WorldWideScience

Sample records for simple sawtooth potential

  1. Seeding Coherent Radiation Sources with Sawtooth Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ratner, Daniel; Chao, Alex; /SLAC

    2012-03-28

    Seed radiation sources have the ability to increase longitudinal coherence, decrease saturation lengths, and improve performance of tapering, polarization control and other FEL features. Typically, seeding schemes start with a simple sinusoidal modulation, which is manipulated to provide bunching at a high harmonic of the original wavelength. In this paper, we consider seeding from sawtooth modulations. The sawtooth creates a clean phase space structure, providing a maximal bunching factor without the need for an FEL interaction. While a pure sawtooth modulation is a theoretical construct, it is possible to approach the waveform by combining two or more of the composite wavelengths. We give examples of sawtooth seeding for HGHG, EEHG and other schemes, and note that the sawtooth modulation may aid in suppression of the microbunching instability.

  2. Sawtooth Period Scaling

    CERN Document Server

    Connor, J W; Hastie, R J; Zocco, A

    2012-01-01

    We discuss the role of neoclassical resistivity and local magnetic shear in the prediction of the sawtooth period in tokamaks. When collisional detrapping of electrons is considered the value of the safety factor on axis, $q(t,0)$, evolves on a new time scale, $\\tau_{*}=\\tau_{\\eta}\

  3. Saw-tooth cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Karatza Ageliki A

    2009-12-01

    Full Text Available Abstract We present an unusual case of cardiomyopathy in a two month old male infant with a grade-I systolic murmur. Echocardiographic examination disclosed left ventricular (LV, dysplasia with saw-tooth like inwards myocardial projections extending from the lateral walls towards the LV cavity. There was mild LV systolic dysfunction with apical hypokinesia. Cardiovascular magnetic resonance demonstrated in detail these cross bridging muscular projections originating from the inferior interventricular septum and lateral LV wall, along with areas of hypokinesis at the LV septum and apex in a noncoronary distribution, without any late gadolinium enhancement. We have termed this condition saw-tooth cardiomyopathy because of the very characteristic appearance.

  4. Relationship between sawtooth events and magnetic storms

    OpenAIRE

    Cai, Xia; J. C. Zhang; Clauer, C. R.; Liemohn, M. W.

    2011-01-01

    The relationship between sawtooth events and magnetospheric substorms has been discussed extensively. However, the relationship between sawtooth events and magnetic storms has not been systematically examined. Using the sawtooth event list and magnetic storm list from January 1998 to December 2007, we investigate whether sawtooth events are storm time phenomena and whether there is a dependence on the strength and phase of storms. We have found that most of sawtooth events occur during storm ...

  5. Control oriented modeling and simulation of the sawtooth instability in nuclear fusion tokamak plasmas

    NARCIS (Netherlands)

    Witvoet, G.; Westerhof, E.; Steinbuch, M.; Doelman, N.J.; Baar, M.R. de

    2009-01-01

    Tokamak plasmas in nuclear fusion are subject to various instabilities. A clear example is the sawtooth instability, which has both positive and negative effects on the plasma. To optimize between these effects control of the sawtooth period is necessary. This paper presents a simple control

  6. Coherence potentials encode simple human sensorimotor behavior.

    Directory of Open Access Journals (Sweden)

    Dhanya Parameshwaran

    Full Text Available Recent work has shown that large amplitude negative periods in the local field potential (nLFPs are able to spread in saltatory manner across large distances in the cortex without distortion in their temporal structure forming 'coherence potentials'. Here we analysed subdural electrocorticographic (ECoG signals recorded at 59 sites in the sensorimotor cortex in the left hemisphere of a human subject performing a simple visuomotor task (fist clenching and foot dorsiflexion to understand how coherence potentials arising in the recordings relate to sensorimotor behavior. In all behaviors we found a particular coherence potential (i.e. a cascade of a particular nLFP wave pattern arose consistently across all trials with temporal specificity. During contrateral fist clenching, but not the foot dorsiflexion or ipsilateral fist clenching, the coherence potential most frequently originated in the hand representation area in the somatosensory cortex during the anticipation and planning periods of the trial, moving to other regions during the actual motor behavior. While these 'expert' sites participated more consistently, other sites participated only a small fraction of the time. Furthermore, the timing of the coherence potential at the hand representation area after onset of the cue predicted the timing of motor behavior. We present the hypothesis that coherence potentials encode information relevant for behavior and are generated by the 'expert' sites that subsequently broadcast to other sites as a means of 'sharing knowledge'.

  7. Diminished electron cloud broadening in a silicon drift detector by sawtooth p{sup +} strips

    Energy Technology Data Exchange (ETDEWEB)

    Sonsky, J.; Valk, H.; Allier, C.P.; Hollander, R.W.; Eijk, C.W.E. van; Sarro, P.M. [Delft Univ. of Technology (Netherlands)

    1999-02-01

    Already in 1993, sawtooth-shaped p{sup +} strips were proposed to diminish lateral diffusion in linear multi-anode silicon drift detectors. The sawtooth structure generates small electric fields directed parallel to the detector surface and perpendicular to the drift direction. These fields confine the drifting electrons within a sawtooth period. In this paper the authors present for the first time experimental proof of the applicability of the concept. For a sawtooth period of 500 {micro}m, the authors have tested the confinement of electron clouds as a function of injected charge up to 5 {times} 10{sup 6} electrons. The maximum number of electrons for which full confinement is achieved has been measured as a function of the potential gutter depth generated by different sawtooth angles.

  8. Sawtooth crashes at high beta on JET

    Energy Technology Data Exchange (ETDEWEB)

    Alper, B.; Huysmans, G.T.A.; Sips, A.C.C. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Nave, M.F.F. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior Tecnico

    1994-07-01

    The sawtooth crashes on JET display features which depend on beta. The main observation is a transient bulging of flux surfaces (duration inferior to 30 microsec.), which is predominantly on the low field side and extends to larger radii as beta increases. This phenomenon reaches the plasma boundary when beta{sub N} exceeds 0.5 and in these cases is followed by an ELM within 50 microsec. These sawtooth/ELM events limit plasma performance. Modelling of mode coupling shows qualitative agreement between observations of the structure of the sawtooth precursor and the calculated internal kink mode at high beta. (authors). 6 refs., 5 figs.

  9. Effect of Sawtooth Oscillations on Energetic Ions

    Energy Technology Data Exchange (ETDEWEB)

    R.B. White; V.V. Lutsenko; Ya. I. Kolesnichenko; Yu. V. Yakovenko

    1999-12-10

    The work summarizes results of the authors' studies on the energetic ion transport induced by sawtooth oscillations in tokamaks. The main attention is paid to description of physical mechanisms responsible for the transport. In addition to overview, the work contains new material. The new results concern the resonant interaction of the particles and the electromagnetic field of the sawtooth crash. In particular, it is discovered that the dominant harmonic of the crash (m = n = 1) can lead to stochastic motion of particles having large orbit width (potatoes). Regular motion of potatoes and quasi-stagnation particles in the presence of an n = 1 mode is studied, and their characteristic displacements associated with quick switching on/off the mode are found.

  10. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    Department of Mechanical Engineering, Indian Institute of Science,. Bangalore 560 012 e-mail: raghu@mecheng.iisc.ernet.in. MS received 21 April 2009; revised 1 February 2010; accepted 23 August 2010. Abstract. A simple method using a combination of conformal mapping and vortex panel method to simulate potential ...

  11. Registration of Sawtooth low-phytate, hulled spring barley

    Science.gov (United States)

    The Agricultural Research Service, U.S. Department of Agriculture (USDA-ARS), has released 'Sawtooth', (Hordeum vulgare L.) (Reg. No. xxxxxx, P.I. xxxxxx). Sawtooth is a hulless, low-phytate, spring barley, the second to be developed and released by the USDA-ARS. Compared to the previously released ...

  12. The sawtooth sign is predictive of obstructive sleep apnea.

    Science.gov (United States)

    Bourne, Michael H; Scanlon, Paul D; Schroeder, Darrell R; Olson, Eric J

    2017-05-01

    The sawtooth sign in spirometry is associated with redundant upper airway tissue and snoring, but its predictive value for identifying obstructive sleep apnea (OSA) is disputed. We retrospectively assessed the predictive value of the spirometric sawtooth sign in terms of the odds ratio (OR) of association with a diagnosis of OSA compared to those without the sign. Consecutive spirometry reports showing a sawtooth sign were identified from our laboratory. We identified 50 subjects with sawtooth sign and 100 control subjects without sawtooth sign, matched for age, BMI, and gender. The electronic medical record of each patient was queried for a diagnosis of OSA based on physician-reported diagnoses. Of the 50 subjects with sawtooth sign, 22 were found to have a current diagnosis of OSA (44%). Twenty-seven of the 100 controls (27%) also had OSA. From logistic regression analysis, sawtooth sign was associated with an increased likelihood of OSA (OR = 2.12, 95% C.I. 1.04 to 4.35). Similar results were obtained after adjustment for age, gender, pack years, and BMI (OR = 2.61, 95% C.I. 1.13 to 6.21). Patients with the sawtooth sign have greater odds of having a diagnosis of OSA compared with those without the sign. If prospectively evaluated, as a result of improved identification, we hypothesize that the sawtooth sign may show an even stronger association with OSA. This relatively common finding, which adds no cost to routine spirometry, may serve as an indicator for OSA workup for some individuals not already identified as having OSA.

  13. Prediction of potential drug targets based on simple sequence properties

    Directory of Open Access Journals (Sweden)

    Lai Luhua

    2007-09-01

    Full Text Available Abstract Background During the past decades, research and development in drug discovery have attracted much attention and efforts. However, only 324 drug targets are known for clinical drugs up to now. Identifying potential drug targets is the first step in the process of modern drug discovery for developing novel therapeutic agents. Therefore, the identification and validation of new and effective drug targets are of great value for drug discovery in both academia and pharmaceutical industry. If a protein can be predicted in advance for its potential application as a drug target, the drug discovery process targeting this protein will be greatly speeded up. In the current study, based on the properties of known drug targets, we have developed a sequence-based drug target prediction method for fast identification of novel drug targets. Results Based on simple physicochemical properties extracted from protein sequences of known drug targets, several support vector machine models have been constructed in this study. The best model can distinguish currently known drug targets from non drug targets at an accuracy of 84%. Using this model, potential protein drug targets of human origin from Swiss-Prot were predicted, some of which have already attracted much attention as potential drug targets in pharmaceutical research. Conclusion We have developed a drug target prediction method based solely on protein sequence information without the knowledge of family/domain annotation, or the protein 3D structure. This method can be applied in novel drug target identification and validation, as well as genome scale drug target predictions.

  14. Acoustic field distribution of sawtooth wave with nonlinear SBE model

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Zhang, Lue; Wang, Xiangda; Gong, Xiufen [Key Laboratory of Modern Acoustics, Ministry of Education, Institute of Acoustics, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    For precise prediction of the acoustic field distribution of extracorporeal shock wave lithotripsy with an ellipsoid transducer, the nonlinear spheroidal beam equations (SBE) are employed to model acoustic wave propagation in medium. To solve the SBE model with frequency domain algorithm, boundary conditions are obtained for monochromatic and sawtooth waves based on the phase compensation. In numerical analysis, the influence of sinusoidal wave and sawtooth wave on axial pressure distributions are investigated.

  15. Chemical potential of one-dimensional simple harmonic oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Mungan, Carl E [Physics Department, US Naval Academy, Annapolis, MD 21402-5002 (United States)], E-mail: mungan@usna.edu

    2009-09-15

    Expressions for the chemical potential of an Einstein solid, and of ideal Fermi and Bose gases in an external one-dimensional oscillatory trap, are calculated by two different methods and are all found to share the same functional form. These derivations are easier than traditional textbook calculations for an ideal gas in an infinite three-dimensional square well. Furthermore, the results indicate some important features of chemical potential that could promote student learning in an introductory course in statistical mechanics at the undergraduate level.

  16. Modelling of electron transport and of sawtooth activity in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Angioni, C

    2001-10-01

    Transport phenomena in tokamak plasmas strongly limit the particle and energy confinement and represent a crucial obstacle to controlled thermonuclear fusion. Within the vast framework of transport studies, three topics have been tackled in the present thesis: first, the computation of neoclassical transport coefficients for general axisymmetric equilibria and arbitrary collisionality regime; second, the analysis of the electron temperature behaviour and transport modelling of plasma discharges in the Tokamak a configuration Variable (TCV); third, the modelling and simulation of the sawtooth activity with different plasma heating conditions. The work dedicated to neoclassical theory has been undertaken in order to first analytically identify a set of equations suited for implementation in existing Fokker-Planck codes. Modifications of these codes enabled us to compute the neoclassical transport coefficients considering different realistic magnetic equilibrium configurations and covering a large range of variation of three key parameters: aspect ratio, collisionality, and effective charge number. A comparison of the numerical results with an analytical limit has permitted the identification of two expressions for the trapped particle fraction, capable of encapsulating the geometrical effects and thus enabling each transport coefficient to be fitted with a single analytical function. This has allowed us to provide simple analytical formulae for all the neoclassical transport coefficients valid for arbitrary aspect ratio and collisionality in general realistic geometry. This work is particularly useful for a correct evaluation of the neoclassical contribution in tokamak scenarios with large bootstrap cur- rent fraction, or improved confinement regimes with low anomalous transport and for the determination of the plasma current density profile, since the plasma conductivity is usually assumed neoclassical. These results have been included in the plasma transport code

  17. Limnology of Sawtooth Valley Lakes in 1995

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, C.; Slater, M.; Budy, P.

    1996-05-01

    Included in this section of the report on limnology of Lakes in the Snake River Plain are descriptions of the limnological characteristics of the four lakes in reference to their potential effect of growth and survival of juvenile sockeye salmon. Physical parameters included light penetration, Secchi transparency, and water temperature; chemical parameters included oxygen, and both dissolved and particulate forms of nitrogen and phosphorus. Phytoplankton parameters included chlorophyll concentration, biovolume of dominant taxa, and rates of primary production; zooplankton parameters included density and biomass estimate, length frequencies, and the number of eggs carried by female cladocerans. 11 figs., 5 tabs.

  18. Binding in pair potentials of liquid simple metals from nonlocality in electronic kinetic energy

    Science.gov (United States)

    Perrot, F.; March, N. H.

    1990-01-01

    The paper presents an explicit expression for the pair potential in liquid simple metals from low-order density-gradient theory when the superposition of single-center displaced charges is employed. Numerical results are presented for the gradient expansion pair interaction in liquid Na and Be. The low-order density-gradient equation for the pair potential is presented.

  19. The Double-Well Potential in Quantum Mechanics: A Simple, Numerically Exact Formulation

    Science.gov (United States)

    Jelic, V.; Marsiglio, F.

    2012-01-01

    The double-well potential is arguably one of the most important potentials in quantum mechanics, because the solution contains the notion of a state as a linear superposition of "classical" states, a concept which has become very important in quantum information theory. It is therefore desirable to have solutions to simple double-well potentials…

  20. Stabilization of Sawtooth Oscillations by the Circulating Energetic Ions

    Energy Technology Data Exchange (ETDEWEB)

    Ya.I. Kolesnichenko; V.S. Marchenko; R.B.White

    2004-05-26

    The influence of the well-circulating energetic ions on the ideal kink instability and semi-collisional tearing mode are studied. It is found that the precession of these ions can be a key factor that affects the instability: it can lead to the stabilization of the mentioned instabilities, the effect being weakly dependent on the direction of the injection. The developed theory is consistent with the experimental observations of the stabilization of sawtooth oscillations during the negative-ion-based neutral beam injection in JT-60U.

  1. Dynamics of fast ions during sawtooth oscillations in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Salewski, Mirko; Bindslev, Henrik

    2011-01-01

    Experimental investigations of sawteeth interaction with fast ions measured by collective Thomson scattering on TEXTOR are presented. Time-resolved measurements of localized 1D fast-ion distribution functions allow us to study fast-ion dynamics during several sawtooth cycles. Sawtooth oscillation...

  2. Growth and Seed Production of Sawtooth Oak (Quercus acutissima) 22 Years After Direct Seeding

    Science.gov (United States)

    J.C.G. Goelz; D.W. Carlson

    1997-01-01

    Sawtooth oak (Quercus acutissima Carruth.) was direct seeded at two locations, one with a poorly drained clay soil and the other with a well-drained silty clay loam. For comparison, Nuttall oak (Q. nuttallii Palmer) was direct seeded on the poorly drained clay soil. On the well-drained silty clay loam, sawtooth oak was 18 ft...

  3. Finite pressure effects on the tokamak sawtooth crash

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Yasutaro

    1998-07-01

    The sawtooth crash is a hazardous, disruptive phenomenon that is observed in tokamaks whenever the safety factor at the magnetic axis is below unity. Recently, Tokamak Test Fusion Reactor (TFTR) experimental data has revealed interesting features of the dynamical pressure evolution during the crash phase. Motivated by the experimental results, this dissertation focuses on theoretical modeling of the finite pressure effects on the nonlinear stage of the sawtooth crash. The crash phase has been studied numerically employed a toroidal magnetohydrodynamic (MHD) initial value code deduced from the FAR code. For the first time, by starting from a concentric equilibrium, it has been shown that the evolution through an m/n = 1/1 magnetic island induces secondary high-n ballooning instabilities. The magnetic island evolution gives rise to convection of the pressure inside the inversion radius and builds up a steep pressure gradient across the island separatrix, or current sheet, and thereby triggers ballooning instabilities below the threshold for the axisymmetric equilibrium. Due to the onset of secondary ballooning modes, concomitant fine scale vortices and magnetic stochasticity are generated. These effects produce strong flows across the current sheet, and thereby significant modify the m = 1 driven magnetic reconnection process. The resultant interaction of the high-n ballooning modes with the magnetic reconnection process is discussed.

  4. Snake River Sockeye Salmon, Sawtooth Valley Project : 1992 Juvenile and Adult Trapping Program : Final Environmental Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-04-01

    Sockeye salmon (Oncorhynchus nerka) runs in the Snake River Basin have severely declined. Redfish Lake near Stanley, Idaho is the only lake in the drainage known to still support a run. In 1989, two adults were observed returning to this lake and in 1990, none returned. In the summer of 1991, only four adults returned. If no action is taken, the Snake River sockeye salmon will probably cease to exist. On November 20, 1991, the National Marine Fisheries Service (NMFS) declared the Snake River sockeye salmon ``endangered`` (effective December 20, 1991), pursuant to the Endangered Species Act (ESA) of 1973. In 1991, in response to a request from the Idaho Department of Fish and Game and the Shoshone-Bannock Tribes, the Bonneville Power Administration (BPA) funded efforts to conserve and begin rebuilding the Snake River sockeye salmon run. The initial efforts were focused on Redfish Lake in the Sawtooth Valley of southcentral Idaho. The 1991 measures involved: trapping some of the juvenile outmigrants (O. nerka) from Redfish Lake and rearing them in the Eagle Fish Health Facility (Idaho Department of Fish and Game) near Boise, Idaho; Upgrading of the Eagle Facility where the outmigrants are being reared; and trapping adult Snake River sockeye salmon returning to Redfish Lake and holding and spawning them at the Sawtooth Hatchery near Stanley, Idaho. This Environmental Assessment (EA) evaluates the potential environmental effects of the proposed actions for 1992. It has been prepared to meet the requirements of the National Environmental Policy Act (NEPA) of 1969 and section 7 of the ESA of 1973.

  5. Oscillations of the Outer Boundary of the Outer Radiation Belt During Sawtooth Oscillations

    Directory of Open Access Journals (Sweden)

    Jae-Hun Kim

    2006-09-01

    Full Text Available We report three sawtooth oscillation events observed at geosynchronous orbit where we find quasi-periodic (every 2-3 hours sudden flux increases followed by slow flux decreases at the energy levels of ˜50-400 keV. For these three sawtooth events, we have examined variations of the outer boundary of the outer radiation belt. In order to determine L values of the outer boundary, we have used data of relativistic electron flux observed by the SAMPEX satellite. We find that the outer boundary of the outer radiation belt oscillates periodically being consistent with sawtooth oscillation phases. Specifically, the outer boundary of the outer radiation belt expands (namely, the boundary L value increases following the sawtooth particle flux enhancement of each tooth, and then contracts (namely, the boundary L value decreases while the sawtooth flux decreases gradually until the next flux enhancement. On the other hand, it is repeatedly seen that the asymmetry of the magnetic field intensity between dayside and nightside decreases (increases due to the dipolarization (the stretching on the nightside as the sawtooth flux increases (decreases. This implies that the periodic magnetic field variations during the sawtooth oscillations are likely responsible for the expansion-contraction oscillations of the outer boundary of the outer radiation belt.

  6. Tearing mode dynamics and sawtooth oscillation in Hall-MHD

    Science.gov (United States)

    Ma, Zhiwei; Zhang, Wei; Wang, Sheng

    2017-10-01

    Tearing mode instability is one of the most important dynamic processes in space and laboratory plasmas. Hall effects, resulted from the decoupling of electron and ion motions, could cause the fast development and perturbation structure rotation of the tearing mode and become non-negligible. We independently developed high accuracy nonlinear MHD code (CLT) to study Hall effects on the dynamic evolution of tearing modes with Tokamak geometries. It is found that the rotation frequency of the mode in the electron diamagnetic direction is in a good agreement with analytical prediction. The linear growth rate increases with increase of the ion inertial length, which is contradictory to analytical solution in the slab geometry. We further find that the self-consistently generated rotation largely alters the dynamic behavior of the double tearing mode and the sawtooth oscillation. National Magnetic Confinement Fusion Science Program of China under Grant No. 2013GB104004 and 2013GB111004.

  7. Oncorhynchus nerka population monitoring in the Sawtooth Valley Lakes

    Energy Technology Data Exchange (ETDEWEB)

    Teuscher, D.M.; Taki, D.; Ariwite, K.

    1996-05-01

    Critical habitat for endangered Snake River sockeye salmon includes five rearing lakes located in the Sawtooth Valley of central Idaho. Most of the lakes contain either introduced or endemic kokanee populations. Snake River sockeye occur naturally in Redfish Lake, and are being stocked in Redfish and Pettit Lakes. Because kokanee compete with sockeye for limited food resources, understanding population characteristics of both species such as spawn timing, egg-to-fry survival, distribution and abundance are important components of sockeye recovery. This chapter describes some of those characteristics. In 1995, hydroacoustic estimates of O. nerka densities in the Sawtooth Valley Lakes ranged from 57 to 465 fish/ha. Densities were greatest in Pettit followed by Redfish (167), Alturas (95), and Stanley Lakes. O. nerka numbers increased from 1994 values in Pettit and Alturas Lakes, but declined in Redfish and Stanley. Despite a decline in total lake abundance, O. nerka biomass estimates in Redfish Lake increased. Approximately 144,000 kokanee fry recruited to Redfish Lake from Fishhook Creek. O. nerka fry recruitment to Stanley and Alturas lake was 5,000 and 30,000 fry, respectively. Egg-to-fry survival was 14% in Fishhook and 7% in Stanley Lake Creek. In Fishhook Creek, kokanee spawning escapement was estimated using stream surveys and a weir. Escapement estimates were 4,860 from weir counts, and 7,000 from stream surveys. As part of the kokanee reduction program, 385 of the spawning female kokanee were culled. Escapement for Stanley Lake Creek was only 60 fish, a ten fold decrease from 1994. In Alturas Lake, kokanee spawners dropped by 50% to 1,600.

  8. An automated sawtooth detection algorithm for strongly varying plasma conditions and crash characteristics

    Science.gov (United States)

    Gude, A.; Maraschek, M.; Kardaun, O.; the ASDEX Upgrade Team

    2017-09-01

    A sawtooth crash algorithm that can automatically detect irregular sawteeth with strongly varying crash characteristics, including inverted crashes with central signal increase, has been developed. Such sawtooth behaviour is observed in ASDEX Upgrade with its tungsten wall, especially in phases with central ECRH. This application of ECRH for preventing impurity accumulation is envisaged also for ITER. The detection consists of three steps: a sensitive edge detection, a multichannel combination to increase detection performance, and a profile analysis that tests generic sawtooth crash features. The effect of detection parameters on the edge detection results has been investigated using synthetic signals and tested in an application to ASDEX Upgrade soft x-ray data.

  9. A simple microcontroller-based sedimentation potential measurement for nanosuspension stability investigations

    Science.gov (United States)

    Joni, I. Made; Zannuary, Ilham; Hidayat, Darmawan; Panatarani, Camellia

    2016-02-01

    This paper report the development of a simple sedimentation potential measurement system to know the state of nanoparticles (NPs) dispersion stability. The state of nanoparticles dispersion stability is very important in applications of nanoparticles since the nature of NPs is easily agglomerate. The developed sedimentation potential consist of graphite electrodes, signal conditioning, microcontroller, and interface circuits provided with a data acquisition applications. The system was designed to obtained sedimentation potential in the range -200 to 200 mV with accuracy of 0.415 mV. From the measured sedimentation potential, the zeta potential can be determined. This system was applied to investigate stability of TiO2 NPS suspension in water media to obtain the performances of the system. Those zeta potentials were determined at various condition such as vary in surface charges by controlling the pH of the suspension, vary in suspension concentrations and sedimentation time. The results show that the higher concentration of the suspension, lower zeta potential of the suspension was obtained. The zeta potential was decreased by the sedimentation time indicated that the agglomeration of particles occurred. Controlling of surface charges by controlling pH also affect the values of obtained zeta potentials. It is concluded that the developed sedimentation potential measurement successfully applied for determination of zeta potential of the TiO2 NPs suspension to evaluate the stability NPs suspension.

  10. Study on sawtooth and transport in part of Japan-TEXTOR collaboration 1995

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, K. [ed.

    1996-02-01

    A collaboration programme `physics of sawtooth and transport` has been performed in the frame work of the Japan-TEXTOR collaboration. The summary of the workshops and collaborations in 1995 is reported. (author)

  11. Constant electric field simulations of the membrane potential illustrated with simple systems.

    Science.gov (United States)

    Gumbart, James; Khalili-Araghi, Fatemeh; Sotomayor, Marcos; Roux, Benoît

    2012-02-01

    Advances in modern computational methods and technology make it possible to carry out extensive molecular dynamics simulations of complex membrane proteins based on detailed atomic models. The ultimate goal of such detailed simulations is to produce trajectories in which the behavior of the system is as realistic as possible. A critical aspect that requires consideration in the case of biological membrane systems is the existence of a net electric potential difference across the membrane. For meaningful computations, it is important to have well validated methodologies for incorporating the latter in molecular dynamics simulations. A widely used treatment of the membrane potential in molecular dynamics consists of applying an external uniform electric field E perpendicular to the membrane. The field acts on all charged particles throughout the simulated system, and the resulting applied membrane potential V is equal to the applied electric field times the length of the periodic cell in the direction perpendicular to the membrane. A series of test simulations based on simple membrane-slab models are carried out to clarify the consequences of the applied field. These illustrative tests demonstrate that the constant-field method is a simple and valid approach for accounting for the membrane potential in molecular dynamics studies of biomolecular systems. This article is part of a Special Issue entitled: Membrane protein structure and function. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. ORBIT modelling of fast particle redistribution induced by sawtooth instability

    Science.gov (United States)

    Kim, Doohyun; Podestà, Mario; Poli, Francesca; Princeton Plasma Physics Laboratory Team

    2017-10-01

    Initial tests on NSTX-U show that introducing energy selectivity for sawtooth (ST) induced fast ion redistribution improves the agreement between experimental and simulated quantities, e.g. neutron rate. Thus, it is expected that a proper description of the fast particle redistribution due to ST can improve the modelling of ST instability and interpretation of experiments using a transport code. In this work, we use ORBIT code to characterise the redistribution of fast particles. In order to simulate a ST crash, a spatial and temporal displacement is implemented as ξ (ρ , t , θ , ϕ) = ∑ξmn (ρ , t) cos (mθ + nϕ) to produce perturbed magnetic fields from the equilibrium field B-> , δB-> = ∇ × (ξ-> × B->) , which affect the fast particle distribution. From ORBIT simulations, we find suitable amplitudes of ξ for each ST crash to reproduce the experimental results. The comparison of the simulation and the experimental results will be discussed as well as the dependence of fast ion redistribution on fast ion phase space variables (i.e. energy, magnetic moment and toroidal angular momentum). Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

  13. Sawtooth control using electron cyclotron current drive in the presence of energetic particles in high performance ASDEX Upgrade plasmas

    CERN Document Server

    Chapman, I T; Maraschek, M; McCarthy, P J; Tardini, G

    2013-01-01

    Sawtooth control using steerable electron cyclotron current drive (ECCD) has been demonstrated in ASDEX Upgrade plasmas with a significant population of energetic ions in the plasma core and long uncontrolled sawtooth periods. The sawtooth period is found to be minimised when the ECCD resonance is swept to just inside the q = 1 surface. By utilising ECCD inside q = 1 for sawtooth control, it is possible to avoid the triggering of neoclassical tearing modes, even at significnatly higher pressure than anticipated in the ITER baseline scenario. Operation at 25% higher normalised pressure has been achieved when only modest ECCD power is used for sawtooth control compared to identical discharges without sawtooth control when neo-classical tearing modes are triggered by the sawteeth. Modelling suggests that the destabilisation arising from the change in the local magnetic shear caused by the ECCD is able to compete with the stabilising influence of the energetic particles inside the q = 1 surface.

  14. A saw-tooth plasma actuator for film cooling efficiency enhancement of a shaped hole

    Science.gov (United States)

    Li, Guozhan; Yu, Jianyang; Liu, Huaping; Chen, Fu; Song, Yanping

    2017-08-01

    This paper reports the large eddy simulations of the effects of a saw-tooth plasma actuator and the laidback fan-shaped hole on the film cooling flow characteristics, and the numerical results are compared with a corresponding standard configuration (cylindrical hole without the saw-tooth plasma actuator). For this numerical research, the saw-tooth plasma actuator is installed just downstream of the cooling hole and a phenomenological plasma model is employed to provide the 3D plasma force vectors. The results show that thanks to the downward force and the momentum injection effect of the saw-tooth plasma actuator, the cold jet comes closer to the wall surface and extends further downstream. The saw-tooth plasma actuator also induces a new pair of vortex which weakens the strength of the counter-rotating vortex pair (CRVP) and entrains the coolant towards the wall, and thus the diffusion of the cold jet in the crossflow is suppressed. Furthermore, the laidback fan-shaped hole reduces the vertical jet velocity causing the disappearance of downstream spiral separation node vortices, this compensates for the deficiency of the saw-tooth plasma actuator. Both effects of the laidback fan-shaped hole and the saw-tooth plasma actuator effectively control the development of the CRVP whose size and strength are smaller than those of the anti-counter rotating vortex pair in the far field, thus the centerline and the spanwise-averaged film cooling efficiency are enhanced. The average film cooling efficiency is the biggest in the Fan-Dc = 1 case, which is 80% bigger than that in the Fan-Dc = 0 case and 288% bigger than that in the Cyl-Dc = 0 case.

  15. Simple techniques suitable for student use to record action potentials from the frog heart.

    Science.gov (United States)

    Yoshida, S

    2001-12-01

    Demonstrating action potentials during class experiments is very educational for science students. It is not easy, however, to obtain a stable intracellular recording of action potentials from the conventionally used skeletal muscle cells, because the tip of a glass microelectrode often comes out or breaks due to muscle contraction. Here, I present a much simpler recording method using a flexible polyethylene electrode with a wide orifice (approximately 1 mm) for a bullfrog heart beating on automaticity. Extracellular recordings of action potentials (electrocardiogram) can be obtained by placing an electrode on the cardiac surface, and transmembrane potentials can be obtained by rupturing the membrane with negative pressure, i.e., whole cell configuration. Once attached to the heart by suction, the polyethylene electrode does not easily come off during contraction of the heart. Perfusion of the heart via the postcaval vein offers us opportunities for observing the effects of either changing ionic compositions of solutions or applying drugs. The techniques shown here provide a simple and convenient way to perform a variety of class experiments.

  16. Mathematical anxiety effects on simple arithmetic processing efficiency: an event-related potential study.

    Science.gov (United States)

    Suárez-Pellicioni, M; Núñez-Peña, M I; Colomé, A

    2013-12-01

    This study uses event-related brain potentials to investigate the difficulties that high math anxious individuals face when processing dramatically incorrect solutions to simple arithmetical problems. To this end, thirteen high math-anxious (HMA) and thirteen low math-anxious (LMA) individuals were presented with simple addition problems in a verification task. The proposed solution could be correct, incorrect but very close to the correct one (small-split), or dramatically incorrect (large-split). The two groups did not differ in mathematical ability or trait anxiety. We reproduced previous results for flawed scores suggesting HMA difficulties in processing large-split solutions. Moreover, large-split solutions elicited a late positive component (P600/P3b) which was more enhanced and delayed in the HMA group. Our study proposes that the pattern of flawed scores found by previous studies (and that we replicate) has to do with HMA individuals'difficulties in inhibiting an extended processing of irrelevant information (large-split solutions). Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Simple peptides derived from the ribosomal core potentiate RNA polymerase ribozyme function

    Science.gov (United States)

    Tagami, Shunsuke; Attwater, James; Holliger, Philipp

    2017-04-01

    The emergence of functional interactions between nucleic acids and polypeptides was a key transition in the origin of life and remains at the heart of all biology. However, how and why simple non-coded peptides could have become critical for RNA function is unclear. Here, we show that putative ancient peptide segments from the cores of both ribosomal subunits enhance RNA polymerase ribozyme (RPR) function, as do derived homopolymeric peptides comprising lysine or the non-proteinogenic lysine analogues ornithine or, to a lesser extent, diaminobutyric acid, irrespective of chirality or chiral purity. Lysine decapeptides enhance RPR function by promoting holoenzyme assembly through primer-template docking, accelerate RPR evolution, and allow RPR-catalysed RNA synthesis at near physiological (≥1 mM) Mg2+ concentrations, enabling templated RNA synthesis within membranous protocells. Our results outline how compositionally simple, mixed-chirality peptides may have augmented the functional potential of early RNAs and promoted the emergence of the first protocells.

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

    Directory of Open Access Journals (Sweden)

    Junaid Iqbal

    2013-01-01

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

  19. Simple unified view of branching process statistics: Random walks in balanced logarithmic potentials

    Science.gov (United States)

    di Santo, Serena; Villegas, Pablo; Burioni, Raffaella; Muñoz, Miguel A.

    2017-03-01

    We revisit the problem of deriving the mean-field values of avalanche exponents in systems with absorbing states. These are well known to coincide with those of unbiased branching processes. Here we show that for at least four different universality classes (directed percolation, dynamical percolation, the voter model or compact directed percolation class, and the Manna class of stochastic sandpiles) this common result can be obtained by mapping the corresponding Langevin equations describing each of them into a random walker confined to the origin by a logarithmic potential. We report on the emergence of nonuniversal continuously varying exponent values stemming from the presence of small external driving - that might induce avalanche merging - that, to the best of our knowledge, has not been noticed in the past. Many of the other results derived here appear in the literature as independently derived for individual universality classes or for the branching process itself. Still, we believe that a simple and unified perspective as the one presented here can help (1) clarify the overall picture, (2) underline the superuniversality of the behavior as well as the dependence on external driving, and (3) avoid the common existing confusion between unbiased branching processes (equivalent to a random walker in a balanced logarithmic potential) and standard (unconfined) random walkers.

  20. Half-cell potentials of semiconductive simple binary sulphides in aqueous solution

    Science.gov (United States)

    Sato, M.

    1966-01-01

    Theoretical consideration of the charge-transfer mechanism operative in cells with an electrode of a semiconductive binary compound leads to the conclusion that the half-cell potential of such a compound is not only a function of ionic activities in the electrolytic solution, but also a function of the activities of the component elements in the compound phase. The most general form of the electrode equation derived for such a compound with a formula MiXj which dissociates into Mj+ and Xi- ions in aqueous solution is. EMiXj = EMiXj0 + R T 2 ij ln [ (sua Mj+)aqi ?? (suaX)jMiXj/ (suaXi-)aqj ?? (suaM)iMiXj],. where. EMiXj0 = 1 2(EM,Mj+0 + EXi-,X). The equation can be modified to other forms. When applied to semiconductive simple binary sulphides, these equations appear to give better descriptions of the observed electrode potentials of such sulphides than any other proposed equations. ?? 1966.

  1. Determination of q during sawtooth from inverse evolution of BAEs in Tore Supra

    Science.gov (United States)

    Amador, C. H. S.; Sabot, R.; Garbet, X.; Guimarães-Filho, Z. O.; Ahn, J.-H.

    2018-01-01

    Measuring the value of the safety factor (q) in the core during sawtooth cycles is still an open issue. A new method to measure q in Tore Supra plasma core is presented here. It relies on the analysis of the time evolution of a set of MHD modes detected after the sawtooth crashes. These modes are in the frequency range of previously observed Beta-induced Alfvén Eigenmodes, but with a frequency declining in time. The mode frequency analysis shows that the q profile is reversed when we have ICRH, after the sawtooth crash. In high current discharges (I_p>1.15 MA), the q-profile remains reversed for a longer time compared with lower plasma current discharges. Non-linear 3D MHD simulations of sawteeth performed with the XTOR-2F code (Lütjens and Luciani 2010 J. Comput. Phys. 229 8130–43) exhibit features that are similar to these observations.

  2. Observation of suprathermal electrons during magnetic reconnection at the sawtooth instability in DIII-D TOKAMAK

    CERN Document Server

    Savrukhin, R V

    2002-01-01

    OAK A271 Observation of suprathermal electrons during magnetic reconnection at the sawtooth instability in DIII-D TOKAMAK. Intense bursts of x-ray and electron cyclotron emission are observed during sawtooth instabilities in high-temperature plasmas in the DIII-D tokamak. The bursts are initiated around the X-point of the m = 1, n = 1 magnetic island at the beginning of the sawtooth crash and are displaced to larger radii later during the temperature collapse. Reconstruction of the magnetic configuration using motional Stark effect (MSE) data and numerical simulations indicates that the bursts can be connected with suprathermal electrons (E sub r approx 30-40 keV) generated during reconnection of the magnetic field around the q = 1 surface.

  3. An Analysis of Sawtooth Noise in the Timing SynPaQ III GPS Sensor

    Directory of Open Access Journals (Sweden)

    Yuriy S. SHMALIY

    2007-05-01

    Full Text Available This paper addresses a probabilistic analysis of sawtooth noise in the one pulse per second (1PPS output of the timing SynPaQ III GPS Sensor. We show that sawtooth noise is uniformly distributed within the bounds caused by period of the Local Time Clock of the sensor and that the probability density function (pdf of this noise is formed with 1ns sampling interval used in the sensor to calculate the negative sawtooth. We also show that the pdf has at zero a spike of 1ns width caused by roll-off. It is demonstrated that an unbiased finite impulse response filter is an excellent suppresser of such a noise in the estimates of the time interval errors of local clocks.

  4. Transcranial alternating current stimulation with sawtooth waves: simultaneous stimulation and EEG recording

    Directory of Open Access Journals (Sweden)

    James eDowsett

    2016-03-01

    Full Text Available Transcranial alternating current stimulation (tACS has until now mostly been administered as an alternating sinusoidal wave. Despite modern tACS stimulators being able to deliver alternating current with any arbitrary shape there has been no systematic exploration into the relative benefits of different waveforms. As tACS is a relatively new technique there is a huge parameter space of unexplored possibilities which may prove superior or complimentary to the traditional sinusoidal waveform. Here we begin to address this with an investigation into the effects of sawtooth wave tACS on individual alpha power. Evidence from animal models suggests that the gradient and direction of an electric current should be important factors for the subsequent neural firing rate; we compared positive and negative ramp sawtooth waves to test this. An additional advantage of sawtooth waves is that the resulting artefact in the electroencephalogram (EEG recording is significantly simpler to remove than a sine wave; accordingly we were able to observe alpha oscillations both during and after stimulation.We found that positive ramp sawtooth, but not negative ramp sawtooth, significantly enhanced alpha power during stimulation relative to sham (p<0.01. In addition we tested for an after-effect of both sawtooth and sinusoidal stimulation on alpha power but in this case did not find any significant effect. This preliminary study paves the way for further investigations into the effect of the gradient and direction of the current in tACS which could significantly improve the usefulness of this technique.

  5. A simple and rapid liquid chromatographic assay for evaluation of potentially counterfeit Tamiflu.

    Science.gov (United States)

    Lindegårdh, N; Hien, T T; Farrar, J; Singhasivanon, P; White, N J; Day, N P J

    2006-10-11

    A simple and rapid liquid chromatographic assay for the evaluation of potentially counterfeit oseltamivir (Tamiflu has been developed and assessed. The assay uses approximately 1mg Tamiflu powder when used for authentication and content estimate. The procedure was validated using 50 replicates analysed during five independent series with a total R.S.D. of 11.2%. The assay can also be used to monitor the exact content of oseltamivir in Tamiflu capsules. One Tamiflu capsule was transferred to a 250mL volumetric flask and 150mL water was added. The flask was placed in an ultrasonic bath at 40 degrees C for 20min to dissolve the capsule. The solution was allowed to cool to room temperature before the flask was filled up to the mark (250mL). A small aliquot was centrifuged and then directly injected into the LC-system for quantification. Oseltamivir was analysed by liquid chromatography with UV detection on a Hypersil Gold column (150mmx4.6mm) using a mobile phase containing methanol-phosphate buffer (pH 2.5; 0.1M) (50:50, v/v) at a flow rate of 1.0mL/min. The assay was implemented for the analysis of Tamiflu purchased over the Internet and at local pharmacies in Thailand and Vietnam.

  6. Fast and simple determination of perfluorinated compounds and their potential precursors in different packaging materials.

    Science.gov (United States)

    Zabaleta, I; Bizkarguenaga, E; Bilbao, D; Etxebarria, N; Prieto, A; Zuloaga, O

    2016-05-15

    A simple and fast analytical method for the determination of fourteen perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) and ten potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs) in different packaging materials was developed in the present work. In order to achieve this objective the optimization of an ultrasonic probe-assisted extraction (UPAE) method was carried out before the analysis of the target compounds by liquid-chromatography-triple quadrupole-tandem mass spectrometry (LC-QqQ-MS/MS). 7 mL of 1 % acetic acid in methanol and a 2.5-min single extraction cycle were sufficient for the extraction of all the target analytes. The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values after correction with the corresponding labeled standard were in the 69-103 % and 62-98 % range for samples fortified at 25 ng/g and 50 ng/g concentration levels, respectively and MDL values in the 0.6-2.2 ng/g range were obtained. The developed method was applied to the analysis of plastic (milk bottle, muffin cup, pre-cooked food wrapper and cup of coffee) and cardboard materials (microwave popcorn bag, greaseproof paper for French fries, cardboard box for pizza and cinema cardboard box for popcorn). To the best of our knowledge, this is the first method that describes the determination of fourteen PFCs and ten potential precursors in packaging materials. Moreover, 6:2 FTCA, 6:2 FTUCA and 5:3 FTCA analytes were detected for the first time in microwave popcorn bags. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Simple physics-based analytical formulas for the potentials of mean force for the interaction of amino acid side chains in water. 2. Tests with simple spherical systems.

    Science.gov (United States)

    Makowski, Mariusz; Liwo, Adam; Maksimiak, Katarzyna; Makowska, Joanna; Scheraga, Harold A

    2007-03-22

    Simple analytical functions consisting of electrostatic, polarization, Lennard-Jones or modified Lennard-Jones, and cavity terms are proposed to express the potentials of mean force analytically for spherical particles interacting in water. The cavity term was expressed either through the molecular-surface area of the solute or by using the Gaussian-overlap model of hydrophobic hydration developed in paper 1 of this series. The analytical expressions were fitted to the potentials of mean force of a methane homodimer, heterodimers composed of a methane molecule, and an ammonium cation or a chloride anion, respectively, and dimers consisting of two chloride anions, two ammonium cations, or a chloride ion and an ammonium cation. The potentials of mean force for these dimers were determined by umbrella-sampling molecular dynamics simulations with the AMBER 7.0 force field with TIP3P water either in our earlier work or in this work. For all systems, the analytical formulas fitted the potentials of mean force very well. However, using the molecular-surface area to express the cavity term provided a good fit only when the nonbonded interactions were expressed by an all-repulsive modified Lennard-Jones potential but also resulted in non-physical values of some of the parameters. Conversely, the use of our new Gaussian-overlap-based expression for the cavity term provided a good fit to the potentials of mean force (PMFs) with Lennard-Jones nonbonded potential, and the values of all parameters were physically reasonable.

  8. Corrosion resistant Zn–Co alloy coatings deposited using saw-tooth ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Micro/nanostructured multilayer coatings of Zn–Co alloy were developed periodically on mild steel from acid chloride bath. Composition modulated multilayer alloy (CMMA) coatings, having gradual change in composition (in each layer) were developed galvanostatically using saw-tooth pulses through single.

  9. Eigenfrequency detecting method with sawtooth wave modulation theory for navigation grade fiber optic gyroscopes

    Science.gov (United States)

    Wang, Xiaxiao; Wang, Xiang; Yu, Jia; Zheng, Yue

    2017-09-01

    Eigenfrequency is a key parameter for the fiber optic gyroscope (FOG). An eigenfrequency detecting method for FOGs, especially for high-grade FOGs, such as the navigation grade FOGs, is proposed. The eigenfrequency is detected with the sawtooth wave modulation theory. Adjusting the frequency of the sawtooth wave to an even integer of the eigenfrequency, the error signal caused by the sawtooth wave modulation will be zero, then the eigenfrequency can be calculated by the value of the sawtooth wave frequency exactly and the bias modulation frequency is at the eigenfrequency accurately. It is demonstrated experimentally with an FOG, the length of whose sensing coil is about 1200 m, that the accuracy of the eigenfrequency measurement is better than 1.2 ppm (0.1 Hz). With its high accuracy, not only can the frequency of the bias modulation be adjusted to the eigenfrequency precisely, but also this method can be used as an eigenfrequency detector for studying the characteristics of the sensing coil according to the eigenfrequency to study the mechanism of the errors generated in the FOGs.

  10. X-ray spectroscopy with a multi-anode sawtooth silicon drift detector: the diffusion process

    Energy Technology Data Exchange (ETDEWEB)

    Sonsky, J. E-mail: sonsky@iri.tudelft.nl; Hollander, R.W.; Sarro, P.M.; Eijk, C.W.E. van

    2002-01-21

    The position sensitive detection of low-energy X-rays can be realized by means of a multi-anode linear silicon drift detector (SDD). However, a severe worsening of the spectroscopic quality of the detector is observed due to the lateral broadening of the X-ray generated electron cloud during drift. Recently, we have proved experimentally that electron confinement can be achieved by means of sawtooth-shaped p{sup +} strips; the sawtooth concept. This paper will present room temperature X-ray spectroscopy measurements clearly demonstrating the improvement of spectroscopic quality of the sawtooth SDD as compared with a traditional linear SDD. Using a sawtooth SDD we have measured an energy resolution of 1.4 keV FWHM at the 13.9 keV peak of {sup 241}Am at room temperature and a substantial reduction of the number of split events is also observed. The calculation of the influence of diffusion on the quality of the pulse height spectrum will also be given.

  11. X-ray spectroscopy with a multi-anode sawtooth silicon drift detector the diffusion process

    CERN Document Server

    Sonsky, J; Sarro, P M; Eijk, C W

    2002-01-01

    The position sensitive detection of low-energy X-rays can be realized by means of a multi-anode linear silicon drift detector (SDD). However, a severe worsening of the spectroscopic quality of the detector is observed due to the lateral broadening of the X-ray generated electron cloud during drift. Recently, we have proved experimentally that electron confinement can be achieved by means of sawtooth-shaped p sup + strips; the sawtooth concept. This paper will present room temperature X-ray spectroscopy measurements clearly demonstrating the improvement of spectroscopic quality of the sawtooth SDD as compared with a traditional linear SDD. Using a sawtooth SDD we have measured an energy resolution of 1.4 keV FWHM at the 13.9 keV peak of sup 2 sup 4 sup 1 Am at room temperature and a substantial reduction of the number of split events is also observed. The calculation of the influence of diffusion on the quality of the pulse height spectrum will also be given.

  12. The saw-tooth sign as a clinical clue for intrathoracic central airway obstruction

    Directory of Open Access Journals (Sweden)

    Nakajima Akira

    2012-07-01

    Full Text Available Abstract Background The saw-tooth sign was first described by Sanders et al in patients with obstructive sleep apnea syndrome as one cause of extrathoracic central airway obstruction. The mechanism of the saw-tooth sign has not been conclusively clarified. The sign has also been described in various extrathoracic central airway diseases, such as in burn victims with thermal injury to the upper airways, Parkinson’s disease, tracheobronchomalacia, laryngeal dyskinesia, and pedunculated tumors of the upper airway. Case presentation A 61-year-old man was referred to our hospital with a two-month history of persistent dry cough and dyspnea. He was diagnosed with lung cancer located in an intrathoracic central airway, which was accompanied by the saw-tooth sign on flow-volume loops. This peculiar sign repeatedly improved and deteriorated, in accordance with the waxing and waning of central airway stenosis by anti-cancer treatments. Conclusion This report suggests that the so-called saw-tooth sign may be found even in intrathoracic central airway obstruction due to lung cancer.

  13. Collective Thomson scattering measurements of fast-ion transport due to sawtooth crashes in ASDEX Upgrade

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Nielsen, Stefan Kragh; Pedersen, Morten Stejner

    2016-01-01

    . Here we present the first collective Thomson scattering (CTS) measurements of sawtooth-induced redistribution of fast ions at ASDEX Upgrade. These also represent the first localized fast-ion measurements on the high-field side of this device. The results indicate fast-ion losses in the phase...

  14. Affective Priming by Simple Geometric Shapes: Evidence from Event-related Brain Potentials

    OpenAIRE

    Wang, Yinan; Zhang, Qin

    2016-01-01

    Previous work has demonstrated that simple geometric shapes may convey emotional meaning using various experimental paradigms. However, whether affective meaning of simple geometric shapes can be automatically activated and influence the evaluations of subsequent stimulus is still unclear. Thus the present study employed an affective priming paradigm to investigate whether and how two geometric shapes (circle vs. downward triangle) impact on the affective processing of subsequently presented ...

  15. Observation of reversed shear Alfvén eigenmodes between sawtooth crashes in the Alcator C-Mod tokamak.

    Science.gov (United States)

    Edlund, E M; Porkolab, M; Kramer, G J; Lin, L; Lin, Y; Wukitch, S J

    2009-04-24

    Groups of frequency chirping modes observed between sawtooth crashes in the Alcator C-Mod tokamak are interpreted as reversed shear Alfvén eigenmodes near the q=1 surface. These modes indicate that a reversed shear q profile is generated during the relaxation phase of the sawtooth cycle. Two important parameters, q_{min} and its radial position, are deduced from comparisons of measured density fluctuations with calculations from the ideal MHD code NOVA. These studies provide valuable constraints for further modeling of the sawtooth cycle.

  16. A Method for Measuring Fast Time Evolutions of the Plasma Potential by Means of a Simple Emissive Probe

    DEFF Research Database (Denmark)

    Iizuka, S.; Michelsen, Poul; Juul Rasmussen, Jens

    1981-01-01

    A method is presented for obtaining the temporal evolution of the plasma potential, which is assumed to be given by the floating potential of a simple emissive probe. The construction of the probe is also described. The method avoids the slow time response of the usual technique where the floating...... potential is measured across a high resistance. During each sweep of the probe voltage, the changing of the sign of the probe current, which is sampled at a specific time, gives rise to a negative pulse, driving the pen-lift of an X-Y recorder. Since the real floating potential is measured where the probe...

  17. Saw-tooth Instability Studies At The Stanford Linear Collider Damping Rings

    CERN Document Server

    Podobedov, B V

    2000-01-01

    Saw-tooth instability occurs during high current operation in the Stanford Linear Collider (SLC) damping rings. This instability is single bunch and it can be cast as a longitudinal microwave instability. It is caused by the beam interaction with short range wakefields in the ring vacuum chamber. The saw-tooth instability manifests itself in the periodic blowup in quadrupole or higher moments in the longitudinal beam distribution. Most of our instability studies have been experimental. Since the measurements of coherent particle motion within a short ultrarelativistic beam are largely unconventional we had to develop some original diagnostics. These includes, for example, the down-conversion of the high frequency (10 GHz) broad-band beam position monitor (BPM) signals. We have also employed the state-of the art Hamamatsu streak camera that is capable of resolving the longitudinal beam distribution with sub-picosecond accuracy. As a result of our streak camera experiments we have quantitatively described the p...

  18. Segregation of a binary granular mixture in a vibrating sawtooth base container.

    Science.gov (United States)

    Mobarakabadi, Shahin; Adrang, Neda; Habibi, Mehdi; Oskoee, Ehsan Nedaaee

    2017-09-01

    A granular mixture of identical particles of different densities can be segregated when the system is shaken. We present an efficient method of continuously segregating a flow of randomly mixed identical spherical particles of different densities by shaking them in a quasi-two-dimensional container with a sawtooth-shaped base. Using numerical simulation we study the effect of direction of shaking (horizontal/vertical), geometry of the sawtooth, and the friction coefficient between the grains and the container walls on the segregation quality. Finally by performing experiments on the same system we compare our simulation results with the experimental results. The good agreement between our simulation and experiment indicates the validity of our simulation approach and will provide a practical way for granular segregation in industrial applications.

  19. Understanding the bursty electron cyclotron emission during a sawtooth crash in the HT-7 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Li, Erzhong, E-mail: rzhonglee@ipp.ac.cn; Hu, Liqun; Chen, Kaiyun [Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China)

    2014-01-15

    Bursts in electron cyclotron emission (ECE) were observed during sawtooth crashes in HT-7 in discharges with ion cyclotron resonance heating injected near the q = 1 rational surface (q is the safety factor). The local ECE measurement indicated that the bursty radiation is only observed on channels near but a little away outward from the q = 1 magnetic surface. In conjunction with the soft x-ray tomography analysis, it was determined that, for the first time, only a compression process survives in the later stage of fast magnetic reconnection but before prompt heat transport. The compression enhanced the electron radiation temperature, the increased amplitude of which agreed well with the estimation according to a kinetic compression theory model [R. J. Hastie and T. C. Hender, Nucl. Fusion 28, 585 (1988)]. This paper presents the experimental evidence that there indeed exists a transient compression phase which results in the bursty ECE radiation during a sawtooth crash.

  20. Understanding the bursty electron cyclotron emission during a sawtooth crash in the HT-7 tokamak

    Science.gov (United States)

    Li, Erzhong; Hu, Liqun; Chen, Kaiyun

    2014-01-01

    Bursts in electron cyclotron emission (ECE) were observed during sawtooth crashes in HT-7 in discharges with ion cyclotron resonance heating injected near the q = 1 rational surface (q is the safety factor). The local ECE measurement indicated that the bursty radiation is only observed on channels near but a little away outward from the q = 1 magnetic surface. In conjunction with the soft x-ray tomography analysis, it was determined that, for the first time, only a compression process survives in the later stage of fast magnetic reconnection but before prompt heat transport. The compression enhanced the electron radiation temperature, the increased amplitude of which agreed well with the estimation according to a kinetic compression theory model [R. J. Hastie and T. C. Hender, Nucl. Fusion 28, 585 (1988)]. This paper presents the experimental evidence that there indeed exists a transient compression phase which results in the bursty ECE radiation during a sawtooth crash.

  1. Effects of sawtooth crashes on beam ions and fusion product tritons in JET

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, F.B.; Hone, M.A.; Jarvis, O.N.; Loughlin, M.J.; Sadler, G. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Adams, J.M.; Bond, D.S.; Watkins, N. [UKAEA Harwell Lab. (United Kingdom). Energy Technology Div.; Howarth, P.J.A. [Birmingham Univ. (United Kingdom)

    1994-07-01

    The effect of a sawtooth crash on the radial distribution of the slowing down fusion product tritons and on beams ions, is examined with measurements of the 2.5 MeV and 14 MeV neutron emission line-integrals before and after sawtooth crashes. In deuterium discharges, the 14 MeV neutron production was wholly attributable to burnup of the 1 MeV fusion product tritons from d-d fusion. The local emissivity of 14 MeV neutrons, and hence of the profile of thermalizing tritons, is shown to be only weakly affected by crashes in the discharges studied. This is in contradiction with the apparent behaviour of injected beam ions as deduced from a study of the considerable changes in local emissivity of the 2.5 MeV neutrons. Nevertheless, the behaviour of the fusion product tritons is consistent with the scaling of the beam injected deuterium. 1 ref., 6 figs.

  2. A general method for propagation of the phase space distribution, with application to the saw-tooth instability

    Energy Technology Data Exchange (ETDEWEB)

    Warnock, R.L.

    2000-03-15

    The authors propose and illustrate a general numerical method to follow the probability distribution in phase space as a function of time. It applies to any multiparticle system governed by Liouville, Vlasov or Vlasov-Fokker-Planck dynamics. The technique, based on discretization of the local Perron-Frobenius operator, is simple in concept, easy to implement, and numerically stable in examples studied to date. The authors illustrate by treating longitudinal dynamics in electron storage rings with realistic wake field. Applied to the SLC damping rings, the method gives the observed current threshold for bunch lengthening, and several aspects of observed behavior above threshold, including the presence of a bursting or sawtooth mode. In contrast to previous particle-in-cell simulations, the authors have very low numerical noise and the ability to follow the motion over several damping times. The method has also been applied to the coherent beam-beam interaction. It appears likely that this approach will be of interest for some of the central problems of this workshop, for instance matching of space-charge dominated beams to a focusing channel, and coherent synchrotron radiation with self-consistent charge/current density.

  3. Estimating limits for the geothermal energy potential of abandoned underground coal mines: A simple methodology

    OpenAIRE

    Rafael Rodríguez Díez; María B. Díaz-Aguado

    2014-01-01

    Flooded mine workings have good potential as low-enthalpy geothermal resources, which could be used for heating and cooling purposes, thus making use of the mines long after mining activity itself ceases. It would be useful to estimate the scale of the geothermal potential represented by abandoned and flooded underground mines in Europe. From a few practical considerations, a procedure has been developed for assessing the geothermal energy potential of abandoned underground coal mines, as we...

  4. Snake River Sockeye Salmon Sawtooth Valley Project Conservation and Rebuilding Program : Supplemental Fnal Environmental Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1995-03-01

    This document announces Bonneville Power Administration`s (BPA) proposal to fund three separate but interrelated actions which are integral components of the overall Sawtooth Valley Project to conserve and rebuild the Snake River Sockeye salmon run in the Sawtooth Valley of south-central Idaho. The three actions are as follows: (1) removing a rough fish barrier dam on Pettit Lake Creek and constructing a weir and trapping facilities to monitor future sockeye salmon adult and smolt migration into and out of Pettit Lake; (2) artificially fertilizing Readfish Lake to enhance the food supply for Snake River sockeye salmon juveniles released into the lake; and (3) trapping kokanee fry and adults to monitor the fry population and to reduce the population of kokanee in Redfish Lake. BPA has prepared a supplemental EA (included) which builds on an EA compled in 1994 on the Sawtooth Valley Project. Based on the analysis in this Supplemental EA, BPA has determined that the proposed actions are not major Federal actions significantly affecting the quality of the human environment. Therefore an Environmental Impact Statement is not required.

  5. Magnetic flux pumping mechanism prevents sawtoothing in 3D nonlinear MHD simulations of tokamak plasmas

    Science.gov (United States)

    Krebs, Isabel; Jardin, Stephen C.; Guenter, Sibylle; Lackner, Karl; Hoelzl, Matthias; Strumberger, Erika; Ferraro, Nate

    2017-10-01

    3D nonlinear MHD simulations of tokamak plasmas have been performed in toroidal geometry by means of the high-order finite element code M3D-C1. The simulations are set up such that the safety factor on axis (q0) is driven towards values below unity. As reported in and the resulting asymptotic states either exhibit sawtooth-like reconnection cycling or they are sawtooth-free. In the latter cases, a self-regulating magnetic flux pumping mechanism, mainly provided by a saturated quasi-interchange instability via a dynamo effect, redistributes the central current density so that the central safety factor profile is flat and q0 1 . Sawtoothing is prevented if β is sufficiently high to allow for the necessary amount of flux pumping to counterbalance the tendency of the current density profile to centrally peak. We present the results of 3D nonlinear simulations based on specific types of experimental discharges and analyze their asymptotic behavior. A set of cases is presented where aspects of the current ramp-up phase of Hybrid ASDEX Upgrade discharges are mimicked. Another set of simulations is based on low-qedge discharges in DIII-D.

  6. Evolution of the central safety factor during stabilized sawtooth instabilities at KSTAR

    Science.gov (United States)

    Messmer, M. C. C.; Ko, J.; Chung, J.; Woo, M. H.; Lee, K.-D.; Jaspers, R. J. E.

    2018-01-01

    A motional Stark effect (MSE) diagnostic has recently been installed in the KSTAR tokamak. A difficulty faced at KSTAR and common to other MSE diagnostics is calibration of the system for absolute measurements. In this report we present our novel calibration routine and discuss first results, evaluating the evolution of the the central safety factor during sawtooth instabilities. The calibration scheme ensures that the bandpass filters typically used in MSE systems are aligned correctly and identifies and removes systematic offsets present in the measurement. This is verified by comparing the reconstructed safety factor profile against various discharges where the locations of rational q surfaces have been obtained from MHD markers. The calibration is applied to analyse the evolution of q 0 in a shot where the sawteeth are stabilized by neutral beam injection. Within the analysed sawtooth periods q 0 drops below unity during the quiescent phase and relaxes close to or slightly above unity at the sawtooth crash. This finding is in line with the classical Kadomtsev model of full magnetic reconnection and earlier findings at JET.

  7. Estimating Limits for the Geothermal Energy Potential of Abandoned Underground Coal Mines: A Simple Methodology

    National Research Council Canada - National Science Library

    Rafael Rodríguez Díez; María B Díaz-Aguado

    2014-01-01

    .... From a few practical considerations, a procedure has been developed for assessing the geothermal energy potential of abandoned underground coal mines, as well as for quantifying the reduction in CO2...

  8. Estimating Limits for the Geothermal Energy Potential of Abandoned Underground Coal Mines: A Simple Methodology

    Directory of Open Access Journals (Sweden)

    Rafael Rodríguez Díez

    2014-07-01

    Full Text Available Flooded mine workings have good potential as low-enthalpy geothermal resources, which could be used for heating and cooling purposes, thus making use of the mines long after mining activity itself ceases. It would be useful to estimate the scale of the geothermal potential represented by abandoned and flooded underground mines in Europe. From a few practical considerations, a procedure has been developed for assessing the geothermal energy potential of abandoned underground coal mines, as well as for quantifying the reduction in CO2 emissions associated with using the mines instead of conventional heating/cooling technologies. On this basis the authors have been able to estimate that the geothermal energy available from underground coal mines in Europe is on the order of several thousand megawatts thermal. Although this is a gross value, it can be considered a minimum, which in itself vindicates all efforts to investigate harnessing it.

  9. A simple electrochemical method for the rapid estimation of antioxidant potentials of some selected medicinal plants.

    Science.gov (United States)

    Amidi, Salimeh; Mojab, Faraz; Bayandori Moghaddam, Abdolmajid; Tabib, Kimia; Kobarfard, Farzad

    2012-01-01

    Clinical and Epidemiological studies have shown that a diet rich in fruits and vegetables is associated with a decreased risk of cardiovascular diseases, cancers and other related disorders. These beneficial health effects have been attributed in part to the presence of antioxidants in dietary plants. Therefore screening for antioxidant properties of plant extracts has been one of the interests of scientists in this field. Different screening methods have been reported for the evaluation of antioxidant properties of plant extracts in the literature. In the present research a rapid screening method has been introduced based on cyclic voltammetry for antioxidant screening of some selected medicinal plant extracts. CYCLIC VOLTAMMETRY OF METHANOLIC EXTRACTS OF SEVEN MEDICINAL PLANTS: Buxus hyrcana, Rumex crispus, Achillea millefolium, Zataria multiflora, Ginkgo biloba, Lippia citriodora and Heptaptera anisoptera was carried out at different scan rates. Based on the interpretation of voltammograms, Rumex crispus, Achillea millefolium and Ginkgo biloba showed higher antioxidant capability than the others while Lippia citriodora contained the highest amount of antioxidants. Cyclic voltammetry is expected to be a simple method for screening antioxidants and estimating the antioxidant activity of foods and medicinal plants.

  10. Complexation Effect on Redox Potential of Iron(III)-Iron(II) Couple: A Simple Potentiometric Experiment

    Science.gov (United States)

    Rizvi, Masood Ahmad; Syed, Raashid Maqsood; Khan, Badruddin

    2011-01-01

    A titration curve with multiple inflection points results when a mixture of two or more reducing agents with sufficiently different reduction potentials are titrated. In this experiment iron(II) complexes are combined into a mixture of reducing agents and are oxidized to the corresponding iron(III) complexes. As all of the complexes involve the…

  11. Potential rapid and simple lateral flow assay for Escherichia coli O111.

    Science.gov (United States)

    Terao, Yoshitaka; Yonekita, Taro; Morishita, Naoki; Fujimura, Tatsuya; Matsumoto, Takashi; Morimatsu, Fumiki

    2013-05-01

    We developed and evaluated a lateral flow assay (LFA) as a simple and rapid method for direct detection of Escherichia coli O111 in food after enrichment. When cell suspensions of 8 E. coli O111 strains and 77 non-E. coli O111 strains were tested with the LFA, the former all yielded positive results and the latter all yielded negative results. The minimum detection limits for the E. coli O111 strains were 1.8 × 10(3) to 5.6 × 10(5) CFU/ml of cell suspension, and the LFA was able to detect live cultures or those killed by autoclaving at nearly the same level of sensitivity. To evaluate the ability of LFA to detect its target in food, enrichment cultures of meat samples inoculated with 10-fold serial dilutions of E. coli O111 were tested with the LFA and PCR. Even when there were very few E. coli O111 cells in the meat samples (1.6 × 10(0) to 1.6 × 10(1) CFU/25 g of food), when they were cultured in modified E. coli broth with novobiocin for 22 h at 42°C, the LFA yielded positive results that corresponded to the PCR results. Although the LFA requires further evaluation and field study, these results suggest that this assay has sufficient sensitivity and specificity. This procedure can be completed with a one-step incubation after the test strip has been inserted into the sample after 22 h of culture, whereas the standard culture method requires multiple cultures, skilled personnel, a well-equipped laboratory, and 4 or 5 days. The speed and simplicity of this LFA make it suitable for use as part of routine screening assays in the food industry.

  12. Waveform Similarity Analysis: A Simple Template Comparing Approach for Detecting and Quantifying Noisy Evoked Compound Action Potentials.

    Directory of Open Access Journals (Sweden)

    Jason Robert Potas

    Full Text Available Experimental electrophysiological assessment of evoked responses from regenerating nerves is challenging due to the typical complex response of events dispersed over various latencies and poor signal-to-noise ratio. Our objective was to automate the detection of compound action potential events and derive their latencies and magnitudes using a simple cross-correlation template comparison approach. For this, we developed an algorithm called Waveform Similarity Analysis. To test the algorithm, challenging signals were generated in vivo by stimulating sural and sciatic nerves, whilst recording evoked potentials at the sciatic nerve and tibialis anterior muscle, respectively, in animals recovering from sciatic nerve transection. Our template for the algorithm was generated based on responses evoked from the intact side. We also simulated noisy signals and examined the output of the Waveform Similarity Analysis algorithm with imperfect templates. Signals were detected and quantified using Waveform Similarity Analysis, which was compared to event detection, latency and magnitude measurements of the same signals performed by a trained observer, a process we called Trained Eye Analysis. The Waveform Similarity Analysis algorithm could successfully detect and quantify simple or complex responses from nerve and muscle compound action potentials of intact or regenerated nerves. Incorrectly specifying the template outperformed Trained Eye Analysis for predicting signal amplitude, but produced consistent latency errors for the simulated signals examined. Compared to the trained eye, Waveform Similarity Analysis is automatic, objective, does not rely on the observer to identify and/or measure peaks, and can detect small clustered events even when signal-to-noise ratio is poor. Waveform Similarity Analysis provides a simple, reliable and convenient approach to quantify latencies and magnitudes of complex waveforms and therefore serves as a useful tool for

  13. Electronic Cigarettes and Indoor Air Quality: A Simple Approach to Modeling Potential Bystander Exposures to Nicotine

    Directory of Open Access Journals (Sweden)

    Stéphane Colard

    2014-12-01

    Full Text Available There has been rapid growth in the use of electronic cigarettes (“vaping” in Europe, North America and elsewhere. With such increased prevalence, there is currently a debate on whether the aerosol exhaled following the use of e-cigarettes has implications for the quality of air breathed by bystanders. Conducting chemical analysis of the indoor environment can be costly and resource intensive, limiting the number of studies which can be conducted. However, this can be modelled reasonably accurately based on empirical emissions data and using some basic assumptions. Here, we present a simplified model, based on physical principles, which considers aerosol propagation, dilution and extraction to determine the potential contribution of a single puff from an e-cigarette to indoor air. From this, it was then possible to simulate the cumulative effect of vaping over time. The model was applied to a virtual, but plausible, scenario considering an e-cigarette user and a non-user working in the same office space. The model was also used to reproduce published experimental studies and showed good agreement with the published values of indoor air nicotine concentration. With some additional refinements, such an approach may be a cost-effective and rapid way of assessing the potential exposure of bystanders to exhaled e-cigarette aerosol constituents.

  14. Electronic cigarettes and indoor air quality: a simple approach to modeling potential bystander exposures to nicotine.

    Science.gov (United States)

    Colard, Stéphane; O'Connell, Grant; Verron, Thomas; Cahours, Xavier; Pritchard, John D

    2014-12-24

    There has been rapid growth in the use of electronic cigarettes ("vaping") in Europe, North America and elsewhere. With such increased prevalence, there is currently a debate on whether the aerosol exhaled following the use of e-cigarettes has implications for the quality of air breathed by bystanders. Conducting chemical analysis of the indoor environment can be costly and resource intensive, limiting the number of studies which can be conducted. However, this can be modelled reasonably accurately based on empirical emissions data and using some basic assumptions. Here, we present a simplified model, based on physical principles, which considers aerosol propagation, dilution and extraction to determine the potential contribution of a single puff from an e-cigarette to indoor air. From this, it was then possible to simulate the cumulative effect of vaping over time. The model was applied to a virtual, but plausible, scenario considering an e-cigarette user and a non-user working in the same office space. The model was also used to reproduce published experimental studies and showed good agreement with the published values of indoor air nicotine concentration. With some additional refinements, such an approach may be a cost-effective and rapid way of assessing the potential exposure of bystanders to exhaled e-cigarette aerosol constituents.

  15. Electronic Cigarettes and Indoor Air Quality: A Simple Approach to Modeling Potential Bystander Exposures to Nicotine

    Science.gov (United States)

    Colard, Stéphane; O’Connell, Grant; Verron, Thomas; Cahours, Xavier; Pritchard, John D.

    2014-01-01

    There has been rapid growth in the use of electronic cigarettes (“vaping”) in Europe, North America and elsewhere. With such increased prevalence, there is currently a debate on whether the aerosol exhaled following the use of e-cigarettes has implications for the quality of air breathed by bystanders. Conducting chemical analysis of the indoor environment can be costly and resource intensive, limiting the number of studies which can be conducted. However, this can be modelled reasonably accurately based on empirical emissions data and using some basic assumptions. Here, we present a simplified model, based on physical principles, which considers aerosol propagation, dilution and extraction to determine the potential contribution of a single puff from an e-cigarette to indoor air. From this, it was then possible to simulate the cumulative effect of vaping over time. The model was applied to a virtual, but plausible, scenario considering an e-cigarette user and a non-user working in the same office space. The model was also used to reproduce published experimental studies and showed good agreement with the published values of indoor air nicotine concentration. With some additional refinements, such an approach may be a cost-effective and rapid way of assessing the potential exposure of bystanders to exhaled e-cigarette aerosol constituents. PMID:25547398

  16. A simple method of equine limb force vector analysis and its potential applications

    Directory of Open Access Journals (Sweden)

    Sarah Jane Hobbs

    2018-02-01

    Full Text Available Background Ground reaction forces (GRF measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of evaluating functional (asymmetry within horses. Methods GRF and kinematic data were collected from 10 horses trotting over a series of four force plates (120 Hz. The kinematic data were used to determine clean hoof contacts. The stance phase of each hoof was determined using a 50 N threshold. Vertical and longitudinal GRF for each stance phase were plotted both as force-time curves and as force vector diagrams in which vectors originating at the centre of pressure on the force plate were drawn at intervals of 8.3 ms for the duration of stance. Visual evaluation was facilitated by overlay of the vector diagrams for different limbs. Summary vectors representing the magnitude (VecMag and direction (VecAng of the mean force over the entire stance phase were superimposed on the force vector diagram. Typical measurements extracted from the force-time curves (peak forces, impulses were compared with VecMag and VecAng using partial correlation (controlling for speed. Paired samples t-tests (left v. right diagonal pair comparison and high v. low vertical force diagonal pair comparison were performed on discrete and vector variables using traditional methods and Hotelling’s T2 tests on normalized stance phase data using SPM. Results Evidence from traditional statistical tests suggested that VecMag is more influenced by the vertical force and impulse, whereas

  17. Novel Pyrochlorelike Crystal with a Photonic Band Gap Self-Assembled Using Colloids with a Simple Interaction Potential

    Science.gov (United States)

    Pattabhiraman, Harini; Avvisati, Guido; Dijkstra, Marjolein

    2017-10-01

    Using computer simulations, we investigate the phase behavior of a system of particles interacting with a remarkably simple repulsive square-shoulder pair potential and report the formation of a novel (and stable) pyrochlorelike crystal phase. The lattice structure of the pyrochlorelike phase formed in our simulations possesses two inherent length scales corresponding to the inter- and intratetrahedral neighbors. We show that it can be used to fabricate a photonic crystal which displays complete photonic band gaps in both the direct and inverted dielectric structures.

  18. High-energy X-ray optics with silicon saw-tooth refractive lenses.

    Science.gov (United States)

    Shastri, S D; Almer, J; Ribbing, C; Cederström, B

    2007-03-01

    Silicon saw-tooth refractive lenses have been in successful use for vertical focusing and collimation of high-energy X-rays (50-100 keV) at the 1-ID undulator beamline of the Advanced Photon Source. In addition to presenting an effectively parabolic thickness profile, as required for aberration-free refractive optics, these devices allow high transmission and continuous tunability in photon energy and focal length. Furthermore, the use of a single-crystal material (i.e. Si) minimizes small-angle scattering background. The focusing performance of such saw-tooth lenses, used in conjunction with the 1-ID beamline's bent double-Laue monochromator, is presented for both short ( approximately 1:0.02) and long ( approximately 1:0.6) focal-length geometries, giving line-foci in the 2 microm-25 microm width range with 81 keV X-rays. In addition, a compound focusing scheme was tested whereby the radiation intercepted by a distant short-focal-length lens is increased by having it receive a collimated beam from a nearer (upstream) lens. The collimation capabilities of Si saw-tooth lenses are also exploited to deliver enhanced throughput of a subsequently placed small-angular-acceptance high-energy-resolution post-monochromator in the 50-80 keV range. The successful use of such lenses in all these configurations establishes an important detail, that the pre-monochromator, despite being comprised of vertically reflecting bent Laue geometry crystals, can be brilliance-preserving to a very high degree.

  19. Dirac fermion reflector by ballistic graphene sawtooth-shaped npn junctions

    OpenAIRE

    Morikawa, Sei; wilmart, quentin; Masubuchi, Satoru; Watanabe, Kenji; Taniguchi, Takashi; Plaçais, Bernard; Machida, Tomoki

    2017-01-01

    We have realized a Dirac fermion reflector in graphene by controlling the ballistic carrier trajectory in a sawtooth-shaped npn junction. When the carrier density in the inner p-region is much larger than that in the outer n-regions, the first straight np interface works as a collimator and the collimated ballistic carriers can be totally reflected at the second zigzag pn interface. We observed clear resistance enhancement around the np+n regime, which is in good agreement with the numerical ...

  20. Categories of Externally Triggered Substorms: Applications to Observable Plasma Sheet Dynamics and Sawtooth Events

    Science.gov (United States)

    Lyons, L. R.; Lee, D.; Zou, S.; Wand, C.; Mende, S. B.

    2005-12-01

    Identification of the different types of external substorm triggers and the differing magnetospheric responses to each type reveal fundamental aspects of the physical processes responsible for the substorm expansion phase. Both IMF changes leading to a reduction of magnetospheric convection and solar wind dynamic pressure increases (following prolonged strongly southward IMF) are found to trigger substorms. Important and observable differences in the plasma sheet and auroral response to these two different substorm triggers can be identified. Furthermore, the interplay between effects of IMF and dynamic pressure changes is found to be important, which, for example, can lead to a cancellation of effects and to "null" events. These results indicate that external substorm triggering works by causing an abrupt reduction in the strength of convection in the inner plasma sheet following a growth phase of enhanced convection. This is a fundamental condition that must be accounted for by any substorm model. Sawtooth events are ideal for evaluating the effects of external substorm triggers because they consist of large and clearly identifiable substorm expansions, and it is demonstrated that the large-majority of sawtooth expansions reflect IMF and dynamic pressure substorm triggers, both acting individually and together.

  1. Sawtooth period changes with mode conversion current drive on Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Parisot, A; Wukitch, S J; Bonoli, P; Greenwald, M; Hubbard, A; Lin, Y; Parker, R; Porkolab, M; Ram, A K; Wright, J C [Plasma Science and Fusion Center, MIT, Cambridge, MA 02139 (United States)

    2007-03-15

    Significant changes in the sawtooth period have been observed on the Alcator C-Mod tokamak during phased ion cyclotron range of frequencies (ICRF) operation in the mode conversion regime. As the mode conversion layer was swept outwards through the q = 1 surface in D({sup 3}He) plasmas, the sawtooth period was found to increase and then decrease for counter-current drive phasing. For co-current drive and heating phasings, it was observed to decrease and then increase. With 2 MW ICRF power, the period varied from 3 to 12 ms. The observed evolution is consistent with localized current drive by mode converted waves in the vicinity of the q = 1 surface. Simulations with the full wave code TORIC indicate that the electron heating and current drive are due to mode converted ion cyclotron waves. The observed evolution for symmetric (heating) phasing is difficult to attribute to localized heating, since temperature profile stiffness prohibits large changes in the resistivity gradient at the q = 1 surface. An alternative explanation is found in TORIC simulations, which predict co-current drive for symmetric phasing due to a strong up-down asymmetry in the ICW wave field.

  2. Potential of simple filters to improve microbial quality of irrigation water used in urban vegetable farming in Ghana

    DEFF Research Database (Denmark)

    Keraita, Bernard; Drechsel, Pay; Konradsen, Flemming

    2008-01-01

    . As part of a larger study on possible interventions for health risk reduction, the potential of simple interventions was explored. Column slow sand filters with three levels of sand depths (0.5 m, 0.75 m and 1 m) and fabric filters made of nylon, cotton and netting were assessed. More than 600 water...... were achieved by fabric filters, with an average removal of 12-62% for helminth eggs and 1 log unit for thermotolerant coliforms. Nylon filters had higher removal rates especially for helminth eggs (58%). Average flow rates for sand filters were 3 m per day and fabric filters had steady flows of about...... samples were analyzed for helminth eggs and thermotolerant coliforms. Flow rates were also measured. From slow sand filters, 71-96% of helminths and 2 log units (from 7 to 5 log units) of thermotolerant coliforms were removed. Sand depths had no significant influence in the removal. Lower removal rates...

  3. It's a dark, dark world: background evolution of interacting phiCDM models beyond simple exponential potentials

    Science.gov (United States)

    Singh, Suprit; Singh, Parminder

    2016-05-01

    We study the background cosmological dynamics with a three component source content: a radiation fluid, a barotropic fluid to mimic the matter sector and a single scalar field which can act as dark energy giving rise to the late-time accelerated phase. Using the well-known dimensionless variables, we cast the dynamical equations into an autonomous system of ordinary differential equations (ASODE), which are studied by computing the fixed points and the conditions for their stability. The matter fluid and the scalar field are taken to be uncoupled at first and later, we consider a coupling between the two of the form Q = √(2/3)κβρṁphi where ρm is the barotropic fluid density. The key point of our analysis is that for the closure of ASODE, we only demand that the jerk, Γ = V V''/V'2 is a function of acceleration, z = -MpV'/V, that is, Γ = 1+f(z). In this way, we are able to accommodate a large class of potentials that goes beyond the simple exponential potentials. The analysis is completely generic and independent of the form of the potential for the scalar field. As an illustration and confirmation of the analysis, we consider f(z) of the forms μ/z2, μ/z, (μ-z)/z2 and (μ-z) to numerically compute the evolution of cosmological parameters with and without coupling. Implications of the approach and the results are discussed.

  4. Simple Machines Made Simple.

    Science.gov (United States)

    St. Andre, Ralph E.

    Simple machines have become a lost point of study in elementary schools as teachers continue to have more material to cover. This manual provides hands-on, cooperative learning activities for grades three through eight concerning the six simple machines: wheel and axle, inclined plane, screw, pulley, wedge, and lever. Most activities can be…

  5. A Simple and Inexpensive Method for Evaluating the Photovoltaic Potential: Its Validation in Buenos Aires and Antarctica

    Directory of Open Access Journals (Sweden)

    Marcelo D. Cabezas

    2016-01-01

    Full Text Available The use of renewable energies requires a precise and detailed quantification of the resource available. Because of the cost of solar stations or limited availability of skilled human resources, in most emerging countries, this assessment is made only on a few points scattered over large areas. We report here a simple and inexpensive method to evaluate the photovoltaic (PV potential for a specific geographic region and a given PV capture technology. The system allows for a direct evaluation of the energy actually obtainable by scaling the measurement array of photovoltaic cells. The proposed measurement system can be installed as a stand-alone unit, or as part of a measurement network, connected to a more sophisticated central hub. The measurement station consists of said PV array (or similar PV array, a resistor, and a portable data logger. The system is calibrated with a device composed of a small array of PV cells, a resistor load bank, and two multimeters. Due to its low cost, this system can be replicated as many times as required with minimal investment. This would make it possible to evaluate the available photovoltaic potential of large regions with accurate and detailed data. Measurements carried out in Buenos Aires and in Antarctica confirm the consistency of the method.

  6. Local properties of magnetic reconnection in nonlinear resistive- and extended-magnetohydrodynamic toroidal simulations of the sawtooth crash

    Science.gov (United States)

    Beidler, M. T.; Cassak, P. A.; Jardin, S. C.; Ferraro, N. M.

    2017-02-01

    We diagnose local properties of magnetic reconnection during a sawtooth crash employing the three-dimensional toroidal, extended-magnetohydrodynamic (MHD) code M3D-C1. To do so, we sample simulation data in the plane in which reconnection occurs, the plane perpendicular to the helical (m,n)=(1,1) mode at the q = 1 surface, where m and n are the poloidal and toroidal mode numbers and q is the safety factor. We study the nonlinear evolution of a particular test equilibrium in a non-reduced field representation using both resistive-MHD and extended-MHD models. We find growth rates for the extended-MHD reconnection process exhibit a nonlinear acceleration and greatly exceed that of the resistive-MHD model, as is expected from previous experimental, theoretical, and computational work. We compare the properties of reconnection in the two simulations, revealing the reconnecting current sheets are locally different in the two models and we present the first observation of the quadrupole out-of-plane Hall magnetic field that appears during extended-MHD reconnection in a 3D toroidal simulation (but not in resistive-MHD). We also explore the dependence on toroidal angle of the properties of reconnection as viewed in the plane perpendicular to the helical magnetic field, finding qualitative and quantitative effects due to changes in the symmetry of the reconnection process. This study is potentially important for a wide range of magnetically confined fusion applications, from confirming simulations with extended-MHD effects are sufficiently resolved to describe reconnection, to quantifying local reconnection rates for purposes of understanding and predicting transport, not only at the q = 1 rational surface for sawteeth, but also at higher order rational surfaces that play a role in disruptions and edge-confinement degradation.

  7. Saw-tooth instability studies at the Stanford Linear Collider damping rings

    Energy Technology Data Exchange (ETDEWEB)

    Podobedov, B.

    1999-12-14

    Saw-tooth instability occurs during high current operation in the Stanford Linear Collider (SLC) damping rings. This instability is single bunch, and it can be cast as a longitudinal microwave instability. It is caused by the beam interaction with short range wakefields in the ring vacuum chamber. The saw-tooth instability manifests itself in the periodic blow-up in quadruple or higher moments in the longitudinal beam distribution. Most of the instability studies have been experimental. Since the measurements of coherent particle motion within a short ultrarelativistic beam are largely unconventional the authors had to develop some original diagnostics. These includes, for example, the down-conversion of the high frequency ({approximately}10 GHz) broad-band beam position monitor (BPM) signals. The authors have also employed a state-of-the-art Hamamatsu streak camera that is capable of resolving the longitudinal beam distribution with sub-picosecond accuracy. As a result of the streak camera experiments the authors have quantitatively described the phase space of unstable bunches. The authors have found the radial structure of the instability mode and established that it only displaces a few percent of the beam particles. In another series of experiments the authors have correlated the instability signals from the beams before the extraction from the damping rings with their trajectories in the linac downstream. This showed that the instability results in a significant transverse beam jitter in the linac which compromises the damping ring performance as an injector. In addition, the authors have studied the instability behavior under the broad range of stored beam parameters using both passive observation and driven excitation. These measurements revealed unexpected beam behavior significantly above the instability threshold. Finally, the authors performed several low current experiments to estimate the damping ring vacuum chamber impedance.

  8. Alcohol and liver disease in Europe--Simple measures have the potential to prevent tens of thousands of premature deaths.

    Science.gov (United States)

    Sheron, Nick

    2016-04-01

    In the World Health Organisation European Region, more than 2,370,000 years of life are lost from liver disease before the age of 50; more than lung cancer, trachea, bronchus, oesophageal, stomach, colon, rectum and pancreatic cancer combined. Between 60-80% of these deaths are alcohol related, a disease for which no pharmaceutical therapy has yet been shown to improve long-term survival. The toxicity of alcohol is dose related at an individual level, and is dose related at a population level; overall liver mortality is largely determined by population alcohol consumption. Trends in alcohol consumption correlate closely with trends in overall liver mortality, with 3-5-fold decreases or increases in liver mortality in different European countries over the last few decades. The evidence base for alcohol control measures aimed at reducing population alcohol consumption has been subjected to rigorous evaluation; most recently by the Organisation for Economic Co-Operation and Development (OECD). Effective alcohol policy measures reduce alcohol mortality, including mortality from liver disease. The most effective and cost effective measures have been summarised by the OECD and the World Health Organisation: regular incremental above inflation tax increases, a minimum price for alcohol, effective protection of children from alcohol marketing and low level interventions from clinicians. Simple, cheap and effective changes to alcohol policy by European Institutions and member states have the potential to dramatically reduce liver mortality in Europe. Copyright © 2016. Published by Elsevier B.V.

  9. Bioreduction potentials of dried root of Zingiber officinale for a simple green synthesis of silver nanoparticles: Antibacterial studies.

    Science.gov (United States)

    Judith Vijaya, J; Jayaprakash, N; Kombaiah, K; Kaviyarasu, K; John Kennedy, L; Jothi Ramalingam, R; Al-Lohedan, Hamad A; V M, Mansoor-Ali; Maaza, M

    2017-12-01

    Green synthesis of silver nanoparticles (Ag NPs) using an extract of dried Zingiber officinale (ginger) root as a reducing and capping agent in the presence of microwave irradiation was herein reported for the first time. The formation of symmetrical spheres is confirmed from the UV-Visible spectrum of Ag NPs. Fourier transform infra-red spectroscopy confirms the formation of the Ag NPs. X-ray diffraction analysis was utilized to calculate the crystallite size of Ag NPs and the value was found to be 10nm. High-resolution transmission electron microscopy and high-resolution scanning electron microscopy were used to investigate the morphology and size of the synthesized samples. The sphere like morphology is confirmed from the images. The purity and crystallinity of Ag NPs is confirmed by energy-dispersive X-Ray analysis and selected area electron diffraction respectively. The electrochemical behavior of the synthesized Ag NPs was assessed by cyclic voltammetry (CV) and shows the redox peaks in the potential range of -1.1 to +1.1V. Agar diffusion method is used to examine the antibacterial activity of Ag NPs. For this purpose, two gram positive and two gram negative bacteria were studied. This single step approach was found to be simple, short time, cost-effective, reproducible, and eco-friendly. Copyright © 2017. Published by Elsevier B.V.

  10. Saw-tooth instability studies at the Stanford Linear Collider damping rings

    Science.gov (United States)

    Podobedov, Boris Vyacheslavovich

    2000-08-01

    Saw-tooth instability occurs during high current operation in the Stanford Linear Collider (SLC) damping rings. This instability is single bunch and it can be cast as a longitudinal microwave instability. It is caused by the beam interaction with short range wakefields in the ring vacuum chamber. The saw-tooth instability manifests itself in the periodic blowup in quadrupole or higher moments in the longitudinal beam distribution. Most of our instability studies have been experimental. Since the measurements of coherent particle motion within a short ultrarelativistic beam are largely unconventional we had to develop some original diagnostics. These includes, for example, the down-conversion of the high frequency (10 GHz) broad-band beam position monitor (BPM) signals. We have also employed the state-of the art Hamamatsu streak camera that is capable of resolving the longitudinal beam distribution with sub-picosecond accuracy. As a result of our streak camera experiments we have quantitatively described the phase space of unstable bunches. We have found the radial structure of the instability mode and established that it only displaces a few percent of the beam particles. In another series of experiments we have correlated the instability signals from the beams before the extraction from the damping rings with their trajectories in the linac downstream. This showed that the instability results in a significant transverse beam jitter in the linac which compromises the damping ring performance as an injector. In addition, we have studied the instability behavior under the broad range of stored beam parameters using both passive and driven excitation. These measurements revealed unexpected beam behavior significantly above the instability threshold. Finally we performed several low current experiments to estimate the damping ring vacuum chamber impedance. We also present some analytical results regarding the instability and compare them to the observations. In

  11. Enhanced boiling in microchannels due to recirculation induced by repeated saw-toothed cross-sectional geometry

    Science.gov (United States)

    Gao, Le; Bhavnani, Sushil H.

    2017-10-01

    A saw-toothed shaped microchannel heat sink is investigated for enhancing flow boiling heat transfer. Tests are conducted at mass fluxes of 444-1776 kg/m2 s and an inlet subcooling of 15 °C. The effects of channel geometry on boiling curves, flow patterns, pressure drops, and heat transfer coefficient are discussed in this letter. It is found that heat transfer performance is enhanced by up to 50% especially at heat flux levels associated with the current generation of microprocessors.

  12. Development, characterization, and annotation of potential simple sequence repeats by transcriptome sequencing in pears (Pyrus pyrifolia Nakai).

    Science.gov (United States)

    Zhou, H; Cai, B H; Lü, Z Q; Gao, Z H; Qiao, Y S

    2016-09-23

    Simple sequence repeats (SSRs), one of the most powerful molecular markers, can be used for DNA fingerprinting, variety identification, genetic mapping, and marker-assisted selection. Using the pear's (Pyrus pyrifolia Nakai) 75,764 unigenes (55,676,271 bp) obtained by deep transcriptome sequencing, a total of 10,622 novel SSRs were identified in 9154 unigenes, accounting for 14.02% of all unigenes. The average length and distribution of these SSRs was about 16 bp and 5.24 kb, respectively. Dinucleotide repeat motifs were the main type, with a frequency of 55.87%, followed by trinucleotides (24.45%). There were 159 kinds of repeat motifs existing in the pear transcriptome. AG/CT was the most frequent motif, accounting for 49.64%. All 9154 SSR-containing unigenes were functionally annotated using Nr (NCBI non-redundant protein database), Nt (NCBI non-redundant nucleotide database), and the Swiss-Prot database, and were classified further by Gene Ontology and Clusters of Orthologous Groups. In addition, a total of 4300 primer pairs were designed from all SSR loci obtained. Of these, 40 primers were randomly selected for PCR amplification and polyacrylamide gel (PAGE) analysis. Among the 40 primer pairs, 31 were successfully separated via PAGE. These findings also confirm that mining SSRs using next-generating sequencing technologies is a fast, effective, and reliable approach.

  13. Entropic potential field formed for a linear-motor protein near a filament: Statistical-mechanical analyses using simple models.

    Science.gov (United States)

    Amano, Ken-Ichi; Yoshidome, Takashi; Iwaki, Mitsuhiro; Suzuki, Makoto; Kinoshita, Masahiro

    2010-07-28

    We report a new progress in elucidating the mechanism of the unidirectional movement of a linear-motor protein (e.g., myosin) along a filament (e.g., F-actin). The basic concept emphasized here is that a potential field is entropically formed for the protein on the filament immersed in solvent due to the effect of the translational displacement of solvent molecules. The entropic potential field is strongly dependent on geometric features of the protein and the filament, their overall shapes as well as details of the polyatomic structures. The features and the corresponding field are judiciously adjusted by the binding of adenosine triphosphate (ATP) to the protein, hydrolysis of ATP into adenosine diphosphate (ADP)+Pi, and release of Pi and ADP. As the first step, we propose the following physical picture: The potential field formed along the filament for the protein without the binding of ATP or ADP+Pi to it is largely different from that for the protein with the binding, and the directed movement is realized by repeated switches from one of the fields to the other. To illustrate the picture, we analyze the spatial distribution of the entropic potential between a large solute and a large body using the three-dimensional integral equation theory. The solute is modeled as a large hard sphere. Two model filaments are considered as the body: model 1 is a set of one-dimensionally connected large hard spheres and model 2 is a double helical structure formed by two sets of connected large hard spheres. The solute and the filament are immersed in small hard spheres forming the solvent. The major findings are as follows. The solute is strongly confined within a narrow space in contact with the filament. Within the space there are locations with sharply deep local potential minima along the filament, and the distance between two adjacent locations is equal to the diameter of the large spheres constituting the filament. The potential minima form a ringlike domain in model 1

  14. Sawtooth waves during REM sleep after administration of haloperidol combined with total sleep deprivation in healthy young subjects

    Directory of Open Access Journals (Sweden)

    L.R. Pinto Jr.

    2002-05-01

    Full Text Available We sought to examine the possible participation of dopaminergic receptors in the phasic events that occur during rapid eye movement (REM sleep, known as sawtooth waves (STW. These phasic phenomena of REM sleep exhibit a unique morphology and, although they represent a characteristic feature of REM sleep, little is known about the mechanisms which generate them and which are apparently different from rapid eye movements. STW behavior was studied in 10 male volunteers aged 20 to 35 years, who were submitted to polysomnographic monitoring (PSG. On the adaptation night they were submitted to the first PSG and on the second night, to the basal PSG. On the third night the volunteers received placebo or haloperidol and spent the whole night awake. On the fourth night they were submitted to the third PSG. After a 15-day rest period, the volunteers returned to the sleep laboratory and, according to a double-blind crossover randomized design, received haloperidol or placebo and spent the whole night awake, after which they were submitted to the fourth PSG. The volunteers who were given haloperidol combined with sleep deprivation exhibited an elevation of the duration and density of the STW, without significant alterations of the other REM sleep phasic phenomena such as rapid eye movement. These findings suggest that sawtooth waves must have their own generating mechanisms and that the dopaminergic receptors must exert a modulating role since REM sleep deprivation, as well as administration of neuroleptics, produces supersensitivity of dopaminergic receptors.

  15. Simple machines

    CERN Document Server

    Graybill, George

    2007-01-01

    Just how simple are simple machines? With our ready-to-use resource, they are simple to teach and easy to learn! Chocked full of information and activities, we begin with a look at force, motion and work, and examples of simple machines in daily life are given. With this background, we move on to different kinds of simple machines including: Levers, Inclined Planes, Wedges, Screws, Pulleys, and Wheels and Axles. An exploration of some compound machines follows, such as the can opener. Our resource is a real time-saver as all the reading passages, student activities are provided. Presented in s

  16. A simple method for fabrication of electrospun fibers with controlled degree of alignment having potential for nerve regeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Vimal, Sunil Kumar; Ahamad, Nadim; Katti, Dhirendra S., E-mail: dsk@iitk.ac.in

    2016-06-01

    In peripheral nerve injuries where direct suturing of nerve endings is not feasible, nerve regeneration has been facilitated through the use of artificially aligned fibrous scaffolds that provide directional growth of neurons to bridge the gap. The degree of fiber alignment is crucial and can impact the directionality of cells in a fibrous scaffold. While there have been multiple approaches that have been used for controlling fiber alignment, however, they have been associated with a compromised control on other properties, such as diameter, morphology, curvature, and topology of fibers. Therefore, the present study demonstrates a modified electrospinning set-up, that enabled fabrication of electrospun fibers with controlled degree of alignment from non-aligned (NA), moderately aligned (MA, 75%) to highly aligned (HA, 95%) sub-micron fibers while keeping other physical properties unchanged. The results demonstrate that the aligned fibers (MA and HA) facilitated directional growth of human astrocytoma cells (U373), wherein the aspect ratio of cells was found to increase with an increase in degree of fibers alignment. In contrast to NA and MA fibers, the HA fibers showed improved contact guidance to U373 cells that was demonstrated by a significantly higher cell aspect ratio and nuclear aspect ratio. In conclusion, the present study demonstrated a modified electrospinning setup to fabricate differentially aligned fibrous scaffolds with the HA fibers showing potential for use in neural tissue engineering. - Highlights: • Modified electrospinning set-up for fabrication of fibers with controlled alignment • Three parameter-based control on the degree of alignment of fibers • The aligned fibers enhanced cell elongation and cell-cell contact. • The aligned fibers show potential for use in nerve regeneration.

  17. Simple Fabrication Process for 2D ZnO Nanowalls and Their Potential Application as a Methane Sensor

    Directory of Open Access Journals (Sweden)

    Zhan-Shuo Hu

    2013-03-01

    Full Text Available Two-dimensional (2D ZnO nanowalls were prepared on a glass substrate by a low-temperature thermal evaporation method, in which the fabrication process did not use a metal catalyst or the pre-deposition of a ZnO seed layer on the substrate. The nanowalls were characterized for their surface morphology, and the structural and optical properties were investigated using scanning electron microscopy (SEM, X-ray diffraction (XRD, transmission electron microscopy (TEM, and photoluminescence (PL. The fabricated ZnO nanowalls have many advantages, such as low growth temperature and good crystal quality, while being fast, low cost, and easy to fabricate. Methane sensor measurements of the ZnO nanowalls show a high sensitivity to methane gas, and rapid response and recovery times. These unique characteristics are attributed to the high surface-to-volume ratio of the ZnO nanowalls. Thus, the ZnO nanowall methane sensor is a potential gas sensor candidate owing to its good performance.

  18. Assessment of Antioxidant Potential of Pomegranate Fruit By-Products via a Direct Approach Using a Simple QUENCHER Method.

    Science.gov (United States)

    2016-04-21

    Fruit and vegetable processing industries produce substantial quantities of phenolic-rich by-products that could be potential sources of natural antioxidants. The measurement of antioxidant activity in plant materials is mostly limited to extraction-based procedures that have several limitations. In this study, a relatively new direct approach, the QUENCHER (quick, easy, new, cheap, and reproducible) procedure was applied to measure total antioxidant capacity in pomegranate fruit by-products, including peel, pith, carpellary membranes, and seeds. Freeze-dried ground samples were directly mixed with free radical solvents in a single operation rather than separating the extract from solid samples. Efficacy of the direct procedure was evaluated against a routine extraction-based procedure using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS); 2,2-diphenyl-1-picrylhydrazyl (DPPH); and ferric reducing antioxidant power assays. Pomegranate peel showed the highest total antioxidant capacity, followed by pith, carpellary membranes, and seeds. Total antioxidant capacity values determined by the direct procedure were significantly higher (P unit extraction operations. The conversion of industrial waste into valuable ingredients would be advantageous for development of pomegranate supplements and added-value products.

  19. Stretch Reflex as a Simple Measure to Evaluate the Efficacy of Potential Flight Countermeasures Using the Bed Rest Environment

    Science.gov (United States)

    Cerisano, J. M.; Reschke, M. F.; Kofman, I. S.; Fisher, E. A.; Harm, D. L.

    2010-01-01

    INTRODUCTION: Spaceflight is acknowledged to have significant effects on the major postural muscles. However, it has been difficult to separate the effects of ascending somatosensory changes caused by the unloading of these muscles during flight from changes in sensorimotor function caused by a descending vestibulo-cerebellar response to microgravity. It is hypothesized that bed rest is an adequate model to investigate postural muscle unloading given that spaceflight and bed rest may produce similar results in both nerve axon and muscle tissue. METHODS: To investigate this hypothesis, stretch reflexes were measured on 18 subjects who spent 60 to 90 days in continuous 6 head-down bed rest. Using a motorized system capable of rotating the foot around the ankle joint (dorsiflexion) through an angle of 10 deg at a peak velocity of approximately 250 deg/sec, a stretch reflex was recorded from the subject's left triceps surae muscle group. Using surface electromyography, about 300 reflex responses were obtained and ensemble-averaged on 3 separate days before bed rest, 3 to 4 times in bed, and 3 times after bed rest. The averaged responses for each test day were examined for reflex latency and conduction velocity (CV) across gender and compared with spaceflight data. RESULTS: Although no gender differences were found, bed rest induced changes in reflex latency and CV similar to the ones observed during spaceflight. Also, a relationship between CV and loss of muscle strength in the lower leg was observed for most bed rest subjects. CONCLUSION: Even though bed rest (limb unloading) alone may not mimic all of the synaptic and muscle tissue loss that is observed as a result of spaceflight, it can serve as a working analog of flight for the evaluation of potential countermeasures that may be beneficial in mitigating unwanted changes in the major postural muscles that are observed post flight.

  20. Staircase and saw-tooth field emission steps from nanopatterned n-type GaSb surfaces

    CERN Document Server

    Kildemo, M.; Le Roy, S.; Søndergård, E.

    2009-01-01

    High resolution field emission experiments from nanopatterned GaSb surfaces consisting of densely packed nanocones prepared by low ion-beam-energy sputtering are presented. Both uncovered and metal-covered nanopatterned surfaces were studied. Surprisingly, the field emission takes place by regular steps in the field emitted current. Depending on the field, the steps are either regular, flat, plateaus, or saw-tooth shaped. To the author’s knowledge, this is the first time that such results have been reported. Each discrete jump in the field emission may be understood in terms of resonant tunneling through an extended surface space charge region in an n-type, high aspect ratio, single GaSb nanocone. The staircase shape may be understood from the spatial distribution of the aspect ratio of the cones.

  1. Energetics of a simple microscopic heat engine.

    Science.gov (United States)

    Asfaw, Mesfin; Bekele, Mulugeta

    2005-11-01

    We model a microscopic heat engine as a particle hopping on a one-dimensional lattice in a periodic sawtooth potential, with or without load, assisted by the thermal kicks it gets from alternately placed hot and cold thermal baths. We find analytic expressions for current and rate of heat flow when the engine operates at steady state. Three regions are identified where the model acts either as a heat engine or as a refrigerator or as neither of the two. At the quasistatic limit both efficiency of the engine and coefficient of performance of the refrigerator go to that for Carnot engine and Carnot refrigerator, respectively. We investigate efficiency of the engine at two operating conditions (at maximum power and at optimum value with respect to energy and time) and compare them with those of the endoreversible and Carnot engines.

  2. Identification of siderophore producing and cynogenic fluorescent Pseudomonas and a simple confrontation assay to identify potential bio-control agent for collar rot of chickpea.

    Science.gov (United States)

    Kotasthane, Anil S; Agrawal, Toshy; Zaidi, Najam Waris; Singh, U S

    2017-06-01

    In soil, plant roots coexist with bacteria and fungi that produce siderophores capable of sequestering the available iron. Microbial cyanogenesis has been demonstrated in many species of fungi and in a few species of bacteria (e.g., Chromobacterium and Pseudomonas). Fluorescent Pseudomonas isolates P29, P59, P144, P166, P174, P187, P191 and P192 were cyanogenic and produced siderophores in the presence of a strong chelater 8-Hydroxyquinoline (50 mg/l). A simple confrontation assay for identifying potential antagonists was developed. Fluorescent Pseudomonas isolates P66, P141, P144, P166 and P174 were antagonistic against both Rhizoctonia solani and Sclerotium rolfsii. Vigorous plant growth was observed following seed bacterization with P141, P200 and P240. In field experiments, seed bacterization with selected bacterial isolates resulted in reduced collar rot (S. rolfsii) incidence.

  3. Estimation of accuracy of an asymptotic solution of the generalized Cauchy problem for the Boussinesq equation as applied to the potential model of tsunami with a "simple" source

    Science.gov (United States)

    Sekerzh-Zen'kovich, S. Ya.

    2017-10-01

    Statement of the hydrodynamic problem in the framework of the potential tsunami model with "simple" source whose solution is chosen as the reference one. Generalized Cauchy problem for the Boussinesq equation and its reduction to the classical one. Analytical solution of the Cauchy problem for the Boussinesq equation. An explanation of the incorrectness of the formulation of the problem. Derivation of an approximate equation for the correct setting of the Cauchy problem. The known reference solution of the problem. An analytical solution of the correct problem and the derivation of its asymptotic representation in the "far zone." Comparison of the graphs of the temporal history of wave height calculated by the formulas of the asymptotic and reference solutions. Estimation of the accuracy of the asymptotic solution by a three-level scale. Discussion. A remark concerning the referees.

  4. Limnology of Sawtooth Lakes - 1995: Effects of winter limnology and lake fertilization on potential production of Snake River sockeye salmon

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, C.; Wurtsbaugh, W.A.; Budy, P.; Steinhart, G.B.; Slater, M.

    1996-05-01

    This Section II of the entire report describes the results of the limnological sampling conducted on Redfish, Altras, Pettit and Stanley Lakes from October 1994 through October 1995. Included are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995, limnological conditions during the spring, summer and fall of 1995, comparison of characteristics among the four lakes; fertilization of Redfish Lake in 1995; effects of fertilization and effects of annual avriations in planktivorous fish abundance. Individual chapters and their subject areas are listed in following abstracts.

  5. Efficacy of simple short-term in vitro assays for predicting the potential of metal oxide nanoparticles to cause pulmonary inflammation.

    Science.gov (United States)

    Lu, Senlin; Duffin, Rodger; Poland, Craig; Daly, Paul; Murphy, Fiona; Drost, Ellen; Macnee, William; Stone, Vicki; Donaldson, Ken

    2009-02-01

    There has been concern regarding risks from inhalation exposure to nanoparticles (NPs). The large number of particles requiring testing means that alternative approaches to animal testing are needed. We set out to determine whether short-term in vitro assays that assess intrinsic oxidative stress potential and membrane-damaging potency of a panel of metal oxide NPs can be used to predict their inflammogenic potency. For a panel of metal oxide NPs, we investigated intrinsic free radical generation, oxidative activity in an extracellular environment, cytotoxicity to lung epithelial cells, hemolysis, and inflammation potency in rat lungs. All exposures were carried out at equal surface area doses. Only nickel oxide (NiO) and alumina 2 caused significant lung inflammation when instilled into rat lungs at equal surface area, suggesting that these two had extra surface reactivity. We observed significant free radical generation with 4 of 13 metal oxides, only one of which was inflammogenic. Only 3 of 13 were significantly hemolytic, two of which were inflammogenic. Potency in generating free radicals in vitro did not predict inflammation, whereas alumina 2 had no free radical activity but was inflammogenic. The hemolysis assay was correct in predicting the proinflammatory potential of 12 of 13 of the particles examined. Using a battery of simple in vitro tests, it is possible to predict the inflammogenicity of metal oxide NPs, although some false-positive results are likely. More research using a larger panel is needed to confirm the efficacy and generality of this approach for metal oxide NPs.

  6. A Simple Hydrogen Electrode

    Science.gov (United States)

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  7. A Simple, Cost-Effective Sensor for Detecting Lead Ions in Water Using Under-Potential Deposited Bismuth Sub-Layer with Differential Pulse Voltammetry (DPV

    Directory of Open Access Journals (Sweden)

    Yifan Dai

    2017-04-01

    Full Text Available This research has developed a simple to use, cost effective sensor system for the detection of lead ions in tap water. An under-potential deposited bismuth sub-layer on a thin gold film based electrochemical sensor was designed, manufactured, and evaluated. Differential pulse voltammetry (DPV measurement technique was employed in this detection. Tap water from the Cleveland, OH, USA regional water district was the test medium. Concentrations of lead ion in the range of 8 × 10−7 M to 5 × 10−4 M were evaluated, showing a good sensitivity over this concentration range. The calibration curve for the DPV measurements of lead ions in tap water showed excellent reproducibility with R2 value of 0.970. This DPV detection system required 3–6 min to complete the detection measurement. A longer measurement time of 6 min was used for the lower lead ion concentration. The selectivity of this lead ion sensor was very good, and Fe III, Cu II, Ni II, and Mg II at a concentration level of 5 × 10−4 M did not interfere with the lead ion measurement.

  8. Characteristics of a micro-gap argon barrier discharge excited by a saw-tooth voltage at atmospheric pressure

    Science.gov (United States)

    Li, Xuechen; Zhang, Qi; Jia, Pengying; Chu, Jingdi; Zhang, Panpan; Dong, Lifang

    2017-03-01

    Using two water electrodes, a micro-gap dielectric barrier discharge excited by a saw-tooth voltage is investigated in atmospheric pressure argon. Through electrical and optical measurements, it is found that, at a lower driving frequency, a stepped discharge mode is obtained per half voltage cycle. Moreover, the duration and amplitude of the current plateau increase with the increase in the applied peak voltage. With the increase in the driving frequency, the stepped discharge mode transits into a pulsed one after a multi-peak mode. During this process, a diffuse discharge at a lower frequency transits into a filamentary one at a higher frequency. Temporal evolutions of the discharges are investigated axially based on fast photography. It is found that the stepped mode is in atmospheric pressure Townsend discharge (APTD) regime. However, there is a transition from APTD to atmospheric pressure glow discharge for the pulsed mode. Spectral intensity ratio of 391.4 nm to 337.1 nm is used to determine the averaged electron energy, which decreases with increasing peak voltage or driving frequency.

  9. Potencial de híbridos simples de milho para extração de linhagens Potential of maize single hybrids to generate inbred lines

    Directory of Open Access Journals (Sweden)

    Odair Bison

    2003-04-01

    favorable alleles at a frequency of 0.5. Therefore, identification of promising single hybrid populations for inbred line extraction is strategic to increase the efficiency of breeding programs. The populations derived from the two commercial single hybrids AG9012 and C333 were assessed to estimate their capacity to inbred line extraction using the genetic and phenotypic parameters estimate, the m+a estimate and Jinks & Pooni (1976 methodology. Two sets of 169 S1 families derived from each hybrid population were assessed during the 1999/2000 growing season in the experimental area of the Biology Department at UFLA in Lavras, MG. The families were assessed in two simple 13 x 13 lattices in 3 m single row plots. The assessed traits were: a incidence of Phaeosphaeria maydis in two sowing periods; b plant height; c ear height; and, d de-hulled ear yield. It was detected that inbred lines with good "per se" performance can be obtained. The C333 hybrid derived population was the most promising for breeding purposes due to its resistance to Phaeosphaeria maydis associated with a higher mean and greater potential to generate superior inbred lines. The Jinks & Pooni (1976 methodology gave more informations to help the population choice than the m+a estimate. However, when it's possible, both can be used together to help the plant breeders to make a choice.

  10. A Simple Model that Identifies Potential Effects of Sea-Level Rise on Estuarine and Estuary-Ecotone Habitat Locations for Salmonids in Oregon, USA

    Science.gov (United States)

    Flitcroft, Rebecca; Burnett, Kelly; Christiansen, Kelly

    2013-07-01

    Diadromous aquatic species that cross a diverse range of habitats (including marine, estuarine, and freshwater) face different effects of climate change in each environment. One such group of species is the anadromous Pacific salmon ( Oncorhynchus spp.). Studies of the potential effects of climate change on salmonids have focused on both marine and freshwater environments. Access to a variety of estuarine habitat has been shown to enhance juvenile life-history diversity, thereby contributing to the resilience of many salmonid species. Our study is focused on the effect of sea-level rise on the availability, complexity, and distribution of estuarine, and low-freshwater habitat for Chinook salmon ( Oncorhynchus tshawytscha), steelhead (anadromous O. mykiss), and coho salmon ( O. kisutch) along the Oregon Coast under future climate change scenarios. Using LiDAR, we modeled the geomorphologies of five Oregon estuaries and estimated a contour associated with the current mean high tide. Contour intervals at 1- and 2-m increments above the current mean high tide were generated, and changes in the estuary morphology were assessed. Because our analysis relied on digital data, we compared three types of digital data in one estuary to assess the utility of different data sets in predicting the changes in estuary shape. For each salmonid species, changes in the amount and complexity of estuarine edge habitats varied by estuary. The simple modeling approach we applied can also be used to identify areas that may be most amenable to pre-emptive restoration actions to mitigate or enhance salmonid habitat under future climatic conditions.

  11. Generalized 3P 0 and 3S 1 annihilation potentials for overlinepp decay into two mesons based on a simple quark model

    Science.gov (United States)

    Bathas, George; Kloet, W. M.

    1993-03-01

    Within the quark model a generalization is proposed of the commonly used annihilation potential to describe antiproton- proton annihilation into two mesons, the so-called 3P 0 and 3S 1 mechanisms. This generalized potential treats the two mechanisms in a more symmetric way, has additional angular dependence, and results in an expanded set of selection rules.

  12. A simple model that identifies potential effects of sea-level rise on estuarine and estuary-ecotone habitat locations for salmonids in Oregon, USA

    Science.gov (United States)

    Rebecca Flitcroft; Kelly Burnett; Kelly. Christiansen

    2013-01-01

    Diadromous aquatic species that cross a diverse range of habitats (including marine, estuarine, and freshwater) face different effects of climate change in each environment. One such group of species is the anadromous Pacific salmon (Oncorhynchus spp.). Studies of the potential effects of climate change on salmonids have focused on both marine and...

  13. Assessment of water-limited winter wheat yield potential at spatially contrasting sites in Ireland using a simple growth and development model

    Directory of Open Access Journals (Sweden)

    Lynch J.P.

    2017-09-01

    Full Text Available Although Irish winter wheat yields are among the highest globally, increases in the profitability of this crop are required to maintain its economic viability. However, in order to determine if efforts to further increase Irish wheat yields are likely to be successful, an accurate estimation of the yield potential is required for different regions within Ireland. A winter wheat yield potential model (WWYPM was developed, which estimates the maximum water-limited yield achievable, within the confines of current genetic resources and technologies, using parameters for winter wheat growth and development observed recently in Ireland and a minor amount of daily meteorological input (maximum and minimum daily temperature, total daily rainfall and total daily incident radiation. The WWYPM is composed of three processes: (i an estimation of potential green area index, (ii an estimation of light interception and biomass accumulation and (iii an estimation of biomass partitioning to grain yield. Model validation indicated that WWYPM estimations of water-limited yield potential (YPw were significantly related to maximum yields recorded in variety evaluation trials as well as regional average and maximum farm yields, reflecting the model’s sensitivity to alterations in the climatic environment with spatial and seasonal variations. Simulations of YPw for long-term average weather data at 12 sites located at spatially contrasting regions of Ireland indicated that the typical YPw varied between 15.6 and 17.9 t/ha, with a mean of 16.7 t/ha at 15% moisture content. These results indicate that the majority of sites in Ireland have the potential to grow high-yielding crops of winter wheat when the effects of very high rainfall and other stresses such as disease incidence and nutrient deficits are not considered.

  14. Precision distance measurement using a two-photon absorption process in a silicon avalanche photodiode with saw-tooth phase modulation.

    Science.gov (United States)

    Tanaka, Yosuke; Tominaka, Seiji; Kurokawa, Takashi

    2015-10-01

    We present a novel configuration of a precision laser distance measurement based on the two-photon absorption (TPA) photocurrent from a silicon avalanche photodiode (Si-APD). The proposed system uses saw-tooth phase modulation, known as serrodyne modulation, in order to shift the frequency of the reference light from that of the probe light. It suppresses the coherent interference noise between the probe and the reference. The serrodyne modulation also enables lock-in detection of the TPA photocurrent. Furthermore, it contributes to the reduction of the system components. The precision measurement is experimentally demonstrated by measuring a fiber length difference of 2.6 m with a standard deviation of 27 μm under constant temperature. The high-precision displacement measurement is also demonstrated by measuring the temperature-induced change in the optical path length difference of a fiber interferometer.

  15. Simple physics-based analytical formulas for the potentials of mean force of the interaction of amino-acid side chains in water. VI. Oppositely charged side chains.

    Science.gov (United States)

    Makowski, Mariusz; Liwo, Adam; Scheraga, Harold A

    2011-05-19

    The two-site coarse-grained model for the interactions of charged side chains, to be used with our coarse-grained UNRES force field for protein simulations proposed in the accompanying paper, has been extended to pairs of oppositely charged side chains. The potentials of mean force of four pairs of molecules modeling charged amino-acid side chains, i.e., propionate-n-pentylamine cation (for aspartic acid-lysine), butyrate-n-pentylamine cation (for glutamic acid-lysine), propionate-1-butylguanidine (for aspartic acid-arginine), and butyrate-1-butylguanidine (for glutamic acid-arginine) pairs were determined by umbrella-sampling molecular dynamics simulations in explicit water as functions of distance and orientation, and the analytical expression was fitted to the potentials of mean force. Compared to pairs of like-charged side chains discussed in the accompanying paper, an average quadrupole-quadrupole interaction term had to be introduced to reproduce the Coulombic interactions, and a multistate model of charge distribution had to be introduced to fit the potentials of mean force of all oppositely charged pairs well. The model reproduces all salt-bridge minima and, consequently, is likely to improve the performance of the UNRES force field. © 2011 American Chemical Society

  16. Oscillations in a simple climate–vegetation model

    Directory of Open Access Journals (Sweden)

    J. Rombouts

    2015-05-01

    Full Text Available We formulate and analyze a simple dynamical systems model for climate–vegetation interaction. The planet we consider consists of a large ocean and a land surface on which vegetation can grow. The temperature affects vegetation growth on land and the amount of sea ice on the ocean. Conversely, vegetation and sea ice change the albedo of the planet, which in turn changes its energy balance and hence the temperature evolution. Our highly idealized, conceptual model is governed by two nonlinear, coupled ordinary differential equations, one for global temperature, the other for vegetation cover. The model exhibits either bistability between a vegetated and a desert state or oscillatory behavior. The oscillations arise through a Hopf bifurcation off the vegetated state, when the death rate of vegetation is low enough. These oscillations are anharmonic and exhibit a sawtooth shape that is characteristic of relaxation oscillations, as well as suggestive of the sharp deglaciations of the Quaternary. Our model's behavior can be compared, on the one hand, with the bistability of even simpler, Daisyworld-style climate–vegetation models. On the other hand, it can be integrated into the hierarchy of models trying to simulate and explain oscillatory behavior in the climate system. Rigorous mathematical results are obtained that link the nature of the feedbacks with the nature and the stability of the solutions. The relevance of model results to climate variability on various timescales is discussed.

  17. Construction of simple pathways and simple cycles in ecosystems.

    Science.gov (United States)

    Kincaid, D T; Pilette, R

    1992-06-01

    We present software tools for overcoming the problem of combinatorics in the enumeration of simple pathways and simple cycles in a first flow-through analysis of carbon transfer in large ecosystems. Rather than search through the very large number of potential routes in a reasonably sized ecosystem for the relatively small number of actual routes, our main algorithm performs an efficient rule-based construction of the actual routes. The enumeration of the unique pathways becomes tractable in terms of CPU time, which increases linearly with ecosystem size and connectedness. Networks of up to 80 entities can be evaluated using our software.

  18. Mean velocity distribution of open channel turbulent flow on a sawtooth riblet surface. Riblet somen kaisuiro ranryu no heikin ryusoku bunpu

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T. (Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering)

    1993-11-01

    The mean velocity distribution of an open channel turbulent flow on a sawtooth riblet surface. The long open channel of 60 cm wide, 25 cm deep and 10 m long was used, and equilateral triangle riblets of 2 mm in edge were laid longitudinally all over the bottom surface of the channel. Flow velocity was measured by pitot tube with a rectangular open section of 0.5 [times] 3 mm. As an experimental result, as the apparent origin of velocity profiles was evaluated assuming the presence of a viscous bottom layer, the coefficient of frictional drag agreed with previous experimental ones, however, the apparent origin descended from a riblet peak with an increase in drag reduction rate. The velocity profile in a buffer region differed remarkably from that on a smooth wall, and the maximum mixing length was found at 80-100 in non-dimensional water depth (Y[sup +]) increasing with the drag reduction rate. From a mixing length profile, as the apparent origin lay at 20-30 in Y[sup +], the logarithmic velocity profile was found in a range over 150 in Y[sup +]. 7 refs., 10 figs., 1 tab.

  19. A comparison of four years of limnology in the Sawtooth Lakes with emphasis on fertilization in Redfish Lake

    Energy Technology Data Exchange (ETDEWEB)

    Budy, P.; Luecke, C.; Wurtsbaugh, W.A.

    1996-05-01

    Included in this section of the report on limnology of Lakes in the Snake River Plain are descriptions of four years of limnological sampling to compare inter and intra annual variability in lake productivity to evaluate potential rearing conditions for juvenile sockeyed salmon. Data was used to evaluate the effects of nutrient enhancement, annual weather patterns, and planktivore consumption on lake productivity.

  20. Simple Machine Junk Cars

    Science.gov (United States)

    Herald, Christine

    2010-01-01

    During the month of May, the author's eighth-grade physical science students study the six simple machines through hands-on activities, reading assignments, videos, and notes. At the end of the month, they can easily identify the six types of simple machine: inclined plane, wheel and axle, pulley, screw, wedge, and lever. To conclude this unit,…

  1. A Simple Method for Decreasing the Liquid Junction Potential in a Flow-through-Type Differential pH Sensor Probe Consisting of pH-FETs by Exerting Spatiotemporal Control of the Liquid Junction

    Science.gov (United States)

    Yamada, Akira; Mohri, Satoshi; Nakamura, Michihiro; Naruse, Keiji

    2015-01-01

    The liquid junction potential (LJP), the phenomenon that occurs when two electrolyte solutions of different composition come into contact, prevents accurate measurements in potentiometry. The effect of the LJP is usually remarkable in measurements of diluted solutions with low buffering capacities or low ion concentrations. Our group has constructed a simple method to eliminate the LJP by exerting spatiotemporal control of a liquid junction (LJ) formed between two solutions, a sample solution and a baseline solution (BLS), in a flow-through-type differential pH sensor probe. The method was contrived based on microfluidics. The sensor probe is a differential measurement system composed of two ion-sensitive field-effect transistors (ISFETs) and one Ag/AgCl electrode. With our new method, the border region of the sample solution and BLS is vibrated in order to mix solutions and suppress the overshoot after the sample solution is suctioned into the sensor probe. Compared to the conventional method without vibration, our method shortened the settling time from over two min to 15 s and reduced the measurement error by 86% to within 0.060 pH. This new method will be useful for improving the response characteristics and decreasing the measurement error of many apparatuses that use LJs. PMID:25835300

  2. A simple method for decreasing the liquid junction potential in a flow-through-type differential pH sensor probe consisting of pH-FETs by exerting spatiotemporal control of the liquid junction.

    Science.gov (United States)

    Yamada, Akira; Mohri, Satoshi; Nakamura, Michihiro; Naruse, Keiji

    2015-04-01

    The liquid junction potential (LJP), the phenomenon that occurs when two electrolyte solutions of different composition come into contact, prevents accurate measurements in potentiometry. The effect of the LJP is usually remarkable in measurements of diluted solutions with low buffering capacities or low ion concentrations. Our group has constructed a simple method to eliminate the LJP by exerting spatiotemporal control of a liquid junction (LJ) formed between two solutions, a sample solution and a baseline solution (BLS), in a flow-through-type differential pH sensor probe. The method was contrived based on microfluidics. The sensor probe is a differential measurement system composed of two ion-sensitive field-effect transistors (ISFETs) and one Ag/AgCl electrode. With our new method, the border region of the sample solution and BLS is vibrated in order to mix solutions and suppress the overshoot after the sample solution is suctioned into the sensor probe. Compared to the conventional method without vibration, our method shortened the settling time from over two min to 15 s and reduced the measurement error by 86% to within 0.060 pH. This new method will be useful for improving the response characteristics and decreasing the measurement error of many apparatuses that use LJs.

  3. Simple arithmetic: not so simple for highly math anxious individuals.

    Science.gov (United States)

    Chang, Hyesang; Sprute, Lisa; Maloney, Erin A; Beilock, Sian L; Berman, Marc G

    2017-12-01

    Fluency with simple arithmetic, typically achieved in early elementary school, is thought to be one of the building blocks of mathematical competence. Behavioral studies with adults indicate that math anxiety (feelings of tension or apprehension about math) is associated with poor performance on cognitively demanding math problems. However, it remains unclear whether there are fundamental differences in how high and low math anxious individuals approach overlearned simple arithmetic problems that are less reliant on cognitive control. The current study used functional magnetic resonance imaging to examine the neural correlates of simple arithmetic performance across high and low math anxious individuals. We implemented a partial least squares analysis, a data-driven, multivariate analysis method to measure distributed patterns of whole-brain activity associated with performance. Despite overall high simple arithmetic performance across high and low math anxious individuals, performance was differentially dependent on the fronto-parietal attentional network as a function of math anxiety. Specifically, low-compared to high-math anxious individuals perform better when they activate this network less-a potential indication of more automatic problem-solving. These findings suggest that low and high math anxious individuals approach even the most fundamental math problems differently. © The Author (2017). Published by Oxford University Press.

  4. Simple guide to Skype

    CERN Document Server

    Winter, Rick

    2013-01-01

    Simple Guides give you Just the Facts Get up to speed with Skypefast! Simple Guides: get you started quickly. No extra clutter, no extra reading. Learn how to set up Skype, as well as how to add and set up all your friends, family, and other contacts. Find out about all the features of Skype, how to change views, set your status and conduct video and audio only calls. Learn about all the different things you can do to contact your friends and family on Skype for free, and start having fun!

  5. Droids Made Simple

    CERN Document Server

    Mazo, Gary

    2011-01-01

    If you have a Droid series smartphone - Droid, Droid X, Droid 2, or Droid 2 Global - and are eager to get the most out of your device, Droids Made Simple is perfect for you. Authors Martin Trautschold, Gary Mazo and Marziah Karch guide you through all of the features, tips, and tricks using their proven combination of clear instructions and detailed visuals. With hundreds of annotated screenshots and step-by-step directions, Droids Made Simple will transform you into a Droid expert, improving your productivity, and most importantly, helping you take advantage of all of the cool features that c

  6. Excel 2010 Made Simple

    CERN Document Server

    Katz, Abbott

    2011-01-01

    Get the most out of Excel 2010 with Excel 2010 Made Simple - learn the key features, understand what's new, and utilize dozens of time-saving tips and tricks to get your job done. Over 500 screen visuals and clear-cut instructions guide you through the features of Excel 2010, from formulas and charts to navigating around a worksheet and understanding Visual Basic for Applications (VBA) and macros. Excel 2010 Made Simple takes a practical and highly effective approach to using Excel 2010, showing you the best way to complete your most common spreadsheet tasks. You'll learn how to input, format,

  7. What Is a Simple Liquid?

    Directory of Open Access Journals (Sweden)

    Trond S. Ingebrigtsen

    2012-03-01

    Full Text Available This paper is an attempt to identify the real essence of simplicity of liquids in John Locke’s understanding of the term. Simple liquids are traditionally defined as many-body systems of classical particles interacting via radially symmetric pair potentials. We suggest that a simple liquid should be defined instead by the property of having strong correlations between virial and potential-energy equilibrium fluctuations in the NVT ensemble. There is considerable overlap between the two definitions, but also some notable differences. For instance, in the new definition simplicity is not a direct property of the intermolecular potential because a liquid is usually only strongly correlating in part of its phase diagram. Moreover, not all simple liquids are atomic (i.e., with radially symmetric pair potentials and not all atomic liquids are simple. The main part of the paper motivates the new definition of liquid simplicity by presenting evidence that a liquid is strongly correlating if and only if its intermolecular interactions may be ignored beyond the first coordination shell (FCS. This is demonstrated by NVT simulations of the structure and dynamics of several atomic and three molecular model liquids with a shifted-forces cutoff placed at the first minimum of the radial distribution function. The liquids studied are inverse power-law systems (r^{-n} pair potentials with n=18,6,4, Lennard-Jones (LJ models (the standard LJ model, two generalized Kob-Andersen binary LJ mixtures, and the Wahnstrom binary LJ mixture, the Buckingham model, the Dzugutov model, the LJ Gaussian model, the Gaussian core model, the Hansen-McDonald molten salt model, the Lewis-Wahnstrom ortho-terphenyl model, the asymmetric dumbbell model, and the single-point charge water model. The final part of the paper summarizes properties of strongly correlating liquids, emphasizing that these are simpler than liquids in general. Simple liquids, as defined here, may be

  8. What Is a Simple Liquid?

    Science.gov (United States)

    Ingebrigtsen, Trond S.; Schrøder, Thomas B.; Dyre, Jeppe C.

    2012-01-01

    This paper is an attempt to identify the real essence of simplicity of liquids in John Locke’s understanding of the term. Simple liquids are traditionally defined as many-body systems of classical particles interacting via radially symmetric pair potentials. We suggest that a simple liquid should be defined instead by the property of having strong correlations between virial and potential-energy equilibrium fluctuations in the NVT ensemble. There is considerable overlap between the two definitions, but also some notable differences. For instance, in the new definition simplicity is not a direct property of the intermolecular potential because a liquid is usually only strongly correlating in part of its phase diagram. Moreover, not all simple liquids are atomic (i.e., with radially symmetric pair potentials) and not all atomic liquids are simple. The main part of the paper motivates the new definition of liquid simplicity by presenting evidence that a liquid is strongly correlating if and only if its intermolecular interactions may be ignored beyond the first coordination shell (FCS). This is demonstrated by NVT simulations of the structure and dynamics of several atomic and three molecular model liquids with a shifted-forces cutoff placed at the first minimum of the radial distribution function. The liquids studied are inverse power-law systems (r-n pair potentials with n=18,6,4), Lennard-Jones (LJ) models (the standard LJ model, two generalized Kob-Andersen binary LJ mixtures, and the Wahnstrom binary LJ mixture), the Buckingham model, the Dzugutov model, the LJ Gaussian model, the Gaussian core model, the Hansen-McDonald molten salt model, the Lewis-Wahnstrom ortho-terphenyl model, the asymmetric dumbbell model, and the single-point charge water model. The final part of the paper summarizes properties of strongly correlating liquids, emphasizing that these are simpler than liquids in general. Simple liquids, as defined here, may be characterized in three quite

  9. (3) Simple processing method

    African Journals Online (AJOL)

    Adeyinka Odunsi

    Simple Processing Method for Recycling Poultry Waste into. Animal Feed Ingredient. *Komolafe, A. A. and Sonaiya, E. B. ... recycled and become consumables to livestock, thus entering the human food chain. Poultry waste is not ... on the concrete roof (20.5 m high) of the Faculty of Agriculture, Obafemi. Awolowo University ...

  10. Modern mathematics made simple

    CERN Document Server

    Murphy, Patrick

    1982-01-01

    Modern Mathematics: Made Simple presents topics in modern mathematics, from elementary mathematical logic and switching circuits to multibase arithmetic and finite systems. Sets and relations, vectors and matrices, tesselations, and linear programming are also discussed.Comprised of 12 chapters, this book begins with an introduction to sets and basic operations on sets, as well as solving problems with Venn diagrams. The discussion then turns to elementary mathematical logic, with emphasis on inductive and deductive reasoning; conjunctions and disjunctions; compound statements and conditional

  11. The simple complex numbers

    OpenAIRE

    Zalesny, Jaroslaw

    2008-01-01

    A new simple geometrical interpretation of complex numbers is presented. It differs from their usual interpretation as points in the complex plane. From the new point of view the complex numbers are rather operations on vectors than points. Moreover, in this approach the real, imaginary and complex numbers have similar interpretation. They are simply some operations on vectors. The presented interpretation is simpler, more natural, and better adjusted to possible applications in geometry and ...

  12. Information technology made simple

    CERN Document Server

    Carter, Roger

    1991-01-01

    Information Technology: Made Simple covers the full range of information technology topics, including more traditional subjects such as programming languages, data processing, and systems analysis. The book discusses information revolution, including topics about microchips, information processing operations, analog and digital systems, information processing system, and systems analysis. The text also describes computers, computer hardware, microprocessors, and microcomputers. The peripheral devices connected to the central processing unit; the main types of system software; application soft

  13. Simple chain grammars and languages

    NARCIS (Netherlands)

    Nijholt, Antinus

    1979-01-01

    A subclass of the LR(0)-grammars, the class of simple chain grammars is introduced. Although there exist simple chain grammars which are not LL(k) for any k>0, this new class of grammars is very closely related to the LL(1) and simple LL(1) grammars. In fact it can be shown that every simple chain

  14. Data processing made simple

    CERN Document Server

    Wooldridge, Susan

    2013-01-01

    Data Processing: Made Simple, Second Edition presents discussions of a number of trends and developments in the world of commercial data processing. The book covers the rapid growth of micro- and mini-computers for both home and office use; word processing and the 'automated office'; the advent of distributed data processing; and the continued growth of database-oriented systems. The text also discusses modern digital computers; fundamental computer concepts; information and data processing requirements of commercial organizations; and the historical perspective of the computer industry. The

  15. Applied mathematics made simple

    CERN Document Server

    Murphy, Patrick

    1982-01-01

    Applied Mathematics: Made Simple provides an elementary study of the three main branches of classical applied mathematics: statics, hydrostatics, and dynamics. The book begins with discussion of the concepts of mechanics, parallel forces and rigid bodies, kinematics, motion with uniform acceleration in a straight line, and Newton's law of motion. Separate chapters cover vector algebra and coplanar motion, relative motion, projectiles, friction, and rigid bodies in equilibrium under the action of coplanar forces. The final chapters deal with machines and hydrostatics. The standard and conte

  16. Theory of simple liquids

    CERN Document Server

    Hansen, Jean-Pierre

    1986-01-01

    This book gives a comprehensive and up-to-date treatment of the theory of ""simple"" liquids. The new second edition has been rearranged and considerably expanded to give a balanced account both of basic theory and of the advances of the past decade. It presents the main ideas of modern liquid state theory in a way that is both pedagogical and self-contained. The book should be accessible to graduate students and research workers, both experimentalists and theorists, who have a good background in elementary mechanics.Key Features* Compares theoretical deductions with experimental r

  17. Beyond Simple Headquarters Configurations

    DEFF Research Database (Denmark)

    Dellestrand, Henrik; Kappen, Philip; Nell, Phillip Christopher

    .e., an innovation that is important for the firm beyond the divisional boundaries, drives dual headquarters involvement in innovation development. Contrary to expectations, on average, a non-significant effect of cross-divisional embeddedness on dual headquarters involvement is found. Yet, both cross......-divisional importance and embeddedness effects are contingent on the overall complexity of the innovation project as signified by the size of the development network. The results lend support for the notion that parenting in complex structures entails complex headquarters structures and that we need to go beyond simple...

  18. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp......-like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data...

  19. ASP made simple

    CERN Document Server

    Deane, Sharon

    2003-01-01

    ASP Made Simple provides a brief introduction to ASP for the person who favours self teaching and/or does not have expensive computing facilities to learn on. The book will demonstrate how the principles of ASP can be learned with an ordinary PC running Personal Web Server, MS Access and a general text editor like Notepad.After working through the material readers should be able to:* Write ASP scripts that can display changing information on a web browser* Request records from a remote database or add records to it* Check user names & passwords and take this knowledge forward, either for their

  20. THE SIMPLE SDD

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, A.; Morlat, T.; Felizardo, M.; Collar, J. I.; Puibasset, J.; Waysand, G.; Miley, Harry S.; Ramos, A. R.; Girard, T. A.; Giuliani, F.; Limagne, D.; Marques, J. G.; Martins, R. C.; Oliveira, C.

    2006-09-01

    SIMPLE (superheated instrument for massive particle search) is an experiment(1,2) to search for evidence of spin-dependent dark matter using fluorine-loaded superheated droplet detectors (SDDs). The application of the detector is based on the presence of fluorine, which possesses the highest figure-of-merit for spin-dependent interactions. Furthermore, these devices are virtually insensitive to the majority of backgrounds associated with such searches. For dark matter applications, less than 10 events kg-1 d-1 are expected. The sensitivity to backgrounds is therefore an important issue for detector use. Following the thermal spike model of Seitz(3), there are two thresholds for bubble nucleation: (1) the deposited energy must be larger than the work of formation of a critical nucleus (Ec) and (2) Ec must be deposited over a distance of the order of a critical radius (rc). Both thresholds can be tuned by modifying the operating conditions as to render the SDD insensitive to radiations depositing less than ~200 keV mm-1. Although the SDD can be made insensitive to energetic muons, gamma rays, X rays and electrons with linear energy transfer (LET) below this threshold, response to neutrons and alpha particles remains problematic. These originate from radioactivity in the rock, detector shielding and the detector itself. We describe the detector fabrication and response studies required by the large volume and concentration of the SIMPLE device.

  1. Probabilistic simple sticker systems

    Science.gov (United States)

    Selvarajoo, Mathuri; Heng, Fong Wan; Sarmin, Nor Haniza; Turaev, Sherzod

    2017-04-01

    A model for DNA computing using the recombination behavior of DNA molecules, known as a sticker system, was introduced by by L. Kari, G. Paun, G. Rozenberg, A. Salomaa, and S. Yu in the paper entitled DNA computing, sticker systems and universality from the journal of Acta Informatica vol. 35, pp. 401-420 in the year 1998. A sticker system uses the Watson-Crick complementary feature of DNA molecules: starting from the incomplete double stranded sequences, and iteratively using sticking operations until a complete double stranded sequence is obtained. It is known that sticker systems with finite sets of axioms and sticker rules generate only regular languages. Hence, different types of restrictions have been considered to increase the computational power of sticker systems. Recently, a variant of restricted sticker systems, called probabilistic sticker systems, has been introduced [4]. In this variant, the probabilities are initially associated with the axioms, and the probability of a generated string is computed by multiplying the probabilities of all occurrences of the initial strings in the computation of the string. Strings for the language are selected according to some probabilistic requirements. In this paper, we study fundamental properties of probabilistic simple sticker systems. We prove that the probabilistic enhancement increases the computational power of simple sticker systems.

  2. A Simple Harmonic Universe

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Peter W.; /Stanford U., ITP; Horn, Bart; Kachru, Shamit; /Stanford U., ITP /SLAC; Rajendran, Surjeet; /Johns Hopkins U. /Stanford U., ITP; Torroba, Gonzalo; /Stanford U., ITP /SLAC

    2011-12-14

    We explore simple but novel bouncing solutions of general relativity that avoid singularities. These solutions require curvature k = +1, and are supported by a negative cosmological term and matter with -1 < w < -1 = 3. In the case of moderate bounces (where the ratio of the maximal scale factor a{sub +} to the minimal scale factor a{sub -} is {Omicron}(1)), the solutions are shown to be classically stable and cycle through an infinite set of bounces. For more extreme cases with large a{sub +} = a{sub -}, the solutions can still oscillate many times before classical instabilities take them out of the regime of validity of our approximations. In this regime, quantum particle production also leads eventually to a departure from the realm of validity of semiclassical general relativity, likely yielding a singular crunch. We briefly discuss possible applications of these models to realistic cosmology.

  3. Simple relation algebras

    CERN Document Server

    Givant, Steven

    2017-01-01

    This monograph details several different methods for constructing simple relation algebras, many of which are new with this book. By drawing these seemingly different methods together, all are shown to be aspects of one general approach, for which several applications are given. These tools for constructing and analyzing relation algebras are of particular interest to mathematicians working in logic, algebraic logic, or universal algebra, but will also appeal to philosophers and theoretical computer scientists working in fields that use mathematics. The book is written with a broad audience in mind and features a careful, pedagogical approach; an appendix contains the requisite background material in relation algebras. Over 400 exercises provide ample opportunities to engage with the material, making this a monograph equally appropriate for use in a special topics course or for independent study. Readers interested in pursuing an extended background study of relation algebras will find a comprehensive treatme...

  4. Molecular genetics made simple

    Directory of Open Access Journals (Sweden)

    Heba Sh. Kassem

    2012-07-01

    Full Text Available Genetics have undoubtedly become an integral part of biomedical science and clinical practice, with important implications in deciphering disease pathogenesis and progression, identifying diagnostic and prognostic markers, as well as designing better targeted treatments. The exponential growth of our understanding of different genetic concepts is paralleled by a growing list of genetic terminology that can easily intimidate the unfamiliar reader. Rendering genetics incomprehensible to the clinician however, defeats the very essence of genetic research: its utilization for combating disease and improving quality of life. Herein we attempt to correct this notion by presenting the basic genetic concepts along with their usefulness in the cardiology clinic. Bringing genetics closer to the clinician will enable its harmonious incorporation into clinical care, thus not only restoring our perception of its simple and elegant nature, but importantly ensuring the maximal benefit for our patients.

  5. SIMPLE LIFE AND RELIGION

    Directory of Open Access Journals (Sweden)

    Ahmet YILDIRIM

    2014-07-01

    Full Text Available Individuals in terms of the economy in which we live is one of the most important phenomenon of the century. This phenomenon present itself as the only determinant of people's lives by entering almost makes itself felt. The mo st obvious objective needs of the economy by triggering motive is to induce people to consume . Consumer culture pervades all aspects of the situation are people . Therefore, these people have the blessing of culture , beauty and value all in the name of w hatever is consumed. This is way out of the siege of moral and religious values we have is to go back again . Referred by local cultural and religious values, based on today increasingly come to the fore and the Muslim way of life appears to be close to th e plain / lean preferred by many people life has been a way of life. Even the simple life , a way of life in the Western world , a conception of life , a philosophy, a movement as it has become widely accepted. Here in determining the Muslim way of life Pr ophet. Prophet (sa lived the kind of life a very important model, sample, and determining which direction is known. Religious values, which is the carrier of the prophets, sent to the society they have always been examples and models. Because every aspect of human life, his life style and the surrounding area has a feature. We also value his life that he has unknowingly and without learning and skills and to understand it is not possible to live our religion . We also our presentation, we mainly of Islam o utlook on life and predicted life - style, including the Prophet of Islam 's (sa simple life to scrutinize and lifestyle issues related to reveal , in short Islam's how life has embraced and the Prophet. Prophet's will try to find answers to questions reg arding how to live.

  6. Energy: Simple Experiments for Young Scientists.

    Science.gov (United States)

    White, Larry

    This book contains simple experiments through which students can learn about the properties of energy. These experiments include making a kitchen "volcano," a soda-pop "cannon," and a puffed-rice "scooter." Topics include: energy and work, fossil fuels, solar energy, kinetic energy, potential energy, mechanical energy, heat energy, sound energy,…

  7. Simple Numerical Model of Laminated Glass Beams

    Directory of Open Access Journals (Sweden)

    A. Zemanová

    2008-01-01

    Full Text Available This paper presents a simple Finite Element model aimed at efficient simulation of layered glass units. The approach is based on considering the independent kinematics of each layer, tied together via Lagrange multipliers. Validation and verification of the resulting model against independent data demonstrate its accuracy, showing its potential for generalization towards more complex problems. 

  8. Entropy Is Simple, Qualitatively

    Science.gov (United States)

    Lambert, Frank L.

    2002-10-01

    Qualitatively, entropy is simple. What it is, why it is useful in understanding the behavior of macro systems or of molecular systems is easy to state: Entropy increase from a macro viewpoint is a measure of the dispersal of energy from localized to spread out at a temperature T. The conventional q in qrev/T is the energy dispersed to or from a substance or a system. On a molecular basis, entropy increase means that a system changes from having fewer accessible microstates to having a larger number of accessible microstates. Fundamentally based on statistical and quantum mechanics, this approach is superior to the non-fundamental "disorder" as a descriptor of entropy change. The foregoing in no way denies the subtlety or the difficulty presented by entropy in thermodynamics—to first-year students or to professionals. However, as an aid to beginners in their quantitative study of thermodynamics, the qualitative conclusions in this article give students the advantage of a clear bird’s-eye view of why entropy increases in a wide variety of basic cases: a substance going from 0 K to T, phase change, gas expansion, mixing of ideal gases or liquids, colligative effects, and the Gibbs equation. See Letter re: this article.

  9. A Simple Accelerometer Calibrator

    Science.gov (United States)

    Salam, R. A.; Islamy, M. R. F.; Munir, M. M.; Latief, H.; Irsyam, M.; Khairurrijal

    2016-08-01

    High possibility of earthquake could lead to the high number of victims caused by it. It also can cause other hazards such as tsunami, landslide, etc. In that case it requires a system that can examine the earthquake occurrence. Some possible system to detect earthquake is by creating a vibration sensor system using accelerometer. However, the output of the system is usually put in the form of acceleration data. Therefore, a calibrator system for accelerometer to sense the vibration is needed. In this study, a simple accelerometer calibrator has been developed using 12 V DC motor, optocoupler, Liquid Crystal Display (LCD) and AVR 328 microcontroller as controller system. The system uses the Pulse Wave Modulation (PWM) form microcontroller to control the motor rotational speed as response to vibration frequency. The frequency of vibration was read by optocoupler and then those data was used as feedback to the system. The results show that the systems could control the rotational speed and the vibration frequencies in accordance with the defined PWM.

  10. Quasispecies made simple.

    Directory of Open Access Journals (Sweden)

    J J Bull

    2005-11-01

    Full Text Available Quasispecies are clouds of genotypes that appear in a population at mutation-selection balance. This concept has recently attracted the attention of virologists, because many RNA viruses appear to generate high levels of genetic variation that may enhance the evolution of drug resistance and immune escape. The literature on these important evolutionary processes is, however, quite challenging. Here we use simple models to link mutation-selection balance theory to the most novel property of quasispecies: the error threshold-a mutation rate below which populations equilibrate in a traditional mutation-selection balance and above which the population experiences an error catastrophe, that is, the loss of the favored genotype through frequent deleterious mutations. These models show that a single fitness landscape may contain multiple, hierarchically organized error thresholds and that an error threshold is affected by the extent of back mutation and redundancy in the genotype-to-phenotype map. Importantly, an error threshold is distinct from an extinction threshold, which is the complete loss of the population through lethal mutations. Based on this framework, we argue that the lethal mutagenesis of a viral infection by mutation-inducing drugs is not a true error catastophe, but is an extinction catastrophe.

  11. Simple Quantum Dynamics with Thermalization.

    Science.gov (United States)

    Jansen, Thomas L C

    2018-01-11

    In this paper, we introduce two simple quantum dynamics methods. One is based on the popular surface-hopping method, and the other is based on rescaling of the propagation on the bath ground-state potential surface. The first method is special, as it avoids specific feedback from the simulated quantum system to the bath and can be applied for precalculated classical trajectories. It is based on the equipartition theorem to determine if hops between different potential energy surfaces are allowed. By comparing with the formally exact Hierarchical Equations Of Motion approach for four model systems we find that the method generally approximates the quantum dynamics toward thermal equilibrium very well. The second method is based on rescaling of the nonadiabatic coupling and also neglect the effect of the state of the quantum system on the bath. By the nature of the approximations, they cannot reproduce the effect of bath relaxation following excitation. However, the methods are both computationally more tractable than the conventional fewest switches surface hopping, and we foresee that the methods will be powerful for simulations of quantum dynamics in systems with complex bath dynamics, where the system-bath coupling is not too strong compared to the thermal energy.

  12. Simple model for molecular scattering

    Science.gov (United States)

    Mehta, Nirav; Ticknor, Christopher; Hazzard, Kaden

    2017-04-01

    The collisions of ultracold molecules are qualitatively different from the collisions of ultracold atoms due to the high density of bimolecular resonances near the collision energy. We present results from a simple N-channel scattering model with square-well channel potentials and constant channel couplings (inside the well) designed to reproduce essential features of chaotic molecular scattering. The potential depths and channel splittings are tuned to reproduce the appropriate density of states for the short-range bimolecular collision complex (BCC), which affords a direct comparison of the resulting level-spacing distribution to that expected from random matrix theory (RMT), namely the so-called Wigner surmise. The density of states also sets the scale for the rate of dissociation from the BCC to free molecules, as approximated by transition state theory (TST). Our model affords a semi-analytic solution for the scattering amplitude in the open channel, and a determinantal equation for the eigenenergies of the short-ranged BCC. It is likely the simplest finite-ranged scattering model that can be compared to expectations from the approximations of RMT, and TST. The validity of these approximations has implications for the many-channel Hubbard model recently developed. This research was funded in part by the National Science Foundation under Grant No. NSF PHY-1125915.

  13. Una historia muy simple

    Directory of Open Access Journals (Sweden)

    Miha Mazzini

    2009-12-01

    Full Text Available Voy a contarles una historia muy simple. Probablemente no les parecerá nada espe- cial y no quiero robarles tiempo, así que voy a tratar de hacerlo lo más rápido posible. Me inscribí en psicología porque eso hizo mi mejor amiga. Éramos compañeras desde jardín de infantes y siempre la seguí en todo. En tercer año de facultad conoció a su novio y continuó sus estudios en otro país; por primera vez no podía seguirla. Cuando rendí todos los exámenes, el profesor me preguntó si estaba interesada en hacer mi tesis sobre el perfil psicológico de los participantes de reality shows. Accedí para no tener que pensar en otro tema, aunque no veía mucho la televisión porque me pasaba las noches entre los libros de estudio. Enseguida me di cuenta de que, evidentemente, el profesor había firmado un contrato con la emisora: a él lo empleaban y y yo era la que iba a tener que trabajar, pero no me importaba. La tesis de licenciatura no es más que eso y hay que hacerla. Yo evaluaba los candidatos y elegía a los participantes que vivirían juntos duran- te algunos meses. Como hacían el programa con una licencia extranjera y ya sabían qué le interesaba a la audiencia, yo tenía preparados los rasgos de los perfiles psicológicos que en ese aislamiento colectivo no resultan bien. Tuve que elegir gente variada, pero dentro de la media; nunca nada verdaderamente especial. Cuando me gradué, tuve las noches libres: de pronto tenía mucho más tiempo y podía haber visto el programa, pero ya había terminado. Pero oí que había sido todo un éxito y que sobre todo a los chicos les había encantado el reality y los participantes elegidos.

  14. Vortex breakdown in simple pipe bends

    Science.gov (United States)

    Ault, Jesse; Shin, Sangwoo; Stone, Howard

    2016-11-01

    Pipe bends and elbows are one of the most common fluid mechanics elements that exists. However, despite their ubiquity and the extensive amount of research related to these common, simple geometries, unexpected complexities still remain. We show that for a range of geometries and flow conditions, these simple flows experience unexpected fluid dynamical bifurcations resembling the bubble-type vortex breakdown phenomenon. Specifically, we show with simulations and experiments that recirculation zones develop within the bends under certain conditions. As a consequence, fluid and particles can remain trapped within these structures for unexpectedly-long time scales. We also present simple techniques to mitigate this recirculation effect which can potentially have impact across industries ranging from biomedical and chemical processing to food and health sciences.

  15. Simple Physics-Based Analytical Formulas for the Potentials of Mean Force of the Interaction of Amino Acid Side Chains in Water. VII. Charged-Hydrophobic/Polar and Polar-Hydrophobic/Polar Side Chains.

    Science.gov (United States)

    Makowski, Mariusz; Liwo, Adam; Scheraga, Harold A

    2017-01-19

    The physics-based potentials of side-chain-side-chain interactions corresponding to pairs composed of charged and polar, polar and polar, charged and hydrophobic, and hydrophobic and hydrophobic side chains have been determined. A total of 144 four-dimensional potentials of mean force (PMFs) of all possible pairs of molecules modeling these pairs were determined by umbrella-sampling molecular dynamics simulations in explicit water as functions of distance and orientation, and the analytical expressions were then fitted to the PMFs. Depending on the type of interacting sites, the analytical approximation to the PMF is a sum of terms corresponding to van der Waals interactions and cavity-creation involving the nonpolar sections of the side chains and van der Waals, cavity-creation, and electrostatic (charge-dipole or dipole-dipole) interaction energies and polarization energies involving the charged or polar sections of the side chains. The model used in this work reproduces all features of the interacting pairs. The UNited RESidue force field with the new side-chain-side-chain interaction potentials was preliminarily tested with the N-terminal part of the B-domain of staphylococcal protein A (PDBL 1BDD ; a three-α-helix bundle) and UPF0291 protein YnzC from Bacillus subtilis (PDB: 2HEP ; an α-helical hairpin).

  16. a simple a simple excitation control excitation control excitation

    African Journals Online (AJOL)

    eobe

    synchronous generator from no-load to full load while maintaining the rated terminal voltage on the stator terminals. The d-q rotor reference frame equations were used for the calculations and it is shown that values of the field voltages determined follow a simple quadratic relationship that offer a very simple control scheme, ...

  17. Simple Rules for Detecting Depression

    NARCIS (Netherlands)

    Jenny, M.A.; Pachur, T.; Williams, S.L.; Becker, E.S.; Margraf, J.

    2013-01-01

    Depressive disorders are major public health issues worldwide. We tested the capacity of a simple lexicographic and noncompensatory fast and frugal tree (FFT) and a simple compensatory unit-weight model to detect depressed mood relative to a complex compensatory logistic regression and a naïve

  18. Simple physics-based analytical formulas for the potentials of mean force of the interaction of amino-acid side chains in water. V. Like-charged side chains.

    Science.gov (United States)

    Makowski, Mariusz; Liwo, Adam; Sobolewski, Emil; Scheraga, Harold A

    2011-05-19

    A new model of side-chain-side-chain interactions for charged side-chains of amino acids, to be used in the UNRES force-field, has been developed, in which a side chain consists of a nonpolar and a charged site. The interaction energy between the nonpolar sites is composed of a Gay-Berne and a cavity term; the interaction energy between the charged sites consists of a Lennard-Jones term, a Coulombic term, a generalized-Born term, and a cavity term, while the interaction energy between the nonpolar and charged sites is composed of a Gay-Berne and a polarization term. We parametrized the energy function for the models of all six pairs of natural like-charged amino-acid side chains, namely propionate-propionate (for the aspartic acid-aspartic acid pair), butyrate-butyrate (for the glutamic acid-glutamic acid pair), propionate-butyrate (for the aspartic acid-glutamic acid pair), pentylamine cation-pentylamine cation (for the lysine-lysine pair), 1-butylguanidine cation-1-butylguanidine cation (for the arginine-arginine pair), and pentylamine cation-1-butylguanidine cation (for the lysine-arginine pair). By using umbrella-sampling molecular dynamics simulations in explicit TIP3P water, we determined the potentials of mean force of the above-mentioned pairs as functions of distance and orientation and fitted analytical expressions to them. The positions and depths of the contact minima and the positions and heights of the desolvation maxima, including their dependence on the orientation of the molecules were well represented by analytical expressions for all systems. The values of the parameters of all the energy components are physically reasonable, which justifies use of such potentials in coarse-grain protein-folding simulations. © 2011 American Chemical Society

  19. Simple educational tool for digital speckle shearography

    Science.gov (United States)

    Schirripa Spagnolo, Giuseppe; Martocchia, Andrea; Papalillo, Donato; Cozzella, Lorenzo

    2012-07-01

    In this study, an educational tool has been prepared for obtaining short-term and more economic training on digital speckle shearography (DSS). Shearography non-destructive testing (NDT) has gained wide acceptance over the last decade, providing a number of important and exciting inspection solutions in aerospace, electronics and medical device manufacturing. For exploring these motivations, it is important to develop didactic tools to understand the potential of digital shearography through training and didactic courses in the field of NDT. In this paper we describe a simple tool for making one familiar with the potential of DSS in the area of education and training. The system is realized with a simple and economic optical setup and a virtual instrument based on the LabVIEW™ and DAQ.

  20. Multiphase flow in geometrically simple fracture intersections

    Science.gov (United States)

    Basagaoglu, H.; Meakin, P.; Green, C.T.; Mathew, M.; ,

    2006-01-01

    A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

  1. Multiphase Flow in Geometrically Simple Fracture Intersections

    Energy Technology Data Exchange (ETDEWEB)

    Hakan Basagaoglu; Paul Meakin; Sauro Succi; Timothy R. Ginn

    2006-03-01

    A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to Study gravity-driven flow in geometrically simple fracture intersections. simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-filin flow oil smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

  2. Saccharomyces cerevisiae glycerol/H+ symporter Stl1p is essential for cold/near-freeze and freeze stress adaptation. A simple recipe with high biotechnological potential is given

    Directory of Open Access Journals (Sweden)

    Ferreira Célia

    2010-11-01

    Full Text Available Abstract Background Freezing is an increasingly important means of preservation and storage of microbial strains used for many types of industrial applications including food processing. However, the yeast mechanisms of tolerance and sensitivity to freeze or near-freeze stress are still poorly understood. More knowledge on this regard would improve their biotechnological potential. Glycerol, in particular intracellular glycerol, has been assigned as a cryoprotectant, also important for cold/near-freeze stress adaptation. The S. cerevisiae glycerol active transporter Stl1p plays an important role on the fast accumulation of glycerol. This gene is expressed under gluconeogenic conditions, under osmotic shock and stress, as well as under high temperatures. Results We found that cells grown on STL1 induction medium (YPGE and subjected to cold/near-freeze stress, displayed an extremely high expression of this gene, also visible at glycerol/H+ symporter activity level. Under the same conditions, the strains harbouring this transporter accumulated more than 400 mM glycerol, whereas the glycerol/H+ symporter mutant presented less than 1 mM. Consistently, the strains able to accumulate glycerol survive 25-50% more than the stl1Δ mutant. Conclusions In this work, we report the contribution of the glycerol/H+ symporter Stl1p for the accumulation and maintenance of glycerol intracellular levels, and consequently cell survival at cold/near-freeze and freeze temperatures. These findings have a high biotechnological impact, as they show that any S. cerevisiae strain already in use can become more resistant to cold/freeze-thaw stress just by simply adding glycerol to the broth. The combination of low temperatures with extracellular glycerol will induce the transporter Stl1p. This solution avoids the use of transgenic strains, in particular in food industry.

  3. Saccharomyces cerevisiae glycerol/H+ symporter Stl1p is essential for cold/near-freeze and freeze stress adaptation. A simple recipe with high biotechnological potential is given

    Science.gov (United States)

    2010-01-01

    Background Freezing is an increasingly important means of preservation and storage of microbial strains used for many types of industrial applications including food processing. However, the yeast mechanisms of tolerance and sensitivity to freeze or near-freeze stress are still poorly understood. More knowledge on this regard would improve their biotechnological potential. Glycerol, in particular intracellular glycerol, has been assigned as a cryoprotectant, also important for cold/near-freeze stress adaptation. The S. cerevisiae glycerol active transporter Stl1p plays an important role on the fast accumulation of glycerol. This gene is expressed under gluconeogenic conditions, under osmotic shock and stress, as well as under high temperatures. Results We found that cells grown on STL1 induction medium (YPGE) and subjected to cold/near-freeze stress, displayed an extremely high expression of this gene, also visible at glycerol/H+ symporter activity level. Under the same conditions, the strains harbouring this transporter accumulated more than 400 mM glycerol, whereas the glycerol/H+ symporter mutant presented less than 1 mM. Consistently, the strains able to accumulate glycerol survive 25-50% more than the stl1Δ mutant. Conclusions In this work, we report the contribution of the glycerol/H+ symporter Stl1p for the accumulation and maintenance of glycerol intracellular levels, and consequently cell survival at cold/near-freeze and freeze temperatures. These findings have a high biotechnological impact, as they show that any S. cerevisiae strain already in use can become more resistant to cold/freeze-thaw stress just by simply adding glycerol to the broth. The combination of low temperatures with extracellular glycerol will induce the transporter Stl1p. This solution avoids the use of transgenic strains, in particular in food industry. PMID:21047428

  4. Simple ocean carbon cycle models

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, K. [Lawrence Livermore National Lab., CA (United States); Hoffert, M.I. [New York Univ., NY (United States). Dept. of Earth System Sciences; Siegenthaler, U. [Bern Univ. (Switzerland). Inst. fuer Physik

    1994-02-01

    Simple ocean carbon cycle models can be used to calculate the rate at which the oceans are likely to absorb CO{sub 2} from the atmosphere. For problems involving steady-state ocean circulation, well calibrated ocean models produce results that are very similar to results obtained using general circulation models. Hence, simple ocean carbon cycle models may be appropriate for use in studies in which the time or expense of running large scale general circulation models would be prohibitive. Simple ocean models have the advantage of being based on a small number of explicit assumptions. The simplicity of these ocean models facilitates the understanding of model results.

  5. Colligative properties of simple solutions.

    Science.gov (United States)

    Andrews, F C

    1976-11-05

    Vapor pressure lowering, osmotic pressure, boiling point elevation, and freezing point depression are all related quantitatively to the decrease in micro(1)(soln) upon the addition of solute in forming a solution. In any equilibrium system, regardless of whether it is in a gravitational field or whether it contains walls, semipermeable membranes, phase transitions, or solutes, all equilibria are maintained locally, in the small region of the equilibrium, by the equality of micro(1)(soln). If there are several subsystems in a gravitational field, at any fixed height, microi will have the same value in each subsystem into which substance i can get, and microi + M(i)gh is constant throughout the entire system. In a solution, there is no mechanism by which solvent and solute molecules could sustain different pressures. Both the solvent and solute are always under identical pressures in a region of solution, namely, the pressure of the solution in that region. Since nature does not know which component we call the solvent and which the solute, equations should be symmetric in the two (acknowledging that the nonvolatile component, if any, is commonly chosen to be solute). Simple molecular pictures illustrate what is happening to cause pressure (positive or negative) in liquids, vapor pressure of liquids, and the various colligative properties of solutions. The only effect of solute involved in these properties is that it dilutes the solvent, with the resulting increase in S and decrease in micro(1)(soln). Water can be driven passively up a tree to enormous heights by the difference between its chemical potential in the roots and the ambient air. There is nothing mysterious about the molecular bases for any of these phenomena. Biologists can use the well-understood pictures of these phenomena with confidence to study what is happening in the complicated living systems they consider.

  6. Chermak-Delgado Simple Groups

    OpenAIRE

    McCulloch, Ryan

    2015-01-01

    This paper provides the first steps in classifying the finite solvable groups having Property A, which is a property involving abelian normal subgroups. We see that this classification is reduced to classifying the solvable Chermak-Delgado simple groups, which the author defines. The author completes a classification of Chermak-Delgado simple groups under certain restrictions on the primes involved in the group order.

  7. Simple machines made simple a teacher resource manual

    CERN Document Server

    Andre, Ralph E St

    1993-01-01

    This book allows you to present scientific principles and simple mechanics through hands-on cooperative learning activities. Using inexpensive materials (e.g., tape, paper clips), students build simple machines-such as levers, pulleys, spring scales, gears, wheels and axles, windmills, and wedges-that demonstrate how things work. Activities have easy-to-locate materials lists, time requirements, and step-by-step directions (usually illustrated) on presentation. Ideas for bulletin boards, learning centers, and computer-assisted instruction are an added bonus.

  8. Practical Session: Simple Linear Regression

    Science.gov (United States)

    Clausel, M.; Grégoire, G.

    2014-12-01

    Two exercises are proposed to illustrate the simple linear regression. The first one is based on the famous Galton's data set on heredity. We use the lm R command and get coefficients estimates, standard error of the error, R2, residuals …In the second example, devoted to data related to the vapor tension of mercury, we fit a simple linear regression, predict values, and anticipate on multiple linear regression. This pratical session is an excerpt from practical exercises proposed by A. Dalalyan at EPNC (see Exercises 1 and 2 of http://certis.enpc.fr/~dalalyan/Download/TP_ENPC_4.pdf).

  9. Simple Combinatorial Optimisation Cost Games

    NARCIS (Netherlands)

    van Velzen, S.

    2005-01-01

    In this paper we introduce the class of simple combinatorial optimisation cost games, which are games associated to {0, 1}-matrices.A coalitional value of a combinatorial optimisation game is determined by solving an integer program associated with this matrix and the characteristic vector of the

  10. A Simple Plant Growth Analysis.

    Science.gov (United States)

    Oxlade, E.

    1985-01-01

    Describes the analysis of dandelion peduncle growth based on peduncle length, epidermal cell dimensions, and fresh/dry mass. Methods are simple and require no special apparatus or materials. Suggests that limited practical work in this area may contribute to students' lack of knowledge on plant growth. (Author/DH)

  11. Simple stålrammebygninger

    DEFF Research Database (Denmark)

    Ellum, J.C.

    Anvisningen gennemgår dimensioneringen og bringer detaljerede konstruktionstegninger til simple stålrammebygninger, dvs. lukkede, fritliggende bygninger i én etage, hvor tagkonstruktionen ud over egenlast kun er påvirket af naturlaster, dvs. sne og vind. Dimensioneringen sker ved at udfylde et...

  12. Determining Salinity by Simple Means.

    Science.gov (United States)

    Schlenker, Richard M.

    This paper describes the construction and use of a simple salinometer. The salinometer is composed, mainly, of a milliammeter and a battery and uses the measurement of current flow to determine the salinity of water. A complete list of materials is given, as are details of construction and operation of the equipment. The use of the salinometer in…

  13. Simple stålrammebygninger

    DEFF Research Database (Denmark)

    Ellum, J.C.

    Anvisningen gennemgår dimensioneringen og bringer detaljerede konstruktionstegninger til simple stålrammebygninger, dvs. lukkede, fritliggende bygninger i én etage, hvor tagkonstruktionen ud over egenlast kun er påvirket af naturlaster, dvs. sne og vind. Dimensioneringen sker ved at udfylde et di...

  14. Simple models with ALICE fluxes

    CERN Document Server

    Striet, J

    2000-01-01

    We introduce two simple models which feature an Alice electrodynamics phase. In a well defined sense the Alice flux solutions we obtain in these models obey first order equations similar to those of the Nielsen-Olesen fluxtube in the abelian higgs model in the Bogomol'nyi limit. Some numerical solutions are presented as well.

  15. Solving Simple Kinetics without Integrals

    Science.gov (United States)

    de la Pen~a, Lisandro Herna´ndez

    2016-01-01

    The solution of simple kinetic equations is analyzed without referencing any topic from differential equations or integral calculus. Guided by the physical meaning of the rate equation, a systematic procedure is used to generate an approximate solution that converges uniformly to the exact solution in the case of zero, first, and second order…

  16. A discerning approach to simple aesthetic orthodontics.

    Science.gov (United States)

    Noar, J H; Sharma, S; Roberts-Harry, D; Qureshi, T

    2015-02-16

    There is currently considerable interest from general dental practitioners (GDPs) in the use of simple orthodontics to treat adult malocclusions. There is controversy in this, particularly in relation to 'quick fixes', simple orthodontics and 'straight teeth in six months' as opposed to more conventional treatment where the whole malocclusion is treated. This article will present a case for the use of simple aesthetic adult orthodontics in a measured and planned way. It will discuss the processes, planning and the importance of consent. It will also highlight how digital technology is used to preview, consent and execute an aesthetic result. Many of the recent systems emerging, have been as a result of the demand and supply of cosmetic dentistry. This, to a degree, has not helped since the implication of a 'quick-fix' is associated with this field. There has also been discussion on what the limits of GDP orthodontics should be. There is variability in how GDPs approach orthodontics, their experience, skill and ability to treat to an acceptable standard. Short courses may be one way of delivering orthodontic training but some of these courses are not regulated and the amount of internal mentoring is variable. This article highlights some of the systems in use, and potential upsides and downsides of this approach.

  17. Simple Indolizidine and Quinolizidine Alkaloids.

    Science.gov (United States)

    Michael, Joseph P

    2016-01-01

    This review of simple indolizidine and quinolizidine alkaloids (i.e., those in which the parent bicyclic systems are in general not embedded in polycyclic arrays) is an update of the previous coverage in Volume 55 of this series (2001). The present survey covers the literature from mid-1999 to the end of 2013; and in addition to aspects of the isolation, characterization, and biological activity of the alkaloids, much emphasis is placed on their total synthesis. A brief introduction to the topic is followed by an overview of relevant alkaloids from fungal and microbial sources, among them slaframine, cyclizidine, Steptomyces metabolites, and the pantocins. The important iminosugar alkaloids lentiginosine, steviamine, swainsonine, castanospermine, and related hydroxyindolizidines are dealt with in the subsequent section. The fourth and fifth sections cover metabolites from terrestrial plants. Pertinent plant alkaloids bearing alkyl, functionalized alkyl or alkenyl substituents include dendroprimine, anibamine, simple alkaloids belonging to the genera Prosopis, Elaeocarpus, Lycopodium, and Poranthera, and bicyclic alkaloids of the lupin family. Plant alkaloids bearing aryl or heteroaryl substituents include ipalbidine and analogs, secophenanthroindolizidine and secophenanthroquinolizidine alkaloids (among them septicine, julandine, and analogs), ficuseptine, lasubines, and other simple quinolizidines of the Lythraceae, the simple furyl-substituted Nuphar alkaloids, and a mixed quinolizidine-quinazoline alkaloid. The penultimate section of the review deals with the sizable group of simple indolizidine and quinolizidine alkaloids isolated from, or detected in, ants, mites, and terrestrial amphibians, and includes an overview of the "dietary hypothesis" for the origin of the amphibian metabolites. The final section surveys relevant alkaloids from marine sources, and includes clathryimines and analogs, stellettamides, the clavepictines and pictamine, and bis

  18. Simple Electromagnetic Analysis in Cryptography

    Directory of Open Access Journals (Sweden)

    Zdenek Martinasek

    2012-07-01

    Full Text Available The article describes the main principle and methods of simple electromagnetic analysis and thus provides an overview of simple electromagnetic analysis.The introductions chapters describe specific SPA attack used visual inspection of EM traces, template based attack and collision attack.After reading the article, the reader is sufficiently informed of any context of SEMA.Another aim of the article is the practical realization of SEMA which is focused on AES implementation.The visual inspection of EM trace of AES is performed step by step and the result is the determination of secret key Hamming weight.On the resulting EM trace, the Hamming weight of the secret key 1 to 8 was clearly visible.This method allows reduction from the number of possible keys for following brute force attack.

  19. Simple techniques can increase motivation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E.A.

    1982-12-01

    Productivity depends upon strong motivation. This article describes how the symptoms of weak motivation can be detected among engineers and other employees and what to do about it. Fortunately, most people want to be productive and respond to simple motivation building techniques. These techniques include establishing twoway communication between supervisor and subordinate, delegating authority on the basis of responsibility, effective organization of time, and the use of positive reinforcement (or rewards) and, when conditions merit it, negative reinforcement (or sanctions).

  20. A simple electron plasma wave

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, G., E-mail: gert.brodin@physics.umu.se [Department of Physics, Umeå University, SE-901 87 Umeå (Sweden); Stenflo, L. [Department of Physics, Linköping University, SE-581 83 Linköping (Sweden)

    2017-03-18

    Considering a class of solutions where the density perturbations are functions of time, but not of space, we derive a new exact large amplitude wave solution for a cold uniform electron plasma. This result illustrates that most simple analytical solutions can appear even if the density perturbations are large. - Highlights: • The influence of large amplitude electromagnetic waves on electrostatic oscillations is found. • A generalized Mathieu equation is derived. • Anharmonic wave profiles are computed numerically.

  1. Instant simple botting with PHP

    CERN Document Server

    Anderson, Shay Michael

    2013-01-01

    do for you, and then get to work with the most important features and tasks. This book is a hands-on Starter guide that takes the reader from initialization to the coding and implementation of bot apps.Instant Simple Botting with PHP targets programmers of all levels who are familiar with common PHP functions and syntax, and who want to learn about bots and how to design and develop bots using objects.

  2. SIMPLE Dark Matter Search Results

    CERN Document Server

    Girard, T A; Morlat, T; Costa, M F; Collar, J I; Limagne, D; Waysand, G; Puibasset, J; Miley, H S; Auguste, M; Boyer, D; Cavaillou, A; Marques, J G; Oliveira, C; Felizardo, M; Fernandes, A C; Ramos, A R; Martins, R C; Girard, TA

    2005-01-01

    We report an improved SIMPLE experiment comprising four superheated droplet detectors with a total exposure of 0.42 kgd. The result yields ~ factor 10 improvement in the previously-reported results, and -- despite the low exposure -- is seen to provide restrictions on the allowed phase space of spin-dependent coupling strengths almost equivalent to those from the significantly larger exposure NAIADCDMS/ZEPLIN searches.

  3. Simple and Realistic Data Generation

    DEFF Research Database (Denmark)

    Pedersen, Kenneth Houkjær; Torp, Kristian; Wind, Rico

    2006-01-01

    This paper presents a generic, DBMS independent, and highly extensible relational data generation tool. The tool can efficiently generate realistic test data for OLTP, OLAP, and data streaming applications. The tool uses a graph model to direct the data generation. This model makes it very simple...... to generate data even for large database schemas with complex inter- and intra table relationships. The model also makes it possible to generate data with very accurate characteristics....

  4. Classification of simple current invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1992-01-01

    We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

  5. Systemic lupus erythematosus complicating simple silicosis.

    Science.gov (United States)

    Lucas, C D; Amft, N; Reid, P T

    2014-07-01

    Inhalation of crystalline silica is known to result in silicosis: an irreversible, disabling and potentially fatal occupational lung disease, which is associated with a variety of pulmonary and non-pulmonary complications including autoimmunity. A potential link between silicosis and systemic lupus erythematosus (SLE) is currently recognized only in cases of acute or accelerated silicosis. We report a case of SLE, a disease which usually affects young females, arising in a male former stonemason with simple silicosis. Epidemiological and clinical literature on the association of silica exposure and development of SLE are briefly reviewed. This case report and literature review highlight the link between occupational silica exposure and autoimmune disease including SLE, establishes that even simple silicosis appears linked to development of autoimmunity and emphasizes the importance of an occupational history, especially in male patients who develop SLE. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Simple waves in Hertzian chains.

    Science.gov (United States)

    McDonald, B Edward; Calvo, David

    2012-06-01

    The discrete system of equations for a chain consisting of a large number of spheres interacting via the Hertz force of index 3/2 in strain is examined in the very long wavelength limit, yielding an effective medium description. The resulting continuum second-order equation of motion possesses a subset of simple waves obeying a first-order equation of reduced index 5/4. These simple waves appear not to have examined before. For a given initial strain, the simple wave solution prescribes initial sphere centroid velocities. Together the initial strain and velocities are used in the second-order discrete system. Results for shock wave development compare very well between the second-order discrete system (minus physically valid oscillations) and the reduced first-order equation. A second-order simulation of colliding waves examines the ability of waves to pass through each other, with a phase advance accruing during the collision process. An arbitrary initial condition is shown to evolve toward a universal similarity solution proportional to (x/t)(4). A closed-form solution is given including the complete history of the waveform, shock location, and amplitude.

  7. Strain-induced ferroelectricity in simple rocksalt binary oxides

    OpenAIRE

    Bousquet, Eric; Spaldin, Nicola A.; Ghosez, Philippe

    2009-01-01

    The alkaline earth binary oxides adopt a simple rocksalt structure and form an important family of compounds because of their large presence in the earth's mantle and their potential use in microelectronic devices. In comparison to the class of multifunctional ferroelectric perovskite oxides, however, their practical applications remain limited and the emergence of ferroelectricity and related functional properties in simple binary oxides seems so unlikely that it was never previously conside...

  8. Computer electronics made simple computerbooks

    CERN Document Server

    Bourdillon, J F B

    1975-01-01

    Computer Electronics: Made Simple Computerbooks presents the basics of computer electronics and explains how a microprocessor works. Various types of PROMs, static RAMs, dynamic RAMs, floppy disks, and hard disks are considered, along with microprocessor support devices made by Intel, Motorola and Zilog. Bit slice logic and some AMD bit slice products are also described. Comprised of 14 chapters, this book begins with an introduction to the fundamentals of hardware design, followed by a discussion on the basic building blocks of hardware (NAND, NOR, AND, OR, NOT, XOR); tools and equipment that

  9. Nonlinear Pendulum: A Simple Generalization

    OpenAIRE

    Neto, J. P. Juchem

    2010-01-01

    In this work we solve the nonlinear second order differential equation of the simple pendulum with a general initial angular displacement ($\\theta(0)=\\theta_0$) and velocity ($\\dot{\\theta}(0)=\\phi_0$), obtaining a closed-form solution in terms of the Jacobi elliptic function $\\text{sn}(u,k)$, and of the the incomplete elliptical integral of the first kind $F(\\varphi,k)$. Such a problem can be used to introduce concepts like elliptical integrals and functions to advanced undergraduate students...

  10. Simple Simulations of DNA Condensation

    Energy Technology Data Exchange (ETDEWEB)

    STEVENS,MARK J.

    2000-07-12

    Molecular dynamics simulations of a simple, bead-spring model of semiflexible polyelectrolytes such as DNA are performed. All charges are explicitly treated. Starting from extended, noncondensed conformations, condensed structures form in the simulations with tetravalent or trivalent counterions. No condensates form or are stable for divalent counterions. The mechanism by which condensates form is described. Briefly, condensation occurs because electrostatic interactions dominate entropy, and the favored Coulombic structure is a charge ordered state. Condensation is a generic phenomena and occurs for a variety of polyelectrolyte parameters. Toroids and rods are the condensate structures. Toroids form preferentially when the molecular stiffness is sufficiently strong.

  11. Systems analysis made simple computerbooks

    CERN Document Server

    Antill, Lyn

    1980-01-01

    Systems Analysis: Made Simple Computerbooks introduces the essential elements of information systems analysis and design and teaches basic technical skills required for the tasks involved. The book covers the aspects to the design of an information system; information systems and the organization, including the types of information processing activity and computer-based information systems; the role of the systems analyst; and the human activity system. The text also discusses information modeling, socio-technical design, man-machine interface, and the database design. Software specification

  12. Simple laws of urban growth

    CERN Document Server

    Masucci, Paolo; Batty, Michael

    2012-01-01

    By analysing the evolution of the street network of Greater London from the late 1700s to the present, we are able to shed light on the inner mechanisms that lie behind the growth of a city. First we define an object called a city as a spatial discontinuous phenomena, from clustering the density of street intersections. Second, we find that the city growth mechanisms can be described by two logistic laws, hence can be determined by a simple model of urban network growth in the presence of competition for limited space.

  13. Windows Phone 7 Made Simple

    CERN Document Server

    Trautschold, Martin

    2011-01-01

    With Windows Phone 7, Microsoft has created a completely new smartphone operating system that focuses on allowing users to be productive with their smartphone in new ways, while offering seamless integration and use of Microsoft Office Mobile as well as other productivity apps available in the Microsoft App Store. Windows Phone 7 Made Simple offers a clear, visual, step-by-step approach to using your Windows Phone 7 smartphone, no matter what the manufacturer. Author Jon Westfall is an expert in mobile devices, recognized by Microsoft as a "Most Valuable Professional" with experience

  14. Simple spectrophotometric determination of monopersulfate.

    Science.gov (United States)

    Wacławek, S; Grübel, K; Černík, M

    2015-10-05

    A simple, sensitive and accurate spectrophotometric method has been developed and validated for the determination of monopersulfate (MPS) which is an active part of potassium monopersulfate triple salt that has the commercial name - Oxone. This work proposes a spectrophotometric determination of monopersulfate based on modification of the iodometric titration method. The analysis of absorption spectra was made for the concentration range from 1.35 to 13.01 ppm of MPS (with a detection and quantification limit of 0.41 and 1.35 ppm, respectively) and different pH values. The influence of several anions on the measurement was also investigated. Furthermore, the absorbance of iron and cobalt (often used as free radical initiators) proved to have no effect on the measurement of MPS concentrations. On the basis of the conducted studies, we propose 395 nm as an optimal wavelength for the determination of MPS concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Methadone radioimmunoassay: two simple methods

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, K.; Smith, R.N. (Metropolitan Police Forensic Science Laboratory, London (UK))

    1983-09-01

    Two simple and economical radioimmunoassays for methadone in blood or urine are described. Haemolysis, decomposition, common anticoagulants and sodium fluoride do not affect the results. One assay used commercially-available (1-/sup 3/H)(-)-methadone hydrobromide as the label, while the other uses a radioiodinated conjugate of 4-dimethylamino-2,2-diphenylpentanoic acid and L-tyrosine methyl ester. A commercially-available antiserum is used in both assays. Normethadone and ..cap alpha..-methadol cross-react to a small extent with the antiserum while methadone metabolites, dextropropoxyphene, dipipanone and phenadoxone have negligible cross-reactivities. The 'cut-offs' of the two assays as described are 30 and 33 ng ml/sup -1/ for blood, and 24 and 21 ng ml/sup -1/ for urine. The assay using the radioiodinated conjugate can be made more sensitive if required by increasing the specific activity of the label.

  16. iPad Made Simple

    CERN Document Server

    Trautschold, Martin; Learning, MSL Made Simple

    2010-01-01

    The new iPad is sleek, powerful, and most importantly, it's much more than just a big iPhone. Your iPad is can be used for reading, surfing the web, emailing, watching TV/Movies, getting work done, and much more. And with the upcoming wave of iPad apps, the possibilities are endless. iPad X Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instructions on how to set up and use the iPad * Illust

  17. Simple lattice model of macroevolution

    Science.gov (United States)

    Borkowski, Wojciech

    2009-04-01

    In future astrobiology, like in modern astrophysics, the numerical simulations can be a very important tool for proving theories. In this paper, I propose a simple lattice model of a multi-species ecosystem suitable for the study of emergent properties of macroevolution. Unlike the majority of ecological models, the number of species is not fixed - they emerge by "mutation" of existing species, then survive or go extinct depending on the balance between local ecological interactions. The Monte-Carlo numerical simulations show that this model is able to qualitatively reproduce phenomena that have been empirically observed, like the dependence between size of the isolated area and the number of species inhabiting there, primary production and species-diversity. The model allows also studying the causes of mass extinctions and more generally, repeatability, and the role of pure chance in macroevolution.

  18. Simple scaling of catastrophic landslide dynamics.

    Science.gov (United States)

    Ekström, Göran; Stark, Colin P

    2013-03-22

    Catastrophic landslides involve the acceleration and deceleration of millions of tons of rock and debris in response to the forces of gravity and dissipation. Their unpredictability and frequent location in remote areas have made observations of their dynamics rare. Through real-time detection and inverse modeling of teleseismic data, we show that landslide dynamics are primarily determined by the length scale of the source mass. When combined with geometric constraints from satellite imagery, the seismically determined landslide force histories yield estimates of landslide duration, momenta, potential energy loss, mass, and runout trajectory. Measurements of these dynamical properties for 29 teleseismogenic landslides are consistent with a simple acceleration model in which height drop and rupture depth scale with the length of the failing slope.

  19. A Simple Demonstration Model of Osmosis

    Science.gov (United States)

    Morse, Joseph G.

    1999-01-01

    A simple device constructed from a wire screen, a large beaker, beans, and oats is described. It provides a simple and effective visual model of the phenomenon of osmosis and, by extension, the origin of other colligative properties of solutions.

  20. Accuracy of simple folding model in the calculation of the direct part ...

    Indian Academy of Sciences (India)

    2014-04-30

    Apr 30, 2014 ... The direct part of real − interaction potential is calculated in the simple folding model using density-dependent Brink–Boeker effective interaction. The simple folding potentials calculated from the short- and finite-range components of this effective interaction are compared with their corresponding double ...

  1. Predicting Mercury's Precession using Simple Relativistic Newtonian Dynamics

    CERN Document Server

    Friedman, Y

    2016-01-01

    We present a new simple relativistic model for planetary motion describing accurately the anomalous precession of the perihelion of Mercury and its origin. The model is based on transforming Newton's classical equation for planetary motion from absolute to real spacetime influenced by the gravitational potential and introducing the concept of influenced direction.

  2. Simple substrates for complex cognition

    Directory of Open Access Journals (Sweden)

    Peter Dayan

    2008-12-01

    Full Text Available Complex cognitive tasks present a range of computational and algorithmic challenges for neural accounts of both learning and inference. In particular, it is extremely hard to solve them using the sort of simple policies that have been extensively studied as solutions to elementary Markov decision problems. There has thus been recent interest in architectures for the instantiation and even learning of policies that are formally more complicated than these, involving operations such as gated working memory. However, the focus of these ideas and methods has largely been on what might best be considered as automatized, routine or, in the sense of animal conditioning, habitual, performance. Thus, they have yet to provide a route towards understanding the workings of rule-based control, which is critical for cognitively sophisticated competence. Here, we review a recent suggestion for a uniform architecture for habitual and rule-based execution, discuss some of the habitual mechanisms that underpin the use of rules, and consider a statistical relationship between rules and habits.

  3. Semiregular factorization of simple graphs

    Directory of Open Access Journals (Sweden)

    Anthony J. Hilton

    2004-11-01

    Full Text Available A graph G is a (d, d + s-graph if the degree of each vertex of G lies in the interval [d, d + s]. A (d, d + 1-graph is said to be semiregular. An (r, r + 1 -factorization of a graph is a decomposition of the graph into edgedisjoint (r, r + 1-factors.We discuss here the state of knowledge about (r, r + 1-factorizations of d -regular graphs and of (d, d + 1-graphs.For r, s ≥ 0, let φ(r, s be the least integer such that, if d ≥ φ(r, s and G is any simple [d, d + s]-graph, then G has an (r, r + 1-factorization.Akiyama and Kano (when r is even and Cai (when r is odd showed that φ(r, s exists for all r, s. We show that, for s ≥ 2, φ(r, s = r(r + s + 1 + 1. Earlier φ(r, 0 was determined by Egawa and Era, and φ(r, 1 was determined by Hilton.

  4. Simple fabrication of gold nanobelts and patterns.

    Directory of Open Access Journals (Sweden)

    Renyun Zhang

    Full Text Available Gold nanobelts are of interest in several areas; however, there are only few methods available to produce these belts. We report here on a simple evaporation induced self-assembly (EISA method to produce porous gold nanobelts with dimensions that scale across nanometer (thickness ∼80 nm and micrometer (width ∼20 µm, to decimeter (length ∼0.15 m. The gold nanobelts are well packed on the beaker wall and can be easily made to float on the surface of the solution for depositing onto other substrates. Microscopy showed that gold nanobelts had a different structure on the two sides of the belt; the density of gold nanowires on one side was greater than on the other side. Electrical measurements showed that these nanobelts were sensitive to compressive or tensile forces, indicating a potential use as a strain sensor. The patterned nanobelts were further used as a template to grow ZnO nanowires for potential use in applications such as piezo-electronics.

  5. Semiclassical catastrophe theory of simple bifurcations

    Science.gov (United States)

    Magner, A. G.; Arita, K.

    2017-10-01

    The Fedoriuk-Maslov catastrophe theory of caustics and turning points is extended to solve the bifurcation problems by the improved stationary phase method (ISPM). The trace formulas for the radial power-law (RPL) potentials are presented by the ISPM based on the second- and third-order expansion of the classical action near the stationary point. A considerable enhancement of contributions of the two orbits (pair consisting of the parent and newborn orbits) at their bifurcation is shown. The ISPM trace formula is proposed for a simple bifurcation scenario of Hamiltonian systems with continuous symmetries, where the contributions of the bifurcating parent orbits vanish upon approaching the bifurcation point due to the reduction of the end-point manifold. This occurs since the contribution of the parent orbits is included in the term corresponding to the family of the newborn daughter orbits. Taking this feature into account, the ISPM level densities calculated for the RPL potential model are shown to be in good agreement with the quantum results at the bifurcations and asymptotically far from the bifurcation points.

  6. MPRINT: VAX printing made simple

    Energy Technology Data Exchange (ETDEWEB)

    Worlton, T.

    1994-08-01

    Users with stand-alone personal computers and personal printers usually find printing simple, but on a VAX computer or VAX cluster there may be many printers of different types located in different areas. The print queues set up for these printers may require different form qualifiers and may not all be able to print all documents. This article describes the basic steps a VAX system manager should take in setting up and managing print queues on a VAX and tells how to access these queues from a VAX, Unix, Macintosh, or DOS Computer. It gives a basic overview, but includes several helpful items that are obscure or completely undocumented. Following this overview, there is a description of a Fortran program, MPRINT, written to simplify printing for users. The MPRINT program simplifies the choice of printers and print forms for users of VAX print queues by allowing them to select from a one line per queue menu. The menu includes queue descriptions and only lists printers which can correctly print the specified file. MPRINT selects the correct form to use based on file type and maximum record length of the file. MPRINT may be useful at your site, and provides examples of a number of system services. MPRINT includes routines to do a user open of a file and get information from the File and Record Access Blocks (FAB and RAB), and a routine to obtain information about print queues. There are also routines to parse a file name, detab a character buffer, and trim trailing nulls and blanks from a character string.

  7. A simple model for studying interacting networks

    Science.gov (United States)

    Liu, Wenjia; Jolad, Shivakumar; Schmittmann, Beate; Zia, R. K. P.

    2011-03-01

    Many specific physical networks (e.g., internet, power grid, interstates), have been characterized in considerable detail, but in isolation from each other. Yet, each of these networks supports the functions of the others, and so far, little is known about how their interactions affect their structure and functionality. To address this issue, we consider two coupled model networks. Each network is relatively simple, with a fixed set of nodes, but dynamically generated set of links which has a preferred degree, κ . In the stationary state, the degree distribution has exponential tails (far from κ), an attribute which we can explain. Next, we consider two such networks with different κ 's, reminiscent of two social groups, e.g., extroverts and introverts. Finally, we let these networks interact by establishing a controllable fraction of cross links. The resulting distribution of links, both within and across the two model networks, is investigated and discussed, along with some potential consequences for real networks. Supported in part by NSF-DMR-0705152 and 1005417.

  8. The Fluid Foil: The Seventh Simple Machine

    Science.gov (United States)

    Mitts, Charles R.

    2012-01-01

    A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

  9. Simple utility functions with Giffen demand

    DEFF Research Database (Denmark)

    Sørensen, Peter Norman

    2007-01-01

    Simple utility functions with the Giffen property are presented: locally, the demand curve for a good is upward sloping. The utility functions represent continuous, monotone, convex preferences......Simple utility functions with the Giffen property are presented: locally, the demand curve for a good is upward sloping. The utility functions represent continuous, monotone, convex preferences...

  10. Sunspots and Their Simple Harmonic Motion

    Science.gov (United States)

    Ribeiro, C. I.

    2013-01-01

    In this paper an example of a simple harmonic motion, the apparent motion of sunspots due to the Sun's rotation, is described, which can be used to teach this subject to high-school students. Using real images of the Sun, students can calculate the star's rotation period with the simple harmonic motion mathematical expression.

  11. Simple Numerical Analysis of Longboard Speedometer Data

    Science.gov (United States)

    Hare, Jonathan

    2013-01-01

    Simple numerical data analysis is described, using a standard spreadsheet program, to determine distance, velocity (speed) and acceleration from voltage data generated by a skateboard/longboard speedometer (Hare 2012 "Phys. Educ." 47 409-17). This simple analysis is an introduction to data processing including scaling data as well as…

  12. Simple bone cysts of two brothers

    Energy Technology Data Exchange (ETDEWEB)

    An, Seo Young; An, Chang Hyeon; Choi, Karp Shik [Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyungpook National University, Daegu (Korea, Republic of)

    2008-09-15

    17-year-old and 14-year-old brothers were referred for evaluation of the cystic lesions on the mandibular anterior area with no symptoms. Neither their mother nor the brothers could recall any past trauma to those areas. Panoramic and intraoral radiographs revealed moderately defined cystic lesions on their mandibular anterior areas. Biopsies on both lesions revealed simple bone cysts. Hereditary cause or familial history of simple bone cysts could not be found in literature review. This case may have been a coincidence. However, further investigation is needed to find the cause of simple bone cysts occurring in patients those are closely related.

  13. Emergent biosynthetic capacity in simple microbial communities.

    Directory of Open Access Journals (Sweden)

    Hsuan-Chao Chiu

    2014-07-01

    Full Text Available Microbes have an astonishing capacity to transform their environments. Yet, the metabolic capacity of a single species is limited and the vast majority of microorganisms form complex communities and join forces to exhibit capabilities far exceeding those achieved by any single species. Such enhanced metabolic capacities represent a promising route to many medical, environmental, and industrial applications and call for the development of a predictive, systems-level understanding of synergistic microbial capacity. Here we present a comprehensive computational framework, integrating high-quality metabolic models of multiple species, temporal dynamics, and flux variability analysis, to study the metabolic capacity and dynamics of simple two-species microbial ecosystems. We specifically focus on detecting emergent biosynthetic capacity--instances in which a community growing on some medium produces and secretes metabolites that are not secreted by any member species when growing in isolation on that same medium. Using this framework to model a large collection of two-species communities on multiple media, we demonstrate that emergent biosynthetic capacity is highly prevalent. We identify commonly observed emergent metabolites and metabolic reprogramming patterns, characterizing typical mechanisms of emergent capacity. We further find that emergent secretion tends to occur in two waves, the first as soon as the two organisms are introduced, and the second when the medium is depleted and nutrients become limited. Finally, aiming to identify global community determinants of emergent capacity, we find a marked association between the level of emergent biosynthetic capacity and the functional/phylogenetic distance between community members. Specifically, we demonstrate a "Goldilocks" principle, where high levels of emergent capacity are observed when the species comprising the community are functionally neither too close, nor too distant. Taken together

  14. [Identification of simple safe practices in a primary care area].

    Science.gov (United States)

    Cañada Dorado, A; García Cubero, C; García Ferradal, I; Alonso Safont, T; Sánchez Márquez, M A; Serrablo Requejo, S; Montero Fernández, M J

    2011-01-01

    To assess the safe practices (SP) prepared by the Health Risk Management Functional Unit (UFGRS), according to their complexity of introduction and the impact on patient safety, and to identify simple SP. A number of important SP have been prepared by the UFGRS of Madrid Health Area 4 Primary Care (PC). They were subsequently assessed according to their complexity of introduction and their potential impact on patient safety, simple SP (SSP) for the prevention of adverse events, low complexity of introduction and impact on patient safety. Lastly, the barriers to their effective introduction were identified, and actions were designed to overcome these barriers. Of the 50 PS prepared, 42 have been applied in the whole Area. Seven Level 1 SP (which fulfil the ideal conditions) were identified as simple SP. The main barriers were due to lack of training, culture, leadership of the management teams and professionals of the centre and lack of knowledge of the SPs. A large number of SP has been prepared by the UFGRS, with simple SP being identified for PC. The majority of these have to do with the safe use of drugs and vaccines. Copyright © 2010 SECA. Published by Elsevier Espana. All rights reserved.

  15. Abundance, composition and distribution of simple sequence ...

    Indian Academy of Sciences (India)

    Abundance, composition and distribution of simple sequence repeats and dinucleotide compositional bias within WSSV genomes. MALATHI SHEKAR, INDRANI KARUNASAGAR and IDDYA KARUNASAGAR*. Department of Fishery Microbiology, UNESCO Centre for Marine Biotechnology,. Karnataka Veterinary, Animal ...

  16. Thirty Simple Ideas for Interactive Whiteboards

    Science.gov (United States)

    Adams, Caralee

    2011-01-01

    This article presents thirty simple ideas for interactive whiteboards and how IWB can make one's teaching life easier. These teaching ideas for the interactive whiteboard can be used by teachers every day. Tips for classroom management are also presented.

  17. A Simple Preparation Method for Diphosphoimidazole

    DEFF Research Database (Denmark)

    Rosenberg, T.

    1964-01-01

    A simple method for the preparation of diphosphoimidazole is presented that involves direct phosphorylation of imidazole by phosphorus oxychloride in alkaline aqueous solution. Details are given on the use of diphosphoimidazole in preparing sodium phosphoramidate and certain phosphorylated amino...

  18. Universal mechanism of (semi-classical) deconfinement and θ-dependence for all simple groups

    National Research Council Canada - National Science Library

    Poppitz, Erich; Schäfer, Thomas; Ünsal, Mithat

    2013-01-01

    .... The mechanism governing the phase transition is universal and valid for all simple groups. The perturbative one-loop potential as well as monopole-instantons generate attraction among the eigenvalues of the Wilson line...

  19. Universal mechanism of deconfinement and I,-dependence for all simple groups

    National Research Council Canada - National Science Library

    Poppitz, Erich; Schafer, Thomas; Unsal, Mithat

    2013-01-01

    .... The mechanism governing the phase transition is universal and valid for all simple groups. The perturbative one-loop potential as well as monopole-instantons generate attraction among the eigenvalues of the Wilson line...

  20. Universal mechanism of (semi-classical) deconfinement and [theta]-dependence for all simple groups

    National Research Council Canada - National Science Library

    Erich Poppitz; Thomas Schäfer; Mithat Ünsal

    2013-01-01

    .... The mechanism governing the phase transition is universal and valid for all simple groups. The perturbative one-loop potential as well as monopole-instantons generate attraction among the eigenvalues of the Wilson line...

  1. Technical note: simple vibroacoustic foetal stimulator.

    Science.gov (United States)

    Stojanović, D; Frković, A; Filiplić-Stojanović, H; Kirincić, N

    2001-01-01

    To build and test a simple vibroacoustic foetal stimulator. A vibroacoustic foetal stimulator was constructed and subjected to bench testing. Clinical trial was carried out in comparison to an electro laynx. Screening specificity of 98% and 100% sensitivity was achieved, with no decrease in specificity due to user's maladjustments. The device was characterized by simple use, maintenance and disinfection. The device is a good screening instrument for foetal health in prenatal care, despite its simplicity and low price.

  2. Simple trophic modules for complex food webs

    OpenAIRE

    Bascompte, Jordi; Carlos J. Melián

    2005-01-01

    There are two common approaches to food webs. On the one hand, empirical studies have described aggregate statistical measures of many-species food webs. On the other hand, theoretical studies have explored the dynamic properties of simple tri-trophic food chains (i.e., trophic modules). The question remains to what extent results based on simple modules are relevant for whole food webs. Here we bridge between these two independent research agendas by exploring the relative fr...

  3. A simple probabilistic model of multibody interactions in proteins.

    Science.gov (United States)

    Johansson, Kristoffer Enøe; Hamelryck, Thomas

    2013-08-01

    Protein structure prediction methods typically use statistical potentials, which rely on statistics derived from a database of know protein structures. In the vast majority of cases, these potentials involve pairwise distances or contacts between amino acids or atoms. Although some potentials beyond pairwise interactions have been described, the formulation of a general multibody potential is seen as intractable due to the perceived limited amount of data. In this article, we show that it is possible to formulate a probabilistic model of higher order interactions in proteins, without arbitrarily limiting the number of contacts. The success of this approach is based on replacing a naive table-based approach with a simple hierarchical model involving suitable probability distributions and conditional independence assumptions. The model captures the joint probability distribution of an amino acid and its neighbors, local structure and solvent exposure. We show that this model can be used to approximate the conditional probability distribution of an amino acid sequence given a structure using a pseudo-likelihood approach. We verify the model by decoy recognition and site-specific amino acid predictions. Our coarse-grained model is compared to state-of-art methods that use full atomic detail. This article illustrates how the use of simple probabilistic models can lead to new opportunities in the treatment of nonlocal interactions in knowledge-based protein structure prediction and design. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  4. Promoting protein crystallization using a plate with simple geometry.

    Science.gov (United States)

    Chen, Rui-Qing; Yin, Da-Chuan; Liu, Yong-Ming; Lu, Qin-Qin; He, Jin; Liu, Yue

    2014-03-01

    Increasing the probability of obtaining protein crystals in crystallization screening is always an important goal for protein crystallography. In this paper, a new method called the cross-diffusion microbatch (CDM) method is presented, which aims to efficiently promote protein crystallization and increase the chance of obtaining protein crystals. In this method, a very simple crystallization plate was designed in which all crystallization droplets are in one sealed space, so that a variety of volatile components from one droplet can diffuse into any other droplet via vapour diffusion. Crystallization screening and reproducibility tests indicate that this method could be a potentially powerful technique in practical protein crystallization screening. It can help to obtain crystals with higher probability and at a lower cost, while using a simple and easy procedure.

  5. A simple probabilistic model of multibody interactions in proteins

    DEFF Research Database (Denmark)

    Johansson, Kristoffer Enøe; Hamelryck, Thomas

    2013-01-01

    beyond pairwise interactions have been described, the formulation of a general multibody potential is seen as intractable due to the perceived limited amount of data. In this article, we show that it is possible to formulate a probabilistic model of higher order interactions in proteins, without...... arbitrarily limiting the number of contacts. The success of this approach is based on replacing a naive table-based approach with a simple hierarchical model involving suitable probability distributions and conditional independence assumptions. The model captures the joint probability distribution of an amino...... predictions. Our coarse-grained model is compared to state-of-art methods that use full atomic detail. This article illustrates how the use of simple probabilistic models can lead to new opportunities in the treatment of nonlocal interactions in knowledge-based protein structure prediction and design....

  6. Surface core-level shifts for simple metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1994-01-01

    We have performed an ab initio study of the surface core-level binding energy shift (SCLS) for 11 of the simple metals by means of a Green’s-function technique within the tight-binding linear-muffin-tin-orbitals method. Initial- and final-state effects are included within the concept of complete....... We discuss the surface shifts of the electrostatic potentials and the band centers in order to trace the microscopic origin of the SCLS in the simple metals and find that the anomalous subsurface core-level shifts in beryllium are caused by charge dipoles, which persist several layers into the bulk....... We furthermore conclude that the unexpected negative sign of the SCLS in beryllium is predominantly an initial-state effect and is caused by the high electron density in this metal....

  7. A simple kinetic theory of auroral arc scales

    Science.gov (United States)

    Chiu, Y. T.

    1986-01-01

    A kinetic theory of the origins of the auroral arc scale spectrum is presented in this paper. The conceptual basis of the theory is current conservation in a turbulent plasma at the magnetospheric equatorial region in which a field-aligned current is generated and the local electrostatic potential structure is forced to adjust to the presence of the field-aligned current. This simple model uses an ad hoc Ohm's law relationship between the perpendicular current and the perpendicular electric field, but with a negative conductance in the generator region so that J(perpendicular) x E(perpendicular) is less than 0. An exact solution of a simple model of the concept yields a bistatic auroral generator for which multiple-arc formation is predicted if the field-aligned current exceeds a critical value. The predicted scale spectrum is inversely proportional to the square root of the field-aligned current strength spectrum.

  8. Regular Simple Queues of Protein Contact Maps.

    Science.gov (United States)

    Guo, Qiang-Hui; Sun, Lisa Hui; Wang, Jian

    2017-01-01

    A protein fold can be viewed as a self-avoiding walk in certain lattice model, and its contact map is a graph that represents the patterns of contacts in the fold. Goldman, Istrail, and Papadimitriou showed that a contact map in the 2D square lattice can be decomposed into at most two stacks and one queue. In the terminology of combinatorics, stacks and queues are noncrossing and nonnesting partitions, respectively. In this paper, we are concerned with 2-regular and 3-regular simple queues, for which the degree of each vertex is at most one and the arc lengths are at least 2 and 3, respectively. We show that 2-regular simple queues are in one-to-one correspondence with hill-free Motzkin paths, which have been enumerated by Barcucci, Pergola, Pinzani, and Rinaldi by using the Enumerating Combinatorial Objects method. We derive a recurrence relation for the generating function of Motzkin paths with [Formula: see text] peaks at level i, which reduces to the generating function for hill-free Motzkin paths. Moreover, we show that 3-regular simple queues are in one-to-one correspondence with Motzkin paths avoiding certain patterns. Then we obtain a formula for the generating function of 3-regular simple queues. Asymptotic formulas for 2-regular and 3-regular simple queues are derived based on the generating functions.

  9. The Design of SimpleITK

    Directory of Open Access Journals (Sweden)

    Bradley Christopher Lowekamp

    2013-12-01

    Full Text Available SimpleITK is a new interface to the Insight Segmentation andRegistration Toolkit (ITK designed to facilitate rapid prototyping, educationand scientific activities, via high level programminglanguages. ITK is a templated C++ library of image processingalgorithms and frameworks for biomedical and other applications, andit was designed to be generic, flexible and extensible. Initially, ITKprovided a direct wrapping interface to languages such as Python andTcl through the WrapITK system. Unlike WrapITK, which exposed ITK'scomplex templated interface, SimpleITK was designed to provide an easyto use and simplified interface to ITK's algorithms. It includesprocedural methods, hides ITK's demand driven pipeline, and provides atemplate-less layer. Also SimpleITK provides practical conveniencessuch as binary distribution packages and overloaded operators. Ouruser-friendly design goals dictated a departure from the directinterface wrapping approach of WrapITK, towards a new facadeclass structure that only exposes the required functionality, hidingITK's extensive template use. Internally SimpleITK utilizes a manualdescription of each filter with code-generation and advanced C++meta-programming to provide the higher-level interface, bringing thecapabilities of ITK to a wider audience. SimpleITK is licensed asopen source software under the Apache License Version 2.0 and more informationabout downloading it can be found at http://www.simpleitk.org.

  10. Steinitz theorems for simple orthogonal polyhedra

    Directory of Open Access Journals (Sweden)

    David Eppstein

    2014-09-01

    Full Text Available We define a simple orthogonal polyhedron to be a three-dimensional polyhedron with the topology of a sphere in which three mutually-perpendicular edges meet at each vertex.By analogy to Steinitz's theorem characterizing the graphs of convex polyhedra, we find graph-theoretic characterizations of three classes of simple orthogonal polyhedra: corner polyhedra, which can be drawn by isometric projection in the plane with only one hidden vertex, xyz polyhedra, in which each axis-parallel line through a vertex contains exactly one other vertex, and arbitrary simple orthogonal polyhedra. In particular, the graphs of xyz polyhedra are exactly the bipartite cubic polyhedral graphs, and every bipartite cubic polyhedral graph with a 4-connected dual graph is the graph of a corner polyhedron. Based on our characterizations we find efficient algorithms for constructing orthogonal polyhedra from their graphs.

  11. Maximal temperature in a simple thermodynamical system

    Science.gov (United States)

    Dai, De-Chang; Stojkovic, Dejan

    2016-06-01

    Temperature in a simple thermodynamical system is not limited from above. It is also widely believed that it does not make sense talking about temperatures higher than the Planck temperature in the absence of the full theory of quantum gravity. Here, we demonstrate that there exist a maximal achievable temperature in a system where particles obey the laws of quantum mechanics and classical gravity before we reach the realm of quantum gravity. Namely, if two particles with a given center of mass energy come at the distance shorter than the Schwarzschild diameter apart, according to classical gravity they will form a black hole. It is possible to calculate that a simple thermodynamical system will be dominated by black holes at a critical temperature which is about three times lower than the Planck temperature. That represents the maximal achievable temperature in a simple thermodynamical system.

  12. Simple microfluidic stagnation point flow geometries.

    Science.gov (United States)

    Dockx, Greet; Verwijlen, Tom; Sempels, Wouter; Nagel, Mathias; Moldenaers, Paula; Hofkens, Johan; Vermant, Jan

    2016-07-01

    A geometrically simple flow cell is proposed to generate different types of stagnation flows, using a separation flow and small variations of the geometric parameters. Flows with high local deformation rates can be changed from purely rotational, over simple shear flow, to extensional flow in a region surrounding a stagnation point. Computational fluid dynamic calculations are used to analyse how variations of the geometrical parameters affect the flow field. These numerical calculations are compared to the experimentally obtained streamlines of different designs, which have been determined by high speed confocal microscopy. As the flow type is dictated predominantly by the geometrical parameters, such simple separating flow devices may alleviate the requirements for flow control, while offering good stability for a wide variety of flow types.

  13. Simple shearing interferometer suitable for vibration measurements

    Science.gov (United States)

    Mihaylova, Emilia M.; Whelan, Maurice P.; Toal, Vincent

    2004-06-01

    Recently there has been an increasing interest in the application of shearography for modal analysis of vibrating objects. New interferometric systems, which are simple and flexible are of interest for engineering and industrial applications. An electronic speckle pattern shearing interferometer (ESPSI) with a very simple shearing device is used for study of vibrations. The shearing device consists of two partially reflective glass plates. The reflection coefficients of the coatings are 0.3 and 0.7 respectively. The distance between the two glass plates controls the size of the shear. The versatility of this simple shearing interferometer is shown. It is demonstrated that the ESPSI system can be used for vibration measurements and phase-shifting implemented for fringe analysis. The results obtained are promising for future applications of the system for modal analysis.

  14. TRSkit: A Simple Digital Library Toolkit

    Science.gov (United States)

    Nelson, Michael L.; Esler, Sandra L.

    1997-01-01

    This paper introduces TRSkit, a simple and effective toolkit for building digital libraries on the World Wide Web. The toolkit was developed for the creation of the Langley Technical Report Server and the NASA Technical Report Server, but is applicable to most simple distribution paradigms. TRSkit contains a handful of freely available software components designed to be run under the UNIX operating system and served via the World Wide Web. The intended customer is the person that must continuously and synchronously distribute anywhere from 100 - 100,000's of information units and does not have extensive resources to devote to the problem.

  15. Uso del simulador SimpleReuse

    OpenAIRE

    Álvarez Martínez, Carlos; Valero Cortés, Mateo

    2005-01-01

    Este report explica el funcionamiento del simulador SimpleReuse (una evolución de SimpleScalar y Wattch) para su uso en simulación de reuso de instrucciones o regiones. Este simulador realiza medidas de tiempo, instrucciones y consumo de potencia de códigos Alpha ejecutados en máquinas de muy distinta complejidad. El simulador no se encuentra disponible en la Web en este momento debido a que está en constante mejora, pero si hay alguien interesado en su uso puede pedirlo directamente a través...

  16. A Simple Sketch Symbolizing Self-Reliance

    Centers for Disease Control (CDC) Podcasts

    2017-02-16

    EID Managing Editor, Byron Breedlove, reads his cover art story, A Simple Sketch Symbolizing Self-Reliance.  Created: 2/16/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/16/2017.

  17. A Simple View of Writing in Chinese

    Science.gov (United States)

    Yeung, Pui-sze; Ho, Connie Suk-han; Chan, David Wai-ock; Chung, Kevin Kien-hoa

    2017-01-01

    This study examined the Chinese written composition development of elementary-grade students in relation to the simple view of writing. Measures of nonverbal reasoning ability, component skills of transcription (stroke sequence knowledge, word spelling, and handwriting fluency), oral language (definitional skill, oral narrative skills, and…

  18. Simple Obstacle Avoidance Algorithm for Rehabilitation Robots

    NARCIS (Netherlands)

    Stuyt, Floran H.A.; Römer, GertWillem R.B.E.; Stuyt, Harry .J.A.

    2007-01-01

    The efficiency of a rehabilitation robot is improved by offering record-and-replay to operate the robot. While automatically moving to a stored target (replay) collisions of the robot with obstacles in its work space must be avoided. A simple, though effective, generic and deterministic algorithm

  19. Simple suture and anchor in rabbit hips

    Science.gov (United States)

    Garcia Filho, Fernando Cal; Guarniero, Roberto; de Godoy Júnior, Rui Maciel; Pereira, César Augusto Martins; Matos, Marcos Almeida; Garcia, Lucas Cortizo

    2012-01-01

    Objective Using biomechanical studies, this research aims to compare hip capsulorrhaphy in rabbits, carried out with two different techniques: capsulorrhaphy with simple sutures and with anchors. Method Thirteen New Zealand Albino (Oryctolaguscuniculus) male rabbits, twenty-six hip joints, were used. First, a pilot project was performed with three rabbits (six hip joints). This experiment consisted of ten rabbits divided into two groups: group 1 underwent capsulorrhaphy on both right and left hips with simple suture using polyglycolic acid absorbable thread, and group 2 underwent capsulorrhaphy with titanium anchors. After a four-week postoperative period, the animals were euthanized and the hip joints were frozen. On the same day of the biomechanical studies, after the hip joints were previously unfrozen, the following parameters were evaluated: rigidity, maximum force, maximum deformity and energy. Results There was no relevant statistical difference in rigidity, maximum force, maximum deformity and energy between the simple suture and anchor groups. Conclusion Through biomechanical analyses, using parameters of rigidity, maximum force, maximum deformity and energy, it has been shown that capsulorrhaphy with simple suture and with anchors has similar results in rabbit hip joints. Level of Evidence II, Prospective Comparative Study. PMID:24453618

  20. A Simple Homemade Polarised Sunglasses Test Card

    Science.gov (United States)

    Bamdad, Farzad

    2016-01-01

    In this article construction of a simple and inexpensive test card which can be used to demonstrate the polarisation ability of sunglasses is described. The card was fabricated simply by using a piece of polariser sheet with one to three layers of cellophane tape fixed on it.

  1. Building systems from simple hyperbolic ones

    NARCIS (Netherlands)

    Zwart, Heiko J.; Le Gorrec, Y.; Maschke, B.

    In this article we introduce a technique that derives from the existence and uniqueness of solutions to a simple hyperbolic partial differential equation (p.d.e.) the existence and uniqueness of solutions to hyperbolic and parabolic p.d.e.’s. Among others, we show that starting with an impedance

  2. A Simple Classroom Demonstration of Natural Convection

    Science.gov (United States)

    Wheeler, Dean R.

    2005-01-01

    This article explains a simple way to demonstrate natural convection, such as from a lit candle, in the classroom using an overhead projector. The demonstration is based on the principle of schlieren imaging, commonly used to visualize variations in density for gas flows.

  3. Tour of a Simple Trigonometry Problem

    Science.gov (United States)

    Poon, Kin-Keung

    2012-01-01

    This article focuses on a simple trigonometric problem that generates a strange phenomenon when different methods are applied to tackling it. A series of problem-solving activities are discussed, so that students can be alerted that the precision of diagrams is important when solving geometric problems. In addition, the problem-solving plan was…

  4. A simple design rule for overlap joints

    NARCIS (Netherlands)

    Straalen, IJ.J. van

    2004-01-01

    For toughened and flexible adhesives it is found that a simple prediction model for overlap joints can be used to calculate the ultimate strength for the static load case. The absolute maximum strength for a lap joint is when the whole of the adhesive layer is at the shear yield strength. An

  5. Strong Bisimilarity of Simple Process Algebras

    DEFF Research Database (Denmark)

    Srba, Jirí

    2003-01-01

    We study bisimilarity and regularity problems of simple process algebras. In particular, we show PSPACE-hardness of the following problems: (i) strong bisimilarity of Basic Parallel Processes (BPP), (ii) strong bisimilarity of Basic Process Algebra (BPA), (iii) strong regularity of BPP, and (iv) ...

  6. Correcting the SIMPLE Model of Free Recall

    Science.gov (United States)

    Lee, Michael D.; Pooley, James P.

    2013-01-01

    The scale-invariant memory, perception, and learning (SIMPLE) model developed by Brown, Neath, and Chater (2007) formalizes the theoretical idea that scale invariance is an important organizing principle across numerous cognitive domains and has made an influential contribution to the literature dealing with modeling human memory. In the context…

  7. Modelling of the simple pendulum Experiment

    Directory of Open Access Journals (Sweden)

    Palka L.

    2016-01-01

    Full Text Available Abstract - work focuses on the design of the simulation embedded in remote experiment “Simple pendulum” built on the Internet School Experimental System (ISES. This platform is intended for wide educational purposes at schools and universities in order to provide the suitable measuring environment for students using conventional computing resources Informatics.

  8. A simple method for complex eigenvalues

    Energy Technology Data Exchange (ETDEWEB)

    Killingbeck, John P [Mathematics Department, University of Hull, Hull HU6 7RX (United Kingdom); Grosjean, Alain [Laboratoire d' Astrophysique de l' Observatoire de Besancon, CNRS, UMR 6091, 41 bis Avenue de l' Observatoire, BP1615, 25010 Besancon Cedex (France); Jolicard, Georges [Laboratoire d' Astrophysique de l' Observatoire de Besancon, CNRS, UMR 6091, 41 bis Avenue de l' Observatoire, BP1615, 25010 Besancon Cedex (France)

    2004-11-05

    A simple iterative method is described for finding the eigenvalues of a general square complex matrix. Several numerical examples involving complex symmetric matrices are treated. In particular, it is found that a naive matrix calculation without complex rotation produces resonant state energies in accord with those given by the recently introduced naive complex hypervirial perturbation theory. (letter to the editor)

  9. SLURM: Simple Linux Utility for Resource Management

    Energy Technology Data Exchange (ETDEWEB)

    Jette, M; Grondona, M

    2002-12-19

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. This paper presents an overview of the SLURM architecture and functionality.

  10. Studying the Greenhouse Effect: A Simple Demonstration.

    Science.gov (United States)

    Papageorgiou, G.; Ouzounis, K.

    2000-01-01

    Studies the parameters involved in a presentation of the greenhouse effect and describes a simple demonstration of this effect. Required equipment includes a 100-120 watt lamp, a 250mL beaker, and a thermometer capable of recording 0-750 degrees Celsius together with a small amount of chloroform. (Author/SAH)

  11. Simple Calculation Programs for Biology Other Methods

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Other Methods. Hemolytic potency of drugs. Raghava et al., (1994) Biotechniques 17: 1148. FPMAP: methods for classification and identification of microorganisms 16SrRNA. graphical display of restriction and fragment map of ...

  12. Simple classical approach to spin resonance phenomena

    DEFF Research Database (Denmark)

    Gordon, R A

    1977-01-01

    A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...

  13. Geometric classification of simple graph algebras

    DEFF Research Database (Denmark)

    Sørensen, Adam Peder Wie

    2013-01-01

    Inspired by Franks’ classification of irreducible shifts of finite type, we provide a short list of allowed moves on graphs that preserve the stable isomorphism class of the associated C ∗ -algebras. We show that if two graphs have stably isomorphic and simple unital algebras then we can use...

  14. Figuring the Acceleration of the Simple Pendulum

    Science.gov (United States)

    Lieberherr, Martin

    2011-01-01

    The centripetal acceleration has been known since Huygens' (1659) and Newton's (1684) time. The physics to calculate the acceleration of a simple pendulum has been around for more than 300 years, and a fairly complete treatise has been given by C. Schwarz in this journal. But sentences like "the acceleration is always directed towards the…

  15. Simple Analysis of Historical Lime Mortars

    Science.gov (United States)

    Pires, Joa~o

    2015-01-01

    A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These…

  16. Simple Activity Demonstrates Wind Energy Principles

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    Wind energy is an exciting and clean energy option often described as the fastest-growing energy system on the planet. With some simple materials, teachers can easily demonstrate its key principles in their classroom. (Contains 1 figure and 2 tables.)

  17. Lumbar Puncture for First Simple Febrile Seizure

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-01-01

    Full Text Available Compliance with American Academy of Pediatrics consensus statement recommendations regarding lumbar puncture for infants 6-18 months of age with a first simple febrile seizure was investigated by a retrospective review of 704 infants evaluated in the pediatric emergency medicine division at Children’s Hospital Boston, MA, Oct 1995-Oct 2006.

  18. Simple wave interaction of an elastic string

    NARCIS (Netherlands)

    Broer, L.J.F.; van Groesen, Embrecht W.C.

    1977-01-01

    The equations for the two-dimensional motion of a completely flexible elastic string can be derived from a Lagrangian. The equations of motion possess four characteristic velocities, to which the following four simple wave solutions correspond: leftward and rightward propagating longitudinal and

  19. Question Answering for Dutch : Simple does it

    NARCIS (Netherlands)

    Hoekstra, A.H.; Hiemstra, Djoerd; van der Vet, P.E.; Huibers, Theo W.C.; Schobbens, Pierre-Yves; Vanhoof, Wim; Schwanen, Gabriel

    2006-01-01

    When people pose questions in natural language to search for information on the web, the role of question answering (QA) systems becomes important. In this paper the QAsystem simpleQA, capable of answering Dutch questions on which the answer is a person or a location, is described. The system's

  20. Knowledge acquisition for a simple expert controller

    Science.gov (United States)

    Bieker, B.

    1987-01-01

    A method is presented for process control which has the properties of being incremental, cyclic and top-down. It is described on the basis of the development of an expert controller for a simple, but nonlinear control route. A quality comparison between expert controller and process operator shows the ability of the method for knowledge acquisition.

  1. A Simple Decoder for Topological Codes

    Directory of Open Access Journals (Sweden)

    James Wootton

    2015-04-01

    Full Text Available Here we study an efficient algorithm for decoding topological codes. It is a simple form of HDRG decoder, which could be straightforwardly generalized to complex decoding problems. Specific results are obtained for the planar code with both i.i.d. and spatially correlated errors. The method is shown to compare well with existing ones, despite its simplicity.

  2. Simple Calculation Programs for Biology Immunological Methods

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Immunological Methods. Computation of Ab/Ag Concentration from EISA data. Graphical Method; Raghava et al., 1992, J. Immuno. Methods 153: 263. Determination of affinity of Monoclonal Antibody. Using non-competitive ...

  3. Simple concurrent garbage collection almost without synchronization

    NARCIS (Netherlands)

    Hesselink, Wim H.; Lali, M.I.

    We present two simple mark and sweep algorithms, A and B, for concurrent garbage collection by a single collector running concurrently with a number of mutators that concurrently modify shared data. Both algorithms are based on the ideas of Ben-Ari's classical algorithm for on-the-fly garbage

  4. Simple tertiary phosphines to hexaphosphane ligands: Syntheses ...

    Indian Academy of Sciences (India)

    Abstract. Designing efficient phosphorus-based ligands to make catalysts for homogeneous catalysis has been a great challenge for chemists. Despite a plethora of phosphorus ligands ranging from simple tertiary phosphines to polyphosphines are known, the enthusiasm to generate new ones is mainly due to the demand.

  5. Simple algebraic data types for C

    NARCIS (Netherlands)

    Hartel, Pieter H.; Muller, Henk L.

    Adt is a simple tool in the spirit of Lex and Yacc that makes monomorphic algebraic data types, polymorphic built-in types like the list and an efficient form of pattern matching available in C programs. C programs built with ADTs typically use NULL pointers only to indicate don't care values, and

  6. Nature versus Nurture: The Simple Contrast

    Science.gov (United States)

    Davidoff, Jules; Goldstein, Julie; Roberson, Debi

    2009-01-01

    We respond to the commentary of Franklin, Wright, and Davies ("Journal of Experimental Child Psychology, 102", 239-245 [2009]) by returning to the simple contrast between nature and nurture. We find no evidence from the toddler data that makes us revise our ideas that color categories are learned and never innate. (Contains 1 figure.)

  7. Simulated Holograms: A Simple Introduction to Holography.

    Science.gov (United States)

    Dittmann, H.; Schneider, W. B.

    1992-01-01

    Describes a project that uses a computer and a dot matrix printer to simulate the holographic recording process of simple object structures. The process' four steps are (1) superposition of waves; (2) representing the superposition of a plane reference wave on the monitor screen; (3) photographic reduction of the images; and (4) reconstruction of…

  8. Simple Approach to Superamphiphobic Overhanging Silicon Nanostructures

    DEFF Research Database (Denmark)

    Kumar, Rajendra; Mogensen, Klaus Bo; Bøggild, Peter

    2010-01-01

    with contact angles up to 152 degrees and roll-off angle down to 8 degrees. Such nonlithographic nanoscale overhanging Structures can also be added to silicon nanograss by deposition of a thin SiO2 layer, which equips the silicon rods with 100-300 nm sized overhanging Structures. This is a simple, fast...

  9. Simple Demonstration of the Seebeck Effect

    Science.gov (United States)

    Molki, Arman

    2010-01-01

    In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. (Contains 3 tables and 3 figures.)

  10. A SIMPLE SPECTROPHOTOMETRIC DETERMINATION OF TRACE ...

    African Journals Online (AJOL)

    a

    ABSTRACT. A simple and sensitive spectrophotometric method has been developed for the determination of trace amounts of vanadium using thionin as a chromogenic reagent. The proposed method is based on the reaction of vanadium(V) with potassium iodide in acid medium to liberate iodine, which bleaches the violet ...

  11. Simple sequence repeats in mycobacterial genomes

    Indian Academy of Sciences (India)

    Prakash

    2006-12-18

    Dec 18, 2006 ... Simple sequence repeats (SSRs) or microsatellites are the repetitive sequence motifs of 1–6 bp (Schlotterer 2000). They are scattered throughout the genomes of all the known organisms ranging from viruses to eukaryotes (Heller et al. 1982; Ellegren 2004). The origin, evolution and ubiquitous occurrence ...

  12. Jacks--A Study of Simple Machines.

    Science.gov (United States)

    Parsons, Ralph

    This vocational physics individualized student instructional module on jacks (simple machines used to lift heavy objects) contains student prerequisites and objectives, an introduction, and sections on the ratchet bumper jack, the hydraulic jack, the screw jack, and load limitations. Designed with a laboratory orientation, each section consists of…

  13. Microwave Radiometer Linearity Measured by Simple Means

    DEFF Research Database (Denmark)

    Skou, Niels

    2002-01-01

    Modern spaceborne radiometer systems feature an almost perfect on-board calibration, hence the primary calibration task to be carried out before launch is a check of radiometer linearity. This paper describes two ways of measuring linearity of microwave radiometers only requiring relatively simple...

  14. Building Simple Hidden Markov Models. Classroom Notes

    Science.gov (United States)

    Ching, Wai-Ki; Ng, Michael K.

    2004-01-01

    Hidden Markov models (HMMs) are widely used in bioinformatics, speech recognition and many other areas. This note presents HMMs via the framework of classical Markov chain models. A simple example is given to illustrate the model. An estimation method for the transition probabilities of the hidden states is also discussed.

  15. Special Relativity as a Simple Geometry Problem

    Science.gov (United States)

    de Abreu, Rodrigo; Guerra, Vasco

    2009-01-01

    The null result of the Michelson-Morley experiment and the constancy of the one-way speed of light in the "rest system" are used to formulate a simple problem, to be solved by elementary geometry techniques using a pair of compasses and non-graduated rulers. The solution consists of a drawing allowing a direct visualization of all the fundamental…

  16. Linear Deterministic Accumulator Models of Simple Choice

    Directory of Open Access Journals (Sweden)

    Andrew eHeathcote

    2012-08-01

    Full Text Available We examine theories of simple choice as a race among evidence accumulation processes. We focus on the class of deterministic race models, which assume that the effects of fluctuations in the parameters of the accumulation processes between choice trials (between-choice noise dominate the effects of fluctuations occurring while making a choice (within-choice noise in behavioural data (i.e., response times and choices. The latter deterministic approximation, when combined with the assumption that accumulation is linear, leads to a class of models that can be readily applied to simple-choice behaviour because they are computationally tractable. We develop a new and mathematically simple exemplar within the class of linear deterministic models, the Lognormal Race (LNR. We then examine how the LNR, and another widely applied linear deterministic model, Brown and Heathcote’s (2008 LBA, account for a range of benchmark simple-choice effects in lexical-decision task data reported by Wagenmakers, Ratcliff, Gomez and McKoon (2008.

  17. A Simple Technique for High Resistance Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguia; Landin, Ramon Ochoa

    2012-01-01

    A simple electronic system for the measurement of high values of resistance is shown. This system allows the measurement of resistance in the range of a few megohm up to 10[superscript 9] [omega]. We have used this system for the evaluation of CdS thin film resistance, but other practical uses in the basic physics laboratory are presented.…

  18. Simple haptotactic gradient generation within a triangular microfluidic channel.

    Science.gov (United States)

    Park, Jungyul; Kim, Deok-Ho; Kim, Gabriel; Kim, Younghoon; Choi, Eunpyo; Levchenko, Andre

    2010-08-21

    Most microfluidic devices developed to date for the analysis of live cells incorporate channels with relatively simple constant rectangular or semi-circular cross-sections, relying on complex channel network geometries rather than alteration of the shapes of the channels themselves for development of diverse functional fluidic controls, e.g., spatial gradients of bioactive ligands. In this study we describe a simple alternative method to create highly defined and predictable gradients of surface bound molecules. This method relies on the generation of a considerable variation in the spatial distribution of flow velocities within a channel with a triangular cross-section. The triangular shape can be easily implemented by using bulk wet etching and polydimethylsiloxane (PDMS) replica molding techniques. By analytical modeling and simulation, we predict that the deposition of the solute onto a channel boundary depends on the local flow rate values, yielding gradient spanning the whole width of the channel. This prediction was validated by direct visualization of the flow rate and fibronectin-rhodamine deposition in a fabricated microchannel. Using this experimental platform, we assessed cell migration in response to a fibronectin gradient deposited in the microchannels. We find that this gradient could induce robust haptotaxis of Chinese Hamster Ovary (CHO) cells towards the areas of higher fibronectin surface density. We propose that the described simple gradient generation method can help to avoid complexity present in many current device designs, allowing to introduce more easily other potentially useful design features.

  19. Estimation of the simple correlation coefficient.

    Science.gov (United States)

    Shieh, Gwowen

    2010-11-01

    This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.

  20. Assessment of daylight quality in simple rooms

    DEFF Research Database (Denmark)

    Johnsen, Kjeld; Dubois, Marie-Claude; Sørensen, Karl Grau

    The present report documents the results of a study on daylight conditions in simple rooms of residential buildings. The overall objective of the study was to develop a basis for a method for the assessment of daylight quality in a room with simple geometry and window configurations. As a tool...... for the analyses the Radiance Lighting Simulation System was used. A large number of simulations were performed for 3 rooms (window configurations) under overcast, intermediate, and 40-50 sunny sky conditions for each window (7 months, three orientations and for every other hour with direct sun penetration through......-to-horizontal illuminance ratio as well as scale of shadow gave valuable information allowing a detailed description of the three-dimensional geometry of daylight in the space. It should be mentioned however, that there is no universal definition of light quality. The approach of this study was to analyse differences...

  1. Is the world simple or complicated

    CERN Document Server

    Barrow, John D

    1998-01-01

    Stop some particle physicists in the street and they will soon be trying to persuade you that the world is altogether simple and symmetrical. But stop a biologist, an economist, or a social scientist and they will tell you quite the opposite: the world is a higgledy-piggledy collection of complexities that owes little to symmetry and displays precious little simplicity. So who is right : is the world really complicated or is it simple ? We shall look at the reasoning that leads to these different conclusions, show why we got different answers to our question, and look at some of the recent developments that have taken place in the study of systems from sand-piles to music on the border between order and chaos. We shall also look at some of the connections between our aesthetic sensibilities and the structure of scientific theories.

  2. A simple solution of the proton crisis

    CERN Document Server

    Pankovic, Vladan

    2014-01-01

    In this work we suggest a simple theoretical model of the proton able to effectively solve proton spin crisis. Within domain of applicability of this simple model proton consists only of two u quarks and one d quarks (two of which have spin opposite to proton and one identical to proton) and one neutral vector phi meson (with spin two times larger than proton spin and directed identically to proton spin). This model is in full agreement not only with existing DIS experiments, but also with spin and electric charge conservation as well as in a satisfactory agreement with rest mass-energy conservation (since phi meson mass is close to proton rest mass). Our model opens an interesting possibility of the solution of the quarks and leptons families problem (proton is not an absolutely non-strange particle, but only a particle with almost totally effectively hidden strange).

  3. Complex Systems Built by Simple Elements

    Directory of Open Access Journals (Sweden)

    Petró Gábor

    2007-02-01

    Full Text Available There are a lot of systems, which behave complexly, around us. We cannot predict their behaviour. Unpredictability is almost a character of complexity but how can we tackle the phenomenon of it. The formal mathematical descriptions of them are more and more complex and only several times solvable. Is the making a system of non-linear equations the only way to handle and descript systems like them? Using simple elements we can build models which show complex behaviour. Simple rule-systems can be a model of a complex system. For example algorithms can be appropriate for this task. We can implement these models for the language of computers, as well, and running simulations. Can we observe or perceive emergent characters? What is the measure of emergent phenomena? These are the questions to which I am searching the answers. The algorithms can give us a better way to understand the complex world.

  4. Simple spherical ablative-implosion model

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, F.J.; Steele, J.T.; Larsen, J.T.

    1980-06-23

    A simple model of the ablative implosion of a high-aspect-ratio (shell radius to shell thickness ratio) spherical shell is described. The model is similar in spirit to Rosenbluth's snowplow model. The scaling of the implosion time was determined in terms of the ablation pressure and the shell parameters such as diameter, wall thickness, and shell density, and compared these to complete hydrodynamic code calculations. The energy transfer efficiency from ablation pressure to shell implosion kinetic energy was examined and found to be very efficient. It may be possible to attach a simple heat-transport calculation to our implosion model to describe the laser-driven ablation-implosion process. The model may be useful for determining other energy driven (e.g., ion beam) implosion scaling.

  5. Simple evaluation of groundwater flow and radionuclide transport at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Dverstorp, B. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Geier, J. [Clearwater Hardrock Consulting, Monmouth, OR, (United States); Voss, C. [Geological Survey, Reston, VA (United States)

    1996-12-01

    A simple evaluation of groundwater flux and potential for radionuclide transport at the Aespoe site, from fundamental hydrologic principles, indicates that, based upon data that are available from surface-based investigations, it is not possible to confirm that the bedrock has a high capacity to retard radionuclide release to the surface environment. This result is primarily due to the high spatial variability of hydraulic conductivity, and high uncertainty regarding the relationship among hydrologic and transport parameters within conductive elements of the bedrock. A comparison between Aespoe and seven other study sites in Sweden indicates that it is difficult or impossible to discriminate among these sites in terms of the geologic barrier function, based upon the types of data that are available from present-day methods of site characterization. Groundwater flux is evaluated by a one-dimensional application of Darcy`s law to a set of simple, potential pathways for groundwater flow from the repository, which are chosen to yield an appraisal of the wide bounds of possible system behaviour. The configurations of the pathways are specified based on simple assumptions of flow-field structure, and hydraulic driving forces are specified from consideration of regional and local topographic differences. Results are expressed in terms of a parameter group that has been shown to control the barrier function. Comparisons with more detailed hydrological modelling of Aespoe show that, although a reduction in uncertainty is achieved, this reduction is not sufficient to distinguish between good and poor performance of the geologic barrier at the site. 38 refs.

  6. Entropy estimates for simple random fields

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Justesen, Jørn

    1995-01-01

    We consider the problem of determining the maximum entropy of a discrete random field on a lattice subject to certain local constraints on symbol configurations. The results are expected to be of interest in the analysis of digitized images and two dimensional codes. We shall present some examples...... of binary and ternary fields with simple constraints. Exact results on the entropies are known only in a few cases, but we shall present close bounds and estimates that are computationally efficient...

  7. Adaptation in simple and complex fitness landscapes

    OpenAIRE

    Jain, Kavita; Krug, Joachim

    2005-01-01

    This is an introductory review of deterministic mutation-selection models for asexual populations (i.e., quasispecies theory) and related topics. First, the basic concepts of fitness, mutations, and sequence space are introduced. Different types of mutation-selection dynamics are defined and their relation to problems of statistical physics are outlined. Then the stationary population distribution in simple, single peak fitness landscapes is discussed at length, with particular emphasis on th...

  8. Central Odontogenic Fibroma of Simple Type

    Directory of Open Access Journals (Sweden)

    Prasanth Thankappan

    2014-01-01

    Full Text Available Central odontogenic fibroma (COF is an extremely rare benign tumor that accounts for 0.1% of all odontogenic tumors. It is a lesion associated with the crown of an unerupted tooth resembling dentigerous cyst. In this report, a 10-year-old male patient is presented, who was diagnosed with central odontogenic fibroma of simple type from clinical, radiological, and histopathological findings.

  9. Simple Open Stance Classification for Rumour Analysis

    OpenAIRE

    Aker, Ahmet; Derczynski, Leon; Bontcheva, Kalina

    2017-01-01

    Stance classification determines the attitude, or stance, in a (typically short) text. The task has powerful applications, such as the detection of fake news or the automatic extraction of attitudes toward entities or events in the media. This paper describes a surprisingly simple and efficient classification approach to open stance classification in Twitter, for rumour and veracity classification. The approach profits from a novel set of automatically identifiable problem-specific features, ...

  10. Simple Benchmark Specifications for Space Radiation Protection

    Science.gov (United States)

    Singleterry, Robert C. Jr.; Aghara, Sukesh K.

    2013-01-01

    This report defines space radiation benchmark specifications. This specification starts with simple, monoenergetic, mono-directional particles on slabs and progresses to human models in spacecraft. This report specifies the models and sources needed to what the team performing the benchmark needs to produce in a report. Also included are brief descriptions of how OLTARIS, the NASA Langley website for space radiation analysis, performs its analysis.

  11. SLURM: Simple Linux Utility for Resource Management

    Energy Technology Data Exchange (ETDEWEB)

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-07-08

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. The design also includes a scalable, general-purpose communication infrastructure. This paper presents a overview of the SLURM architecture and functionality.

  12. Simple scaling model for exploding pusher targets

    Energy Technology Data Exchange (ETDEWEB)

    Storm, E.K.; Larsen, J.T.; Nuckolls, J.H.; Ahlstrom, H.G.; Manes, K.R.

    1977-11-04

    A simple model has been developed which when normalized by experiment or Lasnex calculations can be used to scale neutron yields for variations in laser input power and pulse length and target radius and wall thickness. The model also illucidates some of the physical processes occurring in this regime of laser fusion experiments. Within certain limitations on incident intensity and target geometry, the model scales with experiments and calculations to within a factor of two over six decades in neutron yield.

  13. Implementing successful strategic plans: a simple formula.

    Science.gov (United States)

    Blondeau, Whitney; Blondeau, Benoit

    2015-01-01

    Strategic planning is a process. One way to think of strategic planning is to envision its development and design as a framework that will help your hospital navigate through internal and external changing environments over time. Although the process of strategic planning can feel daunting, following a simple formula involving five steps using the mnemonic B.E.G.I.N. (Begin, Evaluate, Goals & Objectives, Integration, and Next steps) will help the planning process feel more manageable, and lead you to greater success.

  14. Recursion vs. Replication in Simple Cryptographic Protocols

    DEFF Research Database (Denmark)

    Huttel, Hans; Srba, Jiri

    2005-01-01

    's spectrum, become undecidable for a very simple recursive extension of the protocol. The result holds even if no nondeterministic choice operator is allowed. We also show that the extended calculus is capable of an implicit description of the active intruder, including full analysis and synthesis...... of messages in the sense of Amadio, Lugiez and Vanackere. We conclude by showing that reachability analysis for a replicative variant of the protocol becomes decidable....

  15. Convective cells and blob control in a simple magnetized plasma.

    Science.gov (United States)

    Theiler, C; Furno, I; Loizu, J; Fasoli, A

    2012-02-10

    Blob control by creating convective cells using biased electrodes is demonstrated in simple magnetized toroidal plasmas. A two-dimensional array of electrodes is installed on a metal limiter to obtain different biasing schemes. Detailed two-dimensional measurements across the magnetic field reveal the formation of a convective cell, which shows a high degree of uniformity along the magnetic field. Depending on the biasing scheme, radial and vertical blob velocities can be varied significantly. A high level of cross-field currents limits the achievable potential variations to values well below the applied bias voltage. Furthermore, the strongest potential variations are not induced along the biased flux tube, but at a position shifted in the direction of plasma flows.

  16. Vestibular stimulation: A simple but effective intervention in diabetes care.

    Science.gov (United States)

    Sailesh, Kumar Sai; Archana, R; Mukkadan, J K

    2015-01-01

    Despite the complexities of the relationship between vestibular stimulation and endocrine disorders being well known, research efforts to understand these complexities are lacking. Interestingly vestibular stimulation may potentially prevent/delay development/progression of diabetes. Here we review the science behind this concept and highlight the need for necessary translational research in this area. Current evidence supports the use of vestibular stimulation not only as a potential intervention to prevent or delay the development of diabetes mellitus in at-risk population, but also to use it as supplementary therapy for diabetic patients management. We urge clinicians to recommend vestibular stimulation by simple means like swing as a goal in maintaining a healthy lifestyle.

  17. The Monash University Interactive Simple Climate Model

    Science.gov (United States)

    Dommenget, D.

    2013-12-01

    The Monash university interactive simple climate model is a web-based interface that allows students and the general public to explore the physical simulation of the climate system with a real global climate model. It is based on the Globally Resolved Energy Balance (GREB) model, which is a climate model published by Dommenget and Floeter [2011] in the international peer review science journal Climate Dynamics. The model simulates most of the main physical processes in the climate system in a very simplistic way and therefore allows very fast and simple climate model simulations on a normal PC computer. Despite its simplicity the model simulates the climate response to external forcings, such as doubling of the CO2 concentrations very realistically (similar to state of the art climate models). The Monash simple climate model web-interface allows you to study the results of more than a 2000 different model experiments in an interactive way and it allows you to study a number of tutorials on the interactions of physical processes in the climate system and solve some puzzles. By switching OFF/ON physical processes you can deconstruct the climate and learn how all the different processes interact to generate the observed climate and how the processes interact to generate the IPCC predicted climate change for anthropogenic CO2 increase. The presentation will illustrate how this web-base tool works and what are the possibilities in teaching students with this tool are.

  18. Simple Type is Not a Boundary Phenomenon

    CERN Document Server

    Sadun, L A

    1997-01-01

    This is an expository article, explaining recent work by D. Groisser and myself [GS] on the extent to which the boundary region of moduli space contributes to the ``simple type'' condition of Donaldson theory. The presentation is intended to complement [GS], presenting the essential ideas rather than the analytical details. It is shown that the boundary region of moduli space contributes 6/64 of the homology required for simple type, regardless of the topology or geometry of the underlying 4-manifold. The simple type condition thus reduces to a statement about the interior of moduli space, namely that the interior of the (k+1)st ASD moduli space, intersected with two representatives of (4 times) the point class, be homologous to 58 copies of the (k)-th moduli space. This is peculiar, since the only known embeddings of the (k)-th moduli space into the (k+1)st involve Taubes patching, and the image of such an embedding lies entirely in the boundary region.

  19. Modeling reproductive decisions with simple heuristics

    Directory of Open Access Journals (Sweden)

    Peter Todd

    2013-10-01

    Full Text Available BACKGROUND Many of the reproductive decisions that humans make happen without much planning or forethought, arising instead through the use of simple choice rules or heuristics that involve relatively little information and processing. Nonetheless, these heuristic-guided decisions are typically beneficial, owing to humans' ecological rationality - the evolved fit between our constrained decision mechanisms and the adaptive problems we face. OBJECTIVE This paper reviews research on the ecological rationality of human decision making in the domain of reproduction, showing how fertility-related decisions are commonly made using various simple heuristics matched to the structure of the environment in which they are applied, rather than being made with information-hungry mechanisms based on optimization or rational economic choice. METHODS First, heuristics for sequential mate search are covered; these heuristics determine when to stop the process of mate search by deciding that a good-enough mate who is also mutually interested has been found, using a process of aspiration-level setting and assessing. These models are tested via computer simulation and comparison to demographic age-at-first-marriage data. Next, a heuristic process of feature-based mate comparison and choice is discussed, in which mate choices are determined by a simple process of feature-matching with relaxing standards over time. Parental investment heuristics used to divide resources among offspring are summarized. Finally, methods for testing the use of such mate choice heuristics in a specific population over time are then described.

  20. Impact of a 'heavy' SIMPLE on the search for WIMP dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, F [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Morlat, T [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Girard, Ta [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Costa, M Felizardo da [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Marques, Jg [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Ramos, Ar [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal)

    2006-05-15

    We examine the potential impact of a WIMP search based on CF3I-loaded SDDs, projected on the basis of the experience and results of the SIMPLE dark matter search. We find such a 'heavy' SIMPLE experiment to have spin-independent sensitivity comparable to that of leading searches like ZEPLIN-I and CDMS, while preserving the spin-dependent sensitivity of fluorine-based experiments.

  1. A new photosensory function for simple photoreceptors, the intrinsically photoresponsive neurons of the sea slug Onchidium

    Directory of Open Access Journals (Sweden)

    Tsukasa Gotow

    2009-12-01

    Full Text Available Simple photoreceptors, namely intrinsically light-sensitive neurons without microvilli and/or cilia, have long been known to exist in the central ganglia of crayfish, Aplysia, Onchidium, and Helix. These simple photoreceptors are not only first-order photosensory cells, but also second-order neurons (interneurons, relaying several kinds of sensory synaptic inputs. Another important issue is that the photoresponses of these simple photoreceptors show very slow kinetics and little adaptation. These characteristics suggest that the simple photoreceptors of the Onchidium have a function in non-image-forming vision, different from classical eye photoreceptors used for cording dynamic images of vision. The cited literature provides evidence that the depolarizing and hyperpolarizing photoresponses of simple photoreceptors play a role in the long-lasting potentiation of synaptic transmission of excitatory and inhibitory sensory inputs, and as well as in the potentiation and the suppression of the subsequent behavioral outputs. In short, we suggest that simple photoreceptors operate in the general potentiation of synaptic transmission and subsequent motor output; i.e., they perform a new photosensory function.

  2. Higgs potential and fundamental physics

    Science.gov (United States)

    Melo, Ivan

    2017-11-01

    Physics associated with the Higgs field potential is rich and interesting and deserves a concise summary for a broader audience to appreciate the beauty and the challenges of this subject. We discuss the role of the Higgs potential in particle physics, in particular in spontaneous symmetry breaking and in mass generation using an example of a simple reflection symmetry, then continue with temperature and quantum corrections to the potential which lead us to the naturalness problem and vacuum stability.

  3. 40 CFR 80.42 - Simple emissions model.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Simple emissions model. 80.42 Section...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.42 Simple emissions model. (a) VOC emissions. The following equations shall comprise the simple model for VOC emissions. The simple model for...

  4. More than 97% of human papilloma virus type 16 (HPV-16) was found with chrysotile asbestos & relatively smooth round tumor outline, and less than 3% was found with HPV-18 and tremolite asbestos & irregular sawtooth-like zigzag outline in breast cancer tissues in over 500 mammograms of female patients: their implications in diagnosis, treatment, and prevention of breast cancer.

    Science.gov (United States)

    Omura, Yoshiaki; Jones, Marilyn K; Nihrane, Abdallah; Duvvi, Harsha; Shimotsuura, Yasuhiro; Ohki, Motomu

    2013-01-01

    In the past, Human Papillomavirus Type 16 (HPV-16) was considered to be the main cause of cancer in the oropharynx and genital organs. Cervical cancer of the uterus is the most well-known cancer associated with HPV-16. Among the oncogenic HPVs, types 16 and 18 are most responsible for the majority of the HPV-caused cancers. Recently, using EMF Resonance Phenomenon between 2 identical substances, we non-invasively measured HPV-16 and HPV-18 among 25 physicians and 25 dentists and found that all 50 have HPV-16 in oral cavities and oropharynx but not HPV-18. However most dentists have a stronger infection than physicians. Among them were 2 female dentists with breast cancer containing HPV-16 and strong infections of HPV-16 in the oral cavities and oropharynx. When the author checked their breast cancer positive areas as well as the mammograms of cancer positive areas, Chrysotile Asbestos co-existed with an infection of HPV-16. We then examined over 500 published mammograms of women with malignant breast cancer published by other institutes, and we found HPV-16 in more than 97% and HPV-18 in less than 3% of the breast cancer mammograms examined. Less than 0.4% of cases were found as a variety of combination of HPV-16 & HPV-18. We also discovered that breast cancer with HPV-16 always co-exists with increased Chrysotile Asbestos deposits, and the outline of the breast cancer positive area is a relatively smooth and round or oval shape, and breast cancer with HPV-18 always co-exists with increased Tremolite Asbestos, where the tumor outline is an irregular saw-tooth like zigzag pattern. Based on these findings, better methods of diagnosis, treatment and prevention with a vaccine can be developed.

  5. The "Social Cost of Carbon" Made Simple

    OpenAIRE

    Steve Newbold; Charles Griffiths; Moore, Christopher C.; Ann Wolverton; Elizabeth Kopits

    2010-01-01

    The “social cost of carbon” (SCC) is the present value of the future stream of damages from one additional ton of carbon emissions in a particular year. This paper develops a simple model for calculating the SCC and compares estimates of the SCC under certainty and uncertainty. Our model includes the key ingredients shared by several of the more complex integrated assessment models in the climate economics literature, but is designed to be more transparent and easier to use by decision-makers...

  6. Simple Synthesis Method for Alumina Nanoparticle

    Directory of Open Access Journals (Sweden)

    Daniel Damian

    2017-11-01

    Full Text Available Globally, the human population steady increase, expansion of urban areas, excessive industrialization including in agriculture, caused not only decrease to depletion of non-renewable resources, a rapid deterioration of the environment with negative impact on water quality, soil productivity and of course quality of life in general. This paper aims to prepare size controlled nanoparticles of aluminum oxide using a simple synthesis method. The morphology and dimensions of nanomaterial was investigated using modern analytical techniques: SEM/EDAX and XRD spectroscopy.

  7. Simple tangible language elements for young children

    CSIR Research Space (South Africa)

    Smith, Adrew C

    2009-06-01

    Full Text Available stream_source_info Smith_d6_2009.pdf.txt stream_content_type text/plain stream_size 6539 Content-Encoding UTF-8 stream_name Smith_d6_2009.pdf.txt Content-Type text/plain; charset=UTF-8 Simple Tangible Language Elements... for Young Children Andrew Cyrus Smith CSIR Meraka Institute PO Box 395 Pretoria, 0001, South Africa +27 12 8414626 acsmith@csir.co.za 3rd Author 3rd author's affiliation 1st line of address 2nd line of address Telephone number, incl. country code...

  8. Which finite simple groups are unit groups?

    DEFF Research Database (Denmark)

    Davis, Christopher James; Occhipinti, Tommy

    2014-01-01

    We prove that if G is a finite simple group which is the unit group of a ring, then G is isomorphic to either (a) a cyclic group of order 2; (b) a cyclic group of prime order 2^k −1 for some k; or (c) a projective special linear group PSLn(F2) for some n ≥ 3. Moreover, these groups do all occur...... as unit groups. We deduce this classification from a more general result, which holds for groups G with no non-trivial normal 2-subgroup....

  9. Three Spreadsheet Models Of A Simple Pendulum

    Directory of Open Access Journals (Sweden)

    Jan Benacka

    2008-10-01

    Full Text Available The paper gives three spreadsheet models of simple pendulum motion. In two of them, the graph of the pendulum angle is drawn upon the exact integral solution using numeric integration – the simpler model only uses spreadsheet functions, the general model uses a VBA program. The period results directly from the calculations. In the third model, the period is calculated first using the power series formula. The graph of the pendulum angle is drawn afterwards using Euler’s method of solving differential equations. The error in gravity acceleration if calculated upon the standard cosine approximate formula instead of the exact one is graphed.

  10. Chaos from simple models to complex systems

    CERN Document Server

    Cencini, Massimo; Vulpiani, Angelo

    2010-01-01

    Chaos: from simple models to complex systems aims to guide science and engineering students through chaos and nonlinear dynamics from classical examples to the most recent fields of research. The first part, intended for undergraduate and graduate students, is a gentle and self-contained introduction to the concepts and main tools for the characterization of deterministic chaotic systems, with emphasis to statistical approaches. The second part can be used as a reference by researchers as it focuses on more advanced topics including the characterization of chaos with tools of information theor

  11. A simple model of bedform migration

    DEFF Research Database (Denmark)

    Bartholdy, Jesper; Ernstsen, Verner Brandbyge; Flemming, Burg W

    2010-01-01

    A model linking subaqueous dune migration to the effective (grain related) shear stress is calibrated by means of flume data for bedform dimensions and migration rates. The effective shear stress is calculated on the basis of a new method assuming a near-bed layer above the mean bed level in which...... and width) of naturally-packed bed material on the bedform lee side, qb(crest). The model is simple, built on a rational description of simplified sediment mechanics, and its calibration constant can be explained in accordance with estimated values of the physical constants on which it is based. Predicted...

  12. A simple asynchronous replica-exchange implementation

    CERN Document Server

    Bussi, Giovanni

    2008-01-01

    We discuss the possibility of implementing asynchronous replica-exchange (or parallel tempering) molecular dynamics. In our scheme, the exchange attempts are driven by asynchronous messages sent by one of the computing nodes, so that different replicas are allowed to perform a different number of time-steps between subsequent attempts. The implementation is simple and based on the message-passing interface (MPI). We illustrate the advantages of our scheme with respect to the standard synchronous algorithm and we benchmark it for a model Lennard-Jones liquid on an IBM-LS21 blade center cluster.

  13. Question Answering for Dutch: Simple does it

    OpenAIRE

    Hoekstra, A.H.; Hiemstra, Djoerd; van der Vet, P.E.; Huibers, Theo W.C.; Schobbens, Pierre-Yves; Vanhoof, Wim; Schwanen, Gabriel

    2006-01-01

    When people pose questions in natural language to search for information on the web, the role of question answering (QA) systems becomes important. In this paper the QAsystem simpleQA, capable of answering Dutch questions on which the answer is a person or a location, is described. The system's algorithm does not use a lot of complex NLP-techniques, but instead uses the magnitude of and redundancy on the World Wide Web to its advantage. The system has been evaluated on the DISEQuA corpus and ...

  14. Improved acoustic instrumentation of the SIMPLE detector

    Energy Technology Data Exchange (ETDEWEB)

    Felizardo, M. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Instituto de Telecomunicacoes, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Martins, R.C. [Instituto de Telecomunicacoes, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Ramos, A.R. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Morlat, T. [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Girard, T.A. [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal)], E-mail: criodets@cii.fc.ul.pt; Giuliani, F. [Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal); Limagne, D. [INSP - UMR 7588 CNRS, Universite Paris 7 and 6, 75251 Paris (France); Waysand, G. [Laboratoire Souterrain a Bas Bruit, Universite de Nice-Sophia Antipolis, 84400 Rustrel-Pays d' Apt (France); Marques, J.G. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa, 1649-003 Lisbon (Portugal)

    2008-01-21

    The application of Superheated Droplet Detectors in dark matter searches by the SIMPLE project uses an acoustic instrumentation sensitive to the shock wave generated by the bubble nucleation of the refrigerant droplets. Previous instrumentation has been unable to distinguish between true nucleation and background noise events in the device, in particular microleaks associated with the escape of overpressuring nitrogen gas into the surrounding water bath. We here describe the development of an improved instrumentation which is shown to provide this discrimination capacity through a reduced noise level of the transducer amplification circuitry.

  15. Simple Unawareness in Dynamic Psychological Games

    DEFF Research Database (Denmark)

    Nielsen, Carsten Søren; Sebald, Alexander Christopher

    2017-01-01

    Building on Battigalli and Dufwenberg (2009)’s framework of dynamic psychological games and the progress in the modeling of dynamic unawareness by Heifetz, Meier, and Schipper (2013a) we model and analyze the impact of asymmetric awareness in the strategic interaction of players motivated...... by reciprocity and guilt. Specifically we characterize extensive-form games with psychological payoffs and simple unawareness, define extensive-form rationalizability and, using this, show that unawareness has a pervasive impact on the strategic interaction of psychologically motivated players. Intuitively......, unawareness influences players’ beliefs concerning, for example, the intentions and expectations of others which in turn impacts their behavior....

  16. Radon entry into a simple test structure

    DEFF Research Database (Denmark)

    Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

    1992-01-01

    in the cylinder and in selected locations in the soil. In this paper, the test structure is described, and initial results concerning the transport of soil gas and radon under steady-state conditions are reported. It is found that the soil in the vicinity of the structure is partially depleted with respect......A simple test structure for studies of radon entry into houses has been constructed at a field site at Riso National Laboratory. It consists of a 40 1, stainless-steel cylinder placed in a 0.52 m deep quadratic excavation with a side length of 2.4 m. The excavation is lined with an airtight...

  17. A Simple Ripple Filter for FLUKA

    DEFF Research Database (Denmark)

    Bassler, Niels; Herrmann, Rochus

    ). The ripple filter at GSI and HIT consists of several wedge like structures, which widens the Bragg-peak up to e.g. 3 mm. For Monte Carlo simulations of C-12 therapy, the exact setup, including the ripple filter needs to be simulated. In the Monte Carlo particle transport program FLUKA, the ripple filter can...... be realized in several ways. The most simplistic version is to apply the ripples as simple triangles. More elaborate version would account for the exact structure, but the drawback is that this will bloat the FLUKA input file with vast amounts of bodys which needs to be included in the geometrical setup...

  18. A simple experiment for visualizing diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Helseth, L E, E-mail: Lars.Helseth@ift.uib.no [Department of Physics and Technology, University of Bergen, Allegaten 55, N-5007 Bergen (Norway)

    2011-09-15

    We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can be used to print colour patterns in the gel which due to diffusion of ions may disappear entirely.

  19. Simple microwave preionization source for ohmic plasmas

    Science.gov (United States)

    Choe, W.; Kwon, Gi-Chung; Kim, Junghee; Kim, Jayhyun; Jeon, Sang-Jean; Huh, Songwhe

    2000-07-01

    A simple economical 2.45 GHz microwave system has been developed and utilized for preionization on the Korea Advanced Institute of Science and Technology (KAIST)-TOKAMAK. The magnetron microwave source was obtained from a widely used, household microwave oven. Since ac operation of the magnetron is not suitable for tokamak application, the magnetron cathode bias circuit was modified to obtain continuous and stable operation of the magnetron for several hundred milliseconds. Application of the developed microwave system to KAIST-TOKAMAK resulted in a reduction of ohmic flux consumption.

  20. Current-induced forces: a simple derivation

    DEFF Research Database (Denmark)

    Todorov, Tchavdar N.; Dundas, Daniel; Lü, Jing-Tao

    2014-01-01

    We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that-with the help of background literature-should be accessible to physics undergraduates. The discussio...... features at the wire surface, making it a candidate for the nucleation of current-driven structural transformations and failure. Finally we discuss the problem of force noise and the limitations of Ehrenfest dynamics.......We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that-with the help of background literature-should be accessible to physics undergraduates. The discussion...... aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current-the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant...

  1. Simple Models of Many-Fermion Systems

    CERN Document Server

    Maruhn, Joachim Alexander; Suraud, Eric

    2010-01-01

    The purpose of this book is to provide a pedestrians route to the physics of many-particle systems. The material is developed along simple and generic models which allow to illuminate the basic mechanisms beyond each approach and which apply to broad variety of systems in different areas of physics and chemistry. The book is sorted in steps of slowly increasing complexity of the models. Complementing numerical tools help to carry on where analytical methods reach their limits. They provide at the same time a useful training for the typical numerical methods in many-body physics. In order to confine the huge field, we shall focus the discussions on finite systems wherefrom we take the examples of applications. This covers nuclei, atoms, molecules and clusters. The idea of this book is to concentrate first on the generic, robust and simple, approaches and show how they apply to several domains across the specific disciplines. On the other hand, we aim to establish contact with actual research by carrying forth ...

  2. Simple models for containment of a pandemic.

    Science.gov (United States)

    Arino, Julien; Brauer, Fred; van den Driessche, P; Watmough, James; Wu, Jianhong

    2006-06-22

    Stochastic simulations of network models have become the standard approach to studying epidemics. We show that many of the predictions of these models can also be obtained from simple classical deterministic compartmental models. We suggest that simple models may be a better way to plan for a threatening pandemic with location and parameters as yet unknown, reserving more detailed network models for disease outbreaks already underway in localities where the social networks are well identified.We formulate compartmental models to describe outbreaks of influenza and attempt to manage a disease outbreak by vaccination or antiviral treatment. The models give an important prediction that may not have been noticed in other models, namely that the number of doses of antiviral treatment required is extremely sensitive to the number of initial infectives. This suggests that the actual number of doses needed cannot be estimated with any degree of reliability. The model is applicable to pre-epidemic vaccination, such as annual vaccination programs in anticipation of an 'ordinary' influenza outbreak with limited drift, and as a combination of treatment both before and during an epidemic.

  3. Investigating student understanding of simple harmonic motion

    Science.gov (United States)

    Somroob, S.; Wattanakasiwich, P.

    2017-09-01

    This study aimed to investigate students’ understanding and develop instructional material on a topic of simple harmonic motion. Participants were 60 students taking a course on vibrations and wave and 46 students taking a course on Physics 2 and 28 students taking a course on Fundamental Physics 2 on the 2nd semester of an academic year 2016. A 16-question conceptual test and tutorial activities had been developed from previous research findings and evaluated by three physics experts in teaching mechanics before using in a real classroom. Data collection included both qualitative and quantitative methods. Item analysis and whole-test analysis were determined from student responses in the conceptual test. As results, most students had misconceptions about restoring force and they had problems connecting mathematical solutions to real motions, especially phase angle. Moreover, they had problems with interpreting mechanical energy from graphs and diagrams of the motion. These results were used to develop effective instructional materials to enhance student abilities in understanding simple harmonic motion in term of multiple representations.

  4. Simple model dielectric functions for insulators

    Science.gov (United States)

    Vos, Maarten; Grande, Pedro L.

    2017-05-01

    The Drude dielectric function is a simple way of describing the dielectric function of free electron materials, which have an uniform electron density, in a classical way. The Mermin dielectric function describes a free electron gas, but is based on quantum physics. More complex metals have varying electron densities and are often described by a sum of Drude dielectric functions, the weight of each function being taken proportional to the volume with the corresponding density. Here we describe a slight variation on the Drude dielectric functions that describes insulators in a semi-classical way and a form of the Levine-Louie dielectric function including a relaxation time that does the same within the framework of quantum physics. In the optical limit the semi-classical description of an insulator and the quantum physics description coincide, in the same way as the Drude and Mermin dielectric function coincide in the optical limit for metals. There is a simple relation between the coefficients used in the classical and quantum approaches, a relation that ensures that the obtained dielectric function corresponds to the right static refractive index. For water we give a comparison of the model dielectric function at non-zero momentum with inelastic X-ray measurements, both at relative small momenta and in the Compton limit. The Levine-Louie dielectric function including a relaxation time describes the spectra at small momentum quite well, but in the Compton limit there are significant deviations.

  5. A simple 5-DOF walking robot for space station application

    Science.gov (United States)

    Brown, H. Benjamin, Jr.; Friedman, Mark B.; Kanade, Takeo

    1991-01-01

    Robots on the NASA space station have a potential range of applications from assisting astronauts during EVA (extravehicular activity), to replacing astronauts in the performance of simple, dangerous, and tedious tasks; and to performing routine tasks such as inspections of structures and utilities. To provide a vehicle for demonstrating the pertinent technologies, a simple robot is being developed for locomotion and basic manipulation on the proposed space station. In addition to the robot, an experimental testbed was developed, including a 1/3 scale (1.67 meter modules) truss and a gravity compensation system to simulate a zero-gravity environment. The robot comprises two flexible links connected by a rotary joint, with a 2 degree of freedom wrist joints and grippers at each end. The grippers screw into threaded holes in the nodes of the space station truss, and enable it to walk by alternately shifting the base of support from one foot (gripper) to the other. Present efforts are focused on mechanical design, application of sensors, and development of control algorithms for lightweight, flexible structures. Long-range research will emphasize development of human interfaces to permit a range of control modes from teleoperated to semiautonomous, and coordination of robot/astronaut and multiple-robot teams.

  6. Self-management: keeping it simple with “Flo”

    Directory of Open Access Journals (Sweden)

    Cund A

    2015-03-01

    Full Text Available Audrey Cund,1–4 Jayne L Birch-Jones,1,3,4 Martin Kay,1 Patricia Connolly4 1School of Health, Nursing and Midwifery, University of The West of Scotland, Paisley, Scotland, UK; 2Nottinghamshire Health and Social Care Assistive Technology Programme, Mansfield and Ashfield Clinical Commissioning Group, National Health Service, Rainworth, Mansfield, Nottinghamshire, UK; 3Kay Consultancy Ltd, Newark, UK; 4Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK Background: Living with and managing a long-term condition are complex processes that are further compounded by a range of medical and psychosocial factors. The size and scale of long-term conditions in the UK is vast, with strategic drivers seeking to find innovative ways to managing this problem. Methods: This project introduced Simple Telehealth “Florence,” a software-based short message service texting system to monitor a variety of conditions, such as diabetes, hypertension, and wounds, initially in one region of the East Midlands, England, UK. This article discusses the findings from our patient and staff evaluations of using the system. In total, 37 patients across four conditions, diabetes, chronic obstructive pulmonary disease, hypertension, and Asperger's syndrome, evaluated the study and this exercise involved 33 nurses in teams across three locations over a 6-month period. Evaluation was made using a simple, self-completed questionnaire and analysis of qualitative comments. Results: The majority of patients find the service easy to use, reassuring, and reducing the number of contacts they had with their doctor. The results also show that staff did notice a reduction in consultation time, highlighting the potential of the system to save time; the majority viewed it as a support to existing approaches aimed at the management of long-term conditions. Discussion: This study adds to the growing body of evidence that supports community nurses through

  7. Simple approach to study biomolecule adsorption in polymeric microfluidic channels

    Energy Technology Data Exchange (ETDEWEB)

    Gubala, Vladimir, E-mail: V.Gubala@kent.ac.uk [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Medway School of Pharmacy, University of Kent, Central Avenue, Anson 120, Chatham Maritime, Kent ME4 4TB (United Kingdom); Siegrist, Jonathan; Monaghan, Ruairi; O' Reilly, Brian; Gandhiraman, Ram Prasad [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Daniels, Stephen [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); National Centre for Plasma Science and Technology (NCPST), Dublin City University, Dublin 9 (Ireland); Williams, David E. [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical Sciences, University of Auckland, Auckland 1142 (New Zealand); Ducree, Jens [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland)

    2013-01-14

    neutral, hydrogel-like film with polyethylene glycol (PEG) characteristics. This simple analytical approach adds to the fundamental understanding of the interaction forces in real, microfluidic systems. This method provides a straightforward and rapid way to screen surface compositions and chemistry, and relate these to their effects on the sensitivity and resistance to non-specific binding of bioassays using them. In an additional set of experiments, the surface area of the channels in this universal microfluidic chip was increased by precision milling of microscale trenches. This modified surface was then coated with APTES and tested for its potential to serve as a unique protein dilution feature.

  8. A Simple HCCI Engine Model for Control

    Energy Technology Data Exchange (ETDEWEB)

    Killingsworth, N; Aceves, S; Flowers, D; Krstic, M

    2006-06-29

    The homogeneous charge compression ignition (HCCI) engine is an attractive technology because of its high efficiency and low emissions. However, HCCI lacks a direct combustion trigger making control of combustion timing challenging, especially during transients. To aid in HCCI engine control we present a simple model of the HCCI combustion process valid over a range of intake pressures, intake temperatures, equivalence ratios, and engine speeds. The model provides an estimate of the combustion timing on a cycle-by-cycle basis. An ignition threshold, which is a function of the in-cylinder motored temperature and pressure is used to predict start of combustion. This model allows the synthesis of nonlinear control laws, which can be utilized for control of an HCCI engine during transients.

  9. A simple controller for bidimensional image detectors

    Science.gov (United States)

    Angeles, F.; Martínez, L. A.

    2012-07-01

    The increasing use of many and different kind of light detectors to acquire, monitor and control various aspects of the observation imposes the need to standardize the acquisition and processing of images and data. While scientific image acquisition systems usually include a complex controller, some less demanding subsystems require the development of electronics and software to read the image. Most of the times these image detectors are rather small and high speed is of no concern, so controllers need not to be fast; take for instance a telescope guider. With these directives in mind, in this work we present a very simple image acquisition system based on a Texas Instruments microcontroller of the family MSP430 and a serial static memory as a standard instrumentation starting for small image acquisition controllers.

  10. Multiple equilibria in a simple elastocapillary system

    KAUST Repository

    Taroni, Michele

    2012-09-28

    We consider the elastocapillary interaction of a liquid drop placed between two elastic beams, which are both clamped at one end to a rigid substrate. This is a simple model system relevant to the problem of surface-tension-induced collapse of flexible micro-channels that has been observed in the manufacture of microelectromechanical systems (MEMS). We determine the conditions under which the beams remain separated, touch at a point, or stick along a portion of their length. Surprisingly, we show that in many circumstances multiple equilibrium states are possible. We develop a lubrication-type model for the flow of liquid out of equilibrium and thereby investigate the stability of the multiple equilibria. We demonstrate that for given material properties two stable equilibria may exist, and show via numerical solutions of the dynamic model that it is the initial state of the system that determines which stable equilibrium is ultimately reached. © 2012 Cambridge University Press.

  11. Simple Device for Treating Prolapsing Loop Colostomy

    Directory of Open Access Journals (Sweden)

    Ming-Yu Hsieh

    2006-03-01

    Full Text Available Stoma prolapse is a common complication of intestinal stoma. Although various surgical methods yield satisfactory results, nonsurgical treatment may be better for a temporary stoma. We report a case of a patient with a distal limb prolapse of a right transverse colostomy who received nonsurgical treatment with satisfactory results. For the treatment of a temporary transverse loop colostomy with distal limb prolapse, we designed a simple device consisting of a pediatric plastic medicine cup, which was rolled into a towel to shape the bottom of the cup into a compressor. The towel was put on the stoma outside of the colostomy bag with the compressor above the prolapsing limb of the colostomy. An abdominal binder was applied to fix the towel.

  12. Centralizers in simple locally finite groups

    Directory of Open Access Journals (Sweden)

    Mahmut Kuzucuoğlu

    2013-03-01

    Full Text Available This is a survey article on centralizers of finitesubgroups in locally finite, simple groups or LFS-groups as wewill call them. We mention some of the open problems aboutcentralizers of subgroups in LFS-groups and applications of theknown information about the centralizers of subgroups to thestructure of the locally finite group. We also prove thefollowing: Let $G$ be a countably infinite non-linear LFS-groupwith a Kegel sequence $mathcal{K}={(G_i,N_i | iinmathbf{N} }$. If there exists an upper bound for ${ |N_i| |iin mathbf{N} }$, then for any finite semisimplesubgroup $F$ in $G$ the subgroup $C_G(F$ has elements oforder $p_i$ for infinitely many distinct prime $p_i$. Inparticular $C_G(F$ is an infinite group. This answers Hartley'squestion provided that there exists a bound on ${ |N_i| | iin mathbf{N}$.

  13. Simple LDAP Schemas for Grid Monitoring

    Science.gov (United States)

    Smith, Warren; Gunter, Dan; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The purpose of this document is to provide an initial definition of the data we need in a directory service or database so that we can implement a performance monitoring testbed. To begin with, this document describes how to represent producers of events and event schemes. The representation of producers is simple and does not contain information such as who has access to the events and what protocols can be used to access the events. In the future, we will define how to describe consumers of events and add details to our representations. A popular choice for a directory service or database for grid computing is a distributed directory service that is accessed using the Lightweight Directory Access Protocol (LDAP). This document uses LDAP terminology, schemes, and formats to represent the directory service schemes.

  14. iPad 2 Made Simple

    CERN Document Server

    Mazo, Gary; Ritchie, Rene

    2011-01-01

    The iPad 2 is thinner, more powerful, intuitive and very fun for users of all ages. Your iPad can be used for reading, surfing the web, emailing, watching TV and movies, getting work done and much more. And with over 65,000 apps just for the iPad, as well as the ability to run over 30,000 iPhone apps, the possibilities are endless. iPad 2 Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instru

  15. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit...... of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 pm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 run. We demonstrate how the EBL system can...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  16. Recursion Versus Replication in Simple Cryptographic Protocols

    DEFF Research Database (Denmark)

    Hüttel, Hans; Srba, Jiri

    2005-01-01

    's spectrum, become undecidable for a very simple recursive extension of the protocol. The result holds even if no nondeterministic choice operator is allowed. We also show that the extended calculus is capable of an implicit description of the active intruder, including full analysis and synthesis...... of messages in the sense of Amadio, Lugiez and Vanackere. We conclude by showing that reachability analysis for a replicative variant of the protocol becomes decidable.......We use some very recent techniques from process algebra to draw interesting conclusions about the well studied class of ping-pong protocols introduced by Dolev and Yao. In particular we show that all nontrivial properties, including reachability and equivalence checking wrt. the whole van Glabbeek...

  17. Un simple mot, troublant et magique

    Directory of Open Access Journals (Sweden)

    Mathilde Lévêque

    2012-01-01

    Full Text Available Vers le milieu du xixe siècle, un enfant de la ville de Rochefort laisse son imagination dériver. Les gravures d’un livre de prix, les images d’un périodique ou les curiosités rapportées d’Afrique par un grand-oncle médecin sont autant de supports aux rêves du jeune Julien Viaud : « Oh ! ce qu’il avait de troublant et de magique, dans mon enfance, ce simple mot : « les colonies », qui, en ce temps-là, désignait pour moi l’ensemble des lointains pays chauds, avec leurs palmiers, leurs grandes ...

  18. SLURM: Simple Linux Utility for Resource Management

    Energy Technology Data Exchange (ETDEWEB)

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-04-24

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, and scheduling modules. The design also includes a scalable, general-purpose communication infrastructure. Development will take place in four phases: Phase I results in a solid infrastructure; Phase II produces a functional but limited interactive job initiation capability without use of the interconnect/switch; Phase III provides switch support and documentation; Phase IV provides job status, fault-tolerance, and job queuing and control through Livermore's Distributed Production Control System (DPCS), a meta-batch and resource management system.

  19. A Simple Solution to Type Specialization

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Partial evaluation specializes terms, but traditionally this specialization does not apply to the type of these terms. As a result, specializing, e.g., an interpreter written in a typed language, which requires a “universal” type to encode expressible values, yields residual programs with type tags...... all over. Neil Jones has stated that getting rid of these type tags was an open problem, despite possible solutions such as Torben Mogensen's “constructor specialization.” To solve this problem, John Hughes has proposed a new paradigm for partial evaluation, “Type Specialization”, based on type...... inference instead of being based on symbolic interpretation. Type Specialization is very elegant in principle but it also appears non-trivial in practice. Stating the problem in terms of types instead of in terms of type encodings suggests a very simple type-directed solution, namely, to use a projection...

  20. A simple solution to type specialization

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Partial evaluation specializes terms, but traditionally this specialization does not apply to the type of these terms. As a result, specializing, e.g., an interpreter written in a typed language, which requires a “universal” type to encode expressible values, yields residual programs with type tags...... all over. Neil Jones has stated that getting rid of these type tags was an open problem, despite possible solutions such as Torben Mogensen's “constructor specialization.” To solve this problem, John Hughes has proposed a new paradigm for partial evaluation, “Type Specialization”, based on type...... inference instead of being based on symbolic interpretation. Type Specialization is very elegant in principle but it also appears non-trivial in practice. Stating the problem in terms of types instead of in terms of type encodings suggests a very simple type-directed solution, namely, to use a projection...

  1. Thermodynamic stability limits of simple monoatomic materials.

    Science.gov (United States)

    Gallington, Leighanne C; Bongiorno, Angelo

    2010-05-07

    This computational study addresses the thermodynamical stability of superheated crystals. Molecular dynamics simulations are employed to derive the caloric curves of the solid and liquid phases of a material. Caloric curves are used to derive thermodynamic state functions, the parameters of the equilibrium melting phase transition, and the regions of thermodynamical stability of the liquid and solid phases. Molecular dynamics trajectories are also analyzed to gain insight on the mechanisms leading to the instability of the homogeneous superheated solid phase. This study shows that in simple and homogeneous solids the configurational entropy is not zero and that its excitations can occur without disrupting the crystallinity of the lattice. The superheating and supercooling limits of the solid and liquid phases are found to correspond to states of equal entropy and enthalpy.

  2. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used in continu......The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  3. Mesmer et Mozart: un rapport (apparemment simple

    Directory of Open Access Journals (Sweden)

    Stile, Alessandro

    2011-12-01

    Full Text Available [Mesmer and Mozart: an (apparently simple relationship]. Moving from the evidences in the correspondence of the Mozart family, who used to attend the house of Anton Mesmer, the paper examines the relationship between W.A. Mozart and the German physician. Mozart was probably a direct witness of some cases in which “animal magnetism” was applied. The parodistic outline of magnetism in a famous scene of "Così fan tutte" was probably inspired by Mesmer’s professional and private vicissitudes as well as Mozart’s experience. A more underground aspect of the relationship can be seen though. With regard to Così fan tutte it is possible to outline a kind of analogy between the link among the individuals claimed by the magnetism and the passions evoked in Mozart’s work, that go beyond the conventions and are designed to change the very setting of the vocal style of the XIX century.

  4. Virtual Reference Environments: a simple way to make research reproducible.

    Science.gov (United States)

    Hurley, Daniel G; Budden, David M; Crampin, Edmund J

    2015-09-01

    'Reproducible research' has received increasing attention over the past few years as bioinformatics and computational biology methodologies become more complex. Although reproducible research is progressing in several valuable ways, we suggest that recent increases in internet bandwidth and disk space, along with the availability of open-source and free-software licences for tools, enable another simple step to make research reproducible. In this article, we urge the creation of minimal virtual reference environments implementing all the tools necessary to reproduce a result, as a standard part of publication. We address potential problems with this approach, and show an example environment from our own work. © The Author 2014. Published by Oxford University Press.

  5. A simple model for electron dissipation in trapped ion turbulence

    Science.gov (United States)

    Lesur, M.; Cartier-Michaud, T.; Drouot, T.; Diamond, P. H.; Kosuga, Y.; Réveillé, T.; Gravier, E.; Garbet, X.; Itoh, S.-I.; Itoh, K.

    2017-01-01

    Trapped ion resonance-driven turbulence is investigated in the presence of electron dissipation in a simplified tokamak geometry. A reduced gyrokinetic bounce-averaged model for trapped ions is adopted. Electron dissipation is modeled by a simple phase-shift δ between density and electric potential perturbations. The linear eigenfunction features a peak at the resonant energy, which becomes stronger with increasing electron dissipation. Accurately resolving this narrow peak in numerical simulation of the initial-value problem yields a stringent lower bound on the number of grid points in the energy space. Further, the radial particle flux is investigated in the presence of electron dissipation, including kinetic effects. When the density gradient is higher than the temperature gradient, and the phase-shift is finite but moderate ( δ≈0.02 ), the particle flux peaks at an order-of-magnitude above the gyro-Bohm estimate. Slight particle pinch is observed for δ<0.003 .

  6. Anharmonic effects in simple physical models: introducing undergraduates to nonlinearity

    Science.gov (United States)

    Christian, J. M.

    2017-09-01

    Given the pervasive character of nonlinearity throughout the physical universe, a case is made for introducing undergraduate students to its consequences and signatures earlier rather than later. The dynamics of two well-known systems—a spring and a pendulum—are reviewed when the standard textbook linearising assumptions are relaxed. Some qualitative effects of nonlinearity can be anticipated from symmetry (e.g., inspection of potential energy functions), and further physical insight gained by applying a simple successive-approximation method that might be taught in parallel with courses on classical mechanics, ordinary differential equations, and computational physics. We conclude with a survey of how these ideas have been deployed on programmes at a UK university.

  7. Simple emission metrics for climate impacts

    Directory of Open Access Journals (Sweden)

    B. Aamaas

    2013-06-01

    Full Text Available In the context of climate change, emissions of different species (e.g., carbon dioxide and methane are not directly comparable since they have different radiative efficiencies and lifetimes. Since comparisons via detailed climate models are computationally expensive and complex, emission metrics were developed to allow a simple and straightforward comparison of the estimated climate impacts of emissions of different species. Emission metrics are not unique and variety of different emission metrics has been proposed, with key choices being the climate impacts and time horizon to use for comparisons. In this paper, we present analytical expressions and describe how to calculate common emission metrics for different species. We include the climate metrics radiative forcing, integrated radiative forcing, temperature change and integrated temperature change in both absolute form and normalised to a reference gas. We consider pulse emissions, sustained emissions and emission scenarios. The species are separated into three types: CO2 which has a complex decay over time, species with a simple exponential decay, and ozone precursors (NOx, CO, VOC which indirectly effect climate via various chemical interactions. We also discuss deriving Impulse Response Functions, radiative efficiency, regional dependencies, consistency within and between metrics and uncertainties. We perform various applications to highlight key applications of emission metrics, which show that emissions of CO2 are important regardless of what metric and time horizon is used, but that the importance of short lived climate forcers varies greatly depending on the metric choices made. Further, the ranking of countries by emissions changes very little with different metrics despite large differences in metric values, except for the shortest time horizons (GWP20.

  8. Beyond simple charts: Design of visualizations for big health data.

    Science.gov (United States)

    Ola, Oluwakemi; Sedig, Kamran

    2016-01-01

    Health data is often big data due to its high volume, low veracity, great variety, and high velocity. Big health data has the potential to improve productivity, eliminate waste, and support a broad range of tasks related to disease surveillance, patient care, research, and population health management. Interactive visualizations have the potential to amplify big data's utilization. Visualizations can be used to support a variety of tasks, such as tracking the geographic distribution of diseases, analyzing the prevalence of disease, triaging medical records, predicting outbreaks, and discovering at-risk populations. Currently, many health visualization tools use simple charts, such as bar charts and scatter plots, that only represent few facets of data. These tools, while beneficial for simple perceptual and cognitive tasks, are ineffective when dealing with more complex sensemaking tasks that involve exploration of various facets and elements of big data simultaneously. There is need for sophisticated and elaborate visualizations that encode many facets of data and support human-data interaction with big data and more complex tasks. When not approached systematically, design of such visualizations is labor-intensive, and the resulting designs may not facilitate big-data-driven tasks. Conceptual frameworks that guide the design of visualizations for big data can make the design process more manageable and result in more effective visualizations. In this paper, we demonstrate how a framework-based approach can help designers create novel, elaborate, non-trivial visualizations for big health data. We present four visualizations that are components of a larger tool for making sense of large-scale public health data.

  9. A simple and inexpensive way to document simple husbandry in animal care facilities using QR code scanning.

    Science.gov (United States)

    Green, Tyler; Smith, Terry; Hodges, Richard; Fry, W Mark

    2017-12-01

    Record keeping within research animal care facilities is a key part of the guidelines set forth by national regulatory bodies and mandated by federal laws. Research facilities must maintain records of animal health issues, procedures and usage. Facilities are also required to maintain records regarding regular husbandry such as general animal checks, feeding and watering. The level of record keeping has the potential to generate excessive amounts of paper which must be retained in a fashion as to be accessible. In addition it is preferable not to retain within administrative areas any paper records which may have been in contact with animal rooms. Here, we present a flexible, simple and inexpensive process for the generation and storage of electronic animal husbandry records using smartphone technology over a WiFi or cellular network.

  10. Simple queueing approach to segregation dynamics in Schelling model

    OpenAIRE

    Sobkowicz, Pawel

    2007-01-01

    A simple queueing approach for segregation of agents in modified one dimensional Schelling segregation model is presented. The goal is to arrive at simple formula for the number of unhappy agents remaining after the segregation.

  11. Creating Simple Admin Tools Using Info*Engine and Java

    Science.gov (United States)

    Jones, Corey; Kapatos, Dennis; Skradski, Cory; Felkins, J. D.

    2012-01-01

    PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create a simple Info*Engine Tasks capable of saving Windchill 10.0 administration of tedious work.

  12. Bladder Cancer: A Simple Model Becomes Complex

    Science.gov (United States)

    Pierro, Giovanni Battista Di; Gulia, Caterina; Cristini, Cristiano; Fraietta, Giorgio; Marini, Lorenzo; Grande, Pietro; Gentile, Vincenzo; Piergentili, Roberto

    2012-01-01

    Bladder cancer is one of the most frequent malignancies in developed countries and it is also characterized by a high number of recurrences. Despite this, several authors in the past reported that only two altered molecular pathways may genetically explain all cases of bladder cancer: one involving the FGFR3 gene, and the other involving the TP53 gene. Mutations in any of these two genes are usually predictive of the malignancy final outcome. This cancer may also be further classified as low-grade tumors, which is always papillary and in most cases superficial, and high-grade tumors, not necessarily papillary and often invasive. This simple way of considering this pathology has strongly changed in the last few years, with the development of genome-wide studies on expression profiling and the discovery of small non-coding RNA affecting gene expression. An easy search in the OMIM (On-line Mendelian Inheritance in Man) database using “bladder cancer” as a query reveals that genes in some way connected to this pathology are approximately 150, and some authors report that altered gene expression (up- or down-regulation) in this disease may involve up to 500 coding sequences for low-grade tumors and up to 2300 for high-grade tumors. In many clinical cases, mutations inside the coding sequences of the above mentioned two genes were not found, but their expression changed; this indicates that also epigenetic modifications may play an important role in its development. Indeed, several reports were published about genome-wide methylation in these neoplastic tissues, and an increasing number of small non-coding RNA are either up- or down-regulated in bladder cancer, indicating that impaired gene expression may also pass through these metabolic pathways. Taken together, these data reveal that bladder cancer is far to be considered a simple model of malignancy. In the present review, we summarize recent progress in the genome-wide analysis of bladder cancer, and analyse non

  13. Simple sequence proteins in prokaryotic proteomes

    Directory of Open Access Journals (Sweden)

    Ramachandran Srinivasan

    2006-06-01

    Full Text Available Abstract Background The structural and functional features associated with Simple Sequence Proteins (SSPs are non-globularity, disease states, signaling and post-translational modification. SSPs are also an important source of genetic and possibly phenotypic variation. Analysis of 249 prokaryotic proteomes offers a new opportunity to examine the genomic properties of SSPs. Results SSPs are a minority but they grow with proteome size. This relationship is exhibited across species varying in genomic GC, mutational bias, life style, and pathogenicity. Their proportion in each proteome is strongly influenced by genomic base compositional bias. In most species simple duplications is favoured, but in a few cases such as Mycobacteria, large families of duplications occur. Amino acid preference in SSPs exhibits a trend towards low cost of biosynthesis. In SSPs and in non-SSPs, Alanine, Glycine, Leucine, and Valine are abundant in species widely varying in genomic GC whereas Isoleucine and Lysine are rich only in organisms with low genomic GC. Arginine is abundant in SSPs of two species and in the non-SSPs of Xanthomonas oryzae. Asparagine is abundant only in SSPs of low GC species. Aspartic acid is abundant only in the non-SSPs of Halobacterium sp NRC1. The abundance of Serine in SSPs of 62 species extends over a broader range compared to that of non-SSPs. Threonine(T is abundant only in SSPs of a couple of species. SSPs exhibit preferential association with Cell surface, Cell membrane and Transport functions and a negative association with Metabolism. Mesophiles and Thermophiles display similar ranges in the content of SSPs. Conclusion Although SSPs are a minority, the genomic forces of base compositional bias and duplications influence their growth and pattern in each species. The preferences and abundance of amino acids are governed by low biosynthetic cost, evolutionary age and base composition of codons. Abundance of charged amino acids Arginine

  14. Foreshocks and Aftershocks in Simple Earthquake Models

    Science.gov (United States)

    Tiampo, K. F.; Klein, W.; Dominguez, R.; Kazemian, J.; González, P. J.

    2014-12-01

    Natural earthquake fault systems are highly heterogeneous in space; inhomogeneities occur because the earth is made of a variety of materials of different strengths and dissipate stress differently. Because the spatial arrangement of these materials is dependent on the geologic history, the distribution of these various materials can be quite complex and occur over a wide range of length scales. Despite their inhomogeneous nature, real faults are often modeled as spatially homogeneous systems. Here we present a simple earthquake fault model based on the Olami-Feder-Christensen (OFC) and Rundle-Jackson-Brown (RJB) cellular automata models with long-range interactions that incorporates a fixed percentage of stronger sites, or 'asperity cells', into the lattice. These asperity cells are significantly stronger than the surrounding lattice sites but eventually rupture when the applied stress reaches their higher threshold stress. The introduction of these spatial heterogeneities results in temporal clustering in the model that mimics those seen in natural fault systems. We observe sequences of activity that start with a gradually accelerating number of larger events (foreshocks) prior to a mainshock that is followed by a tail of decreasing activity (aftershocks). These recurrent large events occur at regular intervals, as is often observed in historic seismicity, and the time between events and their magnitude are a function of the stress dissipation parameter. The relative length of the foreshock to aftershock sequence depends on the amount of stress dissipation in the system, resulting in relatively long aftershock sequences when the stress dissipation is large versus long foreshock sequences when the stress dissipation is weak. This work provides further evidence that the spatial and temporal patterns observed in natural seismicity are strongly influenced by the underlying physical properties and are not solely the result of a simple cascade mechanism. We find that

  15. Structural and computational aspects of simple and influence games

    OpenAIRE

    Riquelme Csori, Fabián

    2014-01-01

    Simple games are a fundamental class of cooperative games. They have a huge relevance in several areas of computer science, social sciences and discrete applied mathematics. The algorithmic and computational complexity aspects of simple games have been gaining notoriety in the recent years. In this thesis we review different computational problems related to properties, parameters, and solution concepts of simple games. We consider different forms of representation of simple games, regular...

  16. Simple yet Hidden Counterexamples in Undergraduate Real Analysis

    Science.gov (United States)

    Shipman, Barbara A.; Shipman, Patrick D.

    2013-01-01

    We study situations in introductory analysis in which students affirmed false statements as true, despite simple counterexamples that they easily recognized afterwards. The study draws attention to how simple counterexamples can become hidden in plain sight, even in an active learning atmosphere where students proposed simple (as well as more…

  17. A simple and effective method to encapsulate tobacco mesophyll protoplasts to maintain cell viability

    Directory of Open Access Journals (Sweden)

    Rong Lei

    2015-01-01

    • It is very convenient to change or collect the solution without mechanically disturbing the protoplasts. This simple and effective silica sol–gel/alginate two-step immobilization of protoplasts in Transwell has great potential for applications in genetic transformation, metabolite production, and migration assays.

  18. Uncertainty analysis on simple mass balance model to calculate critical loads for soil acidity

    Science.gov (United States)

    Harbin Li; Steven G. McNulty

    2007-01-01

    Simple mass balance equations (SMBE) of critical acid loads (CAL) in forest soil were developed to assess potential risks of air pollutants to ecosystems. However, to apply SMBE reliably at large scales, SMBE must be tested for adequacy and uncertainty. Our goal was to provide a detailed analysis of uncertainty in SMBE so that sound strategies for scaling up CAL...

  19. Effect of the Debye screening on the tunnel current through simple electrochemical bridged contact

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Medvedev, Oleg; Ulstrup, Jens

    2008-01-01

    General equations for tunnel current through electrochemical contact containing a redox-center in molecular bridge group are observed with allowing for potential distribution in the tunnel gap. Simple approximate expressions appropriate for the analysis of experimental data are also derived...

  20. A simple model for atomic layer doped field-effect transistor (ALD-FET) electronic states

    Energy Technology Data Exchange (ETDEWEB)

    Mora R, M.E. [Centro de Investigaciones en Optica, Unidad Aguascalientes. Juan de Montoro 207, Zona Centro, 20000 Aguascalientes (Mexico); Gaggero S, L.M. [Escuela de Fisica, Universidad Autonoma de Zacatecas, Av. Preparatoria 301, 98060 Zacatecas (Mexico)

    1998-12-31

    We propose a simple potential model based on the Thomas-Fermi approximation to reproduce the main properties of the electronic structure of an atomic layer doped field effect transistor. Preliminary numerical results for a Si-based ALD-FET justify why bound electronic states are not observed in the experiment. (Author)

  1. Accuracy of simple folding model in the calculation of the direct part ...

    Indian Academy of Sciences (India)

    action potential solely depends upon two factors: First, the validity of DME method to reproduce the ground state properties of the colliding nuclei and second, the approxima- tion to be made for the local density of the composite system of the colliding nuclei that appears in simple folding model. The DME being truncated ...

  2. A simple model for calculating the bulk modulus of the mixed ionic ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 77; Issue 4. A simple model for calculating the bulk modulus of the mixed ionic ... in terms of the bulk modulus of the end members alone. The calculated values are comparable to those deduced from the three-body potential model (TDPM) by applying Vegard's law.

  3. A simple and useful solution for visualizing the care flow for patients and healthcare professionals.

    Science.gov (United States)

    Chang, Polun; Kuo, Ming Chuan

    2008-11-06

    It has been known that visualization is a user-preferred and more meaningful interface of information systems. We used the Microsoft Visio 2003 and Excel 2003 with the VBA automation tool to design a process flow of Cardiac Catheterization. The results showed the technical feasibility and potentials of using simple tool to visualize the nursing process for both patients and healthcare professionals.

  4. Simple model for daily evaporation from fallow tilled soil under spring conditions in a temperate climate.

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Stroosnijder, L.

    1986-01-01

    A simple parametric model is presented to estimate daily evaporation from fallow tilled soil under spring conditions in a temperate climate. In this model, cumulative actual evaporation during a drying cycle is directly proportional to the square root of cumulative potential evaporation. The model

  5. A simple approach to recycle broiler litter as animal feed | Makinde ...

    African Journals Online (AJOL)

    Broiler litter (BL) is a major waste from poultry production that constitutes serious disposal and environmental pollution problems globally despite its potential as animal feed. Therefore, the objective of this study was to develop a simple procedure for converting broiler litter into animal feed using wheat offal (WO) and cattle ...

  6. Pyglidein – A Simple HTCondor Glidein Service

    Science.gov (United States)

    Schultz, D.; Riedel, B.; Merino, G.

    2017-10-01

    A major challenge for data processing and analysis at the IceCube Neutrino Observatory presents itself in connecting a large set of individual clusters together to form a computing grid. Most of these clusters do not provide a “standard” grid interface. Using a local account on each submit machine, HTCondor glideins can be submitted to virtually any type of scheduler. The glideins then connect back to a main HTCondor pool, where jobs can run normally with no special syntax. To respond to dynamic load, a simple server advertises the number of idle jobs in the queue and the resources they request. The submit script can query this server to optimize glideins to what is needed, or not submit if there is no demand. Configuring HTCondor dynamic slots in the glideins allows us to efficiently handle varying memory requirements as well as whole-node jobs. One step of the IceCube simulation chain, photon propagation in the ice, heavily relies on GPUs for faster execution. Therefore, one important requirement for any workload management system in IceCube is to handle GPU resources properly. Within the pyglidein system, we have successfully configured HTCondor glideins to use any GPU allocated to it, with jobs using the standard HTCondor GPU syntax to request and use a GPU. This mechanism allows us to seamlessly integrate our local GPU cluster with remote non-Grid GPU clusters, including specially allocated resources at XSEDE supercomputers.

  7. Managing Cancer Pain - Simple Rules, Major Benefits

    Directory of Open Access Journals (Sweden)

    Dwight E Moulin

    2004-01-01

    Full Text Available In the developed world, approximately one in three individuals will be diagnosed with cancer and one-half of those will die of progressive disease (1. At least 75% of patients with cancer develop pain before death. It is therefore not surprising that pain is one of the most feared consequences of cancer for both patients and families (2. The good news is that cancer pain can be controlled with relatively simple means in more than 80% of cases based on guidelines from the World Health Organization (3. Mild pain can be treated with acetaminophen or nonsteroidal anti-inflammatory drugs (Step 1 of the analgesic ladder. Moderate pain requires the addition of a 'minor' opioid such as codeine (Step 2, and severe pain mandates the use of a major opioid analgesic such as morphine (Step 3. In this issue of Pain Research & Management, Gallagher et al (pages 188-194 highlight some of the barriers to adequate cancer pain management based on a cross-sectional survey of British Columbian physicians. The survey response rate of 69% attests to the validity of their findings.

  8. Simple mathematical law benchmarks human confrontations

    Science.gov (United States)

    Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

    2013-12-01

    Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a `lone wolf' identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds.

  9. A Simple Model to Study Tau Pathology

    Directory of Open Access Journals (Sweden)

    Alexander L. Houck

    2016-01-01

    Full Text Available Tau proteins play a role in the stabilization of microtubules, but in pathological conditions, tauopathies, tau is modified by phosphorylation and can aggregate into aberrant aggregates. These aggregates could be toxic to cells, and different cell models have been used to test for compounds that might prevent these tau modifications. Here, we have used a cell model involving the overexpression of human tau in human embryonic kidney 293 cells. In human embryonic kidney 293 cells expressing tau in a stable manner, we have been able to replicate the phosphorylation of intracellular tau. This intracellular tau increases its own level of phosphorylation and aggregates, likely due to the regulatory effect of some growth factors on specific tau kinases such as GSK3. In these conditions, a change in secreted tau was observed. Reversal of phosphorylation and aggregation of tau was found by the use of lithium, a GSK3 inhibitor. Thus, we propose this as a simple cell model to study tau pathology in nonneuronal cells due to their viability and ease to work with.

  10. A simple law of star formation

    DEFF Research Database (Denmark)

    Padoan, Paolo; Haugbølle, Troels; Nordlund, Åke

    2012-01-01

    We show that supersonic MHD turbulence yields a star formation rate (SFR) as low as observed in molecular clouds, for characteristic values of the free-fall time divided by the dynamical time, t ff/t dyn, the Alfvénic Mach number, {\\cal M}_a, and the sonic Mach number, {\\cal M}_s. Using a very...... values of t ff/t dyn and {\\cal M}_a. (2) Decreasing values of {\\cal M}_a (stronger magnetic fields) reduce epsilonff, but only to a point, beyond which epsilonff increases with a further decrease of {\\cal M}_a. (3) For values of {\\cal M}_a characteristic of star-forming regions, epsilonff varies...... with {\\cal M}_a by less than a factor of two. We propose a simple star formation law, based on the empirical fit to the minimum epsilonff, and depending only on t ff/t dyn: epsilonff ˜ epsilonwindexp (– 1.6 t ff/t dyn). Because it only depends on the mean gas density and rms velocity, this law...

  11. College Aptitude Test Simple Checker (Version 2

    Directory of Open Access Journals (Sweden)

    Jake G. Maggay

    2017-05-01

    Full Text Available All enrolees of the Cagayan State University are required to take the College Aptitude Test (CAT. The CAT result serves as a basis for recommendation and admission to a specific course or field of specialization, thus, result must be accurate. The study a imed to develop a computerized College Aptitude Test (CAT Simple Checker of Cagayan State University – Lasam Campus to facilitate and to reduce the time of the guidance counsellor in checking many aptitude test papers as well as to ensure accuracy of resu lt. It followed the framework of Design Science Research in Information Systems which consists of six steps such as problem identification and motivation, definition of objectives for a solution based on the identified problem, design and development of th e system, demonstration of the system to the guidance counsellor, evaluation of the system’s functionality and impact and communication which involves documentation and publication. A combination of Visual Basic 6 as the programming language and SQL Server 2005 as the Database Management System (DBMS were used in the development of the system. As a result, the system provides support to the guidance counsellor in performing the assigned tasks by reducing the time consumed in checking aptitude test papers t hat makes the guidance counsellor more effective, efficient and productive.

  12. Simple mathematical models of gene regulatory dynamics

    CERN Document Server

    Mackey, Michael C; Tyran-Kamińska, Marta; Zeron, Eduardo S

    2016-01-01

    This is a short and self-contained introduction to the field of mathematical modeling of gene-networks in bacteria. As an entry point to the field, we focus on the analysis of simple gene-network dynamics. The notes commence with an introduction to the deterministic modeling of gene-networks, with extensive reference to applicable results coming from dynamical systems theory. The second part of the notes treats extensively several approaches to the study of gene-network dynamics in the presence of noise—either arising from low numbers of molecules involved, or due to noise external to the regulatory process. The third and final part of the notes gives a detailed treatment of three well studied and concrete examples of gene-network dynamics by considering the lactose operon, the tryptophan operon, and the lysis-lysogeny switch. The notes contain an index for easy location of particular topics as well as an extensive bibliography of the current literature. The target audience of these notes are mainly graduat...

  13. Simple model of the slingshot effect

    Directory of Open Access Journals (Sweden)

    Gaetano Fiore

    2016-07-01

    Full Text Available We present a detailed quantitative description of the recently proposed “slingshot effect.” Namely, we determine a broad range of conditions under which the impact of a very short and intense laser pulse normally onto a low-density plasma (or matter locally completely ionized into a plasma by the pulse causes the expulsion of a bunch of surface electrons in the direction opposite to the one of propagation of the pulse, and the detailed, ready-for-experiments features of the expelled electrons (energy spectrum, collimation, etc. The effect is due to the combined actions of the ponderomotive force and the huge longitudinal field arising from charge separation. Our predictions are based on estimating 3D corrections to a simple, yet powerful plane 2-fluid magnetohydrodynamic (MHD model where the equations to be solved are reduced to a system of Hamilton equations in one dimension (or a collection of which become autonomous after the pulse has overcome the electrons. Experimental tests seem to be at hand. If confirmed by the latter, the effect would provide a new extraction and acceleration mechanism for electrons, alternative to traditional radio-frequency-based or Laser-Wake-Field ones.

  14. Two simple tools for industrial OR

    Directory of Open Access Journals (Sweden)

    K. Sandrock

    2003-12-01

    Full Text Available At the 1985 Annual Congress of the South African Production & Inventory Control Society it was pointed out that the productivity growth rate for South Africa is completely out of kilter with that for the western industrialised nations. The latter all display positive rates (some as high as that of Japan whereas the rate for South Africa is - NEGATIVE. Partly as a result of this situation, more and more attention is being given to quality control and reliability engineering by our industrialists in their attempts to improve productivity. This is going hand in hand with the introduction of better techniques and better use of the latest technology. We should also give attention to analytical tools that may be used in a simple inexpensive way to improve our methods of analysing industrial data, and in this way to improve our performance at little or no additional cost. To this end two tools are discussed. They are by means new. But it does seem as though they could be more widely applied in the industrial milieu.

  15. Exact Fit of Simple Finite Mixture Models

    Directory of Open Access Journals (Sweden)

    Dirk Tasche

    2014-11-01

    Full Text Available How to forecast next year’s portfolio-wide credit default rate based on last year’s default observations and the current score distribution? A classical approach to this problem consists of fitting a mixture of the conditional score distributions observed last year to the current score distribution. This is a special (simple case of a finite mixture model where the mixture components are fixed and only the weights of the components are estimated. The optimum weights provide a forecast of next year’s portfolio-wide default rate. We point out that the maximum-likelihood (ML approach to fitting the mixture distribution not only gives an optimum but even an exact fit if we allow the mixture components to vary but keep their density ratio fixed. From this observation we can conclude that the standard default rate forecast based on last year’s conditional default rates will always be located between last year’s portfolio-wide default rate and the ML forecast for next year. As an application example, cost quantification is then discussed. We also discuss how the mixture model based estimation methods can be used to forecast total loss. This involves the reinterpretation of an individual classification problem as a collective quantification problem.

  16. ZeroMQ: Messaging Made Simple

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Since its inception in 2007, ZeroMQ has defined a new product category of thin, fast, open source message transports. This little library has now grown into a large, vibrant community of projects tied together with standard protocols and APIs. Applications, written in any language, talk to each other over TCP, multicast, or inproc transports, using a single socket-based API, and a set of "patterns" (pub-sub, request-reply, dealer-router, pipeline). ZeroMQ handles message framing, batching, and I/O, but ignores aspects like serialization and persistence. By focussing on the essentials, and acting as a toolkit rather than a pre-packaged solution, ZeroMQ turns the complex problem of distributed computing into a relatively simple recipe. About the speaker Pieter Hintjens is a writer, programmer, and public speaker who has spent decades building large software systems, organizations, and businesses. He designed the Advanced Message Queuing Protocol (AMQP) in 2006 for JPMorganChase and left ...

  17. Simple Low-Frequency Beam Pickup

    Energy Technology Data Exchange (ETDEWEB)

    Novokhatski, A.; Heifets, S.; /SLAC; Aleksandrov, A.; /Oak Ridge

    2011-10-12

    Detection of the field induced by a beam outside of the beam pipe can be used as a beam diagnostic. Wires placed in longitudinal slots in the outside wall of the beam pipe can be used as a beam pickup. This has a very small beam-coupling impedance and avoids complications of having a feedthrough. The signal can be reasonably high at low frequencies. We present a field waveform at the outer side of a beam pipe, obtained as a result of calculations and measurements. We calculate the beam-coupling impedance due to a long longitudinal slot in the resistive wall and the signal induced in a wire placed in such a slot and shielded by a thin screen from the beam. These results should be relevant for impedance calculations of the slot in an antechamber and for slots in the PEP-II distributed ion pump screens. The design of the low-frequency beam position monitor is very simple. It can be used in storage rings, synchrotron light sources, and free electron lasers, like LINAC coherent light source.

  18. A Simple, Inexpensive Acoustic Levitation Apparatus

    Science.gov (United States)

    Schappe, R. Scott; Barbosa, Cinthya

    2017-01-01

    Acoustic levitation uses a resonant ultrasonic standing wave to suspend small objects; it is used in a variety of research disciplines, particularly in the study of phase transitions and materials susceptible to contamination, or as a stabilization mechanism in microgravity environments. The levitation equipment used for such research is quite costly; we wanted to develop a simple, inexpensive system to demonstrate this visually striking example of standing waves. A search of the literature produced only one article relevant to creating such an apparatus, but the authors' approach uses a test tube, which limits the access to the standing wave. Our apparatus, shown in Fig. 1, can levitate multiple small (1-2 mm) pieces of expanded polystyrene (Styrofoam) using components readily available to most instructors of introductory physics. Acoustic levitation occurs in small, stable equilibrium locations where the weight of the object is balanced by the acoustic radiation force created by an ultrasonic standing wave; these locations are slightly below the pressure nodes. The levitation process also creates a horizontal restoring force. Since the pressure nodes are also velocity antinodes, this transverse stability may be analogous to the effect of an upward air stream supporting a ball.

  19. A Simple Decontamination Approach Using Hydrogen ...

    Science.gov (United States)

    Journal article To evaluate the use of relatively low levels of hydrogen peroxide vapor (HPV) for the inactivation of Bacillus anthracis spores within an indoor environment. Methods and Results: Laboratory-scale decontamination tests were conducted using bacterial spores of both B. anthracis Ames and Bacillus atrophaeus inoculated onto several types of materials. Pilot-scale tests were also conducted using a larger chamber furnished as an indoor office. Commercial off-the-shelf (COTS) humidifiers filled with aqueous solutions of 3% or 8% hydrogen peroxide were used to generate the HPV inside the mock office. The spores were exposed to the HPV for periods ranging from 8 hours up to one week. Conclusions: Four to seven day exposures to low levels of HPV (average air concentrations of approximately 5-10 parts per million) were effective in inactivating B. anthracis spores on multiple materials. The HPV can be generated with COTS humidifiers and household H2O2 solutions. With the exception of one test/material, B. atrophaeus spores were equally or more resistant to HPV inactivation compared to those from B. anthracis Ames. Significance and Impact of Study: This simple and effective decontamination method is another option that could be widely applied in the event of a B. anthracis spore release.

  20. Exploding microbubbles driving a simple electrochemical micropump

    Science.gov (United States)

    Uvarov, Ilia V.; Lemekhov, Sergey S.; Melenev, Artem E.; Svetovoy, Vitaly B.

    2017-10-01

    Electrochemical microactuators and micropumps are too slow for many applications. The use of the alternating polarity electrolysis can strongly reduce the response time of such devices. We investigate a powerful pumping regime of a simple valveless micropump made from polydimethylsiloxane on a glass substrate. Microsecond dynamics of the gas bubbles in the chamber is monitored with fast cameras. After an incubation period of 10-100 ms a microbubble filling the entire chamber pops up in less than 100~μ s and disappears in 10 ms. This bubble pushes liquid out and drives the pump. The phenomenon is interpreted as an explosion of the microbubble containing a mixture of H2 and O2 gases. For higher amplitude of the driving pulses the incubation time can be as short as 1-2 ms but many uncorrelated microbubbles are formed in the chamber, and disappear in 1 ms. As the result a less powerful but faster pumping is possible. A few principles allowing further improve the micropump characteristics are formulated.

  1. Simple goiter in children and juveniles

    Energy Technology Data Exchange (ETDEWEB)

    Wiebel, J.

    1983-10-31

    Non-toxic, simple goiter is the most common cause of thyroid enlargement in adolescents and children. Although initially there are hardly any complaints it should be treated with l-thyroxine to prevent further enlargement, degenerative alterations, development of nodules, possible hyper- or hypothyroidism occurring with increasing age. Anamnesis and clinical features are as important for establishing the diagnosis as laboratory parameters, which are not always necessary. Thyroid nodules in children or adolescents are more likely to be malignant than in later life; their nature has to be clarified by sonography, scintigraphy, fine needle biopsy or even operation. After l-thyroxine therapy has normalized thyroid size (60-90%), goiter prophylaxis with iodine supplementation can be tried, since iodine deficiency exists throughout Germany. If the goiter reappears continuous l-thyroxine treatment is recommended. Following the general introduction of iodine prophylaxis using iodinized salt there has been a significant reduction in goiter incidence in Switzerland, Austria and other areas with iodine deficiency. New legislation in the FRG now allows for the general use of e.g., Bad Reichenhaller Jodsalz, Duera Vollsalz or Bayerisches Vollsalz to prevent the development of the majority of goiters in children and adolescents.

  2. Ten Simple Rules for Drawing Scientific Comics

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Jason E.; Partridge, Matthew; Bromberg, Yana

    2018-01-04

    Institutions around the world are fighting to improve science communication all the time. From calls for journal papers to be simplified to encouraging scientists to take more of an active role through community engagement, there is an impetus to demystify and improve public understanding and engagement with science [1-3]. Technology has greatly helped expand the range of learning styles that a lecturer can call on to reach people in new ways. Social media outlets like Twitter, Facebook, Instagram, and Tumblr have expanded the reach of science communication within and across scientific disciplines and to the lay public [1, 3]. With all the videos, interactive quizzes, and instant feedback it can be easy to overlook one of the simplest methods for communicating complex ideas: comics. There are few scientists that haven’t heard of Randall Munroe, the artist behind the web comic xkcd (https://xkcd.com), which features amazing graphic explanations on everything from climate change (https://xkcd.com/1732/) to data storage (https://xkcd.com/1360/). These comics are so effective that they are posted on walls in laboratories and pubs alike. The ideas that they explain are complicated big ideas but by simplifying them down to the core messages and by providing simple visual analogies the comics educate people that other media can not always reach.

  3. Sustained Attention Ability Affects Simple Picture Naming

    Directory of Open Access Journals (Sweden)

    Suzanne R. Jongman

    2017-07-01

    Full Text Available Sustained attention has previously been shown as a requirement for language production. However, this is mostly evident for difficult conditions, such as a dual-task situation. The current study provides corroborating evidence that this relationship holds even for simple picture naming. Sustained attention ability, indexed both by participants’ reaction times and individuals’ hit rate (the proportion of correctly detected targets on a digit discrimination task, correlated with picture naming latencies. Individuals with poor sustained attention were consistently slower and their RT distributions were more positively skewed when naming pictures compared to individuals with better sustained attention. Additionally, the need to sustain attention was manipulated by changing the speed of stimulus presentation. Research has suggested that fast event rates tax sustained attention resources to a larger degree than slow event rates. However, in this study the fast event rate did not result in increased difficulty, neither for the picture naming task nor for the sustained attention task. Instead, the results point to a speed-accuracy trade-off in the sustained attention task (lower accuracy but faster responses in the fast than in the slow event rate, and to a benefit for faster rates in the picture naming task (shorter naming latencies with no difference in accuracy. Performance on both tasks was largely comparable, supporting previous findings that sustained attention is called upon during language production.

  4. Squid – a simple bioinformatics grid

    Directory of Open Access Journals (Sweden)

    de Miranda Antonio B

    2005-08-01

    Full Text Available Abstract Background BLAST is a widely used genetic research tool for analysis of similarity between nucleotide and protein sequences. This paper presents a software application entitled "Squid" that makes use of grid technology. The current version, as an example, is configured for BLAST applications, but adaptation for other computing intensive repetitive tasks can be easily accomplished in the open source version. This enables the allocation of remote resources to perform distributed computing, making large BLAST queries viable without the need of high-end computers. Results Most distributed computing / grid solutions have complex installation procedures requiring a computer specialist, or have limitations regarding operating systems. Squid is a multi-platform, open-source program designed to "keep things simple" while offering high-end computing power for large scale applications. Squid also has an efficient fault tolerance and crash recovery system against data loss, being able to re-route jobs upon node failure and recover even if the master machine fails. Our results show that a Squid application, working with N nodes and proper network resources, can process BLAST queries almost N times faster than if working with only one computer. Conclusion Squid offers high-end computing, even for the non-specialist, and is freely available at the project web site. Its open-source and binary Windows distributions contain detailed instructions and a "plug-n-play" instalation containing a pre-configured example.

  5. A Quantum Space behind Simple Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Chuan Sheng Chew

    2017-01-01

    Full Text Available In physics, experiments ultimately inform us about what constitutes a good theoretical model of any physical concept: physical space should be no exception. The best picture of physical space in Newtonian physics is given by the configuration space of a free particle (or the center of mass of a closed system of particles. This configuration space (as well as phase space can be constructed as a representation space for the relativity symmetry. From the corresponding quantum symmetry, we illustrate the construction of a quantum configuration space, similar to that of quantum phase space, and recover the classical picture as an approximation through a contraction of the (relativity symmetry and its representations. The quantum Hilbert space reduces into a sum of one-dimensional representations for the observable algebra, with the only admissible states given by coherent states and position eigenstates for the phase and configuration space pictures, respectively. This analysis, founded firmly on known physics, provides a quantum picture of physical space beyond that of a finite-dimensional manifold and provides a crucial first link for any theoretical model of quantum space-time at levels beyond simple quantum mechanics. It also suggests looking at quantum physics from a different perspective.

  6. Simple models of the hydrofracture process

    KAUST Repository

    Marder, M.

    2015-12-29

    Hydrofracturing to recover natural gas and oil relies on the creation of a fracture network with pressurized water. We analyze the creation of the network in two ways. First, we assemble a collection of analytical estimates for pressure-driven crack motion in simple geometries, including crack speed as a function of length, energy dissipated by fluid viscosity and used to break rock, and the conditions under which a second crack will initiate while a first is running. We develop a pseudo-three-dimensional numerical model that couples fluid motion with solid mechanics and can generate branching crack structures not specified in advance. One of our main conclusions is that the typical spacing between fractures must be on the order of a meter, and this conclusion arises in two separate ways. First, it arises from analysis of gas production rates, given the diffusion constants for gas in the rock. Second, it arises from the number of fractures that should be generated given the scale of the affected region and the amounts of water pumped into the rock.

  7. Electromagnetic Sources in Moving Simple Medium

    DEFF Research Database (Denmark)

    Johannsen, Günther

    1970-01-01

    A retarded potential tensor (4-vector) is derived in an arbitrary system of inertia for an arbitrary electromagnetic source in a moving homogeneous, isotropic, nondispersive, lossless dielectric. The velocity is uniform, and the result is relativistic correct. ©1970 The American Institute...

  8. Simple sequence repeats in mycobacterial genomes

    Indian Academy of Sciences (India)

    2006-12-18

    Dec 18, 2006 ... It is therefore interesting to analyse the mycobacterial genomes for distribution and abundance of microsatellites tracts and to look for potentially polymorphic microsatellites. Available mycobacterial genomes, Mycobacterium avium, M. leprae, M. bovis and the two strains of M. tuberculosis (CDC1551 and ...

  9. Violent Potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Søgaard, Thomas Friis

    2015-01-01

    This article explores the social significance of violence as potentiality and performance among former headhunters. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence as “performed violent potentiality...... today abandoned headhunting, the potentials for violence and dominance, which the act of headhunting sought to elicit, remains a critical aspect of masculinity. We propose that a focus on the social significance of performative violent potentiality among Bugkalot men can provide general insights...... that can also be used in other contexts to understand how men construct hegemonic masculinity by strategically adopting the interspace of civility and violence....

  10. Cavitation/boundary effects in a simple head impact model.

    Science.gov (United States)

    Nusholtz, G S; Wylie, B; Glascoe, L G

    1995-07-01

    An experimental and numerical analysis of the impact response of a simple model of the human head is presented. A water-filled 14-cm diameter cylinder was struck by a 10 kg free flying mass. Rigid-body acceleration-time-history and the pressure at the fluid-cylinder interface were monitored during the impact event. Comparisons between the experimental results and the results of a computational model were made. The computational model used is a two-dimensional finite difference code simulating the physical experiment. The code incorporates a thin layer of air and the potential for vaporization along the inside of the cylinder. The study indicates that during a severe impact to the human head, the stresses generated within the brain can result in cavitation on the far side of impact followed by a sudden cavity collapse which can be quite violent. The study identifies how a skull-brain interface and cavitation can potentially affect the internal pressure response of the brain when subjected to a sudden impact.

  11. Relative effectiveness of concurrent forward/backward versus simple forward and simple backward Pavlovian conditioning procedures.

    Science.gov (United States)

    Dess, N K; Patterson, J; Overmier, J B

    1986-01-01

    Concurrent forward/backward Pavlovian conditioning procedures were compared with simple forward and simple backward procedures for differential excitatory and inhibitory conditioning. Four groups of dogs each received 30 shocks while restrained in a Pavlovian harness. One group of dogs (CON) received concurrent conditioning with a clicker signaling shocks and with a tone following shocks. For another group of dogs (SF), a clicker signaled the shocks, whereas the tone was randomly related to shocks. For a third group (SB), the tone followed shock termination, whereas the clicker was randomly related to shocks. For a fourth group (TRC), both the clicker and the tone were randomly related to shocks. All stimuli were then superimposed on a temporally paced avoidance baseline and their associative properties were assessed relative to the TRC group. Differential excitatory-inhibitory conditioning was significantly reduced in the concurrent procedure relative to that which occurred in the simple conditioning procedures despite exactly equal CS + -US and US-CS-contingencies. These results were interpreted with reference to contextual conditioning effects predicted by the Rescorla-Wagner conditioning model and the theoretical issue of independence vs. interdependence of CS-US associative strengths.

  12. An Arduino Investigation of Simple Harmonic Motion

    Science.gov (United States)

    Galeriu, Calin; Edwards, Scott; Esper, Geoffrey

    2014-03-01

    We cannot hope for a new generation of scientists and engineers if we don't let our young students take ownership of their scientific and engineering explorations, if we don't let them enjoy the hands-on cycle of design and production, and if we don't let them implant their creativity into a technologically friendly environment. With this educational philosophy in mind, Massimo Banzi and his team have developed and popularized the open source Arduino microcontroller board. The Arduino board has helped countless people in their science, electronics, robotics, or engineering projects, allowing them to build things that we have not even dreamed of. Physics instructors have also realized the advantages of using Arduino boards for lab experiments. The schools are saving money because the homemade experimental equipment is much cheaper than the commercial alternatives. The students are thankful for an educational experience that is more interesting, more loaded with STEM content, and more fun. As further proof of this new trend in physics education, Vernier5 is now documenting the use of their probes with Arduino boards. This is why we have developed an Arduino-based physics investigation of the simple harmonic motion (SHM) of a mass on a spring. The experimental data are collected with the help of an ultrasonic distance sensor and an Arduino Uno board. The data are then graphed and analyzed using Origin 9. This rich cross-curricular STEM activity integrates electronics, computer programming, physics, and mathematics in a way that is both experimentally exciting and intellectually rewarding.

  13. Simple environmental sensor webs for classroom inquiry

    Science.gov (United States)

    Fatland, D. R.

    2007-12-01

    This paper describes a platform for inquiry-driven learning in environmental science at the secondary and undergraduate levels including preliminary results from two pilot sensor web-driven projects, in progress. The work presented here emphasizes - Documenting construction and use of the platform - Analysis of results over technology used - Open-ended iteration of the inquiry process Cognitive theory suggests that pedagogical modes of 'information-transfer' fall short as a means of building (arguably useful) problem solving and critical thinking skills in comparison with inquiry-driven modes. In view of limited classroom time and constraints such as standardized testing, sensor web-driven environmental inquiry faces a two-fold challenge: Minimize time-intrusion into the curriculum and make that time highly productive and valuable for students. The technology employed here is a wireless microcomputer network ruggedized for outdoor use, interfaces to simple environmental sensors, supplemental data from a low-cost meteorological station, and data recovery and analysis by means of a laptop PC. Target cost of the system (not including the PC) is 2000USD. The baseline study subject is watershed hydrology, with a corollary aim of "identifiying the doorways" into related subjects and story lines. The general plan of action proceeds in these steps: - Build and test the system - Students work with the system in the classroom - Students formulate a deployment plan - Instruments deployed, data acquired and formatted - Student analysis, hypothesis generation, research - Reiterate the previous three steps as possible Once this platform/program is established the idea is to expand to include personalized reflection and self- expression per the curriculum established by the River of Words non-profit organization. The second expansion idea is (per the eScience model) to facilitate Internet-based exchanges and equipment sharing with students located in other geographical regions

  14. A simple deep monitoring well dilution technique.

    Science.gov (United States)

    Rogiers, Bart; Labat, Serge; Gedeon, Matej; Vandersteen, Katrijn

    2015-04-01

    Well dilution techniques are well known and studied as one of the basic techniques to quantify groundwater fluxes. A typical well dilution test consists of the injection of a tracer, a mixing mechanism (e.g. water circulation with a pump) to achieve a homogeneous concentration distribution within the well, and monitoring of the evolution of tracer concentration with time. An apparent specific discharge can be obtained from such a test, and when details on the well construction are known, it can be converted into a specific discharge representative of the undisturbed aquifer. For deep wells however, the injection of tracer becomes less practical and the use of pumps for circulating and mixing the water becomes problematic. This is due to the limited pressure that common pumps can endure at the outlet, as well as the large volume of water that makes it difficult to achieve a homogeneous concentration, and the impracticalities of getting a lot of equipment to large depths in very small monitoring wells. Injection and monitoring of tracer at a specific depth omits several of the problems with deep wells. We present a very simple device that can be used to perform a dilution test at a specific depth in deep wells. The injection device consists of a PVC tube with a detachable rubber seal at its bottom. To minimize disturbance of the water column in the well, we integrated an EC sensor in this injection device, which enables us to use demineralized water or dissolved salts as a tracer. Once at the target depth, the PVC tube is retracted and the EC sensor and tracer become subject to groundwater flow. The device was tested on a shallow well, on which different types of dilution tests were performed. The results of the other tests agree well with the injection tube results. Finally, the device was used to perform a dilution test in a deep well in order to demonstrate the feasibility of the approach.

  15. A simple tool for neuroimaging data sharing

    Science.gov (United States)

    Haselgrove, Christian; Poline, Jean-Baptiste; Kennedy, David N.

    2014-01-01

    Data sharing is becoming increasingly common, but despite encouragement and facilitation by funding agencies, journals, and some research efforts, most neuroimaging data acquired today is still not shared due to political, financial, social, and technical barriers to sharing data that remain. In particular, technical solutions are few for researchers that are not a part of larger efforts with dedicated sharing infrastructures, and social barriers such as the time commitment required to share can keep data from becoming publicly available. We present a system for sharing neuroimaging data, designed to be simple to use and to provide benefit to the data provider. The system consists of a server at the International Neuroinformatics Coordinating Facility (INCF) and user tools for uploading data to the server. The primary design principle for the user tools is ease of use: the user identifies a directory containing Digital Imaging and Communications in Medicine (DICOM) data, provides their INCF Portal authentication, and provides identifiers for the subject and imaging session. The user tool anonymizes the data and sends it to the server. The server then runs quality control routines on the data, and the data and the quality control reports are made public. The user retains control of the data and may change the sharing policy as they need. The result is that in a few minutes of the user’s time, DICOM data can be anonymized and made publicly available, and an initial quality control assessment can be performed on the data. The system is currently functional, and user tools and access to the public image database are available at http://xnat.incf.org/. PMID:24904398

  16. A Simple Space Station Rescue Vehicle

    Science.gov (United States)

    Petro, Andrew

    1995-01-01

    Early in the development of the Space Station it was determined that there is a need to have a vehicle which could be used in the event that the Space Station crew need to quickly depart and return to Earth when the Space Shuttle is not available. Unplanned return missions might occur because of a medical emergency, a major Space Station failure, or if there is a long-term interruption in the delivery of logistics to the Station. The rescue vehicle ms envisioned as a simple capsule-type spacecraft which would be maintained in a dormant state at the Station for several years and be quickly activated by the crew when needed. During the assembly phase for the International Space Station, unplanned return missions will be performed by the Russian Soyuz vehicle, which can return up to three people. When the Station assembly is complete there will be a need for rescue capability for up to six people. This need might be met by an additional Soyuz vehicle or by a new vehicle which might come from a variety of sources. This paper describes one candidate concept for a Space Station rescue vehicle. The proposed rescue vehicle design has the blunt-cone shape of the Apollo command module but with a larger diameter. The rescue vehicle would be delivered to the Station in the payload bay of the Space Shuttle. The spacecraft design can accommodate six to eight people for a one-day return mission. All of the systems for the mission including deorbit propulsion are contained within the conical spacecraft and so there is no separate service module. The use of the proven Apollo re-entry shape would greatly reduce the time and cost for development and testing. Other aspects of the design are also intended to minimize development cost and simplify operations. This paper will summarize the evolution of rescue vehicle concepts, the functional requirements for a rescue vehicle, and describe the proposed design.

  17. Simple approach to study biomolecule adsorption in polymeric microfluidic channels.

    Science.gov (United States)

    Gubala, Vladimir; Siegrist, Jonathan; Monaghan, Ruairi; O'Reilly, Brian; Gandhiraman, Ram Prasad; Daniels, Stephen; Williams, David E; Ducrée, Jens

    2013-01-14

    Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor(®)) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor(®) substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor(®), and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and neutral, hydrogel-like film with polyethylene glycol (PEG) characteristics. This simple analytical approach adds to the fundamental understanding of the interaction forces in real, microfluidic systems. This method provides a straightforward and rapid way to screen surface compositions and chemistry, and relate these to their effects on the sensitivity and resistance to non-specific binding of bioassays using them. In an additional set of experiments, the surface area of the channels in this universal microfluidic chip was increased by precision milling of microscale

  18. Thermal Forces in Simple and Complex Fluids

    Science.gov (United States)

    Piazza, Roberto; Giglio, Marzio

    2004-11-01

    This topical issue of The European Physical Journal E deals with mass transport effects driven by thermal gradients, or, as we shall call them, with “thermal forces”. In simple fluid mixtures, coupling of heat and mass diffusion is due to the Ludwig-Soret effect, also known as thermal diffusion. The Soret effect dramatically lowers the thermal convection threshold, since concentration gradients relax much more slowly than temperature gradients, due to the disparate values of the mass diffusion coefficient and of the thermal diffusivity. Therefore, thermal diffusion plays an important role in naturally occurring processes like thermohaline convection (“salt fingering”) in oceans, crystal growth, component segregation in metallic alloys, volcanic lava and the Earth crust. More recently, its has been shown that thermal diffusion is a very convenient process in the generation of giant non-equilibrium fluctuations in fluid mixtures. Thermophoresis is a closely akin process that takes place both in aerosols and in liquid suspensions, consisting in the drift of dispersed particles induced by thermal inhomogeneities. Thermophoresis of airborne particles has an important role in atmospheric physics and ambient pollution, and can seriously affect semiconductor manufacturing. In macromolecular solutions and colloidal suspensions, these “thermal forces” are generally much stronger than in simple mixtures or in gases: for instance, recent experiments on DNA solutions have shown that thermophoresis may concur with thermal convection in leading to patterns where the local macromolecular concentration is amplified up to a thousandfold. Although known since a long time and clearly framed in terms of non-equilibrium thermodynamics concepts, both the Soret effect and particle thermophoresis in liquids still lack a general microscopic picture. For instance, in most cases the denser component of a binary mixture drifts to the cold, but examples of reverse behaviour are

  19. A simple empirical model estimating atmospheric CO2 background concentrations

    Science.gov (United States)

    Reuter, M.; Buchwitz, M.; Schneising, O.; Heymann, J.; Guerlet, S.; Cogan, A. J.; Bovensmann, H.; Burrows, J. P.

    2012-02-01

    A simple empirical CO2 model (SECM) is presented to estimate column-average dry-air mole fractions of atmospheric CO2 (XCO2) as well as mixing ratio profiles. SECM is based on a simple equation depending on 17 empirical parameters, latitude, and date. The empirical parameters have been determined by least squares fitting to NOAA's (National Oceanic and Atmospheric Administration) assimilation system CarbonTracker version 2010 (CT2010). Comparisons with TCCON (total column carbon observing network) FTS (Fourier transform spectrometer) measurements show that SECM XCO2 agrees quite well with reality. The synthetic XCO2 values have a standard error of 1.39 ppm and systematic station-to-station biases of 0.46 ppm. Typical column averaging kernels of the TCCON FTS, a SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY), and two GOSAT (Greenhouse gases Observing SATellite) XCO2 retrieval algorithms have been used to assess the smoothing error introduced by using SECM profiles instead of CT2010 profiles as a priori. The additional smoothing error amounts to 0.17 ppm for a typical SCIAMACHY averaging kernel and is most times much smaller for the other instruments (e.g. 0.05 ppm for a typical TCCON FTS averaging kernel). Therefore, SECM is well-suited to provide a priori information for state of the art ground-based (FTS) and satellite-based (GOSAT, SCIAMACHY) XCO2 retrievals. Other potential applications are: (i) quick check for obvious retrieval errors (by monitoring the difference to SECM), (ii) near real time processing systems (that cannot make use of models like CT2010 operated in delayed mode), (iii) "CO2 proxy" methods for XCH4 retrievals (as correction for the XCO2 background), (iv) observing system simulation experiments especially for future satellite missions.

  20. Potential Theory

    CERN Document Server

    Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří

    1988-01-01

    Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in­ cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...

  1. A simple X-ray emitter.

    Science.gov (United States)

    Murakami, Hiroaki; Ono, Ryoichi; Hirai, Atsuhiko; Hosokawa, Yoshinori; Kawai, Jun

    2005-07-01

    A compact X-ray emission instrument is made, and the X-ray spectra are measured by changing the applied electric potential. Strong soft X-rays are observed when evacuating roughly and applying a high voltage to an insulator settled in this device. The X-ray intensity is higher as the applied voltage is increased. A light-emitting phenomenon is observed when this device emits X-rays. The present X-ray emitter is made of a small cylinder with a radius of 20 mm and a height of 50 mm. This X-ray generator has a potential to be used as an X-ray source in an X-ray fluorescence spectrometer.

  2. SUDOSCAN: A Simple, Rapid, and Objective Method with Potential for Screening for Diabetic Peripheral Neuropathy

    Science.gov (United States)

    Selvarajah, Dinesh; Cash, Tom; Davies, Jennifer; Sankar, Adithya; Rao, Ganesh; Grieg, Marni; Pallai, Shillo; Gandhi, Rajiv; Wilkinson, Iain D.; Tesfaye, Solomon

    2015-01-01

    Clinical methods of detecting diabetic peripheral neuropathy (DPN) are not objective and reproducible. We therefore evaluated if SUDOSCAN, a new method developed to provide a quick, non-invasive and quantitative assessment of sudomotor function can reliably screen for DPN. 70 subjects (45 with type 1 diabetes and 25 healthy volunteers [HV]) underwent detailed assessments including clinical, neurophysiological and 5 standard cardiovascular reflex tests (CARTs). Using the American Academy of Neurology criteria subjects were classified into DPN and No-DPN groups. Based on CARTs subjects were also divided into CAN, subclinical-CAN and no-CAN. Sudomotor function was assessed with measurement of hand and foot Electrochemical Skin Conductance (ESC) and calculation of the CAN risk score. Foot ESC (μS) was significantly lower in subjects with DPN [n = 24; 53.5(25.1)] compared to the No-DPN [77.0(7.9)] and HV [77.1(14.3)] groups (ANCOVA p<0.001). Sensitivity and specificity of foot ESC for classifying DPN were 87.5% and 76.2%, respectively. The area under the ROC curve (AUC) was 0.85. Subjects with CAN had significantly lower foot [55.0(28.2)] and hand [53.5(19.6)] ESC compared to No-CAN [foot ESC, 72.1(12.2); hand ESC 64.9(14.4)] and HV groups (ANCOVA p<0.001 and 0.001, respectively). ROC analysis of CAN risk score to correctly classify CAN revealed a sensitivity of 65.0% and specificity of 80.0%. AUC was 0.75. Both foot and hand ESC demonstrated strong correlation with individual parameters and composite scores of nerve conduction and CAN. SUDOSCAN, a non-invasive and quick test, could be used as an objective screening test for DPN in busy diabetic clinics, insuring adherence to current recommendation of annual assessments for all diabetic patients that remains unfulfilled. PMID:26457582

  3. Potential Worst-case System for Testing EMI Filters Tested on Simple Filter Models

    Directory of Open Access Journals (Sweden)

    Z. Raida

    2008-09-01

    Full Text Available This paper deals with the approximate worst-case test method for testing the insertion loss of the EMI filters. The systems with 0.1 Ω and 100 Ω impedances are usually used for this testing. These systems are required by the international CISPR 17 standard. The main disadvantage of this system is the use of two impedance transformers. Especially the impedance transformer with 0.1 Ω output impedance is not easy to be produced. These transformers have usually narrow bandwidth. This paper discusses the alternative system with 1 Ω and 100 Ω impedances. The performance of these systems was tested on several filters’ models and the obtained data are depicted, too. The performance comparison of several filters in several systems is also included. The performance of alternate worst-case system is discussed in the conclusion.

  4. A simple method for estimating potential relative radiation (PRR) for landscape-vegetation analysis.

    Science.gov (United States)

    Kenneth B. Jr. Pierce; Todd Lookingbill; Dean. Urban

    2005-01-01

    Radiation is one of the primary influences on vegetation composition and spatial pattern. Topographic orientation is often used as a proxy for relative radiation load due to its effects on evaporative demand and local temperature. Common methods for incorporating this information (i.e., site measures of slope and aspect) fail to include daily or annual changes in solar...

  5. Properties and potential applications of zeolitic materials produced from fly ash using simple method of synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Arkadiusz Derkowski; Wojciech Franus; Elzbieta Beran; Adriana Czimerova [Polish Academy of Sciences, Krakow (Poland). Institute of Geological Sciences

    2006-08-15

    Very low energy-consuming procedure is proposed for synthesis of zeolitic materials from fly ash. Three different zeolite materials (X, P and S), rich in zeolite phases, Na-X (FAU), NaP1 (GIS) and sodalite (SOD) were produced from F-class fly ash, using NaOH and NaCl solutions under atmospheric pressure at temperature below 110{sup o}C. Obtained zeolitic products were analysed for their composition and physicochemical properties then compared to the raw fly ash and commercial adsorbents. The zeolitization results in a significant increase of CEC (from 5.5 up to 239 meq 100 g{sup -1}), and the high ability to adsorb heavy metal ions (over 40 mg g{sup -1}) and retain complex and organic molecules (EGME), mostly evident for material X. Adsorptive purification of waste and working lubricating oils using zeolitic products allow to provide their commercial applications in petroleum industry. Leachability of toxic elements after standard post-reaction washing is environmentally safe.

  6. Simple force feedback for small virtual environments

    Science.gov (United States)

    Schiefele, Jens; Albert, Oliver; van Lier, Volker; Huschka, Carsten

    1998-08-01

    In today's civil flight training simulators only the cockpit and all its interaction devices exist as physical mockups. All other elements such as flight behavior, motion, sound, and the visual system are virtual. As an extension to this approach `Virtual Flight Simulation' tries to subsidize the cockpit mockup by a 3D computer generated image. The complete cockpit including the exterior view is displayed on a Head Mounted Display (HMD), a BOOM, or a Cave Animated Virtual Environment. In most applications a dataglove or virtual pointers are used as input devices. A basic problem of such a Virtual Cockpit simulation is missing force feedback. A pilot cannot touch and feel buttons, knobs, dials, etc. he tries to manipulate. As a result, it is very difficult to generate realistic inputs into VC systems. `Seating Bucks' are used in automotive industry to overcome the problem of missing force feedback. Only a seat, steering wheel, pedal, stick shift, and radio panel are physically available. All other geometry is virtual and therefore untouchable but visible in the output device. In extension to this concept a `Seating Buck' for commercial transport aircraft cockpits was developed. Pilot seat, side stick, pedals, thrust-levers, and flaps lever are physically available. All other panels are simulated by simple flat plastic panels. They are located at the same location as their real counterparts only lacking the real input devices. A pilot sees the entire photorealistic cockpit in a HMD as 3D geometry but can only touch the physical parts and plastic panels. In order to determine task performance with the developed Seating Buck, a test series was conducted. Users press buttons, adapt dials, and turn knobs. In a first test, a complete virtual environment was used. The second setting had a plastic panel replacing all input devices. Finally, as cross reference the participants had to repeat the test with a complete physical mockup of the input devices. All panels and

  7. Sawtooth forces in cutting tropical hardwoods native to South America

    Science.gov (United States)

    S. P. Loehnertz; I. V. Cooz

    As a result of design, operation, and maintenance, sawblades used in tropical sawmills can cause many problems. Improvements in these areas are needed to reduce the waste associated with sawing of tropical species that are regarded as difficult to cut. In this study, cutting experiments that simulated bandsawing of tropical hardwoods showed the effect of chip...

  8. Tackling Tumblr Web Publishing Made Simple

    CERN Document Server

    Hedengren, Thord Daniel

    2011-01-01

    A comprehensive guide to the popular web publishing site Tumblr The popularity of Tumblr is growing by leaps and bounds, as it continues to make a name for itself as a reliable, accessible blogging platform. Yet, there is very little documentation on Tumblr, leaving newcomers confused as to where to start. That's where this helpful book comes in. Written by well-respected author Thord Hedengren, this step-by-step guide is an ideal starting point for Tumblr newcomers as well as web designers who want to take their Tumblblogs to the next level. You'll learn how to maximize the full potential of

  9. Biogas Digester with Simple Solar Heater

    Directory of Open Access Journals (Sweden)

    Kh S Karimov

    2012-10-01

    Full Text Available ABSTRACT: In this research work, the design, fabrication and investigation of a biogas digester with simple solar heater are presented. For the solar heater, a built-in reverse absorber type heater was used. The maximum temperature (50°C inside the methane tank was taken as a main parameter for the design of the digester. Then, the energy balance equation for the case of a static mass of fluid being heated was used to model the process. The parameters of thermal insulation of the methane tank were also included in the calculations. The biogas digester consisted of a methane tank with built-in solar reverse absorber heater to harness the radiant solar energy for heating the slurry comprising of different organic wastes (dung, sewage, food wastes etc.. The methane tank was initially filled to 70% of its volume with organic wastes from the GIK institute’s sewage. The remaining volume was filled with sewage and cow dung from other sources. During a three month period (October-December, 2009 and another two month period (February-March, 2010, the digester was investigated. The effects of solar radiation on the absorber, the slurry’s temperature, and the ambient temperature were all measured during these investigations. It was found that using sewage only and sewage with cow dung in the slurry resulted in retention times of four and two weeks, respectively. The corresponding biogas produced was 0.4 m3 and 8.0 m3, respectively. Finally, this paper also elaborates on the upgradation of biogas through the removal of carbon dioxide, hydrogen sulphide and water vapour, and also the process of conversion of biogas energy into electric powerABSTRAK: Kajian ini membentangkan rekabentuk, fabrikasi dan penyelidikan tentang pencerna biogas dengan pemanas solar ringkas. Sebagai pemanas solar, ia dilengkapkan dengan penyerap pemanas beralik. Suhu maksimum(50oC di dalam tangki metana telah diambil sebagai parameter utama rekabentuk pencerna. Dengan menggunakan

  10. The Simple Rules of Social Contagion

    Science.gov (United States)

    Hodas, Nathan O.; Lerman, Kristina

    2014-03-01

    It is commonly believed that information spreads between individuals like a pathogen, with each exposure by an informed friend potentially resulting in a naive individual becoming infected. However, empirical studies of social media suggest that individual response to repeated exposure to information is far more complex. As a proxy for intervention experiments, we compare user responses to multiple exposures on two different social media sites, Twitter and Digg. We show that the position of exposing messages on the user-interface strongly affects social contagion. Accounting for this visibility significantly simplifies the dynamics of social contagion. The likelihood an individual will spread information increases monotonically with exposure, while explicit feedback about how many friends have previously spread it increases the likelihood of a response. We provide a framework for unifying information visibility, divided attention, and explicit social feedback to predict the temporal dynamics of user behavior.

  11. Scaling of viscous dynamics in simple liquids

    DEFF Research Database (Denmark)

    Bøhling, Lasse; Ingebrigtsen, Trond; Grzybowski, A.

    2012-01-01

    Supercooled liquids are characterized by relaxation times that increase dramatically by cooling or compression. From a single assumption follows a scaling law according to which the relaxation time is a function of h(ρ) over temperature, where ρ is the density and the function h(ρ) depends...... on the liquid in question. This scaling is demonstrated to work well for simulations of the Kob–Andersen binary Lennard-Jones mixture and two molecular models, as well as for the experimental results for two van der Waals liquids, dibutyl phthalate and decahydroisoquinoline. The often used power-law density...... scaling, h(ρ)∝ργ, is an approximation to the more general form of scaling discussed here. A thermodynamic derivation was previously given for an explicit expression for h(ρ) for liquids of particles interacting via the generalized Lennard-Jones potential. Here a statistical mechanics derivation is given...

  12. Simulated measurement of power flow in structures near to simple sources and simple boundaries

    Science.gov (United States)

    Mcgary, Michael C.

    1988-01-01

    Advances in electronics technology along with the advent of low cost multichannel Fast Fourier analyzers have made it practical to use higher order central difference formulas to measure power flow in 1- and 2-D structures. The method discussed uses five point differencing for the spatial derivatives in 1-D and a thirteen point difference pattern for the spatial derivatives in 2-D plates and shells. It is assumed that the measuring transducers are accelerometers. An analytical study of the higher order differencing method and the conventional two accelerometer method was performed as a preliminary to the application of these methods to actual aircraft structures. Some classical problems were analyzed in order to simulate and compare the performance of the two methods under near field measurement conditions. These near field conditions include examples of power flows near simple sources and simple boundaries. The estimates produced by the two methods were compared to the exact solution in each example. Presented are the theory and selected results of the study, which indicate that the bias errors of the two accelerometer method under near field measurement conditions may be much larger than previous studies have suggested.

  13. Clustered Simple Cell Mapping: An extension to the Simple Cell Mapping method

    Science.gov (United States)

    Gyebrószki, Gergely; Csernák, Gábor

    2017-01-01

    When a dynamical system has a complex structure of fixed points, periodic cycles or even chaotic attractors, Cell Mapping methods are excellent tools to discover and thoroughly analyse all features in the state space. These methods discretize a region of the state space into cells and examine the dynamics in the cell state space. By determining one or more image cells for each cell, the global behaviour within the region can be quickly determined. In the simplest case - Simple Cell Mapping (SCM) method - only one image corresponds to a cell and usually a rectangular grid of cells is used. In typical applications the grid of cells is refined at specific locations. This paper, however, introduces a different approach, which is useful to expand the analysed state space region to include all features which properly characterize the global dynamics of the system. Instead of refining the initial cell state space, we start with a small initial state space region, analyse other interesting regions of the state space and incorporate them into a cluster of cell mapping solutions. By this approach, trajectories escaping the original state space region can be followed automatically and additional objects in the state space can be discovered. To illustrate the benefits of the method, we present the exploration of the phase-space of the micro-chaos map - a simple model of digitally controlled systems.

  14. Violent potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Friis Søgaard, Thomas

    2016-01-01

    This article explores the social significance of violence as potentiality and performance among former headhunters engaged in ritual killings. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence....... While most Bugkalot men have today abandoned headhunting, the potentials for violence and dominance, which the act of headhunting sought to elicit, remains a critical aspect of masculinity. We propose that a focus on the social significance of performative violent potentiality among Bugkalot men can...... provide general insights that can also be used in other contexts to understand how men construct hegemonic masculinity by strategically adopting the interspace of civility and violence....

  15. Composition of the cellular infiltrate in patients with simple and complex appendicitis.

    Science.gov (United States)

    Gorter, Ramon R; Wassenaar, Emma C E; de Boer, Onno J; Bakx, Roel; Roelofs, Joris J T H; Bunders, Madeleine J; van Heurn, L W Ernst; Heij, Hugo A

    2017-06-15

    It is now well established that there are two types of appendicitis: simple (nonperforating) and complex (perforating). This study evaluates differences in the composition of the immune cellular infiltrate in children with simple and complex appendicitis. A total of 47 consecutive children undergoing appendectomy for acute appendicitis between January 2011 and December 2012 were included. Intraoperative criteria were used to identify patients with either simple or complex appendicitis and were confirmed histopathologically. Immune histochemical techniques were used to identify immune cell markers in the appendiceal specimens. Digital imaging analysis was performed using Image J. In the specimens of patients with complex appendicitis, significantly more myeloperoxidase positive cells (neutrophils) (8.7% versus 1.2%, P appendicitis. In contrast, fewer CD8+ T cells (0.4% versus 1.3%, P = 0.016), CD20 + cells (2.9% versus 9.0%, P = 0.027), and CD21 + cells (0.2% versus 0.6%, P = 0.028) were present in tissue from patients with complex compared to simple appendicitis. The increase in proinflammatory innate cells and decrease of adaptive cells in patients with complex appendicitis suggest potential aggravating processes in complex appendicitis. Further research into the underlying mechanisms may identify novel biomarkers to be able to differentiate simple and complex appendicitis. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Simple, generalizable route to highly aligned block copolymer thin films

    Science.gov (United States)

    Qiang, Zhe; Cavicchi, Kevin; Vogt, Bryan; University of Akron Team

    Macroscopic alignment of block copolymer domains in thin films is desired for many applications, such as cell responsive surfaces or optical polarizers. Alignment generally requires specialized tools that apply external fields, shear force gradient, or produce topological patterned substrates. This requirement limits the broad academic application of aligned BCPs. Here, we describe a simple modification of commonly utilized solvent vapor annealing (SVA) process for macroscopic alignment of BCPs. Adhering a flat, crosslinked elastomer pad to the BCP film leads to differential swelling between the elastomer pad and BCP to produce a shear force that aligns the ordered BCP domains. The role of elastomer properties, solvent quality, drying rate and degree of segregation of the block copolymer will be discussed to provide generalized rules for alignment with this technique. Cylindrical nanostructures formed in polystyrene-block-polydimethylsiloxane can be transformed into arrays of silica lines and increasing the thickness from a monolayer to bilayer can effectively halve the spacing of the lines. These results illustrate a generalized method for BCP alignment and a potential route for the generation of complex hierarchical assembled structures. A generalized method for block copolymer thin film alignment: solvent vapor annealing with shear.

  17. A simple capacitive method to evaluate ethanol fuel samples

    Science.gov (United States)

    Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

    2017-02-01

    Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few.

  18. Simple magnetic cell patterning using streptavidin paramagnetic particles.

    Science.gov (United States)

    Ho, Vincent H B; Müller, Karin H; Darton, Nicholas J; Darling, David C; Farzaneh, Farzin; Slater, Nigel K H

    2009-03-01

    A simple methodology for cell patterning has been developed that can potentially be used to position different types of mammalian cells with high precision. In this method, cell membrane proteins were first biotinylated and then bound to streptavidin paramagnetic particles. The magnetically labeled cells were then seeded onto culture dishes and patterned using low magnetic fields. Highly defined cell patterns were achieved using HeLa, TE671 cells and human monocytes. HeLa and TE671 cells were also sequentially patterned and successfully co-cultured on the same plate using this technique. Cell viability studies proved that this magnetic labeling method was not toxic to cells. Transmission electron microscopy showed that the magnetically labeled HeLa and TE671 cells internalized some of the paramagnetic particles after two days of culture, while the labeled human monocytes did the same after only one hour. Uptake of these particles did not affect the cell patterning and cell viability. This magnetic labeling process is fast, as it involves affinity-based attachment of paramagnetic particles and does not rely on cellular uptake of magnetic materials. It may be adaptable and scalable for various applications.

  19. A simple solar radiation index for wildlife habitat studies

    Science.gov (United States)

    Keating, Kim A.; Gogan, Peter J.; Vore, John N.; Irby, Lynn R.

    2007-01-01

    Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretically striking an arbitrarily oriented surface during the hour surrounding solar noon on the equinox. Because it derives from first geometric principles and is linearly distributed, SRI offers clear advantages over aspect-based surrogates. The SRI also is superior to hillshade, which we found to be sometimes imprecise and ill-behaved. To illustrate application of our SRI, we assessed niche separation among 3 ungulate species along a single environmental axis, solar radiation, on the northern Yellowstone winter range. We detected no difference between the niches occupied by bighorn sheep (Ovis canadensis) and elk (Cervus elaphus; P = 0.104), but found that mule deer (Odocoileus hemionus) tended to use areas receiving more solar radiation than either of the other species (P solar radiation component.

  20. Simple graph models of information spread in finite populations.

    Science.gov (United States)

    Voorhees, Burton; Ryder, Bergerud

    2015-05-01

    We consider several classes of simple graphs as potential models for information diffusion in a structured population. These include biases cycles, dual circular flows, partial bipartite graphs and what we call 'single-link' graphs. In addition to fixation probabilities, we study structure parameters for these graphs, including eigenvalues of the Laplacian, conductances, communicability and expected hitting times. In several cases, values of these parameters are related, most strongly so for partial bipartite graphs. A measure of directional bias in cycles and circular flows arises from the non-zero eigenvalues of the antisymmetric part of the Laplacian and another measure is found for cycles as the value of the transition probability for which hitting times going in either direction of the cycle are equal. A generalization of circular flow graphs is used to illustrate the possibility of tuning edge weights to match pre-specified values for graph parameters; in particular, we show that generalizations of circular flows can be tuned to have fixation probabilities equal to the Moran probability for a complete graph by tuning vertex temperature profiles. Finally, single-link graphs are introduced as an example of a graph involving a bottleneck in the connection between two components and these are compared to the partial bipartite graphs.

  1. Students conception and perception of simple electrical circuit

    Science.gov (United States)

    Setyani, ND; Suparmi; Sarwanto; Handhika, J.

    2017-11-01

    This research aims to describe the profile of the students’ conception and perception on the simple electrical circuit. The results of this research suppose to be used as a reference by teachers to use learning models or strategies to improve understanding the physics concept. The research method used is descriptive qualitative. Research subjects are the students of physics education program, Universitas Sebelas Maret, Surakarta, Indonesia (49 students). The results showed that students have alternative conceptions. Their conceptions are (1) a high-voltage wire has an electric current and can cause electric shock, (2) the potential difference and the value of resistance used in a circuit is influenced by electric current, (3) the value of resistance of a lamp is proportional to the filament thickness, (4) the amount of electric current that coming out from the positive pole battery is the same for all type of circuit, in series or parallel (battery is constant current sources), (5) the current at any resistor in the series circuit is influenced by the resistor used, (6) the resistor consume the current through it. This incorrect conception can cause misconceptions.

  2. Black Holes Have Simple Feeding Habits

    Science.gov (United States)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  3. Designed Quasi-1D Potential Structures Realized in Compositionally Graded InAs1-xPx Nanowires.

    Science.gov (United States)

    Nylund, Gustav; Storm, Kristian; Lehmann, Sebastian; Capasso, Federico; Samuelson, Lars

    2016-02-10

    III-V semiconductor heterostructures are important components of many solid-state optoelectronic devices, but the ability to control and tune the electrical and optical properties of these structures in conventional device geometries is fundamentally limited by the bulk dimensionality and the inability to accommodate lattice-mismatched material combinations. Here we demonstrate how semiconductor nanowires may enable the creation of arbitrarily shaped one-dimensional potential structures for new types of designed device functionality. We describe the controlled growth of stepwise compositionally graded InAs1-xPx heterostructures defined along the axes of InAs nanowires, and we show that nanowires with sawtooth-shaped composition profiles behave as near-ideal unipolar diodes with ratchet-like rectification of the electron transport through the nanowires, in excellent agreement with simulations. This new type of designed quasi-1D potential structure represents a significant advance in band gap engineering and may enable fundamental studies of low-dimensional hot-carrier dynamics, in addition to constituting a platform for implementing novel electronic and optoelectronic device concepts.

  4. A simple histone code opens many paths to epigenetics.

    Directory of Open Access Journals (Sweden)

    Kim Sneppen

    Full Text Available Nucleosomes can be covalently modified by addition of various chemical groups on several of their exposed histone amino acids. These modifications are added and removed by enzymes (writers and can be recognized by nucleosome-binding proteins (readers. Linking a reader domain and a writer domain that recognize and create the same modification state should allow nucleosomes in a particular modification state to recruit enzymes that create that modification state on nearby nucleosomes. This positive feedback has the potential to provide the alternative stable and heritable states required for epigenetic memory. However, analysis of simple histone codes involving interconversions between only two or three types of modified nucleosomes has revealed only a few circuit designs that allow heritable bistability. Here we show by computer simulations that a histone code involving alternative modifications at two histone positions, producing four modification states, combined with reader-writer proteins able to distinguish these states, allows for hundreds of different circuits capable of heritable bistability. These expanded possibilities result from multiple ways of generating two-step cooperativity in the positive feedback--through alternative pathways and an additional, novel cooperativity motif. Our analysis reveals other properties of such epigenetic circuits. They are most robust when the dominant nucleosome types are different at both modification positions and are not the type inserted after DNA replication. The dominant nucleosome types often recruit enzymes that create their own type or destroy the opposing type, but never catalyze their own destruction. The circuits appear to be evolutionary accessible; most circuits can be changed stepwise into almost any other circuit without losing heritable bistability. Thus, our analysis indicates that systems that utilize an expanded histone code have huge potential for generating stable and heritable

  5. A simple histone code opens many paths to epigenetics.

    Science.gov (United States)

    Sneppen, Kim; Dodd, Ian B

    2012-01-01

    Nucleosomes can be covalently modified by addition of various chemical groups on several of their exposed histone amino acids. These modifications are added and removed by enzymes (writers) and can be recognized by nucleosome-binding proteins (readers). Linking a reader domain and a writer domain that recognize and create the same modification state should allow nucleosomes in a particular modification state to recruit enzymes that create that modification state on nearby nucleosomes. This positive feedback has the potential to provide the alternative stable and heritable states required for epigenetic memory. However, analysis of simple histone codes involving interconversions between only two or three types of modified nucleosomes has revealed only a few circuit designs that allow heritable bistability. Here we show by computer simulations that a histone code involving alternative modifications at two histone positions, producing four modification states, combined with reader-writer proteins able to distinguish these states, allows for hundreds of different circuits capable of heritable bistability. These expanded possibilities result from multiple ways of generating two-step cooperativity in the positive feedback--through alternative pathways and an additional, novel cooperativity motif. Our analysis reveals other properties of such epigenetic circuits. They are most robust when the dominant nucleosome types are different at both modification positions and are not the type inserted after DNA replication. The dominant nucleosome types often recruit enzymes that create their own type or destroy the opposing type, but never catalyze their own destruction. The circuits appear to be evolutionary accessible; most circuits can be changed stepwise into almost any other circuit without losing heritable bistability. Thus, our analysis indicates that systems that utilize an expanded histone code have huge potential for generating stable and heritable nucleosome

  6. Simple synthesis of clay-gold nanocomposites with tunable color.

    Science.gov (United States)

    Zhang, Renyun; Hummelgård, Magnus; Olin, Håkan

    2010-04-20

    Clay-based nanocomposites have been studied for several decades, mainly focusing on clay-polymer nanocomposites. Here, we report on a simple wet chemical method to synthesize clay-APTES-Au (CAAu) nanocomposites, where 3-aminopropyltriethoxysilane (APTES) acts as the linkage. The silane terminal of APTES formed bonds with the clay surface, while the other -NH(2) terminal bonds to gold nanoparticles. The color of clay changed when these CAAu nanocomposites were formed. By changing the size of the gold nanoparticles, the color of CAAu could be adjusted, simply by changing process parameters. TEM characterization of the synthesized nanocomposites showed an even distribution of gold nanoparticles on the clay surfaces. The nanocomposites were stable in strong acid and high concentration of salt conditions, while strong basic solution like NaOH could slightly influence the status of the gold nanoparticles due to the rupture of the Si-O-Si bonds between APTES and clay. To demonstrate the potential for label free sensing application of CAAu nanocomposites, we made hybrids of clay-APTES-Au-HD-Au (CAAuHAu), where hexamethylene diamine (HD) served as links between CAAu nanocomposites and the gold nanoparticles. The color of the composites changed from red to blue, when the hybrids were formed. Moreover, hemoglobin was loaded on the CAAu nanocomposites, which can potentially be used as a biosensor. These synthesized nanocomposites may combine the catalytic properties of clay and the well-known excellent properties of gold nanoparticles, such as the ability to anchor biological and chemical molecules. Furthermore, the color change of CAAu, when the CAAuHAu hybrids were observed, suggests the applications of these nanocomposites in biochemical and chemical sensing.

  7. Pattern recognition with simple oscillating circuits

    Science.gov (United States)

    Hölzel, R. W.; Krischer, K.

    2011-07-01

    Neural network devices that inherently possess parallel computing capabilities are generally difficult to construct because of the large number of neuron-neuron connections. However, there exists a theoretical approach (Hoppensteadt and Izhikevich 1999 Phys. Rev. Lett. 82 2983) that forgoes the individual connections and uses only a global coupling: systems of weakly coupled oscillators with a time-dependent global coupling are capable of performing pattern recognition in an associative manner similar to Hopfield networks. The information is stored in the phase shifts of the individual oscillators. However, to date, even the feasibility of controlling phase shifts with this kind of coupling has not yet been established experimentally. We present an experimental realization of this neural network device. It consists of eight sinusoidal electrical van der Pol oscillators that are globally coupled through a variable resistor with the electric potential as the coupling variable. We estimate an effective value of the phase coupling strength in our experiment. For that, we derive a general approach that allows one to compare different experimental realizations with each other as well as with phase equation models. We demonstrate that individual phase shifts of oscillators can be experimentally controlled by a weak global coupling. Furthermore, supplied with a distorted input image, the oscillating network can indeed recognize the correct image out of a set of predefined patterns. It can therefore be used as the processing unit of an associative memory device.

  8. artdaq: DAQ software development made simple

    Science.gov (United States)

    Biery, Kurt; Flumerfelt, Eric; Freeman, John; Ketchum, Wesley; Lukhanin, Gennadiy; Rechenmacher, Ron

    2017-10-01

    For a few years now, the artdaq data acquisition software toolkit has provided numerous experiments with ready-to-use components which allow for rapid development and deployment of DAQ systems. Developed within the Fermilab Scientific Computing Division, artdaq provides data transfer, event building, run control, and event analysis functionality. This latter feature includes built-in support for the art event analysis framework, allowing experiments to run art modules for real-time filtering, compression, disk writing and online monitoring. As art, also developed at Fermilab, is also used for offline analysis, a major advantage of artdaq is that it allows developers to easily switch between developing online and offline software. artdaq continues to be improved. Support for an alternate mode of running whereby data from some subdetector components are only streamed if requested has been added; this option will reduce unnecessary DAQ throughput. Real-time reporting of DAQ metrics has been implemented, along with the flexibility to choose the format through which experiments receive the reports; these formats include the Ganglia, Graphite and syslog software packages, along with flat ASCII files. Additionally, work has been performed investigating more flexible modes of online monitoring, including the capability to run multiple online monitoring processes on different hosts, each running its own set of art modules. Finally, a web-based GUI interface through which users can configure details of their DAQ system has been implemented, increasing the ease of use of the system. Already successfully deployed on the LArlAT, DarkSide-50, DUNE 35ton and Mu2e experiments, artdaq will be employed for SBND and is a strong candidate for use on ICARUS and protoDUNE. With each experiment comes new ideas for how artdaq can be made more flexible and powerful. The above improvements will be described, along with potential ideas for the future.

  9. Making simple sentences hard: Verb bias effects in simple direct object sentences

    Science.gov (United States)

    Wilson, Michael P.; Garnsey, Susan M.

    2009-01-01

    Constraint-based lexical models of language processing assume that readers resolve temporary ambiguities by relying on a variety of cues, including particular knowledge of how verbs combine with nouns. Previous experiments have demonstrated verb bias effects only in structurally complex sentences, and have been criticized on the grounds that such effects could be due to a rapid reanalysis stage in a two-stage modular processing system. In a self-paced reading experiment and an eyetracking experiment, we demonstrate verb bias effects in sentences with simple structures that should require no reanalyis, and thus provide evidence that the combinatorial properties of individual words influence the earliest stages of sentence comprehension. PMID:20160997

  10. Complexity in phonology: The complex consonants of simple CV ...

    African Journals Online (AJOL)

    CC) which presents challenges for the simple CV-syllable structure of the language. In order for these consonants to fit into the CV syllable template, they have to be analysed as complex consonants that occupy a single C-slot (simple onsets).

  11. Learn about Physical Science: Simple Machines. [CD-ROM].

    Science.gov (United States)

    2000

    This CD-ROM, designed for students in grades K-2, explores the world of simple machines. It allows students to delve into the mechanical world and learn the ways in which simple machines make work easier. Animated demonstrations are provided of the lever, pulley, wheel, screw, wedge, and inclined plane. Activities include practical matching and…

  12. Outcrossing rate in olive assessed by microsatellite and inter simple ...

    African Journals Online (AJOL)

    Olive is known to be an allogamous species. The aim of this study was to estimate the magnitude of cross-pollination rate using microsatellite simple sequence repeats (SSR) and inter simple sequence repeats (ISSR) molecular markers in olive genotypes. The DNA from maternal plants and 23 progenies of two different ...

  13. 13 Comparative Effects of Cassava Starch and Simple Sugar in ...

    African Journals Online (AJOL)

    Arc. Usman A. Jalam

    Comparative effects of simple laboratory quality sugar and cassava starch on grade C35 concrete were studied in the laboratory. The simple white ... hydroxide nuclSei thus forming a more efficient barrier to further hydration than is ... sodium based with sugar content of 1-30%. (Rixom & Mailvaganam, 2007). Molasses.

  14. Simple taper: Taper equations for the field forester

    Science.gov (United States)

    David R. Larsen

    2017-01-01

    "Simple taper" is set of linear equations that are based on stem taper rates; the intent is to provide taper equation functionality to field foresters. The equation parameters are two taper rates based on differences in diameter outside bark at two points on a tree. The simple taper equations are statistically equivalent to more complex equations. The linear...

  15. Investigation of association of Helicobacter pylori and simple nasal ...

    African Journals Online (AJOL)

    Objective: To investigate a possible contribution of Helicobacter pylori (H. Pylori) in the etiopathogenesis of simple nasal polyps. Study Design: Prospective clinical trial. Methods: Twenty five patients with simple nasal polyps underwent nasal polypectomy were studied. Helicobacter pylori DNA was investigated for ...

  16. A simple technique to increase profits in wood products marketing

    Science.gov (United States)

    George B. Harpole

    1971-01-01

    Mathematical models can be used to solve quickly some simple day-to-day marketing problems. This note explains how a sawmill production manager, who has an essentially fixed-capacity mill, can solve several optimization problems by using pencil and paper, a forecast of market prices, and a simple algorithm. One such problem is to maximize profits in an operating period...

  17. Demonstrating the physics of simple pendulum via computer ...

    African Journals Online (AJOL)

    This paper investigates how one can teach 'the physics of simple pendulum in the classroom by means of computer simulation, Employing the fourth order Runge-Kutta method carries out the simulation. It is believed that the simulation helps students to understand the physics of simple pendulum easily The simulation ...

  18. Time series prediction with simple recurrent neural networks ...

    African Journals Online (AJOL)

    Simple recurrent neural networks are widely used in time series prediction. Most researchers and application developers often choose arbitrarily between Elman or Jordan simple recurrent neural networks for their applications. A hybrid of the two called Elman-Jordan (or Multi-recurrent) neural network is also being used.

  19. Novel expressed sequence tag- simple sequence repeats (EST-SSR)

    African Journals Online (AJOL)

    Using different bioinformatic criteria, the SUCEST database was used to mine for simple sequence repeat (SSR) markers. Among 42,189 clusters, 1,425 expressed sequence tag- simple sequence repeats (EST-SSRs) were identified in silico. Trinucleotide repeats were the most abundant SSRs detected. Of 212 primer pairs ...

  20. Temperature dependence of transport coefficients of 'simple liquid ...

    African Journals Online (AJOL)

    ... (MD) simulations has been investigated. The study carried out at two densities, r* = 0.60 and r* = 0.95. Result shows erratic variations of the shear viscosity in the two lattices structures. KeyWords: Temperature effect, face centred, simple cubic, transport properties, simple liquid. [Global Jnl Pure & Appl. Sci. Vol.9(3) 2003: ...

  1. Misconceptions of Mexican Teachers in the Solution of Simple Pendulum

    Science.gov (United States)

    Garcia Trujillo, Luis Antonio; Ramirez Díaz, Mario H.; Rodriguez Castillo, Mario

    2013-01-01

    Solving the position of a simple pendulum at any time is apparently one of the most simple and basic problems to solve in high school and college physics courses. However, because of this apparent simplicity, teachers and physics texts often assume that the solution is immediate without pausing to reflect on the problem formulation or verifying…

  2. Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... simple sequence repeat (ISSR) polymorphism in the genus Oryza. Theor. Appl. Genet. 100: 1311-1320. Kantety RV, Zeng X, Bennetzen JL, Zehr BE (1995). Assessment of genetic diversity in dent and popcorn (Zea mays L.) inbred lines using inter-simple sequence repeat (ISSR) amplification. Mol. Breed.

  3. Early Prediction of Reading Comprehension within the Simple View Framework

    Science.gov (United States)

    Catts, Hugh W.; Herrera, Sarah; Nielsen, Diane Corcoran; Bridges, Mindy Sittner

    2015-01-01

    The simple view of reading proposes that reading comprehension is the product of word reading and language comprehension. In this study, we used the simple view framework to examine the early prediction of reading comprehension abilities. Using multiple measures for all constructs, we assessed word reading precursors (i.e., letter knowledge,…

  4. Comparative Effects of Cassava Starch and Simple Sugar in Cement ...

    African Journals Online (AJOL)

    Comparative effects of simple laboratory quality sugar and cassava starch on grade C35 concrete were studied in the laboratory. The simple white sugar was used at concentrations of 0 to 1% by weight of cement in concrete cured at 3, 7, 14 and 28 days using ordinary Portland cement. Cassava starch of the same ...

  5. A Simple Laboratory Exercise Illustrating Active Transport in Yeast Cells.

    Science.gov (United States)

    Stambuk, Boris U.

    2000-01-01

    Describes a simple laboratory activity illustrating the chemiosmotic principles of active transport in yeast cells. Demonstrates the energy coupling mechanism of active a-glucoside uptake by Saccaromyces cerevisiae cells with a colorimetric transport assay using very simple equipment. (Contains 22 references.) (Author/YDS)

  6. Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated ...

    African Journals Online (AJOL)

    Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated rice species from Ethiopia. ... African Journal of Biotechnology ... The genetic diversity of three wild rice populations of Ethiopia along with three cultivated rice populations were studied using Inter simple sequence repeats (ISSRs) as a molecular marker.

  7. Simple Pleasures, Small Annoyances, and Goal Progress in Daily Life

    NARCIS (Netherlands)

    N.L. Mead (Nicole); V.M. Patrick (Vanessa); M.P. Gunadi (Manissa); W. Hofmann (Wilhelm)

    2016-01-01

    textabstractDespite the explosion of research on goal pursuit, relatively little is known about the shaping of goal progress by the simple experiences that characterize everyday life. Two literatures furnish competing predictions about the relationship between pleasant daily experiences (simple

  8. simple algorithm in the management of fetal sacroccocygeal ...

    African Journals Online (AJOL)

    Understanding a simple way of managing this condition is important in developing countries to prevent morbidities and mortalities. A simplified algorithm of. SIMPLE ALGORITHM IN THE MANAGEMENT OF FETAL SACROCCOCYGEAL. TERATOMA IN ... preeclampsia-like syndrome in the mother. This chain of events may ...

  9. A simple polarized-based diffused reflectance colour imaging system

    African Journals Online (AJOL)

    A simple polarized-based diffuse reflectance imaging system has been developed. The system is designed for both in vivo and in vitro imaging of agricultural specimen in the visible region. The system uses a commercial web camera and a halogen lamp that makes it relatively simple and less expensive for diagnostic ...

  10. Potential theory

    CERN Document Server

    Helms, Lester L

    2014-01-01

    Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...

  11. Item Selection, Evaluation, and Simple Structure in Personality Data.

    Science.gov (United States)

    Pettersson, Erik; Turkheimer, Eric

    2010-08-01

    We report an investigation of the genesis and interpretation of simple structure in personality data using two very different self-reported data sets. The first consists of a set of relatively unselected lexical descriptors, whereas the second is based on responses to a carefully constructed instrument. In both data sets, we explore the degree of simple structure by comparing factor solutions to solutions from simulated data constructed to have either strong or weak simple structure. The analysis demonstrates that there is little evidence of simple structure in the unselected items, and a moderate degree among the selected items. In both instruments, however, much of the simple structure that could be observed originated in a strong dimension of positive vs. negative evaluation.

  12. Simple and facile approach to synthesize magnetite nanoparticles and assessment of their effects on blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Cotica, Luiz F., E-mail: lfcotica@pq.cnpq.br [Department of Physics, Universidade Estadual de Maringa, Maringa, PR 87020900 (Brazil); Freitas, Valdirlei F.; Dias, Gustavo S.; Santos, Ivair A. [Department of Physics, Universidade Estadual de Maringa, Maringa, PR 87020900 (Brazil); Vendrame, Sheila C.; Khalil, Najeh M.; Mainardes, Rubiana M. [Department of Pharmacy, Universidade Estadual do Centro-Oeste, Guarapuava, PR 85040080 (Brazil); Staruch, Margo; Jain, Menka [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States)

    2012-02-15

    In this paper, a very simple and facile approach for the large scale synthesis of uniform and size-controllable single-domain magnetite nanoparticles is reported. These magnetite nanoparticles were synthesized via thermal decomposition of a ferric nitrate/ethylene glycol solution. The structural and morphological properties of the synthesized nanoparticles were carefully studied. Nearly spherical nanoparticles with inverted spinel structure and average particle and crystallite sizes smaller than 20 nm were obtained. The magnetic measurements revealed that magnetite nanoparticles have a magnetic saturation value near that of the bulk magnetite. The erythrocyte cytotoxicity assays showed no hemolytic potential of the samples containing magnetite nanoparticles, indicating no cytotoxic activity on human erythrocytes, which makes these interesting for biotechnological applications. - Highlights: > Simple and facile approach to large scale synthesis of magnetite nanoparticles. > Erythrocyte cytotoxicity assays showed no hemolytic potential of nanoparticles. > Saturation magnetization of nanoparticles reached near that of the bulk magnetite.

  13. Development of simple sequence repeat markers in cymbopogon species.

    Science.gov (United States)

    Kumar, Jitendra; Verma, Vijeshwar; Shahi, Ashok Kumar; Qazi, Gulam Nab; Balyan, Harindra Singh

    2007-03-01

    The genus Cymbopogon comprises about 140 species, which produce characteristic aromatic essential oils. However, the phenotypic identification of species of Cymbopogon has been difficult as a result of widespread occurrence of natural variants, which differ in ploidy levels and chemotaxonomic complexities. Therefore, we have developed a set of simple sequence repeat markers from a genomic library of Cymbopogon jwarancusa to help in the precise identification of the species (including accessions) of Cymbopogon. For this purpose, we isolated 16 simple sequence repeat containing genomic deoxyribonucleic acid clones of C. jwarancusa, which contained a total of 32 simple sequence repeats with a range of 1 to 3 simple sequence repeats per clone. The majority (68.8%) of the 32 simple sequence repeats comprised dinucleotide repeat motifs followed by simple sequence repeats with trinucleotide (21.8%) and other higher order repeat motifs. Eighteen (81.8%) of the 22 designed primers for the above simple sequence repeats amplified products of expected sizes, when tried with genomic DNA of C. jwarancusa, the source species. Thirteen (72.2%) of the 18 functional primers detected polymorphism among the three species of Cymbopogon (C. flexuosus, C. pendulus and C. jwarancusa) and amplified a total of 95 alleles (range 1-18 alleles) with a PIC value of 0.44 to 0.96 per simple sequence repeat. Thus, the higher allelic range and high level of polymorphism demonstrated by the newly developed simple sequence repeat markers are likely to have many applications such as in improvement of essential oil quality by authentication of Cymbopogon species and varieties and mapping or tagging the genes controlling agronomically important traits of essential oils, which can further be utilized in marker assisted breeding.

  14. Recursion relations and branching rules for simple Lie algebras

    CERN Document Server

    Lyakhovsky, V D

    1995-01-01

    The branching rules between simple Lie algebras and its regular (maximal) simple subalgebras are studied. Two types of recursion relations for anomalous relative multiplicities are obtained. One of them is proved to be the factorized version of the other. The factorization property is based on the existence of the set of weights \\Gamma specific for each injection. The structure of \\Gamma is easily deduced from the correspondence between the root systems of algebra and subalgebra. The recursion relations thus obtained give rise to simple and effective algorithm for branching rules. The details are exposed by performing the explicit decomposition procedure for A_{3} \\oplus u(1) \\rightarrow B_{4} injection.

  15. Combinatorial structures to modeling simple games and applications

    Science.gov (United States)

    Molinero, Xavier

    2017-09-01

    We connect three different topics: combinatorial structures, game theory and chemistry. In particular, we establish the bases to represent some simple games, defined as influence games, and molecules, defined from atoms, by using combinatorial structures. First, we characterize simple games as influence games using influence graphs. It let us to modeling simple games as combinatorial structures (from the viewpoint of structures or graphs). Second, we formally define molecules as combinations of atoms. It let us to modeling molecules as combinatorial structures (from the viewpoint of combinations). It is open to generate such combinatorial structures using some specific techniques as genetic algorithms, (meta-)heuristics algorithms and parallel programming, among others.

  16. Fast and simple fat grafting of the breast

    DEFF Research Database (Denmark)

    Kristensen, Rasmus Nygård; Gunnarsson, Gudjon L; Børsen-Koch, Mikkel

    2015-01-01

    in the attached video as visualized surgery. We have used this simple approach for 348 procedures in 176 women to optimize and correct the aesthetic result following all types of breast surgery. We prefer this simple technique as no technique has been shown to be superior to other more costly techniques...... and furthermore there are still questions about the oncologic safety in using adipose derived stem cells (ADSC). Simple fat harvesting using low vacuum and preparation by sedimentation is a fast and effective method to perform FG successfully for correction of shape and volume deficits of the breast following...

  17. Simple Choreographies of the Planar Newtonian N-Body Problem

    Science.gov (United States)

    Yu, Guowei

    2017-08-01

    In the N-body problem, a simple choreography is a periodic solution, where all masses chase each other on a single loop. In this paper we prove that for the planar Newtonian N-body problem with equal masses, N ≧ 3, there are at least 2 N-3 + 2[( N-3)/2] different main simple choreographies. This confirms a conjecture given by Chenciner et al. (Geometry, mechanics, and dynamics. Springer, New York, pp 287-308, 2002). All the simple choreoagraphies we prove belong to the linear chain family.

  18. Simple mucin-type carbohydrate antigens in major salivary glands

    DEFF Research Database (Denmark)

    Therkildsen, M H; Mandel, U; Thorn, J

    1994-01-01

    Simple mucin-type carbohydrate antigens Tn, sialosyl-Tn and T are often markers of neoplastic transformation and have very limited expression in normal tissues. We performed an immunohistological study of simple mucin-type carbohydrate antigens, including H and A variants, with well......-defined monoclonal antibodies (MAb) on frozen and paraffin-embedded normal salivary gland tissue from 22 parotid, 14 submandibular, six sublingual, and 13 labial glands to elucidate the simple mucin-type glycosylation pattern in relation to cyto- and histodifferentiation. The investigated carbohydrate structures...

  19. Percutaneous endoscopic gastrostomy tube replacement: A simple procedure?

    Science.gov (United States)

    Lohsiriwat, Varut

    2013-01-16

    Replacement of gastrostomy tube in patients undergoing percutaneous endoscopic gastrostomy (PEG) is generally considered as a safe and simple procedure. However, it could be associated with serious complications, such as gastrocutaneous tract disruption and intraperitoneal tube placement, which may lead to chemical peritonitis and even death. When PEG tube needs a replacement (e.g., occlusion or breakage of the tube), clinicians must realize that the gastrocutaneous tract of PEG is more friable than that of surgical gastrostomy because there is no suture fixation between gastric wall and abdominal wall in PEG. In general, the tract of PEG begins to mature in 1-2 wk after placement and it is well formed in 4-6 wk. However, this process could take a longer period of time in some patients. Accordingly, this article describes three major principles of a safe PEG tube replacement: (1) good control of the replacement tube along the well-formed gastrocutaneous tract; (2) minimal insertion force during the replacement, and, most importantly; and (3) reliable methods for the confirmation of intragastric tube insertion. In addition, the management of patients with suspected intraperitoneal tube placement (e.g., patients having abdominal pain or signs of peritonitis immediately after PEG tube replacement or shortly after tube feeding was resumed) is discussed. If prompt investigation confirms the intraperitoneal tube placement, surgical intervention is usually required. This article also highlights the fact that each institute should have an optimal protocol for PEG tube replacement to prevent, or to minimize, such serious complications. Meanwhile, clinicians should be aware of these potential complications, particularly if there are any difficulties during the gastrostomy tube replacement.

  20. Metabolic engineering of sugars and simple sugar derivatives in plants.

    Science.gov (United States)

    Patrick, John W; Botha, Frikkie C; Birch, Robert G

    2013-02-01

    Carbon captured through photosynthesis is transported, and sometimes stored in plants, as sugar. All organic compounds in plants trace to carbon from sugars, so sugar metabolism is highly regulated and integrated with development. Sugars stored by plants are important to humans as foods and as renewable feedstocks for industrial conversion to biofuels and biomaterials. For some purposes, sugars have advantages over polymers including starches, cellulose or storage lipids. This review considers progress and prospects in plant metabolic engineering for increased yield of endogenous sugars and for direct production of higher-value sugars and simple sugar derivatives. Opportunities are examined for enhancing export of sugars from leaves. Focus then turns to manipulation of sugar metabolism in sugar-storing sink organs such as fruits, sugarcane culms and sugarbeet tubers. Results from manipulation of suspected 'limiting' enzymes indicate a need for clearer understanding of flux control mechanisms, to achieve enhanced levels of endogenous sugars in crops that are highly selected for this trait. Outcomes from in planta conversion to novel sugars and derivatives range from severe interference with plant development to field demonstration of crops accumulating higher-value sugars at high yields. The differences depend on underlying biological factors including the effects of the novel products on endogenous metabolism, and on biotechnological fine-tuning including developmental expression and compartmentation patterns. Ultimately, osmotic activity may limit the accumulation of sugars to yields below those achievable using polymers; but results indicate the potential for increases above current commercial sugar yields, through metabolic engineering underpinned by improved understanding of plant sugar metabolism. © 2012 The Authors Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  1. Robot-assisted intrafascial simple prostatectomy: novel technique.

    Science.gov (United States)

    Clavijo, Rafael; Carmona, Oswaldo; De Andrade, Robert; Garza, Roberto; Fernandez, Golena; Sotelo, Rene

    2013-03-01

    We describe our initial experience with intrafascial robot-assisted simple prostatectomy (IF-RSP). Potential advantages include reduced blood loss, elimination of the need for postoperative bladder irrigation, and elimination of the risk of residual or future prostate cancer, without interrupting potency or continence. From June 2011 to March 2012, 10 patients with symptomatic prostatomegaly on transrectal ultrasonography (TRUS) (mean 81 g) underwent IF-RSP. Three patients had acute urinary retention. Demographic perioperative and outcome data were recorded up to 1 month follow-up. Average age was 71.7 years (range 60-79 years), estimated blood loss was 375 mL (range 150-900 mL), operative time was 106 minutes (range 60-180 min), hospital stay was 1 day (range 0-3 days), and Foley catheter duration was 8.9 days (range 6-14 days). The drain was removed at a mean 2.8 days (range 0-8 days). Mean prostate volume on preoperative TRUS was 81 cc (range 47-153 cc). Mean specimen weight was 81 g (range 50-150 g). Improvement was noted in the International Prostate Symptom Score (preoperative vs postoperative 18.8 vs 1.7) and peak flow rate (12.4 vs 33.49 mL/min). Sexual Health Inventory for Men score ranged from 12 to 24. All patients were completely continent within 1 month postoperatively, and sexual function was preserved. One patient had urinary tract infection and one patient needed blood transfusion postoperatively. IF-RSP appears to be a feasible procedure in large-volume prostatomegaly. The entire prostate tissue is removed without compromising continence and potency. Larger series and longer-term follow-up are needed to evaluate the proper place of this approach.

  2. arXiv A Simple No-Scale Model of Modulus Fixing and Inflation

    CERN Document Server

    Ellis, John; Romano, Antonio Enea; Zapata, Oscar

    We construct a no-scale model of inflation with a single modulus whose real and imaginary parts are fixed by simple power-law corrections to the no-scale K{\\" a}hler potential. Assuming an uplift of the minimum of the effective potential, the model yields a suitable number of e-folds of expansion and values of the tilt in the scalar cosmological density perturbations and of the ratio of tensor and scalar perturbations that are compatible with measurements of the cosmic microwave background radiation.

  3. Facet Defining Inequalities for the Simple Graph Partioning Polytope

    DEFF Research Database (Denmark)

    Sørensen, Michael Malmros

    2000-01-01

    The simple graph partitioning problem is to partition an edge-weighted graph into mutually disjoint subgraphs, each containing at most b nodes, such that the sum of the weights of all edges in the subgraphs is maximal. In this paper we investigate the facial structure of the simple graph partitio......The simple graph partitioning problem is to partition an edge-weighted graph into mutually disjoint subgraphs, each containing at most b nodes, such that the sum of the weights of all edges in the subgraphs is maximal. In this paper we investigate the facial structure of the simple graph...... partitioning polytopes P(b), b = 3,...,n, associated with the complete graph on n nodes. In particular we introduce two new classes af facet defining inequalities that are induced by cliques and multistars....

  4. A Simple Neural Network System for Wisconsin Card Sorting Test

    National Research Council Canada - National Science Library

    Kaplan, Gulay

    2001-01-01

    .... A simple model based on winner take all network and multi layer perceptron suffices to model the affect of frontal lobe damage, which leads to perseveration as diminishing the influence of reinforcement...

  5. Character-based Recognition of Simple Word Gesture

    Directory of Open Access Journals (Sweden)

    Paulus Insap Santosa

    2013-11-01

    Full Text Available People with normal senses use spoken language to communicate with others. This method cannot be used by those with hearing and speech impaired. These two groups of people will have difficulty when they try to communicate to each other using their own language. Sign language is not easy to learn, as there are various sign languages, and not many tutors are available. This research focused on a simple word recognition gesture based on characters that form a word to be recognized. The method used for character recognition was the nearest neighbour method. This method identified different fingers using the different markers attached to each finger. Testing a simple word gesture recognition is done by providing a series of characters that make up the intended simple word. The accuracy of a simple word gesture recognition depended upon the accuracy of recognition of each character.

  6. A simple technique to assess bacterial attachment to metal surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    Sonak, S.; Bhosle, N

    . Therefore, a simple spectrophotometric method was developed to evaluate bacterial adhesion to metal surface. The method was calibrated using a bacterium Vibrio sp. and aluminium as a model organism and substratum, respectively. The method involves staining...

  7. A Simple HPLC Bioanalytical Method for the Determination of ...

    African Journals Online (AJOL)

    Purpose: To develop a simple, accurate, and precise high performance chromatography (HPLC) method with spectrophotometric detection for the determination of doxorubicin hydrochloride in rat plasma. Methods: Doxorubicin hydrochloride and daunorubicin hydrochloride (internal standard, IS) were separated on a C18.

  8. Two simple amine hydrochlorides from the soft coral Lobophytum strictum

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Naik, C.G.; Das, B.; Kamat, S.Y.

    Two simple amine hydrochlorides, viz., 1-amino-1, 1-dimethyl-3-oxo-butane hydrochloride (1) (Diacetonamine) and 2, 2, 6, 6-tetramethylpiperidone hydrochloride (2) have been isolated from the fraction of the methanolic extract of the soft coral...

  9. Development of a Simple System for the Determination of Arsenic ...

    African Journals Online (AJOL)

    Bioline

    Development of a Simple System for the Determination of Arsenic after Hydride. Generation Atomic Absorption ... Consequently, we were driven by the need to develop an ..... Table 2 Precision and Reproducibility test for Arsenic. Amount of ...

  10. Six simple rules: how to manage complexity without getting complicated

    National Research Council Canada - National Science Library

    Morieux, Yves; Tollman, Peter

    2014-01-01

    Provides managers with six simple rules to manage organizational complexity. The authors show why and how the rules work, enabling managers to reinvigorate employees and foster autonomy and cooperation...

  11. Simple, Micro-Miniature Total Organic Carbon Analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a simple method for on-orbit or advanced mission Total Organic Carbon (TOC) monitoring has been a goal for many years. This proposal seeks to develop...

  12. A simple convex optimization problem with many applications

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1994-01-01

    This paper presents an algorithm for the solution of a simple convex optimization problem. This problem is a generalization of several other optimization problems which have applications to resource allocation, optimal capacity expansion, and vehicle scheduling. The algorithm is based...

  13. A VBA-based Simulation for Teaching Simple Linear Regression

    Science.gov (United States)

    Jones, Gregory Todd; Hagtvedt, Reidar; Jones, Kari

    2004-01-01

    In spite of the name, simple linear regression presents a number of conceptual difficulties, particularly for introductory students. This article describes a simulation tool that provides a hands-on method for illuminating the relationship between parameters and sample statistics.

  14. Operational Factors in Membrane Bioreactors Using a Simple Ceramic Filter

    National Research Council Canada - National Science Library

    HASAN, Md. Mahmudul; NAKAJIMA, Jun

    2014-01-01

    To explore the cost reduction of water reclamation and reuse facilities in developing countries, a simple ceramic filter made of local materials, such as clay and rice bran, was used in a membrane bioreactor (MBR) process...

  15. A simple estimator for correlation in incomplete data

    NARCIS (Netherlands)

    Albers, Willem/Wim; Teulings, M.F.

    1996-01-01

    It seems fair that the usual sample correlation coefficient should allow improvement when additional samples from the marginals are available. However, some intuitive attempts fail badly. Using control variates, a simple method is presented which asymptotically achieves the optimal improvement.

  16. LBA-ECO LC-31 Simple Tropical Ecosystem Model

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This model product provides the Fortran source code and input data for the Simple Tropical Ecosystem Model (SITE). SITE is a simplified point model of...

  17. Simple self-reduction method for anterior shoulder dislocation

    Directory of Open Access Journals (Sweden)

    Reiner Wirbel

    2014-01-01

    Conclusion: The presented Boss-Holzach-Matter method for reduction of anterior shoulder dislocation is a simple method without the need of anaesthesia, but cooperation from patients is crucial. The successful rate is comparable with other established methods.

  18. Stochastic finite element method with simple random elements

    OpenAIRE

    Starkloff, Hans-Jörg

    2008-01-01

    We propose a variant of the stochastic finite element method, where the random elements occuring in the problem formulation are approximated by simple random elements, i.e. random elements with only a finite number of possible values.

  19. SIMPLE-icity in Direct Dark Matter Searches

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, F.; Morlat, T.; Ramos, A. R.; Girard, T. A.; Felizardo da Costa, M.; Marques, J. G.; Martins, R. C.; Miley, Harry S.; Limagne, D.; Waysand, G.

    2007-11-01

    SIMPLE is the European WIMP search based on Superheated Droplet Detectors (SDDs). An SDD consists of an emulsion of metastable liquid droplets in an organic gel, each of which operates on the same principle of the bubble chamber.

  20. Creating Simple Windchill Admin Tools Using Info*Engine

    Science.gov (United States)

    Jones, Corey; Kapatos, Dennis; Skradski, Cory

    2012-01-01

    Being a Windchill administrator often requires performing simple yet repetitive tasks on large sets of objects. These can include renaming, deleting, checking in, undoing checkout, and much more. This is especially true during a migration. Fortunately, PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create simple Info*Engine tasks capable of saving Windchill 10.0 administrators hours of tedious work. It will also show how these tasks can be combined and displayed on a simple JSP page that acts as a "Windchill Administrator Dashboard/Toolbox". The attendee will learn some valuable tasks Info*Engine capable of performing. The attendee will gain a basic understanding of how to perform and implement Info*Engine tasks. The attendee will learn what's involved in creating a JSP page that displays Info*Engine tasks

  1. A Simple Illustration for the Need of Multiple Comparison Procedures

    Science.gov (United States)

    Carter, Rickey E.

    2010-01-01

    Statistical adjustments to accommodate multiple comparisons are routinely covered in introductory statistical courses. The fundamental rationale for such adjustments, however, may not be readily understood. This article presents a simple illustration to help remedy this.

  2. Simple Public Key Infrastructure Protocol Analysis and Design

    National Research Council Canada - National Science Library

    Vidergar, Alexander G

    2005-01-01

    ...). This thesis aims at proving the applicability of the Simple Public Key Infrastructure (SPKI) as a means of PKC. The strand space approach of Guttman and Thayer is used to provide an appropriate model for analysis...

  3. Simple neoclassical point model for transport and scaling in EBT

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, C.L.; Jaeger, E.F.; Spong, D.A.; Guest, G.E.; Krall, N.A.; McBride, J.B.; Stuart, G.W.

    1977-04-01

    A simple neoclassical point model is presented for the ELMO Bumpy Torus experiment. Solutions for steady state are derived. Comparison with experimental observations is made and reasonable agreement is obtained.

  4. Simple Experiments on the Physics of Vision: The Retina

    Science.gov (United States)

    Cortel, Adolf

    2005-01-01

    Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.

  5. Effectiveness of Simple Individual Psychoeducation for Bipolar II Disorder

    Directory of Open Access Journals (Sweden)

    Yuka Saito-Tanji

    2016-01-01

    Full Text Available Several studies have proven the effectiveness of psychoeducation in bipolar II disorder patients; however, simpler psychoeducation is needed in daily medical practice. Therefore, we devised a simple individual psychoeducation program, which involved 20-minute sessions spent reading a textbook aloud in the waiting time before examination. Here, we report a successful case of simple individual psychoeducation with a patient with bipolar II disorder, a 64-year-old woman who had misconceptions surrounding her mood due to 24 years of treatment for depression. Her perception of mood state, particularly mixed state, was dramatically changed, and her quality of life was improved after the simple individual psychoeducation. This case suggests that the simple individual psychoeducation could be effective for bipolar II disorder by improving understanding of the disease and by meeting different individual needs.

  6. LBA-ECO LC-31 Simple Tropical Ecosystem Model

    Data.gov (United States)

    National Aeronautics and Space Administration — This model product provides the Fortran source code and input data for the Simple Tropical Ecosystem Model (SITE). SITE is a simplified point model of vegetation...

  7. Another simple proof of the quintuple product identity

    Directory of Open Access Journals (Sweden)

    Hei-Chi Chan

    2005-01-01

    Full Text Available We give a simple proof of the well-known quintuple product identity. The strategy of our proof is similar to a proof of Jacobi (ascribed to him by Enneper for the triple product identity.

  8. Cure of epoxy resins determined by simple tests

    Science.gov (United States)

    Ladaki, M.; Nigh, W. G.

    1968-01-01

    Rapid visual and simple quantitative tests indicate the degree of cure of particular epoxy resin binders in prepreg stock. It is possible that these tests may be extended to a number of different epoxy formulations.

  9. Development of a Simple Sound Activated Burglar Alarm System

    Directory of Open Access Journals (Sweden)

    Genesis Abah AGBO

    2006-07-01

    Full Text Available The paper presents the design, construction and testing of a simple sound activated burglar alarm. The principle of operation of this burglar alarm is simple. When the intensity of sound exceeds certain intensity, the alarm is triggered and the siren begins to operate. The speaker beeps and the flasher (light flashes. These actions thus alert the owner of the residence and/or security personnel of the presence of an intruder.

  10. Indoor Radar Cross Section Measurements of Simple Targets

    OpenAIRE

    Marcelo Alexandre Souza Miacci; Evandro Luiz Nohara; Inácio Malmonge Martin; Guilherme Gomes Peixoto; Mirabel Cerqueira Rezende

    2012-01-01

    Abstract: This paper has described the radar absorbing materials characterization and radar cross section measurements, in the frequencyrange of 8 to 12 GHz, using a very simple setup. Simple targets like sphere, cylinder, flatplate, and dihedral comer were characterized by measuring the backscattered radiation patterns when these targets were illuminated by monostatic microwave radiation. Measurements were carried out inside an anechoic chamber (9x5x4m3). Typical radar cross section patterns...

  11. Simple isotherm equations to fit type I adsorption data

    OpenAIRE

    Mosquera, Martin A.

    2009-01-01

    A simple model to fit experimental data of adsorption of gases and vapours on microporous adsorbents (type I isotherms) is proposed. The main assumption is that the adsorbate phase can be divided into identical and non-interacting effective subsystems. This gives rise to a simple multiparametric isotherm based on the grand canonical ensemble statistics, whose functional form is a ratio of two polynomial functions. The parameters are interpreted as effective equilibrium constants. A simplified...

  12. A simple approximation of productivity scores of fuzzy production plans

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth

    2005-01-01

    This paper suggests a simple approximation procedure for the assessment of productivity scores with respect to fuzzy production plans. The procedure has a clear economic interpretation and all the necessary calculations can be performed in a spreadsheet making it highly operational......This paper suggests a simple approximation procedure for the assessment of productivity scores with respect to fuzzy production plans. The procedure has a clear economic interpretation and all the necessary calculations can be performed in a spreadsheet making it highly operational...

  13. Poroelastic Foams for Simple Fabrication of Complex Soft Robots.

    Science.gov (United States)

    Mac Murray, Benjamin C; An, Xintong; Robinson, Sanlin S; van Meerbeek, Ilse M; O'Brien, Kevin W; Zhao, Huichan; Shepherd, Robert F

    2015-11-04

    Open-celled, elastomeric foams allow the simple design of fully 3D pneumatic soft machines using common forming techniques. This is demonstrated through the fabrication of simple actuators and an entirely soft, functional fluid pump formed in the shape of the human heart. The device pumps at physiologically relevant frequencies and pressures and attains a flow rate higher than all previously reported soft pumps. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. MAINTENANCE PLANNING OF THE SEWING NEEDLES OF SIMPLE SEWING MACHINES

    Directory of Open Access Journals (Sweden)

    ŞUTEU Marius Darius

    2017-05-01

    Full Text Available The effectiveness of simple sewing machines can be increased through the planning of predictive maintenance activities. The monitoring of the technical condition of the sewing needles of simple sewing machines was based on the measurement of their noise level. For this purpose a Center 322 sonometer was used, while the data obtained during the monitoring process was analyzed through the E322 software. The working speed of the simple sewing machine that was used for obtaining the experimental results varied from 200 stitches/minute to 4000 stitches/minute. The noise levels of a new needle at the working speed of 200 stitches/minute and 4000 stitches/minute were measured. The noise levels for a fault needle at the same working speed of 200 stitches/minute, respectively 4000 stitches/minute were also measured. Using Fuzzy Logic Toolbox ™ module of Matlab®, a decision-making system for determining when replacement of the sewing needles of simple sewing machines should be performed was developed. A case study illustrates the employment of the decision-making system based on fuzzy logic for a simple sewing machine. By replacing the sewing needles of simple sewing machines at the time specified through the decision-making system based on fuzzy logic, the occurrence of the failure can be prevented and the quality of textile products can be improved.

  15. About simple nonlinear and linear superpositions of special exact solutions of Veselov-Novikov equation

    Energy Technology Data Exchange (ETDEWEB)

    Dubrovsky, V. G.; Topovsky, A. V. [Novosibirsk State Technical University, Karl Marx prosp. 20, Novosibirsk 630092 (Russian Federation)

    2013-03-15

    New exact solutions, nonstationary and stationary, of Veselov-Novikov (VN) equation in the forms of simple nonlinear and linear superpositions of arbitrary number N of exact special solutions u{sup (n)}, n= 1, Horizontal-Ellipsis , N are constructed via Zakharov and Manakov {partial_derivative}-dressing method. Simple nonlinear superpositions are represented up to a constant by the sums of solutions u{sup (n)} and calculated by {partial_derivative}-dressing on nonzero energy level of the first auxiliary linear problem, i.e., 2D stationary Schroedinger equation. It is remarkable that in the zero energy limit simple nonlinear superpositions convert to linear ones in the form of the sums of special solutions u{sup (n)}. It is shown that the sums u=u{sup (k{sub 1})}+...+u{sup (k{sub m})}, 1 Less-Than-Or-Slanted-Equal-To k{sub 1} < k{sub 2} < Horizontal-Ellipsis < k{sub m} Less-Than-Or-Slanted-Equal-To N of arbitrary subsets of these solutions are also exact solutions of VN equation. The presented exact solutions include as superpositions of special line solitons and also superpositions of plane wave type singular periodic solutions. By construction these exact solutions represent also new exact transparent potentials of 2D stationary Schroedinger equation and can serve as model potentials for electrons in planar structures of modern electronics.

  16. Simple evaluation method for osteoinductive capacity of cells or scaffolds using ceramic cubes.

    Science.gov (United States)

    Song, In-Hwan; Dennis, James E

    2014-10-01

    Mesenchymal stem cells are good candidates for the clinical application of bone repair because of their osteogenic differentiation potential, but in vivo osteoinduction potential should be verified for culture expanded cells before clinical application. This study analyzed in vivo bone formation by MSCs quantitatively after implantation of MSCs planted porous biphasic ceramic cubes into athymic mice. MSCs were divided into osteogenic differentiation-induced and normal groups and also tested in vitro to evaluate the degree of differentiation into osteoblasts. The osteogenic induced group showed higher alkaline phosphatase and calcium level in vitro and corresponding higher level of bone formation in vivo compared to control group. Whereas there was no bone formation observed in fibroblast-implanted negative control group. In critical sized bone defect models, commonly used for evaluation of bone regeneration ability, it is difficult to distinguish between osteoinduction and osteoconduction, and quantitative analysis is not simple. However, this method for evaluating osteoinduction is both accurate and simple. In conclusion, the analysis of in vivo bone formation using porous ceramic cubes is a powerful and simple method for evaluating the osteoinduction ability of target cells and, furthermore, can be applied for evaluation of scaffolds for their osteoinductive properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. A Simple Metallothionein-Based Biosensor for Enhanced Detection of Arsenic and Mercury

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    Gordon W. Irvine

    2017-03-01

    Full Text Available Metallothioneins (MTs are a family of cysteine-rich proteins whose biological roles include the regulation of essential metal ions and protection against the harmful effects of toxic metals. Due to its high affinity for many toxic, soft metals, recombinant human MT isoform 1a was incorporated into an electrochemical-based biosensor for the detection of As3+ and Hg2+. A simple design was chosen to maximize its potential in environmental monitoring and MT was physically adsorbed onto paper discs placed on screen-printed carbon electrodes (SPCEs. This system was tested with concentrations of arsenic and mercury typical of contaminated water sources ranging from 5 to 1000 ppb. The analytical performance of the MT-adsorbed paper discs on SPCEs demonstrated a greater than three-fold signal enhancement and a lower detection limit compared to blank SPCEs, 13 ppb for As3+ and 45 ppb for Hg2+. While not being as low as some of the recommended drinking water limits, the sensitivity of the simple MT-biosensor would be potentially useful in monitoring of areas of concern with a known contamination problem. This paper describes the ability of the metal binding protein metallothionein to enhance the effectiveness of a simple, low-cost electrochemical sensor.

  18. Simple assay for screening phytoestrogenic compounds using the oestrogen receptor immobilised magnetite nanoparticles.

    Science.gov (United States)

    Busayapongchai, Pimchanok; Siri, Sineenat

    2017-06-01

    With increasing interests of phytoestrogens for their potential applications, a rapid and simple tool for screening these phytochemicals is still required. In this study, a simple assay to detect phytoestrogens was developed based on the competition binding between the tested samples and the fluorescently labelled oestrogen (E2) to the human ligand binding domain of oestrogen receptor (LBD-ER) that was immobilised on the magnetite nanoparticles (MNPs). The 40-kDa LBD-ER peptide was produced in an Escherichia coli system. The synthesised 68.7-nm MNPs were silanised and subsequently covalently linked to the C-terminus of LBD-ER peptide. The LBD-ER immobilised MNPs demonstrated the specific binding for the standard E2 with the equilibrium dissociation constant of 9.56 nM and the binding capacity of 0.08 pmol/1 mg of the MNPs. The LBD-ER immobilised MNPs could evaluate oestrogenic activity of the extracts of Asparagus racemosus and Curcuma comosa , the reported phytoestrogenic plants, but not progesterone (P4) and Raphanus sativus extract, the negative controls. The results of this work clearly demonstrated a potential assay for detecting phytoestrogens of crude plant extracts, which is simple and easily adapted to a high throughput format.

  19. Use of Mesothelial Cells and Biological Matrices for Tissue Engineering of Simple Epithelium Surrogates

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    Christian Claude Lachaud

    2015-08-01

    Full Text Available Tissue engineering technologies have progressed rapidly through last decades resulting in the manufacture of quite complex bioartificial tissues with potential use for human organ and tissue regeneration. The manufacture of avascular monolayered tissues such as simple squamous epithelia was initiated a few decades ago and is attracting increasing interest. Their relative morphostructural simplicity makes of their biomimetization a goal, which is currently accessible. The mesothelium is a simple squamous epithelium in nature and is the monolayered tissue lining the walls of large coelomic cavities (peritoneal, pericardial and pleural and internal organs housed inside. Interestedly, mesothelial cells can be harvested in clinically relevant numbers from several anatomical sources and not less important, they also display high transdifferentiation capacities and are low immunogenic, characteristics, which endow these cells with therapeutic interest. Their combination with a suitable scaffold (biocompatible, degradable and non-immunogenic may allow the manufacture of tailored serosal membranes biomimetics with potential spanning a wide range of therapeutic applications, principally for the regeneration of simple squamous-like epithelia such as the visceral and parietal mesothelium vascular endothelium and corneal endothelium among others. Herein, we review recent research progresses in mesothelial cells biology and their clinical sources. We make a particular emphasis on reviewing the different types of biological scaffolds suitable for the manufacture of serosal mesothelial membranes biomimetics. Finally, we also review progresses made in mesothelial cells-based therapeutic applications and propose some possible future directions.

  20. The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population

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    Castiglione Anna

    2006-11-01

    Full Text Available Abstract Background Fatty liver (FL is the most frequent liver disease in Western countries. We used data from the Dionysos Nutrition & Liver Study to develop a simple algorithm for the prediction of FL in the general population. Methods 216 subjects with and 280 without suspected liver disease were studied. FL was diagnosed by ultrasonography and alcohol intake was assessed using a 7-day diary. Bootstrapped stepwise logistic regression was used to identify potential predictors of FL among 13 variables of interest [gender, age, ethanol intake, alanine transaminase, aspartate transaminase, gamma-glutamyl-transferase (GGT, body mass index (BMI, waist circumference, sum of 4 skinfolds, glucose, insulin, triglycerides, and cholesterol]. Potential predictors were entered into stepwise logistic regression models with the aim of obtaining the most simple and accurate algorithm for the prediction of FL. Results An algorithm based on BMI, waist circumference, triglycerides and GGT had an accuracy of 0.84 (95%CI 0.81–0.87 in detecting FL. We used this algorithm to develop the "fatty liver index" (FLI, which varies between 0 and 100. A FLI Conclusion FLI is simple to obtain and may help physicians select subjects for liver ultrasonography and intensified lifestyle counseling, and researchers to select patients for epidemiologic studies. Validation of FLI in external populations is needed before it can be employed for these purposes.