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Sample records for biologically closed electrical

  1. Biologically closed electrical circuits in venus flytrap.

    PubMed

    Volkov, Alexander G; Carrell, Holly; Markin, Vladislav S

    2009-04-01

    The Venus flytrap (Dionaea muscipula Ellis) is a marvel of plant electrical, mechanical, and biochemical engineering. The rapid closure of the Venus flytrap upper leaf in about 0.1 s is one of the fastest movements in the plant kingdom. We found earlier that the electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf without mechanical stimulation of trigger hairs. The Venus flytrap can accumulate small subthreshold charges and, when the threshold value is reached, the trap closes. Here, we investigated the electrical properties of the upper leaf of the Venus flytrap and proposed the equivalent electrical circuit in agreement with the experimental data.

  2. Circadian rhythms in biologically closed electrical circuits of plants.

    PubMed

    Volkov, Alexander; Waite, Astian J; Wooten, Joseph D; Markin, Vladislav S

    2012-02-01

    The circadian clock regulates a wide range of electrophysiological and developmental processes in plants. Here, we discuss the direct influence of a circadian clock on biologically closed electrochemical circuits in vivo. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), Aloe vera and Mimosa pudica, which regulate their physiology, were analyzed using the charge stimulation method. Plants are able to memorize daytime and nighttime. Even at continuous light or darkness, plants recognize nighttime or daytime and change the input resistance. The circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge, and the speed of transmission of electrical energy from the electrostimulator to plants.

  3. Closed cycle electric discharge laser design investigation

    NASA Technical Reports Server (NTRS)

    Baily, P. K.; Smith, R. C.

    1978-01-01

    Closed cycle CO2 and CO electric discharge lasers were studied. An analytical investigation assessed scale-up parameters and design features for CO2, closed cycle, continuous wave, unstable resonator, electric discharge lasing systems operating in space and airborne environments. A space based CO system was also examined. The program objectives were the conceptual designs of six CO2 systems and one CO system. Three airborne CO2 designs, with one, five, and ten megawatt outputs, were produced. These designs were based upon five minute run times. Three space based CO2 designs, with the same output levels, were also produced, but based upon one year run times. In addition, a conceptual design for a one megawatt space based CO laser system was also produced. These designs include the flow loop, compressor, and heat exchanger, as well as the laser cavity itself. The designs resulted in a laser loop weight for the space based five megawatt system that is within the space shuttle capacity. For the one megawatt systems, the estimated weight of the entire system including laser loop, solar power generator, and heat radiator is less than the shuttle capacity.

  4. 36. SITE BUILDING 004 ELECTRIC POWER STATION CLOSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. SITE BUILDING 004 - ELECTRIC POWER STATION - CLOSE UP VIEW OF 1200 HORSEPOWER STANDBY POWER DIESEL ENGINE/GENERATOR SETS. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  5. Closing of venus flytrap by electrical stimulation of motor cells.

    PubMed

    Volkov, Alexander G; Adesina, Tejumade; Jovanov, Emil

    2007-05-01

    Electrical signaling and rapid closure of the carnivorous plant Dionaea muscipula Ellis (Venus flytrap) have been attracting the attention of researchers since XIX century, but the exact mechanism of Venus flytrap closure is still unknown. We found that the electrical stimulus between a midrib and a lobe closes the Venus flytrap leaf by activating motor cells without mechanical stimulation of trigger hairs. The closing time of Venus flytrap by electrical stimulation of motor cells is 0.3 s, the same as mechanically induced closing. The mean electrical charge required for the closure of the Venus flytrap leaf is 13.6 microC. Ion channel blockers such as Ba(2+), TEACl as well as uncouplers such as FCCP, 2,4-dinitrophenol and pentachlorophenol dramatically decrease the speed of the trap closing. Using an ultra-fast data acquisition system with measurements in real time, we found that the action potential in the Venus flytrap has a duration time of about 1.5 ms. Our results demonstrate that electrical stimulation can be used to study mechanisms of fast activity in motor cells of the plant kingdom.

  6. Biological semiconductor based on electrical percolation.

    PubMed

    Yang, Minghui; Bruck, Hugh Alan; Kostov, Yordan; Rasooly, Avraham

    2010-05-01

    We have developed a novel biological semiconductor (BSC) based on electrical percolation through a multilayer three-dimensional carbon nanotube-antibody bionanocomposite network, which can measure biological interactions directly and electronically. In electrical percolation, the passage of current through the conductive network is dependent upon the continuity of the network. Molecular interactions, such as binding of antigens to the antibodies, disrupt the network continuity causing increased resistance of the network. A BSC is fabricated by immobilizing a prefunctionalized single-walled carbon nanotubes (SWNTs)-antibody bionanocomposite directly on a poly(methyl methacrylate) (PMMA) surface (also known as plexiglass or acrylic). We used the BSC for direct (label-free) electronic measurements of antibody-antigen binding, showing that, at slightly above the electrical percolation threshold of the network, binding of a specific antigen dramatically increases the electrical resistance. Using anti-staphylococcal enterotoxin B (SEB) IgG as a "gate" and SEB as an "actuator", we demonstrated that the BSC was able to detect SEB at concentrations of 1 ng/mL. The new BSCs may permit assembly of multiple sensors on the same chip to create "biological central processing units (CPUs)" with multiple BSC elements, capable of processing and sorting out information on multiple analytes simultaneously.

  7. Circadian variations in biologically closed electrochemical circuits in Aloe vera and Mimosa pudica.

    PubMed

    Volkov, Alexander G; Baker, Kara; Foster, Justin C; Clemmons, Jacqueline; Jovanov, Emil; Markin, Vladislav S

    2011-04-01

    The circadian clock regulates a wide range of electrophysiological and developmental processes in plants. This paper presents, for the first time, the direct influence of a circadian clock on biologically closed electrochemical circuits in vivo. Here we show circadian variation of the plant responses to electrical stimulation. The biologically closed electrochemical circuits in the leaves of Aloe vera and Mimosa pudica, which regulate their physiology, were analyzed using the charge stimulation method. The electrostimulation was provided with different timing and different voltages. Resistance between Ag/AgCl electrodes in the leaf of Aloe vera was higher during the day than at night. Discharge of the capacitor in Aloe vera at night was faster than during the day. Discharge of the capacitor in a pulvinus of Mimosa pudica was faster during the day. The biologically closed electrical circuits with voltage gated ion channels in Mimosa pudica are also activated the next day, even in the darkness. These results show that the circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate ion channels in biologically closed electrochemical circuits. We present the equivalent electrical circuits in both plants and their circadian variation to explain the experimental data.

  8. The electric field close to an undulating interface

    NASA Astrophysics Data System (ADS)

    Kallunki, Jouni; Alava, Mikko; Hellén, E. K. O.

    2006-07-01

    The electric potential close to a boundary between two dielectric material layers reflects the geometry of such an interface. The local variations arise from the combination of material parameters and from the nature of the inhomogeneity. Here, the arising electric field is considered for both a sinusoidally varying boundary and for a "rough," Gaussian test case. We discuss the applicability of a one-dimensional model with the varying layer thickness as a parameter and the generic scaling of the results. As an application we consider the effect of paper roughness on toner transfer in electrophotographic printing.

  9. Airborne biological particles and electric fields

    NASA Astrophysics Data System (ADS)

    Benninghoff, William S.; Benninghoff, Anne S.

    1982-01-01

    In November and December 1977 at McMurdo Station in Antarctica we investigated the kinds, numbers, and deposition of airborne particles larger than 2 μm while measuring electric field gradient at 2.5 m above the ground. Elementary collecting devices were used: Staplex Hi-Volume and Roto-rod samplers, Tauber (static sedimentation) traps, petrolatum-coated microscope slides, and snow (melted and filtered). The electric fields were measured by a rotating dipole (Stanford Radioscience Laboratory field mill number 2). During periods of blowing snow and dust the electric field gradient was + 500 to + 2500 V/m, and Tauber traps with grounded covers collected 2 or more times as much snow and dust as the ones with ungrounded covers. During falling snow the electric field gradient was -1000 to -1500 V/m, and the ungrounded traps collected almost twice as much snow and dust as those grounded. These observations suggest that under the prevailing weather conditions in polar regions the probable net effect is deposition of greater quantities of dust, including diaspores and minute organisms, on wet, grounded surfaces. This hypothesis needs examination for its use in explanation of biological distribution patterns.

  10. MEMS CLOSED CHAMBER HEAT ENGINE AND ELECTRIC GENERATOR

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A. (Inventor)

    2005-01-01

    A heat engine, preferably combined with an electric generator, and advantageously implemented using micro-electromechanical system (MEMS) technologies as an array of one or more individual heat engine/generators. The heat engine is based on a closed chamber containing a motive medium, preferably a gas; means for alternately enabling and disabling transfer of thermal energy from a heat source to the motive medium; and at least one movable side of the chamber that moves in response to thermally-induced expansion and contraction of the motive medium, thereby converting thermal energy to oscillating movement. The electrical generator is combined with the heat engine to utilize movement of the movable side to convert mechanical work to electrical energy, preferably using electrostatic interaction in a generator capacitor. Preferably at least one heat transfer side of the chamber is placed alternately into and out of contact with the heat source by a motion capacitor, thereby alternately enabling and disabling conductive transfer of heat to the motive medium.

  11. Closed cycle osmotic power plants for electric power production

    NASA Astrophysics Data System (ADS)

    Reali, M.

    1980-04-01

    The paper deals with closed-cycle osmotic power plants (CCOPPs), which are not meant for the exploitation of natural salinity gradients but, rather, for the exploitation of those abundant heat sources having temperatures slightly higher than ambient temperature, e.g., geothermal fields, ocean temperature gradients, waste heat from power plants, and solar energy. The paper gives a general description of the CCOPP, along with some indications of its potential for energy generation. The concept of the CCOPP lies in producing electric power by means of the osmotic flows of suitable solvents and subsequently in separating them again from their solutes by means of thermal energy obtained from any available heat source. The discussion covers osmotic phenomena and the CCOPP, as well as important features of the CCOPP.

  12. Pulsed Electric Fields for Biological Weapons Defense

    DTIC Science & Technology

    2002-01-01

    studies of Bacillus atrophaeus (formerly Bacillus subtilis var. niger). 15. SUBJECT TERMS nanosecond high-field electric pulse, electroperturbation...sterility monitoring kit, which utilizes spores of Bacillus atrophaeus (formerly Bacillus subtilis var. niger) deposited on paper in glassine envelopes, has...report a study of the application of ultra- short high-field electric pulses (5 MV/m, 100-ns pulse width, 4-ns rise time) to Bacillus atrophaeus spores

  13. Synthesis of high-complexity rhythmic signals for closed-loop electrical neuromodulation.

    PubMed

    Zalay, Osbert C; Bardakjian, Berj L

    2013-06-01

    We propose an approach to synthesizing high-complexity rhythmic signals for closed-loop electrical neuromodulation using cognitive rhythm generator (CRG) networks, wherein the CRG is a hybrid oscillator comprised of (1) a bank of neuronal modes, (2) a ring device (clock), and (3) a static output nonlinearity (mapper). Networks of coupled CRGs have been previously implemented to simulate the electrical activity of biological neural networks, including in silico models of epilepsy, producing outputs of similar waveform and complexity to the biological system. This has enabled CRG network models to be used as platforms for testing seizure control strategies. Presently, we take the application one step further, envisioning therapeutic CRG networks as rhythmic signal generators creating neuromimetic signals for stimulation purposes, motivated by recent research indicating that stimulus complexity and waveform characteristics influence neuromodulation efficacy. To demonstrate this concept, an epileptiform CRG network generating spontaneous seizure-like events (SLEs) was coupled to a therapeutic CRG network, forming a closed-loop neuromodulation system. SLEs are associated with low-complexity dynamics and high phase coherence in the network. The tuned therapeutic network generated a high-complexity, multi-banded rhythmic stimulation signal with prominent theta and gamma-frequency power that suppressed SLEs and increased dynamic complexity in the epileptiform network, as measured by a relative increase in the maximum Lyapunov exponent and decrease in phase coherence. CRG-based neuromodulation outperformed both low and high-frequency periodic pulse stimulation, suggesting that neuromodulation using complex, biomimetic signals may provide an improvement over conventional electrical stimulation techniques for treating neurological disorders such as epilepsy.

  14. Pulsed Electric Fields for Biological Weapons Defense

    DTIC Science & Technology

    2008-09-30

    nanotubes (CNTs), bio-compatible metal nanowires , or other high-aspect ratio nanoscale structures for delivery of nanoelectropulses to biological systems...Carbon nanotubes. The potential for using carbon nanotubes (CNTs) or other nanowire or nanotube structures as electrodes or sensors in bioelectrics...Marcu, and M. A. Gundersen. 2006. Photostability and pH sensitivity of CdSe /ZnSe/ZnS quantum dots in living cells. Nanotechnology 17:4469-4476. 50. Liu, Y

  15. Multi-Disciplinary Research for High Energy Chemical Lasers, Closed-Cycle ElectricOIL Technology

    DTIC Science & Technology

    2007-10-31

    electrodynamic model predictions a laser system model was utilized to predict the scalability of the system; results indicate that theoretical electrical ...multidisciplinary research program for a high energy closed-cycle laser that is derived from the Electrically assisted Oxygen Iodine Laser (ElectricOlU (EOIL...flow iodine from one reservoir and trap it in another. The principal advantage of the hybrid EOIL system is trading a small fixed mass in electrical

  16. Closed cycle annular-return gas flow electrical discharge laser

    SciTech Connect

    Bletzinger, P.; Garscadden, A.; Hasinger, S.H.; Olson, R.A.; Sarka, B.

    1981-06-16

    A closed cycle, high repetition pulsed laser is disclosed that has a laser flow channel with an annular flow return surrounding the laser flow channel. Ultra high vacuum components and low out-gassing materials are used in the device. An externally driven axial flow fan is used for gas recirculation. A thyratron-switched lowinductance energy storage capacitor is used to provide a transverse discharge between profiled electrodes in the laser cavity.

  17. Intracanopy lighting reduces electrical energy utilization by closed cowpea stands.

    PubMed

    Frantz, J M; Joly, R J; Mitchell, C A

    2001-01-01

    The high planting densities needed to grow edible biomass in sustainable space life support systems will create problems for planophile crops that form closed, self-shading canopies. The use of traditional overhead-lighting configurations will reduce the penetration of photosynthetically active radiation (PAR) into such canopies and will result in substantial shading of understory leaves. Intracanopy lighting, an irradiation approach that allows plants to grow around fixed arrays of low-intensity lamps, reduces overall energy expenditure for crop production by improving light distribution and interception throughout the canopy. Comparing different fluorescent lamp geometries within vegetative canopies of cowpea (Vigna unguiculata L. Walp) revealed great plasticity of leaf orientation to maximize absorption of PAR from lamps arrayed at various nontraditional angles. Varying the amount of photosynthetic energy available within canopies creates considerable potential to manipulate canopy productivity. Increasing lamp number 38% within cowpea canopies raised stand productivity 45%, reflecting the highly efficient interception and absorption of intracanopy PAR. However, combined above/within-canopy lighting did not increase overall PAR interception and vegetative yield, and productivity did not improve relative to the same input wattage of intracanopy lighting alone. Optimization of intracanopy lighting for crops to be used in future space life support systems will substantially reduce power and energy burdens for food-crop production.

  18. Delay-Dependent Response in Weakly Electric Fish under Closed-Loop Pulse Stimulation.

    PubMed

    Forlim, Caroline Garcia; Pinto, Reynaldo Daniel; Varona, Pablo; Rodríguez, Francisco B

    2015-01-01

    In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals. Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics. To investigate how the inter pulse intervals vary in response to external stimuli, we compare the response to a simple closed-loop stimulation protocol and the signals generated without electrical stimulation. The activity-dependent stimulation protocol explores different stimulus delivery delays relative to the fish's own electric discharges. We show that there is a critical time delay in this closed-loop interaction, as the largest changes in inter pulse intervals occur when the stimulation delay is below 100 ms. We also discuss the implications of these findings in the context of information processing in weakly electric fish.

  19. Biological Detection of Low-Level Electric Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Barnes, Frank S.

    1996-03-01

    This paper will review sources of noise in biological systems including thermal noise, shot noise, 1/f noise, signals generated by the biological system, and the background environment. These noise signals will be examined for a model nerve cell and compared with estimates for the electrical and magnetic signals which are typically generated by our power distribution systems at 60 Hz. A number of mechanisms by which biological systems may be able to extract signals from noise will be described. All of these mechanism require biological system nonlinearities and repetitive signals. The results of computer simulation show that computer models of a neural network can be trained to identify a 60-Hz signal with 97% accuracy at signal-to-noise ratios from 1 to 0.001 using a back propagation algorithm. The number of training runs increases with decreasing signal-to-noise ratio. These results will be discussed in terms of biological results which show that sharks can detect electrical signal levels approaching 10-7 V/m and bees can detect changes in magnetic field levels of 10-9 T. Some recent results from our lab on the effects of ELF magnetic fields on the growth rate of pre T cells will also be presented.

  20. Biological Proton Pumping in an Oscillating Electric Field

    NASA Astrophysics Data System (ADS)

    Kim, Young C.; Furchtgott, Leon A.; Hummer, Gerhard

    2009-12-01

    Time-dependent external perturbations provide powerful probes of the function of molecular machines. Here we study biological proton pumping in an oscillating electric field. The protein cytochrome c oxidase is the main energy transducer in aerobic life, converting chemical energy into an electric potential by pumping protons across a membrane. With the help of master-equation descriptions that recover the key thermodynamic and kinetic properties of this biological “fuel cell,” we show that the proton pumping efficiency and the electronic currents in steady state depend significantly on the frequency and amplitude of the applied field, allowing us to distinguish between different microscopic mechanisms of the machine. A spectral analysis reveals dominant reaction steps consistent with an electron-gated pumping mechanism.

  1. Closing the Social Class Achievement Gap for First-Generation Students in Undergraduate Biology

    ERIC Educational Resources Information Center

    Harackiewicz, Judith M.; Canning, Elizabeth A.; Tibbetts, Yoi; Giffen, Cynthia J.; Blair, Seth S.; Rouse, Douglas I.; Hyde, Janet S.

    2014-01-01

    Many students start college intending to pursue a career in the biosciences, but too many abandon this goal because they struggle in introductory biology. Interventions have been developed to close achievement gaps for underrepresented minority students and women, but no prior research has attempted to close the gap for first-generation students,…

  2. Electric and magnetic fields in medicine and biology

    SciTech Connect

    Not Available

    1985-01-01

    Papers Include: The effects of low frequency (50 Hz) magnetic fields on neuro-chemical transmission in vitro; Morphological changes in E Coli subjected to DC electrical fields; An investigation of some claimed biological effects of electromagnetic fields; Electrical phenomena and bone healing - a comparison of contemporary techniques; Clinical evaluations of a portable module emitting pulsed RF energy; The design, construction and performance of a magnetic nerve stimulator; The principle of electric field tomography and its application to selective read-out of information from peripheral nerves; Applied potential tomography - clinical applications; Impendance imaging using a linear electrode array; Mathematics as an aid to experiment: human body currents induced by power frequency electric fields; Effects of electric field near 750KV transmission line and protection against their harmful consequences; Leukemia and electromagnetic fields: a case-control study; Overhead power lines and childhood cancer; Magnetic measurement of nerve action currents - a new intraoperative recording technique; The potential use of electron spin resonance or impedance measurement to image neuronal electrical activity in the human brain.

  3. The Design of a Piezo-Electric Gauge for Closed Vessel No. 21

    DTIC Science & Technology

    1950-09-01

    purposes in the present connection, the design of Piezo-Electric gauge, employing tourmaline as the pressure-sensitive element, has closely... tourmaline . In the case of quartz it is necessary to use a piston as intermediary between the gas pressure and the pressure-sensitive element. Such...respects tourmaline is a superior material, as it is Piezo-Electrically sensitive to hydrostatic pressure and therefore does not require a piston

  4. Time constant determination for electrical equivalent of biological cells

    NASA Astrophysics Data System (ADS)

    Dubey, Ashutosh Kumar; Dutta-Gupta, Shourya; Kumar, Ravi; Tewari, Abhishek; Basu, Bikramjit

    2009-04-01

    The electric field interactions with biological cells are of significant interest in various biophysical and biomedical applications. In order to study such important aspect, it is necessary to evaluate the time constant in order to estimate the response time of living cells in the electric field (E-field). In the present study, the time constant is evaluated by considering the hypothesis of electrical analog of spherical shaped cells and assuming realistic values for capacitance and resistivity properties of cell/nuclear membrane, cytoplasm, and nucleus. In addition, the resistance of cytoplasm and nucleoplasm was computed based on simple geometrical considerations. Importantly, the analysis on the basis of first principles shows that the average values of time constant would be around 2-3 μs, assuming the theoretical capacitance values and the analytically computed resistance values. The implication of our analytical solution has been discussed in reference to the cellular adaptation processes such as atrophy/hypertrophy as well as the variation in electrical transport properties of cellular membrane/cytoplasm/nuclear membrane/nucleoplasm.

  5. Macroscopic electric field inside water-filled biological nanopores.

    PubMed

    Acosta Gutiérrez, Silvia; Bodrenko, Igor; Scorciapino, Mariano Andrea; Ceccarelli, Matteo

    2016-04-07

    Multi-drug resistance bacteria are a challenging problem of contemporary medicine. This is particularly critical for Gram-negative bacteria, where antibiotics are hindered by the outer membrane to reach internal targets. Here more polar antibiotics make use of nanometric water-filled channels to permeate inside. We present in this work a computational all-atom approach, using water as a probe, for the calculation of the macroscopic electric field inside water-filled channels. The method allows one to compare not only different systems but also the same system under different conditions, such as pH and ion concentration. This provides a detailed picture of electrostatics in biological nanopores shedding more light on how the charged residues of proteins determine the electric field inside, and also how medium can tune it. These details are central to unveil the filtering mechanism behind the permeation of small polar molecules through nanometric water-filled channels.

  6. Subcellular Biological Effects of Nanosecond Pulsed Electric Fields

    NASA Astrophysics Data System (ADS)

    Kolb, Juergen F.; Stacey, Michael

    Membranes of biological cells can be charged by exposure to pulsed electric fields. After the potential difference across the barrier reaches critical values on the order of 1 V, pores will form. For moderate pulse parameters of duration and amplitude, the effect is limited to the outer cell membrane. With the exposure to nanosecond pulses of several tens of kilovolts per centimeter, a similar effect is also expected for subcellular membranes and structures. Cells will respond to the disruption by different biochemical processes. This offers possibilities for the development of novel medical therapies, the manipulation of cells and microbiological decontamination.

  7. How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour.

    PubMed

    Kempster, Ryan M; Egeberg, Channing A; Hart, Nathan S; Ryan, Laura; Chapuis, Lucille; Kerr, Caroline C; Schmidt, Carl; Huveneers, Charlie; Gennari, Enrico; Yopak, Kara E; Meeuwig, Jessica J; Collin, Shaun P

    2016-01-01

    Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scientific studies. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with recommendations of their effectiveness. Using a modified stereo-camera system, we quantified behavioural interactions between white sharks (Carcharodon carcharias) and a baited target in the presence of a commercially available, personal electric shark deterrent (Shark Shield Freedom7™). The stereo-camera system enabled an accurate assessment of the behavioural responses of C. carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error) proximity of 131 (± 10.3) cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9) V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5) V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial when in the presence of an active Shark Shield™. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C. carcharias, and an accurate method for testing

  8. How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour

    PubMed Central

    Hart, Nathan S.; Ryan, Laura; Chapuis, Lucille; Kerr, Caroline C.; Schmidt, Carl; Huveneers, Charlie; Gennari, Enrico; Yopak, Kara E.; Meeuwig, Jessica J.; Collin, Shaun P.

    2016-01-01

    Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scientific studies. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with recommendations of their effectiveness. Using a modified stereo-camera system, we quantified behavioural interactions between white sharks (Carcharodon carcharias) and a baited target in the presence of a commercially available, personal electric shark deterrent (Shark Shield Freedom7™). The stereo-camera system enabled an accurate assessment of the behavioural responses of C. carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error) proximity of 131 (± 10.3) cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9) V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5) V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial when in the presence of an active Shark Shield™. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C. carcharias, and an accurate method for testing

  9. Interaction of biological systems with static and ELF electric and magnetic fields

    SciTech Connect

    Anderson, L.E.; Kelman, B.J.; Weigel, R.J.

    1987-01-01

    Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic field strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Delay-Dependent Response in Weakly Electric Fish under Closed-Loop Pulse Stimulation

    PubMed Central

    Forlim, Caroline Garcia; Pinto, Reynaldo Daniel; Varona, Pablo; Rodríguez, Francisco B.

    2015-01-01

    In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals. Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics. To investigate how the inter pulse intervals vary in response to external stimuli, we compare the response to a simple closed-loop stimulation protocol and the signals generated without electrical stimulation. The activity-dependent stimulation protocol explores different stimulus delivery delays relative to the fish’s own electric discharges. We show that there is a critical time delay in this closed-loop interaction, as the largest changes in inter pulse intervals occur when the stimulation delay is below 100 ms. We also discuss the implications of these findings in the context of information processing in weakly electric fish. PMID:26473597

  12. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation

    PubMed Central

    Pais-Vieira, Miguel; Yadav, Amol P.; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A. L.

    2016-01-01

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders. PMID:27605389

  13. A closed-form solution for the price of cross-commodity electricity derivatives

    NASA Astrophysics Data System (ADS)

    Tsitakis, D.; Xanthopoulos, S.; Yannacopoulos, A. N.

    2006-11-01

    We present a method for the valuation of two types of cross-commodity electricity options, European spark spread options and locational spread options. Since the underlying assets here are non-tradeable, the methodology of Black-Scholes-Merton cannot be directly applied. Nevertheless, assuming only absence of arbitrage we provide a closed-form analytic formula for the price of the derivatives in the case where the spot prices of the underlying process follow an exponential Ornstein-Uhlenbeck process.

  14. Biologically based epidemiological studies of electric power and cancer

    SciTech Connect

    Stevens, R.G.

    1993-12-01

    Use of electricity is a hallmark of the industrialization process, but there has been no suspicion that electricity could increase the risk of cancer. Recently, however, a number of epidemiologic studies have suggested that electromagnetic fields (EMF) may do just that. Although few cancer experiments have been done yet, there are a number of biological effects of EMF reported in the literature that might provide bases for designing cancer experiments and epidemiologic studies. These include effects of EMF on: (a) DNA transcription and translation, (b) calcium balance in cells, and (c) pineal production of melatonin. Alterations in DNA transcription and translation could have pleiotropic effects. Disruption of calcium homeostasis has many implications including oncogene activation, promotional activity via protein kinases and ornithine decarboxylase (ODC), and increasing oxidative stress. Reduction of melatonin suggests a possible increased risk of cancers of hormone-dependent tissues such as breast and prostate. The idea that a cancer-causing agent must either be an initiator or a promoter should be discarded; indeed, the phenomenologic meaning of these two terms has become confused with imputed mechanistic necessity in recent years. Agents that affect division of normal cells or of fully transformed cells can play an important role in clinical cancer development quite apart from initiation or promotion. Epidemiologic studies of EMF and cancer should attempt to take account of other products of electric power (e.g., light at night) or factors associated with occupational EMF exposure (e.g., toxic chemicals) that may increase cancer risk and therefore act as cofactors or confounders. Epidemiology and laboratory studies should act synergistically in determining if there is a problem and identifying mitigation strategies if needed. 84 refs., 3 figs., 1 tab.

  15. A Closed Brayton Power Conversion Unit Concept for Nuclear Electric Propulsion for Deep Space Missions

    NASA Astrophysics Data System (ADS)

    Joyner, Claude Russell; Fowler, Bruce; Matthews, John

    2003-01-01

    In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt & Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level.

  16. Prediction and identification of the magnetic field close to electric machines

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Peter J.; Ioannides, Maria G.

    1999-04-01

    The magnetic field around an electric machine operating at full load is predicted numerically and identified experimentally. A precise model of a three-phase induction machine is constructed considering the machine geometry, the windings and the stator and rotor materials. The field distribution close to the machine is determined using the discrete element technique, and actual measurements are carried out for identification purposes. An approximate human model is constructed and the magnetic field inside the human body is computed for a distance of 1 and 5 m from the machine. The magnetic field density is determined at specific points, and the induced current densities are computed.

  17. Closing the Social Class Achievement Gap for First-Generation Students in Undergraduate Biology

    PubMed Central

    Harackiewicz, Judith M.; Canning, Elizabeth A.; Tibbetts, Yoi; Giffen, Cynthia J.; Blair, Seth S.; Rouse, Douglas I.; Hyde, Janet S.

    2014-01-01

    Many students start college intending to pursue a career in the biosciences, but too many abandon this goal because they struggle in introductory biology. Interventions have been developed to close achievement gaps for underrepresented minority students and women, but no prior research has attempted to close the gap for first-generation students, a population that accounts for nearly a fifth of college students. We report a values affirmation intervention conducted with 798 U.S. students (154 first-generation) in an introductory biology course for majors. For first-generation students, values affirmation significantly improved final course grades and retention in the second course in the biology sequence, as well as overall GPA for the semester. This brief intervention narrowed the achievement gap between first-generation and continuing generation students for course grades by 50% and increased retention in a critical gateway course by 20%. Our results suggest that educators can expand the pipeline for first-generation students to continue studying in the biosciences with psychological interventions. PMID:25049437

  18. A collection of homework problems about the application of electricity and magnetism to medicine and biology

    NASA Astrophysics Data System (ADS)

    Roth, Bradley J.; Hobbie, Russell K.

    2014-05-01

    This article contains a collection of homework problems to help students learn how concepts from electricity and magnetism can be applied to topics in medicine and biology. The problems are at a level typical of an undergraduate electricity and magnetism class, covering topics such as nerve electrophysiology, transcranial magnetic stimulation, and magnetic resonance imaging. The goal of these problems is to train biology and medical students to use quantitative methods, and also to introduce physics and engineering students to biological phenomena.

  19. Electrical and Biological Effects of Transmission Lines: A Review.

    SciTech Connect

    Lee, Jack M.

    1989-06-01

    This review describes the electrical properties of a-c and d-c transmission lines and the resulting effects on plants, animals, and people. Methods used by BPA to mitigate undesirable effects are also discussed. Although much of the information in this review pertains to high-voltage transmission lines, information on distribution lines and electrical appliances is included. The electrical properties discussed are electric and magnetic fields and corona: first for alternating-current (a-c) lines, then for direct current (d-c).

  20. The Closed Equilibrated Biological Aquatic System: A 12 months Test of an Artificial Aquatic Ecosystem

    NASA Astrophysics Data System (ADS)

    Blüm, V.; Andriske, M.; Ludwig, Ch.; Paaßen, U.; Voeste, D.

    1999-01-01

    The ``Closed Equilibrated Biological Aquatic System'' (C.E.B.A.S.) is finally disposed for long-term multi-generation experiments with aquatic organisms in a space station. Therefore a minimum operation time of three month is required. It is verified in three versions of laboratory prototypes. The third one passed successfully a 12 months mid-term test in 1995/96 thus demonstrating its high biological stability. The third version of the C.E.B.A.S. consists of a 100 l animal tank, two plant cultivators with a volume of 15 l each with independent illuminations, a 3.0 l semibiological ``mechanical'' filter, a 3.0 l bacteria filter, a heating/cooling device and a dummy filter unit. The live-bearing teleost Xiphophorus helleri is the vertebrate and the pulmonate water snail Biomphalaria glabrata the invertebrate experimental animal in the system. The rootless higher water plant Ceratophyllum demersum is the producer organism. Ammonia oxidizing bacteria and other microorganisms settle in the filters. A simple data acquisition is combined with temperature and plant illumination control. Besides of the space aspects the C.E.B.A.S. proved to be an extremely suitable tool to investigate the organism and subcomponent interactions in a well defined terrestrial aquatic closed ecosystem by providing physical, chemical and biological data which allow an approach to a comprehensive system analysis. Moreover the C.E.B.A.S. is the base for the development of innovative combined animal-plant aquaculture systems for human nutrition on earth which could be implemented into bioregenerative life support systems with a higher degree of complexity suitable for lunar or planetary bases.

  1. Open and closed loop manipulation of charged microchiplets in an electric field

    SciTech Connect

    Lu, J. P. Thompson, J. D.; Whiting, G. L.; Biegelsen, D. K.; Raychaudhuri, S.; Lujan, R.; Veres, J.; Lavery, L. L.; Völkel, A. R.; Chow, E. M.

    2014-08-04

    We demonstrate the ability to orient, position, and transport microchips (“chiplets”) with electric fields. In an open-loop approach, modified four phase traveling wave potential patterns manipulate chiplets in a dielectric solution using dynamic template agitation techniques. Repeatable parallel assembly of chiplets is demonstrated to a positional accuracy of 6.5 μm using electrodes of 200 μm pitch. Chiplets with dipole surface charge patterns are used to show that orientation can be controlled by adding unique charge patterns on the chiplets. Chip path routing is also demonstrated. With a closed-loop control system approach using video feedback, dielectric, and electrophoretic forces are used to achieve positioning accuracy of better than 1 μm with 1 mm pitch driving electrodes. These chip assembly techniques have the potential to enable future printer systems where inputs are electronic chiplets and the output is a functional electronic system.

  2. The close lightning electromagnetic environment: Dart-leader electric field change versus distance

    NASA Astrophysics Data System (ADS)

    Crawford, David E.; Rakov, Vladimir A.; Uman, Martin A.; Schnetzer, George H.; Rambo, Keith J.; Stapleton, Michael V.; Fisher, Richard J.

    2001-07-01

    Net electric field changes due to dart leaders in triggered lightning from experiments conducted in 1997, 1998, and 1999 at the International Center for Lightning Research and Testing at Camp Blanding, Florida, are analyzed and compared with similar data obtained in 1993 at Camp Blanding and at Fort McClellan, Alabama. In 1997-1999 the fields were measured at 2-10 stations with distances from the lightning channel ranging from 10 to 621 m, while in 1993 the fields were measured at three distances, 30, 50, and 110 m, in Florida and at two distances, about 10 and 20 m, in Alabama. With a few exceptions, the 1997-1999 data indicate that the distance dependence of the leader electric field change is close to an inverse proportionality (r-1), in contrast to the 1993 data in which a somewhat weaker distance dependence was observed. The typically observed r-1 dependence is consistent with a uniform distribution of leader charge along the bottom kilometer or so of the channel.

  3. Prospects for Nuclear Electric Propulsion Using Closed-Cycle Magnetohydrodynamic Energy Conversion

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Bitteker, L. J.; Jones, J. E.

    2001-01-01

    Nuclear electric propulsion (NEP) has long been recognized as a major enabling technology for scientific and human exploration of the solar system, and it may conceivably form the basis of a cost-effective space transportation system suitable for space commerce. The chief technical obstacles to realizing this vision are the development of efficient, high-power (megawatt-class) electric thrusters and the development of low specific mass (less than 1 kg/kWe) power plants. Furthermore, comprehensive system analyses of multimegawatt class NEP systems are needed in order to critically assess mission capability and cost attributes. This Technical Publication addresses some of these concerns through a systematic examination of multimegawatt space power installations in which a gas-cooled nuclear reactor is used to drive a magnetohydrodynamic (MHD) generator in a closed-loop Brayton cycle. The primary motivation for considering MHD energy conversion is the ability to transfer energy out of a gas that is simply too hot for contact with any solid material. This has several intrinsic advantages including the ability to achieve high thermal efficiency and power density and the ability to reject heat at elevated temperatures. These attributes lead to a reduction in system specific mass below that obtainable with turbine-based systems, which have definite solid temperature limits for reliable operation. Here, the results of a thermodynamic cycle analysis are placed in context with a preliminary system analysis in order to converge on a design space that optimizes performance while remaining clearly within established bounds of engineering feasibility. MHD technology issues are discussed including the conceptual design of a nonequilibrium disk generator and opportunities for exploiting neutron-induced ionization mechanisms as a means of increasing electrical conductivity and enhancing performance and reliability. The results are then used to make a cursory examination of piloted

  4. A micro flow-meter for closed-loop management of biological samples.

    PubMed

    Accoto, Dino; Damiani, Francesco; Campisi, Michele; Castrataro, Piero; Campolo, Domenico; Guglielmelli, Eugenio; Dario, Paolo

    2005-01-01

    The closed-loop management of biological samples in μTAS requires proper flow-sensors to be inserted in the hydraulic path. The optimal choice between hybrid mounting and monolithic fabrication depends on several design variables, one of which is the technological compatibility between the sensor and the pumping mechanism. Monolithic integration appears to be the eligible solution if both pumps and sensors can be fabricated with the same technological process. In this paper we show that it is actually possible to fabricate a flow-sensor, based on streaming potential detection, with the same soft-lithographic process used for the fabrication of electroosmotic pumps. The device has been fabricated in PDMS and experimentally tested, showing a good linearity. Finally, its time-varying response, related to the aging of the PDMS surface, is discussed.

  5. The Martian and extraterrestrial UV radiation environment--1. Biological and closed-loop ecosystem considerations.

    PubMed

    Cockell, C S; Andrady, A L

    1999-01-01

    The Martian surface is exposed to both UVC radiation (<280 nm) and higher doses of UVB (280-315 nm) compared to the surface of the Earth. Terrestrial organisms have not evolved to cope with such high levels of UVC and UVB and thus any attempts to introduce organisms to Mars, particularly in closed-loop life support systems that use ambient sunlight, must address this problem. Here we examine the UV radiation environment of Mars with respect to biological systems. Action spectra and UV surface fluxes are used to estimate the UV stress that both DNA and chloroplasts would experience. From this vantage point it is possible to consider appropriate measures to address the problem of the Martian UV environment for future long term human exploration and settlement strategies. Some prospects for improving the UV tolerance of organisms are also discussed. Existing artificial ecosystems such as Biosphere 2 can provide some insights into design strategies pertinent to high UV environments. Some prospects for improving the UV tolerance of organisms are also discussed. The data also have implications for the establishment of closed-loop ecosystems using natural sunlight on the lunar surface and elsewhere in the Solar System.

  6. Detecting space-time alternating biological signals close to the bifurcation point.

    PubMed

    Jia, Zhiheng; Bien, Harold; Entcheva, Emilia

    2010-02-01

    Time-alternating biological signals, i.e., alternans, arise in variety of physiological states marked by dynamic instabilities, e.g., period doubling. Normally, a sequence of large-small-large transients, they can exhibit variable patterns over time and space, including spatial discordance. Capture of the early formation of such alternating regions is challenging because of the spatiotemporal similarities between noise and the small-amplitude alternating signals close to the bifurcation point. We present a new approach for automatic detection of alternating signals in large noisy spatiotemporal datasets by exploiting quantitative measures of alternans evolution, e.g., temporal persistence, and by preserving phase information. The technique specifically targets low amplitude, relatively short alternating sequences and is validated by combinatorics-derived probabilities and empirical datasets with white noise. Using high-resolution optical mapping in live cardiomyocyte networks, exhibiting calcium alternans, we reveal for the first time early fine-scale alternans, close to the noise level, which are linked to the later formation of larger regions and evolution of spatially discordant alternans. This robust method aims at quantification and better understanding of the onset of cardiac arrhythmias and can be applied to general analysis of space-time alternating signals, including the vicinity of the bifurcation point.

  7. Biological effects from electric fields associated with high voltage transmission lines

    SciTech Connect

    Not Available

    1983-11-01

    Efforts during the past year by the US Department of Energy and the Electric Power Research Institute-funded laboratories to investigate the biological effects from electric fields are described in resume form. Investigations generally have been summarized with objectives, accomplishments of the past year, and some indication of projected studies.

  8. Non-Contact Measurement of the Electrical Impedance of Biological Tissue

    DTIC Science & Technology

    2007-11-02

    NON-CONTACT MEASUREMENT OF THE ELECTRICAL IMPEDANCE OF BIOLOGICAL TISSUE C.H. Riedel and O.Dössel Institute of Biomedical Engineering, Universität...currents. Keywords—contact-free measurement, electrical im- pedance, coil systems I. Introduction The non-invasive method of measuring the impe- dance...can give information of the electrical characte- ristics of tissue. In some cases the conductivity gra- dient can be an important value. The

  9. The mathematical models of electromagnetic field dynamics and heat transfer in closed electrical contacts including Thomson effect

    NASA Astrophysics Data System (ADS)

    Kharin, Stanislav; Sarsengeldin, Merey; Kassabek, Samat

    2016-08-01

    We represent mathematical models of electromagnetic field dynamics and heat transfer in closed symmetric and asymmetric electrical contacts including Thomson effect, which are essentially nonlinear due to the dependence of thermal and electrical conductivities on temperature. Suggested solutions are based on the assumption of identity of equipotentials and isothermal surfaces, which agrees with experimental data and valid for both linear and nonlinear cases. Well known Kohlrausch temperature-potential relation is analytically justified.

  10. Methods of Using a Magnetic Field Response Sensor Within Closed, Electrically Conductive Containers

    NASA Technical Reports Server (NTRS)

    Woodward, Stanley E.; Taylor, Bryant D.

    2010-01-01

    placed outside the container. The throat is fed through the orifice in the container wall (e.g., fuel tank opening) and connects to the inductor and capacitor via electrical leads to form a closed circuit, Figure 2. Another embodiment is to have the inductor and capacitor fabricated as separate units. In this embodiment, the inductor is mounted external to the container, and the capacitor is mounted internal to the container, Figure 1. Electrical leads are fed through the orifice to connect the inductor and capacitor, Figure 2. When a container holding multiple sensors is made of a conductive material, an antenna can be placed internal to the container. An internal antenna allows all components of the sensors to reside inside the container. The antenna must be separated from the container wall s conductive surface. Additionally, the inductors must be maintained in a fixed position relative to and separated from the container

  11. The neurophysiology of human biological motion processing: a high-density electrical mapping study.

    PubMed

    Krakowski, Aaron I; Ross, Lars A; Snyder, Adam C; Sehatpour, Pejman; Kelly, Simon P; Foxe, John J

    2011-05-01

    The neural processing of biological motion (BM) is of profound experimental interest since it is often through the movement of another that we interpret their immediate intentions. Neuroimaging points to a specialized cortical network for processing biological motion. Here, high-density electrical mapping and source-analysis techniques were employed to interrogate the timing of information processing across this network. Participants viewed point-light-displays depicting standard body movements (e.g. jumping), while event-related potentials (ERPs) were recorded and compared to ERPs to scrambled motion control stimuli. In a pair of experiments, three major phases of BM-specific processing were identified: 1) The earliest phase of BM-sensitive modulation was characterized by a positive shift of the ERP between 100 and 200 ms after stimulus onset. This modulation was observed exclusively over the right hemisphere and source-analysis suggested a likely generator in close proximity to regions associated with general motion processing (KO/hMT). 2) The second phase of BM-sensitivity occurred from 200 to 350 ms, characterized by a robust negative-going ERP modulation over posterior middle temporal regions bilaterally. Source-analysis pointed to bilateral generators at or near the posterior superior temporal sulcus (STS). 3) A third phase of processing was evident only in our second experiment, where participants actively attended the BM aspect of the stimuli, and was manifest as a centro-parietal positive ERP deflection, likely related to later cognitive processes. These results point to very early sensory registration of biological motion, and highlight the interactive role of the posterior STS in analyzing the movements of other living organisms.

  12. [The influence of electric acupuncture on the closing mechanism of the female urethra in cases of stressincontinence (author's transl)].

    PubMed

    Kubista, E; Altmann, P; Kucera, H; Rudelstorfer, B

    1975-09-01

    The influence of electric acupuncture on the sphincter of the femal urethra was checked on 15 patients with stressincontinence without gross anatomic variation recognized by means of simultaneous cystourethrometry. After 30 minutes of electric stimulation through acupuncture-needles, which were placed into the skin of the lower legs and lower abdomen, a significant increase of the so-called "closing pressure" was to be found. 11 patients even showed a positive pressure. In a control collective of 15 other patients, who however did not undergo acupuncture there was only one case of slight increase of closing pressure. In addition 15 patients were given a placebo suppository, in order to eliminate as far as possible any psychical factor. In none of these cases a significant change of the closing pressure could be found. Even though the actual working manner of electric acupuncture is not understood, these experiments seem to confirm the assumption of the electric acupuncture as having a positive influence on the closing mechanism of the femal urethra.

  13. Bioinformatics and molecular biology for the quantification of closely related bacteria.

    PubMed

    Nagarajan, Karthiga; Loh, Kai-Chee; Swarup, Sanjay

    2013-07-01

    Molecular biological methods for mixed culture analysis outshine conventional culture-based techniques in terms of better sensitivity and reliability. The majority of these methods exploit the 16S rRNA sequences of the community DNA, which often fall short for the analysis of closely related microorganisms. This research details the development and validation of a comprehensive methodology to differentiate and quantitatively characterize two Pseudomonas species in a mixed culture. A bioinformatics tool based on whole-genome polymorphism comparison was used to identify marker sequences to differentiate the two bacteria using quantitative real-time PCR. The quantification of the two species was achieved through a correlation of the genomic DNA versus cell number (genomic DNA purification) and threshold cycle number versus genomic DNA (real-time PCR). Several factors including the limitation of genomic DNA purification, effects of substrate concentrations and growth phase on cellular DNA, and choice of simplex or duplex reaction for real-time PCR were considered and evaluated. The developed method was experimentally validated against synthetically constructed consortia.

  14. Signal amplification in biological and electrical engineering systems: universal role of cascades.

    PubMed

    Grubelnik, Vladimir; Dugonik, Bogdan; Osebik, Davorin; Marhl, Marko

    2009-08-01

    In this paper we compare the cascade mechanisms of signal amplification in biological and electrical engineering systems, and show that they share the capacity to considerably amplify signals, and respond to signal changes both quickly and completely, which effectively preserves the form of the input signal. For biological systems, these characteristics are crucial for efficient and reliable cellular signaling. We show that this highly-efficient biological mechanism of signal amplification that has naturally evolved is mathematically fully equivalent with some man-developed amplifiers, which indicates parallels between biological evolution and successful technology development.

  15. Blood Stage Plasmodium falciparum Exhibits Biological Responses to Direct Current Electric Fields

    PubMed Central

    Coronado, Lorena M.; Montealegre, Stephania; Chaverra, Zumara; Mojica, Luis; Espinosa, Carlos; Almanza, Alejandro; Correa, Ricardo; Stoute, José A.; Gittens, Rolando A.

    2016-01-01

    The development of resistance to insecticides by the vector of malaria and the increasingly faster appearance of resistance to antimalarial drugs by the parasite can dangerously hamper efforts to control and eradicate the disease. Alternative ways to treat this disease are urgently needed. Here we evaluate the in vitro effect of direct current (DC) capacitive coupling electrical stimulation on the biology and viability of Plasmodium falciparum. We designed a system that exposes infected erythrocytes to different capacitively coupled electric fields in order to evaluate their effect on P. falciparum. The effect on growth of the parasite, replication of DNA, mitochondrial membrane potential and level of reactive oxygen species after exposure to electric fields demonstrate that the parasite is biologically able to respond to stimuli from DC electric fields involving calcium signaling pathways. PMID:27537497

  16. Nanosecond pulsed electric fields (nsPEF) induce direct electric field effects and biological effects on human colon carcinoma cells.

    PubMed

    Hall, Emily H; Schoenbach, Karl H; Beebe, Stephen J

    2005-05-01

    Nanosecond pulsed electric fields (nsPEFs) are ultrashort pulses with high electric field intensity (kV/cm) and high power (megawatts), but low energy density (mJ/cc). To determine roles for p53 in response to nsPEFs, HCT116 cells (p53+/+ and p53-/-) were exposed to nsPEF and analyzed for membrane integrity, phosphatidylserine externalization, caspase activation, and cell survival. Decreasing plasma membrane effects were observed in both HCT116p53+/+ and p53-/- cells with decreasing pulse durations and/or decreasing electric fields. However, addition of ethidium homodimer-1 and Annexin-V-FITC post-pulse demonstrated greater fluorescence in p53-/- versus p53+/+ cells, suggesting a postpulse p53-dependent biological effect at the plasma membrane. Caspase activity was significantly higher than nonpulsed cells only in the p53-/- cells. HCT116 cells exhibited greater survival in response to nsPEFs than HL-60 and Jurkat cells, but survival was more evident for HCT116p53+/+ cells than for HCT116p53-/- cells. These results indicate that nsPEF effects on HCT116 cells include (1) apparent direct electric field effects, (2) biological effects that are p53-dependent and p53-independent, (3) actions on mechanisms that originate at the plasma membranes and at intracellular structures, and (4) an apparent p53 protective effect. NsPEF applications provide a means to explore intracellular structures and functions that can reveal mechanisms in health and disease.

  17. Combined Mechanical and Electrical Study of Polymers of Biological Origin

    NASA Astrophysics Data System (ADS)

    Zsoldos, G.; Szoda, K.; Marossy, K.

    2017-02-01

    Thermally Simulated Depolarization Current measurement is an excellent but not widely used method for identifying relaxation processes in polymers. The DMA method is used here to analyze the mechanical changes depend on temperature in biopolymers. The two techniques take advantage of the energy changes involved in the various phase transitions of certain polymer molecules. This allows for several properties of the material to be ascertained; melting points, enthalpies of melting, crystallization temperatures, glass transition temperatures and degradation temperatures. The examined biopolymer films are made from biological materials such as proteins and polysaccharides. These materials have gained wide usage in pharmaceutical, medical and food areas. The uses of biopolymer films depend on their structure and mechanical properties. This work is based on pectin and gelatin films. The films were prepared by casting. The casting technique used aqueous solutions in each case of sample preparation. The manufacturing process of the pectin and gelatin films was a single stage solving process.

  18. Measured close lightning leader-step electric-field-derivative waveforms.

    SciTech Connect

    Jordan, Doug M.; Hill, Dustin; Biagi, Christopher J.; Howard, Joseph Sean; Uman, Martin A.; Rakov, Vladimir A.

    2010-12-01

    We characterize the measured electric field-derivative (dE/dt) waveforms of lightning stepped-leader steps from three negative lightning flashes at distances of tens to hundreds of meters. Electromagnetic signatures of leader steps at such close distances have rarely been documented in previous literature. Individual leader-step three-dimensional locations are determined by a dE/dt TOA system. The leader-step field derivative is typically a bipolar pulse with a sharp initial half-cycle of the same polarity as that of the return stroke, followed by an opposite polarity overshoot that decays relatively slowly to background level. This overshoot increases in amplitude relative to the initial peak and becomes dominant as range decreases. The initial peak is often preceded by a 'slow front,' similar to the slow front that precedes the fast transition to peak in first return stroke dE/dt and E waveforms. The overall step-field waveform duration is typically less than 1 {micro}s. The mean initial peak of dE/dt, range-normalized to 100 km, is 7.4 V m{sup -1} {micro}s{sup -1} (standard deviation (S.D.), 3.7 V m{sup -1} {micro}s{sup -1}, N = 103), the mean half-peak width is 33.5 ns (S.D., 11.9 ns, N = 69), and the mean 10-to-90% risetime is 43.6 ns (S.D., 24.2 ns, N = 69). From modeling, we determine the properties of the leader step currents which produced two typical measured field derivatives, and we use one of these currents to calculate predicted leader step E and dE/dt as a function of source range and height, the results being in good agreement with our observations. The two modeled current waveforms had maximum rates of current rise-to-peak near 100 kA {micro}s{sup -1}, peak currents in the 5-7 kA range, current half-peak widths of about 300 ns, and charge transfers of {approx}3 mC. As part of the modeling, those currents were propagated upward at 1.5 x 10{sup 8} m s{sup -1}, with their amplitudes decaying exponentially with a decay height constant of 25 m.

  19. The {open_quotes}obligation to serve{close_quotes} and a competitive electric industry

    SciTech Connect

    Colton, R.D.

    1997-11-01

    This report presents an assessment of what the ``obligation to serve`` might look like in a competitive electric industry. Broadly, this research has three objectives: to define the ``duty to serve`` of a competitive electric industry; to identify those companies to whom that duty applies; and to explain how that duty protects residual classes.

  20. Method and apparatus for guiding ablative therapy of abnormal biological electrical excitation

    NASA Technical Reports Server (NTRS)

    Armoundas, Antonis A. (Inventor); Feldman, Andrew B. (Inventor); Sherman, Derin A. (Inventor); Cohen, Richard J. (Inventor)

    2001-01-01

    This invention involves method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. In particular, it is designed for treatment of cardiac arrhythmias. In the method of this invention electrical signals are acquired from passive electrodes, and an inverse dipole method is used to identify the site of origin of an arrhytmia. The location of the tip of the ablation catheter is similarly localized from signals acquired from the passive electrodes while electrical energy is delivered to the tip of the catheter. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

  1. The importance of restoration of the atmospheric electrical environment in closed bioregenerative life supporting systems

    NASA Astrophysics Data System (ADS)

    Gorgolewski, S.

    1996-01-01

    Earth based Bioregenerative Life Supporting Systems (BLSS) are subject to 4 main physical factors: gravity, light, temperature and electrical environment. The first 3 are obvious to everyone, the Electrical Environment (EE) is not under the majority of prevailing conditions perceived directly by our senses. The EE is one of the important physical factors directly influencing some plants and in a less obvious way also the majority of plants. There are only two long range forces in nature: the electromagnetic and the gravitational forces. Gravity is very much weaker than the electromagnetic forces (Fg/Fel = 10^-38, where Fg is the gravitational Force and Fel are the electromagnetic Forces. The atmospheric electric field prevails all the time over the entire Earth with a mean intensity of 130 V/m. It is therefore a potent factor which may be used by some plants exposed throughout their entire life time to the atmospheric electric field. What effect should the normal atmospheric electric field have on plants? All living plants are good electrical conductors for electrostatic fields. The plants distort the normally vertical field lines, which have to be perpendicular to the plant tissue everywhere in order to avoid the extraction of energy from the field. The meristems concentrate the field lines, thus the electrically charged nutrients are supplied to the growing parts of the plant exposed to the field. This results in electrotropism in some plants. It is very well known that plants do have adaptive capabilities as compared to animals, it is important for their survival, because they cannot run away from trouble. It is found by careful observations of the behaviour of different plants that some plants do respond to the presence of the atmospheric electric field while other plants exposed to the same environment are indifferent to the atmospheric electric field. The plants growing in the Biosphere II were shielded by the metal structure of the Biosphere II. Because

  2. Imaging of the interaction of low frequency electric fields with biological tissues by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Peña, Adrian F.; Devine, Jack; Doronin, Alexander; Meglinski, Igor

    2014-03-01

    We report the use of conventional Optical Coherence Tomography (OCT) for visualization of propagation of low frequency electric field in soft biological tissues ex vivo. To increase the overall quality of the experimental images an adaptive Wiener filtering technique has been employed. Fourier domain correlation has been subsequently applied to enhance spatial resolution of images of biological tissues influenced by low frequency electric field. Image processing has been performed on Graphics Processing Units (GPUs) utilizing Compute Unified Device Architecture (CUDA) framework in the frequencydomain. The results show that variation in voltage and frequency of the applied electric field relates exponentially to the magnitude of its influence on biological tissue. The magnitude of influence is about twice more for fresh tissue samples in comparison to non-fresh ones. The obtained results suggest that OCT can be used for observation and quantitative evaluation of the electro-kinetic changes in biological tissues under different physiological conditions, functional electrical stimulation, and potentially can be used non-invasively for food quality control.

  3. Rectification and signal averaging of weak electric fields by biological cells.

    PubMed Central

    Astumian, R D; Weaver, J C; Adair, R K

    1995-01-01

    Oscillating electric fields can be rectified by proteins in cell membranes to give rise to a dc transport of a substance across the membrane or a net conversion of a substrate to a product. This provides a basis for signal averaging and may be important for understanding the effects of weak extremely low frequency (ELF) electric fields on cellular systems. We consider the limits imposed by thermal and "excess" biological noise on the magnitude and exposure duration of such electric field-induced membrane activity. Under certain circumstances, the excess noise leads to an increase in the signal-to-noise ratio in a manner similar to processes labeled "stochastic resonance." Numerical results indicate that it is difficult to reconcile biological effects with low field strengths. PMID:7731976

  4. On the inversion of polarity of the electric field at very close range from a tower struck by lightning

    NASA Astrophysics Data System (ADS)

    Mosaddeghi, A.; Pavanello, D.; Rachidi, F.; Rubinstein, M.

    2007-10-01

    In this paper, we show that the electric field generated by a lightning return stroke to a tall structure can change polarity at very close distance range, typically at distances of about one tenth the height or so of the struck object. This change in the polarity seems to be a specific signature of the very close vertical electric field. Two different theoretical explanations of such an inversion of polarity are given, the first based on general field equations for a perfectly conducting ground and the second based on the equation derived by Baba and Rakov (2005a) for the case when the return stroke wavefront speed is assumed to be equal to the speed of light and the reflection coefficient at the top of the tall structure is zero. A simple equation is derived which provides an estimate of the critical distance below which such an inversion of polarity might occur. It is also shown that the inversion of polarity depends on the value of the reflection coefficient at the base of the tower and disappears for reflection coefficients close to 1. On the other hand, other parameters such as the return stroke speed, the reflection coefficient at the top of the strike object, and the adopted return stroke model seem not to have an impact on the inversion of polarity. The need of obtaining experimental data on electromagnetic fields at very close range to a tower struck by lightning is emphasized in order to confirm the theoretical finding.

  5. Theoretical analysis of AC electric field transmission into biological tissue through frozen saline for electroporation.

    PubMed

    Xiao, Chunyan; Rubinsky, Boris

    2014-12-01

    An analytical model was used to explore the feasibility of sinusoidal electric field transmission across a frozen saline layer into biological tissue. The study is relevant to electroporation and permeabilization of the cell membrane by electric fields. The concept was analyzed for frequencies in the range of conventional electroporation frequencies and electric field intensity. Theoretical analysis for a variety of tissues show that the transmission of electroporation type electric fields through a layer of frozen saline into tissue is feasible and the behavior of this composite system depends on tissue type, frozen domain temperature, and frequency. Freezing could become a valuable method for adherence of electroporation electrodes to moving tissue surfaces, such as the heart in the treatment of atrial fibrillation or blood vessels for the treatment of restenosis.

  6. Electricity-producing heating apparatus utilizing a turbine generator in a semi-closed brayton cycle

    DOEpatents

    Labinov, Solomon D.; Christian, Jeffrey E.

    2003-10-07

    The present invention provides apparatus and methods for producing both heat and electrical energy by burning fuels in a stove or boiler using a novel arrangement of a surface heat exchanger and microturbine-powered generator and novel surface heat exchanger. The equipment is particularly suited for use in rural and relatively undeveloped areas, especially in cold regions and highlands.

  7. Impact of electric field from a plasma jet on biological targets

    NASA Astrophysics Data System (ADS)

    Douat, Claire; Darny, Thibault; Iseni, Sylvain; Damany, Xavier; Dozias, Sebastien; Pouvesle, Jean-Michel; Robert, Eric; Vijayarangan, Vinodini; Delalande, Anthony; Pichon, Chantal

    2016-09-01

    Atmospheric pressure plasma jets have demonstrated their ability in biomedical applications thanks to their low gas temperature and their capacity to produce radicals, ions, electrons, UV radiation and electric fields. However the understanding of the interactions between the plasma and living cells and tissues is still far from being completely understood. Recently, Robert et al characterized two components of the electric field from a plasma jet and showed that the latter can propagate deeply in tissues on several mm. In this work, we focus on the study of the electric field induced by the plasma and its influence on the cell membrane. Propidium iodide, dextran sulfate and plasmid DNA are used to measure the permeability of the membrane, while an electro-optic probe is used to measure the longitudinal and the radial components of the electric field. The two components are both spatially and temporally resolved. To investigate the contribution of the electric field on the cell membrane, a dielectric barrier is used between the plasma and the biological target. A comparison with and without the barrier will be presented for both biological and agriculture applications.

  8. [Clinical evaluation of Engström's electrically controlled ELSA for low flow closed circuit anesthesia].

    PubMed

    Igarashi, M; Nakae, Y; Ichimiya, N; Watanabe, H; Iwasaki, H; Namiki, A

    1993-02-01

    Many anesthesiologists are now interested in low flow, closed circuit anesthesia from an economical and environmental point of view. In order to evaluate clinically a newly developed electronically controlled anesthesia machine Engström's ELSA, we compared low flow, closed circuit anesthesia on 38 ASA I-II patients using ELSA, with high flow anesthesia on 12 ASA I-II patients using a conventional anesthesia machine. The results were as follows; 1. We could perform safe and economical low flow, closed circuit anesthesia using ELSA's injection vaporizer and accurate monitoring devices for O2, N2O, CO2 and concentrations of various volatile anesthetic agents. 2. Under low flow anesthesia, isoflurane consumption was 5.3 +/- 1.1 ml.h-1 x Vol.%-1 (mean +/- SE) with ELSA, which is about one fourth of the high flow anesthesia consumption (22.6 +/- 2.1 ml.h-1 x Vol.%-1 (mean +/- SE). 3. Low flow closed circuit anesthesia could maintain significantly higher temperature and humidity compared with high flow anesthesia. 4. Under low flow anesthesia of more than 7hrs, color of soda lime becomes blue, but this does not affect FIO2 nor PaCO2, and the method is clinically safe for patients.

  9. Biological effects of electrical or magnetic field application. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    1995-03-01

    The bibliography contains citations concerning the electrical and magnetic field effects on biological materials. Citations discuss effects on cell structures, electromagnetic penetration into biological tissues, induced currents in humans, implantable stimulators, artificial muscles, genetic engineering, and neural activity. Studies of biological effects of electrical and magnetic field applications in biomedical engineering and health care are included. (Contains a minimum of 97 citations and includes a subject term index and title list.)

  10. Biological, physical, and electrical parameters for in vitro studies with ELF magnetic and electric fields: A primer

    SciTech Connect

    Misakian, M.; Sheppard, A.R.; Krause, D.; Frazier, M.E.; Miller, D.L. )

    1993-01-01

    This paper presents material which is intended to assist researchers in identifying and controlling a range of biological, electrical, and other physical parameters that can affect the outcome of in vitro studies with extremely low frequency (ELF) magnetic and electric fields. Brief descriptions of power line magnetic and electric fields are provided and methods for the generation of 60 Hz as well as other ELF fields in the laboratory are surveyed. Methods for calculating and measuring exposure parameters in culture medium are also described. Relating in vitro and internal in vivo exposure conditions across different animal species is discussed to aid researchers in selecting levels of field exposure. The text is purposely elementary, and sometimes brief, with references provided to aid the interested reader in obtaining a fuller understanding of the many topics. Because the range of experimental parameters that can influence the outcome of in vitro studies with ELF fields is so broad, a multidisciplinary approach is normally required to carry out the research. 113 refs.

  11. Selection of a closed Brayton cycle gas turbine for an intermediate-duty solar-electric power plant

    NASA Astrophysics Data System (ADS)

    Vieth, G. L.; Plummer, D. F.

    1980-03-01

    Subsystem and system analyses were performed to select the preferred working gas, performance characteristics and size of a closed cycle gas turbine for an intermediate-duty solar-electric power plant. Capital costs for all major subsystems were evaluated, but the principal selection criterion was the projected cost of electricity produced by the plant. Detailed analyses of the power conversion loop were conducted for both air and helium systems. Since the plant was intended for use on an intermediate-duty cycle, thermal storage was required. The coupling of the storage and power conversion loops in combination with the daily operating cycle influenced plant performance and energy costs in addition to the selection of the power conversion cycle.

  12. Inverted Pendulum Standing Apparatus for Investigating Closed-Loop Control of Ankle Joint Muscle Contractions during Functional Electrical Stimulation.

    PubMed

    Tan, John F; Masani, Kei; Vette, Albert H; Zariffa, José; Robinson, Mark; Lynch, Cheryl; Popovic, Milos R

    2014-01-01

    The restoration of arm-free standing in individuals with paraplegia can be facilitated via functional electrical stimulation (FES). In developing adequate control strategies for FES systems, it remains challenging to test the performance of a particular control scheme on human subjects. In this study, we propose a testing platform for developing effective control strategies for a closed-loop FES system for standing. The Inverted Pendulum Standing Apparatus (IPSA) is a mechanical inverted pendulum, whose angular position is determined by the subject's ankle joint angle as controlled by the FES system while having the subject's body fixed in a standing frame. This approach provides a setup that is safe, prevents falling, and enables a research and design team to rigorously test various closed-loop controlled FES systems applied to the ankle joints. To demonstrate the feasibility of using the IPSA, we conducted a case series that employed the device for studying FES closed-loop controllers for regulating ankle joint kinematics during standing. The utilized FES system stimulated, in able-bodied volunteers, the plantarflexors as they prevent toppling during standing. Four different conditions were compared, and we were able to show unique performance of each condition using the IPSA. We concluded that the IPSA is a useful tool for developing and testing closed-loop controlled FES systems for regulating ankle joint position during standing.

  13. Muscle enhancement using closed-loop electrical stimulation: volitional versus induced torque.

    PubMed

    Langzam, E; Nemirovsky, Y; Isakov, E; Mizrahi, J

    2007-06-01

    In cases of partial deficiency of muscle activation capacity, force augmentation can be achieved by hybrid activation, i.e., by combining electrical stimulation (ES) with volitional activation. In this activation modality the shares of the volitional and induced torques within the overall hybrid torque are unknown. The purpose of this study was to suggest a computational approach to parcel out the volitional and stimulation induced components of joint torque generated during combined voluntary and electrical activation of the Tibialis Anterior muscle (TA). For this purpose, isometric contraction of the TA was studied on 5 healthy subjects, using an activation protocol involving ES alone, volitional activation alone and hybrid activation. Ankle torque and TA EMG were measured. A computational algorithm was developed to dissociate the volitional from the overall torque, based on EMG filtering and on pre-measured calibration curves of volitional torque versus EMG. The results indicated that for a certain hybrid torque there is a linear decaying relationship between the induced torque and the volitional torque shares. Moreover, based on a defined enhancement ratio, the results indicate that within the range of stimulation intensities, there exist regions of increased facilitation, in which the stimulation efficiency is higher under combined compared to isolated conditions.

  14. Animal protein production modules in biological life support systems: Novel combined aquaculture techniques based on the closed equilibrated biological aquatic system (C.E.B.A.S.)

    NASA Astrophysics Data System (ADS)

    Blüm, V.; Andriske, M.; Kreuzberg, K.; Schreibman, M. P.

    Based on the experiences made with the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) which was primarily deveoloped for long-term and multi-generation experiments with aquatic animals and plants in a space station highly effective fresh water recycling modules were elaborated utilizing a combination of ammonia oxidizing bacteria filters and higher plants. These exhibit a high effectivity to eliminate phosphate and anorganic nitrogen compounds and arc. in addidition. able to contribute to the oxygen supply of the aquatic animals. The C.E.B.A.S. filter system is able to keep a closed artificial aquatic ecosystem containing teleost fishes and water snails biologically stable for several month and to eliminate waste products deriving from degraded dead fishes without a decrease of the oxygen concentration down to less than 3.5 mg/l at 25 °C. More advanced C.E.B.A.S. filter systems, the BIOCURE filters, were also developed for utilization in semiintensive and intensive aquaculture systems for fishes. In fact such combined animal-plant aquaculture systems represent highly effective productions sites for human food if proper plant and fish species are selected The present papers elucidates ways to novel aquaculture systems in which herbivorous fishes are raised by feeding them with plant biomass produced in the BIOCURE filters and presents the scheme of a modification which utilizes a plant species suitable also for human nutrition. Special attention is paid to the benefits of closed aquaculture system modules which may be integrated into bioregenerative life support systems of a higher complexity for, e. g.. lunar or planetary bases including some psychologiccal aspects of the introduction of animal protein production into plant-based life support systems. Moreover, the basic reproductive biological problems of aquatic animal breeding under reduced gravity are explained leading to a disposition of essential research programs in this context.

  15. Electrically induced reorganization phenomena of liquid metal film printed on biological skin

    NASA Astrophysics Data System (ADS)

    Guo, Cangran; Yi, Liting; Yu, Yang; Liu, Jing

    2016-12-01

    Liquid metal has been demonstrated to be directly printable on biological skin as physiological measurement elements. However, many fundamental issues remained unclear so far. Here, we disclosed an intriguing phenomenon of electrically induced reorganization of liquid metal film. According to the experiments, when applying an external electric field to liquid metal films which were spray printed on biological skin, it would induce unexpected transformations of the liquid metals among different morphologies and configurations. These include shape shift from a large liquid metal film into a tiny sphere and contraction of liquid metal pool into spherical one. For comprehensively understanding the issues, the impacts of the size, voltage, orientations of the liquid metal electrodes, etc., were clarified. Further, effects of various substrates such as in vitro skin and in vivo skin affecting the liquid metal transformations were experimentally investigated. Compared to the intact tissues, the contraction magnitude of the liquid metal electrode appears weaker on in vivo skin of nude mice under the same electric field. The mechanisms lying behind such phenomena were interpreted through theoretical modeling. Lastly, typical applications of applying the current effect into practical elements such as electrical gating devices were also illustrated as an example. The present findings have both fundamental and practical values, which would help design future technical strategies in fabricating electronically controlled liquid metal electronics on skin.

  16. Biological and Agricultural Studies on Application of Discharge Plasma and Electromagnetic Fields 5. Effects of High Electric Fields on Animals

    NASA Astrophysics Data System (ADS)

    Isaka, Katsuo

    The biological effects of extremely low frequency electric fields on animals are reviewed with emphasis on studies of the nervous system, behavior, endocrinology, and blood chemistry. First, this paper provides a histrical overview of studies on the electric field effects initiated in Russia and the United States mainly regarding electric utility workers in high voltage substations and transmission lines. Then, the possible mechanisms of electric field effects are explained using the functions of surface electric fields and induced currents in biological objects. The real mechanisms have not yet been identified. The thresholds of electric field perception levels for rats, baboons, and humans are introduced and compared. The experimental results concerning the depression of melatonin secretion in rats exposed to electric fields are described.

  17. Monte Carlo simulations of the electric field close to the body in realistic environments for application in personal radiofrequency dosimetry.

    PubMed

    Iskra, S; McKenzie, R; Cosic, I

    2011-11-01

    Personal dosemeters can play an important role in epidemiological studies and in radiofrequency safety programmes. In this study, a Monte Carlo approach is used in conjunction with the finite difference time domain method to obtain distributions of the electric field strength close to a human body model in simulated realistic environments. The field is a proxy for the response of an ideal body-worn electric field dosemeter. A set of eight environments were modelled based on the statistics of Rayleigh, Rice and log-normal fading to simulate outdoor and indoor multipath exposures at 450, 900 and 2100 MHz. Results indicate that a dosemeter mounted randomly within 10-50 mm of the adult or child body model (torso region) will on average underestimate the spatially averaged value of the incident electric field strength by a factor of 0.52 to 0.74 over the frequencies of 450, 900 and 2100 MHz. The uncertainty in results, assessed at the 95 % confidence level (between the 2.5th and 97.5th percentiles) was largest at 2100 MHz and smallest at 450 MHz.

  18. Charge injection through nanocomposite electrode in microfluidic channel for electrical lysis of biological cells

    NASA Astrophysics Data System (ADS)

    Mishra, Madhusmita; Krishna, Anil; Chandra, Aman; Shenoy, B. M.; Hegde, G. M.; Mahapatra, D. Roy

    2013-03-01

    Several concepts have been developed in the recent years for nanomaterial based integrated MEMS platform in order to accelerate the process of biological sample preparation followed by selective screening and identification of target molecules. In this context, there exist several challenges which need to be addressed in the process of electrical lysis of biological cells. These are due to (i) low resource settings while achieving maximal lysis (ii) high throughput of target molecules to be detected (iii) automated extraction and purification of relevant molecules such as DNA and protein from extremely small volume of sample (iv) requirement of fast, accurate and yet scalable methods (v) multifunctionality toward process monitoring and (vi) downward compatibility with already existing diagnostic protocols. This paper reports on the optimization of electrical lysis process based on various different nanocomposite coated electrodes placed in a microfluidic channel. The nanocomposites are synthesized using different nanomaterials like Zinc nanorod dispersion in polymer. The efficiency of electrical lysis with various different electrode coatings has been experimentally verified in terms of DNA concentration, amplification and protein yield. The influence of the coating thickness on the injection current densities has been analyzed. We further correlate experimentally the current density vs. voltage relationship with the extent of bacterial cell lysis. A coupled multiphysics based simulation model is used to predict the cell trajectories and lysis efficiencies under various electrode boundary conditions as estimated from experimental results. Detailed in-situ fluorescence imaging and spectroscopy studies are performed to validate various hypotheses.

  19. Imaging electric properties of biological tissues by RF field mapping in MRI.

    PubMed

    Zhang, Xiaotong; Zhu, Shanan; He, Bin

    2010-02-01

    The electric properties (EPs) of biological tissue, i.e., the electric conductivity and permittivity, can provide important information in the diagnosis of various diseases. The EPs also play an important role in specific absorption rate calculation, a major concern in high-field MRI, as well as in nonmedical areas such as wireless telecommunications. The high-field MRI system is accompanied by significant wave propagation effects, and the RF radiation is dependent on the EPs of biological tissue. On the basis of the measurement of the active transverse magnetic component of the applied RF field (known as B(1)-mapping technique), we propose a dual-excitation algorithm, which uses two sets of measured B(1) data to noninvasively reconstruct the EPs of biological tissues. The finite-element method was utilized in 3-D modeling and B(1) field calculation. A series of computer simulations were conducted to evaluate the feasibility and performance of the proposed method on a 3-D head model within a TEM coil and a birdcage coil. Using a TEM coil, when noise free, the reconstructed EP distribution of tissues in the brain has relative errors of 12%-28% and correlated coefficients of greater than 0.91. Compared with other B(1)-mapping-based reconstruction algorithms, our approach provides superior performance without the need for iterative computations. The present simulation results suggest that good reconstruction of EPs from B1 mapping can be achieved.

  20. Rhipicephalus sanguineus and R. turanicus (Acari:Ixodidae): closely related species with different biological characteristics.

    PubMed

    Ioffe-Uspensky, I; Mumcuoglu, K Y; Uspensky, I; Galun, R

    1997-01-01

    Life cycle parameters of 2 closely related tick species, Rhipicephalus sanguineus Latreille and R. turanicus Pomerantsev, were studied under laboratory conditions. Both Rhipicephalus, which have small adults, demonstrated the same adaptations as large tick species inhabiting deserts and semideserts: high reproductive rate, decrease in egg size, and an increase in interstage growth to compensate for the smaller size at birth. Pronounced quantitative differences between both species were discerned in relation to these adaptations. Female R. turanicus produced twice as many eggs as R. sanguineus which was facilitated by the greater amount of blood engorged by females and by the smaller egg weight in R. turanicus as compared with R. sanguineus. In all developmental stages, the weight increase from unfed to fed ticks was greater in R. turanicus than in R. sanguineus (23% higher in larvae, 118% in nymphs, and 26% in females). The increase in weight in R. turanicus from the unfed larva (0.013 mg) to the unfed female (3.31 mg) was 254-fold, and in R. sanguineus it was 127-fold (from 0.021 to 2.54 mg). In nymphal R. turanicus, the higher density and the greater height of the dorsal epicuticular folds, as well as procuticular indentations found inside the folds allow this tick to stretch its alloscutum during blood engorgement to a greater extent than R. sanguineus. The rates of blood ingestion (for nymphs and females), egg maturation, and metamorphosis were 1.1-1.7 times greater in R. turanicus than in R. sanguineus. A life cycle strategy with both a higher reproductive rate and faster development in R turanicus may be explained by its greater dependence on environmental factors than that in R. sanguineus.

  1. Biological effects of ELF (extremely-low-frequency) electric and magnetic fields

    SciTech Connect

    Anderson, L.E.

    1989-10-01

    Studies have been conducted at the Pacific Northwest Laboratory to examine extremely-low-frequency (ELF) electromagnetic fields for possible biological effects in animals. Two areas of investigation are reported here: (1) studies on the nervous system, including behavior and neuroendocrine function, and (2) experiments on cancer development in animals. In behavioral experiments, preliminary data suggest that short term memory may be affected in albino rats exposed to combined ELF and static magnetic fields. Neuroendocrine studies were conducted to demonstrate an apparent stress-related response in rats exposed to 60-Hz electric fields. Finally, using a chemically-induced mammary tumor model, experiments were conducted in which rats, chronically exposed to 60-Hz electric fields, showed an enhancement in the number of tumors per tumor bearing animal.

  2. [Modeling and experimental study on frequency-domain electricity properties of biological materials].

    PubMed

    Tian, Hua; Luo, Shiqiang; Zhang, Rui; Yang, Gang; Huang, Hua

    2009-12-01

    Frequency-domain electricity properties of four objects, including bullfrog skin, bullfrog muscle, triply distilled water and 0.9% NaCl, were tested in the range of 100Hz-10MHz using home-made electrode and measuring system. The experimental results showed that the resistance of 0.9% NaCl decreased dramatically, that the amplitude frequency characteristics of bullfrog's muscle and skin were similar, but that of triply distilled water did not change significantly. The frequency dependence of 0.9% NaCl showed that the electrode had great influence on the measuring system, so a new equivalent circuit model based on the electrode system was needed. These findings suggest that the new five-parameter equivalent circuit model, which embodies considerations on the interaction between electrodes and tissues, is a reasonable equivalent circuit for studying the electrical characteristics of biological materials.

  3. Solar electric and thermal conversion system in close proximity to the consumer. [solar panels on house roofs

    NASA Technical Reports Server (NTRS)

    Boeer, K. W.

    1975-01-01

    Solar cells may be used to convert sunlight directly into electrical energy and into lowgrade heat to be used for large-scale terrestrial solar-energy conversion. Both forms of energy can be utilized if such cells are deployed in close proximity to the consumer (rooftop). Cadmium-sulfide/copper-sulfide (CdS/Cu2S) solar cells are an example of cells which may be produced inexpensively enough to become economically attractive. Cell parameters relevant for combined solar conversion are presented. Critical issues, such as production yield, life expectancy, and stability of performance, are discussed. Systems-design parameters related to operating temperatures are analyzed. First results obtained on Solar One, the experimental house of the University of Delaware, are given. Economic aspects are discussed. Different modes of operation are discussed in respect to the power utility and consumer incentives.

  4. Biological effects of electrical- or magnetic-field application. (Latest citations from the Life Sciences Collection data base). Published Search

    SciTech Connect

    Not Available

    1992-09-01

    The bibliography contains citations concerning the application of electrical or magnetic fields to organisms. Changes in cell structure, cell shape, metabolism, mitosis, cell orientation, neuron response, germination response, and growth rates are discussed. The citations also examine the effects of electrical or magnetic field exposure from transmission lines. Biological applications of electric field cited include genetic transfer, plant cell fusion, and seed disinfection. (Contains 250 citations and includes a subject term index and title list.)

  5. On The Construction of Models for Electrical Conduction in Biological Tissues

    SciTech Connect

    Gomez-Aguilar, F.; Bernal-Alvarado, J.; Cordova-Fraga, T.; Rosales-Garcia, J.; Guia-Calderon, M.

    2010-12-07

    Applying RC circuit theory, a theoretical representation for the electrical conduction in a biological multilayer system was developed. In particular an equivalent circuit for the epidermis, dermis and the subcutaneous tissue was constructed. This model includes an equivalent circuit, inside the dermis, in order to model a small formation like tumor. This work shows the feasibility to apply superficial electrodes to detect subcutaneous abnormalities. The behavior of the model is shown in the form of a frequency response chart. The Bode and Nyquist plots are also obtained. This theoretical frame is proposed to be a general treatment to describe the bioelectrical transport in a three layer bioelectrical system.

  6. On The Construction of Models for Electrical Conduction in Biological Tissues

    NASA Astrophysics Data System (ADS)

    Gómez-Aguilar, F.; Bernal-Alvarado, J.; Cordova-Fraga, T.; Rosales-García, J.; Guía-Calderón, M.

    2010-12-01

    Applying RC circuit theory, a theoretical representation for the electrical conduction in a biological multilayer system was developed. In particular an equivalent circuit for the epidermis, dermis and the subcutaneous tissue was constructed. This model includes an equivalent circuit, inside the dermis, in order to model a small formation like tumor. This work shows the feasibility to apply superficial electrodes to detect subcutaneous abnormalities. The behavior of the model is shown in the form of a frequency response chart. The Bode and Nyquist plots are also obtained. This theoretical frame is proposed to be a general treatment to describe the bioelectrical transport in a three layer bioelectrical system.

  7. Biological effects of static electric field: Plasma/serum proteome analysis of rats.

    PubMed

    Harutyunyan, Hayk; Artsruni, Gagik

    2013-03-01

    The external static electric field (SEF) of man-made origin brings to the substantially increased SEF background in a human environment the biological activity of which is a moot question. The paper reports on rats blood plasma/serum proteome modifications by means of 1D polyacrilamide gel electrophoresis and clotting process alterations after the short- and long-term SEF exposures of 200 kV/m. The results indicate decrease of fast α1 and α2 globular proteins in plasma coinciding with clotting acceleration after the short-term SEF, and attenuation of clotting-dependent proteome modifications reflected with incomplete coagulation after the long-term SEF exposure. Increased lysozyme activity in serum unlike plasma was observed after both SEF exposures. Applied model of the high-voltage SEF environment indicates dependence of biological systems functioning on the external SEF.

  8. Modeling environment for numerical simulation of applied electric fields on biological cells.

    PubMed

    Suzuki, Daniela Ota Hisayasu; Ramos, Airton; Marques, Jefferson Luiz Brum

    2007-01-01

    The application of electric pulses in cells increases membrane permeability. This phenomenon is called electroporation. Current electroporation models do not explain all experimental findings: part of this problem is due to the limitations of numerical methods. The Equivalent Circuit Method (ECM) was developed in an attempt to solve electromagnetic problems in inhomogeneous and anisotropic media. ECM is based on modeling of the electrical transport properties of the medium by lumped circuit elements as capacitance, conductance, and current sources, representing the displacement, drift, and diffusion current, respectively. The purpose of the present study was to implement a 2-D cell Model Development Environment (MDE) of ionic transport process, local anisotropy around cell membranes, biological interfaces, and the dispersive behaviour of tissues. We present simulations of a single cell, skeletal muscle, and polygonal cell arrangement. Simulation of polygonal form indicates that the potential distribution depends on the geometrical form of cell. The results demonstrate the importance of the potential distributions in biological cells to provide strong evidences for the understanding of electroporation.

  9. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 6: Closed-cycle gas turbine systems. [energy conversion efficiency in electric power plants

    NASA Technical Reports Server (NTRS)

    Amos, D. J.; Fentress, W. K.; Stahl, W. F.

    1976-01-01

    Both recuperated and bottomed closed cycle gas turbine systems in electric power plants were studied. All systems used a pressurizing gas turbine coupled with a pressurized furnace to heat the helium for the closed cycle gas turbine. Steam and organic vapors are used as Rankine bottoming fluids. Although plant efficiencies of over 40% are calculated for some plants, the resultant cost of electricity was found to be 8.75 mills/MJ (31.5 mills/kWh). These plants do not appear practical for coal or oil fired plants.

  10. Property-close source separation of hazardous waste and waste electrical and electronic equipment--a Swedish case study.

    PubMed

    Bernstad, Anna; la Cour Jansen, Jes; Aspegren, Henrik

    2011-03-01

    Through an agreement with EEE producers, Swedish municipalities are responsible for collection of hazardous waste and waste electrical and electronic equipment (WEEE). In most Swedish municipalities, collection of these waste fractions is concentrated to waste recycling centres where households can source-separate and deposit hazardous waste and WEEE free of charge. However, the centres are often located on the outskirts of city centres and cars are needed in order to use the facilities in most cases. A full-scale experiment was performed in a residential area in southern Sweden to evaluate effects of a system for property-close source separation of hazardous waste and WEEE. After the system was introduced, results show a clear reduction in the amount of hazardous waste and WEEE disposed of incorrectly amongst residual waste or dry recyclables. The systems resulted in a source separation ratio of 70 wt% for hazardous waste and 76 wt% in the case of WEEE. Results show that households in the study area were willing to increase source separation of hazardous waste and WEEE when accessibility was improved and that this and similar collection systems can play an important role in building up increasingly sustainable solid waste management systems.

  11. Spectral, electrical conductivity and biological activity properties of some new azopyrimidine derivatives and their complexes.

    PubMed

    Masoud, Mamdouh S; Khalil, Ekram A; Ramadan, Ahmed M; Gohar, Yousry M; Sweyllam, Amr

    2007-07-01

    The electronic absorption spectra of 5-(o-substituted phenylazo)-6-amino-2-thiouracils and 6-(o-substituted phenylazo)-5-aminouracils containing different substituents are studied at different pH's. The dissociation constants are evaluated and discussed. Phenomenon of tautomerism is more supported by (1)H NMR and (13)C NMR spectra. The electrical conductivity of some ligands and their Co(II), Ni(II) and Cu(II) complexes in the temperature range 293-150K favoured their semiconducting properties where the metal ion forms a bridge to facilitate the flow of the current. The biological activity of some ligands and their complexes are tested against a number of Gram-positive and Gram-negative bacteria. The results showed that some of the compounds have a well considerable activity against some of the organisms.

  12. Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Barai, A.; Watson, S.; Griffiths, H.; Patz, R.

    2012-08-01

    Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode-sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50-400 g l-1) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m-1 at 200 kHz, improving to 0.01 S m-1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality.

  13. Homogenization limit for electrical conduction in biological tissues in the radio-frequency range

    NASA Astrophysics Data System (ADS)

    Amar, Micol; Andreucci, Daniele; Bisegna, Paolo; Gianni, Roberto

    2003-07-01

    We study an evolutive model for electrical conduction in biological tissues, where the conductive intra-cellular and extracellular spaces are separated by insulating cell membranes. The mathematical scheme is an elliptic problem, with dynamical boundary conditions on the cell membranes. The problem is set in a finely mixed periodic medium. We show that the homogenization limit u0 of the electric potential, obtained as the period of the microscopic structure approaches zero, solves the equation - div(σ 0∇ xu 0+A 0∇ xu 0+∫ 0tA 1(t-τ)∇ xu 0(x,τ) dτ- F(x,t))=0 where σ0>0 and the matrices A0, A1 depend on geometric and material properties, while the vector function F keeps trace of the initial data of the original problem. Memory effects explicitly appear here, making this elliptic equation of non standard type. To cite this article: M. Amar et al., C. R. Mecanique 331 (2003).

  14. Biological effects of 60-Hz electric fields on small and large laboratory animals

    SciTech Connect

    Phillips, R.D.

    1981-01-01

    Rats and mice were exposed to 60-Hz electric fields up to 330 kV/m for durations as long as four months. No significant effects were found in the following major areas: metabolic status and growth; organ and tissue morphology; brain morphology; cardiovascular function; serum chemistry; reproduction; prenatal growth and development; teratology; bone growth; peripheral nerve function; humoral and cell-mediated immunity; susceptibility to viral infection; cell and membrane function; illness/malaise; and cytogenetics. Statistically significant effects of electric field exposures were observed in the following areas: bone fracture repair; neonatal development; neuromuscular function; endocrinology; hematology; neurochemistry; urine volume and chemistry; sympathetic nervous system; behavior. It is likely that many of the effects observed are secondary to chronic stimulation of the animal by the field. Our research efforts have shifted to an in-depth investigation of nervous system functions, with emphasis in behavior, neurochemistry, neurophysiology, and dosimetry. Current and future research in these areas will focus on: relationship of effects to field strength and duration of exposure; recovery from observed effects; fundamental understanding of observed effects; fundamental understanding of interaction of field with animal (dosimetry); and biological significance of observed effects. (ERB)

  15. Biological effects due to weak electric and magnetic fields: the temperature variation threshold.

    PubMed Central

    Weaver, J C; Vaughan, T E; Martin, G T

    1999-01-01

    A large number of epidemiological and experimental studies suggest that prolonged (>100 s) weak 50-60-Hz electric and magnetic field (EMF) exposures may cause biological effects(NIEHS Working Group, NIH, 1998; Bersani, 1999). We show, however, that for typical temperature sensitivities of biochemical processes, realistic temperature variations during long exposures raise the threshold exposure by two to three orders of magnitude over a fundamental value, independent of the biophysical coupling mechanism. Temperature variations have been omitted in previous theoretical analyses of possible weak field effects, particularly stochastic resonance (Bezrukov and Vodyanoy 1997a. Nature. 385:319-321; Astumian et al., 1997 Nature. 338:632-633; Bezrukov and Vodyanoy, 1997b. Nature. 338:663; Dykman and McClintock, 1998. Nature. 391:344; McClintock, 1998;. Gammaitoni et al., 1998. Rev. Mod. Phys. 70:223-287). Although sensory systems usually respond to much shorter (approximately 1 s) exposures and can approach fundamental limits (Bialek, 1987 Annu. Rev. Biophys. Biophys. Chem. 16:455-468; Adair et al, 1998. Chaos. 8:576-587), our results significantly decrease the plausibility of effects for nonsensory biological systems due to prolonged, weak-field exposures. PMID:10354428

  16. A New Imaging Platform for Visualizing Biological Effects of Non-Invasive Radiofrequency Electric-Field Cancer Hyperthermia

    PubMed Central

    Corr, Stuart J.; Shamsudeen, Sabeel; Vergara, Leoncio A.; Ho, Jason Chak-Shing; Ware, Matthew J.; Keshishian, Vazrik; Yokoi, Kenji; Savage, David J.; Meraz, Ismail M.; Kaluarachchi, Warna; Cisneros, Brandon T.; Raoof, Mustafa; Nguyen, Duy Trac; Zhang, Yingchun; Wilson, Lon J.; Summers, Huw; Rees, Paul; Curley, Steven A.; Serda, Rita E.

    2015-01-01

    Herein, we present a novel imaging platform to study the biological effects of non-invasive radiofrequency (RF) electric field cancer hyperthermia. This system allows for real-time in vivo intravital microscopy (IVM) imaging of radiofrequency-induced biological alterations such as changes in vessel structure and drug perfusion. Our results indicate that the IVM system is able to handle exposure to high-power electric-fields without inducing significant hardware damage or imaging artifacts. Furthermore, short durations of low-power (< 200 W) radiofrequency exposure increased transport and perfusion of fluorescent tracers into the tumors at temperatures below 41°C. Vessel deformations and blood coagulation were seen for tumor temperatures around 44°C. These results highlight the use of our integrated IVM-RF imaging platform as a powerful new tool to visualize the dynamics and interplay between radiofrequency energy and biological tissues, organs, and tumors. PMID:26308617

  17. Electrical Detection of Dengue Biomarker Using Egg Yolk Immunoglobulin as the Biological Recognition Element

    NASA Astrophysics Data System (ADS)

    Figueiredo, Alessandra; Vieira, Nirton C. S.; Dos Santos, Juliana F.; Janegitz, Bruno C.; Aoki, Sergio M.; Junior, Paulo P.; Lovato, Rodrigo L.; Nogueira, Maurício L.; Zucolotto, Valtencir; Guimarães, Francisco E. G.

    2015-01-01

    Nonstructural protein 1 (NS1) is secreted by dengue virus in the first days of infection and acts as an excellent dengue biomarker. Here, the direct electrical detection of NS1 from dengue type 2 virus has been achieved by the measurement of variations in open circuit potential (OCP) between a reference electrode and a disposable Au electrode containing immobilized anti-NS1 antibodies acting as immunosensor. Egg yolk immunoglobulin (IgY) was utilized for the first time as the biological recognition element alternatively to conventional mammalian antibodies in the detection of dengue virus NS1 protein. NS1 protein was detected in standard samples in a 0.1 to 10 µg.mL-1 concentration range with (3.2 +/- 0.3) mV/µg.mL-1 of sensitivity and 0.09 µg.mL-1 of detection limit. Therefore, the proposed system can be extended to detect NS1 in real samples and provide an early diagnosis of dengue.

  18. Electricity

    SciTech Connect

    Sims, B.

    1983-01-01

    Historical aspects of electricity are reviewed with individual articles on hydroelectric dams, coal-burning power plants, nuclear power plants, electricity distribution, and the energy future. A glossary is included. (PSB)

  19. Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography.

    PubMed

    Peña, Adrián F; Doronin, Alexander; Tuchin, Valery V; Meglinski, Igor

    2014-08-01

    The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

  20. Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Peña, Adrián F.; Doronin, Alexander; Tuchin, Valery V.; Meglinski, Igor

    2014-08-01

    The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

  1. Closing the Loop: Involving Faculty in the Assessment of Scientific and Quantitative Reasoning Skills of Biology Majors

    ERIC Educational Resources Information Center

    Hurney, Carol A.; Brown, Justin; Griscom, Heather Peckham; Kancler, Erika; Wigtil, Clifton J.; Sundre, Donna

    2011-01-01

    The development of scientific and quantitative reasoning skills in undergraduates majoring in science, technology, engineering, and mathematics (STEM) is an objective of many courses and curricula. The Biology Department at James Madison University (JMU) assesses these essential skills in graduating biology majors by using a multiple-choice exam…

  2. Electrical manipulation of biological samples in glass-based electrofluidics fabricated by 3D femtosecond laser processing

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2014-03-01

    Electrical manipulation of biological samples using glass-based electrofluidics fabricated by femtosecond laser, in which the microfluidic structures are integrated with microelectric components, is presented. Electro-orientation of movement of living cells with asymmetric shapes such as Euglena gracilis of aquatic microorganisms in microfluidic channels is demonstrated using the fabricated electrofluidics. By integrating the properly designed microelectrodes into microfluidic channels, the orientation direction of Euglena cells can be well controlled.

  3. Magnetoacoustic tomography with magnetic induction (MAT-MI) for imaging electrical conductivity of biological tissue: a tutorial review

    NASA Astrophysics Data System (ADS)

    Li, Xu; Yu, Kai; He, Bin

    2016-09-01

    Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. In the presence of a static magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample’s electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in recent years. First, the physical mechanisms underlying MAT-MI imaging are described, including the magnetic induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared, together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with magnetic induction is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue.

  4. Recent advances in the mitigation of AC voltages occurring in pipelines located close to electric transmission lines

    SciTech Connect

    Southey, R.D.; Dawalibi, F.P. ); Vukonich, W. )

    1994-04-01

    In joint-use corridors where both pipelines and AC electric transmission lines are present, a portion of the energy contained in the electromagnetic field surrounding the electric transmission lines is captured by each pipeline, resulting in induced AC voltages which vary in magnitude throughout the length of each pipeline. During a fault on any of the transmission lines, energization of the earth by supporting structures near the fault can result in large voltages appearing locally between the earth and the steel wall of any nearby pipeline. Some form of mitigation is usually required to reduce these voltages to acceptable levels for the protection of personnel and of the pipeline itself. This paper presents a new mitigation design approach which not only reduces AC voltages effectively and economically, but also provides cathodic protection for the protected pipeline. Performance of this new mitigation method is illustrated with results from computer simulations, which show how important it is to have an accurate electrical model of the soil structure in any interference study. Results from large-scale mitigation design studies performed for ANR Pipeline Company and other gas transmission companies are presented.

  5. Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning

    NASA Astrophysics Data System (ADS)

    Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

    1991-08-01

    Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

  6. [Biological and health effects on electric and magnetic fields at extremely low frequencies].

    PubMed

    Torregrossa, M V

    2005-01-01

    While the enormous benefits of using electricity in everyday life and health care are unquestioned, during the past 20 years the general public has become increasingly concerned about potential adverse health effects of exposure to electric and magnetic fields at extremely low frequencies (ELF). Such exposures arise mainly from the transmission and use of electrical energy at the power frequencies of 50/60 Hz. The international scientific community is addressing the associated health issues through in vitro, in vivo and epidemiological studies, although present research results are often contradictory. The purpose of this paper is to provide information about the possible impacts of exposure to electric and magnetic field at ELF frequencies on health within the community and the workplace. Information comes from recent research studies on this subject and from epidemiological pooled studies recently reviewed by eminent authorities.

  7. Application of hierarchical dissociated neural network in closed-loop hybrid system integrating biological and mechanical intelligence.

    PubMed

    Li, Yongcheng; Sun, Rong; Zhang, Bin; Wang, Yuechao; Li, Hongyi

    2015-01-01

    Neural networks are considered the origin of intelligence in organisms. In this paper, a new design of an intelligent system merging biological intelligence with artificial intelligence was created. It was based on a neural controller bidirectionally connected to an actual mobile robot to implement a novel vehicle. Two types of experimental preparations were utilized as the neural controller including 'random' and '4Q' (cultured neurons artificially divided into four interconnected parts) neural network. Compared to the random cultures, the '4Q' cultures presented absolutely different activities, and the robot controlled by the '4Q' network presented better capabilities in search tasks. Our results showed that neural cultures could be successfully employed to control an artificial agent; the robot performed better and better with the stimulus because of the short-term plasticity. A new framework is provided to investigate the bidirectional biological-artificial interface and develop new strategies for a future intelligent system using these simplified model systems.

  8. Electromagnetic hypersensitivity: biological effects of dirty electricity with emphasis on diabetes and multiple sclerosis.

    PubMed

    Havas, Magda

    2006-01-01

    Dirty electricity is a ubiquitous pollutant. It flows along wires and radiates from them and involves both extremely low frequency electromagnetic fields and radio frequency radiation. Until recently, dirty electricity has been largely ignored by the scientific community. Recent inventions of metering and filter equipment provide scientists with the tools to measure and reduce dirty electricity on electrical wires. Several case studies and anecdotal reports are presented. Graham/Stetzer (GS) filters have been installed in schools with sick building syndrome and both staff and students reported improved health and more energy. The number of students needing inhalers for asthma was reduced in one school and student behavior associated with ADD/ADHD improved in another school. Blood sugar levels for some diabetics respond to the amount of dirty electricity in their environment. Type 1 diabetics require less insulin and Type 2 diabetics have lower blood sugar levels in an electromagnetically clean environment. Individuals diagnosed with multiple sclerosis have better balance and fewer tremors. Those requiring a cane walked unassisted within a few days to weeks after GS filters were installed in their home. Several disorders, including asthma, ADD/ADHD, diabetes, multiple sclerosis, chronic fatigue, fibromyalgia, are increasing at an alarming rate, as is electromagnetic pollution in the form of dirty electricity, ground current, and radio frequency radiation from wireless devices. The connection between electromagnetic pollution and these disorders needs to be investigated and the percentage of people sensitive to this form of energy needs to be determined.

  9. Electrical injuries. Biological values measurements as a prediction factor of local evolution in electrocutions lesions

    PubMed Central

    Teodoreanu, R; Popescu, SA; Lascar, I

    2014-01-01

    Abstract Rationale. Taking into account the incidence and the severity of electrocutions, we consider it extremely necessary to find effective, appropriate and particularized therapeutic solutions aimed at improving the survival, decreasing the mortality, ensuring a superior functional and aesthetic effect and facilitating the social reintegration. Given the severity of the general condition of the electrically injured patient and the fact that any worsening of the lesions has a systemic echo, the selection of the timing for re-excision is very important. The postponement of the surgical timing can break the precarious metabolic equilibrium and can hasten the installation of the multisystem organ failure (MSOF). Objective. The study is intended to establish a possible connection between the clinical evolution of the electrically injured patient and the dynamics of three important biological parameters, able to provide data concerning the therapeutic attitude to be followed. The patients with a diagnostic of high-voltage electrocution, who will be admitted to the Clinic, will be followed for a period of 2 years. The parameters to be followed daily will be: - Creatin-kinase, as a marker of muscular damage - Hemoglobin, as a marker of tissue oxygenation - Leukocytes, as an indicator of a possible septic evolution. The therapeutic alternatives, including the administration of antiplatelet drugs will be studied. Methods and Results. In the period October 2010-June 2013 a total of 12 cases of high-voltage electrocution were admitted in our clinic. Among these, some could be placed in the study of 7 cases, as the remaining patients died within the first 24 hours of hospitalization due to the endured lesions. All the patients were admitted to the ICU ward that supported the treatment and monitoring until their stabilization, at which time they were transferred to the ward. All the patients received anti-thromboxane treatment from their admission (injectable NSAIDs

  10. Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems.

    PubMed

    Hatzell, Marta C; Ivanov, Ivan; Cusick, Roland D; Zhu, Xiuping; Logan, Bruce E

    2014-01-28

    Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m(-3). However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ~1.5× to 118 W h m(-3). Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m(-3) or ~1/3 of that produced through direct hydrogen generation.

  11. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD. [energy conversion efficiency of electric power plants using magnetohydrodynamics

    NASA Technical Reports Server (NTRS)

    Tsu, T. C.

    1976-01-01

    A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to give a topping cycle efficiency of 59.3%; however when combined with an integrated gasifier and optimistic steam bottomer the coal to bus bar efficiency drops to 45.5%. A 1978 K (3100 F) cycle has an efficiency of 55.1% and a power plant efficiency of 42.2%. The high cost of the external heating loop components results in a cost of electricity of 21.41 mills/MJ (77.07 mills/kWh) for the high temperature system and 19.0 mills/MJ (68.5 mills/kWh) for the lower temperature system. It is, therefore, thought that this cycle may be more applicable to internally heated systems such as some futuristic high temperature gas cooled reactor.

  12. On the electric potentials inside a charged soft hydrated biological tissue: streaming potential versus diffusion potential.

    PubMed

    Lai, W M; Mow, V C; Sun, D D; Ateshian, G A

    2000-08-01

    The main objective of this study is to determine the nature of electric fields inside articular cartilage while accounting for the effects of both streaming potential and diffusion potential. Specifically, we solve two tissue mechano-electrochemical problems using the triphasic theories developed by Lai et al. (1991, ASME J. Biomech Eng., 113, pp. 245-258) and Gu et al. (1998, ASME J. Biomech. Eng., 120, pp. 169-180) (1) the steady one-dimensional permeation problem; and (2) the transient one-dimensional ramped-displacement, confined-compression, stress-relaxation problem (both in an open circuit condition) so as to be able to calculate the compressive strain, the electric potential, and the fixed charged density (FCD) inside cartilage. Our calculations show that in these two technically important problems, the diffusion potential effects compete against the flow-induced kinetic effects (streaming potential) for dominance of the electric potential inside the tissue. For softer tissues of similar FCD (i.e., lower aggregate modulus), the diffusion potential effects are enhanced when the tissue is being compressed (i.e., increasing its FCD in a nonuniform manner) either by direct compression or by drag-induced compaction; indeed, the diffusion potential effect may dominate over the streaming potential effect. The polarity of the electric potential field is in the same direction of interstitial fluid flow when streaming potential dominates, and in the opposite direction of fluid flow when diffusion potential dominates. For physiologically realistic articular cartilage material parameters, the polarity of electric potential across the tissue on the outside (surface to surface) may be opposite to the polarity across the tissue on the inside (surface to surface). Since the electromechanical signals that chondrocytes perceive in situ are the stresses, strains, pressures and the electric field generated inside the extracellular matrix when the tissue is deformed, the

  13. Interaction and Aggregation of Colloidal Biological Particles and Droplets in Electrically-Driven Flows

    NASA Technical Reports Server (NTRS)

    Davis, Robert H.; Loewenberg, Michael

    1997-01-01

    The primary objective of this research was to develop a fundamental understanding of aggregation and coalescence processes during electrically-driven migration of cells, particles and droplets. The process by which charged cells, particles, molecules, or drops migrate in a weak electric field is known as electrophoresis. If the migrating species have different charges or surface potentials, they will migrate at different speeds and thus may collide and aggregate or coalesce. Aggregation and coalescence are undesirable, if the goal is to separate the different species on the basis of their different electrophoretic mobilities.

  14. Differential tolerance to biological and subjective effects of four closely spaced doses of N,N-dimethyltryptamine in humans.

    PubMed

    Strassman, R J; Qualls, C R; Berg, L M

    1996-05-01

    Tolerance of the behavioral effects of the short-acting, endogenous hallucinogen, N,N-dimethyltryptamine (DMT) is seen inconsistently in animals, and has not been produced in humans. The nature and time course of responses to repetitive, closely spaced administrations of an hallucinogenic dose of DMT were characterized. Thirteen experienced hallucinogen users received intravenous 0.3 mg/kg DMT fumarate, or saline placebo, four times, at 30 min intervals, on 2 separate days, in a randomized, double-blind, design. Tolerance to "psychedelic" subjective effects did not occur according to either clinical interview or Hallucinogen Rating Scale scores. Adrenocorticotropic hormone (ACTH), prolactin, cortisol, and heart rate responses decreased with repeated DMT administration, although blood pressure did not. These data demonstrate the unique properties of DMT relative to other hallucinogens and underscore the differential regulation of the multiple processes mediating the effects of DMT.

  15. A Novel Robot System Integrating Biological and Mechanical Intelligence Based on Dissociated Neural Network-Controlled Closed-Loop Environment

    PubMed Central

    Wang, Yuechao; Li, Hongyi; Zheng, Xiongfei

    2016-01-01

    We propose the architecture of a novel robot system merging biological and artificial intelligence based on a neural controller connected to an external agent. We initially built a framework that connected the dissociated neural network to a mobile robot system to implement a realistic vehicle. The mobile robot system characterized by a camera and two-wheeled robot was designed to execute the target-searching task. We modified a software architecture and developed a home-made stimulation generator to build a bi-directional connection between the biological and the artificial components via simple binomial coding/decoding schemes. In this paper, we utilized a specific hierarchical dissociated neural network for the first time as the neural controller. Based on our work, neural cultures were successfully employed to control an artificial agent resulting in high performance. Surprisingly, under the tetanus stimulus training, the robot performed better and better with the increasement of training cycle because of the short-term plasticity of neural network (a kind of reinforced learning). Comparing to the work previously reported, we adopted an effective experimental proposal (i.e. increasing the training cycle) to make sure of the occurrence of the short-term plasticity, and preliminarily demonstrated that the improvement of the robot’s performance could be caused independently by the plasticity development of dissociated neural network. This new framework may provide some possible solutions for the learning abilities of intelligent robots by the engineering application of the plasticity processing of neural networks, also for the development of theoretical inspiration for the next generation neuro-prostheses on the basis of the bi-directional exchange of information within the hierarchical neural networks. PMID:27806074

  16. A Novel Robot System Integrating Biological and Mechanical Intelligence Based on Dissociated Neural Network-Controlled Closed-Loop Environment.

    PubMed

    Li, Yongcheng; Sun, Rong; Wang, Yuechao; Li, Hongyi; Zheng, Xiongfei

    2016-01-01

    We propose the architecture of a novel robot system merging biological and artificial intelligence based on a neural controller connected to an external agent. We initially built a framework that connected the dissociated neural network to a mobile robot system to implement a realistic vehicle. The mobile robot system characterized by a camera and two-wheeled robot was designed to execute the target-searching task. We modified a software architecture and developed a home-made stimulation generator to build a bi-directional connection between the biological and the artificial components via simple binomial coding/decoding schemes. In this paper, we utilized a specific hierarchical dissociated neural network for the first time as the neural controller. Based on our work, neural cultures were successfully employed to control an artificial agent resulting in high performance. Surprisingly, under the tetanus stimulus training, the robot performed better and better with the increasement of training cycle because of the short-term plasticity of neural network (a kind of reinforced learning). Comparing to the work previously reported, we adopted an effective experimental proposal (i.e. increasing the training cycle) to make sure of the occurrence of the short-term plasticity, and preliminarily demonstrated that the improvement of the robot's performance could be caused independently by the plasticity development of dissociated neural network. This new framework may provide some possible solutions for the learning abilities of intelligent robots by the engineering application of the plasticity processing of neural networks, also for the development of theoretical inspiration for the next generation neuro-prostheses on the basis of the bi-directional exchange of information within the hierarchical neural networks.

  17. Spectral Properties of Single Gold Nanoparticles in Close Proximity to Biological Fluorophores Excited by 2-Photon Excitation

    PubMed Central

    Anzalone, Andrea; Gabriel, Manuela; Estrada, Laura C.; Gratton, Enrico

    2015-01-01

    Metallic nanoparticles (NPs) are able to modify the excitation and emission rates (plasmonic enhancement) of fluorescent molecules in their close proximity. In this work, we measured the emission spectra of 20 nm Gold Nanoparticles (AuNPs) fixed on a glass surface submerged in a solution of different fluorophores using a spectral camera and 2-photon excitation. While on the glass surface, we observed the presence in the emission at least 3 components: i) second harmonic signal (SHG), ii) a broad emission from AuNPS and iii) fluorescence arising from fluorophores nearby. When on the glass surface, we found that the 3 spectral components have different relative intensities when the incident direction of linear polarization was changed indicating different physical origins for these components. Then we measured by fluctuation correlation spectroscopy (FCS) the scattering and fluorescence signal of the particles alone and in a solution of 100 nM EGFP using the spectral camera or measuring the scattering and fluorescence from the particles. We observed occasional fluorescence bursts when in the suspension we added fluorescent proteins. The spectrum of these burst was devoid of the SHG and of the broad emission in contrast to the signal collected from the gold nanoparticles on the glass surface. Instead we found that the spectrum during the burst corresponded closely to the spectrum of the fluorescent protein. An additional control was obtained by measuring the cross-correlation between the reflection from the particles and the fluorescence arising from EGFP both excited at 488 nm. We found a very weak cross-correlation between the AuNPs and the fluorescence confirming that the burst originate from a few particles with a fluorescence signal. PMID:25909648

  18. Conceptual Design Study of a Closed Brayton Cycle Turbogenerator for Space Power Thermal-To-Electric Conversion System

    NASA Technical Reports Server (NTRS)

    Hansen, Jeff L.

    2000-01-01

    A conceptual design study was completed for a 360 kW Helium-Xenon closed Brayton cycle turbogenerator. The selected configuration is comprised of a single-shaft gas turbine engine coupled directly to a high-speed generator. The engine turbomachinery includes a 2.5:1 pressure ratio compression system with an inlet corrected flow of 0.44 kg/sec. The single centrifugal stage impeller discharges into a scroll via a vaned diffuser. The scroll routes the air into the cold side sector of the recuperator. The hot gas exits a nuclear reactor radiator at 1300 K and enters the turbine via a single-vaned scroll. The hot gases are expanded through the turbine and then diffused before entering the hot side sector of the recuperator. The single shaft design is supported by air bearings. The high efficiency shaft mounted permanent magnet generator produces an output of 370 kW at a speed of 60,000 rpm. The total weight of the turbogenerator is estimated to be only 123 kg (less than 5% of the total power plant) and has a volume of approximately 0.11 cubic meters. This turbogenerator is a key element in achieving the 40 to 45% overall power plant thermal efficiency.

  19. C.E.B.A.S., a closed equilibrated biological aquatic system as a possible precursor for a long-term life support system?

    NASA Astrophysics Data System (ADS)

    Blüm, V.

    C.E.B.A.S.-AQUARACK is a long-term multi-generation experimental device for aquatic organisms which is disposed for utlizitation in a space station. It results from the basic idea of a space aquarium for maintaining aquatic animals for longer periods integrated in a AQUARACK which consists of a modular animal holding tank, a semi-biological/physical water recycling system and an electronical control unit. The basic idea to replace a part of the water recycling system by a continuous culture of unicellular algae primarily leads to a second system for experiments with algae, a botanical AQUARACK consisting of an algal reactor, a water recycling and the electronical control unit. The combination of the zoological part, and the botanical part with a common control system in the AQUARACK, however, results in a ``Closed Equilibrated Biological Aquatic System'' (C.E.B.A.S.) representing an closed artificial ecosystem. Although this is disposed primarily as an experimental device for basic zoological, botanical and interdisciplinary research it opens the theoretical possibility to adapt it for combined production of animal and plant biomass on ground or in space. The paper explains the basic conception of the hardware construction of the zoological part of the system, the corresponding scientific frame program including the choice of the experimental animals and gives some selected examples of the hardware-related resrearch. It furtheron discusses the practical and economical relevance of the system in the development of a controlled aquatical life support system in general.

  20. Cotyledonary somatic embryos of Pinus pinaster Ait. most closely resemble fresh, maturing cotyledonary zygotic embryos: biological, carbohydrate and proteomic analyses.

    PubMed

    Morel, Alexandre; Trontin, Jean-François; Corbineau, Françoise; Lomenech, Anne-Marie; Beaufour, Martine; Reymond, Isabelle; Le Metté, Claire; Ader, Kevin; Harvengt, Luc; Cadene, Martine; Label, Philippe; Teyssier, Caroline; Lelu-Walter, Marie-Anne

    2014-11-01

    Cotyledonary somatic embryos (SEs) of maritime pine are routinely matured for 12 weeks before being germinated and converted to plantlets. Although regeneration success is highly dependent on SEs quality, the date of harvesting is currently determined mainly on the basis of morphological features. This empirical method does not provide any accurate information about embryo quality with respect to storage compounds (proteins, carbohydrates). We first analyzed SEs matured for 10, 12 and 14 weeks by carrying out biological (dry weight, water content) and biochemical measurements (total protein and carbohydrate contents). No difference could be found between collection dates, suggesting that harvesting SEs after 12 weeks is appropriate. Cotyledonary SEs were then compared to various stages, from fresh to fully desiccated, in the development of cotyledonary zygotic embryos (ZEs). We identified profiles that were similar using hierarchical ascendant cluster analysis (HCA). Fresh and dehydrated ZEs could be distinguished, and SEs clustered with fresh ZEs. Both types of embryo exhibited similar carbohydrate and protein contents and signatures. This high level of similarity (94.5 %) was further supported by proteome profiling. Highly expressed proteins included storage, stress-related, late embryogenesis abundant and energy metabolism proteins. By comparing overexpressed proteins in developing and cotyledonary SEs or ZEs, some (23 proteins) could be identified as candidate biomarkers for the late, cotyledonary stage. This is the first report of useful generic protein markers for monitoring embryo development in maritime pine. Our results also suggest that improvements of SEs quality may be achieved if the current maturation conditions are refined.

  1. An Optimized Biological Taser: Electric Eels Remotely Induce or Arrest Movement in Nearby Prey.

    PubMed

    Catania, Kenneth C

    2015-09-01

    Despite centuries of interest in electric eels, few studies have investigated the mechanism of the eel's attack. Here, I review and extend recent findings that show eel electric high-voltage discharges activate prey motor neuron efferents. This mechanism allows electric eels to remotely control their targets using two different strategies. When nearby prey have been detected, eels emit a high-voltage volley that causes whole-body tetanus in the target, freezing all voluntary movement and allowing the eel to capture the prey with a suction feeding strike. When hunting for cryptic prey, eels emit doublets and triplets, inducing whole-body twitch in prey, which in turn elicits an immediate eel attack with a full volley and suction feeding strike. Thus, by using their modified muscles (electrocytes) as amplifiers of their own motor efferents, eel's motor neurons remotely activate prey motor neurons to cause movement (twitch and escape) or immobilization (tetanus) facilitating prey detection and capture, respectively. These results explain reports that human movement is 'frozen' by eel discharges and shows the mechanism to resemble a law-enforcement Taser.

  2. Biological studies of swine exposed to 60-Hz electric fields. Volume 2: Behavior. Final report

    SciTech Connect

    Not Available

    1985-12-01

    The behavioral responses in three generations of miniature swine chronically exposed to a 30-kV/m, 60-Hz electric field have been assessed in a series of screening experiments. Tests were conducted on mature swine as well as on very young swine and weanlings and included measures of: (1) preference for exposure to or shielding from the electric field; (2) early neuromuscular development; (3) exploratory behavior; (4) simple learning and memory function; and (5) short-term memory. Repeated evaluations of behavioral parameters show few statistically significant effects. In the parental (F/sub 0/) generation, exposed sows showed a preference to remain out of the field, particularly during the dark period. Adult first-generation (F/sub 1/) sows, however, failed to demonstrate such a preference to stay out of the field. In other behavioral assessments, the singular significant effect in F/sub 1/ swine was the increased number of vocalizations in both male and female swine during the exploratory behavior test. This result, also inconsistent across generations, was not repeated in the second-generation (F/sub 2/) exploratory tests, where exposed female swine made significantly fewer vocalizations than their sham-exposed counterparts. The study provides no other evidence of an overall behavioral effect in swine of prenatal exposure to electric fields. 13 refs., 5 figs., 11 tabs.

  3. Biological Technicians

    MedlinePlus

    ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ...

  4. Nonlinear electric properties in biological system for stochastic computing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sumida, Saki; Yamaguchi, Harumasa; Ohyama, Hiroshi; Otsuka, Yoichi; Che, Dock-Chil; Matsumoto, Takuya

    2016-09-01

    Nonlinearity is the vital factor for stochastic computing. Toward the realization of brain-mimetic function using molecular network, the nonlinear electric properties of molecular systems are investigated in nanoscale with atomic force microscopy and nano-gap electrodes. Nonlinear current-voltage characteristics were observed for {Mo154/152}-ring, cytochorome c, and cytochrome c/DNA networks where the conduction paths include electron injection into weakly coupled discrete energy levels, electron tunneling through potential well, and electron hopping via Coulomb-blockade network. Stochastic resonance was observed in Cytochrome c/DNA network.

  5. Electrical pumping of potassium ions against an external concentration gradient in a biological ion channel

    NASA Astrophysics Data System (ADS)

    Queralt-Martín, María; García-Giménez, Elena; Aguilella, Vicente M.; Ramirez, Patricio; Mafe, Salvador; Alcaraz, Antonio

    2013-07-01

    We show experimentally and theoretically that significant currents can be obtained with a biological ion channel, the OmpF porin of Escherichia coli, using zero-average potentials as driving forces. The channel rectifying properties can be used to pump potassium ions against an external concentration gradient under asymmetric pH conditions. The results are discussed in terms of the ionic selectivity and rectification ratio of the channel. The physical concepts involved may be applied to separation processes with synthetic nanopores and to bioelectrical phenomena.

  6. Modeling electrical power absorption and thermally-induced biological tissue damage.

    PubMed

    Zohdi, T I

    2014-01-01

    This work develops a model for thermally induced damage from high current flow through biological tissue. Using the first law of thermodynamics, the balance of energy produced by the current and the energy absorbed by the tissue are investigated. The tissue damage is correlated with an evolution law that is activated upon exceeding a temperature threshold. As an example, the Fung material model is used. For certain parameter choices, the Fung material law has the ability to absorb relatively significant amounts of energy, due to its inherent exponential response character, thus, to some extent, mitigating possible tissue damage. Numerical examples are provided to illustrate the model's behavior.

  7. Plant and microorganisms support media for electricity generation in biological fuel cells with living hydrophytes.

    PubMed

    Salinas-Juárez, María Guadalupe; Roquero, Pedro; Durán-Domínguez-de-Bazúa, María Del Carmen

    2016-12-01

    Plant support media may impact power output in a biological fuel cell with living plants, due to the physical and biochemical processes that take place in it. A material for support medium should provide the suitable conditions for the robust microbial growth and its metabolic activity, degrading organic matter and other substances; and, transferring electrons to the anode. To consider the implementation of this type of bio-electrochemical systems in constructed wetlands, this study analyzes the electrochemical behavior of biological fuel cells with the vegetal species Phragmites australis, by using two different support media: graphite granules and a volcanic slag, commonly known as tezontle (stone as light as hair, from the Aztec or Nahuatl language). Derived from the results, both, graphite and tezontle have the potential to be used as support medium for plants and microorganisms supporting a maximum power of 26.78mW/m(2) in graphite reactors. These reactors worked under mixed control: with ohmic and kinetic resistances of the same order of magnitude. Tezontle reactors operated under kinetic control with a high activation resistance supplying 9.73mW/m(2). These performances could be improved with stronger bacterial populations in the reactor, to ensure the rapid depletion of substrate.

  8. Biological treatment of steroidal drug industrial effluent and electricity generation in the microbial fuel cells.

    PubMed

    Liu, Ru; Gao, Chongyang; Zhao, Yang-Guo; Wang, Aijie; Lu, Shanshan; Wang, Min; Maqbool, Farhana; Huang, Qing

    2012-11-01

    The single chamber microbial fuel cells (MFCs) were used to treat steroidal drug production wastewater (SPW) and generate electricity simultaneously. The results indicated that the maximum COD removal efficiency reached 82%, total nitrogen and sulfate removal rate approached 62.47% and 26.46%, respectively. The maximum power density and the Coulombic efficiency reached to 22.3Wm(-3) and 30%, respectively. The scanning electron microscope showed that the dominant microbial populations were remarkably different in morphology on the surface of SPW and acetate-fed anodes. PCR-denaturing gradient gel electrophoresis profiles revealed that the microbial community structure fed with different concentrations of SPW presented a gradual succession and unique bacterial sequences were detected on the SPW and acetate-fed anodes. This research demonstrates that MFCs fed with SPW achieved a high efficiency of power density and simultaneous nutrient removal, and the dominant microorganisms on the anode were related to the types and the concentrations of substrates.

  9. Biological impedance cross evaluation and imaging from composite measurements of magnetic and electrical methods.

    PubMed

    Ran, Peng; Xiao, Xiaoming; He, Wei; Li, Zhangyong

    2015-01-01

    Because of the need for rapid detection and location of diseases in clinical applications, this work proposes a composite measurement of magnetic induction tomography (MIT) and electrical impedance tomography (EIT). This paper is composed of the following aspects: portable and integral hardware design, stable dual constant-current sources, the composite detection method, cross-plane data acquirement, 3-dimensional image reconstruction and so on. A qualitative evaluation of conductivity, resolution and relative position error were taken by combining the EIT and MIT methods via the experiment model. The sensitivities of both methods were analyzed to improve the imaging results. The reconstruction results reveal that the system is capable of obtaining better physiological measurements, which is very useful in clinical monitoring, quick medical diagnosing and preliminary screening of community health.

  10. Electrical transmission lines in Montana: Mitigation of impacts to soil and biological sources

    SciTech Connect

    McCollough, S.A.; Ring, T.W.

    1990-12-31

    In Montana, the routing and construction of large electrical transmission lines are regulated by the Montana Major Facility Siting Act. Under this act, impacts to resources are minimized through avoidance by routing, where possible, and by mitigating remaining impacts. Land disturbed by the construction of transmission lines considered in this paper ranges from 1681 acres for a 500-kV line across 156 miles of mountainous terrain to 11 acres for a 100-kV line across 27 miles of nearly level terrain. Line access accounts for most of the disturbance, especially when graded roads are built in mountainous terrain. Land disturbed by transmission line construction is susceptible to soil erosion and weed infestation. These problems are addressed through revegetation, erosion control, and herbicide application. Transmission lines can displace wildlife from critical habitats by disruptive construction activities or by improving human access to previously secure range. Wildlife impacts can be reduced by restricting construction periods and gating roads.

  11. Biological studies of swine exposed to 60-Hz electric fields. Volume 1. Overview and summary. Final report

    SciTech Connect

    Not Available

    1985-12-01

    Over a three-year period, three generations of female miniature swine and their offspring were exposed to a 30-kV/m, 60-Hz electric field. Such a field approximates the 12-kV/m field that a human would experience under a 765-kV line. After swine exposures varying from 6 to 36 months, project personnel analyzed a wide range of biological parameters including growth, blood cell and serum biochemistry, blood immunoglobulin levels, behavior, peripheral nerve function, cell-mediated immunity, cytogenetics, and reproduction and development. There were no significant differences in health effects between the exposed and sham-exposed swine, except in the area of fetal development. The first breeding produced no significant difference between exposed and control offspring. When those offspring were bred after 18 months of exposure, the fetuses of exposed sows had an increased incidence of morphological malformations and lower body weight than fetuses from control sows. The live-born had lower body weights and increased birth defects. Several factors suggest that electric fields per se may not have caused these reproductive changes. For example, similar types of malformations occurred in control pigs. Also, in second-generation sows, the incidence of fetal malformations was similar for both exposed and control groups. It is possible that other factors such as housing, inbreeding, disease, or treatment of disease may have produced the observed effects. 64 refs., 13 figs., 25 tabs.

  12. Biological Monitoring of Occupational Exposure to Polycyclic Aromatic Hydrocarbons at an Electric Steel Foundry in Tunisia.

    PubMed

    Campo, Laura; Hanchi, Mariem; Olgiati, Luca; Polledri, Elisa; Consonni, Dario; Zrafi, Ines; Saidane-Mosbahi, Dalila; Fustinoni, Silvia

    2016-07-01

    Occupational exposures during iron and steel founding have been classified as carcinogenic to humans, and the exposure to polycyclic aromatic hydrocarbons (PAHs) in this industrial setting may contribute to cancer risk. The occupational exposure to PAHs was assessed in 93 male workers at an electric steel foundry in Tunisia by biomonitoring, with the aims of characterizing the excretion profile and investigating the influence of job title and personal characteristics on the biomarkers. Sixteen 2-6 ring unmetabolized PAHs (U-PAHs) and eight hydroxylated PAH metabolites (OHPAHs) were analyzed by gas chromatography-triple quadrupole tandem mass spectrometry and liquid chromatography triple quadrupole tandem mass spectrometry, respectively. Among U-PAHs, urinary naphthalene (U-NAP) was the most abundant compound (median level: 643ng l(-1)), followed by phenanthrene (U-PHE, 18.5ng l(-1)). Urinary benzo[a]pyrene (U-BaP) level was <0.30ng l(-1) Among OHPAHs, 2-hydroxynaphthalene (2-OHNAP) was the most abundant metabolite (2.27 µg l(-1)). Median 1-hydroxypyrene (1-OHPYR) was 0.52 µg l(-1) Significant correlations among urinary biomarkers were observed, with Pearson's r ranging from 0.177 to 0.626. 1-OHPYR was correlated to benzo[a]pyrene, but not to five- and six-rings PAHs. A multiple linear regression model showed that job title was a significant determinant for almost all U-PAHs. In particular, employees in the steel smelter workshop had higher levels of high-boiling U-PAHs and lower levels of low-boiling U-PAHs than those of workers with other job titles. Among OHPAHs, this model was significant only for naphthols and 1-hydroxyphenanthrene (1-OHPHE). Smoking status was a significant predictor for almost all biomarkers. Among all analytes, U-PHE and 1-OHPHE were the less affected by tobacco smoke, and they were significantly correlated with both low- and high-molecular-weight compounds, and their levels were related to job titles, so they could be proposed as suitable

  13. The biological and electrical trade-offs related to the thickness of conducting polymers for neural applications.

    PubMed

    Baek, Sungchul; Green, Rylie A; Poole-Warren, Laura A

    2014-07-01

    Poly(3,4-ethylenedioxythiophene) (PEDOT) films have attracted substantial interest as coatings for platinum neuroprosthetic electrodes due to their excellent chemical stability and electrical properties. This study systematically examined PEDOT coatings formed with different amounts of charge and dopant ions, and investigated the combination of surface characteristics that were optimal for neural cell interactions. PEDOT samples were fabricated by varying the electrodeposition charge from 0.05 to 1 C cm(-2). Samples were doped with either poly(styrenesulfonate), tosylate (pTS) or perchlorate. Scanning electron micrographs revealed that both thickness and nodularity increased as the charge used to produce the sample was increased, and larger dopants produced smoother films across all thicknesses. X-ray photoelectron spectroscopy confirmed that the amount of charge directly corresponded to the thickness and amount of dopant in the samples. Additionally, with increased thickness and nodularity, the electrochemical properties of all PEDOT coatings improved. However, neural cell adhesion and outgrowth assays revealed that there is a direct biological tradeoff related to the thickness and nodularity. Cell attachment, growth and differentiation was poorer on the thicker, rougher samples, but thin, less nodular PEDOT films exhibited significant improvements over bare platinum. PEDOT/pTS fabricated with a charge density of <0.1Ccm(-2) provided superior electrochemical and biological properties over conventional platinum electrodes and would be the most suitable conducting polymer for neural interface applications.

  14. Silicon nanowire biologically sensitive field effect transistors: electrical characteristics and applications.

    PubMed

    Rim, Taiuk; Baek, Chang-Ki; Kim, Kihyun; Jeong, Yoon-Ha; Lee, Jeong-Soo; Meyyappan, M

    2014-01-01

    The interest in biologically sensitive field effect transistors (BioFETs) is growing explosively due to their potential as biosensors in biomedical, environmental monitoring and security applications. Recently, adoption of silicon nanowires in BioFETs has enabled enhancement of sensitivity, device miniaturization, decreasing power consumption and emerging applications such as the 3D cell probe. In this review, we describe the device physics and operation of the silicon nanowire BioFETs along with recent advances in the field. The silicon nanowire BioFETs are basically the same as the conventional field-effect transistors (FETs) with the exceptions of nanowire channel instead of thin film and a liquid gate instead of the conventional gate. Therefore, the silicon device physics is important to understand the operation of the BioFETs. Herein, physical characteristics of the silicon nanowire FETs are described and the operational principles of the BioFETs are classified according to the number of gates and the analysis domain of the measured signal. Even the bottom-up process has merits on low-cost fabrication; the top-down process technique is highlighted here due to its reliability and reproducibility. Finally, recent advances in the silicon nanowire BioFETs in the literature are described and key features for commercialization are discussed.

  15. Closed-loop afferent electrical stimulation for recovery of hand function in individuals with motor incomplete spinal injury: early clinical results.

    PubMed

    Schildt, Christopher J; Thomas, Sarah H; Powell, Elizabeth S; Sawaki, Lumy; Sunderam, Sridhar

    2016-08-01

    Afferent electrical stimulation is known to augment the effect of rehabilitative therapy through use-dependent cortical plasticity. Experiments pairing transcranial magnetic stimulation (TMS) with peripheral nerve stimulation (PNS) have shown a timing-dependent effect on motor evoked potential (MEP) amplitude suggesting that PNS applied in closed-loop (CL) mode could augment this effect through positive reinforcement. We present early results from a clinical trial in which an EEG brain-machine interface (BMI) was used to apply PNS to two subjects in response to motor intent detected from sensorimotor cortex in a cue-driven hand grip task. Both subjects had stable incomplete cervical spinal cord injury (SCI) with impaired upper limb function commensurate with the injury level. Twelve sessions of CL-PNS applied over a 4-6 week period yielded results suggesting improved hand grip strength and increased task-related modulation of the EEG in one hand of both subjects, and increased TMS-measured motor map area in one. These observations suggest that rehabilitation using such interactive therapies could benefit affected individuals.

  16. Bio-Inspired Concepts: Studies of Biological Response to External Electric Fields for Cellular Manipulation and Diagnostics - Modeling and Experimentation

    DTIC Science & Technology

    2005-05-03

    Dielectric Spectroscopy," IEEE trans. On Dielectrics and Electrical Insulation 8, 253 (2001). 8. M. Smoluchowski, "Drei vortrage uber diffusion...Intensity Electric Fields," IEEE Conf. On Dielectrics and Electrical Insulation (Bio- Electrics Workshop), Cancun, Mexico , Oct. 2002 (invited

  17. How to Sustainably Feed a Microbe: Strategies for Biological Production of Carbon-Based Commodities with Renewable Electricity

    PubMed Central

    Butler, Caitlyn S.; Lovley, Derek R.

    2016-01-01

    As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for the conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H2 produced separately in a electrolyzer, (2) H2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. This review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability. PMID:27965629

  18. How to Sustainably Feed a Microbe: Strategies for Biological Production of Carbon-Based Commodities with Renewable Electricity.

    PubMed

    Butler, Caitlyn S; Lovley, Derek R

    2016-01-01

    As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for the conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H2 produced separately in a electrolyzer, (2) H2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. This review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability.

  19. Open source software for electric field Monte Carlo simulation of coherent backscattering in biological media containing birefringence.

    PubMed

    Radosevich, Andrew J; Rogers, Jeremy D; Capoğlu, Ilker R; Mutyal, Nikhil N; Pradhan, Prabhakar; Backman, Vadim

    2012-11-01

    ABSTRACT. We present an open source electric field tracking Monte Carlo program to model backscattering in biological media containing birefringence, with computation of the coherent backscattering phenomenon as an example. These simulations enable the modeling of tissue scattering as a statistically homogeneous continuous random media under the Whittle-Matérn model, which includes the Henyey-Greenstein phase function as a special case, or as a composition of discrete spherical scatterers under Mie theory. The calculation of the amplitude scattering matrix for the above two cases as well as the implementation of birefringence using the Jones N-matrix formalism is presented. For ease of operator use and data processing, our simulation incorporates a graphical user interface written in MATLAB to interact with the underlying C code. Additionally, an increase in computational speed is achieved through implementation of message passing interface and the semi-analytical approach. Finally, we provide demonstrations of the results of our simulation for purely scattering media and scattering media containing linear birefringence.

  20. Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification-denitrification/solar photo-Fenton/biological processes, at a scale close to industrial--biodegradability enhancement and evolution profile of trace pollutants.

    PubMed

    Silva, Tânia F C V; Silva, M Elisabete F; Cunha-Queda, A Cristina; Fonseca, Amélia; Saraiva, Isabel; Sousa, M A; Gonçalves, C; Alpendurada, M F; Boaventura, Rui A R; Vilar, Vítor J P

    2013-10-15

    A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO. The raw leachate was characterized by a high concentration of humic substances (HS) (1211 mg CHS/L), representing 39% of the dissolved organic carbon (DOC) content, and a high nitrogen content, mainly in the form of ammonium nitrogen (>3.8 g NH4(+)-N/L). In the first biological oxidation step, a 95% removal of total nitrogen and a 39% mineralization in terms of DOC were achieved, remaining only the recalcitrant fraction, mainly attributed to HS (57% of DOC). Under aerobic conditions, the highest nitrification rate obtained was 8.2 mg NH4(+)-N/h/g of volatile suspended solids (VSS), and under anoxic conditions, the maximum denitrification rate obtained was 5.8 mg (NO2(-)-N + NO3(-)-N)/h/g VSS, with a C/N consumption ratio of 2.4 mg CH3OH/mg (NO2(-)-N + NO3(-)-N). The precipitation of humic acids (37% of HS) after acidification of the bio-treated leachate corresponds to a 96% DOC abatement. The amount of UV energy and H2O2 consumption during the photo-Fenton reaction was 30% higher in the experiment without sludge removal and, consequently, the reaction velocity was 30% lower. The phototreatment process led to the depletion of HS >80%, of low-molecular-weight carboxylate anions >70% and other organic micropollutants, thus resulting in a total biodegradability increase of >70%. The second biological oxidation allowed to obtain a final treated leachate in compliance with legal discharge limits regarding water bodies (with the exception of sulfate ions), considering the experiment without sludge. Finally, the high efficiency of the overall treatment

  1. Novel aquatic modules for bioregenerative life-support systems based on the closed equilibrated biological aquatic system (c.e.b.a.s.)

    NASA Astrophysics Data System (ADS)

    Bluem, Volker; Paris, Frank

    2002-06-01

    The closed equilibrated biological aquatic system (C.E.B.A.S) is a man-made aquatic ecosystem which consists of four subcomponents: an aquatic animal habitat, an aquatic plant bioreactor, an ammonia oxidizing bacteria filter and a data acquisition/control unit. It is a precursor for different types of fish and aquatic plant production sites which are disposed for the integration into bioregenerative life-support systems. The results of two successful spaceflights of a miniaturized C.E.B.A.S version (the C.E.B.A.S. MINI MODULE) allow the optimization of aquatic food production systems which are already developed in the ground laboratory and open new aspects for their utilization as aquatic modules in space bioregenerative life support systems. The total disposition offers different stages of complexity of such aquatic modules starting with simple but efficient aquatic plant cultivators which can be implemented into water recycling systems and ending up in combined plant/fish aquaculture in connection with reproduction modules and hydroponics applications for higher land plants. In principle, aquaculture of fishes and/or other aquatic animals edible for humans offers optimal animal protein production under lowered gravity conditions without the tremendous waste management problems connected with tetrapod breeding and maintenance. The paper presents details of conducted experimental work and of future dispositions which demonstrate clearly that aquaculture is an additional possibility to combine efficient and simple food production in space with water recycling utilizing safe and performable biotechnologies. Moreover, it explains how these systems may contribute to more variable diets to fulfill the needs of multicultural crews.

  2. Novel aquatic modules for bioregenerative life-support systems based on the closed equilibrated biological aquatic system (C.E.B.A.S.).

    PubMed

    Bluem, Volker; Paris, Frank

    2002-06-01

    The closed equilibrated biological aquatic system (C.E.B.A.S) is a man-made aquatic ecosystem which consists of four subcomponents: an aquatic animal habitat, an aquatic plant bioreactor, an ammonia oxidizing bacteria filter and a data acquisition/control unit. It is a precursor for different types of fish and aquatic plant production sites which are disposed for the integration into bioregenerative life-support systems. The results of two successful spaceflights of a miniaturized C.E.B.A.S version (the C.E.B.A.S. MINI MODULE) allow the optimization of aquatic food production systems which are already developed in the ground laboratory and open new aspects for their utilization as aquatic modules in space bioregenerative life support systems. The total disposition offers different stages of complexity of such aquatic modules starting with simple but efficient aquatic plant cultivators which can be implemented into water recycling systems and ending up in combined plant/fish aquaculture in connection with reproduction modules and hydroponics applications for higher land plants. In principle, aquaculture of fishes and/or other aquatic animals edible for humans offers optimal animal protein production under lowered gravity conditions without the tremendous waste management problems connected with tetrapod breeding and maintenance. The paper presents details of conducted experimental work and of future dispositions which demonstrate clearly that aquaculture is an additional possibility to combine efficient and simple food production in space with water recycling utilizing safe and performable biotechnologies. Moreover, it explains how these systems may contribute to more variable diets to fulfill the needs of multicultural crews.

  3. Characteristics of electric-field-induced polarization rotation in <001>-poled Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals close to the morphotropic phase boundary

    NASA Astrophysics Data System (ADS)

    Peräntie, J.; Hagberg, J.; Uusimäki, A.; Tian, J.; Han, P.

    2012-08-01

    The special characteristics of polarization rotation and accompanying electric-field-induced ferroelectric-ferroelectric phase transitions in <001>-poled Pb(Mg1/3Nb2/3)1-xTixO3 (x = 27.4, 28.8, and 30.7 mol. %) single crystals close to the morphotropic phase boundary region were studied by means of dielectric and thermal measurements as a function of a unipolar electric field at various temperatures. Discontinuous first-order-type phase transition behavior was evidenced by distinct and sharp changes in polarization and thermal responses with accompanying hysteresis as a function of the electric field. All compositions of crystals showed either one or two reversible discontinuities along the polarization rotation paths, which can be understood by electric-field-induced phase transition sequences to the tetragonal phase through different monoclinic phases previously observed along the polarization rotation path. Together with increasing polarization, a field-induced reversible decrease in temperature was observed with increasing electric field, indicating increased dipolar entropy during the electric-field-induced phase transitions. Constructed electric field-temperature phase diagrams based on the polarization and thermal data suggest that the complex polarization rotation path extends to a wider composition range than previously observed. The measured thermal response showed that a transition from the monoclinic to the tetragonal phase produced a greater thermal change in comparison with a transition within two monoclinic phases.

  4. Improvement of biological total phosphorus release and uptake by low electrical current application in lab-scale bio-electrochemical reactors.

    PubMed

    Zhang, Lehua; Ma, Jingxing; Liu, Yongdi; Li, Dongmei; Shi, Haifeng; Cai, Lankun

    2012-12-01

    The overall process enhancement by different electrical current application on the biological phosphorus release and uptake have been investigated. Five reactors were constructed for three experiments and activated sludge was used as inoculums. In Exp.1 by comparing the control and the bio-electrochemical reactors, it was found that the overall phosphorus removal efficiency could be enhanced at lower electrical current applications of 5mA and 10mA, but were restrained at higher than 20mA, although 20mA could be a sensitive turning point. Moreover, the electrochemical effects of the cathodic and the anodic reactions on the phosphorus release and uptake, respectively, have been further evaluated separately under an electrical current application of 10mA in Exp.2 and Exp.3, respectively. As observed, both of the biological release and uptake were improved by the cathodic reactions in the cathode reactor, but not by the anodic reactions in the anode reactor, and thus indicated that the cathodic reactions play an important role in the improvement of the biological phosphorus release and uptake.

  5. Determination of inverse electric field strength of Ta 218O 5 film produced in biological electrolytes using 18O(p, α) 15N nuclear reaction analysis

    NASA Astrophysics Data System (ADS)

    Wosu, Sylvanus N.

    2005-08-01

    A 18O(p, α) 15N nuclear reaction analysis (NRA) method was developed for the determination of inverse electric field strengths (also referred to as anodic constants) of Ta 2O 5 oxide films prepared in biological solutions (urine, blood plasma and serum). The results show that fresh biological electrolytes have inverse electric field strengths equal to 17.5 ± 1.2, 17.3 ± 1.2, 17.3 ± 0.8 Å/V for plasma, serum and urine, respectively compared to 16.2 ± 0.2 and 15.7 Å/V, for 3% ammonium citrate water and distilled water, respectively. The inverse electric field strength is shown to depend on the pH variation, the metal substrate and the electrolytic ionic concentration. Freezing or aging of the biological sample results in greater variation and reduction of solution pH. Particle-induced X-ray emission (PIXE) and energy dispersive X-ray (EDS) analyses show no incorporation of ions of Z > 11.

  6. Nanoscale analysis of unstained biological specimens in water without radiation damage using high-resolution frequency transmission electric-field system based on FE-SEM

    SciTech Connect

    Ogura, Toshihiko

    2015-04-10

    Scanning electron microscopy (SEM) has been widely used to examine biological specimens of bacteria, viruses and proteins. Until now, atmospheric and/or wet biological specimens have been examined using various atmospheric holders or special equipment involving SEM. Unfortunately, they undergo heavy radiation damage by the direct electron beam. In addition, images of unstained biological samples in water yield poor contrast. We recently developed a new analytical technology involving a frequency transmission electric-field (FTE) method based on thermionic SEM. This method is suitable for high-contrast imaging of unstained biological specimens. Our aim was to optimise the method. Here we describe a high-resolution FTE system based on field-emission SEM; it allows for imaging and nanoscale examination of various biological specimens in water without radiation damage. The spatial resolution is 8 nm, which is higher than 41 nm of the existing FTE system. Our new method can be easily utilised for examination of unstained biological specimens including bacteria, viruses and protein complexes. Furthermore, our high-resolution FTE system can be used for diverse liquid samples across a broad range of scientific fields, e.g. nanoparticles, nanotubes and organic and catalytic materials. - Highlights: • We developed a high-resolution frequency transmission electric-field (FTE) system. • High-resolution FTE system is introduced in the field-emission SEM. • The spatial resolution of high-resolution FTE method is 8 nm. • High-resolution FTE system enables observation of the intact IgM particles in water.

  7. Applying electrical resistivity tomography and biological methods to assess the surface-groundwater interaction in two Mediterranean rivers (central Spain)

    NASA Astrophysics Data System (ADS)

    Iepure, Sanda; Gómez Ortiz, David; Lillo Ramos, Javier; Rasines Ladero, Ruben; Persoiu, Aurel

    2014-05-01

    Delineation of the extent of hyporheic zone (HZ) in river ecosystems is problematic due to the scarcity of spatial information about the structure of riverbed sediments and the magnitude and extent of stream interactions with the parafluvial and riparian zones. The several existing methods vary in both quality and quantity of information and imply the use of hydrogeological and biological methods. In the last decades, various non-invasive geophysical techniques were developed to characterise the streambed architecture and also to provide detailed spatial information on its vertical and horizontal continuity. All classes of techniques have their strengths and limitations; therefore, in order to assess their potential in delineating the lateral and vertical spatial extents of alluvial sediments, we have combined the near-surface images obtained by electrical resistivity tomography (ERT) with biological assessment of invertebrates in two Mediterranean lowland rivers from central Spain. We performed in situ imaging of the thickness and continuity of alluvial sediments under the riverbed and parafluvial zone during base-flow conditions (summer 2013 and winter 2014) at two different sites with distinct lithology along the Tajuña and Henares Rivers. ERT was performed by installing the electrodes (1 m spacing) on a 47 m long transect normal to the river channel using a Wener-Schlumberger array, across both the riparian zones and the river bed. Invertebrates were collected in the streambed from a depth of 20-40 cm, using the Bou-Rouch method, and from boreholes drilled to a depth of 1.5 m in the riparian zone. The ERT images obtained at site 1 (medium and coarse sand dominated lithology) shows resistivity values ranging from ~20 to 80 ohm•m for the in-stream sediments, indicating a permeable zone up to ~ 0.5 m thick and extending laterally for ca. 5 m from the channel. These sediments contribute to active surface/hyporheic water exchanges and to low water retention in

  8. A Hybrid Functional Electrical Stimulation for Real-Time Estimation of Joint Torque and Closed-Loop Control of Muscle Activation

    PubMed Central

    Li, Zhan; Guiraud, David; Andreu, David; Fattal, Charles; Gelis, Anthony; Hayashibe, Mitsuhiro

    2016-01-01

    As a neuroprosthetic technique, functional electrical stimulation (FES) can restore lost motor performance of impaired patients. Through delivering electrical pulses to target muscles, the joint movement can be eventually elicited. This work presents a real-time FES system which is able to deal with two neuroprosthetic missions: one is estimating FES-induced joint torque with evoked electromyograph (eEMG), and the other is artificially controlling muscle activation with such eEMG feedback. The clinical experiment results on spinal cord injured (SCI) patients and healthy subjects show promising performance of the proposed FES system. PMID:27990235

  9. Gradient-based Electrical Properties Tomography (gEPT): a Robust Method for Mapping Electrical Properties of Biological Tissues In Vivo Using Magnetic Resonance Imaging

    PubMed Central

    Liu, Jiaen; Zhang, Xiaotong; Schmitter, Sebastian; Van de Moortele, Pierre-Francois; He, Bin

    2014-01-01

    Purpose To develop high-resolution electrical properties tomography (EPT) methods and investigate a gradient-based EPT (gEPT) approach which aims to reconstruct the electrical properties (EP), including conductivity and permittivity, of an imaged sample from experimentally measured B1 maps with improved boundary reconstruction and robustness against measurement noise. Theory and Methods Using a multi-channel transmit/receive stripline head coil, with acquired B1 maps for each coil element, by assuming negligible Bz component compared to transverse B1 components, a theory describing the relationship between B1 field, EP value and their spatial gradient has been proposed. The final EP images were obtained through spatial integration over the reconstructed EP gradient. Numerical simulation, physical phantom and in vivo human experiments at 7 T have been conducted to evaluate the performance of the proposed methods. Results Reconstruction results were compared with target EP values in both simulations and phantom experiments. Human experimental results were compared with EP values in literature. Satisfactory agreement was observed with improved boundary reconstruction. Importantly, the proposed gEPT method proved to be more robust against noise when compared to previously described non-gradient-based EPT approaches. Conclusion The proposed gEPT approach holds promises to improve EP mapping quality by recovering the boundary information and enhancing robustness against noise. PMID:25213371

  10. Avoidance of an electric field by insects: Fundamental biological phenomenon for an electrostatic pest-exclusion strategy

    NASA Astrophysics Data System (ADS)

    Matsuda, Y.; Nonomura, T.; Kakutani, K.; Kimbara, J.; Osamura, K.; Kusakari, S.; Toyoda, H.

    2015-10-01

    An electric field screen is a physical device used to exclude pest insects from greenhouses and warehouses to protect crop production and storage. The screen consists of iron insulated conductor wires (ICWs) arrayed in parallel and linked to each other, an electrostatic DC voltage generator used to supply a negative charge to the ICWs, and an earthed stainless net placed on one side of the ICW layer. The ICW was negatively charged to polarize the earthed net to create a positive charge on the ICW side surface, and an electric field formed between the opposite charges of the ICW and earthed net. The current study focused on the ability of the screen to repel insects reaching the screen net. This repulsion was a result of the insect's behaviour, i.e., the insects were deterred from entering the electric field of the screen. In fact, when the screen was negatively charged with the appropriate voltages, the insects placed their antennae inside the screen and then flew away without entering. Obviously, the insects recognized the electric field using their antennae and thereby avoided entering. Using a wide range of insects and spiders belonging to different taxonomic groups, we confirmed that the avoidance response to the electric field was common in these animals.

  11. E. coli electroeradication on a closed loop circuit by using milli-, micro- and nanosecond pulsed electric fields: comparison between energy costs.

    PubMed

    Guionet, Alexis; David, Fabienne; Zaepffel, Clément; Coustets, Mathilde; Helmi, Karim; Cheype, Cyril; Packan, Denis; Garnier, Jean-Pierre; Blanckaert, Vincent; Teissié, Justin

    2015-06-01

    One of the different ways to eradicate microorganisms, and particularly bacteria that might have an impact on health consists in the delivery of pulsed electric fields (PEFs). The technologies of millisecond (ms) or microsecond (μs) PEF are still well known and used for instance in the process of fruit juice sterilization. However, this concept is costly in terms of delivered energy which might be too expensive for some other industrial processes. Nanosecond pulsed electric fields (nsPEFs) might be an alternative at least for lower energetic cost. However, only few insights were available and stipulate a gain in cost and in efficiency as well. Using Escherichia coli, the impact of frequency and low rate on eradication and energy consumption by msPEF, μsPEF and nsPEF have been studied and compared. While a 1 log10 was reached with an energy cost of 100 and 158 kJ/L with micro- and millisecond PEFs respectively, nsPEF reached the reduction for similar energy consumption. The best condition was obtained for a 1 log10 deactivation in 0.5h, for energy consumption of 143 kJ/L corresponding to 0.04 W · h when the field was around 100 kV/cm. Improvement can also be expected by producing a generator capable to increase the electric field.

  12. Recovery and biological oxidation of dissolved methane in effluent from UASB treatment of municipal sewage using a two-stage closed downflow hanging sponge system.

    PubMed

    Matsuura, Norihisa; Hatamoto, Masashi; Sumino, Haruhiko; Syutsubo, Kazuaki; Yamaguchi, Takashi; Ohashi, Akiyoshi

    2015-03-15

    A two-stage closed downflow hanging sponge (DHS) reactor was used as a post-treatment to prevent methane being emitted from upflow anaerobic sludge blanket (UASB) effluents containing unrecovered dissolved methane. The performance of the closed DHS reactor was evaluated using real municipal sewage at ambient temperatures (10-28 °C) for one year. The first stage of the closed DHS reactor was intended to recover dissolved methane from the UASB effluent and produce a burnable gas with a methane concentration greater than 30%, and its recovery efficiency was 57-88%, although the amount of dissolved methane in the UASB effluent fluctuated in the range of 46-68 % of methane production greatly depending on the temperature. The residual methane was oxidized and the remaining organic carbon was removed in the second closed DHS reactor, and this reactor performed very well, removing more than 99% of the dissolved methane during the experimental period. The rate at which air was supplied to the DHS reactor was found to be one of the most important operating parameters. Microbial community analysis revealed that seasonal changes in the methane-oxidizing bacteria were key to preventing methane emissions.

  13. Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

    PubMed

    Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

    2016-11-21

    In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

  14. Closed DHS system to prevent dissolved methane emissions as greenhouse gas in anaerobic wastewater treatment by its recovery and biological oxidation.

    PubMed

    Matsuura, N; Hatamoto, M; Sumino, H; Syutsubo, K; Yamaguchi, T; Ohashi, A

    2010-01-01

    Anaerobic wastewater treatment has been focused on its eco-friendly nature in terms of the improved energy conservation and reduction in carbon dioxide emissions. However, the anaerobic process discharges unrecovered methane as dissolved methane. In this study, to prevent the emission of dissolved methane from up-flow anaerobic sludge blanket (UASB) reactors used to treat sewage and to recover it as useful gas, we employed a two-stage down-flow hanging sponge (DHS) reactor as a post-treatment of the UASB reactor. The closed DHS reactor in the first stage was intended for the recovery of dissolved methane from the UASB reactor effluent; the reactor could successfully recover an average of 76.8% of the influent dissolved methane as useful gas (containing methane over 30%) with hydraulic retention time of 2 h. During the experimental period, it was possible to maintain the recovered methane concentrations greater than 30% by adjusting the air supply rate. The remaining dissolved methane after the first stage was treated by the next step. The second closed DHS reactor was operated for oxidation of the residual methane and polishing of the remaining organic carbons. The reactor had a high performance and the influent dissolved methane was mostly eliminated to approximately 0.01 mgCOD L(-1). The dissolved methane from the UASB reactor was completely eliminated--by more than 99%--by the post-treatment after the two-stage closed DHS system.

  15. Circadian rhythms in electrical circuits of Clivia miniata.

    PubMed

    Volkov, Alexander G; Wooten, Joseph D; Waite, Astian J; Brown, Corydon R; Markin, Vladislav S

    2011-10-15

    The biological clock regulates a wide range of physiological processes in plants. Here we show circadian variation of the Clivia miniata responses to electrical stimulation. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), which regulate its physiology, were analyzed in vivo using the charge stimulation method. The electrostimulation was provided with different voltages and electrical charges. Resistance between Ag/AgCl electrodes in the leaf of C. miniata was higher at night than during the day or the following day in the darkness. The biologically closed electrical circuits with voltage gated ion channels in C. miniata are activated the next day, even in the darkness. C. miniata memorizes daytime and nighttime. At continuous light, C. miniata recognizes nighttime and increases the input resistance to the nighttime value even under light. These results show that the circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate voltage gated ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge and speed of transmission of electrical energy from the electrostimulator to the C. miniata leaves. We present the equivalent electrical circuits in C. miniata and its circadian variation to explain the experimental data.

  16. Closing in on Close Reading

    ERIC Educational Resources Information Center

    Boyles, Nancy

    2013-01-01

    "A significant body of research links the close reading of complex text--whether the student is a struggling reader or advanced--to significant gains in reading proficiency and finds close reading to be a key component of college and career readiness" (Partnership for Assessment of Readiness for College and Careers, 2011, p. 7). When the author…

  17. The DuPont, Monsanto, General Electric {open_quotes}Lasagna{close_quotes} Remediation Project - joint R&D and financing

    SciTech Connect

    Palmer, P.A.

    1995-03-01

    The Lasagna project is the first of what we expect will be several large cooperative projects between industry consortia and government to develop improved remediation technologies. In 1992, Monsanto Company began contacting other major corporations to see if they were experiencing similar difficulties in applying cost-effective, or even workable technologies for industrial site remediation. Both General Electric and DuPont were early participants in the effort to develop a meeting with the EPA to discuss technical problems faced in cleanup, research needs, and ways to accelerate development of more cost-effective techniques. This paper provides some background on how this cooperative process came to reality, what the Lasagna process is and how the cooperative arrangements and financing are structured.

  18. Cryo-FIB-SEM serial milling and block face imaging: Large volume structural analysis of biological tissues preserved close to their native state.

    PubMed

    Vidavsky, Netta; Akiva, Anat; Kaplan-Ashiri, Ifat; Rechav, Katya; Addadi, Lia; Weiner, Steve; Schertel, Andreas

    2016-12-01

    Many important biological questions can be addressed by studying in 3D large volumes of intact, cryo fixed hydrated tissues (⩾10,000μm(3)) at high resolution (5-20nm). This can be achieved using serial FIB milling and block face surface imaging under cryo conditions. Here we demonstrate the unique potential of the cryo-FIB-SEM approach using two extensively studied model systems; sea urchin embryos and the tail fin of zebrafish larvae. We focus in particular on the environment of mineral deposition sites. The cellular organelles, including mitochondria, Golgi, ER, nuclei and nuclear pores are made visible by the image contrast created by differences in surface potential of different biochemical components. Auto segmentation and/or volume rendering of the image stacks and 3D reconstruction of the skeleton and the cellular environment, provides a detailed view of the relative distribution in space of the tissue/cellular components, and thus of their interactions. Simultaneous acquisition of secondary and back-scattered electron images adds additional information. For example, a serial view of the zebrafish tail reveals the presence of electron dense mineral particles inside mitochondrial networks extending more than 20μm in depth in the block. Large volume imaging using cryo FIB SEM, as demonstrated here, can contribute significantly to the understanding of the structures and functions of diverse biological tissues.

  19. How close we are to achieving commercially viable large-scale photobiological hydrogen production by cyanobacteria: a review of the biological aspects.

    PubMed

    Sakurai, Hidehiro; Masukawa, Hajime; Kitashima, Masaharu; Inoue, Kazuhito

    2015-03-18

    Photobiological production of H2 by cyanobacteria is considered to be an ideal source of renewable energy because the inputs, water and sunlight, are abundant. The products of photobiological systems are H2 and O2; the H2 can be used as the energy source of fuel cells, etc., which generate electricity at high efficiencies and minimal pollution, as the waste product is H2O. Overall, production of commercially viable algal fuels in any form, including biomass and biodiesel, is challenging, and the very few systems that are operational have yet to be evaluated. In this paper we will: briefly review some of the necessary conditions for economical production, summarize the reports of photobiological H2 production by cyanobacteria, present our schemes for future production, and discuss the necessity for further progress in the research needed to achieve commercially viable large-scale H2 production.

  20. How Close We Are to Achieving Commercially Viable Large-Scale Photobiological Hydrogen Production by Cyanobacteria: A Review of the Biological Aspects

    PubMed Central

    Sakurai, Hidehiro; Masukawa, Hajime; Kitashima, Masaharu; Inoue, Kazuhito

    2015-01-01

    Photobiological production of H2 by cyanobacteria is considered to be an ideal source of renewable energy because the inputs, water and sunlight, are abundant. The products of photobiological systems are H2 and O2; the H2 can be used as the energy source of fuel cells, etc., which generate electricity at high efficiencies and minimal pollution, as the waste product is H2O. Overall, production of commercially viable algal fuels in any form, including biomass and biodiesel, is challenging, and the very few systems that are operational have yet to be evaluated. In this paper we will: briefly review some of the necessary conditions for economical production, summarize the reports of photobiological H2 production by cyanobacteria, present our schemes for future production, and discuss the necessity for further progress in the research needed to achieve commercially viable large-scale H2 production. PMID:25793279

  1. A computational method for the detection of activation/deactivation patterns in biological signals with three levels of electric intensity.

    PubMed

    Guerrero, J A; Macías-Díaz, J E

    2014-02-01

    In the present work, we develop a computational technique to approximate the changes of phase in temporal series associated to electric signals of muscles which perform activities at three different levels of intensity. We suppose that the temporal series are samples of independent, normally distributed random variables with mean equal to zero, and variance equal to one of three possible values, each of them associated to a certain degree of electric intensity. For example, these intensity levels may represent a leg muscle at rest, or active during a light activity (walking), or active during a highly demanding performance (jogging). The model is presented as a maximum likelihood problem involving discrete variables. In turn, this problem is transformed into a continuous one via the introduction of continuous variables with penalization parameters, and it is solved recursively through an iterative numerical method. An a posteriori treatment of the results is used in order to avoid the detection of relatively short periods of silence or activity. We perform simulations with synthetic data in order to assess the validity of our technique. Our computational results show that the method approximates well the occurrence of the change points in synthetic temporal series, even in the presence of autocorrelated sequences. In the way, we show that a generalization of a computational technique for the change-point detection of electric signals with two phases of activity (Esquivel-Frausto et al., 2010 [40]), may be inapplicable in cases of temporal series with three levels of intensity. In this sense, the method proposed in the present manuscript improves previous efforts of the authors.

  2. LASER BIOLOGY AND MEDICINE: Effect of repetitive laser pulses on the electrical conductivity of intervertebral disc tissue

    NASA Astrophysics Data System (ADS)

    Omel'chenko, A. I.; Sobol', E. N.

    2009-03-01

    The thermomechanical effect of 1.56-μm fibre laser pulses on intervertebral disc cartilage has been studied using ac conductivity measurements with coaxial electrodes integrated with an optical fibre for laser radiation delivery to the tissue. The observed time dependences of tissue conductivity can be interpreted in terms of hydraulic effects and thermomechanical changes in tissue structure. The laserinduced changes in the electrical parameters of the tissue are shown to correlate with the structural changes, which were visualised using shadowgraph imaging. Local ac conductivity measurements in the bulk of tissue can be used to develop a diagnostic/monitoring system for laser regeneration of intervertebral discs.

  3. (Study of the behavioral and biological effects of high intensity 60 Hz electric fields): Quarterly technical progress report No. 29

    SciTech Connect

    Orr, J.L.

    1989-07-14

    Activities this quarter involved all phases of the project plus a meeting of the Joint Committee in Tokyo. Detailed mapping of the exposure facility is scheduled to be completed during the week of August 14, 1989. Both electric and magnetic fields should be available for tests of the components of the tether and blood sampling system for the neuroendocrine pilot study in September 1989. The groups for the social behavior study are stabilizing appropriately. Details on the formation of the groups and their status has been provided. Dr. Coelho has included information related to aspects of the social experiment ranging from age estimation in baboons through the cardiovascular consequences of psychosocial stress. In addition, a draft manuscript is included on the data from the previous experiments which describes the effects of 30 and 60 kV/m electric fields on the social behavior of baboons. Tests of the blood handling procedures and analysis methods have been completed. With the exception of the catecholamine analyses, the handling procedures and variability in replicate measurements are satisfactory. Logistic and practical considerations now weigh strongly against including the analysis of the blood samples for catecholamines. Preliminary tests indicate that a sampling procedure which will work for the other compounds is probably not satisfactory for the catecholamines.

  4. Substrate removal and electricity generation in a membrane-less microbial fuel cell for biological treatment of wastewater.

    PubMed

    Wang, Haiping; Jiang, Sunny C; Wang, Yun; Xiao, Bo

    2013-06-01

    Microbial fuel cells have gained popularity in recent years due to its promise in converting organic wastewater into renewable electrical energy. In this study, a membrane-less MFC with a biocathode was developed to evaluate its performance in electricity generation while simultaneously treating wastewater. The MFC fed with a continuous flow of 2g/day acetate produced a power density of 30 mW/m(2) and current density of 245 mA/m(2). A substrate degradation efficiency (SDE) of 75.9% was achieved with 48.7% attributed to the anaerobic process and 27.2% to the aerobic process. Sequencing analysis of the microbial consortia using 16S rDNA pryosequencing showed the predominance of Bacteroidia in the anode after one month of operation, while the microbial community in the cathode chamber was dominated by Gamma-proteobacteria and Beta-proteobacteria. Coulombic efficiencies varied from 19.8% to 58.1% using different acetate concentrations, indicating power density can be further improved through the accumulation of electron-transferring bacteria.

  5. Regulation of SOD2 in Cancer by Histone Modifications and CpG Methylation: Closing the Loop Between Redox Biology and Epigenetics

    PubMed Central

    Cyr, Anthony R.; Hitchler, Michael J.

    2013-01-01

    Abstract Significance: Manganese superoxide dismutase (SOD2), encoded by the nuclear gene SOD2, is a critical mitochondrial antioxidant enzyme whose activity has broad implications in health and disease. Thirty years ago, Oberley and Buettner elegantly folded SOD2 into cancer biology with the free radical theory of cancer, which was built on the observation that many human cancers had reduced SOD2 activity. In the original formulation, the loss of SOD2 in tumor cells produced a state of perpetual oxidative stress, which, in turn, drove genetic instability, leading to cancer development. Recent Advances: In the past two decades, research has established that SOD2 transcriptional activity is controlled, at least in part, via epigenetic mechanisms at different stages in the development of human cancer. These mechanisms, which include histone methylation, histone acetylation, and DNA methylation, are increasingly recognized as being aberrantly regulated in human cancer. Indeed, the epigenetic progenitor model proposed by Henikoff posits that epigenetic events are central governing agents of carcinogenesis. Important recent advances in epigenetics research have indicated that the loss of SOD activity itself may contribute to changes in epigenetic regulation, establishing a vicious cycle that drives further epigenetic instability. Critical Issues: With these observations in mind, we propose an epigenetic revision to the free radical theory of cancer: that loss of SOD activity promotes epigenetic aberrancies, driving the epigenetic instability in tumor cells which produces broad phenotypic effects. Future Directions: The development of next-generation sequencing technologies and novel approaches in systems biology and bioinformatics promise to make testing this exciting model a reality in the near future. Antioxid. Redox Signal. 18, 1946–1955. PMID:22946823

  6. Controllable growth of monolayer MoS2 by chemical vapor deposition via close MoO2 precursor for electrical and optical applications

    NASA Astrophysics Data System (ADS)

    Xie, Yong; Wang, Zhan; Zhan, Yongjie; Zhang, Peng; Wu, Ruixue; Jiang, Teng; Wu, Shiwei; Wang, Hong; Zhao, Ying; Nan, Tang; Ma, Xiaohua

    2017-02-01

    MoO2 is used as a new source material for the growth of large area and high optical quality monolayer MoS2. However, a systematic study of the growth parameters is still missing and large-area growth of discreet single crystals is still challenging. Hereby, we report the shape evolution of monolayer growth of MoS2 and develop a methodology to achieve centimeter-scaled discrete MoS2 by adopting MoO2 as Mo source material in an atmospheric-pressure chemical vapor deposition process. Our results indicate the growth of monolayer MoS2 could benefit from the precise control of the introduction time of sulfur and the S/MoO2 ratio in experiments. Micro-Raman and photoluminescence spectra confirm the properties of the material. E-beam lithography was utilized to make contact with the as-grown MoS2 located at the selective area. The electrical properties of MoS2 with different morphologies were compared. In the end, the persistent photoconductivity properties of monolayer MoS2 were emphasized and the underlying mechanism was proposed. These studies demonstrate a better understanding of the growth and application of MoS2-based 2D materials.

  7. Controllable growth of monolayer MoS2 by chemical vapor deposition via close MoO2 precursor for electrical and optical applications.

    PubMed

    Xie, Yong; Wang, Zhan; Zhan, Yongjie; Zhang, Peng; Wu, Ruixue; Jiang, Teng; Wu, Shiwei; Wang, Hong; Zhao, Ying; Nan, Tang; Ma, Xiaohua

    2017-02-24

    MoO2 is used as a new source material for the growth of large area and high optical quality monolayer MoS2. However, a systematic study of the growth parameters is still missing and large-area growth of discreet single crystals is still challenging. Hereby, we report the shape evolution of monolayer growth of MoS2 and develop a methodology to achieve centimeter-scaled discrete MoS2 by adopting MoO2 as Mo source material in an atmospheric-pressure chemical vapor deposition process. Our results indicate the growth of monolayer MoS2 could benefit from the precise control of the introduction time of sulfur and the S/MoO2 ratio in experiments. Micro-Raman and photoluminescence spectra confirm the properties of the material. E-beam lithography was utilized to make contact with the as-grown MoS2 located at the selective area. The electrical properties of MoS2 with different morphologies were compared. In the end, the persistent photoconductivity properties of monolayer MoS2 were emphasized and the underlying mechanism was proposed. These studies demonstrate a better understanding of the growth and application of MoS2-based 2D materials.

  8. Volume II solicitation package for solicitation no. 522887-5422 {open_quotes}site electrical replacements & substation{close_quotes} subproject: 69 KV substation

    SciTech Connect

    1991-05-03

    This solicitation is for the U.S. Department of Energy under Prime Contract No. DE-AC04-88-DP43495 with EG&G Mound Applied Technologies. Ohio Sales or Use taxes are not to be included in the proposal price. Applicable taxes due or owing to the State of Ohio will be paid by the buyer under Direct Payment Permit No. 98-002230. Refer to Form ML-2487, General Provisions, Article 24, {open_quotes}Federal, State & Local Taxes{close_quotes}. Sellers are advised that purchases of building and construction materials for incorporation into a structure or improvement to a real property which is accepted for ownership by the United States or one of its agencies are exempt from Ohio Sales and Use taxes. Unnecessarily elaborate brochures or other presentations beyond those sufficient to present a complete and effective response to this solicitation are not desired and may be construed as an indication of the seller`s lack of cost consciousness. Elaborate art work, expensive paper and binding, and expensive visual and other presentation aids are neither necessary nor wanted.

  9. Electrical detection of the biological interaction of a charged peptide via gallium arsenide junction-field-effect transistors

    NASA Astrophysics Data System (ADS)

    Lee, Kangho; Nair, Pradeep R.; Alam, Muhammad A.; Janes, David B.; Wampler, Heeyeon P.; Zemlyanov, Dmitry Y.; Ivanisevic, Albena

    2008-06-01

    GaAs junction-field-effect transistors (JFETs) are utilized to achieve label-free detection of biological interaction between a probe transactivating transcriptional activator (TAT) peptide and the target trans-activation-responsive (TAR) RNA. The TAT peptide is a short sequence derived from the human immunodeficiency virus-type 1 TAT protein. The GaAs JFETs are modified with a mixed adlayer of 1-octadecanethiol (ODT) and TAT peptide, with the ODT passivating the GaAs surface from polar ions in physiological solutions and the TAT peptide providing selective binding sites for TAR RNA. The devices modified with the mixed adlayer exhibit a negative pinch-off voltage (VP) shift, which is attributed to the fixed positive charges from the arginine-rich regions in the TAT peptide. Immersing the modified devices into a TAR RNA solution results in a large positive VP shift (>1 V) and a steeper subthreshold slope (˜80 mV/decade), whereas "dummy" RNA induced a small positive VP shift (˜0.3 V) without a significant change in subthreshold slopes (˜330 mV/decade). The observed modulation of device characteristics is analyzed with analytical modeling and two-dimensional numerical device simulations to investigate the electronic interactions between the GaAs JFETs and biological molecules.

  10. Electrical detection of the biological interaction of a charged peptide via gallium arsenide junction-field-effect transistors.

    PubMed

    Lee, Kangho; Nair, Pradeep R; Alam, Muhammad A; Janes, David B; Wampler, Heeyeon P; Zemlyanov, Dmitry Y; Ivanisevic, Albena

    2008-06-01

    GaAs junction-field-effect transistors (JFETs) are utilized to achieve label-free detection of biological interaction between a probe transactivating transcriptional activator (TAT) peptide and the target trans-activation-responsive (TAR) RNA. The TAT peptide is a short sequence derived from the human immunodeficiency virus-type 1 TAT protein. The GaAs JFETs are modified with a mixed adlayer of 1-octadecanethiol (ODT) and TAT peptide, with the ODT passivating the GaAs surface from polar ions in physiological solutions and the TAT peptide providing selective binding sites for TAR RNA. The devices modified with the mixed adlayer exhibit a negative pinch-off voltage (V(P)) shift, which is attributed to the fixed positive charges from the arginine-rich regions in the TAT peptide. Immersing the modified devices into a TAR RNA solution results in a large positive V(P) shift (>1 V) and a steeper subthreshold slope ( approximately 80 mVdecade), whereas "dummy" RNA induced a small positive V(P) shift ( approximately 0.3 V) without a significant change in subthreshold slopes ( approximately 330 mVdecade). The observed modulation of device characteristics is analyzed with analytical modeling and two-dimensional numerical device simulations to investigate the electronic interactions between the GaAs JFETs and biological molecules.

  11. Biological studies of swine exposed to 60-Hz electric fields. Volume 4: growth, reproduction, and development. Final report

    SciTech Connect

    Not Available

    1985-12-01

    Swine were exposed to uniform, vertical, 60-Hz, 30-kV/m electric fields for 20 hours/day, 7 days/week. The parental generation (F/sub 0/ gilts) was bred after 4 months on study; some were killed for teratologic study at 100 days of gestation (dg), and the others produced a first-generation (F/sub 1/) of offspring. The pooled incidence of terata in these litters was similar in the exposed and sham-exposed groups. The F/sub 0/ females, which produced the F/sub 1/ generation, were rebred after 18 months of exposure and were killed at 100 dg: malformation incidence in exposed litters (75%) was significantly greater than in sham-exposed litters (29%). Types of malformations were not dissimilar between the two groups. The F/sub 1/ gilts were bred at 18 months of age; there were indications of impaired copulatory behavior and decreased fertility in the exposed animals. Defective offspring were found in significantly more of the exposed litters (71%) than in sham-exposed litters (33%). The F/sub 1/ sows were bred again 10 months later, and teratologic evaluations were performed on their second litters at 100 dg. The percentage of litters with malformed fetuses was essentially identical in the exposed and sham-exposed groups (70 and 73%, respectively). The change in malformation incidences between generations and between the first and second breedings makes it difficult to unequivocally conclude that chronic exposure to a strong electric field caused developmental effects in swine, although it appears there may be an association. It is also possible that other factors, such as housing, inbreeding, disease or its treatment may have contributed to the results. 22 refs., 9 figs., 28 tabs.

  12. Close encounters of the small kind: adverse effects of man-made materials interfacing with the nano-cosmos of biological systems.

    PubMed

    Shvedova, Anna A; Kagan, Valerian E; Fadeel, Bengt

    2010-01-01

    Engineered nanomaterials have unique physico-chemical properties that make them promising for many technological and biomedical applications, including tissue regeneration, drug and gene delivery, and in vivo monitoring of disease processes. However, with the burgeoning capabilities to manipulate structures at the nano-scale, intentional as well as unintentional human exposures to engineered nanomaterials are set to increase. Nanotoxicology is an emerging discipline focused on understanding the properties of engineered nanomaterials and their interactions with biological systems, and may be viewed as the study of the undesirable interference between man-made nanomaterials and cellular nanostructures or nanomachines. In this review, we discuss recognition of engineered nanomaterials by the immune system, our primary defense system against foreign invasion. Moreover, as oxidative stress is believed to be one of the major deleterious consequences of exposure to nanomaterials, we explore triggering of pro- and antioxidant pathways as well as biomarkers of oxidative stress. Finally, we highlight in vivo studies of the toxicological outcomes of engineered nanomaterials, including carbon nanotubes, with an emphasis on inflammation and genotoxic responses.

  13. Defining the biomechanical and biological threshold of murine mild traumatic brain injury using CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration).

    PubMed

    Namjoshi, Dhananjay R; Cheng, Wai Hang; Bashir, Asma; Wilkinson, Anna; Stukas, Sophie; Martens, Kris M; Whyte, Tom; Abebe, Zelalem A; McInnes, Kurt A; Cripton, Peter A; Wellington, Cheryl L

    2017-03-05

    CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration) is a recently described animal model of traumatic brain injury (TBI) that primarily produces diffuse axonal injury (DAI) characterized by white matter inflammation and axonal damage. CHIMERA was specifically designed to reliably generate a variety of TBI severities using precise and quantifiable biomechanical inputs in a nonsurgical user-friendly platform. The objective of this study was to define the lower limit of single impact mild TBI (mTBI) using CHIMERA by characterizing the dose-response relationship between biomechanical input and neurological, behavioral, neuropathological and biochemical outcomes. Wild-type male mice were subjected to a single CHIMERA TBI using six impact energies ranging from 0.1 to 0.7J, and post-TBI outcomes were assessed over an acute period of 14days. Here we report that single TBI using CHIMERA induces injury dose- and time-dependent changes in behavioral and neurological deficits, axonal damage, white matter tract microgliosis and astrogliosis. Impact energies of 0.4J or below produced no significant phenotype (subthreshold), 0.5J led to significant changes for one or more phenotypes (threshold), and 0.6 and 0.7J resulted in significant changes in all outcomes assessed (mTBI). We further show that linear head kinematics are the most robust predictors of duration of unconsciousness, severity of neurological deficits, white matter injury, and microgliosis following single TBI. Our data extend the validation of CHIMERA as a biofidelic animal model of DAI and establish working parameters to guide future investigations of the mechanisms underlying axonal pathology and inflammation induced by mechanical trauma.

  14. Biological effect of an alternating electric field on cell proliferation and synergistic antimitotic effect in combination with ionizing radiation

    PubMed Central

    Kim, Eun Ho; Kim, Ye Jin; Song, Hyo Sook; Jeong, Youn Kyoung; Lee, Ji Young; Sung, Jiwon; Yoo, Seung Hoon; Yoon, Myonggeun

    2016-01-01

    Alternating electric fields at an intermediate frequency (100~300 kHz), referred to as tumour-treating fields (TTF), are believed to interrupt the process of mitosis via apoptosis and to act as an inhibitor of cell proliferation. Although the existence of an antimitotic effect of TTF is widely known, the proposed apoptotic mechanism of TTF on cell function and the efficacy of TTF are controversial issues among medical experts. To resolve these controversial issues, a better understanding of the underlying molecular mechanisms of TTF on cell function and the differences between the effects of TTF alone and in combination with other treatment techniques is essential. Here, we report experimental evidence of TTF-induced apoptosis and the synergistic antimitotic effect of TTF in combination with ionizing radiation (IR). For these experiments, two human Glioblastoma multiforme (GBM) cells (U373 and U87) were treated either with TTF alone or with TTF followed by ionizing radiation (IR). Cell apoptosis, DNA damage, and mitotic abnormalities were quantified after the application of TTF, and their percentages were markedly increased when TTF was combined with IR. Our experimental results also suggested that TTF combined with IR synergistically suppressed both cell migration and invasion, based on the inhibition of MMP-9 and vimentin. PMID:27556699

  15. How Close Is Close Reading?

    ERIC Educational Resources Information Center

    Saccomano, Doreen

    2014-01-01

    Close Reading is a strategy that can be used when reading challenging text. This strategy requires teachers to provide scaffolding, and create opportunities for think-alouds and rereading of text in order to help students become active readers who focus on finding text-based support for their answers. In addition, teachers must also be aware of…

  16. Long-term biological effects of air ions and D.C. electric fields on Namru mice: First year report

    NASA Astrophysics Data System (ADS)

    Kellogg, E. W.; Yost, M. G.; Reed, E. J.; Krueger, A. P.

    1985-09-01

    This report describes for the first time the effects of long-term continuous exposures of animals to small air ions and D.C. electric fields. In this study we exposed 200 female NAMRU mice (25/cage) to the following conditions: ± high ions (2×105/cm3), ± low ions (2×103/cm3), ± field only and ground (ion depleted, no field). Specially designed cages provided a defined D.C. field of about 2 kV/meter in ionized environments, with somewhat lower values in the field only cages. Detailed mapping of ion flux originating from a tritium foil generating system (multiple sources in an overhead plate) indicated a well defined, but heterogenous pattern with eight peak areas. Using a 100 cm2 probe, ion flux values ranged from 10-12 10-14 A/cm2, with an average flux of 8.7±6.8×10-13 A/cm2 in high negative ion cages, with good reproducibility between cages. Measurements of serum glucose, cholesterol, and urea nitrogen (samples taken every three months) showed a number of small but consistent and statistically significant differences between animals maintained in different environments during the first year of exposure. Serum globulin and whole blood serotonin, however, did not show any significant environmental effects. Interestingly, pairwise comparisons between high negative and low negative ion conditions, or between high positive and low positive ion conditions, or between the two ground conditions, revealed no significant differences between cages. This argues for a similarity of environmental responses for the mice maintained in each of the compared conditions. The results of a multiple classification analysis for the entire first year showed a preponderence of effects for the ionized cages, although other conditions also had highly significant differences as compared to the grand mean value. While this study has shown effects of only small magnitude (compared to normal physiological variations) in the female NAMRU mice studied here, the significance of these results

  17. Plant electrical memory.

    PubMed

    Volkov, Alexander G; Carrell, Holly; Adesina, Tejumade; Markin, Vladislav S; Jovanov, Emil

    2008-07-01

    Electrical signaling, short-term memory and rapid closure of the carnivorous plant Dionaea muscipula Ellis (Venus flytrap) have been attracting the attention of researchers since the XIX century. We found that the electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf without mechanical stimulation of trigger hairs. The closing time of Venus flytrap by electrical stimulation is the same as mechanically induced closing. Transmission of a single electrical charge between a lobe and the midrib causes closure of the trap and induces an electrical signal propagating between both lobes and midrib. The Venus flytrap can accumulate small subthreshold charges, and when the threshold value is reached, the trap closes. Repeated application of smaller charges demonstrates the summation of stimuli. The cumulative character of electrical stimuli points to the existence of short-term electrical memory in the Venus flytrap.

  18. Closed Cycle Electric Discharge Laser Design Investigation

    DTIC Science & Technology

    1978-03-01

    lem has been made. It is clear that the medium will strongly affect the phase distribution of the laser beam and phase correction will be...92803 Attn: Dr. J. Winocur (D/528. HA 14) D-10 • 76. 77. 78. Rockwell International Corporation Rocketdyne Division 6633 Canoga Avenue

  19. Bottle Biology.

    ERIC Educational Resources Information Center

    Jager, Peter

    1993-01-01

    Describes activities which utilize plastic drink bottles and are designed to foster the development of a wide range of biological and ecological concepts. Includes instructions for making a model compost column and presents a model that illustrates open versus closed ecosystems. (DDR)

  20. Electricity and colloidal stability: how charge distribution in the tissue can affects wound healing.

    PubMed

    Farber, Paulo Luiz; Hochman, Bernardo; Furtado, Fabianne; Ferreira, Lydia Masako

    2014-02-01

    The role of endogenous electric fields in wound healing is still not fully understood. Electric fields are of fundamental importance in various biological processes, ranging from embryonic development to disease progression, as described by many investigators in the last century. This hypothesis brings together some relevant literature on the importance of electric fields in physiology and pathology, the theory of biologically closed electric circuits, skin battery (a phenomenon that occurs after skin injury and seems to be involved in tissue repair), the relationship between electric charge and interstitial exclusion, and how skin tissues can be regarded as colloidal systems. The importance of electric charges, as established in the early works on the subject and the relevance of zeta potential and colloid stability are also analyzed, and together bring a new light for the physics involved in the wound repair of all the body tissues.

  1. Moving droplets between closed and open microfluidic systems.

    PubMed

    Wang, Weiqiang; Jones, Thomas B

    2015-05-21

    In electric-field-mediated droplet microfluidics, there are two distinct architectures - closed systems using parallel-plate electrodes and open systems using coplanar electrodes fabricated on an open substrate. An architecture combining both closed and open systems on a chip would facilitate many of the chemical and biological processes now envisioned for the laboratory on a chip. To accomplish such an integration requires a means to move droplets back and forth between the two. This paper presents an investigation of the requirements for such manipulation of both water and oil droplets. The required wetting conditions for a droplet to cross the open/closed boundary is revealed by a force balance analysis and predictions of this model are compared to experimental results. Water droplets can be moved between closed and open systems by electrowetting actuation; droplet detachment from the upper plate is facilitated by the use of beveled edge. The force model predicts that driving an oil droplet from a closed to an open structure requires an oleophobic surface. This prediction has been tested and confirmed using <100> silicon wafers made oleophobic by re-entrant microstructures etched into the surface.

  2. Study of the behavioral and biological effects of high-strength 60-Hz electric fields. Quarterly technical progress report number 10, 18 December 1982-18 March 1983

    SciTech Connect

    Not Available

    1983-04-20

    The objective of this contract is to use the baboon as a surrogate for the human in studies of the possible deleterious effects of exposure to high strength, 60 Hz electric fields. The specific aims of this contract are to (1) design and construct an exposure facility in which baboons can be exposed to an electric field up to 60 kV/m in intensity for experiments and (2) to develop computer models relating the fields and currents produced in both baboons and humans by exposure to high strength, 60 Hz electric fields.

  3. Study of the behavioral and biological effects of high-strength 60-Hz electric fields. Quarterly progress report, 11 October 1981-10 January 1982. [Research plan

    SciTech Connect

    Rogers, W.R.

    1982-01-01

    The primary objective of this research is to study the effects of high intensity, 60 Hz electric fields on baboon behavior to obtain information which will assist in the determination of the degree of risk of deleterious consequences for humans exposed to such fields. The generalization of results obtained with the baboon to predictions concerning humans will be aided by the development of computer models relating the surface electric field intensities and internal current densities produced in baboons and humans by exposure to high intensity, 60 Hz electric fields. Research plans are described.

  4. Study of the behavioral and biological effects of high strength 60 HZ electric fields. Quarterly technical progress report No. 15, 12 May 1984-3 August 1984

    SciTech Connect

    Not Available

    1984-08-15

    Progress is reported in the construction of a test facility for studying the effects of high intensity, 60 Hz electric fields on baboons. Effects to be studied include operant out social behaviors. (ACR)

  5. 7 CFR 1786.105 - Closing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Prepayments on RUS Notes in the Event of a Merger of Certain RUS Electric Borrowers § 1786.105 Closing. (a... the prepayment agreement. RUS shall designate the date of closing which in no event shall be later... paying all current interest due on the date of prepayment, a borrower shall prepay the RUS Notes...

  6. Status report of current biological, medical, and engineering research and significant study results regarding potential human health effects associated with power-frequency electric and magnetic fields. Report for May 1989-August 1990

    SciTech Connect

    Not Available

    1990-09-01

    The report reviews planned and ongoing research on biological and health effects of 50- and 60-Hz electric and magnetic fields. The purpose of the report was to review results from research since May 1989 to determine new significant findings regarding potential human health impacts from electric-power frequency fields at levels expected from transmission and distribution sources. Information in the report came from a variety of sources (scientific meetings, sponsors of directed site visits and project reviews, International Data Base of ongoing and planned research on electric and magnetic fields) and may not appear in the scientific literature for several years. Information is presented on 120 ongoing and planned research projects throughout the world, of which many are focused in 4 major areas: cancer, reproduction and development, neuroendocrine system and mechanisms of interaction at the cellular and subcellular levels. There are 25 ongoing epidemiology studies, of which 21 are concerned with cancer and 4 with reproduction and development. Results from ongoing epidemiology studies dealing with cancer in which data are available support the results of many of the earlier studies in which there is an association between exposure to electric and magnetic fields and the incidence of cancer, particularly of the hematopoetic system and nervous system.

  7. Window-closing safety system

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    A safety device includes a wire loop embedded in the glass of a passenger car window and routed near the closing leading-edge of the window. The wire loop carries microwave pulses around the loop to and from a transceiver with separate output and input ports. An evanescent field only and inch or two in radius is created along the wire loop by the pulses. Just about any object coming within the evanescent field will dramatically reduce the energy of the microwave pulses received back by the transceiver. Such a loss in energy is interpreted as a closing area blockage, and electrical interlocks are provided to halt or reverse a power window motor that is actively trying to close the window.

  8. Window-closing safety system

    DOEpatents

    McEwan, T.E.

    1997-08-26

    A safety device includes a wire loop embedded in the glass of a passenger car window and routed near the closing leading-edge of the window. The wire loop carries microwave pulses around the loop to and from a transceiver with separate output and input ports. An evanescent field only an inch or two in radius is created along the wire loop by the pulses. Just about any object coming within the evanescent field will dramatically reduce the energy of the microwave pulses received back by the transceiver. Such a loss in energy is interpreted as a closing area blockage, and electrical interlocks are provided to halt or reverse a power window motor that is actively trying to close the window. 5 figs.

  9. Electric Field-Controlled Ion Transport In TiO2 Nanochannel.

    PubMed

    Li, Dan; Jing, Wenheng; Li, Shuaiqiang; Shen, Hao; Xing, Weihong

    2015-06-03

    On the basis of biological ion channels, we constructed TiO2 membranes with rigid channels of 2.3 nm to mimic biomembranes with flexible channels; an external electric field was employed to regulate ion transport in the confined channels at a high ionic strength in the absence of electrical double layer overlap. Results show that transport rates for both Na+ and Mg2+ were decreased irrespective of the direction of the electric field. Furthermore, a voltage-gated selective ion channel was formed, the Mg2+ channel closed at -2 V, and a reversed relative electric field gradient was at the same order of the concentration gradient, whereas the Na+ with smaller Stokes radius and lower valence was less sensitive to the electric field and thus preferentially occupied and passed the channel. Thus, when an external electric field is applied, membranes with larger nanochannels have promising applications in selective separation of mixture salts at a high concentration.

  10. Cell injury by electric forces.

    PubMed

    Lee, Raphael C

    2005-12-01

    The molecular architecture of biological systems is heavily influenced by the highly polar interactions of water. Thus, macromolecules such as proteins that are highly water soluble must be electrically polar. Energy generation methods needed to support cell metabolic processes depend on compartmentalizing mobile ions and thus require electrical ion transport barriers such as membranes. One consequence of these biological design constraints is vulnerability to injury by electrical forces. Supraphysiological electric forces cause damage to cells and tissues by disrupting cell membranes and altering the conformation of biomolecules. In addition, prolonged passage of electrical current leads to damage by thermal mechanisms. This review will focus on the non-thermal effects.

  11. Equation of state and electrical conductivity of {open_quotes}synthetic Uranus,{close_quotes} a mixture of water, ammonia, and isopropanol, at shock pressure up to 200 GPa (2 Mbar)

    SciTech Connect

    Nellis, W.J.; Holmes, N.C.; Mitchell, A.C.; Hamilton, D.C.; Nicol, M.

    1997-12-01

    Equation-of-state, temperature, and electrical-conductivity data were measured for a solution of water, ammonia, and isopropanol at shock pressures up to 200 GPa. The chemical composition is similar to that of the fluid mixture thought to be the major constituent of the giant planets Uranus and Neptune. {copyright} {ital 1997 American Institute of Physics.}

  12. A subsequent closed-form description of propagated signaling phenomena in the membrane of an axon

    NASA Astrophysics Data System (ADS)

    Melendy, Robert. F.

    2016-05-01

    I recently introduced a closed-form description of propagated signaling phenomena in the membrane of an axon [R.F. Melendy, Journal of Applied Physics 118, 244701 (2015)]. Those results demonstrate how intracellular conductance, the thermodynamics of magnetization, and current modulation, function together in generating an action potential in a unified, closed-form description. At present, I report on a subsequent closed-form model that unifies intracellular conductance and the thermodynamics of magnetization, with the membrane electric field, Em. It's anticipated this work will compel researchers in biophysics, physical biology, and the computational neurosciences, to probe deeper into the classical and quantum features of membrane magnetization and signaling, informed by the computational features of this subsequent model.

  13. School Closings in Philadelphia

    ERIC Educational Resources Information Center

    Jack, James; Sludden, John

    2013-01-01

    In 2012, the School District of Philadelphia closed six schools. In 2013, it closed 24. The closure of 30 schools has occurred amid a financial crisis, headlined by the district's $1.35 billion deficit. School closures are one piece of the district's plan to cut expenditures and close its budget gap. The closures are also intended to make…

  14. Mechanism of biological effects observed in honey bees (Apis mellifera, L. ) hived under extra-high-voltage transmission lines: implications derived from bee exposure to simulated intense electric fields and shocks

    SciTech Connect

    Bindokas, V.P.; Gauger, J.R.; Greenberg, B.

    1988-01-01

    This work explores mechanisms for disturbance of honey bee colonies under a 765 kV, 60-Hz transmission line (electric (E) field = 7 kV/m) observed in previous studies. Proposed mechanisms fell into two categories: direct bee perception of enhanced in-hive E fields and perception of shock from induced currents. The adverse biological effects could be reproduced in simulations where only the worker bees were exposed to shock or to E field in elongated hive entranceways (= tunnels). We now report the results of full-scale experiments using the tunnel exposure scheme, which assesses the contribution of shock and intense E field to colony disturbance. Exposure of worker bees (1400 h) to 60-Hz E fields including 100 kV/m under moisture-free conditions within a nonconductive tunnel causes no deleterious affect on colony behavior. Exposure of bees in conductive (e.g., wet) tunnels produces bee disturbance, increased mortality, abnormal propolization, and possible impairment of colony growth. We propose that this substrate dependence of bee disturbance is the result of perception of shock from coupled body currents and enhanced current densities postulated to exist in the legs and thorax of bees on conductors. Similarly, disturbance occurs when bees are exposed to step-potential-induced currents. At 275-350 nA single bees are disturbed; at 600 nA bees begin abnormal propolization behavior; and stinging occurs at 900 nA. We conclude that biological effects seen in bee colonies under a transmission line are primarily the result of electric shock from induced hive currents. This evaluation is based on the limited effects of E-field exposure in tunnels, the observed disturbance thresholds caused by shocks in tunnels, and the ability of hives exposed under a transmission line to source currents 100-1,000 times the shock thresholds.

  15. Introduction: Applying Chemical Biology to Ion Channels.

    PubMed

    Pless, Stephan A; Ahern, Christopher A

    2015-01-01

    Ion channels are membrane-spanning proteins that control the flow of ions across biological membranes through an aqueous pathway. The opening or closing of this pore can be controlled by a myriad of physiological inputs (voltage, ligands, temperature, metabolites, pH), which in turn allow for the controlled flux of ions across membranes, resulting in the generation of minute electrical signals. The functional implications of ion channel function on physiological processes are vast. Electrical impulses, in the form of action potentials or diverse chemo-electrical signals, coordinate the syncytium of the heart beat, support a myriad of neuronal communication pathways, insulin secretion, and are central to the immune response, with more roles being discovered virtually everyday. Thus, ion channel function is a biophysical process that is central to biological life at many levels. And with over 500 channel-forming subunits known today in humans, this large class of proteins is also increasingly recognised as important drug targets, as inherited or acquired ion channel dysfunction are known causes of disease.

  16. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  17. Closed Orbits in Phase Space

    NASA Astrophysics Data System (ADS)

    Murphy, Andrew; Haestad, Jace; Morgan, Thomas

    2015-09-01

    We report characteristics of closed classical orbits in an electric field in phase space produced in photoabsorption. Rydberg states of atomic and molecular hydrogen and helium are considered. The core potential used for the hydrogen molecule is an effective one electron one center core potential evaluated at the internuclear equilibrium distance. Poincare surfaces of section in phase space are generated by integrating the equations of motion in semiparabolic coordinates u = (r + z) 1 / 2 and v = (r - z) 1 / 2, and plotting the location in phase space (pv versus v) whenever u = 0, with the electric field in the z direction. Combination orbits produced by Rydberg electron core scattering are studied and the evolution in phase space of these combination orbits due to scattering from one closed orbit into another is investigated. Connections are made to measured laser photoabsorption experiments that excite Rydberg states (20 < n < 30) and produce accompanying scaled energy recurrence spectra. The phase space structures responsible for the spectra are identified.

  18. Bionanoelectronics: Getting close to the action

    NASA Astrophysics Data System (ADS)

    Parpura, Vladimir

    2012-03-01

    Two independent groups have demonstrated that nanoscale electrodes can record action potentials in neurons and cardiac muscle cells, and a third group has shown that nanowire field-effect transistors can make electrical measurements on biological materials with unprecedented spatial resolution.

  19. Electrical injury

    MedlinePlus

    ... damage, especially to the heart, muscles, or brain. Electric current can cause injury in three ways: Cardiac arrest ... How long you were in contact with the electricity How the electricity moved through your body Your ...

  20. Electricity Customers

    EPA Pesticide Factsheets

    This page discusses key sectors and how they use electricity. Residential, commercial, and industrial customers each account for roughly one-third of the nation’s electricity use. The transportation sector also accounts for a small fraction of electricity.

  1. Electricity from biogas

    SciTech Connect

    Augenstein, D.; Benemann, J.; Hughes, E.

    1994-12-31

    Biogas is a medium-Btu methane and carbon dioxide mix produced by bacterial decomposition of organic matter. Its sources include landfills, waste water sludges, and animal wastes. It can fuel energy applications, of which electricity generation is a frequently-preferred option. The greatest current U.S. biogas recovery and energy use is at landfills, where biogas at about 80 landfill sites fuels a total of approximately 300 MWe. Wastewater treatment plants and confined animal waste management systems support additional electric power production. Generation of electricity from biogas can present difficulties due to the generally small scale of the generating facility, variable energy content of the gas, fluctuating availability, contaminant problems, and often-demanding control needs. However, such difficulties are being successfully addressed and economics for electricity generation are often favorable as biogas can be essentially {open_quotes}free{close_quotes} fuel. Biogas recovery and use has the additional advantage of mitigating a potent greenhouse gas. Biogas from U.S. landfills alone could fuel about 1% of U.S. electrical generation while giving climate change benefit equivalent to reducing CO{sub 2} emissions in the electricity sector by more than 10%. Growth in landfill gas use will be facilitated by recent regulations, advances in equipment, and improved management techniques such as {open_quotes}controlled landfilling{close_quotes}. The potential for biogas recovery and electricity production from sewage sludges, animal wastes and other organic resources such as agricultural residues is uncertain but probably exceeds the estimate for landfills.

  2. Electrical percolation based biosensors.

    PubMed

    Bruck, Hugh Alan; Yang, Minghui; Kostov, Yordan; Rasooly, Avraham

    2013-10-01

    A new approach to label free biosensing has been developed based on the principle of "electrical percolation". In electrical percolation, long-range electrical connectivity is formed in randomly oriented and distributed systems of discrete elements. By applying this principle to biological interactions, it is possible to measure biological components both directly and electronically. The main element for electrical percolation biosensor is the biological semiconductor (BSC) which is a multi-layer 3-D carbon nanotube-antibody network. In the BSC, molecular interactions, such as binding of antigens to the antibodies, disrupt the network continuity causing increased resistance of the network. BSCs can be fabricated by immobilizing conducting elements, such as pre-functionalized single-walled carbon nanotubes (SWNTs)-antibody complex, directly onto a substrate, such as a Poly(methyl methacrylate) (PMMA) surface (also known as plexi-glass or Acrylic). BSCs have been demonstrated for direct (label-free) electronic measurements of antibody-antigen binding using SWNTs. If the concentration of the SWNT network is slightly above the electrical percolation threshold, then binding of a specific antigen to the pre-functionalized SWNT dramatically increases the electrical resistance due to changes in the tunneling between the SWNTs. Using anti-staphylococcal enterotoxin B (SEB) IgG as a "gate" and SEB as an "actuator", it was demonstrated that the BSC was able to detect SEB at concentrations of 1 ng/ml. Based on this concept, an automated configuration for BSCs is described here that enables real time continuous detection. The new BSC configuration may permit assembly of multiple sensors on the same chip to create "biological central processing units (CPUs)" with multiple biological elements, capable of processing and sorting out information on multiple analytes simultaneously.

  3. Close to the Sky

    NASA Astrophysics Data System (ADS)

    2007-11-01

    Today, a new ALMA outreach and educational book was publicly presented to city officials of San Pedro de Atacama in Chile, as part of the celebrations of the anniversary of the Andean village. ESO PR Photo 50a/07 ESO PR Photo 50a/07 A Useful Tool for Schools Entitled "Close to the sky: Biological heritage in the ALMA area", and edited in English and Spanish by ESO in Chile, the book collects unique on-site observations of the flora and fauna of the ALMA region performed by experts commissioned to investigate it and to provide key initiatives to protect it. "I thank the ALMA project for providing us a book that will surely be a good support for the education of children and youngsters of San Pedro de Atacama. Thanks to this publication, we expect our rich flora and fauna to be better known. I invite teachers and students to take advantage of this educational resource, which will be available in our schools", commented Ms. Sandra Berna, the Mayor of San Pedro de Atacama, who was given the book by representatives of the ALMA global collaboration project. Copies of the book 'Close to the sky' will be donated to all schools in the area, as a contribution to the education of students and young people in northern Chile. "From the very beginning of the project, ALMA construction has had a firm commitment to environment and local culture, protecting unique flora and fauna species and preserving old estancias belonging to the Likan Antai culture," said Jacques Lassalle, who represented ALMA at the hand-over. "Animals like the llama, the fox or the condor do not only live in the region where ALMA is now being built, but they are also key elements of the ancient Andean constellations. In this sense they are part of the same sky that will be explored by ALMA in the near future." ESO PR Photo 50c/07 ESO PR Photo 50c/07 Presentation of the ALMA book The ALMA Project is a giant, international observatory currently under construction on the high-altitude Chajnantor site in Chile

  4. Closing the Advising Session.

    ERIC Educational Resources Information Center

    Jeon, Mihyon

    2003-01-01

    This study investigates closing patterns for an institutional conversation in an ELP (English Language Program) at a university in the United States, noting the relationship between the closing patterns of the participants and their level of proficiency in English. By indicating that ESL learners, especially beginners, face difficulty in closing…

  5. Surviving a School Closing

    ERIC Educational Resources Information Center

    De Witt, Peter M.; Moccia, Josephine

    2011-01-01

    When a beloved school closes, community emotions run high. De Witt and Moccia, administrators in the Averill Park School District in upstate New York, describe how their district navigated through parents' anger and practical matters in closing a small neighborhood elementary school and transferring all its students to another school. With a group…

  6. Electrical memory in Venus flytrap.

    PubMed

    Volkov, Alexander G; Carrell, Holly; Baldwin, Andrew; Markin, Vladislav S

    2009-06-01

    Electrical signaling, memory and rapid closure of the carnivorous plant Dionaea muscipula Ellis (Venus flytrap) have been attracting the attention of researchers since the XIX century. The electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf in 0.3 s without mechanical stimulation of trigger hairs. Here we developed a new method for direct measurements of the exact electrical charge utilized by the D. muscipula Ellis to facilitate the trap closing and investigated electrical short memory in the Venus flytrap. As soon as the 8 microC charge for a small trap or a 9 microC charge for a large trap is transmitted between a lobe and midrib from the external capacitor, the trap starts to close at room temperature. At temperatures 28-36 degrees C a smaller electrical charge of 4.1 microC is required to close the trap of the D. muscipula. The cumulative character of electrical stimuli points to the existence of short-term electrical memory in the Venus flytrap. We also found sensory memory in the Venus flytrap. When one sustained mechanical stimulus was applied to only one trigger hair, the trap closed in a few seconds.

  7. Electrical Curriculum.

    ERIC Educational Resources Information Center

    EASTCONN Regional Educational Services Center, North Windham, CT.

    The purpose of this electrical program is to prepare students for service, repair, and assembly of electrically driven or controlled devices. The program theory and application includes mechanical assemblies, electrical circuitry, and electronic principles including basic digital circuitry. The electrical program manual includes the following…

  8. 8. Close view looking from the east to show cistern ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Close view looking from the east to show cistern and electric meter - Piece Sur Piece Building (House), On dirt road off of Highway 494, about 1 1/2 miles Northwest of Bermuda, Bermuda, Natchitoches Parish, LA

  9. 49 CFR 236.786 - Principle, closed circuit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.786 Principle, closed circuit. The principle of circuit design where a normally energized electric circuit...

  10. Electric fields are novel determinants of human macrophage functions.

    PubMed

    Hoare, Joseph I; Rajnicek, Ann M; McCaig, Colin D; Barker, Robert N; Wilson, Heather M

    2016-06-01

    Macrophages are key cells in inflammation and repair, and their activity requires close regulation. The characterization of cues coordinating macrophage function has focused on biologic and soluble mediators, with little known about their responses to physical stimuli, such as the electrical fields that are generated naturally in injured tissue and which accelerate wound healing. To address this gap in understanding, we tested how properties of human monocyte-derived macrophages are regulated by applied electrical fields, similar in strengths to those established naturally. With the use of live-cell video microscopy, we show that macrophage migration is directed anodally by electrical fields as low as 5 mV/mm and is electrical field strength dependent, with effects peaking ∼300 mV/mm. Monocytes, as macrophage precursors, migrate in the opposite, cathodal direction. Strikingly, we show for the first time that electrical fields significantly enhance macrophage phagocytic uptake of a variety of targets, including carboxylate beads, apoptotic neutrophils, and the nominal opportunist pathogen Candida albicans, which engage different classes of surface receptors. These electrical field-induced functional changes are accompanied by clustering of phagocytic receptors, enhanced PI3K and ERK activation, mobilization of intracellular calcium, and actin polarization. Electrical fields also modulate cytokine production selectively and can augment some effects of conventional polarizing stimuli on cytokine secretion. Taken together, electrical signals have been identified as major contributors to the coordination and regulation of important human macrophage functions, including those essential for microbial clearance and healing. Our results open up a new area of research into effects of naturally occurring and clinically applied electrical fields in conditions where macrophage activity is critical.

  11. All biology is computational biology

    PubMed Central

    2017-01-01

    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science. PMID:28278152

  12. All biology is computational biology.

    PubMed

    Markowetz, Florian

    2017-03-01

    Here, I argue that computational thinking and techniques are so central to the quest of understanding life that today all biology is computational biology. Computational biology brings order into our understanding of life, it makes biological concepts rigorous and testable, and it provides a reference map that holds together individual insights. The next modern synthesis in biology will be driven by mathematical, statistical, and computational methods being absorbed into mainstream biological training, turning biology into a quantitative science.

  13. Closed Large Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    article title:  Closed Large Cell Clouds in the South Pacific     ... unperturbed by cyclonic or frontal activity. When the cell centers are cloudy and the main sinking motion is concentrated at cell ...

  14. Closed Circular Chains

    ERIC Educational Resources Information Center

    Caglayan, Günhan

    2016-01-01

    A Steiner chain is defined as the sequence of n circles that are all tangent to two given non-intersecting circles. A closed chain, in particular, is one in which every circle in the sequence is tangent to the previous and next circles of the chain. In a closed Steiner chain the first and the "n"th circles of the chain are also tangent…

  15. The electrical response of plants under radiation

    NASA Astrophysics Data System (ADS)

    Islam, Mohammad; Xi, Wenze; Feng, David J. Y.; Choa, Fow-Sen

    2014-05-01

    Plant electricity was discovered about 100 years ago. Until recent two decades, researchers started to notice that the electricity play a key role for plant's communications and defense. Recently, we have demonstrated a wound-generated electrical signal, up to a few hundred mV, can be produced and propagate through the whole plant. As plants defense reactions the wound signal will activate genes and induce subsequent molecular biology responses. In this study, we further investigate the electrical response of plants when they are under nuclear radiation. We discovered nuclear radiation could produce internal voltage gradient in living trees, resulting in measureable voltage and current signals. The results was measured by attaching one of electrodes to a lower branch, close to the roots and attaching the other one to an upper branch. During irradiating, trees were set up at 1-meter far from a NIST-certified 241AmBe neutron source (30 mCi). It will produce a neutron field of about 13 mrem/h, corresponding to an actual absorbed dose of ~ 1 mrad/h by assuming the tissue is primarily water content. Once the radioactive source is pulled up from a shielded container below the tree, the system potential starts to drop and in about 6-7 hours it drops down to -220mV, eventually stabilizing at around -250mV after 10 hours of radiation. We have further observed plant electricity changes caused by x-ray, gamma-ray, and beta-ray radiations. After the sources were removed, the terminal voltage recovered and eventually returned to the original value.

  16. Electrically driven and electrically tunable quantum light sources

    NASA Astrophysics Data System (ADS)

    Lee, J. P.; Murray, E.; Bennett, A. J.; Ellis, D. J. P.; Dangel, C.; Farrer, I.; Spencer, P.; Ritchie, D. A.; Shields, A. J.

    2017-02-01

    Compact and electrically controllable on-chip sources of indistinguishable photons are desirable for the development of integrated quantum technologies. We demonstrate that two quantum dot light emitting diodes (LEDs) in close proximity on a single chip can function as a tunable, all-electric quantum light source. Light emitted by an electrically excited driving LED is used to excite quantum dots in the neighbouring diode. The wavelength of the quantum dot emission from the neighbouring driven diode is tuned via the quantum confined Stark effect. We also show that we can electrically tune the fine structure splitting.

  17. Electrical Generation.

    ERIC Educational Resources Information Center

    Science and Children, 1990

    1990-01-01

    Described are two activities designed to help children investigate electrical charges, electric meters, and electromagnets. Included are background information, a list of materials, procedures, and follow-up questions. Sources of additional information are cited. (CW)

  18. Grafts in "closed" rhinoplasty.

    PubMed

    Scattolin, A; D'Ascanio, L

    2013-06-01

    Rhinoplasty is a fascinating and complex surgical procedure aiming at attaining a well-functioning and aesthetically pleasant nose. The use of grafts is of the utmost importance for the nasal surgeon to achieve such results. However, the philosophy and technical use of nasal grafts are different in "closed" and "open" rhinoplasty. The aim of this paper is not detailed description of the numerous grafts reported in the literature; we will describe the main principles of grafts use in "closed" rhinoplasty derived from our experience, with special reference to the philosophical and technical differences in their employment between "closed" and "open" rhinoplasty. Some cases are reported as an example of graft use in "endonasal" approach rhinoplasty.

  19. 49 CFR 236.786 - Principle, closed circuit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit which... 49 Transportation 4 2012-10-01 2012-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  20. 49 CFR 236.786 - Principle, closed circuit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit which... 49 Transportation 4 2013-10-01 2013-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  1. 49 CFR 236.786 - Principle, closed circuit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit which... 49 Transportation 4 2011-10-01 2011-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  2. 49 CFR 236.786 - Principle, closed circuit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit which... 49 Transportation 4 2014-10-01 2014-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  3. Sparks fly over electric cars

    SciTech Connect

    Griffith, V.

    1994-10-01

    While the US automobile industry scrambles to meet 1998 deadlines to put electric vehicles on the market, controversy about the environmental benefits and commercial viability of battery-operated cars is mounting. Circumstances in the US increasingly favor the electric car. Air quality laws in California and Massachusetts now demand that {open_quotes}zero-emission{close_quotes} vehicles comprise 2 percent of total sales in the car market by 1998. Electric cars are the only vehicles to meet such standards so far. Other states are considering similar laws. This article examines the pros and cons of electric vehicle use.

  4. Chemical Detection using Electrically Open Circuits having no Electrical Connections

    NASA Technical Reports Server (NTRS)

    Woodward, Stanley E.; Olgesby, Donald M.; Taylor, Bryant D.; Shams, Qamar A.

    2008-01-01

    This paper presents investigations to date on chemical detection using a recently developed method for designing, powering and interrogating sensors as electrically open circuits having no electrical connections. In lieu of having each sensor from a closed circuit with multiple electrically connected components, an electrically conductive geometric pattern that is powered using oscillating magnetic fields and capable of storing an electric field and a magnetic field without the need of a closed circuit or electrical connections is used. When electrically active, the patterns respond with their own magnetic field whose frequency, amplitude and bandwidth can be correlated with the magnitude of the physical quantities being measured. Preliminary experimental results of using two different detection approaches will be presented. In one method, a thin film of a reactant is deposited on the surface of the open-circuit sensor. Exposure to a specific targeted reactant shifts the resonant frequency of the sensor. In the second method, a coating of conductive material is placed on a thin non-conductive plastic sheet that is placed over the surface of the sensor. There is no physical contact between the sensor and the electrically conductive material. When the conductive material is exposed to a targeted reactant, a chemical reaction occurs that renders the material non-conductive. The change in the material s electrical resistance within the magnetic field of the sensor alters the sensor s response bandwidth and amplitude, allowing detection of the reaction without having the reactants in physical contact with the sensor.

  5. Biologically-inspired, electrically small antenna arrays

    NASA Astrophysics Data System (ADS)

    Masoumi, Amir Reza

    First, the motivation behind adding a passive external coupling network after antenna arrays is discussed, the concept of biomimetic antenna arrays (BMAAs) introduced and some of the previous work done in this area have been reviewed. Next, a BMAA which achieves an angular resolution of roughly 15 times its regular counterpart is introduced and fully characterized. The introduced BMAA employs transformers which considerably degrade its performance, namely its output power. To cicumvent this shortcoming a new architecture of a BMAA that does not employ transformers and therefore yields a higher output power for the same angular resolution has been subsequently presented. Moreover, a detailed noise analysis of this BMAA is carried out and the output noise of the new architecture is compared with the output noise of the original design. The modified twoelement BMAA architecture is then extended to multiple elements. A novel nonlinear optimization process is introduced that maximizes the total power captured by the BMAA for a given angular resolution and the concept illustrated for a three-element antenna array. Next an optimum two-element BMAA which achieves the maximum possible angular resolution while obtaining the same output power level of a regular antenna array with the same elements and spacing is introduced. A novel two-element superdirective array based on this optimum BMAA has been also discussed. The passive BMAAs discussed in this thesis have a relatively narrow bandwidth. To extend the bandwidth of BMAAs, non- Foster networks have been employed in their external coupling networks and it has been demonstrated that they can increase their bandwidth by a factor of roughly 33. Finally, the BMAA concept has been extended to nano-antenna arrays and a concept for designing sub-wavelength angle-sensing detectors at optical wavelengths has been introduced.

  6. Glucose Suppresses Biological Ferroelectricity in Aortic Elastin

    NASA Astrophysics Data System (ADS)

    Liu, Yuanming; Wang, Yunjie; Chow, Ming-Jay; Chen, Nataly Q.; Ma, Feiyue; Zhang, Yanhang; Li, Jiangyu

    2013-04-01

    Elastin is an intriguing extracellular matrix protein present in all connective tissues of vertebrates, rendering essential elasticity to connective tissues subjected to repeated physiological stresses. Using piezoresponse force microscopy, we show that the polarity of aortic elastin is switchable by an electrical field, which may be associated with the recently discovered biological ferroelectricity in the aorta. More interestingly, it is discovered that the switching in aortic elastin is largely suppressed by glucose treatment, which appears to freeze the internal asymmetric polar structures of elastin, making it much harder to switch, or suppressing the switching completely. Such loss of ferroelectricity could have important physiological and pathological implications from aging to arteriosclerosis that are closely related to glycation of elastin.

  7. The relief of microtherm inhibition for p-fluoronitrobenzene mineralization using electrical stimulation at low temperatures.

    PubMed

    Zhang, Xueqin; Feng, Huajun; Liang, Yuxiang; Zhao, Zhiqing; Long, Yuyang; Fang, Yuan; Wang, Meizhen; Yin, Jun; Shen, Dongsheng

    2015-05-01

    Low temperature aggravates biological treatment of refractory p-fluoronitrobenzene (p-FNB) because of microtherm inhibition of microbial activity. Considering the potential characterization of energy supply for microbial metabolism and spurring microbial activity by electrical stimulation, a bioelectrochemical system (BES) was established to provide sustaining electrical stimulation for p-FNB mineralization at a low temperature. Electrical stimulation facilitated p-FNB treatment and bioelectrochemical reaction rate constants for the removal and defluorination of p-FNB at 10 °C were 0.0931 and 0.0054 h(-1), which were higher than the sums of the rates found using a biological system and an electrocatalytic system by 62.8 and 64.8%, respectively. At a low temperature, microbial activity in terms of dehydrogenase and ATPase was found to be higher with electrical stimulation, being 121.1 and 100.1% more active than that in the biological system. Moreover, stronger antioxidant ability was observed in the BES, which implied a better cold-resistance and relief of microtherm inhibition by electrical stimulation. Bacterial diversity analysis revealed a significant evolution of microbial community by electrical stimulation, and Clostridia was uniquely enriched. One bacterial sequence close to Pseudomonas became uniquely predominant, which appeared to be crucial for excellent p-FNB treatment performance in the BES at a low temperature. Economic evaluation revealed that the energy required to mineralize an extra mole of p-FNB was found to be 247 times higher by heating the system than by application of electrical stimulation. These results indicated that application of electrical stimulation is extremely promising for treating refractory waste at low temperatures.

  8. Electric vehicles

    NASA Astrophysics Data System (ADS)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  9. Closed Small Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    ... (right)   The structure of tightly packed "closed cells" in a layer of marine stratocumulus over the southeastern Pacific Ocean ... into interesting structures such as those shown here. These cells are notably small, with diameters ranging from 10-15 kilometers, instead ...

  10. Closing the Performance Gap.

    ERIC Educational Resources Information Center

    Riggins, Cheryl G.

    2002-01-01

    Describes how the principal of a K-2, 400-student suburban elementary school near Flint, Michigan, worked with her staff and superintendent to develop and implement a strategic plan to close the student achievement gap. Reports significant improvement in reading and math scores after 1 year. (PKP)

  11. Surgical wound care -- closed

    MedlinePlus

    ... around the incision increases or becomes thick, tan, green, or yellow, or smells bad (pus). Also call if your temperature is above 100°F (37.7°C) for more than 4 hours. Alternative Names Surgical incision care; Closed wound care References Leong M, Phillips LG. ...

  12. Closing the Loop Sampler.

    ERIC Educational Resources Information Center

    California Integrated Waste Management Board, Sacramento.

    Closing the Loop (CTL) is a science curriculum designed to introduce students to integrated waste management through awareness. This document presents five lesson plans focusing on developing an understanding of natural resources, solid wastes, conservation, and the life of landfills. Contents include: (1) "What Are Natural Resources?"; (2)…

  13. Review: The Closing Circle

    ERIC Educational Resources Information Center

    Environment, 1972

    1972-01-01

    Two views of prominent biologists are presented side-by-side. Focal point is Barry Commoner's book, The Closing Circle, with a subsequent review by Paul Ehrlich. Growth of population, increases in affluence, and increased pollution from products of technology are considered. (BL)

  14. Close encounters with DNA

    PubMed Central

    Maffeo, C.; Yoo, J.; Comer, J.; Wells, D. B.; Luan, B.; Aksimentiev, A.

    2014-01-01

    Over the past ten years, the all-atom molecular dynamics method has grown in the scale of both systems and processes amenable to it and in its ability to make quantitative predictions about the behavior of experimental systems. The field of computational DNA research is no exception, witnessing a dramatic increase in the size of systems simulated with atomic resolution, the duration of individual simulations and the realism of the simulation outcomes. In this topical review, we describe the hallmark physical properties of DNA from the perspective of all-atom simulations. We demonstrate the amazing ability of such simulations to reveal the microscopic physical origins of experimentally observed phenomena and we review the frustrating limitations associated with imperfections of present atomic force fields and inadequate sampling. The review is focused on the following four physical properties of DNA: effective electric charge, response to an external mechanical force, interaction with other DNA molecules and behavior in an external electric field. PMID:25238560

  15. Closed-Cycle Rare-Gas Electrical-Discharge Laser

    DTIC Science & Technology

    1977-04-01

    Shtyrkov and E. V. Subbes, "Characteristics of Pulsed Laser Action in Helium-Neon and Helium-Argon Mixtures," Optics and Spectroscopy 21, 143 (August 1966...34Etude du Deplacement des Raies Laser Infrarouges du Xenon sous l’Influence de la Pression," Phys. Lett. 33A, 398 (November 1970). 89. L. A. Newman

  16. ELECTRIC CONTACT MEANS

    DOEpatents

    Grear, J.W. Jr.

    1959-03-10

    A switch adapted to maintain electrical connections under conditions of vibration or acceleration is described. According to the invention, thc switch includes a rotatable arm carrying a conductive bar arranged to close against two contacts spaced in the same plane. The firm and continuous engagement of the conductive bar with the contacts is acheived by utilizeing a spring located betwenn the vbar and athe a rem frzme and slidable mounting the bar in channel between two arms suspendef from the arm frame.

  17. Close Quarters Combat Shooting

    DTIC Science & Technology

    2010-04-14

    1994.at the Palm Beach Community College Criminal Justice Institute ofLakeworth, Florida to the more dynamic force-on-force, realistic scenario...Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington, DC...Shooting is the Superior Method for Close Quarters Combat 5b. GRANT NUMBER Shooting" N/A Sc. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR( S ) Sd. PROJECT

  18. Closing the Pay Gap

    DTIC Science & Technology

    2000-10-01

    the pay gap has been narrowed, hut only to just under 10 percent. And current military compensation legislation does not close the gap until 2026. There...will continue to be a pay gap until 2026 unless the next administration and the next Congress provide more for pay above the 1999 legislated ramp- up...of .5 percent (one half of one percent) per year to attain pay equality . That means that soldiers, sailors, airmen, marines and Coast Guardsmen

  19. 78 FR 20118 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; Cancer Biology and Therapy. Date: April...

  20. [Physicochemical and biological characteristics of coastal saline soil under different vegetation cover].

    PubMed

    Zhou, Jian; Li, Gang; Zhou, Jian; Qin, Pei

    2011-04-01

    Taking seven plots of coastal saline soil under different vegetation cover in North Jiangsu as study sites, this paper studied the seasonal fluctuations of soil basic physicochemical and biological characteristics, and analyzed the relationships between these fluctuations and vegetation cover. In the test plots, there was a greater variability of soil basic physicochemical and biological characteristics. The average soil electrical conductivity was lower in crop plots (0.95 dS m(-1)) than in natural vegetation plots (2.77 dS m(-1)), but parts of the crop plots showed an increased soil electrical conductivity compared with pre-planting. Overall, the soil fertility of the plots was generally at a low level, with the hydrolysable nitrogen content averagely lower than 50 mg kg(-1), available phosphorus content (except fertilized plots) lower than 3 mg kg(-1), and organic matter content less than 1%. Due to fertilization, the soil conditions in crop plots somewhat improved. For the test coastal saline soil, its electrical conductivity and nutrient level were the key factors affecting the vegetation distribution and plant growth, and soil electrical conductivity was most important. There existed close correlations between soil nitrogen and phosphorus contents and soil microbial amount. The seasonal fluctuations of soil characteristics were closely related with vegetation type and human disturbance, being relatively stable under higher vegetation coverage and lesser human disturbance, and dramatic in bare land and castor experimental plots.

  1. Electrical stator

    DOEpatents

    Fanning, Alan W.; Olich, Eugene E.

    1994-01-01

    An electrical stator of an electromagnetic pump includes first and second spaced apart coils each having input and output terminals for carrying electrical current. An elongate electrical connector extends between the first and second coils and has first and second opposite ends. The connector ends include respective slots receiving therein respective ones of the coil terminals to define respective first and second joints. Each of the joints includes a braze filler fixedly joining the connector ends to the respective coil terminals for carrying electrical current therethrough.

  2. Electric propulsion

    NASA Astrophysics Data System (ADS)

    Garrison, Philip W.

    Electric propulsion (EP) is an attractive option for unmanned orbital transfer vehicles (OTV's). Vehicles with solar electric propulsion (SEP) could be used routinely to transport cargo between nodes in Earth, lunar, and Mars orbit. Electric propulsion systems are low-thrust, high-specific-impulse systems with fuel efficiencies 2 to 10 times the efficiencies of systems using chemical propellants. The payoff for this performance can be high, since a principal cost for a space transportation system is that of launching to low Earth orbit (LEO) the propellant required for operations between LEO and other nodes. Several aspects of electric propulsion, including candidate systems and the impact of using nonterrestrial materials, are discussed.

  3. Biological Filters.

    ERIC Educational Resources Information Center

    Klemetson, S. L.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. The review is concerned with biological filters, and it covers: (1) trickling filters; (2) rotating biological contractors; and (3) miscellaneous reactors. A list of 14 references is also presented. (HM)

  4. Rings from Close Encounters

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Weve recently discovered narrow sets of rings around two minor planets orbiting in our solar system. How did these rings form? A new study shows that they could be a result of close encounters between the minor planets and giants like Jupiter or Neptune.Unexpected Ring SystemsPositions of the centaurs in our solar system (green). Giant planets (red), Jupiter trojans (grey), scattered disk objects (tan) and Kuiper belt objects (blue) are also shown. [WilyD]Centaurs are minor planets in our solar system that orbit between Jupiter and Neptune. These bodies of which there are roughly 44,000 with diameters larger than 1 km have dynamically unstable orbits that cross paths with those of one or more giant planets.Recent occultation observations of two centaurs, 10199 Chariklo and 2060 Chiron, revealed that these bodies both host narrow ring systems. Besides our four giant planets, Chariklo and Chiron are the only other bodies in the solar system known to have rings. But how did these rings form?Scientists have proposed several models, implicating collisions, disruption of a primordial satellite, or dusty outgassing. But a team of scientists led by Ryuki Hyodo (Paris Institute of Earth Physics, Kobe University) has recently proposed an alternative scenario: what if the rings were formed from partial disruption of the centaur itself, after it crossed just a little too close to a giant planet?Tidal Forces from a GiantHyodo and collaborators first used past studies of centaur orbits to estimate that roughly 10% of centaurs experience close encounters (passing within a distance of ~2x the planetary radius) with a giant planet during their million-year lifetime. The team then performed a series of simulations of close encounters between a giant planet and a differentiated centaur a body in which the rocky material has sunk to form a dense silicate core, surrounded by an icy mantle.Some snapshots of simulation outcomes (click for a closer look!) for different initial states of

  5. Mathematical modeling relevant to closed artificial ecosystems

    USGS Publications Warehouse

    DeAngelis, D.L.

    2003-01-01

    The mathematical modeling of ecosystems has contributed much to the understanding of the dynamics of such systems. Ecosystems can include not only the natural variety, but also artificial systems designed and controlled by humans. These can range from agricultural systems and activated sludge plants, down to mesocosms, microcosms, and aquaria, which may have practical or research applications. Some purposes may require the design of systems that are completely closed, as far as material cycling is concerned. In all cases, mathematical modeling can help not only to understand the dynamics of the system, but also to design methods of control to keep the system operating in desired ranges. This paper reviews mathematical modeling relevant to the simulation and control of closed or semi-closed artificial ecosystems designed for biological production and recycling in applications in space. Published by Elsevier Science Ltd on behalf of COSPAR.

  6. Mathematical modeling relevant to closed artificial ecosystems.

    PubMed

    DeAngelis, Donald L

    2003-01-01

    The mathematical modeling of ecosystems has contributed much to the understanding of the dynamics of such systems. Ecosystems can include not only the natural variety, but also artificial systems designed and controlled by humans. These can range from agricultural systems and activated sludge plants, down to mesocosms, microcosms, and aquaria, which may have practical or research applications. Some purposes may require the design of systems that are completely closed, as far as material cycling is concerned. In all cases, mathematical modeling can help not only to understand the dynamics of the system, but also to design methods of control to keep the system operating in desired ranges. This paper reviews mathematical modeling relevant to the simulation and control of closed or semi-closed artificial ecosystems designed for biological production and recycling in applications in space.

  7. Charge induced closing of Dionaea muscipula Ellis trap.

    PubMed

    Volkov, Alexander G; Adesina, Tejumade; Jovanov, Emil

    2008-11-01

    In terms of bioelectrochemistry, Venus flytrap responses can be considered in three stages: stimulus perception, electrical signal transmission, and induction of mechanical and biochemical responses. When an insect touches the trigger hairs, these mechanosensors generate receptor potentials, which induce solitary waves activating the motor cells. We found that the electrical charge injected between a midrib and a lobe closes the Venus flytrap leaf by activating motor cells without mechanical stimulation of trigger hairs. The mean electrical charge required for the closure of the Venus flytrap leaf is 13.6 muC. To close the trap, electrical charge can be submitted as a single charge or applied cumulatively by small portions during a short period of time. Ion channel blocker such as Zn(2+) as well as an uncoupler CCCP, dramatically decreases the speed of the trap closing a few hours after treatment of the soil. This effect is reversible. After soil washing by distilled water, the closing time of Venus flytrap treated by CCCP or ZnCl(2) decreases back from 2-5 s to 0.3 s, but higher electrical charge is needed for trap closure. The mechanism behind closing the upper leaf of Venus flytrap is discussed.

  8. Electric machine

    DOEpatents

    El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Reddy, Patel Bhageerath [Madison, WI

    2012-07-17

    An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

  9. Teaching Electricity.

    ERIC Educational Resources Information Center

    Iona, Mario

    1982-01-01

    To clarify the meaning of electrical terms, a chart is used to compare electrical concepts and relationships with a more easily visualized system in which water flows from a hilltop reservoir through a pipe to drive a mill at the bottom of the hill. A diagram accompanies the chart. (Author/SK)

  10. Electric Mars: The first survey of Martian parallel electric fields.

    NASA Astrophysics Data System (ADS)

    Collinson, G.; Mitchell, D. L.; Glocer, A.; Grebowsky, J. M.; Peterson, W. K.; Connerney, J. E. P.; Andersson, L.; Espley, J. R.; Mazelle, C. X.; Savaud, J. A.; Fedorov, A.; Ma, Y.; Bougher, S. W.; Lillis, R. J.; Ergun, R. E.; Jakosky, B. M.

    2015-12-01

    We present the results of the first survey of parallel electric fields at Mars, using electron measurements from the MAVEN Solar Wind Electron Analyzer (SWEA), and the Magnetometer (MAG). We discuss three fields: (1) The first upper limit on the strength of the "Polar Wind" ambipolar electric field; (2) The "trans-terminator" field, a newly discovered electric force accelerating ions on closed field lines from day to nightside, and (3) possible signatures of very high strength electrostatic mirroring during the passage of a Coronal Mass Ejection.

  11. Closing the loop.

    PubMed

    Dassau, E; Atlas, E; Phillip, M

    2011-02-01

    Closed-loop algorithms can be found in every aspect of everyday modern life. Automation and control are used constantly to provide safety and to improve quality of life. Closed-loop systems and algorithms can be found in home appliances, automobiles, aviation and more. Can one imagine nowadays driving a car without ABS, cruise control or even anti-sliding control? Similar principles of automation and control can be used in the management of diabetes mellitus (DM). The idea of an algorithmic/technological way to control glycaemia is not new and has been researched for more than four decades. However, recent improvements in both glucose-sensing technology and insulin delivery together with advanced control and systems engineering made this dream of an artificial pancreas possible. The artificial pancreas may be the next big step in the treatment of DM since the use of insulin analogues. An artificial pancreas can be described as internal or external devices that use continuous glucose measurements to automatically manage exogenous insulin delivery with or without other hormones in an attempt to restore glucose regulation in individuals with DM using a control algorithm. This device as described can be internal or external; can use different types of control algorithms with bi-hormonal or uni-hormonal design; and can utilise different ways to administer them. The different designs and implementations have transitioned recently from in silico simulations to clinical evaluation stage with practical applications in mind. This may mark the beginning of a new era in diabetes management with the introduction of semi-closed-loop systems that can prevent or minimise nocturnal hypoglycaemia, to hybrid systems that will manage blood glucose (BG) levels with minimal user intervention to finally fully automated systems that will take the user out of the loop. More and more clinical trials will be needed for the artificial pancreas to become a reality but initial encouraging

  12. Do closed universes recollapse?

    NASA Astrophysics Data System (ADS)

    Tipler, Frank J.

    The conditions for recollapse in universes with compact maximal hypersurfaces are investigated theoretically, reviewing the results of recent investigations. The importance of recollapse for observational astrophysics is briefly discussed, and particular attention is given to the implications of maximal hypersurfaces and to recollapse in S3 Friedmann universes. It is conjectured that all globally hyperbolic C2 maximally extended spatially homogeneous closed universes with S3 or S2 x S1 topology and with stress-energy tensors obeying the strong-energy, positive-pressure, dominant-energy, and matter-regularity conditions do expand from an all-encompassing initial singularity to a maximal hypersurface and then recollapse to an all-encompassing final singularity.

  13. Research for electric energy systems -- an annual report

    SciTech Connect

    Anderson, W.E.

    1993-10-01

    This report documents the technical progress in the two investigations which make up the project {open_quotes}Support of Research Projects for Electrical Energy Systems,{close_quotes} Department of Energy Task Order Number 137, funded by the US Department of Energy and performed by the Electricity Division of the National Institute of Standards and Technology (NIST). The first investigation is concerned with the measurement of magnetic fields in support of epidemiogical and in vitro studies of biological field effects. During 1992, the derivation of equations which predict differences between the average magnetic flux density using circular coil probes and the flux density at the center of the probe, assuming a dipole magnetic field, were completed. The information gained using these equations allows the determination of measurement uncertainty due to probe size when magnetic fields from many electrical appliances are characterized. Consultations with various state and federal organizations and the development of standards related to electric and magnetic field measurements continued. The second investigation is concerned with two different activities related to compressed-gas insulated high voltage systems: (1) the measurement of dissociative electron attachment cross sections and negative ion production in S{sub 2}F{sub 10}, S{sub 2}OF{sub 10}, and S{sub 2}O{sub 2}F{sub 10}, and (2) Monte-Carlo simulations of ac-generated partial-discharge pulses that can occur in SF{sub 6}-insulated power systems and can be sources of gas decomposition.

  14. Electrical connector

    DOEpatents

    Dilliner, Jennifer L.; Baker, Thomas M.; Akasam, Sivaprasad; Hoff, Brian D.

    2006-11-21

    An electrical connector includes a female component having one or more receptacles, a first test receptacle, and a second test receptacle. The electrical connector also includes a male component having one or more terminals configured to engage the one or more receptacles, a first test pin configured to engage the first test receptacle, and a second test pin configured to engage the second test receptacle. The first test receptacle is electrically connected to the second test receptacle, and at least one of the first test pin and the second test pin is shorter in length than the one or more terminals.

  15. Electrical Conductivity.

    ERIC Educational Resources Information Center

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  16. Electrical Conductivity.

    ERIC Educational Resources Information Center

    Allen, Philip B.

    1979-01-01

    Examines Drude's classical (1900) theory of electrical conduction, details the objections to and successes of the 1900 theory, and investigates the Quantum (1928) theory of conduction, reviewing its successes and limitations. (BT)

  17. Electric generator

    DOEpatents

    Foster, Jr., John S.; Wilson, James R.; McDonald, Jr., Charles A.

    1983-01-01

    1. In an electrical energy generator, the combination comprising a first elongated annular electrical current conductor having at least one bare surface extending longitudinally and facing radially inwards therein, a second elongated annular electrical current conductor disposed coaxially within said first conductor and having an outer bare surface area extending longitudinally and facing said bare surface of said first conductor, the contiguous coaxial areas of said first and second conductors defining an inductive element, means for applying an electrical current to at least one of said conductors for generating a magnetic field encompassing said inductive element, and explosive charge means disposed concentrically with respect to said conductors including at least the area of said inductive element, said explosive charge means including means disposed to initiate an explosive wave front in said explosive advancing longitudinally along said inductive element, said wave front being effective to progressively deform at least one of said conductors to bring said bare surfaces thereof into electrically conductive contact to progressively reduce the inductance of the inductive element defined by said conductors and transferring explosive energy to said magnetic field effective to generate an electrical potential between undeformed portions of said conductors ahead of said explosive wave front.

  18. Kinetics and mechanism of Dionaea muscipula trap closing.

    PubMed

    Volkov, Alexander G; Adesina, Tejumade; Markin, Vladislav S; Jovanov, Emil

    2008-02-01

    The Venus flytrap (Dionaea muscipula) possesses an active trapping mechanism to capture insects with one of the most rapid movements in the plant kingdom, as described by Darwin. This article presents a detailed experimental investigation of trap closure by mechanical and electrical stimuli and the mechanism of this process. Trap closure consists of three distinctive phases: a silent phase with no observable movement; an accelerated movement of the lobes; and the relaxation of the lobes in their closed state, resulting in a new equilibrium. Uncouplers and blockers of membrane channels were used to investigate the mechanisms of different phases of closing. Uncouplers increased trap closure delay and significantly decreased the speed of trap closure. Ion channel blockers and aquaporin inhibitors increased time of closing. Transmission of a single electrical charge between a lobe and the midrib causes closure of the trap and induces an electrical signal propagating between both lobes and midrib. The Venus flytrap can accumulate small subthreshold charges, and when the threshold value is reached, the trap closes. Repeated application of smaller charges demonstrates the summation of stimuli. The cumulative character of electrical stimuli points to the existence of electrical memory in the Venus flytrap. The observed fast movement can be explained by the hydroelastic curvature model without invoking buckling instability. The new hydroelastic curvature mechanism provides an accurate description of the authors' experimental data.

  19. Energetics and forces of the Dionaea muscipula trap closing.

    PubMed

    Volkov, Alexander G; Murphy, Veronica A; Clemmons, Jacqueline I; Curley, Michael J; Markin, Vladislav S

    2012-01-01

    The Venus flytrap is the most famous carnivorous plant. The electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf in 0.3s without mechanical stimulation of trigger hairs. Here we present results for direct measurements of the closing force of the trap of Dionaea muscipula Ellis after mechanical or electrical stimulation of the trap using the piezoelectric thin film or Fuji Prescale indicating sensor film. The closing force was 0.14N and the corresponding pressure between rims of two lobes was 38 kPa. We evaluated theoretically using the Hydroelastic Curvature Model and compared with experimental data velocity, acceleration and kinetic energy from the time dependencies of distance between rims of lobes during the trap closing. The Charge Stimulation Method was used for trap electrostimulation between the midrib and lobes. From the dependence of voltage between two Ag/AgCl electrodes in the midrib and one of the lobes, we estimated electrical charge, current, resistance, electrical energy and electrical power dependencies on time during electrostimulation of the trap.

  20. Comparison of coupling of humans to electric and magnetic fields with frequencies between 100 Hz and 100 kHz

    SciTech Connect

    Kaune, W.T.; Guttman, J.L.; Kavet, R.

    1997-03-01

    Recent laboratory and epidemiological results have stimulated interest in the hypothesis that human beings may exhibit biological responses to magnetic and/or electric field transients with frequencies in the range between 100 Hz and 100 kHz. Much can be learned about the response of a system to a transient stimulation by understanding its response to sinusoidal disturbances over the entire frequency range of interest. Thus, the main effort of this paper was to compare the strengths of the electric fields induced in homogeneous ellipsoidal models by uniform 100 Hz through 100 kHz electric and magnetic fields. Over this frequency range, external electric fields of about 25--2,000 V/m (depending primarily on the orientation of the body relative to the field) are required to induce electric fields inside models of adults and children that are similar in strength to those induced by an external 1 {mu}T magnetic field. Additional analysis indicates that electric fields induced by uniform external electric and magnetic fields and by the nonuniform electric and magnetic fields produced by idealized point sources will not differ by more than a factor of two until the sources are brought close to the body. Published data on electric and magnetic field transients in residential environments indicate that, for most field orientations, the magnetic component will induce stronger electric fields inside adults and children than the electric component. This conclusion is also true for the currents induced in humans by typical levels of 60 Hz electric and magnetic fields in US residences.

  1. The closed fuel cycle

    SciTech Connect

    Froment, Antoine; Gillet, Philippe

    2007-07-01

    Available in abstract form only. Full text of publication follows: The fast growth of the world's economy coupled with the need for optimizing use of natural resources, for energy security and for climate change mitigation make energy supply one of the 21. century most daring challenges. The high reliability and efficiency of nuclear energy, its competitiveness in an energy market undergoing a new oil shock are as many factors in favor of the 'renaissance' of this greenhouse gas free energy. Over 160,000 tHM of LWR1 and AGR2 Used Nuclear Fuel (UNF) have already been unloaded from the reactor cores corresponding to 7,000 tons discharged per year worldwide. By 2030, this amount could exceed 400,000 tHM and annual unloading 14,000 tHM/year. AREVA believes that closing the nuclear fuel cycle through the treatment and recycling of Used Nuclear Fuel sustains the worldwide nuclear power expansion. It is an economically sound and environmentally responsible choice, based on the preservation of natural resources through the recycling of used fuel. It furthermore provides a safe and secure management of wastes while significantly minimizing the burden left to future generations. (authors)

  2. Is synthetic biology mechanical biology?

    PubMed

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  3. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including chi-square tests on a microcomputer, an integrated biology game, microscope slides of leaf stomata, culturing soil nematodes, technique for watering locust egg-laying tubes, hazards of biological chemicals (such as benzene, benzidene, calchicine,…

  4. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including use of dwarf cichlids (fishes) in secondary school biology, teaching edge effects on stomatal diffusion, computer program on effects of selection on gene frequencies, biological oxidation/reduction reactions, short cuts with Drosophila, computer program…

  5. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  6. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Presents experiments, demonstrations, activities and ideas relating to various fields of biology to be used in biology courses in secondary schools. Among those experiments presented are demonstrating the early stages of ferns and mosses and simple culture methods for fern prothalli. (HM)

  7. Insurance for electric and magnetic field litigation: Are you covered

    SciTech Connect

    Anderson, E.R.; Stewart, C.A. III

    1993-04-01

    Electrical power generating companies, power transmission companies and large generators and users of electrical power recently felt the sting of a second shock. The first shock came when lawsuits were first filed against companies in the electrical power industry claiming real or imagined damages from electrical and magnetic fields ([open quotes]EMFs[close quotes]). The new and second shock is potentially more devastating because it comes from the [open quotes]safe hands[close quotes] of the insurance industry. Standard-form comprehensive general liability ([open quotes]CGL[close quotes]) insurance policies purchased by nearly every company in the electrical power industry for generations are supposed to cover EMF bodily injury and property damage claims. Not so, say the lawyers for the most prominent insurance company selling insurance coverage to electric utilities, Associated Electric Gas Insurance Services, Ltd. ([open quotes]AEGIS[close quotes]).

  8. Optimization of closed Brayton cycles for space power generation

    NASA Technical Reports Server (NTRS)

    Hanlon, James C.

    1992-01-01

    A development status evaluation is presented for methods that allow accurate preliminary design and optimization of closed Brayton cycle engines for space electrical power generation. The basis for such work is the Closed Cycle Engine Performance simulation code, in conjunction with the optimization code COPES/ADS; the joining of the two codes has greatly expedited the optimization process. Attention is given to a variety of other model-versatility enhancers.

  9. Open-closed string duality at tree level.

    PubMed

    Sen, Ashoke

    2003-10-31

    We study the decay of unstable D-branes in string theory in the presence of an electric field, and show that the classical open string theory results for various properties of the final state agree with the properties of closed string states into which the system is expected to decay. This suggests a duality between tree level open string theory on unstable D-branes and closed strings at high density.

  10. Electrical safety during transplantation.

    PubMed

    Amicucci, G L; Di Lollo, L; Fiamingo, F; Mazzocchi, V; Platania, G; Ranieri, D; Razzano, R; Camin, G; Sebastiani, G; Gentile, P

    2010-01-01

    Technologic innovations enable management of medical equipment and power supply systems, with improvements that can affect the technical aspects, economics, and quality of medical service. Herein are outlined some technical guidelines, proposed by Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro, for increasing the effectiveness of the power supply system and the safety of patients and surgeons in the operating room, with particular focus on transplantation. The dependence of diagnoses and therapies on operation of the electrical equipment can potentially cause great risk to patients. Moreover, it is possible that faulty electrical equipment could produce current that may flow through the patient. Because patients are particularly vulnerable when their natural protection is considerably decreased, as during transplantation or other surgery, power supply systems must operate with a high degree of reliability and quality to prevent risk, and must be designed to reduce hazards from direct and indirect contact. Reliability of the power supply system is closely related to the quality of the project, choice of materials, and management of the system (eg, quality and frequency of servicing). Among the proposed guidelines, other than normal referencing, are (1) adoption of a monitoring system to improve the quality of the electrical parameters in the operating room, (2) institution of emergency procedures for management of electrical faults, (3) a procedure for management of fires in the operating room, (4) and maintenance interventions and inspections of medical devices to maintain minimal requirements of safety and performance.

  11. Close Reading in Elementary Schools

    ERIC Educational Resources Information Center

    Fisher, Douglas; Frey, Nancy

    2012-01-01

    Close reading is a recommended instructional approach to meet the challenges of teaching complex texts. But close readings are more common in high school and college than in elementary schools. In this article, we identify the components of close reading that were developed after a group of elementary school teachers observed their colleges in…

  12. Biological Oceanography

    NASA Astrophysics Data System (ADS)

    Dyhrman, Sonya

    2004-10-01

    The ocean is arguably the largest habitat on the planet, and it houses an astounding array of life, from microbes to whales. As a testament to this diversity and its importance, the discipline of biological oceanography spans studies of all levels of biological organization, from that of single genes, to organisms, to their population dynamics. Biological oceanography also includes studies on how organisms interact with, and contribute to, essential global processes. Students of biological oceanography are often as comfortable looking at satellite images as they are electron micrographs. This diversity of perspective begins the textbook Biological Oceanography, with cover graphics including a Coastal Zone Color Scanner image representing chlorophyll concentration, an electron micrograph of a dinoflagellate, and a photograph of a copepod. These images instantly capture the reader's attention and illustrate some of the different scales on which budding oceanographers are required to think. Having taught a core graduate course in biological oceanography for many years, Charlie Miller has used his lecture notes as the genesis for this book. The text covers the subject of biological oceanography in a manner that is targeted to introductory graduate students, but it would also be appropriate for advanced undergraduates.

  13. Neurochemostat: A Neural Interface SoC With Integrated Chemometrics for Closed-Loop Regulation of Brain Dopamine.

    PubMed

    Bozorgzadeh, Bardia; Schuweiler, Douglas R; Bobak, Martin J; Garris, Paul A; Mohseni, Pedram

    2016-06-01

    This paper presents a 3.3×3.2 mm(2) system-on-chip (SoC) fabricated in AMS 0.35 μm 2P/4M CMOS for closed-loop regulation of brain dopamine. The SoC uniquely integrates neurochemical sensing, on-the-fly chemometrics, and feedback-controlled electrical stimulation to realize a "neurochemostat" by maintaining brain levels of electrically evoked dopamine between two user-set thresholds. The SoC incorporates a 90 μW, custom-designed, digital signal processing (DSP) unit for real-time processing of neurochemical data obtained by 400 V/s fast-scan cyclic voltammetry (FSCV) with a carbon-fiber microelectrode (CFM). Specifically, the DSP unit executes a chemometrics algorithm based upon principal component regression (PCR) to resolve in real time electrically evoked brain dopamine levels from pH change and CFM background-current drift, two common interferents encountered using FSCV with a CFM in vivo. Further, the DSP unit directly links the chemically resolved dopamine levels to the activation of the electrical microstimulator in on-off-keying (OOK) fashion. Measured results from benchtop testing, flow injection analysis (FIA), and biological experiments with an anesthetized rat are presented.

  14. Electrically powered hand tool

    DOEpatents

    Myers, Kurt S.; Reed, Teddy R.

    2007-01-16

    An electrically powered hand tool is described and which includes a three phase electrical motor having a plurality of poles; an electrical motor drive electrically coupled with the three phase electrical motor; and a source of electrical power which is converted to greater than about 208 volts three-phase and which is electrically coupled with the electrical motor drive.

  15. BIOLOGICAL WARFARE

    PubMed Central

    Beeston, John

    1953-01-01

    The use of biological agents as controlled weapons of war is practical although uncertain. Three types of agents are feasible, including pathogenic organisms and biological pests, toxins, and synthetic hormones regulating plant growth. These agents may be chosen for selective effects varying from prolonged incipient illness to death of plants, man and domestic animals. For specific preventive and control measures required to combat these situations, there must be careful and detailed planning. The nucleus of such a program is available within the existing framework of public health activities. Additional research and expansion of established activities in time of attack are necessary parts of biological warfare defense. PMID:13059641

  16. Foldit Biology

    DTIC Science & Technology

    2015-07-31

    Report 8/1/2013-7/31/2015 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Foldit Biology NOOO 14-13-C-0221 Sb. GRANT NUMBER N/A Sc. PROGRAM ELEMENT...Include area code) Unclassified Unclassified Unclassified (206) 616-2660 Zoran Popović Foldit Biology (Task 1, 2, 3, 4) Final Report...Period Covered by the Report August 1, 2013 – July 31, 2015 Date of Report: July 31, 2015 Project Title: Foldit Biology Contract Number: N00014-13

  17. Biological monitoring

    SciTech Connect

    Ho, M.H.; Dillon, H.K.

    1986-02-01

    Biological monitoring is defined as the measurement and assessment of workplace agents or their metabolites in tissues, secreta, excreta, expired air, or any combination of these to evaluate exposure and health risk compared to an appropriate reference. Biological monitoring offers several advantages: it takes into account individual variability in biological activity resulting from a chemical insult. It takes into account the effects of personal physical activity and individual life styles. It is a valuable adjunct to ambient monitoring and health surveillance. The importance of chemical speciation in the toxicity of pollutants is discussed. Basic protocols for lead, aluminum, cadmium, mercury, selenium, and nickel are presented. Basic criteria for biological monitoring methods are presented. 11 references, 1 table.

  18. Bottle Biology.

    ERIC Educational Resources Information Center

    CSTA Journal, 1995

    1995-01-01

    Provides hands-on biology activities using plastic bottles that allow students to become engaged in asking questions, creating experiments, testing hypotheses, and generating answers. Activities explore terrestrial and aquatic systems. (MKR)

  19. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Ten ideas that have been tried out by the authors in schools are presented for biology teachers. The areas covered include genetics, dispersal of seeds, habituation in earthworms, respiration, sensory neurons, fats and oils. A reading list is provided. (PS)

  20. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Twelve new experiments in biology are described by teachers for use in classrooms. Broad areas covered include enzyme action, growth regulation, microscopy, respiration, germination, plant succession, leaf structure and blood structure. Explanations are detailed. (PS)

  1. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1973

    1973-01-01

    Some helpful ideas are proposed for use by biology teachers. Topics included are Food Webs,'' Key to Identification of Families,'' Viruses,'' Sieve Tube,'' Woodlice,'' Ecology of Oak Leaf Roller Moth,'' and Model Making.'' (PS)

  2. Camera shutter is actuated by electric signal

    NASA Technical Reports Server (NTRS)

    Neff, J. E.

    1964-01-01

    Rotary solenoid energized by an electric signal opens a camera shutter, and when the solenoid is de-energized a spring closes it. By the use of a microswitch, the shutter may be opened and closed in one continuous, rapid operation when the solenoid is actuated.

  3. Shaping bursting by electrical coupling and noise.

    PubMed

    Medvedev, Georgi S; Zhuravytska, Svitlana

    2012-02-01

    Gap-junctional coupling is an important way of communication between neurons and other excitable cells. Strong electrical coupling synchronizes activity across cell ensembles. Surprisingly, in the presence of noise synchronous oscillations generated by an electrically coupled network may differ qualitatively from the oscillations produced by uncoupled individual cells forming the network. A prominent example of such behavior is the synchronized bursting in islets of Langerhans formed by pancreatic β-cells, which in isolation are known to exhibit irregular spiking (Sherman and Rinzel, Biophys J 54:411-425, 1988; Sherman and Rinzel, Biophys J 59:547-559, 1991). At the heart of this intriguing phenomenon lies denoising, a remarkable ability of electrical coupling to diminish the effects of noise acting on individual cells. In this paper, building on an earlier analysis of denoising in networks of integrate-and-fire neurons (Medvedev, Neural Comput 21 (11):3057-3078, 2009) and our recent study of spontaneous activity in a closely related model of the Locus Coeruleus network (Medvedev and Zhuravytska, The geometry of spontaneous spiking in neuronal networks, submitted, 2012), we derive quantitative estimates characterizing denoising in electrically coupled networks of conductance-based models of square wave bursting cells. Our analysis reveals the interplay of the intrinsic properties of the individual cells and network topology and their respective contributions to this important effect. In particular, we show that networks on graphs with large algebraic connectivity (Fiedler, Czech Math J 23(98):298-305, 1973) or small total effective resistance (Bollobas, Modern graph theory, Graduate Texts in Mathematics, vol. 184, Springer, New York, 1998) are better equipped for implementing denoising. As a by-product of the analysis of denoising, we analytically estimate the rate with which trajectories converge to the synchronization subspace and the stability of the latter to

  4. Rapid and Enhanced Proteolytic Digestion using Electric-Field-oriented Enzyme Reactor

    PubMed Central

    Zhou, Yu; Yi, Tie; Park, Sung-Soo; Chadwick, Wayne; Shen, Rong-Fong; Wu, Wells W.; Martin, Bronwen; Maudsley, Stuart

    2011-01-01

    We have created a novel enzyme reactor using electric field-mediated orientation and immobilization of proteolytic enzymes (trypsin/chymotrypsin) on biocompatible PVDF membranes in a continuous flow-through chamber. Using less than 5 minutes, this reactor in various enzyme combinations can produce enhanced rapid digestion for standardized prototypic proteins, hydrophilic proteins and hydrophobic transmembrane proteins when compared to in-solution techniques. With improved digestive efficiency, our reactor improved the overall functional analysis of lipid raft proteomes by identifying more closely functionally linked proteins and elucidated a richer set of biological processes and pathways linked to the proteins than traditional in-solution methods. PMID:21338726

  5. Silicon smelting in a closed furnace

    SciTech Connect

    Dosaj, V.; Brumels, M.D.; Haines, C.M.; May, J.B. )

    1991-01-01

    Dow Corning has been working towards the advancement of silicon smelting in a closed furnace over the past four years. A 200 kVA closed furnace pilot plant unit was built to investigate the operating parameters for smelting silicon. The single electrode furnace is operated under totally sealed conditions. The feed from the feed hoppers is fed through air locks to the furnace. The off-gas from the furnace, consisting of by-product CO as well as volatiles from the feeds, pass through a venturi scrubber, where water is introduced to scrub out the fume from the furnace and cool the gas. The mixed scrubber water and off-gas pass into a centrifugal mist eliminator where the water and fume disengage from the gas. The fume slurry is passed through bag filters where the fume is separated from the water. The clean off-gas from the furnace was evaluated for its calorific value and evaluated for conversion to useful products. A number of silicon smelting tests were conducted during this program. Various levels of charcoal and coal mixtures were evaluated to determine the optimum mix. A low volatile coal was preferred over typical Blue Gem coal. The coal amount in the mix was maximized without compromising the smelting performance. A raw material mix consisting of 30% charcoal and 70% low volatile coal was determined to be an optimum mix for closed furnace operation. Silicon recoveries in the low nineties were demonstrated using this mix. Four quartz sources were also evaluated in the closed furnace. The closed furnace operation for silicon smelting was identified to offer significant advantages over an open furnace from the standpoint of reduced carbon oxidation losses, electrode consumption, electrical energy consumption and silicon yield improvement. Other advantages in addition to process off-gas recovery included improved safety from reduced heat and fume exposure, and improved pollution control to the environment. 1 ref.

  6. Silicon smelting in a closed furnace

    SciTech Connect

    Dosaj, V.; Brumels, M.D.; Haines, C.M.; May, J.B.

    1991-12-31

    Dow Corning has been working towards the advancement of silicon smelting in a closed furnace over the past four years. A 200 kVA closed furnace pilot plant unit was built to investigate the operating parameters for smelting silicon. The single electrode furnace is operated under totally sealed conditions. The feed from the feed hoppers is fed through air locks to the furnace. The off-gas from the furnace, consisting of by-product CO as well as volatiles from the feeds, pass through a venturi scrubber, where water is introduced to scrub out the fume from the furnace and cool the gas. The mixed scrubber water and off-gas pass into a centrifugal mist eliminator where the water and fume disengage from the gas. The fume slurry is passed through bag filters where the fume is separated from the water. The clean off-gas from the furnace was evaluated for its calorific value and evaluated for conversion to useful products. A number of silicon smelting tests were conducted during this program. Various levels of charcoal and coal mixtures were evaluated to determine the optimum mix. A low volatile coal was preferred over typical Blue Gem coal. The coal amount in the mix was maximized without compromising the smelting performance. A raw material mix consisting of 30% charcoal and 70% low volatile coal was determined to be an optimum mix for closed furnace operation. Silicon recoveries in the low nineties were demonstrated using this mix. Four quartz sources were also evaluated in the closed furnace. The closed furnace operation for silicon smelting was identified to offer significant advantages over an open furnace from the standpoint of reduced carbon oxidation losses, electrode consumption, electrical energy consumption and silicon yield improvement. Other advantages in addition to process off-gas recovery included improved safety from reduced heat and fume exposure, and improved pollution control to the environment. 1 ref.

  7. Electrical Injuries

    MedlinePlus

    ... your injuries are depends on how strong the electric current was, what type of current it was, how it moved through your body, and how long you were exposed. Other factors include how ... you should see a doctor. You may have internal damage and not realize it.

  8. Single Cell Electrical Characterization Techniques

    PubMed Central

    Mansor, Muhammad Asraf; Ahmad, Mohd Ridzuan

    2015-01-01

    Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell’s electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell’s electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed. PMID:26053399

  9. A chamber design for closed ecological systems research

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, H.; Stofan, P. E.

    1981-01-01

    A single-plant growth chamber is described which is closed with respect to nutrient and gas flows, in order to serve as a tool in the investigation of control over biological systems. Such control procedures are essential for the use of biological components in the development of a closed ecological life support system (CELSS). The chamber's design consists of two concentric clear plastic cylinders equipped with aeroponic feed tubing, a supporting platform for the plant and a set of sensors that includes an anemometer, thermistors, pressure and strain gauges, and humidity sensors.

  10. 7. SOUTHWEST CORNER OF EAST PHOTO TOWER. CLOSED WINDOW ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. SOUTHWEST CORNER OF EAST PHOTO TOWER. CLOSED WINDOW ON WEST SIDE; ELECTRICAL POWER BOX ON EAST SIDE OF PHOTO TOWER. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  11. Closed landfills to solar energy power plants: Estimating the solar potential of closed landfills in California

    NASA Astrophysics Data System (ADS)

    Munsell, Devon R.

    Solar radiation is a promising source of renewable energy because it is abundant and the technologies to harvest it are quickly improving. An ongoing challenge is to find suitable and effective areas to implement solar energy technologies without causing ecological harm. In this regard, one type of land use that has been largely overlooked for siting solar technologies is closed or soon to be closed landfills. Utilizing Geographic Information System (GIS) based solar modeling; this study makes an inventory of solar generation potential for such sites in the state of California. The study takes account of various site characteristics in relation to the siting needs of photovoltaic (PV) geomembrane and dish-Stirling technologies (e.g., size, topography, closing date, solar insolation, presence of landfill gas recovery projects, and proximity to transmission grids and roads). This study reaches the three principal conclusions. First, with an estimated annual solar electricity generation potential of 3.7 million megawatt hours (MWh), closed or soon to be closed landfill sites could provide an amount of power significantly larger than California's current solar electric generation. Secondly, the possibility of combining PV geomembrane, dish-Stirling, and landfill gas (LFG) to energy technologies at particular sites deserves further investigation. Lastly, there are many assumptions, challenges, and limitations in conducting inventory studies of solar potential for specific sites, including the difficulty in finding accurate data regarding the location and attributes of potential landfills to be analyzed in the study. Furthermore, solar modeling necessarily simplifies a complex phenomenon, namely incoming solar radiation. Additionally, site visits, while necessary for finding details of the site, are largely impractical for a large scale study.

  12. Flower biology and biologically-based integrated fire blight management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fire blight infection is generally initiated in flowers, and thus, research has been directed to the biology and microbial ecology of flowers as related to this disease. In addition to investigations involving apple and pear flowers, Manchurian crab apple (Malus manchurica), closely related to appl...

  13. New optoelectronic sensor for measuring biologically effective irradiance

    NASA Astrophysics Data System (ADS)

    Kosyachenko, Leonid A.; Sklyarchuk, Valery M.

    1997-12-01

    A new optoelectronic sensor whose spectral responsivity to UV radiation is almost identical with that of the human skin or of the eyes is presented. The sensor comprises two closely-spaced UV-sensitive Au-SiC diode, one of which is fitted with a glass filter. The photodiodes are connected to electronics that amplifies, combines and subtracts electrical signals generated by radiation in the photodiodes. The responsivity of the Au-SiC diode structure with a semitransparent gold electrode covers the whole UV spectrum, with the long-wavelength end bounded by the semiconductor bandgap. The photodiode with a filter absorbing wavelengths shorter than 315-320 nm is responsive in the UV-A region, while the difference between the electrical signals generated in the filter-containing and filter-free diodes is determined by the UV-B + IV-C radiation. The measuring of biologically effective radiation over the entire UV spectral range is achieved through combining the signal generated by UV-A radiation and the previously amplified difference signal generated by UV-B + UV-C radiation. The sensor spectral responsivity thus obtained is very close to the tabular curve of the relative spectral effectiveness of UV radiation on the normal human skin or eyes.

  14. Hierarchical structure of biological systems

    PubMed Central

    Alcocer-Cuarón, Carlos; Rivera, Ana L; Castaño, Victor M

    2014-01-01

    A general theory of biological systems, based on few fundamental propositions, allows a generalization of both Wierner and Berthalanffy approaches to theoretical biology. Here, a biological system is defined as a set of self-organized, differentiated elements that interact pair-wise through various networks and media, isolated from other sets by boundaries. Their relation to other systems can be described as a closed loop in a steady-state, which leads to a hierarchical structure and functioning of the biological system. Our thermodynamical approach of hierarchical character can be applied to biological systems of varying sizes through some general principles, based on the exchange of energy information and/or mass from and within the systems. PMID:24145961

  15. A chemist building paths to cell biology.

    PubMed

    Weibel, Douglas B

    2013-11-01

    Galileo is reported to have stated, "Measure what is measurable and make measurable what is not so." My group's trajectory in cell biology has closely followed this philosophy, although it took some searching to find this path.

  16. Gas Foil Bearing Technology Advancements for Closed Brayton Cycle Turbines

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; Bruckner, Robert J.; DellaCorte, Christopher; Radil, Kevin C.

    2007-01-01

    Closed Brayton Cycle (CBC) turbine systems are under consideration for future space electric power generation. CBC turbines convert thermal energy from a nuclear reactor, or other heat source, to electrical power using a closed-loop cycle. The operating fluid in the closed-loop is commonly a high pressure inert gas mixture that cannot tolerate contamination. One source of potential contamination in a system such as this is the lubricant used in the turbomachine bearings. Gas Foil Bearings (GFB) represent a bearing technology that eliminates the possibility of contamination by using the working fluid as the lubricant. Thus, foil bearings are well suited to application in space power CBC turbine systems. NASA Glenn Research Center is actively researching GFB technology for use in these CBC power turbines. A power loss model has been developed, and the effects of a very high ambient pressure, start-up torque, and misalignment, have been observed and are reported here.

  17. Magnetic and electric characteristics of the electric fish Gymnotus carapó.

    PubMed

    Baffa, O; Côrrea, S L

    1992-08-01

    The fresh water fish Gymnotus carapó produces a continuous series of weak pulsed electric fields in its surroundings and senses disturbances of this field as part of its sensory system. The electric and magnetic properties of the electric organ of this fish were studied. Magnetic fields close to the fish on the order of nT are produced by currents on the order of 10(-4) A in the electric organ of the fish. The electromotive force, the internal resistance, the current, and the electric power of the equivalent circuit were determined noninvasively.

  18. What makes closed ecological systems sustainable?

    NASA Astrophysics Data System (ADS)

    Gitelson, I.; Degermendzhy, A.; Rodicheva, E.

    A closed ecosystem has some properties that an open systems lacks. Let us consider the ones that increase the sustainability of an ecosystem. The common feature of biological and physicochemical life support systems is that basically they are both catalytic. There are two fundamental properties distinguishing biological systems: 1) they are auto-catalytic: their catalysts - enzymes of protein nature - are continuously reproduced when the system functions; 2) the program of every process performed by enzymes and the program of their reproduction are inherent in the biological system itself - in the totality of genomes of the species involved in the functioning of the ecosystem. Actually, one cell with the genome capable of the phenotypic realization is enough for the self- restoration of the function performed by the cells of this species in the ecosystem. The multi-cellular organisms with stem cells are constantly ready to repair themselves by intensifying the continuous process of regeneration. We (Gitelson) have made a quantitative investigation of this process by studying the regeneration and reparation of erythrocytes in mammals. The continuous microalgal culture of Chlorella vulgaris was taken to investigate quantitatively the similar functional process of self-restoration in unicellular algae (Rodicheva). Based on the data obtained, we proposed a mathematical model of the restoration process in the cell population that has suffered an acute radiation damage. Besides these general biological mechanisms responsible for their sustainability, closed systems also possess specific features enhancing their stability. They are as follows: 1. Nutrients cannot leave the system. 2. The metabolic pathways of the material cycling are closed. 3. The rates of interlink metabolism are in conformity with each other due to their mutual limitation. We present the data obtained in the Bios-3 experiments that prove the efficiency of this mechanism as a factor of the

  19. Biological Oceanography

    NASA Technical Reports Server (NTRS)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  20. Biological preconcentrator

    DOEpatents

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  1. Electricity unplugged

    NASA Astrophysics Data System (ADS)

    Karalis, Aristeidis

    2009-02-01

    The judge was driving back late one cold winter night. Entering the garage, the battery-charging indicator in his wirelessly powered electric car came on. "Home at last," crossed his mind. He swiped his personal smartcard on the front-door detector to be let in. He heard a "charging" beep from his mobile phone. The blinking cursor on the half-finished e-mail on the laptop had been waiting all day on the side table. He picked the computer up and walked towards his desk. "Good evening, your honour. Your wirelessly heated robe," said the butler-robot as it approached from the kitchen. Putting on the electric garment, he sat on the medical desk chair. His artificial heart was now beating faster.

  2. Electric power

    SciTech Connect

    Chase, M.

    1988-01-01

    This text examines the critical problems faced by the electric power industry, shown in the context of a detailed description of the history and development of the industry. A new industry initiative is proposed that will allow for a more effective response to industry fluctuations. Topics covered include developments in power technology federal nuclear power regulation and legislation, environmentalism and conservationism, industry financial problems, capital minimization, and responses to utility responsibility.

  3. Electric Car

    NASA Technical Reports Server (NTRS)

    1977-01-01

    NASA's Lewis Research Center undertook research toward a practical, economical battery with higher energy density. Borrowing from space satellite battery technology, Lewis came up with a nickel-zinc battery that promises longer life and twice the range of the lead-acid counterpart. Lewis researchers fabricated a prototype battery and installed it in an Otis P-500 electric utility van, using only the battery space already available and allowing battery weight equal to that of the va's conventional lead-acid battery

  4. (Biological dosimetry)

    SciTech Connect

    Sega, G.A.

    1990-11-06

    The traveler participated in an International Symposium on Trends in Biological Dosimetry and presented an invited paper entitled, Adducts in sperm protamine and DNA vs mutation frequency.'' The purpose of the Symposium was to examine the applicability of new methods to study quantitatively the effects of xenobiotic agents (radiation and chemicals) on molecular, cellular and organ systems, with special emphasis on human biological dosimetry. The general areas covered at the meeting included studies on parent compounds and metabolites; protein adducts; DNA adducts; gene mutations; cytogenetic end-points and reproductive methods.

  5. Lightweight Valve Closes Duct Quickly

    NASA Technical Reports Server (NTRS)

    Fournier, Walter L.; Burgy, N. Frank

    1991-01-01

    Expanding balloon serves as lightweight emergency valve to close wide duct. Uninflated balloon stored in housing of duct. Pad resting on burst diaphragm protects balloon from hot gases in duct. Once control system triggers valve, balloon inflates rapidly to block duct. Weighs much less than does conventional butterfly, hot-gas, or poppet valve capable of closing duct of equal diameter.

  6. Postdivorce Father-Adolescent Closeness

    ERIC Educational Resources Information Center

    Scott, Mindy E.; Booth, Alan; King, Valarie; Johnson, David R.

    2007-01-01

    Research indicates that closeness of the father-child bond following parental divorce is associated with better outcomes for children and adolescents. Unlike other investigations, this study takes a long-term developmental approach to understanding stability and change in postdivorce father-adolescent relationship closeness. Drawing on Add Health…

  7. School Closings Policy. Issue Brief

    ERIC Educational Resources Information Center

    Research For Action, 2013

    2013-01-01

    The nation's largest school districts have increasingly turned to building closures to address budget deficits, demographic shifts, and the movement of students to charter schools. Over the past decade, 70 large or mid-sized cities closed schools--averaging 11 buildings per closure. This trend shows no signs of slowing. Washington, D.C. closed 23…

  8. Studies on the possible biological effects of 50 Hz electric and/or magnetic fields: evaluation of some glycolytic enzymes, glycolytic flux, energy and oxido-reductive potentials in human erythrocytes exposed in vitro to power frequency fields.

    PubMed

    Dachà, M; Accorsi, A; Pierotti, C; Vetrano, F; Mantovani, R; Guidi, G; Conti, R; Nicolini, P

    1993-01-01

    An attempt has been made to understand whether 50 Hz electric and magnetic fields (EMFs) are involved in producing bioeffects by exposing human erythrocytes in vitro. The study evaluated some key glycolytic enzymes, glucose consumption, lactate production, energy charge, 2,3-diphosphoglycerate, and reduced glutathione levels, all of which are biochemical parameters significant to erythrocyte function. Cells exposed to individual or superimposed EMFs have not shown any significant difference compared with the controls.

  9. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Presents content information and/or laboratory procedures and experiments on different biology topics including small-scale cultivation of watercress and its use in water-culture experiments, microbiology of the phylloplane, use of mouthbrooders in science class, and the gene. (DC)

  10. Marine Biology

    ERIC Educational Resources Information Center

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  11. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including water relation exercise on auxin-treated artichoke tuber tissue; aerobic respiration in yeast; an improved potometer; use of mobiles in biological classification, and experiments on powdery mildews and banana polyphenol oxidase. Includes reading lists…

  12. Cancer Biology

    ERIC Educational Resources Information Center

    Dominiecki, Mary E.

    2004-01-01

    University of Colorado's Virtual Student Fellowship available at and developed by Bakemeier, Richard F. This website is designed to give students applying for a fellowship an overview of basic topics in biology and how they are used by cancer researchers to develop new treatments.

  13. (Biological dosimetry)

    SciTech Connect

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  14. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Describes equipment, activities, and experiments useful in biology and environmental education instruction, including, among others, sampling in ecology using an overhead projector, the slide finder as an aid to microscopy, teaching kidney function, and teaching wildlife conservation-sand dune systems. (SK)

  15. Scaffolded biology.

    PubMed

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  16. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1984

    1984-01-01

    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  17. Biology Excursions

    ERIC Educational Resources Information Center

    Baldock, R. N.

    1973-01-01

    Provides many useful suggestions and cautions for planning and executing a biology field excursion. Specific procedures are outlined for investigating land communities and coastal areas, and a number of follow-up laboratory activities are described. The appendix provides an extensive bibliography with useful comments on the literature. (JR)

  18. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1979

    1979-01-01

    Organized by topic is a reading list for A- and S-level biology. Described are experiments for measuring rate of water uptake in a shoot; questions to aid students in designing experiments; rise of overhead projection to demonstrate osmosis and blood cell counting; and microbial manufacture of vinegar. (CS)

  19. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes nine biology experiments, including osmosis, genetics; oxygen content of blood, enzymes in bean seedlings, preparation of bird skins, vascularization in bean seedlings, a game called "sequences" (applied to review situations), crossword puzzle for human respiration, and physiology of the woodlouse. (CS)

  20. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  1. Modelling the Effects of Electrical Coupling between Unmyelinated Axons of Brainstem Neurons Controlling Rhythmic Activity

    PubMed Central

    Hull, Michael J.; Soffe, Stephen R.; Willshaw, David J.; Roberts, Alan

    2015-01-01

    Gap junctions between fine unmyelinated axons can electrically couple groups of brain neurons to synchronise firing and contribute to rhythmic activity. To explore the distribution and significance of electrical coupling, we modelled a well analysed, small population of brainstem neurons which drive swimming in young frog tadpoles. A passive network of 30 multicompartmental neurons with unmyelinated axons was used to infer that: axon-axon gap junctions close to the soma gave the best match to experimentally measured coupling coefficients; axon diameter had a strong influence on coupling; most neurons were coupled indirectly via the axons of other neurons. When active channels were added, gap junctions could make action potential propagation along the thin axons unreliable. Increased sodium and decreased potassium channel densities in the initial axon segment improved action potential propagation. Modelling suggested that the single spike firing to step current injection observed in whole-cell recordings is not a cellular property but a dynamic consequence of shunting resulting from electrical coupling. Without electrical coupling, firing of the population during depolarising current was unsynchronised; with coupling, the population showed synchronous recruitment and rhythmic firing. When activated instead by increasing levels of modelled sensory pathway input, the population without electrical coupling was recruited incrementally to unpatterned activity. However, when coupled, the population was recruited all-or-none at threshold into a rhythmic swimming pattern: the tadpole “decided” to swim. Modelling emphasises uncertainties about fine unmyelinated axon physiology but, when informed by biological data, makes general predictions about gap junctions: locations close to the soma; relatively small numbers; many indirect connections between neurons; cause of action potential propagation failure in fine axons; misleading alteration of intrinsic firing

  2. The Effect of the Nonlinearity of the Response of Lipid Membranes to Voltage Perturbations on the Interpretation of Their Electrical Properties. A New Theoretical Description

    PubMed Central

    Mosgaard, Lars D.; Zecchi, Karis A.; Heimburg, Thomas; Budvytyte, Rima

    2015-01-01

    Our understanding of the electrical properties of cell membranes is derived from experiments where the membrane is exposed to a perturbation (in the form of a time-dependent voltage or current change) and information is extracted from the measured output. The interpretation of such electrical recordings consists in finding an electronic equivalent that would show the same or similar response as the biological system. In general, however, there is no unique circuit configuration, which can explain a single electrical recording and the choice of an electric model for a biological system is based on complementary information (most commonly structural information) of the system investigated. Most of the electrophysiological data on cell membranes address the functional role of protein channels while assuming that the lipid matrix is an insulator with constant capacitance. However, close to their melting transition the lipid bilayers are no inert insulators. Their conductivity and their capacitance are nonlinear functions of both voltage, area and volume density. This has to be considered when interpreting electrical data. Here we show how electric data commonly interpreted as gating currents of proteins and inductance can be explained by the nonlinear dynamics of the lipid matrix itself. PMID:26426061

  3. Three-dimensional noninvasive ultrasound Joule heat tomography based on the acousto-electric effect using unipolar pulses: a simulation study.

    PubMed

    Yang, Renhuan; Li, Xu; Song, Aiguo; He, Bin; Yan, Ruqiang

    2012-11-21

    Electrical properties of biological tissues are highly sensitive to their physiological and pathological status. Thus it is of importance to image electrical properties of biological tissues. However, spatial resolution of conventional electrical impedance tomography (EIT) is generally poor. Recently, hybrid imaging modalities combining electric conductivity contrast and ultrasonic resolution based on the acousto-electric effect has attracted considerable attention. In this study, we propose a novel three-dimensional (3D) noninvasive ultrasound Joule heat tomography (UJHT) approach based on the acousto-electric effect using unipolar ultrasound pulses. As the Joule heat density distribution is highly dependent on the conductivity distribution, an accurate and high-resolution mapping of the Joule heat density distribution is expected to give important information that is closely related to the conductivity contrast. The advantages of the proposed ultrasound Joule heat tomography using unipolar pulses include its simple inverse solution, better performance than UJHT using common bipolar pulses and its independence of a priori knowledge of the conductivity distribution of the imaging object. Computer simulation results show that using the proposed method, it is feasible to perform a high spatial resolution Joule heat imaging in an inhomogeneous conductive media. Application of this technique on tumor scanning is also investigated by a series of computer simulations.

  4. 76 FR 41273 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting....395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support;...

  5. 75 FR 66770 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research;...

  6. 75 FR 42449 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting....395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support;...

  7. 75 FR 79010 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Treatment Research; 93.396, Cancer Biology ] Research; 93.397, Cancer Centers Support; 93.398,...

  8. 75 FR 14172 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ... Prevention Research; 93.394, Cancer Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research Manpower; 93.399... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  9. 78 FR 41939 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ... Research; 93.394, Cancer Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research Manpower; 93.399, Cancer... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  10. 77 FR 20831 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... Prevention Research; 93.394, Cancer Detection and ] Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research Manpower; 93.399... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  11. 78 FR 12766 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... Research; 93.394, Cancer Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research Manpower; 93.399, Cancer... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  12. 78 FR 26055 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Committee: National Cancer Institute Special Emphasis Panel; Early-Stage Development of Informatics... Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  13. 76 FR 26310 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ..., Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel, Population-based Research Optimizing...

  14. 78 FR 20119 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group; Subcommittee I--Transition to Independence....

  15. 75 FR 65364 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ... and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; Epitope Mapping Technologies. Date: December...

  16. 76 FR 20693 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group; Subcommittee G--Education. Date: May 24,...

  17. 76 FR 50234 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ..., Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group; Subcommittee G--Education. Date: September...

  18. 76 FR 78013 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ..., Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group, Subcommittee G--Education. Date: January 24,...

  19. 76 FR 1446 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ..., Cancer Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group; Subcommittee F--Manpower & Training. To...

  20. 77 FR 24969 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group; Subcommittee I--Career Development. Date: June...

  1. 76 FR 3641 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; Methylation Meeting. Date: March 8, 2011....

  2. 75 FR 21643 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398, Cancer Research... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group, Subcommittee F--Manpower & Training. Date: May...

  3. 76 FR 14675 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ..., Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; IMAT. Date: April 6, 2011. Time: 3 p.m. to 5...

  4. 78 FR 18357 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ..., Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93.398... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Initial Review Group Subcommittee J--Career Development. Date: July...

  5. 78 FR 26056 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; NCI Omnibus Review. Date: May 29, 2013....

  6. 77 FR 28612 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; Limited Competition: Comprehensive...

  7. 75 FR 14172 - National Cancer Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ....395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers Support; 93... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed Meeting... Committee: National Cancer Institute Special Emphasis Panel; NCI-CNP (U54) Review. Date: April 7-9,...

  8. 76 FR 3642 - National Cancer Institute; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... Cancer Diagnosis, Staging and Treatment. Date: March 8, 2011. Time: 8 a.m. to 6 p.m. Agenda: To review..., Cancer Detection and Diagnosis Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  9. 78 FR 28237 - National Cancer Institute; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... Abundance Cancer-Related Proteins/ Peptides. Date: June 20, 2013. Time: 1:00 p.m. to 5:00 p.m. Agenda: To... Research; 93.395, Cancer Treatment Research; 93.396, Cancer Biology Research; 93.397, Cancer Centers... HUMAN SERVICES National Institutes of Health National Cancer Institute; Notice of Closed...

  10. Undergraduates' Views about Biology and Physics

    ERIC Educational Resources Information Center

    Spall, Katie; Barrett, Stephanie; Stanisstreet, Martin; Dickson, Dominic; Boyes, Edward

    2003-01-01

    There is continuing concern about the low enrolment of students on to some undergraduate science courses, especially physics. Here we explore some of the reasons that might underpin this. The views about physics and biology of Year 1 undergraduate students on English, physics and biology programmes of study were compared using a closed-form…

  11. To Close or Not to Close: Guantanamo Bay

    DTIC Science & Technology

    2009-04-01

    world will be the least of our worries. 15 Closing it Down Like any controversial issue, there are also arguments on the side of the... waterboarding is an acceptable interrogation technique to coerce information from detainees. He specifically mentioned his approval of this method on Khalid...weakening its influence and effectives throughout the international community. President Obama shared this sentiment and made the closing of

  12. Magneto-Electric Conversion of Optical Energy to Electricity

    DTIC Science & Technology

    2015-07-06

    rotation of the molecule which contributes some heating to the system . While not significant in the context of magnetization, this finding sets a limit... efficiency estimated from heat generated by rotational excitations to be 999.0 , very close to unity and much higher than the limits of photovoltaic...nonlinearities of interest in this work arise from dynamic symmetry-breaking by the optical magnetic field. 15.  SUBJECT TERMS magneto-electric, efficiency

  13. Climate Action Benefits: Electricity

    EPA Pesticide Factsheets

    This page provides background on the relationship between electricity and climate change and describes what the CIRA Electricity analyses cover. It provides links to the subsectors Electricity Demand and Electricity Supply.

  14. Electrical receptacle

    DOEpatents

    Leong, R.

    1993-06-22

    The invention is a receptacle for a three prong electrical plug which has either a tubular or U-shaped grounding prong. The inventive receptacle has a grounding prong socket which is sufficiently spacious to prevent the socket from significantly stretching when a larger, U-shaped grounding prong is inserted into the socket, and having two ridges to allow a snug fit when a smaller tubular shape grounding prong is inserted into the socket. The two ridges are made to prevent the socket from expanding when either the U-shaped grounding prong or the tubular grounding prong is inserted.

  15. Electrical receptacle

    DOEpatents

    Leong, Robert

    1993-01-01

    The invention is a receptacle for a three prong electrical plug which has either a tubular or U-shaped grounding prong. The inventive receptacle has a grounding prong socket which is sufficiently spacious to prevent the socket from significantly stretching when a larger, U-shaped grounding prong is inserted into the socket, and having two ridges to allow a snug fit when a smaller tubular shape grounding prong is inserted into the socket. The two ridges are made to prevent the socket from expanding when either the U-shaped grounding prong or the tubular grounding prong is inserted.

  16. Solar Electricity

    NASA Technical Reports Server (NTRS)

    1988-01-01

    ARCO Solar manufactures PV Systems tailored to a broad variety of applications. PV arrays are routinely used at remote communications installations to operate large microwave repeaters, TV and radio repeaters rural telephone, and small telemetry systems that monitor environmental conditions. Also used to power agricultural water pumping systems, to provide electricity for isolated villages and medical clinics, for corrosion protection for pipelines and bridges, to power railroad signals, air/sea navigational aids, and for many types of military systems. ARCO is now moving into large scale generation for utilities.

  17. Signal Cloaking by Electric Fish.

    PubMed

    Stoddard, Philip K; Markham, Michael R

    2008-01-01

    Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less-detectable high-frequency spectral ranges. Hypopomid electric fish evolved a signal-cloaking strategy that reduces their detectability by predators in the lab (and thus presumably their risk of predation in the field). These fish produce broad-frequency electric fields close to the body, but the heterogeneous local fields merge over space to cancel the low-frequency spectrum at a distance. Mature males dynamically regulate this cloaking mechanism to enhance or suppress low-frequency energy. The mechanism underlying electric-field cloaking involves electrogenic cells that produce two independent action potentials. In a unique twist, these cells orient sodium and potassium currents in the same direction, potentially boosting their capabilities for current generation. Exploration of such evolutionary inventions could aid the design of biogenerators to power implantable medical devices, an ambition that would benefit from the complete genome sequence of a gymnotiform fish.

  18. Signal Cloaking by Electric Fish

    PubMed Central

    STODDARD, PHILIP K.; MARKHAM, MICHAEL R.

    2010-01-01

    Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less-detectable high-frequency spectral ranges. Hypopomid electric fish evolved a signal-cloaking strategy that reduces their detectability by predators in the lab (and thus presumably their risk of predation in the field). These fish produce broad-frequency electric fields close to the body, but the heterogeneous local fields merge over space to cancel the low-frequency spectrum at a distance. Mature males dynamically regulate this cloaking mechanism to enhance or suppress low-frequency energy. The mechanism underlying electric-field cloaking involves electrogenic cells that produce two independent action potentials. In a unique twist, these cells orient sodium and potassium currents in the same direction, potentially boosting their capabilities for current generation. Exploration of such evolutionary inventions could aid the design of biogenerators to power implantable medical devices, an ambition that would benefit from the complete genome sequence of a gymnotiform fish. PMID:20209064

  19. Basic Electricity. Part 2.

    ERIC Educational Resources Information Center

    Kilmer, Donald C.

    This guide, the second (part 2) in a set of four guides, is designed for the student interested in a vocation in electrical work, and includes two units: Unit IV--Electrical Theory, covering thirteen lessons (matter, the atom, electrical charges in the atom, rules of electric charges, electricity, atoms in an electrical conductor, electrical…

  20. Crusts: biological

    USGS Publications Warehouse

    Belnap, Jayne; Elias, Scott A.

    2013-01-01

    Biological soil crusts, a community of cyanobacteria, lichens, mosses, and fungi, are an essential part of dryland ecosystems. They are critical in the stabilization of soils, protecting them from wind and water erosion. Similarly, these soil surface communities also stabilized soils on early Earth, allowing vascular plants to establish. They contribute nitrogen and carbon to otherwise relatively infertile dryland soils, and have a strong influence on hydrologic cycles. Their presence can also influence vascular plant establishment and nutrition.

  1. Close-up of SSME

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A close-up view of a Space Shuttle Main Engine during a test at the John C. Stennis Space Center shows how the engine is gimballed, or rotated, to evaluate the performance of its components under simulated flight conditions.

  2. Marine biology

    SciTech Connect

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  3. Closed loop spray cooling apparatus

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Schwab, W. B.; Furman, E. R. (Inventor)

    1979-01-01

    A closed loop apparatus for jet spraying coolant against the back of a radiation target is described. The coolant is circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material is disposed between the bubble and the surface of the liquid coolant which is below the bubble at a predetermined level. In a second arrangement no inert gas is used, the bubble consists of vapor produced when the coolant is sprayed against the target.

  4. Distributed resources in a more competitive electric industry

    SciTech Connect

    Nesbitt, J.

    1995-12-01

    Wisconsin Electric (WE) has been very active in the public discussion of new structures for the electric utility industry. The third revision of {open_quotes}Wisconsin Electric`s View of a More Competitive Electric Industry{close_quotes} was released on March 10, 1995. A fourth revision is now in the works, due to new ideas and issues that have been raised in the last four months. Application of Distributed Resource (DR) alternatives have not yet been addressed in publications. This paper will briefly discuss potential opportunities for DR applications in a more competitive electric industry.

  5. Electrically detected ferromagnetic resonance

    SciTech Connect

    Goennenwein, S. T. B.; Schink, S. W.; Brandlmaier, A.; Boger, A.; Opel, M.; Gross, R.; Keizer, R. S.; Klapwijk, T. M.; Gupta, A.; Huebl, H.; Bihler, C.; Brandt, M. S.

    2007-04-16

    We study the magnetoresistance properties of thin ferromagnetic CrO{sub 2} and Fe{sub 3}O{sub 4} films under microwave irradiation. Both the sheet resistance {rho} and the Hall voltage V{sub Hall} characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonance (EDFMR) signals closely match the conventional FMR, measured simultaneously, in both resonance fields and line shapes. The sign and the magnitude of the resonant changes {delta}{rho}/{rho} and {delta}V{sub Hall}/V{sub Hall} can be consistently described in terms of a Joule heating effect. Bolometric EDFMR thus is a powerful tool for the investigation of magnetic anisotropy and magnetoresistive phenomena in ferromagnetic micro- or nanostructures.

  6. A SERS and electrical sensor from gas-phase generated Ag nanoparticles self-assembled on planar substrates.

    PubMed

    Wang, S; Tay, L-L; Liu, H

    2016-03-07

    Optical excitation of coupled plasmonic nanoparticles supports intense localized electromagnetic "hot-spots" which enable a variety of surface enhanced spectroscopies with the best known example being surface enhanced Raman scattering (SERS), currently of great interest for sensing applications. In this study, we present a novel SERS and electrical dual transduction chemical sensor based on gas-phase generated, negatively charged, silver nanoparticles self-assembled on glass slide forming a close-packed plasmonic monolayer thin-film that supports both SERS and electrical sensing. We demonstrate broad tunability of the localized surface plasmon resonance (LSPR) of the close-packed plasmonic nanoparticle monolayer thin-film sensors through control of the nanoparticle (NP) deposition time which directly influences the plasmonic coupling between neghibouring NPs. This broad tunability supports strong SERS activity from visible to near infrared (NIR) excitation wavelengths. We performed SERS and electrical measurements of a non-resonant molecule 4-mercaptobenzonitrile (4-MBN) as a sample Raman reporter molecule to determine the SERS enhancement factor of our SERS substrate. We measured an average SERS enhancement factor of 10(7) from our close-packed plasmonic nanoparticle monolayer thin-film sensor. Films which were grown below or above one nanoparticle monolayer both exhibited significantly lower SERS performance in one or more of SERS enhancement factor (EF), uniformity or repeatability. Our close-packed plasmonic nanoparticle monolayer thin-film sensors are highly uniform from point-to-point across the entire substrate and showed good reproducibility from batch-to-batch. These qualities are highly desirable for quantifiable detection of chemical and biological molecules. As an example application, this type of substrates provides an affordable and reliable sensing and identification capability for combatting new and emerging chemical and biological threats in

  7. Complete hunting cycle of Dionaea muscipula: consecutive steps and their electrical properties.

    PubMed

    Volkov, Alexander G; Pinnock, Monique-Renée; Lowe, Dennell C; Gay, Ma'Resha S; Markin, Vladislav S

    2011-01-15

    The total hunting cycle of the Venus flytrap consists of five stages: 1. Open state→2. Closed state→3. Locked state→4. Constriction and digestion→5. Semi-open state→1. Open state. The opening of the trap after digestion consists of two steps: opening of the lobes, and changing of their curvature from concave to convex shape. Uncouplers carbonylcyanide-4-trifluoromethoxyphenyl hydrazone (FCCP) and carbonylcyanide-3-chlorophenylhydrazone (CCCP) inhibit the trap from opening for two weeks and antracene-9-carboxylic acid inhibits the trap from constricting. Different stages of the hunting cycle have different electrical characteristics. The biologically closed electrochemical circuits in the Venus flytrap are analyzed using the charged capacitor method. If the initial voltage applied to the Venus flytrap is 0.5V or greater, changing the polarity of the electrodes between the midrib and one of the lobes results in a rectification effect and in different kinetics of discharge capacitance. These effects can be caused by the fast transport of ions through ion channels. The electrical properties of the Venus flytrap were investigated and equivalent electrical circuits within the upper leaf were proposed to explain the experimental data.

  8. Unifying Quantum Physics with Biology

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2014-09-01

    We find that the natural logarithm of the age of the universe in quantum mechanical units is close to 137. Since science is not religion, it is our moral duty to recognize the importance of this finding on the following ground. The experimentally obtained number 137 is a mystical number in science, as if written by the hand of God. It is found in cosmology; unlike other theories, it works in biology too. A formula by Boltzmann also works in both: biology and physics, as if it is in the heart of God. His formula simply leads to finding the logarithm of microstates. One of the two conflicting theories of physics (1) Einstein's theory of General Relativity and (2) Quantum Physics, the first applies only in cosmology, but the second applies in biology too. Since we have to convert the age of the universe, 13 billion years, into 1,300,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 Planck times to get close to 137, quantum physics clearly shows the characteristics of unifying with biology. The proof of its validity also lies in its ability to extend information system observed in biology.

  9. Electrically controllable artificial PAN muscles

    NASA Astrophysics Data System (ADS)

    Salehpoor, Karim; Shahinpoor, Mohsen; Mojarrad, Mehran

    1996-02-01

    Artificial muscles made with polyacrylonitrile (PAN) fibers are traditionally activated in electrolytic solution by changing the pH of the solution by the addition of acids and/or bases. This usually consumes a considerable amount of weak acids or bases. Furthermore, the synthetic muscle (PAN) itself has to be impregnated with an acid or a base and must have an appropriate enclosure or provision for waste collection after actuation. This work introduces a method by which the PAN muscle may be elongated or contracted in an electric field. We believe this is the first time that this has been achieved with PAN fibers as artificial muscles. In this new development the PAN muscle is first put in close contact with one of the two platinum wires (electrodes) immersed in an aqueous solution of sodium chloride. Applying an electric voltage between the two wires changes the local acidity of the solution in the regions close to the platinum wires. This is because of the ionization of sodium chloride molecules and the accumulation of Na+ and Cl- ions at the negative and positive electrode sites, respectively. This ion accumulation, in turn, is accompanied by a sharp increase and decrease of the local acidity in regions close to either of the platinum wires, respectively. An artificial muscle, in close contact with the platinum wire, because of the change in the local acidity will contract or expand depending on the polarity of the electric field. This scheme allows the experimenter to use a fixed flexible container of an electrolytic solution whose local pH can be modulated by an imposed electric field while the produced ions are basically trapped to stay in the neighborhood of a given electrode. This method of artificial muscle activation has several advantages. First, the need to use a large quantity of acidic or alkaline solutions is eliminated. Second, the use of a compact PAN muscular system is facilitated for applications in active musculoskeletal structures. Third, the

  10. Crafting Creative Nonfiction: From Close Reading to Close Writing

    ERIC Educational Resources Information Center

    Dollins, Cynthia A.

    2016-01-01

    A process writing project in a third-grade classroom explored the idea of using nonfiction mentor texts to assist students in writing their own creative informational texts about animals. By looking at author craft and structure during close reading activities with nonfiction Twin Texts, students were taught how to emulate these techniques in…

  11. Random close packing in protein cores

    NASA Astrophysics Data System (ADS)

    Ohern, Corey

    Shortly after the determination of the first protein x-ray crystal structures, researchers analyzed their cores and reported packing fractions ϕ ~ 0 . 75 , a value that is similar to close packing equal-sized spheres. A limitation of these analyses was the use of `extended atom' models, rather than the more physically accurate `explicit hydrogen' model. The validity of using the explicit hydrogen model is proved by its ability to predict the side chain dihedral angle distributions observed in proteins. We employ the explicit hydrogen model to calculate the packing fraction of the cores of over 200 high resolution protein structures. We find that these protein cores have ϕ ~ 0 . 55 , which is comparable to random close-packing of non-spherical particles. This result provides a deeper understanding of the physical basis of protein structure that will enable predictions of the effects of amino acid mutations and design of new functional proteins. We gratefully acknowledge the support of the Raymond and Beverly Sackler Institute for Biological, Physical, and Engineering Sciences, National Library of Medicine training grant T15LM00705628 (J.C.G.), and National Science Foundation DMR-1307712 (L.R.).

  12. CLOSED-LOOP STRIPPING ANALYSIS (CLSA) OF ...

    EPA Pesticide Factsheets

    Synthetic musk compounds have been found in surface water, fish tissues, and human breast milk. Current techniques for separating these compounds from fish tissues require tedious sample clean-upprocedures A simple method for the deterrnination of these compounds in fish tissues has been developed. Closed-loop stripping of saponified fish tissues in a I -L Wheaton purge-and-trap vessel is used to strip compounds with high vapor pressures such as synthetic musks from the matrix onto a solid sorbent (Abselut Nexus). This technique is useful for screening biological tissues that contain lipids for musk compounds. Analytes are desorbed from the sorbent trap sequentially with polar and nonpolar solvents, concentrated, and directly analyzed by high resolution gas chromatography coupled to a mass spectrometer operating in the selected ion monitoring mode. In this paper, we analyzed two homogenized samples of whole fish tissues with spiked synthetic musk compounds using closed-loop stripping analysis (CLSA) and pressurized liquid extraction (PLE). The analytes were not recovered quantitatively but the extraction yield was sufficiently reproducible for at least semi-quantitative purposes (screening). The method was less expensive to implement and required significantly less sample preparation than the PLE technique. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water,

  13. Microgyroscope with closed loop output

    NASA Technical Reports Server (NTRS)

    Challoner, A. Dorian (Inventor); Gutierrez, Roman C. (Inventor); Tang, Tony K. (Inventor); Cargille, Donald R. (Inventor)

    2002-01-01

    A micro-gyroscope (10) having closed loop operation by a control voltage (V.sub.TY), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides wide-band, closed-loop operation for a micro-gyroscope (10) and allows the drive frequency to be closely tuned to a high Q sense axis resonance. A differential sense signal (S1-S2) is compensated and fed back by differentially changing the voltage on the drive electrodes to rebalance Coriolis torque. The feedback signal is demodulated in phase with the drive axis signal (K.sub..omega..crclbar..sub.x) to produce a measure of the Coriolis force.

  14. Closing volume during normal pregnancy.

    PubMed Central

    Garrard, G S; Littler, W A; Redman, C W

    1978-01-01

    Serial lung function studies were performed in ten healthy, primiparous women aged 21--28. Measurements were made at two-monthly intervals during pregnancy and included functional residual capacity (FRC), total lung capacity (TLC), vital capacity (VC), specific conductance (SGaw) and closing volume (CV) on each occasion. Closing volume expressed as formular: (see text), showed a progressive rise during pregnancy in all subjects with a linear relationship to time (P less than 0.001, P greater than 0.01, respectively). No consistent changes in lung volume could be shown during pregnancy over the study period. It is suggested that the increase in closing volume during pregnancy might result in abnormalities of distribution of ventilation sufficient to explain the maternal blood gas disturbances of pregnancy. PMID:694802

  15. Resolving the biophysics of axon transmembrane polarization in a single closed-form description

    NASA Astrophysics Data System (ADS)

    Melendy, Robert F.

    2015-12-01

    When a depolarizing event occurs across a cell membrane there is a remarkable change in its electrical properties. A complete depolarization event produces a considerably rapid increase in voltage that propagates longitudinally along the axon and is accompanied by changes in axial conductance. A dynamically changing magnetic field is associated with the passage of the action potential down the axon. Over 75 years of research has gone into the quantification of this phenomenon. To date, no unified model exist that resolves transmembrane polarization in a closed-form description. Here, a simple but formative description of propagated signaling phenomena in the membrane of an axon is presented in closed-form. The focus is on using both biophysics and mathematical methods for elucidating the fundamental mechanisms governing transmembrane polarization. The results presented demonstrate how to resolve electromagnetic and thermodynamic factors that govern transmembrane potential. Computational results are supported by well-established quantitative descriptions of propagated signaling phenomena in the membrane of an axon. The findings demonstrate how intracellular conductance, the thermodynamics of magnetization, and current modulation function together in generating an action potential in a unified closed-form description. The work presented in this paper provides compelling evidence that three basic factors contribute to the propagated signaling in the membrane of an axon. It is anticipated this work will compel those in biophysics, physical biology, and in the computational neurosciences to probe deeper into the classical and quantum features of membrane magnetization and signaling. It is hoped that subsequent investigations of this sort will be advanced by the computational features of this model without having to resort to numerical methods of analysis.

  16. Resolving the biophysics of axon transmembrane polarization in a single closed-form description

    SciTech Connect

    Melendy, Robert F.

    2015-12-28

    When a depolarizing event occurs across a cell membrane there is a remarkable change in its electrical properties. A complete depolarization event produces a considerably rapid increase in voltage that propagates longitudinally along the axon and is accompanied by changes in axial conductance. A dynamically changing magnetic field is associated with the passage of the action potential down the axon. Over 75 years of research has gone into the quantification of this phenomenon. To date, no unified model exist that resolves transmembrane polarization in a closed-form description. Here, a simple but formative description of propagated signaling phenomena in the membrane of an axon is presented in closed-form. The focus is on using both biophysics and mathematical methods for elucidating the fundamental mechanisms governing transmembrane polarization. The results presented demonstrate how to resolve electromagnetic and thermodynamic factors that govern transmembrane potential. Computational results are supported by well-established quantitative descriptions of propagated signaling phenomena in the membrane of an axon. The findings demonstrate how intracellular conductance, the thermodynamics of magnetization, and current modulation function together in generating an action potential in a unified closed-form description. The work presented in this paper provides compelling evidence that three basic factors contribute to the propagated signaling in the membrane of an axon. It is anticipated this work will compel those in biophysics, physical biology, and in the computational neurosciences to probe deeper into the classical and quantum features of membrane magnetization and signaling. It is hoped that subsequent investigations of this sort will be advanced by the computational features of this model without having to resort to numerical methods of analysis.

  17. Evolution of Close Binary Systems

    SciTech Connect

    Yakut, K; Eggleton, P

    2005-01-24

    We collected data on the masses, radii, etc. of three classes of close binary stars: low-temperature contact binaries (LTCBs), near-contact binaries (NCBs), and detached close binaries (DCBs). They restrict themselves to systems where (1) both components are, at least arguably, near the Main Sequence, (2) the periods are less than a day, and (3) there is both spectroscopic and photometric analysis leading to reasonably reliable data. They discuss the possible evolutionary connections between these three classes, emphasizing the roles played by mass loss and angular momentum loss in rapidly-rotating cool stars.

  18. Numerical design of microfluidic-microelectric hybrid chip for the separation of biological cells.

    PubMed

    Ye, Ting; Li, Hua; Lam, K Y

    2011-03-15

    A miniature microfluidic-microelectric hybrid chip is numerically designed for separation of biological cells, where the characteristic length of the chip is close to the cell radius. A mathematical model is developed to characterize the motion and deformation of a biological cell in the hydrodynamic and nonuniform electric coupled fields, in which the mechanical and dielectric behaviors of the cell are taken into consideration. Subsequently, the model is validated by comparing with the experimental results published previously. By taking a red blood cell (RBC) as the sample of biological cell, the chip structure is numerically designed from the viewpoints of the electrode width, fluid flow velocity, and electric potential, respectively. Using the designed microfluidic-microelectric hybrid chip, the effects of the shape and initial position of the RBC on the separation ability are then analyzed. After that, the separation of the RBCs with the different permittivities or conductivities using the designed chip is simulated, and the deformation behaviors of the RBCs are discussed as well. At the high frequency, the permittivities of the RBCs play a dominant role in the separation of the RBCs, which causes the RBCs moving toward or away from the electrode array. However, the conductivity of the RBC plays a significant role at the low frequency. With suitable suspending fluid therefore, the separation of cells with different permittivities or conductivities can be achieved using the microfluidic-microelectric hybrid chip designed by the present work.

  19. Green electricity: Tracking systems for environmental disclosure

    SciTech Connect

    Biewald, B.E.; Ramey, J.A.

    1997-12-31

    For the first time, electricity consumers in the US are beginning to choose their generation providers. One of the opportunities created by the introduction of retail choice in electricity is the chance for customers to influence the mix of generating resources through their purchasing decisions. Some environmentally aware consumers will want {open_quotes}clean,{close_quotes} {open_quotes}green,{close_quotes} or renewable power. While some suppliers will attempt to differentiate themselves according to their environmental performance, such claims for green electricity can be particularly difficult to verify given the complexity of the interconnected electric system. Because electricity is delivered over an integrated transmission grid and kilowatt-hours at the point of retail sale are indistinguishable from each other; disclosure requires tracking protocols to attribute generation at power plants to sales at the customers` meters. Fortunately, it is possible to implement a workable disclosure system. Some states have already included disclosure requirements in their electric industry restructuring orders and legislation. In this paper, a set of design criteria for an environmental disclosure system are presented along with two methods for disclosure: the company approach and the product approach. In addition, the authors discuss of power pools, data availability issues, and propose a company-based disclosure system using a {open_quotes}wholesale sales first{close_quotes} approach to transaction accounting.

  20. Atmospheric electricity

    NASA Technical Reports Server (NTRS)

    1987-01-01

    In the last three years the focus was on the information contained in the lightning measurement, which is independent of other meteorological measurements that can be made from space. The characteristics of lightning activity in mesoscale convective systems were quantified. A strong relationship was found between lightning activity and surface rainfall. It is shown that lightning provides a precursor signature for wet microbursts (the strong downdrafts that produce windshears hazardous to aircraft) and that the lightning signature is a direct consequence of storm evolution. The Universities Space Research Association (USRA) collaborated with NASA scientists in the preliminary analysis and scientific justification for the design and deployment of an optical instrument which can detect lightning from geostationary orbit. Science proposals for the NASA mesoscale science program and for the Tethered Satellite System were reviewed. The weather forecasting research and unmanned space vehicles. Software was written to ingest and analyze the lightning ground strike data on the MSFC McIDAS system. The capabilities which were developed have a wide application to a number of problems associated with the operational impacts of electrical discharge within the atmosphere.

  1. 75 FR 51277 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ... Reproductive Sciences Integrated Review Group; Integrative Physiology of Obesity and Diabetes Study Section... HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meetings... 20892, 301-443- 8519. Name of Committee: Biological Chemistry and Macromolecular Biophysics...

  2. 77 FR 74675 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meetings... Committee: Center for Scientific Review Special Emphasis Panel; Member Conflict: Skeletal Biology...

  3. 77 FR 71429 - Center for Scientific Review; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meeting... Committee: Center for Scientific Review Special Emphasis Panel; Member Conflict: Cell Biology....

  4. 77 FR 296 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-04

    ... HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meetings... patentable material, and personal information concerning individuals associated with the grant applications... Committee: Biological Chemistry and Macromolecular Biophysics Integrated Review Group,...

  5. 77 FR 27468 - Center for Scientific Review, Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-10

    ... HUMAN SERVICES National Institutes of Health Center for Scientific Review, Notice of Closed Meetings... patentable material, and personal information concerning individuals associated with the grant applications...@csr.nih.gov . Name of Committee: Biological Chemistry and Macromolecular Biophysics Integrated...

  6. 77 FR 77080 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ....nih.gov . Name of Committee: Biological Chemistry and Macromolecular Biophysics Integrated Review... HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meetings... Committee: Center for Scientific Review Special Emphasis Panel; Biophysics and Biochemistry of...

  7. 76 FR 28236 - Center for Scientific Review; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Center for Scientific Review; Notice of Closed Meeting... Committee: Center for Scientific Review Special Emphasis Panel, Member Conflict: Reproductive Biology....

  8. Temporal Code-Driven Stimulation: Definition and Application to Electric Fish Signaling.

    PubMed

    Lareo, Angel; Forlim, Caroline G; Pinto, Reynaldo D; Varona, Pablo; Rodriguez, Francisco de Borja

    2016-01-01

    Closed-loop activity-dependent stimulation is a powerful methodology to assess information processing in biological systems. In this context, the development of novel protocols, their implementation in bioinformatics toolboxes and their application to different description levels open up a wide range of possibilities in the study of biological systems. We developed a methodology for studying biological signals representing them as temporal sequences of binary events. A specific sequence of these events (code) is chosen to deliver a predefined stimulation in a closed-loop manner. The response to this code-driven stimulation can be used to characterize the system. This methodology was implemented in a real time toolbox and tested in the context of electric fish signaling. We show that while there are codes that evoke a response that cannot be distinguished from a control recording without stimulation, other codes evoke a characteristic distinct response. We also compare the code-driven response to open-loop stimulation. The discussed experiments validate the proposed methodology and the software toolbox.

  9. Temporal Code-Driven Stimulation: Definition and Application to Electric Fish Signaling

    PubMed Central

    Lareo, Angel; Forlim, Caroline G.; Pinto, Reynaldo D.; Varona, Pablo; Rodriguez, Francisco de Borja

    2016-01-01

    Closed-loop activity-dependent stimulation is a powerful methodology to assess information processing in biological systems. In this context, the development of novel protocols, their implementation in bioinformatics toolboxes and their application to different description levels open up a wide range of possibilities in the study of biological systems. We developed a methodology for studying biological signals representing them as temporal sequences of binary events. A specific sequence of these events (code) is chosen to deliver a predefined stimulation in a closed-loop manner. The response to this code-driven stimulation can be used to characterize the system. This methodology was implemented in a real time toolbox and tested in the context of electric fish signaling. We show that while there are codes that evoke a response that cannot be distinguished from a control recording without stimulation, other codes evoke a characteristic distinct response. We also compare the code-driven response to open-loop stimulation. The discussed experiments validate the proposed methodology and the software toolbox. PMID:27766078

  10. Close Call: Breaking the Rules.

    ERIC Educational Resources Information Center

    Journal of Adventure Education and Outdoor Leadership, 1993

    1993-01-01

    Contrary to a rule to never teach students to lead climb, an instructor taught several youth to lead climb at a parent's request. These students planned to pursue rock climbing on their own after they left school, and preparing them was deemed a safety precaution. Analysis of this "close call" offers guidelines for introducing students…

  11. Noncommutative via closed star product

    NASA Astrophysics Data System (ADS)

    Kupriyanov, V. G.; Vitale, P.

    2015-08-01

    We consider linear star products on of Lie algebra type. First we derive the closed formula for the polydifferential representation of the corresponding Lie algebra generators. Using this representation we define the Weyl star product on the dual of the Lie algebra. Then we construct a gauge operator relating the Weyl star product with the one which is closed with respect to some trace functional, Tr ( f ⋆ g) = Tr ( f · g). We introduce the derivative operator on the algebra of the closed star product and show that the corresponding Leibniz rule holds true up to a total derivative. As a particular example we study the space R {/θ 3} with type noncommutativity and show that in this case the closed star product is the one obtained from the Duflo quantization map. As a result a Laplacian can be defined such that its commutative limit reproduces the ordinary commutative one. The deformed Leibniz rule is applied to scalar field theory to derive conservation laws and the corresponding noncommutative currents.

  12. Closed-Loop Neuromorphic Benchmarks

    PubMed Central

    Stewart, Terrence C.; DeWolf, Travis; Kleinhans, Ashley; Eliasmith, Chris

    2015-01-01

    Evaluating the effectiveness and performance of neuromorphic hardware is difficult. It is even more difficult when the task of interest is a closed-loop task; that is, a task where the output from the neuromorphic hardware affects some environment, which then in turn affects the hardware's future input. However, closed-loop situations are one of the primary potential uses of neuromorphic hardware. To address this, we present a methodology for generating closed-loop benchmarks that makes use of a hybrid of real physical embodiment and a type of “minimal” simulation. Minimal simulation has been shown to lead to robust real-world performance, while still maintaining the practical advantages of simulation, such as making it easy for the same benchmark to be used by many researchers. This method is flexible enough to allow researchers to explicitly modify the benchmarks to identify specific task domains where particular hardware excels. To demonstrate the method, we present a set of novel benchmarks that focus on motor control for an arbitrary system with unknown external forces. Using these benchmarks, we show that an error-driven learning rule can consistently improve motor control performance across a randomly generated family of closed-loop simulations, even when there are up to 15 interacting joints to be controlled. PMID:26696820

  13. Police close unsolved 'climategate' investigation

    NASA Astrophysics Data System (ADS)

    Lavender, Gemma

    2012-09-01

    Police in Norfolk in the UK have closed an investigation into the hacking of e-mails at the University of East Anglia's Climate Research Unit (CRU) after admitting that they will not be able to find the hackers who broke into CRU computer servers.

  14. Ecological Challenges for Closed Systems

    NASA Astrophysics Data System (ADS)

    Nelson, Mark; Dempster, William; Allen, John P.

    2012-07-01

    Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, the sustaining of healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and measures and options which may be necessary to ensure long-term operation of closed ecological systems.

  15. Creating biological nanomaterials using synthetic biology

    NASA Astrophysics Data System (ADS)

    Rice, MaryJoe K.; Ruder, Warren C.

    2014-02-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  16. Creating biological nanomaterials using synthetic biology.

    PubMed

    Rice, MaryJoe K; Ruder, Warren C

    2014-02-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  17. Carbon recycling in materially closed ecological life support systems

    NASA Technical Reports Server (NTRS)

    Obenhuber, D. C.; Folsome, C. E.

    1988-01-01

    Results of studies are presented of materially closed energetically open microbial ecosystems or 'closed ecosystems'. These are natural marine ecosystems that have been sealed in glass containers to prevent material exchange with the environment but allow energy to pass freely through them. They represent model life support systems for the future human habitation of space. The results are discussed analytically and indicate that these ecosystems, when subjected to a constant energy flux, seem to be reliable and self-sufficient systems for recycling of biologically produced carbon compounds.

  18. Structural Biology Fact Sheet

    MedlinePlus

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  19. Microfluidics and Coagulation Biology

    PubMed Central

    Colace, Thomas V.; Tormoen, Garth W.

    2014-01-01

    The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices facilitate measurements of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, pharmacology, and clinical diagnostics. An experimental session can accommodate 100s to 1000s of unique clotting events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor under constant flow rate or constant pressure drop conditions. Distinct shear rates can be created on a device with a single perfusion pump. Microfluidic devices facilitated the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidics are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to the mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics. PMID:23642241

  20. The Electric Car Challenge.

    ERIC Educational Resources Information Center

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  1. Fluidic Active Transducer for Electricity Generation

    PubMed Central

    Yang, YoungJun; Park, Junwoo; Kwon, Soon-Hyung; Kim, Youn Sang

    2015-01-01

    Flows in small size channels have been studied for a long time over multidisciplinary field such as chemistry, biology and medical through the various topics. Recently, the attempts of electricity generation from the small flows as a new area for energy harvesting in microfluidics have been reported. Here, we propose for the first time a new fluidic electricity generator (FEG) by modulating the electric double layer (EDL) with two phase flows of water and air without external power sources. We find that an electric current flowed by the forming/deforming of the EDL with a simple separated phase flow of water and air at the surface of the FEG. Electric signals between two electrodes of the FEG are checked from various water/air passing conditions. Moreover, we verify the possibility of a self-powered air slug sensor by applying the FEG in the detection of an air slug. PMID:26511626

  2. Fluidic Active Transducer for Electricity Generation.

    PubMed

    Yang, YoungJun; Park, Junwoo; Kwon, Soon-Hyung; Kim, Youn Sang

    2015-10-29

    Flows in small size channels have been studied for a long time over multidisciplinary field such as chemistry, biology and medical through the various topics. Recently, the attempts of electricity generation from the small flows as a new area for energy harvesting in microfluidics have been reported. Here, we propose for the first time a new fluidic electricity generator (FEG) by modulating the electric double layer (EDL) with two phase flows of water and air without external power sources. We find that an electric current flowed by the forming/deforming of the EDL with a simple separated phase flow of water and air at the surface of the FEG. Electric signals between two electrodes of the FEG are checked from various water/air passing conditions. Moreover, we verify the possibility of a self-powered air slug sensor by applying the FEG in the detection of an air slug.

  3. Agricultural Electricity. Electric Motors. Student Manual.

    ERIC Educational Resources Information Center

    Benson, Robert T.

    Addressed to the student, this manual, which includes supplementary diagrams, discusses the following topics and principles: Electromagnetic fields, electromagnets, parts of an electric motor, determining speed of an electric motor, types of electric motors in common use (split-phase, capacitor, repulsion-induction, three-phase), the electric…

  4. Electrical safety guidelines

    SciTech Connect

    Not Available

    1993-09-01

    The Electrical Safety Guidelines prescribes the DOE safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety standards and guidance for DOE installations in order to affect a reduction or elimination of risks associated with the use of electrical energy. The objectives of these guidelines are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  5. DOE handbook electrical safety

    SciTech Connect

    1998-01-01

    Electrical Safety Handbook presents the Department of Energy (DOE) safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety guidance and information for DOE installations to effect a reduction or elimination of risks associated with the use of electrical energy. The objectives of this handbook are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  6. Simulating Biological and Non-Biological Motion

    ERIC Educational Resources Information Center

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  7. Narrowband thermal radiation from closed-end microcavities

    SciTech Connect

    Kohiyama, Asaka; Shimizu, Makoto; Iguchi, Fumitada; Yugami, Hiroo

    2015-10-07

    High spectral selectivity of thermal radiation is important for achieving high-efficiency energy systems. In this study, intense, narrowband, and low directional absorption/radiation were observed in closed-end microcavity which is a conventional open-end microcavity covered by a semi-transparent thin metal film. The quality factor (Q factor) of optical absorption band strongly depended on the film electrical conductivity. Asymmetric and narrow absorption band with a Q factor of 25 at 1.28 μm was obtained for a 6-nm-thick Au film. Numerical simulations suggest that the formation of a fixed-end mode at the cavity aperture contributes to the narrowband optical absorption. The closed-end microcavity filled with SiO{sub 2} exhibits intense and isotropic thermal radiation over a wide solid angle according to numerical simulation. The narrow and asymmetric absorption spectrum was experimentally confirmed in a model of closed-end microcavity.

  8. Autaptic regulation of electrical activities in neuron under electromagnetic induction

    PubMed Central

    Xu, Ying; Ying, Heping; Jia, Ya; Ma, Jun; Hayat, Tasawar

    2017-01-01

    Realistic neurons may hold complex anatomical structure, for example, autapse connection to some internuncial neurons, which this specific synapse can connect to its body via a close loop. Continuous exchanges of charged ions across the membrane can induce complex distribution fluctuation of intracellular and extracellular charged ions of cell, and a time-varying electromagnetic field is set to modulate the membrane potential of neuron. In this paper, an autapse-modulated neuron model is presented and the effect of electromagnetic induction is considered by using magnetic flux. Bifurcation analysis and sampled time series for membrane potentials are calculated to investigate the mode transition in electrical activities and the biological function of autapse connection is discussed. Furthermore, the Gaussian white noise and electromagnetic radiation are considered on the improved neuron model, it is found appropriate setting and selection for feedback gain and time delay in autapse can suppress the bursting in neuronal behaviors. It indicates the formation of autapse can enhance the self-adaption of neuron so that appropriate response to external forcing can be selected, this biological function is helpful for encoding and signal propagation of neurons. It can be useful for investigation about collective behaviors in neuronal networks exposed to electromagnetic radiation. PMID:28240314

  9. Autaptic regulation of electrical activities in neuron under electromagnetic induction.

    PubMed

    Xu, Ying; Ying, Heping; Jia, Ya; Ma, Jun; Hayat, Tasawar

    2017-02-27

    Realistic neurons may hold complex anatomical structure, for example, autapse connection to some internuncial neurons, which this specific synapse can connect to its body via a close loop. Continuous exchanges of charged ions across the membrane can induce complex distribution fluctuation of intracellular and extracellular charged ions of cell, and a time-varying electromagnetic field is set to modulate the membrane potential of neuron. In this paper, an autapse-modulated neuron model is presented and the effect of electromagnetic induction is considered by using magnetic flux. Bifurcation analysis and sampled time series for membrane potentials are calculated to investigate the mode transition in electrical activities and the biological function of autapse connection is discussed. Furthermore, the Gaussian white noise and electromagnetic radiation are considered on the improved neuron model, it is found appropriate setting and selection for feedback gain and time delay in autapse can suppress the bursting in neuronal behaviors. It indicates the formation of autapse can enhance the self-adaption of neuron so that appropriate response to external forcing can be selected, this biological function is helpful for encoding and signal propagation of neurons. It can be useful for investigation about collective behaviors in neuronal networks exposed to electromagnetic radiation.

  10. Autaptic regulation of electrical activities in neuron under electromagnetic induction

    NASA Astrophysics Data System (ADS)

    Xu, Ying; Ying, Heping; Jia, Ya; Ma, Jun; Hayat, Tasawar

    2017-02-01

    Realistic neurons may hold complex anatomical structure, for example, autapse connection to some internuncial neurons, which this specific synapse can connect to its body via a close loop. Continuous exchanges of charged ions across the membrane can induce complex distribution fluctuation of intracellular and extracellular charged ions of cell, and a time-varying electromagnetic field is set to modulate the membrane potential of neuron. In this paper, an autapse-modulated neuron model is presented and the effect of electromagnetic induction is considered by using magnetic flux. Bifurcation analysis and sampled time series for membrane potentials are calculated to investigate the mode transition in electrical activities and the biological function of autapse connection is discussed. Furthermore, the Gaussian white noise and electromagnetic radiation are considered on the improved neuron model, it is found appropriate setting and selection for feedback gain and time delay in autapse can suppress the bursting in neuronal behaviors. It indicates the formation of autapse can enhance the self-adaption of neuron so that appropriate response to external forcing can be selected, this biological function is helpful for encoding and signal propagation of neurons. It can be useful for investigation about collective behaviors in neuronal networks exposed to electromagnetic radiation.

  11. Simulation for close air support

    NASA Astrophysics Data System (ADS)

    Hench, David L.

    2009-05-01

    Close Air Support (CAS) is the use of air power in close proximity to friendly forces against enemy combatants. CAS requires precise and detailed communication between the personnel on the ground and the air vehicles. To be useful, a network simulation should be a superposition on the planning simulations for these activities. In a CAS mission, all of the above activities are critical. A hypothetical CAS mission is modeled as an "as is" solution with stove-piped communications and a "to be" network enabled solution. A co-simulation laboratory using OPNET with SITL (SYSTEM in the Loop, cosim, JFORCES (Joint Force Operational Readiness Combat Effectiveness Simulator), and JSAF (Joint Semi-Automated Forces) simulation system is described.

  12. Close supermassive binary black holes.

    PubMed

    Gaskell, C Martin

    2010-01-07

    It has been proposed that when the peaks of the broad emission lines in active galactic nuclei (AGNs) are significantly blueshifted or redshifted from the systemic velocity of the host galaxy, this could be a consequence of orbital motion of a supermassive black-hole binary (SMBB). The AGN J1536+0441 ( = SDSS J153636.22+044127.0) has recently been proposed as an example of this phenomenon. It is proposed here instead that J1536+0441 is an example of line emission from a disk. If this is correct, the lack of clear optical spectral evidence for close SMBBs is significant, and argues either that the merging of close SMBBs is much faster than has generally been hitherto thought, or if the approach is slow, that when the separation of the binary is comparable to the size of the torus and broad-line region, the feeding of the black holes is disrupted.

  13. From biologically-inspired physics to physics-inspired biology From biologically-inspired physics to physics-inspired biology

    NASA Astrophysics Data System (ADS)

    Kornyshev, Alexei A.

    2010-10-01

    couple of billion years of evolutionary history; 'you cannot expect to explain so wise an old bird in a few simple words'. It is indisputably so, but it is followed by two other competing sub-dogmas: Dogma N6a: Physics wants to simplify and unify things, as much as possible, biology resists the reductionist approach and is happy about diversification and complexity. In my opinion all these dogmas have been beaten by this icon, the understanding of which gave rise to the idea of DNA replication and all the following principles of molecular biology. Not only 'this will happen again' but on a smaller scale this happens all the time. Generally, through centuries, physics and mathematics have changed our lives completely. In a short article one cannot give a full list of such achievements from Aristotle's time, but I name just a few of the summits of the last two centuries. A great physicist Rutherford (who was, by the way, a Nobel Laureate in Chemistry for 'his investigations into the disintegration of the elements, and the chemistry of radioactive substances') was also famous for an extreme (and definitely outdated) statement: 'All science is either stamp collecting or physics'. Let us paraphrase him and collect some stamps. I have no space to stop on the Faraday-Ampere laws of stationary electricity (who cares, electric current comes from a plug would be the answer of most of people unfamiliar with physics, and forget about electricity that is supplied to biological laboratories). So, let us go straight away to James Clerk Maxwell. He derived four equations that related electricity and magnetism and, as the legend tells us, it took him seven years to write the fourth equation to complete the set with four unknown variables. The story of the fourth Maxwell equation is one of the most dramatic stories in the history of science [4]. As a solution of that set he obtained relativistically-invariant electromagnetic waves, which no one saw and the consequences of which no one had

  14. Aequorin-expressing yeast emits light under electric control.

    PubMed

    Vilanova, Cristina; Hueso, Angeles; Palanca, Carles; Marco, Guillem; Pitarch, Miguel; Otero, Eduardo; Crespo, Juny; Szablowski, Jerzy; Rivera, Sara; Domínguez-Escribà, Laura; Navarro, Emilio; Montagud, Arnau; de Córdoba, Pedro Fernández; González, Asier; Ariño, Joaquín; Moya, Andrés; Urchueguía, Javier; Porcar, Manuel

    2011-03-20

    In this study, we show the use of direct external electrical stimulation of a jellyfish luminescent calcium-activated protein, aequorin, expressed in a transgenic yeast strain. Yeast cultures were electrically stimulated through two electrodes coupled to a standard power generator. Even low (1.5 V) electric pulses triggered a rapid light peak and serial light pulses were obtained after electric pulses were applied periodically, suggesting that the system is re-enacted after a short refraction time. These results open up a new scenario, in the very interphase between synthetic biology and cybernetics, in which complex cellular behavior might be subjected to electrical control.

  15. SARS Patients and Their Close Contacts

    MedlinePlus

    ... Fact Sheet for SARS Patients and Their Close Contacts Format: Select one PDF [256 KB] Recommend on ... that are not now known. What does "close contact" mean? In the context of SARS, close contact ...

  16. US Competitiveness in Synthetic Biology.

    PubMed

    Gronvall, Gigi Kwik

    2015-01-01

    Synthetic biology is an emerging technical field that aims to make biology easier to engineer; the field has applications in strategically important sectors for the US economy. While the United States currently leads in synthetic biology R&D, other nations are heavily investing in order to boost their economies, which will inevitably diminish the US leadership position. This outcome is not entirely negative--additional investments will expand markets--but it is critical that the US government take steps to remain competitive: There are applications from which the US population and economy may benefit; there are specific applications with importance for national defense; and US technical leadership will ensure that US experts have a leading role in synthetic biology governance, regulation, and oversight. Measures to increase competitiveness in S&T generally are broadly applicable for synthetic biology and should be pursued. However, the US government will also need to take action on fundamental issues that will affect the field's development, such as countering anti-GMO (genetically modified organism) sentiments and anti-GMO legislation. The United States should maintain its regulatory approach so that it is the product that is regulated, not the method used to create a product. At the same time, the United States needs to ensure that the regulatory framework is updated so that synthetic biology products do not fall into regulatory gaps. Finally, the United States needs to pay close attention to how synthetic biology applications may be governed internationally, such as through the Nagoya Protocol of the Convention on Biological Diversity, so that beneficial applications may be realized.

  17. US Competitiveness in Synthetic Biology

    PubMed Central

    2015-01-01

    Synthetic biology is an emerging technical field that aims to make biology easier to engineer; the field has applications in strategically important sectors for the US economy. While the United States currently leads in synthetic biology R&D, other nations are heavily investing in order to boost their economies, which will inevitably diminish the US leadership position. This outcome is not entirely negative—additional investments will expand markets—but it is critical that the US government take steps to remain competitive: There are applications from which the US population and economy may benefit; there are specific applications with importance for national defense; and US technical leadership will ensure that US experts have a leading role in synthetic biology governance, regulation, and oversight. Measures to increase competitiveness in S&T generally are broadly applicable for synthetic biology and should be pursued. However, the US government will also need to take action on fundamental issues that will affect the field's development, such as countering anti-GMO (genetically modified organism) sentiments and anti-GMO legislation. The United States should maintain its regulatory approach so that it is the product that is regulated, not the method used to create a product. At the same time, the United States needs to ensure that the regulatory framework is updated so that synthetic biology products do not fall into regulatory gaps. Finally, the United States needs to pay close attention to how synthetic biology applications may be governed internationally, such as through the Nagoya Protocol of the Convention on Biological Diversity, so that beneficial applications may be realized. PMID:26690379

  18. Future Electric Ship and Power and Energy

    DTIC Science & Technology

    2010-09-01

    Navy Hybrid Electric Ship S&T Issues/Challenges Power Generation, Energy Storage , Power Distribution & Control, and Thermal Closing Thoughts...development of efficient power systems. 1. Power Generation: • Fuel Cells & Fuel Reforming • Advanced Generators 2. Energy Storage : • Batteries... Storage : •Advanced materials (high purity, high dielectric breakdown) •Increased energy density and high temperature operation Goal: Increased

  19. Electricity: Today's Technologies, Tomorrow's Alternatives. Revised Edition.

    ERIC Educational Resources Information Center

    Electric Power Research Inst., Palo Alto, CA.

    This book traces the relatively new role of electricity in our energy history, discusses old and new ways of producing it (and related environmental issues), and closes with an agenda of technology-related issues that await decisions. Topics are presented in nine chapters. Chapters focus on (1) energy use; (2) energy demand; (3) energy supply; (4)…

  20. Operational Results of a Closed Brayton Cycle Test-Loop

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.; Fuller, Robert; Lipinski, Ronald J.; Nichols, Kenneth; Brown, Nicholas

    2005-02-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kWth with a maximum outlet temperature of ˜1000 K.

  1. Research for electric energy systems

    NASA Astrophysics Data System (ADS)

    Anderson, W. E.

    1993-10-01

    This report documents the technical progress in the two investigations which make up the project 'Support of Research Projects for Electrical Energy Systems,' Department of Energy Task Order Number 137, funded by the US Department of Energy and performed by the Electricity Division of the National Institute of Standards and Technology (NIST). The first investigation is concerned with the measurement of magnetic fields in support of epidemiogical and in vitro studies of biological field effects. During 1992, the derivation of equations which predict differences between the average magnetic flux density using circular coil probes and the flux density at the center of the probe, assuming a dipole magnetic field, were completed. The information gained using these equations allows the determination of measurement uncertainty due to probe size when magnetic fields from many electrical appliances are characterized. Consultations with various state and federal organizations and the development of standards related to electric and magnetic field measurements continued. The second investigation is concerned with two different activities related to compressed-gas insulated high voltage systems: the measurement of dissociative electron attachment cross sections and negative ion production in S2F10, S2OF10, and S2O2F10, and Monte-Carlo simulations of ac-generated partial-discharge pulses that can occur in SF6-insulated power systems and can be sources of gas decomposition.

  2. Open-closed switching of synthetic tubular pores

    NASA Astrophysics Data System (ADS)

    Kim, Yongju; Kang, Jiheong; Shen, Bowen; Wang, Yanqiu; He, Ying; Lee, Myongsoo

    2015-10-01

    While encouraging progress has been made on switchable nanopores to mimic biological channels and pores, it remains a great challenge to realize long tubular pores with a dynamic open-closed motion. Here we report μm-long, dynamic tubular pores that undergo rapid switching between open and closed states in response to a thermal signal in water. The tubular walls consist of laterally associated primary fibrils stacked from disc-shaped molecules in which the discs readily tilt by means of thermally regulated dehydration of the oligoether chains placed on the wall surfaces. Notably, this pore switching mediates a controlled water-pumping catalytic action for the dehydrative cyclization of adenosine monophosphate to produce metabolically active cyclic adenosine monophosphate. We believe that our work may allow the creation of a variety of dynamic pore structures with complex functions arising from open-closed motion.

  3. Open–closed switching of synthetic tubular pores

    PubMed Central

    Kim, Yongju; Kang, Jiheong; Shen, Bowen; Wang, Yanqiu; He, Ying; Lee, Myongsoo

    2015-01-01

    While encouraging progress has been made on switchable nanopores to mimic biological channels and pores, it remains a great challenge to realize long tubular pores with a dynamic open–closed motion. Here we report μm-long, dynamic tubular pores that undergo rapid switching between open and closed states in response to a thermal signal in water. The tubular walls consist of laterally associated primary fibrils stacked from disc-shaped molecules in which the discs readily tilt by means of thermally regulated dehydration of the oligoether chains placed on the wall surfaces. Notably, this pore switching mediates a controlled water-pumping catalytic action for the dehydrative cyclization of adenosine monophosphate to produce metabolically active cyclic adenosine monophosphate. We believe that our work may allow the creation of a variety of dynamic pore structures with complex functions arising from open–closed motion. PMID:26456695

  4. Electricity in the Atmosphere.

    ERIC Educational Resources Information Center

    Sampath, S.; Kumar, V. Sasi

    1991-01-01

    The theory of the atmospheric electric circuit and a discussion of the fair-weather electrical are presented. The ion concentration, mobility, conductivity, and electric field altitudinal profiles are explained. An outline of the electrical processes inside thunderstorms along with a description of the lightning strike are included. (Author)

  5. Singularities and Closed String Tachyons

    SciTech Connect

    Silverstein, Eva; /SLAC /Stanford U., Phys. Dept.

    2006-03-17

    A basic problem in gravitational physics is the resolution of spacetime singularities where general relativity breaks down. The simplest such singularities are conical singularities arising from orbifold identifications of flat space, and the most challenging are spacelike singularities inside black holes (and in cosmology). Topology changing processes also require evolution through classically singular spacetimes. I briefly review how a phase of closed string tachyon condensate replaces, and helps to resolve, basic singularities of each of these types. Finally I discuss some interesting features of singularities arising in the small volume limit of compact negatively curved spaces and the emerging zoology of spacelike singularities.

  6. Bounce Rock Close-Up

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This high-resolution panoramic camera blue filter image of the rock dubbed 'Bounce' was obtained up close, just before the rover placed its instruments on the rock for detailed study. The rock has a number of shiny surfaces and textures on it, some of which are unlike those seen in the Eagle Crater rock outcrop. Also, the rock was apparently moved or shaken when it was hit with the airbags, as can be seen by the gap and cracks in the soil around the rock. This image from sol 65 of the rover's journey was acquired using the panoramic camera's 430 nanometer filter.

  7. On Closed Shells in Nuclei

    DOE R&D Accomplishments Database

    Mayer, M. G.

    1948-02-01

    It has been suggested in the past that special numbers of neutrons or protons in the nucleus form a particularly stable configuration.{sup1} The complete evidence for this has never been summarized, nor is it generally recognized how convincing this evidence is. That 20 neutrons or protons (Ca{sup40}) form a closed shell is predicted by the Hartree model. A number of calculations support this fact.{sup2} These considerations will not be repeated here. In this paper, the experimental facts indicating a particular stability of shells of 50 and 82 protons and of 50, 82, and 126 neutrons will be listed.

  8. Close-up of Moe

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This close-up of the rock 'Moe' was taken from the Sojourner rover's front left camera on Sol 70 (September 13). Flute-like textures on the rock, possibly caused by wind abrasion, are clearly visible.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  9. Closed inductively coupled plasma cell

    DOEpatents

    Manning, Thomas J.; Palmer, Byron A.; Hof, Douglas E.

    1990-01-01

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy.

  10. Closed inductively coupled plasma cell

    DOEpatents

    Manning, T.J.; Palmer, B.A.; Hof, D.E.

    1990-11-06

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies is disclosed. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy. 1 fig.

  11. Alternating-Current Motor Drive for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.; Rippel, W. E.

    1982-01-01

    New electric drive controls speed of a polyphase as motor by varying frequency of inverter output. Closed-loop current-sensing circuit automatically adjusts frequency of voltage-controlled oscillator that controls inverter frequency, to limit starting and accelerating surges. Efficient inverter and ac motor would give electric vehicles extra miles per battery charge.

  12. Closeup view of a general electric company demand meter which ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of a general electric company demand meter which formerly monitored railroad power usage obtained from Philadelphia Electric Company sources. - Thirtieth Street Station, Load Dispatch Center, Thirtieth & Market Streets, Railroad Station, Amtrak (formerly Pennsylvania Railroad Station), Philadelphia, Philadelphia County, PA

  13. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    PubMed

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  14. Electrically insulating and sealing frame

    DOEpatents

    Guthrie, Robin J.

    1983-11-08

    A combination gas seal and electrical insulator having a closed frame shape interconnects a fuel cell stack and a reactant gas plenum of a fuel cell generator. The frame can be of rectangular shape including at least one slidable spline connection in each side to permit expansion or contraction consistent with that of the walls of the gas plenum and fuel cell stack. The slidable spline connections in the frame sides minimizes lateral movement between the frame side members and sealing material interposed between the frame and the fuel cell stack or between the frame and the reactant gas plenum.

  15. Microorganisms in closed periapical lesions.

    PubMed

    Abou-Rass, M; Bogen, G

    1998-01-01

    The purpose of this study was to investigate the microorganisms of strictly selected closed periapical lesions associated with both refractory endodontic therapy and pulpal calcification. Definitive criteria were established that assured complete clinical isolation of the periapical lesion from the oral and periodontal environment. A total of 13 criteria-referenced lesions were selected from 70 patients with endodontic surgical indications. A well controlled culturing method was used in all cases and samples were taken by one clinician at three separate sites during each surgery. Samples taken at the surgical window and within the body of the lesion served as controls, whilst a third sample was taken at the apex. In all 13 cases, samples taken from the apex yielded microorganisms comprising 63.6% obligate anaerobes and 36.4% facultative anaerobes. Prevalence of the isolated species was 31.8% for Actinomyces sp., 22.7% Propionibacterium sp., 18.2% Streptococcus sp., 13.6% Staphlyococcus sp., 4.6% Porphyromonas gingivalis, 4.6% Peptostreptococcus micros and 4.6% Gram-negative enterics. The results of this investigation indicate that closed periapical lesions associated with calcified teeth or those resistant to root canal treatment harbour bacteria. The inability to eradicate all root canal microorganisms during root canal treatment, along with anatomical factors, may allow further bacterial colonization of the root apex and surrounding periapical tissues, and consequently prevent healing.

  16. CLOSED-LOOP STRIPPING ANALYSIS (CLSA) OF ...

    EPA Pesticide Factsheets

    Synthetic musk compounds are used as inexpensive fragrance materials for the production of perfumes and as additives to soap, detergent, and shampoo. They have been found in surface water, fish tissues, and human breast milk. The ubiquity of this class of compounds in the environment is attributable to high use and release into the environment. Current techniques for separating these compounds from fish tissues require tedious sample clean-up procedures. To obtain fat-free extracts, gel permeation chromatography (GPC), column chromatography using alumina, and silica gel, and thin layer chromatography (TLC clean-up procedures are frequently employed. Despite the considerable effort and resources devoted to these processes, a fraction of the lipids and lipid-like compounds frequently remains in the extracts. These low-level lipids foul injection liners, contaminate columns, and yield elevated baselines during gas chromatographic analysis of synthetic musk compounds. In this study, a simple method for the determination of synthetic musk compounds in fish tissues has been developed. Closed-loop stripping of saponified fish tissues in a I -L Wheaton purge- and-trap vessel, is used to strip compounds with high vapor pressures such as synthetic musks from the matrix onto a solid sorbent (Abselut Nexus). This technique is useful for screening biological tissues that contain lipids for musk compounds. Analytes are desorbed from the sorbent trap sequentially with polar an

  17. 7 CFR 1942.123 - Loan closing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false Loan closing. 1942.123 Section 1942.123 Agriculture... Loan closing. (a) Ordering loan checks. Checks will not be ordered until: (1) Form FmHA or its... closing instructions, except for those actions which are to be completed on the date of loan closing...

  18. 7 CFR 1942.123 - Loan closing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Loan closing. 1942.123 Section 1942.123 Agriculture... Loan closing. (a) Ordering loan checks. Checks will not be ordered until: (1) Form FmHA or its... closing instructions, except for those actions which are to be completed on the date of loan closing...

  19. 50 CFR 648.76 - Closed areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Closed areas. 648.76 Section 648.76... Clam and Ocean Quahog Fisheries § 648.76 Closed areas. (a) Areas closed because of environmental degradation. Certain areas are closed to all surfclam and ocean quahog fishing because of...

  20. Transmission Lines: An Overview of Electrical Properties and Environmental Effects.

    SciTech Connect

    United States. Bonneville Power Administration. Biological Studies Task Team.

    1982-03-01

    A brief overview is provided of environmental and biological effects of high-voltage power transmission lines. Paragraph length descriptions of electric fields, induced voltage and currents, biological effects, magnetic fields, corona, radio and television interference, and ozone are given. 13 figs.

  1. Biology's built-in Faraday cages

    NASA Astrophysics Data System (ADS)

    Klee, Maurice M.

    2014-05-01

    Biological fluids are water-based, ionic conductors. As such, they have both high relative dielectric constants and substantial conductivities, meaning they are lossy dielectrics. These fluids contain charged molecules (free charges), whose movements play roles in essentially all cellular processes from metabolism to communication with other cells. Using the problem of a point source in air above a biological fluid of semi-infinite extent, the bound charges in the fluid are shown to perform the function of a fast-acting Faraday cage, which protects the interior of the fluid from external electric fields. Free charges replace bound charges in accordance with the fluid's relaxation time, thereby providing a smooth transition between the initial protection provided by the bound charges and the steady state protection provided by the free charges. The electric fields within the biological fluid are thus small for all times just as they would be inside a classical Faraday cage.

  2. Evolving refractory major depressive disorder diagnostic and treatment paradigms: toward closed-loop therapeutics.

    PubMed

    Ward, Matthew P; Irazoqui, Pedro P

    2010-01-01

    Current antidepressant therapies do not effectively control or cure depressive symptoms. Pharmaceutical therapies altogether fail to address an estimated 4 million Americans who suffer from a recurrent and severe treatment-resistant form of depression known as refractory major depressive disorder. Subjective diagnostic schemes, differing manifestations of the disorder, and antidepressant treatments with limited theoretical bases each contribute to the general lack of therapeutic efficacy and differing levels of treatment resistance in the refractory population. Stimulation-based therapies, such as vagus nerve stimulation, transcranial magnetic stimulation, and deep brain stimulation, are promising treatment alternatives for this treatment-resistant subset of patients, but are plagued with inconsistent reports of efficacy and variable side effects. Many of these problems stem from the unknown mechanisms of depressive disorder pathogenesis, which prevents the development of treatments that target the specific underlying causes of the disorder. Other problems likely arise due to the non-specific stimulation of various limbic and paralimbic structures in an open-loop configuration. This review critically assesses current literature on depressive disorder diagnostic methodologies, treatment schemes, and pathogenesis in order to emphasize the need for more stringent depressive disorder classifications, quantifiable biological markers that are suitable for objective diagnoses, and alternative closed-loop treatment options tailored to well-defined forms of the disorder. A closed-loop neurostimulation device design framework is proposed, utilizing symptom-linked biomarker abnormalities as control points for initiating and terminating a corrective electrical stimulus which is autonomously optimized for correcting the magnitude and direction of observed biomarker abnormality.

  3. Evolving Refractory Major Depressive Disorder Diagnostic and Treatment Paradigms: Toward Closed-Loop Therapeutics

    PubMed Central

    Ward, Matthew P.; Irazoqui, Pedro P.

    2010-01-01

    Current antidepressant therapies do not effectively control or cure depressive symptoms. Pharmaceutical therapies altogether fail to address an estimated 4 million Americans who suffer from a recurrent and severe treatment-resistant form of depression known as refractory major depressive disorder. Subjective diagnostic schemes, differing manifestations of the disorder, and antidepressant treatments with limited theoretical bases each contribute to the general lack of therapeutic efficacy and differing levels of treatment resistance in the refractory population. Stimulation-based therapies, such as vagus nerve stimulation, transcranial magnetic stimulation, and deep brain stimulation, are promising treatment alternatives for this treatment-resistant subset of patients, but are plagued with inconsistent reports of efficacy and variable side effects. Many of these problems stem from the unknown mechanisms of depressive disorder pathogenesis, which prevents the development of treatments that target the specific underlying causes of the disorder. Other problems likely arise due to the non-specific stimulation of various limbic and paralimbic structures in an open-loop configuration. This review critically assesses current literature on depressive disorder diagnostic methodologies, treatment schemes, and pathogenesis in order to emphasize the need for more stringent depressive disorder classifications, quantifiable biological markers that are suitable for objective diagnoses, and alternative closed-loop treatment options tailored to well-defined forms of the disorder. A closed-loop neurostimulation device design framework is proposed, utilizing symptom-linked biomarker abnormalities as control points for initiating and terminating a corrective electrical stimulus which is autonomously optimized for correcting the magnitude and direction of observed biomarker abnormality. PMID:20631824

  4. Closing the loop with blur

    NASA Astrophysics Data System (ADS)

    Tani, Jacopo

    A great variety of systems use image sensors to provide measurements for closed loop operation. A drawback of using image sensors in real-time feedback is that they provide measurements at slower sampling rates as compared to the actuators, typically around 30 Hz for CCD cameras, hence acting as the bottleneck for closed loop control bandwidths. While high speed cameras exist, higher frame rates imply an upper bound on exposures which lowers the signal-to-noise-ratio (SNR), reducing measurements accuracy. The integrative nature of image sensors though offers the opportunity to prolong the exposure window and collect motion blurred measurements. This research describes how to exploit the dynamic information of observed system outputs, encoded in motion blur, to control fast systems at the fast rate through slow rate image sensors. In order to achieve this objective it is necessary to (a) design a controller providing fast rate input to the system based on the slow image measurements. Ideally such a controller would require a fast rate estimate of the system's state variables in order to provide the necessary control action, therefore an (b) image blur based estimator is to be developed. State estimators typically need a model of the system in order to provide their estimates, so (c) a system identification problem has to be addressed, where a reliable model describing the frequency content of the system, up to frequencies corresponding to the fast rate, has to be determined through slow rate image sensor measurements. Alternatively when such a procedure is not possible for lack, e.g., of knowledge of the input to the system, then (d) a method to reconstruct the output signal frequency content up to frequencies above those set by the limitations of the sampling theorem is to be devised. Therefore in order to "close the loop with blur", this work describes how to pose and solve the problems of, namely: system identification , state estimation, closed loop control and

  5. Closed loop electrostatic levitation system

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Saffren, M. M.; Elleman, D. D. (Inventor)

    1985-01-01

    An electrostatic levitation system is described, which can closely control the position of objects of appreciable size. A plurality of electrodes surround the desired position of an electrostatically charged object, the position of the objects is monitored, and the voltages applied to the electrodes are varied to hold the object at a desired position. In one system, the object is suspended above a plate-like electrode which has a concave upper face to urge the object toward the vertical axis of the curved plate. An upper electrode that is also curved can be positioned above the object, to assure curvature of the field at any height above the lower plate. In another system, four spherical electrodes are positioned at the points of a tetrahedron, and the voltages applied to the electrodes are varied in accordance with the object position as detected by two sensors.

  6. Heat Shield Flank Close Up

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity features an up-close view of the flank piece of the rover's broken heat shield.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact. Overall, engineers were interested in evaluating the performance of the heat shield's thermal protection system.

    This is the the panormamic camera team's best current attempt at generating a 'true color' view of what this scene would look like if viewed by a human on Mars. It was generated from a mathematical combination of six calibrated, left-eye panoramic camera images acquired around 3:07 p.m. local solar time on Opportunity's sol 331 (Dec. 28, 2004) using filters ranging in wavelengths from 430 to 750 nanometers.

  7. Closed loop steam cooled airfoil

    DOEpatents

    Widrig, Scott M.; Rudolph, Ronald J.; Wagner, Gregg P.

    2006-04-18

    An airfoil, a method of manufacturing an airfoil, and a system for cooling an airfoil is provided. The cooling system can be used with an airfoil located in the first stages of a combustion turbine within a combined cycle power generation plant and involves flowing closed loop steam through a pin array set within an airfoil. The airfoil can comprise a cavity having a cooling chamber bounded by an interior wall and an exterior wall so that steam can enter the cavity, pass through the pin array, and then return to the cavity to thereby cool the airfoil. The method of manufacturing an airfoil can include a type of lost wax investment casting process in which a pin array is cast into an airfoil to form a cooling chamber.

  8. Closed cell metal foam method

    DOEpatents

    Patten, James W.

    1978-01-01

    Foamed metals and metal alloys which have a closed cellular structure are prepared by heating a metal body containing entrapped inert gas uniformly distributed throughout to a temperature above the melting point of the metal and maintaining the body at this temperature a period of time sufficient to permit the entrapped gas to expand, forming individual cells within the molten metal, thus expanding and foaming the molten metal. After cell formation has reached the desired amount, the foamed molten metal body is cooled to below the melting temperature of the metal. The void area or density of the foamed metal is controlled by predetermining the amount of inert gas entrapped in the metal body and by the period of time the metal body is maintained in the molten state. This method is useful for preparing foamed metals and metal alloys from any metal or other material of which a body containing entrapped inert gas can be prepared.

  9. Electrical conductivity of hot QCD matter.

    PubMed

    Cassing, W; Linnyk, O; Steinert, T; Ozvenchuk, V

    2013-05-03

    We study the electric conductivity of hot QCD matter at various temperatures T within the off-shell parton-hadron-string dynamics transport approach for interacting partonic, hadronic or mixed systems in a finite box with periodic boundary conditions. The response of the strongly interacting system in equilibrium to an external electric field defines the electric conductivity σ(0). We find a sizable temperature dependence of the ratio σ(0)/T well in line with calculations in a relaxation time approach for T(c)close to T(c), and becomes approximately constant (~0.3) above ~5T(c). Our findings imply that the QCD matter even at T ≈ T(c) is a much better electric conductor than Cu or Ag (at room temperature).

  10. Electrical Conductivity of Hot QCD Matter

    NASA Astrophysics Data System (ADS)

    Cassing, W.; Linnyk, O.; Steinert, T.; Ozvenchuk, V.

    2013-05-01

    We study the electric conductivity of hot QCD matter at various temperatures T within the off-shell parton-hadron-string dynamics transport approach for interacting partonic, hadronic or mixed systems in a finite box with periodic boundary conditions. The response of the strongly interacting system in equilibrium to an external electric field defines the electric conductivity σ0. We find a sizable temperature dependence of the ratio σ0/T well in line with calculations in a relaxation time approach for Tcclose to Tc, and becomes approximately constant (˜0.3) above ˜5Tc. Our findings imply that the QCD matter even at T≈Tc is a much better electric conductor than Cu or Ag (at room temperature).

  11. Molecular ferroelectrics: where electronics meet biology

    PubMed Central

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-01-01

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by overview on the fundamentals of ferroelectricity. Latest development in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also noted. PMID:24018952

  12. Molecular ferroelectrics: where electronics meet biology.

    PubMed

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-12-28

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with the ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by an overview of the fundamentals of ferroelectricity. The latest developments in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also described.

  13. Modeling Electrically Active Viscoelastic Membranes

    PubMed Central

    Roy, Sitikantha; Brownell, William E.; Spector, Alexander A.

    2012-01-01

    The membrane protein prestin is native to the cochlear outer hair cell that is crucial to the ear's amplification and frequency selectivity throughout the whole acoustic frequency range. The outer hair cell exhibits interrelated dimensional changes, force generation, and electric charge transfer. Cells transfected with prestin acquire unique active properties similar to those in the native cell that have also been useful in understanding the process. Here we propose a model describing the major electromechanical features of such active membranes. The model derived from thermodynamic principles is in the form of integral relationships between the history of voltage and membrane resultants as independent variables and the charge density and strains as dependent variables. The proposed model is applied to the analysis of an active force produced by the outer hair cell in response to a harmonic electric field. Our analysis reveals the mechanism of the outer hair cell active (isometric) force having an almost constant amplitude and phase up to 80 kHz. We found that the frequency-invariance of the force is a result of interplay between the electrical filtering associated with prestin and power law viscoelasticity of the surrounding membrane. Paradoxically, the membrane viscoelasticity boosts the force balancing the electrical filtering effect. We also consider various modes of electromechanical coupling in membrane with prestin associated with mechanical perturbations in the cell. We consider pressure or strains applied step-wise or at a constant rate and compute the time course of the resulting electric charge. The results obtained here are important for the analysis of electromechanical properties of membranes, cells, and biological materials as well as for a better understanding of the mechanism of hearing and the role of the protein prestin in this mechanism. PMID:22701528

  14. [Biology of size and gravity].

    PubMed

    Yamashita, Masamichi; Baba, Shoji A

    2004-03-01

    Gravity is a force that acts on mass. Biological effects of gravity and their magnitude depend on scale of mass and difference in density. One significant contribution of space biology is confirmation of direct action of gravity even at the cellular level. Since cell is the elementary unit of life, existence of primary effects of gravity on cells leads to establish the firm basis of gravitational biology. However, gravity is not limited to produce its biological effects on molecules and their reaction networks that compose living cells. Biological system has hierarchical structure with layers of organism, group, and ecological system, which emerge from the system one layer down. Influence of gravity is higher at larger mass. In addition to this, actions of gravity in each layer are caused by process and mechanism that is subjected and different in each layer of the hierarchy. Because of this feature, summing up gravitational action on cells does not explain gravity for biological system at upper layers. Gravity at ecological system or organismal level can not reduced to cellular mechanism. Size of cells and organisms is one of fundamental characters of them and a determinant in their design of form and function. Size closely relates to other physical quantities, such as mass, volume, and surface area. Gravity produces weight of mass. Organisms are required to equip components to support weight and to resist against force that arise at movement of body or a part of it. Volume and surface area associate with mass and heat transport process at body. Gravity dominates those processes by inducing natural convection around organisms. This review covers various elements and process, with which gravity make influence on living systems, chosen on the basis of biology of size. Cells and biochemical networks are under the control of organism to integrate a consolidated form. How cells adjust metabolic rate to meet to the size of the composed organism, whether is gravity

  15. Closed and Not Closed: Mitigating a Mystery on Chandra's Door

    NASA Technical Reports Server (NTRS)

    Odom, Brian

    2015-01-01

    The Chandra X-ray Observatory is part of NASA's fleet of "Great Observatories" along with the Hubble Space Telescope, the Spitzer Space Telescope, and the now deorbited Compton Gamma Ray Observatory. The observatory was designed to detect x-ray emissions from some of the hottest regions of the galaxy including exploded stars, clusters of galaxies, and matter around black holes. One of the observatory's key scientific instruments is the Advanced CCD Imaging Spectrometer (ACIS), which is one of four primary and two focal plane instruments. Due to the sensitivity of the charged coupled devices (CCD's), an aperture door was designed and built by Lockheed-Martin that protected the instrument during testing and the time leading up to launch. The design called for a system of wax actuators (manufactured by STARSYS Corp) to be used as components in a rotary actuator that would open and close the door during ground testing and on-orbit operations. Another feature of the design was an internal shear disc located in each actuator to prevent excessive internal pressure and to shield other components from damage.

  16. Biological warfare agents.

    PubMed

    Pohanka, Miroslav; Kuca, Kamil

    2010-01-01

    Biological warfare agents are a group of pathogens and toxins of biological origin that can be potentially misused for military or criminal purposes. The present review attempts to summarize necessary knowledge about biological warfare agents. The historical aspects, examples of applications of these agents such as anthrax letters, biological weapons impact, a summary of biological warfare agents and epidemiology of infections are described. The last section tries to estimate future trends in research on biological warfare agents.

  17. Electric arc saw apparatus

    DOEpatents

    Deichelbohrer, Paul R [Richland, WA

    1986-01-01

    A portable, hand held electric arc saw has a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc to erode a workpiece. Electric current is supplied to the blade by biased brushes and a slip ring which are mounted in the frame. A pair of freely movable endless belts in the form of crawler treads stretched between two pulleys are used to facilitate movement of the electric arc saw. The pulleys are formed of dielectric material to electrically insulate the crawler treads from the frame.

  18. Electric potential and electric field imaging

    NASA Astrophysics Data System (ADS)

    Generazio, E. R.

    2017-02-01

    The technology and methods for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field made be used for "illuminating" volumes to be inspected with EFI. The baseline sensor technology (e-Sensor) and its construction, optional electric field generation (quasi-static generator), and current e-Sensor enhancements (ephemeral e-Sensor) are discussed. Demonstrations for structural, electronic, human, and memory applications are shown. This new EFI capability is demonstrated to reveal characterization of electric charge distribution creating a new field of study embracing areas of interest including electrostatic discharge (ESD) mitigation, crime scene forensics, design and materials selection for advanced sensors, dielectric morphology of structures, tether integrity, organic molecular memory, and medical diagnostic and treatment efficacy applications such as cardiac polarization wave propagation and electromyography imaging.

  19. The Electrophysiology of Electric Organs of Marine Electric Fishes

    PubMed Central

    Bennett, M. V. L.; Wurzel, M.; Grundfest, H.

    1961-01-01

    Single electroplaques of Torpedo nobiliana have been studied with microelectrode recording. Direct evidence is presented that the only electrogenically reactive membrane of the cells is on the innervated surface and that this membrane is electrically inexcitable. Responses are not evoked by depolarizing currents applied to this membrane, but only by stimulating the innervating nerve fibers. The responses arise after a latency of 1 to 3 msec. This latency is not affected by large depolarizing or hyperpolarizing changes in membrane potential. Various properties that have been theoretically associated with electrically inexcitable responses have been also demonstrated to occur in the electroplaques. The neurally evoked response is not propagated actively in the membrane and may have different amplitudes and forms in closely adjacent regions. The maximal responses frequently are slightly larger than the recorded resting potential but the apparent small overshoot may be due to difficulty in recording the full resting potential. The responses are subject to electrochemical gradation and appear inverted in sign on applying strong outward currents across the innervated membrane. This membrane is cholinoceptive and shows marked desensitization. The membrane of the uninnervated surface has a very low resistance, a factor that aids maximum output of current during the discharge of the electric organ. PMID:19873534

  20. Close-packed array of light emitting devices

    DOEpatents

    Ivanov, Ilia N.; Simpson, John T.

    2013-04-09

    A close-packed array of light emitting diodes includes a nonconductive substrate having a plurality of elongate channels extending therethrough from a first side to a second side, where each of the elongate channels in at least a portion of the substrate includes a conductive rod therein. The conductive rods have a density over the substrate of at least about 1,000 rods per square centimeter and include first conductive rods and second conductive rods. The close-packed array further includes a plurality of light emitting diodes on the first side of the substrate, where each light emitting diode is in physical contact with at least one first conductive rod and in electrical contact with at least one second conductive rod.

  1. Close binary neutron star systems

    NASA Astrophysics Data System (ADS)

    Marronetti, Pedro

    1999-12-01

    We present a method to calculate solutions to the initial value problem in (3 + 1) general relativity corresponding to binary neutron-star systems (BNS) in irrotational quasi-equilibrium orbits. The initial value equations are solved using a conformally flat spatial metric tensor. The stellar fluid dynamics corresponds to that of systems with zero vorticity in the inertial reference frame. Irrotational systems like the ones analyzed in the present work are likely to resemble the final stages of the evolution of neutron-star binaries, thus providing insights on the inspiral process. The fluid velocity is derived from the gradient of a scalar potential. A numerical program was developed to solve the elliptic equations for the metric fields and the fluid velocity potential. We discuss the different numerical techniques employed to achieve high resolution across the stellar volume, as well as the methods used to find solutions to the Poisson-like equations with their corresponding boundary conditions. We present sequences of quasi-stable circular orbits which conserve baryonic mass. These sequences mimic the time evolution of the inspiral and are obtained without solving the complex evolution equations. They also provide sets of initial value data for future time evolution codes, which should be valid very close to the final merger. We evaluate the emission of gravitational radiation during the evolution through multipole expansions methods.

  2. Simulations of Closed Timelike Curves

    NASA Astrophysics Data System (ADS)

    Brun, Todd A.; Wilde, Mark M.

    2017-03-01

    Proposed models of closed timelike curves (CTCs) have been shown to enable powerful information-processing protocols. We examine the simulation of models of CTCs both by other models of CTCs and by physical systems without access to CTCs. We prove that the recently proposed transition probability CTCs (T-CTCs) are physically equivalent to postselection CTCs (P-CTCs), in the sense that one model can simulate the other with reasonable overhead. As a consequence, their information-processing capabilities are equivalent. We also describe a method for quantum computers to simulate Deutschian CTCs (but with a reasonable overhead only in some cases). In cases for which the overhead is reasonable, it might be possible to perform the simulation in a table-top experiment. This approach has the benefit of resolving some ambiguities associated with the equivalent circuit model of Ralph et al. Furthermore, we provide an explicit form for the state of the CTC system such that it is a maximum-entropy state, as prescribed by Deutsch.

  3. Electricity and Magnetism

    NASA Astrophysics Data System (ADS)

    Glazebrook, R. T.

    2016-10-01

    1. Electrostatics: fundamental facts; 2. Electricity as a measurable quantity; 3. Measurement of electric force and potential; 4. Condensers; 5. Electrical machines; 6. Measurement of potential and electric force; 7. Magnetic attraction and repulsion; 8. Laws of magnetic force; 9. Experiments with magnets; 10. Magnetic calculations; 11. Magnetic measurements; 12. Terrestrial magnetism; 13. The electric current; 14. Relation between electromagnetic force and current; 15. Measurement of current; 16. Measurement of resistance and electromotive force; 17. Measurement of quantity of electricity, condensers; 18. Thermal activity of a current; 19. The voltaic cell (theory); 20. Electromagnetism; 21. Magnetisation of iron; 22. Electromagnetic instruments; 23. Electromagnetic induction; 24. Applications of electromagnetic induction; 25. Telegraphy and telephony; 26. Electric waves; 27. Transference of electricity through gases: corpuscles and electrons; Answers to examples; Index.

  4. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M. M.

    2012-09-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  5. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-11-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  6. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-10-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  7. Electrical Burns: First Aid

    MedlinePlus

    ... be caused by a number of sources of electricity, such as lightning, stun guns and contact with ... person who has been injured by contact with electricity should be seen by a doctor. Sometimes an ...

  8. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2013-04-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  9. Autonomous Biological System (ABS) experiments.

    PubMed

    MacCallum, T K; Anderson, G A; Poynter, J E; Stodieck, L S; Klaus, D M

    1998-12-01

    Three space flight experiments have been conducted to test and demonstrate the use of a passively controlled, materially closed, bioregenerative life support system in space. The Autonomous Biological System (ABS) provides an experimental environment for long term growth and breeding of aquatic plants and animals. The ABS is completely materially closed, isolated from human life support systems and cabin atmosphere contaminants, and requires little need for astronaut intervention. Testing of the ABS marked several firsts: the first aquatic angiosperms to be grown in space; the first higher organisms (aquatic invertebrate animals) to complete their life cycles in space; the first completely bioregenerative life support system in space; and, among the first gravitational ecology experiments. As an introduction this paper describes the ABS, its flight performance, advantages and disadvantages.

  10. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance

    PubMed Central

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

    2016-01-01

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices. PMID:27622466

  11. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance.

    PubMed

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P; Triantafyllou, Michael

    2016-09-13

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.

  12. From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance

    NASA Astrophysics Data System (ADS)

    Asadnia, Mohsen; Kottapalli, Ajay Giri Prakash; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

    2016-09-01

    We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.

  13. Advanced technology cogeneration system conceptual design study: Closed cycle gas turbines

    NASA Technical Reports Server (NTRS)

    Mock, E. A. T.; Daudet, H. C.

    1983-01-01

    The results of a three task study performed for the Department of Energy under the direction of the NASA Lewis Research Center are documented. The thermal and electrical energy requirements of three specific industrial plants were surveyed and cost records for the energies consumed were compiled. Preliminary coal fired atmospheric fluidized bed heated closed cycle gas turbine and steam turbine cogeneration system designs were developed for each industrial plant. Preliminary cost and return-on-equity values were calculated and the results compared. The best of the three sites was selected for more detailed design and evaluation of both closed cycle gas turbine and steam turbine cogeneration systems during Task II. Task III involved characterizing the industrial sector electrical and thermal loads for the 48 contiguous states, applying a family of closed cycle gas turbine and steam turbine cogeneration systems to these loads, and conducting a market penetration analysis of the closed cycle gas turbine cogeneration system.

  14. Modeling Electrically Evoked Otoacoustic Emissions

    NASA Astrophysics Data System (ADS)

    Grosh, K.; Deo, N.; Parthasarathi, A. A.; Nuttall, A. L.; Zheng, J. F.; Ren, T. Y.

    2003-02-01

    Electrical evoked otoacoustic emissions (EEOAE) are used to investigate in vivo cochlear electromechanical function. Round window electrical stimulation gives rise to a broad frequency EEOAE response, from 100 Hz or below to 40 kHz in guinea pigs. Placing bipolar electrodes very close to the basilar membrane (in the scala vestibuli and scala tympani) gives rise to a much narrower frequency range of EEOAE, limited to around 20 kHz when the electrodes are placed near the 18 kHz best frequency place. Model predictions using a three dimensional fluid model in conjunction with a simple model for outer hair cell (OHC) activity are used to interpret the experimental results. The model is solved using a 2.5D finite-element formulation. Predictions show that the high-frequency limit of the excitation is determined by the spatial extent of the current stimulus (also called the current spread). The global peaks in the EEOAE spectra are interpreted as constructive interference between electrically evoked backward traveling waves and forward traveling waves reflected from the stapes. Steady-state response predictions of the model are presented.

  15. Miniature electrically operated diaphragm valve

    DOEpatents

    Adkins, Douglas R.; Spletzer, Barry L.; Wong, Chungnin C.; Frye-Mason, Gregory C.; Fischer, Gary J.; Hesketh, Peter J.

    2001-01-01

    The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.

  16. Electric Field Imaging Project

    NASA Technical Reports Server (NTRS)

    Wilcutt, Terrence; Hughitt, Brian; Burke, Eric; Generazio, Edward

    2016-01-01

    NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields. This work is intended to bring electrostatic imaging to the forefront of new inspection technologies, and new technologies in general. The specific goals are to specify the electric potential and electric field including the electric field spatial components emanating from, to, and throughout volumes containing objects or in free space.

  17. Electric arc saw apparatus

    DOEpatents

    Deichelbohrer, P.R.

    1983-08-08

    A portable, hand-held electric arc saw apparatus comprising a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc between the blade and a workpiece of opposite polarity. Electrically conducting means are provided on said frame for transmitting current to said blade. A pair of freely movable endless belts in the form of crawler treads are employed to facilitate movement of the apparatus relative to the workpiece.

  18. Research for Electric Energy Systems

    SciTech Connect

    Anderson, W.E.

    1991-06-01

    This report documents the technical progress in investigations. The first investigation is concerned with the measurement of magnetic fields in support of epidemiogical and in vitro studies of biological field effects. NIST cohosted a workshop on exposure and biological parameters that should be considered during the vitro studies with extremely low frequency (ELF) magnetic and electric fields. Also, equations were developed to predict the magnetic field in a parallel plate magnetic field exposure system. The second investigation is concerned with two different activities: the detection of trace levels of S{sub 2}F{sub 10} in SF{sub 6} and the development of an improved stochastic analyzer for pulsating phenomena (SAPP). The detection of S{sub 2}F{sub 10} in the presence of SF{sub 6} using mass-spectrometric detection coupled to a gas chromatograph is difficult because of the similar mass spectra. A technique is described that enables the detection of S{sub 2}F{sub 10} in gaseous SF{sub 6} down to the ppb level using a modified gas chromatograph-mass spectrometer. The new system was applied to an investigation of the stochastic behavior of negative corona (Trichel pulses) and the effect of a dielectric barrier on these discharges. The third investigation is concerned with breakdown and prebreakdown phenomena in liquid dielectrics. The activity reported here was a study of negative steamers preceding electric breakdown in hexanes. Using the image preserving optical delay, the growth of the streamers associated with partial discharges at a point cathode are photographed at high magnification. The last investigation is concerned with the evaluation and improvement of methods for measuring fast transients in electrical power systems such as might be associated with an electromagnetic impulse. A compact resistive divider, NIST4, was designed. It is anticipated that this divider together with some Kerr electro-optical devices will be used as the reference system at NIST.

  19. Electric Vehicle Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  20. Electricity Serves Our Community.

    ERIC Educational Resources Information Center

    Rakow, Steven J., Ed.

    1992-01-01

    Features a color poster entitled "Electricity Serves Our Community" and describes how the poster can be used to help teach about energy, electricity concepts, and types of electrical generation. Explains how teachers can obtain other resources such as posters, lesson plans, and kits from the National Energy Foundation. (PR)

  1. Electric Current Solves Mazes

    ERIC Educational Resources Information Center

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  2. ELECTRICAL PROPERTIES OF FOODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foods, especially liquid foods, conduct electricity. Unlike in metals, the charge carriers in foods are ions, instead of electrons. Under normal applications, ions carry the charges as the mass of ions moves along the electrical field. The concentration and mobility of ions determine the electrical ...

  3. Electricity demand curtailment planning

    SciTech Connect

    Allentuck, J; Carroll, O; Schnader, M

    1980-01-01

    The state of electricity demand curtailment planning for long term electricity supply disruptions is reviewed. Legal, institutional and technological problems associated with demand curtailment plans are examined, and the existence of well defined social objectives on the part of planners is questioned. A linear programming approach to electricity demand curtailment planning is presented.

  4. Learning Biology by Designing

    ERIC Educational Resources Information Center

    Janssen, Fred; Waarlo, Arend Jan

    2010-01-01

    According to a century-old tradition in biological thinking, organisms can be considered as being optimally designed. In modern biology this idea still has great heuristic value. In evolutionary biology a so-called design heuristic has been formulated which provides guidance to researchers in the generation of knowledge about biological systems.…

  5. Biological conversion system

    DOEpatents

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  6. Precision closed bomb calorimeter for testing flame and gas producing initiators

    NASA Technical Reports Server (NTRS)

    Carpenter, D. R., Jr.; Taylor, A. C., Jr.

    1972-01-01

    A calorimeter has been developed under this study to help meet the needs of accurate performance monitoring of electrically or mechanically actuated flame and gas producing devices, such as squib-type initiators. A ten cubic centimeter closed bomb (closed volume) calorimeter was designed to provide a standard pressure trace and to measure a nominal 50 calorie output, using the basic components of a Parr Model 1411 calorimeter. Two prototype bombs were fabricated, pressure tested to 2600 psi, and extensively evaluated.

  7. Binary and ternary gas mixtures for use in glow discharge closing switches

    DOEpatents

    Hunter, Scott R.; Christophorou, Loucas G.

    1990-01-01

    Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue of the combined physio-electric properties of the mixture components.

  8. Cervical cancer detection by electrical impedance in a Colombian setting

    NASA Astrophysics Data System (ADS)

    Miranda, David A.; Corzo, Sandra P.; González Correa, C. A.

    2013-04-01

    Electrical properties of normal and neoplastic cervical tissues in a heterogeneous group of 56 Colombian women were studied by electrical impedance spectroscopy and a model based on the Generalized Effective-Medium Theory of Induced Polarization (GEMTIP). Differences between the electrical bioimpedance spectra were correlated with cellular and tissue parameters. The analysis performed by the proposed model suggest that the number of different types of cellular layers that form the biological tissue, the intracellular and extracellular conductivity could be used to explain the differences between electrical bioimpedance spectra in normal and neoplastic tissues.

  9. 76 FR 53986 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... informs the public that an appeal of the closing of the Pinehurst Village Station, Pinehurst, North... received a petition for review of the Postal Service's determination to close the Pinehurst Village...

  10. 76 FR 55425 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... informs the public that an appeal of the closing of the Watson, Alabama post office has been filed. It... for review of the Postal Service's determination to close the Watson post office in Watson,...

  11. 76 FR 20052 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ... informs the public that an appeal of the closing of the Rogers Avenue Station in Fort Smith, Arkansas has... for review of the closing of the Rogers Avenue Station in Fort Smith, Arkansas. The petition,...

  12. 76 FR 58057 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... informs the public that an appeal of the closing of the Burnt Prairie, Illinois post office has been filed... for review of the Postal Service's determination to close the Burnt Prairie post office in...

  13. 76 FR 53984 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... informs the public that an appeal of the closing of the Prairie Hill, Texas post office has been filed. It... for review of the Postal Service's determination to close the Prairie Hill post office in Prairie...

  14. 76 FR 44385 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... informs the public that an appeal of the closing of the Peach Orchard, Arkansas post office has been filed... review of the closing of the Peach Orchard, Arkansas post office. The petition, which was filed...

  15. 76 FR 19149 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Wesleyville Post Office in...

  16. 75 FR 77921 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice; correction. SUMMARY: The... an appeal of the closing of the Graves Mill, Virginia post office. The procedural schedule...

  17. 76 FR 11824 - Post Office Closing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Post Office Closing AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY: This document informs the public that an appeal of the closing of the Mitchellville Post Office in...

  18. Closed reduction of a fractured bone

    MedlinePlus

    Fracture reduction - closed ... pain medicine you receive. There may be new fractures that occur with the reduction. If the reduction ... BD, Jupiter JBl, Krettek C, Anderson PA. Closed fracture management. In: Browner BD, Jupiter JB, Krettek C, ...

  19. Reheating for closed string inflation

    SciTech Connect

    Cicoli, Michele; Mazumdar, Anupam E-mail: a.mazumdar@lancaster.ac.uk

    2010-09-01

    We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N = 1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation.

  20. Anisotropic electric surface resistance of Cu(110)

    SciTech Connect

    Otto, A.; Lilie, P.; Dumas, P.; Hirschmugl, C.; Pilling, M.; Williams, Gwyn P.

    2007-08-01

    The electric surface resistance is measured without contacts by grazing incidence of p-polarized infrared (IR) radiation for the adsorbates CO and C{sub 2}H{sub 4}, which settle on top of the close packed atomic ridges of Cu(110) in the <1, -1, 0> direction. Surface resistance has only been observed for the IR electric currents in this direction. This can be explained by the assumption that IR induced currents in the <001> direction can only flow in the second and deeper layers of Cu(110). Therefore, in this direction, there is no friction with the adsorbates and hence no surface resistance.