)

    BIGI,I.; BOLTON,T.; FORMAGGIO,J.; HARRIS,D.; MORFIN,J.; SPENTZOURIS,P.; YU,J.; KAYSER,B.; KING,B.J.; MCFARLAND,K.; PETROV,A.; SCHELLMAN,H.; VELASCO,M.; SHROCK,R.

    2000-05-11

    Conceptual design studies are underway for both muon colliders and high-current non-colliding muon storage rings that have the potential to become the first true neutrino factories. Muon decays in long straight sections of the storage rings would produce uniquely intense and precisely characterized two-component neutrino beams--muon neutrinos plus electron antineutrinos from negative muon decays and electron neutrinos plus muon antineutrinos from positive muons. This article presents a long-term overview of the prospects for these facilities to greatly extend the capabilities for accelerator-based neutrino physics studies for both high rate and long baseline neutrino experiments. As the first major physics topic, recent experimental results involving neutrino oscillations have motivated a vigorous design effort towards dedicated neutrino factories that would store muon beams of energies 50 GeV or below. These facilities hold the promise of neutrino oscillation experiments with baselines up to intercontinental distances and utilizing well understood beams that contain, for the first time, a substantial component of multi-GeV electron-flavored neutrinos. In deference to the active and fast-moving nature of neutrino oscillation studies, the discussion of long baseline physics at neutrino factories has been limited to a concise general overview of the relevant theory, detector technologies, beam properties, experimental goals and potential physics capabilities. The remainder of the article is devoted to the complementary high rate neutrino experiments that would study neutrino-nucleon and neutrino-electron scattering and would be performed at high performance detectors placed as close as is practical to the neutrino production straight section of muon storage rings in order to exploit beams with transverse dimensions as small as a few tens of centimeters.

  3. THE POTENTIAL FOR NEUTRINO PHYSICS AT MUON COLLIDERS AND DEDICATED HIGH CURRENT MUON STORAGE RINGS

    International Nuclear Information System (INIS)

    BIGI, I.; BOLTON, T.; FORMAGGIO, J.; HARRIS, D.; MORFIN, J.; SPENTZOURIS, P.; YU, J.; KAYSER, B.; KING, B.J.; MCFARLAND, K.; PETROV, A.; SCHELLMAN, H.; VELASCO, M.; SHROCK, R.

    2000-01-01

    Conceptual design studies are underway for both muon colliders and high-current non-colliding muon storage rings that have the potential to become the first true neutrino factories. Muon decays in long straight sections of the storage rings would produce uniquely intense and precisely characterized two-component neutrino beams--muon neutrinos plus electron antineutrinos from negative muon decays and electron neutrinos plus muon antineutrinos from positive muons. This article presents a long-term overview of the prospects for these facilities to greatly extend the capabilities for accelerator-based neutrino physics studies for both high rate and long baseline neutrino experiments. As the first major physics topic, recent experimental results involving neutrino oscillations have motivated a vigorous design effort towards dedicated neutrino factories that would store muon beams of energies 50 GeV or below. These facilities hold the promise of neutrino oscillation experiments with baselines up to intercontinental distances and utilizing well understood beams that contain, for the first time, a substantial component of multi-GeV electron-flavored neutrinos. In deference to the active and fast-moving nature of neutrino oscillation studies, the discussion of long baseline physics at neutrino factories has been limited to a concise general overview of the relevant theory, detector technologies, beam properties, experimental goals and potential physics capabilities. The remainder of the article is devoted to the complementary high rate neutrino experiments that would study neutrino-nucleon and neutrino-electron scattering and would be performed at high performance detectors placed as close as is practical to the neutrino production straight section of muon storage rings in order to exploit beams with transverse dimensions as small as a few tens of centimeters

  4. Magnetic control of Leidenfrost drops.

    Science.gov (United States)

    Piroird, Keyvan; Clanet, Christophe; Quéré, David

    2012-05-01

    We show how a magnetic field can influence the motion of a paramagnetic drop made of liquid oxygen in a Leidenfrost state on solids at room temperature. It is demonstrated that the trajectory can be modified in both direction and velocity and that the results can be interpreted in terms of classical mechanics as long as the drop does not get too close to the magnet. We study the deviation and report that it can easily overcome 180∘ and even diverge under certain conditions, leading to situations where a drop gets captured. In the vicinity of the magnet, another type of trapping is observed, due to the deformation of the drop in this region, which leads to a strong energy dissipation. Conversely, drops can be accelerated by moving magnets (slingshot effect).

  5. Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells.

    Science.gov (United States)

    Liu, F; Weng, S-J; Yang, X-L; Zhong, Y-M

    2015-10-01

    Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-β-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway. Copyright

  6. Artificial intelligence in diagnosis of obstructive lung disease: current status and future potential.

    Science.gov (United States)

    Das, Nilakash; Topalovic, Marko; Janssens, Wim

    2018-03-01

    The application of artificial intelligence in the diagnosis of obstructive lung diseases is an exciting phenomenon. Artificial intelligence algorithms work by finding patterns in data obtained from diagnostic tests, which can be used to predict clinical outcomes or to detect obstructive phenotypes. The purpose of this review is to describe the latest trends and to discuss the future potential of artificial intelligence in the diagnosis of obstructive lung diseases. Machine learning has been successfully used in automated interpretation of pulmonary function tests for differential diagnosis of obstructive lung diseases. Deep learning models such as convolutional neural network are state-of-the art for obstructive pattern recognition in computed tomography. Machine learning has also been applied in other diagnostic approaches such as forced oscillation test, breath analysis, lung sound analysis and telemedicine with promising results in small-scale studies. Overall, the application of artificial intelligence has produced encouraging results in the diagnosis of obstructive lung diseases. However, large-scale studies are still required to validate current findings and to boost its adoption by the medical community.

  7. Current situation, potentials and prospects for the development of organic farming in Šumadija

    Directory of Open Access Journals (Sweden)

    Brković Duško

    2016-01-01

    Full Text Available Šumadija is rich in natural potentials which provide a good basis for the future development of organic farming, given the fact that natural resources are limited. The composition and structure of natural resources are highly suitable for organic production. The region's relatively unpolluted land, favourable climate, abundant water resources and preserved biodiversity are some of the main organic farming requirements satisfied. Organic production is not possible without ensuring at least a minimum level of preservation of natural resources in areas where organic farming is practised; on the other hand, organic production itself has a positive effect on the preservation and improvement of environmental quality in these areas. Small plots of land can be advantageous for this production, particularly in upland areas, and used specifically for organic production as the conversion period is short. They can be used for vegetable farming because the soil is uncontaminated owing to distance from roads. Positive experience indicates that potatoes, rye, oats and root vegetables can be successfully grown in these areas. Another advantage is the wealth of indigenous cultivars of apples, pears and plums which are highly resistant to pathogenic pests and environmental conditions, and hence suitable for cultivation without the use of mineral fertilisers and chemical agents. Major issues currently facing organic farming are a small-scale organic market and low prices of organic products, a low level of consumer awareness of the advantages of organic farming, suspicion and ignorance, low purchasing power, low availability of organic products through sales channels, etc.

  8. Current Government Actions and Potential Policy Options for Reducing Obesity in Queensland Schools.

    Science.gov (United States)

    Alsharairi, Naser A

    2018-01-29

    School nutrition policies provide promising avenues towards the improvement of children's eating habits and the prevention of obesity. Childhood obesity rates and related chronic diseases are increasing in Queensland, in part as a result of unhealthy eating habits and lack of physical activity. There is a very high investment by the Queensland government in maintaining healthy weight and promoting nutrition and physical activity among schoolchildren through delivering a range of initiatives across the state. However, there is a lack of evidence concerning the effectiveness of nutrition/physical education and parental involvement programs addressing obesity delivered in Queensland schools. This paper can be used to guide government and policy-makers regarding the most effective policy options that will promote healthy eating and physical activity among Queensland schoolchildren. The aim of this paper is to: (i) summarize current evidence on Queensland government responses to obesity; and (ii) discuss potential policy options that could support healthy eating and regular physical activity, and examine the evidence base for each option and suggest new areas for future research.

  9. African medicinal plants and their derivatives: Current efforts towards potential anti-cancer drugs.

    Science.gov (United States)

    Mbele, Mzwandile; Hull, Rodney; Dlamini, Zodwa

    2017-10-01

    Cancer is a leading cause of mortality and morbidity worldwide and second only to cardiovascular diseases. Cancer is a challenge in African countries because generally there is limited funding available to deal with the cancer epidemic and awareness and this should be prioritised and all possible resources should be utilized to prevent and treat cancer. The current review reports on the role of African medicinal plants in the treatment of cancer, and also outlines methodologies that can also be used to achieve better outcomes for cancer treatment. This review outlines African medicinal plants, isolated compounds and technologies that can be used to advance cancer research. Chemical structures of isolated compounds have an important role in anti-cancer treatments; new technologies and methods may assist to identify more properties of African medicinal plants and the treatment of cancer. In conclusion, African medicinal plants have shown their potential as enormous resources for novel cytotoxicity compounds. Finally it has been noted that the cytotoxicity depends on the chemical structural arrangements of African medicinal plants compounds. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Computer-aided diagnosis for screening of breast cancer on mammograms. Current status and future potential

    International Nuclear Information System (INIS)

    Doi, Kunio

    2007-01-01

    Described are the history, current status and future potential of computer-aided diagnosis (CAD) with particular emphasis on screening mammography for breast cancer. The systematic basic and clinical studies on CAD started around 20 years before and the significance of CAD has been well recognized to be evident because of human errors occurring in the visual check by doctors of so numerous screening images. Improvement of diagnostic accuracy by CAD has been demonstrated by statistical analysis of ROC (receiver operating characteristic) curves. In mammography, reviewed is detection of the early stage breast cancer like microcalcifications by computer alone, by CAD plus one or more doctors' reading, and by practical clinical CAD diagnosis. For differential diagnosis for malignancy, microcalcifications and masses are given their characteristic image properties and the results are that the Az-value (area under ROC curve) is higher in CAD than in doctor's (0.80 vs 0.61) in the former and, doctor's (0.93) is improved by CAD to 0.96 in the latter masses. In this diagnosis, similar images in the digital database are useful and the database can learn by repeated input of individual data by neural network. Detection of the lesion and especially, its differential diagnosis will be more important in parallel to database development and CAD will be also useful for doctor' carrier as an educational mean. (R.T.)

  11. Bariatric surgery and nonalcoholic fatty liver disease: current and potential future treatments

    Directory of Open Access Journals (Sweden)

    Akira eSasaki

    2014-10-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD and nonalcoholic steatohepatitis (NASH are increasingly common cause of chronic liver disease worldwide. The diagnosis of NASH is challenging as most affected patients are symptom-free and the role of routine screening is not clearly established. Most patients with severe obesity who undergo bariatric surgery have NAFLD, which is associated insulin resistance, type 2 diabetes mellitus (T2DM, hypertension, and obesity-related dyslipidemia. The effective treatment for NAFLD is weight reduction through lifestyle modifications, antiobesity medication, or bariatric surgery. Among these treatments, bariatric surgery is the most reliable method for achieving substantial, sustained weight loss. This procedure is safe when performed by a skilled surgeon, and the benefits include reduced weight, improved quality of life, decreased obesity-related comorbidities, and increased life expectancy. Further research is urgently needed to determine the best use of bariatric surgery with NAFLD patients at high risk of developing liver cirrhosis and its role in modulating complications of NAFLD, such as T2DM and cardiovascular disease. The current evidence suggests that bariatric surgery for patients with severe obesity decreases the grade of steatosis, hepatic inflammation, and fibrosis. However, further long-term studies are required to confirm the true effects before recommending bariatric surgery as a potential treatment for nonalcoholic steatohepatitis.

  12. Applications of Ni3Al Based Intermetallic Alloys—Current Stage and Potential Perceptivities

    Science.gov (United States)

    Jozwik, Pawel; Polkowski, Wojciech; Bojar, Zbigniew

    2015-01-01

    The paper presents an overview of current and prospective applications of Ni3Al based intermetallic alloys—modern engineering materials with special properties that are potentially useful for both structural and functional purposes. The bulk components manufactured from these materials are intended mainly for forging dies, furnace assembly, turbocharger components, valves, and piston head of internal combustion engines. The Ni3Al based alloys produced by a directional solidification are also considered as a material for the fabrication of jet engine turbine blades. Moreover, development of composite materials with Ni3Al based alloys as a matrix hardened by, e.g., TiC, ZrO2, WC, SiC and graphene, is also reported. Due to special physical and chemical properties; it is expected that these materials in the form of thin foils and strips should make a significant contribution to the production of high tech devices, e.g., Micro Electro-Mechanical Systems (MEMS) or Microtechnology-based Energy and Chemical Systems (MECS); as well as heat exchangers; microreactors; micro-actuators; components of combustion chambers and gasket of rocket and jet engines as well components of high specific strength systems. Additionally, their catalytic properties may find an application in catalytic converters, air purification systems from chemical and biological toxic agents or in a hydrogen “production” by a decomposition of hydrocarbons.

  13. Applications of Ni3Al Based Intermetallic Alloys—Current Stage and Potential Perceptivities

    Directory of Open Access Journals (Sweden)

    Pawel Jozwik

    2015-05-01

    Full Text Available The paper presents an overview of current and prospective applications of Ni3Al based intermetallic alloys—modern engineering materials with special properties that are potentially useful for both structural and functional purposes. The bulk components manufactured from these materials are intended mainly for forging dies, furnace assembly, turbocharger components, valves, and piston head of internal combustion engines. The Ni3Al based alloys produced by a directional solidification are also considered as a material for the fabrication of jet engine turbine blades. Moreover, development of composite materials with Ni3Al based alloys as a matrix hardened by, e.g., TiC, ZrO2, WC, SiC and graphene, is also reported. Due to special physical and chemical properties; it is expected that these materials in the form of thin foils and strips should make a significant contribution to the production of high tech devices, e.g., Micro Electro-Mechanical Systems (MEMS or Microtechnology-based Energy and Chemical Systems (MECS; as well as heat exchangers; microreactors; micro-actuators; components of combustion chambers and gasket of rocket and jet engines as well components of high specific strength systems. Additionally, their catalytic properties may find an application in catalytic converters, air purification systems from chemical and biological toxic agents or in a hydrogen “production” by a decomposition of hydrocarbons.

  14. Meniscus repair and regeneration: review on current methods and research potential

    Directory of Open Access Journals (Sweden)

    C Scotti

    2013-01-01

    Full Text Available Meniscus regeneration is an unsolved clinical challenge. Despite the wide acceptance of the degenerative consequences of meniscectomy, no surgical procedure has succeeded to date in regenerating a functional and long-lasting meniscal fibrocartilage. Research proposed a number of experimental approaches encompassing all the typical strategies of regenerative medicine: cell-free scaffolds, gene therapy, intra-articular delivery of progenitor cells, biological glues for enhanced bonding of reparable tears, partial and total tissue engineered meniscus replacement. None of these approaches has been completely successful and can be considered suitable for all patients, as meniscal tears require specific and patient-related treatments depending on the size and type of lesion. Recent advances in cell biology, biomaterial science and bioengineering (e.g., bioreactors have now the potential to drive meniscus regeneration into a series of clinically relevant strategies. In this tutorial paper, the clinical need for meniscus regeneration strategies will be explained, and past and current experimental studies on meniscus regeneration will be reported.

  15. Current Status and Future Potential of Energy Derived from Chinese Agricultural Land: A Review

    Directory of Open Access Journals (Sweden)

    Ningning Zhai

    2015-01-01

    Full Text Available Energy crisis is receiving attention with regard to the global economy and environmental sustainable development. Developing new energy resources to optimize the energy supply structure has become an important measure to prevent energy shortage as well as achieving energy conservation and emission reduction in China. This study proposed the concept of energy agriculture and constructed an energy agricultural technical support system based on the analysis of energy supply and demand and China’s foreign dependence on energy resources, combined with the function of agriculture in the energy field. Manufacturing technology equipment and agricultural and forestry energy, including crop or forestry plants and animal feces, were used in the system. The current status and future potential of China’s marginal land resources, energy crop germplasm resources, and agricultural and forestry waste energy-oriented resources were analyzed. Developing the function of traditional agriculture in food production may promote China’s social, economic, and environmental sustainable development and achieve energy saving and emission reduction.

  16. Stem cell technology for bone regeneration: current status and potential applications

    Directory of Open Access Journals (Sweden)

    Asatrian G

    2015-02-01

    Full Text Available Greg Asatrian,1 Dalton Pham,1,2 Winters R Hardy,3 Aaron W James,1–3 Bruno Peault3,4 1Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, 2Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, 3UCLA/Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center, Los Angeles, CA, USA; 4Medical Research Council Centre for Regenerative Medicine, Edinburgh, Scotland, UK Abstract: Continued improvements in the understanding and application of mesenchymal stem cells (MSC have revolutionized tissue engineering. This is particularly true within the field of skeletal regenerative medicine. However, much remains unknown regarding the native origins of MSC, the relative advantages of different MSC populations for bone regeneration, and even the biologic safety of such unpurified, grossly characterized cells. This review will first summarize the initial discovery of MSC, as well as the current and future applications of MSC in bone tissue engineering. Next, the relative advantages and disadvantages of MSC isolated from distinct tissue origins are debated, including the MSC from adipose, bone marrow, and dental pulp, among others. The perivascular origin of MSC is next discussed. Finally, we briefly comment on pluripotent stem cell populations and their possible application in bone tissue engineering. While continually expanding, the field of MSC-based bone tissue engineering and regeneration shows potential to become a clinical reality in the not-so-distant future.Keywords: mesenchymal stem cell, pericyte, bone tissue engineering, MSC, ASC, DMSC

  17. Substance use by Egyptian youth: current patterns and potential avenues for prevention.

    Science.gov (United States)

    Loffredo, Christopher A; Boulos, Dina N K; Saleh, Doa'a A; Jillson, Irene A; Garas, Magdy; Loza, Nasser; Samuel, Philip; Shaker, Yousri Edward; Ostrowski, Mar-Jan; Amr, Sania

    2015-04-01

    Substance abuse in Egypt is a serious public health threat. Recent studies have demonstrated increases in the prevalence of the use of tobacco, illegal drugs, and over-the-counter drugs, particularly among youth. We conducted focus groups with a total of 40 male and female youth participants, ages 12-14 and 15-18, recruited from two different areas (Cairo and Alexandria) in 2012. We investigated their knowledge and perceptions regarding current substance use, its sources, and promoting and protecting factors, broadly addressing the use of tobacco products, illicit and prescription drugs, inhaled substances such as glue and solvents, and alcohol. Our findings suggest that: (1) youth in Egypt had access to and were actively using substances encountered in similar research worldwide, including tobacco, alcohol, illicit drugs, glue sniffing, and pharmaceutical agents; (2) smoking cigarettes and using hashish were the most common practices, and Tramadol was the most commonly used pharmaceutical drug; (3) peer pressure from friends stood out as the most common reason to start and continue using substances, followed by adverse life events and having a parent or family member who used substances; (4) strict parenting, religiosity, and having non-user friends were among the factors perceived by youth to prevent substance use or help them quit using substances; (5) most youths were aware of the adverse health effects of substance use. These findings will inform the design of quantitative surveys aimed at estimating the prevalence of specific behaviors related to substance use among youth and potential avenues for prevention.

  18. The initial regime of drop coalescence

    Science.gov (United States)

    Anthony, Christopher; Harris, Michael; Basaran, Osman

    2017-11-01

    Drop coalescence plays a key role in both industry and nature. Consequently, study of the phenomenon has been the focus of numerous experimental, computational and theoretical works to date. In coalescence, two drops come into contact and a liquid bridge forms between them. As time advances, this bridge grows from microscopic to macroscopic scales. Despite the large volume of work dedicated to this problem, currently experiment, theory, and computation are not in perfect agreement with respect to the earliest times following the initial contact of the drops. Experiments report an initial regime where the radius of the connecting bridge grows linearly in time before a transition to either a Stokes regime or an inertial regime where either viscous or inertial forces balance capillary force. In the initial linear regime, referred to as the inertially-limited viscous regime, all three forces are thought to be important. This is in contrast to theory which predicts that all coalescence events begin in the Stokes regime. We use high accuracy numerical simulation to show that the existing discrepancy in the literature can be resolved by paying careful attention to the initial conditions that set the shape and size of the bridge connecting the two drops.

  19. CASSINI SS/S RPWS CALIBRATED LP POTENTIAL CURRENT V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Radio and Plasma Wave Science (RPWS) Langmuir Probe Sweep voltage-current data set comprises calibrated Voltage-Current (U-I) characteristics acquired...

  20. Pool impacts of Leidenfrost drop

    Science.gov (United States)

    Darbois Texier, Baptiste; Maquet, Laurent; Dorbolo, Stephane; Dehandschoewercker, Eline; Pan, Zhao; Truscott, Tadd

    2015-11-01

    This work concerns the impact of a droplet made of a volatile liquid (typically HFE) on a pool of an other liquid (typically silicone oil) which temperature is above the boiling point of the drop. Depending on the properties of the two liquids and the impacting conditions, four different regimes are observed. For low impacting speeds, the droplet bounces on the surface of the bath and finally levitates above it in a Leidenfrost state. Such a regime occurs as soon as the pool temperature exceeds the boiling point of the drop. This observation means that there is no threshold in temperature for a Leidenfrost effect on a liquid surface contrary to the case of a solid substrate. For intermediate impacting velocities, the pinch-off of the surface of the pool entraps the drop in the liquid bulk. The entrapped drop is separated from the pool by a layer of its own vapour in a similar way of antibulles. For increasing impacting speeds, the vapour layer between the drop and the pool does not hold during the pinch-off event. The contact of the drop with the hot liquid provokes a sudden and intense evaporation. At very large impacting speeds, the drop rapidely contacts the pool, spreads and finally induces a hemi-spherical cavity. In the end, these four different regimes are summarized in a Froud-Weber diagram which boundaries are discussed.

  1. Laboratory animal science in China: current status and potential for adoption of Three R alternatives.

    Science.gov (United States)

    Kong, Qi; Qin, Chuan

    2010-03-01

    R alternatives, and animal welfare, and shows that there is currently great potential for the adoption of alternatives. The information will help scientists and organisations around the world to gain better insight into the current state of laboratory animal science in China, and hopefully, will enable them to give advice on how we can improve the adoption of Three R alternatives in our country. 2010 FRAME.

  2. Determining the current status and potential of nuclear medicine in Poland.

    Science.gov (United States)

    Pachocki, Krzysztof A; Sackiewicz-Slaby, Agata

    2013-01-01

    Through its use of ionising radiation, the field of nuclear medicine forms a unique and significant part of medical diagnostics and patient treatment. Objectives. To assess the operational potential of nuclear medicine in Poland based on existing database/literature sources together with conducting a survey on the relevant healthcare facilities available, staffing, expertise and performance. To gather all available literature data on the medical use of ionising radiation in Poland several data bases were used, since currently, there are no single statistical data base devoted to this issue. Data on radiation hygiene were thus collected from the Statistical Bulletin of the Ministry of Health, Annual reports from the National Atomic Energy Agency and Central Statistics Office. Additionally, national and provincial reports were used, as well as those received from the European Society of Nuclear Medicine. At present, the Public Healthcare system in Poland has 55 nuclear medicine departmental facilities operating and 8 that are private/non-public. These are staffed by 252 doctors, of whom 151 are qualified as nuclear medicine specialists; constituting one specialist per 300,000 inhabitants. In addition, 170 highly qualified staff (biologists, chemists, physicists, electronics engineers and IT specialists) provide indispensable scientific/operational support and are vital for the development of nuclear medicine departments. They are mainly responsible for ensuring that all equipment functions effectively and for developing new diagnostic techniques, together with new radiopharmaceuticals. Furthermore, there are approximately 500 other staff at intermediate-level also involved in nuclear medicine departments, such as technicians, nurses and support workers. The survey demonstrated an average of 22 persons employed per nuclear medicine department. For all institutions, it is estimated that there are 127 gamma cameras, 10 PET/CT scanners and 16 hybrid SPECT/CT systems

  3. Oscillating and star-shaped drops levitated by an airflow.

    Science.gov (United States)

    Bouwhuis, Wilco; Winkels, Koen G; Peters, Ivo R; Brunet, Philippe; van der Meer, Devaraj; Snoeijer, Jacco H

    2013-08-01

    We investigate the spontaneous oscillations of drops levitated above an air cushion, eventually inducing a breaking of axisymmetry and the appearance of "star drops". This is strongly reminiscent of the Leidenfrost stars that are observed for drops floating above a hot substrate. The key advantage of this work is that we inject the airflow at a constant rate below the drop, thus eliminating thermal effects and allowing for a better control of the flow rate. We perform experiments with drops of different viscosities and observe stable states, oscillations, and chimney instabilities. We find that for a given drop size the instability appears above a critical flow rate, where the latter is largest for small drops. All these observations are reproduced by numerical simulations, where we treat the drop using potential flow and the gas as a viscous lubrication layer. Qualitatively, the onset of instability agrees with the experimental results, although the typical flow rates are too large by a factor 10. Our results demonstrate that thermal effects are not important for the formation of star drops and strongly suggest a purely hydrodynamic mechanism for the formation of Leidenfrost stars.

  4. Trapping leidenfrost drops with crenelations.

    Science.gov (United States)

    Dupeux, Guillaume; Le Merrer, Marie; Clanet, Christophe; Quéré, David

    2011-09-09

    Drops placed on very hot solids levitate on a cushion of their own vapor, as discovered by Leidenfrost. This confers to these drops a remarkable mobility, which makes problematic their control and manipulation. Here we show how crenelated surfaces can be used to increase the friction of Leidenfrost drops by a factor on the order of 100, making them decelerate and be trapped on centimetric distances instead of the usual metric ones. We measure and characterize the friction force as a function of the design of the crenelations.

  5. Drop impact and rebound dynamics on an inclined superhydrophobic surface.

    Science.gov (United States)

    Yeong, Yong Han; Burton, James; Loth, Eric; Bayer, Ilker S

    2014-10-14

    Due to its potential in water-repelling applications, the impact and rebound dynamics of a water drop impinging perpendicular to a horizontal superhydrophobic surface have undergone extensive study. However, drops tend to strike a surface at an angle in applications. In such cases, the physics governing the effects of oblique impact are not well studied or understood. Therefore, the objective of this study was to conduct an experiment to investigate the impact and rebound dynamics of a drop at various liquid viscosities, in an isothermal environment, and on a nanocomposite superhydrophobic surface at normal and oblique impact conditions (tilted at 15°, 30°, 45°, and 60°). This study considered drops falling from various heights to create normal impact Weber numbers ranging from 6 to 110. In addition, drop viscosity was varied by decreasing the temperature for water drops and by utilizing water-glycerol mixtures, which have similar surface tension to water but higher viscosities. Results revealed that oblique and normal drop impact behaved similarly (in terms of maximum drop spread as well as rebound dynamics) at low normal Weber numbers. However, at higher Weber numbers, normal and oblique impact results diverged in terms of maximum spread, which could be related to asymmetry and more complex outcomes. These asymmetry effects became more pronounced as the inclination angle increased, to the point where they dominated the drop impact and rebound characteristics when the surface was inclined at 60°. The drop rebound characteristics on inclined surfaces could be classified into eight different outcomes driven primarily by normal Weber number and drop Ohnesorge numbers. However, it was found that these outcomes were also a function of the receding contact angle, whereby reduced receding angles yielded tail-like structures. Nevertheless, the contact times of the drops with the coating were found to be generally independent of surface inclination.

  6. Studying the field induced breakup of acoustically levitated drops

    Science.gov (United States)

    Warschat, C.; Riedel, J.

    2017-10-01

    Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of

  7. Evaluating Cloud and Precipitation Processes in Numerical Models using Current and Potential Future Satellite Missions

    Science.gov (United States)

    van den Heever, S. C.; Tao, W. K.; Skofronick Jackson, G.; Tanelli, S.; L'Ecuyer, T. S.; Petersen, W. A.; Kummerow, C. D.

    2015-12-01

    Cloud, aerosol and precipitation processes play a fundamental role in the water and energy cycle. It is critical to accurately represent these microphysical processes in numerical models if we are to better predict cloud and precipitation properties on weather through climate timescales. Much has been learned about cloud properties and precipitation characteristics from NASA satellite missions such as TRMM, CloudSat, and more recently GPM. Furthermore, data from these missions have been successfully utilized in evaluating the microphysical schemes in cloud-resolving models (CRMs) and global models. However, there are still many uncertainties associated with these microphysics schemes. These uncertainties can be attributed, at least in part, to the fact that microphysical processes cannot be directly observed or measured, but instead have to be inferred from those cloud properties that can be measured. Evaluation of microphysical parameterizations are becoming increasingly important as enhanced computational capabilities are facilitating the use of more sophisticated schemes in CRMs, and as future global models are being run on what has traditionally been regarded as cloud-resolving scales using CRM microphysical schemes. In this talk we will demonstrate how TRMM, CloudSat and GPM data have been used to evaluate different aspects of current CRM microphysical schemes, providing examples of where these approaches have been successful. We will also highlight CRM microphysical processes that have not been well evaluated and suggest approaches for addressing such issues. Finally, we will introduce a potential NASA satellite mission, the Cloud and Precipitation Processes Mission (CAPPM), which would facilitate the development and evaluation of different microphysical-dynamical feedbacks in numerical models.

  8. Bio-scaffolds in organ-regeneration: Clinical potential and current challenges.

    Science.gov (United States)

    Yesmin, S; Paget, M B; Murray, H E; Downing, R

    2017-09-01

    Cadaveric organ transplantation represents the definitive treatment option for end-stage disease but is restricted by the shortage of clinically-viable donor organs. This limitation has, in part, driven current research efforts for in vitro generation of transplantable tissue surrogates. Recent advances in organ reconstruction have been facilitated by the re-purposing of decellularized whole organs to serve as three-dimensional bio-scaffolds. Notably, studies in rodents indicate that such scaffolds retain native extracellular matrix components that provide appropriate biochemical, mechanical and physical stimuli for successful tissue/organ reconstruction. As such, they support the migration, adhesion and differentiation of reseeded primary and/or pluripotent cell populations, which mature and achieve functionality through short-term conditioning within specialized tissue bioreactors. Whilst these findings are encouraging, significant challenges remain to up-scale the present technology to accommodate human-sized organs and thereby further the translation of this approach towards clinical use. Of note, the diverse structural and cellular composition of large mammalian organ systems mean that a "one-size fits all" approach cannot be adopted either to the methods used for their decellularization or the cells required for subsequent re-population, to create fully functional entities. The present review seeks to highlight the clinical potential of decellularized organ bio-scaffolds as a route to further advance the field of tissue- and organ-regeneration, and to discuss the challenges which are yet to be addressed if such a technology is ever to become a credible rival to conventional organ allo-transplantation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Obtaining subjects' consent to publish identifying personal information: current practices and identifying potential issues.

    Science.gov (United States)

    Yoshida, Akiko; Dowa, Yuri; Murakami, Hiromi; Kosugi, Shinji

    2013-11-25

    In studies publishing identifying personal information, obtaining consent is regarded as necessary, as it is impossible to ensure complete anonymity. However, current journal practices around specific points to consider when obtaining consent, the contents of consent forms and how consent forms are managed have not yet been fully examined. This study was conducted to identify potential issues surrounding consent to publish identifying personal information. Content analysis was carried out on instructions for authors and consent forms developed by academic journals in four fields (as classified by Journal Citation Reports): medicine general and internal, genetics and heredity, pediatrics, and psychiatry. An online questionnaire survey of editors working for journals that require the submission of consent forms was also conducted. Instructions for authors were reviewed for 491 academic journals (132 for medicine general and internal, 147 for genetics and heredity, 100 for pediatrics, and 112 for psychiatry). Approximately 40% (203: 74 for medicine general and internal, 31 for genetics and heredity, 58 for pediatrics, and 40 for psychiatry) stated that subject consent was necessary. The submission of consent forms was required by 30% (154) of the journals studied, and 10% (50) provided their own consent forms for authors to use. Two journals mentioned that the possible effects of publication on subjects should be considered. Many journal consent forms mentioned the difficulties in ensuring complete anonymity of subjects, but few addressed the study objective, the subjects' right to refuse consent and the withdrawal of consent. The main reason for requiring the submission of consent forms was to confirm that consent had been obtained. Approximately 40% of journals required subject consent to be obtained. However, differences were observed depending on the fields. Specific considerations were not always documented. There is a need to address issues around the study

  10. Obtaining subjects’ consent to publish identifying personal information: current practices and identifying potential issues

    Science.gov (United States)

    2013-01-01

    Background In studies publishing identifying personal information, obtaining consent is regarded as necessary, as it is impossible to ensure complete anonymity. However, current journal practices around specific points to consider when obtaining consent, the contents of consent forms and how consent forms are managed have not yet been fully examined. This study was conducted to identify potential issues surrounding consent to publish identifying personal information. Methods Content analysis was carried out on instructions for authors and consent forms developed by academic journals in four fields (as classified by Journal Citation Reports): medicine general and internal, genetics and heredity, pediatrics, and psychiatry. An online questionnaire survey of editors working for journals that require the submission of consent forms was also conducted. Results Instructions for authors were reviewed for 491 academic journals (132 for medicine general and internal, 147 for genetics and heredity, 100 for pediatrics, and 112 for psychiatry). Approximately 40% (203: 74 for medicine general and internal, 31 for genetics and heredity, 58 for pediatrics, and 40 for psychiatry) stated that subject consent was necessary. The submission of consent forms was required by 30% (154) of the journals studied, and 10% (50) provided their own consent forms for authors to use. Two journals mentioned that the possible effects of publication on subjects should be considered. Many journal consent forms mentioned the difficulties in ensuring complete anonymity of subjects, but few addressed the study objective, the subjects’ right to refuse consent and the withdrawal of consent. The main reason for requiring the submission of consent forms was to confirm that consent had been obtained. Conclusion Approximately 40% of journals required subject consent to be obtained. However, differences were observed depending on the fields. Specific considerations were not always documented. There is a need

  11. Semisupervised Community Detection by Voltage Drops

    Directory of Open Access Journals (Sweden)

    Min Ji

    2016-01-01

    Full Text Available Many applications show that semisupervised community detection is one of the important topics and has attracted considerable attention in the study of complex network. In this paper, based on notion of voltage drops and discrete potential theory, a simple and fast semisupervised community detection algorithm is proposed. The label propagation through discrete potential transmission is accomplished by using voltage drops. The complexity of the proposal is OV+E for the sparse network with V vertices and E edges. The obtained voltage value of a vertex can be reflected clearly in the relationship between the vertex and community. The experimental results on four real networks and three benchmarks indicate that the proposed algorithm is effective and flexible. Furthermore, this algorithm is easily applied to graph-based machine learning methods.

  12. Disease and region-related cardiac fibroblast potassium current variations and potential functional significance.

    Science.gov (United States)

    Wu, Chia-Tung; Qi, Xiao-Yan; Huang, Hai; Naud, Patrice; Dawson, Kristin; Yeh, Yung-Hsin; Harada, Masahide; Kuo, Chi-Tai; Nattel, Stanley

    2014-06-01

    Fibroblasts, which play an important role in cardiac function/dysfunction, including arrhythmogenesis, have voltage-dependent (Kv) currents of unknown importance. Here, we assessed the differential expression of Kv currents between atrial and ventricular fibroblasts from control dogs and dogs with an atrial arrhythmogenic substrate caused by congestive heart failure (CHF). Left atrial (LA) and ventricular (LV) fibroblasts were freshly isolated from control and CHF dogs (2-week ventricular tachypacing, 240 bpm). Kv currents were measured with whole-cell voltage-clamp, mRNA by quantitative polymerase chain reaction (qPCR) and fibroblast proliferation by (3)H-thymidine incorporation. Robust voltage-dependent tetraethylammonium (TEA)-sensitive K(+) currents (IC50 ∼1 mM) were recorded. The morphologies and TEA responses of LA and LV fibroblast Kv currents were similar. LV fibroblast Kv-current densities were significantly greater than LA, and Kv-current densities were significantly less in CHF than control. The mRNA expression of Kv-channel subunits Kv1.5 and Kv4.3 was less in LA vs. LV fibroblasts and was down-regulated in CHF, consistent with K(+)-current recordings. Ca(2+)-dependent K(+)-channel subunit (KCa1.1) mRNA and currents were less expressed in LV vs. LA fibroblasts. Inhibiting LA fibroblast K(+) current with 1 mmol/L of TEA or KCa1.1 current with paxilline increased proliferation. Fibroblast Kv-current expression is smaller in CHF vs. control, as well as LA vs. LV. KCa1.1 current is greater in LA vs. LV. Suppressing Kv current with TEA enhances fibroblast proliferation, suggesting that Kv current might act to check fibroblast proliferation and that reduced Kv current in CHF may contribute to fibrosis. Fibroblast Kv-current remodelling may play a role in the atrial fibrillation (AF) substrate; modulating fibroblast K(+) channels may present a novel strategy to prevent fibrosis and AF. Published on behalf of the European Society of Cardiology. All rights

  13. Urocortin2 prolongs action potential duration and modulates potassium currents in guinea pig myocytes and HEK293 cells.

    Science.gov (United States)

    Yang, Li-Zhen; Zhu, Yi-Chun

    2015-07-05

    We previously reported that activation of corticotropin releasing factor receptor type 2 by urocortin2 up-regulates both L-type Ca(2+) channels and intracellular Ca(2+) concentration in ventricular myocytes and plays an important role in cardiac contractility and arrhythmogenesis. This study goal was to further test the hypothesis that urocortin2 may modulate action potentials as well as rapidly and slowly activating delayed rectifier potassium currents. With whole cell patch-clamp techniques, action potentials and slowly activating delayed rectifier potassium currents were recorded in isolated guinea pig ventricular myocytes, respectively. And rapidly activating delayed rectifier potassium currents were tested in hERG-HEK293 cells. Urocortin2 produced a time- and concentration-dependent prolongation of action potential duration. The EC50 values of action potential duration and action potential duration at 90% of repolarization were 14.73 and 24.3nM respectively. The prolongation of action potential duration of urocortin2 was almost completely or partly abolished by H-89 (protein kinase A inhibitor) or KB-R7943 (Na(+)/Ca(2+) exchange inhibitor) pretreatment respectively. And urocortin2 caused reduction of rapidly activating delayed rectifier potassium currents in hERG-HEK293 cells. In addition, urocortin2 slowed the rate of slowly activating delayed rectifier potassium channel activation, and rightward shifted the threshold of slowly activating delayed rectifier potassium currents to more positive potentials. Urocortin2 prolonged action potential duration via activation of protein kinase A and Na(+)/ Ca(2+) exchange in isolated guinea pig ventricular myocytes in a time- and concentration- dependent manner. In hERG-HEK293 cells, urocortin2 reduced rapidly activating delayed rectifier potassium current density which may contribute to action potential duration prolongation. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 45-FOOT HIGH DROP TOWER

    Data.gov (United States)

    Federal Laboratory Consortium — The Drop Tower is used to simulate and measure the impact shocks that are exerted on parachute loads when they hit the ground. It is also used for HSL static lift to...

  15. Shaping drops with textured surfaces

    Science.gov (United States)

    Ehlinger, Quentin; Biance, Anne-Laure; Ybert, Christophe

    2017-11-01

    When a drop impacts a substrate, it can behave differently depending on the nature of the surface and of the liquid (spreading, bouncing, resting, splashing ...). Understanding these behaviors is crucial to predict the drop morphology during and after impact. Whereas surface wettability has extensively been studied, the effect of surface roughness remains hardly explored. In this work, we consider the impact of a drop in a pure non-wetting situation by using superheated substrates i.e. in the Leidenfrost regime. The surface texture consists of a well-controlled microscopic defect shaped with photolithography on a smooth silicon wafer. Different regimes are observed, depending on the distance between the defect and the impact point and the defect size. Comparing the lamella thickness versus the defect height proves relevant as the transition criteria between regimes. Others characteristics of the drop behavior (direction of satellite droplet ejection, lamella rupture) are also well captured by inertial/capillary models. Drop impacts on multiple defects are also investigated and drop shape well predicted considering the interactions between the local flow and the defects.

  16. Euler potentials for two current sheets along ambient uniform magnetic field

    Czech Academy of Sciences Publication Activity Database

    Romashets, E. P.; Vandas, Marek

    2012-01-01

    Roč. 117, July (2012), A07221/1-A07221/8 ISSN 0148-0227 R&D Projects: GA ČR GA205/09/0170; GA MŠk ME09032 Institutional support: RVO:67985815 Keywords : aligned currents * birkeland currents * magnetosphere Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.174, year: 2012

  17. Potassium currents induced by hydrostatic pressure modulate membrane potential and transmitter release in vestibular type II hair cells.

    Science.gov (United States)

    Duong Dinh, Thien An; Haasler, Thorsten; Homann, Georg; Jüngling, Eberhard; Westhofen, Martin; Lückhoff, Andreas

    2009-06-01

    Vestibular type II hair cells respond to increases in the hydrostatic pressure with pressure-dependent K(+) currents. We examined whether such currents may modulate transmitter release (assessed as membrane capacitance increments) by altering membrane potentials and voltage-gated Ca(2+) currents. Capacitance increments were dependent on voltage-gated Ca(2+) influx. Stimulating currents (0.7 nA) in current clamp induced depolarisations that were more negative by 8.7 +/- 2.1 mV when the bath height was elevated from 0.2 to 0.5 cm. In voltage clamp, protocols were used that simulated the time course of the membrane potential in current clamp at either low (control) or high hydrostatic pressure (high bath). The low bath protocol induced significantly larger Ca(2+) currents and increases in capacitance than the high bath protocol. We conclude that pressure-dependent K(+) currents may alter the voltage response of vestibular hair cells to an extent critical for Ca(2+) currents and transmitter release. This mechanism may contribute to vestibular dysfunction in Meniere's disease.

  18. The relationship between mothers' child abuse potential and current mental health symptoms: implications for screening and referral.

    Science.gov (United States)

    Rinehart, Deborah J; Becker, Marion A; Buckley, Pamela R; Dailey, Kathy; Reichardt, Charles S; Graeber, Carla; VanDeMark, Nancy R; Brown, Ellen

    2005-01-01

    This analysis examined data from mothers at 2 of the 9 sites participating in Substance Abuse and Mental Health Services Administration's (SAMHSA's) national Women Co-occurring Disorders and Violence Study (WCDVS). According to previous literature, it was hypothesized that women in the WCDVS would be at high risk of perpetrating child abuse. This research examined mothers' potential for physical child abuse and assessed the association between child abuse potential, current mental health symptoms, alcohol and drug use severity, and trauma. Results revealed that participants had significant potential for child abuse. Hierarchical regression analyses revealed that current mental health symptoms were the strongest predictor of mothers' scores on the Child Abuse Potential (CAP) Inventory. This study highlights the important relationships between commonly used instruments across the mental health, substance, and child welfare fields and the potential dual use of these instruments. Implications for policy and practice are discussed.

  19. Differential roles of two delayed rectifier potassium currents in regulation of ventricular action potential duration and arrhythmia susceptibility.

    Science.gov (United States)

    Devenyi, Ryan A; Ortega, Francis A; Groenendaal, Willemijn; Krogh-Madsen, Trine; Christini, David J; Sobie, Eric A

    2017-04-01

    Arrhythmias result from disruptions to cardiac electrical activity, although the factors that control cellular action potentials are incompletely understood. We combined mathematical modelling with experiments in heart cells from guinea pigs to determine how cellular electrical activity is regulated. A mismatch between modelling predictions and the experimental results allowed us to construct an improved, more predictive mathematical model. The balance between two particular potassium currents dictates how heart cells respond to perturbations and their susceptibility to arrhythmias. Imbalances of ionic currents can destabilize the cardiac action potential and potentially trigger lethal cardiac arrhythmias. In the present study, we combined mathematical modelling with information-rich dynamic clamp experiments to determine the regulation of action potential morphology in guinea pig ventricular myocytes. Parameter sensitivity analysis was used to predict how changes in ionic currents alter action potential duration, and these were tested experimentally using dynamic clamp, a technique that allows for multiple perturbations to be tested in each cell. Surprisingly, we found that a leading mathematical model, developed with traditional approaches, systematically underestimated experimental responses to dynamic clamp perturbations. We then re-parameterized the model using a genetic algorithm, which allowed us to estimate ionic current levels in each of the cells studied. This unbiased model adjustment consistently predicted an increase in the rapid delayed rectifier K + current and a drastic decrease in the slow delayed rectifier K + current, and this prediction was validated experimentally. Subsequent simulations with the adjusted model generated the clinically relevant prediction that the slow delayed rectifier is better able to stabilize the action potential and suppress pro-arrhythmic events than the rapid delayed rectifier. In summary, iterative coupling of

  20. About applicability of thermodynamic parameters to small drops and clusters

    Science.gov (United States)

    Kharlamov, G. V.; Onischuk, A. A.; Vosel, S. V.; Purtov, P. A.

    2012-11-01

    In our paper the results of molecular dynamics calculations of nanodrops are presented. The density profiles, the Irving-Kirkwood pressure tensors, the chemical potentials of the systems, the equimolar radii of the drops and the radii of tension, the mechanical and thermodynamic surface tensions have been calculated. It is shown that both the mechanical and thermodynamic surface tensions decrease with the decrease of the equimolar radius of the drop and reach zero at the same R0 depending on temperature. With the further equimolar radius decrease the surface tension becomes negative. It means that such droplet is metastable and that the notion of the macroscopic surface tension cannot be applied to such small drops. The dependence of the ratio of the drop surface tension to the surface tension of the flat liquid-vapor interface on the ratio of the drop equimolar radius to R0 is a universal function.

  1. About applicability of thermodynamic parameters to small drops and clusters

    International Nuclear Information System (INIS)

    Kharlamov, G V; Onischuk, A A; Vosel, S V; Purtov, P A

    2012-01-01

    In our paper the results of molecular dynamics calculations of nanodrops are presented. The density profiles, the Irving-Kirkwood pressure tensors, the chemical potentials of the systems, the equimolar radii of the drops and the radii of tension, the mechanical and thermodynamic surface tensions have been calculated. It is shown that both the mechanical and thermodynamic surface tensions decrease with the decrease of the equimolar radius of the drop and reach zero at the same R 0 depending on temperature. With the further equimolar radius decrease the surface tension becomes negative. It means that such droplet is metastable and that the notion of the macroscopic surface tension cannot be applied to such small drops. The dependence of the ratio of the drop surface tension to the surface tension of the flat liquid-vapor interface on the ratio of the drop equimolar radius to R 0 is a universal function.

  2. Assessing current and future techno-economic potential of concentrated solar power and photovoltaic electricity generation

    NARCIS (Netherlands)

    Köberle, Alexandre C.; Gernaat, David E H J; van Vuuren, Detlef P.

    2015-01-01

    CSP and PV technologies represent energy sources with large potentials. We present cost-supply curves for both technologies using a consistent methodology for 26 regions, based on geoexplicit information on solar radiation, land cover type and slope, exploring individual potential and

  3. Modulation of Whole-Cell Currents in Plasmodium Falciparum-Infected Human Red Blood Cells by Holding Potential and Serum

    Science.gov (United States)

    Staines, Henry M; Powell, Trevor; Clive Ellory, J; Egée, Stéphane; Lapaix, Franck; Decherf, Gaëtan; Thomas, Serge L Y; Duranton, Christophe; Lang, Florian; Huber, Stephan M

    2003-01-01

    Recent electrophysiological studies have identified novel ion channel activity in the host plasma membrane of Plasmodium falciparum-infected human red blood cells (RBCs). However, conflicting data have been published with regard to the characteristics of induced channel activity measured in the whole-cell configuration of the patch-clamp technique. In an effort to establish the reasons for these discrepancies, we demonstrate here two factors that have been found to modulate whole-cell recordings in malaria-infected RBCs. Firstly, negative holding potentials reduced inward currents (i.e. at negative potentials), although this result was highly complex. Secondly, the addition of human serum increased outward currents (i.e. at positive potentials) by approximately 4-fold and inward currents by approximately 2-fold. These two effects may help to resolve the conflicting data in the literature, although further investigation is required to understand the underlying mechanisms and their physiological relevance in detail. PMID:12937282

  4. Faster multiple emulsification with drop splitting.

    Science.gov (United States)

    Abate, Adam R; Weitz, David A

    2011-06-07

    Microfluidic devices can form emulsions in which the drops have an intricate, controlled structure; however, a challenge is that the droplets are produced slowly, typically only a few millilitres per hour. Here, we present a simple technique to increase the production rate. Using a large drop maker, we produce large drops at a fast volumetric rate; by splitting these drops several times in a splitting array, we create drops of the desired small size. The advantage of this over forming the small drops directly using a small drop maker is that the drops can be formed at much faster rates. This can be applied to the production of single and multiple emulsions.

  5. Thermocapillary reorientation of Janus drops

    Science.gov (United States)

    Rosales, Rodolfo; Saenz, Pedro

    2017-11-01

    Janus drops, named after the Ancient Roman two-faced god, are liquid drops formed from two immiscible fluids. Experimental observations indicate that a Janus drop may re-orientate in response to an applied external thermal gradient due to the Marangoni effect. Depending on the angle between the interior interface and the direction of the temperature gradient, disparities in the physical properties of the constituent liquids may lead to asymmetries in the thermocapillary flow. As a result, the drop will move along a curved path until a torque-free configuration is achieved, point after which it will continue on a straight trajectory. Here, we present the results of a theoretical investigation of this realignment phenomenon in the Stokes regime and in the limit of non-deformable interfaces. A 3D semi-analytical method in terms of polar spherical harmonics is developed to characterize and rationalize the hydrodynamic response (forces and torques), flow (velocity and temperature distribution) and trajectory of a Janus drop moving during the temperature-driven reorientation process. Furthermore, we discuss how this phenomenon may be exploited to develop dynamically reconfigurable micro-lenses. This work was partially supported by the US National Science Foundation through Grants DMS-1614043 and DMS-1719637.

  6. Assessement of rheumatic diseases with computational radiology: current status and future potential

    DEFF Research Database (Denmark)

    Peloschek, Philipp; Boesen, Mikael; Donner, Rene

    2009-01-01

    In recent years, several computational image analysis methods to assess disease progression in rheumatic diseases were presented. This review article explains the basics of these methods as well as their potential application in rheumatic disease monitoring, it covers radiography, sonography...

  7. Mutagenic and genotoxic potential of direct electric current in Escherichia coli and Salmonella thyphimurium strains.

    Science.gov (United States)

    Gomes, Marina das Neves; Cardoso, Janine Simas; Leitão, Alvaro Costa; Quaresma, Carla Holandino

    2016-05-01

    Direct electric current has several therapeutic uses such as antibacterial and antiprotozoal action, tissues scarring and regeneration, as well as tumor treatment. This method has shown promising results in vivo and in vitro, with significant efficacy and almost no side effects. Considering lack of studies regarding direct electric current mutagenic and/or genotoxic effects, the present work evaluated both aspects by using five different bacterial experimental assays: survival of repair-deficient mutants, Salmonella-histidine reversion mutagenesis (Ames test), forward mutations to rifampicin resistance, phage reactivation, and lysogenic induction. In these experimental conditions, cells were submitted to an approach that allows evaluation of anodic, cathodic, and electro-ionic effects generated by 2 mA of direct electric current, with doses ranging from 0.36 to 3.60 Coulombs. Our results showed these doses did not induce mutagenic or genotoxic effects. © 2016 Wiley Periodicals, Inc.

  8. Climate Analogues Suggest Limited Potential for Intensification of Production on Current Croplands Under Climate Change

    Science.gov (United States)

    Pugh, T. A. M.; Mueller, C.; Elliott, J.; Deryng, D.; Folberth, C.; Olin, S.; Schmid, E.; Arneth, A.

    2016-01-01

    Climate change could pose a major challenge to efforts towards strongly increase food production over the coming decades. However, model simulations of future climate-impacts on crop yields differ substantially in the magnitude and even direction of the projected change. Combining observations of current maximum-attainable yield with climate analogues, we provide a complementary method of assessing the effect of climate change on crop yields. Strong reductions in attainable yields of major cereal crops are found across a large fraction of current cropland by 2050. These areas are vulnerable to climate change and have greatly reduced opportunity for agricultural intensification. However, the total land area, including regions not currently used for crops, climatically suitable for high attainable yields of maize, wheat and rice is similar by 2050 to the present-day. Large shifts in land-use patterns and crop choice will likely be necessary to sustain production growth rates and keep pace with demand.

  9. Negative-ion current density dependence of the surface potential of insulated electrode during negative-ion implantation

    International Nuclear Information System (INIS)

    Tsuji, Hiroshi; Okayama, Yoshio; Toyota, Yoshitaka; Gotoh, Yasuhito; Ishikawa, Junzo; Sakai, Shigeki; Tanjyo, Masayasu; Matsuda, Kouji.

    1994-01-01

    Positive ion implantation has been utilized as the method of impurity injection in ultra-LSI production, but the problem of substrate charging cannot be resolved by conventional charge compensation method. It was forecast that by negative ion implantation, this charging problem can be resolved. Recently the experiment on the negative ion implantation into insulated electrodes was carried out, and the effect of negative ion implantation to this problem was proved. However, the dependence of charged potential on the increase of negative ion current at the time of negative ion implantation is a serious problem in large current negative ion implantation hereafter. The charged potential of insulated conductor substrates was measured by the negative ion implantation using the current up to several mA/cm 2 . The experimental method is explained. Medium current density and high current density negative ion implantation and charged potential are reported. Accordingly in negative ion implantation, if current density is optimized, the negative ion implantation without charging can be realized. (K.I.)

  10. Energy Yield Potential Estimation Using Marine Current Turbine Simulations for the Bosphorus

    DEFF Research Database (Denmark)

    Yazicioglu, Hasan; Tunc, K. M. Murat; Ozbek, Muammer

    2017-01-01

    In this work, several simulations and analyses are carried out to investigate the feasibility of generating electricity from sea underwater currents at Istanbul Bosphorus Strait. Bosphorus is a natural canal which forms a border between Europe and Asia by connecting Black Sea and Marmara Sea...

  11. Atlas of current and potential future distributions of common trees of the eastern United States

    Science.gov (United States)

    Louis R. Iverson; Anantha M. Prasad; Betsy J. Hale; Elaine Kennedy Sutherland

    1999-01-01

    This atlas documents the current and possible future distribution of 80 common tree species in the Eastern United States and gives detailed information on environmental characteristics defining these distributions. Also included are outlines of life history characteristics and summary statistics for these species. Much of the data are derived from Forest Inventory and...

  12. A current sensor based on the giant magnetoresistance effect: design and potential smart grid applications.

    Science.gov (United States)

    Ouyang, Yong; He, Jinliang; Hu, Jun; Wang, Shan X

    2012-11-09

    Advanced sensing and measurement techniques are key technologies to realize a smart grid. The giant magnetoresistance (GMR) effect has revolutionized the fields of data storage and magnetic measurement. In this work, a design of a GMR current sensor based on a commercial analog GMR chip for applications in a smart grid is presented and discussed. Static, dynamic and thermal properties of the sensor were characterized. The characterizations showed that in the operation range from 0 to ±5 A, the sensor had a sensitivity of 28 mV·A(-1), linearity of 99.97%, maximum deviation of 2.717%, frequency response of −1.5 dB at 10 kHz current measurement, and maximum change of the amplitude response of 0.0335%·°C(-1) with thermal compensation. In the distributed real-time measurement and monitoring of a smart grid system, the GMR current sensor shows excellent performance and is cost effective, making it suitable for applications such as steady-state and transient-state monitoring. With the advantages of having a high sensitivity, high linearity, small volume, low cost, and simple structure, the GMR current sensor is promising for the measurement and monitoring of smart grids.

  13. Gasification of solid waste — potential and application of co-current moving bed gasifiers

    NARCIS (Netherlands)

    Groeneveld, M.J.; van Swaaij, Willibrordus Petrus Maria

    1979-01-01

    A review is given of gasification processes for solid fuels with special emphasis on waste gasification. Although the co-current moving bed gasifier has not been under consideration for a long time, it offers interesting possibilities for waste gasification. Some operational data are given. Two

  14. Internal oscillating current-sustained RF plasmas: Parameters, stability, and potential for surface engineering

    DEFF Research Database (Denmark)

    Ostrikov, K.; Tsakadze, E.L.; Tsakadze, Z.L.

    2005-01-01

    A new source of low-frequency (0.46 MHz) inductively coupled plasmas sustained by the internal planar "unidirectional" RF current driven through a specially designed internal antenna configuration has been developed. The experimental results of the investigation of the optical and global argon pl...... applications and surface engineering. (c) 2005 Elsevier B.V. All rights reserved....

  15. A Current Sensor Based on the Giant Magnetoresistance Effect: Design and Potential Smart Grid Applications

    Directory of Open Access Journals (Sweden)

    Shan X. Wang

    2012-11-01

    Full Text Available Advanced sensing and measurement techniques are key technologies to realize a smart grid. The giant magnetoresistance (GMR effect has revolutionized the fields of data storage and magnetic measurement. In this work, a design of a GMR current sensor based on a commercial analog GMR chip for applications in a smart grid is presented and discussed. Static, dynamic and thermal properties of the sensor were characterized. The characterizations showed that in the operation range from 0 to ±5 A, the sensor had a sensitivity of 28 mV·A−1, linearity of 99.97%, maximum deviation of 2.717%, frequency response of −1.5 dB at 10 kHz current measurement, and maximum change of the amplitude response of 0.0335%·°C−1 with thermal compensation. In the distributed real-time measurement and monitoring of a smart grid system, the GMR current sensor shows excellent performance and is cost effective, making it suitable for applications such as steady-state and transient-state monitoring. With the advantages of having a high sensitivity, high linearity, small volume, low cost, and simple structure, the GMR current sensor is promising for the measurement and monitoring of smart grids.

  16. Modeling fire-driven deforestation potential in Amazonia under current and projected climate conditions

    NARCIS (Netherlands)

    Le Page, Y.; van der Werf, G.R.; Morton, D.C.; Pereira, J.M.C.

    2010-01-01

    Fire is a widely used tool to prepare deforested areas for agricultural use in Amazonia. Deforestation is currently concentrated in seasonal forest types along the arc of deforestation, where dry-season conditions facilitate burning of clear-felled vegetation. Interior Amazon forests, however, are

  17. Finite element formulation using magnetic vector potential approach: effects of displacement current in magneto-electro-elastic cylindrical shells

    International Nuclear Information System (INIS)

    Biju, B; Ganesan, N; Shankar, K

    2010-01-01

    Displacement current is associated with the generation of magnetic fields due to time-varying electric fields. The harmonic response of a magneto-electro-elastic axisymmetric cylinder accounting for displacement current is carried out using the semi-analytical finite element method. The non-conservative electric field is represented using a magnetic vector potential. Studies are carried out for the first circumferential harmonics of the shell structure with the clamped–free boundary condition. The contribution made to the magnetic flux density by the electric displacement current is very small at lower frequencies but it becomes significant at higher frequencies

  18. ABCXYZ: vector potential (A) and magnetic field (B) code (C) for Cartesian (XYZ) geometry using general current elements

    International Nuclear Information System (INIS)

    Anderson, D.V.; Breazeal, J.; Finan, C.H.; Johnston, B.M.

    1976-01-01

    ABCXYZ is a computer code for obtaining the Cartesian components of the vector potential and the magnetic field on an observed grid from an arrangement of current-carrying wires. Arbitrary combinations of straight line segments, arcs, and loops are allowed in the specification of the currents. Arbitrary positions and orientations of the current-carrying elements are also allowed. Specification of the wire diameter permits the computation of well-defined fields, even in the interiors of the conductors. An optical feature generates magnetic field lines. Extensive graphical and printed output is available to the user including contour, grid-line, and field-line plots. 12 figures, 1 table

  19. Eye-Drops for Activation of DREADDs

    Directory of Open Access Journals (Sweden)

    William T. Keenan

    2017-11-01

    Full Text Available Designer Receptors Exclusively Activated by Designer Drugs (DREADDs are an important tool for modulating and understanding neural circuits. Depending on the DREADD system used, DREADD-targeted neurons can be activated or repressed in vivo following a dose of the DREADD agonist clozapine-N-oxide (CNO. Because DREADD experiments often involve behavioral assays, the method of CNO delivery is important. Currently, the most common delivery method is intraperitoneal (IP injection. IP injection is both a fast and reliable technique, but it is painful and stressful particularly when many injections are required. We sought an alternative CNO delivery paradigm, which would retain the speed and reliability of IP injections without being as invasive. Here, we show that CNO can be effectively delivered topically via eye-drops. Eye-drops robustly activated DREADD-expressing neurons in the brain and peripheral tissues and does so at the same dosages as IP injection. Eye-drops provide an easier, less invasive and less stressful method for activating DREADDs in vivo.

  20. Interfacial Instabilities in Evaporating Drops

    Science.gov (United States)

    Moffat, Ross; Sefiane, Khellil; Matar, Omar

    2007-11-01

    We study the effect of substrate thermal properties on the evaporation of sessile drops of various liquids. An infra-red imaging technique was used to record the interfacial temperature. This technique illustrates the non-uniformity in interfacial temperature distribution that characterises the evaporation process. Our results also demonstrate that the evaporation of methanol droplets is accompanied by the formation of wave-trains in the interfacial temperature field; similar patterns, however, were not observed in the case of water droplets. More complex patterns are observed for FC-72 refrigerant drops. The effect of substrate thermal conductivity on the structure of the complex pattern formation is also elucidated.

  1. The effect of ultraviolet on direct current potentials of the human skin

    Directory of Open Access Journals (Sweden)

    A. O. Lazarev

    2017-01-01

    Full Text Available Aim of the study. investigation of the suntan on the level of omnipresent electrical potential of skin in frames of development of the hypothesis about the melanocyte participation in skin electrical activity formation. Material and methods. 11 men and 11 women on summer holyday took part in investigation. The relationship between the levels of skin omnipresent electrical potential and the reflection factor were investigated. The omnipresent electrical potentials were registered as the potential differences between the two areas on skin using the Orion 261S pH meter and the liquid Ag/AgCl electrodes of the same company. The reflecting factor was estimated with the help of the spectroradiometer LI-1800 (“LI-COR” using the included intgrational sphere 1800-12 coated with barium sulfate. Hole size was 1,45 cm. The reflection factor was estimated at the wave band 375-800 nanometers with the scanning pitch 1 nm. Main results. There is a mathematical relation between the magnitudes of potential differences and the reflection factors of the areas of sunburnt skin and the areas of the skin not affected with sun at wave light 620-729 nm. The relationship could be approximated in linear equation. Spearman correlation factor between these two parameters was -0,43 (p = 0,045, between the differences in levels of skin omnipresent electrical potential and the reflection factors of the sunburnt skin was r = -0,52 (p = 0,01, between the differences of the electrical potentials of sunburnt skin and the skin not affected with sun was r = -0,28 (p = 0,2. The presented results of investigation and the data from literature allow to conclude that there is a positive correlation between the level of omnipresent electrical potential of skin and the quantity of melanosomes filled with melanin. Conclusion. It is suggested that melanocytes take part in formation of the skin electrical activity via melanosomes filled with melanin. At the same time the melanocyte

  2. Assessement of rheumatic diseases with computational radiology: Current status and future potential

    International Nuclear Information System (INIS)

    Peloschek, Philipp; Boesen, Mikael; Donner, Rene; Kubassova, Olga; Birngruber, Erich; Patsch, Janina; Mayerhoefer, Marius; Langs, Georg

    2009-01-01

    In recent years, several computational image analysis methods to assess disease progression in rheumatic diseases were presented. This review article explains the basics of these methods as well as their potential application in rheumatic disease monitoring, it covers radiography, sonography as well as magnetic resonance imaging in quantitative analysis frameworks.

  3. Current Problems in Developing the Natural Resource Potential of the Russian Exclave in the Baltic

    Science.gov (United States)

    Fedorov, Gennady M.; Gritsenko, Vladimir A.; Dedkov, Viktor P.; Zotov, Sergey I.; Chernyshkov, Pavel P.

    2016-01-01

    The compact Kaliningrad region boasts relatively favourable environmental conditions and a remarkable diversity of natural resources. This article seeks to compare the natural resources of the exclave and other Russian regions. The authors examine recent statistical data to estimate the region's natural and resource potential, analyse its…

  4. Euler potentials of current-free fields expressed in spherical harmonics

    Science.gov (United States)

    Stern, David P.

    1994-01-01

    Given a magnetic field B = -del(vector differential operator)(sub gamma) with gamma expanded in spherical harmonics, it is shown that analytic Euler potentials may be derived for B if gamma is asymmetrical but contains only the contribution of a single index n. This work generalizes a result for sectorial harmonics with n = m, derived by Willis and Gardiner (1988).

  5. The emerging field of radiomics in esophageal cancer : Current evidence and future potential

    NARCIS (Netherlands)

    van Rossum, Peter S N; Xu, Cai; Fried, David V.; Goense, Lucas; Court, Laurence E.; Lin, Steven H.

    2016-01-01

    'Radiomics' is the name given to the emerging field of extracting additional information from standard medical images using advanced feature analysis. This innovative form of quantitative image analysis appears to have future potential for clinical practice in patients with esophageal cancer by

  6. The Development of B2C E-Commerce in Greece: Current Situation and Future Potential.

    Science.gov (United States)

    Kardaras, Dimitris; Papathanassiou, Eleutherios

    2000-01-01

    Reports on the results of a survey of 120 companies in Greece that evaluated the potential of business to customer (B2C) Internet applications and investigated how the Internet and e-commerce can offer new opportunities for businesses to improve their customers' satisfaction. Discusses electronic commerce problems and future technology. (Contains…

  7. Analytical Evaluation of Preliminary Drop Tests Performed to Develop a Robust Design for the Standardized DOE Spent Nuclear Fuel Canister

    International Nuclear Information System (INIS)

    Ware, A.G.; Morton, D.K.; Smith, N.L.; Snow, S.D.; Rahl, T.E.

    1999-01-01

    The Department of Energy (DOE) has developed a design concept for a set of standard canisters for the handling, interim storage, transportation, and disposal in the national repository, of DOE spent nuclear fuel (SNF). The standardized DOE SNF canister has to be capable of handling virtually all of the DOE SNF in a variety of potential storage and transportation systems. It must also be acceptable to the repository, based on current and anticipated future requirements. This expected usage mandates a robust design. The canister design has four unique geometries, with lengths of approximately 10 feet or 15 feet, and an outside nominal diameter of 18 inches or 24 inches. The canister has been developed to withstand a drop from 30 feet onto a rigid (flat) surface, sustaining only minor damage - but no rupture - to the pressure (containment) boundary. The majority of the end drop-induced damage is confined to the skirt and lifting/stiffening ring components, which can be removed if de sired after an accidental drop. A canister, with its skirt and stiffening ring removed after an accidental drop, can continue to be used in service with appropriate operational steps being taken. Features of the design concept have been proven through drop testing and finite element analyses of smaller test specimens. Finite element analyses also validated the canister design for drops onto a rigid (flat) surface for a variety of canister orientations at impact, from vertical to 45 degrees off vertical. Actual 30-foot drop testing has also been performed to verify the final design, though limited to just two full-scale test canister drops. In each case, the analytical models accurately predicted the canister response

  8. A Brief Review of Current Lithium Ion Battery Technology and Potential Solid State Battery Technologies

    OpenAIRE

    Ulvestad, Andrew

    2018-01-01

    Solid state battery technology has recently garnered considerable interest from companies including Toyota, BMW, Dyson, and others. The primary driver behind the commercialization of solid state batteries (SSBs) is to enable the use of lithium metal as the anode, as opposed to the currently used carbon anode, which would result in ~20% energy density improvement. However, no reported solid state battery to date meets all of the performance metrics of state of the art liquid electrolyte lithiu...

  9. Review of comparative LCAs of food waste management systems – Current status and potential improvements

    International Nuclear Information System (INIS)

    Bernstad, A.; Cour Jansen, J. la

    2012-01-01

    Highlights: ► GHG-emissions from different treatment alternatives vary largely in 25 reviewed comparative LCAs of bio-waste management. ► System-boundary settings often vary largely in reviewed studies. ► Existing LCA guidelines give varying recommendations in relation to several key issues. - Abstract: Twenty-five comparative cycle assessments (LCAs) addressing food waste treatment were reviewed, including the treatment alternatives landfill, thermal treatment, compost (small and large scale) and anaerobic digestion. The global warming potential related to these treatment alternatives varies largely amongst the studies. Large differences in relation to setting of system boundaries, methodological choices and variations in used input data were seen between the studies. Also, a number of internal contradictions were identified, many times resulting in biased comparisons between alternatives. Thus, noticed differences in global warming potential are not found to be a result of actual differences in the environmental impacts from studied systems, but rather to differences in the performance of the study. A number of key issues with high impact on the overall global warming potential from different treatment alternatives for food waste were identified through the use of one-way sensitivity analyses in relation to a previously performed LCA of food waste management. Assumptions related to characteristics in treated waste, losses and emissions of carbon, nutrients and other compounds during the collection, storage and pretreatment, potential energy recovery through combustion, emissions from composting, emissions from storage and land use of bio-fertilizers and chemical fertilizers and eco-profiles of substituted goods were all identified as highly relevant for the outcomes of this type of comparisons. As the use of LCA in this area is likely to increase in coming years, it is highly relevant to establish more detailed guidelines within this field in order to

  10. The current bioenergy production potential of semi-arid and arid regions in sub-Saharan Africa

    NARCIS (Netherlands)

    Wicke, B.; Smeets, E.M.W.; Watson, H.; Faaij, A.P.C.

    2011-01-01

    This article assesses the current technical and economic potential of three bioenergy production systems (cassava ethanol, jatropha oil and fuelwood) in semi-arid and arid regions of eight sub-Saharan African countries. The results indicate that the availability of land for energy production ranges

  11. A Study of Second-Year Engineering Students' Alternative Conceptions about Electric Potential, Current Intensity and Ohm's Law

    Science.gov (United States)

    Periago, M. Cristina; Bohigas, Xavier

    2005-01-01

    The aim of this research was to evaluate and analyse second-year industrial engineering and chemical engineering students prior knowledge of conceptual aspects of "circuit theory". Specifically, we focused on the basic concepts of electric potential and current intensity and on the fundamental relationship between them as expressed by Ohm's law.…

  12. Shared Solar: Current Landscape, Market Potential, and the Impact of Federal Securities Regulation; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-27

    This presentation provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program's structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  13. Estimating urban forest carbon sequestration potential in the southern United States using current remote sensing imagery sources

    Science.gov (United States)

    Krista Merry; Pete Bettinger; Jacek Siry; J. Michael Bowker

    2015-01-01

    With an increased interest in reducing carbon dioxide in the atmosphere, tree planting and maintenance in urban areas has become a viable option for increasing carbon sequestration. Methods for assessing the potential for planting trees within an urban area should allow for quick, inexpensive, and accurate estimations of available land using current remote sensing...

  14. Will Robots Ever Replace Attendants? Exploring the Current Capabilities and Future Potential of Robots in Education and Rehabilitation.

    Science.gov (United States)

    Lees, David; LePage, Pamela

    1994-01-01

    This article describes the current capabilities and future potential of robots designed as supplements or replacements for human assistants or as tools for education and rehabilitation of people with disabilities. Review of robots providing educational, vocational, or independent living assistance concludes that eventually effective, reliable…

  15. Models of the impact of dengue vaccines: a review of current research and potential approaches

    Science.gov (United States)

    Johansson, Michael A.; Hombach, Joachim; Cummings, Derek A.T.

    2015-01-01

    Vaccination reduces transmission of pathogens directly, by preventing individual infections, and indirectly, by reducing the probability of contact between infected individuals and susceptible ones. The potential combined impact of future dengue vaccines can be estimated using mathematical models of transmission. However, there is considerable uncertainty in the structure of models that accurately represent dengue transmission dynamics. Here, we review models that could be used to assess the impact of future dengue immunization programmes. We also review approaches that have been used to validate and parameterize models. A key parameter of all approaches is the basic reproduction number, R0, which can be used to determine the critical vaccination fraction to eliminate transmission. We review several methods that have been used to estimate this quantity. Finally, we discuss the characteristics of dengue vaccines that must be estimated to accurately assess their potential impact on dengue virus transmission. PMID:21699949

  16. Models of the impact of dengue vaccines: a review of current research and potential approaches.

    Science.gov (United States)

    Johansson, Michael A; Hombach, Joachim; Cummings, Derek A T

    2011-08-11

    Vaccination reduces transmission of pathogens directly, by preventing individual infections, and indirectly, by reducing the probability of contact between infected individuals and susceptible ones. The potential combined impact of future dengue vaccines can be estimated using mathematical models of transmission. However, there is considerable uncertainty in the structure of models that accurately represent dengue transmission dynamics. Here, we review models that could be used to assess the impact of future dengue immunization programmes. We also review approaches that have been used to validate and parameterize models. A key parameter of all approaches is the basic reproduction number, R(0), which can be used to determine the critical vaccination fraction to eliminate transmission. We review several methods that have been used to estimate this quantity. Finally, we discuss the characteristics of dengue vaccines that must be estimated to accurately assess their potential impact on dengue virus transmission. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Euler potentials for two current sheets of nonzero thickness along ambient uniform magnetic field

    Czech Academy of Sciences Publication Activity Database

    Vandas, Marek; Romashets, E.

    2014-01-01

    Roč. 119, č. 4 (2014), s. 2579-2592 ISSN 2169-9380 R&D Projects: GA ČR GA205/09/0170; GA MŠk ME09032 Grant - others:GA ČR(CZ) GA14–19376S Institutional support: RVO:67985815 Keywords : Euler potentials * magnetic fields * energetic particles Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.426, year: 2014

  18. Survey of current Swiss pig feeding practices and potential for ammonia emission reduction

    OpenAIRE

    Spring, P.; Bracher, A.

    2017-01-01

    Controlling potentially harmful and polluting emissions from farms is important in the developed world, where legislation exists in many countries limiting emissions such as ammonia and controlling how manure is disposed of from intensive farming operations. In Switzerland, there are legal agreements concerning controls of ammonia emissions, most especially from farms. Ammonia production from pig farms can be controlled by dietary intervention, such as reducing protein levels, which in turn r...

  19. Fatigue Risk Management in Aviation Maintenance: Current Best Practices and Potential Future Countermeasures

    Science.gov (United States)

    2011-06-01

    a maintenance organization to permit a maintainer who is significantly impaired by fatigue or a psychoactive substance to carry out maintenance on...recommended that the person avoids the routine consumption of caffeinated drinks, as caffeine is less effective as an alerting agent for people...of sleep loss for some mili- tary missions (Caldwell et al., 2009). There have been suggestions that such substances may have potential as fatigue

  20. Effect of ethanol on action potential and ionic membrane currents in rat ventricular myocytes

    Czech Academy of Sciences Publication Activity Database

    Bébarová, M.; Matejovič, P.; Pásek, Michal; Ohlídalová, D.; Jansová, D.; Šimurdová, M.; Šimurda, J.

    2010-01-01

    Roč. 200, č. 4 (2010), s. 301-314 ISSN 1748-1708 Institutional research plan: CEZ:AV0Z20760514 Keywords : action potential * ethanol * rat ventricular myocyte Subject RIV: BO - Biophysics Impact factor: 3.138, year: 2010 http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=15&SID=Y1pmpi@7k2HPEc8ehEE&page=1&doc=1&colname=WOS

  1. Current View on Osteogenic Differentiation Potential of Mesenchymal Stromal Cells Derived from Placental Tissues.

    Science.gov (United States)

    Kmiecik, Gabriela; Spoldi, Valentina; Silini, Antonietta; Parolini, Ornella

    2015-08-01

    Mesenchymal stromal cells (MSC) isolated from human term placental tissues possess unique characteristics, including their peculiar immunomodulatory properties and their multilineage differentiation potential. The osteogenic differentiation capacity of placental MSC has been widely disputed, and continues to be an issue of debate. This review will briefly discuss the different MSC populations which can be obtained from different regions of human term placenta, along with their unique properties, focusing specifically on their osteogenic differentiation potential. We will present the strategies used to enhance osteogenic differentiation potential in vitro, such as through the selection of subpopulations more prone to differentiate, the modification of the components of osteo-inductive medium, and even mechanical stimulation. Accordingly, the applications of three-dimensional environments in vitro and in vivo, such as non-synthetic, polymer-based, and ceramic scaffolds, will also be discussed, along with results obtained from pre-clinical studies of placental MSC for the regeneration of bone defects and treatment of bone-related diseases.

  2. Sensitivity of Rabbit Ventricular Action Potential and Ca2+ Dynamics to Small Variations in Membrane Currents and Ion Diffusion Coefficients

    Directory of Open Access Journals (Sweden)

    Yuan Hung Lo

    2013-01-01

    Full Text Available Little is known about how small variations in ionic currents and Ca2+ and Na+ diffusion coefficients impact action potential and Ca2+ dynamics in rabbit ventricular myocytes. We applied sensitivity analysis to quantify the sensitivity of Shannon et al. model (Biophys. J., 2004 to 5%–10% changes in currents conductance, channels distribution, and ion diffusion in rabbit ventricular cells. We found that action potential duration and Ca2+ peaks are highly sensitive to 10% increase in L-type Ca2+ current; moderately influenced by 10% increase in Na+-Ca2+ exchanger, Na+-K+ pump, rapid delayed and slow transient outward K+ currents, and Cl− background current; insensitive to 10% increases in all other ionic currents and sarcoplasmic reticulum Ca2+ fluxes. Cell electrical activity is strongly affected by 5% shift of L-type Ca2+ channels and Na+-Ca2+ exchanger in between junctional and submembrane spaces while Ca2+-activated Cl−-channel redistribution has the modest effect. Small changes in submembrane and cytosolic diffusion coefficients for Ca2+, but not in Na+ transfer, may alter notably myocyte contraction. Our studies highlight the need for more precise measurements and further extending and testing of the Shannon et al. model. Our results demonstrate usefulness of sensitivity analysis to identify specific knowledge gaps and controversies related to ventricular cell electrophysiology and Ca2+ signaling.

  3. Pressure drop in contraction flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find...

  4. Fluid flow in drying drops

    NARCIS (Netherlands)

    Gelderblom, Hanneke

    2013-01-01

    When a suspension drop evaporates, it leaves behind a drying stain. Examples of these drying stains encountered in daily life are coffee or tea stains on a table top, mineral rings on glassware that comes out of the dishwasher, or the salt deposits on the streets in winter. Drying stains are also

  5. Drops, contact lines, and electrowetting

    NARCIS (Netherlands)

    't Mannetje, Dieter

    2013-01-01

    In this work, we study the behaviour of drops and contact lines under the influence of electric fields, and how these can answer fundamental and industrial questions. Our focus is on studying the varying balance of the electric field, hysteresis forces and inertia as the speed of a contact line

  6. Marine phospholipids: The current understanding of their oxidation mechanisms and potential uses for food fortification

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2017-01-01

    and storage of marine PL. For example, nonenzymatic browning reactions may occur between lipid oxidation products and primary amine group from phosphatidylethanolamine or amino acid residues that are present inmarine PL. Therefore, marine PL contain products from nonenzymatic browning and lipid oxidation...... reactions, namely, Strecker aldehydes, pyrroles, oxypolymers, and other impurities that may positively or negatively affect the oxidative stability and quality of marine PL. This review was undertaken to provide the industry and academia with an overview of the current understanding of the quality changes...... taking place in PL during their production and their storage as well as with regards to their utilization for food fortification....

  7. How to harness the performance potential of current multi-core processors

    International Nuclear Information System (INIS)

    Jarp, Sverre; Lazzaro, Alfio; Leduc, Julien; Nowak, Andrzej

    2011-01-01

    Leakage currents have put a stop to the semiconductor industry's ability to increase processor frequency in order to enhance the performance of new microprocessors. Instead, we observe a slew of changes inside the micro-architecture with an aim of enhancing the performance. Several of these changes, however, do not translate into automatic speed improvements for the software. This paper discusses the increased complexity of modern microprocessors by separating out into dimensions each feature that impacts performance and mentions briefly ways of improving software, in particular that of the High Energy Physics community, to take full advantage.

  8. Smart grids in the colombian electric system: Current situation and potential opportunities

    Directory of Open Access Journals (Sweden)

    William Mauricio Giral Ramírez

    2017-07-01

    Full Text Available Context: This paper focuses on providing a functional analysis of smart grids, with the purpose of establishing a framework to identify the main characteristics of the current electric interconnection system in Colombia. It also names the positive incentives proposed by the Colombian government to support both research and development projects that implement non-conventional energy sources and promoting energy management based on efficiency. Method: An architecture model that describes the components interoperability of a smart grid is presented using a descriptive methodology. Results: The results include a list of the objectives established by the Colombian public and private entities related to energy development, specially focusing on the opportunities to provide some kind of artificial intelligence to the current electrical system. Conclusions: It is necessary for the Colombian energy system to supply the energy demand considering electrical safety, social equity, and the minimum environmental impact. These restrictions impose new challenges for the energy system itself: From a technical point of view, the traditional electrical grid must be outfitted with the characteristics of a smart grid, and from a legal perspective, it is essential to generate a clear regulatory framework that promotes the development of this type of technology.

  9. Transcranial Alternating Current Stimulation: A potential risk for genetic generalized epilepsy patients (Study Case

    Directory of Open Access Journals (Sweden)

    Daniel San Juan Orta

    2016-11-01

    Full Text Available Transcranial alternating current stimulation (tACS is a re-emergent neuromodulation technique that consists in the external application of oscillating electrical currents that induces changes in cortical excitability. We present the case of a 16-year-old female with pharmaco-resistant juvenile myoclonic epilepsy to three antiepileptic’s drugs characterized by four myoclonic and 20 absence seizures monthly. She received tACS at 1mA@3Hz pulse train during 60 minutes over Fp1-Fp2 (10-20 EEG international system position during 4 consecutive days using an Endeavor™ IOM Systems device® (Natus Medical Incorporated, Middleton, WI, USA. At the one-month follow-up, she reported a 75% increase in seizures frequency (only myoclonic and tonic-clonic events and developed a 24h myoclonic status epilepticus that resolved with oral clonazepam and intravenous valproate. At the two-month follow-up, the patient reported a 15-day seizure-free period.

  10. Therapeutic potential of mesenchymal stem cells in gastrointestinal cancers – current evidence

    Directory of Open Access Journals (Sweden)

    Qin J

    2016-09-01

    Full Text Available Jiwei Qin,1 Yue Zhao,2 Yan Wang,1 Christopher Betzler,2 Felix C Popp,2 Arvid Sen Gupta,2 Daniela Augsburger,2 Peter Camaj,2 Peter J Nelson,3 Christiane J Bruns2 1Department of Surgery, University of Munich, Munich, Germany; 2Department of Surgery, Otto-von-Guericke University, Magdeburg, Germany; 3Clinical Biochemistry Group, Medizinische Klinik und Poliklinik IV, University of Munich, Munich, Germany Abstract: Mesenchymal stem (or stromal cells (MSCs are nonhematopoietic progenitor cells that can be obtained from bone marrow and adipose tissue. Due to the ability of MSCs to migrate to damaged and cancerous tissue, this behavior of MSCs has been exploited as a tumor-targeting strategy for cell-based cancer therapy to improve the efficacy and minimize the toxicity of current gene therapy approaches in the treatment of cancers. In this review, we focus on the current developments of MSC-based gene therapy in gastrointestinal cancer studies, in particular, the role of MSCs as tumor-targeted therapy vehicles and the prospects in their clinical application. Keywords: mesenchymal stem cells, gastrointestinal cancers, cancer therapy

  11. Understanding the current status and exploring the potential for distance education in public health in India.

    Science.gov (United States)

    Sharma, Kavya; George, Sunil; Zodpey, Sanjay

    2011-01-01

    Continuing education of health care providers plays an important role in producing a health work force that is efficient and effective. In India public health education has primarily relied on conventional methods of training. However, such methods have limitations in equipping the health workforce of a vast and varied country like India. This paper analyzes the current status of distance education in public health and lists the various courses that are presently available in India through the distance education mode. Presently 25 institutions in India are offering 69 courses in various domains of public health through distance education. The providers of these programs comprised both government and private educational institutions. This paper also points out the role and importance of various stakeholders in the design and delivery of distance education programs in public health and raises key areas that need attention in the governance of such programs. It urges the use of digital technology in the delivery of distance education programs and points out how distance education that is designed and delivered using the latest technology could address the current gap in training human resources for health in India.

  12. An improved current potential method for fast computation of stellarator coil shapes

    Science.gov (United States)

    Landreman, Matt

    2017-04-01

    Several fast methods for computing stellarator coil shapes are compared, including the classical NESCOIL procedure (Merkel 1987 Nucl. Fusion 27 867), its generalization using truncated singular value decomposition, and a Tikhonov regularization approach we call REGCOIL in which the squared current density is included in the objective function. Considering W7-X and NCSX geometries, and for any desired level of regularization, we find the REGCOIL approach simultaneously achieves lower surface-averaged and maximum values of both current density (on the coil winding surface) and normal magnetic field (on the desired plasma surface). This approach therefore can simultaneously improve the free-boundary reconstruction of the target plasma shape while substantially increasing the minimum distances between coils, preventing collisions between coils while improving access for ports and maintenance. The REGCOIL method also allows finer control over the level of regularization, it preserves convexity to ensure the local optimum found is the global optimum, and it eliminates two pathologies of NESCOIL: the resulting coil shapes become independent of the arbitrary choice of angles used to parameterize the coil surface, and the resulting coil shapes converge rather than diverge as Fourier resolution is increased. We therefore contend that REGCOIL should be used instead of NESCOIL for applications in which a fast and robust method for coil calculation is needed, such as when targeting coil complexity in fixed-boundary plasma optimization, or for scoping new stellarator geometries.

  13. Graduated driver licensing policy in the Great Lakes states: current benefits and future potential.

    Science.gov (United States)

    Corden, Timothy E; Tonellato, Daniel J; Frisch, Keri B; Laud, Purushottam W

    2009-11-01

    Motor vehicle crashes are the leading cause of teenage deaths in the United States. Graduated Driver Licensing (GDL) policies effectively decrease teenage crash deaths. Emerging research is identifying the most effective components of GDL. This study examines GDL policies across 6 Great Lakes states, describing the beneficial impact, and investigating how evidence-based policy modifications could further reduce teenage driving deaths and injuries. GDL policies were reviewed in 6 Great Lakes states (Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin). Incidence rate ratios for fatal and injury crashes for 16-year-old drivers were obtained from the Nationwide Review of GDL Study. Ratios were applied to the fatal and injury crashes reported from each state between 2002 and 2006 for 16-year-old drivers. The potential impact (crashes avoided) for each state was determined based on the state using a 3-phase GDL policy (a learner and intermediate stage prior to full licensure). In addition, the impact on crash reductions for each state if they had employed 5 of the recommended GDL components was determined. All 6 states had a 3-phase GDL policy, resulting in potential avoidance of 124 fatal and more than 21,000 injury crashes. The 6 states had 1 to 3 of the qualifying GDL components. If these states had adopted 5 of the qualifying components, an additional 309 fatal and more than 27,000 injury crashes could have been avoided. Three-phase GDL policy is effective at saving the lives of teenage drivers and vehicle occupants; evidence-based modification of GDL has the potential to further reduce teenage motor vehicle crash deaths and injuries.

  14. Clinical potential of methylphenidate in the treatment of cocaine addiction: a review of the current evidence

    Directory of Open Access Journals (Sweden)

    Dürsteler KM

    2015-06-01

    Full Text Available Kenneth M Dürsteler,1,2 Eva-Maria Berger,1 Johannes Strasser,1 Carlo Caflisch,2 Jochen Mutschler,2 Marcus Herdener,2 Marc Vogel1 1Center for Addictive Disorders, Psychiatric University Clinics Basel, Basel, Switzerland; 2Center for Addictive Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland Background: Cocaine use continues to be a public health problem, yet there is no proven effective pharmacotherapy for cocaine dependence. A promising approach to treating cocaine dependence may be agonist-replacement therapy, which is already used effectively in the treatment of opioid and tobacco dependence. The replacement approach for cocaine dependence posits that administration of a long-acting stimulant medication should normalize the neurochemical and behavioral perturbations resulting from chronic cocaine use. One potential medication to be substituted for cocaine is methylphenidate (MPH, as this stimulant possesses pharmacobehavioral properties similar to those of cocaine. Aim: To provide a qualitative review addressing the rationale for the use of MPH as a cocaine substitute and its clinical potential in the treatment of cocaine dependence. Methods: We searched MEDLINE for clinical studies using MPH in patients with cocaine abuse/dependence and screened the bibliographies of the articles found for pertinent literature. Results: MPH, like cocaine, increases synaptic dopamine by inhibiting dopamine reuptake. The discriminative properties, reinforcing potential, and subjective effects of MPH and cocaine are almost identical and, importantly, MPH has been found to substitute for cocaine in animals and human volunteers under laboratory conditions. When taken orally in therapeutic doses, its abuse liability, however, appears low, which is especially true for extended-release MPH preparations. Though there are promising data in the literature, mainly from case reports and

  15. A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

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    Junaid Iqbal

    2013-01-01

    Full Text Available Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30% in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics.

  16. Current and potential roles of archaeology in the development of cultural evolutionary theory.

    Science.gov (United States)

    Garvey, Raven

    2018-04-05

    Archaeology has much to contribute to the study of cultural evolution. Empirical data at archaeological timescales are uniquely well suited to tracking rates of cultural change, detecting phylogenetic signals among groups of artefacts, and recognizing long-run effects of distinct cultural transmission mechanisms. Nonetheless, these are still relatively infrequent subjects of archaeological analysis and archaeology's potential to help advance our understanding of cultural evolution has thus far been largely unrealized. Cultural evolutionary models developed in other fields have been used to interpret patterns identified in archaeological records, which in turn provides independent tests of these models' predictions, as demonstrated here through a study of late Prehistoric stone projectile points from the US Southwest. These tests may not be straightforward, though, because archaeological data are complex, often representing events aggregated over many years (or centuries or millennia), while processes thought to drive cultural evolution (e.g. biased learning) operate on much shorter timescales. To fulfil archaeology's potential, we should continue to develop models specifically tailored to archaeological circumstances, and explore ways to incorporate the rich contextual data produced by archaeological research.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).

  17. Targeting nociceptive transient receptor potential channels to treat chronic pain: current state of the field.

    Science.gov (United States)

    Moran, Magdalene M; Szallasi, Arpad

    2017-09-19

    Control of chronic pain is frequently inadequate and/or associated with intolerable adverse effects, prompting a frantic search for new therapeutics and new therapeutic targets. Nearly two decades of preclinical and clinical research supports the involvement of transient receptor potential (TRP) channels in temperature perception, nociception and sensitization. Although there has been considerable excitement around the therapeutic potential of this channel family since the cloning and identification of TRPV1 cation channels as the capsaicin receptor more than 20 years ago, only modulators of a few channels have been tested clinically. TRPV1 channel antagonists have suffered from side effects related to the channel's role in temperature sensation; however, high dose formulations of capsaicin have reached the market and shown therapeutic utility. A number of potent, small molecule antagonists of TRPA1 channels have recently advanced into clinical trials for the treatment of inflammatory and neuropathic pain, and TRPM8 antagonists are following closely behind for cold allodynia. TRPV3, TRPV4, TRPM2 and TRPM3 channels have also been of significant interest. This review discusses the preclinical promise and status of novel analgesic agents that target TRP channels and the challenges that these compounds may face in development and clinical practice. © 2017 The British Pharmacological Society.

  18. Usefulness of brain atlases in neuroradiology: Current status and future potential.

    Science.gov (United States)

    Nowinski, Wieslaw L

    2016-08-01

    Human brain atlases, although prevalent in medical education and stereotactic and functional neurosurgery, are not yet applied practically in neuroradiology. In a step towards introducing brain atlases to neuroradiology, we discuss nine different situations of potential atlas use: (1) to support interpretation of brain scans with clearly visible structures (to increase confidence of non-neuroradiologists); (2) to delineate and label scans of low anatomical content (with indiscernible or poorly visible anatomy); (3) to assist in generating the structured report; (4) to assist in interpreting small deep lesions, since an atlas's anatomical parcellation is higher than that of the interpreted scan; (5) to approximate distorted due to pathology (and unknown to the interpreter) anatomy and label it; (6) to cope with data explosion; (7) to assist in the interpretation of functional scans (to label the activation foci with the underlying anatomy and Brodmann's areas); (8) to support ischemic stroke image handling by means of atlases of anatomy and blood supply territories; and (9) to communicate image interpretation results (diagnosis) to others. The usefulness of the atlas for automatic structure identification, localisation, delineation, labelling and quantification, as well as for reporting and communication, potentially increases the interpreter's efficiency and confidence, as well as expedites image interpretation. © The Author(s) 2016.

  19. Migraine Treatment: Current Acute Medications and Their Potential Mechanisms of Action.

    Science.gov (United States)

    Ong, Jonathan Jia Yuan; De Felice, Milena

    2017-12-12

    Migraine is a common and disabling primary headache disorder with a significant socioeconomic burden. The management of migraine is multifaceted and is generally dichotomized into acute and preventive strategies, with several treatment modalities. The aims of acute pharmacological treatment are to rapidly restore function with minimal recurrence, with the avoidance of side effects. The choice of pharmacological treatment is individualized, and is based on the consideration of the characteristics of the migraine attack, the patient's concomitant medical problems, and treatment preferences. Notwithstanding, a good understanding of the pharmacodynamic and pharmacokinetic properties of the various drug options is essential to guide therapy. The current approach and concepts relevant to the acute pharmacological treatment of migraine will be explored in this review.

  20. Environmental assessment of waste management in Greenland: current practice and potential future developments

    DEFF Research Database (Denmark)

    Eisted, Rasmus; Christensen, Thomas Højlund

    2013-01-01

    The majority of the waste in Greenland is disposed of in open dumps or incinerated in simple small-scale incinerators. There are relatively few environmental regulations that control the emissions of leachate, landfill gas and/or flue gases from incineration. Only some scrap metal and hazardous...... waste are collected separately and exported to Europe. The impacts from the current waste management system were modelled from a life-cycle perspective using the LCA-waste model EASEWASTE. Impacts with regard to global warming, acidification, etc. are small (a few hundred person-equivalents (PE...... for district heating and separation of hazardous waste probably could improve Greenland’s waste management system. Segregation of recyclable materials as paper, cardboard and biowaste will do little to environmentally improve the waste management system due to loss of energy recovery from incineration...

  1. Omics-based biomarkers: current status and potential use in the clinic

    Directory of Open Access Journals (Sweden)

    Héctor Quezada

    2017-05-01

    Full Text Available In recent years, the use of high-throughput omics technologies has led to the rapid discovery of many candidate biomarkers. However, few of them have made the transition to the clinic. In this review, the promise of omics technologies to contribute to the process of biomarker development is described. An overview of the current state in this area is presented with examples of genomics, proteomics, transcriptomics, metabolomics and microbiomics biomarkers in the field of oncology, along with some proposed strategies to accelerate their validation and translation to improve the care of patients with neoplasms. The inherent complexity underlying neoplasms combined with the requirement of developing well-designed biomarker discovery processes based on omics technologies present a challenge for the effective development of biomarkers that may be useful in guiding therapies, addressing disease risks, and predicting clinical outcomes.

  2. Current source density of sustained potential shifts associated with electrographic seizures and with spreading depression in rat hippocampus.

    Science.gov (United States)

    Wadman, W J; Juta, A J; Kamphuis, W; Somjen, G G

    1992-01-20

    The membrane currents responsible for the sustained potential shifts associated with electrographic seizures and with spreading depression in hippocampus were studied in the anesthetized rat. Probes incorporating 16 sensors in a straight line, spaced at 150-microns distances, were recording the potential changes with DC-coupled amplifiers in CA1 and dentate gyrus (DG) of one hemisphere. Seizures and spreading depression were provoked by repetitive stimulation of different afferent pathways. Seizures always began in DG before CA1, regardless of the pathway stimulated. Tonic seizures were associated with a sustained negative potential shift that was largest in the cell body layers. Current source density was computed from these recordings and confirmed the presence of a current sink limited to the cell body layer throughout the duration of electrographic seizures. Spreading depression was associated with a very large sink located in the layer of apical dendrites, maximal among the proximal segment of dendrites, to which the cell body layer served as a source. We conclude that seizures are associated with an inward current in neuron cell bodies, probably flowing through membrane channels of as yet no know physiological function.

  3. Smooth pursuit eye movement preferentially facilitates motor-evoked potential elicited by anterior-posterior current in the brain.

    Science.gov (United States)

    Hiraoka, Koichi; Ae, Minori; Ogura, Nana; Komuratani, Sayo; Sano, Chisa; Shiomi, Keigo; Morita, Yuji; Yokoyama, Haruka

    2014-03-26

    Neural interaction between the eye and hand movement centers must be a critical part of the mechanism underlying eye-hand coordination. One of the previous findings supporting this view is smooth pursuit eye movement-induced suppression of motor-evoked potential (MEP) in the hand muscles. The purpose of this study was to determine which descending volleys contributing to MEP are preferentially modulated by smooth pursuit eye movement. MEP in the first dorsal interosseous muscle was elicited by different directions of current in the brain during the steady-state phase of smooth pursuit eye movement. Smooth pursuit eye movement facilitated MEP elicited by anterior-posterior (AP) current, but this effect was not seen in MEP elicited by lateromedial or posterior-anterior current. Latency of MEP elicited by AP current was significantly longer than latencies of MEPs elicited by other directions of current, indicating that AP current in the brain predominantly elicited later I-waves. We conclude that smooth pursuit eye movement in the steady-state phase preferentially facilitates MEP predominantly elicited by later I-waves generated by AP current in the brain.

  4. Electric generation and ratcheted transport of contact-charged drops

    Science.gov (United States)

    Cartier, Charles A.; Graybill, Jason R.; Bishop, Kyle J. M.

    2017-10-01

    We describe a simple microfluidic system that enables the steady generation and efficient transport of aqueous drops using only a constant voltage input. Drop generation is achieved through an electrohydrodynamic dripping mechanism by which conductive drops grow and detach from a grounded nozzle in response to an electric field. The now-charged drops are transported down a ratcheted channel by contact charge electrophoresis powered by the same voltage input used for drop generation. We investigate how the drop size, generation frequency, and transport velocity depend on system parameters such as the liquid viscosity, interfacial tension, applied voltage, and channel dimensions. The observed trends are well explained by a series of scaling analyses that provide insight into the dominant physical mechanisms underlying drop generation and ratcheted transport. We identify the conditions necessary for achieving reliable operation and discuss the various modes of failure that can arise when these conditions are violated. Our results demonstrate that simple electric inputs can power increasingly complex droplet operations with potential opportunities for inexpensive and portable microfluidic systems.

  5. A Novel Method for Measuring In-Shoe Navicular Drop during Gait

    Directory of Open Access Journals (Sweden)

    Henrik Karstoft

    2012-08-01

    Full Text Available Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user.

  6. Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia

    Science.gov (United States)

    Wakie, Tewodros; Evangelista, Paul H.; Jarnevich, Catherine S.; Laituri, Melinda

    2014-01-01

    We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM) were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species-occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC) curve (AUC). Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC = 0.94), while the potential habitat for future infestations is 5,024 km2 (AUC = 0.95). Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.

  7. Induced pluripotent stem cells: current progress and potential for regenerative medicine.

    Science.gov (United States)

    Amabile, Giovanni; Meissner, Alexander

    2009-02-01

    Lineage-restricted cells can be reprogrammed to a pluripotent state through overexpression of defined transcription factors. Here, we summarize recent progress in the direct reprogramming field and discuss data comparing embryonic stem (ES) and induced pluripotent stem (iPS) cells. Results from many independent groups suggest that mouse and human iPS cells, once established, generally exhibit a normal karyotype, are transcriptionally and epigenetically similar to ES cells and maintain the potential to differentiate into derivatives of all germ layers. Recent developments provide optimism that safe, viral-free human iPS cells could be derived routinely in the near future. An important next step will be to identify ways of assessing which iPS cell lines are sufficiently reprogrammed and safe to use for therapeutic applications. The approach of generating patient-specific pluripotent cells will undoubtedly transform regenerative medicine in many ways.

  8. Applications of Scheimpflug Imaging in Glaucoma Management: Current and Potential Applications

    Directory of Open Access Journals (Sweden)

    Alexander T. Nguyen

    2016-01-01

    Full Text Available Scheimpflug photography is the basis for a variety of imaging devices that are highly versatile. The applications of Scheimpflug imaging are wide in scope, spanning from evaluation of corneal ectasia to quantifying density in nuclear sclerotic cataracts. The potential uses for Scheimpflug-based devices are expanding and a number of them are relevant in glaucoma. In particular, they can provide three-dimensional image reconstruction of the anterior segment which includes assessment of the iridocorneal angle. Photographic analyses allow also for a noncontact method of estimating central corneal thickness (CCT and intraocular pressure (IOP, as well as the study of various corneal biomechanical properties, which may be useful for stratifying glaucoma risk.

  9. Current and Potential Developments of Cortisol Aptasensing towards Point-of-Care Diagnostics (POTC

    Directory of Open Access Journals (Sweden)

    Azrul Syafiq Zainol Abidin

    2017-05-01

    Full Text Available Anxiety is a psychological problem that often emerges during the normal course of human life. The detection of anxiety often involves a physical exam and a self-reporting questionnaire. However, these approaches have limitations, as the data might lack reliability and consistency upon application to the same population over time. Furthermore, there might be varying understanding and interpretations of the particular question by the participant, which necessitating the approach of using biomarker-based measurement for stress diagnosis. The most prominent biomarker related to stress, hormone cortisol, plays a key role in the fight-or-flight situation, alters the immune response, and suppresses the digestive and the reproductive systems. We have taken the endeavour to review the available aptamer-based biosensor (aptasensor for cortisol detection. The potential point-of-care diagnostic strategies that could be harnessed for the aptasensing of cortisol were also envisaged.

  10. ISTANBUL’S CURRENT STATUS AND POTENTIAL FOR BECOMINGAN INTERNATIONAL FINANCIAL CENTRE

    Directory of Open Access Journals (Sweden)

    Hasmet Sarigul

    2012-07-01

    Full Text Available The Turkish government has been pursuing a goal to turn Istanbul into aregionalcentre for finance and then, an international one.However, creating aninternationalfinancial centre where international demand and supply of fundsmeet is not an easy process. In this context,we aimed toexamine the currentstatus and the potential of Istanbul to become an international financial centre. Inorder to reach the aim of the study, firstly,the characteristics of an internationalfinancial centre have been explained and a brief overview ofthe Turkishgovernment’sofficial plans of development of theinternational financial centrehavebeen given. Then,the strengths, weaknesses, opportunities and threats ofIstanbul havebeen analyzed.Finally,we have made assessments and put forwardsome suggestions.

  11. Towards interprofessional networking in medication management of the aged: current challenges and potential solutions in Finland.

    Science.gov (United States)

    Kallio, Sonja; Kumpusalo-Vauhkonen, Anne; Järvensivu, Timo; Mäntylä, Antti; Pohjanoksa-Mäntylä, Marika; Airaksinen, Marja

    2016-12-01

    The Finnish Medicines Agency (Fimea) initiated a programme in 2012 for enhancing interprofessional networking in the medication management of the aged. The goal is to develop national guidelines for interprofessional collaboration with respect to medication management. This study aims to explore the challenges and potential solutions experienced by existing health care teams in managing medication of the aged: (1) at the individual and team level (micro level), (2) organisational level (meso level) and (3) structural level (macro level). Group discussions (n = 10), pair (n = 3) and individual interviews (n = 2). Abductive content analysis combining data and theory was applied. Networking was used as a theoretical framework. Meetings (n = 15) organised by Fimea in the formation phase of the interprofessional network in 2012. Health care professionals (n = 55). Challenges and solutions in the medication management of the aged at the micro, meso and macro levels. Challenges in interprofessional collaboration, problems with patient record systems, and the organisation of work and lack of resources were present at all the levels contributing to patients' medication problems. Participants suggested multiple potential solutions to improve interprofessional collaboration, sharing of tasks and responsibilities, better exploitation of pharmaceutical knowledge and developing tools as being the most commonly mentioned. Optimising medication use of the aged requires new systemic solutions within and between different system levels. The main challenges can be solved by clarifying responsibilities, enhancing communication and applying operational models that involve pharmacists and the use of information technology in medication management. KEY POINTS An interprofessional team approach has been suggested as a solution to promote rational medicine use among the aged. Fragmented health care system and lack of coordinated patient care are reasons for medication

  12. Proven and potential clinical benefits of washing red blood cells before transfusion: current perspectives

    Directory of Open Access Journals (Sweden)

    Schmidt AE

    2016-08-01

    Full Text Available Amy E Schmidt, Majed A Refaai, Scott A Kirkley, Neil Blumberg Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA Abstract: Red blood cells (RBCs are washed for a variety of reasons such as to remove excess potassium, cytokines, and other allergen proteins from the supernatant and/or to mitigate the effects of the storage lesion. The storage lesion is a product of RBC aging and include leakage of potassium and chloride from the RBCs, depletion of 2,3-diphosphoglycerate and adenosine triphosphate, loss of phospholipids and cholesterol, exposure of phosphatidylserine, elaboration of lipid mediators, loss of glutathione, autoxidation of hemoglobin to methemoglobin contributing to decreased blood flow viscosity and adherence to endothelial cells, increased microparticle formation, and disruption of NO-mediated vasodilation. A storage lesion is thought to be caused in part by oxidative stress, which is characterized by functional and structural changes to the RBCs. The effects of the RBC storage lesion on patient morbidity and mortality have been studied intensively with mixed results. Here, we will summarize the potential benefits of RBC washing. Notably, all patient-based studies on washed RBCs are single-center, small randomized studies or observational data, which await replication and tests of generalizability. Some of the most promising preliminary data suggest that washed transfusions of red cells and platelets reduce mortality in low risk, younger patients with acute myeloid leukemia, mitigate lung injury, and substantially reduce mortality in cardiac surgery. Larger randomized trials to replicate or refute these findings are urgently needed and, most importantly, have the potential to strikingly improve clinical outcomes following transfusion. Keywords: washed blood, transfusion, immunomodulation, red blood cell

  13. Clinical potential of regulatory T cell therapy in liver diseases: An overview and current perspectives

    Directory of Open Access Journals (Sweden)

    Hannah Claire Jeffery

    2016-09-01

    Full Text Available The increasing demand for liver transplantation and the decline in donor organs has highlighted the need for alternative novel therapies to prevent chronic active hepatitis, which eventually leads to liver cirrhosis and liver cancer. Liver histology of chronic hepatitis is composed of both effector and regulatory lymphocytes. The human liver contains different subsets of effector lymphocytes, that are kept in check by a subpopulation of T cells known as Regulatory T cells (Treg. The balance of effector and regulatory lymphocytes generally determines the outcome of hepatic inflammation: resolution, fulminant hepatitis or chronic active hepatitis. Thus, maintaining and adjusting this balance is crucial in immunological manipulation of liver diseases. One of the options to restore this balance is to enrich Treg in the liver disease patients.Advances in the knowledge of Treg biology and development of clinical grade isolation reagents, cell sorting equipment and Good Manufacturing Practice (GMP facilities have paved the way to apply Treg cells as a potential therapy to restore peripheral self-tolerance in autoimmune liver diseases, chronic rejection and post-transplantation. Past and on-going studies have applied Treg in type-1 diabetes mellitus, systemic lupus erythematosus, graft versus host diseases (GVHD and solid organ transplantations. There have not been any new therapies for the autoimmune liver diseases for more than three decades; thus the clinical potential for the application of autologous Treg cell therapy to treat autoimmune liver disease is an attractive and novel option. However, it is fundamental to understand the deep immunology, genetic profiles, biology, homing behavior and microenvironment of Treg before applying the cells to the patients.

  14. Pressure drop and arterial compliance - Two arterial parameters in one measurement.

    Science.gov (United States)

    Rotman, Oren M; Zaretsky, Uri; Shitzer, Avraham; Einav, Shmuel

    2017-01-04

    Coronary artery pressure-drop and distensibility (compliance) are two major, seemingly unrelated, parameters in the cardiovascular clinical setting, which are indicative of coronary arteries patency and atherosclerosis severity. While pressure drop is related to flow, and therefore serves as a functional indicator of a stenosis severity, the arterial distensibility is indicative of the arterial stiffness, and hence the arterial wall composition. In the present study, we hypothesized that local pressure drops are dependent on the arterial distensibility, and hence can provide information on both indices. The clinical significance is that a single measurement of pressure drop could potentially provide both functional and bio-mechanical metrics of lesions, and thus assist in real-time decision making prior to stenting. The goal of the current study was to set the basis for understanding this relationship, and define the accuracy and sensitivity required from the pressure measurement system. The investigation was performed using numerical fluid-structure interaction (FSI) simulations, validated experimentally using our high accuracy differential pressure measurement system. Simplified silicone mock coronary arteries with zero to intermediate size stenoses were used, and various combinations of arterial distensibility, diameter, and flow rate were simulated. Results of hyperemic flow cases were also compared to fractional flow reserve (FFR). The results indicate the potential clinical superiority of a high accuracy pressure drop-based parameter over FFR, by: (i) being more lesion-specific, (ii) the possibility to circumvent the FFR dependency on pharmacologically-induced hyperemia, and, (iii) by providing both functional and biomechanical lesion-specific information. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Benefits of externships with pediatric dentistry programs for potential residents: program directors' and current residents' perceptions.

    Science.gov (United States)

    Klein, Ulrich; Storey, Bryan; Hanson, Peter D

    2014-03-01

    This study's goal was to understand the extent, framework, and benefits of externships with prospective residency programs undertaken by predoctoral dental students or dentists interested in applying for a residency program. In 2012, a questionnaire was sent to all pediatric dentistry residents and program directors in the United States (63 percent and 74 percent return rate, respectively). Externships were offered by fifty-seven of the seventy-six programs. Most program directors (95 percent) agreed that externships are beneficial and compensate at least partially for the lack of numerical National Board Dental Examination scores or class rankings. Among the responding residents, 61 percent were female. The top reasons given by residents for choosing to extern with a certain program were its location and perceived reputation. Of the 249 respondents who did an externship, 47 percent externed with their current program. The acceptance rate into the number one choice of program was similar among those who did an externship vs. those who did not (73 percent vs. 75 percent). No relationship was found between gender and externships among the 341 respondents who were accepted into their top choice. Most of the residents (98.8 percent) felt that completing an externship was beneficial, and 88 percent got an increased understanding for the differences between university- and non-university-based residency programs.

  16. Therapeutic Potential of Curcumin in Treatment of Pancreatic Cancer: Current Status and Future Perspectives.

    Science.gov (United States)

    Hosseini, Mina; Hassanian, Seyed Mahdi; Mohammadzadeh, Elham; ShahidSales, Soodabeh; Maftouh, Mina; Fayazbakhsh, Hasan; Khazaei, Majid; Avan, Amir

    2017-07-01

    Pancreatic cancer is among the leading cause of deaths due to cancer with extremely poor prognosis. Gemcitabine is being used in the treatment of patient with pancreatic ductal adenocarcinoma (PDAC), although, the response rate is bellow 12%. A recent phase III trial revealed that FOLFIRINOX could be an option for the treatment of metastatic PDAC patients, although it is associated with increased toxicity. Therefore, identification of novel agents that either improves gemcitabine activity, within novel combinatorial approaches, or with a better efficacy than gemcitabine is warranted. The antitumor activity of curcumin in several tumors, including prostate, breast and colorectal cancers have investigated. A recent phase II trial explored the effects of curcumin in advanced pancreatic cancer patient. They found that oral curcumin was well tolerated. Another trial showed the activity of 8,000 mg of curcumin in combination with gemcitabine in patients with advanced pancreatic cancer. This review summarizes the current knowledge about possible molecular mechanisms of curcumin in PDAC with particular emphasis on preclinical/clinical studies in pancreatic cancer treatment. J. Cell. Biochem. 118: 1634-1638, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Potential of nanotechnology as a delivery platform against tuberculosis: current research review.

    Science.gov (United States)

    Choudhary, S; Kusum Devi, V

    2015-03-28

    This review focusses on the current ongoing research in the field of tuberculosis comprising the resistant strains. It specifies a proper data analysis with results in concise form from areas gripping in: diagnostic nanotechnology, vaccine nanotechnology and the prime field of interest i.e., therapeutic nanotechnology. Primarily, therapeutic area recollects the research findings from advanced drug delivery (primary era) to the targeted drug delivery (modern era). The vaccine-based area derives the immune-specific targeting with enhanced emphasis on vaccine extraction and preparation of nanoparticles. Finally, the diagnostic area signifies the imaging techniques that may be employed in the diagnosis of TB. Not only that, there are some researches that emphasized on finding the comparable diagnostic differences between normal and resistant strains. With the advent of carbon nanotubes, metallic NPs, a newer hope has emerged out in diagnostic research, which may extend to therapeutic research applications too. Modifications of natural polymers, least or no use of organic solvents, size controlled NPs, optimized methodology, etc., are fields that need more effort to bypass toxicity. If above desired possibilities get the priority during research, it may lead to shift in the timeline towards much more oriented research. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Asthma and obesity in children: current evidence and potential systems biology approaches.

    Science.gov (United States)

    Frey, U; Latzin, P; Usemann, J; Maccora, J; Zumsteg, U; Kriemler, S

    2015-01-01

    Both obesity and asthma are highly prevalent, complex diseases modified by multiple factors. Genetic, developmental, lung mechanical, immunological and behavioural factors have all been suggested as playing a causal role between the two entities; however, their complex mechanistic interactions are still poorly understood and evidence of causality in children remains scant. Equally lacking is evidence of effective treatment strategies, despite the fact that imbalances at vulnerable phases in childhood can impact long-term health. This review is targeted at both clinicians frequently faced with the dilemma of how to investigate and treat the obese asthmatic child and researchers interested in the topic. Highlighting the breadth of the spectrum of factors involved, this review collates evidence regarding the investigation and treatment of asthma in obese children, particularly in comparison with current approaches in 'difficult-to-treat' childhood asthma. Finally, the authors propose hypotheses for future research from a systems-based perspective. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Current applications and potential future role of wireless capsule technology in Crohn's disease.

    Science.gov (United States)

    Hall, Barry; Holleran, Grainne; McNamara, Deirdre

    2014-11-01

    The development of capsule technology has modified our approach to the diagnosis of gastrointestinal disease. The relatively rapid uptake of capsule endoscopy as an important clinical tool can be largely ascribed to a number of key factors, including the fact that it is a relatively easy examination to perform in an outpatient setting. It has been established as an integral part of the investigation pathway for obscure gastrointestinal bleeding and suspected small bowel Crohn's disease (CD). CURRENT USE OF CAPSULE ENDOSCOPY: Small bowel CD can be a challenging entity to diagnose. Capsule endoscopy has been shown to be both useful and safe in patients with both suspected and established small bowel CD. In suspected disease, capsule endoscopy has both a high diagnostic yield and negative predictive value. Capsule findings lead to changes in management in up to 73% of patients with established CD. However, while the technology appears capable of detecting subtle mucosal changes not readily apparent on alternate imaging modalities, the question of what actually constitutes small bowel CD as described by capsule is an issue that remains unresolved to date. Thus, capsule endoscopy is best utilised in tandem with advanced imaging and endoscopic techniques such as balloon- assisted enteroscopy. The development of a capsule capable of viewing the colon coupled with improvements in image quality and battery life are likely to lead to the increasing uptake of this technology. In the future, 'interactive' capsules with the ability to view the entire gastrointestinal tract may be a reality.

  20. Current status of potential applications of repurposed Cas9 for structural and functional genomics of plants.

    Science.gov (United States)

    Seth, Kunal; Harish

    2016-11-25

    Redesigned Cas9 has emerged as a tool with various applications like gene editing, gene regulation, epigenetic modification and chromosomal imaging. Target specific single guide RNA (sgRNA) can be used with Cas9 for precise gene editing with high efficiency than previously known methods. Further, nuclease-deactivated Cas9 (dCas9) can be fused with activator or repressor for activation (CRISPRa) and repression (CRISPRi) of gene expression, respectively. dCas9 fused with epigenetic modifier like methylase or acetylase further expand the scope of this technique. Fluorescent probes can be tagged to dCas9 to visualize the chromosome. Due to its wide-spread application, simplicity, accessibility, efficacy and universality, this technique is expanding the structural and functional genomic studies of plant and developing CRISPR crops. The present review focuses on current status of using repurposed Cas9 system in these various areas, with major focus on application in plants. Major challenges, concerns and future directions of using this technique are discussed in brief. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Current and Potential Treatments for Reducing Campylobacter Colonization in Animal Hosts and Disease in Humans

    Science.gov (United States)

    Johnson, Tylor J.; Shank, Janette M.; Johnson, Jeremiah G.

    2017-01-01

    Campylobacter jejuni is the leading cause of bacteria-derived gastroenteritis worldwide. In the developed world, Campylobacter is usually acquired by consuming under-cooked poultry, while in the developing world it is often obtained through drinking contaminated water. Once consumed, the bacteria adhere to the intestinal epithelium or mucus layer, causing toxin-mediated inhibition of fluid reabsorption from the intestine and invasion-induced inflammation and diarrhea. Traditionally, severe or prolonged cases of campylobacteriosis have been treated with antibiotics; however, overuse of these antibiotics has led to the emergence of antibiotic-resistant strains. As the incidence of antibiotic resistance, emergence of post-infectious diseases, and economic burden associated with Campylobacter increases, it is becoming urgent that novel treatments are developed to reduce Campylobacter numbers in commercial poultry and campylobacteriosis in humans. The purpose of this review is to provide the current status of present and proposed treatments to combat Campylobacter infection in humans and colonization in animal reservoirs. These treatments include anti-Campylobacter compounds, probiotics, bacteriophage, vaccines, and anti-Campylobacter bacteriocins, all of which may be successful at reducing the incidence of campylobacteriosis in humans and/or colonization loads in poultry. In addition to reviewing treatments, we will also address several proposed targets that may be used in future development of novel anti-Campylobacter treatments. PMID:28386253

  2. Microscopic description of a drop on a solid surface.

    Science.gov (United States)

    Ruckenstein, Eli; Berim, Gersh O

    2010-06-14

    Two approaches recently suggested for the treatment of macro- or nanodrops on smooth or rough, planar or curved, solid surfaces, based on fluid-fluid and fluid-solid interaction potentials are reviewed. The first one employs the minimization of the total potential energy of a drop by assuming that the drop has a well defined profile and a constant liquid density in its entire volume with the exception of the monolayer nearest to the surface where the density has a different value. As a result, a differential equation for the drop profile as well as the necessary boundary conditions are derived which involve the parameters of the interaction potentials and do not contain such macroscopic characteristics as the surface tensions. As a consequence, the macroscopic and microscopic contact angles which the drop profile makes with the surface can be calculated. The macroscopic angle is obtained via the extrapolation of the circular part of the drop profile valid at some distance from the surface up to the solid surface. The microscopic angle is formed at the intersection of the real profile (which is not circular near the surface) with the surface. The theory provides a relation between these two angles. The ranges of the microscopic parameters of the interaction potentials for which (i) the drop can have any height (volume), (ii) the drop can have a restricted height but unrestricted volume, and (iii) a drop cannot be formed on the surface were identified. The theory was also extended to the description of a drop on a rough surface. The second approach is based on a nonlocal density functional theory (DFT), which accounts for the inhomogeneity of the liquid density and temperature effects, features which are missing in the first approach. Although the computational difficulties restrict its application to drops of only several nanometers, the theory can be applied indirectly to macrodrops by calculating the surface tensions and using the Young equation to determine the

  3. How Far Could the Alien Boatman Trichocorixa verticalis verticalis Spread? Worldwide Estimation of Its Current and Future Potential Distribution

    Science.gov (United States)

    Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J.; Millán, Andrés

    2013-01-01

    Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on

  4. The potential impact of gut microbiota on your health:Current status and future challenges.

    Science.gov (United States)

    Sirisinha, Stitaya

    2016-12-01

    Our health and probably also our behaviors and mood depend not only on what we eat or what we do (lifestyle behaviors), but also on what we host. It is well established for decades that all vertebrates including humans are colonized by a wide array of bacteria, fungi, eukaryotic parasites and viruses, and that, at steady state (homeostasis), this community of microbes establishes a friendly mutual relationship with the host. The term microbiota was originally meant to represent an ecological community of commensals and potentially pathogenic microbes that live within our bodies, but it is now used interchangeably with the term microbiome which was initially meant to represent a collective genome of the microbiota. Although the number of microbes that live in or on our body was previously estimated to outnumber that of their hosts by 10 to 1, the latest estimate put the ratio to be closer to 1:1. On the other hand, their collective genomes (microbiome) outnumber those of the host by 100-200 times. It is not surprising therefore that these microbes not only provide the host with a variety of metabolic impact, but can also modulate tissue integrity and immune defense, all of which lead to a healthy ecosystem (symbiosis) that is unfavorable for colonization and invasion of pathogens. Microbiota is well known for its role in development and education of immune system. However, its link with diseases is less known and it is only recently that there is a surge of interest in the potential impact of microbiota on human health and disease. The diversity and composition of microbiota (healthy microbiota profile) are dynamics, depending not only on the host physical status, genotype and immune phenotype, but also on the environmental factors like diet, antibiotic usage and lifestyle behaviors. These environmental factors may adversely alter gut ecosystem (dysbiosis) that is frequently associated with increased susceptibility to infections as well as to non

  5. Towards interprofessional networking in medication management of the aged: current challenges and potential solutions in Finland

    Science.gov (United States)

    Kallio, Sonja; Kumpusalo-Vauhkonen, Anne; Järvensivu, Timo; Mäntylä, Antti; Pohjanoksa-Mäntylä, Marika; Airaksinen, Marja

    2016-01-01

    Objective The Finnish Medicines Agency (Fimea) initiated a programme in 2012 for enhancing interprofessional networking in the medication management of the aged. The goal is to develop national guidelines for interprofessional collaboration with respect to medication management. This study aims to explore the challenges and potential solutions experienced by existing health care teams in managing medication of the aged: (1) at the individual and team level (micro level), (2) organisational level (meso level) and (3) structural level (macro level). Design Group discussions (n = 10), pair (n = 3) and individual interviews (n = 2). Abductive content analysis combining data and theory was applied. Networking was used as a theoretical framework. Setting Meetings (n = 15) organised by Fimea in the formation phase of the interprofessional network in 2012. Subjects Health care professionals (n = 55). Main outcome measures Challenges and solutions in the medication management of the aged at the micro, meso and macro levels. Results Challenges in interprofessional collaboration, problems with patient record systems, and the organisation of work and lack of resources were present at all the levels contributing to patients’ medication problems. Participants suggested multiple potential solutions to improve interprofessional collaboration, sharing of tasks and responsibilities, better exploitation of pharmaceutical knowledge and developing tools as being the most commonly mentioned. Conclusions Optimising medication use of the aged requires new systemic solutions within and between different system levels. The main challenges can be solved by clarifying responsibilities, enhancing communication and applying operational models that involve pharmacists and the use of information technology in medication management. KEY POINTSAn interprofessional team approach has been suggested as a solution to promote rational medicine use among the aged.Fragmented health

  6. A comparative study of sheath potential profile measurements with laser-heated and current-heated emissive probes

    Science.gov (United States)

    Kella, Vara Prasad; Mehta, Payal; Sarma, A.; Ghosh, J.; Chattopadhyay, P. K.

    2016-04-01

    Emissive Langmuir probe is one of the most efficient diagnostic tools available for plasma potential measurements. Extensive studies have been carried out in designing different kinds of conventional (electrically heated) emissive probes (CEPs) to estimate the plasma potential. Laser heated emissive probe (LHEP) has been developed with certain advantages over the conventional probes such as low evaporation rate of the probe material, high lifetime, and high emission levels. Most importantly, the LHEP uses laser to heat the probe-tip and does not require electric current to heat the probe-tip like in CEP. The heating current in CEP substantially affects the plasma potential measurements, especially in the regions of plasma where high electric and magnetic field gradients are present. In this paper, we studied the plasma potential structures in sheath-presheath region using both LHEP and CEP in an unmagnetized dc-filament discharge plasma. Measurements of sheath spatial potential profile using laser heated emissive probe are compared with those obtained using conventional emissive probe.

  7. Evolution of probiotics in aquatic world: Potential effects, the current status in Egypt and recent prospectives

    Science.gov (United States)

    Ibrahem, Mai D.

    2013-01-01

    The increase in the human population in addition to the massive demand for protein of animal origin forced the authorities to seek for additional sources of feed supplies. Aquaculture is the world worth coming expansion to compensate the shortage in animal protein. Feed in aquaculture plays an important role in the production cycle and exert threshold on both practical and economic aspects. Feed additive sectors are expanding day after day to achieve better growth and health for fish and shrimp and to meet the potential requirements of the culturists. Probiotic proved its successes in human and animal feeding practices and recently gained attention in aquaculture; it has beneficial effects in diseases control and competes with various environmental stressors as well as to promote the growth of the cultured organisms. Probiotics have the privilege to manipulate the non-specific innate immunity among fishes, hence help them into resist many pathogenic agents and are actively used worldwide. The present review is an informative compilation of the probiotics, their mode of action and their useful effects on fishes. The review also highlights the status of probiotics in aquaculture of Egypt, probiotic recent prospective for the possible role of probiotics in fish external and internal environment. PMID:26644914

  8. Evolution of probiotics in aquatic world: Potential effects, the current status in Egypt and recent prospectives

    Directory of Open Access Journals (Sweden)

    Mai D. Ibrahem

    2015-11-01

    Full Text Available The increase in the human population in addition to the massive demand for protein of animal origin forced the authorities to seek for additional sources of feed supplies. Aquaculture is the world worth coming expansion to compensate the shortage in animal protein. Feed in aquaculture plays an important role in the production cycle and exert threshold on both practical and economic aspects. Feed additive sectors are expanding day after day to achieve better growth and health for fish and shrimp and to meet the potential requirements of the culturists. Probiotic proved its successes in human and animal feeding practices and recently gained attention in aquaculture; it has beneficial effects in diseases control and competes with various environmental stressors as well as to promote the growth of the cultured organisms. Probiotics have the privilege to manipulate the non-specific innate immunity among fishes, hence help them into resist many pathogenic agents and are actively used worldwide. The present review is an informative compilation of the probiotics, their mode of action and their useful effects on fishes. The review also highlights the status of probiotics in aquaculture of Egypt, probiotic recent prospective for the possible role of probiotics in fish external and internal environment.

  9. Potential use of mesenchymal stem cells in human meniscal repair: current insights

    Directory of Open Access Journals (Sweden)

    Pak J

    2017-03-01

    Full Text Available Jaewoo Pak,1–3* Jung Hun Lee,1,4* Kwang Seung Park,4 Jeong Ho Jeon,4 Sang Hee Lee4 1Stems Medical Clinic, Gangnamgu, Seoul, Republic of Korea; 2TEDA‑Puhua International Hospital, Tianjin, People’s Republic of China; 3Life Science Institute, Komplek Permata Senayan, Jalan Tentara Pelajar, Jakarta Selatan, Indonesia; 4National Leading Research Laboratory, Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea *These authors contributed equally to this work Abstract: The menisci of the human knee play an important role in maintaining normal functions to provide stability and nutrition to the articular cartilage, and to absorb shock. Once injured, these important structures have very limited natural healing potential. Unfortunately, the traditional arthroscopic meniscectomy performed on these damaged menisci may predispose the joint toward early development of osteoarthritis. Although a very limited number of studies are available, mesenchymal stem cells (MSCs have been investigated as an alternative therapeutic modality to repair human knee meniscal tears. This review summarizes the results of published applications of MSCs in human patients, which showed that the patients who received MSCs (autologous adipose tissue-derived stem cells or culture-expanded bone marrow-derived stem cells presented symptomatic improvements, along with magnetic resonance imaging evidences of the meniscal repair. Keywords: adipose tissue-derived stem cells, bone marrow-derived stem cells, human knee, meniscal tear, articular cartilage, therapeutic modality

  10. Potential role of stem cells in severe spinal cord injury: current perspectives and clinical data

    Directory of Open Access Journals (Sweden)

    Paspala SA

    2012-09-01

    Full Text Available Syed AB Paspala,1,2 Sandeep K Vishwakarma,1 Tenneti VRK Murthy,2 Thiriveedi N Rao,2 Aleem A Khan11PAN Research Foundation, CARE, 2The Institute of Medical Sciences, Hyderabad, IndiaAbstract: Stem cell transplantation for spinal cord injury (SCI along with new pharmacotherapy research offers the potential to restore function and ease the associated social and economic burden in the years ahead. Various sources of stem cells have been used in the treatment of SCI, but the most convincing results have been obtained with neural progenitor cells in preclinical models. Although the use of cell-based transplantation strategies for the repair of chronic SCI remains the long sought after holy grail, these approaches have been to date the most successful when applied in the subacute phase of injury. Application of cell-based strategies for the repair and regeneration of the chronically injured spinal cord will require a combinational strategy that may need to include approaches to overcome the effects of the glial scar, inhibitory molecules, and use of tissue engineering strategies to bridge the lesion. Nonetheless, cell transplantation strategies are promising, and it is anticipated that the Phase I clinical trials of some form of neural stem cell-based approach in SCI will commence very soon.Keywords: stem cell therapy, regeneration, spinal cord injury, cell dosing, cell tracking

  11. Potential Biomolecules and Current Treatment Technologies for Diabetic Foot Ulcer: an Overview.

    Science.gov (United States)

    Khashim, Zenith; Samuel, Shila; Duraisamy, Nallusamy; Krishnan, Kathiravan

    2017-05-18

    Diabetic foot ulceration remains a major challenge and is one of the most expensive and leading causes of major and minor amputations among patients with diabetic foot ulcer. Hence the purpose of this review is to emphasize on potential molecular markers involved in diabetic foot ulcer physiology, the efficacy of different types of dressing materials, adjunct therapy and newer therapeutic approach like nanoparticles for the treatment of diabetic foot ulcer. We conducted a systematic literature review search by using Pubmed and other web searches. The quality evidence of diabetic foot ulcer biomolecules and treatments was collected, summarized and compared with other studies. The present investigation suggested that impaired wound healing in diabetic patients is an influence of several factors. All the advanced therapies and foot ulcer dressing materials are not suitable for all types of diabetic foot ulcers, however more prospective follow ups and in vivo and in vitro studies are needed to draw certain conclusion. Several critical wound biomolecules have been identified and are in need to be investigated in diabetic foot ulcers. The application of biocompatible nanoparticles holds a promising approach for designing dressing materials for the treatment of diabetic foot ulcer. Understanding the cellular and molecular events and identifying the appropriate treatment strategies for different foot ulcer grades will reduce recurrence of foot ulcer and lower limb amputation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Current reversals of coupled driven and damped particles evolving in a tilted potential landscape

    Science.gov (United States)

    Mulhern, C.; Hennig, D.

    2011-09-01

    We explore the driven and damped dynamics of two coupled particles evolving in a symmetric and periodic substrate potential that is subjected to a static bias force. In addition, each particle is time-periodically driven with the same magnitude as, but out of phase to, its counterpart. It is shown that, for a certain parameter regime, the coupled particles can become self-organized and go against the direction of the bias force. This self-organization involves the particles becoming frequency locked with the driving force, and thus periodic motion ensues. We employ numerical arguments to show that running periodic states provide solutions of the system. Further, heuristic evidence is provided explaining how the two particles can travel against the bias force. In an effort to unearth coupling phenomena within the system, a detailed analysis of how the coupling strength affects the nonlinear dynamics is carried out. We show that within a range of coupling strengths the existence of periodic running solutions associated with negative mobility. To examine the robustness of our results we compare the deterministic system with the corresponding Langevin system. It is shown that, below a critical temperature, the qualitative behavior of the system remains the same.

  13. Current and potential impacts of mosquitoes and the pathogens they vector in the Pacific region

    Science.gov (United States)

    LaPointe, Dennis

    2007-01-01

    Mosquitoes and the pathogens they transmit are ubiquitous throughout most of the temperate and tropical regions of the world. The natural and pre-European distribution and diversity of mosquitoes and mosquito-borne diseases throughout much of the Pacific region, however, depicts a depauperate and relatively benign fauna reinforcing the dream of “paradise regained”. In the central and South Pacific few mosquito species were able to colonize the remotest islands and atolls. Native mosquitoes are limited to a few far-ranging species and island endemics are typically restricted to the genera of Aedes and Culex. Only lymphatic filariasis appears to have been present as an endemic mosquito-borne disease before European contact. In nearby Australia, however, some 242 species of mosquitoes are known to occur and more than 70 arboviruses have been identified (Mackenzie 1999). In this regard Australia is more similar to the rest of the tropic and subtropical world than the smaller islands of Oceania. In our ever-shrinking world of global commerce, military activity and travel, the nature of mosquito-borne disease in the Pacific was bound to change. This paper is a brief summary of introduced mosquitoes in the Pacific and their potential impacts on human and wildlife health.

  14. Technical Challenges in Current Primo Vascular System Research and Potential Solutions

    Directory of Open Access Journals (Sweden)

    Kyung A. Kang

    2016-12-01

    Full Text Available Since Bonghan Kim's discovery of the Bonghan system (BHS in the 1960s, numerous reports have suggested that the system is fundamental for maintaining mammalian life. The BHS is a circulatory system independent of the blood or the lymphatic system, forms an extensive network throughout the entire mammalian body, has been reported to be the acupuncture meridian, stores distinct types of stem cells, and appears to have some roles in cancer metastasis. Despite Kim's first report having been published as early as 1962, research progress has been rather slow mainly because the system is very small and translucent, making it optically difficult to distinguish it from the hemoglobin-rich surrounding tissues. Unfortunately, Kim did not describe in detail the methods that he used for identifying and harvesting the system and the components of the system. In 2000, Kwang-Sup Soh reopened the BHS research, and since then, new and important scientific findings on the system have been reported, and many of Kim's results have been verified. In 2010, the BHS was renamed the primo vascular system. Nevertheless, good tools to properly deal with this system are still lacking. In this article, we address some of the technical difficulties involved in studying the primo vascular system and attempt to discuss potential ways to overcome those difficulties.

  15. Applying quantitative structure–activity relationship approaches to nanotoxicology: Current status and future potential

    International Nuclear Information System (INIS)

    Winkler, David A.; Mombelli, Enrico; Pietroiusti, Antonio; Tran, Lang; Worth, Andrew; Fadeel, Bengt; McCall, Maxine J.

    2013-01-01

    The potential (eco)toxicological hazard posed by engineered nanoparticles is a major scientific and societal concern since several industrial sectors (e.g. electronics, biomedicine, and cosmetics) are exploiting the innovative properties of nanostructures resulting in their large-scale production. Many consumer products contain nanomaterials and, given their complex life-cycle, it is essential to anticipate their (eco)toxicological properties in a fast and inexpensive way in order to mitigate adverse effects on human health and the environment. In this context, the application of the structure–toxicity paradigm to nanomaterials represents a promising approach. Indeed, according to this paradigm, it is possible to predict toxicological effects induced by chemicals on the basis of their structural similarity with chemicals for which toxicological endpoints have been previously measured. These structure–toxicity relationships can be quantitative or qualitative in nature and they can predict toxicological effects directly from the physicochemical properties of the entities (e.g. nanoparticles) of interest. Therefore, this approach can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal testing. The purpose of this review is to provide a summary of recent key advances in the field of QSAR modelling of nanomaterial toxicity, to identify the major gaps in research required to accelerate the use of quantitative structure–activity relationship (QSAR) methods, and to provide a roadmap for future research needed to achieve QSAR models useful for regulatory purposes

  16. Current knowledge on agarolytic enzymes and the industrial potential of agar-derived sugars.

    Science.gov (United States)

    Yun, Eun Ju; Yu, Sora; Kim, Kyoung Heon

    2017-07-01

    Agar is a major cell wall carbohydrate of red macroalgae (Rhodophyta). Sugars derived from agar, such as agarooligosaccharides (AOSs), neoagarooligosaccharides (NAOSs), neoagarobiose (NAB), and 3,6-anhydro-L-galactose (L-AHG), possess various physiological activities. These agar-derived sugars can be produced by hydrolysis using chemicals or agarolytic enzymes. Despite the industrial potential of agar-derived sugars, their application has been hampered mainly due to the absence of efficient processes for the liquefaction and saccharification of agar. In this review, we have focused on strategies for producing high value-added sugars from agarose via chemical or enzymatic liquefaction and enzymatic saccharification. The liquefaction of agarose is a key step for preventing gelling and increasing the solubility of agarose in water by prehydrolyzing agarose into AOSs or NAOSs. For the industrial use of agar-derived sugars, AOS, NAOS, NAB, and L-AHG can be used as functional biomaterials owing to their physiological activities such as antiinflammation, skin whitening, and moisturizing. Recently, it was reported that AHG could be considered as a new anticariogenic sugar to replace xylitol. This review provides a comprehensive overview of processes for the hydrolysis of agar or agarose to produce high value-added sugars and the industrial application of these sugars.

  17. Current data on radio chemotherapy and potential of targeted therapies for cervical cancers

    International Nuclear Information System (INIS)

    Magne, N.; Deutsch, E.; Haie-Meder, C.

    2008-01-01

    The present review represents an up-to-date focus on the particular topic of cervix carcinoma. An exhaustive description of the actual data and the near-future combination of radiotherapy and drugs with the specific potential of targeted therapies are presented. This approach represents one of the next challenges to improve results. Studies conducted in 1999, 2000, and 2002 reported the results of six large-scale prospective randomized trials using concomitant chemo radiation with a significant progression-free and overall survival rate improvement compared to radiotherapy only. These results were confirmed by the two last meta-analyses. Nowadays, the concurrent radio chemotherapy schedule used in the treatment of high risk cervical cancer is a standard practice. More growing evidences suggest that intracellular signal pathways play a significant role in radiation response. Several prognostic factors on tumoral radiosensitivity have been identified, including intracellular signal pathways, in the particular case of cervix carcinoma. Promising results have been obtained in experimental studies assessing the combined use of specific inhibitors and radiotherapy. Based on these data, a number of clinical trials have been started to enhance tumor responses and thus, to decrease the rate of recurrences. (authors)

  18. Microalgae Potential and Multiple Roles—Current Progress and Future Prospects—An Overview

    Directory of Open Access Journals (Sweden)

    Balasubramani Ravindran

    2016-11-01

    Full Text Available Substantial progress has been made in algal technologies in past few decades. Initially, microalgae drew the attention of the scientific community as a renewable source of biofuels due to its high productivity over a short period of time and potential of significant lipid accumulation. As of now, a technological upsurge has elaborated its scope in phycoremediation of both organic and inorganic pollutants. The dual role of microalgae—i.e., phycoremediation coupled with energy production—is well established, however, commercially, algal biofuel production is not yet sustainable due to high energy inputs. Efforts are being made to make the algal biofuel economy through modification in the cultivation conditions, harvesting, and extraction of value added products. Recent studies have demonstrated algal biomass production with various types of wastewater and industrial effluents. Similarly, the recent advent of eco-friendly harvesting technologies—such as low-cost green coagulants, electrochemical harvesting, etc.—are energy efficient and economical. Contemporary improvement in efficient lipid extraction from biomass will make algal biodiesel economical. The absolute extraction of all the value added products from algal biomass, either whole cell or lipid extracted biomass, in a complete biorefinery approach will be more economical and eco-friendly.

  19. Regional modeling of large wildfires under current and potential future climates in Colorado and Wyoming, USA

    Science.gov (United States)

    West, Amanda; Kumar, Sunil; Jarnevich, Catherine S.

    2016-01-01

    Regional analysis of large wildfire potential given climate change scenarios is crucial to understanding areas most at risk in the future, yet wildfire models are not often developed and tested at this spatial scale. We fit three historical climate suitability models for large wildfires (i.e. ≥ 400 ha) in Colorado andWyoming using topography and decadal climate averages corresponding to wildfire occurrence at the same temporal scale. The historical models classified points of known large wildfire occurrence with high accuracies. Using a novel approach in wildfire modeling, we applied the historical models to independent climate and wildfire datasets, and the resulting sensitivities were 0.75, 0.81, and 0.83 for Maxent, Generalized Linear, and Multivariate Adaptive Regression Splines, respectively. We projected the historic models into future climate space using data from 15 global circulation models and two representative concentration pathway scenarios. Maps from these geospatial analyses can be used to evaluate the changing spatial distribution of climate suitability of large wildfires in these states. April relative humidity was the most important covariate in all models, providing insight to the climate space of large wildfires in this region. These methods incorporate monthly and seasonal climate averages at a spatial resolution relevant to land management (i.e. 1 km2) and provide a tool that can be modified for other regions of North America, or adapted for other parts of the world.

  20. Content knowledge development in a chemistry teacher preparation program: A current potentials and challenges

    Science.gov (United States)

    Widhiyanti, Tuszie; Treagust, David F.; Mocerino, Mauro; Vishnumolakala, Venkat

    2017-08-01

    One of the essential facets in teacher education program is the development of the teachers' content knowledge and it has been suggested by many scholars that the study to analyse the process of content knowledge development in teacher education program is necessary. Regarding this, the aim of this research is to evaluate the existing program of developing pre-service chemistry teachers' content knowledge, especially in the topic about the particulate nature of matter. The curriculum of content knowledge development was analysed using the forms of the curriculum evaluation (Akker, 1998; Goodlad, Klein, and Tye (1979); Treagust, 1987). Within this framework, the curriculum was evaluated in several aspects including the vision and intention of the curriculum as mentioned in the curriculum documents (intended curriculum), the users' interpretation and perception about the curriculum (perceived curriculum), the actual process of curriculum implementation (implemented curriculum), and the outcomes of the curriculum (achieved curriculum). According to the framework used for this study, the research combined qualitative and quantitative methods of data collection and the interpretation including document analysis, classroom observation, interviews, and two-tier diagnostic test. Through this research we examined the coherence among those aspects. The results reveal that although the content knowledge development is explicitly intended in a curriculum, its implementation and lecturers' perceptions give influence in the results as appear in pre-service teachers' achievements. In general, this research provides basic information about the effectiveness of the program including the challenges and the potentials for a reconsideration of the program in the future.

  1. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential

    Directory of Open Access Journals (Sweden)

    Roland N Boubela

    2014-02-01

    Full Text Available Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by fluctuation related signals, e.g. head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to true neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA.Our preliminary results indicate that fast (TR< 0.5s scanning may help to identify and eliminate physiologic components, increasing tSNR and functional contrast. In addition, biological variability can be studied and task performance better correlated to other measures. This should increase specificity and reliability in fMRI studies. Furthermore, physiological signal changes during scanning may then be recognized as a source of information rather than a nuisance. As we are currently still undersampling the complexity of the brain, even at a rather coarse macroscopic level, we should be very cautious in the interpretation of neuroscientific findings, in particular when comparing different groups (e.g., age, sex, medication, pathology, etc.. From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion towards a better understanding and a more quantitative use of fMRI.

  2. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential

    Science.gov (United States)

    Boubela, Roland N.; Kalcher, Klaudius; Nasel, Christian; Moser, Ewald

    2017-01-01

    Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by physiology related signals, e.g., head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to “true” neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA. Our preliminary results indicate that fast (TR <0.5 s) scanning may help to identify and eliminate physiologic components, increasing tSNR and functional contrast. In addition, biological variability can be studied and task performance better correlated to other measures. This should increase specificity and reliability in fMRI studies. Furthermore, physiological signal changes during scanning may then be recognized as a source of information rather than a nuisance. As we are currently still undersampling the complexity of the brain, even at a rather coarse macroscopic level, we should be very cautious in the interpretation of neuroscientific findings, in particular when comparing different groups (e.g., age, sex, medication, pathology, etc.). From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion toward a better understanding and a more quantitative use of fMRI. PMID:28164083

  3. Hydroxyethyl starch: a review of pharmacokinetics, pharmacodynamics, current products, and potential clinical risks, benefits, and use.

    Science.gov (United States)

    Glover, Polly A; Rudloff, Elke; Kirby, Rebecca

    2014-01-01

    To review and summarize the pharmacokinetics and pharmacodynamics of hydroxyethyl starch (HES), as well as reported risks and benefits of HES infusion, and to provide administration and monitoring recommendations for HES use in dogs and cats. Veterinary and human peer-reviewed medical literature, including scientific reviews, clinical and laboratory research articles, and authors' clinical experience. HES solutions are the most frequently used synthetic colloid plasma volume expanders in human and veterinary medicine. The majority of research in human medicine has focused on the adverse effects of HES infusion, with emphasis on acute kidney injury and coagulation derangements. The studies often differ in or fail to report factors, such as the type, amount, interval, and concentration of HES administered; the patient population studied; or concurrent fluids administered. Currently, there is no definitive clinical evidence that the reported adverse effects of HES use in human medicine occur in veterinary species. There is little information available on HES administration techniques or simultaneous administration of additional fluids in human and veterinary medicine. The rationale for HES use in small animals has been largely extrapolated from human medical studies and guidelines. A controlled approach to intravenous fluid resuscitation using crystalloid and HES volumes titrated to reach desired resuscitation end point parameters is outlined for small animal practitioners. The extrapolation of data from human studies directly to small animals should be done with the knowledge that there may be species variations and different pharmacokinetics with different HES solutions. Veterinary reports indicate that bolus and continuous rate infusions of 6% hetastarch solutions at moderate doses are well tolerated in feline and canine subjects. Further research in domesticated species is necessary to better define and expand the knowledge regarding use of HES solutions in small

  4. Current state of Czech astronomy popularization and its potential for enhancing science career interest

    Science.gov (United States)

    Kříček, Radek

    2015-08-01

    The Czech Republic has a dense net of observatories, astronomical clubs and other activities for both adults and children. Can we use it to improve skills of our pupils and their motivation to choose their career in science? Does the situation in the Czech Republic differ from abroad? What can we improve in the future? These questions were not answered satisfactorily so far. We decided to contribute to solve this issue.We present our survey of current state based mainly on electronic sources and personal dealings. Besides of 56 observatories working with public and many interest clubs, there are other possibilities to meet astronomy. For example, Astronomical Olympiad attracts thousands of pupils across the country each year to solve both theoretical and practical tasks in astronomy. In other projects, children can visit Dark-Sky Parks, design experiments for a stratospheric balloon, observe with CCD or radio devices or build their own rockets.We outline our ongoing project to examine the link between popularization activities and pupils’ or high school students’ attitude toward science and science career. We plan to create a typology of both popularization activities and life stories of people dealing with astronomy. From the methodological point of view, the mixed method design, combining both the qualitative and quantitative approach, will be used to solve the research problems. The basic research plan will be a case study. So far the project is based on interviews with various subjects. We choose people with different life stories, all connected with astronomy or astronomy popularization in some period. We focus on important moments in their career, similarities between subjects, and various types of possible motivation to participate in astronomy-related activities or to study science at university.Future results can be used to help interested organizations such as universities, observatories or astronomical societies. They will be able to work more

  5. A Critical Assessment of the Resource Depletion Potential of Current and Future Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jens F. Peters

    2016-12-01

    Full Text Available Resource depletion aspects are repeatedly used as an argument for a shift towards new battery technologies. However, whether serious shortages due to the increased demand for traction and stationary batteries can actually be expected is subject to an ongoing discussion. In order to identify the principal drivers of resource depletion for battery production, we assess different lithium-ion battery types and a new lithium-free battery technology (sodium-ion under this aspect, applying different assessment methodologies. The findings show that very different results are obtained with existing impact assessment methodologies, which hinders clear interpretation. While cobalt, nickel and copper can generally be considered as critical metals, the magnitude of their depletion impacts in comparison with that of other battery materials like lithium, aluminum or manganese differs substantially. A high importance is also found for indirect resource depletion effects caused by the co-extraction of metals from mixed ores. Remarkably, the resource depletion potential per kg of produced battery is driven only partially by the electrode materials and thus depends comparably little on the battery chemistry itself. One of the key drivers for resource depletion seems to be the metals (and co-products in electronic parts required for the battery management system, a component rather independent from the actual battery chemistry. However, when assessing the batteries on a capacity basis (per kWh storage capacity, a high-energy density also turns out to be relevant, since it reduces the mass of battery required for providing one kWh, and thus the associated resource depletion impacts.

  6. Endocannabinoid system: An overview of its potential in current medical practice.

    Science.gov (United States)

    Mouslech, Zadalla; Valla, Vasiliki

    2009-01-01

    The endocannabinoid system (ECS) is a lipid signalling system, comprising of the endogenous cannabis-like ligands (endocannabinoids) anandamide (AEA) and 2-arachidonoylglycerol (2-AG), which derive from arachidonic acid. These bind to a family of G-protein-coupled receptors, called CB1 and CB2. The cannabinoid receptor 1 (CB1R) is distributed in brain areas associated with motor control, emotional responses, motivated behaviour and energy homeostasis. In the periphery, the same receptor is expressed in the adipose tissue, pancreas, liver, GI tract, skeletal muscles, heart and the reproduction system. The CB2R is mainly expressed in the immune system regulating its functions. Endocannabinoids are synthesized and released upon demand in a receptor-dependent way. They act as retrograde signalling messengers in GABAergic and glutamatergic synapses and as modulators of postsynaptic transmission, interacting with other neurotransmitters. Endocannabinoids are transported into cells by a specific uptake system and degraded by the enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). The ECS is involved in various pathophysiological conditions in central and peripheral tissues. It is implicated in the hormonal regulation of food intake, cardiovascular, gastrointestinal, immune, behavioral, antiproliferative and mammalian reproduction functions. Recent advances have correlated the ECS with drug addiction and alcoholism. The growing number of preclinical and clinical data on ECS modulators is bound to result in novel therapeutic approaches for a number of diseases currently treated inadequately. The ECS dysregulation has been correlated to obesity and metabolic syndrome pathogenesis. Rimonabant is the first CB1 blocker launched to treat cardiometabolic risk factors in obese and overweight patients. Phase III clinical trials showed the drug's ability to regulate intra-abdominal fat tissue levels, lipidemic, glycemic and inflammatory parameters. However

  7. Dropped fuel damage prediction techniques and the DROPFU code

    International Nuclear Information System (INIS)

    Mottershead, K.J.; Beardsmore, D.W.; Money, G.

    1995-01-01

    During refuelling, and fuel handling, at UK Advanced Gas Cooled Reactor (AGR) stations it is recognised that the accidental dropping of fuel is a possibility. This can result in dropping individual fuel elements, a complete fuel stringer, or a whole assembly. The techniques for assessing potential damage have been developed over a number of years. This paper describes how damage prediction techniques have subsequently evolved to meet changing needs. These have been due to later fuel designs and the need to consider drops in facilities outside the reactor. The paper begins by briefly describing AGR fuel and possible dropped fuel scenarios. This is followed by a brief summary of the damage mechanisms and the assessment procedure as it was first developed. The paper then describes the additional test work carried out, followed by the detailed numerical modelling. Finally, the paper describes the extensions to the practical assessment methods. (author)

  8. CURRENT, POTENTIAL AND FUTURE ISSUES: SEMESTA SENIOR HIGH SCHOOL AS MODEL SCHOOL OF EMERGING ICT TO ANSWER 2013 CURRICULUM IMPLEMENTATION

    OpenAIRE

    Candradewi Wahyu Anggraeni; Wasi‘ah Kurniaty; Windhariyati Dyah Kusumawanti

    2017-01-01

    Semesta Senior High School was chosen as the model school of the implementation of 2013 curriculum because it has emerged ICT to teaching learning process, teaching profession and school management. In addition, Semesta Foundation named Pasiad has collaborated with some public schools in Indonesia. The problems of this study are (a) how is the use of ICT in Semesta?; (b) how are the current, potential, and future issues of emerging ICT in education? The study objectives are (a) describing the...

  9. Perceptions of current and potential public health involvement of pharmacists in developing nations: The case of Zimbabwe.

    Science.gov (United States)

    Mdege, Noreen Dadirai; Chevo, Tafadzwa; Toner, Paul

    There is increasing recognition of the potential significant contribution that pharmacy personnel can make to improve the public's health. However, there is an evidence gap in developing countries on the public health role of pharmacy personnel. This study aimed to explore the current public health activities that pharmacy professionals in Zimbabwe are currently involved in, and the potential of expanding this role. The study utilized individual, face-to-face, semi-structured qualitative interviews with 9 key informants. The sample reflected the diversity of pharmacy practice groups and levels as well as professional experience, and included a representative from a patient group, and a non-pharmacist national level public health expert. Data collection and analysis was an iterative process informed both by the currently available literature on the topic, as well as themes emerging from the data. Framework analysis was utilized with two independent analyses performed. There was a general consensus among participants that pharmacy practice in Zimbabwe was mainly focused on curative services, with very limited involvement in public health oriented activities. The following were identified as pharmacists' current public health activities: supply chain management of pharmaceutical products, provision of medications and other pharmaceutical products to patients, therapy monitoring, identification and monitoring of chronic illnesses, information provision and training of pharmacists. Nevertheless, there were concerns regarding the quality of some of these services, and lack of consistency in provision across pharmacies. Other potential areas for pharmacists' public health practice were identified as emergency response, drug abuse, addressing social determinants of health particularly promoting healthy lifestyles, applied health research, counterfeit and substandard medicines, and advocacy. There is perceived potential for Zimbabwean pharmacists to become more involved in

  10. Device for making liquid drops

    International Nuclear Information System (INIS)

    Yamada, Masao; Fukuda, Fumito; Nishikawa, Masana; Ishii, Takeshi.

    1976-01-01

    Object: To provide a device for producing liquid drops in the form of liquefied gases indispensable to make deuterium and tritium ice pellets used as a fusion fuel in a tokamak type fusion reactor. Structure: First, pressure P 1 at the upper surface of liquefied gas in a container and outlet pressure P 2 of a nozzle disposed at the lower part of the container are adjusted into the state of P 1 >= P 2 , and it is preset so that even under such conditions, the liquefied gas from the nozzle is not naturally flown out. Next, a vibration plate disposed within the container is rapidly downwardly advanced toward the nozzle through a predetermined distance. As a result, pressure of the liquefied gas within a depression under the vibration plate rises instantaneously or in a pulse fashion to dissatisfy the aforesaid set condition whereby the liquefied gas may be flown out from the nozzle in the form of liquid drops. In accordance with the present device, it is possible to produce a suitable number of drops at a suitable point. (Yoshihara, H.)

  11. Dancing drops over vibrating substrates

    Science.gov (United States)

    Borcia, Rodica; Borcia, Ion Dan; Helbig, Markus; Meier, Martin; Egbers, Christoph; Bestehorn, Michael

    2017-04-01

    We study the motion of a liquid drop on a solid plate simultaneously submitted to horizontal and vertical harmonic vibrations. The investigation is done via a phase field model earlier developed for describing static and dynamic contact angles. The density field is nearly constant in every bulk region (ρ = 1 in the liquid phase, ρ ≈ 0 in the vapor phase) and varies continuously from one phase to the other with a rapid but smooth variation across the interfaces. Complicated explicit boundary conditions along the interface are avoided and captured implicitly by gradient terms of ρ in the hydrodynamic basic equations. The contact angle θ is controlled through the density at the solid substrate ρ S , a free parameter varying between 0 and 1 [R. Borcia, I.D. Borcia, M. Bestehorn, Phys. Rev. E 78, 066307 (2008)]. We emphasize the swaying and the spreading modes, earlier theoretically identified by Benilov and Billingham via a shallow-water model for drops climbing uphill along an inclined plane oscillating vertically [E.S. Benilov, J. Billingham, J. Fluid Mech. 674, 93 (2011)]. The numerical phase field simulations will be completed by experiments. Some ways to prevent the release of the dancing drops along a hydrophobic surface into the gas atmosphere are also discussed in this paper.

  12. Effect of the intra-layer potential distributions and spatial currents on the performance of graphene SymFETs

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mehdi; Sensale-Rodriguez, Berardi, E-mail: berardi.sensale@utah.edu [Department of Electrical and Computer Engineering, The University of Utah, Salt Lake City, Utah 84112 (United States)

    2015-09-15

    In this paper, a two-dimensional (2-D) model for a graphene symmetric field effect transistor (SymFET), which considers (a) the intra-graphene layer potential distributions and (b) the internal current flows through the device, is presented and discussed. The local voltages along the graphene electrodes as well as the current-voltage characteristics of the device are numerically calculated based on a single-particle tunneling model. Our numerical results show that: (i) when the tunneling current is small, due to either a large tunneling thickness (≥ 2 atomic layers of BN) or a small coherence length, the voltage distributions along the graphene electrodes have almost zero variations upon including these distributed effects, (ii) when the tunnel current is large, due to either a small tunneling thickness (∼ 1 atomic layer of BN) or due to a large coherence length, the local voltage distributions along the graphene electrodes become appreciable and the device behavior deviates from that predicted by a 1-D approximation. These effects, which are not captured in one-dimensional SymFET models, can provide a better understanding about the electron dynamics in the device and might indicate potential novel applications for this proposed device.

  13. Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current.

    Science.gov (United States)

    Liu, Pin W; Blair, Nathaniel T; Bean, Bruce P

    2017-10-04

    Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC 50 action potentials of small-diameter rat DRG neurons showed spike broadening at frequencies as low as 1 Hz and that spike broadening resulted predominantly from frequency-dependent inactivation of Kv3 channels. Spike width helps to control transmitter release, conduction velocity, and firing patterns and understanding the role of particular potassium channels can help to guide new pharmacological strategies for targeting pain-sensing neurons selectively. Copyright © 2017 the authors 0270-6474/17/379705-10$15.00/0.

  14. Effect of the intra-layer potential distributions and spatial currents on the performance of graphene SymFETs

    Directory of Open Access Journals (Sweden)

    Mehdi Hasan

    2015-09-01

    Full Text Available In this paper, a two-dimensional (2-D model for a graphene symmetric field effect transistor (SymFET, which considers (a the intra-graphene layer potential distributions and (b the internal current flows through the device, is presented and discussed. The local voltages along the graphene electrodes as well as the current-voltage characteristics of the device are numerically calculated based on a single-particle tunneling model. Our numerical results show that: (i when the tunneling current is small, due to either a large tunneling thickness (≥ 2 atomic layers of BN or a small coherence length, the voltage distributions along the graphene electrodes have almost zero variations upon including these distributed effects, (ii when the tunnel current is large, due to either a small tunneling thickness (∼ 1 atomic layer of BN or due to a large coherence length, the local voltage distributions along the graphene electrodes become appreciable and the device behavior deviates from that predicted by a 1-D approximation. These effects, which are not captured in one-dimensional SymFET models, can provide a better understanding about the electron dynamics in the device and might indicate potential novel applications for this proposed device.

  15. Active connectors for microfluidic drops on demand

    Energy Technology Data Exchange (ETDEWEB)

    Galas, Jean-Christophe; Studer, Vincent [Laboratoire de Neurobiologie, ESPCI-CNRS UMR 7637, 10 rue Vauquelin 75231 Paris cedex 05 (France); Bartolo, Denis [PMMH-ESPCI-CNRS UMR 7636-Universite Paris 6-Universite Paris 7, 10 rue Vauquelin 75231 Paris cedex 05 (France)], E-mail: jean-christophe.galas@espci.fr, E-mail: denis.bartolo@espci.fr, E-mail: vincent.studer@espci.fr

    2009-07-15

    We introduce a simple and versatile microfluidic drop-on-demand solution that enables independent and dynamical control of both the drop size and the drop production rate. To do so, we combine a standard microfluidic T-junction and a novel active switching component that connects the microfluidic channel to the macroscopic liquid reservoirs. Firstly, we explain how to make this simple but accurate drop-on-demand device. Secondly, we carefully characterize its dynamic response and its range of operations. Finally, we show how to generate complex two-dimensional drop patterns dynamically in single or multiple synchronized drop-on-demand devices.

  16. A computational model of the ionic currents, Ca2+ dynamics and action potentials underlying contraction of isolated uterine smooth muscle.

    Directory of Open Access Journals (Sweden)

    Wing-Chiu Tong

    2011-04-01

    Full Text Available Uterine contractions during labor are discretely regulated by rhythmic action potentials (AP of varying duration and form that serve to determine calcium-dependent force production. We have employed a computational biology approach to develop a fuller understanding of the complexity of excitation-contraction (E-C coupling of uterine smooth muscle cells (USMC. Our overall aim is to establish a mathematical platform of sufficient biophysical detail to quantitatively describe known uterine E-C coupling parameters and thereby inform future empirical investigations of physiological and pathophysiological mechanisms governing normal and dysfunctional labors. From published and unpublished data we construct mathematical models for fourteen ionic currents of USMCs: Ca2+ currents (L- and T-type, Na+ current, an hyperpolarization-activated current, three voltage-gated K+ currents, two Ca2+-activated K+ current, Ca2+-activated Cl current, non-specific cation current, Na+-Ca2+ exchanger, Na+-K+ pump and background current. The magnitudes and kinetics of each current system in a spindle shaped single cell with a specified surface area:volume ratio is described by differential equations, in terms of maximal conductances, electrochemical gradient, voltage-dependent activation/inactivation gating variables and temporal changes in intracellular Ca2+ computed from known Ca2+ fluxes. These quantifications are validated by the reconstruction of the individual experimental ionic currents obtained under voltage-clamp. Phasic contraction is modeled in relation to the time constant of changing [Ca2+]i. This integrated model is validated by its reconstruction of the different USMC AP configurations (spikes, plateau and bursts of spikes, the change from bursting to plateau type AP produced by estradiol and of simultaneous experimental recordings of spontaneous AP, [Ca2+]i and phasic force. In summary, our advanced mathematical model provides a powerful tool to

  17. Testing the price and affordability of healthy and current (unhealthy diets and the potential impacts of policy change in Australia

    Directory of Open Access Journals (Sweden)

    Amanda J. Lee

    2016-04-01

    Full Text Available Abstract Background Price and affordability of foods are important determinants of health. Targeted food pricing policies may help improve population diets. However, methods producing comparable data to inform relevant policy decisions are lacking in Australia and globally. The objective was to develop and pilot standardised methods to assess the price, relative price and affordability of healthy (recommended and current (unhealthy diets and test impacts of a potential policy change. Methods Methods followed the optimal approach proposed by INFORMAS using recent Australian dietary intake data and guidelines. Draft healthy and current (unhealthy diet baskets were developed for five household structures. Food prices were collected in stores in a high and low SES location in Brisbane, Australia. Diet prices were calculated and compared with household incomes, and with potential changes to the Australian Taxation System. Wilcoxen-signed rank tests were used to compare differences in price. Results The draft tools and protocols were deemed acceptable at household level, but methods could be refined. All households spend more on current (unhealthy diets than required to purchase healthy (recommended diets, with the majority (53–64 % of the food budget being spent on ‘discretionary’ choices, including take-away foods and alcohol. A healthy diet presently costs between 20–31 % of disposable income of low income households, but would become unaffordable for these families under proposed changes to expand the GST to apply to all foods in Australia. Conclusions Results confirmed that diet pricing methods providing meaningful, comparable data to inform potential fiscal and health policy actions can be developed, but draft tools should be refined. Results suggest that healthy diets can be more affordable than current (unhealthy diets in Australia, but other factors may be as important as price in determining food choices.

  18. Testing the price and affordability of healthy and current (unhealthy) diets and the potential impacts of policy change in Australia.

    Science.gov (United States)

    Lee, Amanda J; Kane, Sarah; Ramsey, Rebecca; Good, Elizabeth; Dick, Mathew

    2016-04-12

    Price and affordability of foods are important determinants of health. Targeted food pricing policies may help improve population diets. However, methods producing comparable data to inform relevant policy decisions are lacking in Australia and globally. The objective was to develop and pilot standardised methods to assess the price, relative price and affordability of healthy (recommended) and current (unhealthy) diets and test impacts of a potential policy change. Methods followed the optimal approach proposed by INFORMAS using recent Australian dietary intake data and guidelines. Draft healthy and current (unhealthy) diet baskets were developed for five household structures. Food prices were collected in stores in a high and low SES location in Brisbane, Australia. Diet prices were calculated and compared with household incomes, and with potential changes to the Australian Taxation System. Wilcoxen-signed rank tests were used to compare differences in price. The draft tools and protocols were deemed acceptable at household level, but methods could be refined. All households spend more on current (unhealthy) diets than required to purchase healthy (recommended) diets, with the majority (53-64 %) of the food budget being spent on 'discretionary' choices, including take-away foods and alcohol. A healthy diet presently costs between 20-31 % of disposable income of low income households, but would become unaffordable for these families under proposed changes to expand the GST to apply to all foods in Australia. Results confirmed that diet pricing methods providing meaningful, comparable data to inform potential fiscal and health policy actions can be developed, but draft tools should be refined. Results suggest that healthy diets can be more affordable than current (unhealthy) diets in Australia, but other factors may be as important as price in determining food choices.

  19. Short Duration Reduced Gravity Drop Tower Design and Development

    Science.gov (United States)

    Osborne, B.; Welch, C.

    The industrial and commercial development of space-related activities is intimately linked to the ability to conduct reduced gravity research. Reduced gravity experimentation is important to many diverse fields of research in the understanding of fundamental and applied aspects of physical phenomena. Both terrestrial and extra-terrestrial experimental facilities are currently available to allow researchers access to reduced gravity environments. This paper discusses two drop tower designs, a 2.0 second facility built in Australia and a proposed 2.2 second facility in the United Kingdom. Both drop towers utilise a drag shield for isolating the falling experiment from the drag forces of the air during the test. The design and development of The University of Queensland's (Australia) 2.0 second drop tower, including its specifications and operational procedures is discussed first. Sensitive aspects of the design process are examined. Future plans are then presented for a new short duration (2.2 sec) ground-based reduced gravity drop tower. The new drop tower has been designed for Kingston University (United Kingdom) to support teaching and research in the field of reduced gravity physics. The design has been informed by the previous UQ drop tower design process and utilises a catapult mechanism to increase test time and also incorporates features to allow participants for a variety of backgrounds (from high school students through to university researchers) to learn and experiment in reduced gravity. Operational performance expectations for this new facility are also discussed.

  20. Electrostatic interaction between Interball-2 and the ambient plasma. 1. Determination of the spacecraft potential from current calculations

    Directory of Open Access Journals (Sweden)

    M. Bouhram

    2002-03-01

    Full Text Available The Interball-2 spacecraft travels at altitudes extending up to 20 000 km, and becomes positively charged due to the low-plasma densities encountered and the photoemission on its sunlit surface. Therefore, a knowledge of the spacecraft potential Fs is required for correcting accurately thermal ion measurements on Interball-2. The determination of Fs  is based on the balance of currents between escaping photoelectrons and incoming plasma electrons. A three-dimensional model of the potential structure surrounding Interball-2, including a realistic geometry and neglecting the space-charge densities, is used to find, through particle simulations, current-voltage relations of impacting plasma electrons Ie (Fs and escaping photoelectrons Iph (Fs . The inferred relations are compared to analytic relationships in order to quantify the effects of the spacecraft geometry, the ambient magnetic field B0 and the electron temperature Te . We found that the complex geometry has a weak effect on the inferred currents, while the presence of B0 tends to decrease their values. Providing that the photoemission saturation current density Jph0 is known, a relation between Fs and the plasma density Ne can be derived by using the current balance. Since Jph0 is critical to this process, simultaneous measurements of Ne from Z-mode observations in the plasmapause, and data on the potential difference Fs  - Fp  between the spacecraft and an electric probe (p are used in order to reverse the process. A value Jph0 ~ = 32 µAm-2 is estimated, close to laboratory tests, but less than typical measurements in space. Using this value, Ne and Fs  can be derived systematically from electric field measurements without any additional calculation. These values are needed for correcting the distributions of low-energy ions measured by the Hyperboloid experiment on Interball-2. The effects of the potential structure on ion trajectories reaching Hyperboloid are discussed

  1. Nectar and pollination drops: how different are they?

    Science.gov (United States)

    Nepi, Massimo; von Aderkas, Patrick; Wagner, Rebecca; Mugnaini, Serena; Coulter, Andrea; Pacini, Ettore

    2009-08-01

    Pollination drops and nectars (floral nectars) are secretions related to plant reproduction. The pollination drop is the landing site for the majority of gymnosperm pollen, whereas nectar of angiosperm flowers represents a common nutritional resource for a large variety of pollinators. Extrafloral nectars also are known from all vascular plants, although among the gymnosperms they are restricted to the Gnetales. Extrafloral nectars are not generally involved in reproduction but serve as 'reward' for ants defending plants against herbivores (indirect defence). Although very different in their task, nectars and pollination drops share some features, e.g. basic chemical composition and eventual consumption by animals. This has led some authors to call these secretions collectively nectar. Modern techniques that permit chemical analysis and protein characterization have very recently added important information about these sugary secretions that appear to be much more than a 'reward' for pollinating (floral nectar) and defending animals (extrafloral nectar) or a landing site for pollen (pollination drop). Nectar and pollination drops contain sugars as the main components, but the total concentration and the relative proportions are different. They also contain amino acids, of which proline is frequently the most abundant. Proteomic studies have revealed the presence of common functional classes of proteins such as invertases and defence-related proteins in nectar (floral and extrafloral) and pollination drops. Invertases allow for dynamic rearrangement of sugar composition following secretion. Defence-related proteins provide protection from invasion by fungi and bacteria. Currently, only few species have been studied in any depth. The chemical composition of the pollination drop must be investigated in a larger number of species if eventual phylogenetic relationships are to be revealed. Much more information can be provided from further proteomic studies of both

  2. Horizontal Drop of 21- PWR Waste Package

    International Nuclear Information System (INIS)

    A.K. Scheider

    2001-01-01

    The objective of this calculation is to determine the structural response of the waste package (WP) dropped horizontally from a specified height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in terms of stress intensities. The information provided by the sketches (Attachment I) is that of the potential design of the type of WP considered in this calculation, and all obtained results are valid for that design only. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 16). AP-3.12Q, ''Calculations'' (Ref. 11) is used to perform the calculation and develop the document. The sketches attached to this calculation provide the potential dimensions and materials for the 21-PWR WP design

  3. Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Simulation-Based Evaluationof Technology and Potential

    Energy Technology Data Exchange (ETDEWEB)

    Reagan, Matthew; Moridis, George J.; Collett, Timothy; Boswell, Ray; Kurihara, M.; Reagan, Matthew T.; Koh, Carolyn; Sloan, E. Dendy

    2008-02-12

    Gas hydrates are a vast energy resource with global distribution in the permafrost and in the oceans. Even if conservative estimates are considered and only a small fraction is recoverable, the sheer size of the resource is so large that it demands evaluation as a potential energy source. In this review paper, we discuss the distribution of natural gas hydrate accumulations, the status of the primary international R&D programs, and the remaining science and technological challenges facing commercialization of production. After a brief examination of gas hydrate accumulations that are well characterized and appear to be models for future development and gas production, we analyze the role of numerical simulation in the assessment of the hydrate production potential, identify the data needs for reliable predictions, evaluate the status of knowledge with regard to these needs, discuss knowledge gaps and their impact, and reach the conclusion that the numerical simulation capabilities are quite advanced and that the related gaps are either not significant or are being addressed. We review the current body of literature relevant to potential productivity from different types of gas hydrate deposits, and determine that there are consistent indications of a large production potential at high rates over long periods from a wide variety of hydrate deposits. Finally, we identify (a) features, conditions, geology and techniques that are desirable in potential production targets, (b) methods to maximize production, and (c) some of the conditions and characteristics that render certain gas hydrate deposits undesirable for production.

  4. Drag and drop display & builder

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, Timofei B.; Petrov, Andrey D.; /Fermilab

    2007-12-01

    The Drag and Drop (DnD) Display & Builder is a component-oriented system that allows users to create visual representations of data received from data acquisition systems. It is an upgrade of a Synoptic Display mechanism used at Fermilab since 2002. Components can be graphically arranged and logically interconnected in the web-startable Project Builder. Projects can be either lightweight AJAX- and SVG-based web pages, or they can be started as Java applications. The new version was initiated as a response to discussions between the LHC Controls Group and Fermilab.

  5. Distinguishing between microscale gaseous bubbles and liquid drops

    Science.gov (United States)

    Tan, Beng Hau; An, Hongjie; Chan, Chon U.; Ohl, Claus-Dieter

    2015-11-01

    In recent years, there has been strong research interest in decorating surfaces with tiny bubbles and drops due to their potential applications in reducing slippage in micro and nanofluidic devices. Both nanobubbles and nanodrops are typically nucleated by exchanging fluids over a suitable substrate. However, the nucleation experiments present many challenges, such as reproducibility and the possibility of contamination. The use of one-use plastic syringes and needle cannulas in nucleation experiments can introduce polymeric contamination. A contaminated experiment may nucleate bubbles, drops or both. Moreover, it is surprisingly difficult to distinguish between bubbles and drops under the usual atomic force microscopy or optical techniques. Here we present an experimental study comparing bubbles and oil (PDMS) drops on an atomically smooth surface (HOPG). Instead of nucleating the objects via solvent exchange, we directly introduced bubbles via electrolysis, and oil drops by injecting a dilute solution. Contrary to previous reports, we find that under careful AFM characterisation, liquid drops and gaseous bubbles respond differently to a change in imaging force, and moreover present different characteristic force curves.

  6. Surface potential based modeling of charge, current, and capacitances in DGTFET including mobile channel charge and ambipolar behaviour

    Science.gov (United States)

    Jain, Prateek; Yadav, Chandan; Agarwal, Amit; Chauhan, Yogesh Singh

    2017-08-01

    We present a surface potential based analytical model for double gate tunnel field effect transistor (DGTFET) for the current, terminal charges, and terminal capacitances. The model accounts for the effect of the mobile charge in the channel and captures the device physics in depletion as well as in the strong inversion regime. The narrowing of the tunnel barrier in the presence of mobile charges in the channel is incorporated via modeling of the inverse decay length, which is constant under channel depletion condition and bias dependent under inversion condition. To capture the ambipolar current behavior in the model, tunneling at the drain junction is also included. The proposed model is validated against TCAD simulation data and it shows close match with the simulation data.

  7. DOES THE COMPRESSION OR THE EXPANSION OF A SIMPLE TOPOLOGY POTENTIAL MAGNETIC FIELD LEAD TO THE DEVELOPMENT OF CURRENT SHEETS?

    International Nuclear Information System (INIS)

    Aly, J. J.; Amari, T.

    2010-01-01

    Janse and Low have most recently addressed the following question. Consider a cylindrical domain containing a simple topology potential magnetic field threading its lower and upper horizontal faces, and a perfectly conducting plasma. Suppose that this domain is made to slowly contract or expand in the vertical direction, so driving the field into a quasi-static evolution through a series of force-free configurations. Then are these configurations smooth, or do they contain current sheets (CSs)? We reexamine here their three-step argument leading to the conclusion that CSs form most generally. We prove analytically that the field has to evolve through 'topologically untwisted' and 'nonpotential' configurations, thus confirming the first two steps. However, we find the third step-leading to the conclusion that a smooth untwisted force-free field is necessarily potential-to be very disputable.

  8. Vibration-Induced Climbing of Drops

    Science.gov (United States)

    Brunet, P.; Eggers, J.; Deegan, R. D.

    2007-10-01

    We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

  9. The potential impact of a prophylactic vaccine for human papillomavirus on the current cervical screening programme in Hong Kong.

    Science.gov (United States)

    Koljonen, Paul A

    2007-08-01

    To review and summarise current controversies in cervical screening in Hong Kong and discuss the potential impact of prophylactic human papillomavirus vaccination. Literature search of Medline to December 2006, the Hong Kong Cancer Registry, and Centre of Disease Control. Key words search terms were: 'human papillomavirus', 'vaccine', 'cervical cancer', 'screening programme', and 'Hong Kong'. Original articles, review papers, books, and the worldwide web. Cervical cancer is one of the most common cancers in Hong Kong, and can be prevented if detected at its pre-cancerous stage. Despite the huge disease burden this imposes on our society and robust advocacy by the academic sector, an appropriate screening programme is still not in place. Existence of a vaccine that could potentially reduce the costs of universal screening should prompt our government to re-consider subsidising such a programme. While a combined screening-vaccination programme may be more cost-effective than screening alone, the vaccine is still costly, and the government must consider all the pros and cons. The new human papillomavirus vaccine, combined with an organised screening programme, is probably a more cost-effective way of preventing morbidity and mortality due to cervical cancer than the current programme in Hong Kong. More research and cost-effectiveness analyses are needed to decide on the ideal ages for primary vaccination and the requirement for booster shots.

  10. Transient receptor potential (TRP) A1 activated currents in TRPV1 and cholecystokinin-sensitive cranial visceral afferent neurons.

    Science.gov (United States)

    Choi, Myung-Jin; Jin, Zhenhua; Park, Yong Seek; Rhee, Young Kyoung; Jin, Young-Ho

    2011-04-06

    Culinary use of the pungent spices has potential health benefits including a reduction in food intake. Pungent spices often contain ingredients that activate members of the transient receptor potential (TRP) family A1 and evoke pain from capsaicin-sensitive somatosensory neurons. TRPA1 channel have also been identified on cranial visceral afferent neurons but their distribution and functional contributions are poorly understood. Visceral vagal neurons transduce mechanical and chemical signals from peripheral organs to the nucleus tractus solitarii. Many capsaicin-sensitive vagal afferents participate in peripheral satiety signaling that includes cholecystokinin (CCK) sensitive neurons. To assess signaling, the TRPA1 selective agonist allyl isothiocyanate (AITC) was tested together with CCK and capsaicin (200nM), a TRPV1 specific agonist. In isolated nodose neurons, AITC (0.05-0.2mM) evoked concentration-dependent inward currents in 38% of the tested neurons. The TRPA1 specific antagonist HC-030031 (10μM) blocked AITC responses. TRPA1 responses were mixed across neurons that were capsaicin-sensitive and -insensitive. However CCK evoked inward currents only on capsaicin-sensitive neurons and 28% of the CCK-sensitive neurons expressed TRPA1. Our results indicate that TRPA1 is co-expressed with TRPV1 in CCK-sensitive nodose neurons. The findings indicate a potential mechanism by which spices can act within cranial visceral afferent pathways mediating satiety and contribute to the reduction of the food intake associated with spiced diets. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Sodium Overload Due To a Persistent Current That Attenuates The Arrhythmogenic Potential of a Novel LQT3 Mutation

    Directory of Open Access Journals (Sweden)

    Adrien eMoreau

    2013-10-01

    Full Text Available Long QT syndrome (LQTS is a congenital abnormality of cardiac repolarization that manifests as a prolonged QT interval on 12-lead electrocardiograms. The syndrome may lead to syncope and sudden death from ventricular tachyarrhythmias known as torsades de pointes. An increased persistent Na+ current is known to cause a Ca2+ overload in case of ischemia for example. Such increased Na+ persistent current is also usually associated to the LQT3 syndrome. The purpose of this study was to investigate the pathological consequences of a novel mutation in a family affected by LQTS. The impact of biophysical defects on cellular homeostasis are also investigated.Genomic DNA was extracted from blood samples, and a combination of PCR and DNA sequencing of several LQTS-linked genes was used to identify mutations. The mutation was reproduced in vitro and was characterized using the patch clamp technique and in silico quantitative analysis.A novel mutation (Q1476R was identified on the SCN5A gene encoding the cardiac Na+ channel. Cells expressing the Q1476R mutation exhibited biophysical alterations, including a shift of SS inactivation and a significant increase in the persistent Na+ current. The in silico analysis confirmed the arrhythmogenic character of the Q1476R mutation. It further revealed that the increase in persistent Na+ current causes a frequency-dependent Na+ overload in cardiomyocytes co-expressing WT and mutant Nav1.5 channels, that, in turn, exerts a moderating effect on the lengthening of the action potential duration caused by the mutation.The Q1476R mutation in SCN5A results in a three-fold increase in the window current and a persistent inward Na+ current. These biophysical defects may expose the carrier of the mutation to arrhythmias that occur preferentially in the patient at rest or during tachycardia. However, the Na+ overload counterbalances the gain-of-function of the mutation and is beneficial in that it prevents severe arrhythmias at

  12. Hydrocarbon Degradation In Poultry Droppings And Cassava Peels ...

    African Journals Online (AJOL)

    This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels (CP) for nutrient-enhanced biodegradation of petroleum hydrocarbon (THC) in a well drained Typic Paleustults using the THC levels and degradation duration as remediation indices. The performance of the organic ...

  13. 24 hydrocarbon degradation in poultry droppings and cassava peels

    African Journals Online (AJOL)

    OLUWOLE AKINNAGBE

    2009-01-01

    Jan 1, 2009 ... ABSTRACT. This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels. (CP) for nutrient-enhanced biodegradation of petroleum hydrocarbon (THC) in a well drained Typic. Paleustults using the THC levels and degradation duration as remediation indices.

  14. Changes in the action potential and transient outward potassium current in cardiomyocytes during acute cardiac rejection in rats.

    Science.gov (United States)

    Luo, Wenqi; Jia, Yixin; Zheng, Shuai; Li, Yan; Han, Jie; Meng, Xu

    2017-01-01

    Acute cardiac rejection contributes to the changes in the electrophysiological properties of grafted hearts. However, the electrophysiological changes of cardiomyocytes during acute cardiac rejection are still unknown. An understanding of the electrophysiological mechanisms of cardiomyocytes could improve the diagnosis and treatment of acute cardiac rejection. So it is important to characterize the changes in the action potential ( AP ) and the transient outward potassium current ( I to ) in cardiomyocytes during acute cardiac rejection. Heterotopic heart transplantation was performed in allogeneic [Brown Norway (BN)-to-Lewis] and isogeneic (BN-to-BN) rats. Twenty models were established in each group. Ten recipients were sacrificed at the 2nd day and the other ten recipients were sacrificed at the 4 th day after the operation in each group. Histopathological examinations of the grafted hearts were performed in half of the recipients in each group randomly. The other half of the grafted hearts were excised rapidly and enzymatically dissociated to obtain single cardiomyocytes. The AP and I to current were recorded using the whole cell patch-clamp technique. Forty grafted hearts were successfully harvested and used in experiments. Histologic examination showed mild rejection at the 2 nd day and moderate rejection at the 4 th day in the allogeneic group after cardiac transplantation, while no evidence of histologic lesions of rejection were observed in the isogeneic group. Compared with the isogeneic group, the action potential duration ( APD ) of cardiomyocytes in the allogeneic group was significantly prolonged ( APD 90 was 49.28±5.621 mV in the isogeneic group and 88.08±6.445 mV in the allogeneic group at the 2 nd day, P=0.0016; APD 90 was 59.34±5.183 mV in the isogeneic group and 104.0±9.523 mV in the allogeneic group at the 4 th day, P=0.0064). The current density of I to was significantly decreased at the 4 th day after cardiac transplantation. The APD of

  15. Surface potential, charging and local current transport of individual Ge quantum dots grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Singha, R.K. [Department of Physics, Visva-Bharati, Santiniketan 731235 (India); Manna, S.; Bar, R.; Das, S. [Department of Physics, Indian Institute of Technology-Kharagpur, Kharagpur 721302 (India); Ray, S.K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics, Indian Institute of Technology-Kharagpur, Kharagpur 721302 (India)

    2017-06-15

    Highlights: We have elaborately explained the individual Ge QD charging phenomena and current transport, which is very important to understand the Ge/Si nano devices. This paper will give a flavor to properly understand these phenomena linked together along with the photocurrent mechanism which is related to the Ge/Si valence band offset. • Both the CAFM and KPFM techniques point out the functionality of doping nature of the underneath Si substrate on the aforementioned characteristics of Ge QDs. • Analysis of the surface potential mapping using KPFM technique yields an approximate valence band offset measurement which is required to understand the intra-valence transition of holes for the realization of long wavelength infrared photodetector. • KPFM and CAFM can be utilized to explore the charging/discharging phenomena of dots and their composition variations. • Current-voltage (I–V) characteristics of the individual Ge QD strongly depends on the individual QD size. • Energy band diagrams for diamond tip and Ge QD shows the higher barrier for electrons and lower barrier for holes allowing the easy tunneling for holes to dominate the transport. - Abstract: It is fundamentally important to understand the nanoscale electronic properties of a single quantum dot (QD) contrary to an ensemble of QDs. Kelvin probe force microscopy (KPFM) and conductive atomic force microscopy (CAFM) are two important tools, which could be employed to probe surface potential, charging phenomena, and current transport mechanism of individual QD. We demonstrate the aforementioned characteristics of self-assembled Ge QDs, which was grown on Si substrates by solid source molecular beam epitaxy driven by the Stranski-Krastanov method. Study reveals that each Ge QD acts as charge storage node even at zero applied bias. The shape, size and density of QDs could be well probed by CAFM and KPFM, whereas QD facets could be better resolved by the conductive tip. The CAFM investigation

  16. Leidenfrost drops on a heated liquid pool

    Science.gov (United States)

    Maquet, L.; Sobac, B.; Darbois-Texier, B.; Duchesne, A.; Brandenbourger, M.; Rednikov, A.; Colinet, P.; Dorbolo, S.

    2016-09-01

    We show that a volatile liquid drop placed at the surface of a nonvolatile liquid pool warmer than the boiling point of the drop can be held in a Leidenfrost state even for vanishingly small superheats. Such an observation points to the importance of the substrate roughness, negligible in the case considered here, in determining the threshold Leidenfrost temperature. A theoretical model based on the one proposed by Sobac et al. [Phys. Rev. E 90, 053011 (2014), 10.1103/PhysRevE.90.053011] is developed in order to rationalize the experimental data. The shapes of the drop and of the liquid substrate are analyzed. The model notably provides scalings for the vapor film thickness profile. For small drops, these scalings appear to be identical to the case of a Leidenfrost drop on a solid substrate. For large drops, in contrast, they are different, and no evidence of chimney formation has been observed either experimentally or theoretically in the range of drop sizes considered in this study. Concerning the evaporation dynamics, the radius is shown to decrease linearly with time whatever the drop size, which differs from the case of a Leidenfrost drop on a solid substrate. For high superheats, the characteristic lifetime of the drops versus the superheat follows a scaling law that is derived from the model, but, at low superheats, it deviates from this scaling by rather saturating.

  17. Electrohydrodynamics of drops in strong electric fields: Simulations and theory

    Science.gov (United States)

    Saintillan, David; Das, Debasish

    2016-11-01

    Weakly conducting dielectric liquid drops suspended in another dielectric liquid exhibit a wide range of dynamical behaviors when subject to an applied uniform electric field contingent on field strength and material properties. These phenomena are best described by the much celebrated Maylor-Taylor leaky dielectric model that hypothesizes charge accumulation on the drop-fluid interface and prescribes a balance between charge relaxation, the jump in Ohmic currents and charge convection by the interfacial fluid flow. Most previous numerical simulations based on this model have either neglected interfacial charge convection or restricted themselves to axisymmetric drops. In this work, we develop a three-dimensional boundary element method for the complete leaky dielectric model to systematically study the deformation and dynamics of liquid drops in electric fields. The inclusion of charge convection in our simulation permits us to investigate drops in the Quincke regime, in which experiments have demonstrated symmetry-breaking bifurcations leading to steady electrorotation. Our simulation results show excellent agreement with existing experimental data and small deformation theories. ACSPRF Grant 53240-ND9.

  18. Neck extensor muscle weakness (Dropped head syndrome) following radiotherapy

    International Nuclear Information System (INIS)

    Bhatia, S.; Miller, R.C.; Lachance, D.L.

    2006-01-01

    Background. Dropped head syndrome is an unusual condition in which the head cannot be held upright in its normal anatomic position secondary to pronounced, isolated, neck extensor muscle weakness. Case report. A case of dropped head syndrome in a female with a history of radiotherapy for Hodgkin's lymphoma and a clinical history consistent with multiple sclerosis is presented, and potential etiologies are discussed. Conclusions. Muscular atrophy and lower motor neuron injury secondary to isolated anterior horn cell injury from radiotherapy emerge as the most likely etiology. (author)

  19. Surface potential effects in low-energy current image diffraction patterns observed on the Al(001) surface

    International Nuclear Information System (INIS)

    Fine structure observed in high-resolution low-energy electron diffraction (LEED) measurements near the energy threshold for emergence of new beams has been attributed to surface barrier effects. Recently, the surface barrier has been suggested as the source of the fine structure observed in current image diffraction (CID) patterns obtained by rastering the primary beam across an Al(001) crystal surface at a constant energy. This suggestion was based on kinematic arguments which correlated the emergence angle for a new electron beam with the observed structure in the CID pattern. In this work, the angular dependence of the elastic component of the total crystal reflectivity is calculated at constant energy. The calculations are based on full dynamical theories such as used in LEED but incorporating different surface barrier models to account for the saturating image potential. The results are compared with the experimental CID results

  20. Effects of electrical water bath stunning current frequencies on the spontaneous electroencephalogram and somatosensory evoked potentials in hens.

    Science.gov (United States)

    Raj, A B M; O'Callaghan, M

    2004-04-01

    1. The effectiveness of water bath electrical stunning of chickens with a constant root mean square (rms) current of 100 mA per bird delivered for 3 s using 100, 200, 400, 800 and 1500 Hz sine wave alternating current (AC) was investigated in layer hens. The quantitative changes occurring in the electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) were used to determine the effectiveness of stunning. The changes occurring in the EEG were evaluated using Fast Fourier Transformations (FFT) and the SEPs were averaged to determine whether they were present or abolished. 2. The results of FFT indicated that stunning of chickens with a constant rms current of 100 mA per bird using 100 or 200 Hz induced epileptiform activity in all the hens, immediately followed by a reduction in the total (2 to 30 Hz) and relative (13 to 30 Hz) power contents in the EEG frequency bands indicative of unconsciousness and insensibility. The SEPs were abolished in the majority of hens stunned with 100 Hz and all the hens stunned with 200 Hz. 3. By contrast, stunning using 400, 800 or 1500 Hz failed to induce epileptiform activity in all the birds, the total and relative power contents in the EEG frequency bands showed a substantial increase, rather than reduction, and the SEPs were also retained in the majority of chickens. It is therefore suggested that stunning using these frequencies failed to stun them satisfactorily. In these birds, occurrence of a painful arousal, rather than unconsciousness, could not be ruled out. 4. It is therefore suggested that water bath electrical stunning of chickens with a minimum rms current of 100 mA per bird delivered using 100 or 200 Hz would be adequate to ensure bird welfare under commercial conditions, provided both the carotid arteries in the neck are severed at slaughter. On humanitarian and bird welfare grounds, a rms current of greater than 100 mA per bird should be applied whilst using frequencies of 400 Hz or more of sine wave AC

  1. Predicting the current and future potential distributions of lymphatic filariasis in Africa using maximum entropy ecological niche modelling.

    Directory of Open Access Journals (Sweden)

    Hannah Slater

    Full Text Available Modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. Here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (LF, in Africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. We used 508 community-specific infection presence data collated from the published literature in conjunction with five predictive environmental/climatic and demographic variables, and a maximum entropy niche modelling method to construct the first ecological niche maps describing potential distribution and burden of LF in Africa. We also ran the best-fit model against climate projections made by the HADCM3 and CCCMA models for 2050 under A2a and B2a scenarios to simulate the likely distribution of LF under future climate and population changes. We predict a broad geographic distribution of LF in Africa extending from the west to the east across the middle region of the continent, with high probabilities of occurrence in the Western Africa compared to large areas of medium probability interspersed with smaller areas of high probability in Central and Eastern Africa and in Madagascar. We uncovered complex relationships between predictor ecological niche variables and the probability of LF occurrence. We show for the first time that predicted climate change and population growth will expand both the range and risk of LF infection (and ultimately disease in an endemic region. We estimate that populations at risk to LF may range from 543 and 804 million currently, and that this could rise to between 1.65 to 1.86 billion in the future depending on the climate scenario used and thresholds applied to signify infection presence.

  2. Current status and future potential of somatic mutation testing from circulating free DNA in patients with solid tumours.

    Science.gov (United States)

    Aung, K L; Board, R E; Ellison, G; Donald, E; Ward, T; Clack, G; Ranson, M; Hughes, A; Newman, W; Dive, C

    2010-12-01

    Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient's cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.

  3. Diethylcarbamazine increases activation of voltage-activated potassium (SLO-1) currents in Ascaris suum and potentiates effects of emodepside.

    Science.gov (United States)

    Buxton, Samuel K; Robertson, Alan P; Martin, Richard J

    2014-01-01

    Diethylcarbamazine is a drug that is used for the treatment of filariasis in humans and animals; it also has effects on intestinal nematodes, but its mechanism of action remains unclear. Emodepside is a resistance-busting anthelmintic approved for treating intestinal parasitic nematodes in animals. The novel mode of action and resistance-breaking properties of emodepside has led to its use against intestinal nematodes of animals, and as a candidate drug for treating filarial parasites. We have previously demonstrated effects of emodepside on SLO-1 K+-like currents in Ascaris suum. Here, we demonstrate that diethylcarbamazine, which has been proposed to work through host mediated effects, has direct effects on a nematode parasite, Ascaris suum. It increases activation of SLO-1 K+ currents and potentiates effects of emodepside. Our results suggest consideration of the combination of emodepside and diethylcarbamazine for therapy, which is predicted to be synergistic. The mode of action of diethylcarbamazine may involve effects on parasite signaling pathways (including nitric oxide) as well as effects mediated by host inflammatory mediators.

  4. GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.; Ekechukwu, A.; Milliken, C.

    2011-05-17

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

  5. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    Science.gov (United States)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-10-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  6. Green chemistry and nanofabrication in a levitated Leidenfrost drop.

    Science.gov (United States)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-01-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  7. Colloidal assembly in Leidenfrost drops for noniridescent structural color pigments.

    Science.gov (United States)

    Lim, Che Ho; Kang, Hyelim; Kim, Shin-Hyun

    2014-07-22

    Noniridescent structural color pigments have great potential as alternatives to conventional chemical color pigments in many coloration applications due to their nonbleaching and color-tunable properties. In this work, we report a novel method to create photonic microgranules composed of glassy packing of silica particles and small fraction of carbon black nanoparticles, which show pronounced structural colors with low angle-dependency. To prepare isotropic random packing in each microgranule, a Leidenfrost drop, which is a drop levitated by its own vapor on a hot surface, is employed as a template for fast consolidation of silica particles. The drop randomly migrates over the hot surface and rapidly shrinks, while maintaining its spherical shape, thereby consolidating silica particles to granular structures. Carbon black nanoparticles incorporated in the microgranules suppress incoherent multiple scattering, thereby providing improved color contrast. Therefore, photonic microgranules in a full visible range can be prepared by adjusting the size of silica particles with insignificant whitening.

  8. Vertical Drop Test of a YS-11 Fuselage Section

    Science.gov (United States)

    Minegishi, Masakatsu; Kumakura, Ikuo; Iwasaki, Kazuo; Shoji, Hirokazu; Yoshimoto, Norio; Terada, Hiroyuki; Sashikuma, Hirofumi; Isoe, Akira; Yamaoka, Toshihiro; Katayama, Noriaki; Hayashi, Toru; Akaso, Tetsuya

    The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) and Kawasaki Heavy Industories, Ltd. (KHI) conducted a vertical drop test of a fuselage section cut from a NAMIC YS-11 transport airplane at NAL vertical drop test facility in December 2001. The main objectives of this program were to obtain background data for aircraft cabin safety by drop test of a full-scale fuselage section and to develop computational method for crash simulation. The test article including seats and anthropomorphic test dummies was dropped to a rigid impact surface at a velocity of 6.1 m/s (20 ft/s). The test condition and result were considered to be severe but potentially survivable. A finite element model of this test article was also developed using the explicit nonlinear transient-dynamic analysis code, LS-DYNA3D. An outline of analytical method and comparison of analysis result with drop test data are presented in this paper.

  9. Star-shaped oscillations of Leidenfrost drops

    Science.gov (United States)

    Ma, Xiaolei; Liétor-Santos, Juan-José; Burton, Justin C.

    2017-03-01

    We experimentally investigate the self-sustained, star-shaped oscillations of Leidenfrost drops. The drops levitate on a cushion of evaporated vapor over a heated, curved surface. We observe modes with n =2 -13 lobes around the drop periphery. We find that the wavelength of the oscillations depends only on the capillary length of the liquid and is independent of the drop radius and substrate temperature. However, the number of observed modes depends sensitively on the liquid viscosity. The dominant frequency of pressure variations in the vapor layer is approximately twice the drop oscillation frequency, consistent with a parametric forcing mechanism. Our results show that the star-shaped oscillations are driven by capillary waves of a characteristic wavelength beneath the drop and that the waves are generated by a large shear stress at the liquid-vapor interface.

  10. Sepsis from dropped clips at laparoscopic cholecystectomy

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Sarwat E-mail: sarwathussain@hotmail.com

    2001-12-01

    We report seven patients in whom five dropped surgical clips and two gallstones were visualized in the peritoneal cavity, on radiological studies. In two, subphrenic abscesses and empyemas developed as a result of dropped clips into the peritoneal cavity during or following laparoscopic cholecystectomy. In one of these two, a clip was removed surgically from the site of an abscess. In two other patients dropped gallstones, and in three, dropped clips led to no complications. These were seen incidentally on studies done for other indications. Abdominal abscess secondary to dropped gallstones is a well-recognized complication of laparoscopic cholecystectomy (LC). We conclude that even though dropped surgical clips usually do not cause problems, they should be considered as a risk additional to other well-known causes of post-LC abdominal sepsis.

  11. Sepsis from dropped clips at laparoscopic cholecystectomy

    International Nuclear Information System (INIS)

    Hussain, Sarwat

    2001-01-01

    We report seven patients in whom five dropped surgical clips and two gallstones were visualized in the peritoneal cavity, on radiological studies. In two, subphrenic abscesses and empyemas developed as a result of dropped clips into the peritoneal cavity during or following laparoscopic cholecystectomy. In one of these two, a clip was removed surgically from the site of an abscess. In two other patients dropped gallstones, and in three, dropped clips led to no complications. These were seen incidentally on studies done for other indications. Abdominal abscess secondary to dropped gallstones is a well-recognized complication of laparoscopic cholecystectomy (LC). We conclude that even though dropped surgical clips usually do not cause problems, they should be considered as a risk additional to other well-known causes of post-LC abdominal sepsis

  12. Single and combined metal contamination in coastal environments in China: current status and potential ecological risk evaluation.

    Science.gov (United States)

    Manzoor, Romana; Zhang, Tingwan; Zhang, Xuejiao; Wang, Min; Pan, Jin-Fen; Wang, Zhumei; Zhang, Bo

    2018-01-01

    With the development of industrialization and urbanization, metal and metalloid pollution is one of the most serious environmental problems in China. Current contamination status of metals and metalloid and their potential ecological risks along China's coasts were reviewed in the present paper by a comprehensive study on metal contents in marine waters and sediments in the past few decades. The priority metals/metalloid cadmium (Cd), mercury (Hg), chromium (Cr), lead (Pb), and arsenic (As), which were the target elements of the designated project "Comprehensive Prevention and Control of Heavy Metal Pollution" issued by the Chinese government in 2011, were selected considering their high toxicity, persistence, and prevalent existence in coastal environment. Commonly used environmental quality evaluation methods for single and combined metals were compared, and we accordingly suggest the comprehensive approach of joint utilization of the Enrichment Factor and Effect Range Median combined with Pollution Load Index and Mean Effect Range Median Quotient (EEPME); this battery of guidelines may provide consistent, internationally comparable, and accurate understanding of the environment pollution status of combined metals/metalloid and their potential ecological risk.

  13. Susceptibility of Aphelinus certus to foliar-applied insecticides currently or potentially registered for soybean aphid control.

    Science.gov (United States)

    Frewin, Andrew J; Schaafsma, Arthur W; Hallett, Rebecca H

    2012-02-01

    Soybean aphid, a serious economic pest of soybean in North America, is currently managed by applying non-selective foliar insecticides during outbreaks according to decision thresholds and crop maturity. Natural enemies, such as the parasitoid Aphelinus certus Yasnosh, potentially play an important role in suppressing soybean aphid. Using selective insecticides that preserve A. certus may enhance the biological control service they provide and thus prevent or reduce the severity of soybean aphid outbreaks. The toxicity of five insecticides (λ-cyhalothrin, dimethoate, flonicamid, mineral oil, spirotetramat) and the biopesticide Beauveria bassiana to A. certus was assessed. The LD50 values of λ-cyhalothrin and dimethoate were similar; however, the hazard quotient of dimethoate was greater than that of λ-cyhalothrin. In a screening bioassay, the descending order of toxicity for the recommended rates 48 h after application was dimethoate>λ-cyhalothrin>flonicamid>mineral oil>Beauveria bassiana>spirotetramat. Overall, λ-cyhalothrin and dimethoate were both harmful to A. certus. The other insecticides tested were harmless to A. certus and are potential candidates for inclusion in soybean aphid management programs. Copyright © 2011 Society of Chemical Industry.

  14. Hydrothermal waves in evaporating sessile drops

    OpenAIRE

    Brutin, D.; Rigollet, F.; Niliot, C. Le

    2009-01-01

    Drop evaporation is a simple phenomena but still unclear concerning the mechanisms of evaporation. A common agreement of the scientific community based on experimental and numerical work evidences that most of the evaporation occurs at the triple line. However, the rate of evaporation is still empirically predicted due to the lack of knowledge on the convection cells which develop inside the drop under evaporation. The evaporation of sessile drop is more complicated than it appears due to the...

  15. Soft drop jet mass measurement

    CERN Document Server

    Roloff, Jennifer Kathryn; The ATLAS collaboration

    2018-01-01

    Calculations of jet substructure observables that are accurate beyond leading-logarithm accuracy have recently become available. Such observables are significant not only for probing the collinear regime of QCD that is largely unexplored at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider. This poster documents a measurement of the first jet substructure quantity at a hadron collider to be calculated at next-to-next-to-leading-logarithm accuracy. The normalized, differential cross-section is measured as a function of log( ρ^2), where ρ is the ratio of the soft-drop mass to the ungroomed jet transverse momentum. This quantity is measured in dijet events from 32.9 ifb of sqrt(s) = 13 TeV proton-proton collisions recorded by the ATLAS detector. The data are unfolded to correct for detector effects and compared to precise QCD calculations and leading-logarithm particle-level Monte Carlo simulations.

  16. Role of action potential configuration and the contribution of C²⁺a and K⁺ currents to isoprenaline-induced changes in canine ventricular cells.

    Science.gov (United States)

    Szentandrássy, N; Farkas, V; Bárándi, L; Hegyi, B; Ruzsnavszky, F; Horváth, B; Bányász, T; Magyar, J; Márton, I; Nánási, P P

    2012-10-01

    Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca²⁺ current (I(Ca)), slow delayed rectifier K⁺ current (I(Ks)) and fast delayed rectifier K⁺ current (I(Kr)) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the I(Kr) blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the I(Ks) blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the I(Ca) blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating I(Ca) followed by a rise in I(Ks) , both currents increased with increasing the cycle length. The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of I(Ks) - but not I(Kr) - may be responsible for the observed shortening of action potentials. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

  17. Role of action potential configuration and the contribution of Ca2+ and K+ currents to isoprenaline-induced changes in canine ventricular cells

    Science.gov (United States)

    Szentandrássy, N; Farkas, V; Bárándi, L; Hegyi, B; Ruzsnavszky, F; Horváth, B; Bányász, T; Magyar, J; Márton, I; Nánási, PP

    2012-01-01

    BACKGROUND AND PURPOSE Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca2+ current (ICa), slow delayed rectifier K+ current (IKs) and fast delayed rectifier K+ current (IKr) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. EXPERIMENTAL APPROACH Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. KEY RESULTS In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the IKr blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the IKs blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the ICa blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating ICa followed by a rise in IKs, both currents increased with increasing the cycle length. CONCLUSIONS AND IMPLICATIONS The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of IKs– but not IKr– may be responsible for the observed shortening of action potentials. PMID:22563726

  18. Surface potential distribution and airflow performance of different air-exposed electrode plasma actuators at different alternating current/direct current voltages

    International Nuclear Information System (INIS)

    Yang, Liang; Yan, Hui-Jie; Qi, Xiao-Hua; Hua, Yue; Ren, Chun-Sheng

    2015-01-01

    Asymmetric surface dielectric barrier discharge (SDBD) plasma actuators have been intensely studied for a number of years due to their potential applications for aerodynamic control. In this paper, four types of actuators with different configurations of exposed electrode are proposed. The SDBD actuators investigated are driven by dual-power supply, referred to as a fixed AC high voltage and an adjustable DC bias. The effects of the electrode structures on the dielectric surface potential distribution, the electric wind velocity, and the mean thrust production are studied, and the dominative factors of airflow acceleration behavior are revealed. The results have shown that the actions of the SDBD actuator are mainly dependent on the geometry of the exposed electrode. Besides, the surface potential distribution can effectively affect the airflow acceleration behavior. With the application of an appropriate additional DC bias, the surface potential will be modified. As a result, the performance of the electric wind produced by a single SDBD can be significantly improved. In addition, the work also illustrates that the actuators with more negative surface potential present better mechanical performance

  19. Assessment of Power Potential of Tidal Currents and Impacts of Power Extraction on Flow Conditions in Indonesia

    Science.gov (United States)

    Orhan, Kadir; Mayerle, Roberto

    2017-04-01

    Climate change is an urgent and potentially irreversible threat to human societies and the planet and thus requires an effective and appropriate response, with a view to accelerating the reduction of global greenhouse gas emissions. At this point, a worldwide shift to renewable energy is crucial. In this study, a methodology comprising of the estimates of power yield, evaluation of the effects of power extraction on flow conditions, and near-field investigations to deliver wake characteristics, recovery and interactions is described and applied to several straits in Indonesia. Site selection is done with high-resolution, three-dimensional flow models providing sufficient spatiotemporal coverage. Much attention has been given to the meteorological forcing, and conditions at the open sea boundaries to adequately capture the density gradients and flow fields. Model verifications using tidal records show excellent agreement. Sites with adequate depth for the energy conversion using horizontal axis tidal turbines, average kinetic power density greater than 0.5 kW/m2, and surface area larger than 0.5km2 are defined as energy hotspots. Spatial variation of the average extractable electric power is determined, and annual tidal energy resource is estimated for the straits in question. The results showed that the potential for tidal power generation in Indonesia is likely to exceed previous predictions reaching around 4,800MW. Models with higher resolutions have been developed to assess the impacts of devices on flow conditions and to resolve near-field turbine wakes in greater detail. The energy is assumed to be removed uniformly by sub-grid scale arrays of turbines. An additional drag force resulting in dissipation of the pre-existing kinetic power from 10% to 60% within a flow cross-section is introduced to capture the impacts. k-ɛ model, which is a second order turbulence closure model is selected to involve the effects of the turbulent kinetic energy and turbulent

  20. Many Drops Make a Lake

    Directory of Open Access Journals (Sweden)

    Chaitanya S. Mudgal

    2014-03-01

    greater knowledge, better skills and disseminate this knowledge through this journal to influence as many physicians and their patients as possible. They have taken the knowledge of their teachers, recognized their giants and are now poised to see further than ever before. My grandmother often used to quote to me a proverb from India, which when translated literally means “Many drops make a lake”. I cannot help but be amazed by the striking similarities between the words of Newton and this Indian saying. Therefore, while it may seem intuitive, I think it must be stated that it is vital for the betterment of all our patients that we recognize our own personal lakes to put our drops of knowledge into. More important is that we recognize that it is incumbent upon each and every one of us to contribute to our collective lakes of knowledge such as ABJS. And finally and perhaps most importantly we need to be utterly cognizant of never letting such lakes of knowledge run dry.... ever.

  1. Physical Watermarking for Securing Cyber-Physical Systems via Packet Drop Injections

    Energy Technology Data Exchange (ETDEWEB)

    Ozel, Omur [Carnegie Mellon Univ., Pittsburgh, PA (United States); Weekrakkody, Sean [Carnegie Mellon Univ., Pittsburgh, PA (United States); Sinopoli, Bruno [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-10-23

    Physical watermarking is a well known solution for detecting integrity attacks on Cyber-Physical Systems (CPSs) such as the smart grid. Here, a random control input is injected into the system in order to authenticate physical dynamics and sensors which may have been corrupted by adversaries. Packet drops may naturally occur in a CPS due to network imperfections. To our knowledge, previous work has not considered the role of packet drops in detecting integrity attacks. In this paper, we investigate the merit of injecting Bernoulli packet drops into the control inputs sent to actuators as a new physical watermarking scheme. With the classical linear quadratic objective function and an independent and identically distributed packet drop injection sequence, we study the effect of packet drops on meeting security and control objectives. Our results indicate that the packet drops could act as a potential physical watermark for attack detection in CPSs.

  2. Sustained attention in skilled and novice martial arts athletes: a study of event-related potentials and current sources

    Directory of Open Access Journals (Sweden)

    Javier Sanchez-Lopez

    2016-01-01

    Full Text Available Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows where only one of them (an arrow pointing up right required a motor response (i.e., target. CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200 as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus and limbic (mainly in the Anterior Cingulate

  3. Sustained attention in skilled and novice martial arts athletes: a study of event-related potentials and current sources.

    Science.gov (United States)

    Sanchez-Lopez, Javier; Silva-Pereyra, Juan; Fernandez, Thalia

    2016-01-01

    Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP) are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention) are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes) analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT) and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows) where only one of them (an arrow pointing up right) required a motor response (i.e., target). CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200) as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus) and limbic (mainly in the Anterior Cingulate Gyrus) lobes

  4. Self-wrapping of an ouzo drop induced by evaporation on a superamphiphobic surface

    NARCIS (Netherlands)

    Tan, Huanshu; Diddens, Christian; Versluis, Michel; Butt, Hans-Juergen; Lohse, Detlef; Zhang, Xuehua

    2017-01-01

    Evaporation of multi-component drops is crucial to various technologies and has numerous potential applications because of its ubiquity in nature. Superamphiphobic surfaces, which are both superhydrophobic and superoleophobic, can give a low wettability not only for water drops but also for oil

  5. New and modified techniques for studying nitrogen-fixing bacteria in small mammal droppings.

    Science.gov (United States)

    C.Y. Li; Chris. Maser

    1986-01-01

    Nitrogen-fixing bacteria in small mammal droppings are potentially important to forest productivity. As we study this phenomenon, however, we continually find unknowns, such as bacteria that we cannot isolate and purify because we do not know which techniques to use. For example, we have recently observed acetylene reduction in the droppings of the tundra vole (

  6. Drop test facility available to private industry

    International Nuclear Information System (INIS)

    Shappert, L.B.; Box, W.D.

    1983-01-01

    In 1978, a virtually unyielding drop test impact pad was constructed at Oak Ridge National Laboratory's (ORNL's) Tower Shielding Facility (TSF) for the testing of heavy shipping containers designed for transporting radioactive materials. Because of the facility's unique capability for drop-testing large, massive shipping packages, it has been identified as a facility which can be made available for non-DOE users

  7. Total Site Heat Integration Considering Pressure Drops

    Directory of Open Access Journals (Sweden)

    Kew Hong Chew

    2015-02-01

    Full Text Available Pressure drop is an important consideration in Total Site Heat Integration (TSHI. This is due to the typically large distances between the different plants and the flow across plant elevations and equipment, including heat exchangers. Failure to consider pressure drop during utility targeting and heat exchanger network (HEN synthesis may, at best, lead to optimistic energy targets, and at worst, an inoperable system if the pumps or compressors cannot overcome the actual pressure drop. Most studies have addressed the pressure drop factor in terms of pumping cost, forbidden matches or allowable pressure drop constraints in the optimisation of HEN. This study looks at the implication of pressure drop in the context of a Total Site. The graphical Pinch-based TSHI methodology is extended to consider the pressure drop factor during the minimum energy requirement (MER targeting stage. The improved methodology provides a more realistic estimation of the MER targets and valuable insights for the implementation of the TSHI design. In the case study, when pressure drop in the steam distribution networks is considered, the heating and cooling duties increase by 14.5% and 4.5%.

  8. Impact of potential changes to the current bovine spongiform encephalopathy surveillance programs for slaughter cattle and fallen stock in Japan.

    Science.gov (United States)

    Sugiura, Katsuaki; Murray, Noel; Shinoda, Naoki; Onodera, Takashi

    2009-07-01

    Cattle slaughtered in Japan for human consumption, regardless of their age, have been tested for bovine spongiform encephalopathy (BSE) since October 2001. Beginning in April 2004, all fallen stock from 24 months of age also have been tested. We evaluated the impact of potential changes to the current BSE surveillance programs for both slaughter cattle and fallen stock using a simple stochastic model. We calculated the probability that a BSE-infected dairy cow, Wagyu beef animal, Wagyu-Holstein cross steer or heifer, or Holstein steer slaughtered for human consumption or arising as fallen stock would be tested and detected. Four surveillance strategies were explored for cattle slaughtered for human consumption, with the minimum age at testing set at 0, 21, 31, or 41 months. Three surveillance strategies were explored for fallen stock, with the minimum age at testing set at 24, 31, or 41 months. Increasing the minimum age of testing from 0 to 21 months for both dairy cattle and Wagyu beef cattle had very little impact on the probability that a BSE-infected animal slaughtered for human consumption would be detected. Although increasing the minimum age at testing from 21 to 31 or 41 months would lead to fewer slaughtered animals being tested, the impact on the probability of detecting infected animals would be insignificant. The probability of infected Wagyu-Holstein crosses and Holstein steers being detected at slaughter or as fallen stock would be very low under all surveillance strategies.

  9. Algorithms for Computing the Magnetic Field, Vector Potential, and Field Derivatives for Circular Current Loops in Cylindrical Coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-24

    A numerical algorithm for computing the field components Br and Bz and their r and z derivatives with open boundaries in cylindrical coordinates for circular current loops is described. An algorithm for computing the vector potential is also described. For the convenience of the reader, derivations of the final expressions from their defining integrals are given in detail, since their derivations (especially for the field derivatives) are not all easily found in textbooks. Numerical calculations are based on evaluation of complete elliptic integrals using the Bulirsch algorithm cel. Since cel can evaluate complete elliptic integrals of a fairly general type, in some cases the elliptic integrals can be evaluated without first reducing them to forms containing standard Legendre forms. The algorithms avoid the numerical difficulties that many of the textbook solutions have for points near the axis because of explicit factors of 1=r or 1=r2 in the some of the expressions.

  10. Algorithms for Computing the Magnetic Field, Vector Potential, and Field Derivatives for a Thin Solenoid with Uniform Current Density

    Energy Technology Data Exchange (ETDEWEB)

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    A numerical algorithm for computing the field components Br and Bz and their r and z derivatives with open boundaries in cylindrical coordinates for radially thin solenoids with uniform current density is described in this note. An algorithm for computing the vector potential Aθ is also described. For the convenience of the reader, derivations of the final expressions from their defining integrals are given in detail, since their derivations are not all easily found in textbooks. Numerical calculations are based on evaluation of complete elliptic integrals using the Bulirsch algorithm cel. The (apparently) new feature of the algorithms described in this note applies to cases where the field point is outside of the bore of the solenoid and the field-point radius approaches the solenoid radius. Since the elliptic integrals of the third kind normally used in computing Bz and Aθ become infinite in this region of parameter space, fields for points with the axial coordinate z outside of the ends of the solenoid and near the solenoid radius are treated by use of elliptic integrals of the third kind of modified argument, derived by use of an addition theorem. Also, the algorithms also avoid the numerical difficulties the textbook solutions have for points near the axis arising from explicit factors of 1/r or 1/r2 in the some of the expressions.

  11. The effect of transcranial direct current stimulation on contrast sensitivity and visual evoked potential amplitude in adults with amblyopia

    Science.gov (United States)

    Ding, Zhaofeng; Li, Jinrong; Spiegel, Daniel P.; Chen, Zidong; Chan, Lily; Luo, Guangwei; Yuan, Junpeng; Deng, Daming; Yu, Minbin; Thompson, Benjamin

    2016-01-01

    Amblyopia is a neurodevelopmental disorder of vision that occurs when the visual cortex receives decorrelated inputs from the two eyes during an early critical period of development. Amblyopic eyes are subject to suppression from the fellow eye, generate weaker visual evoked potentials (VEPs) than fellow eyes and have multiple visual deficits including impairments in visual acuity and contrast sensitivity. Primate models and human psychophysics indicate that stronger suppression is associated with greater deficits in amblyopic eye contrast sensitivity and visual acuity. We tested whether transcranial direct current stimulation (tDCS) of the visual cortex would modulate VEP amplitude and contrast sensitivity in adults with amblyopia. tDCS can transiently alter cortical excitability and may influence suppressive neural interactions. Twenty-one patients with amblyopia and twenty-seven controls completed separate sessions of anodal (a-), cathodal (c-) and sham (s-) visual cortex tDCS. A-tDCS transiently and significantly increased VEP amplitudes for amblyopic, fellow and control eyes and contrast sensitivity for amblyopic and control eyes. C-tDCS decreased VEP amplitude and contrast sensitivity and s-tDCS had no effect. These results suggest that tDCS can modulate visual cortex responses to information from adult amblyopic eyes and provide a foundation for future clinical studies of tDCS in adults with amblyopia. PMID:26763954

  12. Crossover design in transcranial direct current stimulation studies on motor learning: potential pitfalls and difficulties in interpretation of findings.

    Science.gov (United States)

    Biabani, Mana; Farrell, Michael; Zoghi, Maryam; Egan, Gary; Jaberzadeh, Shapour

    2017-12-12

    Crossover designs are used by a high proportion of studies investigating the effects of transcranial direct current stimulation (tDCS) on motor learning. These designs necessitate attention to aspects of data collection and analysis to take account of design-related confounds including order, carryover, and period effects. In this systematic review, we appraised the method sections of crossover-designed tDCS studies of motor learning and discussed the strategies adopted to address these factors. A systematic search of 10 databases was performed and 19 research papers, including 21 experimental studies, were identified. Potential risks of bias were addressed in all of the studies, however, not in a rigorous and structured manner. In the data collection phase, unclear methods of randomization, various lengths of washout period, and inconsistency in the counteracting period effect can be observed. In the analytical procedures, the stratification by sequence group was often ignored, and data were treated as if it belongs to a simple repeated-measures design. An inappropriate use of crossover design can seriously affect the findings and therefore the conclusions drawn from tDCS studies on motor learning. The results indicate a pressing need for the development of detailed guidelines for this type of studies to benefit from the advantages of a crossover design.

  13. Review of the current understanding of the potential for containment failure from in-vessel steam explosions

    International Nuclear Information System (INIS)

    1985-06-01

    A group of experts was convened to review the current understanding of the potential for containment failure from in-vessel steam explosions during core meltdown accidents in LWRs. The Steam Explosion Review Group (SERG) was requested to provide assessments of: (1) the conditional probability of containment failure due to a steam explosion, (2) a Sandia National Laboratory (SNL) report entitled ''An Uncertainty Study of PWR Steam Explosions,'' NUREG/CR-3369, (3) a SNL proposed steam explosion research program. This report summarizes the results of the deliberations of the review group. It also presents the detailed response of each individual member to each of the issues. The consensus of the SERG is that the occurrence of a steam explosion of sufficient energetics which could lead to alpha-mode containment failure has a low probability. The SERG members disagreed with the methodology used in NUREG/CR-3369 for the purpose of establishing the uncertainty in the probability of containment failure by a steam explosion. A consensus was reached among SERG members on the need for a continuing steam explosion research program which would improve our understanding of certain aspects of steam explosion phenomenology

  14. A smoking cessation programme for current and recent ex-smokers following diagnosis of a potentially curable cancer.

    Science.gov (United States)

    Ong, J; Plueckhahn, I; Cruickshank, D; Churilov, L; Mileshkin, L

    2016-09-01

    Cancer patients who quit smoking have improved survival rates. The time of diagnosis provides a 'teachable moment' when healthcare providers can offer smoking-cessation treatment. To assess the impact on quit rates of a tailored smoking-cessation intervention for patients diagnosed with a potentially curable cancer. A prospective, one-arm cohort study of current smokers and recent quitters (cancer was performed. Intervention involved an initial motivational interview, regular follow up and pharmacotherapy when appropriate. Quit rates were measured at 1, 3, 6 and 12 months by self-reported abstinence and biochemical confirmation. The primary end point was prolonged abstinence at 12 months. Changes in quality of life parameters and distress were also assessed. Seventy-one patients were recruited, with a median age of 56 years. Forty-one patients (58%) had a smoking-related cancer. The prolonged abstinence rate at 12 months was 24% (95% confidence interval 14-36%). Factors associated with successful quitting included being in the preparation or action phase of readiness to change at study entry (P = 0.012) and having complications of treatment requiring hospitalisation (P = 0.024). Between baseline and 12 months, quitters reported improvement in self-control (P cancer require intensive support to quit. An individualised behavioural and pharmacological intervention can be successful in helping patients quit smoking, with quality of life improvements seen amongst successful quitters. Population measures to stop people starting smoking remain essential. © 2016 Royal Australasian College of Physicians.

  15. Fifty Years of Technological Innovation: Potential and Limitations of Current Technologies in Abdominal Magnetic Resonance Imaging and Computed Tomography.

    Science.gov (United States)

    Attenberger, Ulrike I; Morelli, John; Budjan, Johannes; Henzler, Thomas; Sourbron, Steven; Bock, Michael; Riffel, Philipp; Hernando, Diego; Ong, Melissa M; Schoenberg, Stefan O

    2015-09-01

    Magnetic resonance imaging (MRI) has become an important modality for the diagnosis of intra-abdominal pathology. Hardware and pulse sequence developments have made it possible to derive not only morphologic but also functional information related to organ perfusion (dynamic contrast-enhanced MRI), oxygen saturation (blood oxygen level dependent), tissue cellularity (diffusion-weighted imaging), and tissue composition (spectroscopy). These techniques enable a more specific assessment of pathologic lesions and organ functionality. Magnetic resonance imaging has thus transitioned from a purely morphologic examination to a modality from which image-based disease biomarkers can be derived. This fits well with several emerging trends in radiology, such as the need to accurately assess response to costly treatment strategies and the need to improve lesion characterization to potentially avoid biopsy. Meanwhile, the cost-effectiveness, availability, and robustness of computed tomography (CT) ensure its place as the current workhorse for clinical imaging. Although the lower soft tissue contrast of CT relative to MRI is a long-standing limitation, other disadvantages such as ionizing radiation exposure have become a matter of public concern. Nevertheless, recent technical developments such as dual-energy CT or dynamic volume perfusion CT also provide more functional imaging beyond morphology.The aim of this article was to review and discuss the most important recent technical developments in abdominal MRI and state-of-the-art CT, with an eye toward the future, providing examples of their clinical utility for the evaluation of hepatic and renal pathologies.

  16. Drop dispensing in a viscous outer liquid

    Directory of Open Access Journals (Sweden)

    Claudiu PATRASCU

    2017-12-01

    Full Text Available The formation and detachment of Newtonian drops in viscous external liquids is investigated. A global analysis of two necking processes is presented in order to highlight the behavior of such thinning phenomena, when controlled either by inertia or by viscous effects. Moving detached droplets in an immiscible outer liquid were studied in terms of velocity and drop-travel distance. Theoretical predictions are proposed and compared with experimental data for the volume of the drop and for the subsequent dynamics that follow after detachment. Our investigations point out that the drop rapidly achieves constant velocity, the value of it being in a satisfactory agreement with the model. Both the influence of the flow rate and that of the material properties on drop volume are pursued.

  17. Breakfast patterns of frozen impacted drops

    Science.gov (United States)

    Thievenaz, Virgile; Josserand, Christophe; Seon, Thomas

    2017-11-01

    We investigate experimentally the solidification of a water drop during its impact on a sub-zero cooled metallic plate. As the drop impacts the substrate, a first thin layer of ice builds-up in the briefest moment. Afterwards, the competition between the liquid solidification and its retraction on this ice layer leads to a variety of frozen drop patterns. Typically, with a change of temperature the drop can freeze into a fried egg or a doughnut shape. These frozen motifs experience different sizes and can even disappear so only the thin pancake remains. These patterns have been explored through a range of parameters such as : plate temperature, thermal properties, drop size and impact velocity. Phase-diagrams show the range and the transition temperatures between the different patterns as a function of those parameters. The experimental results are discussed using a scaling law approach, allowing basic understanding of the underlying physics.

  18. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  19. Development of a Simplified Calculation Tool for Voltage Drop caused by Transformer Inrush in Distribution System

    Science.gov (United States)

    Nakachi, Yoshiki; Fukae, Takayuki; Sugahara, Toshinori; Nakamura, Hayato; Koyama, Mitsuaki; Ueda, Fukashi

    It is well known that the voltage drop due to the inrush current at energizing transformer, may at times, interrupt electrical equipment. Generally, the voltage drop is calculated by using the sophisticated tool such as EMTP, so the transformer saturation phenomenon has been properly represented. However, it is not practical for distribution system engineers to calculate the voltage drop with transformer inrush by using EMTP, because there are a lot of network access requests needing such calculations with many kinds of transformers. Therefore, in this paper, a simplified and easy-to-use calculation tool for voltage drop caused by transformer inrush in distribution system is developed. In order to grasp the voltage drop by inrush current during the planning stage, it is formulated by considering the transformer saturation/unsaturation periods in each winding type, the developed tool is based on the versatile spreadsheet software such as Microsoft Excel®. It can be used with accuracy almost similar to the EMTP.

  20. Basin-scale simulation of current and potential climate changed hydrologic conditions in the Lake Michigan Basin, United States

    Science.gov (United States)

    Christiansen, Daniel E.; Walker, John F.; Hunt, Randall J.

    2014-01-01

    The Great Lakes Restoration Initiative (GLRI) is the largest public investment in the Great Lakes in two decades. A task force of 11 Federal agencies developed an action plan to implement the initiative. The U.S. Department of the Interior was one of the 11 agencies that entered into an interagency agreement with the U.S. Environmental Protection Agency as part of the GLRI to complete scientific projects throughout the Great Lakes basin. The U.S. Geological Survey, a bureau within the Department of the Interior, is involved in the GLRI to provide scientific support to management decisions as well as measure progress of the Great Lakes basin restoration efforts. This report presents basin-scale simulated current and forecast climatic and hydrologic conditions in the Lake Michigan Basin. The forecasts were obtained by constructing and calibrating a Precipitation-Runoff Modeling System (PRMS) model of the Lake Michigan Basin; the PRMS model was calibrated using the parameter estimation and uncertainty analysis (PEST) software suite. The calibrated model was used to evaluate potential responses to climate change by using four simulated carbon emission scenarios from eight general circulation models released by the World Climate Research Programme’s Coupled Model Intercomparison Project phase 3. Statistically downscaled datasets of these scenarios were used to project hydrologic response for the Lake Michigan Basin. In general, most of the observation sites in the Lake Michigan Basin indicated slight increases in annual streamflow in response to future climate change scenarios. Monthly streamflows indicated a general shift from the current (2014) winter-storage/snowmelt-pulse system to a system with a more equally distributed hydrograph throughout the year. Simulated soil moisture within the basin illustrates that conditions within the basin are also expected to change on a monthly timescale. One effect of increasing air temperature as a result of the changing

  1. Water and Land Use Efficiency in Current and Potential Future US Corn and Brazilian Sugarcane Ethanol Systems

    Science.gov (United States)

    Warner, E. S.; Zhang, Y.; Newmark, R. L.

    2012-12-01

    Biofuels represent an opportunity for domestic fuel production from renewable energy sources with potential environmental and social benefits such as reducing greenhouse gas (GHG) and promoting rural development. However, as demand for biofuel continues to increase worldwide, concerns about land competition between food and fuel, excessive water usage and other unintended environmental consequences have grown. Through a comparative study between US corn ethanol and Brazilian sugarcane ethanol, we examine the energy, land, water and GHG performance of the two largest industrial fuel ethanol production systems in the world. Our comparisons include current and potential future systems with improved agronomic practices, crop yields, ethanol conversion processes, and utilization of agricultural residues. Our results suggest that the average water footprints of US corn ethanol and Brazilian sugarcane ethanol are fairly close (108 and 110 m3/GJ of ethanol, respectively) while the variations can range from 50 to 250 m3/GJ for sugarcane ethanol and 50 to380 m3/GJ for corn ethanol. Results emphasize the need to examine the water footprint within the context of local and regional climatic variability, water availability, competing uses (e.g. agricultural, industrial, and municipal water needs) and other ecosystem constraints. Research is under way (at the National Renewable Energy Laboratory and other institutions) to develop models to analyze water supply and demand at the watershed-scale for current and future biomass production, and to understand the tradeoffs among water supply, demand and quality due to more intensive agricultural practices and expansion of biofuels. Land use efficiency metrics, with regards to life cycle GHG emissions (without land use change) savings through gasoline displacement with ethanol, illustrate the progression of the biofuel industry and the importance of maximizing bioenergy production by utilizing both the crops and the residues. A recent

  2. Water Sensitive Urban Design: An Investigation of Current Systems, Implementation Drivers, Community Perceptions and Potential to Supplement Urban Water Services

    Directory of Open Access Journals (Sweden)

    Ashok K. Sharma

    2016-06-01

    Full Text Available Large scale centralised water, wastewater and stormwater systems have been implemented for over 100 years. These systems have provided a safe drinking water supply, efficient collection and disposal of wastewater to protect human health, and the mitigation of urban flood risk. The sustainability of current urban water systems is under pressure from a range of challenges which include: rapid population growth and resulting urbanisation, climate change impacts, and infrastructure that is ageing and reaching capacity constraints. To address these issues, urban water services are now being implemented with Integrated Urban Water Management (IUWM and Water Sensitive Urban Design (WSUD approaches. WSUD systems can deliver multiple benefits including water conservation, stormwater quality improvement, flood control, landscape amenity and a healthy living environment. These systems can be provided as stand-alone systems or in combination with centralised systems. These systems are still novel and thus face knowledge gaps that are impeding their mainstream uptake. Knowledge gaps cover technical, economic, social, and institutional aspects of their implementation. This paper is based on the outcomes of a comprehensive study conducted in South Australia which investigated impediments for mainstream uptake of WSUD, community perceptions of WSUD and potential of WSUD to achieve water conservation through the application of alternative resources, and in flood management. The outcomes are discussed in this paper for the benefit of water professionals engaged with WSUD planning, implementation, community consultation and regulation. Although the paper is based on a study conducted in South Australia, the comprehensive framework developed to conduct this detailed study and investigation can be adopted in any part of the world.

  3. Drop impact splashing and air entrapment

    KAUST Repository

    Thoraval, Marie-Jean

    2013-03-01

    Drop impact is a canonical problem in fluid mechanics, with numerous applications in industrial as well as natural phenomena. The extremely simple initial configuration of the experiment can produce a very large variety of fast and complex dynamics. Scientific progress was made in parallel with major improvements in imaging and computational technologies. Most recently, high-speed imaging video cameras have opened the exploration of new phenomena occurring at the micro-second scale, and parallel computing allowed realistic direct numerical simulations of drop impacts. We combine these tools to bring a new understanding of two fundamental aspects of drop impacts: splashing and air entrapment. The early dynamics of a drop impacting on a liquid pool at high velocity produces an ejecta sheet, emerging horizontally in the neck between the drop and the pool. We show how the interaction of this thin liquid sheet with the air, the drop or the pool, can produce micro-droplets and bubble rings. Then we detail how the breakup of the air film stretched between the drop and the pool for lower impact velocities can produce a myriad of micro-bubbles.

  4. Effects of temperature on simulated electrotonic potentials and their current kinetics of human motor axons at 20°C-42°C.

    Science.gov (United States)

    Stephanova, D I; Daskalova, M

    2014-09-01

    To expand our studies on accommodation in human motor nerve axons, the effects of temperature on polarizing nodal and internodal electrotonic potentials and their current kinetics are investigated. The computations use our temperature dependent multi-layered model of the myelinated human motor nerve fiber and the temperature is increased from 20°C to 42°C. The results show that for temperatures from 28°C to 37°C, the polarizing electrotonic potentials almost coincide, as the kinetics of their ionic currents is changed a little. The normal (at 37°C) resting membrane potential is further depolarized or hyperpolarized during hypothermia (≤ 25°C) or hyperthermia (≥ 40°C), respectively and its change is determined by the flow of ionic currents through the internodal axolemma during the polarizing current stimuli. The polarizing electrotonic potentials are more altered during hypothermia and are most altered during hyperthermia. During hyperthermia, the depolarizing nodal and internodal electrotonic potentials are determined by the nodal slow (I Ks ) and internodal fast (I Kf ) and slow (I Ks ) potassium currents. The hyperpolarizing internodal electrotonic potentials are determined by the activation of internodal channels, which are different during hyperthermia at 40°C and 42°C. These potentials are determined by the internodal I Ks current at 40°C and by the internodal inward rectifier (I IR ) and leakage (I Lk ) currents at 42°C. The difference in accommodation to hyperpolarizing currents during focal and uniform hyperthermia at 42°C is discussed. The present results are essential for the interpretation of mechanisms of threshold electrotonus measurements in subjects with symptoms of cooling, warming and fever, which can result from alterations in body temperature.

  5. Self-wrapping of an ouzo drop induced by evaporation on a superamphiphobic surface.

    Science.gov (United States)

    Tan, Huanshu; Diddens, Christian; Versluis, Michel; Butt, Hans-Jürgen; Lohse, Detlef; Zhang, Xuehua

    2017-04-12

    Evaporation of multi-component drops is crucial to various technologies and has numerous potential applications because of its ubiquity in nature. Superamphiphobic surfaces, which are both superhydrophobic and superoleophobic, can give a low wettability not only for water drops but also for oil drops. In this paper, we experimentally, numerically and theoretically investigate the evaporation process of millimetric sessile ouzo drops (a transparent mixture of water, ethanol, and trans-anethole) with low wettability on a superamphiphobic surface. The evaporation-triggered ouzo effect, i.e. the spontaneous emulsification of oil microdroplets below a specific ethanol concentration, preferentially occurs at the apex of the drop due to the evaporation flux distribution and volatility difference between water and ethanol. This observation is also reproduced by numerical simulations. The volume decrease of the ouzo drop is characterized by two distinct slopes. The initial steep slope is dominantly caused by the evaporation of ethanol, followed by the slower evaporation of water. At later stages, thanks to Marangoni forces the oil wraps around the drop and an oil shell forms. We propose an approximate diffusion model for the drying characteristics, which predicts the evaporation of the drops in agreement with experiment and numerical simulation results. This work provides an advanced understanding of the evaporation process of ouzo (multi-component) drops.

  6. Molecular dynamics study of the vaporization of an ionic drop

    Science.gov (United States)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  7. Combining spray nozzle simulators with meshes: characterization of rainfall intensity and drop properties

    Science.gov (United States)

    Carvalho, Sílvia C. P.; de Lima, João L. M. P.; de Lima, M. Isabel P.

    2013-04-01

    Rainfall simulators can be a powerful tool to increase our understanding of hydrological and geomorphological processes. Nevertheless, rainfall simulators' design and operation might be rather demanding, for achieving specific rainfall intensity distributions and drop characteristics. The pressurized simulators have some advantages over the non-pressurized simulators: drops do not rely on gravity to reach terminal velocity, but are sprayed out under pressure; pressurized simulators also yield a broad range of drop sizes in comparison with drop-formers simulators. The main purpose of this study was to explore in the laboratory the potential of combining spray nozzle simulators with meshes in order to change rainfall characteristics (rainfall intensity and diameters and fall speed of drops). Different types of spray nozzles were tested, such as single full-cone and multiple full-cone nozzles. The impact of the meshes on the simulated rain was studied by testing different materials (i.e. plastic and steel meshes), square apertures and wire thicknesses, and different vertical distances between the nozzle and the meshes underneath. The diameter and fall speed of the rain drops were measured using a Laser Precipitation Monitor (Thies Clima). The rainfall intensity range and coefficients of uniformity of the sprays and the drop size distribution, fall speed and kinetic energy were analysed. Results show that when meshes intercept drop trajectories the spatial distribution of rainfall intensity and the drop size distribution are affected. As the spray nozzles generate typically small drop sizes and narrow drop size distributions, meshes can be used to promote the formation of bigger drops and random their landing positions.

  8. Drop Tower Facility at Queensland University of Technology

    Science.gov (United States)

    Plagens, Owen; Castillo, Martin; Steinberg, Theodore; Ong, Teng-Cheong

    The Queensland University of Technology (QUT) Drop Tower Facility is a {raise.17exscriptstyle˜}2.1 second, 21.3 m fall, dual capsule drop tower system. The dual capsule comprises of an uncoupled exterior hollow drag shield that experiences drag by the ambient atmosphere with the experimental capsule falling within the drag shield. The dual capsule system is lifted to the top of the drop tower via a mechanical crane and the dropping process is initiated by the cutting of a wire coupling the experimental package and suspending the drag shield. The internal experimental capsule reaches the bottom of the drag shield floor just prior to the deceleration stage at the air bag and during this time experience gravity levels of {raise.17exscriptstyle˜}10textsuperscript{-6} g. The deceleration system utilizes an inflatable airbag where experimental packages can be designed to experience a maximum deceleration of {raise.17exscriptstyle˜}10textsuperscript{18} g for {raise.17exscriptstyle˜}0.1 seconds. The drag shield can house experimental packages with a maximum diameter of 0.8 m and height of 0.9 m. The drag shield can also be used in foam mode, where the walls are lined with foam and small experiments can be dropped completely untethered. This mode is generally used for the study of microsatellite manipulation. Payloads can be powered by on-board power systems with power delivered to the experiment until free fall occurs. Experimental data that can be collected includes but is not limited to video, temperature, pressure, voltage/current from the power supply, and triggering mechanisms outputs which are simultaneously collected via data logging systems and high speed video recording systems. Academic and commercial projects are currently under investigation at the QUT Drop Tower Facility and collaboration is openly welcome at this facility. Current research includes the study of heterogeneously burning metals in oxygen which is aimed at fire safety applications and

  9. The human ether-a-go-go-related gene (hERG) current inhibition selectively prolongs action potential of midmyocardial cells to augment transmural dispersion.

    Science.gov (United States)

    Yasuda, C; Yasuda, S; Yamashita, H; Okada, J; Hisada, T; Sugiura, S

    2015-08-01

    The majority of drug induced arrhythmias are related to the prolongation of action potential duration following inhibition of rapidly activating delayed rectifier potassium current (I(Kr)) mediated by the hERG channel. However, for arrhythmias to develop and be sustained, not only the prolongation of action potential duration but also its transmural dispersion are required. Herein, we evaluated the effect of hERG inhibition on transmural dispersion of action potential duration using the action potential clamp technique that combined an in silico myocyte model with the actual I(Kr) measurement. Whole cell I(Kr) current was measured in Chinese hamster ovary cells stably expressing the hERG channel. The measured current was coupled with models of ventricular endocardial, M-, and epicardial cells to calculate the action potentials. Action potentials were evaluated under control condition and in the presence of 1, 10, or 100 μM disopyramide, an hERG inhibitor. Disopyramide dose-dependently increased the action potential durations of the three cell types. However, action potential duration of M-cells increased disproportionately at higher doses, and was significantly different from that of epicardial and endocardial cells (dispersion of repolarization). By contrast, the effects of disopyramide on peak I(Kr) and instantaneous current-voltage relation were similar in all cell types. Simulation study suggested that the reduced repolarization reserve of M-cell with smaller amount of slowly activating delayed rectifier potassium current levels off at longer action potential duration to make such differences. The action potential clamp technique is useful for studying the mechanism of arrhythmogenesis by hERG inhibition through the transmural dispersion of repolarization.

  10. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-07-18

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  11. Transient Receptor Potential Vanilloid 4 Activation-Induced Increase in Glycine-Activated Current in Mouse Hippocampal Pyramidal Neurons

    Directory of Open Access Journals (Sweden)

    Mengwen Qi

    2018-02-01

    Full Text Available Background/Aims: Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4 is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Methods: Whole-cell patch clamp recording was employed to record glycine-activated current (IGly and Western blot was conducted to assess GlyRs subunits protein expression. Results: Application of TRPV4 agonist (GSK1016790A or 5,6-EET increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047 and GlyR (strychnine, indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC (BIM II or D-sphingosine or calcium/calmodulin-dependent protein kinase II (CaMKII (KN-62 or KN-93 antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv. injected with GSK1016790A for 5 d. Conclusion: Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission.

  12. An Analysis of Current Energy Policy Initiatives in New Mexico. What are the Potential Impacts to the State's Water Resources?

    Science.gov (United States)

    Klise, G. T.; Hart, W. E.; Kobos, P. H.; Malczynski, L. A.; Tidwell, V. C.

    2008-12-01

    Population in New Mexico is increasing rapidly with recent projections showing that the state will add more than 1 million people by 2035. This growth will create a demand for additional energy and water supplies that have yet to be developed. New Mexico currently exports about 50% of the energy generated within the state to neighboring states, and existing power plants predominately utilize traditional fossil fuels such as coal, oil and natural gas. Because traditional electric generation technologies utilize large quantities of water, New Mexico can also be seen as exporting water for the benefit of electricity consumed in neighboring states. As it is, both surface water and groundwater supplies are stretched thin and these internal and external stresses stemming from population growth will have a substantial impact on the state's water resources. In 2004, the Governor laid out a plan to make New Mexico a "Clean Energy State" by implementing renewable portfolio standards, developing renewable energy transmission infrastructure, creating an alternative energy innovation fund and creating state specific tax credits for renewable energy production and manufacturing. Recent work in the National Energy-Water Roadmap has pointed out that certain renewable sources of energy utilize less water than traditional power plants, and technological fixes to existing power plants will result in less water consumption. If New Mexico carries out its energy initiative, what will be the impacts to the state's water resources? Will it be possible to meet competing demands for this water? These questions and others will be analyzed in a decision-support tool that can look at the connection between both the physical and economic systems to see what the tradeoffs might be as a result of specific policy decisions. The ability to plan for future energy needs and understanding potential impacts to the state's limited water resources will be an invaluable tool for decision-makers in New

  13. What's down below? Current and potential future applications of geophysical techniques to identify subsurface permafrost conditions (Invited)

    Science.gov (United States)

    Douglas, T. A.; Bjella, K.; Campbell, S. W.

    2013-12-01

    For infrastructure design, operations, and maintenance requirements in the North the ability to accurately and efficiently detect the presence (or absence) of ground ice in permafrost terrains is a serious challenge. Ground ice features including ice wedges, thermokarst cave-ice, and segregation ice are present in a variety of spatial scales and patterns. Currently, most engineering applications use borehole logging and sampling to extrapolate conditions at the point scale. However, there is high risk of over or under estimating the presence of frozen or unfrozen features when relying on borehole information alone. In addition, boreholes are costly, especially for planning linear structures like roads or runways. Predicted climate warming will provide further challenges for infrastructure development and transportation operations where permafrost degradation occurs. Accurately identifying the subsurface character in permafrost terrains will allow engineers and planners to cost effectively create novel infrastructure designs to withstand the changing environment. There is thus a great need for a low cost rapidly deployable, spatially extensive means of 'measuring' subsurface conditions. Geophysical measurements, both terrestrial and airborne, have strong potential to revolutionize our way of mapping subsurface conditions. Many studies in continuous and discontinuous permafrost have used geophysical measurements to identify discrete features and repeatable patterns in the subsurface. The most common measurements include galvanic and capacitive coupled resistivity, ground penetrating radar, and multi frequency electromagnetic induction techniques. Each of these measurements has strengths, weaknesses, and limitations. By combining horizontal geophysical measurements, downhole geophysics, multispectral remote sensing images, LiDAR measurements, and soil and vegetation mapping we can start to assemble a holistic view of how surface conditions and standoff measurements

  14. Transcranial Direct Current Stimulation in Patients with Prolonged Disorders of Consciousness: Combined Behavioral and Event-Related Potential Evidence

    Directory of Open Access Journals (Sweden)

    Ye Zhang

    2017-11-01

    Full Text Available BackgroundThe electrophysiological evidence supporting the therapeutic efficacy of multiple transcranial direct current stimulation (tDCS sessions on consciousness improvement in patients with prolonged disorders of consciousness (DOCs has not been firmly established.ObjectivesTo assess the effects of repeated tDCS in patients with prolonged DOCs by Coma Recovery Scale-Revised (CRS-R score and event-related potential (ERP.MethodUsing a sham-controlled randomized double-blind design, 26 patients were randomly assigned to either a real [five vegetative state (VS and eight minimally conscious state (MCS patients] or sham (six VS and seven MCS patients stimulation group. The patients in the real stimulation group underwent 20 anodal tDCS sessions of the left dorsolateral prefrontal cortex (DLPFC over 10 consecutive working days. The CRS-R score and P300 amplitude and latency in a hierarchical cognitive assessment were recorded to evaluate the consciousness level before tDCS and immediately after the 20 sessions.ResultsThe intra-group CRS-R analysis revealed a clinically significant improvement in the MCS patients in the real stimulation group. The inter-group CRS-R analysis showed a significant difference in CRS-R between VS and MCS patients at baseline in both the real and sham stimulation groups. The intra-group ERP analysis revealed a significant increase in P300 amplitude after tDCS in the MCS patients in the real stimulation group, but no significant differences in P300 latency. For the inter-group ERP analysis, we observed significant differences regarding the presence of P300 at baseline between the VS and MCS patients in both groups.ConclusionThe repeated anodal tDCS of the left DLPFC could produce clinically significant improvements in MCS patients. The observed tDCS-related consciousness improvements might be related to improvements in attention resource allocation (reflected by the P300 amplitude. The findings support the use of tDCS in

  15. A novel bioenergy feedstock in Latin America? Cultivation potential of Acrocomia aculeata under current and future climate conditions

    NARCIS (Netherlands)

    Plath, Mirco; Moser, Christine; Bailis, Rob; Brandt, Patric; Hirsch, Heidi; Klein, Alexandra Maria; Walmsley, David; Wehrden, von Henrik

    2016-01-01

    Plant oil is a key commodity in the global economy, particularly for food and bioenergy markets. However, current production practices often impair smallholder livelihoods, cause land use changes, and compete for food production. The neotropical palm Acrocomia aculeata is currently being promoted

  16. Cardiac Repolarization Abnormalities and Potential Evidence for Loss of Cardiac Sodium Currents on ECGs of Patients with Chagas' Heart Disease

    Science.gov (United States)

    Schlegel, T. T.; Medina, R.; Jugo, D.; Nunez, T. J.; Borrego, A.; Arellano, E.; Arenare, B.; DePalma, J. L.; Greco, E. C.; Starc, V.

    2007-01-01

    were not significantly different between groups. Patients with Chagas heart disease have increased cardiac repolarization abnormalities, especially by advanced ECG. Moreover, as a group, they have decreased uncorrected JT and QT interval durations and increased filtered QRS interval durations (versus age/gender-matched controls), all suggesting a potential loss of cardiac sodium channel function that might be mediated, in part, by cardiac autonomic damage. Overall findings support Brugada et al's recent hypothesis that the pathway leading to sudden death may often be similar in Chagas' disease and Brugada syndrome i.e., damage to the sodium channel (infectious/immunologic/autonomic in Chagas' genetic in Brugada) with consequent loss of sodium currents may facilitate a phase II-reentry based arrhythmic substrate for ventricular fibrillation in both conditions. In general, JT interval-related results have been underreported in the Chagas literature.

  17. Pressure drop in flashing flow through obstructions

    International Nuclear Information System (INIS)

    Weinle, M.E.; Johnston, B.S.

    1985-01-01

    An experiment was designed to investigate the pressure drop for flashing flow across obstructions of different geometries at various flow rates. Tests were run using two different orifices to determine if the two-phase pressure drop could be characterized by the single phase loss coefficient and the general behavior of the two-phase multiplier. For the geometries studied, it was possible to correlate the multiplier in a geometry-independent fashion

  18. Microgravity Experiment Programs for Students at the Bremen Drop Tower

    Science.gov (United States)

    Könemann, Thorben; Eigenbrod, Christian; Von Kampen, Peter; Laemmerzahl, Claus

    The Center of Applied Space Technology and Microgravity (ZARM) founded by Prof. Dr.-Ing. Hans J. Rath in 1985 is part of the Department of Production Engineering at the University of Bremen, Germany. ZARM established as a research center and currently headed by Prof. Dr. Claus Lämmerzahl is mainly concentrated on fundamental investigations of gravitational and space-related phenomenas under conditions of weightlessness as well as questions and developments related to technologies for space. At ZARM more than 70 scientists, engineers and administrative staff as well as many students from different departments are employed. Today, ZARM is still one of the largest and most important university institutes for space sciences and technologies in Europe as well as worldwide well known in the space community. With a height of 146 m the Bremen Drop Tower is the predominant facility of ZARM and also the only drop tower of its class in Europe. ZARM’s ground-based laboratory offers the opportunity for daily short-term experiments under conditions of high-quality weightlessness at a level of 10 (-6) g (microgravity). The provided quality is one of the purest for experiments under weightlessness worldwide achieved. The scientists may choose between a single drop experiment with 4.74 s in simple free fall and a catapult experiment with 9.3 s of weightlessness. Either in the drop or in the worldwide unique catapult operation routine the repetition rates of microgravity experiments at ZARM are always the same, generally up to 3 times per day. Since the start of operation of the facility in 1990, over 6750 launches of more than 160 different experiment types from various scientific fields like Fundamental Physics, Combustion, Fluid Dynamics, Planetary Formation / Astrophysics, Biology and Materials Sciences have been successfully accomplished so far. In our paper we will report and inform about microgravity experiment programs for students like "Drop Your Thesis!“ by ESA and

  19. An Evaluation of Structural Damage (Window Breakage) Potential in Callente, NV Under Current Supersonic Flight Restrictions at Nellis AFB

    National Research Council Canada - National Science Library

    Garrelick, Joel

    1997-01-01

    .... The project objective is to perfect measurement techniques that simulate structural response to sonic booms, and in turn allow one to assess potential damage, especially to unconventional structures...

  20. Development of Drop/Shock Test in Microelectronics and Impact Dynamic Analysis for Uniform Board Response

    Science.gov (United States)

    Kallolimath, Sharan Chandrashekar

    -joints. No ring test conditions was proposed and verified for the current widely used JEDEC standard. The significance of impact loading parameters such as pulse magnitude, pulse duration, pulse shapes and board dynamic parameter such as linear hysteretic damping and dynamic stiffness were discussed. Third, Kirchhoff's plate theory by principle of minimum potential energy was adopted to develop the FEA formulation to consider the effect of material hysteretic damping for the currently used JEDEC board test and proposed no-ring response test condition. Fourth, a hexagonal symmetrical board model was proposed to address the uniform stress and strain distribution throughout the test board and identify the critical failure factors. Dynamic stress and strain of the hexagonal board model were then compared with standard JEDEC board for both standard and proposed no-ring test conditions. In general, this line of research demonstrates that advanced techniques of FEA analysis can provide useful insights concerning the optimal design of drop test in microelectronics.

  1. Study of complex resistivity measurement using current and potential waveform data; Denryu to den`i hakei data wo riyoshita fukusohi teiko sokutei no kento

    Energy Technology Data Exchange (ETDEWEB)

    Shima, H.; Sakurai, K.; Yamashita, Y. [OYO Corp., Tokyo (Japan)

    1997-10-22

    This paper proposes a measurement method for complex resistivity using both current and potential waveforms. This method was applied to actual data. Especially, chargeability was discussed among complex resistivities. A method was proposed for determining the complex resistivity. At first, digital measurements of both current and potential waveforms were conducted. For the potential waveform, zero-order self-potential was canceled. Then, the FFT technique was applied to both current and potential waveforms, to determine both current and potential in the frequency domain. Hereafter, complex resistivity was determined through simple division. Since the inductive coupling was observed at higher frequencies, it was difficult to apply Cole-Cole model, simply. However, the inductive coupling could be removed using proper sampling frequency. Thus, a proper Cole-Cole dispersion curve could be obtained. Using this Cole-Cole dispersion curve, new chargeability could be defined. A linear relation between this chargeability and the ordinary time domain chargeability was made clear. 4 refs., 10 figs.

  2. Development of Active Learning Curriculum for CASPER's Microgravity Drop Tower

    Science.gov (United States)

    Carmona-Reyes, Jorge; Wang, Li; York, Judy; Matthews, Lorin; Laufer, Rene; Cook, Mike; Schmoke, Jimmy; Hyde, Truell

    2016-10-01

    As CASPER's new drop tower comes on line, plans for correlated educational research curricula are underway. CASPER's educational research team is working on developing curricula specific to the CASPER drop tower, modeled on a contest currently in use by (BEST) Robotics Inc. within central Texas independent school districts. The curricula integrates age specific use of computer programming software packages such as ``Scratch'' with industry standard communication protocols and augmented reality applications. Content is constructed around an earth and space science framework, covering subjects such as stars and galaxies, matter and energy, fusion and fission at a middle school level. CASPER faculty are partnering with the Region 12 Service Center; this combination provides a wide range of expertise that includes professional development, pedagogical methods, computational thinking in addition to microgravity and space science research expertise. The details of this work will be presented and samples of the manner in which it is impacting the CASPER research and educational outreach partnership will be discussed.

  3. Influence of the inter-electrode gap on the cathode sheath characteristics (voltage drop across it and its thickness)

    Science.gov (United States)

    Lisovskiy, V. A.; Artushenko, K. P.; Yegorenkov, V. D.

    2017-05-01

    This paper is devoted to studying how the inter-electrode distance affects the voltage drop across electrodes, the cathode sheath thickness, and the axial distribution of plasma parameters. The experiment demonstrates the simultaneous growth of both the voltage drop across the electrodes and the cathode sheath thickness when on increasing the gap the anode is moved away from the cathode while remaining in the negative glow. This effect is most clearly pronounced under low gas pressure and high current values when the negative glow length is large. The discharge axial structure dynamics is studied with the Langmuir probe technique and with the OOPIC Pro code. The inter-electrode gap growth with the current fixed is found to be accompanied by the plasma concentration increase in the negative glow. The positive plasma potential is shown to cause the current to the grounded anode to be transported by fast electrons accelerated in the cathode sheath. Moving the anode away from the cathode through the negative glow weakens the flow of fast electrons coming to the anode, thus decreasing the discharge current. In order to restore the discharge current, one has to increase the voltage across the electrodes, leading to the cathode sheath thickness increase and the plasma concentration growth in the negative glow.

  4. Vertical Drop Test of a YS-11 Fuselage Section (Part 2)

    Science.gov (United States)

    Iwasaki, Kazuo; Kumakura, Ikuo; Minegishi, Masakutsu; Shoji, Hirokazu; Yoshimoto, Norio; Miyaki, Hiromitsu; Terada, Hiroyuki; Isoe, Akira; Yamaoka, Toshihiro; Katayama, Noriaki; Hayashi, Toru; Akaso, Tetsuya; Kosaka, Hideyuki

    The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) and Kawasaki Heavy Industries, Ltd. (KHI) conducted the 2nd vertical drop test of a fuselage section cut from a NAMC YS-11 transport airplane in July 2002. The main objective of this test program was to obtain background data for aircraft cabin safety by drop test of a full-scale fuselage section and to develop computational tool for crash simulation of aircraft fuselage structure. The test article including seats and anthropomorphic test dummies was dropped to a rigid impact surface by free-fall method at a velocity of 7.6m/s (25ft/s). The impact environment and the resultant response of the fuselage structure and the passenger dummies were considered to be severe but potentially survivable. A description of the results of the 1st drop test and the 2nd drop test is presented in this paper.

  5. Pressure drop – flow characteristic investigations of ATF filter in automatic transmissions (AT of cars

    Directory of Open Access Journals (Sweden)

    Tadeusz Dziubak

    2014-12-01

    Full Text Available [b]Abstract[/b]. Potentials effects of pressure drop-flow characteristics of ATF filter on the hydraulic pumps are discussed. Draft device to investigations pressure drop-flow characteristics of ATF filter used in automatic transmissions constructed based on SAE J2312 standard is presented. Method of investigation pressure drop-flow characteristics of ATF filter used in automatic transmission is presented. The results of investigation pressure drop-flow characteristics Δp = f(QV of two types ATF filter (metal mesh and filter cloth in two technical conditions (at the beginning of the operation and after are presented and analyzed.[b]Keywords[/b]: AT — automatic transmissions, ATF — automatic transmission fluid, ATF filter, pressure drop-flow characteristic

  6. The activity of spontaneous action potentials in developing hair cells is regulated by Ca(2+-dependence of a transient K+ current.

    Directory of Open Access Journals (Sweden)

    Snezana Levic

    Full Text Available Spontaneous action potentials have been described in developing sensory systems. These rhythmic activities may have instructional roles for the functional development of synaptic connections. The importance of spontaneous action potentials in the developing auditory system is underpinned by the stark correlation between the time of auditory system functional maturity, and the cessation of spontaneous action potentials. A prominent K(+ current that regulates patterning of action potentials is I(A. This current undergoes marked changes in expression during chicken hair cell development. Although the properties of I(A are not normally classified as Ca(2+-dependent, we demonstrate that throughout the development of chicken hair cells, I(A is greatly reduced by acute alterations of intracellular Ca(2+. As determinants of spike timing and firing frequency, intracellular Ca(2+ buffers shift the activation and inactivation properties of the current to more positive potentials. Our findings provide evidence to demonstrate that the kinetics and functional expression of I(A are tightly regulated by intracellular Ca(2+. Such feedback mechanism between the functional expression of I(A and intracellular Ca(2+ may shape the activity of spontaneous action potentials, thus potentially sculpting synaptic connections in an activity-dependent manner in the developing cochlea.

  7. Land Use and Water Efficiency in Current and Potential Future U.S. Corn and Brazilian Sugarcane Ethanol Systems (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Warner, E.; Zhang, Y.; Chum, H.; Newmark, R.

    2012-11-01

    The potential for unintended consequences of biofuels--competition for land and water--necessitates that sustainable biofuel expansion considers the complexities of resource requirements within specific context (e.g., technology, feedstock, supply chain, local resource availability).

  8. Integration of hydrogen energy technologies in stand-alone power systems analysis of the current potential for applications

    International Nuclear Information System (INIS)

    Zoulias, E.I.; Lymberopoulos, N.; Tsoutsos, T.; Glockner, R.; Mydske, H.J.; Vosseler, I.; Gavalda, O.; Taylor, P.

    2006-01-01

    The European study entitled: 'Market Potential Analysis for Introduction of Hydrogen Energy Technology in Stand-Alone Power Systems (H-SAPS)' aimed to establish a broad understanding of the market potential for H-SAPS and provide a basis for promoting in wide scale new technological applications. The scope of the study was limited to small and medium installations, up to a few hundred kW power rating and based on RE as the primary energy source. The potential for hydrogen technology in SAPS was investigated through an assessment of the technical potential for hydrogen, the market analysis and the evaluation of external factors. The results are mostly directed towards action by governments and the research community but also industry involvement is identified. The results include targeted market research, establishment of individual cost targets, regulatory changes to facilitate alternative grid solutions, information and capacity building, focused technology research and bridging the technology gaps. (author)

  9. Potential symmetry and invariant solutions of Fokker-Planck equation in cylindrical coordinates related to magnetic field diffusion in magnetohydrodynamics including the Hall current

    Science.gov (United States)

    Khater, A. H.; Callebaut, D. K.; Abdelhameed, T. N.

    2006-03-01

    Lie groups involving potential symmetries are applied in connection with the system of magnetohydrodynamic equations for incompressible matter with Ohm's law for finite resistivity and Hall current in cylindrical geometry. Some simplifications allow to obtain a Fokker-Planck type equation. Invariant solutions are obtained involving the effects of time-dependent flow and the Hall-current. Some interesting side results of this approach are new exact solutions that do not seem to have been reported in the literature.

  10. Technical potentials of biomass for energy services from current agriculture and forestry in selected countries in Europe, The Americas and Asia

    DEFF Research Database (Denmark)

    Bentsen, Niclas Scott; Felby, Claus

    This report is a survey on the technical potential of biomass from current agriculture and forestry in the regions; Europe incl. Russia and Ukraine, USA, Canada, Brazil, Argentina, China and India. The report provides projections for agricultural residue production assuming availability of fertil......This report is a survey on the technical potential of biomass from current agriculture and forestry in the regions; Europe incl. Russia and Ukraine, USA, Canada, Brazil, Argentina, China and India. The report provides projections for agricultural residue production assuming availability...

  11. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.

    2013-04-29

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting on a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, article 264506). These dynamics mainly occur within 50 -s after the first contact, requiring imaging at 1 million f.p.s. For a water drop impacting on a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Reynolds number Re above -12 000, up to 10 partial bubble rings have been observed at the base of the ejecta, starting when the contact is -20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into micro-bubbles. The different refractive index in the pool liquid reveals the destabilization of the vortices and the formation of streamwise vortices and intricate vortex tangles. Fine-scale axisymmetry is thereby destroyed. We show also that the shape of the drop has a strong influence on these dynamics. 2013 Cambridge University Press.

  12. Drop Testing Representative Multi-Canister Overpacks

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Spencer D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Morton, Dana K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    The objective of the work reported herein was to determine the ability of the Multi- Canister Overpack (MCO) canister design to maintain its containment boundary after an accidental drop event. Two test MCO canisters were assembled at Hanford, prepared for testing at the Idaho National Engineering and Environmental Laboratory (INEEL), drop tested at Sandia National Laboratories, and evaluated back at the INEEL. In addition to the actual testing efforts, finite element plastic analysis techniques were used to make both pre-test and post-test predictions of the test MCOs structural deformations. The completed effort has demonstrated that the canister design is capable of maintaining a 50 psig pressure boundary after drop testing. Based on helium leak testing methods, one test MCO was determined to have a leakage rate not greater than 1x10-5 std cc/sec (prior internal helium presence prevented a more rigorous test) and the remaining test MCO had a measured leakage rate less than 1x10-7 std cc/sec (i.e., a leaktight containment) after the drop test. The effort has also demonstrated the capability of finite element methods using plastic analysis techniques to accurately predict the structural deformations of canisters subjected to an accidental drop event.

  13. Drop impact on spherical soft surfaces

    Science.gov (United States)

    Chen, Simeng; Bertola, Volfango

    2017-08-01

    The impact of water drops on spherical soft surfaces is investigated experimentally through high-speed imaging. The effect of a convex compliant surface on the dynamics of impacting drops is relevant to various applications, such as 3D ink-jet printing, where drops of fresh material impact on partially cured soft substrates with arbitrary shape. Several quantities which characterize the morphology of impacting drops are measured through image-processing, including the maximum and minimum spreading angles, length of the wetted curve, and dynamic contact angle. In particular, the dynamic contact angle is measured using a novel digital image-processing scheme based on a goniometric mask, which does not require edge fitting. It is shown that the surface with a higher curvature enhances the retraction of the spreading drop; this effect may be due to the difference of energy dissipation induced by the curvature of the surface. In addition, the impact parameters (elastic modulus, diameter ratio, and Weber number) are observed to significantly affect the dynamic contact angle during impact. A quantitative estimation of the deformation energy shows that it is significantly smaller than viscous dissipation.

  14. Multi-centre European study of breakthrough cancer pain: pain characteristics and patient perceptions of current and potential management strategies

    DEFF Research Database (Denmark)

    Davies, Andrew; Zeppetella, Giovambattista; Andersen, Steen

    2011-01-01

    This study involved 320 cancer patients from four Northern European countries. Patients with breakthrough pain were questioned about the characteristics of their pain, the current management of their pain, and the acceptability/utility of alternative routes of administration. The median number of...

  15. Galvanic Couple Current and Potential Distribution between a Mg Electrode and 2024-T351 under Droplets Analyzed by Microelectrode Arrays

    Science.gov (United States)

    2015-11-04

    concentration of a given elec- trolyte varies with ambient RH.21–23 As a given deposited hygroscopic salt deliquesces on a surface it will, over time... liquid electrolyte layer. H2 bubbles could be seen to form and move under the salt cap and the magnitude of the cathodic current density on each AA2024

  16. Euler potentials for two layers with non-constant current densities in the ambient magnetic field aligned to the layers

    Czech Academy of Sciences Publication Activity Database

    Vandas, Marek; Romashets, E.

    2016-01-01

    Roč. 34, č. 12 (2016), s. 1165-1173 ISSN 0992-7689 R&D Projects: GA ČR(CZ) GA14-19376S Institutional support: RVO:67985815 Keywords : magnetospheric physics * scale birkeland currents * charged particles Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.610, year: 2016

  17. ABCXYZ: vector potential (A) and magnetic field (B) code (C) for Cartesian (XYZ) geometry using general current elements. [In LRL TRAN for CDC > 600 computer

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.V.; Breazeal, J.; Finan, C.H.; Johnston, B.M.

    1976-09-14

    ABCXYZ is a computer code for obtaining the Cartesian components of the vector potential and the magnetic field on an observed grid from an arrangement of current-carrying wires. Arbitrary combinations of straight line segments, arcs, and loops are allowed in the specification of the currents. Arbitrary positions and orientations of the current-carrying elements are also allowed. Specification of the wire diameter permits the computation of well-defined fields, even in the interiors of the conductors. An optical feature generates magnetic field lines. Extensive graphical and printed output is available to the user including contour, grid-line, and field-line plots. 12 figures, 1 table.

  18. Current Advances in the Antimicrobial Potential of Species of Genus Ganoderma (Higher Basidiomycetes) against Human Pathogenic Microorganisms (Review).

    Science.gov (United States)

    Rai, Mahendra K; Gaikwad, Swapnil; Nagaonkar, Dipali; dos Santos, Carolina Alves

    2015-01-01

    Ganoderma spp. are very important therapeutic mushrooms and have been used traditionally for 4000 years in the treatment of various human disorders. Different species of Ganoderma possess bioactive compounds, which have already demonstrated antiviral, antibacterial, and antifungal activities. Various bioactive compounds such as triterpenoids, colossolactones, and polysaccharides, which are responsible for the antimicrobial potential of the genus, are discussed here in detail. Some Ganoderma spp. have been reported to be potential agents for the synthesis of metal nanoparticles. These nanoparticles have demonstrated antimicrobial activity and also are reviewed herein. The main aim of this review is to discuss the possible use of Ganoderma extracts and their active principles in antimicrobial therapy.

  19. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Dipen N. (Los Alamos, NM)

    1998-01-01

    Ultrasonic characterization of single drops of liquids. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities.

  20. Superheated drop as a neutron spectrometer

    Science.gov (United States)

    Das, Mala; Chatterjee, B. K.; Roy, B.; Roy, S. C.

    2000-09-01

    Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. The application of superheated drops in neutron research especially in neutron dosimetry is a subject of intense research for quite sometime. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquid makes it possible to use it as a neutron spectrometer. Neutron detection efficiency of superheated drops made of R12 exposed to Am-Be neutron source has been measured over a wide range of temperature -17-60°C and the results have been utilised to construct the energy spectrum of the neutron source. This paper demonstrates that a suitable neutron spectrometer may be constructed by using a single liquid and varying the temperature of the liquid suitably at a closer grid.

  1. Superheated drop as a neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Das, Mala; Chatterjee, B.K.; Roy, B. E-mail: biva@bosemain.boseinst.ernet.in; Roy, S.C

    2000-09-21

    Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. The application of superheated drops in neutron research especially in neutron dosimetry is a subject of intense research for quite sometime. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquid makes it possible to use it as a neutron spectrometer. Neutron detection efficiency of superheated drops made of R12 exposed to Am-Be neutron source has been measured over a wide range of temperature -17-60 deg. C and the results have been utilised to construct the energy spectrum of the neutron source. This paper demonstrates that a suitable neutron spectrometer may be constructed by using a single liquid and varying the temperature of the liquid suitably at a closer grid.

  2. Tunable Transport of Drops on a Vibrating Fiber

    Science.gov (United States)

    Bick, Alison; Sauret, Alban; Boulogne, Francois; Stone, Howard

    2014-11-01

    Transport of liquid drops on a fibrous medium is common in engineering systems such as fog harvesting and textile cleaning. The control of the drop movement on fibrous media can make these engineering systems more efficient. We investigated how to move drops along a single inclined fiber by controlling fiber vibration. Drop motion: static, sliding or falling, depends on the fiber inclination angle, drop volume, and the distance of the drop from the vibrating source. Specifically, by vibrating the fiber the transition between the three drop motion states can be controlled. By defining the response of drop movement to vibration frequency, we can model the drop movement transition. This knowledge is directly useful for controlling drop movement on the fiber. In particular, we experimentally demonstrated that vibration frequency can be used to transport a drop along a fiber.

  3. Evaluation of current literature to determine the potential effects of radio frequency identification on technology used in diabetes care.

    Science.gov (United States)

    Christe, Barbara

    2009-03-01

    This article examines recently published studies exploring the impact of radio frequency identification (RFID) systems on the technology involved in patient care. The conclusions will be extrapolated to include insulin delivery devices. Background material will also be presented to support examination of the variables involved in electromagnetic fields and potential interference from these RFID systems. (c) 2009 Diabetes Technology Society.

  4. Modified Drop Tower Impact Tests for American Football Helmets.

    Science.gov (United States)

    Rush, G Alston; Prabhu, R; Rush, Gus A; Williams, Lakiesha N; Horstemeyer, M F

    2017-02-19

    A modified National Operating Committee on Standards for Athletic Equipment (NOCSAE) test method for American football helmet drop impact test standards is presented that would provide better assessment of a helmet's on-field impact performance by including a faceguard on the helmet. In this study, a merger of faceguard and helmet test standards is proposed. The need for a more robust systematic approach to football helmet testing procedures is emphasized by comparing representative results of the Head Injury Criterion (HIC), Severity Index (SI), and peak acceleration values for different helmets at different helmet locations under modified NOCSAE standard drop tower tests. Essentially, these comparative drop test results revealed that the faceguard adds a stiffening kinematic constraint to the shell that lessens total energy absorption. The current NOCSAE standard test methods can be improved to represent on-field helmet hits by attaching the faceguards to helmets and by including two new helmet impact locations (Front Top and Front Top Boss). The reported football helmet test method gives a more accurate representation of a helmet's performance and its ability to mitigate on-field impacts while promoting safer football helmets.

  5. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-12-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  6. Investigations on contribution of glial inwardly-rectifying K+ current to membrane potential and ion flux: An experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Sheng-Nan Wu

    2015-01-01

    Full Text Available The inwardly rectifying K+ current [IK(IR] allows large inward K+ currents at potentials negative to K+ equilibrium potential (EK and it becomes small outward K+ currents at those positive to EK. How changes of such currents enriched in glial cells can influence the functions of glial cell, neurons, or both is not clearly defined, although mutations of Kir4.1 channels have been demonstrated to cause serious neurological disorders. In this study, we identified the presence of IK(IR in human glioma cells (U373 and U87 cells. The amplitude of IK(IR in U373 cells was subject to inhibition by amitriptyline, arecoline, or BaCl2. The activity of inwardly rectifying K+ channels was also clearly detected, and single-channel conductance of these channels was calculated to be around 23 pS. Moreover, based on a simulation model derived from neuron–glial interaction mediated by ion flux, we further found out that incorporation of glial IK(IR conductance into the model can significantly contribute to regulation of extracellular K+ concentrations and glial resting potential, particularly during high-frequency stimulation. Glial cells and neurons can mutually modulate their expression of ion channels through K+ ions released into the extracellular space. It is thus anticipated that glial IK(IR may be a potential target utilized to influence the activity of neuronal and glial cells as well as their interaction.

  7. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  8. Energy Absorption of Distribution Line Arresters due to Lightning Back Flow Current and Ground Potential Rise for Lightning Hit to Wind Turbine Generator System

    Science.gov (United States)

    Okamoto, Hiroshi; Sekioka, Shozo; Ebinuma, Yasumitsu; Yamamoto, Kazuo; Yasuda, Yoh; Funabashi, Toshihisa; Yokoyama, Shigeru

    In the coast of the Japan Sea which has many good places for wind turbine generator system, winter lightning occurs frequently. Many results of investigation have been reported not only damages of wind turbine generator system itself but also failures of distribution line arresters caused by part of the lightning current which flows into distribution lines when the customer's structure is struck by lightning. The lightning back flow current and ground potential rise are also important factors for a lightning protection design of distribution line arresters, which are connected to the wind turbine generator system struck by lightning. This paper describes simulation results of the energy absorption to estimate the lightning damages in the arresters considering the back flow current and the ground potential rise using the EMTP.

  9. Anaplastic Thyroid Carcinoma: Current Treatments and Potential New Therapeutic Options with Emphasis on TfR1/CD71

    Directory of Open Access Journals (Sweden)

    Rosalba Parenti

    2014-01-01

    Full Text Available Anaplastic thyroid carcinoma (ATC is one of the most aggressive human cancers. Actually, ATC is refractory to conventional therapies, including surgery, chemotherapy, radiotherapy, and radioiodine (131I therapy. Accordingly, genetic and molecular characterizations of ATC have been frequently and periodically reviewed in order to identify potential biological markers exploitable for target therapy. This review briefly focuses on main molecular events that characterize ATC and provides an update about preclinical studies. In addition, the overexpression of transferrin receptor 1 (TfR1/CD71 by neoplastic cells of ATC is emphasized in that it could represent a potential therapeutic target. In this regard, new therapeutic approaches based on the use of monoclonal or recombinant antibodies, or transferrin-gallium-TfR1/CD71 molecular complexes, or lastly small interfering RNAs (siRNAs are proposed.

  10. Past, current and potential utilisation of active and intelligent packaging systems for meat and muscle-based products: A review.

    Science.gov (United States)

    Kerry, J P; O'Grady, M N; Hogan, S A

    2006-09-01

    Interest in the use of active and intelligent packaging systems for meat and meat products has increased in recent years. Active packaging refers to the incorporation of additives into packaging systems with the aim of maintaining or extending meat product quality and shelf-life. Active packaging systems discussed include oxygen scavengers, carbon dioxide scavengers and emitters, moisture control agents and anti-microbial packaging technologies. Intelligent packaging systems are those that monitor the condition of packaged foods to give information regarding the quality of the packaged food during transport and storage. The potential of sensor technologies, indicators (including integrity, freshness and time-temperature (TTI) indicators) and radio frequency identification (RFID) are evaluated for potential use in meat and meat products. Recognition of the benefits of active and intelligent packaging technologies by the food industry, development of economically viable packaging systems and increased consumer acceptance is necessary for commercial realisation of these packaging technologies.

  11. An overview of current practice in external beam radiation oncology with consideration to potential benefits and challenges for nanotechnology.

    Science.gov (United States)

    King, Raymond B; McMahon, Stephen J; Hyland, Wendy B; Jain, Suneil; Butterworth, Karl T; Prise, Kevin M; Hounsell, Alan R; McGarry, Conor K

    2017-01-01

    Over the past two decades, there has been a significant evolution in the technologies and techniques employed within the radiation oncology environment. Over the same period, extensive research into the use of nanotechnology in medicine has highlighted a range of potential benefits to its incorporation into clinical radiation oncology. This short communication describes key tools and techniques that have recently been introduced into specific stages of a patient's radiotherapy pathway, including diagnosis, external beam treatment and subsequent follow-up. At each pathway stage, consideration is given towards how nanotechnology may be combined with clinical developments to further enhance their benefit, with some potential opportunities for future research also highlighted. Prospective challenges that may influence the introduction of nanotechnology into clinical radiotherapy are also discussed, indicating the need for close collaboration between academic and clinical staff to realise the full clinical benefit of this exciting technology.

  12. Computation of potentials from current electrodes in cylindrically stratified media: A stable, rescaled semi-analytical formulation

    Science.gov (United States)

    Moon, Haksu; Teixeira, Fernando L.; Donderici, Burkay

    2015-01-01

    We present an efficient and robust semi-analytical formulation to compute the electric potential due to arbitrary-located point electrodes in three-dimensional cylindrically stratified media, where the radial thickness and the medium resistivity of each cylindrical layer can vary by many orders of magnitude. A basic roadblock for robust potential computations in such scenarios is the poor scaling of modified-Bessel functions used for computation of the semi-analytical solution, for extreme arguments and/or orders. To accommodate this, we construct a set of rescaled versions of modified-Bessel functions, which avoids underflows and overflows in finite precision arithmetic, and minimizes round-off errors. In addition, several extrapolation methods are applied and compared to expedite the numerical evaluation of the (otherwise slowly convergent) associated Sommerfeld-type integrals. The proposed algorithm is verified in a number of scenarios relevant to geophysical exploration, but the general formulation presented is also applicable to other problems governed by Poisson equation such as Newtonian gravity, heat flow, and potential flow in fluid mechanics, involving cylindrically stratified environments.

  13. Seismic II over I Drop Test Program results and interpretation

    International Nuclear Information System (INIS)

    Thomas, B.

    1993-03-01

    The consequences of non-seismically qualified (Category 2) objects falling and striking essential seismically qualified (Category 1) objects has always been a significant, yet analytically difficult problem, particularly in evaluating the potential damage to equipment that may result from earthquakes. Analytical solutions for impact problems are conservative and available for mostly simple configurations. In a nuclear facility, the open-quotes sourcesclose quotes and open-quotes targetsclose quotes requiring evaluation are frequently irregular in shape and configuration, making calculations and computer modeling difficult. Few industry or regulatory rules are available on this topic even though it is a source of considerable construction upgrade costs. A drop test program was recently conducted to develop a more accurate understanding of the consequences of seismic interactions. The resulting data can be used as a means to improve the judgment of seismic qualification engineers performing interaction evaluations and to develop realistic design criteria for seismic interactions. Impact tests on various combinations of sources and targets commonly found in one Savannah River Site (SRS) nuclear facility were performed by dropping the sources from various heights onto the targets. This report summarizes results of the Drop Test Program. Force and acceleration time history data are presented as well as general observations on the overall ruggedness of various targets when subjected to impacts from different types of sources

  14. Electromagnetic radiation from linearly and nonlinearly oscillating charge drops

    Science.gov (United States)

    Grigor'ev, A. I.; Shiryaeva, S. O.

    2016-12-01

    It has been shown that analytic calculations of the intensity of electromagnetic radiation from an oscillating charged drop in the approximation linear in the oscillation amplitude (small parameter is on the order of 0.1) give only the quadrupole component of the total radiation. The dipole component can only be obtained in calculations using higher-order approximations. Nevertheless, the intensity of the dipole radiation turns out to be substantially higher (by 14-15 orders of magnitude). This is because the decomposition of radiation from a system of charges into multipole components (differing even in the rates of decrease in the potential with the distance) is carried out using the expansion in a substantially smaller parameter, viz., the ratio of the size of the emitting system (in our case, a drop of radius 10 μm) to the distance to the point of observation in the wave zone of the emission of radiation (emitted wavelength) of 100-1000 m. As a result, this second small parameter is on the order of 10-7 to 10-8. On the other hand, in accordance with the field theory, the ratio of intensities of quadrupole and dipole radiations is proportional to the squared ratio of the hydrodynamic velocity of the oscillating surface of a charged drop to the velocity of propagation of an electromagnetic signal in vacuum (velocity of light), which yields a ratio of 10-14 to 10-15.

  15. Impact and Penetration of Nanoparticle Suspension Drops into Porous Membranes

    Science.gov (United States)

    Sahu, Rakesh; Yarin, Alexander; Pourdeyhimi, Behnam

    2014-03-01

    The impacts and dynamic penetration of drops with suspended nanoparticles into porous membranes are studied experimentally and theoretically. This type of penetration is radically different from the wettability-driven imbibition. Two types of membranes are used in the experiments: (i) glass fiber filter membrane (wettable) and (ii) PTFE depth filter (non-wettable). The nanoparticle entrainment and deposition inside the membrane bulk is used to mostly visualize the ultimate penetration fronts of the carrier fluid by observing the cut cross-sections of the filter membranes, albeit also provides an insight into potentially new applications like circuit printing on nonwovens. The experimental results demonstrate that during the dynamic focusing responsible for water penetration into micro- and nanopores, water can penetrate into a non-wettable porous medium (PTFE). Water also penetrates by the same focusing mechanism into the wettable glass fiber membrane, where it additionally spreads on a much longer time scale due to the wettability-driven flow. A theory explaining dynamic penetration of liquid into porous medium after drop impact is proposed. It is used to explain and predict water penetration into the non-wettable media after drop impact, and the results are compared with the experimental data. The work was supported by the Nonwovens Cooperative Research Center (NCRC).

  16. Subcutaneous Immunotherapy and Sublingual Immunotherapy: Comparative Efficacy, Current and Potential Indications, and Warnings--United States Versus Europe.

    Science.gov (United States)

    Nelson, Harold S; Makatsori, Melina; Calderon, Moises A

    2016-02-01

    Subcutaneous immunotherapy and sublingual immunotherapy are effective for allergic rhinitis and allergic asthma and with some support for use in selected patients with atopic dermatitis. The sequence of immunologic responses is the same, irrespective of the route of administration, and similar disease modification has been demonstrated. However, there are differences between the two approaches. The most important is the greatly reduced likelihood of sublingual immunotherapy producing systemic reactions. There are major drawbacks for sublingual immunotherapy in regard to dosing. Finally, there is the question of relative clinical efficacy, with the currently available data favoring subcutaneous immunotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. An evaporation model of multicomponent solution drops

    Science.gov (United States)

    Sartori, Silvana; Liñán, Amable; Lasheras, Juan C.

    2010-11-01

    Solutions of polymers are widely used in the pharmaceutical industry as tablets coatings. These allow controlling the rate at which the drug is delivered, taste or appearance. The coating is performed by spraying and drying the tablets at moderate temperatures. The wetting of the coating solution on the pill's surface depends on the droplet Webber and Re numbers, angle of impact and on the rheological properties of the droplet. We present a model for the evaporation of multicomponent solutions droplets in a hot air environment with temperatures substantially lower than the boiling temperature of the solvent. As the liquid vaporizes from the surface the fluid in the drop increases in concentration, until reaching its saturation point. After saturation, precipitation occurs uniformly within the drop. As the surface regresses, a compacting front formed by the precipitate at its maximum packing density advances into the drop, while the solute continues precipitating uniformly. This porous shell grows fast due to the double effect of surface regression and precipitation. The evaporation rate is determined by the rates at which heat is transported to the droplet surface and at which liquid vapor diffuses away from it. When the drop is fully compacted, the evaporation is drastically reduced.

  18. Spontaneous evaporation of the acetone drop

    Science.gov (United States)

    Dunin, S. Z.; Nagornov, O. V.

    2017-12-01

    The exact solution of the problem on evaporation of the acetone sessile drop at solid substrate is derived. The solution allows us to analyze the temperature field behavior at various thermodynamic parameters. The Marangoni forces are calculated in explicit form. The solution can be used to check numerical approaches for similar problems.

  19. Check valves with drop-shaped disk

    Energy Technology Data Exchange (ETDEWEB)

    1943-03-19

    This report discusses improvements possible with drop check valves. Up to the time of the report, the most important improvements had been: (1) lightening of the drop by hollowing it out, (2) reducing lift to reduce impact, (3) increasing clearance in the guide to minimize the danger of it getting stuck, (4) drilling of a safety hole which would indicate excessive wear of the housing by a leak. Other possibilities for the above improvements had produced the following conclusions: (1) a further lightening of the drop was found possible by milling out the halves with a milling cutter, by welding them together and thus eliminating the threaded portion, or by having the drop open on the bottom; (2) further reduction in lift was not found possible in most sizes, but for reduction of the impact effect by a cushion of oil or paste, the seating surface was widened as much as possible; (3) sticking of certain check valves caused by ferrous sulfide deposits could be solved by use of a certain bushing in the housing; (4) some plants favored and some disfavored the safety hole, but in general, plants were to service check valves and change them at such regular intervals as experience dictated; (5) the seat plate was no longer solid steel, but a welded piece.

  20. Goose droppings as food for reindeer

    NARCIS (Netherlands)

    van der Wal, R; Loonen, MJJE

    Feeding conditions for Svalbard reindeer, Rangifer tarandus platyrhynchus, on Spitsbergen are generally poor, owing to low availability of forage. We report on coprophagy: the use of goose faeces as an alternative food source for reindeer. Fresh droppings from Barnacle Geese, Branta leucopsis,

  1. Modeling merging behavior at lane drops.

    Science.gov (United States)

    2015-02-01

    In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In : addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improvin...

  2. 49 CFR 178.603 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... of natural wood, Plywood boxes, Reconstituted wood boxes, Fiberboard boxes, Plastic boxes, Steel or... drums, Plastic drums and Jerricans, Composite packagings which are in the shape of a drum Six—(three for... Administrator. (c) Special preparation of test samples for the drop test. (1) Testing of plastic drums, plastic...

  3. 49 CFR 178.965 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... Large Packaging design types and performed periodically as specified in § 178.955(e) of this subpart. (b... § 178.960(d). (d) Test method. (1) Samples of all Large Packaging design types must be dropped onto a... be restored to the upright position for observation. (2) Large Packaging design types with a capacity...

  4. The stability of cylindrical pendant drops

    CERN Document Server

    McCuan, John

    2018-01-01

    The author considers the stability of certain liquid drops in a gravity field satisfying a mixed boundary condition. He also considers as special cases portions of cylinders that model either the zero gravity case or soap films with the same kind of boundary behavior.

  5. Reactor Flow and Pressure Drop Study

    Energy Technology Data Exchange (ETDEWEB)

    Keyes, R. E.

    1969-07-15

    A study was made to determine the flow rates and pressure drops for all primary system flow paths through the FTR. The main data and results are in tables, diagrams and curves. The results are intended to provide a common basis for evaluation of parametric changes in the system.

  6. Biomechanical analysis of drop and countermovement jumps

    NARCIS (Netherlands)

    Bobbert, M. F.; Mackay, M.T.; Schinkelshoek, D.; Huijing, P. A.; van Ingen Schenau, G. J.

    For 13 subjects the performance of drop jumps from a height of 40 cm (DJ) and of countermovement jumps (CMJ) was analysed and compared. From force plate and cine data biomechanical variables including forces, moments, power output and amount of work done were calculated for hip, knee and ankle

  7. Scaling the drop size in coflow experiments

    International Nuclear Information System (INIS)

    Castro-Hernandez, E; Gordillo, J M; Gundabala, V; Fernandez-Nieves, A

    2009-01-01

    We perform extensive experiments with coflowing liquids in microfluidic devices and provide a closed expression for the drop size as a function of measurable parameters in the jetting regime that accounts for the experimental observations; this expression works irrespective of how the jets are produced, providing a powerful design tool for this type of experiments.

  8. Scaling the drop size in coflow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Castro-Hernandez, E; Gordillo, J M [Area de Mecanica de Fluidos, Universidad de Sevilla, Avenida de los Descubrimientos s/n, 41092 Sevilla (Spain); Gundabala, V; Fernandez-Nieves, A [School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)], E-mail: jgordill@us.es

    2009-07-15

    We perform extensive experiments with coflowing liquids in microfluidic devices and provide a closed expression for the drop size as a function of measurable parameters in the jetting regime that accounts for the experimental observations; this expression works irrespective of how the jets are produced, providing a powerful design tool for this type of experiments.

  9. Analysis of the Capacity Potential of Current Day and Novel Configurations for New York's John F. Kennedy Airport

    Science.gov (United States)

    Glaab, Patricia; Tamburro, Ralph; Lee, Paul

    2016-01-01

    In 2015, a series of systems analysis studies were conducted on John F. Kennedy Airport in New York (NY) in a collaborative effort between NASA and the Port Authority of New York and New Jersey (PANYNJ). This work was performed to build a deeper understanding of NY airspace and operations to determine the improvements possible through operational changes with tools currently available, and where new technology is required for additional improvement. The analysis was conducted using tool-based mathematical analyses, video inspection and evaluation using recorded arrival/departure/surface traffic captured by the Aerobahn tool (used by Kennedy Airport for surface metering), and aural data archives available publically through the web to inform the video segments. A discussion of impacts of trajectory and operational choices on capacity is presented, including runway configuration and usage (parallel, converging, crossing, shared, independent, staggered), arrival and departure route characteristics (fix sharing, merges, splits), and how compression of traffic is staged. The authorization in March of 2015 for New York to use reduced spacing under the Federal Aviation Administration (FAA) Wake Turbulence Recategorization (RECAT) also offers significant capacity benefit for New York airports when fully transitioned to the new spacing requirements, and the impact of these changes for New York is discussed. Arrival and departure capacity results are presented for each of the current day Kennedy Airport configurations. While the tools allow many variations of user-selected conditions, the analysis for these studies used arrival-priority, no-winds, additional safety buffer of 5% to the required minimum spacing, and a mix of traffic typical for Kennedy. Two additional "novel" configurations were evaluated. These configurations are of interest to Port Authority and to their airline customers, and are believed to offer near-term capacity benefit with minimal operational and

  10. Biophysical characterization of inwardly rectifying potassium currents (I(K1) I(K,ACh), I(K,Ca)) using sinus rhythm or atrial fibrillation action potential waveforms.

    Science.gov (United States)

    Tang, Chuyi; Skibsbye, Lasse; Yuan, Lei; Bentzen, Bo H; Jespersen, Thomas

    2015-10-01

    Although several physiological, pathophysiological and regulatory properties of classical inward rectifier K+ current I(K1), G-protein coupled inwardly-rectifying K+ current I(K,ACh) and the small-conductance Ca2+ activated K+ current I(K,Ca) have been identified, quantitative biophysical details remain unclear. Both I(K1) and I(K,ACh) are implicated in atrial fibrillation (AF), and recently also I(K,Ca) has been speculated to be linked with the genesis and sustainability of AF. All these three currents have been shown to be involved in the electrical remodeling in the atria of patients suffering from AF, and it is therefore important to characterize their biophysical properties and compare their relative current contribution in atrial electrophysiology in both sinus rhythm (SR) and AF. The aim of this study is to investigate the contribution of the three potassium currents when subjected to voltage protocols adapted from atrial action potentials recorded in human tissue at 1 and 3 Hz. The current recordings were performed in the HEK-293 heterologous cell system expressing either I(K1), I(K,ACh) or I(K,Ca) to establish the individual contribution of each of these currents during the voltage changes of atrial action potential waveforms. I(K1) primarily contributes to the atrial electrophysiology at the latter part of repolarization and during the diastolic phase, while both I(K,Ca) under high [Ca2+]i and I(K,ACh) contribute relatively most during repolarization.

  11. Evaluation of potential surface rupture and review of current seismic hazards program at the Los Alamos National Laboratory. Final report

    International Nuclear Information System (INIS)

    1991-01-01

    This report summarizes the authors review and evaluation of the existing seismic hazards program at Los Alamos National Laboratory (LANL). The report recommends that the original program be augmented with a probabilistic analysis of seismic hazards involving assignment of weighted probabilities of occurrence to all potential sources. This approach yields a more realistic evaluation of the likelihood of large earthquake occurrence particularly in regions where seismic sources may have recurrent intervals of several thousand years or more. The report reviews the locations and geomorphic expressions of identified fault lines along with the known displacements of these faults and last know occurrence of seismic activity. Faults are mapped and categorized into by their potential for actual movement. Based on geologic site characterization, recommendations are made for increased seismic monitoring; age-dating studies of faults and geomorphic features; increased use of remote sensing and aerial photography for surface mapping of faults; the development of a landslide susceptibility map; and to develop seismic design standards for all existing and proposed facilities at LANL

  12. Current use of impact models for agri-environment schemes and potential for improvements of policy design and assessment.

    Science.gov (United States)

    Primdahl, Jørgen; Vesterager, Jens Peter; Finn, John A; Vlahos, George; Kristensen, Lone; Vejre, Henrik

    2010-06-01

    Agri-Environment Schemes (AES) to maintain or promote environmentally-friendly farming practices were implemented on about 25% of all agricultural land in the EU by 2002. This article analyses and discusses the actual and potential use of impact models in supporting the design, implementation and evaluation of AES. Impact models identify and establish the causal relationships between policy objectives and policy outcomes. We review and discuss the role of impact models at different stages in the AES policy process, and present results from a survey of impact models underlying 60 agri-environmental schemes in seven EU member states. We distinguished among three categories of impact models (quantitative, qualitative or common sense), depending on the degree of evidence in the formal scheme description, additional documents, or key person interviews. The categories of impact models used mainly depended on whether scheme objectives were related to natural resources, biodiversity or landscape. A higher proportion of schemes dealing with natural resources (primarily water) were based on quantitative impact models, compared to those concerned with biodiversity or landscape. Schemes explicitly targeted either on particular parts of individual farms or specific areas tended to be based more on quantitative impact models compared to whole-farm schemes and broad, horizontal schemes. We conclude that increased and better use of impact models has significant potential to improve efficiency and effectiveness of AES. (c) 2009 Elsevier Ltd. All rights reserved.

  13. Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions.

    Science.gov (United States)

    Cao, Yang; Ma, Zheng Feei; Zhang, Hongxia; Jin, Yifan; Zhang, Yihe; Hayford, Frank

    2018-04-12

    The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS) and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.

  14. Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions

    Directory of Open Access Journals (Sweden)

    Yang Cao

    2018-04-01

    Full Text Available The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.

  15. An overview of current and potential use of information and communication technologies for immunization promotion among adolescents.

    Science.gov (United States)

    Amicizia, Daniela; Domnich, Alexander; Gasparini, Roberto; Bragazzi, Nicola Luigi; Lai, Piero Luigi; Panatto, Donatella

    2013-12-01

    Information and communication technologies (ICT), such as the Internet or mobile telephony, have become an important part of the life of today's adolescents and their main means of procuring information. The new generation of the Internet based on social-networking technologies, Web 2.0, is increasingly used for health purposes by both laypeople and health professionals. A broad spectrum of Web 2.0 applications provides several opportunities for healthcare workers, in that they can reach large numbers of teenagers in an individualized way and promote vaccine-related knowledge in an interactive and entertaining manner. These applications, namely social-networking and video-sharing websites, wikis and microblogs, should be monitored in order to identify current attitudes toward vaccination, to reply to vaccination critics and to establish a real-time dialog with users. Moreover, the ubiquity of mobile telephony makes it a valuable means of involving teenagers in immunization promotion, especially in developing countries.

  16. The construction of airfoil pressure models by the plate method: Achievements, current research, technology development and potential applications

    Science.gov (United States)

    Lawing, P. L.

    1985-01-01

    A method of constructing airfoils by inscribing pressure channels on the face of opposing plates, bonding them together to form one plate with integral channels, and contour machining this plate to form an airfoil model is described. The research and development program to develop the bonding technology is described as well as the construction and testing of an airfoil model. Sample aerodynamic data sets are presented and discussed. Also, work currently under way to produce thin airfoils with camber is presented. Samples of the aft section of a 6 percent airfoil with complete pressure instrumentation including the trailing edge are pictured and described. This technique is particularly useful in fabricating models for transonic cryogenic testing, but it should find application in a wide ange of model construction projects, as well as the fabrication of fuel injectors, space hardware, and other applications requiring advanced bonding technology and intricate fluid passages.

  17. Phase-space holes due to electron and ion beams accelerated by a current-driven potential ramp

    Directory of Open Access Journals (Sweden)

    M. V. Goldman

    2003-01-01

    Full Text Available One-dimensional open-boundary simulations have been carried out in a current-carrying plasma seeded with a neutral density depression and with no initial electric field. These simulations show the development of a variety of nonlinear localized electric field structures: double layers (unipolar localized fields, fast electron phase-space holes (bipolar fields moving in the direction of electrons accelerated by the double layer and trains of slow alternating electron and ion phase-space holes (wave-like fields moving in the direction of ions accelerated by the double layer. The principal new result in this paper is to show by means of a linear stability analysis that the slow-moving trains of electron and ion holes are likely to be the result of saturation via trapping of a kinetic-Buneman instability driven by the interaction of accelerated ions with unaccelerated electrons.

  18. The influence of local glucose oxidase activity on the potential/current distribution on stainless steel: A study by the wire beam electrode method

    International Nuclear Information System (INIS)

    Wang Wei; Zhang Xia; Wang Jia

    2009-01-01

    The wire beam electrode (WBE) method was first used to study the activity of local glucose oxidase (GOD) on stainless steel surface in seawater. Glucose oxidase was immobilized in calcium alginate gel capsules, which were embedded in a layer of artificial biofilm (calcium alginate gel) on the WBE surface. The potential/current distributions on the WBE surface were mapped using a newly developed device for the WBE method in our lab. The results demonstrated that the catalysis of H 2 O 2 formation by GOD can produce local noble potential peaks and cathodic current zones on the stainless steel surface. An interesting fluctuant current distribution around cathodic zones was observed the first time. The potential and current maps showed that the enzyme heterogeneity of the artificial biofilm caused a corresponding electrochemical heterogeneity at the biofilm/metal interface. The application of the WBE method to ennoblement study enables us to observe the heterogeneous electrochemistry at biofilm/stainless steel interface directly, providing us with a powerful tool to investigate other biofilm-related processes such as microbially influenced corrosion (MIC).

  19. The current status of drug development of hypoxic cell radiosensitizers and their potential role in gynecologic oncology

    International Nuclear Information System (INIS)

    Coleman, C.N.; Ballon, S.C.; Howes, A.E.; Martinez, A.; Halsey, J.; Hirst, V.K.

    1984-01-01

    Both laboratory and clinical data suggest that hypoxia contributes to the failure of radiotherapy to achieve local control of bulky gynecologic tumors. As part of a Phase I trial of hypoxic cell radiosensitizers, 19 women at Stanford University with advanced (n . 6) or recurrent (n . 13) pelvic neoplasms were treated with radiotherapy plus desmethylmisonidazole. Complete or partial response occurred in 42% of patients with some patients achieving local control for over 1 year. It is unknown if the sensitizer added to the results of radiotherapy alone. A Phase I trial of a theoretically superior sensitizer, SR-2508, is soon to begin. It is anticipated that the dose-limiting neurotoxicity seen with misonidazole and desmethylmisonidazole will either be eliminated or will occur at a much higher total dose of drug. Many patients with gynecologic tumors could potentially benefit from participation in the new drug trials

  20. Appearance traits in fish farming: progress from classical genetics to genomics, providing insight into current and potential genetic improvement

    Directory of Open Access Journals (Sweden)

    Nelson eColihueque

    2014-08-01

    Full Text Available Appearance traits in fish, those external body characteristics that influence consumer acceptance at point of sale, have come to the forefront of commercial fish farming, as culture profitability is closely linked to management of these traits. Appearance traits comprise mainly body shape and skin pigmentation. Analysis of the genetic basis of these traits in different fish reveals significant genetic variation within populations, indicating potential for their genetic improvement. Work into ascertaining the minor or major genes underlying appearance traits for commercial fish is emerging, with substantial progress in model fish in terms of identifying genes that control body shape and skin colors. In this review, we describe research progress to date, especially with regard to commercial fish, and discuss genomic findings in model fish in order to better address the genetic basis of the traits. Given that appearance traits are important in commercial fish, the genomic information related to this issue promises to accelerate the selection process in coming years.

  1. Current use of impact models for agri-environment schemes and potential for improvements of policy design and assessment

    DEFF Research Database (Denmark)

    Primdahl, Jorgen; Vesterager, Jens Peter; Finn, John A.

    2010-01-01

    Agri-Environment Schemes (AES) to maintain or promote environmentally-friendly farming practices were implemented on about 25% of all agricultural land in the EU by 2002. This article analyses and discusses the actual and potential use of impact models in supporting the design, implementation...... and evaluation of AES. Impact models identify and establish the causal relationships between policy objectives and policy outcomes. We review and discuss the role of impact models at different stages in the AES policy process, and present results from a survey of impact models underlying 60 agri-environmental...... schemes in seven EU member states. We distinguished among three categories of impact models (quantitative, qualitative or common sense), depending on the degree of evidence in the formal scheme description, additional documents, or key person interviews. The categories of impact models used mainly...

  2. Involvement of patients with cancer in patient safety: a qualitative study of current practices, potentials and barriers.

    Science.gov (United States)

    Martin, Helle Max; Navne, Laura Emdal; Lipczak, Henriette

    2013-10-01

    Patient involvement in patient safety is widely advocated but knowledge regarding implementation of the concept in clinical practice is sparse. To investigate existing practices for patient involvement in patient safety, and opportunities and barriers for further involvement. A qualitative study of patient safety involvement practices in patient trajectories for prostate, uterine and colorectal cancer in Denmark. Observations from four hospital wards and interviews with 25 patients with cancer, 11 hospital doctors, 10 nurses, four general practitioners and two private practicing gynaecologists were conducted using ethnographic methodology. Patient safety was not a topic of attention for patients or dominant in communication between patients and healthcare professionals. The understanding of patient safety in clinical practice is almost exclusively linked to disease management. Involvement of patients is not systematic, but healthcare professionals and patients express willingness to engage. Invitation and encouragement of patients to become involved could be further systematised and developed. Barriers include limited knowledge of patient safety, of specific patient safety involvement techniques and concern regarding potential negative impact on doctor-patient relationship. Involvement of patients in patient safety must take into account that despite stated openness to the idea of involvement, patients and health professionals may not in practice show immediate concern. Lack of systematic involvement can also be attributed to limited knowledge about how to implement involvement beyond the focus of self-monitoring and compliance and a concern about the consequences of patient involvement for treatment outcomes. To realise the potential of patients' and health professionals' shared openness towards involvement, there is a need for more active facilitation and concrete guidance on how involvement can be practiced by both parties.

  3. Chlorinated volatile organic compounds (Cl-VOCs) in environment - sources, potential human health impacts, and current remediation technologies.

    Science.gov (United States)

    Huang, Binbin; Lei, Chao; Wei, Chaohai; Zeng, Guangming

    2014-10-01

    Chlorinated volatile organic compounds (Cl-VOCs), including polychloromethanes, polychloroethanes and polychloroethylenes, are widely used as solvents, degreasing agents and a variety of commercial products. These compounds belong to a group of ubiquitous contaminants that can be found in contaminated soil, air and any kind of fluvial mediums such as groundwater, rivers and lakes. This review presents a summary of the research concerning the production levels and sources of Cl-VOCs, their potential impacts on human health as well as state-of-the-art remediation technologies. Important sources of Cl-VOCs principally include the emissions from industrial processes, the consumption of Cl-VOC-containing products, the disinfection process, as well as improper storage and disposal methods. Human exposure to Cl-VOCs can occur through different routes, including ingestion, inhalation and dermal contact. The toxicological impacts of these compounds have been carefully assessed, and the results demonstrate the potential associations of cancer incidence with exposure to Cl-VOCs. Most Cl-VOCs thus have been listed as priority pollutants by the Ministry of Environmental Protection (MEP) of China, Environmental Protection Agency of the U.S. (U.S. EPA) and European Commission (EC), and are under close monitor and strict control. Yet, more efforts will be put into the epidemiological studies for the risk of human exposure to Cl-VOCs and the exposure level measurements in contaminated sites in the future. State-of-the-art remediation technologies for Cl-VOCs employ non-destructive methods and destructive methods (e.g. thermal incineration, phytoremediation, biodegradation, advanced oxidation processes (AOPs) and reductive dechlorination), whose advantages, drawbacks and future developments are thoroughly discussed in the later sections. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation

    Directory of Open Access Journals (Sweden)

    Miriam Solana

    2016-06-01

    Full Text Available A counter-current CO2 fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With respect to the temperature and pressure conditions investigated, results show that the highest separation efficiency was obtained at 35 °C and 10.34 MPa. At these operating conditions, 92.3% of the butanol present in the feed solution was extracted, and a concentration of 787.5 g·L−1 of butanol in the extract was obtained, starting from a feed solution of 20 g·L−1. Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was detected in the water-rich fraction (raffinate, whereas the highest concentration of acetone was found in the butanol rich fraction (extract.

  5. CpG Methylation Analysis—Current Status of Clinical Assays and Potential Applications in Molecular Diagnostics

    Science.gov (United States)

    Sepulveda, Antonia R.; Jones, Dan; Ogino, Shuji; Samowitz, Wade; Gulley, Margaret L.; Edwards, Robin; Levenson, Victor; Pratt, Victoria M.; Yang, Bin; Nafa, Khedoudja; Yan, Liying; Vitazka, Patrick

    2009-01-01

    Methylation of CpG islands in gene promoter regions is a major molecular mechanism of gene silencing and underlies both cancer development and progression. In molecular oncology, testing for the CpG methylation of tissue DNA has emerged as a clinically useful tool for tumor detection, outcome prediction, and treatment selection, as well as for assessing the efficacy of treatment with the use of demethylating agents and monitoring for tumor recurrence. In addition, because CpG methylation occurs early in pre-neoplastic tissues, methylation tests may be useful as markers of cancer risk in patients with either infectious or inflammatory conditions. The Methylation Working Group of the Clinical Practice Committee of the Association of Molecular Pathology has reviewed the current state of clinical testing in this area. We report here our summary of both the advantages and disadvantages of various methods, as well as the needs for standardization and reporting. We then conclude by summarizing the most promising areas for future clinical testing in cancer molecular diagnostics. PMID:19541921

  6. Orthopaedic surgeon attitudes towards current limitations and the potential for robotic and technological innovation in arthroscopic surgery.

    Science.gov (United States)

    Jaiprakash, Anjali; O'Callaghan, William B; Whitehouse, Sarah L; Pandey, Ajay; Wu, Liao; Roberts, Jonathan; Crawford, Ross W

    2017-01-01

    To determine the perceptions of surgeons at both consultant and resident level to the difficulties of performing knee arthroscopy and to determine their willingness to adopt robotic technology. A questionnaire was designed to discern the attitude of orthopaedic consultants and residents to the technical challenges of performing knee arthroscopy and the possible role of robotically enhanced surgery. The questionnaire included 31 questions across five key domains. Iatrogenic damage to articular cartilage was thought to occur in at least 1 in 10 cases by 50% of respondents with 15% believing that it occurred in every case. One hundred or more procedures were thought to be necessary to overcome the learning curve by 40% of respondents and 77.5% believed that 50 procedures or above were necessary. Ninety-nine per cent of respondents agreed that higher technical skills would decrease unintended damage. Despite such difficulties with the procedure and no prior experience with robotic surgery, 47% of respondents see a role for semiautonomous arthroscopic systems in the future. Surgeons believe that knee arthroscopy is a difficult procedure with a long learning curve and a high incidence of iatrogenic cartilage damage. Many find it ergonomically challenging and have frustration with current tools and technology. This is the first study that highlights surgeons' difficulties performing knee arthroscopy despite the commonly held attitudes that it is a straightforward procedure. Systems that are able to decrease these problems should improve patients' outcomes and decrease the risk of harm.

  7. Vertical Drop Of 21-PWR Waste Package On Unyielding Surface

    International Nuclear Information System (INIS)

    S. Mastilovic; A. Scheider; S.M. Bennett

    2001-01-01

    The objective of this calculation is to determine the structural response of a 21-PWR (pressurized-water reactor) Waste Package (WP) subjected to the 2-m vertical drop on an unyielding surface at three different temperatures. The scope of this calculation is limited to reporting the calculation results in terms of stress intensities in two different WP components. The information provided by the sketches (Attachment I) is that of the potential design of the type of WP considered in this calculation, and all obtained results are valid for that design only

  8. District heating and cogeneration in the EU-28: Current situation, potential and proposed energy strategy for its generalisation

    Directory of Open Access Journals (Sweden)

    Enrique Rosales-Asensio

    2016-10-01

    Full Text Available Yearly, EU-28 conventional thermal generating plants reject a greater amount of energy than what ultimately is utilised by residential and commercial loads for heating and hot water. If this waste heat were to be used through district heating networks, given a previous energy valorisation, there would be a noticeable decrease in imported fossil fuels for heating. As a consequence, benefits in the form of an energy efficiency increase, an energy security improvement, and a minimisation of emitted greenhouse gases would occur. Given that it is not expected for heat demand to decrease significantly in the medium term, district heating networks show the greatest potential for the development of cogeneration. However, to make this happen, some barriers that are far from being technological but are mostly institutional and financial need to be removed. The purpose of this review is to provide information on the potential of using waste heat from conventional thermal power plants (subsequently converted into cogeneration plants in district heating networks located in the EU-28. For this, a preliminary assessment is conducted in order to show an estimate of the cost of adopting an energy strategy in which district heating networks are a major player of the energy mix. From this assessment, it is possible to see that even though the energy strategy proposed in this paper, which is based on a dramatic increase in the joint use of district heating networks and cogeneration, is capital-intensive and would require an annual investment of roughly 300 billion euros, its adoption would result in a reduction of yearly fuel expenses in the order of 100 billion euros and a shortening of about 15% of the total final energy consumption, which makes it of paramount interest as an enabler of the legal basis of the “Secure, Clean and Efficient Energy” future enacted by the EU-28 Horizon 2020.

  9. Treatment of multi-word lexical items in the dictionary: the current situation and the potential problems facing dictionary users

    Directory of Open Access Journals (Sweden)

    Marjeta Vrbinc

    2011-05-01

    Full Text Available In this article, we first discuss the inclusion of idioms in the latest printed editions of monolingual learner’s dictionaries; we then consider and evaluate the success of look-up operations in connection with the recognition of the correct part of speech. The central part of the article discusses and justifies the macro- and microstructural treatment of multi-word lexical items. Finally, we address the issue of including idioms in the microstructure as special senses of the lemma, as usage examples and/or in the idioms section. The inclusion and treatment of multi-word lexical items depends on the needs of potential dictionary users. Lexicographers should therefore strive to adopt a pragmatic approach that would help the user to locate a multi-word lexical item with minimal effort. When compiling a bilingual dictionary, contrastive differences between source and target languages should also be taken into consideration. http://dx.doi.org/10.5128/ERYa7.15

  10. African horse sickness: The potential for an outbreak in disease-free regions and current disease control and elimination techniques.

    Science.gov (United States)

    Robin, M; Page, P; Archer, D; Baylis, M

    2016-09-01

    African horse sickness (AHS) is an arboviral disease of equids transmitted by Culicoides biting midges. The virus is endemic in parts of sub-Saharan Africa and official AHS disease-free status can be obtained from the World Organization for Animal Health on fulfilment of a number of criteria. AHS is associated with case fatality rates of up to 95%, making an outbreak among naïve horses both a welfare and economic disaster. The worldwide distributions of similar vector-borne diseases (particularly bluetongue disease of ruminants) are changing rapidly, probably due to a combination of globalisation and climate change. There is extensive evidence that the requisite conditions for an AHS epizootic currently exist in disease-free countries. In particular, although the stringent regulations enforced upon competition horses make them extremely unlikely to redistribute the virus, there are great concerns over the effects of illegal equid movement. An outbreak of AHS in a disease free region would have catastrophic effects on equine welfare and industry, particularly for international events such as the Olympic Games. While many regions have contingency plans in place to manage an outbreak of AHS, further research is urgently required if the equine industry is to avoid or effectively contain an AHS epizootic in disease-free regions. This review describes the key aspects of AHS as a global issue and discusses the evidence supporting concerns that an epizootic may occur in AHS free countries, the planned government responses, and the roles and responsibilities of equine veterinarians. © 2016 EVJ Ltd.

  11. Part I. Evaluation of thermodynamic and kinetic parameters for electron transfer and following chemical reaction from a global analysis of current-potential-time data. Part II. Electro-catalytic detection in high-performance liquid chromatography of vitamin B[sub 12] and other molecules of biological and environmental interest

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V.T.

    1992-01-01

    Simultaneous evaluation of electron transfer rate constant, k[sup 0], following chemical reaction rate constant, k[sub f], electron transfer coefficient, [alpha] and standard potential, E[sup 0][prime] for an electrochemical reaction following the EC mechanism is described. A mathematical model for the current response to a potential step is developed, starting with the Butler-Volmer equation for electrode kinetics and concentration expressions for the redox couple. The resulting integral equations are solved numerically via the Step Function method. Current-potential and current-time curves are simulated and tested under limiting conditions. The four parameters of the system are evaluated by fitting simulated current-voltage-time (i-E-t) surface to the theoretical equation. The method is applied to study an important biological molecule, viz., methyl cobalamin, in DMSO. Included in the discussion part is the use of kinetic zone diagrams to depict chronoamperometric current response as a function of dimensionless rate constants for the EC reaction scheme. This compact display of the influence of the two rate constants on current in all time windows can be used to select the best data for analysis. Theoretical limits of measurable rate constants can be estimated from the zone diagram. The development of a dropping mercury electrode detector for High Performance Liquid Chromatography (HPLC) and its application to analysis of B[sub 12] and other vitamins is described. This EC detector is able to achieve high levels of sensitivity by exploiting the catalytic hydrogen evolution undergone by many nitrogenous organic molecules. Vitamin B[sub 12], thiamine, riboflavin and niacinamide were analyzed individually and in mixtures on reverse phase C18 column. Preliminary results from the analysis of commercial multivitamin preparations are also discussed.

  12. Analytical solutions of electric potential and impedance for a multilayered spherical volume conductor excited by time-harmonic electric current source: application in brain EIT

    Science.gov (United States)

    Xiao, Chunyan; Lei, Yinzhao

    2005-06-01

    A model of a multilayered spherical volume conductor with four electrodes is built. In this model, a time-harmonic electric current is injected into the sphere through a pair of drive electrodes, and electric potential is measured by the other pair of measurement electrodes. By solving the boundary value problem of the electromagnetic field, the analytical solutions of electric potential and impedance in the whole conduction region are derived. The theoretical values of electric potential on the surface of the sphere are in good accordance with the experimental results. The analytical solutions are then applied to the simulation of the forward problem of brain electrical impedance tomography (EIT). The results show that, for a real human head, the imaginary part of the electric potential is not small enough to be ignored at above 20 kHz, and there exists an approximate linear relationship between the real and imaginary parts of the electric potential when the electromagnetic parameters of the innermost layer keep unchanged. Increase in the conductivity of the innermost layer leads to a decrease of the magnitude of both real and imaginary parts of the electric potential on the scalp. However, the increase of permittivity makes the magnitude of the imaginary part of the electric potential increase while that of the real part decreases, and vice versa.

  13. Analytical solutions of electric potential and impedance for a multilayered spherical volume conductor excited by time-harmonic electric current source: application in brain EIT

    International Nuclear Information System (INIS)

    Xiao Chunyan; Lei Yinzhao

    2005-01-01

    A model of a multilayered spherical volume conductor with four electrodes is built. In this model, a time-harmonic electric current is injected into the sphere through a pair of drive electrodes, and electric potential is measured by the other pair of measurement electrodes. By solving the boundary value problem of the electromagnetic field, the analytical solutions of electric potential and impedance in the whole conduction region are derived. The theoretical values of electric potential on the surface of the sphere are in good accordance with the experimental results. The analytical solutions are then applied to the simulation of the forward problem of brain electrical impedance tomography (EIT). The results show that, for a real human head, the imaginary part of the electric potential is not small enough to be ignored at above 20 kHz, and there exists an approximate linear relationship between the real and imaginary parts of the electric potential when the electromagnetic parameters of the innermost layer keep unchanged. Increase in the conductivity of the innermost layer leads to a decrease of the magnitude of both real and imaginary parts of the electric potential on the scalp. However, the increase of permittivity makes the magnitude of the imaginary part of the electric potential increase while that of the real part decreases, and vice versa

  14. High concentration effects of neutral-potential-well interface traps on recombination dc current-voltage lineshape in metal-oxide-silicon transistors

    Science.gov (United States)

    Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

    2008-11-01

    Steady-state Shockley-Read-Hall kinetics is employed to explore the high concentration effect of neutral-potential-well interface traps on the electron-hole recombination direct-current current-voltage (R-DCIV) properties in metal-oxide-silicon field-effect transistors. Extensive calculations include device parameter variations in neutral-trapping-potential-well electron interface-trap density NET (charge states 0 and -1), dopant impurity concentration PIM, oxide thickness Xox, forward source/drain junction bias VPN, and transistor temperature T. It shows significant distortion of the R-DCIV lineshape by the high concentrations of the interface traps. The result suggests that the lineshape distortion observed in past experiments, previously attributed to spatial variation in surface impurity concentration and energy distribution of interface traps in the silicon energy gap, can also arise from interface-trap concentration along surface channel region.

  15. Coalescence collision of liquid drops I: Off-center collisions of equal-size drops

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2011-09-01

    Full Text Available The Smoothed Particle Hydrodynamics method (SPH is used here to model off-center collisions of equal-size liquid drops in a three-dimensional space. In this study the Weber number is calculated for several conditions of the droplets dynamics and the velocity vector fields formed inside the drops during the collision process are shown. For the permanent coalescence the evolution of the kinetic and internal energy is shown and also the approaching to equilibrium of the resulting drop. Depending of the Weber number three possible outcomes for the collision of droplets is obtained: permanent coalescence, flocculation and fragmentation. The fragmentation phenomena are modeled and the formation of small satellite drops can be seen. The ligament that is formed follows the “end pinching” mechanism and it is transformed into a flat structure.

  16. Extension of the source-sink potential approach to Hartree-Fock and density functional theory: A new tool to visualize the ballistic current through molecules

    Science.gov (United States)

    Fias, Stijn; Stuyver, Thijs

    2017-11-01

    The recent source and sink potential approach by Pickup et al. [J. Chem. Phys. 143, 194105 (2015)] is extended to Hartree-Fock and density functional theory, allowing the calculation of the transmission and the visualization of ballistic currents through molecules at these levels of theory. This visualization allows the study of the transmission process in real-space, providing an important tool to better understand the conduction process.

  17. Simvastatin as a Potential Disease-Modifying Therapy for Patients with Parkinson’s Disease: Rationale for Clinical Trial, and Current Progress

    OpenAIRE

    Carroll, Camille B.; Wyse, Richard K.H.

    2017-01-01

    Many now believe the holy grail for the next stage of therapeutic advance surrounds the development of disease-modifying approaches aimed at intercepting the year-on-year neurodegenerative decline experienced by most patients with Parkinson’s disease (PD). Based on recommendations of an international committee of experts who are currently bringing multiple, potentially disease-modifying, PD therapeutics into long-term neuroprotective PD trials, a clinical trial involving 198 patients is under...

  18. X-38 Drop Model: Landing Sequence Collage from Cessna Drop Test

    Science.gov (United States)

    1995-01-01

    This sequence of photographs shows a 4-foot-long model of NASA's X-38 gliding to earth after being dropped from a Cessna aircraft in late 1995. The model was used to test the ram-air parafoil landing system, which could allow for accurate and controlled landings of an emergency Crew Return Vehicle spacecraft returning to earth. The X-38 Crew Return Vehicle (CRV) research project is designed to develop the technology for a prototype emergency crew return vehicle, or lifeboat, for the International Space Station. The project is also intended to develop a crew return vehicle design that could be modified for other uses, such as a joint U.S. and international human spacecraft that could be launched on the French Ariane-5 Booster. The X-38 project is using available technology and off-the-shelf equipment to significantly decrease development costs. Original estimates to develop a capsule-type crew return vehicle were estimated at more than $2 billion. X-38 project officials have estimated that development costs for the X-38 concept will be approximately one quarter of the original estimate. Off-the-shelf technology is not necessarily 'old' technology. Many of the technologies being used in the X-38 project have never before been applied to a human-flight spacecraft. For example, the X-38 flight computer is commercial equipment currently used in aircraft and the flight software operating system is a commercial system already in use in many aerospace applications. The video equipment for the X-38 is existing equipment, some of which has already flown on the space shuttle for previous NASA experiments. The X-38's primary navigational equipment, the Inertial Navigation System/Global Positioning System, is a unit already in use on Navy fighters. The X-38 electromechanical actuators come from previous joint NASA, U.S. Air Force, and U.S. Navy research and development projects. Finally, an existing special coating developed by NASA will be used on the X-38 thermal tiles to

  19. Control of Drop Motion by Mechanical Vibrations

    Science.gov (United States)

    Bestehorn, Michael

    2014-11-01

    Since the first experimental observations of Michael Faraday in 1831 it is known that a vibrating liquid may show an instability of its flat free surface with respect to oscillating regular surface patterns. We study thin liquid films on a horizontal substrate in the long wave approximation. The films are parametrically excited by mechanical horizontal or inclined oscillations. Inertia effects are taken into account and the standard thin film formulation is extended by a second equation for the vertically averaged mass flux. The films can be additionally unstable by Van der Waals forces on a partially wetting substrate, leading to the formation of drops. These drops can be manipulated by the vibrations to move in a desired direction. Linear results based on a damped complex valued Mathieu equation as well as fully nonlinear results using a reduced model will be presented, for more details see.

  20. A pressure drop model for PWR grids

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dong Seok; In, Wang Ki; Bang, Je Geon; Jung, Youn Ho; Chun, Tae Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A pressure drop model for the PWR grids with and without mixing device is proposed at single phase based on the fluid mechanistic approach. Total pressure loss is expressed in additive way for form and frictional losses. The general friction factor correlations and form drag coefficients available in the open literatures are used to the model. As the results, the model shows better predictions than the existing ones for the non-mixing grids, and reasonable agreements with the available experimental data for mixing grids. Therefore it is concluded that the proposed model for pressure drop can provide sufficiently good approximation for grid optimization and design calculation in advanced grid development. 7 refs., 3 figs., 3 tabs. (Author)